ADVANCES AND CHALLENGES WITH MICRO-IRRIGATION
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Non-Orthogonal Multiple Access (NOMA) for Indoor Visible Light CommunicationsRefik Caglar Kizilirmak Corbett Ray Rowell Dept. of Electrical and Electronics EngineeringNazarbayev UniversityAstana, Kazakhstanrefik.kizilirrn a********.kz,*********************.kz Abstract-Providing multiple access support to visible light communication (VLC) systems requires new networking architectures. Non-orthogonal multiple access (NOMA) is a proposed multiple access technique for future cellular systems. In this work, based on a realistic indoor channel conditions, we apply NOMA to indoor VLC channels and demonstrate its superior performance over orthogonal frequency division multiple access (OFDMA).Index Terms-visible light communication, OFDMA, NOMA, successive interference cancellationI. INTRODUCTIONVisible light communications (VLC) has recently received considerable attention as an alternative to wireless access technologies operating in radio frequency bands. VLC uses unlicensed spectrum, avoids the health concerns associated with electromagnetic radiation in the microwave bands, and achieves high data rates [1]. Although most of the recent advances in the field consider point-to-point transmission, networking with multiple access (MA) support for VLC is essential to provide multi-user wireless services such as Internet access in an office environment.Most of the MA techniques in radio and optical engineering can be applied to indoor VLC channels. For instance, well known cellular MA techniques such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA) together with some optical MA techniques such as wavelength division multiple access (WDMA) and space division multiple access (SDMA) have already been proposed for visible light communications [2].NOMA is fundamentally different than other multiple access schemes which provide orthogonal access to the users eitherin time, frequency, code, or space. In NOMA, each user operates in the same band and at the same time where they are distinguished by their power levels. NOMA uses superposition coding [3][4] at the transmitter such that the successive interference cancellation (SIC) receiver can separate the users bothin the uplink and downlink channels. NOMA was originally proposed as a candidate radio access technology for 5G cellular systems [4]. Although the practical implementation of NOMA in 5G cellular networks is still under discussion, it can be readily employed by VLC systems. First, the SIC receiver978-1-4673-7726-3/15/$31.00 ©20151EEE 98Murat UysalDept. of Electrical and Electronics EngineeringOzyegin UniversityIstanbul, Turkey***********************.trperforms better with fewer users; this is usually the case for VLC, but not for cellular networks. Secondly, superposition coding requires the channel knowledge for each user in order to adjust the power split between them; in VLC, unlike cellular networks, user terminals are usually stable and the channel is deterministic. VLC network characteristics perfectly match with the requirements for a successful NOMA implementation. In this work, we propose the use of NOMA in a VLC downlink channel with a two-user scenario and compare its performance with OFDMA based VLC networks. DC biased optical OFDM (DCO-OFDM) [5] is used for both NOMA and OFDMA as it is most commonly used bipolar-to-unipolar conversion technique in optical OFDM systems. A concurrent study in [6] also discusses application of NOMA to VLC systems. Our work is different from [6] in two major aspects: First, we consider optical OFDM transmission and compare the achievable capacities of NOMA and OFDMA and second, we include the impact of cancellation error in SIC receiver and analyzed for VLC systems with further comparison of NOMA and OFDMA systems.The paper is organized as follows: Section 2 introduces the channel models for two user scenario. Section 3 presents DCO-OFDM based NOMA and OFDMA. Section 4 presents the results of the numerical studies, and finally, Section 5 concludes the paper.II. INDOOR CHANNEL MODELThe room is modeled as an indoor office space with dimensions 5x5x3meters (Fig. 1) where two user equipments (VEs) are sharing the common downlink channel.In order to obtain the channel impulse responses, the methodology described in [7] is followed based on ray tracing simulations using Zemax@ [8]. The reflection coefficients of the walls, ceiling, floor and desk surface are taken as 0.8, 0.8, 0.3 and 0.8, respectively. When the location of the center of the ground is set at (0,0,0), the locations of the light source, VEl and VE2 are respectively chosen as (0,0,3), (0, 0, 0.7) and (1.7, 1.9, 0.7). Fig. 2 presents the obtained channel impulse responses hI (t) and h2(t) for UEI and UE2, respectively. The electrical channel DC gains are then calculated as GI I hI(t)dt -52 dB and GI I hI(t)dt -58 dB respectively for VEl and VE2.h y2.5 m i, .' ............ _-t ........__ , ". G : : •••• 2 :G : •..• : ' : ..... . , . Sm , OFDMA 1 1 UEI UE2 conjugate I ( NOMA1 . 1 conjugate I .... symmetric ----. 1 I � Bandwidth ---- 1 1 Fig. 1. Room with two users sharing the common downlink channel. 4.5 .5 � 2.5 1.5 0.5-6 xlOtime (nsec)(a) � 0.8� 0.60.402 -6 xlOtime (nsec) (b)Fig. 2. Channel impulse responses with respect to 1 watt transmitted optical power for (a) VEl (b) VE2. III. SYSTEM MODELNOMA and conventional OFDMA are illustrated conceptually in Fig. I where in OFDMA, the two users share thedifferent parts of the bandwidth whereas NOMA utilizes allthe band for each user. In this section, we first present NOMA,then discuss OFDMA as a benchmark.A. NOMA with DCO-OFDM Fig. 3 shows the block diagram of DCO-OFDM basedNOMA system in downlink. The NOMA transmitter processesthe information of both users in parallel and obtains OFDMsignals Xl(t) and X 2(t) for VEl and VE2. In DCO-OFDM,the complex symbols s (PSK, QAM etc.) are first assignedto a subcarrier vector. The OFDM time domain signal isthen obtained by IFFT operation. One important constraintin IMIDD optical communication is that the waveform whichmodulates the LEDs should be real-valued and non-negative.It is known that when the complex subcarrier vector X satisfiesthe Hermitian symmetry property, the time signal at the output IFFT becomes real [9]. Hermitian symmetry can be imposedby constructing X as 99where N is the number of subcarriers. As seen in (1), obtaining a real-valued Xl(t) and X 2(t)sacrifices approximately half of the spectral efficiency for each user. The transmitter then applies superposition coding and forms the transmitted waveform as [3][4] where P is the total available power for the transmitted signal and Kn is the power splitting factor which defines the power levels to be allocated to each information signal. In (2), lE[lxl(t)12] and IE[lXl(t)l 2] are normalized to one. It is also possible to apply superposition coding first and then apply IFFT Finally, the DC biased signal x N (t) modulates the luminary which consists of L number of LED chips. The electrical signal at the receiver of VE k , k E 1, 2, can then be written as LI'JPL hk(t)Q9x(t) + nk(t) (3) i=l L I'L hk(t) (t) + Kn )X 2(t)] i=l2015 4th International Workshop on Optical Wireless Communications (I W OW)2010o 10 15 20Rate of user 2 (Mbps)25 30 35Fig. 5. Boundary of rate pairs (Mbps) for NOMA and OFDMA. Perfect interference cancellation is assumed for NOMA.2010o 10 15 20Rate of user 2 (Mbps)25 30 35Fig. 6. Boundary of rate pairs (Mbps) for NOMA and OFDMA. Imperfect interference cancellation is assumed for NOMA.V. CONCLUSIONIn this work, NOMA has been proposed and analyzed for indoor VLC downlink channels. For a realistic indoor channel model with illumination design constraints, the superior performance of NOMA over conventional OFDMA scheme has been demonstrated. Although, the receiver complexity can be seen as a drawback for NOMA, the return is considerable. Future work includes developing power allocation mechanism for higher number of users and building a prototype.ACKNOWLEDGEMENTWe would like to thank Mr. Farshad Miramirkhani for his kind assistance in preparation of Fig. 2 in Section 2.REFERENCES[1] T. Komine, M. Nakagawa,"Fundamental analysis for visible-light communication system using LED lightings", IEEE Trans. on Comsun.Electron.,vol. 50, pp. 100-107, 2004.[2] H. Elgala, R. Mesleh, H. Haas, "Indoor optical wireless communication:potential and state-of-the-art",IEEE Communications Magazine, vol. 49, no: 9, pp. 56-62, 2011.[3] Y. Saito,et. ai, "System level performance evaluation of downlinknonorthogonal multiple access (NOMA)," in Proc. IEEE Symposium on Personal, Indoor and Mobile Radio Communications (PlMRC), Sept.2013.[4] Y. Saito, et, ai, "Non-orthogonal multiple access (NOMA) for future radioaccess," in Proc. IEEE Vehiccular Technology Conference (VTC Spring), pp. 1-5, Sept. 2013.[5] J. Armstrong, "OFDM for optical communications", Journal of LightwaveTech., vo1.27, no.3, pp. 189-204, Feb., 2009.[6] H. Marshoud, V. M. Kapinas, G. K. Karaganniadis, S. Muhadiat,"Non-orthogonal multiple access for visible light communications,"lpdf/1504.oo934.pdf.[7] E. Sarbazi, M. Uysal, M. Abdallah and K.Qaraqe, "Indoor channelmodeling and characterization for visible light communications", 16th International Conference on Transparent Optical Networks (ICTON), July 2014.[8] [9] R. Mesleh, H. Elgala, and H. Haas, "On the performance of differentOFDM based optical wireless communication systems", J. Opt. Commun.Netw., vol. 3, no. 8, pp. 620-628, 2011.[10] J. Grubor, S. Randel, K-D. Langer, and J. W. Walewski, "Broadbandinformation broadcasting using LED-based interior lighting", J. of Lightwave Tech., vol. 26, no. 24, pp. 3883-3892, 2008.[11] J. G. Andrews, and T. H. Meng, "Optimum Power Control for SuccessiveInterference Cancellation With Imperfect Channel Estimation", IEEE Trans. on Wireless Comm., vol. 2, no. 2, pp. 375-383, 2003.[12] D. Tse and P. Vishwanathan, "Multiuser capacity and opportunisticcommunication," Fundamentals of Wireless Communication, 2005. [13] S. A. Colak, R.C. Kizilirmak, M. Uysal, "On the Performance ofDCO-OFDM Visible Light Communication Systems under illumination Constraints", in Proc. Int'1. Con! on Transparent Optical Networks (ICTON), pp.I-4, 2015.[14] Cree XLamp XP-E2 LEDs, datasheet.[15] M Rahaim, A Miravakili, T Borogovac, IDC Little, V Joyner, "Demonstration of a software Defined Visible Light Communication System," in Proc. the 17th Annual International Conference on Mobile Computing and Networking, Mobicom20 11.[16] I. Stefan, H. Burchardt, and H. Haas, "Area spectral efficiency performance comparison between VLC and RF femtocell networks," in Proc.IEEE Inti Con! on Commun. (ICC) , pp. 3825-3829, 2013.101。
搅拌对甲烷水合物生成的影响郝文峰1,2,樊栓狮23,王金渠1(11大连理工大学化工学院,大连 116012;21中国科学院广州能源研究所天然气水合物中心,广州 510640)摘要:通过有无搅拌条件下甲烷水合物生成过程中的反应速率和液相温度的变化的对比,表明采用间歇搅拌的方式可以有效缩短反应诱导时间,提高反应速率,同时研究了不同搅拌时间和搅拌速率对甲烷水合物生成的影响。
在压力510M Pa 、温度274135K 、搅拌速率400r m in 、搅拌时间30m in ,可以获得159V V 以上的储气效果,而且可以缩短反应的操作时间。
关键词:甲烷水合物;生成过程;搅拌转速;搅拌时间中图分类号:TQ 02617 文献标识码:A 文章编号:100129219(2005)03205203修改稿日期:2005201204;基金项目:国家自然科学基金资助(编号N o 150176051);作者简介:郝文峰(19742),博士生。
3联系人,电邮fan ss @m s 1giec 1ac 1cn ,传真020*********。
0 引言天然气水合物是由一种或几种烃类气体在一定的温度和压力下和水作用生成的一种非化学计量的笼型晶体化合物。
形成天然气水合物的主要成分是甲烷,甲烷体积分数超过9919%的天然气水合物通常称为甲烷水合物[123]。
甲烷水合物属于 型水合物[4],一体积水合物可以储存150~180体积标准状态的天然气[5,6]。
利用这一性质进行天然气水合物储运更安全更有效[7]。
水合物储运技术主要包括制备、处理、储存运输和分解等过程。
但是这些技术的进展还处于初级阶段,其中最重要的制备过程的研究,一般集中在表面活性剂促进水合物的生成上[8210]。
此外,提出了各种反应器及其操作方法[11213]。
但是搅拌对生成过程的研究还不够完善。
因此,本文对搅拌(搅拌时间、搅拌速率)在甲烷水合物生成过程的影响进行进一步的研究。
如何提升科研潜力英语作文Title: Enhancing Research Potential。
In today's rapidly evolving world, scientific research plays a pivotal role in driving progress and innovation. However, maximizing one's research potential requires a strategic approach encompassing various facets. In this essay, we will explore several effective strategies to enhance research potential.Firstly, cultivating a strong foundation in fundamental knowledge is essential. This involves mastering the basics of one's field of interest through rigorous study and exploration. Understanding the underlying principles and theories provides a solid framework upon which to build further research endeavors. Additionally, staying updated with the latest advancements and trends ensures relevance and informs future directions of inquiry.Moreover, developing critical thinking skills isparamount in research. The ability to analyze information critically, evaluate evidence, and draw logical conclusions is fundamental to the research process. Engaging inactivities such as problem-solving, brainstorming, and debate sharpens these skills and fosters a deeper understanding of complex issues. Furthermore, seeking constructive feedback from peers and mentors helps refine ideas and methodologies, ultimately enhancing the qualityof research output.Another crucial aspect of enhancing research potentialis effective time management. Research projects oftenrequire substantial time and effort, and it is imperativeto allocate resources efficiently. Setting clear goals, prioritizing tasks, and adhering to timelines are key strategies for maximizing productivity. Additionally, establishing a balance between work and personal life is essential for maintaining motivation and preventing burnout.Furthermore, collaboration plays a significant role in expanding research potential. Working with colleagues, both within and outside one's discipline, fostersinterdisciplinary perspectives and facilitates the exchange of ideas. Collaborative projects enable researchers to leverage each other's expertise and resources, leading to innovative solutions and impactful outcomes. Furthermore, participating in conferences, workshops, and seminars provides opportunities for networking and forging valuable connections within the research community.In addition to collaboration, effective communication skills are essential for disseminating research findingsand engaging with diverse audiences. Writing clear and concise research papers, presenting findings at conferences, and engaging in public outreach activities are all integral components of effective science communication. Furthermore, embracing digital platforms and social media can amplifythe reach of research efforts and facilitate knowledge exchange on a global scale.Moreover, cultivating resilience and perseverance is crucial in overcoming challenges and setbacks encountered during the research process. Research inherently involves uncertainty and failure, and it is essential to approachobstacles with a growth mindset and learn from setbacks. Embracing resilience enables researchers to navigate adversity, adapt to changing circumstances, and ultimately succeed in their endeavors.In conclusion, enhancing research potential requires a multifaceted approach encompassing various strategies and skills. By cultivating a strong foundation in fundamental knowledge, developing critical thinking skills, mastering time management, fostering collaboration, honing communication abilities, and cultivating resilience, researchers can unlock their full potential and make meaningful contributions to their respective fields. Ultimately, a commitment to continuous learning and improvement is essential for achieving success in the dynamic and ever-evolving landscape of scientific research.。
In the contemporary world,the spirit of entrepreneurship is a driving force that propels innovation and economic growth.It is a multifaceted concept that can be inspired by various elements,including cultural diversity,technological advancements,and societal needs.Here is an essay that explores how these elements can ignite the passion for entrepreneurship.Cultural Diversity as a Source of InspirationCultural diversity is a rich tapestry of ideas,values,and practices that can inspire entrepreneurs to create unique products and services.When individuals from different backgrounds come together,they bring a wealth of perspectives that can lead to innovative solutions.For instance,the fusion of culinary traditions from around the world has given rise to new food products that cater to diverse tastes and preferences. Entrepreneurs who are sensitive to cultural nuances can tap into this diversity to create businesses that resonate with a global audience.Technological Advancements as CatalystsThe rapid pace of technological advancements provides a fertile ground for entrepreneurial ventures.Innovations in fields such as artificial intelligence, biotechnology,and renewable energy offer vast opportunities for those who are willing to explore and adapt.Entrepreneurs can leverage these technologies to develop solutions that address pressing issues,such as climate change or healthcare challenges.Moreover, the internet and social media platforms have democratized access to information and markets,enabling entrepreneurs to reach a wider customer base with relatively low costs.Societal Needs as MotivatorsSocietal needs and challenges often serve as the impetus for entrepreneurial initiatives. Entrepreneurs who are attuned to the needs of their communities can develop businesses that not only generate profit but also contribute positively to society.For example,social entrepreneurs focus on creating sustainable solutions to social problems,such as poverty alleviation,education,and healthcare.By identifying gaps in the market and addressing them with innovative approaches,these entrepreneurs can make a significant impact on the world.The Role of Education and MentorshipEducation plays a crucial role in nurturing the entrepreneurial spirit.Institutions that offer courses in entrepreneurship,business management,and innovation can equip aspiringentrepreneurs with the skills and knowledge necessary to start and grow their businesses. Furthermore,mentorship from experienced entrepreneurs can provide invaluable guidance and support,helping newcomers navigate the complexities of starting a business.Government Policies and SupportGovernments can also play a significant role in fostering an environment conducive to entrepreneurship.Policies that encourage investment,provide tax incentives,and support research and development can help entrepreneurs bring their ideas to fruition. Additionally,governmentsponsored incubators and accelerators can offer resources and networking opportunities that are essential for the growth of startups.ConclusionThe passion for entrepreneurship is ignited by a combination of cultural diversity, technological innovation,societal needs,educational opportunities,and supportive government policies.By recognizing and leveraging these factors,individuals can embark on entrepreneurial journeys that are not only personally rewarding but also contribute to the betterment of society as a whole.The spirit of entrepreneurship is a testament to human ingenuity and the relentless pursuit of progress,and it is a force that will continue to shape the future of our world.。
biomaterials advances issn -回复Biomaterials Advances: Understanding the InnovationsBiomaterials advances ISSN is a unique identifier that is given to a particular scientific journal. The topics that are usually discussed in this journal are related to biomaterials usage and its relevant advancements. In this article, we will discuss in-depth what biomaterials are, how they are used, what the biomaterials advances ISSN is, and what kind of topics are covered in this scientific journal.What are Biomaterials?Biomaterials refer to substances that are engineered and used in medical implants or other medical devices. These substances can be naturally occurring or man-made. The purpose of using biomaterials is to promote the growth of new tissues and organs, repair damaged tissues, or replace missing tissues. Biomaterials can also be used to deliver medication to certain parts of the body.Examples of biomaterials are metals, ceramics, polymers, and composites. In most cases, the specific properties of biomaterialsare engineered to elicit a specific response from the body, such as providing suitable mechanical properties, biocompatibility, or the ability to degrade naturally.Understanding the Usage of BiomaterialsBiomaterials in medical devices are used in a wide range of applications, including surgical implants, prosthetics, drug delivery systems, and diagnostic devices. They are also used in dental implants, medical adhesives, and contact lenses. In some cases, biomaterials can also be used to make clothing and accessories, such as shoes, watches, and jewelry.The biomaterials used in medical applications are typically made from biocompatible materials that are non-toxic and do not cause harm to the body. They are also designed to provide adequate mechanical properties based on the intended application.What is Biomaterials Advances ISSN?Biomaterials Advances ISSN is a scientific journal that focuses on the latest advances in the field of biomaterials. This journalpublishes peer-reviewed articles that are related to the development, characterization, and application of biomaterials.The topics that are covered in the Biomaterials Advances Journal include but are not limited to:1. Materials engineering and characterization2. Biocompatibility and toxicity studies3. Materials processing and manufacturing4. Regenerative medicine and tissue engineering5. Biomaterials design and implantation studies6. Drug delivery and diagnostics7. Bioactive materials and coatings8. Synthesis and biosynthesis of biomaterials9. Biomaterials in oral and dental applications10. Nano-biomaterials and nanomedicine11. Engineering and fabrication of biomaterials12. Bio-inspired materials and design13. Biomimetics and bioengineeringAdvancement in biomaterials research has led to significant breakthroughs in the medical field. The research and development of biomaterials have led to the creation of new medical devices, artificial organs, and prosthetics that change the lives of many people around the world.ConclusionIn conclusion, biomaterials are an essential aspect of modern medicine. The Biomaterials Advances ISSN is an important scientific journal that provides information to researchers, academicians, andprofessionals on the latest developments in biomaterials. The journal covers various topics on materials engineering, characterization, biocompatibility, toxicity studies, drug delivery, diagnostics, and much more. With ever-improving advancement in biomaterials research, we can expect many more innovative medical devices and treatments that improve the quality of human life.。
好氧堆肥用枯草芽抱杆菌GX2产芽抱工艺优化李月月心,李秀芬&心,齐希光',李健心,任月萍心,王新华心,夏琼琼5(1.江南大学环境科学与工程学院,江苏无锡214122;2.江苏省厌氧生物技术重点实验室,江苏无锡214122;3.江苏省水处理技术与材料协同创新中心,江苏苏州215009;4.江南大学食品学院,江苏无锡214122;5.中国市政工程华北设计研究总院有限公司,天津300074)摘要:芽,杆菌是好氧堆肥微生物菌剂的重要组成部分,为降低菌剂生产成本、改善其品质及应用效果,对芽,杆菌产芽,工艺进行研究$首先,在摇瓶上进行枯草芽,杆菌GX2的培养基及培养条件优化,在此基础上,在3L发酵罐中进行分批补料优化研究,进一步提高细胞浓度,最后,通过单因素及正交试验研究,在3L发酵罐中对产芽,工艺进行了优化。
结果表明,当pH为6.8、温度为50七和搅拌转速为150r/min时,发酵液中的活菌数达1.57x1010CFU/mL,芽,数达1.32x l010CFU/mL,芽,率为84.1%。
堆肥用枯草芽,杆菌GX2的发酵及产芽,工艺优化可有效提高发酵液中的活菌数及芽,率,降低菌剂的发酵及生产成本,为后续工业化生产及应用奠定基础&关键词:微生物菌剂;枯草芽,杆菌;芽,率;工艺优化中图分类号:Q815文章编号:1673-1689(2021)01-0091-09DOI:10.3969/j.issn.1673-1689.2021.01.012Optimization of Sporulation Parameters for Aerobic CompostingBacillus subtilis GX2Strains*1,2,3,QI Xiguang4,LI Jian1,2,3,LI Yueyue1,2,3,LI XiufenREN Yueping1,2,3,WANG Xinhua1,2,3,XIA Qiongqion,(1.School of Environmental and Civil Engineering,Jiangnan University,Wuxi214122,China;2.Jiangsu KeyLaboratory of Anaerobic Biotechnology,Wuxi214122,China; 3.Jiangsu Cooperative Innovation Center ofTechnology and Material of Water Treatment,Suzhou215009,China; 4.School of Food Science andTechnology,Jiangnan University,Wuxi214122,China; 5.North China Municipal Engineering Design&Research Institute Co.Ltd.,Tianjin300074,China)Abstract:Bacillus subtilis is an important microbial agent during the aerobic composting.Toreduce the production cost and improve the quality and applicability of bacteria,the sporeproduction process of Bacillus subtilis was studied.Firstly,the culture medium and environmentalconditions of Bacillus subtilis GX2were optimized using shaking flasks.Cell concentration wasfurther increased by a batch feed optimization method in a3L fermenter.Finally,single-factor andorthogonal experiments were applied to optimize the spore-forming process.The results showed thatthe number of viable cells and spores in the fermentation broth reached1.57 x1010CFU/mL and 收稿日期:2019-06-11基金项目:国家&十三五’重点研发计划项目(2016YFC0400707)。
近年来,随着中小企业的飞速发展,中小企业融资问题,已经成为一些中小企业进一步发展所面临的“瓶颈”。
在我国经济体制转型和经济结构调整的特殊历史时期,中小企业融资问题不仅表现得较为突出,也更为复杂。
下面是搜索整理的中小企业融资问题英文参考文献,欢迎借鉴参考。
中小企业融资问题英文参考文献一:[1]XUE-FENG JI. Analysis on Financing Problems of SME in Internet Finance Mode[P]. 2nd International Conference on Advanced Education and Management Engineering (AEME 2017),2017.[2]Xiao-juan GUO. Difficulties and Countermeasures on the Financing of SMEs[P]. 4th International Conference on Economics and Management (ICEM 2017),2017.[3]Jing Zhang,J. Ke. The Financing Efficiency of Enterprises Listed on SMEs Board[P]. 3rd International Conference on Society Science and Economics Development (ICSSED 2018),2018.[4]Wan-rong ZHANG. A Study on Financing Difficulties of SMEs in China[P]. 4th International Conference on Economics and Management (ICEM 2017),2017.[5]Zhao-Hui CHEN,Zhi-Juan ZHOU. Problems and Suggestions on the Mode of Intellectual Property Financing of Small and Medium-sized Technological Enterprises[P]. 4th International Conference on Social Science (ICSS 2017),2017.[6]YU SHI. Research on Problems and Countermeasures of Small and Medium Sized Enterprises Financing[P]. 2nd International Conference on Advanced Education and Management Engineering (AEME 2017),2017.[7]Yuping Wei. Empirical Analysis on Financing Constraints of SMEs of China — Proofs from Pre-IPO three Years’ Panel Data of China’s Listed Companies Listed in 2015[P]. DEStech Transactions on Materials Science and Engineering,2016.[8]Ru-Xin WANG. Financing Management of SMEs Under Internet[P]. DEStech Transactions on Economics, Business and Management,2018.[9]Yi-ning SUN. The Impact of Supply Chain Finance on SME Financing[P]. DEStech Transactions on Social Science, Education and Human Science,2018.[10]Wen-bo MA,Meng-wei TANG. Financing SMEs and Innovation[P]. DEStech Transactions on Social Science, Education and Human Science,2018.[11]A-Tai ZHENG. Influence of Internet Finance on SME Financing — A Case Study of P2P Model[P]. 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Journal of Banking and Finance,2017,81.[17]Peter Quartey,Ebo Turkson,Joshua Y. Abor,Abdul Malik Iddrisu. Financing the growth of SMEs in Africa: What are the contraints to SME financing within ECOWAS?[J]. Review of Development Finance,2017,7(1).[18]Qaiser Munir,Sook Ching Kok,Tamara Teplova,Tongxia Li. Powerful CEOs, debt financing, and leasing in Chinese SMEs: Evidence from threshold model[J]. North American Journal of Economics and Finance,2017,42.[19]Iftekhar Hasan,Krzysztof Jackowicz,Oskar Kowalewski,?ukasz Koz?owski. Do local banking market structures matter for SME financing and performance? New evidence from an emerging economy[J]. Journal of Banking and Finance,2017.[20]Renate Kersten,Job Harms,Kellie Liket,Karen Maas. Small Firms, large Impact?A systematic review of the SME Finance Literature[J]. World Development,2017,97.[21]Anahí Briozzo,Diana Albanese,Diego Santolíquido. Corporate governance, financing and gender: A study of SMEs from Argentinean Securities Markets[J]. 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《生物材料技术进展综述》近年来,生物材料技术在医学、生物工程、再生医学等领域取得了长足进展。
生物材料不仅可以用于医疗器械、生物传感器等领域,还可以帮助再生组织、促进伤口愈合等,对人类健康和医疗领域起到了重要作用。
在本文中,我将综述生物材料技术的最新进展,探讨其在医学与生物工程领域的应用,并共享我的个人观点和理解。
一、生物材料技术的起源和发展生物材料技术起源于人类对材料与生物组织相互作用的认识和探索。
早期的生物材料多应用于人工关节、牙科材料等领域。
随着科学技术的不断进步,生物材料的种类和应用领域也在不断扩展。
生物材料技术的发展主要经历了材料的功能性、生物相容性、生物活性等方面的不断革新和突破,为其在医学领域的应用打下了坚实基础。
二、生物材料技术的主要应用领域1. 医疗器械:生物材料在医疗器械方面的应用日益广泛,如人工关节、心脏起搏器、血管支架等。
这些生物材料不仅要求具备良好的生物相容性,还需要具备足够的力学性能和稳定性。
2. 生物传感器:生物材料在生物传感器领域的应用也取得了重大进展,例如生物光子晶体材料、纳米材料等。
这些生物材料可以用于检测生物分子、病原体等,为医学诊断和生物研究提供了有力支持。
3. 再生医学:生物材料在再生医学领域的应用也备受关注,如干细胞支架、生物打印等。
这些生物材料可以帮助再生组织、促进伤口愈合,为肿瘤治疗、器官再生等提供了新的解决方案。
三、生物材料技术的最新进展1. 生物可降解材料:随着对环保和可持续发展的重视,生物可降解材料成为了研究热点,如聚乳酸、明胶、壳聚糖等。
这些生物材料不仅具备良好的生物相容性,还可以在体内逐渐降解,减少对环境的污染。
2. 生物仿生材料:生物仿生材料的研究也取得了重大突破,如仿生人工晶状体、仿生人工关节等。
这些生物材料模拟自然组织和器官的结构和功能,为医疗器械的设计和研发提供了新的思路和方法。
3. 生物材料表面改性技术:生物材料表面改性技术的发展也极大地拓展了生物材料的应用领域,如生物材料表面涂层技术、表面微纳结构技术等。
课程名称课程英文名称发展社会学专题Development Sociology中国概况 A Brief Introduction of “The General Situation of China”英美经典短篇小说赏析 A Guide to Classic Short Stories in British and AmericanLiterature对策论 A Primer in Game Throry对策论 A Primer in Game Throry植物蛋白研究进展Aadvance of Vegetable Protein Research植物蛋白研究进展Aadvance of Vegetable Protein Research作物遗传育种专业英语Academic English作物遗传育种专业英语(必修)Academic English会计学Accounting高等农业机械化管理与模拟Adanvced Agricultural Mechanization Management and System Simulation高等农业机械化管理与系统模拟Adanvced Agricultural Mechanization Management and System Simulation调整型抽样Adjusting Sampling行政法Administrative Law高等动力学Advaced Dynamics动物传染病学专题Advance in Animal Infectious Diseases动物传染病学Advance in Animal Infectious Diseases动物传染病专题Advance in Animal Infectious Diseases动物病理学进展Advance in Animal Pathology动物病理学进展Advance in Animal Pathology植物病害生物防治进展Advance in Biological Control of Plant Diseases植物病害生物防治Advance in Biological Control of Plant Diseases植物逆境信号传递研究Advance in Plant Stress Signaling植物逆境信号传递研究Advance in Plant Stress Signaling先进制造技术Advance Manufacture Technology蛋白质互作的研究方法进展Advance of Methods for Analysis of Protein-protein Interaction 国际农药残留分析进展Advance of Pesticide Residue Analysis in Foreign Countries国际农药残留分析进展Advance of Pesticide Residue Analysis in Foreign Countries果蔬采后生理研究进展Advance of Postharvest Physiology of Fruit and Vegetable果蔬采后生理研究进展Advance of Postharvest Physiology of Fruit and Vegetable资源环境科学进展Advance of Recources and Enviromental Science高级建筑设计Advanced Garden Building Design高级园林建筑设计Advanced Garden Building Design高级生物气象学Advanced Biometeorology高级生物气象学Advanced Biometeorology高级会计理论与实务Advanced Accounting Theory and Practice高等农业机械学Advanced Agricultural Machinery高等农业机械学Advanced Agricultural Machinery高等农业机械学Advanced Agricultural Machinery高等农业机械学Advanced Agricultural Machinery高等农业机械化管理Advanced Agricultural Mechanization Management高等农业机械化管理Advanced Agricultural Mechanization Management农业机械化工程新技术讲座Advanced Agricultural Mechanization New TechnologyLectures农业机械化工程新技术讲座Advanced Agricultural Mechanization New TechnologyLectures人工智能Advanced Artificial Intelligence高级人工智能Advanced Artificial Intelligence高级审计理论与实务Advanced Auditing Theory and Practice高级生物化学Advanced Biochemistry高级生物化学Advanced Biochemistry高级生物信息SEMI.Advanced Bioinformatics Seminar高级生物信息学Seminar Advanced Bioinformatics Seminar高级害虫生物防治Advanced Biological Control of Insect Pests高级害虫生物防治Advanced Biological Control of Insect Pests高级蔬菜育种学Advanced Breeding of Vegetable Crops高级蔬菜育种学Advanced Breeding of Vegetable Crops高级财务管理Advanced Corporate Finance高级财务管理Advanced Corporate Finance高级园林植物遗传育种学Advanced Course of Ornamental Plant Breeding高级园林植物遗传育种学Advanced Course of Ornamental Plant Breeding高级作物育种学I Advanced Crop Breeding I高级作物育种学ⅠAdvanced Crop Breeding I高级作物育种学II Advanced Crop Breeding II高级作物育种学ⅡAdvanced Crop Breeding II作物生态学Advanced Crop Ecology高级作物生态学Advanced Crop Ecology高级作物生理学Advanced Crop Physiology高级细胞遗传学Advanced Cytogenetics高级发展学Advanced Development Studies高级发展学Advanced Development Studies高等结构动力学Advanced Dynamics of Structures高级计量经济学Advanced Econometrics高级计量经济学Advanced Econometrics高级园林植物生理生态学Advanced Eco-physiology of Ornamental Plants高级园林植物生理生态Advanced Eco-physiology of Ornamental Plants高等工程热力学Advanced Engineering Thermodynamics高等工程热力学Advanced Engineering Thermodynamics高级试验设计与数据分析Advanced Experimental Design and Data Analysis 高级试验设计与数据分析Advanced Experimental Design and Data Analysis 兽医免疫高级实验Advanced Experiments of Veterinary Immunology 兽医免疫高级实验Advanced Experiments of Veterinary Immunology 高级饲料分析技术Advanced Feed Analysis Technology高级饲料分析技术Advanced Feed Analysis Technology高级财务管理理论与实务Advanced Financial Management食品微生物学专题Advanced Food Microbiology动物遗传工程Advanced Gene Engineering高级基因工程Advanced Gene Engineering高级葡萄生理与分子生物专题Advanced Grape Physiology and Molecular Biology 高级葡萄生理与分子生物学专题Advanced Grape Physiology and Molecular Biology 高级昆虫生理生化Advanced Insect Physiology and Biochemistry高级昆虫生理生化Advanced Insect Physiology and Biochemistry高级昆虫毒理学Advanced Insect Toxicology高级昆虫毒理学Advanced Insect Toxicology高等内燃机学Advanced Internal-combustion Engine高等内燃机学Advanced Internal-combustion Engine高级实验动物学Advanced Laboratory Animal Science高级实验动物学Advanced Laboratory Animal Science高级园林设计Advanced Landscape Design高级园林设计Advanced Landscape Design高级园林工程Advanced Landscape Engineering高级环境绿地规划Advanced Landscape Planning高级宏观经济学Advanced Macroeconomics高级宏观经济学Advanced Macroeconomics高级管理会计理论与实务Advanced Management Accounting管理科学与工程专业Seminar Advanced Management Science and Engineering (Ph.D)管理科学与工程专业Seminar Advanced Management Science and Engineering (Ph.D)高级市场营销学Advanced Marketing高级市场营销Advanced Marketing高等金属学Advanced Metal高等金属学Advanced Metal高级微生物遗传学Advanced Microbial Genetics高级微生物遗传学Advanced Microbial Genetics高级微生物学进展Advanced Microbiological Seminar高级微生物学进展(全年)Advanced Microbiological Seminar高级微观经济学Advanced Microeconomics高级微观经济学Advanced Microeconomics高级运筹学Advanced Operations Research高级运筹学Advanced Operations Research高级果树生理学Advanced Physiology of Fruit Trees高级果树生理学Advanced Physiology of Fruit Trees高级植物与细胞生物学Seminar Advanced Plant and Cell Biology Seminars高级植物与细胞生物学Seminar Advanced Plant and Cell Biology Seminars高级植物营养学Advanced Plant Nutrition高级植物营养学Advanced Plant Nutrition高级植物生理生态Advanced Plant Physiological Ecology高级植物生理生态Advanced Plant Physiological Ecology高级植物生理学专题Advanced Plant Physiology高级植物生理学Advanced Plant Physiology高级植物生理学Advanced Plant Physiology高级植物生理学专题Advanced Plant Physiology高级观赏植物采后生理Advanced Postharvest Physiology of Ornamental Plants 高级观赏植物采后生理Advanced Postharvest Physiology of Ornamental Plants 高级植物营养进展Advanced Progress in Plant Nutrition高级设施园艺学Advanced Protected Horticulture高级设施园艺学Advanced Protected Horticulture高级可再生资源工程专题Advanced Renewable Resource Engineering现代可再生资源工程学Advanced Renewable Resource Engineering国际食品研究进展Advanced Research of Food Science植物细胞信号转导研究中的反向遗传学与细胞生物学研究技术与方法Advanced Reverse Genetic and Cell Biological Approaches to Study Signal Transduction in Plant高级生物化学与分子生物学Seminar Advanced Seminar for Biochemistry and Molecular Biology高级生物化学与分子生物学SeminarAdvanced Seminar for Biochemistry and Molecular Biology高级遗传学Seminar Advanced Seminar for Genetics高级遗传学Seminar Advanced Seminar for Genetics高级生物质工程Seminar Advanced Seminar on Biomass Engineering高级社会统计Advanced Social Statistics高级社会统计Advanced Social Statistics高级生化专题Ⅲ(生物膜)Advanced Topics in Biochemistry:Biomembrane 高级生化专题Ⅲ(生物膜)Advanced Topics in Biochemistry:Biomembrane高级生化专题IV(酶学及代谢调控)Advanced Topics in Biochemistry:Enzymology and Metabolism Control高级生化专题Ⅳ(酶学与代谢调控)Advanced Topics in Biochemistry:Enzymology and Metabolism Control高级生化专题II(核酸化学)Advanced Topics in Biochemistry:Nucleic Acid高级生化专题Ⅱ(核酸化学)Advanced Topics in Biochemistry:Nucleic Acid高级生化专题Ⅰ(蛋白质化学)Advanced Topics in Biochemistry:Protein高级生化专题Ⅰ(蛋白质化学)Advanced Topics in Biochemistry:Protein农产品物料干燥技术特论Advanced Topics in Drying Technology:Drying of PorousMedia高级分子生物学专题Advanced Topics in Molecular Biology高级分子生物学专题Advanced Topics in Molecular Biology高级城市规划Advanced Urban Planning高级蔬菜生理学Advanced Vegetable Physiology高级蔬菜生理学Advanced Vegetable Physiology高级杂草学Advanced Weeds高级杂草学Advanced Weeds高级兽医寄生虫学Advanceds Veterinary Parasitology高级兽医寄生虫学Advanceds Veterinary Parasitology高级兽医微生物学Advances in Veterinary Microbiology高级兽医微生物学Advances in Veterinary Microbiology作物栽培新技术专题Advances in 4H Crop Cultivation作物分子生理与生物技术Advances in Agricultural Biotechnology农业水土工程研究进展Advances in Agricultural Water-soil Research农业水土工程研究进展Advances in Agricultural Water-soil Research动物育种专题Advances in Animal Breeding动物育种专题Advances in Animal Breeding动物病理生理学专题Advances in Animal Pathophysiology动物病理生理学专题Advances in Animal Pathophysiology动物科学研究进展Advances in Animal Science动物科学研究进展Advances in Animal Science害虫生物防治理论与实践新进展Advances in Biological Control of Insect Pests害虫生物防治理论与实践新进展Advances in Biological Control of Insect Pests细胞生物学进展Advances in Cell Biology细胞生物学进展Advances in Cell Biology农副产品化学进展Advances in Chemistry of Agricultural Byproducts农副产品化学进展Advances in Chemistry of Agricultural Byproducts作物营养与水分生理专题Advances in Crop Nutrition and Water Physiology作物光合、产量与品质生理专题Advances in Crop Photosynthesis,Yield and Quality能源作物与生物质工程专题Advances in Crop Physiology and Ecology作物科学研究进展Advances in Crop Science作物科学研究进展Advances in Crop Science作物逆境生理专题Advances in Crop Stress Physiology发育生物学进展Advances in Developmental Biology数字农业研究进展Advances in Digital Agriculture Research 农作制度理论与技术专题Advances in Farming System Science果树学进展讨论Advances in Fruit Sciences果树学进展讨论Advances in Fruit Sciences现代果树遗传学研究进展Advances in Genetics of Fruit Crops分子遗传学进展Advances in Molecular Genetics病毒学进展Advances in Molecular Virology营养科学研究进展Advances in Nutritional Sciences营养科学技术研究进展Advances in Nutritional Sciences杀菌剂药理学及抗药性研究进展Advances in Pharmacology and Fungicide Resistance in Phytopathogen药理学与毒理学专题Advances in Pharmacology and Toxicology药理学与毒理学专题Advances in Pharmacology and Toxicology植物同化物运输高级讲座Advances in Photoassimilate Transport Mechanisms 植物同化物运输高级讲座Advances in Photoassimilate Transport Mechanisms 植物生物学进展Advances in Plant Biology植物激素与化学控制专题Advances in Plant Hormones and Chemical Regulation 植物病毒学进展Advances in Plant Virus Research植物病毒学进展Advances in Plant Virus Research家禽营养与饲养技术(案例)Advances in Poultry Nutrition and feeding Technology 种子病理学进展Advances in Seed Pathology种子病理学进展Advances in Seed Pathology兽医免疫学进展Advances in Veterinary Immunology兽医免疫学进展Advances in Veterinary Immunology兽医科学进展Advances in Veterinary Medicine兽医科学进展Advances in Veterinary Medicine水资源研究进展专题Advances in Water Resource Science水资源研究进展专题Advances in Water Resource Science分子植物病理学研究进展Advances of Molecular Plant Pathology分子植物病理学研究进展Advances of Molecular Plant Pathology生物环境与能源工程综合专题Seminar Advances on Agricultural and Bioenvironmental Engineering农业生物环境与能源工程研究进展Advances on Agricultural and Bioenvironmental Engineering 食品保藏技术研究进展Advances on Food Preservation Technology食品保藏技术研究进展Advances on Food Preservation Technology水土保持与荒漠化防治新技术研究进展Advances on Soil and Water Conservation and Deforestation Control水土保持与荒漠化防治研究进展Advances on Soil and Water Conservation and DeforestationControl结构工程研究新进展Advances on Structure Engineering城镇与区域规划Advances on Urban and Regional Planning城镇与区域规划研究进展Advances on Urban and Regional Planning近代水文学及水资源研究进展Advances on Water Concervancy Project水利工程研究进展Advances on Water Concervancy Project农业商务管理Agri-business Management农业产业组织Agribusiness Organization核技术农业应用基础Agricultural Application Foundation of Nuclear Technology 核技术农业应用基础Agricultural Application Foundation of Nuclear Technology 核技术农业应用基础Agricultural Application Foundation of Nuclear Technology农业可控管理技术Agricultural Controllable Management Technology农业可控管理技术Agricultural Controllable Management Technology农业发展经济学Agricultural Development Economics农业经济理论与政策Agricultural Economics: Theory and Policy农业经济理论与政策Agricultural Economics: Theory and Policy农业装备开发与设计Agricultural Equipment Development and Design农产品期货市场Agricultural Futures Markets农产品期货市场Agricultural Futures Markets农业历史文献选读Agricultural History Literature农业历史文献选读(必修)Agricultural History Literature农业信息系统工程Agricultural Information and System Engineering农业信息系统工程Agricultural Information and System Engineering农业保险Agricultural Insurance农产品市场分析Agricultural Market Analysis农产品市场分析Agricultural Market and Analysis农产品市场分析Agricultural Market and Analysis有害生物治理的原理与方法Agricultural Pests Prevention and Control农业有害生物的预防与控制Agricultural Pests Prevention and Control农业资源与利用Agricultural Resources and Utilization核技术农业应用专论Agricultural Specialized Application of Nuclear Technology 核技术农业应用专论Agricultural Specialized Application of Nuclear Technology 农业系统工程Agricultural Systems Engineering农村技术创新与知识系统Agricultural Technology Innovation and Knowledge System 农村技术创新与知识系统Agricultural Technology Innovation and Knowledge System 农业与食品企业管理Agriculture and Food Corporate Managemnt农业信息学Agriculture Informatics农业科技与“三农政策”Agriculture Technology and Rural Development农业装备机电一体化技术Agricutural Equipment Mechantronics农业项目的计划与管理Agricutural Project Plan and Management农业工程项目规划Agricutural Project Plan and Management农产品国际贸易实务Agri-goods International Trade Practice农业生态系统分析Analysis and Simulation of Ecosystem生态系统分析与模拟Analysis and Simulation of Ecosystem农业关联产业分析Analysis of Agribusiness国情分析和发展战略Analysis of Country Situation and Development Stratagem 兽医临床病例分析Analysis of Veterinary Clinical Cases兽医临床病例分析Analysis of Veterinary Clinical Cases现代食品分析技术Analytic Technology of Modern Food Science现代食品分析技术Analytic Technology of Modern Food Science古汉语Ancient Chinese古汉语Ancient Chinese动物病理剖检诊断技术Animal Autopsy Technique for Pathological Diagnosis克隆动物与转基因动物Animal Cloning and Transgensis克隆动物与转基因动物Animal Cloning and Transgensis动物源食品卫生检验技术Animal Derived Food Inspection Technique动物实验方法Animal Experiment Technology动物消化道微生物Animal Gastrointestinal Tract Microbiology动物消化道微生物Animal Gastrointestinal Tract Microbiology动物遗传资源Animal Genetic Resource 动物卫生行政法学Animal Health Management 动物卫生行政法学Animal Health Management 畜牧工程Animal Husbandry Engineering 动物营养代谢病Animal Metabolic Diseases 动物营养代谢病专题Animal Metabolic Diseases 人类疾病模型的构建与应用Animal Models for Human Diseases 动物分子病毒学Animal Molecular Virology 动物分子病毒学Animal Molecular Virology 动物神经生物学Animal Neurobiology 动物神经生物学Animal Neurobiology 动物营养与免疫专题Animal Nutrion and Immunology 动物营养与免疫专题Animal Nutrion and Immunology 动物保护与福利Animal Protection and Welfare 动物生殖内分泌学Animal Reproduction and Endocrinology 动物生殖内分泌学Animal Reproduction and Endocrinology 动物繁殖学SeminarAnimal Reproduction Seminar 动物繁殖学SeminarAnimal Reproduction Seminar动物繁殖理论与现代生物技术(案例)Animal Reproduction Theory and Modern Biotechnology 动物生殖生理学实验Animal Reproductive Physiology 动物生殖生理学Animal Reproductive Physiology动物生殖生理学实验Animal Reproductive Physiology Experiment 动物生殖生理学实验Animal Reproductive Physiology Experiment 动物功能基因组学Animl Functional Genomics 动物功能基因组学Animl Functional Genomics 人类学与中国社会研究Anthropology and Chinese Society 人类学与中国社会研究Anthropology and Chinese Society 植物抗菌化合物专题Antimicrobial Compounds from Plants 植物抗菌化合物专题Antimicrobial Compounds from Plants 3S 技术农业应用Application of 3S in Agriculture 3S 技术在水利工程中的应用Application of 3S Techniques on Soil and Water Conservation生物多样性与应用Application of Biodiversity 生物多样性与利用Application of Biodiversity 生物多样性与利用Application of Biodiversity 3S 技术应用Application of GIS, GPS and RS 3S 技术应用Application of GIS, GPS and RS应用数理统计Application of Mathematical Statistics 应用数理统计Application of Mathematical Statistics 分子生物学在昆虫学中的应用Application of Molecular Biology to Entomology 分子生物学在昆虫学中的应用Application of Molecular Biology to Entomology 植物生理生态仪器Application of Plant Physiology and Ecology 植物生理生态仪器Application of Plant Physiology and Ecology 3S 在水文模拟中的应用Applications of "3S" to Hydrology Simulation电力系统最优化技术Applications of Optimization Method in Electrical Power System 电力系统最优化技术Applications of Optimization Method in Electrical Power System 稳定同位素在生态环境研究中的应用Applications of Stable Isotopes in Studies of Environment and Ecology 稳定同位素在生态环境研究中的应用Applications of Stable Isotopes in Studies of Environment and Ecology 应用数理统计Applied Mathematical Statistics应用经济学Seminar Applied Economics Seminar应用地质地貌与土地资源Applied Geology Geomorphology and Land Resource应用地质地貌与土地资源Applied Geology Geomorphology and Land Resource应用植物生物技术Applied Plant Biotechnology农业应用随机过程Applied Stochastic in Agriculture应用随机过程Apply Stochastic Processes园林设计研究进展Approach of Landscape Architecture风景园林研究进展Approach of Landscape Architecture观赏植物生理生态研究进展Approach of Ornamental Horticulture观赏园艺研究进展Approach of Ornamental Horticulture英语教学法Approaches and Methods in Language Teaching英语教学法Approaches and Methods in Language Teaching水生昆虫学Aquatic Entomology水生昆虫学Aquatic Entomology艺术设计Art Design人工智能原理Artificial Intelligence人工智能技术Artificial Intelligence结构抗震减震分析原理Aseismic Analysis Principle of Structure兽药安全评价技术Assessment Technique of Veterinary Drug Safety不对称合成Asymmetric Synthesis不对称合成Asymmetric SynthesisAutoCAD 二次开发技术Auto CAD Customization自动控制技术Automatic Control Technology自动控制理论Automatical Control Theory自动控制理论Automatical Control Theory自动机械设计Automatical Machine Design禽类生理学Avian Physiology禽类生理学Avian Physiology遗传分析原理Basic Concepts of Genetic Analysisi基础分子生物学实验Basic Experiment of Molecar Biology基础分子生物学实验Basic Experiment of Molecar Biology新能源发电技术基础Basic of Renewable Energy Generation Technology交通规划理论与方法Basic Theory and Method of Traffic-layou放射卫生防护知识Basical Knowledge of Radiation Protection放射卫生防护知识Basical Knowledge of Radiation Protection放射卫生防护知识Basical Knowledge of Radiation Protection土壤物理与作物学基础Basics of Soil Physics and Crop土壤物理与作物学基础Basics of Soil Physics and Crop篮球Basketball生化分析Biochemical Analysis生化分析Biochemical Analysis生物气候模型与信息系统Bioclimatological Model and Information System生物气候模型与信息系统Bioclimatological Model and Information System畜牧生物工程专业硕士生Seminar Bio-engineering Seminar in Animal配子与胚胎生物工程Bio-engineering Technology in Animal Gamete and Embryo 配子与胚胎生物工程Bio-engineering Technology in Animal Gamete and Embryo 植物小RNA的生物合成和功能Biogenesis and Function of Small RNAs in Plant生物地球化学Biogeochemistry生物地球化学Bio-geochemistry生物信息学Bioinformatics生物信息学Bioinformatics生物信息学Bioinformatics生物信息学算法Bioinformatics Algorithm生物信息学算法Bioinformatics Algorithm生物信息检测与处理专题Bioinformatics Detection and Processing Topic生物信息学SEMI.Bioinformatics Seminar生物信息学Seminar Bioinformatics Seminar植物病害生物防治Biological Control of Plant Diseases植物病害生物防治Biological Control of Plant Diseases生物饲料加工与利用Biological Feed Processing and Application植物病原细菌生物学Biology of Plant Pathogenic Bacteria植物病原细菌生物学Biology of Plant Pathogenic Bacteria生物质工程Bio-mass Engineering Theory生物质工程原理Bio-mass Engineering Theory生物膜与信号转导Biomembrane and Signal Transduction生物膜与信号传导Biomembrane and Signal Transduction生物物理学BiophysicsBioprocessing and Food Quality Bioprocessing and Food QualityBioprocessing Engineering Bioprocessing Engineering生物生产自动化与机器人Bio-production and Robot生物生产自动化与机器人Bio-production and Robot生化反应动力学与反应器Bioreaction Engineering生化反应动力学与反应器Bioreaction Engineering生物修复Bioremediation生物修复Bioremediation农业生物安全Biosafty for Agriculture生物系统动力学(Biosystem)Biosystem Dynamics生物系统动力学Biosystem Dynamics观赏植物生物技术Biotechnology of Ornamental Plants蔬菜生物技术Biotechnology to Vegetable Science植物源杀虫剂及作用机理Botanic Pesticide植物源杀虫剂及其作用机理Botanic 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ADVANCES AND CHALLENGES WITH MICRO-IRRIGATION †CHANDRA A.MADRAMOOTOO AND JANE MORRISON *Brace Centre for Water Resources Management,McGill University,Macdonald Campus,Sainte-Anne-de-Bellevue,Quebec,CanadaABSTRACTAs global concerns surrounding water scarcity and food security escalate,there will be more demand for micro-irrigation to meet growing food demands.Micro-irrigation offers many advantages over conventional irrigation methods,including the ability to apply limited amounts of water directly to the crop root zone,incorporation of fertigation,reduced weed and pest infestation,and lower capital and operating costs.In recent decades,there has been considerable growth in the acreage under micro-irrigation,mainly as a result of lower costs,improvements in filtration and emitter technology,and increased grower con fidence in the technology.Research advances and technological improvements have made micro-irrigation applicable to a more diverse set of applications,cropping systems,and water quality conditions.Cost and availability of water are also major drivers.Research in nano-and bio filtration techniques,soil moisture sensors,and precision irrigation shows great promise for the advancement of micro-irrigation.Nevertheless,several technological challenges remain,especially for non-row or non-orchard crops,and in regions where water quality is severely impaired.Innovations in these areas are required,as well as a transfer of the technology to small farmers in water-scarce regions who traditionally surface irrigate.Copyright ©2013John Wiley &Sons,Ltd.key words:micro-irrigation;drip irrigation;water use ef ficiency;agriculture;food security Received 16July 2012;Revised 3October 2012;Accepted 3October 2012RÉSUMÉEn réponse aux préoccupations grandissantes concernant la raretéde l ’eau et la sécuritéalimentaire et aux enjeux afférents,on peut s ’attendre àune augmentation de la demande de micro-irrigation pour faire face aux besoins alimentaires micro-irrigation offre plusieurs avantages lorsqu ’elle est comparée aux méthodes conventionnelles d ’irrigation.Cela inclut la capacitéd ’appliquer des quantités limitées d ’eau directement dans la couche arable des cultures,l ’incorporation de la fertirrigation,la réduction de l ’infestation par des espèces nuisibles,végétales ou animales,ainsi que la réduction des coûts d ’investissements et de fonctionnement.Durant les dernières décennies,il y a eu une croissance considérable des zones micro-irriguées,principalement grâce aux réductions de coûts,aux améliorations dans les technologies de filtration et d ’émetteurs électroniques,et àla con fiance grandissante des producteurs envers cette technologie.Les avancées de la recherche et l ’amélioration des technologies ont rendu la micro-irrigation applicable àun groupe plus diversi fiéd ’applications,de systèmes de récolte,et de conditions de qualitéd ’eau.Le coût et la disponibilitéde l ’eau sont aussi des facteurs recherche sur les techniques de nano filtration et de bio-filtration,sur les capteurs d ’humiditédu sol,et sur l ’agriculture de précision permet d ’entrevoir des avancées certaines de la micro-irrigation.Cependant,il reste beaucoup de défis technologiques,surtout pour les cultures qui ne sont pas en rangées et celles qui ne font pas partie d ’un verger,ainsi que dans les régions oùla qualitéde l ’eau est gravement détériorée.Des innovations dans ces domaines sont nécessaires,ainsi qu ’un transfert de technologie envers les petits cultivateurs qui utilisent traditionnellement l ’irrigation de surface dans des régions pauvres en eau.Copyright ©2013John Wiley &Sons,Ltd.mots clés:micro-irrigation;irrigation au goutte-à-goutte;ef ficacitéde l ’utilisation de l ’eau;agriculture;sécuritéalimentaireINTRODUCTIONThe irrigation sector is under pressure to increase its ef ficiency since it is the major user of fresh water globally.This is exacerbated as water resources become scarcer due to climate change,and as the competition for water from other economic*Correspondence to:Jane Morrison,Brace Centre for Water Resources Management,McGill University,Macdonald Campus,Sainte-Anne-de-Bellevue,Quebec,Canada.E-mail:jane.morrison@mail.mcgill.ca †Avancées et défis de la micro-irrigation.IRRIGATION AND DRAINAGEIrrig.and Drain.(2013)Published online in Wiley Online Library ()DOI :10.1002/ird.1704and environmental uses increases.Demand for more efficient water applications is therefore on the rise.Micro-irrigation, which is the precise application of water on or below the soil surface at low pressure using small devices that spray,mist, sprinkle,or drip water,is becoming more attractive(Hla and Scherer2003).In the past,micro-irrigation required high capital investment and was therefore mostly used for high-value cash crops,such as vegetables and fruit trees,and was infrequently used for lower-value staple crops(Brouwer et al.1988).In recent decades,increased sales and improve-ments in technology have resulted in greater adoption of micro-irrigation worldwide.Drip irrigation is a common form of micro-irrigation;Table I shows the worldwide growth in drip irrigation since its conception in the1970s.Table II displays the rapid growth in acreage under drip irrigation within selected countries between the years1974and2006. Table III compares the areas of sprinkler irrigation and micro-irrigation by country,and their percentage of the total irrigated area.In some countries,such as Spain,Korea,Israel,Poland,and Chile,the area cropped to drip irrigation is higher than that which is sprinkler irrigated(Table III).It is also worthy of note that India’s percentage of drip irrigated area is increasing and is not far behind its sprinkler irrigated area(ICID,2011).Several government and non-government organizations are actively promoting micro-irrigation in developing countries(Varma et al.2006).The high-value horticultural,ornamental,and landscape industries have taken advantage of micro-irrigation,and remain its biggest users.Small-scale cash crop growers have expanded their production by adopting drip irrigation.This is particularly evident in the case of vegetable production in periurban areas in some parts of Africa and Asia.However, more innovations are required to expand the use of drip irrigation for non-orchard crops such as rice,wheat,and maize.In order to significantly expand the area under micro-irrigation,these technological innovations will have to come with lower capital costs and the ability to irrigate with poorer quality water.ADVANTAGES AND BENEFITSMicro-irrigation provides a constant supply of water in the crop root zone and has been proven to provide a higher crop yield and increased water use efficiency over conventional irrigation methods.Micro-irrigation systems offer a high level of control over water applications.These systems are also very economical as they use a low volume of water,at low pressure,resulting in low energy costs(Varma et al.2006). With micro-irrigation there is no percolation to groundwater and there is also no surface runoff.In addition,because of a reduced wetted area,less water is lost to evaporation.Due to its high water use efficiency,micro-irrigation is increasingly being used as a strategy to address water scarcity and poverty.Researchers,such as Shah(2011), have pointed to the water savings and yield increases due to micro-irrigation(Table IV).In addition to farm productiv-ity(crop yield and output),farmer income and food security are also increased.With earlier harvests,labour costs are reduced.Improvements in drip irrigated crop quality have also been observed(Madramootoo and Rigby1991). Generally,micro-irrigation systems are easy to install and manage,and can be used for a variety of orchard and row crops,particularly for fruit and nd levelling is not necessary because system components,pressure regulat-ing valves and pressure compensating emitters,allow for a uniform water distribution and application rate.A major innovation has been the development of fertilizer injectors which can be attached to micro-irrigation systems to allow for fertigation,thereby improving crop nutrient management. Both water and fertilizer can be applied throughout the grow-ing season in judicious amounts to match crop requirements. Additionally,incidence of pest and weed invasion,and other plant diseases,occurs less frequently due to a reduced wetted area and drier soil surface.By reducing the labour needed to protect crops,and by reducing pesticide/herbicide use,there is an overallfinancial saving to the farmer(Varma et al.2006).MAJOR ADVANCESMajor advances have taken place in micro-irrigation technol-ogy,resulting in increased adoption and a growing number ofTable I.Worldwide growth in drip irrigation(Postel et al.2001) Year Global acreage under drip irrigation(million ha) 1970s0.0561991 1.62001%2.8Table II.Acreage under drip irrigation for selected countries(ha)CountryAcreage under drip irrigation 1974–198119912000–2006China n.a.19000a759500b(2006)India20b(1981)70680b578200b(2004)Israel6073c(1974)104300b168800b(2004)South Africa3482c(1974)102300a178000b(2000)United States29150c(1974)606000a1615000b(2005)a Postel(1992).b Food and Agriculture Organization of the United Nations(2012).c Gustafson(1974).C.A.MADRAMOOTOO AND J.MORRISONadvantages.In addition,innovations allow for a more diverseset of applications.Clogging and inefficient waterfiltration have traditionallybeen major issues when employing micro-irrigation.Theinvention of functional and cost-effective sand and screen filtration devices has helped to overcome this issue,and has ultimately resulted in an expanded use of micro-irrigation inareas with low-quality water.Micro-irrigation can be combined with precision irrigationscheduling,enabling the application of water at a time and ratethat are based on a crop’s precise water requirement.Withprecision irrigation,scheduling is synchronized with weatherand soil conditions,and a crop’s evapotranspiration rate(Jones2004).Precision irrigation saves water and money,and reduces runoff and energy consumption.In addition,byirrigating crops with a precise amount of water suited to thecrop’s growth stage,there is also the potential to increase cropyield(Cooley et al.2009).The development of time domain and frequency domainreflectometry sensors which provide information on soil mois-ture levels on a real-time basis has enabled the automation of irrigation systems.In the past,farmers decided when to irrigate based on intuition,weather,and physical plant/soil conditions.Sensors used for real-time irrigation scheduling take into account crop type,growth stage,soil type,and soil moisture status in order to take the guesswork out of irrigating and provide farmers with a more efficient and accurate way of determining when to apply water and for how long.Modern equipment allows for real-time data on soil water status to be available directly in thefield,enabling farmers to make timely irrigation decisions.In addition,with advanced technology, irrigation operations can be automatically triggered,consis-tently applying an accurate amount of water to crops(avoiding unnecessary excess or deficits in water applications).Recent work by Jaria and Madramootoo(2011)has shown how auto-mated soil moisture sensors and weather measurements can be used in a computerized system,to determine irrigation triggers,thereby permitting the farmer to better and more precisely schedule drip irrigation applications.Improved knowledge about the interactions between the plant,soil,and water continuum has paved the way for innovative water regulating mechanisms.For example,withTable III.Areas of sprinkler and micro-irrigation for selected countries(ICID,2011†)CountryTotalirrigated area(million ha)Sprinkler irrigation Micro-irrigationYear ofreporting Area%of total Area%of totalirrigated area(ha)irrigated area(ha)USA24.701230000050.01640000 6.62009 India60.903040000 5.01900000 3.12010 China59.302930000 4.91670000 2.82009 Russia 4.50350000077.8200000.42008 Brazil 4.45241000054.23280007.42006 Spain 3.4173300021.5163000047.82010 Italy 2.6798100036.857100021.42010 France 2.90138000047.6103000 3.62011 South Africa 1.6792000055.136500021.92007 Saudi Arabia 1.6271600044.219800012.22004 Iran8.70460000 5.3270000 3.12009 Australia 2.5552400020.61910007.52000 Canada0.8768300078.560300.72004 Mexico 6.20400000 6.5200000 3.21999 Korea 1.0120000019.840000039.62009 Israel0.236000026.017000073.62000 Morocco 1.6519000011.582500.52003 Syria 1.28930007.362000 4.82000 Turkey 5.34110000 2.1260000.52009 United Kingdom0.1110500095.56000 5.52005 Portugal0.6340000 6.425000 4.01999 Chile 1.0916000 1.523000 2.12006 Chinese Taipei0.3818900 5.08750 2.32009 Bulgaria0.5921000 3.630000.52008 Czech Rep.0.15110007.25000 3.32007 Philippines 1.5271800.566400.42004 Poland0.105000 5.080008.02008 Malaysia0.3820000.55000 1.32009 Estonia0.00150050.050050.02010ADVANCES AND CHALLENGES WITH MICRO-IRRIGATIONdeficit irrigation,water is applied below the crop’s full water requirement(a percentage of a crop’s evapotranspiration rate), reducing irrigated water use and conserving water.Water use effectiveness is increased by stressing crops,but only to a point which does not adversely affect yields(Fereres and Soriano2007).Partial root zone drying is another strategy that can be employed with micro-irrigation for a more efficient use of irrigation water.The process requires that half of a crop’s rooting system be exposed to alternate wetting and drying; essentially half of the root system is put in a drying state while the remainder remains irrigated.The alternating frequency is a function of the crop type,growth stage,and specific water requirement.This technique is based on an understanding of the mechanisms controlling transpiration, and requires sophisticated management and highly accurate monitoring(McCarthy et al.2002).With this process there is a potential to reduce water use while increasing canopy vigour and maintaining yields in regions of water scarcity. Micro-irrigation technology is enabling new and diverse methods of providing dependable irrigation in water-scarce regions.Treated and untreated wastewater can be applied in a manner which targets only suitable crops.Micro-irrigation is more appropriate than other irrigation methods for the reuse of wastewater because there is no aerosol gener-ation and no wastewater comes into contact with plant foliage. There are also fewer problems with odours,ponding,and runoff.In addition,studies suggest that the nitrogen present in wastewater is better absorbed by plants and less likely to pollute groundwater when applied directly to plant roots. When using wastewater with micro-irrigation it is necessary to ensure that emitters do not clog.Systems must be closely monitored to ensure a uniform application and full functional-ity(Casey et al.1999).Another strategy for overcoming water shortages is the use of reverse osmosis in subsurface drip irrigation lines. Reverse osmosis technology enables the use of brackish water,frequently found in groundwater aquifers,as a source of irrigation water;allowing water that would nor-mally be deemed unsuitable to be used for irrigating food crops.Desalination is achieved using a semi-permeable reverse osmosis membrane within the drip line,supply-ing purified water to irrigated crops and preventing the accumulation of salts in the soil.Unlike conventional reverse osmosis systems which require the use of high-energy pumps,the transport of water across the reverse osmosis membrane within a drip line is driven by the matrix potential of the soil.Reverse osmosis subsurface drip irrigation systems are lowflow,low pressure,and have an especially high water use efficiency because water extraction is a direct function of the water require-ment of the crop(Leslie2010).FUTURE CHALLENGESThere remain several obstacles which must be overcome in order to increase the adoption of micro-irrigation,particularly in developing countries where small farms predominate.Table IV.Drip vs surface irrigation—water saving and increase in yield(Shah2011)Yield(kg haÀ1)IrrigationCrop Increase Saving Surface Drip Surface Drip(%)(%) Beet root57088054861879 Bitter gourd3200430034763357 Brinjal910014800631686462 Broccoli140001950039706014 Chili171002740060271833 Cucumber42306090441094262 Okra155002250045542456 Onion284003420020522650 Potato172002910069602854 Radish1050119013461176 Sweet potato4240589039632560 Tomato6180887044501179 Banana5750087500521769745 Grapes264003250023532847 Papaya1300023000772287368 Pomegranate3400670097211624 Watermelon821050400514722565C.A.MADRAMOOTOO AND J.MORRISONMicro-irrigation is best suited for irrigating individual plants or trees,or row crops,but is generally deemed unsuit-able for close-growing crops such as rice or other cereals (Brouwer et al.1988).As a result,farmers in regions which rely on these types of close-growing crops have been unable to benefit from micro-irrigation.However,with advances in technology,micro-irrigation is being adapted for a wider variety of crops.The driver is to increase water use efficiency and food security in water-scarce regions and developing countries which depend on cereal crops as dietary staples. Rice,which is traditionallyflood irrigated,uses large volumes of water.With drip irrigation the water requirement is50–60%less.Drip irrigation keeps the moisture availability in the soil continuously close to the crop’s water requirement. However,non-flooding leads to increased weed presence, making herbicide use a critical element when using drip irriga-tion in rice farming(Soman2012).More knowledge about the specific water requirements of different cereal crops and more adapted equipment and technology are needed in regions which rely on these types of crops.The benefits of using a buried drip irrigation system as opposed to a surface drip irrigation layout are being examined. On one hand,buried systems have a longer lifespan as they are less likely to be damaged or tampered with byfieldworkers and rodents.Studies have shown that with buried drip lines, crop yields are equal to,or better than,those in which surface drip lines are installed.In addition,the water and fertilizer requirements for buried systems are equal to or lower than those for surface irrigation.However,some subsurface drip systems are complex,requiring air entry ports andflushing manifolds.The ability for subsurface irrigation to maintain a dry soil surface is an advantage for some crop situations (i.e.to reduce weed growth),while it is a disadvantage in other situations(i.e.for germination of shallow-planted seeds).An additional benefit is the use of subsurface irrigation in waste-water applications.This results in fewer odour problems, and the deeper placement of phosphorus in the soil profile facilitates plant uptake(Camp et al.2000).As we move to automated irrigation scheduling,more research is required to determine the most appropriate place-ment of soil moisture sensors.Currently,sensors are only able to provide soil water status at a particular point and depth at a given site.As such,placement of the sensor is important in order to provide a representative measurement for making comprehensive irrigation decisions.Placement of the sensor in terms of the wetted area in relation to the crop root zone is crucial for triggering irrigation systems on and off.An evolving area of research is the application of satellite-positioning systems,geographic information systems,auto-mated machine guidance,and remote-sensing technologies for precision irrigation scheduling and improved agricultural water management(Joseph and Morrison2006).Thermal im-agery using low-flying unmanned aerial vehicles,drones,aircraft,or satellites can determine the water content of soilor plant water status at high spatial resolution,and conse-quently trigger irrigation precisely in a specific location.As aresult,water conservation and crop productivity can be opti-mized.This technology can overcome obstacles associatedwith soil heterogeneity andfield variability in order to ensureindividual areas are being irrigated according to their specificwater requirements.However,the technology is still being re-fined in order to overcome issues associated with cloud inter-ference or the need for frequent imaging.Systems whichutilize crop simulation models in addition to remote sensinghave been proposed in order to overcome these obstacles andeffectively manage precision or variable rate irrigation(Barneset al.2000).Further research is required to improve the accu-racy and cost-effectiveness of these techniques.There is potential to capitalize on the use of nanotechnol-ogy and biotechnology in micro-irrigation,particularly withrespect to water quality improvement,filtration techniques,and reduced emitter clogging.Nanomaterial-based biosensorscan recognize,measure,and monitor the presence of contami-nants,with the potential to operate on site,in real time.Nano-filtration membrane technology enables the identification and trapping of particles at the nanoscale,and the capability for partial desalination.In addition,there is reduced fouling of membranes andfilters.Nanotechnology is also used in soil moisture sensor design,achieving a high level of accuracy, rapid response rates,compact size,and robustness.With these innovations,the challenge lies in transferring research into practice.Improved cost-effectiveness,availability,and in-formed management will help to increase the adoption of these promising technologies(Organisation for Economic Co-operation and Development(OECD)2011).Although technological development and simplificationhave reduced the overall cost of micro-irrigation systems,the technology is still expensive.Additionally,a high levelof technical skill is required for proper system design,main-tenance,and optimal efficiency.Advancements to furtherreduce costs,labour,and to facilitate the initial system de-sign and installation will make this technology increasinglyattractive to farmers.Due to the high initial investment required for taking up orswitching to micro-irrigation systems,small farmers in devel-oping countries have been slow to adopt this practice.In addi-tion,a lack of cash and expertise,and the crop specificityassociated with available micro-irrigation technologies,furtherreduce its desirability(Varma et al.2006).Studies have shownthat farmers are rarely motivated by the water and energy sav-ings potential of new technologies.In many countries,wateris not metered and power is subsidized,giving farmers nofinan-cial incentive to strive for resource conservation.Furthermore,in countries where farmers have practised surface irrigationfor decades and are accustomed to having water delivered incanals,they see no immediate benefit to culturally changingADVANCES AND CHALLENGES WITH MICRO-IRRIGATIONto other methods of irrigation.Farmers tend to look for new technologies which promise increased profit(Soman2012). As such,strong institutional support,promotion,product subsi-dies,and improved access to credit are needed for an increased uptake of micro-irrigation technology in developing countries (Varma et al.2006).CONCLUSIONSSince the introduction of micro-irrigation technology over40years ago,there is now close to some3million ha of drip irrigation worldwide.Micro-irrigation has been particularly successful for horticultural,ornamental,and landscape applications,and has been applied to a wide range of climatic conditions from humid to arid and semi-arid regions.Its advantages with respect to water and energy savings,reduced labour,and improved fertilizer application through fertigation are well recognized.Micro-irrigation will continue to attract attention as water resources become increasingly limited.Its suitability for sloping and undulat-ing topography,and applicability to any size of farm,offer several advantages compared to other irrigation techniques. Advances in emitter and dripper technology,the introduc-tion of inexpensive drip tape,and the development of low-cost sand and screenfilters have also helped to expand the acreage under micro-irrigation.Additionally,new soil moisture sensors have enabled the automation of these irrigation systems.Ongoing research with bio-and nanofiltration systems, particularly the incorporation of nanofilters in the emitters and drip lines,will allow micro-irrigation to be more widely used in regions that suffer from poor water quality,and in situations where wastewater is used for irrigation.The latter will become increasingly important in regions affected by water scarcity.The use of soil moisture sensor technology, together with remote sensing of soil and crop parameters, geographic information systems,global positioning systems,and crop growth models,will allow for improved water management and water use efficiency under micro-irrigation.The goal is to make precision irrigation or vari-able rate irrigation an essential facet of micro-irrigation.A significant challenge is to apply drip irrigation technol-ogy to the production of cereal crops,particularly in devel-oping countries.In these parts of the world,there are several social,technical,and institutional challenges which must be cation and knowledge transfer must be accelerated.Energy and water subsidies must be removed to see the full benefits of drip irrigation.ACKNOWLEDGEMENTSThis article is based on a keynote presentation given by the senior author at the8th Micro-irrigation Congress,held in Tehran on21October2011.The senior author is grateful to the Congress organizers for this invitation.The senior author was President of ICID at the time of the Congress.Special thanks go to Mr Felix Jaria,graduate student at the Brace Centre for Water Resources Management,McGill University, who helped to compile some of the statistics for the paper. The senior author gratefully acknowledges the following agencies which generously support his research programme in irrigation and water management:McGill University,Canadian Foundation for Innovation,Natural Sciences and Engineering Research Council of Canada, Canadian International Development Agency,Interna-tional Development Research Centre of Canada,Agricul-ture and Agri-Food Canada,Max Bell Foundation,Fonds de recherche du Québec-Nature et technologies,Ontario Ministry of Agriculture,Food and Rural Affairs,and the Canadian Water Network.REFERENCESBarnes EM,Pinter PJ Jr,Kimball BA,Hunsaker DJ,Wall GW,LaMorte RL.2000.Precision irrigation management using modeling and remote sensing approaches.Presented at the4th Decennial National Irrigation Symposium.American Society of Agricultural Engineers,Phoenix, Arizona,14–16November.Brouwer C,Prins K,Kay M,Heibloem M.1988.Irrigation Water Manage-ment:Irrigation Methods.Food and Agriculture Organization of the United Nations:New York,USA.Camp CR,Lamm FR,Evans RG,Phene CJ.2000.Subsurface drip irriga-tion—past,present,and future.Presented at the4th Decennial National Irrigation Symposium.American Society of Agricultural Engineers, Phoenix,Arizona,14–16November.Casey P,Lake A,Falvey C,Ross JA,Frame K.1999.Spray and Drip Irrigation for Wastewater Reuse,Disposal.National Small Flows Clear-ing House,West Virginia University:Morgantown,W.Va.Cooley H,Christian-Smith J,Gleick PH.2009.Sustaining Agriculture in an Uncertain Future:the Role of Water Efficiency.Pacific Institute: Oakland,Calif.,USA.Fereres E,Soriano MA.2007.Deficit irrigation for reducing agricultural water use.Journal of Experimental Botany58(2):147–159.Food and Agriculture Organization of the United Nations.2012.AQUASTAT. 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