2023-2024学年河北省承德市高中高一下学期期末考试英语试题Our broadcasting camp will open on August 1st. This unique opportunity is designed to attract participants to the world of broadcasting and media production.Camp DetailsDuration: 2 weeksCapacity: 50 participantsVenue: National Media Center, New York Training SchedulesOur camp will cover a wide range of topics, including storytelling, audio and video production techniques, live broadcast and studio operations, social media and digital broadcasting. Each day will be a blend (融合) of lectures, hands-on workshops, and interactive sessions with industry professionals.Benefits for ParticipantsGain practical skills in broadcasting and media production.Network with industry experts and fellow enthusiasts.Receive a certificate of completion recognized by leading media institutions.Opportunities to showcase talent through live broadcasts and digital platforms.Why Join Us?Our camp promises to be an enriching experience that not only equips you with the necessary skills but also opens doors to a career in the broadcasting industry. Whether you’re a student looking to explore your passion or a professional seeking to enhance your skills, our camp is the perfect platform for your growth.Don’t miss this chance to inspire your passion for broadcasting. Apply now and let your voice heard! For more information and to register, click here.1. What does the broadcasting camp feature?A．A very low price. B．Many relative topics.C．The process of production. D．The ways to know experts.2. How can you sign up for the broadcasting camp?A．By visiting a website. B．By registering on-site.C．By calling a teacher. D．By writing to the camp.3. What is the purpose of the text?A．To focus on broadcasting. B．To introduce social media.C．To promote the camp. D．To develop students’ hobbies.Some of the classrooms at Taft Elementary in Santa Clara, California, have one disadvantage in common: They don’t have windows. That’s true for Logan Earnest’s fifth grade classroom, and he felt it was affecting his students.“Most of the day, they’re inside,” Earnest told CBS News. “And they don’t really get to see any trees, grass, or the blue sky.” He said the gray walls could be depre ssing to the kids and may affect their attention and even their attendance.This was confirmed by former school psychologist Ernesto Rodriguez, who said the lack of windows does affect kids, because research shows being in and around nature eases anxiety and benefits students. Though no longer a practicing psychologist, perhaps he knows now more than ever the impact nature has on mental health. Rodriguez became a park ranger (公园管理员) on Southern California’s Catalina Island and began focusing on his passion—landscape photography.It was during his training to become a park ranger that he learned a fact that kids who have views out windows to trees do better academically, emotionally and creatively. So an idea to bring nature into rooms occurred to him: Why not bring landscapes in classrooms—via the ceiling (天花板), because teachers don’t typically use them.Rodriguez took 360 degree shots of tree canopies (树冠) using his photography skills, then he printed them and fit them onto the classroom ceiling of Earnest’s fifth grade. “Beautiful,”one student said as she entered the room. Another student said the trees brought him peace, “When you look up, it feels like you’re sitting under a tree.”Earnest said he thought there would be many positive effects on his students. “I think my attendance is going to go up. The kids are going to want to come here more frequently. Overall, I think the kids are going to be happier,” he said.4. What is the common challenge shared by some classrooms at Taft Elementary?A．Lack of fresh air. B．Absence of windows.C．Insufficient lighting. D．Limited access to technology.5. Why did Ernesto Rodriguez bring landscapes into classrooms?A．To connect the students with nature.B．To promote his photography skills.C．To improve the teac hers’ performance.D．To create an exciting environment for the students.6. How did the students react to Rodriguez’s pictures on the classroom ceiling?A．They did not notice the change.B．They failed to concentrate on lessons.C．They preferred the original gray ceiling.D．They were in favour of the new additions.7. What’s Logan Earnest’s attitude towards the change in the classroom?A．Cautious and objective. B．Appreciative and supportive.C．Concerned but doubtful. D．Curious but unsure.Elephan ts’ important role in maintaining biodiversity and healthy ecosystems has earned them various names including ecosystem engineers and forest gardeners. However, African forest elephants — a species living in the rainforests of central Africa — are increasingly recognized by another name: “climate heroes”.African forest elephants help lessen climate change by increasing carbon storage in their forest habitats, meaning they help remove heat-trapping CO2 from the atmosphere. They do this by influencing the forest structure, including by increasing the diversity and abundance of plant species. It’s estimated that one forest elephant can increase the net carbon capture (捕获) capacity of the forest by almost 250 acres. This is equal to removing from the atmosphere a year’s worth of emissions (排放量) from 2,047 cars.“As strange as it seems, all that eating and destruction help the forest pull more carbon out of the air,” says Alison Pearce Stevens in the book Animal Climate Heroes! . Elephants eat more than 400 pounds of food a day, so they spend a lot of time searching for food. As they walk through the forest, they do a lot of damage to the surrounding smaller trees, leading to the survival of trees that have the ability to absorb and store more CO2.In addition, their thirst for fruits also helps to promote forest growth. This is because elephants disperse fruit seeds. In other words, the seeds pass through the elephant bodies until they drop back to the forest floor.But African forest elephants are seriously endangered and continue to face threats. These mainly come from hunting for the illegal international trade in elephant ivory (象牙), but also from habitat loss and fewer food sources. The number of forest elephants fell by more than 86% over a period of 31 years, and their habitats are thought to have reduced by 75%. Protecting forest elephants and the forests they depend on means we are safeguarding their ecological contributions that we all rely on.8. How do African forest elephants help relieve climate change?A．They increase the diversity of wildlife species.B．They help to maintain the plants of the forest.C．They take in heat-trapping CO 2 from the atmosphere.D．They promote the net carbon capture ability of the forest.9. What does the underlined word “disperse” in paragraph 4 mean?A．Consume. B．Preserve. C．Spread. D．Gather.10. What are the threats facing African forest elephants?A．Illegal hunting and habitat loss.B．The disturbed balance of the forest ecosystem.C．Natural disasters resulting from climate change.D．Competition for water sources with other animals.11. What can be a suitable title for the text?A．Preserving Forests: Elephants’ ContributionB．New Role of African Forest Elephants: Climate HeroesC．Ivory Trade Threatens African Forest ElephantsD．Forest Elephants Are Approaching the Edge of ExtinctionSpace engineers from the University of Glasgow have published new research showing how reflectors (反射器) placed in orbit around Earth could increase the output of future large-scale solar farms by reflecting additional sunlight toward them even after the sun has set.In their paper, the researchers described how they used advanced computer models to help determine the most effective method of using orbiting solar reflectors to produce additional power. Their models showed that putting 20 thin reflectors into orbit 1,000 kilometers from Earth could reflect sunlight to solar farms for an extra two hours each day on average. The additional sunlight could increase the output of the worl d’s future solar farms, particularly after sunset when electricity demand is high. The output could be scaled up further by adding more reflectors or increasing their size.The team developed an algorithm (算法) to determine how the reflectors could be arranged to catch the sun’s rays most effectively, maximizing the additional sunlight reflected to solar farms around Earth in the early morning and late evening. The researchers suggested that 20 reflectors could produce an extra 728 MWh of electricity per day — equal to adding an additional large solar power farm to Earth without the cost of construction.Dr. Onur Çelik, one author of the paper, said, “Solar power has the potential to speed our race to reach net-zero, helping us to relieve the global impacts of climate change by reducing our reliance on fossil fuels.”Moreover, the price of solar panels (太阳能电池板) has dropped quickly in recent years, increasing the pace of their adoption and paving the way for the creation of large solar farms around the world.One of the major limitations of solar power, of course, is that it can only be generated during daylight hours. Putting orbiting solar reflectors in space would help to maximize the effectiveness of solar farms in the years to come. Strategically placing new solar farms in locations which receive the most additional sunlight from the reflectors could make them even more effective.12. What is the purpose of placing reflectors in space?A．To improve communication between Earth and space.B．To bring the effects of climate change under control.C．To produce electricity for agricultural use.D．To increase the production of solar power.13. What may contribute to the application of large-scale solar farms?A．The increased demand for electricity. B．The decrease in the cost of solar panels.C．The development of space technology. D．The requirement to preserve theenvironment.14. What can be inferred about the future of solar farms?A．They’ll replace fossil fuels completely.B．They’ll become the main source of e nergy.C．They’ll be more cost-effective and efficient.D．They’ll rely mainly on orbiting reflectors for sunlight.15. Where is the text most probably taken from?A．A news report. B．A maths website.C．A marketing brochure. D．A policy brief.Adapting to different cultures is an enriching journey that broadens our opinions and improves global understanding. Here are some steps to help you embrace (拥抱) cultural diversity.Admitting cultural differencesAcknowledge and accept that each culture has its own way of life. Admit that no culture is superior or inferior; they are simply different. 16 .Seeking cultural understandingYou should understand the fundamental aspects of the culture you come across. 17 . Engage in conversations with locals to gain insights into their daily lives and values. This approach will not only enrich your knowledge but also deepen your appreciation for the culture.Exploring local food Food is a window into a culture’s soul. Try the local cuisine to experience the diversity of fla vors and cooking styles. 18 , each bite can offer a connection to the culture’s heritage (遗产).Sharing your own cultureRemember, cultural adaptation is reciprocal (相应的). While you’re learning about others, you also have the chance to share stories and aspects of your own culture. 19 .In a word, adapting to different cultures is about embracing the diversity with an open heart and mind. 20 . By doing so, you can enrich your life with new viewpoints and experiences.Ten-year-old Hallee McCoombes was born with spina bifida (脊柱裂), which didn’t stop her becoming a star athlete.As Hallee approached the finish line of the 800-metre run for kids with a _________, the crowd was cheering wildly and calling her _________. With only ten metres to go, Hallee _________ with every strength, without feeling in her waist and knees but _________. When Hallee crossed the finish line and felt _________, her twin, Jada, he ld her up, whispering, “You came in third!”Hallee has set _________ Australian track-and-field records in events for athletes with her type of disability-long-distance running, long jump, discus and javelin. It’s an amazing achievement for someone who was n’t expected to _________. Born with spina bifida, Hallee underwent immediate _________ to repair her spinal cord. After recovery, she tried efforts to walk on her own and_________ upper leg muscle and core support.Her mother, Christine McCoombes, trembled (颤抖) when __________ Hallee’s diagnosis. “The doctors also told us they didn’t know what kind of brain __________ she would have with hydrocephalus (脑积水). We really didn’t know how much she would be able to function physically and __________,” the mothe r said.Every time Hallee’s parents watched their __________ daughter compete, their hearts burst with pride. “I __________ every time, especially when people started cheering for her,” admitted her dad, Gavin. “Hallee has gone against all __________ by becoming a runner despite her spinal condition.”21.A．goal B．hope C．basis D．disability22.A．parents B．twins C．name D．mission23.A．set off B．pushed forward C．broke up D．faded away24.A．fortune B．resource C．energy D．pain25.A．tired B．bored C．confused D．scared26.A．limited B．normal C．several D．flexible27.A．walk B．gather C．grow D．settle28.A．reflection B．option C．permission D．operation29.A．transmit B．maintain C．ignore D．select30.A．spotting B．enjoying C．remembering D．imagining31.A．form B．tension C．range D．function32.A．socially B．mentally C．financially D．environmentally 33.A．weak B．determined C．frightened D．intelligent34.A．cried B．rested C．hesitated D．regretted35.A．intentions B．proposals C．expectations D．arrangements阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
Carbon footprint of rice production under biochar amendment –a case study in a Chinese rice cropping systemQ I L I U 1,2,B E N J U A N L I U 1,2,P E R A M B U S 3,Y A N H U I Z H A N G 4,V E R O N I K A H A N S E N 3,Z H I B I N L I N 1,2,D A C H U N S H E N 5,G A N G L I U 1,Q I C H E N G B E I 1,J I A N G U O Z H U 1,X I A O J I E W A N G 1,2,J I N G M A 1,2,X I N G W U L I N 1,Y O N G C H A N G Y U 1,6,C H U N W U Z H U 1and ZUBI N XIE 11State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing210008,China,2University of Chinese Academy of Sciences,Beijing,100049,China,3Department of Chemical and Biochemical Engineering,Technical University of Denmark,DK-2800,Lyngby,Denmark,4School of Life Sciences,Huaibei Normal University,Huaibei 235000,China,5College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China,6Nantong Science and Technology College,Nantong 226007,ChinaAbstractAs a controversial strategy to mitigate global warming,biochar application into soil highlights the need for life cycle assessment before large-scale practice.This study focused on the effect of biochar on carbon footprint of rice production.A field experiment was performed with three treatments:no residue amendment (Control),6t ha À1yr À1corn straw (CS)amendment,and 2.4t ha À1yr À1corn straw-derived biochar amendment (CBC).Car-bon footprint was calculated by considering carbon source processes (pyrolysis energy cost,fertilizer and pesti-cide input,farmwork,and soil greenhouse gas emissions)and carbon sink processes (soil carbon increment and energy offset from pyrolytic gas).On average over three consecutive rice-growing cycles from year 2011to 2013,the CS treatment had a much higher carbon intensity of rice (0.68kg CO 2-C equivalent (CO 2-C e )kg À1grain)than that of Control (0.24kg CO 2-C e kg À1grain),resulting from large soil CH 4emissions.Biochar amendment significantly increased soil carbon pool and showed no significant effect on soil total N 2O and CH 4emissions relative to Control;however,due to a variation in net electric energy input of biochar production based on dif-ferent pyrolysis settings,carbon intensity of rice under CBC treatment ranged from 0.04to 0.44kg CO 2-C e kg À1grain.The results indicated that biochar strategy had the potential to significantly reduce the carbon footprint of crop production,but the energy-efficient pyrolysis technique does matter.Keywords:biochar,carbon footprint,CH 4,life cycle assessment,N 2O,riceReceived 3October 2014;revised version received 25December 2014and accepted 5January 2015IntroductionGlobal surface temperature has increased 0.78Æ0.06°C since the late 19th century,which is attributed to enhanced greenhouse gas (GHG)emissions by anthro-pogenic activities (IPCC,2013a).Annual total GHG emissions from agriculture are estimated to be 1.4–1.6Gt CO 2-C equivalent (CO 2-C e )yr À1,corresponding to 10–12%of the human-induced warming effect (IPCC,2014).Thus,it is of great necessity to reduce GHG emis-sions from agriculture to mitigate climate change.Recently,biochar,a product of biomass treated at high temperature under limited oxygen conditions (pyrolysis),has been suggested as one possible strategyto alleviate global warming via its recalcitrant carbon storage in soil (Lehmann,2007).Matovic (2011)figured that about 3Gt C yr À1of biochar,accompanied with 1.8Gt CO 2-C e yr À1of energy offset (pyrolytic gas),could be produced globally from 6.1Gt C yr À1of available biomass,having the potential to offset half of the annual current anthropogenic CO 2-C e emissions.However,Woolf et al.(2010)estimated that biochar application could only mitigate a maximum of 12%of current anthropogenic CO 2-C e emissions based on conversion of sustainable procured biomass resource by high-yield and low-emission pyrolysis method.The mitigation potential of biochar application into soil depends on various aspects,including feedstock source,biochar-carbon stability in soil,crop yield response,soil GHG emissions alteration,and energetic performance of biochar production system (CayuelaCorrespondence:Zubin Xie,tel.+862586881105,fax +862586881000,e-mail:zbxie@©2015John Wiley &Sons Ltd 1GCB Bioenergy (2015),doi:10.1111/gcbb.12248et al.,2010;Woolf et al.,2010;Field et al.,2013).Previous studies indicated that biochar might have inconsistent effects on crop yield and soil GHG emissions,depend-ing on biochar properties,soil types,crop species,and farmland management(Jeffery et al.,2011;Cayuela et al.,2014).In addition,it is still common to produce biochar from inefficient small-scale kilns rather than highly advanced industrial facilities,which may risk high energy input(Field et al.,2013).These aspects lead to an uncertainty in the carbon mitigation value of bio-char amendment.Therefore,it is imperative to make a holistic life cycle analysis of biochar implementation to judge whether biochar is a notable strategy to remove CO2from the atmosphere and what is the major sensi-tive influencing factor(Roberts et al.,2010;Hammond et al.,2011;Sparrevik et al.,2013).An indicator to evaluate the contribution of an indi-vidual event to global warming is carbon footprint(CF), which sums up all the carbon sources and carbon sinks by conversion to CO2-C e emissions over a life cycle of a product or consumption(Wiedmann&Minx,2008). Such data provide detailed information of each process, which distinguishes superior and inferior sectors and instructs a direction to mitigate carbon equivalent emis-sions(Finkbeiner,2009).As such,CF assessment on bio-char application could provide an insight into its carbon mitigation potential.China is the largest rice producing country with the world’s second largest rice area of30Mha(Chen& Zhang,2010).It was estimated that about7.4Tg CH4yrÀ1(Yan et al.,2009)and50.3Gg N2O yrÀ1(Cai, 2012)were released from Chinese ricefields during rice-growing period,comprising2.7%and29.2%of Chi-nese total anthropogenic and agricultural GHG emis-sions,respectively(Chen&Zhang,2010).To avoid pollution from straw burning and increase soil organic carbon,straw application into soil has been promoted by scientists and governments.However,straw applica-tion in the paddy season stimulates significant CH4 emissions due to straw-carbon decomposition,which may exacerbate the global warming problem(Xie et al., 2010).Based on biochar’s potential not only to increase soil carbon content(Luo et al.,2011;Xie et al.,2013)but also to reduce soil CH4emissions(Feng et al.,2012) resulting from biochar-carbon recalcitrance(Brewer et al.,2009),we hypothesize that the conversion of straw into biochar may decrease the CF of rice production. The aim of this study was to quantify the carbon foot-print of rice production,taking into accountfield man-agement,soil GHG emissions,soil carbon dynamics, rice yield,and energy budget of biochar production. Three different scenarios were included as follows:(i) no residue application,(ii)straw application,and(iii) straw-derived biochar application.This analysis is expected to improve our understanding of the climate change abatement potential of biochar amendment in paddy soils.Materials and methodsStudy site and soil characteristicsThe study site is located in Xiaoji town,Jiangdu city,Jiangsu Province of China(119°420E,32°350N).Wheat-rice or corn-rice rotation is the dominant agricultural practice in this region and has been so for more than1000years.The site is in a subtropi-cal marine climatic region(5m above sea level)and has a mean annual air temperature of14–16°C,precipitation of1100–1200mm,and evaporation of more than1100mm.Specially for rice-growing season from mid-June to late October,mean air temperature and precipitation were23–25°C and500–800mm,respectively.The soil is classified as inceptisol in US Soil Taxonomy with a sandy loam texture of20%sand(1–0.05mm),58%silt(0.05–0.001mm),and22%clay(<0.001mm). Soil bulk density is1.12g cmÀ3and porosity is57%.More detailed properties of the inceptisol are listed in Table1. Biochar productionBiochar was produced under no oxygen conditions using a pat-ented slow-pyrolysis process(China patent No. ZL200920232191.9).The facility has a furnace reactor of1m3 (1m91m91m)inside,which was heated by external elec-trical heaters.The capacity for biomass feeding is up to40kg per stove.Before biochar production,air-dried corn straw was cut into small segments(<5cm length)and fed into the biochar reactor,and then,the reactor was closed tightly.The heating temperature was elevated to400°C at a rate of8.5°C minÀ1andTable1Basic properties of the soil,corn straw,and corn straw-derived biochar in the experimentpH C N TP TK Avai.P Avai.K CECg kgÀ1mg kgÀ1cmol kgÀ1Inceptisol 6.816.8 1.90.6415.2134912.4 Straw–412.08.5 1.0413.5–––Biochar9.6597.713.4 2.4729.812811237117.0 TP,total phosphorus;TK,total potassium.©2015John Wiley&Sons Ltd,GCB Bioenergy,doi:10.1111/gcbb.12248 2Q.LIU et al.maintained for about8–10h until no more smoke was released from the gas ventilation pipe.The electrical power consumed during the temperature rising and maintaining stage was34.0 and7.5kW,respectively.The biochar prepared forfield appli-cation varied in size from veryfine powder(<5mm)to small-sized chunks(5–50mm)(about65%was less than5mm). Properties of corn straw and biochar are shown in Table1.The pyrolysis of corn straw at400°C resulted in40%biochar,>37% bio-oil,and<23%pyrolytic gas.The conversion of straw to bio-char led to elemental losses of41.5%carbon,36.5%nitrogen, 11.0%potassium,and4.0%phosphorous.Field experiment setupAfield experiment of three treatments was initiated from the paddy season in2011.Treatments were as follows:(i)no resi-due amendment(Control),(ii)6t haÀ1yrÀ1corn straw amendment(CS),and(iii)2.4t haÀ1yrÀ1corn straw-derived biochar amendment(CBC).The residue application rate in CS treatment matches the corn straw yield from current corn-rice rotation croppingfield(all the harvested corn straw was amended at the following rice season),and in CBC treatment, biochar application rate was based on the biomass-to-biochar conversion ratio of40%under current400°C pyrolysis condi-tion(2.4t haÀ1biochar derived from6t haÀ1straw).Straw (<3cm by shredding)or biochar has been added into soil once a year for three consecutive paddy seasons(years2011, 2012,and2013).The material was plowed evenly to a depth of15cm in mid-June before seedling transplantation.The experimental layout was a completely randomized design with three replicates,resulting in9plots separated by embankments of0.5m width.Each plot(2.594m2)has an individual irrigation inlet and drainage outlet.Rice seeds (Oryza sativa L.,cv.Nan Jing40)were sown in the nursery bed in mid-May and seedlings were transplanted into the experimentfield plots in mid-June with a density of24hills per square meter and three seedlings per hill.All treatments were amended with the same level of fertilizers.Nitrogen(N) was applied as urea at200kg N haÀ1in three doses:50% before seedling transplantation,10%at tillering stage,and 40%at heading stage.Calcium superphosphate(P, 31kg haÀ1)and potassium chloride(K,58kg haÀ1)were applied once as base fertilizer before seedling transplantation. The water regime was managed in aflooding–drainage–mois-ture pattern(moisture means a stage with intermittent irriga-tion to keep soil moist).Rice was harvested in late October after a growing period of about120days.Throughout the rice-growing period,soil redox potential(Eh)was measured using Pt-tipped electrodes(Hirose Rika Co.Ltd.Japan) inserted at a soil depth of5cm and an oxidation-reduction potential meter with a reference electrode(Toa PRN-41). HarvestAt maturity,2m²(48hills)of rice from each plot(excluding plants in the borders)was harvested.Grains were separated from straw with a thresher,air-dried,and weighed for grain yield.Soil sampling and analysisSoil samples were taken with a stainless steel auger(2.5cm diameter)to a depth of15cm after each rice harvest.For each sample from each plot,twelve soil cores were collected ran-domly across the whole plot,mixed in plastic bags,taken to the laboratory,and air-dried.A subsample taken from each sample was ground to pass through a0.15-mm sieve for total carbon(C)analysis by combustion(Perkin Elmer2400,Series II CHNS/O analyzer,Perkin Elmer Inc.,Waltham,MA,USA) after careful removal of visible plant debris by hand.Soil total C(g kgÀ1)was converted to mass per unit area(kg C haÀ1)by multiplication with soil bulk density and sampling depth.N2O and CH4measurementsN2O and CH4emissions were measured using the static closed chamber method(Hutchinson&Mosier,1981).One PVC(poly-vinyl chloride)soil collar with an area of54936cm2and 20cm in height was pushed20cm into the soil in each plot. Four hills of rice were planted in each soil collar.When gas samples were to be collected,a PVC chamber of60or120cm in height,depending on rice height,was mounted into a water-filled groove on the top edge of the soil collar to form an air-tight system.A fan mounted inside the chamber was operated to mix headspace air.Insulating foam and aluminum foil were wrapped around the outer surface of the chamber to minimize temperature changes during gas sampling.Three gas samples were taken from each chamber using a30-mL gas sampling syringe at0,20,and40min after closure.Gas samples were stored in pre-evacuated20-mL glass vials with silicon seals (SVF-20,Nichiden-Rika,Kobe,Japan).Gasflux measurements were conducted at6to8days interval over rice season,and additionally,more frequent samplings(1to2days interval) were supplemented during peak emissions after N fertilization. Concentrations of N2O and CH4were determined using a Var-ian3380gas chromatograph equipped with electron capture (ECD)andflame ionization(FID)detectors(Varian America Inc.,Dickinson,TX,USA).The CH4and N2Ofluxes were calcu-lated using a linear regression analysis of the temporal changes in CH4and N2O concentrations in the chamber headspace. The global warming potential(GWP)expressed in CO2 equivalent of N2O and CH4was calculated by multiplication with298and34,respectively,considering a life-time horizon of 100y(IPCC,2013b).Carbon footprint protocolA schematic model of carbon footprint(CF)budget in the life cycle of rice production under biochar implementation is shown in Fig.1.In this study,the CF of rice production was assessed by considering fertilizer and pesticide consumption, farmwork(plowing,seedling transplantation,fertilizer and pes-ticide spraying,irrigation,and harvest),soil N2O and CH4 emissions,soil carbon increment,and energy budget of biochar production.Carbon cost from straw or biochar transportation was ignored based on the assumption that the pyrolysis unit for producing biochar was fed by a local straw supply.Nor did©2015John Wiley&Sons Ltd,GCB Bioenergy,doi:10.1111/gcbb.12248ASSESSMENT OF BIOCHAR ON CARBON FOOTPRINT OF RICE3we include any extra carbon cost related to straw or biochar application because the materials could be mixed into the soil in the process of soil plowing.Bio-oil is an important by-prod-uct during biomass pyrolysis and has the potential to provide a high-value energy fuel or industrial chemical;however,due to the complexity in bio-oil refining and lack of data on its valua-tion,bio-oil utilization was not considered in this study.The total CF of rice production is calculated using the fol-lowing equation:CF ¼X ðA i Âf j Þwhere A i is the total amount of each agricultural input (such asfertilizer or pesticide consumption in kg,electricity cost in kwh);f j is the emission factor,that is,individual carbon emis-sion in kg equivalent carbon per unit volume or mass of the item of each agricultural input.Carbon intensity (Cheng et al.,2011),the CO 2-C e emission induced by one unit mass of grain production,is calculated as follows:CI ¼CF Ywhere CI is the carbon intensity (kg CO 2-C e kg À1grain);CF is the total carbon footprint (kg CO 2-C e ha À1);Y is rice yield (kg grain ha À1).The CF and CI in the current rice cropping system were evaluated based on the average value of soil GHG emissions,rice yield,and field operations across the three consecutive rice seasons from 2011to 2013(soil GHG emissions were only observed in 2011and 2012).The annual soil carbon increment was calculated from a linear regression analysis of the soil car-bon dynamics over the three-year scale.Regarding the energy budget of biochar production,this study intended to modelpyrolysis scenarios (pyrolytic gas is recycled for electricity gen-eration)ranging from low-efficiency system to highly advanced system based on data compiled from peer-reviewed literatures and our own study.Net electric energy input of biochar production (E net )is the total electric energy cost for driving the pyrolysis process (E cost )(such as equipment start-up,blower engine running,feedstock heating,and pyrolytic gas purifying)subtracted by the electric energy offset via pyrolytic gas recovery (E off ).According to previous literatures and our own study,E cost was in the range of 0.13–8.90MJ kg À1dry feedstock due to a variety of pyrolysis scenarios with different energy efficiency (Table S1,Supporting Information).Relationship of pyrolytic gas production with pyrolysis temperature was established from literatures (Fig.S1,Supporting Information).Based on the 400°C pyrolysis temper-ature of current experiment and the gas-to-electricity conver-sion efficiency of 38%(Clausen et al.,2011),E off was generated to be 0.25MJ kg À1dry feedstock.Consequently,the E net value considered in this study was in the range of À0.12–8.65MJ kg À1dry feedstock (negative value denotes a net elec-tric energy production from biomass pyrolysis).The lowest and highest carbon footprints in CBC treatment were exhibited as CBC min and CBC max ,which were calculated according to the minimum and maximum E net values,respectively.StatisticsStatistical analyses of the results were performed using the univariate custom in General Linear Model of SPSS 17.0(Chicago,IL,USA)to test the effects of biochar on soil carbon dynamics,soil CH 4and N 2O emissions,rice yield,and soil car-bon footprint.The level of significance was defined at P value less than0.05.Fig.1Schematic model of carbon footprint budget in one life cycle of crop production under biochar amendment.Carbon foot-print =CO 2-C e sources –CO 2-C e sinks.CO 2-C e sources involve plowing,sowing,irrigation,fertilizer and pesticide input,harvest,soil N 2O and CH 4emissions,and total electric energy cost for pyrolysis process.CO 2-C e sinks include soil carbon increment and electric energy offset via pyrolytic gas recovery.©2015John Wiley &Sons Ltd,GCB Bioenergy ,doi:10.1111/gcbb.122484Q.LIU et al.ResultsSoil carbon dynamicsAlong with residue amendment years,soil total carbon of CS and CBC treatments increased,whereas that of Control was almost constant(Fig.2).Over the three years observation,an average soil carbon increment rate in CBC treatment was 1.4t C haÀ1yrÀ1,much higher than that in CS treatment at0.5t haÀ1yrÀ1 (Fig.2).Soil N2O and CH4emissionsOver the two rice-growing seasons(2011and2012)when we observed,all treatments showed similar N2O emis-sions pattern,which is sensitive to water regime and N fertilization(Fig.3c and d).During thefirst35–37days underflooded condition,N2O emissions were low,even after two N fertilization events.Water drainage thereafter induced an increase in N2O emissions along with the con-current increasing soil Eh.In particular,the urea input during the drainage period resulted in a steep rise in N2O emissions to peak values.The stimulated N2O emis-sions lasted for about4–7days and decreased dramati-cally with the incident of reflooding.The cumulative N2O emissions under mid-season drainage period constituted 51–65%of the seasonal total emissions.During moisture period with noncontinuousflooding,a moderate increase and later slow decrease in N2O emissions were observed in2011,whereas in2012,consistent low N2O emissions were kept within this stage(Fig.3c and d).As compared with Control,the CBC treatment tended to decrease N2O emissions by72%(P=0.09)and47% (P=0.09)on day50and58,respectively,in2011;mean-while,the CS treatment significantly enhanced N2O emissions by63%(P=0.04)from day67to82in2011 (Fig.3c).Nevertheless,there was no significant differ-ence in total N2O emissions among all the treatments for the two consecutive rice seasons(Table2). Emissions of CH4were mainly affected by water regime.Between77to95%of the total CH4emissions took place underflooding stage(Fig.3e and f).Average CH4emission rates of Control,CS,and CBC during flooding were 4.7,48.7,and 3.8mg CH4-C mÀ2hÀ1, respectively,in2011,and were2.2,24.3,and1.8mg CH4-C mÀ2hÀ1,respectively,in2012.Drainage resulted in a marked decrease in CH4emissions to a low level, which was remained till the end of rice season(Fig.3e and f).The CS treatment significantly increased the cumula-tive CH4emissions by a factor of7.3(in2011)to9.3(in 2012)as compared with Control,with an extra emitted CH4-C accounting for8.2%(in2012)to16.1%(in2011) of the applied straw-carbon.In comparison,there was no significant difference in cumulative CH4emissions between CBC and Control(Table2).The GWP of the emitted N2O and CH4in CS treat-ment was4.1-fold(in2012)to4.3-fold(in2011)higher than that in Control,while no significant difference of that was observed between CBC and Control(Table2). Carbon footprintThe carbon footprint was calculated on average over the three rice-growing cycles.Among the carbon sources(a)(b)(c)Fig.2Soil total carbon dynamics in the upper15-cm layeralong with residue amendment years from treatments:Control(a);CS(b),and CBC(c).Error bars represent one standarderror(n=3).©2015John Wiley&Sons Ltd,GCB Bioenergy,doi:10.1111/gcbb.12248ASSESSMENT OF BIOCHAR ON CARBON FOOTPRINT OF RICE5across Control and CS treatment,the soil CH4and N2O emissions acted as the major contributor,accounting for 61to87%of the total carbon source value(Fig.4).The following contributors were farmwork and fertilizers, contributing6to18%and6to17%of the total carbon source value,respectively(Fig.4).Among farmwork, 85%of the CO2-C e emissions were derived from irriga-tion,and among fertilizers,93%of the CO2-C e emissions were attributed to N fertilizer(Table3).Pesticide utilization is a relatively low carbon source,correspond-ing to about1to4%of the total carbon source value (Fig.4).Biochar production-associated carbon emissions vary widely depending on energetic performance of pyroly-sis systems(Fig.4).The highest energy consumption pattern(CBC max scenario)in this study induced large amount of CO2-C e emissions,contributing65%of the total carbon source value.In comparison,the lowest(a)(b)(c)(d)(e)(f)Fig.3Precipitation(column)(a,b),soil Eh(curve)(a,b),and seasonal dynamics of N2O(c,d)and CH4(e,f)flux during the respec-tive2011and2012rice seasons.The vertical arrows in(c)and(d)denote urea application events.F represents theflooding stage,D represents the mid-season drainage,and M represents the moisture stage with intermittent irrigation.©2015John Wiley&Sons Ltd,GCB Bioenergy,doi:10.1111/gcbb.12248 6Q.LIU et al.energy consumption pattern(CBC min scenario)was car-bon beneficial,acting as a slight carbon sink and com-pensating3%of the total carbon source value(Fig.4). Carbon footprint of rice production in CS treatment was2.9times higher than that in Control,resulting from stimulated soil CH4emissions and low soil carbon increment(Fig.4).The following was CBC max scenario, which significantly enhanced CF by93%compared with Control due to high energy cost for biochar production. In contrary,CBC min scenario greatly lowered CF by85% than Control,benefiting from significant soil carbon sequestration(Fig.4).Due to nonsignificant difference in rice yields across all the treatments on average over three rice seasons(Table4),carbon intensity(CI)of rice production was also highest in CS,followed by CBC max, Control,and CBC min,respectively(Fig.5). DiscussionSoil N2O emissionsNitrous oxide production in soils is directly associated with inorganic N and microbial catalysis pathways. Microbial catalysis pathways of N2O emissions include nitrification and denitrification controlled mainly by soil water and Eh(Cai et al.,1997;Stevens et al.,1997;Kesik et al.,2006).At water-filled pore spaces(WFPS)below 65to75%,nitrification is typically the major pathway of N2O emissions,while denitrification will dominate when WFPS exceeds80%(Linn&Doran,1984;Boll-mann&Conrad,1998).Correspondingly,soil Ehs of400 mv and0mv are the two boundary conditions for N2O production via nitrification and denitrification,respec-tively(Kralova et al.,1992).During theflooding period when soil Eh was below À200mV(Fig.3a and b),low N2O emissions(Fig.3c and d)were probably due to limited NO3Àsubstrate and strong denitrification with complete reduction of N2O to dinitrogen(N2)gas(Cai et al.,1997).At the beginning of drainage period,increased N2O emissions following soil Eh rising were presumably produced mainly via nitrification,that is,the conversion of abun-dant NH4+from water-logged condition into NO3À. Within drainage period,due to rain-inducedfluctuation of soil Eh,nitrification and denitrification might concur-rently exist,which provided optimum condition for N2O production and thus led to N2O emission peaks after urea fertilization.During moisture stage,soil Eh was increased up to300–500mv(Fig.3a and b),under which nitrification was assumed to control N2O produc-tion.The relative low N2O emissions during moisture period might result from limited available N substrate. The lower N2O emissions in CBC treatment than Con-trol treatment observed on day50and58in2011 (Fig.3c)companied with rain-induced reduction in soil Eh(Fig.3a)were possibly due to stronger denitrifica-tion process in the presence of biochar.Cayuela et al. (2013)observed that biochar decreased N2O emissions under denitrification conditions(90%WFPS)with a reduction of the N2O/(N2+N2O)ratio;the authors sug-gested that an‘electron shuttle’derived from quinone and hydroquinone groups on biochar surface promotes the transfer of electrons to soil denitrification microor-ganisms and facilitated a further reduction of N2O to N2.Besides,we suppose that biochar’s hydrophilic property(Karhu et al.,2011)and combination of biochar particles with soil micro-aggregates(Lehmann et al., 2005;Liang et al.,2006)would protect soil microsites from exposure to oxygen,which might support reduced condition favorable for N2O conversion to N2.During the early moisture period(day67to82)in 2011,where soil Eh was sharply increased,the CSTable2Cumulative soil GHG emissions and global warming potential(GWP)during paddy season in year2011and2012 (MeanÆSE,n=3)Year Treatments GHGN2O(kg N2O-N haÀ1)CH4(kg CH4-C haÀ1)GWP(t CO2-C e haÀ1)Year2011Control 5.3Æ0.4a*62.6Æ22.8b 1.5Æ0.2b CS 5.9Æ0.5a459.6Æ57.1a 6.4Æ0.7aCBC 4.5Æ0.2a47.7Æ11.6b 1.2Æ0.2bYear2012Control 4.1Æ0.3a24.5Æ5.8b0.8Æ0.1b CS 3.6Æ0.1a227.5Æ49.5a 3.3Æ0.6aCBC 3.9Æ0.9a17.6Æ8.2b0.7Æ0.2b Average Control 4.7Æ0.3a43.5Æ13.5b 1.1Æ0.1b CS 4.8Æ0.3a343.5Æ48.9a 4.9Æ0.6aCBC 4.2Æ0.4a32.6Æ4.0b0.9Æ0.1b*Values followed by the same letter in one column within the same year are not significantly different according to LSD test at P≤0.05,n=3.©2015John Wiley&Sons Ltd,GCB Bioenergy,doi:10.1111/gcbb.12248ASSESSMENT OF BIOCHAR ON CARBON FOOTPRINT OF RICE7。
1.Four characteristics of community structure(空间分布)physical appearance, species diversity or richness（多样性）, species abundance（丰度）, niche structure（生态地位结构）.2.Three major factors affect species diversity: latitude（纬度）in terrestrial communities（地球群落）; depthin aquatic system; pollution in aquatic system（水环境）.3.Where is most of the W orld’s Biodiversity Found?Tropical rain forests, coral reefs, the deep sea, largetropical lakes.4.What determines the number of species on island?Size and degree of isolation（隔离程度）.5.Four types of species:native species（本土物种）: normally live and thrive（繁衍）in a particular ecosystem; nonnative species: migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem by humans;indicator species（指示性生物）: serves early warnings of damage to a community or an ecosystem(Birds are excellent biological indicators because they are found almost everywhere and respond quickly toenvironmental change.); keystone species（关键物种）: the roles of some species in an ecosystem are much more important than their abundance or biomass suggests.6.Five basic types of interaction between species: interspecific competition, predation（掠夺）, parasitism（寄生）, mutualism（互利共生）, commensalism（共生）7.Intraspecific competition: competition between members of the same species for the same resources.Interspecific competition: competition between members of two or more different species for food, space, or any other limited resource.8.What is the competitive exclusion principle?Sometimes one species eliminates another species in aparticular area through competition for limited resources.9.How have some species reduced or avoided competition? One way this happens is through resourcepartitioning，the dividing up of scarce（紧缺的）resources so that species with similar needs use them(1) at different times, (2)in different ways, (3)in different places.10.Symbiosis: a relationship in which species live together in an intimate associatio n（密切联合）. Three types:parasitism, mutualism, and commensalism.11.Parasitism: occurs when one species feeds on part of another organism by living on or in the host（宿主）.In this relationship, the parasite（寄生物）benefits and the host is harmed.12.Mutualism: two species involved in a symbiotic relationship interact in ways that benefit both. Suchbenefits include(1)having pollen and seeds dispersed for reproduction, (2)being supplied with food,or(3)receiving protection.mensalism: a symbiotic interaction that benefits one species but neither harms nor helps the otherspecies much, if at all.14.Tectonic plates: both convection currents and mantle plumes move upward as the heated material isdisplaced by denser, cooler material sinking under the influence of gravity. These flows of energy and heated material in the mantle convection cells cause movement of rigid plates.Plate tectonics（构造板块）: The theory explaining the movement of the plates and the processes that occur at their boundaries.15.Mineral: an element or inorganic compound that occurs naturally and is solid.16.Rock: any material that makes up a large, natural, continuous part of the earth’s crust.17.Three major rock types and their characteristics: Igneous rock（火成岩）, sedimentary rock（水成岩）,metamorphic rock（变质岩）.18.Rock cycle: Rocks are constantly exposed to various physical and chemical conditions that can changethem over time. The interaction of processes that change rocks from one type to another.19.Earthquakes: stress in earth’s crust can cause solid rock to deform until it suddenly fractures and shiftsalong the fracture, producing a fault. The faulting or a later abrupt movement on an existing fault causes anearthquake.20.Risk: the possibility of suffering harm from a hazard that can cause injury, disease, economic loss, orenvironmental damage. Risk is expressed in terms of probability: a mathematical statement about how likely it is that some event or effect will occur.21.Risk assessment（评估）: （1）identifying a real or potential hazard, （2）determining the probability of itsoccurrence, （3）and assessing the severity（严重程度）of its health, environmental, economic, and social impact. Risk management: ⑪serious it is compared to other risks, ⑫how much the risk should bereduced, ⑬how such risk reduction can be accomplished, and ⑭how much money should be devoted to reducing the risk to an acceptable level.22.What determines whether a chemical is harmful? Whether a chemical is harmful depends on ⑪the sizeof the dose over a certain period of time,⑫how often an exposure occurs, ⑬who is exposed, ⑭how well the body’s detoxification systems work, an d⑮genetic makeup that determines an individual’s sensitivity toa particular toxic.23.Poison: a chemical that has an LD50 of 50 milligrams or less per kilogram of body weight.24.Toxic chemicals: defined as substances that are fatal to more than 50% of test animals (LD50) at givenconcentrations.25.Mutagens: agents, such as chemicals and ionizing radiation, that cause random mutation, or changes, in theDNA molecules found in cells.26.Teratogens: chemicals radiation, or viruses that cause birth defects while the human embryo is growing anddeveloping during pregnancy, especially during the first 3 months.27.Nontransmissible disease: not caused by living organisms and does not spread from one person to another.Transmissible disease: caused by a living organism and can be spread from one person to another.Risk analysis: ⑪identifying hazards and evaluating their associated risks, ⑫ranking risks, ⑬determining options and making decisions about reducing or eliminating risks, and ⑭informing decision makers and the public about risks.28.Populations grow or decline through the interplay of three factors: births, deaths, and migration.Population change: calculated by subtracting the number of people leaving a population from the number entering it during a specific period of time:Population change= (Births + Immigration)-(Deaths + Emigration)29.Factors affect birth rate and fertility rates:①importance of children as a part of the labor force; ②urbanization; ③cost of raising and educating children; ④educational and employment opportunities for women; ⑤infant mortality rate（夭折率）, ⑥average age at marriage, ⑦availability（有效性）of private and public pension system（抚恤金体系）, ⑧availability of legal abortions; ⑨availability of reliable birth control methods; ⑩religious beliefs（宗教信仰）, traditions, and cultural norms（规范）.30.Factor affects death rate: two useful indicators（指标）of overall health of people in a country or regionare (1)life expectancy and (2)the infant mortality rate.31.age structure: the proportion of the population at each age level. Demographers typically construct apopulation age structure diagram by plotting the percentages or numbers of males and females in the total population in each of three age categories: (1)prereproductive, (2)reproductive, and (3)postreproductive 32.Three system provide Us with food: (1)croplands（耕地）(mostly for producing grains, which provideabout 76% of the world’s food); (2)rangelands牧场(which supply about 17% of the world’s food);(3)oceanic fisheries海洋渔业(which supply about 7% of the world’s food).33.What plants and animals feed the world? Although the earth has perhaps 30,000plants species with partsthat people can eat, only 15plant and 8 terrestrial animal species supply an estimated 90% of our global intake of caloriesMajor types of food production: industrialized agriculture(high-input agriculture); plantation agriculture大垦殖农业; Traditional subsistence agriculture传统温饱型农业; traditional intensive agriculture传统集约耕作.34.Green revolution: most of the increase in global food production has come from increased yields per unitof area of cropland in a process.35.Three steps of green revolution: (1)developing and planting monocultures of selectively bred orgenetically engineered high-yield varieties of key crops such as rice, wheat, and corn; (2)producing high yields by using large inputs of fertilizer, pesticides, and water on crops;(3)increasing the number of crops grown per year on a plot of land through multiple cropping.36.Undernutrition: people who cannot grow or buy enough food to meet their basic energy needs.37.Malnutrition: people who are forced to live on a low-protein, high-carbohydrate diet consisting only ofgrains such as wheat, rice, or corn.38.What are the environmental effects of producing food? Future ability to produce more food will belimited by a combination of (1)soil erosion侵蚀, (2)desertification沙漠化, (3)salinization and waterlogging 水浸of irrigated lands, (4)water deficits and droughts, (5)loss of wild species that provide the genetic resources for improved foams of foods, and (6)the effects of global warming.39.Important properties of water: (1)there are strong forces of attraction between molecules of water;(2)water sexists as liquid over a wide temperature range because of the strong forces of attraction betweenmolecules; (3)liquid water changes temperature very slowly because it can store a large amount of heat without a large change in temperature; (4)it takes a lot of heat to evaporate liquid water because of the strong forces of attraction between its molecules; (5)liquid water can dissolve a variety of compounds;(6)water molecules can break down into hydrogen ions and hydroxide ions, which help maintain a balancebetween acids and bases in cells, as measured by the pH of water solutions; (7)the strong attractive forces between the molecules of liquid water cause its surface to contract and to adhere to and coat a solid;(8)water filters out wavelengths of ultraviolet radiation that would harm some aquatic organism; (9)unlikemost liquid, water expands when it freezes40.Surface runoff: precipitation that does not infiltrate the ground or return to the atmosphere by evaporation.41.Groundwater: some precipitation infiltrates the ground and percolates downward through voids in soil androck.42.Recharge area: any area of land through which water passes downward or laterally into an aquifer.43.Natural recharge: aquifers are replenished naturally by precipitation that percolates downward through soiland rock in what is called ~44.How can we increase freshwater supplies? Six ways to increase the supply of fresh water in a particulararea are to (1)build dams and reservoirs to store runoff, (2)bring in surface water from another area,(3)withdraw groundwater, (4)convert salt water to fresh water, (5)waste less water, and (6)import food toreduce water use.45.Advantages of withdrawing groundwater: (1)can be removed as needed year round, (2)is not lost byevaporation, and (3)usually is less expensive to develop than surface water systems.46.Disadvantages of withdrawing groundwater: (1)water table lowering, (2)aquifer depletion, (3)aquifersubsidence; (4)intrusion of salt water into aquifers, (5)drawing of chemical contamination in groundwater toward wells, and (6)reduced stream flow.47.Desalination: removing dissolved salts from ocean water or from brackish groundwater. Two majordisadvantages: it is expensive because it takes large amounts of energy; it produces large quantities of wastewater containing high level of salt and other minerals.48.Floodplain: heavy rain or rapid melting of snow is the major cause of natural flooding by streams. Thiscauses water in a stream to overflow its normal channel and flood the adjacent area.49.Methods of reducing flood risks: (1)straightening and deepening streams; (2)building levees; (3)buildingdams; (4)restoring wetlands to take advantage of the natural flood control provided by floodplains;(5)identifying and managing flood-prone areas.50.Petroleum(crude oil): a thick liquid consisting of hundreds of combustible hydrocarbons along with smallamounts of sulfur, oxygen, and nitrogen impurities.51.Advantage of nuclear: large fuel supply; low environmental impact; emits 1/6 as much CO2 as coal;moderate land disruption and water pollution; moderate land use; low risk of accidents because of multiple safety systems.Disadvantage of nuclear: high cost; low net energy yield; high environmental impact; catastrophicaccidents can happen; no acceptable solution for long-term storage of radioactive wastes anddecommissioning worn-out plants; spreads knowledge and technology for building nuclear weapons.52.Energy effects能源效应: the percentage of total energy input into an energy conversion device or systemthat does useful work and is not converted to low-quality, essentially useless heat.53.Advantage of use solar energy: moderate net energy; moderate environmental impact; no CO2 emissions;fast construction; costs reduced with natural gas turbine backup.Disadvantage: low efficiency; high costs; needs backup or storage system; need access to sun most of the time; high land use; may disturb desert areas.54.Advantage of using solar cells: fairly high net energy; work on cloudy days; quick installation; easilyexpanded or moved; no CO2 emissions; low environmental impacts; last 20-40years; low land use; reduces dependence on fossil fuels.Disadvantage: need access to sun; low efficiency; need electricity storage system or backup; high land use could disrupt desert areas; high costs; DC current must be converted to AC.55.Advantage of using large dams: moderate to high net energy; high efficiency(80%); low-cost electricity;long life span; no CO2 emissions during operation; may provide flood control below dam; provides water for year-round irrigation of crop land; reservoir is useful for fishing and recreation.Disadvantage: high construction costs; high environmental impacts; high CO2 emissions from biomass decay in shallow tropical reservoirs; flood natural areas; converts land habitat to take habitat; danger of collapse; uproots people; decreases fish harvest below dam; decreases flow of natural fertilizer to land below dam.58. Advantage of using wind: moderate to high net energy; high efficiency; moderate capital cost; very lowenvironmental impact; no CO2 emissions; quick construction; easily expanded; land below turbines can be used to grow crops or graze livestock.Disadvantage: steady winds needed; backup systems needed when winds are low; high land use for wind farm; visual pollution; noise when located near populated areas; may interfere in flights of migratory birds and kill birds of prey.59. Advantage of burning solid biomass: large potential supply in some areas; moderate costs; no net CO2increase if harvested and burned sustainably; plantation can be located on semiarid land not needed for crops; plantation can help restore degraded lands; can make use of agricultural, timber, and urban wastes;Disadvantage: nonrenewable if harvested unsustainably; moderate to high environmental impact; CO2 emissions if harvested and burned unsustainably; low photosynthetic efficiency; soil erosion, water pollution, and loss of wildlife habitat; plantation could compete with cropland; often burned in inefficient andpolluting open-fires and stoves,60.Advantage of using geothermal energy: very high efficiency; moderate net energy at accessible sites;lower CO2 emissions than fossil fuels; low cost at favorable sites; low land use; low land disturbance;moderate environmental impact.Disadvantage: scarcity of suitable sites; depleted if used too rapidly; CO2 emissions; moderate to high local air pollution; noise and odor; cost too high expect at the most concentrated and accessible sources.61.Atmosphere: we lived at bottom of a sea of air.62.Troposphere对流层: ~, which expends延伸only about 17 kilometers above sea level at the equator赤道and about 8 kilometers over the poles极地.63.Air pollution: the percentage of one or more chemicals in the atmosphere in sufficient quantities andduration to (1) cause harm to us, other forms of life, and materials or (2)alter climate.64.Photochemical smog: a mixture of primary and secondary pollutants formed under the influence of sunlight.65.Industrial smog: consisting mostly of (1)sulfur dioxide; (2)suspended droplets of sulfuric acid, and (3)avariety of suspended solid particles and droplets.66.Green effects: it occurs because molecules of certain atmospheric gases, warm the lower atmosphere byabsorbing some of the infrared radiation radiated by the earth’s surface.(CO2, CH4, N2O, CFOs, HCFCs, HFCs, Halons, Carbon tetrachloride)67.Global warming: most climate scientists believe that increased inputs of CO2 and other greenhouse gasesfrom human activities will (1)enhance the earth’s natural greenhouse effect and (2)raise the average global temperature of the atmosphere near the earth’s surface.68.Effects of warmer atmosphere: (1)less severe winters; (2)more precipitation in some dry areas; (3)lessprecipitation in some wet areas; (4)increased food production in some areas; (5)expanded population and range for some plant and animal species adapted to higher temperature.69.W ater pollution: any chemicals, biological, or physical change in water quality that has a harmful effect onliving organisms or makes water unsuitable for desired uses.70.Point sources: discharge pollutants at specific locations through pipes, ditches, or sewers into bodies ofsurface water.Nonpoint sources: cannot be traced to any single site of discharge. They are usually large land areas or airsheds that pollute water by runoff, subsurface flow, or deposition from the atmosphere.71.Cultural eutrophication: near urban or agricultural areas, human activities can greatly accelerate the inputof plant nutrient to a lake, which results in a process.72. Why is groundwater pollution such a serious problem?(1)storage lagoons, (2)septic tanks, (3)landfills;(4)hazardous waste dumps, and (5)deep injection wells.73.How can we protect groundwater? Contaminated aquifers are almost impossible to clean because oftheir (1)enormous volume, (2)inaccessibility, and (3)slow movement.74.Solid waste: any unwanted or discarded material that is not a liquid or a gas.75.Hazardous waste: legally defined as any discarded solid or liquid material that (1)contains one or more of 39 toxic, carcinogenic, mutagenic, or teratogenic compounds at levels that exceed established limits,(2)catches fire easily , (3)is reactive or unstable enough to explode or release toxic fumes, or (4)is capable of corroding metal containers such as tanks, drums, and barrels. Does not include: (1)radioactive wastes,(2)hazardous and toxic material discarded by household, (3)mining wastes, (4)oil-and gas-drilling wastes, (5)liquid wastes containing organic hydrocarbon compounds, (6)cement kiln dust, produced when liquid hazardous wastes are burned in a cement kiln, and (7)wastes from the thousands of small businesses and factories that generate less than 100 kilograms.76.Advantage of incinerating solid and hazardous wastes: reduced trash volume, less need for landfills, low water pollution.Disadvantage: high cost; air pollution; produces a highly toxic ash; encourage waste producting.77.Advantage of injecting liquid hazardous wastes: simple technology; safe method if sites are chosen carefully; wastes can be retrieved if problems develop; easy to do; low cost.Disadvantage: leaks or spills at surface; leaks from corrosion of well casing; existing fractures or earthquakes can allow wastes to escape to groundwater; encourages waste production.。
