I. Introduction Various utilization of predictive control in parallel machine tools

传感器与检测技术英文书籍英语Sensors and Detection Technologies: A Comprehensive Guide.Introduction.Sensors and detection technologies play a crucial role in various scientific, industrial, and commercial applications. These technologies enable us to measure, monitor, and analyze physical, chemical, and biological parameters in real-time or over time. This guide provides a comprehensive overview of the different types of sensors, their working principles, applications, and advancements in sensing technologies.Types of Sensors.1. Physical Sensors:Pressure sensors: Measure force or pressure applied toan object.Temperature sensors: Detect changes in temperature and provide real-time temperature readings.Position sensors: Determine the position or displacement of an object.Velocity and acceleration sensors: Measure the speed and acceleration of moving objects.2. Chemical Sensors:Gas sensors: Detect and measure the presence and concentration of gases in the environment.Biosensors: Utilize biological recognition elements to detect specific molecules or analytes.Chemical arrays: Employ multiple sensors to provide a comprehensive analysis of chemical composition.3. Biological Sensors:Biosensors: Detect and measure biological substancesor organisms.Microfluidic devices: Enable precise control and manipulation of small fluid volumes for biological analysis.Lab-on-a-chip: Integrate multiple analytical functions into a single portable device.4. Optical Sensors:Optical fiber sensors: Utilize optical fibers to transmit light signals and detect changes in thesurrounding environment.Fiber Bragg grating (FBG) sensors: Measure strain, temperature, and other parameters based on the wavelength shift of reflected light.Surface plasmon resonance (SPR) sensors: Utilize theinteraction of light with metal nanoparticles to detect changes in refractive index caused by specific molecules.Working Principles.Sensors convert physical, chemical, or biological signals into electrical or optical signals. The working principles vary depending on the sensor type:1. Physical Sensors:Piezoelectric sensors: Generate an electrical charge when subjected to mechanical stress or vibration.Thermistors and thermocouples: Change their electrical resistance or generate voltage in response to temperature changes.Potentiometers: Measure position or displacement by varying resistance as a movable contact slides along a resistive element.2. Chemical Sensors:Electrochemical sensors: Utilize electrochemical reactions to generate electrical signals proportional to the analyte concentration.Optical sensors: Detect changes in light absorption, reflection, or fluorescence caused by the presence of specific molecules.3. Biological Sensors:Antibody-based sensors: Employ specific antibodies to bind and detect target molecules or organisms.Nucleic acid-based sensors: Utilize DNA or RNA sequences to detect and analyze specific genetic material.Applications.Sensors and detection technologies find applications in a wide range of fields, including:Environmental monitoring: Air quality, water quality, and soil analysis.Industrial automation: Process control, robotics, and quality assurance.Medical diagnostics: Blood analysis, disease detection, and patient monitoring.Agricultural technology: Crop monitoring, soilnutrient analysis, and pest detection.Aerospace and defense: Navigation, guidance, andtarget detection.Advancements in Sensing Technologies.Miniaturization and integration: Development of smaller, more integrated sensors with improved portability and cost-effectiveness.Enhanced sensitivity and selectivity: Advancements in materials science and signal processing techniques to achieve higher detection limits and reduced false positives.Wireless connectivity: Integration of sensors with wireless communication technologies for remote monitoring and data transmission.Artificial intelligence (AI): Utilization of AI algorithms to enhance sensor performance, analyze data in real-time, and make predictions or recommendations.Conclusion.Sensors and detection technologies are essential tools for scientific research, industrial processes, and various commercial applications. The different types of sensors, their working principles, and recent advancements enable us to gather valuable information, monitor processes, and make informed decisions. Continued research and development in sensing technologies hold the promise of further innovation and expanded capabilities in the future.。

KeysUnit 5Part I Pre-readingSection B Listening Practice1. adventures2. passport3. adjustment4. alternative5. destinations6. confusingPart II Active Reading: Cultural ConflictsTask One1. C2. B3. D4. B5. CPart III Language FocusTask One1. roar2. prominent3. recoiled4. loomed5. insane6. boost7. outrages8. trigger9. alternately 10. switchTask Two1. I would bet all I have that he learned his lesson about gambling.2. She was indignant that her voice was neglected in work.3. Hopefully, I could switch myself from the legal profession to the business side of things.4. The majority of the local residents are still struggling to be compliant with environmental regulations.5. The public accuse the retail giant of exploiting its workers and discriminating against female employees.6. In winter, we slithered down the slope covered with snow.Part IV Chinese & Foreign Culture IntroductionTask OneDragons are commonly used as auspicious sign; it is one of the most typical of the Chinese nation’s traditional culture. Dragons are deeply rooted in Chinese culture, so the Chinese often consider themselves as "the descendants of the dragon". In Chinese culture, dragons are generous and wise. They are closely connected with the ancient royal family. Dragon culture also exists in the Western world. However, dragons have different reputation in western culture. The Western dragons are evil animals from hell. They usually have wings and can send out fire from their mouths.Task Two不同文化对私人空间和身体接触有不同的期望。

ReviewPreparation and applications of surface-confined ionic-liquid stationary phases for liquid chromatographyMingliang Zhang a ,b ,Xiaojing Liang a ,Shengxiang Jiang a ,Hongdeng Qiu a ,⇑aKey Laboratory of Chemistry of Northwestern Plant Resources,Key Laboratory for Natural Medicine of Gansu Province,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China bUniversity of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100049,Chinaa r t i c l e i n f o Keywords:HPLCLiquid chromatography Ionic liquidRoom-temperature ionic liquid RTIL SCILSolid-phase microextraction Stationary phaseSurface-confined ionic liquid Synthesisa b s t r a c tIonic liquids (ILs)are a class of substances completely comprised of ions.Due to their unique properties (e.g.,electric conductivity,low volatility,thermostability and tenability),their use has attracted consid-erable interest,including an increasing number of publications on their use in preparing stationary phases (SPs)of high-performance liquid chromatography.We highlight the existing pathways for making IL-based SPs,and we propose potential strategies for synthesis.We also give up-to-date information on their applications in different chromatographic modes.Ó2013Elsevier Ltd.All rights reserved.Contents 1.Introduction ..........................................................................................................602.Preparations of surface-confined ionic-liquid stationary phases.................................................................612.1.Monomeric route.................................................................................................612.2.Polymeric route..................................................................................................652.3.Practicable new routes ............................................................................................663.Applications of surface-confined ionic-liquid stationary phases.................................................................694.Other applications .....................................................................................................705.Conclusions...........................................................................................................70Acknowledgements ....................................................................................................71References ...........................................................................................................711.IntroductionIonic liquids (ILs),namely room-temperature ILs (RTILs),can be defined as a class of ionic,non-molecular ually,the cat-ionic component of an IL is organic,such as imidazolium,pyridini-um,alkylammonium and phosphonium,while the anionic part could be inorganic and organic,such as halide,nitrate,acetate,hexafluorophosphate,tetrafluoroborate and trifluoromethanesulfo-nimide,as shown in Fig.1.It is not until the first introduction of a stable imidazole-based RTIL in 1992that research on the prepa-rations,properties and applications of ILs gained momentum in the chemistry community [1].As solvents,ILs are capable of dissolving a wide range of sub-stances,from inorganic minerals to organic polymeric materials.They are seen as green solvents due to their stability,thermocon-ductivity,mobility,non-combustibility and non-volatility.The big family of ILs is still expanding.Amongst ILs,the alkyl-substituted imidazolium has attracted more attention,because of its availabil-ity and convenient tunability [2–4].0165-9936/$-see front matter Ó2013Elsevier Ltd.All rights reserved./10.1016/j.trac.2013.09.011Corresponding author.Tel.:+869314968877;Fax:+869318277088.E-mail address:hdqiu@ (H.Qiu).The physicochemical properties of an IL are simultaneously influenced by both its cation and anion.For example,the density of IL with a given anion would decrease with increasing length of the alkyl chain,whereas the viscosity would increase.Also,water solubility depends on both cation and anion.For example,highly water-soluble1-butyl-3-methylimidazolium chloride would be-come slightly soluble or insoluble on replacing the butyl group with an octyl one or the chloride with hexafluorophosphate.In view of the remarkable differences resulting from combinations of diverse cations and anions,ILs are deemed‘‘tunable’’materials, which could be purposefully designed and modified to satisfy var-ious needs.The essential applied value of ILs is universally acknowledged. Undeniably,there is much room for the development of ILs for specific tasks.With the advance of research,the utilization of ILs has extended from its cradle(i.e.synthesis chemistry)to many fields,such as material chemistry,catalytic chemistry and spectroscopy,as highlighted in the literature[5–8].Applications of ILs in analytical chemistry have been a research hotspot because of their excellent properties and convenient tunability.[9–12] ILs also play an exceptionally important role in high-perfor-mance liquid chromatography(HPLC),where they have been used as additives to the mobile phase(MP)in place of conventional aliphatic amines.This approach is found to be convenient and effective when separating polar analytes on a C18column,as selectivity,retentivity and efficiency towards originally poorly separated analytes tend to be greatly improved[13–16],so the ILs are believed to surpass organic amines due to their capability of performing multiple interactions with the analytes,plus shield-ing the residual silanol groups on the silica surface.However,the addition of ILs to the mobile phase can cause interference during detection.In particular,when using an evaporative light-scattering detector(ELSD)or a mass spectrometry(MS)detector,ILs are inap-plicable as additives due to their non-volatility.Also,the ultravio-let absorption of ILs used in the mobile phase usually causes fluctuations of the baseline.In order to bypass these disadvantages,an approach involving confinement of ILs to the surface of the stationary phase(SP) seemed a practical choice.The imidazolium-bonded silica SP was first prepared in2004[17].Undoubtedly,this generation of surface-confined IL(SCIL)packing material ushered in a brand new methodology for preparation of SPs and enlarged the scope for utilization of HPLC SPs[18–40].It should be borne in mind that, once bound to a solid support,the cation/anion pair no longer con-stitutes a true IL.However,the ability to modify the properties of the silica-based SP by changing easily the structural make-up of the cation/anion pair draws obvious correlations to the tunability of classic ILs[19].Although the morphology of ILs varies upon immobilization,the intrinsic characteristics,which depend on the structure of cation cores,substituents and anions,can be pre-served,guaranteeing the participation of multiple interactions, such as hydrophobic(hydrophilic),dipole-dipole,p-p and electro-static interactions,plus hydrogen bonding,in LC separation.Also, the tunability of ILs leaves much leeway for intentional modifica-tion of the SPs.In this review,we summarize the development of SCIL SPs.We illustrate the existing routes concerning the preparations of SCIL SPs,and propose viable new procedures.We wish to integrate the techniques of synthesis and hopefully offer useful concepts for more task-specific SPs.2.Preparations of surface-confined ionic-liquid stationary phasesThe diversity and the multi-functionality of heteroatomic ILs have given HPLC desirable chromatographic performance.Irrefut-ably,the foundation of all chromatographic evaluations is the successful preparation of the SP,so it is necessary to adopt an effective scheme for synthesis.A handling procedure using obtain-able reagents operated in non-harsh conditions is advisable. Another factor to be taken into consideration is that such a proce-dure must achieve relatively high bonding,as bonding has a direct, decisive impact on the chromatographic behavior of the SP.The preparation of SCIL SPs usually involves using silane-coupling agents,which bridge the silica substrate and the IL ligands.As displayed in Fig.2,the agents frequently employed are terminally functionalized propyltrimethoxylsilane(PTMS), such as c-chloro-PTMS(CPTMS)and c-mercapto-PTMS(MPS), with CPTMS being preferred in the synthesis of monomerically IL-bonded SPs,and MPS for IL-polymerized SPs.Accordingly,the following description is divided into two parts,viz monomeric and polymeric.The primary structures of reported SCIL SPs are exhibited in Tables1and2.The abbreviation for each SP is used corresponding to the original paper,except for post-fixing the anion.2.1.Monomeric routeAs the term suggests,ligands are bonded to SPs in the form of monomer via the monomeric route.To achieve successful immobi-lization,the silica must be pre-modified so as to carryactive Fig.1.Structural diagrams of selected cations and anions of common ionic liquids(ILs).groups,which are expected to provide further derivations using the desired precursor.In surface modification of silica,silane-coupling agents are often the best choice,due to their commercial availability,high reactivity and abundant organofunctional groups; also,they can noticeably affect the surface properties,such as hydrophilicity,porosity and tenacity[41–43].One category of those coupling agents contains trialkoxyl groups(TAS)and another contains trichloride(TCS).Both alkoxyl and chlorine are highly reactive towards silanol,whereby they eventually form stable silyl ether.However,due to steric hindrance,not all reactive sites can be consumed.Generally,the TAS is more applied than its chlorine counterparts,since the latter are extremely caustic,incompatible with active hydrogen,and release a great deal of hydrogen chloride during reaction.However,there are hardly any organofunctional groups available for TCS’s alkyl arm,besides haloalkyl and alkyl groups.In the monomeric syntheses of SCIL SPs,c-halopropyltrialkox-ylsilane is an effective linkage between silica substrate and IL li-gands.Among this kind of silane,CPTMS is the most popular,but reaction involving CPTMS tends to need a longer time and a higher temperature on account of the lower reactivity of the chlorine atom.Meanwhile,c-bromopropyltrimethoxysilane(BPTMS)with higher reactivity is also suitable,but its much higher cost precludes wider application.c-iodopropyltrimethoxysilane(IPTMS)with the highest reactivity also suffers lower popularity due to the cost and its relatively lower thermo-and photo-stability.Though it rarely appears in syntheses of SPs,IPTMS has found wide application in other areas[44–46].IPTMS can de facto be synthesized from CPTMS using a simple ion-exchange technique in dry acetone with satis-factory yields.There is one coupling agent having a longer alkyl chain–x-bro-mooctyltrichlorosilane(BOTCS)to be exact–but it is commercially unavailable,as shown in Table1.BOTCS was prepared in house via hydrosilylation using trichlorosilane and8-bromo-1-octene as starting materials,but no information detailing the synthesis pro-cedure was available.According to literature[47],this reaction is catalyzed by a transitional metal complex,bearing much similarity to high-pressure hydrogenation.To date,SCIL SPs with decent chromatographic performance have been successfully obtained using BOTCS[23,30–32],even though relevant comprehensive uti-lization is quite limited[48,49].No matter what the coupling agent may be,it must possess a halo atom at the terminal position in order to quaternize the imid-azole and/or pyridine ring.Normally,there are two different path-ways,as shown in Fig.3.In the monomeric heterogeneous process(mHTP),silica isfirst modified by the coupling agent,then imidazole with or without substituents is attached to the haloalkyl chain to form the IL in situ.In the monomeric homogeneous pro-cess(mHMP),the coupling agent isfirst treated with imidazole to build up the IL,which could be seen as a new coupling agent, then it is immobilized on silica.The mHTP is more convenient,as it only requires an anhydrous environment in thefirst step,and no organic intermediate needs to be isolated or characterized. The mHMP is more complicated,because an intermediate is pro-duced,and isolation and purification may be required;moreover, the solubility of the new coupling agent is unknown,so it would be difficult to choose an appropriate solvent in the second step.In spite of the identical SCILs being formed via mHTP and mHMP,mHMP should be preferred if greater bonding is desired, drawing on organosilicon-related experiences[50,51],demonstrat-ing that bonding can be almost doubled via mHMP rather than mHTP,since the reaction between the effective ligand and linkage in mHTP is hampered much more,whereas,in HMT,the effective ligand has already transformed into a part of the new coupling agent,and the reaction between alkoxyl and silanol occurs much more readily than quaternization.As for the solvent issue,immobi-lization can be performed in polar aprotic media,such as acetoni-trile(ACN),N,N-dimethylformamide(DMF)and dimethyl sulfoxide (DMSO).Once a coupling agent is selected,the following work is bonding imidazole or its functionalized derivatives.As shown in Table1,the functionalized derivatives are chiefly alkylimidazoles with various aliphatic or benzyl groups.1-alkylimidazoles with shorter aliphatic chains,including methyl,ethyl and butyl,and benzyl group,are commercially available.Aliphatic chains of odd numbers are rarely seen,except methyl and propyl.Longer chains,such as octyl and decyl,are scarce commercially,so necessitating the synthesis of a 1-alkylimidazole precursor.There is voluminous literature[52–58]dealing with the syntheses of1-alkylimidazole in laboratory settings(Fig.4).The most widely employed approach is the depro-tonation of imidazole with strong bases,such as sodium hydroxide, sodium hydride and sodium alcoholate,to produce sodium imidaz-olate,then to the alcoholic or tetrahydrofuran(THF)solution a proper alkyl halide is added to generate the1-substituted imidaz-ole derivative.Likewise,the new coupling agent generated in mHMP is the result of1-functionalization of imidazole by CPTMS in toluene(ImPTMS)[29,59],where a bulky tertiary amine(trieth-ylamine or N,N-diisopropylethylamine)instead of sodium acts as acid acceptor.Due to the S n2characteristics of this reaction,chlo-ride-based starting materials,though less reactive than their bro-mide-and iodide-based analogues,are more likely to guarantee a complete reaction;furthermore,from economic andecological mon imidazolium-based stationary phases.Table1Summary of structures of monomeric IL-based stationary phasesSilprIm-NTf2 1.24[25]SiO2OOSi NCl-, Br-HOSilprMIm-ClSilprMIm-BrIR,TGA,XPS,XRD2.4,3.1,1.2,2.30.8[17],[26]a,[24],[25][27]SilprEMIm-Cl XPS0.9,1.3[24],[25]BPIM-modifiedsilicaTGA,solid state13C and29SiNMR0.8[27]SiImPS-Cl TGA,XPS 1.5[28]SilprHIm-Cl- 1.8[29]SilprDIm-Cl- 1.6[29]BIM-Br-0.7,1.8,1.0[30],[31],[32]MIM-Br- 1.0[32]BzIM-Br-0.6[32]nBSIM- 1.7[32]IR:infrared spectra;TGA:thermogravimetric analysis;XPS:X-ray photo-electronic spectroscopy;NMR:nuclear magnetic resonance.a Supports are hybrid ZrO2-SiO2material.M.Zhang et al./Trends in Analytical Chemistry53(2014)60–7263viewpoints,the chloride-based materials are usually much less expensive,and they can minimize the mass of the waste by pro-ducing NaCl rather than heavier NaBr and NaI when yielding equi-molar1-functionalized imidazoles.Thus,the use of chloride-based materials is completely practicable and beneficial.Multiple substituted imidazoles,which possess alkyl chains at 2-and4-instead of1-and3-positions,were employed[24,25]. The synthesis technique for imidazole derivatives with such multiple substituents distinctly differs from that for1-substituted ones.The Radziszewski reaction(Fig.5),which was initially theindustrial synthesis strategy to produce imidazole,generates imi-dazoles with one or more substituents by cyclocondensation of ring fragments,typically the combination of glyoxal,ammonia, aldehyde and a primary amine(chiral or achiral)[60–66].Nev-ertheless,the Radziszewski reaction was notably beset by side reactions and poor yields.With the assistance of a phase-transfer catalyst and microwaves,the result can be improved[67,68].As displayed in Fig.5,if all the R groups are hydrogen,thefinal prod-uct is imidazole.Variation of any R group will lead to the formation of a different imidazole derivative.In addition,any of the R groups could be highly functionalized.Another advantage is that,through this multi-component reaction,incorporation of one or more bulky substituents,such as iso-propyl,anthracene,and phenanthrene, into the imidazole ring becomes feasible,unlike the N-alkylation in Fig.4,which is significantly influenced by steric hindrance.SCIL SPs bearing a sulfonate group are often acquired by sulfoalkylating alkylimidazole with1,3-propane sultone or1,4-bu-tane sultone under homogeneous or heterogeneous conditions [28,32,33,69].These sultones are highly reactive;the sulfoalkyla-tion reaction is nearly quantitative under homogeneous conditions.Most of the SCIL SPs are obtained by imidazole derivatives pre-pared through N-alkylation and not highly functionalized,and highly functionalized imidazole derivatives produced through the Radziszewski reaction have found little application,so we expect a wide variety of functionalized imidazoles would instill new vital-ity into preparation of SCIL SPs.2.2.Polymeric routeIn the polymeric route(Fig.6),SCIL SPs are prepared from having allyl or vinyl groups using MPS as the coupling agent.There is a great similarity between the polymeric route and HMP in theFig.3.General processes for the monomeric synthesis of surface-confined ionic-liquid stationary phases. Fig.4.Preparation of mono-substituted imidazole.Fig.5.Preparation of multiple-substituted imidazole.monomeric route,which is that IL is not formed in situ on the sur-face of silica.Also,the polymeric and monomeric routes are nota-bly dissimilar;as Table2shows,the extent of bonding by the polymeric route is generally much greater than that by the mono-meric route,because theoretically more than one imidazolium cat-ion is immobilized by each MPS,but each CPTMS only consumes one imidazole molecule.Without exception,the ILs employed in the polymeric route are synthesized from starting materials containing alkenyl groups. Most conveniently,the imidazolium-bearing side arm at3-posi-tion can be built by treating1-vinyl or1-allylimidazole with alkyl halide or sultone.When using alkyl halide,usually an alkyl bro-mide,the reaction can be performed in polar aprotic solvent (ACN,THF)under mild conditions.In the case of sultone,the reac-tion can be run neat[33,34,70,71].If the alkyl chain is sufficiently long,such as1-bromohexadecane,the isolation of the product would be simple;sometimes,it would precipitate from solvent. For the short alkyl chain,the product could be viscous oil;purifica-tion can be achieved by distillation or precipitation in a non-polar aprotic solvent,such as pared to1-allylimidazole,the vinyl analogue has a higher reactivity towards polymerization,so 1-vinylimidazole should be given priority in design of synthesis. Another way to prepare the imidazolium-containing alkenyl group is to treat1-alkylimidazole with a certain reactant having halide and unsaturated group respectively at each end of it,as shown by our previous work[37],in which the alkenyl group was intro-duced by the esterification of acryloyl chloride with11-bromoun-decanol.More polymerizable ILs can be obtained by this treatment, because of its applicability to a similar reactant,as long as it has a hydroxyl group at the a-position and a halide at the x-position, such as10-bromodecanol,12-bromododecanol and16-bromo-hexadecanol.The IL obtained from alkenylimidazole or alkylimi-dazole is subjected to immobilization in large excess to MPS-modified silica(1/1,w.t./w.t.)via the surface-initiated radical chain-transfer reaction initiated by azobisisobutyronitrile(AIBN) (1-3w.t%)[34,37].Normally,the polymerization process is per-formed heterogeneously,also known as‘‘grafting from’’,similar to mHTP.There is no case involving homogeneous polymerization, also known as‘‘grafting to’’,in preparation of polymeric SCIL SPs, possibly due to the unknown solubility,sensitivity to moisture and the difficulty in characterization of the target polymer.But there are two examples involving homogeneous polymerization of1-vinylimidazole and4-allylpyridine,leaving the tertiary amine position vacant[72,73].Regardless of no IL taking shape hereby, useful references could be drawn for the preparation of SCIL SPs in the future.Another approach to modify polymeric SCIL SPs is to substitute the halide anion with other anions.The substitution is realized through a metathesis reaction,which is simple and effective,as long as there are differences between the concentrations and the solubilities of the original anion and the anion desired.The substi-tution can be executed by rinsing not only the IL or IL-immobilized silica,but also on-column with a high concentration of the desired anion solution.The shortcoming of the metathesis reaction is that the new anions tend to run off gradually or be superseded by other anions.To tackle the problem,the co-polymerization technique used in otherfields can be followed[74–77].A prerequisite for co-polymerization use in SCIL SPs is that both the cation and the anion must have an alkenyl group,preferably a vinyl group.To car-ry out co-polymerization,the polymerizable anion has to replace the original anion in advance through the metathesis reaction. After this treatment,the new IL is ready to be co-polymerized via the same procedure in polymerization.The slow drain on the anion is avoided by co-polymerization of the cation and anion pair,as they are entirely connected to silica by the covalent bond,besides the electrostatic attraction.The extent of bonding is sensitive to the shape of the ion pair,as observed[39];the negative effect of a linear anion on the extent of bonding is much less than that of a planar anion,as is that of a less bulky cation.It can be anticipated that if the cation(anion)is bulkier,the extent of bonding would be even less.We can conclude that the polymeric route is advantageous over monomeric route in enhancing the stabilities of SCIL SPs and ele-vating the extent of bonding.In addition,the polymeric route en-ables the modification of SCIL SPs by a polymerizable anion. However,it is hardlyflawless,as the degree of polymerization is not easy to control;moreover,instead of polymerization,simple addition reaction between mercapto and alkenyl groups at stoichiometric ratio could occur at times.2.3.Practicable new routesApart from above-mentioned synthesis methodologies,there are several workable schemes for preparing SCIL SPs,which do not necessarily encompass the use of c-haloalkyltrialkoxysilanes and MPS.These schemes are proposed on the ground of experimental results obtained by authors not specializing in separation science,but the chemical rules involved are universally applicable.As displayed in Table1and Table2,the dominant coupling agents for preparation of SCIL SPs are CPTMS and MPS,whereby materials of commendable chromatographic properties have been produced[24,25,29,34,35,39].Nevertheless,merely two available functional groups,i.e.haloalkyl and mercapto,are definitely insufficient for the development of more multi-functional SCIL SPs.It is well-known that there is a broad variety ofsilane Fig.6.General processes for polymeric synthesis of surface-confined ionic-liquid stationary phases.coupling agents,such as c-glycidyloxypropyltrimethoxysilane (GPTMS),c-aminopropyltrimethoxy(APTMS),c-(ethylene amino) propyltrimethoxysilane(EAPTMS).Except for one case covering the use of GPTMS in preparation of IL-functionalized b-cyclodex-trin SP[78],their long absence from the synthesis of IL-based materials may have been a great loss to the innovation of SCIL SPs.One of the potentially useful coupling agents is GPTMS,which contains an epoxide(oxirane),which is an extremely versatile group,enabling further derivation by a large range of nucleo-philes,electrophiles and so on under mild conditions.Under solvent-free conditions,epoxides can undergo ring-opening by imidazole,forming imidazolyl alcohols[79].As proposed in Fig.7,imidazole can be treated by GPTMS to produce a new cou-pling agent.Further quaternization by a-haloalkane or x-halo multifunctional alkane on the3-position of imidazole can pro-duce new ILs.Another idea for introducing functional groups is treating deprotonated imidazole with equimolar epichlorohydrin(EPCH), producing1-(oxiran-2-ylmethyl)-1H-imidazole.Herein,modifica-tion can go further in two ways:first is ring-opening of the epoxide group by amine-con-taining APTMS or EAPTMS(Fig.8),but it is uncertainwhether the resulting secondary amine could consumeanother equimolar1-(oxiran-2-ylmethyl)-1H-imidazole orhalo-containing reagent;and,second is quaternization of imidazole by CPTMS,leaving the epoxide group intact for further modification byamines,alcohols and carboxylic acids.Treatment of deprotonated imidazole with excessive EPCH gives an IL,namely1,3-diglycidylimidazolium chloride[80].Be-cause of the identical reactivity of the two epoxide groups,selec-tive ring-opening is difficult.But it is possible to perform the selective ring-opening reaction heterogeneously.The remaining epoxide can be further converted.The superiority of EPCH over a,x-dihaloalkane in preparation of ILs is that the latter has no selectivity towards the two nitrogen atoms of imidazole;instead,the epoxide group is unreactive to-wards tertiary amine,so formation of polyimidazolium salts is pre-vented.Also,even if imidazole or imidazolium-containing haloalkyl groups were obtained,further derivatization would stillFig.7.Functionalization of imidazole by c-glycidyloxypropyltrimethoxysilane(GPTMS).Fig.8.Functionalization of imidazole by epichlorohydrin(EPCH).Table3Summary of applications of SCIL stationary phasesStationary phase Analytes OperationmodeRef.SilprPy-Cl Inorganic anions:chloride,nitrite,bromide,nitrateBenzene,anthracene,benzyl alcohol,benzonitrile and nitronaphthaleneIE,RP[22] SilocPy-Br Mainly aromatic derivatives RP[23] SilprDipy-Cl PAHs,phenolic compounds,hydroxybenzoatesInorganic anionsRP,IE[85]SilprIm-ClSilprIm-BF4SilprIm-NTf2Phenols,aromatic amines,pyridine derivativesInorganic anions and cationsTheobromine,theophylline,caffeine,guanine,thymine,cytosine,xylose and glucoseRP,IE,HILIC[18,24,25]SilprMIm-ClSilprMIm-Br Inorganic ionsTheobromine,theophylline,caffeine,guanine,thymine,cytosine,xylose and glucosePhenols,aromatic amines and aromatic acidsIE,HILIC,RP,NP[17,24–27]SilprEMIm-Cl Theobromine,theophylline,caffeine,guanine,thymine,cytosine,xylose and glucose RP,HILIC[24,25] BPIM-modifiedsilicaAromatic acids RP[27] SiImPS-Cl Inorganic ions and organic cations,vitamin B and nucleic acid bases IE,RP[28]SilprHIm-Cl Inorganic anions,nucleic acid bases,benzenes,aromatic amines and phenols IERP [29]SilprDIm-ClBIM-Br Peptides and aromatic derivatives RP[30–32]polycyclic aromatic hydrocarbons that are priority pollutants(SRM1647e)with(a)C18-m,(b)C18-p,(c)SIL-BrMobile phase:100%methanol;flow rate:1.0mL minÀ1;UV:254nm;column temperature:30°C.Peaks:naphthalenephenanthrene(5);anthracene(6);fluoranthene(7);pyrene(8);benzo[a]anthracene(9);chrysenebenzo[a]pyrene(13);dibenzo[a,h]anthracene(14);benzo[ghi]perylene(15);indeno[1,2,3-cd]pyrene(16).(Reprinted68M.Zhang et al./Trends in Analytical Chemistry53(2014)60–72。

四级介绍说明类作文模板英文回答：Expository Essay Template for HSK Level 4。

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Topic sentence: Support the thesis statement with the first point.research to back up the point.Transition sentence: Connect the first body paragraph to the second.III. Body Paragraph 2。

Topic sentence: Support the thesis statement with the second point.Supporting evidence: Use specific examples, data, or research to back up the point.Transition sentence: Connect the second body paragraph to the third.IV. Body Paragraph 3。

Topic sentence: Support the thesis statement with the third point.research to back up the point.Transition sentence: Connect the third body paragraph to the conclusion.V. Conclusion。

III. 拟定提纲；OutlineCreating an outline for your article makes you prepared. You have an idea of what to do first and make a plan for your succeeding steps. Being prepared makes the job easier and faster. Being organized will allow for disorientation to be shunned away.An outline can act as the design or blueprint for your article. This will guide you in creating the introduction, body and conclusion of your article. Here in this point, you can write down some of the ideas and sentences that you feel will look good in your article. This could be some of the focal point that could help make your article creative, interesting and appealing to a reader.1. An outline aids in the process of writinghelps you organize your ideaspresents your materials in a logical formshows the relationships among ideas in your writing constructs an ordered overview of your writingdefines boundaries and groups2. How do I create an outline?Brainstorm: list all the ideas that you want to include in your paper.Organize: group related ideas together.Order: arrange materials in subsections fromgeneral to specific or from abstract toconcrete.Label: create main and sub-headings.3. Four Main Components for Effective OutlinesIdeally, you should follow these 4 suggestions to create an effective outline.1.Parallelism :Each heading and subheading should preserve parallel structure. If the first heading is a verb, the second heading should be a verb.Example: Why I Apply To This University1.Choose Desired Colleges2.Find out the advantages and disadvantages3.Prepare Application("Choose" ,“find out”and "Prepare" are all verbs.)2.Coordination （协调）All the information contained in Heading 1 should have the same significance as the information contained in Heading 2. The same goes for the other subheadings (which should be less significant than the previous headings).Example:1.Visit and evaluate college campuses2.Visit and evaluate college websites1.Note important statistics2.Look for interesting classes(Campus and website visits are equally significant, as are statistics and classes found on college websites.)3.SubordinationThe information in the headings should be more general, while the information in the subheadings should be more specific.Example:Describe influential persons in your life1.Favorite high school teachers2.Grandparent(A favorite teacher and grandparent are specific examples of influential people.)DivisionEach heading should be divided into 2 or more parts.提纲的种类( 1 ) 句子提纲：sentence outline( 2 ) 主题提纲：topic/point outline Sample Outline ( sentence outline )Title :Foreign Trade Is Beneficial to and Indispensablefor All NationsI. Introduction : The utilization of different economic resources and the development of different skills form the foundation of foreign trade.II. Trade in commodities ( visible trade ) is necessary between nations.A. No nation has all the commodities it needs..B. A nation may not have enough of certaincommodities.C. A nation may sell certain commodities at a profit.test innovations and different styles ofcommodities may make foreign trade necessary. E. All nations strive to maintain favorable balance oftrade so as to be assured of the means to buy necessary goods.III. Exchange of services between nations ( invisible trade ) is part of foreign tradeA. Nations vie in providing transportation for foreigntrade.B. Prudent exporters purchase insurance for theircargoes.C. Tourism brings a nation huge profits.D. Technology is also exported and imported.IV. Conclusion : The purpose of foreign trade is to earn money for necessary imports and it is important to keep the balance of payments.A topic outlineI. Introduction : The foundation of foreign tradeII. The necessity of foreign tradeA. Lack of certain commoditiesB. Insufficiency of particular items.C. Comparative advantage in certain itemstest innovations and different styles ofcommoditiesE. The importance of a favorable balance of trade III. The necessity of invisible trade------exchange of services between nationsA. Transportation1.A23B. InsuranceC. TourismD. TechnologyIV. Conclusion: The purpose of foreign trade and the importance of the balance of payments两种格式不能混为一谈。

nc命令参数-回复NC(Command) Parameters: A Step-by-Step GuideIntroduction:The NC command, also known as Netcat, is a versatile networking tool used for communication between computers over TCP or UDP connections. It allows users to send and receive data across networks, making it an essential utility for network administrators and security professionals. In this article, we will explore the various parameters and their functionalities to gain a comprehensive understanding of this powerful command.I. What is NC?NC, short for Netcat, is a command-line utility used for reading and writing network connections using TCP or UDP protocols. It can establish connections, listen for incoming connections, and transfer data between hosts. Its flexibility and simplicity make it awidely-used tool for network troubleshooting, port scanning, and even for creating backdoors or remote administration tools.II. Basic Usage:The basic syntax for using NC is as follows: "nc [options] [hostname] [port]". Let's break it down step-by-step:1. Options:There are several options available with NC, including:- "-l" for listening mode: This parameter allows NC to listen for incoming connections rather than initiating them.- "-p" followed by a port number: Specify the port number to use for the connection.- "-u" for UDP mode: Switch to using UDP instead of TCP as the transport protocol.- "-v" for verbose mode: Displays more detailed information during the connection.2. Hostname:The hostname parameter specifies the target device or IP address to which NC will connect. This can be a domain name or an IP address.3. Port:The port parameter specifies the port number to which NC will connect or listen. It can be any valid port number, ranging from 1 to65535.III. Advanced Parameters:Now that we have covered the basics, let's delve into some advanced parameters and their functionalities.1. "-e" for executing a command:NC allows the execution of a shell command once the connection is established. This can be achieved by specifying the "-e" option followed by the desired command. For example, "nc -l -p 1234 -e /bin/bash" will launch a shell session upon connection.2. "-k" for keep-alive:The "-k" parameter enables the keep-alive feature, which sends periodic data packets to ensure the connection stays active. This is particularly useful when establishing long-duration connections.3. "-z" for scanning ports:The "-z" option allows NC to scan a range of ports on a target device without establishing a connection. It sends a TCP or UDP probe to check for open ports, helping identify potential vulnerabilities.4. "-r" for randomizing source ports:Using the "-r" parameter randomizes the source port for sending data. This adds an extra layer of security by making it harder for potential attackers to track the origin of the connection.IV. Use Cases:Now, let's explore some practical applications of the NC command with various parameters.1. File Transfer:NC can be used to transfer files between computers. By running one instance of NC in listening mode on the receiving end and another instance in client mode on the sending end, files can be sent through the network. For example, "nc -l -p 1234 > received_file" on the receiving end and "nc [receiver_ip] [receiver_port] < file_to_send" on the sending end.2. Port-forwarding:NC can act as a port-forwarding tool, allowing connections to be forwarded from one host to another. For example, "nc -l -p 8080 nc [internal_host] [internal_port]" would forward incomingconnections on port 8080 to an internal host and port.3. Network Scanning:The "-z" parameter enables port scanning capabilities with NC. By specifying a range of ports, NC will probe each port to determine if it is open or closed. This can be useful for identifying services running on target devices and potential vulnerabilities in a network.V. Conclusion:The NC command, with its extensive range of parameters, offers network administrators and security professionals a powerful tool for communication, troubleshooting, and security analysis. Understanding the various options available and their functionalities enables efficient utilization of NC's capabilities. By following this step-by-step guide and exploring its practical applications, users can harness the full potential of NC for their networking needs.。

Keys新融合大学英语综合教程4答案- Unit 5Part I Pre-readingSection B Listening Practice1. adventures2. passport3. adjustment4. alternative5. destinations6. confusingPart II Active Reading: Cultural ConflictsTask One1. C2. B3. D4. B5. CPart III Language FocusTask One1. roar2. prominent3. recoiled4. loomed5. insane6. boost7. outrages8. trigger9. alternately 10. switchTask Two1. I would bet all I have that he learned his lesson about gambling.2. She was indignant that her voice was neglected in work.3. Hopefully, I could switch myself from the legal profession to the business side of things.4. The majority of the local residents are still struggling to be compliant with environmental regulations.5. The public accuse the retail giant of exploiting its workers and discriminating against female employees.6. In winter, we slithered down the slope covered with snow.Part IV Chinese & Foreign Culture IntroductionTask OneDragons are commonly used as auspicious sign; it is one of the most typical of the Chinese nation’s traditional culture.Dragons are deeply rooted in Chinese culture, so the Chinese often consider themselves as "the descendants of the dragon". In Chinese culture, dragons are generous and wise. They are closely connected with the ancient royal family. Dragon culture also exists in the Western world. However, dragons have different reputation in western culture. The Western dragons are evil animals from hell. They usually have wings and can send out fire from their mouths.Task Two不同文化对私人空间和身体接触有不同的期望。

A topic outlineThesis: Foreign trade is beneficial to and indispensible for all nationsI. Introduction: The foundation of foreign tradeII. The necessity of visible trade2.1. Lack of certain commodities2.2. Insufficiency of particular items2.3. Comparative advantage in certain items2.4. Latest innovations and different styles of commodities2.5. The importance of a favorable balance of tradeIII. The necessity of invisible trade----exchange of services between nations3.1. Transportation3.2. Insurance3.3. Tourism3.4. TechnologyIV. Conclusion: The purpose of foreign trade and the importance of the balance of paymentsA sentence outlineThesis: Foreign trade is beneficial to and indispensible for all nationsI. Introduction: The utilization of different economic resources and the development of different skills form the foundation of foreign tradeII. Trade in commodities (visible trade) is necessary between nations2.1. No nations has all the commodities it needs2.2. A nation may not have enough of certain commodities2.3. A nation sell certain commodities at a profit2.4. Latest innovations and different styles of commodities may make foreign tradenecessary2.5. All nations strive to maintain a favorable balance of trade so as to be assured of themeans to buy necessary goodsIII. Exchange of services between nations (invisible trade) is part of foreign trade3.1. Nations vie (compete) in providing transportation for foreign trade3.2. Prudent exporters purchase insurance for their cargoes3.3. Tourism brings a nation huge profits3.4. Technology is also exported and importedIV. Conclusion: The purpose of foreign trade is to earn money for necessary imports and it is important to keep the balance of payments。

关于公共市民使用大学操场的英语作文Title: Utilization of University Sports Ground by the PublicIntroduction:The university sports ground, often bustling with activity, serves as more than just a venue for students' athletic endeavors. It stands as a communal space thatfosters physical well-being, social interaction, and community engagement. However, the question arises: Should the general public have access to these facilities? In this essay, we will explore the various aspects of allowing public use of university sports grounds.Benefits to the Community:Opening university sports grounds to the public offers numerous benefits to the community. Firstly, it promotes a healthier lifestyle by providing access to high-qualitysports facilities. Regular physical activity is crucial for maintaining good health, and allowing public access to these facilities encourages individuals to engage in exercise and sports. Moreover, it creates a sense of inclusivity and belonging within the community, as people from different backgrounds come together to pursue their fitness goals.Enhancing Social Cohesion:Public use of university sports grounds fosters social cohesion by bringing people together in shared spaces. These grounds become hubs for social interaction, where individuals from diverse backgrounds converge to engage in recreational activities. Such interactions promote understanding, tolerance, and mutual respect among community members, contributing to the overall harmony and unity of society.Opportunities for Skill Development:Granting public access to university sports grounds provides opportunities for skill development and talentidentification. Individuals, regardless of age or socio-economic status, can hone their athletic abilities anddiscover new talents in various sports. This inclusivity encourages participation and excellence in sports, nurturinga culture of athleticism and achievement within the community.Promoting Lifelong Learning:Universities are centers of learning, not only academically but also in terms of physical education and sportsmanship. Allowing public use of sports grounds extends this culture of learning beyond the campus borders. People of all ages can benefit from the expertise of university coaches and trainers, gaining valuable insights into sports techniques, strategies, and fitness regimes. This exchange of knowledge promotes lifelong learning and skill enhancement among community members.Challenges and Considerations:While the idea of opening university sports grounds tothe public holds various benefits, it also poses certain challenges and considerations. Firstly, there may be concerns regarding the maintenance and upkeep of the facilities. Increased footfall from the public may lead to greater wear and tear, necessitating additional resources for maintenance and repairs. Furthermore, managing the scheduling andallocation of resources to accommodate both universitystudents and the public requires careful planning and coordination.Another consideration is the issue of security and safety. Opening sports grounds to the public means entrusting the facilities to individuals who may not be affiliated with the university. Ensuring the safety of users and safeguarding university property becomes paramount, requiring the implementation of effective security measures and regulations.Conclusion:In conclusion, the utilization of university sports grounds by the public presents a multifaceted opportunity to promote health, social cohesion, skill development, and lifelong learning within the community. By opening these facilities to the public, universities can extend their impact beyond campus boundaries, enriching the lives of individuals and fostering a culture of well-being and inclusivity. However, to realize the full potential of this initiative, careful consideration must be given to addressing challenges such as maintenance, security, and resource allocation. Overall, the benefits of public access to university sports grounds outweigh the challenges, making it a worthwhile endeavor for universities to pursue in their commitment to serving the broader community.。