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1.
INTRODUCTIONInthelastdecade,remotesensinghasbeenincreasinglyidentifiedasanobjective,standardized,possiblycheaperandfastermethodologyforcropproductionsurveysthanconventionalfieldinves-tigations(Bauman,1992).Muchprogresshasbeenmadethroughintensivestudiesoninventoryandproductionforecastingformajorcrops,suchaswheat,rice,cottonandmaize(Tennakoonetal.,1992;Rayetal.,1994;Fangetal.,1998).China,adevelopingcountrywith1.2billionpeople,hasbeenpayingcloseattentiontoitsex-istingandfuturefoodproduction… 相似文献
2.
Comparative mapping of QTLs for Al tolerance in rice and identification of positional Al-induced genes 总被引：2，自引：0，他引：2
INTRODUCTION Aluminum (Al) toxicity is one of the mostimportant yield-limiting factors for crop grown onacid upland and lowland acid sulphate soils (IRRI,1978). Al toxicity results in a reduced and damagedroot system, which in turn causes the affectedplants to be susceptible to drought stress and min-eral nutrient deficiencies (Foy, 1988). The physio-logical and biochemical mechanisms of the toxiceffect of Al on root elongation had been extensivelyinvestigated (Matsumoto, 2000). T… 相似文献
3.
The English have an island culture-quirky(古怪的)and self-contained(持重的).Much of theirhumour is highly sophisticated(老于世故的)andelusively(难以理解)subtle(隐晦的). The English rarely say what they mean andtend towards reticence(节制)and understatement 相似文献
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Concentration and temperature dependence of viscosity of uranium solutions in H_2O and 3 mol/L HNO_3
INTRODUCTIONJone-Doleequation(JonesandDole,1929)isbeingusedextensivelyforstudyingion-solventinteractionsfordilutesolutions(Fahim-ud-Dinetal.,1990).Valuesofion-solventinteractioncoef-ficientdependupontheparticularelectrolyte,concentrationofelectrolyte,temperatureandsol-ventunderconsideration(Afzaletal.,1989).Mohi-ud-DinandIsmail(1983)attemptedtode-scribetheconcentrationdependenceofviscosityintermsofanempiricalisothermalequation,Eq.(1),obtainedfromtheVogel-Tammann-Fulcher(VTF)equation(… 相似文献
5.
Design of ERT system 总被引：2，自引：0，他引：2
INTRODUCTION Electrical resistance tomography (ERT) is a technique producing images based upon variations in conductivity, and has great potential in process ap- plications (Tapp et al., 2003). In an ERT system, current is injected to a pair of drive electrodes and voltage measurements are taken between sense elec- trode pairs, yielding resistance information for image reconstruction (Cilliers et al., 2001). Traditional ERT systems usually use high fre- quency sinusoidal waveforms as … 相似文献
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The world itself is becoming much smaller by using modern traffic and moderncommunication means(通讯设备).Life today is much easier than it was hundred ofyears ago, but it has brought new problems. One of the biggest is pollution(污染).To pollute means to make things dirty. Pollution comes in many ways. We see it, smell it, drink it and even hear it. 相似文献
7.
Once upon a time the colors of the world started to quarrel(争吵). All claimed(声称) that they were the best; the most important, the most useful, and the favorite. 相似文献
8.
盛平兴 《上海大学学报(英文版)》1997,1(2):91-94
Inthispaper,thefollowingKdV-Burgersequationinonedimensionisconcerned:wherev>0andadoarephysicalparametersandII(l.x)isdetlnedonClearlyonemayfirstprovidesomeinitialconditionsu(0,x)=u,(x)EC(R).Sinceweareinterestedinqualitativeanalysisofinfinite-dimensionaldyn… 相似文献
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IntroductionCode-switchingwhichmaybebrieflydefinedasthealternationbetweentwo(ormore)languages,I(Eldridge1996:3O3).Ithasbeenreceivinggrowingattentioninrecentyears.Farfrombeingviewed'asarandomphenomenon,ithascometobeseenasahigh-lypurposefulactivityHowever,themajOrityof=thestudieshavebeenconductedinau-thenticbilinguaIspeechcommunities,ratherthaninthelanguageclassroom,whichwillbethefocusofmystudy.LanguageAttitudes)lTheideaofavoidingthernothertongueinlanguageteachingdatesbackfrornaroundtheturno… 相似文献
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INTRODUCTION Preparation and electrical properties ofpoly(arylene)s having π-conjugation system along thepolymer chain are the subject of recent interest(Skotheim et al., 1997; Nalwa, 1997; Yamamoto,2002). Among the poly(arylene)s, poly(p-phenylene),poly(pyridine-2,5-diyl) and poly(thiophene-2,5-diyl)are the most fundamental polymers and had beenextensively studied (Skotheim et al., 1997; Yama-moto, 2002; Nurulla et al., 2001). However, thesepolymers show only… 相似文献
11.
INDRODUCTIONMeso-poroussilicafilmswithanexcellentheat-insulatingpropertyandtherelativelylowdielectricvalueplayparticularlyimportantroleinelectronicandmagneticdevices(Moonetal.,1997),etc.;thosewithporesizesof5nmto50nmarealsoofinterestforapplicationsinphotonics,optoelec-tronics,lightweightstructuralmaterialthermalin-sulation,opticalcoating(Moonetal.,1997;HusingandSchulert,1998;Davis,2002).Theirspecialnetworkstructureisusedinsounddetector(HusingandSchubert,1998);theirexcellentinsulatingpro… 相似文献
12.
A hundred years ago, the game we now call football did not exist (存在). American football started during a game between two colleges. The teams had gotten together to play what called “football”, but each team played by different rules. One team played what we now call soccer.The other played what we now call rugby (橄榄球). 相似文献
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Jeremy’s bedroom furniture (家具) was having an argument. “I am definitely the most important,” said the chest of drawers (五斗柜).“Jeremy always looks in my bottom drawer for his socks. He looks in my middle drawer for his shirts and my top drawer for his jeans (牛仔裤). If it were not for me, he would not be able to find his clothes.” 相似文献
14.
Early association of electrocardiogram alteration with infarct size and cardiac function after myocardial infarction 总被引：1，自引：0，他引：1
INTRODUCTIONInpatientswithcongestiveheartfailurespe-cificelectrocardiogram(ECG)alterations,suchaspathologicalQwavesorpersistentSTsegmentelevationsinMI-relatedleads,maybeseenaftertransmuralmyocardialinfarction(MI).Infarctex-pansionoccurswithinhoursofmyocyteinjury,resultsinwallthinningandventriculardilation,andcausestheelevationofdiastolicandsystolicwallstresses(Warrenetal.,1988).Ventricularremod-elingmaycontinueforweeksormonthsuntilthedistendingforcesarecounterbalancedbythetensilestren… 相似文献
15.
INTRODUCTION The adsorption of gas molecules on metals,metal oxides or alloys had been researched widelyto find a solution for the problem of air pollution(Davies and Craig Jr., 2003; Yanagisawa, 1996;Tominaga et al., 1999). NO could be adsorbed onthe particle surface and desorbed as N2 from thesurface by temperature programmed desorption(TPD) (Davies and Craig Jr., 2003; Yanagisawa,1996). The calculation of cluster model was estab-lished with molecular orbital (MO) theory (Ry… 相似文献
16.
Toxicity of cadmium to soil microbial biomass and its activity：Effect of incubation time on Cd ecological dose in a paddy soil 总被引：4，自引：0，他引：4
INTRODUCTION Cadmium (Cd) is ubiquitous in the human en-vironment and has been recognized as one of the mostdeleterious heavy metal pollutants (Robards andWorsfold, 1991; Christine, 1997). It may easily movefrom soil to food plants through root absorption andaccumulate in their tissues (Oliver, 1997). In this way,Cd may enter the food chain and affect human health(Adriano, 1986). Among many heavy metals pollut-ing soil, Cd is of concern because of its potentiallyharmful effects on… 相似文献
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INTRODUCTION Cyanohydrin compounds are useful syntheticintermediates in organic synthesis and are importantstarting materials for the synthesis of pharmaceuticals(Klibanov, 1990). Optically active cyanohydrin esterscan be obtained by enzymatic transesterification ofracemic cyanohydrins in organic solvent (Wang et al.,1989). (S)-α-cyano-3-phenoxybenzyl (CPB) alcoholis an important building block of pyrethroid insecti-cides and has received increasing interest for use inbiological agroche… 相似文献
18.
INTRODUCTIONSuppose{Xn,n1}isasequenceofinde-pendentandidenticallydistributedrandomvari-ableswithcommoncontinuousdistributionfunc-tionFX(x).DefineMn(X)=max(X1,X2,,Xn).WeconsiderthenondegeneratedlimitdistributionofPr{Mn(X)anx bn}whereanandbnaresomenormalizingconstants{}()limPr()XnnnnGxMXxab=?.Fori.i.d.randomvariablesX,FisherandTippettfoundin1928thatlimitdistributionsexistandthatthereareonlythreetypesofdistributions,theso-calledExtremeValueDistributionsandthatGX(x)iseitherofthefol… 相似文献
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Design of non-polarizing thin film edge filters 总被引：3，自引：0，他引：3
INTRODUCTION The design of tilted edge filters which avoid the polarization problems is a much more difficult task than that of polarizer design and there is no com-pletely effective method (Macleod, 2001). Edge fil-ters are divided into two main groups, long-wave-pass and short-wave-pass. They are widely used for vari-ous optical purposes, especially in wavelength divi-sion multiplexers (WDM) (Nosu et al., 1979) and multimedia color projection display (Zhang et al., 1999). Unfortunate… 相似文献
20.
Objective: This study was aimed at evaluating and comparing the quality of life in patients who underwent laparo-scopic and open cholecystectomy for chronic cholecystolithiasis. Methods: The study included 25 patients with laparoscopic cholecystectomy (LC group) and 26 with open cholecystectomy (OC group). The quality of life was measured with the Gastrointestinal Quality of Life Index (GLQI) preoperatively, thereafter regularly at 2, 5, 10 and 16 weeks after the operation. Results: The mean preoperative overall GLQI scores were 112.5 and 110.3 in LC and OC group respectively (P>0.05). In the LC group, the mean overall GLQI score reduced slightly to 110.0 two weeks after the operation (P>0.05). The LC group showed significant improvement in overall score and in the aspects of symptomatology, emotional and physiological status from 5 to 16 weeks postoperatively. In the OC group, the GLQI score reduced to 102.0 two weeks after surgery (P<0.05). Significant reductions were shown in the aspects of symptomatology, physiological and social status. The GLQI scores returned to the preoperative level of 115.6 ten weeks after the operation (P>0.05). The patients experienced significant improvements of GLQI sixteen weeks after OC operation (P<0.01-0.05). Within the 10 postoperative weeks, the LC group had significantly higher GLQI scores than the OC group (P<0.05). Conclusions: LC can improve the quality of life postoperatively better and more rapidly than OC. The assessment of quality of life assessment is a valid method for measuring the effects of surgical treatment. 相似文献