简介:TheintegratedeffectofirrigationandagriculturalpracticesonsoilsalinityintheJordanValley(JV),whereover60%ofJordan'sagriculturalproduceisgrown,wasinvestigatedinthisstudyduring2009-2010.Duetothedifferencesinagriculturaloperations,croppingpatterns,irrigationmanagement,andweatherconditions,206top-andsub-soilsamplesweretakenevery1to3kmfromrepresentativefarmsalonganorth-south(N-S)transectwith1to2kmlateralextents.Soilelectricalconductivityofsaturatedextract(EC_(se)),Ca,Mg,K,Na,Cl,andNaadsorptionratio(SAR)weredeterminedinsaturatedpasteextracts.Resultsindicatedthatabout63%ofsoilsintheJVareindeedsaline,outofwhichalmost46%aremoderatelytostronglysaline.AlongtheN-StransectoftheJV,EC_(se)increasedfrom4.5to14.1dSm~(-1)intop-soilsamples.Similarincreasewasobservedforthesub-soilsamples.Themajorchemicalcomponentsofsoilsalinity;i.e.,Ca,Mg,andCl,alsoshowedasimilarincreasealongtheN-Stransectofthevalley.Moreover,comparedtopreviousfieldsampling,resultsshowedthatchangesinsoilsalinityintheJVweredramatic.Inaddition,itwasfoundthatClimposedanexistingandpotentialthreattosensitivecropsin60%ofthesoilsintheJV,whereClconcentrationsweregreaterthan710mgL~(-1).UndertheprevalentaridMediterraneanconditions,improvingthemanagementofirrigationwater,crops,andnutrientinputsandincreasingwaterandfertilizeruseefficienciesshouldbeindispensabletoconserveandsustainthealreadyfragileagriculturalsoilsintheJV.
简介:Manyenvironmentproblemsofthefullusingofseveralcategoriesofprocessingincludemining,heatgenerators,directcombustionofforestfires,cementproduction,powerplant,transport,medicalwaste.Dioxin/furanreleasesfromthesecategoriesareoneoftheseenvironmentproblems.PossiblelinesofreducingthePCDD/PCDF(Polychlorinateddibenzo-para-dioxins/Polychlorinateddibenzofurans)releasesfromthesecategoriesareelucidated.Thecontributionofthispaperispresenttheidentificationandestimationofthelatestfigureofdioxin/furanreleasesintheclimateofenvironmentofJordanintheperiod2000-2008fromthefollowingcategories(cement,aluminum,ceramic,medicalwaste,powerplant,landfill,ferrousandnon-ferrousmetals,uncontrolledcombustionprocess(biomassburning,wasteburning,accidentalfiresinhouse,transport).ThesefindingshowsthesignofgrowthofestimatedPCDD/PCDFreleasesfromcategorieswhichdidnotcalculatedandfollowedafter2003.TheresultshowsthehighestPCDD/PCDFreleasefromlandfillfires(62.75gTEQ/year),medicalwaste(8.8264gTEQ/year),andtransport(3.0145gTEQ/year).Jordanseeksbynextyears,areductionintotalreleasesofdioxinsandfuransfromsourcesresultingfromhumanactivity.ThischallengewillapplytotheaggregateofreleasestotheairnationwideandofreleasestothewaterwithintheJordanarea.Jordanshouldconductairmonitoringfordioxininordertotrackfluctuationsinatmosphericdepositionlevels.
简介:设L是希尔伯特空间H上的一个CSL,AlgL是相应地CSL代数。一族线性映射δ={δn,δn:AlgL→AlgL,n∈N}在Ω∈AlgLJordan高阶可导,如果对所有n∈N,∑i+j=n[δi(A)δj(B)+δj(B)δi(A)]=δ(Ω),其中A,B∈AlgL,AB+BA=Ω。给出了一族线性映射δ={δn:AlgL→AlgL}在0点Jordan高阶可导的充要条件。利用此结果证明了不可约CDCSL代数,因子vonNeumann代数上的套子代数(特别地,希尔伯特空间套代数)到其自身的一族线性映射δ={δn,n∈N}在0点Jordan高阶可导当且仅当它是一个高阶导子。
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简介:探讨了交换半环上全矩阵代数的广义Jordan导子是否能退化成广义导子的问题.令R表示2-非挠的交换半环,证明了R上的全矩阵代数Mn(R)上的每个广义Jordan导子都是广义内导子,进而它也是一个广义导子.
简介:设L是希尔伯特空间H上的一个CSL,AlgL是相应地CSL代数。一族线性映射δ={δn,δn:AlgL→AlgL,n∈N}在Ω∈AlgLJordan高阶可导,如果对所有n∈N,∑i+j=n[δi(A)δj(B)+δj(B)δi(A)]=δ(Ω),其中A,B∈AlgL,AB+BA=Ω。给出了一族线性映射δ={δn:AlgL→AlgL}在0点Jordan高阶可导的充要条件。利用此结果证明了不可约CDCSL代数,因子vonNeumann代数上的套子代数(特别地,希尔伯特空间套代数)到其自身的一族线性映射δ={δn,n∈N}在0点Jordan高阶可导当且仅当它是一个高阶导子。更多还原
简介:导子对研究算子代数的结构起着重要的作用.文中引入了零点广义Jordan可导映射的概念,并通过对文[1方法的应用得到了如下主要结果:在vonNeumann代数中,范数连续的零点广义Jordan可导映射是内导子与一固定元与恒等映射乘积的和,并得出在Hilbert空间上的全体有界线性算子上的零点广义Jordan可导映射也有同样的结论.
简介:Inthisarticle,theauthorcharacterizesorthogonalpolynomialsonanarbi-trarysmoothJordancurvebyasemi-conjugatematrixboundaryvalueproblem,whichisdifferentfromtheRiemann-HilbertproblemsthatappearinthetheoryofRiemann-HilbertapproachtoasymptoticanalysisfororthogonalpolynomialsonarealintervalintroducedbyFokas,Its,andKitaevandontheunitcircleintroducedbyBaik,Deift,andJohansson.Theauthorhopesthattheircharacterizationmaybeappliedtoasymptoticanalysisforgeneralorthogonalpolynomialsbycombiningwithanewextensionofsteepestdescentmethodwhichwearelookingfor.
简介:本文提出了求矩阵A的Jordan标准形的另一方法:利用rank(λ(E-A)^P的结果,得出了对应于特征(λi的Jordan块的阶数和个数,然后求出矩阵A的Jordan标准形.
简介:探讨了交换半环上上三角矩阵代数的广义Jordan导子的刻画问题,证明了交换半环R上的上三角矩阵代数T_n(R)到T_n(R)-双模M的每个广义Jordan导子都可以分解成一个广义导子和一个反导子之和。