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数字图像处理技术在蔬菜叶面积测量中的应用

农业工程学报 2002年第4期18卷 155-158页

作者：杨劲峰陈清韩晓日李晓林 h.p.liebig 沈阳农业大学中国农业大学 hohenheimUniversity stuttgartd70593

采用平台扫描仪获取叶片的数字图像 ,建立运用数字图像处理技术测定蔬菜叶面积的方法。同时与目前较常用的交叉网格法、CID仪器法、复印称重法和生产上常用的直尺法进行比较分析。结果表明 :图像处理方法和上述传统的叶面积测定方法的... 详细信息

采用平台扫描仪获取叶片的数字图像 ,建立运用数字图像处理技术测定蔬菜叶面积的方法。同时与目前较常用的交叉网格法、CID仪器法、复印称重法和生产上常用的直尺法进行比较分析。结果表明 :图像处理方法和上述传统的叶面积测定方法的测定结果呈极显著的线性相关关系 ,适用于叶面积的测量工作 ;和其它方法相比具有准确、快速、适用范围广、容易普及等优点 ,适用于科研和生产推广使用。试验还得出采用直尺法时 ,油菜和空心菜的叶面积的校正系数分别为 0 .792和 0 .

关键词：数字图像处理技术蔬菜叶面积测量应用

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不同水氮管理对菠菜生长和水氮利用的影响

植物营养与肥料学报 2002年第1期8卷 48-53页

作者：张宏彦陈清汤丽玲李花粉李晓林 h.p.liebig 中国农业大学植物营养开放实验室北京100094 hohenheim大学蔬菜与果树科学研究所德国d70593

针对传统水肥方式中存在的投入过量问题 ,采用控制耕层土壤湿度以及应用KNS氮素推荐系统对菠菜的产量及水氮利用进行了研究。结果表明 ,推荐施氮处理与传统施氮处理对菠菜的生长没有明显的差异 ,而控制耕层土壤水分含量为植物有效的土... 详细信息

针对传统水肥方式中存在的投入过量问题 ,采用控制耕层土壤湿度以及应用KNS氮素推荐系统对菠菜的产量及水氮利用进行了研究。结果表明 ,推荐施氮处理与传统施氮处理对菠菜的生长没有明显的差异 ,而控制耕层土壤水分含量为植物有效的土壤含水量的 5 0 %～ 80 %及 6 0 %～ 90 %时的处理产量比传统灌水处理有显著性增加。推荐灌水施氮模式同传统灌水施氮模式相比 ,菠菜产量没有明显的差异 ,但是氮素以及水分供应量分别减少了 73.6 %和 39 2 % ,相应地水分利用效率提高 6 4% ,氮素利用效率也有显著提高。推荐的水氮处理在菠菜收获后土壤无机氮残留量比传统处理明显降低。因此在合理灌溉的基础上进行氮素推荐。

关键词：菠菜水分管理氮素管理利用效率 KNS氮素推荐方法生长

不同灌溉与施氮措施对露地菜田土壤无机氮残留的影响

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植物营养与肥料学报 2002年第3期8卷 282-287页

作者：汤丽玲陈清张宏彦张晓晟李晓林 h.p.liebig 农业部植物营养学重点开放实验室教育部植物土壤相互作用过程重点开放实验室中国农业大学植物营养系北京100094 hohenheim大学蔬菜研究所

在华北地区露地生产条件下 ,通过监测 5季轮作蔬菜 (苋菜 -菠菜 -花椰菜 -苋菜 -菠菜 )的产量和土壤无机N(Nmin)的变化 ,比较了传统的和采用平衡方法进行推荐的水分和N素处理对土壤Nmin残留数量的影响。结果表明 ,除花椰菜试验外 ,传统... 详细信息

在华北地区露地生产条件下 ,通过监测 5季轮作蔬菜 (苋菜 -菠菜 -花椰菜 -苋菜 -菠菜 )的产量和土壤无机N(Nmin)的变化 ,比较了传统的和采用平衡方法进行推荐的水分和N素处理对土壤Nmin残留数量的影响。结果表明 ,除花椰菜试验外 ,传统N素处理与推荐的N素处理在蔬菜产量上没有显著差异 ,但传统的N素处理皆可导致深层土体中Nmin的大量累积。在 4季蔬菜轮作后 ,传统灌溉措施条件下的N素处理都不同程度地造成了土体的N素淋失 ,所影响的土层深度已经达到了 15 0～ 180cm土层。

关键词：灌溉施氮措施露地菜田土壤无机氮残留水氮供应蔬菜轮作

Exploring one material for dual applications:A red-emitting Mg2GeO4:Eu3+ nanophosphor for future generation energy efficient WLEDs and dosimetric applications

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Journal of Rare Earths 2024年第10期42卷 1835-1845页

作者： Akshay Arjun G.p.Darshan S.C.Sharma h.Nagabhushana D.V.Sunitha h.B.premkumar Department of physics Faculty of Mathematical and Physical SciencesM.S.Ramaiah University of Applied Sciences Jain University C.N.R.Rao Centre for Advanced Materials Tumkur University School of Applied Sciences (physics) REVA University

The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly *** this in mind,a series of forsterite-structured Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was synthesized via a solution combustion method using oxalyl dihydrazide as a *** X-ray diffraction patterns confirm the orthorhombic crystal system with a puma space *** results clearly show irregularly shaped cluster-like structures with aggregation of the *** diffuse reflectance spectra,the optical energy band gap of the Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was estimated and obtained to be～4.12-4.32 *** photoluminescence emission spectra exhibit intense peaks at ～579,589,610,661,and 707 nm,which are due to characteristic5D0→7F0,5D0→7F1,5Do→7F2,5D0→7F3and5D0→7F4transitions of Eu3+ions,*** Commission International de L'Eclairage color coordinates are gradually tuned from pale red（0.5980,0.4012） to a pure red（0.6385,0.3611） *** glow peaks showcase excellent super-linear response at low doses of γ-irradiations,indicating that the prepared phosphor can be used in thermoluminescent personal dosimetry which is a biological tissue *** aforementioned results demonstrate that the prepared Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors are considered an excellent candidate for dual applications,i.e.,red component in future generation white-light-emitting diodes（WLEDs） and personal dosimetric applications.

关键词： Dosimetry Nanophosphors photoluminescence photometric properties Rare earths Thermoluminescence

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese physics B 2024年第2期33卷 108-114页

作者： U.S.Mahabaleshwar G.p.Vanitha L.M.pérez Emad h.Aly I.pop Department of Studies in Mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of Mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in h_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/h_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/h_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production

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Animal Nutrition 2024年第3期18卷 49-56页

作者： peter h.Selle Shemil p.Macelline Mehdi Toghyani Sonia Yun Liu poultry Research Foundation within the University of Sydney CamdenNSW 2570Australia Sydney School of Veterinary Science The University of SydneyCamdenNSW 2570Australia School of Life and Environmental Sciences Faculty of ScienceThe University of SydneyCamdenNSW 2570Australia

This review explores the potential of including glutamine,a so-called non-essential amino acid,in the formulation of reduced-crude protein(Cp)diets for broiler *** is a precedent for benefits when including glycine and serine in reduced-Cp *** this is due to decreases in non-essential amino acid concentrations in reduced-Cp diets—an unavoidable consequence of reducing Cp without amino acid *** situation for glutamine is complicated because analysed dietary concentrations are very rarely provided as standard assays do not differentiate between glutamine and glutamate and are reported on a combined basis as glutamic *** dietary requirement for glutamic acid is approximately 36.3 g/kg but it is increasingly unlikely that this requirement will be met as dietary Cp levels are progressively *** is an abundant and versatile amino acid and constitutes 50.5 mg/g of whole-body chicken protein and is the dominant free amino acid in systemic plasma where it has been shown to provide 22.6%(139.9 of 620.3μg/mL)of the total in birds offered 215 g/kg Cp,wheat-based *** addition to dietary intakes,glutamine biosynthesis is derived mainly from the condensation of glutamate and ammonia(Nh3)catalysed by glutamine synthetase,a reaction that is pivotal to Nh3 *** and Nh3 are converted to glutamine by phosphate-dependent glutaminase in the reciprocal reaction;thus,glutamine and glutamate are interchangeable amino ***,the rate of glutamine biosynthesis may not be adequate in rapidly growing broiler chickens and exogenous and endogenous glutamine levels are probably insufficient in birds offered reduced-Cp *** many functional roles of glutamine,including Nh3 detoxification and maintenance of acid-base homeostasis,then become *** feeding studies were identified where dietary glutamine supplementation,usually 10 g/kg,was evaluated in birds kept under thermoneutral ***

关键词： Broiler chicken Glutamate Glutamic acid Glutamine

Fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

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Matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.X.Wang X.L.Zhu S.M.Weng p.Li X.F.Li h.Ai h.R.pan Z.M.Sheng Key Laboratory for Laser plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser Fusion of China Academy of Engineering physics MianyangSichuan 621900China State key Laboratory of high Field Laser physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(Thz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or Thz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or Thz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and Thz spectral ranges.

关键词： laser ultrashort photon

Effect of radiative loss mechanisms on FIR thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

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Journal of Rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： C.Y.Morassuti A.p.L Silva L.A.O.Nunes S.M.Lima L.h.C.Andrade Optical and photothermal Spectroscopy Group(GEOF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil Renato Archer Information Technology Center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of physics of São Carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIR)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIR parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio Optical thermometry Judd-Ofelt Rare earths

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.huang K.Jiang C.N.Wu h.peng p.C.hen R.Li h.B.Zhuo C.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense