检索结果-南通市图书馆

Higher-order approximate solutions of fractional stochastic point kinetics equations in nuclear reactor dynamics

在线全文

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2019年第3期30卷 114-126页

作者： s.singh s.saha Ray Department of Mathematics National Institute of Technology Rourkela

stochastic point kinetics equations(sPKEs) are a system of Ito? stochastic differential equations whose solution has been obtained by higher-order *** this study, a fractional model of sPKEs has been analyzed. The efficiency of the proposed higher-order approximation scheme has been discussed in the results section. The solutions of sPKEs in the presence of Newtonian temperature feedback have also been provided to further discuss the physical behavior of the fractional model.

关键词： Fractional stochastic point reactor kinetics equations Fractional calculus Higher-order approximation Caputo derivative Neutron population

Finite deformation analysis of crack tip fields in plastically compressible hardening–softening–hardening solids

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica sinica 2017年第1期33卷 148-158页

作者： D.Khan s.singh A.Needleman Mechanical Engineering Department Indian Institute of Technology Banaras Hindu University Department of Materials science & Engineering Texas A&M University College Station

Crack tip fields are calculated under plane strain small scale yielding conditions. The material is characterized by a finite strain elastic-viscoplastic constitutive relation with various hardening-softening-hardening hardness functions. Both plastically compressible and plastically incompressible solids are considered. Displacements corresponding to the isotropic linear elastic mode I crack field are prescribed on a remote boundary. The initial crack is taken to be a semi-circular notch and symmetry about the crack plane is imposed. Plastic compressibility is found to give an increased crack opening displacement for a given value of the applied loading. The plastic zone size and shape are found to depend on the plastic compressibility, but not much on whether material softening occurs near the crack tip. On the other hand, the near crack tip stress and deformation fields depend sensitively on whether or not material softening occurs. The combination of plastic compressibility and softening (or softening-hardening) has a particularly strong effect on the near crack tip stress and deformation fields.

关键词： Plasticity Crack tip fields Fracture Compressible solids Material softening

Copper-Induced Changes in the Urea Uptake and Urease Activity in the Cyanobacteria Anabaena doliolum and Anacystis nidulans:Interaction With sulphur Containing Amino Acids

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 1995年第2期8卷 158-163页

作者： s.singh B.B.singh 等 DepartmentofMicrobiology NorthMaharashtraUniversityJalgaon－425001India DepartmentofMicrobiology Nor

Copper-induced changes in the urea uptake and urease activity have been investigated in the cyanobacteria Anabaena doliolum and Anacystis nidulans. Copper, at and above 5 μmol/L concentration, inhibited urea uptake and urease activity systems in both the cyanobacteria in a concentration dependent manner. However, the urea uptake and urease activity systems in A. nidulans appeared slightly more tolerant to copper than that of ***. The inhibitory effect of copper on urea uptake and urease activity was mitigated by sulphur containing amino acids (cystine and cysteine), however, methionine could not do so, indicating the involvement of sulfhydryl (-sH) groups in the assimilation of urea in cyanobacteria

关键词： Activity HEPEs Copper-Induced Changes in the Urea Uptake and Urease Activity in the Cyanobacteria Anabaena doliolum and Anacystis nidulans

Influence of Vitamin E on Preventive or Therapeutic Effect of MFA and DTPA in Cadmium Toxicity

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 1995年第1期8卷 59-64页

作者： s.K.TANDON s.singh IndustrialToxicologyResearchCentre PostBoxNo.80MahatmaGnadhiMargLucknow226001India IndustrialToxic

The influence of vitamin E supplementation on the ability of α-mercapto-β(2-furyl)acrylic acid (MFA) or calcium trisodium dicthylenetriamine pentaacetate (DTPA) to reduce body burden of cadmium and reverse Cd-induced biochemical alterations was investigated in Cd-exposed rats. The treatment with MFA-vitamin E or CaNa3 DTPAvitandn E was more effective than either vitamin E or chelating agent alone, in depleting blood and tissue Cd. However, the combined treatment showed only limited advantage over the individuals in restoring Cd-induced biochemical changes. Further, the treatment with chelator-vitamin E concomitantly with the exposure to Cd was more effective than post-Cd exposure treatment.

关键词： DTPA MFA

Renal Toxicity of Nickel,sodium Lauryl sulphate and Their Combination after Dermal Application in Guinea Pigs

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 1993年第3期6卷 231-236页

作者： A.K.MATHUR B.N.GUPTA A.singh s.singh RAVIsHANKER Industrial IndustrialIndustrialIndustrialIndustrial Toxicology Research CentreP.B.No80Mahatoma Gandhi MargLucknow-226001IndiaToxicology Research CentreP.B.No80Mahatoma Gandhi MargLucknow-226001IndiaToxicology Research CentreP.B.No80Mahatoma Gandhi MargLucknow-226001IndiaToxicology Research CentreP.B.No80Mahatoma Gandhi MargLucknow-226001IndiaToxicology Research CentreP.B.No80Mahatoma Gandhi MargLucknow-226001India

The guinea pigs were dermally exposed to nickel (Ni), sodium lauryl sulphate (sLs) and in their combination for 7 and 14 days. The exposure to Ni and sLs produced changes in enzymes and lipid peroxidation in kidney. The exposure to Ni or sLs depicted slight changes while combined exposure to Ni plus sLs exhibited more degenerative changes in kidney. The result of the study suggests that industrial workers and/or populations exposed simultaneously to Ni and sLs produces more damage to kidney.

关键词： sLs Ni Renal Toxicity of Nickel,sodium Lauryl sulphate and Their Combination after Dermal Application in Guinea Pigs

Dermal Toxicity of Paraphenylenediamine

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 1992年第4期5卷 321-324页

作者： A.K.MATHUR B.N.GUPTA s.singh A.singh s.NARANG Industrial Toxicology Research Centre P.B. 80 Mahatama Gandhi MargIndustrial Toxicology Research Centre P.B. 80 Mahatama Gandhi MargIndustrial Toxicology Research Centre P.B. 80 Mahatama Gandhi MargIndustrial Toxicology Research Centre P.B. 80 Mahatama Gandhi MargIndustrial Toxicology Research Centre P.B. 80 Mahatama Gandhi Marg Lucknow 226001 IndiaLucknow 226001 IndiaLucknow 226001 IndiaLucknow 226001 IndiaLucknow 226001 India

The guinea pigs were dermally exposed to paraphenylenediamine (PPD) and in presence of an oxidising agent hydrogen peroxide for 15 and 30 d to assess their effects on some enzymes, lipid peroxidation and histamine contents in the skin. The activities of acid and alkaline phosphatases, β-glucuronidase, gamma glutamyl transpeptidase, histidase and tyrosinase were enhanced after application of either PPD or PPD plus hydrogen peroxide. The lipid peroxidation and histamine contents also showed marked elevation following exposure to the chemicals.

关键词： PPD Dermal Toxicity of Paraphenylenediamine

Computational simulations of near-continuum gas flow using Navier-stokes-Fourier equations with slip and jump conditions based on the modal discontinuous Galerkin method

在线全文

学校读者我要写书评

暂无评论

Advances in Aerodynamics 2020年第1期2卷 145-181页

作者： T.Chourushi A.Rahimi s.singh R.s.Myong school of Mechanical and Aerospace Engineering and ACTRC&ReCAPT Gyeongsang National UniversityJinjuGyeongnam 52828South Korea school of Physical and Mathematical sciences Nanyang Technological University21 Nanyang LinkSingapore 637371Singapore

Blunt-body configurations are the most common geometries adopted for non-lifting re-entry *** re-entry vehicles experience different flow regimes during flight due to drastic changes in atmospheric *** conventional Navier-stokes-Fourier equations with no-slip and no-jump boundary conditions may not provide accurate information regarding the aerothermodynamic properties of blunt-bodies in flow regimes away from the *** addition,direct simulation Monte Carlo method requires significant computational resources to analyze the near-continuum flow *** overcome these shortcomings,the Navier-stokes-Fourier equations with slip and jump conditions were numerically solved.A mixed-type modal discontinuous Galerkin method was employed to achieve the appropriate numerical *** computational simulations were conducted for different blunt-body configurations with varying freestream Mach and Knudsen *** results show that the drag coefficient decreases with an increased Mach number,while the heat flux coefficient *** the other hand,both the drag and heat flux coefficients increase with a larger Knudsen ***,for an Apollo-like blunt-body configuration,as the flow enters into non-continuum regimes,there are considerable losses in the lift-to-drag ratio and stability.

关键词： Near-continuum flow Discontinuous Galerkin method slip and jump conditions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

黑麦性状在小麦遗传背景下的表达

国外农学（麦类作物） 1993年第2期 8-11页

作者： s.singh 吕颖

利用一个可自交的、纯合矮秆黑麦品种与小麦杂交,研究了17个黑麦性状在24个普通小麦×黑麦和8个硬粒小麦×黑麦杂交种中的表达情况。在所有的杂交种中,黑麦花梗上的茸毛性状表现都很明显。在硬粒小麦×黑麦的杂交种中,叶片呈深绿色的性... 详细信息

利用一个可自交的、纯合矮秆黑麦品种与小麦杂交,研究了17个黑麦性状在24个普通小麦×黑麦和8个硬粒小麦×黑麦杂交种中的表达情况。在所有的杂交种中,黑麦花梗上的茸毛性状表现都很明显。在硬粒小麦×黑麦的杂交种中,叶片呈深绿色的性状与黑麦相似,而这一性状在普通小麦×黑麦的杂种中只是部分地表达。黑麦的叶耳不具茸毛,在多数硬粒小麦×黑麦的杂交中也没有;但是,在普通小麦×黑麦的杂种中则不然。由此表明,这些性状的有无常常受小麦D染色体组的控制,而不是由A或B染色体组控制。多数蛋白质含量较低的杂种,其叶鞘上具有很厚的粉霜,基部没有未发育小穗,这些特征与黑麦相似。同样,绝大多数双单倍体的子叶鞘、茎和茎节的花色素也与黑麦的相似。小麦中,存在着由A或B染色体组控制的一些限制因子,表明有些小麦基因型表达了黑麦性状,例如很厚的蜡被、茎节上的花色素以及基部没有未发育小穗。杂种颖片中脉上的刚毛密度和长度提高,可能是因为小麦与黑麦相互作用的结果。如同黑麦一样,小花和小穗数减少,说明在不同的小麦遗传背景下其特性表达程度不同。部分黑麦基因的表达可能还受着黑麦基因与小麦细胞质互作或与环境互作的影响。

关键词：黑麦小麦杂交育种遗传

Ultraviolet ZnO Photodetectors with High Gain

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic science and Technology of China 2010年第1期8卷 55-59页

作者： Ghusoon M.Ali s.singh P.Chakrabarti Centre for Research in Microelectronics Department of Electronics EngineeringInstitute of TechnologyBanaras Hindu UniversityVaranasi-221005India

Fabrication and characterization of metal-semiconductor-metal ultraviolet （MsM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd schottky contact are reported. The ZnO thin film was grown on glass substrate by thermal oxidation of preeposited zinc films using vacuum deposition technique. With applied voltage in the range from -3V to 3V, the contrast ratio, responsivity, and detectivity for an incident radiation of 0.1 mW at 365 nm wavelength were estimated. The proposed device exhibited a high gain which was attributed to the hole trapping at semiconductor-metal interface. I-V characteristics were studied and the parameters, such as ideality factor, leakage current, resistance-areaproduct, and barrier height, were extracted from the measured data.

关键词： Metal-semiconductor-metal (MsM),schottky contacts ultraviolet (UV) detector zinc oxide(ZnO).