检索结果-南通市图书馆

seasonal Inhomogeneity of soot Particles over the Central Indo-Gangetic Plains,India:Influence of Meteorology

Journal of Meteorological Research 2015年第6期29卷 935-949页

作者： sINGH B.P. TIWARI s. HOPkE Philip k. sINGH R.s. BIsHT D.s. srivastava A.k. sINGH R.k. DUMkA U.C. sINGH A.k. RAI B.N. srivastava Manoj k. Department of Geophysics Banaras Hindu University Indian Institute of Tropical Meteorology(New Delhi Branch) Clarkson University Department of Chemical Engineering Banaras Hindu University Aryabhatta Research Institute of Observational sciences Department of Physics Banaras Hindu University

Black carbon（BC） particles play a unique and important role in earth’s climate *** was measured（in-situ） in the central part of the Indo-Gangetic Plains（IGP） at Varanasi,which is a highly populated and polluted region due to its topography and extensive emission *** annual mean BC mass concentration was 8.92 ± 7.0 μg m-3,with 34%of samples exceeding the average ***,BC was highest during the post-monsoon and winter periods（approximately 18 μg m-3） and lower in the premonsoon/monsoon seasons（approximately 6 μg m-3）.The highest frequency（approximately 46%） observed for BC mass was in the interval from 5 to 10 μg ***,during the post-monsoon season,the most common values（approximately 23%） were between 20 and 25 μg *** nighttime concentrations of BC were approximately twice as much as the daytime values because of lower boundary layer heights at *** Angstrom exponent was significantly positively correlated（0.55） with ground-level BC concentrations,indicating the impact of BC on the columnar aerosol *** estimated mean absorption Angstrom exponent was 1.02 ± 0.08 μg m-3,indicating that the major source of BC was from fossil fuel *** negative correlations between BC mass and meteorological parameters indicate a pronounced effect of atmospheric dynamics on the BC mass in this *** highest mean BC mass concentration（18.1 ± 6.9 μg m-3） as a function of wind speed was under calm wind conditions（38%of the time）.

关键词： black carbon Indo-Gangetic Plains absorption Angstr(o|¨)m exponent biomass fossil fuel

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Drillability prediction in some metamorphic rocks using composite penetration rate index(CPRI)–An approach

引用

International Journal of Mining science and Technology 2021年第4期31卷 631-641页

作者： Gaurav kumar srivastava M.s.R.Murthy Vemavarapu Department of Mining Engineering Indian Institute of Technology(Indian School of Mines)Dhanbad 826004India

Assessment of drillability of rocks is vital in the selection,operation,and performance evaluation of cutting tools used in various excavation machinery deployed in mining and *** commonly used rock drillability prediction methods,namely,drilling rate index(DRI)and Cerchar hardness index(CHI)have limitations in predicting the penetration rate due to differential wear of the cutting tool in rocks with varied hardness and *** cutting tools get blunt differently in different rocks,the stress beneath the tip of the bit decreases until it reaches a threshold value beyond which the penetration rate becomes *** this research,a new composite penetration rate index(CPRI)is suggested based on the investigations on four metamorphic rocks ***,gneiss,schist and phyllite with varied hardness-abrasivity *** penetration-time behavior was classified into active,moderate,passive,and dormant phases based on the reduction in penetration rate at different stages of drilling.A comparison of predicted penetration rate values using DRI and CPRI with actual penetration rate values clearly establishes the supremacy of ***-structure and hardness-based index was also developed and correlated with *** new indices can help predict cutting tool penetration and its consumption more accurately.

关键词： Abrasivity Hardness Drillability Metamorphic rocks Composite penetration rate index(CPRI)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nanostructural Features and Optical Performance of RF Magnetron sputtered ZnO Thin Films

引用

Journal of Materials science & Technology 2010年第11期26卷 986-990页

作者： A.k.srivastava Praveen M.Arora s.k.Gupta B.R.Chakraborty s.Chandra s.Toyoda H.Bahadur Natonal Physical Laboratory Council of Scientific and Industrial Research Indian Institute of Technology Okayama University of science

Zinc oxide （ZnO） thin films were grown on silicon substrate by RF （radio frequency） magnetron *** topography of these films exhibited a nanostructured granular appearance with the size of individual grains between 50 to 100 *** cross-sectional electron micrographs revealed columnar grains in the form of aggregated nanorods/wires with length of about 500 nm,similar to the thickness of these thin films of ZnO nucleated and grown vertically on the silicon *** resolution lattice scale imaging using high resolution transmission electron microscope （HRTEM） elucidated the single crystalline 1010 planes of hexagonal-ZnO constituting the columnar grains with the individual nanorod diameter between 3 and 4 *** photoluminescence measurements showed the prominent emission peak at around 460 nm for the blue band,normally attributed to intrinsic defects in particular interstitial zinc （Zn）.These films were further characterized by X-ray diffraction （XRD）,Fourier transform infrared spectroscopy （FTIR）,Raman spectroscopy and electron paramagnetic resonance （EPR） to evaluate various aspects on preferred growth orientations,band structures and vibrational modes originated in such fascinating nano-grained thin films of *** present investigations inferred that these films are advantageous in various potential applications for fabricating nano-scaled devices.

关键词： Electron microscopy Nanomaterials ZnO RF sputtering Photoluminescence spectroscopy Electron paramagnetic resonance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in the structural Composition of Biomass:Fundamental and Bioenergy Applications

引用

Journal of Renewable Materials 2021年第4期9卷 615-636页

作者： Neha srivastava Akshay shrivastav Rajeev singh Mohammed Abohashrh k.R.srivastava safia Irfan Manish srivastava P.k.Mishra Vijai kumar Gupta Vijay kumar Thakur Department of Chemical Engineering and Technology Indian Institute of Technology(BHU)Varanasi221005India Department of Chemical Engineering Madan Mohan Malaviya University of TechnologyGorakhpur273010India Department of Environmental studies Satyawati CollegeUniversity of DelhiDelhi110052India Department of Basic Medical sciences College of Applied Medical SciencesKing Khalid UniversityAbhaSaudi Arabia Departentof Biotechnology Faculty of BiosciencesIntegral UniversityLucknow226026India Biorefining and Advanced Materials Research Center Scotland’s Rural College(SRUC)EdinburghEH93JGUK

Increased environmental pollution due to the organic wastes over the world is one of the most burning *** organic wastes lie under the category of biodegradable waste and can be effectively degraded from their complex compound into simple one by the action of microbes or other living ***,lignocellulosic biomass is a major part of the biodegradable waste and belongs to the group of renewable energy source,which can be very effective for bioenergy *** are made up of different compounds such as cellulose,hemicelluloses,lignin and *** from these components,based on the structural analysis biomass also consist of bioactive substances such as carotenoids,flavonoids,lignin and *** review explores a complete overview of the classification,component and the structure of the ***,it discusses how biomasses can play the key role of substrate in many sectors such as industrial bioenergy production including gaseous and liquid biofuels.

关键词： Biomass classification composition bioactive substance biofuels

来源：

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

Role of activation energies of individual phases in two-phase range on constitutive equation of Zr-2.5Nb-0.5Cu alloy

引用

Transactions of Nonferrous Metals society of China 2017年第1期27卷 172-183页

作者： k.k.sAXENA s.k.JHA V.PANCHOLI G.P.CHAUDHARI D.srivastava G.k.DEY N.sAIBABA Department of Metallurgical and Materials Engineering Indian Institute of TechnologyRoorkee-247667UttarakhandIndia Nuclear Fuel Complex Limited Hyderabad-501301India Materials science Division Bhabha Atomic Research CenterMumbai-40085India Department of Mechanical Engineering Insitute of Engineering and TechnologyGLA UinversityMathura-281406Uttar PradeshIndia

Dominant phase during hot deformation in the two-phase region of Zr-2.5Nb-0.5Cu （ZNC） alloy was studied using activation energy calculation of individual phases. Thermo-mechanical compression tests were performed on a two-phase ZNC alloy in the temperature range of 700-925 ℃ and strain rate range of 10-2-10 s-l, Flow stress data of the single phase were extrapolated in the two-phase range to calculate flow stress data of individual phases. Activation energies of individual phases were then calculated using calculated flow stress data in the two-phase range, Comparison of activation energies revealed that a phase is the dominant phase （deformation controlling phase） in the two-phase range. Constitutive equations were also developed on the basis of the deformation temperature range （or according to phases present） using a sine-hyperbolic type constitutive equation. The statistical analysis revealed that the constitutive equation developed for a particular phase showed good agreement with the experimental results in terms of correlation coefficient （R） and average absolute relative error （AARE）.

关键词： Zr-2.5Nb-0.5Cu alloy hot deformation activation energy constitutive equation two-phase material

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Radiation Losses in the Microwave X Band in Al-Cr substituted Y-Type Hexaferrites

引用

Chinese Physics Letters 2017年第4期34卷 35-38页

作者： D.Basandrai R.k.Bedi A.Dhami J.sharma s.B.Narang k.Pubby A.k.srivastava Research scholar Department of Physics I. K. Gujral Punjab Technical University Jalandhar India Department of Physics Lovely Professional University Phagwara India principal Satyam Institute of Engineering & Technology Amritsar India Department of Electronic Technology Guru Nanak Dev University Amritsar India

We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 （x = 0, 0.5 and 1.0）. The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25dB （99.999% loss） at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.

关键词： Ba Al Radiation Losses in the Microwave X Band in Al-Cr substituted Y-Type Hexaferrites Cr

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mechanical properties and microstructural evolution of ultrafine grained zircaloy-4 processed through multiaxial forging at cryogenic temperature

引用

Transactions of Nonferrous Metals society of China 2015年第7期25卷 2221-2229页

作者： D.FULORIA s.GOEL R.JAYAGANTHAN D.srivastava G.k.DEY N.sAIBABA Department of Metallurgical and Materials Engineering Centre of Nanotechnology ⅡT Roorkee Materials science Division Bhabha Atomic Research Center Nuclear Fuel Complex Limited

The mechanical properties and microstructural evolution of zircaloy-4 subjected to cumulative strains of 1.48,2.96,4.44 and 5.91 through multiaxial forging（MAF） at cryogenic temperature（77 k） were *** mechanical properties of the MAF treated alloy were measured through universal tensile testing and Vickers hardness testing *** zircaloy-4 deformed up to a cumulative strain of 5.91 showed improvement in both ultimate tensile strength and hardness from 474 MPa to 717 MPa and from HV 190 to HV 238,respectively,as compared with the as-received ***,there was a noticeable decrement in ductility（from 18%to 3.5%） due to the low strain hardening ability of deformed *** improvement in strength and hardness of the deformed alloy is attributed to the grain size effect and higher dislocation density generated during multiaxial *** microstructural evolutions of deformed samples were characterized by optical microscopy and transmission electron microscopy（TEM）.The evolved microstructure at a cumulative strain of 5.91 obtained after MAF up to 12 cycles depicted the formation of ultrafine grains with an average size of 150-250 nm.

关键词： zircaloy-4 multiaxial forging cryogenic temperature ultrafine-grain microstructural evolution mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optical properties of amorphous thin film of se-Te-Ag system prepared by using thermal evaporation technique

引用

Progress in Natural science:Materials International 2011年第1期21卷 36-39页

作者： Madhu MIsHRA Rashmi CHAUHAN Anju kATIYAR k.k.srivastava Department of Physics Dayanand Braiendra Swarup D.B.S.(P.G.) CollegeKanpur(U.P.)India Department of Physics D.A-V.(P.G.) CollegeKanpur(U.P.)India Department of Physics Dayanand Brajendra Swarup D.B.S.(P.G.) CollegeKanpur(U.P.)India

Optical reflection and transmission spectra of se80-xTe20Agx(where x=0,5,10 and 15,molar percent) chalcogenide thin films have been obtained in the range 300-1 200 nm at room *** samples are prepared by melt quenching technique and thin films are obtained by using vacuum evaporation technique on glass transition at room *** present paper reports the effect of Ag contents on various optical parameters such as optical band gap,refractive index,extinction coefficient,absorption *** spectra are used for calculating these optical *** band gap Egis determined from the plot of (ahv)1/2versus *** and imaginary parts of the dielectric constant changes slightly with the variation of Ag contents in different *** film exhibits indirect band gap which increases with increasing Ag *** observed behavior is explained on the basis of Davis and Mott model for the density of *** absorption coefficient of thin films exhibits linear dependence on photon *** optical parameters are calculated by using theory of *** the optical parameters change with the variation of the film *** spectrophotometer JAsCO-UV/VIs/NIR is used to determine optical constants.

关键词： chalcogenide thin film band gap optical constant

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Analyzing Parabolic Profile Path for Underwater Towed-Cable

引用

Journal of Marine science and Application 2014年第2期13卷 185-192页

作者： Vineet k. srivastava IsRO Telemetry Tracking and Command Network (ISTRAC) Bangalore 560058 India

This article discusses the dynamic state analysis of underwater towed-cable when tow-ship changes its speed in a direction making parabolic profile path. A three-dimensional model of underwater towed system is studied. The established governing equations for the system have been solved using the central implicit finite-difference method. The obtained difference non-linear coupled equations are solved by Newton＇s method and satisfactory results were achieved. The solution of this problem has practical importance in the estimation of dynamic loading and motion, and hence it is directly applicable to the enhancement of safety and the effectiveness of the offshore activities.

关键词： underwater towed-cable underwater towed system parabolic profile central implicit finite-difference method Newton's method offshore activities

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A NEW INTEGRAL TRANsFORM AND ITs APPLICATIONs

引用

Acta Mathematica scientia 2015年第6期35卷 1386-1400页

作者： H.M.srivastava 罗旻杰 R.k.RAINA Department of Mathematics and statistics University of Victoria Department of Mathematics East China Normal University Department of Mathematics M.P.University of Agriculture and Technology

In the present paper, the authors introduce a new integral transform which yields a number of potentially useful （known or new） integral transfoms as its special cases. Many fundamental results about this new integral transform, which are established in this paper, in- clude （for example） existence theorem, Parseval-type relationship and inversion formula. The relationship between the new integral transform with the H-function and the H-transform are characterized by means of some integral identities. The introduced transform is also used to find solution to a certain differential equation. some illustrative examples are also given.

关键词： Laplace transform sumudu transform natural transform H-function H- transform inversion formula Parseval-type relationship existence theorem Borel-Dzrbashjan transform Fubini's theorem Weierstrass's test Heaviside generalized function

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：