检索结果-南通市图书馆

Effects of clump spacing on nutrient distribution and root activity of Dendrocalamus strictus in the humid region of Kerala,peninsular India

引用

Journal of Forestry Research 2017年第6期28卷 1133-1144页

作者： b. H. Kittur K. sudhakara b. Mohan Kumar T. K. Kunhamu P. sureshkumar Department of silviculture and Agroforestry College of Forestry Kerala Agricultural UniversityVellanikkara Thrissur Kerala 680656 India school of Ecology and Environment studies Nalanda University Rajgir District Nalanda Bihar 803116 India Department of soil science and Agricultural Chemistry Radio-tracer Laboratory College of Horticulture Kerala Agricultural University Vellanikkara ThrissurKerala 680656 India

The humid agroclimatic conditions of Kerala,India permit the cultivation of an array of bamboo species of which Dendrocalamus strictus Roxb.(Nees.) is an important one on account of its high growth rate and multiple uses. stand density, a potential tool in controlling the productivity of woody ecosystems, its effect on growth and root distribution patterns may provide a better understanding of productivity optimization especially when bamboo-based intercropping options are *** attributes of 7-year-old bamboo(D. strictus) stands managed at variable spacing(4×4 m, 6×6 m, 8×8 m,10×10 m, 12×12 m) were studied. Functional root activity among bamboo clumps were also studied using a radio tracer soil injection method in which the radio isotopeP was applied to soil at varying depths and lateral distances from the clump. Results indicate that spacing exerts a profound influence on growth of bamboo. Widely spaced bamboo exhibited higher clump diameters and crown widths while clump heights were better under closer spacing. Clump height was 30% lower and DbH 52%higher at the widest spacing(12×12 m) compared to the closest spacing(4×4 m). With increasing soil depth and lateral distance, root activity decreased significantly. Root activity near the clump base was highest(809 counts per minute, cpm; 50 cm depth and 50 cm lateral distance) at 4×4 m. Tracer study further showed wider distribution of root activity with increase in clump spacing. It may be concluded that the intensive foraging zone of bamboo is within a 50-cm radius around the clump irrespective of spacing. N, P and K content in the upper 20 cm was 2197,21, and 203 kg/ha respectively for the closely spaced bamboo(4×4 m) which were significantly higher than corresponding nutrient content at wider spacings. About 50% of N, P and K were present within the 0–20 cm soil layer, which decreased drastically beyond the 20 cm *** results suggest that stand management practices through planting density regula

关键词： bamboo Clump spacing Functional root activity Radio tracer 32P soil nutrients

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

Diversity and structural composition of species in dipterocarp forests:a study from Fasiakhali Wildlife sanctuary, bangladesh

引用

Journal of Forestry Research 2018年第5期29卷 1241-1249页

作者： s.C.Das M.s.Alam M.A.Hossain Institute of Forestry and Environmental sciences University of Chittagong

Fasiakhali Wildlife sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）*** present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DbH ≥ 11 cm belonging to 24 genera and 19 *** forest is low in plant diversity as represented by shannon–Wiener diversity and simpson Dominance *** turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value *** firmum and Tectona grandis followed in terms of *** structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DbH and 16–20 m height ranges）,whereas *** was the only species that dominated most of the growth *** stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and *** study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of *** will also contribute to identifying threatened plants to undertake *** based conservation and sustainable management of the Fasiakhali Wildlife sanctuary.

关键词： species diversity structural composition Protected area Importance value index Cluster analysis

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

Growth and Characterization of Organic NLO Crystal:β-Naphthol

引用

Journal of Materials science & Technology 2011年第3期27卷 271-274页

作者： s.Janarthanan R.sugaraj samuel s.selvakumar Y.C.Rajan D.Jayaraman s.Pandi Department of Physics Presidency College Department of Chemistry Presidency College Department of Physics L.N.Govt.College Department of Material science Engineering National Chiao Tung University

single crystals of β-Naphthol （/3N）, an organic nonlinear optical （NLO） material was successfully grown by temperature lowering method using chloroform as solvent. The initial compound was purified by repeated recrystallization process. As-grown crystals were characterized by single crystal X-ray diffraction （XRD） studies to ascertain that βN crystal crystallized in the monoclinic system with a noncemtrosymmetric space group. Vibrational frequencies of various functional groups in the crystals were derived from Fourier transform infrared （FTIR） spectroscopy and proton nuclear magnetic resonance （NMR） spectrum. Optical characterization was done using UV-Visible near-infrared （NIR） spectroscopy. The thermal behaviour of the material was studied by thermo gravimetric and differential thermal plots. scanning electron microscopy （sEM） study was carried out on the surface of the grown crystals to investigate the nature of defects in the crystal surface and the NLO property of the crystal was tested by Nd：YAG laser as a source.

关键词： Crystal growth Fourier transform infrared (FTIR) spectroscopy Nonlinear optical crystal scanning electron microscopy (sEM)

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

On q-n-gonal Klein surfaces

引用

Acta Mathematica sinica,English series 2007年第10期23卷 1833-1844页

作者： b.EsTRADA R.A.HIDALGO E.MARTINEZ Departamento de Matemáticas Fundamentales UNEDPaseo Senda del Rey 928040 MadridSpain Departamento de Matemática Universidad Técnica Federico Santa MaríaCasilla 110-V ValparaisoChile

We consider proper Klein surfaces X of algebraic genus p ≥ 2, having an automorphism φ of prime order n with quotient space X/（φ） of algebraic genus q. These Klein surfaces axe called q-n-gonal surfaces and they are n-sheeted covers of surfaces of algebraic genus q. In this paper we extend the results of the already studied cases n ≤ 3 to this more general situation. Given p ≥ 2, we obtain, for each prime n, the （admissible） values q for which there exists a q-n-gonal surface of algebraic genus p. Furthermore, for each p and for each admissible q, it is possible to check all topological types of q-n-gonal surfaces with algebraic genus p. several examples are given： q-pentagonal surfaces and q-n-gonal bordered surfaces with topological genus g = 0, 1.

关键词： Klein surfaces Riemann surfaces automorphism groups non-Euclidean crystallographic groups

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

Microstructural Analysis of Ultrasonic Welded AA6061 by Electron backscattered Diffraction

引用

稀有金属材料与工程 2009年第A3期38卷 147-151页

作者： Zhu Z Wynne b P Ghassemieh E siddiq A Nanchang University Nanchang 330031 China University of sheffield Sheffield S1 3JD UK IMMPETUs Institute for Microstructural and Mechanical Process Engineering University of Sheffield Sheffield S 1 3JD UK

Ultrasonic welding can be used to join plastic and metal through high-frequency (more than 20 kHz) acoustic vibrations. Aluminium alloy is widely used in electronics, automotive and aerospace. The mechanical vibrations used during ultrasonic metal welding are introduced horizontally. During ultrasonic metal welding, a complex process is triggered involving static forces, oscillating shearing forces and a moderate temperature increase in the welding area. As the energy is introduced to the weld zone, there are three important phenomena occurring which are surface effect, volume effect and thermal effect. As it is known, microstructure is directly linked to the mechanical properties including fatigue resistance, fatigue life and fracture strength. so the microstructure analysis is important to evaluate the ultrasonically welded aluminium alloy’s properties. Also, mechanical properties of metal sheets, such as plastic anisotropy and formability, can be improved by a proper crystallographic texture control. That means the texture has great influence on the plastic anisotropy of the final recrystallized sheets. Optical microscopy (OM) can be used for showing the grain size and grain shape. However, to examine the relationship between mechanical behaviour and microstructure of the weldment, optical microscopy(OM) is not sufficient. OM cannot delineate a grain structure in the weld zone. The etched surface exhibited granularity at the micron level, but it was not clear if that reflected the grain structure. Electron backscatter diffraction (EbsD) in an sEM has become the most widely used technique for determination of microtexture. In this research, high-resolution electron backscatter diffraction is used to study the effects of the vibration on the evolution of microstructure in AA6061. The orientation image maps (OIM), polar figures (PF), and orientation distribution functions (ODF) of the samples are obtained. The characteristics of the crystallographic orientation, the

关键词：超声波焊接塑料复合材料抗疲劳强度

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

bF_3·OEt_2 Promoted solvent-free synthesis of benzimidazole Derivatives

引用

Chinese Chemical Letters 2006年第4期17卷 453-456页

作者： Rahul R.NAGAWADE Devanand b.sHINDE Division of Medicinal Chemistry-New Drug Discovery Wockhardt Research CentreAurangabad-431210 (M.S.)India Department of Chemical TechnologyDr.Babasaheb Ambedkar Marathwada UniversityAurangabad-431004 (M.S.)India Department of Chemical Technology Dr.Babasaheb Ambedkar Marathwada UniversityAurangabad-431004 (M.S.)India

Differently substituted benzimidazoles have been synthesized in very good yields in solvent-free conditions from o-phenylenediamine and aldehydes in the presence of bF3·OEt2 as a catalyst. The method is applicable to aromatic, unsaturated and aliphatic aldehydes and to substituted o-phenylenediamines without significant differences.

关键词： bF3·OEt2 aldehydes benzimidazoles solvent-free reactions drugs.

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

Forecasting macro parameters representing the behavior of an applied multi-agent system

引用

International Journal of Modeling, simulation, and scientific Computing 2018年第6期9卷 57-71页

作者： L.s.Kuravsky s.I.Popkov Faculty of Computer science Moscow state University of Psychology and Education Moscow Russia

Under consideration is the method of probabilistic forecasting of macro parameters representing general patterns of an applied multi-agent system *** system introduces the game interaction between a set of agents and a *** behavior dynamics of such a system is described by a discrete-state discrete-time Markov random process and represented in the terms,which are considered convenient for interpretation and practical control of macro *** corresponding calculations are based on common characteristics of the initial *** probabilistic model of behavior of the system is generalized for the case of the mobile target and supplemented with formulas for the dynamical calculation of probabilistic distributions of the target’s defeat by the agents as well as the agent’s defeat by the target.

关键词： Multi-agent systems group control Markov process behavior control for applied multi-agent systems.

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

One-pot three-component synthesis of α-amino nitriles catalyzed by nano powder TiO_2 P 25

引用

Chinese Chemical Letters 2011年第5期22卷 555-558页

作者： seyed Meysam baghbanian Maryam Farhang Robabeh b aharfar Chemistry Department Islamic Azad UniversityRasht BranchPole-taleshanPO Box 41325-3516RashtIran Department of Chemistry Mazandaran UniversityBabolsar 47415Iran

A simple and efficient method has been developed for the synthesis ofα-amino nitriles from aldehydes,amines and trimethylsilyl cyanide（Me_3siCN） in the presence of a catalytic amount of cyanuric acid at room temper... 详细信息

关键词： Nano powder TiO_2 P 25 α-Amino nitriles One-pot three-component synthesis strecker reaction Trimethylsilyl cyanide

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

Light meson spectrum and their leptonic decay widths in the frame work of constituent quark models

引用

Chinese Physics C 2010年第9期34卷 1396-1398页

作者： K.b.Vijaya Kumar Antony Prakash Monteiro Department of Physics Mangalore University

The phenomenological non-relativistic quark model has been employed to obtain the ground state masses of light vector mesons and their radially excited states and their decay *** full hamiltonian used in the investigation has kinetic energy,the confinement potential and the one-gluon-exchange potential.A good agreement is obtained with the experimental masses and their leptonic decay widths.

关键词： meson spectrum leptonic decay width constituent quark model OGEP

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

Entropy analysis of unsteady magneto-nanofluid flow past accelerating stretching sheet with convective boundary condition

引用

Applied Mathematics and Mechanics(English Edition) 2015年第12期36卷 1593-1610页

作者： s.DAs s.CHAKRAbORTY R.N.JANA O.D.MAKINDE Department of Mathematics University of Gour Banga Department of Applied Mathematics Vidyasagar University Faculty of Military science Stellenbosch University

The unsteady laminar magnetohydrodynamics （MHD） boundary layer flow and heat transfer of nanofluids over an accelerating convectively heated stretching sheet are numerically studied in the presence of a transverse magnetic field with heat source/sink The unsteady governing equations are solved by a shooting method with the Runge-Kutta- Fehlberg scheme. Three different types of water based nanofluids, containing copper, aluminium oxide, and titanium dioxide, are taken into consideration. The effects of the pertinent parameters on the fluid velocity, the temperature, the entropy generation num- ber, the bejan number, the shear stress, and the heat transfer rate at the sheet surface are graphically and quantitatively discussed in detail. A comparison of the entropy generation due to the heat transfer and the fluid friction is made with the help of the bejan number. It is observed that the presence of the metallic nanoparticles creates more entropy in the nanofluid flow than in the regular fluid flow.

关键词： unsteady MHD flow nanofluid heat source/sink entropy generation bejan number

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：