检索结果-南通市图书馆

Impact of water scarcity on spruce and beech forests

Journal of Forestry Research 2019年第3期30卷 899-909页

作者： Lenka Krupkova Katerina Havrankova Jan Krejza Pavel Sedlak Michal v.Marek Global Change Research Institute Czech Academy of SciencesBelidla 986/4a60300 BrnoCzech Republic Institute of Atmospheric Physics Czech Academy of SciencesBocni II 140114131 PragueCzech Republic

One of the greatest threats posed by ongoing climate change may be regarded the drought caused by changes in precipitation distribution. The aim of presented study was to characterize reactions to dry conditions and conditions without drought stress on gross primary production (GPP) and net ecosystem production (NEP) of spruce and beech forests, as these two species dominate within the European continent. daily courses of GPP and NEP of these two species were evaluated in relation to an expected decrease in CO2 uptake during dry days. The occurrence of CO2 uptake hysteresis in daily production was also investigated. Our study was performed at Bily Kriz(spruce) and Stitna(beech) mountain forest sites during 2010–2012 period. We applied eddy covariance technique for the estimation of carbon fluxes, vapor pressure deficit and precipitation characteristics together with the SoilClim model for the determination of drought conditions, and the inverse of the Penman–Monteith equation to compute canopy conductance. Significant differences were found in response to reduced water supply for both species. Spruce reacts by closing its stomata before noon and maintaining a reduced photosynthetic activity for the rest of the day, while beech keeps its stomata open as long as possible and slightly reduces photosynthetic activity evenly throughout the entire day. In the spruce forest, we found substantial hysteresis in the light response curve of GPP. In the beech forest, the shape of this curve was different: evening values exceeded morning values.

关键词： Picea abies Fagus sylvatica drought stress Hysteresis Eddy covariance

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

dielectric studies of binary mixtures of ethylene glycol mono phenyl ether with 1-butanol at different temperatures

引用

Journal of Advanced dielectrics 2017年第4期7卷 10-16页

作者： H.A.Chaube v.A.Rana department of Physics School of Sciences Gujarat UniversityAhmedabad 380009 GujaratIndia

Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 and 323.15 K)have been *** the experimental data,parameters such as excess static permittivity(ε^(E)),excess permittivity at optical frequency(ε^(E)_(∞)),effective Kirkwood correlation factor(g^(eff)),corrective Kirkwood correlation factor(g^(f))and Bruggeman factor(f^(b))have been calculated to obtain qualitative and quantitative information about the complex formation through H-bond in binary *** order to predict the static permittivity of polar–polar binary mixtures six mixing rules were applied and for refractive index five mixing rule were *** results of permittivity(ε)and refractive index(n)are compared with those obtained from theoretical *** parameters were fitted to the Redlich–Kister type polynomial equation.

关键词： Static permittivity refractive index Kirkwood correlation factor permittivity models refractive index models Redlich-Kister equation

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

Biological protection of plants in agricultular landscape—state of the art, problems and ways of their decision

引用

浙江大学学报（农业与生命科学版） 2004年第4期30卷 398-400页

作者： Sokolov M S Kolombet L v Research Center for Toxicology and Hygienic Regulation of Biopreparations State Research Center for Applied Microbiology 142279 Obolensk Moscow Region Russia 142253 Serpukhov Moscow reg. Russia

Biological protection of plants: definition and objectives. Technologically, biological protection of plants (hereinafter bioprotection) is a high agricultural technology involving agricultural landscape approach and basee on an ecological imperative, namely “use living beings against living beings”. In a wide sense, present-day bioprotection is a fundamental and applied field of knowledge providing harmless suppression of harmful agents during cultivation and storage of agricultural crops by use natural and (or) artificially constructed organisms (including genetically modified ones having pesticidal properties) and products of their live cycle. The overall objective of bioprotection consists in producing harmless, profitable and high-quality vegetative raw material, food, fodder. At the same time, bioprotection agrotechnologies are important environment forming and environment maintaining factors, steady and positively influencing the health of both rural ethnos, and agrosphere as a whole. Realization of integrated bioprotection approaches should provide minimum destruction of beneficial and non-target organisms, excluding the succession of harmful species and appearance of species resistant to biocontrol agents. 2. Theoretical foundation of bioprotection. The following postulates and imperatives of biosphere science, agrarian and social ecology make the scientific basis of bioprotection: “The Nature knows the how and why of things better”; Steady, balanced development of agrosphere (proceeding from a presumption of life support) is based on biocentrism and biosystem relations, or consortism of its consorbents; Control of the agrosphere by human beings could be effective only in case of primary realization of biocenotic regulation; Biocenotic regulation, dynamics of the number and species diversity of agrosphere is realized through trophically similar cenoconsorcia and tritrophic systems, that provides maintenance and preservation of trophically proved critica

关键词：植物生物保护农业景观农业气候设施园艺

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

Analysis of Internal Cooling Geometry variations in Gas Turbine Blades

引用

Journal of Thermal Science 2009年第4期18卷 289-293页

作者： M.Eifel v.Caspary H.Hnen P.Jeschke Institute of Jet Propulsion and Turbomachinery RWTH Aachen University MAN Turbo AG

The present investigation analyzes the effects of major geometrical modifications to the interior of a convectioncooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on theheat transfer. An experimental approach is performed with flow visualization via paint injection into water. Alsonumerical calculations are carried out in two sets, on the one hand water calculations accompanying the experimentsand on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculationsare still ongoing delivering preliminary *** geometry configurations are investigated, three of them with differing turbulator arrangements in the leadingedge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modifiedgeometries the pressure ratio is held constant compared to the *** several investigated configurations one could be identified that leads to a heat transfer enhancement inone leading edge channel 7 % larger compared to the base.

关键词：燃气涡轮叶片几何配置内部冷却变化分析涡轮转子叶片流通渠道数值计算强化传热

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

Identifying the optimal HvOF spray parameters to attain minimum porosity and maximum hardness in iron based amorphous metallic coatings

引用

defence Technology（防务技术） 2017年第2期13卷 101-110页

作者： S.vignesh K.Shanmugam v.Balasubramanian K.Sridhar Centre for Materials Joining and Research (CEMAJOR) Department of Manufacturing Engineering Annamalai University Annamalai Nagar 608 002 Tamil Nadu India Protective Technologies department Naval Materials Research Laboratory (NMRL) Ambernath Thane (Dist) Maharashtra India

Flow based Erosion e corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosionecorrosion damage in the above components, iron based amorphous coatings are considered to be more effective to combat erosionecorrosion problems. High velocity oxy-fuel(HvOF)spray process is considered to be a better process to coat the iron based amorphous powders. In this investigation, iron based amorphous metallic coating was developed on 316 stainless steel substrate using HvOF spray technique. Empirical relationships were developed to predict the porosity and micro hardness of iron based amorphous coating incorporating HvOF spray parameters such as oxygen flow rate, fuel flow rate, powder feed rate, carrier gas flow rate, and spray distance. Response surface methodology(RSM) was used to identify the optimal HvOF spray parameters to attain coating with minimum porosity and maximum hardness.

关键词： High velocity oxy fuel spray Iron based amorphous metallic coating Micro-hardness Porosity

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 Prime Spectrum of Maximal Subgroups in Finite Groups

引用

Algebra Colloquium 2018年第4期25卷 579-584页

作者： Chi Zhang Wenbin Guo Natalia v.Maslova danila O.Revin department of Mathematics University of Science and Technology of ChinaHefei 230026China Krasovskii Institute of Mathematics and Mechanics UB RAS and Ural Federal University Yekaterinburg 620990Russia Sobolev Institute of Mathematics SB RAS and Novosibirsk State University Novosibirsk 630090Russia

For a positive integer n,we denote byπ(n)the set of all prime divisors of *** a finite group G,the setπ(G):=π(|G|)is called the prime spectrum of *** M 详细信息

For a positive integer n,we denote byπ(n)the set of all prime divisors of *** a finite group G,the setπ(G):=π(|G|)is called the prime spectrum of *** Md k(G)=min{|π(G)\π(M)|:Md k(G)are unbounded in *** implies that the problem"Are k(G)and K(G)bounded by some constant k?",raised by Monakhov and Skiba in 2016,is solved in the negative.

关键词： finite group finite simple group prime spectrum maximal subgroup

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

花生的抗锈性成分研究

引用

中国油料 1990年第3期12卷 9-13页

作者：廖伯寿 F.Waliyar P.v.SubbaRao d.Mcdonald 中国农科院油料作物研究所国际半干旱所-ICRISAT

本项研究用温室整株接种和实验室离体生根叶片接种的方法对一些新鉴定出的花生抗锈种质材料的8个抗锈性成分进行观察。结果表明这些花生种质材料在抗锈性成分上存在较大的变异。多数抗性成分在高抗材料或低抗(感病)材料之间是整齐一致的... 详细信息

本项研究用温室整株接种和实验室离体生根叶片接种的方法对一些新鉴定出的花生抗锈种质材料的8个抗锈性成分进行观察。结果表明这些花生种质材料在抗锈性成分上存在较大的变异。多数抗性成分在高抗材料或低抗(感病)材料之间是整齐一致的,而且与田间锈病级数高度吻合,但抗性成分在中抗材料之间有较大的变异。本文对栽培花生与种间杂种衍生材料在抗锈性成分上的差异也作了分析。所有抗性成分的广义遗传力均较高,具有遗传改良的潜力。

关键词：花生抗性成分锈病

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

Genotypic variation for seed protein and mineral content among post-rainy season-grown sorghum genotypes

引用

The Crop Journal 2016年第1期4卷 61-67页

作者： Ashok Badigannavar G.Girish v.Ramachandran T.R.Ganapathi Nuclear Agriculture and Biotechnology division Bhabha Atomic Research Centre Agricultural Research Station University of Agriculture SciencesGulbarga

Sorghum is an important staple food crop of Asian and African *** a poor man s crop",it provides dietary starch,protein,and some vitamins and *** are important for various physiological functions in the human *** a major staple crop of central and southern Indian provinces,sorghum landraces are a source of supplementary *** of micronutrients and protein and yield parameters were studied using 112 local landraces and *** analysis revealed wide variation for iron(1.10-9.54 mg 100 g^(-1)),zinc(1.12-7.58 mg 100 g^(-1)),protein(3.50-12.60%),and grain yield(2.50-76.50 g) among the *** estimates of genetic/phenotypic coefficient of variation,and genetic advances over the mean were identified for landraces and *** heritabilities were also identified for yield and mineral *** estimates among the genotypes indicated that grain yield was positively correlated with copper and protein with copper and *** analysis based on Euclidean distance resolved all of the genotypes into three major *** wide range of values with high heritability estimates may favor the use of these landraces in recombination breeding to improve nutritional quality in sorghum.

关键词： Mineral content Post-rainy sorghum Genetic correlation 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

Frailty:Past,present,and future?

引用

Sports Medicine and Health Science 2021年第1期3卷 1-10页

作者： dongmin Kwak Ladora v.Thompson division of Sport Science Hanyang UniversityAnsanSouth Korea department of Physical Therapy and Athletic Training Boston UniversityBostonMAUSA

The prevalence of frailty across the world in older adults is increasing dramatically and having frailty places a person at increased risk for many adverse health outcomes,including impaired mobility,falls,hospitalizations,and ***,the concept of frailty is gaining attention and the scientific field has made great strides in identifying and conceptually defining frailty through consensus conferences,in advancing the overall science of frailty by drawing on basic science discoveries including concepts surrounding the hallmarks of aging,resilience,and intrinsic capacities,and in identifying the many challenges faced by professionals within diverse clinical ***,it is thought that frailty is preventable,thus the identification of a person's degree of frailty is *** of frailty is achievable through widely used frailty screening tools,which are valid,reliable,and easy to *** the identification of a person's degree of frailty,targeted intervention strategies,such as physical activity programs must be *** this perspective,we provide a historical perspective of the frailty field since the last quarter of the 20th century to *** identify the proposed underlying patho-physiology of multiple physiological systems,including compromised homeostasis and ***,we outline the available screening tools for frailty with a physical performance assessment and highlight specific benefits of physical ***,we discuss current scientific evidence supporting the physical activity rec-ommendations for the aging population and for older adults with *** goal is to emphasize early detection of frailty and stress the value of physical activity.

关键词： Frailty phenotype Intrinsic capacity Physical activity guidelines Multicomponent physical activity programs 2018 PAGAC Scientific Report

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

A word about the teacher

引用

Research in Astronomy and Astrophysics 2019年第3期19卷 35-46页

作者： Galina N.dryomova Olga v.Eretnova Tatyana S.Polushina Russian Federal Nuclear Centre named after academician E.I.Zababakhin Chelyabinsk State University Ural Federal University named after the First President of Russia B.N.Yeltsin

This is a memorial report on the biography and scientific heritage of M.A. Svechnikov — an outstanding scientist and teacher, the founder of the Ural school of close binary stars and the author of the classification ... 详细信息

关键词： catalogs photometric-spectroscopic-stars eclipsing variables classification scheme-close binary stars

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：