检索结果-南通市图书馆

环太平洋特大干旱导致公元1644年明朝首都的陷落（英文）

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

science bulletin 2024年第19期 3106-3114页

作者：陈峰王涛赵晓恩 Jan Esper Fredrik charpentier Ljungqvist Ulf büntgen hans W.Linderholm David Meko 许红娜岳伟鹏王世杰袁玉江郑景云潘威 Fidel Roig Martín Ha.a. 胡茂魏家昌陈发虎 Yunnan Key Laboratory of International Rivers and Transboundary Eco-security Institute of International Rivers and Eco-Security Yunnan University southwest United Graduate school Regional climate Group Department of Earth Sciences University of Gothenburg climate change Research center and Nansen-Zhu International Research centre Institute of Atmospheric Physics Chinese Academy of Sciences Department of Geography Johannes Gutenberg University Global change Research Institute (czech Globe) Czech Academy of Sciences Department of History Stockholm University bolin centre for climate Research Stockholm University swedish collegium for Advanced study Linneanum Department of Geography University of Cambridge Department of Geography Faculty of Science Masaryk University swiss Federal Research Institute (WsL) Laboratory of Tree-Ring Research University of Arizona collaborative Innovation center on Forecast and Evaluation of Meteorological Disasters (cIc FEMD) Nanjing University of Information Science and Technology Key Laboratory of Tree-ring Physical and chemical Research Institute of Desert Meteorology China Meteorological Administration Key Laboratory of Land surface Pattern and simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Key Laboratory of Digital Human Technology R&D and Application of Yunnan Provincial Department of Education Yunnan University Laboratorio de Dendrocronología e Historia.a.biental IANIGLA-CCT CONICET-Universidad Nacional de Cuyo Hémera centro de Observación de La Tierra Escuela de Ingeniería Forestal Facultad de Ciencias Universidad Mayor Laboratorio de Dendrocronología de Zonas áridas cIGEObIO (cONIcET-UNsJ) Gabinete de Geología Ambiental (INGEO-UNSJ) ALPha State Key Laboratory of Tibetan Plateau Earth System Environment and Resources (TPESER) Institute of Tibetan Plateau Research Chinese Academy of Sciences college of Resources and Environment University of Chinese Academy of Sciences MOE Key Laboratory of We

Historical documents provide evidence for regional droughts preceding the political turmoil and fall of beijing in 1644 cE, when more than 20 million people died in northern china during the late Ming famine period. However, the role climate and environmental changes may have played in this pivotal event in chinese history remains unclear. Here, we provide tree-ring evidence of persistent megadroughts from1576 to 1593 cE and from 1628 to 1644 cE in northern china, which coincided with exceptionally cold summers just before the fall of beijing. Our a.a.ysis reveals that these regional hydroclimatic extremes are part of a series of megadroughts along the Pacific Rim, which not only impacted the ecology and society of monsoonal northern china, but likely also exacerbated external geopolitical and economic pressures. This finding is corroborated by last millennium rea.a.ysis da.a.and numerical climate model simulations revealing internally driven Pacific sea surface temperature variations and the predominance of deca.a. scale La Ni?a-like conditions to be responsible for precipitation decreases over northern china.a. well as extensive monsoon regions in the Americas. These teleconnection patterns provide a mechanistic expla.a.ion for reoccurring drought spells during the late Ming Dynasty and the environmental framework fostering the fall of beijing in 1644 cE, and the subsequent demise of the Ming Dynasty.

关键词：

Interactions Ticks, Hosts and Pastures： case of the Girolando Dairy cattle and the Artificial Pastures of Panicum maximum and Panicurn maximum var. c1

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

Journal of Agricultural science and Technology 2011年第4期5卷 433-442页

作者： A. G. Zoffoun s. salifou M. Houinato A. b. sinsin National Institute of Agricultural Researches of benin （I.N.R.A.b.） 01 P.O. Box 884 Cotonou Benin Polytechnic school of Abomey-ca.a.i University of Abomey-Calavi （UAC） Ol P.O. Box 2009 Cotonou Benin Laboratory of Applied Ecology Faculty of the Agronomic Sciences University of Abomey-Calavi （UAC） O1 P.O. Box 526 Cotonou Benin

On the Kpinnou ranch in benin, it was observed that the Girolando dairy cattle which graze Panieum maximum var. cI are more susceptible to infestation of ticks. The purpose of this study was to highlight the interactions between ticks and their bovine hosts and two types of artificial grazing pastures. Nineteen young Girolando dairy cattle were used during the big rainy season （March-June） 2009. All present ticks on the animals have been counted according to the body region. The bovine have been divided into two relatively homogeneous groups often and nine animals. The group I of 10 animals had been grazed on Panicum maximum whereas the group 2 of 9 animals had been grazed on Panicum maximum var. c 1. During the two months of grazing, a weekly monitoring of the evolution of the load in ticks has been achieved. Four genera of ticks were identified on the bovine Girolandos （Amblyomma, Hyalomma, Rhipicephalus and boophilus）. The boophilus genus is the most abundant （P 〈 0.05）. The animals having grazed Panicum maximum var. c I are more infested than those that have been grazed Panicum maximum. A variation of the rate of infestation of the animals has been observed in relation to the different body areas. The colour of the coat also has an effect on the load in tick of the bovine. The bovine of dark coat are in general more infested （P 〈 0.05） than those of clear colour.

关键词： Ticks cattle Panicum maximum Panicum maximum var. cI Kpinnou ranch.

Kinetic and Mechanistic study of Oxidation of Piperazines by bromamine-T in Acidic Medium

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modern Research in ca.a.ysis 2013年第4期2卷 157-163页

作者： chandrashekar &nbsp b. M. Venkatesha s. a.a.da Netkal M. Made Gowda Department of chemistry PES College of Engineering Mandya India Department of chemistry Western Illinois University Macomb USA Department of chemistry Yuvaraja’s College University of Mysore Mysore India Department of studies in chemistry Manasagangothri University of Mysore Mysore India

Oxidations of piperazine, 1-methylpiperazine and 1-ethylpiperazine by bromamine-T (bAT) in buffered acidic medium have been kinetically studied at 303 K. The reaction shows a first-order dependence of the rate each on [bAT]0 and [piperazine]0, and an inverse fractional-order dependence on [H+]. The additions of halide ions and the reduction product of bAT, p-toluenesulfonamide, have no effect on the reaction rate. The variation of ionic strength of the solvent medium has no influence on the rate. Activation pa.a.eters have been evaluated from the Arrhenius and Eyring plots. A common mechanism consistent with the kinetic da.a.has been proposed for all piperazines. The protonation constants of substrates have been evaluated. The hammett linear free-energy relationship has been observed for the reaction with ρ = ?0.5 indicating that the electron-donating groups enhance the reaction rate by stabilizing the transition state. An isokinetic relationship observed shows β = 368 K indicating the dominance of enthalpy factors on the reaction rate.

关键词： Piperazines Oxidation Kinetics Mechanism bromamine-T buffer

Multiple Response Optimization of Three-body Abrasive Wear behaviour of Graphite Filled carbon-Epoxy comPosites Using Grey-b.s.d Taguchi Approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Minerals and Materials cha.a.terization and Engineering 2012年第9期11卷 876-884页

作者： K.M. subba.a.N. Rajendra Y.s. Va.a.a.a.an b. suresha Department of Industrial & Production Engineering The National Institute of Engineering Mysore INDIA Department of Mechanical Engineering The National Institute of Engineering Mysore INDIA

The three-body abrasive wear behaviour of carbon fabric reinforced epoxy (c-E) composites has been evaluated by the addition of graphite (G) particles as a secondary reinforcement. Three-body abrasive wear test were conducted using dry sand rubber wheel abrasion tester as per AsTM G-65 with three process pa.a.eters load, abrading distance and filler content. To assess the abrasive wear behaviour of particulate filled c-E composites satisfying multiple performance measure, grey-b.s.d Taguchi approach has been adopted. The experiments were designed according to Taguchi’s orthogonal array (L?27). The grey relational a.a.ysis was applied to convert a multi response process optimization to a single response. Using a.a.ysis of variance, significant contributions of process pa.a.eters have been determined. The results indicate that the addition of graphite particles into c-E composite increased the wear resistance considerably. It was observed that highest wear resistance of c-E composite was achieved with incorporation of 10 wt. % of graphite filler. Results indicate that the filler content and grit size of abrasive paper were found to be the most significant factor which has influence on the abrasive wear of c-E composite. The worn surface features were examined through scanning electron microscope to probe the wear mechanism.

关键词： composites Three-body Abrasion Grey Relational a.a.ysis scanning Electron Microscope

Amphetamine conditioned Place Preference in Pla.a.ians

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of behavioral and brain science 2013年第1期3卷 131-136页

作者： Robert b. Raffa sumira shah christopher s. Tallarida scott M. Rawls center for substance Ab.s. Research Temple University School of Medicine Philadelphia USA Department of Pharmaceutical sciences Temple University School of Pharmacy Philadelphia USA Neuroscience Program Temple University Philadelphia USA

Meth- and other amphetamines currently present major drug-ab.s. concerns. However, the demonstration and study of ab.s.-related behaviors expressed in animal models is expensive and time-consuming. We previously reported a novel model of conditioned place preference (cPP), which is a standard tool in ab.s. research, in invertebrates (pla.a.ians). In the present study, pla.a.ians were tested for light/dark preference, then exposed for 5 min to either d-amphetamine or vehicle (water) in light and then re-tested for place preference (light vs dark). The pla.a.ians’ natural strong preference for dark (15 of 16) was significantly altered by amphetamine experience, such that 12 of 16 preferred the unnatural, but amphetamine-associated, light side. These results extend the demonstration of cPP to this invertebrate species and provide further evidence in support of this model to testing/screening amphetamine-like and possibly other drugs of ab.s..

关键词： Amphetamine conditioned Place Preference Drug Ab.s. Pla.a.ia

The Generalized <i>r</i>-Whitney Numbers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2017年第1期8卷 117-132页

作者： b. s. El-Desouky F. A. shiha Ethar M. shokr Department of Mathematics Faculty of Science Mansoura University Mansoura Egypt

In this paper, we define the generalized r-Whitney numbers of the first and second kind. Moreover, we drive the generalized Whitney numbers of the first and second kind. The recurrence relations and the generating functions of these numbers are derived. The relations between these numbers and generalized stirling numbers of the first and second kind are deduced. Furthermore, some special cases are given. Finally, matrix representation of the relations between Whitney and stirling numbers is given.

关键词： Whitney Numbers r-Whitney Numbers p-stirling Numbers Generalized q-stirling Numbers Generalized stirling Numbers

Extension of Generalized bernoulli Learning Models

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Modelling and simulation 2015年第1期3卷 26-31页

作者： b. s. El-Desouky F. A. shiha.a. M. Ma.a. Department of Mathematics Faculty of Science Mansoura University Mansoura Egypt

In this article, we study the generalized bernoulli learning model b.s.d on the probability of success pi = ai /n where i = 1,2,...n 0a.a.ann and n is positive integer. This gives the previous results given by Abdulnasser and Khidr [1], Rashad [2] and EL-Desouky and Mahfouz [3] as special cases, where pi = i/n pi = i2/n2 and pi = ip/np respectively. The probability function P(Wn = k) of this model is derived, some properties of the model are obtained and the limiting distribution of the model is given.

关键词： stirling Numbers bernoulli Learning Models comtet Numbers Inclusion-Exclusion Principle

simulating Ocean and Tidal current Power Plants with Homer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

computational Water, Energy, and Environmental Engineering 2015年第3期4卷 38-55页

作者： Andrea Fischer Jones s. silva.a.exandre beluco Luiz Emílio b. Almeida Instituto Federal sul Riograndense (IFsUL) Pelotas RS Brazil Instituto de Pesquisas Hidráulicas Universidade Federal do Rio Grande do Sul (UFRGS) Porto Alegre Brazil

The oceans can provide us with several direct sources of renewable energy, such as wave energy, energy from currents and energy in thermal gradients among other energy resources. The uses of these resources have not yet reached technical and economic maturity, but they have experienced significant advances in recent years. In this process, tools for feasibility a.a.ysis of hybrid systems including specific power plants are important. This article is dedicated to the feasibility study of hybrid systems containing power plants b.s.d on the energy of ocean and tidal currents. The software currently a.a.lable for feasibility studies do not present specific models already developed for the simulation of this kind of power plants. Thus, this technical note shows how Homer software (Legacy version) can be used to conduct this type of study in pre-feasibility level. This article also presents a case study in which Homer is applied, focused only on Homer a.a.tation but without exhausting the subject, showing a feasibility window that would include current power plants with certain cost and efficiency in an existing PV wind biodiesel hybrid system.

关键词： Ocean Energy Ocean current Energy Tidal current Energy computational simulation Feasibility study software Homer

The influences of meteorological factors on the health and functional state of human

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2013年第12期5卷 2068-2076页

作者： Reza sha.a.i Volodymyr b. bogdanov Dmytro s. Gorlov Yuriy P. Gorgo Kyiv Polytechnic Institute Kiev Ukraine Ta.a. shevchenko National University of Kyiv Kiev Ukraine University of Liege Liege Belgium

The influence of fluctuations of atmospheric pressure on the functional state of the humans was studied during spring, autumn and winter seasons. sensory-motor reaction time and selfreported wellbeing, activity and mood were used for evaluation of functional state. The inter-individual variations of those pa.a.eters were compared to meteorological pa.a.eters using rank order correlation and general linear model. It was found that atmospheric pressure fluctuations have a stronger negative effect with periods of 120-1200 s and 20-120 s on psychological self-assessment and with periods of 10-20 s and 5-10 s on sensory-motor reaction time than the fluctuations with other periods.

关键词： Weather Functional state Reaction Time Task Wellbeing Activity Mood