检索结果-南通市图书馆

Frontiers of Mathematics in China 2015年第2期10卷 351-365页

作者： Yong rEN Tingting HOU r. SAKTHIvEL Department of Mathematics Anhui Normal University Wuhu 241000 China Department of Mathematics Sungkyunkwan University Suwon 440-746 Korea

We study a class of non-densely defined impulsive neutral stochastic functional differential equations driven by an independent cylindrical fractional Brownian motion （fBm） with Hurst parameter H ∈ （1/2, 1） in the Hilbert space. We prove the existence and uniqueness of the integral solution for this kind of equations with the coefficients satisfying some non-Lipschitz conditions. The results are obtained by using the method of successive approximation.

关键词： Stochastic functional differential equation non-densely defined operator cylindrical fractional Brownian motion (fBm) impulsive effect

An evolutionary perspective on conflict and compensation in physiological and functional traits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2014年第6期60卷 755-767页

作者： Jerry F. HUSAK Simon r LAILvAUX Department of Biology University of St. Thomas 2115 Summit Avenue St Paul MN 55105 USA Department of Biological Sciences University of New Orleans 2000 Lakeshore Drive New Orleans LA 70148 USA

Physiological and functional traits, especially those related to behavior and whole-organism performance capacities, are subject to a variety of both parallel and opposing natural and sexual selection pressures. These selection pressures show considerable interspeciflc variation, shaping contemporary behavioral and functional diversity, but the form and intensity of selection on physiological and functional traits can also vary intraspecifically. The same suites of traits can experience quite different se- lection pressures, depending on the sex or age of a given individual, as well as the presence and nature of alternative reproductive strategies and tactics. These inter- and intra-locus genetic conflicts have potentially important consequences for the evolutionary trajectories of traits subject to them. Consequently, any intraspecific conflicts which could displace traits from their selective op- tima in certain classes of individuals relative to others are expected to result in selection for mechanisms to compensate for devia- tion from those optima. Such conflicts include interlocus sexual conflict, intralocus sexual conflict, and interacting phenotypes, as well as conflict within a sex. In this paper, we consider the evidence for, and implications of, such conflicts for physiological and functional traits in diverse taxa, including both vertebrates and invertebrates, and evaluate the various mechanisms, ranging from behavioral and mechanical to energetic and genetic, enabling compensation. We also discuss how pre- and post-mating conflicts, as well as interacting phenotypes, might affect the evolution of behavior and physiological and functional traits. Investigators that seek to understand the links among behavior, morphology, physiology, and function should consider such conflicts.

关键词： Sexual Conflict Compensation Sexual Selection Whole-organism Performance

From granulite fluids to quartz-carbonate megashear zones:The gold rush

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2014年第5期5卷 747-758页

作者： Bin Fu Jacques L.r.Touret research School of Earth Sciences The Australian National University Institut de Mineralogie.de Physique des Materiaux et de Cosmochimie(IMPMC) Sorbonne Universites UPMC Univ Paris 06.UMR CNRS 7590 Museum National d'Histoire Naturelle IRD UMR 206.4 Place Jussieu.F-75005 Paris.France

At peak granulite-facies metamorphic conditions, lower continental crust is arguably fluxed by large amounts of two key low water activity fluids：（i） high-density CO2 and/or （ii） concentrated saline so- lutions. These fluids are either internally-derived, generated by mineral reactions or dehydration melting or, notably for CO2, externally-derived, issued from the underlying mantle. Postmetamorphic evolution results in complete disappearance of these fluids, except for minute remnants preserved in minerals as fluid inclusions. Two major processes are involved：（i） at peak conditions, granitoid magmas form, migrate upward, and crystallize as shallow intrusions in the upper crust （mineralized porphyry types or reduced intrusions）; （ii） during the rapid decompression which almost systematically follows a period of post-peak isobaric cooling, especially for ultrahigh-temperature granulites （anticlockwise P-T paths）, quartz-carbonate megashear zones are formed by repeated periods of seismic activity. Seismic activity may continue until all free fluids have disappeared, resulting in the ultramylonites and pseudotachylites that are found in many granulite domes. A great majority of vein-type Au deposits worldwide occur in the above-mentioned settings or nearby. We suggest that the Au has been scavenged by the granulite fluids, then redistributed and concentrated during the formation of veins and related phenomena.

关键词： Granulite CO2 BrinesMegashear zonesAu mineralization

Agricultural pesticide use and food safety:California's model

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

Journal of Integrative Agriculture 2015年第11期14卷 2340-2357页

作者： Minghua Zhang Michael r Zeiss Shu Geng Department of Land Air and Water ResourcesUniversity of California California Department of Pesticide regulation Sino-US Joint Food Safety research Center Northwest A&F University Department of Plant Sciences University of California

Pesticides have been an essential part of agriculture to protect crops and livestock from pest infestations and yield reduction for many decades. Despite their usefulness, pesticides could pose potential risks to food safety and the environment as well as human health. This paper reviews the positive benefits of agricultural pesticide use as well as some potential negative impacts on the environment and food safety. In addition, using the case of California, we discuss the need for both residue monitoring and effective pest management to promote food safety. Twenty years＇ pesticide residue data from California＇s pesticide residue monitoring program were analyzed. results showed that more than 95% of food samples were in compliance with US pesticide residue standards （tolerances）. However, certain commodities from certain sources had high percentages of residues above tolerance levels. Even when residues above tolerance levels were detected, most were at levels well below 1 mg kg^-1, and most posed negligible acute health risk. However, a few detected residues had the potential to cause health effects. Therefore, establishing an effective food residue monitoring program is important to ensure food quality throughout the marketplace.

关键词： food safety food security pesticide use residue monitoring environmental impacts IPM tolerances maximum residue limits (MrLs)

Bio-Economic Strategy to Combat Non-Point Pollution in China

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

Pedosphere 2005年第2期15卷 156-163页

作者： B. DAvIDSON r.E.WHITE Institute of Land and Food resources Institute of Land and Food Resources The University of MelbourneParkville Victoria 3010 (Australia)The University of MelbourneParkville Victoria 3010 (Australia)

While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment.

关键词： crop production integrated biophysical-economic model non-point pollution policy instrument sustainable strategy

Semantic Based Greedy Levy Gradient Boosting Algorithm for Phishing Detection

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

Computer Systems Science & Engineering 2022年第5期41卷 525-538页

作者： r.Sakunthala Jenni S.Shankar Department of Computer Science and Engineering Hindusthan College of Engineering and TechnologyCoimbatore641032India

The detection of phishing and legitimate websites is considered a great challenge for web service providers because the users of such websites are *** websites also create traffic in the entire *** phishing issue is the broadening malware of the entire network,thus highlighting the demand for their detection while massive datasets(i.e.,big data)are *** the application of boosting mechanisms in phishing detection,these methods are prone to significant errors in their output,specifically due to the combination of all website features in the training *** upcoming big data system requires Mapreduce,a popular parallel programming,to process massive *** address these issues,a probabilistic latent semantic and greedy levy gradient boosting(PLS-GLGB)algorithm for website phishing detection using Mapreduce is proposed.A feature selection-based model is provided using a probabilistic intersective latent semantic preprocessing model to minimize errors in website phishing ***,the missing data in each UrL are identified and discarded for further processing to ensure data ***,with the preprocessed features(UrLs),feature vectors are updated by the greedy levy divergence gradient(model)that selects the optimal features in the UrL and accurately detects the ***,greedy levy efficiently differentiates between phishing websites and legitimate *** are conducted using one of the largest public corpora of a website phish tank *** show that the PLS-GLGB algorithm for website phishing detection outperforms stateof-the-art phishing detection *** amounts of phishing detection time and errors are also saved during the detection of website phishing.

关键词： Web service providers probabilistic intersective latent semantic greedy levy divergence gradient phishing detection big data

Modern radical Organizations and Their Impact on National and International Security

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 Radical Organizations and Their Impact on National an...

作者： B0Z0r0v ABUZHABBOr 山东大学

学位级别：硕士

At the present stage,many have begun to realize that any radical extremist organizations are purposefully working to achieve their political ambitions and goals and have begun to affect the national and regional security of entire regions *** purpose of this work is to study modern radical organizations and their impact on national and regional security and its sources of *** the goal,the following research objectives were identified:Analyze global threats,modern challenges and the problem of modern radical organizations for regional security;investigate the forms of youth involvement in some terrorist organizations;analysis of sources of financing of terrorist and extremist organizations;analyze the impact of religious extremism on the national security of the Central Asian states;analysis of international terrorism as a factor in the destabilization of the situation in Central Asia;explore the specifics of international terrorism,radical religious extremism,and separatism;explore the cooperation of the Central Asian states in countering terrorism,extremism and radical organizations;analyze the main trends in the politicization of Islam in Central Asia;consider forms of manifestation of religious extremism on the security of Central Asia;to investigate the forms of manifestation of internal terrorism in the states of Central Asia;Analyze the prospects of countering religious extremism and international terrorism in the *** object of research is radical organizations,and the subject of research is the activities of these organizations and the activities of specific structures and countries to counter *** novelty of the work consists in the fact that when I studied the existing literature-scientific works,materials of international conferences and publications,I periodically made an attempt to analyze the influence of modern radical organizations on national and regional security alongside with investigation the forms of involving young peop

关键词： Modern radical organizations their impact national security international security

Copper Salt of 12-Tungstophosphoric Acid： An Efficient and reusable Heteropoly Acid for the Click Chemistry

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2013年第4期31卷 534-538页

作者： K. v. Purnima D. Sreenu N. Bhasker K. Nagaiah N. Lingaiah B. v. Subba reddy J. S. Yadav Division of Organic Chemistry Indian Institute of Chemical Technology Hyderabad 500 007 India Division oflnorganie and Physical Chemistry Indian Institute of Chemical Technology Hyderabad 500 007 India

Three components coupling of alkyl bromide, sodium azide and alkyne has been achieved using a catalytic amount of copper-exchanged phosphotungstic acid （Cu-TPA） in the presence of triethyl amine in DMF to afford substituted triazoles in good yields with high selectivity. Interestingly, the coupling of alkyl azide with alkyne pro- ceeds readily at room temperature to furnish 1,2,3-triazoles in excellent yields. The catalyst can be recovered and reused for three to four subsequent runs with a minimal decrease of activity. The use of copper modified heter- opolyacids makes this procedure simple, convenient and environmentally friendly.

关键词： Cu-exchanged heteropoly acids click reaction three-component reactions triazoles

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2016年第2期3卷 97-103页

作者： Amit Banerjee P. r. Mishra Ashok Mohanty K. Chakravarty r. Das Biswas r. Sahu S. Chakravarty Analytical Chemistry Division CSIR - NationalMetallurgical Laboratory Jamshedpur Jharkhand 831007India Department of Metallurgical and Materials Engineering National Institute of Technology JamshedpurJharkhand 831014 India r&D Tata Steel Ltd Jamshedpur Jharkhand 831007 India

Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of this work is to analyze the quality of Indian Coals and obtain their mineral species-specific information at different depths. The samples were obtained from Talcher Coalfield, Odisha, India. Coal from four seam sections in the Talcher coalfield, India are mainly high ash coal （〉50 %） and volatile matter deceases along with the seam depth. XrD results show that the major mineral phases present in the coal are quartz and kaolinite. Siderite, illite, and anatase were found in minor quantities. It has been observed that the clay minerals （kaolinite, silimanite, illite） decompose at higher temperature and traces of dolomite, mullite, hematite etc. are formed during the process of combustion. Among the four seams （M2, M12, M24 and M43） studied, ash of M43 has high A1203%, TIO2% and K20% content and low SIO2%, CaO% and MgO% content. High acid- to-base ratios contributed to high ash fusion temperatures （IDT 〉 1500 ℃） and low slagging potential of the coals studied. relatively low fouling index （〈0.3） was estimated for all the coal seams studied. Furthermore, thermodynamic modeling software, FactSage, have been used to envision the mineral phase transformations that take place between 800 and 1500℃ during coal combustion.

关键词： Proximate analysis - Ultimate analysis FactSage XrD AFT Talcher coalfield

Ion Mobility in the Fluorite Solid Solutions 50PbF2–30BiF3–20K(Na)F According to 19F, 23Na NMr Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Materials Physics and Chemistry 2012年第4期2卷 71-73页

作者： v.Ya. Kavun A.B. Slobodyuk I.A. Telin r.M. Yaroshenko I.G. Maslennikova v.K. Goncharuk v.I. Kharchenko a Institute of Chemistry Far Eastern Branch of RAS Vladivostok Russia Far-Eastern Federal University Vladivostok Russia Institute of Chemistry Far Eastern Branch of RAS Vladivostok Russia

Ion mobility in solid solutions of the fluorite structure 50Pb2–30BiF3–20KF (I) and 50Pb2–30BiF3–20NaF (II) was studied by NMr method. Analysis of 19F, 23Na NMr spectra made it possible to reveal the character of ion motions in the fluoride and sodium sublattices with temperature variation, to determine the types and temperature ranges in which they took place. It was found that the dominant form of ionic mobility in the samples I and II above 380 K was the diffusion of fluoride and sodium ions. According to preliminary results of electro-physical studies, the conductivity reached values of ~ 2×10–2 – 10–3 S/cm above 500 K. The solid solutions I and II can be recommended as a basis for use in the development of new functional materials.

关键词： Solid Solutions 50PbF2–30BiF3–20K(Na)F Ion Mobility Ionic Conductivity 19F 23Na NMr spectra functional materials