自然数方幂和的包含Bernoulli数的精确表示式

证明自然数方幂和可以用多项式表示，并用两种方法给出其系数的包含Ｂｅｒｎｏｕｌｌｉ数的几种精确表示式。     

Bifurcation for a Type of Quasilinear Elliptic Equations On R" under the Natural Growth Conditions

The article proved the existence of H~1 (R) ∩ L~∞ (R~n) at the bifurcation λ= 0 by discussing the following nonlinear eigenvalue:—D-(ij)(a_(ij)(x,u)D_ju) +1/2a_(iju)(x,u)D_iuD_ju — q(x)|u|~σu = λu0≠u∈H~1(R~n) ,0<σ< 4/n,n≥3,x∈ R~nMeanwhile the article studied the conditions of q(x) under which λ=0 was a bifurcation point for the nonlinear eigenvalue . Here a_(ij) are not required to be bounded as u varies.     

文艺复兴绘画中的科学精神

把自然科学原理引入绘画 ,运用透视学、光学、解剖学等原理 ,融合科学精神 ,实现了精确地摹仿和再现物象 ,构建了文艺复兴时期西方绘画的新体系     

论生态价值观的转变

文章结合当代生态环境建设中存在的实际问题,提出了生态价值观转变的新思路,即从思维方式、价值的外延和价值内涵等三个方面实现生态价值观的根本转变,从而建构一种互益的、广义的、系统的新生态价值观。这种新生态价值观将有助于人与自然的和谐统一和人类社会的可持续发展。     

PBT/PET平列型潜在卷曲丝工业化生产技术探讨

介绍了100d／24f平列型潜在卷曲FDY长丝生产的关键工艺技术．通过组件的合理设计及加工精确度的控制、前后纺工艺的调整，生产出质量优异且永久弹性的平列型潜在卷曲FDY长丝．     

《伊利亚特》中的史诗明喻及其影响

《伊利亚特》中大量的史诗明喻是构成这部史诗雄伟壮丽风格的一个重要方面。荷马史诗明喻的喻体都取自自然物象和与古希腊人生活密切相关的活动和事务,显得原始古朴、苍劲雄奇,生活气息浓烈,极富人情味,具有较高的审美价值。由于这些特点及其较强的叙事功能,史诗明喻遂成为一种优美的语用传统,这种传统在以后的史诗中能明显地感受到。     

Compressed Natural Gas Bus Safety: A Quantitative Risk Assessment

This study assesses the fire safety risks associated with compressed natural gas (CNG) vehicle systems, comprising primarily a typical school bus and supporting fuel infrastructure. The study determines the sensitivity of the results to variations in component failure rates and consequences of fire events. The components and subsystems that contribute most to fire safety risk are determined. Finally, the results are compared to fire risks of the present generation of diesel-fueled school buses. Direct computation of the safety risks associated with diesel-powered vehicles is possible because these are mature technologies for which historical performance data are available. Because of limited experience, fatal accident data for CNG bus fleets are minimal. Therefore, this study uses the probabilistic risk assessment (PRA) approach to model and predict fire safety risk of CNG buses. Generic failure data, engineering judgments, and assumptions are used in this study. This study predicts the mean fire fatality risk for typical CNG buses as approximately 0.23 fatalities per 100-million miles for all people involved, including bus passengers. The study estimates mean values of 0.16 fatalities per 100-million miles for bus passengers only. Based on historical data, diesel school bus mean fire fatality risk is 0.091 and 0.0007 per 100-million miles for all people and bus passengers, respectively. One can therefore conclude that CNG buses are more prone to fire fatality risk by 2.5 times that of diesel buses, with the bus passengers being more at risk by over two orders of magnitude. The study estimates a mean fire risk frequency of 2.2 x 10(-5) fatalities/bus per year. The 5% and 95% uncertainty bounds are 9.1 x 10(-6) and 4.0 x 10(-5), respectively. The risk result was found to be affected most by failure rates of pressure relief valves, CNG cylinders, and fuel piping.     

清人词体发生诸说检讨

清人根据各自对词体特性的认识展开对词体发生问题的探究与解说。从“学”而言,清人大体上将词体发生时间定在盛唐至五代,并认为词体由诗与乐府衍变而来。关于词体生成方式,清人主要有“文体代嬗”与“音律递变”两种观点,其中以“音律递变论”为主流观点。从“术”而言,清人探究词体发生问题的着眼点主要在文体和音乐两个向度。在具体问题的论述上,清人注重文献实证,同时又能对不同视角的观点博观约取、汲异补正,显示出崇尚实证的学术路径与包容通变的学术思想。     

西周至秦汉关税收入增长原因分析

从西周至秦汉,国家对过往客商征收关税的总额有逐渐增高的趋势,因而关税收入在国家财政收入中所占的比重也愈益增大。考察封建国家关税收入增长的原因,不可忽视以下三个重要因素,即关税征收范围的扩大、关卡的增设以及关税税率的提高。这是自西周设关征税至秦汉,关税发展的总的趋势。     

人口与资源可持续发展

自然界和人类社会的一切有价值的物质都是资源 ,人类一切发展都是自然资源的物质变换。资源观包括物质观、辩证观、经济观和稀缺论等 ;人口观包括人力资源论、适度人口论、人口爆炸论等。人口增长对土地、淡水、森林和矿产等自然资源压力巨大 ,不仅来自人口绝对数量的增加 ,而且来自每个人资源消耗增长 ,在人均资源减少过程中显示出很强的加权效应。按照新思路探讨可持续发展 ,人口与经济可持续发展是基础 ,人口与社会可持续发展是目的 ,人口与环境可持续发展是前提 ,人口与资源可持续发展是全部可持续发展的条件和终极因素。实现人口与资源可持续发展 ,除了提高人口素质、资源定价及建立价值体系外 ,更重要的是应从以占有和配置自然资源为主的资源经济、工业经济转向以占有和配置智力资源为主的知识经济和信息经济