汽轮发电机组轴系磁阻尼器抑振方案优选计算分析

采用有限元与轴承及磁阻尼器动特性线性简化模型建立大型汽轮机转子系统不平衡振动响应计算模型;选择典型不平衡状态,采用多种磁阻尼器布置方案对BBC公司汽轮发电机组轴系振动的抑振效果进行分析对比优选,结果表明在中压转子段采用大阻尼参数磁阻尼器抑振效果最佳。     

Summary of the Workshop on Issues in Risk Assessment: Quantitative Methods for Developmental Toxicology

This report summarizes the proceedings of a conference on quantitative methods for assessing the risks of developmental toxicants. The conference was planned by a subcommittee of the National Research Council's Committee on Risk Assessment Methodology ⁴ in conjunction with staff from several federal agencies, including the U.S. Environmental Protection Agency, U.S. Food and Drug Administration, U.S. Consumer Products Safety Commission, and Health and Welfare Canada. Issues discussed at the workshop included computerized techniques for hazard identification, use of human and animal data for defining risks in a clinical setting, relationships between end points in developmental toxicity testing, reference dose calculations for developmental toxicology, analysis of quantitative dose-response data, mechanisms of developmental toxicity, physiologically based pharmacokinetic models, and structure-activity relationships. Although a formal consensus was not sought, many participants favored the evolution of quantitative techniques for developmental toxicology risk assessment, including the replacement of lowest observed adverse effect levels (LOAELs) and no observed adverse effect levels (NOAELs) with the benchmark dose methodology.     

深圳经济发展的战略分析

本文对深圳经济后１５年发展具有长远意义的战略因素和战略措施进行分析和评论，并就经济发展的指导思想定位作了简要探讨。     

《红楼梦》语篇体裁标记语的英译

近年来《红楼梦》英译研究发展迅速,许多学者都从不同领域对其进行研究。但将功能语篇分析理论应用到《红楼梦》及其英译文的对比研究,国内外尚不多见。本文将以韩礼德系统功能语言学作为理论基础,从语篇分析的角度,以《红楼梦》原著及其杨宪益夫妇的英译本为语料,重点讨论《红楼梦》作为章回小说,其语篇体裁标记语在英译文中如何处理的。     

对我院理财环境的分析与思考

高校理财环境是制约高校发展的瓶颈,影响我院理财环境的因素主要有三个,即社会外部因素,高校内部因素和财务管理本身的因素,本文通过深入分析这三个方面的因素,提出我们应该树立财务管理的目标,建立有效的财务管理人才激励机制和全员动员,寻求新的理财途径三个方面努力营造良好的理财环境为我院的发展提供坚实的财务保障。     

Uncertain Numbers and Uncertainty in the Selection of Input Distributions—Consequences for a Probabilistic Risk Assessment of Contaminated Land

Risks from exposure to contaminated land are often assessed with the aid of mathematical models. The current probabilistic approach is a considerable improvement on previous deterministic risk assessment practices, in that it attempts to characterize uncertainty and variability. However, some inputs continue to be assigned as precise numbers, while others are characterized as precise probability distributions. Such precision is hard to justify, and we show in this article how rounding errors and distribution assumptions can affect an exposure assessment. The outcome of traditional deterministic point estimates and Monte Carlo simulations were compared to probability bounds analyses. Assigning all scalars as imprecise numbers (intervals prescribed by significant digits) added uncertainty to the deterministic point estimate of about one order of magnitude. Similarly, representing probability distributions as probability boxes added several orders of magnitude to the uncertainty of the probabilistic estimate. This indicates that the size of the uncertainty in such assessments is actually much greater than currently reported. The article suggests that full disclosure of the uncertainty may facilitate decision making in opening up a negotiation window. In the risk analysis process, it is also an ethical obligation to clarify the boundary between the scientific and social domains.     

渝西经济走廊县域产业结构:一些发现及解释

应用对应分析方法对渝西经济走廊各区市县的三次产业结构进行了实证研究,分析了该经济区产业结构及发展水平的县域差异,同时发现该经济区三次产业结构总体上呈"三足鼎立"的均衡格局,据此提出了调整产业结构、促进工业化与城镇化协同发展的四大策略:结构趋异、产业集群、人口聚集和商贸拓展。     

动态定位中机动和粗差检测延迟的探讨

动态定位数据处理中,判定运动载体何时开始机动,测量数据何时出现粗差是一个困难的问题。为了在实时动态定位中尽可能快地检测出运动载体机动和观测数据何时出现粗差,文中提出了一种对机动和粗差检测的新方法。该检测算法是基于机动和粗差检测延迟最小的准则。通过分析,对不同的显著水平和机动幅度存在一个最优窗口长度。     

基于规则的客户关系管理系统建模方法

客户关系管理系统(CRM)是提高企业核心竞争力的有力武器。以工作流和过程建模技术为基础,研究CRM系统的建模,是CRM系统的建立和顺畅运行的关键。因此,将动态过程建模的思想引入CRM系统的建模过程中,按照逐层分解的建模方式来简化系统的复杂性,并采用事件驱动的、基于扩展业务规则的方法进行CRM系统的过程建模和系统性能评价,是针对CRM系统进行建模的有效手段。通过以上方法,可以建立出全面支持CRM系统运行、监控、仿真和性能评价的过程模型。根据该方法建立的CRM系统的模型经过仿真实验和企业实际应用,证明具有良好的应用效果。     

农民增收途径系统分析

由于农业结构调整滞后,农业资源配置不当,乡镇企业吸纳农村剩余劳动力的能力减弱,导致农民增收趋缓。农民增收的有效途径是:以市场为导向调整产业结构,促进农业产业化,加快小城镇建设,政府加大宏观支持力度。