王徵——欧洲科学技术与文化的传播者

王徵是明代末年著名的科学技术研究者和传播者,也是最早一代接受来自欧洲的科技和文化并皈依天主教的中国学者之一,在跨文化的知识传播及中国宗教史上占有重要的地位。王徵的父亲和舅父对他一生的治学宗旨及宗教观的形成有很大的影响。虽然王徵曾长时间研究佛教、道教,并最终在耶稣会士的影响下皈依了天主教,但本质上他从未背弃儒家的核心道德理念。儒家理念直接影响了他的工程技术实践及其对西方知识的选择。王徵将儒家经世思想与其对技术和机械制造方面的兴趣结合起来,成为一名敢于任事官吏及对维护社会稳定有贡献的士绅,并最终为效忠明王朝牺牲了自己的生命。他与邓玉函合译的《远西奇器图说录最》是最早系统介绍西方力学知识的中文著作,在中国力学史上具有里程碑的意义。     

农业机械标书评价指标体系设计原理

在农业机械购置补贴过程中，采取招投标的形式是实现科学选型的有效措施。然而在标书评价中，影响因素及评价指标的选取往往存在较大的主观随意性。针对此问题，根据辩证法的对立统一等哲学原理，从指标体系的设计过程入手，提出从影响主体确定、案例归纳与推理、评价主客体换位思考、影响因素显性化与系统体系形成相结合的农业机械标书评价指标体系设计原理，并详细剖析了设计原理具体实现的步骤。     

机械制造专业应用型人才培养方案的改革与实践

以中国制造发展战略和江苏的国际制造业基地建设规划为背景,依据高等学校机械学科本科专业规范、机械工程师资格考试大纲、应用型人才培养目标定位及其知识、能力、素质结构,重新设计了机械设计制造及其自动化专业机械制造方向人才培养方案。该方案以数控机床设计、制造、运用人才为培养目标,注重综合实践与工程训练,强化数字化设计制造应用能力培养,注意道德法律、技术经济、质量管理教育,提出以一个核心、两条路线、四个层面、五种意识、七种能力、八个环节构建实践教学体系。新方案的初步实践,正在展现其提高人才培养质量的成效。     

机械原理课程实验教学改革探讨

机械原理实验课程是培养学生创新意识和实践能力的重要教学环节。文章从构建新型实验课程体系,更新实验教学手段,虚拟实验同传统实验手段相结合,合理安排实验,加强对实验教学考核等几方面对机械原理实验课程教学改革进行了有益的探索。     

机车牵引电机电器故障可靠性诊断分析系统

为了提高机车研究、设计、制造以及维修水平,提高机车牵引电机、电器设备的可靠度,有必要开发机车牵引电视、电器故障可靠性诊断系统.文中介绍了在WINDOWS98下开发的机车牵引电机、电器故障可靠性诊断分析系统的设计方法和实现技术,主要包括系统目标、系统设计及实现中的关键技术.     

博学多才的古代科学家祖冲之:纪念祖冲之逝世1500周年

简要介绍祖冲之的生平，阐述他在数学、天文、机械等方面的十项重要成就。     

Environmental Tobacco Smoke Revisited: The Reliability of the Data Used for Risk Assessment

Several epidemiological studies have found a weak, but consistent association between lung cancer in nonsmokers and exposure to environmental tobacco smoke (ETS). In addition, a purported link between such exposure and coronary heart disease (CHD) has been of major concern. Although it is biologically plausible that ETS has a contributory role in the induction of lung cancer in nonsmoking individuals, dose-response extrapolation-supported by the more solid database for active smokers-gives an additional risk for lung cancer risk that is more than one order of magnitude lower than that indicated by major positive epidemiological studies. The discrepancy between available epidemiological data and dosimetric estimates seems, to a major part, to reflect certain systematic biases in the former that are difficult to control by statistical analysis when dealing with risks of such low magnitudes. These include, most importantly, misclassification of smoking status, followed by inappropriate selection of controls, as well as certain confounding factors mainly related to lifestyle, and possibly also hereditary disposition. A significant part of an association between lung cancer and exposure to ETS would disappear, if, on the average, 1 patient out of 20 nonsmoking cases had failed to tell the interviewer that he had, in fact, recently stopped smoking. In the large International Agency for Research on Cancer (IARC) multicenter study even lower misclassification rates would abolish the weak, statistically nonsignificant associations that were found. In the former study an apparent significant protective effect from exposure to ETS in childhood with respect to lung cancer later in life was reported, a most surprising finding. The fact that the mutation spectrum of the p53 tumor suppressor gene in lung tumors of ETS-exposed nonsmokers generally differs from that found in tumors of active smokers lends additional support to the notion that the majority of tumors found in ETS-exposed nonsmokers have nothing to do with tobacco smoke. The one-sided preoccupation with ETS as a causative factor of lung cancer in nonsmokers may seriously hinder the elucidation of the multifactorial etiology of these tumors. Due to the high prevalence of cardiovascular disease in the population, even a modest causal association with ETS would, if valid, constitute a serious public health problem. By pooling data from 20 published studies on ETS and heart disease, some of which reported higher risks than is known to be caused by active smoking, a statistically significant association with spousal smoking is obtained. However, in most of these studies, many of the most common confounding risk factors were ignored and there appears to be insufficient evidence to support an association between exposure to ETS and CHD. Further, it seems highly improbable that exposure to a concentration of tobacco smoke at a level that is generally much less than 1% of that inhaled by a smoker could result in an excess risk for CHD that-as has been claimed-is some 30% to 50% of that found in active smokers. There are certainly valid reasons to limit exposure to ETS as well as to other air pollutants in places such as offices and homes in order to improve indoor air quality. This goal can be achieved, however, without the introduction of an extremist legislation based on a negligible risk of lung cancer as well as an unsupported and highly hypothetical risk for CHD.     

Protecting Children and Young People from Tobacco‐Related Harm: A Review

Tobacco use continues to be a serious public health issue. Although declining in middle‐ to high‐income countries, smoking rates are often higher in disadvantaged communities and vulnerable groups. Knowledge about tobacco‐related harm also tends to be incomplete. To date, legislation has focused on public domains, but the pressure to protect children in the home and other private spaces is fast becoming a focal point for potential legislation and intervention. Negotiating the boundary between privacy and protection is likely to become a matter of professional concern.     

1.5m2高频振动筛结构改进

针对目前在矿棉板备浆生产线上广泛使用的高频振动筛存在的噪音大、动力消耗大、筛板易堵塞、除渣效果差等 问题,对高频振动筛筛框结构、筛板形状和减震弹簧等进行了优化改进,对振动频率、振幅、筛板的孔径通过理论计算得 出几个基本数值范围,再通过对基本数值范围内的不同数值的实际测试,确定最佳数值。新设计的振动筛经实际使用表 明运行稳定,浆料利用率高,能耗低,噪音小,取得了很好的经济效果。     

铸铁烘缸椭圆人孔盖的计算

为了解决铸铁烘缸承压元件椭圆形人孔盖设计计算的困扰,设计人员基于国内规范结合ASME规范寻求一种新 的设计计算方法,即利用ASME规范提供的数表找到适合于铸铁烘缸人孔盖材料的特性曲线,将此特性曲线提供的特性 数值代入已经成熟的算例当中,从而计算出人孔盖的承压能力。此方法一旦成熟可以解决椭圆形人孔盖设计计算的难 题,使铸铁烘缸人孔盖的设计进一步的优化