辩证法概念：马克思与黑格尔的异同再考查

黑格尔思辨辩证法在于 :作为主体的人是思维着的精神 ,方法即为“从概念自身发展出的必然过程” ,意识的诸形态既实现自身也自我消解 ,以及辩证法是基于本体论概念基础上的内在的超越。马克思辩证法作为非本体论的辩证的叙述方法植根于社会历史范域 ,凸显“死和爱是否定辩证法的神话”及特殊规定性的全部关系 ,而且 ,与黑格尔的理解了的世界才是现实世界不同 ,马克思强调对象化的东西即为现实世界     

Potential exposures and risks from beryllium-containing products.

Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.     

What to Do at Low Doses: A Bounding Approach for Economic Analysis

To quantify the health benefits of environmental policies, economists generally require estimates of the reduced probability of illness or death. For policies that reduce exposure to carcinogenic substances, these estimates traditionally have been obtained through the linear extrapolation of experimental dose-response data to low-exposure scenarios as described in the U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment (1986). In response to evolving scientific knowledge, EPA proposed revisions to the guidelines in 1996. Under the proposed revisions, dose-response relationships would not be estimated for carcinogens thought to exhibit nonlinear modes of action. Such a change in cancer-risk assessment methods and outputs will likely have serious consequences for how benefit-cost analyses of policies aimed at reducing cancer risks are conducted. Any tendency for reduced quantification of effects in environmental risk assessments, such as those contemplated in the revisions to EPA's cancer-risk assessment guidelines, impedes the ability of economic analysts to respond to increasing calls for benefit-cost analysis. This article examines the implications for benefit-cost analysis of carcinogenic exposures of the proposed changes to the 1986 Guidelines and proposes an approach for bounding dose-response relationships when no biologically based models are available. In spite of the more limited quantitative information provided in a carcinogen risk assessment under the proposed revisions to the guidelines, we argue that reasonable bounds on dose-response relationships can be estimated for low-level exposures to nonlinear carcinogens. This approach yields estimates of reduced illness for use in a benefit-cost analysis while incorporating evidence of nonlinearities in the dose-response relationship. As an illustration, the bounding approach is applied to the case of chloroform exposure.     

梁启超为什么能推动近代小说的发展

晚清的小说出现了前所未有的繁荣,这一繁荣与当时的城市发展市民人口的增长并不同步,而是由梁启超发动的小说界革命所推动的。梁启超的努力适应了当时小说家安身立命的需要,他们自觉响应梁启超,政治小说成为当时小说的核心。梁启超的小说观念适应了士大夫文学观念的需要,他们抛弃了鄙视小说的看法,参与到小说的创作和阅读中来,他们对梁启超的认同,大大扩大了小说的市场,帮助小说繁荣。     

科技特派员制度生命力的探析

地处闽北的南平市在发展当地经济、促进农业重大转型的特定时期,启动科技特派员制度,有其深刻的时代背景和现实意义。本文从科技特派员制度创举与活力切入,分析这一制度创举深层次的原因,并进一步探讨这一制度生命力如何在新时期持续和创新。     

Dose-Response and Risk Assessment of Airborne Hexavalent Chromium and Lung Cancer Mortality

This study evaluates the dose-response relationship for inhalation exposure to hexavalent chromium [Cr(VI)] and lung cancer mortality for workers of a chromate production facility, and provides estimates of the carcinogenic potency. The data were analyzed using relative risk and additive risk dose-response models implemented with both Poisson and Cox regression. Potential confounding by birth cohort and smoking prevalence were also assessed. Lifetime cumulative exposure and highest monthly exposure were the dose metrics evaluated. The estimated lifetime additional risk of lung cancer mortality associated with 45 years of occupational exposure to 1 microg/m3 Cr(VI) (occupational exposure unit risk) was 0.00205 (90%CI: 0.00134, 0.00291) for the relative risk model and 0.00216 (90%CI: 0.00143, 0.00302) for the additive risk model assuming a linear dose response for cumulative exposure with a five-year lag. Extrapolating these findings to a continuous (e.g., environmental) exposure scenario yielded an environmental unit risk of 0.00978 (90%CI: 0.00640, 0.0138) for the relative risk model [e.g., a cancer slope factor of 34 (mg/kg-day)-1] and 0.0125 (90%CI: 0.00833, 0.0175) for the additive risk model. The relative risk model is preferred because it is more consistent with the expected trend for lung cancer risk with age. Based on statistical tests for exposure-related trend, there was no statistically significant increased lung cancer risk below lifetime cumulative occupational exposures of 1.0 mg-yr/m3, and no excess risk for workers whose highest average monthly exposure did not exceed the current Permissible Exposure Limit (52 microg/m3). It is acknowledged that this study had limited power to detect increases at these low exposure levels. These cancer potency estimates are comparable to those developed by U.S. regulatory agencies and should be useful for assessing the potential cancer hazard associated with inhaled Cr(VI).     

基因序列的可专利性研究

从基因序列的发明发现之争、基因序列的创造性和实用性分析、基因序列专利保护对社会公共利益的影响三个方面出发,对基因序列的专利保护问题进行了深入具体的分析探讨,最终发现:从理论上讲,没有足够充分的理由阻止基因序列的专利保护,但是各国对基因序列的专利保护应当根据本国基因资源拥有、生物科技的发展等具体情况而定。     

科技发展与人的发展

在社会实践活动中,科学技术引导人在真、善、美三个方面充分展现自己的本性和才能,是人发展与完善自身的内在动力。由于科技发展与人的社会责任、知识成果运用的动机与效果之间存在可能的冲突,科技发展对人的发展也具有否定性影响。必须对科技活动的主体提出自我调适的要求,促进人类健康发展。     

我国银行卡市场发展的若干问题及对策

银行卡作为商业银行的一种复合型金融工具在现代银行竞争中的作用日益显著 ,我国拥有着巨大的并且快速发展的银行卡市场 ,开发和完善我国的银行卡市场可以作为商业银行迎接加入 WTO挑战和与国际同行竞争的突破口。本文着重论述我国银行卡市场的现状和存在的问题 ,并据此提出整合经营、采用积分制等具有针对性的建议     

中国近30 年来的农村改革发展历程回顾与展望

文章重点从农村改革的整体性、综合性、协调性和党在农村政策的稳定性、连续性、实效性等方面入手,把我国近30年来的农村改革发展历程划分为三个不同的时期:即从1978年到1988年,是农村改革的起步阶段,出现了第一个“黄金发展期”;从1988年到1998年,是农村改革的停滞阶段,出现了“三农综合症”;从1998年10月至今,是农村改革的快速推进阶段,出现了第二个“黄金发展期”。全面准确地认识和把握我国农村改革的历史进程,对于科学制定农村综合改革的整体方案及相关配套政策措施至关重要。