试论人民当家作主实现形式的原则

江泽民同志在十六大报告中强调要坚持和完善社会主义民主制度,要健全民主制度、丰富民主形式,要着重加强制度建设,实现社会民主政治的制度化、规范化和程序化。在现阶段,努力探求人民当家作主民主权利的实现形式是社会主义民主政治建设的重要内容。而探求民主实现形式的原则在此过程中发挥着关键作用。     

我国雾霾污染的环境库兹涅茨曲线检验

本文以我国160个地级及以上城市作为研究样本,以PM25和PM10作为雾霾污染的衡量指标,构建空间Tobit模型对雾霾污染的环境库兹涅茨曲线假说(EKC)进行了实证检验.研究发现:我国城市雾霾污染呈现明显的空间集聚特征;在控制了经济规模等变量之后,雾霾污染与经济发展之间不支持倒“U”型的EKC假说,而是呈现线性递减关系,由此可见,我国的雾霾污染治理已经取得了阶段性的成效;在诸多控制变量中,经济规模、产业结构、人口密度对雾霾污染存在显著的正向影响,而经济密度的提高有助于降低雾霾污染,且雾霾污染与地理区位之间存在密切关联.尽管目前雾霾污染的治理取得了一定成效,但应清醒地认识到雾霾污染的治理是一个长期过程,在未来经济发展的过程中,要更加注重加快转变经济发展方式、调整优化经济结构.     

Testing the Equality of Two Proportions for Combined Unilateral and Bilateral Data

In many medical comparative studies (e.g., comparison of two treatments in an otolaryngological study), subjects may produce either bilateral (e.g., responses from a pair of ears) or unilateral (response from only one ear) data. For bilateral cases, it is meaningful to assume that the information between the two ears from the same subject are generally highly correlated. In this article, we would like to test the equality of the successful cure rates between two treatments with the presence of combined unilateral and bilateral data. Based on the dependence and independence models, we study ten test statistics which utilize both the unilateral and bilateral data. The performance of these statistics will be evaluated with respect to their empirical Type I error rates and powers under different configurations. We find that both Rosner's and Wald-type statistics based on the dependence model and constrained maximum likelihood estimates (under the null hypothesis) perform satisfactorily for small to large samples and are hence recommended. We illustrate our methodologies with a real data set from an otolaryngology study.     

Contents of heavy metals in arable soils and birth defect risks in Shanxi, China: a small area level geographic study

The burgeoning demands of China’s urbanization and industrial development put pressure on the resources of the entire country and have direct and indirect effects on the health of individuals, at times in areas far removed from cities themselves. Current evidence suggests that heavy metal pollution in soil, a common by-product of coal mining and other industrial activities, may be linked to risk of birth defects. We examine this hypothesis using small area level data including soil samples and detailed birth records from 2002 to 2004 from 97 villages in Shanxi province, a heavy coal-mining region. We find that soils containing arsenic, lead, and nickel are significantly correlated with the incidence of birth defects. In particular, we find a strong positive dose-dependent association of birth defects with lead, a moderate positive effect with arsenic, and a dose-dependent negative association with nickel. These results are consistent with the postulated link between arsenic and lead and human birth defects, but raise questions about the effects of nickel in this context. China’s rapid urbanization underscores the need for closer attention to the relationship between the health and the environment.     

A transnational networked public sphere of air pollution: analysis of a Twitter network of PM2.5 from the risk society perspective

ABSTRACT

Drawing on digitaltrace data, publicly accessible government documents, and journalistic reports, this research integrates Beck’s risk society theory with digital media theories to examine the mediated process of risk definition and assessment of PM2.5 (particulate matters with a diameter less than 2.5 micrometers) in a networked public sphere. Network and content analysis of a PM2.5 Twitter network shows that political and professional elite remained the most powerful producers of risk definition. Established media played a key role, yet faced challenges from a variety of actors who disseminated and filtered information. Laypersons, while peripheral, actively interacted with elite and established media. The blurring geographic boundary in the PM2.5 Twitter network revealed an emerging transnational public sphere, which, however, was segregated by language. This research advances a layered understanding of the contingent, paradoxical media impact for social changes in a risk society.     

拥有自有品牌零售商的平台开放策略研究

随着电子商务的快速发展，零售商之间竞争加剧，自有品牌战略成为零售商获取竞争优势的关键。研究拥有自有品牌零售商的平台开放策略，通过对比零售商不开放平台和开放平台下的均衡利润，给出零售商平台开放策略选择条件，并分析产品之间价格影响系数、固定成本和潜在需求差异系数对零售商平台开放策略选择的影响，最后结合数值分析和京东自有品牌的发展现状验证了本文的主要研究结论。研究发现：第一，随着固定成本的增加，佣金费率逐渐减少，随着潜在需求差异系数的增加，佣金费率逐渐增加；第二，当产品之间的价格影响系数较小（较大）时，平台开放（不开放）是零售商的最优选择；第三，当固定成本较小（较大）时，平台开放（不开放）是零售商的最优选择；第四，当潜在需求差异系数较小（较大）时，平台开放（不开放）是零售商的最优选择。     

基于句子级情感的中文网络评论的情感极性分类

为提高网络评论段落的情感极性分类准确率,在考虑人们表达习惯和语料粒度的基础上,提出一种基于句子情感的段落情感极性分类方法． 该方法通过句子的情感极性和句子的情感极性贡献度来对段落进行情感分类,采用传统分类方法预测句子的情感极性,提出等权重、相关度、情感条件假设 3 种方法,能够根据训练语料的统计数据动态地确定段落中不同位置句子的情感极性贡献度． 最后,以超过2个句子的手机和酒店网络评论为对象进行实验分析,实验结果显示,与传统方法相比,考虑了人们表达习惯的相关度和情感条件假设方法显著提高了段落分类的准确率,且具有一定的自适应性．     

Assessing Risk‐Based Upper Limits of Melamine Migration from Food Containers

Melamine contamination of food has become a major food safety issue because of incidents of infant disease caused by exposure to this chemical. This study was aimed at establishing a safety limit in Taiwan for the degree of melamine migration from food containers. Health risk assessment was performed for three exposure groups (preschool children, individuals who dine out, and elderly residents of nursing homes). Selected values of tolerable daily intake (TDI) for melamine were used to calculate the reference migration concentration limit (RMCL) or reference specific migration limit (RSML) for melamine food containers. The only existing values of these limits for international standards today are 1.2 mg/L (0.2 mg/dm²) in China and 30 mg/L (5 mg/dm²) in the European Union. The factors used in the calculations included the specific surface area of food containers, daily food consumption rate, body weight, TDI, and the percentile of the population protected at a given migration concentration limit (MCL). The results indicate that children are indeed at higher risk of melamine exposure at toxic levels than are other groups and that the 95th percentile of MCL (specific surface area = 5) for children aged 1–6 years should be the RMCL (0.07 mg/dm²) for protecting the sensitive and general population.     

基于微分博弈的供应链质量协调研究

文章以一个制造商和一个供应商所构成的两级供应链为研究对象,应用微分博弈的方法分析了四种不同的质量管理博弈情形下,制造商和供应商的最优质量管理策略、收益和整条供应链的总收益。研究结果表明,当制造商和供应商的收益分配比满足一定条件时,从Nash非合作质量管理博弈情形,到弱激励Stackelberg博弈情形,再到强激励Stackelberg博弈情形,最后到合作质量管理博弈情形,对于制造商、供应商以及整个供应链系统来说都是一种帕累托改进。所以,合作质量管理博弈情形是供应链质量管理所追求的最理想的情形,为了有效促进该情形的实现,文章应用Nash讨价还价模型对该情形下合作双方关于供应链系统的剩余利润分配进行了分析。最后,在对一家电风扇制造商的供应链进行调查来获得仿真数据的基础上,通过算例分析验证了理论推导的结果。     

基于新型工业化的黑龙江省产业结构分析

走新型工业化道路标志着以物质资源高消耗为基础的传统工业经济的衰落。从三次产业结构、工业企业类型结构、所有制结构和就业结构四个方面看,黑龙江省的产业结构现状同沿海地区存在较大差异,存在结构非均衡、缺乏产业发展战略、增长粗放等问题。应利用后发优势进行技术和制度创新,走以供给结构产业的优化带动需求结构升级的新型工业化道路。