粘土矿物产状和微结构对地层损害的影响

对120块岩样XRD、SEM分析结果表明,下二门油田纵向粘土矿物演化规律明显,浅、上层系以蒙皂石—高岭石组合为主,中、下层系为绿泥石—高岭石—伊/蒙间层组合,深层系为绿泥石—伊利石组合。发育七种粘土微结构类型,地层微粒的稳定性由占主导地位的微结构类型决定。微结构稳定性序列为层流状>绒球状>畴状>叠片支架状>絮团状>蜂窝状>支架状。预测碱敏、水敏、盐敏和出砂是最严重的地层损害方式。     

空气质量、投资者情绪与股票收益率

  环境因素对股票市场的影响一直是行为金融学探讨的热点话题，行为金融学理论认为股票价格除了受其基本面影响外，投资者情绪也是一个很重要的影响因素。而大量的心理学研究证实，环境的确会影响人们的情绪。当人们暴露在受到污染的环境中，会产生明显的沮丧、焦虑等负面情绪。近年来，已有研究探讨空气污染对股市收益率的影响，但空气污染如何影响股票回报的具体机制却鲜有涉及。         采用2014年至2015年环保部发布的全国252个城市的空气质量指数和股票日收益率数据，构建分城市的股票组合。利用空气质量作为外生的环境变量，通过分城市检验、面板回归和蒙特卡洛模拟等方法，从投资者情绪的视角研究空气质量与股票回报的关系，并进一步从增加悲观情绪和降低交易意愿两个角度对空气质量影响股票回报的机制进行探讨。         研究结果表明，平均来看，空气质量越差的城市，股票收益率越低，该结果在控制季节因素、公司特征和城市固定效应后依然成立。进一步研究发现，空气质量越差，股票组合的换手率越低，流动性也越低，说明空气质量通过降低本地投资者交易意愿而不是增加其悲观情绪影响股票价格。空气质量影响投资情绪的渠道确实存在，当投资者暴露在污染的环境中时，会因为产生负面情绪而使交易意愿降低，从而损害股票的流动性。         研究充分控制城市固定效应，更好地解决内生性问题。研究结果为投资者的非理性投资行为提供支持，环境的因素往往也对投资者的交易产生影响，因此环境也可以作为资产价格的一个因子发挥作用，这对投资者构建交易策略具有启发意义。     

Propensity score prediction for electronic healthcare databases using super learner and high-dimensional propensity score methods

ABSTRACT

The optimal learner for prediction modeling varies depending on the underlying data-generating distribution. Super Learner (SL) is a generic ensemble learning algorithm that uses cross-validation to select among a ‘library’ of candidate prediction models. While SL has been widely studied in a number of settings, it has not been thoroughly evaluated in large electronic healthcare databases that are common in pharmacoepidemiology and comparative effectiveness research. In this study, we applied and evaluated the performance of SL in its ability to predict the propensity score (PS), the conditional probability of treatment assignment given baseline covariates, using three electronic healthcare databases. We considered a library of algorithms that consisted of both nonparametric and parametric models. We also proposed a novel strategy for prediction modeling that combines SL with the high-dimensional propensity score (hdPS) variable selection algorithm. Predictive performance was assessed using three metrics: the negative log-likelihood, area under the curve (AUC), and time complexity. Results showed that the best individual algorithm, in terms of predictive performance, varied across datasets. The SL was able to adapt to the given dataset and optimize predictive performance relative to any individual learner. Combining the SL with the hdPS was the most consistent prediction method and may be promising for PS estimation and prediction modeling in electronic healthcare databases.     

A Qualitative Case Study on Recovery and Personal Growth in Korean Drug Addicts

ABSTRACT

In recent years, crimes related to drug smuggling and production have gradually increased in Korea. This qualitative case study explores the experiences of Koreans recovering from drug addiction and identifies specific details and mechanisms of recovery. For this purpose, participants were selected based on criteria such as engaging in social activities after recovery from addiction for 3 years or more. Next, one-on-one in-depth interviews were conducted with five voluntarily consenting participants. Data were analyzed using the within-/cross-case analysis suggested by Creswell. Substantial personal growth took place in the recovery process for drug addicts. Nineteen themes were identified as manifestations of personal growth through within-case analysis. Four common themes were then derived through cross-case analysis. These four common themes were “reconnection with reality,” “embracing the essence of one's own existence,” “reconstructing oneself in social relations,” and “self-love.” The study's results suggest that a recovery program needs to be developed wherein the program not only enables drug addicts to reflect on their current existence but also allows them to develop their specific coping skills. Future research should be broadened to consider the social support mechanism and viewpoints of people including family and local community members in close contact with drug addicts.     

从治标到治本:房地产业政策调控与房产税制度创新

面对近期我国一线、二线城市相继出现的房地产市场“过热”迹象,各地政府不得不纷纷再次启动限购、限贷等行政调控措施.然而多年以来的经验总结表明,此类手段往往“治标不治本”,造成楼市的冷热迅速变换“打摆子”状况.文章以标本兼治、治本为上的原则为指导,从制度供给这一龙头因素视角探讨了在住房保有环节开征房地产税的五大方面积极作用,并就关于房地产税的五种主要反对观点和意见从学理和实践两个层面分析了推进我国房地产税改革的可行性.基于此,文章提出了当前及未来一段时期,推动房地产税立法工作与相关改革的思路和要领,对开征房地产税的方案构想和可借鉴的国际经验作了讨论.     

长江经济带省域物流效率及空间差异研究

基于“物流距离”设定空间权重矩阵,采用数据包络分析和空间自相关分析法,揭示长江经济带省域物流效率及空间差异.研究发现,长江经济带省域物流效率总体呈现持续提升的态势,但地区间和地区内物流效率存在明显的差异;长江经济带省域物流效率呈现空间正相关性,物流效率相近的省市在空间上集聚分布;长江经济带省域物流效率呈现阶梯状分布格局,下游地区持续领先,中游地区快速提升,上游地区增长缓慢.为了促进长江经济带物流业跨地区协调高效发展,应构建区域整体物流联盟、下游地区推进物流业溢出效应、中游地区发挥物流业通道优势、上游地区培育物流业增长极.     

论马克思主义与中国传统文化的结合方式

中国的具体实际无疑构成了马克思主义中国化的现实根据与直接动力,而赓续数千年的中国传统文化则构成了马克思主义中国化的内在基础与文化底蕴。中国的马克思主义者通过“借言赋意”(概念层面)、“耦合再造”(思维层面)和“溯本开新”(价值层面)的方式所实现的马克思主义与中国传统文化的“结合”,既是一个历史过程,更是一个创造过程。     

Increasing Returns and Social Contagion in Cultural Industries

A formal definition of cultural industries is developed following four distinct features of cultural goods: (a) oversupply, (b) quality uncertainty, (c) network effects and (d) demand reversal. Drawing on economic and socio-psychological notions of ‘network’, increasing returns and social contagion effects are distinguished. Increasing returns may govern the adoption of standards when choices are binary, social contagion explains the diffusion of cultural goods when choices are multiple. Together, the four structural features delineating cultural industries account for curious competitive dynamics prevalent in cultural markets, such as the notorious 10 : 90 proportionality (under which 10% of cultural goods account for 90% of the market), causal ambiguity about the reasons for success, and the formation of fashions. Six managerial recommendations are advanced, focusing on a criticial circulation point triggering self-sustaining diffusion patterns. Finally ‘project-based enterprises’ and ‘network forms of governance’ are identified as the organizational forms most suited to the dynamics of the cultural markets.     

中国摩托车行业’98分析报告

中国摩托车行业自５０年代初开始迈步,经过２０年（６０、７０年代）的摸索、１０年（１９８０—１９９０年）的进步、５年（１９９１—１９９５年）的快速发展,开始走向成熟。１９９６、１９９７年产量增幅放慢,分别比上年增长１８．５７％与７．９６％,较之“八五”...     

《劳动合同法》对企业成本影响的测算方法与实证研究——金融危机下的应急措施

<劳动合同法>实施以来,在国内学术界和实业界引起了轩然大波.2008年以来,一些企业的倒闭、搬迁,更将这部立意颇好的法律推到了风口浪尖.针对实施<劳动合同法>对企业成本影响的问题,采用分层目录抽样方法,抽取了珠三角、粤东、粤西、粤北地区13个具有代表性的城市,不同类型、不同行业共650户企业进行调研,运用成本测算直接法和间接法,对广东调研企业成本进行统计测算.测算结果显示,广东实施<劳动合同法>对企业人均人工成本的影响区间为2.54%～4.90%,用调研事实澄清了社会上流传的10%～70%的谬误.还从政府、企业和员工角度分别提出在实施<劳动合同法>过程中应对金融危机的对策,为各级政府和企业决策提供依据.