区块链技术应用于政府采购信用体系建设中的价值与路径

随着政府采购的深入发展，政府采购信用体系逐渐出现政府采购信誉减损、信用信息开放和共享程度较低、信用信息的安全威胁增加、信用监管效果不佳以及失信惩戒政策执行遭遇阻塞等问题。区块链技术应用于政府采购信用体系建设中有利于提供安全的信息环境、有利于多主体参与、有助于多中心协同、能促进信用监管多元化。区块链技术在政府采购信用体系建设中的应用路径:以区块链思维重新架构政府采购信用体系的信用管理基础；以“去中心化”的信任机制完善信用信息公开与共享平台；以分布式账本结构打造多主体监管参与机制；以智能合约机制实现信用评估智能化。     

A misspecification test for the higher order co-moments of the factor model

The traditional estimation of higher order co-moments of non-normal random variables by the sample analog of the expectation faces a curse of dimensionality, as the number of parameters increases steeply when the dimension increases. Imposing a factor structure on the process solves this problem; however, it leads to the challenging task of selecting an appropriate factor model. This paper contributes by proposing a test that exploits the following feature: when the factor model is correctly specified, the higher order co-moments of the unexplained return variation are sparse. It recommends a general to specific approach for selecting the factor model by choosing the most parsimonious specification for which the sparsity assumption is satisfied. This approach uses a Wald or Gumbel test statistic for testing the joint statistical significance of the co-moments that are zero when the factor model is correctly specified. The asymptotic distribution of the test is derived. An extensive simulation study confirms the good finite sample properties of the approach. This paper illustrates the practical usefulness of factor selection on daily returns of random subsets of S&P 100 constituents.     

长三角26个城市民生高质量发展测评报告

民生高质量发展作为"六个高质量"的一个方面,既是高质量发展的逻辑起点,也是高质量发展的最终目的.通过对民生高质量发展各指标进行计算加总,最终得出长三角26个城市的民生高质量发展指数及排名.杭州是长三角城市群中民生高质量发展的首位城市,南京紧随其后.苏州、无锡、宁波、常州、绍兴、嘉兴和金华的民生高质量发展水平相对较高,湖州、台州、舟山、镇江、上海的城市民生高质量发展水平位于平均水平之上.     

融资融券扩容和流动性

  流动性是市场的灵魂，金融创新的目的和结果是提高资产的流动性。2010年3月31日，证监会以促进市场流动性为目的，正式推出融资融券业务试点，并在2011年至2013年先后3次扩大中国A股市场融资融券标的股票的范围。因此，研究中国融资融券是否促进流动性并探究其内在机制具有非常重要的现实意义。         排除股指期货和股指期权等卖空机制的影响，运用面板回归方法和适合政策评估的双重差分法，分别检验2011年至2013年3次融资融券扩容对标的股票流动性的影响，并从融资和融券交易者的短期交易策略和标的股票股东结构变化两个方面探讨买空卖空机制与流动性因果关系的内在机制。         研究结果表明，融资和融券交易的双重引入降低了交易成本和价格影响，提高了标的股票的流动性。随着融资融券业务的深入开展和发展，融资融券标的股票扩容对价格影响方面的流动性的影响越来越强。融资交易者的短期动量交易策略降低了价格影响和交易成本，融券交易者的短期动量交易策略降低了价格影响，而对交易成本影响不显著。由于部分机构投资者退场，偏好短线投机炒作的中大型个体投资者入场，换手率高、流通市值低和特质波动率低等类型的标的股票组合的流动性提高更为明显。         融资融券交易提高标的股票流动性的研究结论补充了已有研究关于买空卖空机制对市场质量影响方面的实证证据，也为中国融资融券业务的发展和完善提供借鉴意义。     

Co-Occurring Psychosocial Problems and Multiple Sexual Partners among Men Who Have Sex with Men in Shanghai,China: A Syndemic Approach

We aimed to apply syndemic theory to verify the association and reinforcing effects between psychosocial problems and multiple sexual partners (MSP) of men who have sex with men (MSM) in Shanghai, China. A cross-sectional study was conducted among 547 MSM in Shanghai, China using a face-to-face survey. Sociodemographic and psychosocial data were collected, as well as information on MSP and condomless anal sex. In the 6 months prior to the survey, 54.3% of the MSM sample had had MSP. Univariate analysis showed that self-esteem, depression, loneliness, sexual compulsivity, and involuntary subordination (IS) were associated with MSP. Sexual compulsivity (multivariate odds ratio [ORm] = 2.94, 95% CI = 1.76–4.91) and IS (ORm = 1.79, 95% CI = 1.14–2.81) remained significant in multivariate analysis. MSM with five or more psychosocial problems had greater odds of (adjusted odds ratios = 3.06, 95% CI = 1.49–6.25) having MSP in the previous 6 months than the non-syndemic group. Our findings provide preliminary confirmation of the additive relationship of syndemic psychosocial health conditions and MSP among MSM in Shanghai, China. An integrated intervention with special focus on sexual compulsivity and IS is needed.     

凝固型大米风味酸奶的研制

用大米蛋白或大米蛋白水解物部分替代牛乳粉生产大米风味酸奶,以谷糠乳杆菌和乳酸乳球菌乳酸亚种为发酵菌种,以酸度和感官为评价指标,通过大米蛋白及其水解物添加量、大米蛋白水解度、乳糖补加及蔗糖添加研究对大米风味酸奶酸度和感官的影响。结果表明,大米风味酸奶的酸度和感官评分随大米蛋白添加量的增加而降低。产品酸度随大米蛋白水解度增加而增大,大米蛋白水解度为7.5%时感官得分最高;产品酸度和感官评分随大米水解物添加量增加而降低,大米蛋白水解物添加量在40%以下时,均可生产出合格的大米风味酸奶。补加乳糖对产品酸度和感官无显著影响。添加蔗糖对产品酸度无显著影响,但对产品感官影响显著,蔗糖添加量在4~6%时,大米风味酸奶的感官得分最高,表现为色泽均匀,质地较细腻,未见乳清析出,凝乳稳定,口感较细腻柔滑,酸甜度适中,米香风味浓郁。     

“生存”与“自由”:“感性活动”的辩证实质与时代价值

“感性活动”是马克思主义唯物史观的基本范畴。经创造性继承费尔巴哈“感性对象”原则与黑格尔否定的辩证法，马克思阐发了“感性活动”的物质基础与能动原则，赋予其三重规定：为生存资料需要的物质生产活动、形成社会关系社会矛盾的物质交往活动、为个性自由推翻现实矛盾的革命改造活动。马克思将人的“需要”机制作为推动和创造原则论证了感性活动从“生存”到“自由”的辩证运动过程，从而揭开了整个社会历史形成与发展之谜，确立了其哲学的实践基础，实现了对唯心主义和直观唯物主义的整体超越。而对感性活动进行生存、反思与自由的当代诠释，是为新时代中国特色社会主义主要矛盾论断找到重要哲学支撑，这既从学理上丰富了马克思主义，印证了不平衡不充分发展的特殊历史性，又在实践层面预示了实现美好生活需要的必然性，为社会创造活动提供了精神动力。     

秦巴山区人口分布的影响因素分析及分区引导——以陕西省安康市为例

随着人口城镇化步伐的加快,秦巴山区人口空间结构将进一步重组。本文基于安康市的乡镇单元,采用空间分析合理划分人口集聚区的等级,结合地理加权回归模型分析人口密度与经济发展、社会发展、自然环境的空间相关性,试图揭示人口分布的主要影响因素,并针对不同人口集聚区进行策略引导。研究表明:1人口集聚区等级的划分可结合人口增速与人口总量;2不同影响因素对人口集聚产生的效应具有明显的差异性,如经济发展水平对人口集聚具有"马太效应";医疗条件对人口集聚的影响存在正效应,也存在着边际效用递增的规律;交通条件对人口集聚的影响存在边际递减效应;高程对人口聚集的影响存在负效应,并存在着边际效用递减;而耕地对人口集聚的影响与产业结构相关;3影响人口聚集的需求要素具有显著的差异,即经济发展需求>土地需求>便捷的交通需求>良好的医疗条件需求>低海拔需求。4对于秦巴山区来说,人口集聚的引导策略应结合"地情"进行统筹谋划,如人口高度集聚区以道路交通建设和集约高效利用土地为重点,人口次高度集聚区以道路交通建设为重点,人口中度集聚区以医疗服务设施完善为重点,人口低度集聚区以高山人口转移为重点。     

四川盆地中三叠世盐盆分布与演化特征研究

四川盆地卤水分布广泛，资源丰富, 早为世人所瞩目，中三叠统雷口坡组是四川盆地最早开采天然气和盐卤的层系之一。根据盆地雷口坡组大量钻井资料研究表明，盆地雷口坡组主要成盐期分别为雷三2 期和雷四2 期，在盆地东部和南部由于受到古隆起的影响，盐岩地层已被剥蚀难以保存，现今盐岩主要分布在开江古隆起和泸州古隆起的西部以及天井山古隆起的南部（华蓥山以西—龙门山以东的川西—川中地区）。印支运动对盆地雷口坡组盐岩在平面的迁移起着十分重要的作用，根据不同时期盐岩统计数据看，两期盐盆在平面上具有向西迁移、叠加的特征，其中川中的GS1 井就钻遇了这两期的盐岩。     

Life Satisfaction of Rural Migrant Workers in Urban China: The Roles of Community Service Participation and Identity Integration

Abstract

China is home to approximately 245 million rural-to-urban migrant workers. The influx of migrants into urban areas has posed various challenges for local social service systems. Recently, increasing number of community services have been developed to meet the growing service demands from the migrant population. However, whether increase in community service use results in improved wellbeing among migrant workers remains critically unexplored. As such, this study examines the role of community service use in migrant workers’ life satisfaction and the potential mediating effect of identity integration in Shenzhen, China. Bootstrapped models were adopted to examine relationship among variables. Drawing from a sample of 1,087 rural-to-urban migrant workers, we found that community service use is positively correlated with both identity integration and migrant workers’ life satisfaction. Moreover, identity integration served as a partial mediator between community service use and life satisfaction. The mediating effect of identity integration was found to increase with age. This study highlights that diverse services should be implemented to address divergent needs of migrants in different age groups. Community service can also serve as a vehicle to foster integration among migrant workers in host communities, especially for older age groups. Future studies may further investigate the relationships between community social capital, community social support, quality of community-based organization and frequency of service use so as to optimize the life satisfaction of migrant workers.