干渴的梯田:王金庄村水资源的分配与管理

河北省涉县旱作梯田系统是中国重要农业文化遗产。 其核心保护区域王金庄村位于太行山东麓,地形条件复杂,缺土少水、旱涝频发,但梯田系统因独特的人文智慧延续近八百年而不衰。 文章以水为切入点,阐释水资源短缺情形下百姓的生存逻辑与生计策略。 村庄作为一个系统对自然环境进行着补救性适应、抗风险适应与常态适应,这些文化适应性举措使旱作梯田的可持续发展得以实现,也展示出古老农耕智慧对于农业永续发展的重要意义。 因此,保护农业文化遗产不仅是对传统文化与社会系统的保护,更是对现代农业后果的生态补救,对农业与农村发展的现实反思,对可持续发展之路的探寻。     

水平井中砂泥岩互层的双侧向测井响应研究

摘要：针对砂泥岩互层的复杂测井环境，采用三维有限元数值模拟方法，计算了多层介质模型的水平井双侧向测井响应。结果表明，井眼半径、泥浆电阻率和围岩（砂岩、泥岩）的电阻率及侵入半径与电阻率对水平井双侧向测井响应都有不同程度的影响。在砂泥岩地层中，井眼尺寸越大，泥浆电阻率越高，对视电阻率的影响越严重；当目的层厚大于8 m 后，视电阻率受围岩（砂岩、泥岩）影响很小，基本上反映地层的真实电阻率，并且曲线变化规律大致相同，此时可近似为三层介质模型；对于低阻侵入，侵入越深，视电阻率越偏离真实地层电阻率。     

Let Me Go: The Influences of Crawling Experience and Temperament on the Development of Anger Expression

Infants’ emerging ability to move independently by crawling is associated with changes in multiple domains, including an increase in expressions of anger in situations that block infants’ goals, but it is unknown whether increased anger is specifically because of experience with being able to move autonomously or simply related to age. To examine the influence of locomotion on developmental change in anger, infants’ (N = 20) anger expressions during an arm restraint procedure were observed longitudinally at a precrawling baseline assessment and 2 and 6 weeks after the onset of crawling. Infant age at each crawling stage was unrelated to the frequency of anger expressed in response to arm restraint. At 6 weeks postcrawling onset, infants whose mothers rated them as temperamentally higher in distress to limitations, compared with those rated lower, showed a greater increase in the frequency of anger expressed during the arm restraint relative to earlier assessments and took longer to reduce the frequency of anger expressed when no longer restrained. Findings suggest that experience with autonomous crawling has an effect on anger expression, independent of age, and that a temperamental tendency to become distressed by limitations may exacerbate the effect of crawling on anger expression.     

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。     

我国学前教育地方立法研究

学前教育地方立法是我国学前教育立法体系的有机组成部分，截至2020 年1 月，我国现行有效的学前教育地方性法规 规章共61 部，呈现出立法时间跨度大，立法主体覆盖面广，立法模式体例多样等特征。地方立法一定程度上规范着地方学前 教育的有序开展，但也存在部分省市立法机关对当地学前教育立法关注度不高、部分立法难以满足当前学前教育发展需求、表 达不规范、可操作性欠佳、缺乏地方特色以及冲突与越位等问题。对此，应从科学确定学前教育地方立法内容、建立地方性法 律适时更新制度、健全学前教育地方立法调研制度、加强地方立法专业化制度建设等方面予以优化。     

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.     

论回族爱情叙事诗的悲剧美--以《马五哥与尕豆妹》为例

作为回族民间文学重要组成部分的爱情叙事诗,由于具有鲜明的民族特色和独特的艺术风格,在长期的传播中赢得了回族及周边各族人民的喜爱。同时,它又以粗犷、直率、沉郁的语言抒发了一种悲壮的感情,令人回味无穷。文章欲以在西北农村广泛传唱的“花儿”体叙事长诗《马五哥与尕豆妹》为例,试图利用社会人类学的功能理论来尝试性的分析回族爱情叙事诗的悲剧美。     

1991-2014年藏文古籍文献研究文献综述——以中文核心期刊载文为例

文章以CNKI中的“中国期刊全文数据库”为检索源,以1991-2014年全国中文核心期刊发“藏文古籍文献”为主题的载文信息为检索内容,通过检测得知1991-2014年以“藏文古籍文献”为主题的研究成果共有45篇文章。这些研究成果具有以下特点：一是内容丰富全面,涉及面广;二是研究视角的多元化;三是研究领域的多种化;四是研究形式多样化。笔者根据研究内容所涉及藏文的古籍文献保护与抢救研究、古籍文献的开发与利用研究、古籍收藏与古籍研究、古籍目录学研究、古籍文献数字化信息服务研究、藏学文献馆藏建设研究和其他与藏文古籍文献相关的研究等多视角对“藏文古籍文献”的研究成果进行了介绍,以期在展示精华的同时,力图为“藏文古籍文献”研究的深入研究提供可借鉴性的综合史料。     

Inference on Causal Effects in a Generalized Regression Kink Design

We consider nonparametric identification and estimation in a nonseparable model where a continuous regressor of interest is a known, deterministic, but kinked function of an observed assignment variable. We characterize a broad class of models in which a sharp “Regression Kink Design” (RKD or RK Design) identifies a readily interpretable treatment‐on‐the‐treated parameter (Florens, Heckman, Meghir, and Vytlacil (2008)). We also introduce a “fuzzy regression kink design” generalization that allows for omitted variables in the assignment rule, noncompliance, and certain types of measurement errors in the observed values of the assignment variable and the policy variable. Our identifying assumptions give rise to testable restrictions on the distributions of the assignment variable and predetermined covariates around the kink point, similar to the restrictions delivered by Lee (2008) for the regression discontinuity design. Using a kink in the unemployment benefit formula, we apply a fuzzy RKD to empirically estimate the effect of benefit rates on unemployment durations in Austria.     

A nonparametric hypothesis test for heteroscedasticity

In this paper, a hypothesis test for heteroscedasticity is proposed in a nonparametric regression model. The test statistic, which uses the residuals from a nonparametric fit of the mean function, is based on an adaptation of the well-known Levene's test. Using the recent theory for analysis of variance when the number of factor levels goes to infinity, the asymptotic distribution of the test statistic is established under the null hypothesis of homocedasticity and under local alternatives. Simulations suggest that the proposed test performs well in several situations, especially when the variance is a nonlinear function of the predictor.