农户兼业对秸秆还田技术采纳的影响机制及效应分析——基于冀皖鄂1150份农户调查数据的实证

基于河北、安徽、湖北三省1150份农户的实地调查数据,采用倾向得分匹配法构建“反事实”框架,探讨了农户兼业对秸秆还田技术采纳的影响效应,并进一步验证了其中介效应及务工距离的作用机制。研究结果表明：（1）相比纯农户,兼业户更倾向于采纳秸秆还田技术;（2）农户兼业通过风险分担间接影响秸秆还田技术采纳,间接影响占比为24.43%;（3）当纯农户选择在乡内务工时,秸秆还田技术采纳率会提高15.0%,选择在县内乡外务工时,兼业对农户秸秆还田技术采纳行为没有显著性影响,但当纯农户选择省内县外务工时,秸秆还田技术采纳率提高了9.2%,选择省外务工时秸秆还田技术采纳率提高了10.0%。因此,为更好促进秸秆还田技术推广,政府部门应该引导和鼓励农户就近务工,保障农村劳动力就业质量,培育和支持农机社会化服务组织并加强对秸秆还田技术的指导和培训。     

农户持续参加科普培训意愿的影响因素

持续参与科普培训对提升农户科学素质具有关键作用。基于社会认知理论,将外部环境划分为参与环境和人际环境两个维度,将农户结果期望划分为素质结果期望和收入结果期望两个维度,采用陕西省305户农户随机分层抽样调研数据,运用Probit模型对农户科普培训持续参与意愿影响因素进行实证分析。研究发现:外部环境和结果期望对农户持续参与意愿均有显著的正向影响,其中素质结果期望在参与环境、人际环境对持续参与意愿的关系中具有中介作用,收入结果期望在参与环境对持续参与意愿的关系中具有中介作用。据此提出营造良好外部环境、增强科普培训的实用性以满足农户结果期望等提升农户持续参与科普培训的建议。     

Origins and destinies: Immigration to the United States since World War II

Contemporary immigration to the United States and the formation of new ethnic groups are the complex and unintended social consequences of the expansion of the nation to its post-World War II position of global hegemony. Immigrant communities in the United States today are related to a history of American military, political, economic, and cultural involvement and intervention in the sending countries, especially in Asia and the Caribbean Basin, and to the linkages that are formed in the process that open a variety of legal and illegal migration pathways. The 19.8 million foreign-born persons counted in the 1990 U.S. census formed the largest immigrant population in the world, though in relative terms, only 7.9% of the U.S. population was foreign-born, a lower proportion than earlier in this century. Today's immigrants are extraordinarily diverse, a reflection of polar-opposite types of migrations embedded in very different historical and structural contexts. Also, unlike the expanding economy that absorbed earlier flows from Europe, since the 1970s new immigrants have entered an hourglass economy with reduced opportunities for social mobility, particularly among the less educated, and new waves of refugees have entered a welfare state with expanded opportunities for public assistance. This paper seeks to make sense of the new diversity. A typology of contemporary immigrants is presented, and their patterns of settlement, their distinctive social and economic characteristics compared to major native-born racial-ethnic groups, and their different modes of incorporation in—and consequences for—American society are considered.     

利用数控增益放大器提高A/D转换器的分辨率

文章介绍利用数控增益放大器LH0086大幅度提高A／D转换器分辨率的方法,可将8位A／D转换器的分辨率提高到接近16位A／D的水平,适用于高速数据系采集系统,给出了相应的硬件原理图和软件框图。     

Asian Women,Job Training and the Social Organization of Immigrant Labor Markets

This paper examines the entry of Asian immigrant women into a gendered labor market via government-funded job training programs. The focus is on the intake processing of clients into an employment training program operated by a community based organization. The study reveals that women's family responsibilities and the cultural capital they bring function to screen them into or out of training programs and ultimately shape their location in the workforce. The study thus draws attention to how race, class, and gender enter into the organization of Asian immigrant women into the labor market. This investigation is based in institutional ethnography (Smith 1987), a research strategy which displays how activities in a particular setting are coordinated with more extended forms of social organization. The study shows that the overriding concern with successful placement in a job as mandated by government regulations is a critical factor in selecting the women for these programs.     

Contextualizing the Employment Decisions of New Mothers

This paper suggests that the employment behavior and stated preferences of new mothers are not simply a product of choices that individual women make or characteristics that they have. Rather, using qualitative interview data from a sample of new parents, this paper illustrates some of the interactional and institutional contexts in which new mothers' approaches to paid work are embedded, with a particular focus on gender. Among the themes explored are the influence of husbands' preferences on women's decisions, the role of economic processes in structuring parenting arrangements, as well as the prominence of gendered cultural imagery in new parents' accounts about their work and family arrangements.     

从生成史略论《水浒传》的主题

本文从《水浒传》生成史的角度,将《水浒传》的成书和作品主题的嬗变联系起来,论证梁山故事在流传过程中不断出现的传奇色彩和归正倾向。它是封建社会全社会被压迫者与有志之士的反抗与追求的“交响曲”,是对封建社会后期现实的一种“全景式的综合反映”。     

Correlates of honor ratings in a clinical clerkship employing a faculty forum evaluation system

5he purpose of this study was to determine whether or not suspected variables affected a surgery clerk's chances of being awarded an honor rating. Findings indicated a significant relationship between a student receiving an honor rating and his or her preceptor's predetermined level of student advocacy, the number of completed patient interview and physical examination write-ups, and final examination scores. There was no significant relationship found between honor ratings and the preceptor's status, the sequence in which the student was discussed or the length of time spent discussing the student at the final evaluation meeting, or the number of clinical faculty present at the meeting. These results lend support to the faculty forum evaluation approach, but suggest a need for further scrutiny of some influencing variables to ensure all students are fairly considered and honor ratings judiciously awarded.     

Physician perceptions of medical malpractice and defensive medicine

Using judgments obtained in interviews with 33 Massachusetts physicians, the annual statewide volume of expenditures incurred for defensive medical reasons in 1982 was estimated to be $1.0 billion, 12% of all medical care expenditures. Estimates for the nation were $37 billion, 14% of expenditures. Nationally, 180,000 cesarean deliveries were thought to be performed for defensive motives. In their own institutions, respondents judged 43% of all skull x-rays following injury to be medically justified, 30% to be defensive medicine, 16% to be placebos, and 11% to be physician misjudgments. In considering the economic and noneconomic costs of medical malpractice procedures, the dollar costs of insurance were considered most serious, followed closely by defensive medicine, unfairness, and poorer relations with patients. Thirty-two percent of the responsibility for the negative aspects of malpractice processes was assigned to lawyers, 21% to physicians, 18% to legislatures and courts, 16% to patients, and 13% to insurance companies.