梅河高速公路某滑坡的滑动分析及加固措施

梅河高速K111+286～+433右侧滑坡经过两次加固后,仍出现了较大的变形.根据此滑坡的工程地质条件、滑坡病害迹象以及监测资料,通过锚索拉力确定的滑坡安全系数,具体分析了滑坡的滑动机理,并提出了补强加固措施的方案.     

Perceived Risks of Conventional and Organic Produce: Pesticides, Pathogens, and Natural Toxins

Public risk perceptions and demand for safer food are important factors shaping agricultural production practices in the United States. Despite documented food safety concerns, little attempt has been made to elicit consumers' subjective risk judgments for a range of food safety hazards or to identify factors most predictive of perceived food safety risks. In this study, over 700 conventional and organic fresh produce buyers in the Boston area were surveyed for their perceived food safety risks. Survey results showed that consumers perceived relatively high risks associated with the consumption and production of conventionally grown produce compared with other public health hazards. For example, conventional and organic food buyers estimated the median annual fatality rate due to pesticide residues on conventionally grown food to be about 50 per million and 200 per million, respectively, which is similar in magnitude to the annual mortality risk from motor vehicle accidents in the United States. Over 90% of survey respondents also perceived a reduction in pesticide residue risk associated with substituting organically grown produce for conventionally grown produce, and nearly 50% perceived a risk reduction due to natural toxins and microbial pathogens. Multiple regression analyses indicate that only a few factors are consistently predictive of higher risk perceptions, including feelings of distrust toward regulatory agencies and the safety of the food supply. A variety of factors were found to be significant predictors of specific categories of food hazards, suggesting that consumers may view food safety risks as dissimilar from one another. Based on study findings, it is recommended that future agricultural policies and risk communication efforts utilize a comparative risk approach that targets a range of food safety hazards.     

试析社会主义生产关系的具体化

由于历史的局限性,社会主义生产关系在具体化过程中产生了偏差,因此,在生产力水平不高的情况下,把直接所有权与间接所有权相结合,是社会主义公有制中人民对生产资料所有权的最佳实现形式.     

新疆兵团企业为主体产学研合作模式的构建

该文分析了新疆生产建设兵团现有的产学研合作模式,探讨了兵团产学研合作模式运作中存在的主要问题,提出构建兵团以企业为主体产学研合作模式遵循的基本原则,在此基础上构建了兵团以企业为主体产学研合作的具体运作模式,包括兵团企业为主体合作开发模式、兵团企业为主体委托开发模式、兵团企业为主体共建企业技术中心模式和共建工程技术中心模式。     

微博在构建和谐社会中的作用分析

随着互联网、手机的普及,微博在现实社会中的作用越来越大,对社会公共事务的影响也逐渐由旁观者走向参与者。如何发挥其优点,限制其不足,日益成为人们的关注点。加强微博话语平台在构建和谐社会、法治社会方面的作用,需要做到三点:一是坚持法治化策略,二是坚持多元化策略,三是进行广泛的新媒体素养教育。     

A comparison between genetic algorithms and the RAND method for solving the joint replenishment problem

The purpose of this paper is to compare the performance of genetic algorithms (GAs) and the best available heuristic, known as the RAND, for solving the joint replenishment problem (JRP). An important feature of the JRP which makes it suitable for GAs is that it can be formulated as a problem having one continuous decision variable and a number of integer decision variables equal to the number of products being produced or ordered. Experiments on randomly generated problems indicate that GAs can provide better solutions to the JRP than the RAND for some problems, and at worst can almost match the performance of the RAND from a practical point of view for the rest of the problems. GAs never converged to solution with a total cost of more than 0.08% of the total cost of the RAND for 1600 randomly generated problems. In addition, GAs have the advantages of: (i) being easy to implement (e.g. less than 200 lines of code); (ii) having a code which is easy to understand and modify; and (iii) dealing easily with constrained JRPs which are neglected by most of the available methods including the RAND, in spite of their importance in practice.     

Development and teaching a computer-assisted course in production planning

Abstract. Course development and student activities are described for a successful computer-assisted senior level course in production planning. Development was guided by the view that students must (1) understand the elements being integrated, (2) understand the problems that are being resolved through integration, and (3) participate in the integration activity. Production planning is treated as a hierarchy of individual decision situations which are to be integrated. Each decision is assisted by a software-based technique. A menu program and a common database were developed to allow a student to become the 'integrator' by directing the information flow among the individual decision situations. The paper describes the development tasks, the course elements, and student activities which provide guidelines for others developing similar courses.     

Branding the self as an “authentic feminist”: negotiating feminist values in post-feminist digital cultural production

Freelancers who produce creative content online work in an increasingly precarious neoliberal economy, which requires self-branding, self-promotion, and constant audience engagement to succeed. Creating feminist content in a digital environment thus requires the negotiation of individual self-branding and promotional activities alongside the advancement of collective feminist politics. In this study, interviews with 11 feminist online writers reveal that they reconcile the individualistic undertakings required to succeed in the digital economy and their collective feminist values in three ways. Firstly, they incorporate “authentic feminism” into their personal branding endeavors; secondly, they redefine feminism to more closely match the values of post-feminism; and, thirdly, they advance peripheral collective goals in their creative communities. It is through these strategies that feminist values are negotiated and reworked, enabling producers to succeed as feminists in a digital economy that is more closely aligned with post-feminism.     

Aging and Cardiometabolic Risk in European HEMS Pilots: An Assessment of Occupational Old‐Age Limits as a Regulatory Risk Management Strategy

Old‐age limits are imposed in some occupations in an effort to ensure public safety. In aviation, the “Age 60 Rule” limits permissible flight operations conducted by pilots aged 60 and over. Using a retrospective cohort design, we assessed this rule's validity by comparing age‐related change rates of cardiometabolic incapacitation risk markers in European helicopter emergency medical service (HEMS) pilots near age 60 with those in younger pilots. Specifically, individual clinical, laboratory, and electrocardiogram (ECG)‐based risk markers and an overall cardiovascular event risk score were determined from aeromedical examination records of 66 German, Austrian, Polish, and Czech HEMS pilots (average follow‐up 8.52 years). Risk marker change rates were assessed using linear mixed models and generalized additive models. Body mass index increases over time were slower in pilots near age 60 compared to younger pilots, and fasting glucose levels increased only in the latter. Whereas the lipid profile remained unchanged in the latter, it improved in the former. An ECG‐based arrhythmia risk marker increased in younger pilots, which persisted in the older pilots. Six‐month risk of a fatal cardiovascular event (in or out of cockpit) was estimated between 0% and 0.3%. Between 41% and 95% of risk marker variability was due to unexplained time‐stable between‐person differences. To conclude, the cardiometabolic risk marker profile of HEMS pilots appears to improve over time in pilots near age 60, compared to younger pilots. Given large stable interindividual differences, we recommend individualized risk assessment of HEMS pilots near age 60 instead of general grounding.     

21世纪的高等工程教育

评述了工业生产系统及其随着各种相关高技术的进展而带来的变化 ,在与农业生产系统比较后 ,纵览了生产系统的一般发展趋势 ,在此背景评述的基础上 ,描述了大学的作用 ,并对社会在 2 1世纪需要何种类型的大学毕业生提出了见解