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31.
王静 《山西高等学校社会科学学报》2008,20(11):89-92
高等教育诸多方面存在着不适应建设和谐社会的问题。这种不和谐问题主要是由于高等教育体系在诸多方面还不能完全满足个人或适应社会的需求。产生问题的原因主要是高等教育体系在教育资源、运行机制、教育教学、教师等方面存在诸多需要改进之处。所有这些问题产生的根源可归结为高等教育质量问题。 相似文献
32.
王春光 《中国农业大学学报(社会科学版)》2008,25(3):55-67
文章从社会学角度探讨了过去30年以来中国的城市化及其引发的社会结构变迁。文章指出,在过去30年中国的城市化经历了飞速的发展,进入了快速城市化阶段,离基本城市化阶段越来越近,但由于中国独特的城乡制度以及行政管理体制,中国城市化呈现两种模式——主动城市化模式和被动城市化模式,并呈现多种城市化主体,而政府和企业则是中国城市化的主导性主体。这背后最主要的动力机制还是制度和利益,彰显出中国社会结构变迁趋势:在利益机制驱使下,中国社会渐渐地形成了城乡差别不断扩大、城市内部分化明显的利益分配格局;由于缺乏公开、公正、民主的配置机制,各个城市化主体之间的博弈大多屈从于弱肉强食的“丛林法则”,从而导致各种暴力冲突、相互仇视的问题,这在一定程度上破坏了城市社会运行秩序特别是支撑这些秩序的信任机制,显现出相当严重的合法性危机,对未来中国的城市化提出了严峻的挑战。为此,文章提出了中国未来城市化的几种可能的路径。 相似文献
33.
The benchmark dose (BMD) is an exposure level that would induce a small risk increase (BMR level) above the background. The BMD approach to deriving a reference dose for risk assessment of noncancer effects is advantageous in that the estimate of BMD is not restricted to experimental doses and utilizes most available dose-response information. To quantify statistical uncertainty of a BMD estimate, we often calculate and report its lower confidence limit (i.e., BMDL), and may even consider it as a more conservative alternative to BMD itself. Computation of BMDL may involve normal confidence limits to BMD in conjunction with the delta method. Therefore, factors, such as small sample size and nonlinearity in model parameters, can affect the performance of the delta method BMDL, and alternative methods are useful. In this article, we propose a bootstrap method to estimate BMDL utilizing a scheme that consists of a resampling of residuals after model fitting and a one-step formula for parameter estimation. We illustrate the method with clustered binary data from developmental toxicity experiments. Our analysis shows that with moderately elevated dose-response data, the distribution of BMD estimator tends to be left-skewed and bootstrap BMDL s are smaller than the delta method BMDL s on average, hence quantifying risk more conservatively. Statistically, the bootstrap BMDL quantifies the uncertainty of the true BMD more honestly than the delta method BMDL as its coverage probability is closer to the nominal level than that of delta method BMDL. We find that BMD and BMDL estimates are generally insensitive to model choices provided that the models fit the data comparably well near the region of BMD. Our analysis also suggests that, in the presence of a significant and moderately strong dose-response relationship, the developmental toxicity experiments under the standard protocol support dose-response assessment at 5% BMR for BMD and 95% confidence level for BMDL. 相似文献
34.
Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Traditionally, this parameter
has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health
at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions
were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the
tree crown was classified as either healthy or unhealthy based on vegetation index values. At the whole tree scale, raster
based statistical analysis was used to calculate tree health index which is the ratio of healthy pixels to entire tree pixels
within the tree crown. The tree was classified as healthy if the index was greater than 70%. Accuracy was checked against
a random sample of 1,186 trees. At the whole tree level, 86% of campus trees were classified as healthy with 88% mapping accuracy.
At the pixel level, 86% of the campus tree cover was classified as healthy. This tree health evaluation approach allows managers
to identify the location of unhealthy trees for further diagnosis and treatment. It can be used to track the spread of disease
and monitor seasonal or annual changes in tree health. Also, it provides tree health information that is fundamental to modeling
and analysis of the environmental, social, and economic services produced by urban forests. 相似文献
35.
文章根据经济全球化和知识化的客观要求,在分析国有无形资产流失的特征、途径的基础上,从强化观念、建立机构、完善制度、制定战略、营造环境等方面提出了防止国有无形资产流失的一系列对策。 相似文献
36.
1999年《蒙特利尔公约》随着美国作为第30个国家的加入,已于2003年11月4日正式生效。经我国人民代表大会批准,公约于2005年7月31日对我国生效。本文通过对《蒙特利尔公约》与其之前的公约(华沙公约体系和IATA责任体制)进行比较,阐述了公约的重要意义及重要新增内容,探讨了公约相关问题。 相似文献
37.
38.
The total fertility rate of women of childbearing age of Dongguan County in China has been decreasing gradually from 5.9 during the period following the liberation in 1949 to 2.05 in 1982. In order to encourage young couples to implement the policy of family planning consciously, the people's government of Dongguan county decided in July 1980 that all cadres and employees in county towns who received 1-child certificates would be exempted from house rent of 45 square meters from the time they get their certificates and would be allocated a living space of a 2-children family until their children reached age 16. It also stipulated that every couple could enjoy 1 month's holiday every year for 3 years and during the holiday, their salary, bonus and rate of attendance would not be affected. Because women bear less children today, they are relieved from heavy household chores and become the main working force in collective production. As a result, the development of town-run enterprises was stimulated and the total industrial output value of these enterprises increased. The average monthly salary of each female worker is about 100 yuan. In 1984, the average income per capita of the country rose to 649.2 yuan. The implementation of family planning work has eased the tension in the education field. Previously, because of the large number of school-age children in rural areas, teachers had to teach 2 classes. In the past 4 years, great emphasis was laid on intellectual investment. During this period, 2351 schools were built and several fundraising projects were implemented. Since 1981, more than 200 new running water projects were built, and new public services have been developed, including old age homes. 相似文献
39.
This paper models household fertility decisions by using a generalized Poisson regression model. Since the fertility data
used in the paper exhibit under-dispersion, the generalized Poisson regression model has statistical advantages over both
standard Poisson and negative binomial regression models, and is suitable for analysis of count data that exhibit either over-dispersion
or under-dispersion. The model is estimated by the method of maximum likelihood. Approximate tests for the dispersion and
goodness-of-fit measures for comparing alternative models are discussed. Based on observations from the Panel Study of Income
Dynamics of 1989 interviewing year, the empirical results support the fertility hypothesis of Becker and Lewis (1973).
Received January 7, 1997 /Accepted April 3, 1997 相似文献
40.
汪超 《浙江大学学报(人文社会科学版)》1993,5(5):204
近20年来,词学研究有所进展,但仍存在一些问题。词学研究应在多重网络中展开。首先,词学是专门之学,但研究者仍需建构开放的知识网络。词乐研究虽有不少成果,但仍处于相对低潮。这与研究者受限于音乐知识,无法有效介入有关。词谱、词律等专门之学亦是如此。其次,可以尝试词学研究的时空延展,打造通观的“全息网络”,通过长时段的、大量的文本分析发现新话题。同时,注意域外汉籍,因为它们可以提供新文献,启发新视角,丰富文本网络。最后,要注意数字人文的发展趋向,要建设词学检索库,善用新技术,更新研究理念,以便及时因应。但数字人文终究只是辅助研究手段,技术取代不了阅读与思考,只有在传统研究的基础上,技术才能发挥更大的作用。 相似文献