内开槽螺纹波导冷腔色散特性模拟研究

根据螺纹波导中模式间的耦合方程组及冷腔色散方程进行了数值计算,分析了2个模式的相互耦合机理。基于圆柱形波导中线性极化TE11模式存在极化简并的特性,将线极化TE11脉冲作为1个探针,采用粒子模拟软件对该腔体进行了3维冷腔模拟;并将模拟结果与数值计算结果进行了比较,两者基本一致。通过计算机模拟得出了混合模式的电场等位线分布图,结合色散方程数值计算分析了内开槽螺纹几何特性变化对波导色散特性的影响规律。     

回归生活世界重建德育模式

传统的思想道德教育模式远离现实生活,面对思想道德领域层出不穷的新问题,改革传统的思想道德教育模式势在必行.道德教育改革与发展的价值取向应是回归生活,道德教育内容、德育方式、德育原则等都应围绕回归生活来重建.     

渣铁冶炼炉污染治理的研究

本文通过对攀枝花渣铁冶炼的基本情况行分析,总结了重力、湿式、过滤式、电除尘四种方法的优缺点,在实际工程中自行设计了一套工艺流程取得了成功,为西部的环境保护提供了有益的参考。     

Bootstrap Estimation of Benchmark Doses and Confidence Limits with Clustered Quantal Data

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.     

现代艺术的生态审美批判

作为地球生态系统中的重要方面,精神生态危机与自然生态危机之间存在着必然的内在联系,两者都是生态文化运动所要关注的对象。本文试图从生态文化的视角出发,对现代艺术领域里的非生态现象进行批判,并阐述生态审美的基本原则及其本体论基础,希望生态审美研究能成为推动艺术生态与精神生态和谐的第一步。     

中国农地制度的合理性探微：一个组织的制度分析范式

中国农村土地制度长期坚持以集体所有和家庭承包为内核，这不仅是国家层面的主观需要，也有集体和家庭分别作为两种制度安排的内在合理性。集体和家庭都体现着长期历史的自然选择，法律的规定只是让原有的非正式制度显化为正式的制度安排，外加非正式制度的配合，农地制度更易形成有效率的制度结构；集体和家庭在不同时期表征不同的功能，节约不同层次的交易费用，它们均具有较强的适应农地制度变革的能力。深化农地集体所有制改革需契合客观存在的自然法序，注重正式制度与非正式制度的功能配合，增强中国农地制度的稳定性和灵活性。     

Demographic aspects of abortion

The author discusses the need to emphasize the use of contraceptive methods in Poland, where women's desired family size is 2.0 to 2.2, and this number is realized by the age of 30-35. It is asserted that a higher cultural level, which includes a more sophisticated attitude toward sex, would eliminate the need to pass antiabortion legislation.     

Procreative attitudes of newly married couples

Results are presented from a 1985 survey conducted among newly married couples in Poland concerning ideal and planned number of children. Both husbands and wives participated in the survey. Comparisons are made with results from a previous survey undertaken in 1975.     

Fertility prospects in Poland

The three phases of the demographic transition in Poland are described with emphasis on changes in fertility. The author notes that the country had entered the third phase of low fertility by 1965. Despite a slight temporary increase due to pronatalist incentives, fertility has since remained low and will probably continue at this level or decline further.     

延迟支付条件下易逝品的最优订货决策研究

本文在考虑延期支付的情况下构建了二级供应链关于易逝品的最优订货决策模型,其中供应链由单个供应商和多个面临资金约束的零售商组成。在不允许缺货的情况下,供应商为零售商提供延迟支付来缓解零售商的资金压力,同时零售商对产品的定价将随易逝品的价值变质而变化。本文利用遗传算法对模型进行了算例分析,同时对模型中的相关参数进行了敏感性分析。结果表明,延迟支付能够提高供应链总利润并降低风险,从而有利于供应链整体效益的提高。在延期支付条件下,供应链各成员获得的收益增量存在较大差距,其中供应商能够获得更多收益。最后,通过敏感性分析,我们还发现产量及易逝品保质期的变动会对供应链整体利润产生不同程度的影响。