邓小平的政治观与当代中国政治转型

邓小平是我国改革开放的总设计师,他对社会主义政治内涵的新诠释和政治与经济关系的阐述以及提出的处理政治与经济关系的基本方略,为人们认识社会主义政治的科学内涵,从理论和实践上推动当代中国政治转型,为当代中国政治文明建设奠定了基础。     

多媒体呈现流程的形式化描述及内容表示

交互式多媒体呈现系统一般由呈现内容和呈现控制流程两部分组成。通过引入通用转换网络,对交互式多媒体应用系统的内部呈现流程进行了形式化描述;讨论了该形式化描述下呈现流程的重用性;提出了将呈现流程与呈现内容相分离的系统实现策略;给出了呈现内容描述和可呈现对象相结合的呈现内容表示方法。该策略和方法可用于设计实现交互式多媒体呈现系统创作平台,利用该平台创作的呈现系统能够并发地呈现多种媒体形式的信息,系统及其组成部件具有良好的可重用性。     

我国历史上疆域形成、变迁的理论研究

文章就我国历史上疆域形成及变迁的有关理论问题进行了研究。作者回顾了半个世纪以来我国疆域研究取得的成就,分析了有关论述观点的得失,提出了深化此项研究的对策。     

A Bayesian Hierarchical Model for the Evaluation of a Website

Consider a website and the surfers visiting its pages. A typical issue of interest, for example while monitoring an advertising campaign, concerns whether a specific page has been designed successfully, i.e. is able to attract surfers or address them to other pages within the site. We assume that the surfing behaviour is fully described by the transition probabilities from one page to another, so that a clickstream (sequence of consecutively visited pages) can be viewed as a finite-state-space Markov chain. We then implement a variety of hierarchical prior distributions on the multivariate logits of the transition probabilities and define, for each page, a content effect and a link effect. The former measures the attractiveness of the page due to its contents, while the latter signals its ability to suggest further interesting links within the site. Moreover, we define an additional effect, representing overall page success, which incorporates both effects previously described. Using WinBUGS, we provide estimates and credible intervals for each of the above effects and rank pages accordingly.     

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.     

Uncertain Numbers and Uncertainty in the Selection of Input Distributions—Consequences for a Probabilistic Risk Assessment of Contaminated Land

Risks from exposure to contaminated land are often assessed with the aid of mathematical models. The current probabilistic approach is a considerable improvement on previous deterministic risk assessment practices, in that it attempts to characterize uncertainty and variability. However, some inputs continue to be assigned as precise numbers, while others are characterized as precise probability distributions. Such precision is hard to justify, and we show in this article how rounding errors and distribution assumptions can affect an exposure assessment. The outcome of traditional deterministic point estimates and Monte Carlo simulations were compared to probability bounds analyses. Assigning all scalars as imprecise numbers (intervals prescribed by significant digits) added uncertainty to the deterministic point estimate of about one order of magnitude. Similarly, representing probability distributions as probability boxes added several orders of magnitude to the uncertainty of the probabilistic estimate. This indicates that the size of the uncertainty in such assessments is actually much greater than currently reported. The article suggests that full disclosure of the uncertainty may facilitate decision making in opening up a negotiation window. In the risk analysis process, it is also an ethical obligation to clarify the boundary between the scientific and social domains.     

PES-C,(PP/Bis-T)PES的次级松驰与转变

描述了酚酞型聚芳醚砜(PES-C)的次级松驰和转变与其结构的关系.TBA和动态力学实验结果表明:PES-C及其共聚物(PP/Bis-T)PES分别在0～50℃和-100℃附近呈现出两个次级松驰峰;双酚T单元的引入导致了PES-C在0～50℃之间的次级松驰位置改变.证实了Cardo侧基的存在对-100℃的次级松驰有较大的贡献.     

Analytical approximations for iterated bootstrap confidence intervals

Standard algorithms for the construction of iterated bootstrap confidence intervals are computationally very demanding, requiring nested levels of bootstrap resampling. We propose an alternative approach to constructing double bootstrap confidence intervals that involves replacing the inner level of resampling by an analytical approximation. This approximation is based on saddlepoint methods and a tail probability approximation of DiCiccio and Martin (1991). Our technique significantly reduces the computational expense of iterated bootstrap calculations. A formal algorithm for the construction of our approximate iterated bootstrap confidence intervals is presented, and some crucial practical issues arising in its implementation are discussed. Our procedure is illustrated in the case of constructing confidence intervals for ratios of means using both real and simulated data. We repeat an experiment of Schenker (1985) involving the construction of bootstrap confidence intervals for a variance and demonstrate that our technique makes feasible the construction of accurate bootstrap confidence intervals in that context. Finally, we investigate the use of our technique in a more complex setting, that of constructing confidence intervals for a correlation coefficient.     

阶段的过渡与本质的上升——20世纪90年代至21世纪初国际社会发展本质特点的系统与实证分析

论述了冷战结束以来 ,国际社会在“一个主题”(和平与发展 )“两个趋势”(经济全球化、政治多极化 )的总特征前提下发生的一系列深刻的结构性变化。提出了旧的国际格局被打破、新的格局尚未形成 ,在新旧体系转换的过程中 ,不同的国际关系主体为了其各自的根本利益、为在未来的新格局中占据更加有利的地位而展开了新一轮的较量。在此过程中 ,国际社会呈现出过渡时期所特有的一系列纷繁复杂的特征 ,并进一步影响着国际形势的走势。我们应当立足于从形式到本质的认知途径对这些变化特征进行深刻的分析 ,以求准确地把握新时期国际社会发展的本质性特征和规律     

汉初时代转型与《淮南子》的学术境遇

汉初的时代转型,有着如下特质:在社会经济状况方面,经历了从“休养生息”到“争于奢侈”的过程;在政治局势上,由“诸侯割据”演化为“强干弱枝”政策的全面推行;在思想与学术方面,“黄老擅权”的状况转变为“儒术独尊”之势。《淮南子》之所以未受当政者的推崇,主要原因即在于未能合乎时代转型之需。