Quantifying uncertainty in the biospheric carbon flux for England and Wales

Summary.  A crucial issue in the current global warming debate is the effect of vegetation and soils on carbon dioxide (CO₂) concentrations in the atmosphere. Vegetation can extract CO₂ through photosynthesis, but respiration, decay of soil organic matter and disturbance effects such as fire return it to the atmosphere. The balance of these processes is the net carbon flux. To estimate the biospheric carbon flux for England and Wales, we address the statistical problem of inference for the sum of multiple outputs from a complex deterministic computer code whose input parameters are uncertain. The code is a process model which simulates the carbon dynamics of vegetation and soils, including the amount of carbon that is stored as a result of photosynthesis and the amount that is returned to the atmosphere through respiration. The aggregation of outputs corresponding to multiple sites and types of vegetation in a region gives an estimate of the total carbon flux for that region over a period of time. Expert prior opinions are elicited for marginal uncertainty about the relevant input parameters and for correlations of inputs between sites. A Gaussian process model is used to build emulators of the multiple code outputs and Bayesian uncertainty analysis is then used to propagate uncertainty in the input parameters through to uncertainty on the aggregated output. Numerical results are presented for England and Wales in the year 2000. It is estimated that vegetation and soils in England and Wales constituted a net sink of 7.55 Mt C (1 Mt C = 10¹² g of carbon) in 2000, with standard deviation 0.56 Mt C resulting from the sources of uncertainty that are considered.     

解读人与自然的和谐

人与自然和谐包含着丰富和深刻的内涵 ,从理论层面上看 ,它应是人与自然互相适应的辩证统一 ;从实践层面上讲 ,它应是人与自然双方均处于既被改造又应保护的关系之中。必须反对在这个问题上的各种片面的观点与看法     

从盐业契约看民事诉讼模式的转变

在现代民事诉讼制度中，一直存在职权主义诉讼与当事人主义诉讼两种模式之争，而我国的民事诉讼制度可以说基本上属于职权主义模式。在四川井盐生产历史过程中，保留了丰富的盐业契约档案，这些契约规范着各类的盐业生产经营活动，调解着复杂的盐业诉讼纠纷盐业契约以其突出的自由性、合意性以及遵从习惯等特点，在过去有效地调节着复杂的经济关系，我们探析其中有价值的成分，对于思考我国的民事诉讼制度应更多地引入当事人主义模式一定会有所启示。     

Fast retraction of evidence in a probabilistic expert system

We present and justify a propagation algorithm to facilitate the simultaneous calculation, for every node in a probabilistic exper system of the distribution of the associated random quantity, conditional on all the evidence obtained about the remaining nodes.     

Women's Changing Attitudes Toward Divorce, 1974–2002: Evidence for an Educational Crossover

This article examines trends in divorce attitudes of young adult women in the United States by educational attainment from 1974 to 2002. Women with 4‐year college degrees, who previously had the most permissive attitudes toward divorce, have become more restrictive in their attitudes toward divorce than high school graduates and women with some college education, whereas women with no high school diplomas have increasingly permissive attitudes toward divorce. We examine this educational crossover in divorce attitudes in the context of variables correlated with women's educational attainment, including family attitudes and religion, income and occupational prestige, and family structure. We conclude that the educational crossover in divorce attitudes is associated most strongly with work and family structure variables.     

乌鲁木齐县安宁渠镇社会经济变化调查报告

该文通过对乌鲁木齐县安宁渠镇的调查 ,揭示了城镇化进程中所发生的社会经济变化 ,以及这一变化所产生的后果 ;论述了加快安宁渠镇发展急需解决的问题 ,即社会意识整合问题、知识更新问题、基础设施建设问题、体制问题等。     

二十世纪八九十年代女性文学变革探析

二十世纪八九十年代女性文学在传统女性文学的基础上发生嬗变,在中国文坛上引起巨大的震撼。试图从女性生存的环境和女性性别意识诠释女性文学发生流变的真实状态。探讨女性文学在变革时期所走过的不寻常的路。剥离出对现在文学有启迪的、有价值的女性文学。     

生物学中的相异构想及转变探讨

研究表明，学生学习科学的过程是一种由前概念向科学概念转变的过程。学生头脑中形成的与科学概念不一致的相异构想是造成学生学习困难的重要原因。本文分析了学生在生物学学习中相异构想的成因及来源，并在此基础上提出了生物学教学中相异构想的转变模式及策略。     

傣族龙图腾文化刍议

“龙”是中华民族文化积淀的重要标志,中国人有龙的子孙之说。相关资料证明,“龙”与傣民族图腾之来由亦有密切联系,通过研究可以揭示出各民族宗教艺术融合中产生的多元化变异的现象。     

土地治权的变动与政权变迁

在传统农耕社会的制度框架中,土地不仅是一种经济学意义上的自然资源,更为重要的是作为一种政治活动的对象而存在。国家以政权的形式赋予土地所有权、土地经营方式以合法性的依据。土地治权与国家政权之间存在着一种内在的张力,土地治权作为国家意志在土地之中的凝结,其变动是对于社会利益的一种强制性的分割,与传统社会的政权变动有着内在性的相关。