A Bayesian Non-parametric Approach to Survival Analysis Using Polya Trees

This paper presents a Bayesian non-parametric approach to survival analysis based on arbitrarily right censored data. The analysis is based on posterior predictive probabilities using a Polya tree prior distribution on the space of probability measures on [0, ∞). In particular we show that the estimate generalizes the classical Kaplanndash;Meier non-parametric estimator, which is obtained in the limiting case as the weight of prior information tends to zero.     

中英语言中植物词语的文化内涵比较

通过分析语言与文化的关系、词汇文化内涵的产生,比较了中英语言中部分植物词汇的文化内涵差异.借助于这些比较,说明由于中西方文化传统的差异,导致各自语言中同一植物词汇,却具有相似或截然不同的文化内涵.这种内涵的差异,直接影响着跨文化交际中的理解与沟通,直接影响着跨文化交际的效果.     

Vegetation of the urban habitats in the Nile Delta region,Egypt

The present study aims at identifying the plant communities of the urban habitats in the Nile Delta region, Egypt. Four hundred and five stands were selected to represent the variation in eight major types of habitat recognized in the study area. Twenty-five vegetation groups were recognized after application of TWINSPAN. Their ordination using DECORANA indicates moisture, pH, fertility and texture gradients; the hygronitrophilous communities (the moist and fertile stands) inhabit the wet refuse areas (Echinochloa stagnina-Eichhornia crassipes group), mesonitrophilous communities inhabit the dry refuse areas, motor roads and railways (Pluchea dioscoridis, Cynodon dactylon, Panicum repens and Phragmites australis groups), mesic-dry subnitrophilous communities occur on sandy soils (Hordeum murinum, Alhagi graecorum and Desmostachia bipinnata groups) and the dry thermophilous communities of new anthropogenic habitats with coarser texture of sandy and infertile soil along the railways and motor roads at the borders of the Nile Delta (Zygophyllum album and Cornulaca monacantha groups). These results suggest that urban vegetation in the Nile Delta region is favored where disturbance, nutrient and water resources are more abundant.     

戴柳、插柳风俗考论

本文对我国的戴柳、插柳风俗流行的地域、时间、内容、功用等进行了分析归纳,着重探讨了戴柳、插柳风俗的原始功能意义,认为它是由古代先民植物崇拜、生殖崇拜发展演化而来的一种民俗事象。     

The geography of corporate production: Urban,industrial, and organizational systems

This paper examines how the territorial organization of corporate production — the extent to which firms connect places in the city system through intraorganizational relationships of ownership and control — is shaped by urban, industrial, and organization factors. Specifically, we study the determinants of the dispersion of corporate production facilities in the U.S. urban system. We analyze the number of U.S. cities and states in which the largest 500 industrial corporations operated plants in 1964 as a function of the characteristics of the location of the corporate headquarters, the predominant industries in which their plants produce, and their organizational structure. We find that corporate dispersion is shaped by some of the same factors that have been shown to organize the market-based territorial division of labor — the size and functional specialization of cities and the locational requirements of industry. But in addition, organizational attributes — a firm's industrial diversity, its age, and the extent to which it is controlled by families as opposed to managerial coalitions — also influence its geographic dispersion.An earlier version of this paper was presented at the 1983 annual meetings of the American Sociological Association in Detroit, Michigan.     

关于放射性物质浓度预估模型的研究

放射性物质的浓度预测问题就是为了更好的估计气体的污染程度,让人们做好预防准备．对于核电站的泄漏进行适时的测量和估计是非常必要的．以2011年西安某高校数学建模竞赛A题为例．对无风时放射性气体扩散情况进行预估,预测核电站泄漏对周边地区的影响．再分析预测风对放射性气体扩散的影响,预估此时核电站泄漏对周边地区的影响,并以此大致预估实际上核电站泄漏对周边地区的影响,做好预防工作．     

基因专利与第二代生物燃料开发

随着世界能源的匮乏,各国竞争的日益加剧,新能源开发成为保证人类存续和社会可持续发展的极其重要的研究课题。以基因技术为核心的第二代生物燃料产业化必将成为新能源产业的关键性支柱。因此,推进基因专利保护,通过立法和司法的完善为生物燃料开发提供保障机制和激励机制,是我国的新能源战略。通过分析第二代生物燃料产业下基因技术保护遇到的困难,并据此提出在关注基因技术进步的同时完善知识产权保护制度配套规则的建议。     

北京奥林匹克森林公园游客对植物景观偏好研究

北京奥林匹克森林公园为模拟和营造自然植物景观,集中地采用多种植物造景手法。以问卷方式对来园游客展开调查,研究游客对该公园植物景观的偏好和游憩环境的感受情况。调查游客的基本特征包括性别、年龄、学历、职业和居住地;调查范围基本覆盖了公园的各个游憩区和景点。通过统计游客对不同类型的观赏植物、植物群落、植物空间环境和植物景观的偏好程度,分析其各自的特点及原因。研究结果表明：观花植物、乔灌草混交群落、半封闭的植物空间和林中溪流景观是多数游客的最爱;不同性别、年龄游客的偏好程度在某些方面存在差异。     

风仙等药用植物防治玉米丝黑穗病的试验

9种药用植物对玉米丝轴黑粉病原菌抑制、杀灭作用的试验,结果表明,风仙等4种药用植物药效显著。幼苗期室内观察,应用风仙,可使感病自交系埃及205和黄早4受病原菌侵入的幼芽鞘上活细胞数分别由对照的8.6%及12.4%提高到78.4%及62.7%。田间试验的发病率,分别由对照的22.9%及27.1%减少到4.1%及6.25%。     

云南传统植物染料及其开发

在多民族聚居的云南高原，传统植物染料在各民族衣物染制中占有相当重要的位置。随着社会的发展，化工染料进入人们的生活中，逐步取代了植物染料。半个多世纪以来，人们通过比较，认为植物染料对人体有益无害，这是化学染料无法相比的。特别是发达国家更重视植物染料。云南植物染料资源丰富，优势突出，应让传统的加工、染制技术在开发绿色产业、发展民族经济和西部大开发中发挥更重要的作用。