A NUMERICAL STUDY ON NATURAL CONVECTION IN A CLOSED CAVITY PARTIALLY FILLED WITH POROUS MEDIUM

The present paper decribes numerical analytical results of natural convection in a closed cavity partially filled with porous medium by means of Forchheimer-Brinkman model. The effects of heated rate,permeability,height of porous region,heat conduction coefficients and aspect ratio on flow and heat transfar in the cavity are systematically investigated. Velocity and temperature fields in the cavity are given and dependence of average Nu on time is obtained.     

Empirical Study of the Support System of New Venture Creation

The Support System of New Venture Creation is the main parts of national and regional innovation system. At presently ,many study on the Support System are from angle of view of the macro or government ,little study from the New Venture. University Science Park in China have enough New Venture which can be the representation of New Venture Creation. The authors study the former theory ,use the method of Empirical Study, Based on the questionnaire investigation of Chongqing University Science Park, analyze different requirements of the enterprises in different sizes and different stages, and bring forward some advises.     

部分水稻品种对稻瘟病菌群体的抗病性分析

利用生物间遗传学关于毒力频率和联合抗病性分析的方法，分析了16个品种对稻瘟病菌群体的抗瘟性。结果表明，参试病菌群体对各个品种的毒力以及不同稻区的病菌群体对同一品种的毒力均存在明显差异，筛选出毒力频率较低的4个品种：汕优多系1号、Ⅱ优多系1号、金优431和金优多系1号。用联合致病性系数和联合抗病性系数分析了品种搭配在生产上的应用前景。     

Empirical Study on the Sustainable Growth of the Public Companies in China

The sustainable growth is the corporation's final object to the maximum of the stock-holder's wealth. To validate the development of the Chinese public companies after Dengxiaoping's Nanxun speech ,this paper tests the sustainable growth status of the Chinese public companies during the period from 1993 to 2000 by using mathematical statistics method and sustainable growth model brought forward by Robert Higgins and James Van Herne. These companies are classified by trade. The test results show that no trade realized sustainable growth except electronic and electric trade. Results also indicate that public companies in light industry and agricultural sectors have a trend of under-investment while those in other sectors have a trend of over investment.     

小麦株高相关性状与SNP标记全基因组关联分析

株高是影响小麦产量和控制倒伏的重要因素,研究小麦株高相关性状的遗传机制对高产育种具有指导意义。以205份中国冬麦区小麦品种(系)为材料,利用分布于小麦全基因组的24 355个单核苷酸多态性(SNP)标记对株高相关性状进行关联分析。共发现38个与株高相关性状显著关联(P0.0001)的SNP,分布在1B、2A、2B、3A、3B、3D、4A、4B、5A和6D染色体上。其中,11个位点至少在2个环境中稳定表达,可用于开发CAPS标记。同时,发掘了一批株高性状相关基因的优异等位变异,如降低株高的等位变异Bob White_c48009_52,平均降低株高12.9 cm;控制穗下节间长的等位变异BS00039422_51-C和IAAV1698-A,分别调控穗下节间长5.9 cm和6.6 cm。本研究发掘的控制小麦株高基因位点为在分子水平上研究小麦株高复杂性状提供了有价值的参考。     

基于层次分析法的江西省可持续食物安全评价

选取化肥用量等23个指标,采用层次分析法测算江西省可持续食物安全度.结果表明,1978-2003年江西省可持续食物安全度逐步提高,目前食物处于安全水平.江西省食物生产因子、资源禀赋因子和气候因子安全水平较高,对食物安全较有保障;食物保障因子和社会经济因子安全水平偏低,是可持续食物安全的薄弱环节;可持续环境因子的安全水平正逐步加强,有利于提高可持续食物安全度.     

猫儿山优势种空间点格局和种间关系分析

黔稠、榕叶冬青和青冈是猫儿山植物群落中分布相对广泛的3个优势种。对它们在不同海拔上的径级结构分析结果表明:3个物种在2个海拔梯度上径级都呈现峰型分布,最高峰都集中在4～8 cm的中小径级范围内,中小个体储备充足,会在相当长一段时间内保持其在群落中的优势地位。通过连续取样的L方程点格局分析方法,对其空间格局和种间关系分析显示:3个物种在样地中不同尺度上以空间显著聚集分布为主,在极少数尺度上仍然存在随机分布和均匀分布格局。3个物种在50 m范围内的分布几乎都表现为独立不相关性。而黔稠和青冈同属于青冈属,在2个样地中的一些小尺度上表现为显著的正相关性。      

基于产业链发展的职业院校食品加工类专业群构建研究——以河南省为例

论述了河南省高职院校食品加工类专业群建设与食品产业链发展现状及存在的问题,提出了基于产业链发展的高职院校食品加工类专业群构建原则。     

石化企业循环经济发展综合评价及实证研究

依据循环经济的相关理论,构建了涵盖减量化、再利用、无害化3个子系统的石化企业循环经济发展水平综合评价体系。运用层次分析法确定各指标权重系数,采取模糊综合评价法对石化企业循环经济发展水平进行综合评价,在此基础上对某石化企业进行了实证研究。