Convective Filmwise Condensation of R-11 inside a Vertical Tube

Partial condensation of refrigerant R-11 was experimentally and theoretically studied. The test apparatus consisted of two concentric tubes, with the vapor flowing downward in the inner tube and the cooling water in the annular space in countercurrent direction. By using the available dimensionless correlation, the mean heat transfer coefficient of the cooling water was determined, and then the mean condensationheat transfer coefficient was calculated from the overall heat transfer coefficient.The model of a homogeneous two-phase mixture of liquid and vapor, and Prandtl's principle of analogy between the momentum and heat transfer were used to establish the type of the correlation. Adopting the methods of the gradually linear regression and F-level evidence testing, the present paper proposed the dimensionless correlation to predict the relationship among the mean Nusselt number, Prandtl number, Kutateladze number and the dimensionless tube length.     

海洛因中毒小鼠睾丸的组织形态改变

通过腹腔注射海洛因使小鼠染毒,观察了生精小管上皮细胞的形态变化,并应用图像分析系统对实级精母细胞的形态参数进行了分析。结果表明,一定剂量的海洛因对小鼠初级精母细胞的细胞面积、细胞周长、核面积、浆面积、核浆比例、核灰度及细胞圆形度均有影响。提示海洛因可明显改变小鼠生殖细胞的形态结构。     

江西寻乌地区蜻蜓调查初报

1996－1007年在江西省寻乌山区捕获蜻蜒26种,分隶6科、20属。其中20种是江西省新记录。     

广东普通工科高等教育的办学效益分析研究

对广东普通工科高等教育的办学效益问题,从结构布局效益、层次与规模效益进行了讨论,提出了提高办学效益的基本对策。     

Estimation with right‐censored observations under a semi‐Markov model

The semi‐Markov process often provides a better framework than the classical Markov process for the analysis of events with multiple states. The purpose of this paper is twofold. First, we show that in the presence of right censoring, when the right end‐point of the support of the censoring time is strictly less than the right end‐point of the support of the semi‐Markov kernel, the transition probability of the semi‐Markov process is nonidentifiable, and the estimators proposed in the literature are inconsistent in general. We derive the set of all attainable values for the transition probability based on the censored data, and we propose a nonparametric inference procedure for the transition probability using this set. Second, the conventional approach to constructing confidence bands is not applicable for the semi‐Markov kernel and the sojourn time distribution. We propose new perturbation resampling methods to construct these confidence bands. Different weights and transformations are explored in the construction. We use simulation to examine our proposals and illustrate them with hospitalization data from a recent cancer survivor study. The Canadian Journal of Statistics 41: 237–256; 2013 © 2013 Statistical Society of Canada     

An alternative proof for a version of cochran's theorem under elliptical settings

For an elliptically contoured n × p random matrix Y with mean μ and covariance proportional to ∑_Y, the necessary and sufficient conditions, under which (Y?μ)′W(Y?μ) with nonnegative definite W is generalized Wishart distributed, are obtained by using the higher moments of Y. This version of Cochran's theorem is general as the assumptions on ∑_Y=A?∑ with nonnegative definite A and ∑, P(Y?μ)=0, and P(Y≠μ)<1 have been relaxed. An example on two way balanced mixed models is given for illustration ot our main results.     

调整利息税率对中国居民人均消费影响的实证分析—基于1985—2008年的经验数据

 本文通过所构建的居民消费效用函数模型,得到利息税率调整引起居民人均消费的变化量,并利用中国1985—2007年的数据估计出模型中的参数。通过实证分析发现：第一,调整利息税率对我国人均消费产生的收入效应大于替代效应;第二,调整利息税率对城镇和农村居民的人均消费影响的效应不同：提高利息税率对城镇居民人均消费产生的总效应相对较大,而降低利息税率对农村居民人均消费产生的总效应相对较大;第三,城镇居民消费时间偏好、储蓄效用因子大于农村居民的消费时间偏好和储蓄效用因子。     

绿洲与绿洲城市：从农牧时代到工业时代新疆城市发展的特点

新疆特殊的自然地理环境,尤其是其独特的绿洲生态系统对新疆城市的影响显著.绿洲和绿洲城市成为新疆城市区别于中国其他区域城市的一个十分重要的特点.农牧业时代新疆绿洲城市的特点主要表现为两个方面,一是绿洲城市与绿洲具有一致性特点--不平衡性、分散性和封闭性;二是新疆绿洲城市数量少、规模小,长期发展缓慢.进入工业时代,新疆绿洲城市的发展出现新的特点,一是城市数量增多,城市规模扩大,初步形成绿洲城市区域体系;二是绿洲城市从封闭走向开放;三是经济城市从单一功能向综合性多功能发展,城市功能不断强化;四是绿洲城市出现可持续发展的新趋势.在国家实施"一带一路"战略的背景下,新疆绿洲城市迎来了新的发展机遇.     

机器学习视角下中国去产能产业的识别

随着中国环境压力的增加,政府提出了供给侧改革,去产能是改革的主要内容,但是由于产业特征的实时演变,需要对政策进行完善。文章运用模糊C均值算法和支持向量机算法分析现阶段需要进行去产能的产业,结果发现在现行去产能政策中大部分行业是需要去产能的,但煤炭开采和洗选业以及铁路、船舶、航空航天和其他运输设备制造业已不适合继续去产能,同时将化学原料和化学制品制造业加入去产能行列中。     

公司治理结构与投资决策安排

厂商的投资决策在受体制模式制约的同时,也在很大程度上受制于企业的制度安排.公司治理结构之于投资决策安排,属于市场经济体制模式下的制度与行为之间的微观制约关系.联系宏观经济运行看问题,这种制约关系的格局会影响到经济运行和发展.本文在对两者之相关性作出概要解说的基础上,重点分析公司治理结构对投资决策安排的内在规定性,并以此为基础透视了我国现阶段公司治理结构的基本特征在哪些方面决定着公司的投资决策安排;作为对公司治理问题的一种探讨,文章穿插了对我国特定制度环境下公司治理模式的两种主要类型的讨论,认为不同类型的公司治理模式具有不同的投资决策机理.