关于上海地区屋顶绿化的思考

在上海市平面绿化工作已初见成效,大型公共绿地越来越多,城市越来越美之时,构建立体绿化 成为当务之急。本文通过对上海地区屋顶绿化的现状及存在的问题的阐述,结合绿化植物的选择和维护的一 些基本理论,展示了屋顶绿化广阔的发展前景。     

Drug testing in the transportation industry: The maritime case

The maritime industry provides an interesting case study of the design and implementation of drug-testing programs in the transportation industry during the 1980s. It is clear that such programs were designed and implemented less because of empirical evidence of safety problems than for political reasons. The results in the maritime industry are indicative of a program that is expensive to operate, intrusive with regard to employee privacy, and which will have little or no impact on safety. Focusing such programs on the issue of impairment rather than on the issue of drug usage per se is likely to improve the outcome of the programs. Although, despite common belief, there is little evidence that drug usage or the “drug problem” in U.S. society as a whole had gotten worse in the preceding years (Schonsheck, 1989, 250–251).     

公有制内按生产要素分配实现形式探析

一般理论认为,按生产要素分配主要体现在非公有制领域和公有制领域内劳动者收入来源的多样性上.但事实上,随着我国劳动力市场的发展和完善,按生产要素分配在公有制领域内将有更大的作用空间.其具体实现形式之一,即为公有制范围内劳动收入由V+Vm构成,而且对企业利润(M)中分配后的剩余部分,仍可实行按生产要素分配,而后者是建立国有资产保值增值机制的一种新思路.     

区域产业簇群的发展与政府职责

本文认为,现代产业簇群是基于地缘关系、产业技术链、同业交往等关系而共生的产生群体,是提高国家经济实力和国际竞争力的重要途径。它的产生与发展是技术进步和社会分工的结果,是产业发展的客观规律,经济全球化是现代产业簇群的必然趋势。为了促进我国产业簇群的发展,文章提出,政府在产业簇群的发展中应遵循产业簇群的发展规律,充分发挥其在重视与定位、研究与规划、宣传与传播、引导与协调、支持与宽容、保障与政策等方面的职能。     

Symmetry and order in the portfolio allocation problem

Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001     

面向可持续发展的会计模式变迁

旅游饭店业和其他工业企业一样 ,也存在污染和资源浪费问题。本文主要指出了当今中国旅游饭店业的现状和面临的环境保护问题 ,阐述了实施绿色营销的必要性 ,探讨了实施绿色营销的思路和方法。     

Rural Population Growth, 1950–1990: The Roles of Human Capital, Industry Structure, and Government Policy

Human capital raises rural incomes, but this effect is swamped by higher returns to human capital in urban markets. This leads to "brain drain" from rural areas. Populations grow more rapidly in rural counties that have a diversified employment base. Farm population grows faster (or declines more slowly) in counties with relatively high farm income, and nonfarm populations grow faster in counties with relatively high nonfarm income. However, higher farm incomes lead to slower nonfarm population growth and vice versa. Rural county government services financed by local taxes or debt have neutral or negative effects on population growth.     

论旅游市场营销环境与旅游业可持续发展

随着科学技术的高度发展,旅游者的选择性强,旅游活动范围大,使旅游供给者面临越来越激烈的竞争。旅游企业要求得生存和发展必须要对旅游市场进行准确定位,在可持续发展观念指导下开展市场营销活动。创造良好的、协调发展的旅游市场营销环境是实现旅游业可持续发展的基础和保证。