浅谈污泥减量技术

本文综述了目前国内外对污泥减量化研究的主要理论和方法,介绍了隐形生长、生物捕食、微生物强化、代谢解偶联和投加酶等污泥减量技术,比较了各种技术的优缺点,可供相关工程技术人员参考.     

Uncertainty Associated with Future Environmental Costs and the Market's Differential Response to Earnings Information

This study examines whether the uncertainty arising from a firm's exposure to future environmental costs (environmental uncertainty) affects the market's price sensitivity to reported earnings. Specifically, when environmental uncertainty is significantly high, are investors more responsive to reported earnings released by 'high-polluting' firms than reported earnings announced by 'low-polluting' firms within the same industry? The initial impact of Title IV (the acid rain provisions) of the 1990 Clean Air Act Amendments (1990 CAAA) on the US electric utility industry provides the research setting required to isolate the effects of environmental uncertainty while addressing this question. Consistent with theoretical predictions, we find that the earnings response coefficients (ERCs) of high-polluting electric utilities are significantly greater than those of their low-polluting counterparts during a predicted period of elevated environmental uncertainty. In adjoining sample years associated with lower environmental uncertainty, we observe no statistical difference in the magnitude of the ERCs between these two groups. In addition, the study's findings suggest that the magnitude of the ERC is increasing in the firm's exposure to future environmental costs, after controlling for other factors that potentially affect ERCs.     

Reforming the Direct–Indirect Tax Mix

This paper provides a new framework for evaluating the welfare effects of commodity tax reforms. It is shown that tax reforms are welfare improving if and only if they satisfy the following intuitive property: on average, consumer prices fall for commodities with high marginal excess burdens. The rule is then applied to analyze a shift from differentiated commodity taxation to direct flat-rate taxation of labour income. The welfare impact of such reforms can be decomposed into two effects: (i) the increase in welfare associated with substitution among taxed commodities, and (ii) the loss in welfare associated with substitution between commodities and leisure. On balance, a shift towards direct taxation is desirable when inter-commodity substitution effects are large relative to commodity–leisure substitution effects. The analysis allows us to reconcile the apparently conflicting results of the tax reform and optimal taxation literatures.     

Gender-Based Vicarious Sensitivity to Disempowering Behavior in Organizations: Exploring an Expanded Concept of Hostile Working Environment

The purpose of this study was to explore evidence of gender-based vicarious sensitivity to disempowering behavior in organizations, expanding the concept of hostile working environment beyond the context of sexual harassment. Male and female graduate and undergraduate students viewed 10 video segments of Anita Hill's interview by U.S. senators during the October 1991 confirmation hearings of Supreme Court Justice Nominee, Clarence Thomas. Although no significant relationship was found between the personal attributes of age and ethnicity to perceptions of disempowering behavior, female participants reported seeing significantly more offensive behavior in the video segments than did male participants. The results are discussed in terms of greater female sensitivity to common forms of disempowering behavior in organizations, and having a disparate negative impact and systematically placing women at a disadvantage in today's workforce.     

融资约束与公司投资关系研究综述

公司的融资约束和投资-现金流量敏感性之间的关系成为财务管理的焦点问题。本文通过对国内外融资约束与投资关系众多文献的分析,研究了融资约束的影响因素,探讨了不同情况下融资与投资的关系,并分析了现存的投资-现金流敏感性模型的应用现状。最后,对我国进行投资-现金流敏感性问题的研究提出了建议。     

羧甲基壳聚糖/海藻酸钠水凝胶pH值对溶胀行为的影响

以CaCl2为交联剂制备了一系列羧甲基壳聚糖/海藻酸钠水凝胶。研究了羧甲基壳聚糖与海藻酸钠溶液的配比、交联剂的用量以及pH值对水凝胶溶胀率的影响,并分析了不同pH值时水凝胶的红外谱图。结果表明,pH=1.0、3.0时,水凝胶收缩,而pH=5.0、7.4、9.0、13.0时,水凝胶溶胀随pH值增高,其溶胀率增大。当两者配比为1:3,pH 9.0时溶涨率最大。同时,红外谱图证明,水凝胶的pH敏感行为是氨基和羧基基团结构的变化所引起的。     

The Application of Sensitivity Analysis on Comprehensive Transportation Evaluation

Comprehensive transportation evaluation objects using multi-objective decision method is a process of choosing the best one from a few objects through calculating, analyzing, and comparing the index system. The result may be different because of the difference of the index weight and index value. Therefore, sensitivity analysis should be one of the necessary parts of the decision-making. It is desired to give the index with higher sensitivity and its varying scope to control the index strictly during the execution process. This paper derives transfer index weight, which changes the rank evaluation order of the projects. Meanwhile, a simple, effective and practical method based on sensitivity district and sensitivity matrix is proposed for the sensitivity analysis of decision-making. As an example, the index sensitivity in decision-making of some provinces comprehensive transportation objects, and their influence on the final decision are discussed.     

Investment opportunities and cash holdings of firms: an empirical study on Korean firms

We find that the cash flow sensitivity of cash holdings of firms whose investment opportunities are lower is significantly higher by examining a panel data of 898 Korean firms for 1999–2014. The cash flow sensitivity of investment is also found to be lower in case of low investment opportunity. Both findings suggest that firms decide to hold cash in response to an increase in cash flow when they do not have a good investment opportunity. Precautionary motive because of financial constraints and uncertainty, and agency problems, however, are not associated with the cash flow sensitivity of cash holdings. These findings imply that it is necessary to develop new investment opportunities to encourage firms to spend more cash in Korea.     

Some properties of the length of the shortest half

This paper discusses some properties of the length of the shortest half proposed by Rousseeuw and Leroy (1988) as a robust scale estimator.     

上市公司控制权转移与市场反应

国外有研究表明,控制权转移能给目标公司股东带来20%左右的超额收益率.本文通过考察我国1997-2003发生控制权转移的282个样本,发现控制权转移能给目标公司带来9%以上的累积超额收益率.而且,转移后变更行业、变更董事长或总经理、民营转给国有的样本转移时可获得的累积超额收益率甚至更高.最后,我们用多元回归模型进一步分析了累积超额收益率的影响因素,进一步证明行业变更、董事长或总经理变更、转移类型对控制权转移的市场反应有显著影响.