可持续发展研究的3个关键课题与中国转型发展

从数量扩张的增长模式转向质量提升的发展模式,是中国未来30年转型发展的核心问题.本文介绍了20世纪90年代以来可持续发展在3个关键课题上的研究进展.在经济增长与社会富祉的关系上,指出经济增长对于社会富祉的贡献存在着门槛,跨过这个门槛经济增长对福利贡献的边际效用开始递减;在经济增长与资源环境的关系上,指出经济增长没有导致资源环境消耗的倒U型曲线,在自然资本存在限制的情况下无限的经济增长是不可能的;在政府支出与民生发展的关系上,指出公共支出增大并不必然导致社会福利的提高,而公共支出的结构与方式对民生发展却是极其重要的.在对每个问题分析事实依据、原因解释、政策意义的基础上,针对中国转型发展提出了一些具有长期意义的理论思考与政策思考.     

A review of biochars' potential role in the remediation, revegetation and restoration of contaminated soils

Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich material. Their large surface areas and cation exchange capacities, determined to a large extent by source materials and pyrolysis temperatures, enables enhanced sorption of both organic and inorganic contaminants to their surfaces, reducing pollutant mobility when amending contaminated soils. Liming effects or release of carbon into soil solution may increase arsenic mobility, whilst low capital but enhanced retention of plant nutrients can restrict revegetation on degraded soils amended only with biochars; the combination of composts, manures and other amendments with biochars could be their most effective deployment to soils requiring stabilisation by revegetation. Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability.     

财政分权对中国环境污染影响程度的实证分析

财政分权体现了中央政府和地方政府间的财政权力分配关系,它可以通过支出分权度和收入分权度两个指标进行衡量。从理论上分析,大多数研究结论都认为财政分权与污染量排放存在负激励,但是缺乏相应的实证研究。本文利用1998年到2009年的省级面板数据,对中国财政分权与污染物排放规模之间的关系进行了实证分析。本文选取工业废气排放量、工业固体废弃物排放量、工业废水排放量和二氧化硫排放量作为衡量污染物排放规模的指标,选择支出分权度与收入分权度作为解释变量,选择人均GDP、人口密度、城市化水平、外商投资总额、工业化水平作为控制变量。本文还将所有省份按照地理位置划分为东部和中西部两组进行稳健性检验。研究结果表明:以支出分权度衡量的财政分权指标与污染物排放规模负相关,且实证结果具有稳健性,以收入分权度衡量的财政分权指标与污染物排放规模的关系从实证的角度来讲不确定。     

Three Critical Issues in Sustainable Development Studies and the Transition Development of China

The core issue for China transition development in the next 30 years is to shift from the quantity growth model to the quality improvement model. The paper introduces the research progress in three key areas of sustainable development studies since the 1990s. It is pointed out that there is a well-being thresh-old at which the margin utility of economic growth for human well-being will decline, that there is an ecological limit beyond which more economic growth in terms of physical scale will be impossible, and that the creation of human well-being is related not only to the amount but also to the structure and efficiency of public expenditure from government. After an in-depth discussion on facts, origins and policy implications of each issue, some theory and policy thinking with long-lasting significance are raised for the transition development of China.     

Physiological and behavioral aspects of Calanus euxinus females (Copepoda: Calanoida) during vertical migration across temperature and oxygen gradients

 In the Black Sea, during summer stratification, Calanus euxinus (Hulsemann) undertakes diel vertical migrations with an amplitude of about 117 m from oxygenated, warm (18 °C) surface layers to hypoxic (∼0.8 mg O₂ l⁻¹) zones with lower temperature (7.9 °C). When such changes in temperature and oxygen concentration are reproduced in the laboratory, total metabolism, basal metabolism and scope of activity of copepods decrease 7.2, 7.8 and 6.7 times, respectively, while the frequency of locomotory acts and mechanical power decline 3.4- and 9.5-fold, respectively. These changes allowed the copepods to conserve a significant portion of food consumed near the surface for transformation to lipid reserves. Diel respiratory oxygen consumption of migrating individuals, calculated so as to include actual duration of residence in layers with different temperature and oxygen concentrations, is estimated at 17.87 μg O₂ ind⁻¹. The net energy cost of vertical migration made up only 11.6% of the total. Copepods expend 78.6% of diel energy losses during approximately 10 h in the surface layers, while about 5.4% is required during about 9 h at depth. Hypoxia is shown to have a significant metabolic advantage during diel vertical migrations of C. euxinus in the Black Sea. Received: 1 October 1999 / Accepted: 11 July 2000     

Cardiovascular Strain of Sawmill Workers in South-Western Nigeria

This study aimed to assess cardiovascular strain during sawmilling operations in terms of physical workload, based on heart rate changes. We measured resting and working heart rates and calculated cardiovascular load (%CVL), cardiovascular strain (%CVS) and relative heart rate (%RHR) in 35 sawmill workers. Based on heart rate only, the work in sawmills was classified as very heavy and extremely heavy. Similarly, a high-level category was recorded for %CVL and a very high range for %CVS. Thus, the workload in sawmill operations is usually very high and can lead to physiological strain of the workers. There is a need to redesign the work content of this occupation to prevent excessive strain in the workers, as this will increase their productivity and reduce their health risk.     

Cooling Suits,Physiological Response,and Task Performance in Hot Environments for the Power Industry

Heat stress on workers working outdoors in the power industry may result in fatigue and deterioration in task performance. This research collected and analyzed data on task performance of workers working indoors and outdoors with and without a cooling suit. The task performance was compared on the basis of heart rate, oxygen consumption, tympanic temperature, subjective responses, productivity, and error rates. Based on One-Way Analysis Of Variance (ANOVA) results, a significantly lower estimated working oxygen consumption was observed (p < .001) when the cooling suit was worn. The productivity was higher while workers wore the cooling suit as compared to no cooling suit (p = .011) whereas the error rates were significantly lower(p < .001). Also a significantly lower self-reported discomfort was observed in the neck and shoulders while working wearing the cooling suit (p = .004). This study concluded that wearing a cooling suit while working outdoors was associated with physiological benefits as well as improved task performance of the study participants.     

基于支付能力与支付意愿的居民生活用水水价承受能力研究——以广州市番禺区为例

从支付能力和支付意愿的角度,应用扩展线性支出系统(ELES)模型和条件价值评估法(CVM),定量研究居民生活用水水价承受能力.以广州市番禺区为例,通过2005~2009年截面数据资料和问卷调查数据,定量研究了城镇和农村居民生活用水水价支付能力和支付意愿,并分析了2011年番禺区居民对新调整居民生活用水水价的承受能力.结果表明,2005~2009年,达到平均收入水平的番禺区居民对水价具有支付能力,其基本用水需求能得到满足,但低收入户,尤其是农村低收入户的水价支付能力有限,是水价改革应重点关注的对象;CVM调查结果显示,番禺区居民对2011年生活用水水价的支付意愿为2.163元/m3;2011年,番禺区居民生活用水价格由2.00元/m3上调为2.15元/m3,达到平均收入水平的番禺区居民对新水价具有承受能力.     

Ventilation or nest defense—parental care trade-offs in a fish with male care

Brood guarding animals face many critical trade-offs. Sand goby males (Pomatoschistus minutus) build nests with larger openings during low oxygen conditions, presumably to enhance ventilation. However, this may make the nest easier for egg predators to detect and harder for guarding males to defend. Manipulating oxygen level and predator presence (a small crab) for small and large males, we found support for a parental trade-off between fanning and nest defense. An increased fanning activity resulted in less time for guarding. Small males and males in low oxygen showed a higher fanning expenditure than large males and males in high oxygen, but surprisingly, filial cannibalism did not differ between these groups. Males built larger nest openings in low than high oxygen. However, males in both high and low oxygen treatments reduced their nest opening size in the presence of a predator, again indicating an important trade-off between ventilation and nest defense.     

Effects of female mating status on copulation behaviour and sperm expenditure in the freshwater crayfish <Emphasis Type="Italic">Austropotamobius italicus</Emphasis>

Sperm competition models predict that males should adjust their sperm expenditure according to the risk and/or intensity of sperm competition. In this paper, we analysed copulatory behaviour of both sexes and sperm expenditure in relation to female mating status (virgin or mated) in the freshwater crayfish Austropotamobius italicus, a species where males have been reported to feed on and remove sperm laid by other males. The same females were allowed to be inseminated sequentially by two males, and we compared the sexual behaviours of partners between the first (virgin females) and the second mating (mated females). We found that female resistance did not differ between the first and the second mating, nor males refused or took more time to mount a mated female. However, when mating with a mated female, males reached an effective copulation position significantly later. This occurred because second-mating males removed, by eating, all or most spermatophores previously deposited by first males. As removal was often incomplete, this resulted in a larger amount of sperm being deposited on female ventral parts after the second mating, although second males did not allocate more sperm to mated females than first males did. Thus, the peculiar mode of sperm competition, where males remove previously deposited sperm, and the consequent predictable strong last male prevalence in paternity likely led to the observed lack of adjustment of sperm expenditure to female mating status in this species.