1949年以来中国环境与发展关系的演变

从IPAT方程出发,发现了环境影响随着经济发展或时间的演变依次遵循三个"倒U型"曲线规律,即环境影响强度的倒U型曲线、人均环境影响的倒U型曲线和环境影响总量的倒U型曲线。根据此规律,可以将该演化过程划分为四个阶段即:环境影响强度高峰前阶段、环境影响强度高峰到人均环境影响量高峰阶段、人均环境影响量高峰到环境影响总量高峰阶段以及环境影响总量稳定下降阶段。在环境演变的不同阶段,主要驱动力存在着明显的差异。在环境影响强度高峰前阶段,资源消耗或污染物排放增长更多地由资源或污染密集型技术进步驱动;在资源消耗或污染物强度高峰到人均资源消耗或污染物排放高峰阶段,主要由经济增长驱动;而在人均资源消耗或污染物排放高峰到资源消耗或污染物排放总量高峰阶段以及总量高峰以后的发展阶段,则主要由节约高效技术或污染减排技术进步来驱动。实证分析表明,中国目前环境与发展关系基本上处于经济增长主要驱动的环境影响强度高峰向人均环境影响高峰过渡阶段,这同时意味着中国要在短期内实现人均环境影响和环境影响总量高峰的跨越是异常困难的。     

火灾中闭式喷头响应时间的概率分布特性研究

喷淋系统中闭式喷头响应时间受火灾增长因子、径向安装距离和喷头响应时间指数等因素的影响。通过对喷头响应时间的模拟数据的统计分析,建立了包含火灾增长因子、径向距离和喷头响应时间指数等参数的喷头响应时间模型。考虑火灾增长因子和径向距离的随机性,获得了喷头响应时间的概率分布特性。研究结果表明,径向距离和火灾增长因子对喷头响应时间的分布特性影响显著。随着火灾增长因子的增大和径向距离的缩小,喷头在较短时间内响应的概率增大。随着径向距离的缩小,喷头响应时间指数对喷头响应时间分布的影响变小。研究可为优化喷头布置和评估喷头响应的有效性提供分析工具。     

Evaluation of effects of exposure time on aquatic toxicity with zooplanktons using a reduced life expectancy model

Traditionally in toxicological studies time is not studied as quantifiable variable but as a fixed endpoint. The Reduced Life Expectancy (RLE) model which relates exposure time and exposure concentration with lethal toxic effects was tested previously using fish data. In this current paper the effects of exposure time on aquatic toxicity with zooplanktons and various toxicants were evaluated using the RLE model based on ambient exposure concentration. The model was evaluated by plotting ln LT₅₀ against LC₅₀ using toxicity data with zooplanktons from the literature for metal, metalloid and organic compounds. Most of the experimental data sets can be satisfactorily correlated by use of the RLE model, but deviations occurred for some data sets. Those data sets were satisfactorily fitted by a two stage RLE model. This model was based on two phases: one in the peripheral system and other in the central system. Both the single and two stage RLE model support the hypothesis that toxicity is time dependent and decreases in a systematic way with increasing exposure time. A calculated normal life expectancy (NLT) can be obtained from the single stage model and is in accord with reported NLT but those obtained from the two stage RLE model are in excellent agreement.     

Climatic hazards warning process in Bangladesh: Experience of,and lessons from,the 1991 April cyclone

Science and technology cannot control entirely the causes of natural hazards. However, by using multifaceted programs to modify the physical and human use systems, the potential losses from disasters can effectively be minized. Predicting, identifying, monitoring, and forecasting extreme meteorological events are the preliminary actions towards mitigating the cyclone-loss potential of coastal inhabitants, but without the successful dissemination of forecasts and relevant information, and without appropriate responses by the potential victims, the loss potential would probably remain the same. This study examines the process through which warning of the impending disastrous cyclone of April 1991 was received by the local communities and disseminated throughout the coastal regions of Bangladesh. It is found that identification of the threatening condition due to atmospheric disturbance, monitoring of the hazard event, and dissemination of the cyclone warning were each very successful. However, due to a number of socioeconomic and cognitive factors, the reactions and responses of coastal inhabitants to the warning were in general passive, resulting in a colossal loss, both at the individual and national level. The study recommends that the hazard mitigation policies should be integrated with national economic development plans and programs. Specifically, it is suggested that, in order to attain its goals, the cyclone warning system should regard the aspects of human response to warnings as a constituent part and accommodate human dimensions in its operational design.     

超补偿理论及其在虫害控制中的意义

本文较为系统地阐述了作物对虫害损伤的超补偿理论,表明超补偿广泛存在于各种作物中,并对超补偿所需条件、基本原因以及与害虫控制的关系作进一步讨论。     

Scientist and policy-maker response types and times in suburban watersheds

Differences between scientist and policy-maker response types and times, or the “how” and “when” of action, constrain effective water resource management in suburbanizing watersheds. Policy-makers are often rushed to find a single policy that can be applied across an entire, homogeneous, geopolitical region, whereas scientists undertake multiyear research projects to appreciate the complex interactions occurring within heterogeneous catchments. As a result, watershed management is often practiced with science and policy out of synch. Meanwhile, development pressures in suburban watersheds create changes in the social and physical fabric and pose a moving target for science and policy. Recent and anticipated advances in the scientific understanding of urbanized catchment hydrology and pollutant transport suggest that management should become increasingly sensitive to spatial heterogeneities in watershed features, such as soil types, terrain slopes, and seasonal watertable profiles. Toward this end, policy-makers should encourage funding scientific research that characterizes the impacts of these watershed heterogeneities within a geopolitical zoning and development framework.     

论我国耕地保护与粮食安全

耕地资源关系到国家经济发展、社会稳定和粮食安全。对我国而言，经济飞速增长，人地矛盾十分突出，每寸土地都显得弥足珍贵。在收集我国1997-2005年耕地面积变化的资料，并作相关分析的基础上，研究得出我国耕地资源呈现不断减少的趋势，其中生态退耕和非农建设用地占用耕地是其变化的主要原因。耕地资源的减少引起了粮食总产量和单产量的变化，而耕地复种指数也是影响耕地产量的主要原因之一。在此基础上分析了耕地保护和粮食安全的内在关系，并提出适合我国的耕地资源可持续利用与粮食安全的措施。     

响应面法优化养殖水体中炔雌醇的固相萃取条件

在单因素试验、Plackett-Burman设计试验基础上,采用Box-Behnken响应面法对养殖水体中炔雌醇(EE2)的固相萃取条件进行优化。结果表明,洗脱液体积、洗脱液组成和淋洗液体积是影响EE2固相萃取回收率的3个主要因素;EE2的最佳固相萃取条件为:水样pH值为3,进样流量为3.0 mL/min,淋洗液为体积分数为10%的甲醇水溶液,淋洗液体积7.0 mL,洗脱液为乙酸乙酯-正己烷混合溶液(体积比为9∶1),洗脱液体积12.0 mL。该条件下养殖水样中EE2固相萃取回收率为81.6%～86.7%。     

苯甲酰苯胺类化合物溶解度和分配系数的测定及定量结构—性质相关研究

本文采用摇瓶法测定了１４各甲酰苯胺类化合物的溶解度及正辛醇／水分配系数，二者之间具有较好的相关性，应用线性溶剂化相关方法获得的相关方程，能更好地预测测苯甲酰苯胺类化合物的的水溶解度和正辛醇／水分配系数。