中国工业二氧化硫排放变化指标分解研究

基于生产理论框架,应用基于Shephard输出距离函数的方法,将我国SO2排放变化指标分解为技术效率影响、技术变化影响、输入增加影响、输出结构影响等5项指标,并对中国28个地区2000~2006年SO2排放变化面板数据进行了实证分析.结果表明:引起我国2000~2006年SO2排放增加的主要因素是工业能源消耗、资本投入及产出结构变化,技术变化则在一定程度上减少了工业SO2排放.“十五”期间国家工业SO2排放控制政策,对工业SO2排放控制技术进步及技术效率的提高有明显的促进作用.在区域层面上,东、中、西3个地区的技术变化都促进了工业SO2的减排,其中东部地区由于技术变化所导致的SO2减排较为明显.     

能源价格变动对中国节能降耗的影响效应

在分析我国能源比价扭曲对能耗强度影响效应的基础上,建立了Bayesian时变动态回归模型,测算了能源价格变动对能耗的影响效果及变动趋势。主要结论为:①能源比价关系的调整比单种能源价格的国际接轨更为重要。相比国际市场的能源比价结构,中国能源商品价格结构的扭曲度提高了中国的能耗强度,促进了第二产业的增长。②能源价格的变动对单位GDP能耗的影响效应具有显著的时变特征。在电力、煤炭、石油三种能源中,电力价格的变动对能耗强度的影响最大。电力价格变化对单位GDP能耗的影响边际效应在逐年下降,但节能的效果仍很显著。煤电价格联动制约及"从量计征"的资源税偏低使得煤炭价格的上涨反而加大了能耗强度,且1996年以来煤炭价格的提高对单位GDP能耗上升的影响效应还在不断加强,原油价格的提高对单位GDP能耗的影响在不同的时间段有不同的作用,但相对煤炭及电力价格来说,石油价格的影响效应最小。2002年以前石油价格的上升对能耗的上升起助推作用,2003年后石油价格的上升对能耗的上升起降低作用且强度逐年加大。     

寒区隧道溶洞安全距离及衬砌冻胀影响规律研究

为了探究寒区溶洞的大小、远近对隧道结构安全的影响规律,依托寒区某高铁岩溶隧道建立三维有限元模型,通过不同工况的模拟得出溶洞距隧道安全距离临界值与溶洞隧道体积比成正比关系,并拟合出安全距离临界值随溶洞与隧道体积比的变化曲线和关系式。探究溶腔积水冻胀力对衬砌结构的影响规律,基于该寒区隧道周边不同位置、远近的溶洞对其影响进行模拟,研究结果表明:隧底处溶洞冻胀力影响最为显著,且距隧底超过10 m时,小型溶腔冻胀力对隧道的影响较小,衬砌变形值渐趋稳定。研究结果可为该寒区隧道溶洞处理提供依据,并为后续类似工程提供借鉴。     

Body size and reserve protection affect flight initiation distance in parrotfishes

Flight initiation distance (FID), the distance at which an organism begins to flee an approaching threat, is an important component of antipredator behavior and a potential indicator of an animal’s perception of threat. In a field study on parrotfishes, we tested the predictions that FID in response to a diver will increase with body size, a correlate of reproductive value, and with experience of threat from humans. We studied a broad size range in four species on fringing reefs inside and outside the Barbados Marine Reserve. We used the Akaike's Information Criterion modified for small sample sizes (AICc) and model averaging to select and assess alternative models. Body size, reserve protection, and distance to a refuge, but not species, had strong support in explaining FID. FID increased with body size and generally remained two to ten times fish total length. FID was greater outside the reserve, especially in larger fish. Although we were not able to completely rule out other effects of size or reserve, this study supports predictions of an increase in FID with reproductive value and threat from humans.     

How near is near? The distance perceptions of residents of a nuclear emergency planning zone

This paper reports the results of a study conducted within the emergency planning zone (EPZ) of the Nine Mile Point (NMP) nuclear complex located in Oswego County, New York. An EPZ is the area in the vicinity of a nuclear power plant for which detailed plans are implemented for the management of emergencies and for the communication of the risks of nuclear energy production. EPZs are subdivided into emergency response planning areas (ERPAs) according to distance from the plant. This study aimed at discovering how residents of the NMP EPZ perceived distance to the nuclear plant. Distance was conceptualized in five different and complementary ways: estimated straight line distance, estimated driving distance, actual straight distance, actual driving distance and perceived distance. The results indicate that people living at a very short distance from the nuclear plant perceive and estimate distance differently than people living farther away. These results have policy implications and suggest alternative and potentially more efficient ways to redesign ERPAs. Fundamental geographic variables and concepts such as distance, location, proximity and their associated human perceptions are important human dimensions of risk analysis. These results should be of interest to nuclear emergency planners and are probably applicable to many other hazard planning activities.     

煤气化过程中气态污染物采样分析的研究进展（续）

通过考察气态污染物采样方法的基本原理,对比分析国内外常压采样系统和加压采样系统的设计特征,选择煤气化过程中5种常见气态污染物为分析对象,列举常用的化学分析法和仪器分析法,为加压气化装置采样系统的设计提供参考材料和建议,归纳了一些有助于提高气态污染物检测数据可靠性的措施,希望能为煤气化过程中（特别是加压煤气化过程中）气态污染物采样系统的设计提供思路和借鉴。     

When is overfishing underfishing?

The term overfishing is being used with increasing frequency to designate an undesirable level of fisheries exploitation. All too often, however, the term is taken as being self-evident. This article demonstrates that many definitions of overfishing are possible, depending essentially on what objective is being pursued for the fishery. Various possible biological and economic objectives are considered, both in a static and dynamic model of the fishery. Consideration is given to the best utilization of the fish stock from the viewpoint of the individual fishermen as well as that of society. It is shown that overfishing by one definition may be underfishing by another, and it is concluded therefore that anyone using the term overfishing ought, as a matter of course, to define it.     

THE UNIT HYDROGRAPH: A SATISFACTORY MODEL OF WATERSHED RESPONSE?1

ABSTRACT: Some 96 flood events larger than the mean annual flood from 16 watersheds in the Commonwealth of Pennsylvania were used to derive unit hydrographs by the least-squares method. Analyses of the unit hydrographs were conducted to ascertain their response to watershed parameters, climatic and storm variables and locations within different hydrologic regions. Significant differences both within and among watersheds led to the formulation and testing of hypotheses stating that differences among watersheds are caused by physiographic differences while differences within watersheds result from climatic and storm differences. The analysis showed, that while many watersheds parameters strongly influence the shape of the unit hydrograph, only the storm variables duration and volume of precipitation excess produce significant differences. Seasonal differences were apparent but not proven statistically significant.     

UNIT HYDROGRAPHS FOR DEVELOPING DESIGN FLOOD HYDROGRAPHS1

ABSTRACT: In Illinois, a procedure has been developed to derive unit hydrographs for generating 100-year and probable maximum flood hydrographs, on the basis of 11 parameters that define the hydrograph shape very well. Regional regressions of these parameters with basin factors show very high correlation. Thus satisfactory values of parameters can be determined for ungaged areas or those with a few years' record. The nonlinearity in unit hydrographs derived from usual floods is largely attributed to mixing within-channel and overbank-flow flood events. To minimize the effects of nonlinearity and to derive unit hydrographa suitable for calculating spillway design floods, use of the proposed method of developing such hydrographs is recommended.     

圆形烟道断面烟气测试中采样点距烟道内壁的距离讨论

本文根据圆形烟道采样点划分原则，给出了一种方便适用的采样点距烟道内壁的距离公式，并就现有文献中采样点距烟壁的距离值表格的误差进行了修正。