水分条件对中山杉406光合特性的影响

采用室内盆栽方式,以两年生落羽杉属杂交树种中山杉406(Taxodium‘Zhongshanshan 406’)为试验材料,设置对照、渍水和淹水3种处理,研究了水分条件对中山杉406叶片的叶绿体色素、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2摩尔分数(Ci)等光合特性的影响。结果表明,中山杉406的叶绿素a、叶绿素a+b和类胡萝卜素质量分数随土壤水分增加而逐渐降低,但处理间均无显著差异。同样,不同处理间的Tr、Gs和Ci等光合参数无明显规律。光合-光强响应曲线表现出明显的光饱和限制。不同光强下,对照与淹水处理的中山杉406叶片净光合速率高于渍水处理,但处理间没有显著差异。而光饱和在对照处理显著(P<0.05)高于渍水和淹水处理。在渍水和淹水下,中山杉406的光合特性没有发生明显变化,表明其具有良好的耐湿耐水特性,在湿地的恢复与构建方面有广阔的应用前景。     

Impacts of methanol fuel on vehicular emissions: A review

● Methanol effectively reduces CO, HC, CO₂, PM, and PN emissions of gasoline vehicles. ● Elemental composition of methanol directly affects the reduction of emissions. ● Several physicochemical properties of methanol help reduce vehicle emissions. The transport sector is a significant energy consumer and a major contributor to urban air pollution. At present, the substitution of cleaner fuel is one feasible way to deal with the growing energy demand and environmental pollution. Methanol has been recognized as a good alternative to gasoline due to its good combustion performance. In the past decades, many studies have investigated exhaust emissions using methanol-gasoline blends. However, the conclusions derived from different studies vary significantly, and the explanations for the effects of methanol blending on exhaust emissions are also inconsistent. This review summarizes the characteristics of CO, HC, NO_x, CO₂, and particulate emissions from methanol-gasoline blended fuels and pure methanol fuel. CO, HC, CO₂, particle mass (PM), and particle number (PN) emissions decrease when methanol-blended fuel is used in place of gasoline fuel. NO_x emission either decreases or increases depending on the test conditions, i.e., methanol content. Furthermore, this review synthesizes the mechanisms by which methanol-blended fuel influences pollutant emissions. This review provides insight into the pollutant emissions from methanol-blended fuel, which will aid policymakers in making energy strategy decisions that take urban air pollution, climate change, and energy security into account.     

灰色灾变预测模型的改进及实例分析

灾害不同于一般的预测对象，对其预测精度应予高度重视，而目前灰色灾变预测的预测精度，较高的仅仅是预测原点附近的一、二个数据。基于此，本文提出了准灰信息的概念，建立了准灰色灾变预测模型，并通过实例证明了运用准灰色灾变预测模型进行预测，可提高预测精度。     

A comparison of chemical mechanisms based on TRAMP-2006 field data

A comparison of a model using five widely known mechanisms (RACM, CB05, LaRC, SAPRC-99, SAPRC-07, and MCMv3.1) has been conducted based on the TexAQS II Radical and Aerosol Measurement Project (TRAMP-2006) field data in 2006. The concentrations of hydroxyl (OH) and hydroperoxy (HO₂) radicals were calculated by a zero-dimensional box model with each mechanism and then compared with the OH and HO₂ measurements. The OH and HO₂ calculated by the model with different mechanisms show similarities and differences with each other and with the measurements. First, measured OH and HO₂ are generally greater than modeled for all mechanisms, with the median modeled-to-measured ratios ranging from about 0.8 (CB05) to about 0.6 (SAPRC-99). These differences indicate that either measurement errors, the effects of unmeasured species or chemistry errors in the model or the mechanisms, with some errors being independent of the mechanism used. Second, the modeled and measured ratios of HO₂/OH agree when NO is about 1 ppbv, but the modeled ratio is too high when NO was less and too low when NO is more, as seen in previous studies. Third, mechanism–mechanism HO_x differences are sensitive to the environmental conditions – in more polluted conditions, the mechanism–mechanism differences are less. This result suggests that, in polluted conditions, the mechanistic details are less important than in cleaner conditions, probably because of the dominance of reactive nitrogen chemistry under polluted conditions.     

区域可持续发展的人地关系探讨

本文从人的生存空间、活动空间以及人的生存活动、社会生产活动与自然环境的物质、能量、信息交流来论述人地关系，并且从人的生存与发展需求的角度讨论了人地关系矛盾的内涵与外在表现，进而提出了实现区域可持续发展的一般原则     

作业条件危险性评价方法在建筑物爆破拆除的应用

运用作业条件危险性评价方法原理，对建筑物爆破拆除中危险有害因素进行分析和赋值，建立评价关系式，对存在的危险有害因素进行危险度分级，确定重大危险岗位，并针对性地提出了有效的安全措施，确保建筑物爆破拆除中的安全性。     

西部资源型工矿城市可持续发展对策研究

西部资源型工矿城市曾经为我国的工业化、现代化和城市化做出重要贡献 ,但是 ,由于资源的不可再生性 ,工矿城市面临矿竭城衰等问题。如何解决这一问题 ,本文从八个方面提出了可持续发展的对策。     

关于工厂企业绿地建设的探讨：以宝钢为例

生态园林是现代城市绿化发展的趋势和方向。对于污染较为集中的工厂企业来主，绿地建设是环境保护的重要方面。而发展生态园林，走绿地的生态建设道路已成为工厂企业发化的有效途径。本文从生态园林的指导思想出发，结合宝钢的绿化实例，探讨了工厂企业在绿地建设方面的若干问题。     

“3.24”重大油污染事故引起的思考

概述了“３．２４”珠江口重大船舶溢油事故的起因，主管机关所采取的应急行动及控制清除油污的措施。介绍了污染损害及索赔情况，分析并指出了本次事故所暴露出的主要问题，并提出合理的建议，以引起决策人士的重视和社会的关系。     

基于帕雷托分级法的台风灾害社会易损性比较及其在东南沿海地区的应用

以东南沿海6省市(江苏、上海、浙江、福建、广东、海南)为研究对象,提出了基于帕雷托分级法的社会易损性评价方法.通过该方法得到沿海6省市的社会易损性等级,易损性等级反映了各地区在台风灾害时可能遭受损失的相对大小,即其等级越高,可能遭受的经济损失和人员伤亡越大.结果表明,海南的社会易损性等级为1;福建的社会易损性等级为2;江苏的社会易损性等级为3;上海、广东和浙江的社会易损性最大,易损性等级为4.本研究为社会减灾工作尤其是长期救灾规划提供了指导.