县域尺度下生态补偿机制构建初探——以桐庐县为例

为了保护水源区生态环境和推进区域经济社会的可持续发展,需要建立和完善生态补偿制度。在评价桐庐县现有生态补偿现状的基础上,整合优化财政补助结构,提出了建立生态补偿专项资金,各乡镇的生态补偿资金分配与地区对县域生态环境贡献率、交界断面水质考核和资金使用绩效挂钩的生态补偿制度。     

基于宏基因组学探讨东平湖水库的菌群结构、耐药基因谱及其公共健康风险

水库中长时间滞留的水体会成为耐药基因的存储库,因此研究其菌群结构、耐药基因谱及其潜在的健康风险具有重要的公共卫生学意义.本研究以东平湖水库的水体和沉积物为研究对象,采用宏基因组测序技术,系统分析其在旱季和雨季中的菌群结构、耐药基因谱、耐药基因水平转移以及携带耐药基因的致病菌类型.结果表明,与水库沉积物相比,水体中的菌群...     

水平井油基钻井液气侵溶解气膨胀运移规律研究

天然气进入井筒并溶解于油基钻井液会对钻井安全产生潜在威胁,溶解气随钻井液运移到井口附近突然发生析出 并膨胀,使气侵早期监测及预警的难度显著增加。为了降低井喷发生概率和钻井作业风险,针对水平井油基钻井液溶解 气运移规律进行了研究。采用气液两相流模型,模拟了不同初始气侵速率情况下甲烷溶解气和游离气随钻井液在水平段 和垂直段的运移过程,得到环空中钻井液的流速变化、甲烷析出过程、井筒环空气液两相流流型变化、泥浆池增量随时 间变化和截面含气率沿程分布等规律。模拟结果表明,油基钻井液发生气侵时的初始进气率存在临界值;在小气侵速率 情况下,侵入环空的甲烷将以溶解气的形式运移到井口,在井口分离释放,对钻井安全构成的威胁较小;而当气侵量超 过临界值时,在环空上部发生气体分离,分离点迅速下移,如不及时控制,在极短时间内便可演化为井喷,危险性极大 。     

Horizontal lifelines – review of regulations and simple design method considering anchorage rigidity

Among the many occupational risks construction workers encounter every day falling from a height is the most dangerous. The objective of this article is to propose a simple analytical design method for horizontal lifelines (HLLs) that considers anchorage flexibility. The article presents a short review of the standards and regulations/acts/codes concerning HLLs in Canada the USA and Europe. A static analytical approach is proposed considering anchorage flexibility. The analytical results are compared with a series of 42 dynamic fall tests and a SAP2000 numerical model. The experimental results show that the analytical method is a little conservative and overestimates the line tension in most cases with a maximum of 17%. The static SAP2000 results show a maximum 2.1% difference with the analytical method. The analytical method is accurate enough to safely design HLLs and quick design abaci are provided to allow the engineer to make quick on-site verification if needed.     

Result-oriented approaches to the management of drinking water catchments in agricultural landscapes

Management of water quality in drinking water catchments is of ongoing, high importance as nitrate concentrations are often still very high. We analysed the Augsburg catchment in Germany, a unique example where a result-oriented approach has been implemented. We investigated the historical evolution of the water protection programme, the result-oriented payment contracts with farmers, and farmer satisfaction with the contracts, based on interviews with the water utility and farmers as well as an analysis of the literature. Today, the water protection programme has been successfully implemented, and a significant reduction of nitrate concentration was achieved due to the following factors: (1) investment of non-negligible amounts of money for high compensation and remuneration payments, (2) different contract options, (3) farmers’ participation in the negotiation process for result-oriented payment contracts, (4) involvement of “outside” people and institutions in negotiation processes, (5) anticipation of starting a programme when nitrate levels were still far below legislative thresholds, and (6) a political and legislative framework allowing direct decisions by a water supplier.     

Forest Protection and Reforestation in Costa Rica: Evaluation of a Clean Development Mechanism Prototype

/ Costa Rica has recently established a program that provides funds for reforestation and forest protection on private lands, partly through the sale of carbon certificates to industrialized countries. Countries purchasing these carbon offsets hope one day to receive credit against their own commitments to limit emissions of greenhouse gases. Costa Rica has used the proceeds of the sale of carbon offsets to Norway to help finance this forest incentive program, called the Private Forestry Project, which pays thousands of participants to reforest or protect forest on their lands. The Private Forestry Project is accompanied by a monitoring program conducted by Costa Rican forest engineers that seeks to determine net carbon storage accomplished on these lands each year. The Private Forestry Project, which is officially registered as an Activity Implemented Jointly, is a possible model for bundled projects funded by the Clean Development Mechanism (CDM) established by the 1997 Kyoto Protocol to the UN Framework Convention on Climate Change. It also serves as an interesting example for the CDM because it was designed by a developing country host-not by an industrialized country investor. Accordingly, it reflects the particular "sustainable development" objectives of the host country or at least the host planners. Early experience in implementing the Private Forestry Project is evaluated in light of the main objectives of the CDM and its precursor-Activities Implemented Jointly. It is concluded that the project appears to meet the criteria of global cost-effectiveness and financing from non-ODA sources. The sustainable development implications of the project are specific to the region and would not necessarily match the ideals of all investing and developing countries. The project may be seen to achieve additional greenhouse gas abatement when compared against some (although not all) baselines.     

成都龙泉山地区建设用地生态适宜性评价

随着景观格局与生态过程之间的关系日益受到重视,传统的评价方法已经不能满足生态适宜性评价的发展需要。本文以成都市龙泉山地区为例,从景观类型、生态功能、生态价值、土壤侵蚀敏感性和地质灾害敏感性5个方面建立评价指标体系,分别采用最小累积阻力模型和模糊综合评判法描述水平生态过程和垂直生态过程下的生态适宜性,综合两种评价结果进行建设用地的生态适宜性评价。研究结果表明,模型机理的差异使评价结果有着很大的区别,两种方法的综合应用可以有效弥补彼此的不足,本文将研究区的生态适宜性评价结果划分为禁止开发区、严格限建区、一般限建区、重点开发区和优化开发区5个分区,各区的面积分别为259．70km^2、793．89km2、1220．35km2、739．68km2和490．42km2。以往的生态适宜性评价方法往往单一地考虑水平或者垂直生态过程,本文构建的这种综合水平和垂直生态过程的评价方法为生态适宜性评价的方法研究提供了有益的尝试和补充。     

Investigation of modified horizontal wing cut twisted tapes fitted with rod and spacer at trailing edge on heat transfer properties in Double Glazing V-Trough solar water heaters

An experimental analysis of heat transfer efficiency in double glazing solar water heating system having full-length Horizontal wing cut twisted tapes having twist ratio 3 fitted with rod or spacer of dimensions 125 mm, 250 mm, and 500 mm as length at the trailing edges has been dealt in this work. The experimental results have been compared with a plain tube with similar operating conditions and concluded that variation in the Nusselt number, as well as friction factor, are ±12.56% and ±10.17%, respectively. The result of empirical correlation concludes that Nusselt number is maximal for horizontal wing cut twisted tapes having rod or spacer at its ends while comparing with full-length horizontal wing cut twisted tapes. The friction factor is low for full-length horizontal wing cut twisted tapes than the horizontal wing cut twisted tapes fitted with rod or spacer. The horizontal wing cut twisted tapes fitted with rod has superior performance than twist fitted with spacer.     

水平基因转移及其在污染修复中的应用

水平基因转移加速了部分生物体基因组的进化和革新;但随着基因改造生物的大量运用,由水平基因转移引起的生态安全问题越来越成为人们争论的焦点.由于大量异生污染物的产生,污染地区成为细菌水平基因转移的一个"热点"区域.为了实现污染地区的生物修复及强化难降解废水处理的效果,人为的制造和加快特定降解基因的水平转移被认为是解决这些问题的一个新思路.图2参57     

春季不同天气城市街头绿地内PM2.5质量浓度分布特征研究

于2012年春季,采用水平分布监测法监测了3种天气下距交通污染源不同距离的街头绿地中的PM2.5质量浓度,研究了不同天气下PM2.5的日变化、水平分布规律及绿地对PM2.5的净化效应,为城市街头绿地、城市公园建设及市民合理选择休闲锻炼时间和地点提供理论依据。结果表明：1）晴天和多云时,PM2.5质量浓度上午高于下午,7：00浓度最高,15：00最低;雨后阴天基本保持上升趋势。2）PM2.5日均质量浓度为晴天（61.67μg·m-3）〈多云（187.98μg·m-3）〈雨后阴天（291.48μg·m-3）。晴天除5：00和7：00外,其他时刻均达到国家二级标准,且13：00—15：00达到国家一类功能区空气质量要求;多云和雨后阴天PM2.5质量浓度分别超过国家二级浓度限值150.6%和288.6%。3）观测时段内,无论哪种天气,5：00、7：00、11：00和15：00绿地的净化功能较强,19：00净化功能均最差,所有监测点无一例外的表现为负效应。4）3种天气下,PM2.5质量浓度在距离道路10~25 m最高,绿地的净化效应最差,55 m外基本可以形成稳定的森林内环境。5）在南方高湿环境下,空气相对湿度是影响PM2.5质量浓度的主要因素,晴天和多云天气PM2.5浓度与相对湿度呈显著正相关,而雨后阴天二者呈负相关关系。6）在一定阈值内,街头绿地能够缓解PM2.5污染,为居民提供良好的休闲环境。从游憩时间来看,市民可以选择晴天进入街头绿地休闲,多云和雨后阴天尽量减少外出;从活动最佳地段来看,距离污染源55 m以上适宜休闲锻炼;从街头绿地的规划面积来看,半径以不小于55 m为宜。