干法脱硫袋除尘器滤袋袋底破损原因研究

针对烟气干法脱硫配套布袋除尘器部分滤袋袋底破损问题,进行原因分析研究,提出了滤袋伸长率的概念,通过试验和理论计算分析,确定了干法脱硫配套布袋除尘器的滤袋和袋笼最佳配合设计尺寸,以保证滤袋的使用寿命和除尘器的长期高效运行。     

溴氟丙烯/13X沸石复合粉体抑制汽油火的试验研究

为提高粉体灭火介质的灭火性能,基于粉体灭火剂在火灾防治领域的重要性,通过减压吸附的方法,将洁净高效的气体灭火剂溴氟丙烯负载在13X沸石的孔洞之中,形成气-固复合粉体灭火剂。采用X-射线衍射仪、扫描电镜等对复合粉体的结构和组分进行表征。通过模拟试验研究溴氟丙烯含量不同的复合粉体对汽油油池火的灭火效果,并和普通的干粉灭火剂进行对比。结果证明,溴氟丙烯和13X沸石所形成的气-固复合粉体灭火剂针对汽油油池火具有很好的灭火性能,在同样的试验条件下,其灭火时间和灭火剂用量远少于普通的干粉灭火剂,且随着复合粉体中溴氟丙烯的含量增加,复合粉体的灭火性能逐渐提高。     

广西乐业大石围天坑群多环芳烃的干湿沉降

为研究大气多环芳烃(PAHs)的沉降对广西乐业大石围天坑群喀斯特生态环境的影响,选择典型的大石围天坑,采用大气干湿采样器分季节进行了为期1 a(2007-03～2008-03)的大气干湿沉降样品采集,利用气相色谱-质谱联用仪(GC-MS)测定了16种PAHs优先控制污染物.结果表明,大气干湿沉降中PAHs的干湿沉降通量为132.36～1 655.27 ng.(m2.d)-1,平均值为855.00 ng.(m2.d)-1,大石围天坑的PAHs沉降量为51.98 g.a-1;PAHs的组成以苯并[b]荧蒽、、苯并[a]芘、苯并[k]荧蒽、蒽、菲、萘7种为主,占总量PAHs的78.5%;大气PAHs沉降通量的空间分布为东垭口>南垭口>西峰>北垭口;不同季节的沉降通量为春季>夏季>秋季>冬季,春、夏季PAHs沉降通量高于秋、冬季4.6倍,春、夏季以4～6环PAHs为主,而秋、冬季以2～3环PAHs为主;研究区大气PAHs沉降通量与降雨量、风向、风速、温度气象因子及污染源的方位密切相关;大石围天坑群大气PAHs沉降通量在春季、夏季呈季节性增高可能来源于高气温、低海拔的广西工业发达地区.     

不同秸秆翻埋还田对旱地和水田土壤微生物群落结构的影响

以水稻、小麦、玉米秸秆和油菜、蚕豆青秆为研究对象,采用磷脂脂肪酸(PLFA)方法,并结合主成分分析方法,研究了不同秸秆翻埋还田对旱地和水田土壤微生物数量、菌群分布、群落结构特征等的影响.PLFA分析结果表明,旱地土壤PLFA总量变幅为8.35~25.15 nmol·g-1,大小顺序为油菜蚕豆玉米水稻小麦,5种秸秆翻埋还田均能提高土壤微生物PLFA总量,其中油菜、蚕豆处理分别是不加秸秆处理的2.18、2.08倍,差异显著;5种秸秆处理各菌群PLFA量均高于不加秸秆处理,其中真菌量均显著提高,微生物群落物种丰富度值也显著提高.水田土壤PLFA总量变幅为4.04~22.19nmol·g-1,大小顺序为水稻玉米小麦油菜蚕豆,其中油菜和蚕豆处理低于不加秸秆处理;除蚕豆外其余秸秆处理真菌PLFA量均显著高于不加秸秆处理,蚕豆处理细菌和PLFA总量均显著低于其他处理,各处理间放线菌、革兰氏阳性菌(G+)、革兰氏阴性菌(G-)无显著差异;水稻、小麦、玉米、油菜均能显著提高水田土壤微生物的物种丰富度指数和优势度指数.主成分分析结果表明蚕豆青秆对旱地土壤微生物群落结构影响最大,油菜青秆和小麦秸秆对水田土壤微生物群落结构影响最大.     

载体结构对Co/MgO-Al2O3催化剂催化C2H6/CO2反应性能的影响

采用共沉淀-浸渍法制备了不同载体结构的Co/Al₂O₃、Co/MgO_（25）-Al₂O_3（75） （Co/M₁A₃-Spinel）、Co/MgO_（75）-Al₂O_3（25） （Co/M₃A₁-Solid）和Co/MgO催化剂,用于CO₂氧化乙烷脱氢（ODEC）和乙烷干重整（DRE）反应.XRD、Raman、H₂-TPR、XPS表征结果表明,载体结构显著影响催化剂上Co物种的落位、结构和还原性能.Co³⁺和Co²⁺在C₂H₆/CO₂反应气氛中可相互转化,促进C₂H₆和CO₂活化;尖晶石结构中的Co物种比固溶体中的Co物种可还原性强,在高温ODEC反应条件下,催化剂表面的Co物种会被还原成Co⁰,协同Co³⁺/Co²⁺导致C—C键和/或CC键断裂,使得反应路径向DRE转变.MgO基固溶体结构中Co物种与载体相互作用更强,在高温ODEC反应中避免了被大量还原为低价态的Co⁰,ODEC反应可稳定进行.     

Navigating multi‐level natural resource governance: an analytical guide

A plethora of terms are used to describe the form of governance of complex social‐ecological systems, such as multi‐level governance, polycentricity and network governance. This plethora of terms is associated with a diffuse literature from which it can be challenging to identify which variables are important for investigation of the governance system and what questions could be asked. The purpose of this article is to present the development of a guide for the analysis of the complex governance systems of renewable natural resources, informed by a breadth of literature from which key characteristics, challenges and concepts are identified. The guide consists of three dimensions: multiplicities of levels, actors and institutions; the existence, opportunities for, and challenges of, interactions within and between levels (vertical and horizontal interactions); and an assessment of governance performance through application of governance principles. The guide is applied to a case study of mangrove forests in Kenya, to illustrate its utility in generating understanding and identification of challenges and opportunities for more effective multi‐level governance. It is proposed that the guide could be beneficial to researchers and practitioners seeking to develop an understanding of structures, performance and outcomes of multi‐level governance.     

Tracking collaboration: forest planning and local participation on the San Juan National Forest,Colorado

The proliferation of community-based collaborative approaches to public land management and planning has spawned many questions regarding issues of community representation and the effects of participation for local residents. This paper presents a longitudinal assessment of local resident participation in collaborative forest planning on local community–forest relations in southwestern Colorado. Using survey data of participants involved in the San Juan National Forest's forest plan revision community study groups from 1998 to 2003, we assess participation in terms of community representation and the effects of community-based collaboration upon individuals' forest uses, forest values, and the level and form of involvement in forest management and planning activities. Results show that community representation remains slanted towards existing active stakeholders, and that while forest values, uses, and frequencies of involvement change little, participants cite positive effects in terms of the development of new knowledge, personal relationships, and greater confidence to engage in forest management affairs.     

水中总有机碳测定方法研究进展

本文对总有机碳（TOC）测定的原理、常用的氧化方法、检测技术、TOC与COD的相关性等作了较全面的评述，并指出了TOC目前在应用中存在的一些问题及其研究进展。     

Measuring Asset Values and Flow Benefits of Non-Traded Products and Ecosystems Services of Forest and Woodland Resources in South Africa

Conventional measures of economic output, national income and wealth highly underestimate the value and contribution of natural resources to economic welfare. This paper makes estimates of the asset values and flow benefits of non-traded goods and services from forests and woodland resources in South Africa. Four benefit categories were included, namely direct consumptive use values (timber and non-timber products), non-consumptive use values (recreation for example), indirect use values (environmental services such as carbon sequestration, watershed protection, etc.), and non-use values (based on contingent valuation by tourists). Asset values were calculated knowing the change in physical stocks and the relevant prices. In South Africa, the increase in assets was equivalent to 1.1% of gross domestic product (GDP) (forests were improving, but fynbos deteriorating), and the flow benefits were equivalent to 0.8% of GDP. These are large magnitudes.