促进循环经济发展的税收政策

循环经济是一种全新的经济模式,它关注的是资源减量、循环及再利用的问题。介绍了国外发展循环经济所采取的税收政策,指出我国目前在该领域所存在的问题,并根据我国的实际情况,提出了促进发展循环经济的税收政策,包括:完善现有税种,开征环境保护税,建立“绿色关税”体系,尽早开征燃油税,制定激励机制,开征社会保障税。     

甘薯燃料乙醇循环经济发展模式研究

非粮食生物质燃料乙醇产业在我国还属于幼稚产业,目前对此类农产品加工企业循环经济发展模式的实证研究很少。文章以重庆环球甘薯燃料乙醇生产为例,从循环经济理念出发,以甘薯燃料乙醇生产及相关企业为基本研究单元,运用工业生态系统集成和物质代谢的系统分析方法,深刻剖析甘薯燃料乙醇企业循环经济发展模式。     

发展湛江生态旅游农业

阐述了生态旅游农业的概念，并结合国内外的发展状况，论述了发展生态旅游农业的意义。在此基础上，提出了湛江发展生态旅游农业的优势构想。     

牡丹江流域水环境质量状况及特征分析

牡丹江流域是松花江水系的重要组成部分,近年来随着流域经济的不断发展,水环境污染和水资源短缺问题日益严重,本文从水环境出发,以环境与经济协调发展为目标,对牡丹江水流城环境质量进行分析研究,本文作者结合自身的实际工作,评价了牡丹江流域的水环境质量,并指出了牡丹江流域水环境污染特征.为制订合理的治理方案,并有重点、有计划、有目标地推进污染源的整治工作具有现实意义,同时对研究牡丹江流域水环境的可持续发展具有重要的实用价值和指导意义.     

基于经济发展阶段理论的土地利用变化研究——以广西江州区为例

土地利用在不同的经济发展阶段表现出不同特点。广西江州区属于我国西部经济欠发达地区,经济发展正处于工业化初期的起步阶段,土地利用变化特点主要表现为:以农业生产用地和生态用地竞争为主,耕地变化是土地利用变化的主要内容;建设用地低效、缓慢增长,农村居民点增长面积占较大比重;人均农村居民点面积逐渐增加。以1978-2002年的统计数据为基础,用主成分分析和回归分析相结合,对耕地面积变化的驱动力进行了研究,结果表明:人口增长、经济发展和土地管理使得耕地面积不断增长,收入和消费的提高以及农业产业结构调整导致耕地面积减少。发达地区的发展历程表明,经济高速发展必然引起农地快速非农化,江州区在土地利用中,必须注意节约用地,保护耕地,减少土地资源浪费,防止环境污染,实现区域土地的可持续利用。     

包头市气象因素对空气自动监测结果的影响分析

气象因素对大气污染的形成、扩散、稀释、迁移密切相关,进而直接影响空气质量的监测,为了更好的掌握空气污染的变化规律,了解分析气象因素对监测的影响是十分重要的.     

Spatial Analysis of Volatile Organic Compounds from a Community-Based Air Toxics Monitoring Network in Deer Park,Texas, USA

In the summer of 2003, ambient air concentrations of volatile organic compounds (VOCs) were measured at 12 sites within a 3-km radius in Deer Park, Texas near Houston. The purpose of the study was to assess local spatial influence of traffic and other urban sources and was part of a larger investigation of VOC spatial and temporal heterogeneity influences in selected areas of Houston. Seventy 2-h samples were collected using passive organic vapor monitors. Most measurements of 13 VOC species were greater than the method detection limits. Samplers were located at 10 residential sites, a regulatory air monitoring station, and a site located at the centroid of the census tract in which the regulatory station was located. For residential sites, sampler placement locations (e. g., covered porch vs. house eaves) had no effect on concentration with the exception of methyl tertiary-butyl ether (MTBE). Relatively high correlations (Pearson r > 0.8) were found between toluene, ethylbenzene, and o,m,p-xylenes suggesting petroleum-related influence. Chloroform was not correlated with these species or benzene (Pearson r < 0.35) suggesting a different source influence, possibly from process-related activities. As shown in other spatial studies, wind direction relative to source location had an effect on VOC concentrations.     

逆出水方向曝气反冲洗在动态膜生物反应器中的应用

采用逆出水方向曝气措施对以无纺布构建的动态膜生物反应器生活污水处理系统中的动态膜进行在线反冲洗.当反冲洗曝气强度为5.6 m³/(m²·h)、反冲洗时间为5　min时,生物动态膜的恢复需要45　min,生物动态膜恢复后出水浊度保持在5　NTU以下.在该反冲洗条件下,反应器稳定运行2个月,反冲洗周期可以稳定在15　h左右.扫描电镜观察表明,逆出水方向曝气反冲洗能够有效破坏附着在膜基材上的生物动态膜.生物动态膜截留能力研究表明,新的生物动态膜形成后,反应器对相对分子质量3×10⁴以上的有机物的截留率大于50％.逆出水方向曝气是一种经济有效的动态膜反应器在线清洗方法.     

Comparison of Numerical and Experimental Results for the Evaluation of the Depollution Effectiveness of Photocatalytic Coverings in Street Canyons

Towards the aim of improving the air quality in the urban environment via the application of innovative TiO₂ based photocatalytic coverings, a field campaign took place within the frame of the EU PICADA project () to asses the expected depollution efficiency of such materials under realistic conditions. Furthermore, extensive numerical modeling was performed via the application of the RANS CFD code for microscale applications MIMO, in an effort to asses the sensitivity of the developing flow field and the corresponding dispersion mechanism and hence of the depollution efficiency of the PICADA products on a wide range of factors, with most notably the length of the street canyon, the thermal exchange between the heated street canyon walls and the air and the approaching wind direction. For the needs of the PICADA project a new, simple module had to be implemented into MIMO to be able to model the removal of NO_x from a street canyon whose walls have been treated with a photocatalytic product. The model simulations results presented in this paper, show that MIMO is indeed capable of predicting the effectiveness of the photocatalytic products in question. At the same time, they reveal a strong dependence of the developing flow and concentration fields inside the field site street canyon configuration on most of the aforementioned factors with most notably the direction of the approaching wind.

南通市移动通信基站电磁辐射时空分布特征

为了解南通市移动通信基站电磁辐射时空分布特征,随机实测504座典型基站,着重从水平和垂直方向50 m范围内开展监测,并选取典型基站开展24 h连续监测。结果表明,南通市移动通信基站电磁辐射水平满足《电磁环境控制限值》(GB 8702—2014)中公众曝露控制限值要求;基站电磁辐射水平分布随距离增大呈现先增加后逐渐减小的趋势,地面最大投射点的距离基本为20~30 m;垂直方向最大监测值出现在与天线高度相近的楼层;24 h基站电场强度随时间呈明显变化,与话务量和数据流量分别进行相关性分析,相关系数为0.968 3和0.709 8,说明目前话务量仍是电磁辐射强度的重要影响因素。