城市轨道交通规划环境影响评价指标体系探讨

城市轨道交通将成为我国未来公共交通建设的重点,将在很大程度上改善城市交通拥堵问题和机动车尾气对城市大气环境污染问题,并促进城市建设和推动城市的经济发展.城市轨道交通项目投资巨大,工期长,特别是其线路走向及布置对城市土地利用,发展格局及城市化进程起着重要的作用,且轨道交通对线路周围的环境会产生噪声,振动等污染影响.城市轨道交通是一个复杂的体系,且城市轨道交通规划环评指标体系尚未形成一套健全的体系,因此开展城市轨道交通环评指标体系的研究具有重大的现实意义.利用规划环境影响评价的指导思想和原则,分析了城市轨道交通规划环境影响评价指标体系的筛选方法及规划的环境影响识别,解释了指标含义;建立了城市轨道交通规划环境影响评价指标体系.     

Distribution and temporal trends of butyltins monitored by molluscs along the Chinese Bohai coast from 2002 to 2005

Thirteen areas around the Chinese Bohai coast, individuals including ten kinds of bivalves and two kinds of snails were collected during the period of 2002-2005 for the investigation of spatial distribution and temporal variations of butyltin compounds (BTs). BTs including tributyltin (TBT) and its derivates, dibutyltin (DBT) and monobutyltin (MBT) were quantified by gas chromatography/flame photometric detection after extraction and Grignard derivatization. BTs compounds were widely existed in the samples and TBT was the dominant composition, indicating recent TBT input along Bohai coast. As a whole, BTs concentration remained high during the sampling years except a slightly decreased in samples from several sites in 2005. The contamination characteristics of BTs in different sampling sites were analyzed using principal component analysis (PCA) method, and the species specific bioaccumulation of BTs was also identified using cluster analysis.     

Runoff variation affected by precipitation change and human activity in Hailiutu River basin,China

For recent years, runoff generation and hydrological processes in Hailiutu River basin have been greatly changed by climate change and human activity, especially water and soil conservation construction. In this study, the trends in precipitation, evapotranspiration (ET) and river runoff as well as the effects of precipitation change and human activity on runoff variation have been studied. The results showed that during 1960–2000, annual precipitation and river runoff, monthly precipitation and ET in September and October as well as monthly runoff in all months showed a significant decrease. In addition, peak flow and base flow had a large decrease. Under the joint influence of precipitation change and human activity, the mean annual runoff decreased by 35 million m³ from the baseline period (1960–1985) to the change period (1986–2000), which accounted for 60.9% and 39.1% of the total runoff decrease, respectively. Precipitation change played a primary role in the decrease of annual runoff whereas human activity, particularly water and soil conservation construction, also had remarkable impacts on runoff variation.     

基于耕作半径分析的县域农村居民点空间布局优化——以安徽省埇桥区为例

分析了安徽省埇桥区农村居民点与耕地的空间邻接特征和数量结构关系,通过“均等”和“耕聚比”的方法分别求算耕作半径并构造缓冲区,得出两种耕作压力系数的分布,对其进行比较并提出了农村居民点布局优化策略。结果表明：耕地是皖北平原地区影响农村居民点布局的主要因子,基于各乡（镇）统计的耕地与农村居民点面积存在较好的线性相关;基于“耕聚比”的计算模型较好地解决了农村居民点规模因素对耕作半径计算造成的影响;基于“耕聚比”的方法计算的耕作压力分布在评价耕地与农村居民点的分布合理性上更为实用;耕作压力系数分布对农村居民点合理布局具有一定的指导意义,布局调整中应将压力系数高的地区的拆旧和压力系数低的地区的建新相挂钩     

Function of Agricultural Land Use and Its Evolvement in Peri-urban Area: A Case Study of Beijing

Abstract

Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the development of the multifunctional agriculture and urbanization any more, so multifunctional agricultural land use is going to be promoted in the city. This article proposes the evolvement of the land use change from 1992 to 2004 and discusses some evolvement views.     

Application of Tradable Emission Permits in Europe

Abstract

The purpose of this study is merely to review the current situation in the designing and implementation of the emission trading programs in Europe. Historical data show that although there is a series of shortcomings in their current functioning, employing such instruments for GHG reduction policy making is strongly expected to be efficient and effective. The European Union Emission Trading Scheme (EU ETS), Clean Development Mechanism (CDM) and Joint Implementation (JI) are just a few examples of the ambitious EU initiative that heavily relies on such instruments. We dwell on their operations and achievements by far and all the content in this article is expected to convince the Chinese government and regional public authorities to take positive actions and attitudes in promoting these instruments.     

辽宁省自然灾害及基本特点

辽宁是一个自然灾害较多的省,地质灾害、气象灾害、海洋灾害、农业灾害和林业灾害部比较频繁。本文在总结上述灾害的基础上,指出了辽宁自然灾害的特点,即自然灾害的分布严格受自然地理和地质构造条件的控制;人类生产活动恶化了原有的自然环境,从而加速了灾害的发生和发展;灾害类型多,成灾面积广;灾害的频度逐年增加。     

A novel view of biologically active electromagnetic fields

Over the past decades, strong evidence has accumulated that low-frequency electromagnetic fields (EMFs) can be useful in treating human pathologies, such as bone fractures, soft tissue illnesses, and pain. Common strategies for the design of commercial therapeutic devices are to generate EMFs that simulate body endogenous EMFs, or EMFs that resonate with a particular biological process, such as the natural motions of ions. We recently came across a biologically active commercial EMF signal that seems to be different. The signal is generated by summing the fundamental frequencies and harmonics of several periodic base signals which remain proprietary to the company. When first examined in the time domain, the signal resembled electronic noise; however, when critically analyzed, the signal is not identical with noise. Rather, it is a highly complex waveform exhibiting a very wide range of values for the time derivative of the magnetic field density (dB/dt) and a beat frequency in the Extremely Low-Frequency range. In this paper, we speculate on the mechanism of action of this and similar signals. We consider it less likely that cells, or cell components, act like filters to extract and couple with individual signals that make up the complex EMF signal. Consequently, we favor the possibility that with the signal discussed here cells respond to the very complex signal and that the biological response can be modified by the presence of a beat in the signal, in this case a low-frequency beat. More generally, this would suggest the hypothesis that biological processes can be regulated by noise-like signals and that the effects of a noisy signal can be modified by the presence of signal repetition patterns, such as beats. Given the very small energy that signals like these can transduce into a biological system, biological effects can be expected only when the molecular processes involved are poised so that the available energy leads to molecular reactions that achieve the activation state for the reaction.     

Development of a coupled reservoir operation and water diversion model: Balancing human and environmental flow requirements

Maintaining a natural flow regime helps preserve the health of riverine ecosystems. Conventional studies on reservoir operations have focused mainly on identifying optimal operational schemes for satisfying human water demands. To systematically reflect the ecological effects of both natural and human-induced hydrologic alterations, water diversions downstream of the reservoirs should be considered as well. This research focused on a coupled reservoir operation and water diversion (CROWD) model, created through the integration of a reservoir operation model and a water diversion model. The proposed model considers both human and environmental flow requirements, and represents a compromise that balances ecological protection (preservation of the natural flow regime of a river) and human needs (reduced water shortages). In the reservoir operation model, the reservoir space is divided into three zones and different operating rules are developed for directing reservoir operation when water levels are in different zones; in the water diversion model, different water users are assigned different supply priorities with the instream flows no more than the minimum environmental flows having the highest priority; and the two models are coupled by the water mass balance between the two hydraulic facilities. The non-dominated-sorting genetic algorithm II (NSGA-II) was used to determine the parameters of the developed CROWD model and the model was applied to support the joint operational management of the Tanghe Reservoir and the Liaoyang Diversion in the Tang river basin, China. The resulting reservoir operation and water diversion schemes indicate that the CROWD model is useful for optimizing the operation of reservoirs and water diversion schemes. Moreover, it helps to analyze tradeoffs between human and environmental water needs, resulting in solutions that reduce the risk of water shortages and minimize ecological integrity disturbances.     

Performance of amine-multilayered solid sorbents for CO2 removal: Effect of fabrication variables

The emission of fossil fuel carbon dioxide (CO₂) to the atmosphere is implicated as the predominant cause of global climate change; therefore, advanced CO₂ capture technologies are of the utmost importance. In this study, innovative amine-multilayered sorbents were fabricated using layer-by-layer (LbL) nanoassembly technology via alternate deposition of a CO₂-adsorbing amine polymer (e.g. polyethylenimine or PEI) and an oppositely-charged polymer (e.g. polystyrene sulfonate or PSS). We found that the developed sorbents could be used for CO₂ capture and that LbL nanoassembly allows us to engineer their CO₂ capture performance through the fabrication variables (e.g. deposition polymers, deposition media, and number of bilayers). PEI/PSS was found to be the best polymer combination for developing sorbents with relatively high CO₂ capture capacity. The amine-multilayered solid sorbents possessed fine microstructures and may have similar polymer deposition within and on the surface of solid sorbents. These amine-multilayered sorbents had much faster CO₂ desorption rates compared to sorbents prepared using the current PEI-impregnation approach. Such fast CO₂ desorption could make sorbents a good option for CO₂ removal from power plants and even the atmosphere.