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。     

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.     

苗期棉花对向日葵列当种子萌发诱导作用初探

以5个推广棉花（Gossypium hirsutum L.）品种（中棉所63、中棉所57、中棉所47、中棉所44和中棉所41）为研究对象,利用盆栽试验分别采集棉花苗期3个时期（二叶一心、四叶一心和六叶一心期）的根际土和植株样品,并用其甲醇浸提测试对向日葵列当（Orobanche cumana Wallr.）种子的发芽率。结果表明,根际土、植株样（根、茎和叶）甲醇浸提液诱导种子发芽率高低顺序为根际土〉根〉茎〉叶,表明棉花的根际土和根的甲醇提取液对向日葵列当种子的萌发诱导作用较强。3个时期中,二叶一心期诱导向日葵列当的发芽在品种之间不存在显著性差异,表现为较稳定的诱导种子萌发作用。综合得出,棉花二叶一心期的根际土和根的甲醇提取液对向日葵列当种子萌发的诱导作用较强,二叶一心期为棉花作为＂诱捕作物＂生物防除寄生杂草提供科学依据。     

系统工程方法建设应急救援平台的探讨

功能全面、实用高效的应急救援平台是实施科学、有效的应急救援的基础之一,也是一个复杂的人、机、信息综合系统,系统工程的分析方法及思想对指导应急救援平台的建设具有较强的针对性和指导意义.在分析了国内外应急救援平台的现状并明确了其功能、要求后,运用系统工程方法从应急救援方式、设备、人员、信息系统、移动平台5个方面进行了分析和...     

Markov reliability model research of monitoring process in digital main control room of nuclear power plant

Monitoring process is an important part in a high safety digital main control room of nuclear power plant (NPP), it is the source extracted information and found abnormal information in time. As the human factors events arisen from monitoring process recently take place more and more frequent, the authors propose a reliability Markov model to effectively decrease these abnormal events. The model mainly analyzes next monitoring object probability in terms of current information and plant state. The authors divide digital human–machine interface into two parts that are referred as logical homogeneous Markov and logical heterogeneous Markov. For the former, a series of methods of probability evaluation are proposed, such as, Markov transition probability with condition, probability distributed function with human factors, system state and alarm; for the latter, the authors propose the calculation of probability of correlation degree between last time and next time and probability calculation methods with multi-father nodes. The methods can effectively estimate the transition probability from a monitoring component to next monitoring component at time t, can effectively analyze which information is more important in next monitoring process and effectively find more useful information in time t + 1, so that the human factors events in monitoring process can greatly be decreased.     

单兵用主动式听力保护技术研究现状分析

战场噪声是造成单兵听力损伤的重要原因,通常要求单兵处于大于85dBA的噪声环境中需佩戴听力保护装置。听力保护装置通常包括耳罩式和耳塞式。新型单兵用耳塞式听力保护装置具有听力保护、环境声音的监听、持续及脉冲噪声抑制、通信接入等多种功能。     

Mobilization and plant accumulation of prometryne in soil by two different sources of organic matter

Prometryne is a selective herbicide of the s-triazine chemical family. Due to its weak absorption onto soil, it readily leaches down through the soil and contaminates underground water. Application of organic manure to soil has become a widespread practice as a disposal strategy to improve soil properties. In this study, we demonstrated the effect of pig manure compost (PMC) and lake-bed sludge (SL) on the sorption/desorption, mobility and bioavailability of prometryne in soil using comprehensive analysis approaches. Downward movement of prometryne was monitored in the packed soil column. Addition of PMC or SL decreased considerably the mobility and total concentration of prometryne in the soil leachate. Bioavailability analyses with wheat plants revealed that addition of the organic matter reduced accumulation of prometryne in tissues and increased plant elongation and biomass. These results indicate that the organic amendments are effective in modifying adsorption and mobility of the pesticide in soil.