Mutual interactions in bioelectromagnetics

This paper discusses mutual interactions phenomena especially in the case of Transverse ElectroMagnetic (TEM) cell applications as an exposure system in technical and biomedical studies. In many publications is described problem of influence of an object upon the electromagnetic field (EMF) distribution inside a exposure system while inverse effect—influence of exposure system on tested object is overlooked. The problem plays primary role if a correlation between investigations carried out in an enclosure (e.g. TEM cell) and that in the free space is looked for.     

On experimental setup in bioelectromagnetics

Bioeffects created by electromagnetic field (EMF) are the subject of intensive studies. This paper critically considers estimations of exposure to EMF in bioelectromagnetic experiments. Results of calculations presented herein show the significant role of the presence of conducting bodies (the exposure system) near an object under test on EMF energy absorption as well as mutual interactions between simultaneously exposed objects. Our aims herein are twofold: firstly to find a way to refer measurement results to free-space conditions in order to enable comparison of results obtained in different laboratories, and secondly to show that EMF energy absorption in any exposed object is different and that this difference is a function of the size of the exposure system, the number of exposed objects, and the particular properties (i.e., the electromagnetic structure) of the objects. In the authors’ opinion the existence of interactions caused by the presence of the exposure system and other exposed objects is a reason why remarkable differences are observed between experiments performed even under supposedly identical conditions. The presented considerations and conclusion suggest wider participation of physicists and engineers in bioelectromagnetic experiments in order to ensure the correctness of metrological aspects of these experiments.     

Evolution of the Stewardship Idea in American Country Life

Theological and secular concepts ofstewardship evolved markedly in the 20thcentury. During this period of evolution, theAmerican Country Life Association through itschurch, academic, farm organization, andgovernmental affiliations, served as a bridgingand bonding agent in developing the stewardshipidea. As in any evolutionary process, thestewardship concept was subjected to a broadarray of influences and characterized bynotable highlights such as the Lynn Smithcritique of the Judaeo-Christian ethic, theman-in-nature statement of Douglas John Hall,and the environmental concerns of ecologistsand philosophers of the post-Rachel Carson era.Some gains have been made in understanding theplace of humans in nature, but the stewardshipidea continues as work in process.     

转型期西安市产业结构演进分析

选取了12个产业指标,运用区位熵和灰色关联分析相结合的方法测度了西安市各产业的区位优势及产业结构的关联度,分析了转型期西安市产业结构的演进.结果显示,西安市的三次产业结构组合仍需升级优化;在各行业演进中,科技、金融和房地产具有显著的区位优势.此外,通过对各产业发展的相似性测度得出2003年之前就业人员在第一、二产业之间的2-3个产业部门游移,之后从业人员开始在第三产业的一般性服务业(5-7个部门)游移,这显示出第三产业未来巨大的发展潜力与活力.     

Ethics in agricultural research

Utilitarian ethics provides a model for evaluating moral responsibility in agricultural research decisions according to the balance of costs and benefits accruing to the public at large. Given the traditions and special requirements of agricultural research planning, utilitarian theory is well adapted to serve as a starting point for evaluating these decisions, but utilitarianism has defects that are well documented in the philosophical literature. Criticisms of research decisions in agricultural mechanization and biotechnology correspond to documented defects in utilitarian theory. Research administrators can expect that application of a utilitarian standard ignoring these deficiencies will become the occasion for predictable attacks by critics. Administrators who are sensitive to the strengths and weaknesses of utilitarian ethics are equipped to make a better allocation of research effort.     

中国区域海洋经济差异演化研究

中国海洋经济区域系统的时空差异随着海洋经济迅速增长已成为学术界关注的热点问题.在采用莫兰指数、变异系数和Theil指数分析不同尺度的中国海洋经济时间和空间差异演化的基础上,采用主成分分析法对差异显著年份区域海洋经济的综合实力水平进行评分.通过多种方法的综合运用,综合分析发现我国区域海洋经济在经历了较大幅度的差异变动后有收敛趋势,空间依赖性逐渐增强,根据结论提出发展对策.     

Analysis of an intermediate-temperature proton-conducting SOFC hybrid system

The performance of an intermediate-temperature proton-conducting solid oxide fuel cell (pSOFC) hybrid system is investigated in this work. The hybrid system consists of a 20-kW pSOFC, a micro gas turbine (MGT), and heat exchangers. Heat exchangers are used to recover waste heat from pSOFC and MGT. The performance of the system is analyzed by using Matlab/Simulink/Thermolib. Flow rates of air and hydrogen are controlled by assigning different stoichiometric ratio (St). St considered in this study is between 2 and 3.5 for air, and between 1.25 and 1.45 for hydrogen. Results show that the combined heat and power (CHP) efficiency increases as the fuel St decreases or air St increases. This is because lowering fuel St means fewer fuel will be wasted from the fuel cell stack, so the CHP efficiency increases. On the other hand, as air St increases, the amount of recovered waste heat increases, so does the CHP efficiency.     

辽宁省海洋产业结构演进与部门发展动态研究

海洋产业是海洋经济发展历史与发展水平的重要标志,同时对海洋资源的合理开发利用和海洋环境的保护有重要影响。基于此,直观描述了东北地区唯一的沿海省份——辽宁省的海洋产业结构演进过程,利用SSM对各大产业部门的发展进行了阶段性的具体分析,认为加强海陆联动与科技投入是推进辽宁省海洋产业高级化的必要途径。同时,海洋产业部门的增长优势与结构优势明显,但竞争力优势有待加强且显现出较严重的部门分化,因此对资源进行有效整合,通过集约化经营提高经济效益将是今后发展的重要手段。     

Validation of a hybrid life-cycle inventory analysis method

The life-cycle inventory analysis step of a life-cycle assessment (LCA) may currently suffer from several limitations, mainly concerned with the use of incomplete and unreliable data sources and methods of assessment. Many past LCA studies have used traditional inventory analysis methods, namely process analysis and input-output analysis. More recently, hybrid inventory analysis methods have been developed, combining these two traditional methods in an attempt to minimise their limitations. In light of recent improvements, these hybrid methods need to be compared and validated, as these too have been considered to have several limitations. This paper evaluates a recently developed hybrid inventory analysis method which aims to improve the limitations of previous methods. It was found that the truncation associated with process analysis can be up to 87%, reflecting the considerable shortcomings in the quantity of process data currently available. Capital inputs were found to account for up to 22% of the total inputs to a particular product. These findings suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependent upon data quality and availability. The use of input-output data assists in improving the system boundary completeness of life-cycle inventories. However, the use of input-output analysis alone does not always provide an accurate model for replacing process data. Further improvements in the quantity of process data currently available are needed to increase the reliability of life-cycle inventories.     

北京市地热资源开发的时空变化

简要介绍了北京地热资源特点,分析了北京地热资源开发的时空演变规律.在搜集资料和实地调查的基础上,绘制出了北京城区地热井分布示意图,并针对其开发利用中可能出现的问题提出了对策.     

和田河流域景观空间格局演变的初步分析

利用1990年、1999年TM和2002年中巴假彩色合成卫星遥感影像数据作主要信息源,经图像增强处理和解译,获得了和田河流域的区域土地利用景观类型图.采用景观生态学的方法,对研究区域进行土地利用景观空间格局演变进行了初步分析,并根据生态系统学基本理论,提出了综合利用水资源进行和田河流域生态环境整治的基本方案.     

遥感技术在城市湖泊演变研究中的应用

以武汉市东湖和沙湖为例,以多时相TM影像为数据源,利用ERDAS软件提取东湖和沙湖1991年、2001年和2006年的水域面积信息从时空两方面对湖泊水域面积的演化特征进行了系统分析。结果表明,1991—2006年湖泊水域面积出现急剧下降,减少了1040.43hm2。分析认为,随着城市经济的发展,对土地的需求会更为迫切,城市湖泊的保护也将面临巨大挑战。遥感技术具有宏观性、动态性与实时性的优势,能够快速、准确地获取大范围地区水域面积变化信息,定量地分析城市湖泊演化规律,为城市湖泊的合理开发、利用和保护提供重要依据。     

河南省林业经济差异与空间演变

采用经济重心研究法和变异系数法对河南省林业经济进行了计量分析,发现该省林业经济差异在不断扩大,林业经济重心偏向东南方向,有北移和西移的趋势,对此现象进行了合理的解释.在此基础上,提出了河南省林业经济发展的建议：①转变林业经济增长方式;②豫北山区培育形成特色经济林基地;③豫南山区加强名优经济林种植及深加工;④豫东豫中平原区大力发展速生丰产林和用材林.     

Major Forest Types and the Evolution of Sustainable Forestry in China

In this article, we introduce China’s major forest types and discuss the historical development of forest management in China, including actions taken over the last decade toward achieving SMF. Major challenges are identified, and a strategy for SFM implementation in China is presented. China’s forests consist of a wide variety of types with distinctive distributional patterns shaped by complex topography and multiple climate regimes. How to manage this wide array of forest resources has challenged forest managers and policy-makers since the founding of the country. Excessive exploitation of China's forest resources from the 1950s to the late 1990s contributed to environmental problems and calamities, such as floods, soil erosion, and desertification. At the start of the new millennium, the Chinese government decided to shift its emphasis from timber production towards the achievement of sustainable forest management (SFM). With a series of endeavors such as the implementation of the “Six Key Forestry Projects” and the reform of forest tenure policies, and the adoption of a classification system for China's forests, a beginning has been made at reversing the trend of environmental degradation that occurred throughout the latter half of the last century. At the same time, huge challenges remain to be tackled for the development of forestry in China.     

酒嘉地区中心城区扩张的时空格局演化研究

基于统计数据和酒(泉)嘉(峪关)地区1987—2013年5个时相卫星遥感数据,采用空间关联、网格分割等方法分析了酒嘉地区中心城区建设用地空间扩张的集聚特征及时空格局演化过程。研究结果表明:1酒(泉)嘉(峪关)中心城区呈一体化扩张,2000年以前呈背向式扩张,2000年以后呈现出酒泉向西为主,向南为辅,嘉峪关向东为主,向西为辅的相向式扩张,预计未来3—5年两市将自然融合为一体。2酒嘉中心城区建设用地扩张规模变化具有明显的阶段性特征,2000年以后中心城区扩张速度明显高于以前,建设用地扩张强度指数表现出先增后减的特征。3建设用地扩张的热点区从孤立点逐渐轮换、跃迁、延伸、粘合,形成连片趋势发展的团状聚集结构,建设用地扩张高值簇的比重出现了先降后升再降的现象。4酒嘉中心城区扩张具有定向开发、沿交通线轴向发展、从中心向外围扩张、逐河流沿岸和绿洲盆地分布、较多占用戈壁荒草地的特征。     

歙县居民对徽州方言使用与演化的感知研究

作为十大汉语方言区之一,徽州方言是一种极具特点和研究价值的方言;同时徽州方言又是我国三大地域文化——徽州文化的重要组成部分。以歙县居民为调查对象,研究了他们对于徽州方言使用和演变的感知,有助于客观地认识徽州方言的存在状态及其未来的某些走向,这是拓展方言演变研究路径的重要尝试。调查结果显示,歙县属于双言现象区,当地居民在使用徽州方言的同时也使用普通话。从年龄差异上看,老年人比年轻人使用徽州方言的频率更高。虽然当地绝大多数居民喜欢使用当地的徽州方言,并赞成采取有效措施保护徽州方言,但是从现实需要以及下一代的语言习惯和语言教育中看,当地的徽州方言面临着萎缩的危机。徽州方言的这种演变趋势主要是受到人口流动、经济发展、自然环境、政策、社会文化发展等方面因素的影响。最后提出了徽州方言保护的若干措施。     

基于核心—边缘理论的中国旅游发展水平时空演化分析

基于核心—边缘理论建立了区域旅游发展水平的空间自相关模型,对中国旅游业发展水平的区域核心—边缘空间格局时空演化和结构形态进行了分析,揭示了区域旅游发展水平的空间差异和区域经济空间格局时空演变模式.结果表明,中国旅游业的发展将长期处在核心—边缘空间结构中,其核心区与边缘区之间差异较大,空间格局的演变虽然以集聚型极化发展为主,但是扩散力量正在不断增强,其空间格局形态也逐渐由集聚型向扩散型演变,表现为集聚与扩散并存的空间格局形态.