Changes in negative air ions concentration under different light intensities and development of a model to relate light intensity to directional change

The purpose of this research was to determine changes in negative air ion (NAI) concentrations produced by plants grown under different light intensities. NAI concentrations were observed and analyzed in an outdoor green space with five plant species (Aloe arborescens, Clivia miniata, Chlorophytum comosum, Opuntia brunnescens, Crassula portulacea) and A. arborescens was then grown under controlled-light conditions in an enclosed space for the subsequent light intensity experiment.     

生态旅游环境教育功能的实现途径研究

生态旅游是一项具有保护自然生态与文化多样性,提高旅游者环境意识及维护当地居民生活双重责任的旅游活动,具有较强的环境教育功能。但其功能的发挥不是旅游活动的自然结果,而有赖于人的自觉和切实有效的环境教育。本研究基于对生态旅游环境教育功能及其影响因素正确认识基础上,构建生态旅游环境教育功能实现的基本框架,并系统阐述环境解说、产品设计、舆论监督、宣传教育、环境管理等途径。本研究对促进生态旅游健康发展和国民环境教育具有重要意义。     

环境库兹涅茨曲线假说在中国的经验研究

改革开放以来,中国年均98%的经济持续增长举世瞩目,然而对经济增长所付出的环境代价却存在着诸多争议。环境库兹涅茨曲线（EKC）假说是对环境 收入关系研究的经典表述,可以直观地展现环境与收入变化的关系。在前人研究EKC时运用单一或多个单一指标测量污染程度存在缺陷的基础上,基于 1982～2006年中国6类环境污染物,用改进的熵值法计算出代表我国整体环境污染状况的环境污染指数,利用协整检验来研究中国环境库兹涅茨曲线的存在性及其“本土化”特征,发现与一般发达国家和新兴发展中国家的“倒U”型环境库兹涅茨曲线不同,中国综合环境污染模型呈“正U”型,以21世纪初为分界点,之前环境污染水平不断下降,之后环境污染又开始有所恶化;利用脉冲响应函数来考察环境污染和经济增长的互动关系,发现经济增长在追溯期内对环境污染均为正向影响,而环境污染仅在短期对经济增长有促进作用。这一研究旨在为制定符合中国国情的环境、经济政策,实现经济与环境协调发展提供理论依据.     

The effects of scale and spatial heterogeneities on diffusion in volcanic breccias and basalts: Amchitka Island, Alaska

Knowledge of the factors that influence the diffusion of contaminants, such as the diffusivity and the connected porosity, is crucial to modeling the long-term fate and transport of contaminants in subsurface systems with small or negligible advective flow, such as in fractured crystalline rock. Fractured rock is naturally heterogeneous, and hence, understanding the diffusivity of a molecule through this material (or the formation factor of the medium) becomes a complex problem, with critical concerns about the scale of laboratory measurements and about the spatial variability of these measurements relative to the scale needed for fate and transport modeling. This study employed both electrical and tracer-based laboratory methods to investigate the effects of scale and pore system connectivity on the diffusivity for volcanic matrix rock derived from the study site, a former underground nuclear test site at Amchitka Island, Alaska. The results of these investigations indicate a relatively well-connected pore system with scale effects generally limited to approximately 6 cm lengths and well-correlated to observed heterogeneous features. An important conclusion resulting from this study, however, is that there is a potential for the estimated diffusivity to be misrepresented by an order of magnitude if multiple samples or longer sample lengths are not used. Given the relatively large number of measurements resulting from these investigations, an analysis of the probability density function (PDF) of the diffusivity was possible. The PDF of the diffusivity was shown to generally follow a normal distribution for individual geologic layers. However, when all of the geologic layers are considered together, the distribution of the subsurface as a whole was shown to follow a lognormal distribution due to the order of magnitude differences amongst the layers. An understanding of these distributions is essential for future stochastic modeling efforts.     

Preferred modes of travel among older adults: What factors affect the choice to walk instead of drive?

Introduction

There are many factors that influence older adults' travel choices. This paper explores the associations between mode of travel choice for a short trip and older adults' personal characteristics.

Methods

This study included 406 drivers over the age of 64 who were enrolled in a large integrated health plan in the United States between 1991 and 2001. Bivariate analyses and generalized linear modeling were used to examine associations between choosing to walk or drive and respondents' self-reported general health, physical and functional abilities, and confidence in walking and driving.

Results

Having more confidence in their ability to walk versus drive increased an older adult's likelihood of walking to make a short trip by about 20% (PR = 1.22; 95% CI: 1.06-1.40), and walking for exercise increased the likelihood by about 50% (PR = 1.53; 95% CI = 1.22-1.91). Reporting fair or poor health decreased the likelihood of walking, as did cutting down on the amount of driving due to a physical problem.

Discussion

Factors affecting a person's decision to walk for exercise may not be the same as those that influence their decision to walk as a mode of travel. It is important to understand the barriers to walking for exercise and walking for travel to develop strategies to help older adults meet both their exercise and mobility needs. Impact on Industry: Increasing walking over driving among older adults may require programs that increase confidence in walking and encourage walking for exercise.     

铁碳微电解法在废水处理中的研究进展及应用现状

介绍了铁碳微电解法处理废水的作用机理,概述了近10年来国内外利用铁碳微电解法及其组合工艺对印染、造纸、焦化、炸药、制药等废水处理方面的研究进展及实际的应用状况.提出了铁碳微电解法在运行过程中存在的几个问题,并对今后研究工作的大体方向做了初步的探讨.     

人-机系统事故预防理论研究

分析人-机系统事故发生原因,剖析经典以人失误为主因的事故致因模型存在的不足,在该模型基础上增加"刺激"形成的原因,构建了改进事故致因模型。对两模型进行比较研究,指出人机工程学与防止事故的关系,提出了人机工程学防止事故的方法,并给出人机界面合理性主观评价检查表。研究及论证表明:预防人-机系统事故的本质在于有效防止人失误的发生,除安全管理措施以外,最重要的是人机工程学问题,笔者提出的基于人机工程学的人-机系统事故预防理论,对人-机系统事故的预防起到积极的指导作用。     

矿井通风系统安全性的多层次模糊综合评价

按照事故致因理论,并进行系统安全分析和易发事故分析,建立了矿井通风系统安全性的多层次评价体系;应用层次分析法和Matlab软件,确定矿井通风系统安全性评价体系中各子系统及各指标的权重;结合实际经验,根据安全规范构造各指标隶属度;进而根据评价集构造了梯形分布的隶属函数,并得到各指标对评价集的最终隶属度、模糊关系矩阵和综合评价矩阵;求得矿井通风系统安全状况的综合得分,进而划分安全评价等级,并提出了对应各等级的处理措施。将该评价方法应用到重庆开县桃园联合煤矿,取得了良好的效果。     

Relationship between cultivated land use functions and land rental behavior of rural households: empirical evidence from different dominant functional regions in central China

This paper analyzes the relationship between the cultivated land use functions and the land rental decisions of rural households in three Dominant Functional Zones of Hubei, China. The results indicate that 41.10% of the rural households in the study areas participated in the land rental market. The land rental market in the Key Development Zone has both a higher participation rate and land rent; the Agricultural Production Zone has a higher participation rate but a lower land rent; and the land rental market in the Key Ecological Zone is underdeveloped. The difference in regional function and economic level leads to a significant difference in the spatial variation of the cultivated land use multifunction. Overall, the cultivated land function of rural households has a significant impact on their land transfer behavior. The higher the Functions of Economic Contribution, Food Production, and Pension & Employment, the more willing the rural households are to rent in the land, while the higher the Function of Inheritance and Retainment of the cultivated land use, the more likely the peasants are to retain their cultivated land resources. Furthermore, the correlation coefficient is significantly higher in the Key Development Zone than in the Key Ecological Zone.     

基于高通量测序的工业园区地下水和土壤细菌群落结构比较研究

为探究工业园区地下水和土壤细菌群落结构、多样性变化特征,采用高通量测序技术对地下水和土壤细菌16S r RNA基因高变区域进行序列测定。通过对Alpha多样性、物种组成、丰度和群落结构的分析,比较地下水和土壤细菌群落结构的异同。Alpha多样性的比较结果表明,土壤细菌群落多样性和丰富度明显高于地下水,地下水细菌群落多样性指数反映出地下水已受到周边污染源的影响。物种注释结果表明,地下水样品共检出48个细菌门,土壤样品共检出50个细菌门。变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)是地下水细菌群落的优势类群,共占93.54%,且该工业园区地下水细菌群落呈现出典型的淡水种群特征;土壤中优势细菌门为Proteobacteria、放线菌门(Actinobacteria)、酸杆菌门(Acidobacteria)、Firmicutes和芽单胞菌门(Gemmatimonadetes),共占85.21%。由于地下水和土壤两者的生态系统和理化环境的差异,致使Actinobacteria、Acidobacteria、绿弯菌门(Chloroflexi)、硝化螺旋菌门(Nitrospirae)、α-变形菌纲(Alphaproteobacteria)、δ-变形菌纲(Deltaproteobacteria)和Gemmatimonadetes占比在地下水和土壤细菌群落间差异显著,同时使地下水和土壤细菌群落各含有一些特有的优势细菌属(地下水2个,土壤4个)。基于高通量测序技术对工业园区样品的测序结果可以为地下水和土壤环境的生态评价提供方法依据。