福建省山仔水库生态安全评价

从经济状态、环境状态、社会状态3个方面建立了水库生态安全评价指标体系,应用全排列多边形图示指标法构建评价模型,对福建省山仔水库2000-2003年生态安全状况进行了评价。结果表明：2000-2003年期间,山仔水库经济状态、环境状态、社会状态总体上呈上升趋势,但仍然处于较差水平;综合考虑经济状态指数、环境状态指数、社会状态指数后,山仔水库生态安全状况优劣顺序为：2002年〉2003年〉2001年〉2000年。评价结果较为客观地反映了该区域生态环境安全状况,对于生态安全薄弱区的生态环境保护、资源利用和可持续发展具有指导意义。     

基于水土流失的赣州市生态安全评价

为定量评价赣州地区30 a来水土流失治理对生态环境变化的影响,基于水土流失状况构建了赣州市生态安全评价指标体系。利用"压力—状态—响应"模型,从水土流失角度,采用频度统计法和专家咨询法,构建了17个评价指标,首次对赣州地区生态安全状况进行了评价。结果表明:(1)经过30 a的水土流失治理,赣州地区生态安全水平得到明显提高,但局部地区出现了不同程度降低,整体生态安全等级处于Ⅲ级水平,生态环境有待进一步的改善;(2)赣州地区水土流失与生态安全呈现明显的负相关性,经过30 a的水土流失治理,赣州市水土流失与生态安全的负相关性逐渐减弱,水土流失对该地区的生态安全影响逐步降低,因此,水土保持是改善该地区生态环境的重要途径之一。     

半干旱区水保生态修复集成技术与环境响应分析

定西市安定区属典型的干旱半干旱地区,在生态修复过程中依据"源于自然,还原自然"的思路,紧紧围绕提高生态自我修复能力,将植被恢复技术与调整土地利用和产业结构、农村基础设施建设、规范法制保障机制、生态农业与社区发展等各项综合技术系统集成,实现了"两个趋于"、"三个保证"、"四个到位"、"五个改变",增强了农业综合生产能力和社区文明程度,促进了生态修复,提出了"生态修复+生态农业+社区发展"的生态经济发展模式,并对生态修复环境响应、经济结构调整及经济增长途径、生态环境质量效益监测情况初步进行了分析评价。     

佛山市土地利用的生态安全评价

以佛山市为例,从土地可持续利用的角度出发,采用PSR模型,从生态环境系统状态、生态环境系统压力、生态环境系统响应3方面建立了佛山市生态安全评价指标体系,运用层次分析法和综合评分法对2004年佛山市生态安全进行了评价。评价结果表明:2004年佛山市生态安全综合值为0.508 4,属于"较差"安全等级;佛山市生态环境的状态子系统较好,但面临的压力较大,并且响应较弱。针对评价结果,提出了区域土地可持续利用的生态安全对策。     

甘肃省徽县生态经济系统健康评价

 区域生态经济系统健康由多因素决定,通过评价县域生态经济系统健康状况,为县域生态环境的规划、管理和保护以及综合治理提供决策依据。从生态系统、社会经济系统、人类健康和政策4方面评价县域生态经济系统的健康程度,以"生态环境、自然资源、社会经济和可持续性"评价体系为基础,选择森林覆盖率、水土流失率、水环境指数、径流深、耕地坡度状况等29个评价指标,利用层次分析法和熵技术对徽县的3个水土保持功能分区进行生态系统健康评价。结果表明,该县3个水土保持功能区的生态经济系统基本处于健康或亚健康状态,但是Ⅰ区及Ⅱ区的社会经济发展和可持续性方面存在问题,应作相应调整。     

陕南地区生态环境状况综合评价及对策

根据国家环保总局颁布实施的<生态环境状况评价技术规范(试行)>制定的评价方法,采用生物丰度、植被覆盖、水网密度、土地退化和环境质量指数5个指标,对陕南地区的生态环境状况进行了综合评价与系统分析.结果表明,陕南地区植被覆盖度高,生物多样性丰富.生态系统稳定,生态环境状况总体处于优等水平.结合生态环境状况指数(EI)分析了陕南地区生态环境方面存在的不足,认为水土流失是该区目前主要的生态环境问题,并提出了实施生态移民、生态安全经济效益宣传等对策与建议.     

江西省可持续发展动态分析

基于生态足迹理论, 提出了生态压力指数、生态占用指数和生态经济协调指数3 个概念, 并构建了可持续发展评价模型。利用该模型对江西省1990~2007 年的生态安全、消费水平、生态与经济协调发展状况进行定量研究, 结果表明: 江西省的生态压力指数从1990 年的1.56 增高到2007 年的1.96, 17 年间生态压力指数提高25.64%, 生态环境始终处于很不安全状态(2 级); 生态占用指数从1990 年的0.79 逐年提高到2007 年的0.88, 始终属于较贫穷状态(2 级); 生态经济协调指数从1990 年的0.50 逐年降低到2007 年的0.45, 始终处于很差等级(1 级); 可持续发展指数从1990 年的0.19 逐渐降低到2007 年的0.13, 始终处于很差等级(1 级)。     

定西市安定区植被覆盖遥感调查方法研究

植被覆盖度是研究地表植被状况的重要指标。以定西市安定区为研究区域,以混合像元分解模型为基础,探讨了遥感估算植被覆盖度的方法和一般工作流程,其结果经检验与定西市水土保持科学研究所的地面实测数据基本相符。该方法不需要进行大范围的野外考察,节约成本,经济方便,适于植被覆盖度的动态监测研究。     

西藏高原生态安全评价方法与应用—以西藏自治区曲松县为例

用生态安全的PSR(压力-状态-响应)概念模型和层次分析法,建立了西藏曲松县生态安全评价体系,综合评价了曲松县生态安全现状.结果表明,当前曲松县生态安全状况处于预警状态,生态环境问题已成为制约当地经济发展和社会进步的主要因素.从气候变化、资源利用和人类经济活动的角度阐述造成这一严重生态环境问题的自然和社会根源,提出适合曲松县改善生态安全现状的主要途径.     

首都圈多伦地区荒漠化生态安全评价

 以多伦地区为例,提出了荒漠化地区生态安全评价的具体指标体系和构建原则,并采用数量化原理与方法,对各指标进行了具体量级划分,利用关联度分析方法,确定了指标的系数,并提出了衡量生态安全程度的数量化指标、生态安全系数及其计算方法。以土壤养分、植被状况、水分条件和地表抗蚀性4个影响生态安全的因子确定了指标体系。以土壤有机质含量、植被盖度、降水量和土壤黏粒为生态安全评价的具体指标,计算了各个因子对生态安全的影响程度。根据土地利用情况,确定了多伦215个土地利用单元的生态安全系数,采用GIS平台得到了多伦地区的生态安全评价图。研究成果可直接为环北京防沙治沙重点工程的实施提供具体指导,研究方法可供区域生态安全评价借鉴。     

Physical Properties of the Soils of Sibay City of the Republic of Bashkortostan

Eurasian Soil Science - The results of the study of the properties of urban soils of the city of Sibay located in the mining region of the Republic of Bashkortostan are presented. A specific...     

食用仙人掌萎蔫气象条件分析

塑料大棚内种植的食用仙人掌在土壤墒情较好时也有萎蔫现象发生，通过试验观测和对仙人掌生理习性的分析，发现阴雨过后天气突然放晴温度急剧上升易使仙人掌发生萎蔫现象，并提出了田间管理的应对措施。     

Heterogeneity of Organic Matter of Aggregates of Protocalcic Chernozems

Eurasian Soil Science - Layers were step-by-step removed from macroaggregates (2–1 mm in diameter) of Protocalcic Chernozems via successive abrasion in a revolving rotator during 5, 10, 15,...     

青海省耕地资源开发利用分析及对策研究

分析论述了青海省耕地资源开发利用的现状、特点和问题。在此基础上,提出了对青海省耕地资源进行研究的框架体系和思路,同时基于GIS/RS技术设计了相关的技术路线。最后依据所做设计对青海省耕地资源开发利用做了初步分析,并进行了相关的对策研究分析。     

Characterization of physical and chemical properties of Varzea soils of Goias State of Brazil

Abstract

Brazil has approximately 30 million hectares of lowland areas, known locally as “Varzea,”; distributed throughout the country. Soils in these areas have the potential to support agricultural production, but very little is known about their fertility. The current experiment was undertaken to characterize the chemical and physical properties of representative “Varzea”; soils collected at 0–20, 20–40, 40–60, and 60–80 cm depth intervals from 23 sites in Goias State of Brazil. Organic matter contents averaged 42 g/kg in the surface 20 cm of soil and should make a significant contribution to overall nutrient availability. Soil pH increased slightly with depth from a mean value of 5.2 in the surface 20 cm of soil to a mean value of 5.4 in the 60–80 cm depth interval. Several soils had exchangeable Al values ≥ 1.0 cmol Al/kg, but soil Al saturation was generally less than the 60% level frequently associated with Al toxicity. However, cereal and legume production could benefit from lime addition in many of these soils. Although base saturation was fairly low in some soils, exchangeable Ca and Mg levels were, in general, adequate throughout the profile. Extractable P levels were adequate in most surface soil samples. Extractable K levels in these soils were generally low, and the application of K fertilizers should be beneficial, especially in conjunction with lime addition. The high clay content “Varzea”; soils of the Brazilian lowlands have some drainage problems but generally exhibit favorable chemical properties for crop production when compared to soils of the well‐drained Cerrados.     

Estimation of potential nitrogen-fixing activity of agrophytocenoses soils of the subtropical zone of Russia

An estimation of potential nitrogen-fixing activity of various soil types under agrophytocenoses of tea, filbert, peach, and pawpaw which grow in the area of Greater Sochi is given. High indicators of nitrogen fixation activity in the soil in the course of vegetation were characteristic of agrocenoses of pawpaw, peach, and filbert. The lowest level of nitrogen fixation was noted in the soil of a tea plantation. A negative correlation dependence of potential nitrogen-fixing activity on the acidity of the soil solution was established. A study of the seasonal dynamics of the activity of nitrogen fixation of soils of agrocenoses of the subtropical zone of Russia made it possible to distinguish a less active winter and more active spring-summer-autumn periods.     

Kinetics of Popping of Popcorn

The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements.     

物联网安全及解决措施

物联网是一个集信息通信、数据交换、传感器技术与软件工程于一体的综合性产业,探讨和分析了物联网的结构体系与发展中遇到的安全问题。     

荔枝种子结构的扫描电镜观察

荔枝种子从果实中剥离出来后, 即使在室内条件下, 也极易失水干缩, 潮湿环境中又易发霉而腐烂。扫描电镜观察表明: 种皮上布满纹孔, 水分散失面积很大; 种脐部为疏松的海绵组织, 且营养丰富。据此, 生产上应对种子彻底清洗, 并保存于适当湿度的环境中, 以提高其发芽率。