基于生态威胁的湖泊生态安全指标体系研究

在分析不同层次生态安全定义的基础上,采用逆向思维定义了湖泊生态安全,即湖泊在各种生态威胁冲击下仍保持可持续发展的状态,其表现形式为湖泊各项指标在可持续发展范围内的动态波动;提出了湖泊生态威胁理论与模型,并采用德尔菲法把湖泊生态威胁特征分为富营养化、湖泊萎缩和水污染,基于此通过层次分析法和主成分分析法筛选出了评价湖泊生态安全的35个指标,从而构建了湖泊生态安全指标体系.     

城市创新生态评价研究

文章在对城市创新生态的概念及结构进行界定的基础上,从结构和状态两方面建立了城市创新生态的评价指标体系,然后在对国内大中型城市进行筛选的基础上,收集相关指标数据,运用集对分析法,对我国19个样本城市的创新生态进行了实证分析.结果表明,经济发展水平较高的城市,往往也是创新生态比较好的城市,并且被评价的19个城市可以划分为状态-结构均衡型、结构劣势型和状态劣势型等三种类型.     

基于PSR模型的煤炭资源型城市生态安全评价研究——以鄂尔多斯市为例

以煤炭资源型城市--鄂尔多斯的自然生态环境及经济社会发展特点为出发点,基于PSR模型构建了一个包含3个准则9个要素35个指标的生态安全评价指标体系,用层次分析法确定各指标权重,依据生态安全综合指数法对2003～2008年鄂尔多斯的生态安全状况进行了评价研究.结果表明,鄂尔多斯生态安全处于较不安全状态,生态问题较为严重,生态风险较大,但从2003年起,生态安全状况逐年改善,2006年起改善效果更为显著.     

基于指标规范值的区域生态环境质量灰色聚类评价

[目的]采用指标规范值的灰色聚类法对区域生态环境质量进行评价.[方法]以巢湖流域为例,介绍了基于指标规范值的区域生态环境质量灰色聚类评价法,并将评价结果与未确知测度法得出的评价结果相比较,进一步验证该方法在区域生态环境质量评价中的可行性.[结果]基于指标规范值的区域生态环境质量灰色聚类评价,将同级标准规范值相近的指标归为一类,同属一类的指标只需设计为相同的白化函数,从而大大减少了白化函数的设计个数.将指标规范值的灰色聚类法用于巢湖流域的区域生态环境质量评价,其评价结果与未确知测度评价法的评价结果基本一致,除流域总体相差一级外,合肥、巢湖、六安的生态环境质量分别属于3级(及格)、4级(较差)、5级(差),表明该方法具有实用性.[结论]该研究可为区域生态环境综合治理对策的制定提供理论依据.     

循环经济评价指标体系的基本框架

国家统计局“循环经济评价指标体系”课题组将循环经济评价指标体系的基本框架分为五部分：资源利用效率指标、资源消耗率指标、资源回收与循环利用率指标、废物排放与处置指标和其他指标。     

建立新一代钢厂精准设计评价指标体系的研究

新一代钢厂的设计水平对钢厂的实际运行水平具有决定性的影响.为了提高新一代钢厂的精准设计水平,按照系统性、层次性等原则建立了新一代钢厂精准设计评价指标体系.指标体系包含49个末端指标和16个中间指标,分为经济投资水平、工艺设备水平、流程运行高效化、生态化水平四大类指标.该指标体系能反映新一代钢铁制造流程装备、工艺先进、流...     

基于RS与GIS的流域生态安全评价研究

流域生态安全评价是实现流域可持续发展的一项重要调控措施.该文基于1988、1998和2007年的遥感影像,以生态环境的压力-状态-响应概念模型为指导,构建了多层次指标体系,采用综合评价方法对东江流域各县市的生态安全状况进行了评价,并构建了生态安全动态度模型,分析了东江流域各县市1988～2007年间生态安全变化的趋势和程度.结果较准确地反映了东江流域各县市的生态安全状况,可为流域生态安全的管理和保护提供辅助决策.     

生态脆弱区经济与环境协调性研究

生态脆弱区经济与环境的协调发展是生态环境保护急需解决的问题。在分析生态脆弱区特征的基础上,研究生态脆弱区经济与环境协调性,并依据可持续发展的驱使力(Driving Force)-状态(State)-响应(Response)模型建立生态脆弱区经济与资源环境协调发展指标体系;阐明了经济与环境协调发展的耦合模型对指标体系分析的适用特征,从而掌握了生态脆弱区与环境发展的协调性关系。     

基于主成分模糊评价分析的干旱区土地利用生态安全评价

选取新疆干旱区乌鲁木齐市、克拉玛依市、石河子市和五家渠市4市为研究对象,结合其土地生态利用指标,构建4个城市的土地利用生态安全评价指标体系,运用主成分和模糊综合分析法,得出4市的评价等级。结果表明:乌鲁木齐市、克拉玛依市、石河子市、五家渠市的评价等级得分为2.323 672、2.675 64、2.391 087、1.961 43,乌鲁木齐市、克拉玛依市和石河子市的评价值都大于2,说明土地利用生态为安全,而五家渠市的土地利用生态为一般。总的来说,这4个市的土地利用生态都为安全。基于评价结果分析,最后提出了提升土地利用生态安全水平的对策建议。     

莱钢创建生态型企业的探讨

本文根据工业生态学的理论，借鉴国内外研究成果，提出莱钢创建生态型企业的可行性，并提出了创建生态型企业的涵义、要素和指标体系及实施的技术路线等。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.