鲈鱼溶藻弧菌病的血液生理生化指标研究

对患溶藻弧菌病的鲈鱼进行了血液生理生化指标检测.结果表明,与健康鲈鱼相比,病鱼的红细胞、白细胞、血红蛋白、甘油三脂、钠、氯含量减少,而血沉、脆性、肌酐、钾、磷含量及血清碱性磷酸酶、谷丙转氨酶、谷草转氨酶、乳酸脱氢酶活性增加.由此说明溶藻弧菌对鲈鱼具有极强的致病性,它能引起鲈鱼体内各主要组织器官发生严重而广泛的病变.     

海带病烂发生过程中的生理生化变化研究——I．糖、蛋白、总抗氧化能力、SOD的变化

为了研究海带自然病烂过程中生理、生化变化，在实验生态条件下，人工促使海带病烂，每隔3d取样，对幼苗可溶性糖含量、可溶性蛋白含量、总抗氧化能力、超氧化物歧化酶(superoxide dismutase，SOD)活性的变化进行连续检测。结果表明，在海带幼苗由健康到病烂的过程中，可溶性糖含量表现为逐渐下降的趋势；可溶性蛋白含量先升高后逐渐下降；总抗氧化能力和超氧化物歧化(SOD)的活性呈现出先升高后降低的变化规律。     

塔里木河中、下游地区沉积环境与地方病的关系

本文是“塔里木河中、下游地区地方性氟中毒,缺碘性疾病地理环境机制的研究”课题的组成部分,以阿克苏地区、巴音郭楞蒙古自治州调查的氟、碘性疾病资料为基础,探讨干旱区地质、地貌、气候、水文、土壤等自然地理各因子对地方性疾病发生、分布的影响,研究沉积、沉积类型与氟、碘等致病元素和病区发病轻重的圈定。为防病、治土、改水对策的制定提供理论基础和科学依据。     

山东省生态环境中硒及其有关元素与克山病关系*

山东省克山病主要分布于鲁中南低山丘陵棕壤与褐土的复合区,化学生态环境为微量元素缺乏区,尤其是元素硒的贫乏是克山病区的共同特征。在同一地点间隔十年的追踪调查表明,近几年来病情减轻的原因与人体硒水平上升有密切关系。1987年与1976年相比,由于病区居民硒摄入量随着膳食构成比例的变化而提高,未服硒地区的人发硒值与服硒点的人发硒值呈同样上升趋势。复合病因研究表明,克山病从环境到人体低Se外,低Mo高Mn、V等元素的不协调,可能起着与低Se复合致病作用。     

shortest path routing algorithm based

ructed which takes into account all objectives and constraints.It applies the CNN algorithm to 9-node and 15-node network model,respectively.The shortest path could be found for single and multiple packets request.Simulation results show it validating that using chaotic noise neural network to solve the shortest path problem in a communication network.Chaotic neural networks;Computer network;Shortest path全国优秀博士学位论文作者专项基金资助项目(200250);     

Airline networks and the international diffusion of severe acute respiratory syndrome (SARS)

In fewer than four months in 2003, severe acute respiratory syndrome (SARS) spread from China to 25 countries and Taiwan, becoming the first new, easily transmissible infectious disease of the twenty-first century. The role of air transport in the diffusion of the disease became obvious early in the crisis; to assess that role more carefully, this study relates the spatial-temporal pattern of the SARS outbreak to a measure of airline network accessibility. Specifically, the accessibility from those countries that were infected by SARS, beginning with China, to other countries was measured using airline schedules. The country-pair accessibility measure, along with other country-level factors relevant to the disease, were tested as determinants of the speed with which SARS arrived in infected countries as well as its failure to arrive in most countries. The analyses indicate that airline network accessibility was an especially influential variable but also that the importance of this variable diminished in the latter weeks of the outbreak. The latter finding is partly attributable to public health measures, particularly health screening in airports. The timing and geography of those measures are reviewed using data from media reports and interim World Health Organization (WHO) documents during the outbreak. The uneven effort to curtail the international diffusion of SARS suggests further planning is needed to develop a concerted response to contain future epidemics.     

Ecologies of actor-networks and (non)social labor within the urban political economies of nature

On September 16th, 2005 the United States began restricting the entry of commodities shipped from abroad in wood packaging materials that do not conform to phytosanitation measures meant to prevent the spread of pests and pathogens. This action results from expensive lessons learned as global commerce facilitates pandemics like Dutch elm disease. Marxist political ecology is well suited to investigate such scenarios with its emphasis on the social production of nature within accumulation regimes. Some scholars contend, however, that Marxist accounts of the contradictions that result from nature’s commodification relegate nonhuman organisms to an apolitical role in environmental transformation while reinforcing the nature/society dichotomy. Often viewed as antithetical to Marxism, actor-network theory or ANT emphasizes the ability of actants (both human and nonhuman) to enroll other actants into heterogeneous assemblages or networks. Thus, it is claimed that nonhuman organisms can be attributed ontological status in processes of environmental change, much like their human counterparts. Despite this apparent theoretical discord, political ecologists are increasingly integrating aspects of both Marx and ANT into their analyses. But a more explicit articulation of the ontological basis and epistemic import of theoretical synthesis is warranted. This paper therefore prioritizes and links the ontological status of labor in both of these theories in order to expand the definition of urban environmental politics to include the role of nonhuman organisms. By demonstrating the laboring capacity of Dutch elm disease within the networks of urban political economy, the epistemology of environmental politics is thus expanded.     

土壤-青菜系统中~(125)Ⅰ的生物地球化学迁移及其动态变化

采用同位素示踪技术研究了土壤-青菜生态系统中125I的生物地球化学迁移与转化机制,并运用箱式模型分析了125I的动态变化。研究结果表明,引入土壤的125I随深度而衰减,绝大部分滞留在土壤0～10cm表层内,125I的滞留量与土壤质地有关;青菜通过根部能很快吸收土壤中的125I,并可将大部分转运至地上部分,青菜各部位125I的富集系数为根>茎>叶柄>叶,嫩叶中富集的125I明显大于老叶;土壤和青菜中125I的动态分布服从指数变化方程,土壤和青菜中的碘可以相向迁移,青菜中碘的积累量即为土壤和青菜中碘迁移量的差值。     

空间大数据支持下的城市区域评估及其关键技术

针对人口拥挤、交通拥堵、环境污染、住房困难等一系列"城市病"问题,为了客观、定量评估城市现状,找到"城市病"根源,本文面向城市区域评估,利用空间大数据全面、客观、准确的特点,对城市进行全方位的评估,从人口、资源、环境、住房、公共设施、道路交通、经济发展及城市安全等多方面为治理"城市病"提供基础数据。本文从城市区域评估的内涵入手,设计了城市区域评估的总体流程,建立了全面的评估体系,并对实现城市区域评估的关键技术进行了阐述。通过城市区域评估的方式,对城市现状客观扫描,将使"城市病"的病重程度得到客观度量,是根治"城市病"的首要条件。