摄食水平和氨氮对梭鱼幼鱼食物消化及生长的影响

以鮻鱼(Liza haematocheila)为研究对象,采用半静态实验法探讨了摄食水平和氨氮联合作用对鮻鱼幼鱼摄食、食物转化率、生长、肠胃蛋白酶等方面的影响。结果表明:氨氮对鮻鱼幼鱼的摄食具有抑制作用,高浓度氨氮(3.32mg·L-1)对幼鱼摄食的抑制率达28.78%。鮻鱼幼鱼对食物的转化率(FCE)随氨氮浓度升高而减小,随着摄食水平的增加而增加,FCE最大值出现在饱食未添加氨氮组(BS5),为19.83%;最小值出现在低摄食水平的高浓度氨氮组(HS1),为-22.19%。鮻鱼幼鱼特定生长率(SGR)的增长水平受摄食水平和氨氮的影响与幼鱼的FCE变化一致。氨氮对实验幼鱼肠胃蛋白酶活性的影响因摄食水平而不同,本实验中,仅饱食条件下高浓度氨氮对幼鱼的肠胃蛋白酶有显著抑制效应,这可能与氨氮胁迫情况下幼鱼摄食量较小有关;氨氮浓度相同时,对照组和低氨氮浓度组鮻鱼幼鱼肠胃蛋白酶活性受摄食水平影响显著,而高氨氮浓度条件下,由于饱食组幼鱼肠胃蛋白酶活性受抑制,导致摄食水平对肠胃蛋白酶活性影响不显著。研究证实,摄食水平是影响鮻鱼生长及肠胃蛋白酶活性的主要因素,氨氮会抑制鮻鱼摄食,进而影响蛋白酶活性。     

特种设备使用单位风险评价指标体系构建研究

从人、机、环、管4个方面系统分析了我国特种设备在使用过程中可能存在的风险因素,并根据风险因素设置了相应的指标体系,为特种设备使用单位的风险评价及分类监管奠定基础。     

特种机电设备安全科技支撑体系建设探讨

针对机电类特种设备的特点和安全科技现状,提出了构建特种机电设备安全科技支撑体系的架构。根据机电类特种设备的安全形势,以全面提升特种机电设备检验检测技术机构的能力,保障特种机电设备安全为目的,探讨特种机电设备安全科技支撑体系,研究分析由检验检测技术平台、风险评估技术平台、安全监测预警平台、应急救援技术平台、科技应用服务平台5个支撑平台构成的支撑体系的建设主体和建议。     

生产作业区重大危险源评估方法研究

危险源是危险的根源,是系统中存在的可能发生意外释放能量的危险物质,开展重大危险源评估工作可有效预防和控制生产作业区重大安全事故的发生,保障人民群众生命财产安全,同时也为生产作业区安全监督管理提供依据。以某生产作业区为例,研究了生产作业区重大危险源辨识标准及分类分级方法,研究了重大危险源安全现状及危害等级的安全评估方法,指出了企业在重大危险源安全管理上应采取的安全技术措施和安全管理措施,为提高生产作业区安全管理水平,制定重大危险源专项应急预案提供了依据,上述辨识和评估思路和方法可为其他企业借鉴参考。     

承压类特种设备系统性风险研究

传统的风险评估或基于风险的检验主要针对设备的失效可能性和失效后果,而失效后果未考虑失效对社会产生的影响和冲击力。同一类型的设备在网络知情人数不同或人们心理承受能力不同的场合发生失效后产生的社会影响力存在差异。本文引入失效事件对社会的影响力修正因素即影响力强度,影响力强度既反映事故等级,又反映网民对事故的关注程度。在传统的风险概念的基础上,由影响力强度对失效后果进行修正后形成系统性风险模型。当事故等级较高,或当一个事故的关注度高,网络知情人数初值增大,影响力强度增大,系统性风险也随之增大。所建立的系统性风险模型很好地解释了同一类设备失效后在不同场合的社会影响力不同的现象。     

Air pollutant emission potentials of cotton textile manufacturing industry

Cotton textile manufacturing operations cause air pollution. Air pollutants are generated by fossil fuel fired combustors due to their flues and/or a variety of chemicals in use for production. Excessive use of chemicals can be stopped or minimized by replacing them or by optimizing the production processes. Energy and water conservation are important goals in textile workplaces as well. There is substantial research and development to minimize pollution potentials of textile operations. In this paper air polluting potentials of cotton textile manufacturing operations are discussed and some quantitative examples are given for evaluating the risks to the environment. Studied impacts to environment cover direct discharges into the ambient air as well as the workplace atmosphere. Further studies are recommended for minimizing the impacts to the local and global air quality due to cotton textile production facilities.     

Does nutritional surveillance have a role to play in early warning of food crisis and in the management of relief operations?*

A major area of investment in data collection in developing countries has been that of nutritional surveillance and monitoring. From recent debate it is clear that there is currently no consensus on the potential role of nutritional status as an early warning indicator. The author presents a synthesis of the broad spectrum of views on the role nutritional surveillance could or should have in early warning. Conceptual problems and technical difficulties are reviewed in the light of recent experiences in Africa and Asia. The author raises a number of issues for future discussion in this ongoing debate.     

AIRPORT WASTES AND WATER QUALITY1

ABSTRACT: Waste waters from various operations at the Miami International Airport are characterized. Servicing, maintenance, overhauling, and washing of aircraft seem to be the most significant waste water producing operations. Pollutional constitutents commonly found in the airport wastes include acids, alkalis, detergents, oil, grease, and oxygen demanding substances. Phenols are of concern when stripping and repainting operations occur. Although most airport wastes may be treatable, a great reduction in influent load can be achieved by proper housekeeping methods.     

机载导弹特殊环境分析

目的为避免由于设计阶段环境适应性要求涵盖范围的缩小造成使用风险,对机载导弹特殊环境进行分析。方法梳理机载导弹寿命期内除典型环境外的特殊气候、力学和综合应力环境,深入分析每项特殊环境产生的机理和应力特点,以及其对机载导弹功能、性能产生的不利影响和在这些特殊环境下使用的风险。结果在此基础上对机载导弹适应这些特殊环境需开展的工作进行了梳理,提出了综合解决方案。结论机载导弹研制中应尽快开展针对特殊环境的设计和试验验证工作。     

某异型结构振动夹具的设计及试验验证

目的完成某异型飞行器的振动夹具设计。方法对初步设计的夹具进行有限元模态仿真计算、传递均匀性仿真计算,结合仿真计算结果,有针对性地对夹具进行设计改进。经仿真计算,设计改进后夹具满足设计固有频率及均匀性要求。结果夹具固有频率的试验结果与仿真计算误差约为7%,均匀性也较吻合。结论验证了仿真计算结果的正确性、设计的合理性,该异型飞行器振动试验进一步验证了该夹具传递特性也较好。