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31.
Bladder outlet obstructions are a diverse and heterogeneous group of developmental abnormalities that generally involve obstruction of the proximal urethra in the male fetus. Indications for prenatal intervention are few and are usually restricted to the male fetus because bladder outlet obstruction in female fetuses is usually caused by complex cloacal development anomalies. We report on a female fetus with an enlarged bladder and a dilated proximal urethra (known as typical keyhole sign). A vesicoamniotic shunt was performed despite non-reassuring prognostic factors, but the procedure resulted in a successful outcome. We propose that in selected cases of bladder outlet obstruction, fetal intervention should be considered even when the fetus is female. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
32.
结合某炼油企业重整装置四合一加热炉出口集合管盲板法兰腐蚀现状,分析产生腐蚀的机理,利用Fluent软件模拟分析不同处理量下发生腐蚀的出口集合管盲板结构处的速度失量图、涡量图等,得出了与腐蚀现状相吻合的结论。对盲板结构进行改进,并进行数值模拟分析,得出优化后的结构可以有效避免出口集合管盲板法兰腐蚀的结论。  相似文献   
33.
根据2010—2013年对浙江舟山2个污水处理厂排污口邻近海域14个站位的表层海水铜、铅、锌、镉、砷、总铬、总汞、p H值、无机氮、活性磷酸盐、石油类、化学耗氧量、悬浮物和粪大肠菌群等14项污染因子的调查,采用单因子指数法和营养指数法对监测海域海水水质进行评价。结果表明,舟山污水处理厂排污口邻近海域表层海水质量总体良好,基本符合第二类海水水质标准;主要污染因子为无机氮、活性磷酸盐和悬浮物,其他水质指标则较低;2个污水处理厂排污口邻近海域海水均呈高富营养化状态,并受到一定程度的铅污染。  相似文献   
34.
To the average layman, the distinction between opinion and attitude is artificial at best, and is neither consistent nor logically defensible. For many purposes one need not distinguish between the two. However, when assessing opinion and attitude the disparity becomes quite evident. Opinion surveys are characteristically concerned with replies to specific questions which need not be related. The responses are kept separately as opposed to being combined into a total score. Attitude scales, on the other hand, typically yield a total score indicating both a direction and intensity of an individual's feelings, thoughts, and predispositions to act toward a given concept. Further, in the construction of an attitude scale, the different statements are designed to measure a single attitude or unidimensional variable. The Likert method of constructing attitude measuring instruments requires a large number of judges to indicate their own attitudes by responding to statements thought to pertain to an attitude in question. Five possible responses are provided for each item. The procedure for construction of a Thurstone type scale utilizes the Law of Categorical Judgment as a basis. Statements are obtained and analyzed for the various categories and in final form, the attitude scale is presented to the respondent who indicates statements with which he agrees or disagrees.  相似文献   
35.
废纸回收企业的竞争和国家再生资源税收政策的实施,对我国废纸回收行业影响很大,分析了产业环境的变化对废纸行业的影响,以及废纸回收行业面临的困境,被提出废纸回收行业走出困境的做法和建设。  相似文献   
36.
Environmental education is essential to the success of Agenda 21. Yet currently it is without focus and effectively side-lined. This paper presents the results of preliminary investigations on the environmental attitudes and knowledge of Indian and Filipino primary and secondary school students, and their readiness to engage in pro-environmental behavior that could involve some change in their personal lifestyle. For the most part, environmental education efforts are embedded mainly into various science subjects. The relationship between environmental education and environmental awareness is analyzed to examine whether schools' environmental education could contribute to the shaping of environmental attitudes. A strategy and accompanying methodology for establishing environmental education is supplied.  相似文献   
37.
居民对资源开发的态度是资源开发管理的重要社会与公众基础。基于对煤矿社区居民的调研数据,实证分析了居民资源开发态度的特征及其影响因素差异。结果显示:煤矿社区居民对资源开发总体呈现比较反对的态度。居民社会人口属性方面,受教育水平越高其对资源开发态度的支持程度越高;女性比男性更支持煤矿开采。在社会文化层面,就业机会和社会个人利益正向、显著影响居民资源开发态度;煤矿开采对居民生活和健康的不利影响负向、显著影响居民资源开发态度。在经济交通层面,资源开发的配套设施建设正向、显著影响居民资源开发态度;土地破坏和粮食减产负向、显著影响居民资源开发态度。在生态环境层面,自然灾害和地质灾害发生情况以及水质和水量的下降情况负向、显著影响居民资源开发态度。建议未来应制定针对性政策,改善居民资源开发态度,并着眼于资源开发沟通机制的完善、居民参与资源开发规划的制定和外部管理制度建设能力的提升。  相似文献   
38.
目的研究舰载系留气球在海洋环境下对系留缆绳以及球体姿态的影响。方法采用ADAMS二次开发宏命令来建立离散化系留缆绳模型,并将离散化系留缆绳几何模型在相邻微段圆柱间添加Bushing轴套力,设置相关刚性系数和阻尼系数获得完整特效的缆绳模型。同时根据船用起重机的相关设计规范,考虑船体横摇5°和纵摇2°等运动影响,分析船体运动情况可知,纵摇时系留缆绳下端系固点位置较之横摇波动幅度更大,对缆绳的影响更大,因此主要研究船体纵摇2°情况下对于系留缆绳的影响,并分析对比船体静止以及船体纵摇2°情况下对于舰载系留气球系留缆绳以及球体姿态的影响。结果获得了在船体静止状态以及纵摇激励影响下舰载系留气球系留缆绳张力变化曲线以及球体姿态变化曲线。船体纵摇2°情况时,系留缆绳在仿真开始阶段承受冲击载荷较大,峰值达到150 kN,随后缆绳载荷基本在25 k N上下浮动。张力变化曲线整体呈现周期变化,周期与船体纵摇周期一致,为10 s。球体横滚角和航向角变化与船体静止状下仿真结果基本一致,球体俯仰角变化幅度较大。结论船体纵摇时会对系留缆绳带来较大的冲击载荷,同时对球体的俯仰姿态产生影响。该仿真结果对舰载系留气球的可行性分析和适装性研究以及系留缆绳的选用具有较大的指导意义。  相似文献   
39.
介绍了高炉出铁口烟尘捕集的重要性和困难性,分析和比较了三种主要大型高炉出铁口烟尘捕集方式的特点,指出了其发展趋势。  相似文献   
40.
IntroductionSpeeding is a major cause of unintentional roadway death in the United States. Existing data show that U.S. drivers tend to speed less as they age, but reasons for this change remain largely unknown. Limited research has examined why U.S. drivers decide to speed or why U.S. drivers decide not to speed, and none to date has determined why speeding behaviors change over the life course. Research into these issues can provide insight that may be harnessed for more effective anti-speeding interventions that catalyze decisions not to speed. Methods: The current study asked a national sample of U.S. drivers (N = 309) about their driving behaviors and how they have changed over time using an open-ended prompt in an online survey. The authors qualitatively coded responses using a narrative analysis lens to identify common themes. Results: Results show U.S. drivers often make deliberate choices to speed and some do not consider speeding to be dangerous after achieving perceived mastery of driving skills. Participants tended to report speeding less over time, citing increased concern for family and other roadway users, which may help explain national speeding data trends. Several other themes emerged identifying individual cognitive factors, environmental contexts, and key persons impacting speeding decisions. Practical Applications: Findings show that the most effective means of encouraging U.S. drivers to decide not to speed may be multi-pronged intervention approaches highlighting how speeding reduces roadway driver control, connecting speeding with safety, and encompassing road design and law enforcement strategies.  相似文献   
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