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11.

Introduction  

Initial geosmin degradation was closely related to water temperature and natural geosmin concentration of sampling environment. Here, for the first time, we evaluated the biodegradation of geosmin by microorganisms in biofilm from biological treatment unit of actual potable water treatment plant.  相似文献   
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Ti/RuO_2-Pt电极电化学降解苯酚废水研究   总被引:1,自引:0,他引:1  
研究以典型的难降解有机污染物苯酚为对象,用Ti/RuO2-Pt阳极进行电催化氧化降解研究,讨论了电解质、苯酚初始浓度、电流密度以及氨氮对苯酚降解效果的影响。研究结果表明:以NaCl为电解质比Na2SO4为电解质时处理苯酚的效果明显,而且电流密度越大、NaCl的添加量越多,苯酚全部降解所需的时间越短;在10mA/cm2的电流密度,0.3g/L氯化钠的添加量下,将苯酚从8mg/L降解为0需要30min。在电流浓度10mA/cm2,氯化钠添加量1.0g/L下,苯酚由20、40、80mg/L降解为0分别需要30、60、130min,降解时间随着浓度的增加呈接近正比增加;氨氮的存在不影响苯酚的电化学降解,而且苯酚优先降解,然后氨氮降解。  相似文献   
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This paper undertakes an in-depth analysis of six least developed countries (LDCs) in South and Southeast Asia to assess the extent of mainstreaming climate change adaptation into national development plans by reviewing their National Adaptation Programmes of Action (NAPAs), national development plans, and Strategic Programs for Climate Resilience (SPCRs) (where available). The paper proposes two perspectives to analyze the level of mainstreaming and five factors that may affect such a level. The results show that there is a significant difference in the success of their mainstreaming efforts: mainstreaming is relatively advanced in Bangladesh, limited in Lao People’s Democratic Republic, the Maldives, and Nepal, and still minimal in Bhutan and Cambodia. Among the factors, the study finds that the inter-ministerial coordination supported by the highest levels of government is most relevant to the success of mainstreaming, which is measured by the integration of climate adaptation consideration into development priorities and a country’s own initiatives, particularly those involving budget allocation. Recognition of the need for mainstreaming and monitoring and evaluation also affect the success of mainstreaming efforts in LDCs. Another important factor is to make adaptation plans compatible with national development plans in terms of their time horizon, and SPCRs effectively facilitate this process. As all countries still require external support for advancing mainstreaming, the role of development partners is instrumental. The paper points to issues that need to be incorporated in the relevant NAPAs including updating to facilitate mainstreaming.  相似文献   
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Physical processes of the lagoon are influenced by structural interventions. Understanding the complex reality of physical processes sometimes difficult with field observations thus a model provides a simplified abstract view. Two dimensional hydrodynamic model is used to describe, restoration efforts to Koggala lagoon, a combined freshwater and estuarine complex of rich ecosystem on the southern coast of Sri Lanka. The lagoon mouth was naturally closed by a sand bar which controlled the seawater intrusion. Due to large-scale sand removal at lagoon mouth, formation of the sandbar shifted towards the lagoon. After the removal of natural sand barrier, rubble mound groyne structures were built to avoid sand deposition in the lagoon and to protect the highway bridge from the sea wave attack. Construction of the groyne resulted in the lagoon mouth being permanently open which in turn led to many environmental problems with saline intrusion. The aim of this study is to evaluate the current situation of the lagoon and propose alternative structural interventions for minimization of seawater intrusion and subsequently improve lagoon ecosystem. Hydrological parameters were investigated and mathematical models for hydrodynamic behavior of the lagoon were applied in order to describe the lagoon physical processes and flow characteristics. Existing rubble mound structures were redesigned in order to minimize the seawater intrusion. Numerical simulations were carried out for two different mouth widths (40 m and 20 m) with appropriate structural interventions. Existing salting factor for the lagoon is 0.68 and numerical simulation results showed salting factor for 40 m and 20 m openings are 0.61 and 0.54 respectively. This shows the mouth width can be reduced up to 20 m in order to obtain a slating factor close to 0.5, which indicates the predominant influence of fresh water which in turn leads lagoon to a fresh water ecosystem.  相似文献   
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This systematic review and meta-analysis aimed to review the optimal timing of delivery at term for neonates with prenatally diagnosed congenital diaphragmatic hernia (CDH). We reviewed the literature up to December 19, 2022 using MEDLINE and the Cochrane Library databases. The inclusion criteria were original articles, comparative studies of CDH neonates delivered at an early term (37–38 weeks of gestation) and at full term (39 weeks of gestation or later), and comparative studies investigating outcomes of CDH neonates. Six studies met the inclusion criteria, including 985 neonates delivered at an early term and 629 delivered at full term. The cumulative rate of survival to discharge showed no significant difference between CDH neonates delivered at an early term (395/515; 76.7%) or at full term (345/467; 73.9%) (risk ratio [RR] 1.01; 95% confidence interval [CI], 0.89–1.16; p = 0.85). Furthermore, the number of neonates requiring oxygen therapy at discharge was not significantly different between CDH neonates delivered at an early term (32/370; 8.6%) and at full term (14/154; 9.1%) (RR, 0.99; 95% CI, 0.36–2.70; p = 0.99). Therefore, the optimal timing of delivery at term for neonates with CDH remains unclear.  相似文献   
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Summary. Under field conditions significantly more black chafer, Holotrichia loochooana loochooana (Sawada) (Coleoptera: Scarabaeidae) males landed on black and gray sources than white ones containing 10 mg of female pheromone, anthranilic acid. When a broader spectrum of colours was tested the frequency of male landing was intensively proportional to as the lightness of the colour of the lures. These findings demonstrated that mate location by H. l. loochooana males is dependent on both olfactory and visual stimuli of the source. In contrast, female aggregation was not affected by colour.  相似文献   
20.
综合自然灾害风险管理--全面整合的模式与中国的战略选择   总被引:27,自引:3,他引:27  
综合自然灾害风险管理是目前国际上防灾减灾和灾害管理较先进的措施和模式,是针对各种自然灾害的全灾害的管理,是贯穿于灾害管理全过程,集中于灾害风险和承灾体脆弱性分析并强调多层面、多元化和多学科参与合作的全面整合的灾害管理模式。介绍了综合自然灾害风险管理的必要性、概念和本质,探讨了综合自然灾害管理的基本理论、对策及其实施过程和实施战略,在此基础上提出了对我国实施综合自然灾害风险管理的建议,为强化和推动我国综合自然灾害风险管理提供参考。  相似文献   
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