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11.
高能等离子体分解CO_2气体研究   总被引:3,自引:0,他引:3       下载免费PDF全文
为治理温室气体CO_2,本工作在低温常压条件下,利用超高压脉冲电晕放电产生的高能量(20~50eV)非平衡等离子体作用于CO_2气体分子,使CO_2分子化学结合键断裂,在定向化学反应作用下,将CO_2气体分解成单原子气体分子O_2和单质固体微粒C。CO_2分解率在90%以上。  相似文献   
12.
This paper focuses on the valuable utilisation of spray dryer ash (SDA) and investigates its performance in concrete for structural applications. Based on the challenges associated with the disposal of coal combustion products (including SDA) and the economic costs linked to cement production, this research seeks to provide an environmentally friendly and more cost-effective concrete product by utilising SDA in partial replacement of cement in concrete. With the exception of a relatively high-sulphur content, SDA exhibits very useful properties that are closely related to Class C fly ash and Portland cement.

Experimental tests were carried out to determine the effect of SDA replacement of Portland cement (ranging from 0 to 50% replacement) on the compressive strength, bond strength, freeze-thaw performance and corrosion resistance of concrete. The addition of SDA in non-air entrained concrete provided a general increase in its strength with optimal limits ranging between 25 and 35% replacement. The addition of SDA produced a negligible effect on the freeze-thaw durability of the concrete (air entrained). Results for corrosion performance were not as definitive, but indicate that the use of SDA does not significantly change the likelihood of reinforcing bar corrosion.  相似文献   
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14.
农业病虫害的灾变预测及预报精度分析   总被引:1,自引:0,他引:1  
赵惠燕  汪世泽 《灾害学》1993,8(4):10-14
在农业病虫害突变规律的研究基础上,建立了定性与定量的尖角突变模型,确定了各病虫的突变区域。根据综合控制变量所确定的边界值,对未来病虫发生发展趋势进行预测。经多年历史资料检验和1992年农业病虫害发生突变的趋势预报证明:准确率高,覆盖面广。  相似文献   
15.
煤层底板突水的突变理论预测方法及其应用   总被引:10,自引:6,他引:10  
基于煤层底板突水的尖点突变特征 ,应用突变理论的方法 ,针对煤层底板突水预测指标监测信号 ,分析了单变量序列尖点突变模型及其稳定判据 ,提出了煤层底板突水的突变理论预测方法。实例表明 ,预测结果与现场工程实际情况相一致 ,证明了该方法可望成为预测煤层底板突水危险性的一条新的有效途径  相似文献   
16.
为揭示不同初始氧化温度下浸水长焰煤的氧化自燃特性,利用红外光谱和热分析实验手段以及MS数值模拟方法研究其氧化自燃规律,并采用线性拟合的方法阐述自由基变化特性。结合分子键能的变化,分析浸水条件下二次氧化的煤氧链式反应过程。研究结果表明:经过120 ℃预氧化后,浸水风干长焰煤的还原性官能团甲基、亚甲基、羟基均高于原煤,而羰基、羧基低于原煤;与原煤相比,浸水风干后的煤预氧化温度在120 ℃时最大升温速率最高(0.036 9 ℃/s),表现出更强的自燃倾向性;MS模拟优化得出煤中各官能团在预氧化120 ℃时键能变化较大,结合热分析实验,确立预氧化后浸水风干煤体氧化自燃特性机制。  相似文献   
17.
对锈蚀混凝土偏压构件抗弯刚度退化的影响因素进行了研究,采用刚度解析法对粘结性能退化后偏压构件的截面刚度进行了理论分析,引入了锈蚀钢筋滑移的粘结退化综合影响系数,建立了考虑滑移的锈蚀钢筋混凝土偏压构件抗弯刚度的计算模型。经试验验证,模型的抗弯刚度计算值与试验实测值结果吻合较好,故模型计算值可为锈蚀混凝土偏心受压构件性能的评估提供参考。  相似文献   
18.
The author uses his own data gleaned from over 10 years of commercial forestry insurance across the world to propose that despite a low intrinsic fire risk across most of Southeast Asia, especially Indonesia, commercial fire losses are unacceptably high, and could be reduced substantially within the current financial legal and political framework within which forestry companies operate. Opening with a statement about the dearth of forest fire loss data in the commercial sector, it is observed that the consequent inability of general insurers to estimate the rate of fire loss leads to very low insurance participation in forestry within Indonesia. A summary is then provided of the financial and environmental benefits of insurance participation in commercial forestry were this situation to be changed. A short discussion on risk perceptions is introduced to make the point that without reliable commercial forest fire loss data, risk perceptions of fire exposure in Southeast Asia by the financial sector, including insurers, is a barrier to risk transfer and investment. While real fire risk and perceived fire risk for Indonesia seem at present to be in agreement, the paper challenges that this should the case. Comparisons are made with different parts of the world with the knowledge that, in commercial terms, plantations in the low latitudes behave similarly everywhere in terms of fire causes, fire propagation factors, and characteristics of plantation or managed mixed forest fires. A review of the fire sizes within commercial forests is a good indicator of the efficiency of fire management strategies, and profiles from a high fire risk territory and Indonesia are compared. Using commercial and unidentified data the author then demonstrates that commercial growers in Indonesia have a high annual rate of forest fire loss and may also have a significant catastrophe fire exposure. This ‘cat’ exposure is far greater than for equivalent plantations in clearly higher fire risk environments. These conclusions are and should be discussed with forestry companies to change attitude and investment levels. Practical points for improved plantation fire management are made along with comments about the resources required. A parallel discussion then reviews fire risk assessment and management by the insurers to prevent their own ‘forest fire’ losses if they are to get further involved with the provision of Indonesian commercial forest risk transfer. The explanation of how insurers price risk within a portfolio helps identify the specific data needed for a proper risk management strategy to be developed.  相似文献   
19.
Sovereign financial disaster risk management: The case of Mexico   总被引:1,自引:0,他引:1  
In 2006, Mexico became the first transition country to transfer part of its public-sector natural catastrophe risk to the international reinsurance and capital markets. The Mexican case is of considerable interest to highly exposed transition and developing countries, many of which are considering similar transactions. Risk financing instruments can assure governments of sufficient post-disaster capital to provide emergency response, disaster relief to the affected population and repair public infrastructure. The costs of financial instruments, however, can greatly exceed expected losses, and for this reason it is important to closely examine their benefits and alternatives. This paper analyzes the Mexican case from the perspective of the risk cedent (the Ministry of Finance and Public Credit), which was informed by analyses provided by the International Institute for Applied Systems Analysis (IIASA). The rationale for a government to insure its contingent liabilities is presented along with the fiscal, legal and institutional context of the Mexican transaction. Using publicly available data, the paper scrutinizes the choice the authorities faced between two different risk-transfer instruments: reinsurance and a catastrophe bond. Making use of IIASA's catastrophe simulation model (CATSIM), this financial risk management decision is analyzed within the context of a public investment decision.  相似文献   
20.
巨灾债券与政府灾害救助   总被引:1,自引:0,他引:1  
发生概率小而损失巨大的巨灾无疑对国民经济有着重要的影响。我国幅员辽阔,尽管每年灾害的性质和发生地点不同,但是损失总量和政府救灾的支付总量却是一个稳定的大数,然而依然不能满足救灾与恢复生产的需要。借鉴经济发达国家保险业的巨灾债券,首次提出在政府救灾中引入市场机制——发行政府巨灾债券。这对于投资者是收益高的风险投资,对于政府可以减轻公共财政负担,而对于受灾地区则可以获得更多的资金支援,加快恢复生产,保证经济增长的稳定性。  相似文献   
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