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811.
生态产品价值实现是推动绿水青山转化为金山银山、促进人与自然和谐共生的关键路径和有效举措,对加快生态文明建设具有重要意义。本文根据生态产品的产权界限、公益性程度和供给消费方式,系统梳理了不同类型的生态产品价值实现模式,深入剖析了当下生态产品价值实现的制约瓶颈,如产权界定不清、法律制度不完善、市场机制不健全、生态补偿机制和保障体系有待进一步优化等。在此基础上,研究提出完善生态产品价值实现的针对性对策建议:(1)完善生态产品产权体系,夯实“绿水青山”向“金山银山”转化的制度基础;(2)培育生态产品市场建设,拓宽“绿水青山”向“金山银山”转化的市场化通道;(3)健全生态补偿机制,优化多主体利益联结机制;(4)强化生态产品价值实现保障体系,提升生态产品转化成效。  相似文献   
812.
A feasible and relatively readily available analytical method was adapted for the assessment of alcohol ethoxylates (AE) and fatty alcohols (FA) in sediments. This study illustrates the simultaneous measurement of 38 of 114 possible alcohol ethoxylate ethoxymers (AE) and fatty alcohols (FA) found in commercially important AE products. We predicted toxicity for all identified fractions, as well as the total mixture toxicity, relative to three exposure scenarios via sewage treatment plants (STP) for these widely used chemicals in consumer products and hence generate a preliminary environmental risk screening for AE and FA in sediments. The method is based on derivatization of solvent or solid-phase extracts with 2-fluoro-N-methylpyridinium p-toluenesulfonate (Pyr+). The derivatized extracts were analyzed with liquid chromatography/mass spectrometry (LC/MS) operating in the positive ion electrospray mode. The extraction efficiency of AE and FA in three different sediments of varying composition was evaluated with spike-recovery studies, ranging from 64% to 80%. The detection limits for individual ethoxymers typically ranged from 1 to 5ngg−1on a dry weight basis. The mean limit of detection (LOD) was 6ngg−1and the median LOD was 3ngg−1. AE and FA in sediments were found to be stable for two weeks if preserved with 3% (v/v) formalin and stored at 4–6C. Based on equilibrium partitioning, background concentrations of AE and FA were predicted to be below concentrations known to elicit chronically toxic effects. Total worst case mixture toxicities for all AE ethoxymers combined with FA were predicted to result in a risk quotient less than 0.6. Activated sludge treatment (STP) significantly reduced the release of total AE and FA by four-fold, suggesting that the total mixture risk quotient would be < 0.15 for sediment dependent organisms.  相似文献   
813.
Popularity of herbal drugs is increasing all over the world because of lesser side effects as compared to synthetic drugs. Besides, it costs less and easily available to poor people particularly in developing countries. But quality assurance of herbal drugs is very necessary prior to its use. Because in today's polluted environment, even herbal drugs are not safe. Berberis spp. is very important medicinal plant, having various medicinal properties. It is also included in Indian and British pharmacopoeias. Its demand is quite high in herbal drug market. So, to check the quality of market samples of this drug, ten different samples were procured from different drug markets of India for heavy metal estimation. Besides, genuine samples of four species of Berberis viz. B. aristata, B. chitria, B. lycium, B. asiatica were also collected from natural habitats to compare heavy metal concentration in both market and genuine samples. It was found that market samples were much more contaminated than genuine samples. Lead (Pb) concentration is far beyond from WHO permissible limit (10 ppm) for herbal drugs, reaching to maximum 49.75 ppm in Amritsar market sample. Likewise, concentration of all other metals like Cd, Cr and Ni were also very high in market samples as compared to genuine samples.  相似文献   
814.
为揭示蒸汽爆炸灾害形成机制,建立了大质量熔融铝液遇水自触发爆炸反应模拟装置。根据反应特征和破坏程度,熔融铝液遇水爆炸反应可分为柔和爆炸、剧烈爆炸与猛烈爆炸等3种类型;基于爆炸相似准则,定量化描述了爆炸反应的冲击波破坏效应;热效应则来自冲击波绝热压缩和产物热交换耦合作用;从热力学角度来看,铝液与容器底面夹裹形成过热亚稳态水,可认为是爆炸反应的触发源。  相似文献   
815.
电催化还原CO2转化为清洁能源或有用的化学品被认为是减排CO2的一种有效方式。金属有机框架(MOFs)材料由于分散的金属中心和可调的化学结构等特点而被广泛应用于电催化领域。综述了MOFs材料用于电催化还原CO2的研究进展,对比了近年来MOFs材料及其衍生物电催化CO2化学转化的效率及产物选择性,并对MOFs材料作为电催化材料的应用前景进行了展望。  相似文献   
816.
This paper presents the results of an intensive monitoring activity of the particulate, fall-out and soil of selected living areas in Italy with the aim to detect the asbestos concentration in air and subsequent risk of exposure for the population in ambient living environments, and to assess the nature of the other mineral phases composing the particulate matrix. Some areas were sorted out because of the presence of asbestos containing materials on site whereas others were used as blank spots in the attempt to detect the background environmental concentration of asbestos in air. Because the concentration of asbestos in ambient environments is presumably very low, and it is well known that conventional low–medium flow sampling systems with filters of small diameter (25 mm) may collect only a very small fraction of particulate over a short period, for the first time here, an intense monitoring activity was conducted with a high flow sampling system. The high flow system requires the use of large cellulose filters with the advantage that, increasing the amount of collected dust, the probability to collect asbestos fibers increases. Both the protocol of monitoring and analysis are novel and prompted by the need to increase the sensitivity towards the small number of expected fibers. With this goal, the collection of fall-out samples (the particulate falling into a collector filled with distilled water during the monitoring shift) and soil samples was also accomplished. The analytical protocol of the matrix particulate included preliminary X-ray powder diffraction (XRPD), optical microscopy and quantitative electron microscopy (SEM and TEM). Correlations with climatic trends and PM10 concentration data were also attempted.The surprising outcome of this work is that, despite the nature of the investigated site, the amount of dispersed asbestos fibers is very low and invariably lower than the theoretical method detection limits of the SEM and TEM techniques for identification and counting of asbestos fibers. The results are compared to the literature data worldwide and an updated model for asbestos fibers dispersion in ambient environments is proposed.  相似文献   
817.
农贸市场噪声对其周围环境的影响   总被引:3,自引:0,他引:3  
对某农贸市场的场内噪声,场界噪声及其周围居民区环境噪声进行了监测,结果表明,农贸市场营业时,噪声监测值内,场界及居民区均超标;农贸市场不营业时,场界除3个测点略超标外,余达标,居民区略超标。就农贸市场噪声对其周围环境的影响,提出了控制对策。  相似文献   
818.
Hybrid mixtures are widely encountered in industries such as coal mines, paint factories, pharmaceutical industries, or grain elevators. Hybrid mixtures explosions involving dust and gas can cause great loss of lives and properties. The lower flammability limit (LFL) is a critical parameter when conducting a hazard assessment or developing mitigation methods for processes involving hybrid mixtures. Unlike unitary dust or gas explosions, which have been widely studied in past decades, only minimal research focuses on hybrid mixtures, and data concerning hybrid mixtures can rarely be found. Although methods to predict the LFL have been developed by using either Le Chatelier's Law, which was initially proposed for homogeneous gas mixtures, or the Bartknecht curve, which was adopted for only certain hybrid mixtures, significant deviations still remain. A more accurate correlation to predict an LFL for a hybrid mixtures explosion is necessary for risk assessment. This work focuses on the study of hybrid mixtures explosions in a 36 L dust explosion apparatus including mixtures of methane/niacin, methane/cornstarch, ethane/niacin and ethylene/niacin in air. By utilizing basic characteristics of unitary dust or gas explosions, a new formula is proposed to improve the prediction of the LFL of the mixture. The new formula is consistent with Le Chatelier's Law.  相似文献   
819.
为揭示对向公交换乘距离与换乘乘客横穿道路的相互关系,约请272名受试者,完成城市公交汽车换乘试验。基于换乘试验统计出横穿马路人数,采用非参数估计方法估计换乘乘客的最大忍耐换乘距离,利用SPSS软件,构建拟合程度最高的对向换乘生存距离二次项函数模型,并对模型的有效性进行验证。结果表明,违规过街行人数随公交换乘距离的增大而增多;生存率随换乘距离的增大呈现"缓慢减小-迅速减小-平缓减小"的变化趋势,换乘距离增加至126 m后,越来越多的乘客难以接受这样的距离;换乘距离相同时,男性相比女性更容易横穿马路;根据构建的对向公交换乘生存距离模型,85%的换乘乘客可接受的换乘距离为124 m,50%的换乘乘客可接受的换乘距离为174 m。  相似文献   
820.
Due to increasing societal awareness, nowadays companies need to consider environmental issues in their business activities. A requirement that has entered the agenda is the design of products to support efficient end‐of‐life management. However, though previous research has addressed various disassembly aspects there is a need for more understanding on which product properties are essential for efficient disassembly processes. Better understanding is also required regarding when, during the product development process, these properties are established. On the basis of empirical studies of disassembly of electrical and electronic equipment and vehicles, this paper suggests a number of product properties that are essential for efficiency of the disassembly process. Furthermore, the paper analyses when these properties are set in the product development process. Four product properties, denoted disassembly properties, have been identified: ease of identification; accessibility; ease of separation; and ease of handling. The analysis shows that these properties are affected during all product development phases. Especially in the early phases it is crucial to consider the disassembly properties in order to avoid unnecessary and costly design changes that may occur in the later development phases if the design solutions are pulled in the wrong direction.  相似文献   
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