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1.
酞酸酯对人与环境的危害   总被引:32,自引:1,他引:32  
酞酸酯是一种增塑剂,随着时间的推移,可由塑料中转移到外环境,现已成为地球上最为广泛存在的环境污染物。该文较系统地介绍了酞酸酯的理化性质,毒性和致癌作用,以及其对环境的影响,环境行为,动物的吸收,分布、代谢和排泄等等,最后还对酞酸酯的有关毒性评价作了部分介绍。  相似文献   
2.
Environmental Science and Pollution Research - Economies that depend on natural resources can experience a resource drag effect when economic growth is limited by constraints on the availability of...  相似文献   
3.
We have investigated manure management practices at three farm scales in Chinese pig and poultry production. The concept of ecological rationality was employed to explore empirically how environmental concerns drive adoption of environmental-friendly manure management technologies at different farm scales. The more developed Rudong County in Jiangsu Province and the less developed Zhongjiang County in Sichuan Province were chosen as cases for study of 258 animal breeders. On the contrary to our hypothesis, medium-scale farmers were not always found to be laggards in adoption of manure management technologies. Government ecological rationality played a key role to induce environmental-friendly technology adoption on its own, but also in cooperation with ecologically rational individual or network drivers. Authorities no longer applied their efforts in a conventional command-and-control way, but more in the form of incentives, stimulation, and information to farmers. Individual farmers in general showed low environmental responsibility in relation to manure handling.  相似文献   
4.
催化湿式氧化农药废水及催化剂的研究   总被引:4,自引:0,他引:4  
通过浸渍法制备了4种氧化物为主活性组分的负载固定型催化剂,用于过氧化氢催化湿式氧化(CWHPO)处理有机农药废水。用实验确定了催化湿式氧化的条件,不同催化剂处理效果的比较表明,四元组合MnO2CuOCeO2CoO催化剂性能较好,当反应在常温常压下,维持pH=7~9,反应时间为40min时,COD的去除率大于80%,色度去除率大于90%。  相似文献   
5.
介绍了中洛线热媒炉在使用过程中出现的问题,指出热媒炉附属设备多、系统复杂、工作不可靠、故障率高、维修困难、维修费用高,严重影响安全生产,是目前难以解决的问题,也是中洛线热媒炉全部更换为直接加热炉的原因.  相似文献   
6.
基于2019年三亚城区站点PM2.5中水溶性离子在线观测数据,分析了水溶性离子的质量浓度水平、不同时间尺度和不同PM2.5浓度下的特征,探讨了气象因子对离子组分的影响,通过主成分分析(PCA)解析来源.结果表明:2019年三亚城区总水溶性离子(TWSI)质量浓度为8.173 μg·m-3,占ρ(PM2.5)的58.4%,各离子质量浓度大小依次为:ρ(SO42-) > ρ(NO3-) > ρ(K+) > ρ(NH4+) > ρ(Na+) > ρ(Cl-) > ρ(Ca2+) > ρ(F-) > ρ(Mg2+) > ρ(NO2-),其中二次离子SO42-、NO3-、NH4+(SNA)和K+为主要离子组分,占总水溶性离子的80.0%,海盐粒子Na+及Cl-之和占比为14.7%,且与风速呈显著正相关;TWSI季节浓度变化特征明显,秋季最高,春冬季次之,夏季最低,主要与秋冬季风速较大、主导风向转为东北风,易受外来传输有关;SO42-在各个季节均是浓度及占比最高的离子,硫氧化率(SOR)的日均值均大于0.1,存在显著的SO2向SO42-转化的过程;PCA分析结果表明三亚城区水溶性离子主要受海洋源、二次源及生物质燃烧源的影响.  相似文献   
7.
采用大变形弹塑性有限无理论,用ANSYS5.5软件对不同模具参数下钨合金静液挤压过程进行了数值模拟研究,得出了挤压压力随模具参数的变化规律,并与光刻网格的挤压结果进行了比较,说明有限元法的计算结果和实验结果符合很好。  相似文献   
8.
结合实例总结并分析了铂铑测温丝材加工中,影响产品质量的主要因素为熔炼时的杂质元素及成分偏析,加工过程中配模不合理、模具失效、设备失效等。最后提出了配合ISO9000质量体系认证,从技术和管理方面的质量解决方案。  相似文献   
9.
京津地区大气颗粒物的表征及来源鉴别   总被引:24,自引:2,他引:24  
采用中子活化分析及质子激发X荧光分析测定了160个样品中的45种元素含量,研究了不同粒径颗粒物中元素浓度的分布规律,得知对人体有害的元素主要富集在粒径小于2μm的细颗粒中。根据测定的元素浓度特征,可分成七个主要污染来源,即煤、土壤、石油、汽车尾气、建筑材料、海盐及冶金工业。化学元素平衡计算结果表明,天津地区七个污染源中,尘土和燃煤对大气颗粒物的贡献最大。  相似文献   
10.
Porosity and permeability of porous and fractured geological media decrease with the exploitation of formation fluids such as petroleum, natural gas, or ground water. This may result in ground subsidence and a decrease of recovery of petroleum, natural gas, or ground water. Therefore, an evaluation of the behavior of permeability and porosity under formation fluid pressure changes is important to petroleum and ground water industries. This study for the first time establishes a method, which allows for the measurement of permeability, porosity, and pore size distribution of cores simultaneously. From the observation of the pore size distribution by low-field nuclear magnetic resonance (NMR) relaxation time spectrometry the mechanisms of pressure-dependent porosity and permeability change can be derived. This information cannot be obtained by traditional methods. As the large-size pores or fractures contribute significantly to the permeability, their change consequently leads to a large permeability change. The contribution of fractures to permeability is even larger than that of pores. Thus, the permeability of the cores with fractures decreased more than that of cores without fractures during formation pressure decrease. Furthermore, it did not recover during formation pressure increase. It can be concluded that in fractures, mainly plastic deformation takes place, while matrix pores mainly show elastic deformation. Therefore, it is very important to keep an appropriate formation fluid pressure during the exploitation of ground water and petroleum in a fractured formation.  相似文献   
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