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991.
基于对铜川市森林资源及林业产业发展现状的调查分析,总结出了铜川市林业产业发展中存在的问题。结合铜川市林业产业的自身特点,提出了促进铜川市林业产业快速发展的措施和建议。 相似文献
992.
未焊透缺陷是压力管道焊接接头常见的一种缺陷,严重时可导致管道的承载能力明显降低,进而引发严重的安全事故。为了研究未焊透缺陷对管道安全性的影响,提出了采用非线性有限元分析方法,对含未焊透缺陷压力管道的影响因素进行简化,通过研究其极限内压和极限弯矩随未焊透深度、环向长度等影响因素的变化规律,进一步获得了单一载荷作用下的含未焊透缺陷压力管道的极限载荷估算公式和极限载荷曲线簇。最终在试验验证基础上建立一种未焊透管道的安全评价方法,并通过试验验证结果表明该方法可用于含缺陷工业管道的安全评定是可行的。 相似文献
993.
近年来,稻田Cd污染引起的环境及健康问题日益突出。应用钝化技术对土壤中有效性Cd进行钝化对稻田生态系统中Cd的生物地球化学循环具有重要的理论和实际意义。在广东省韶关市仁化县董塘镇红星村一受Cd污染的稻田上,设置大田试验,研究铁基生物炭对Cd在大田土壤-水稻系统迁移的影响以及对作物产量的影响。试验共设6个处理:(1)空白对照;(2)每一季水稻插秧前,一次性施加1500 kg·hm-2的普通生物炭;(3)每一季水稻插秧前,一次性施加75 kg·hm-2的零价铁(Fe0);(4)每一季水稻插秧前,一次性施加1500 kg·hm-2、ω(Fe)=1%的铁基生物炭(ω(Fe)=1%in Fe-Biochar);(5)每一季水稻插秧前,一次性施加1500 kg·hm-2、ω(Fe)=3%的铁基生物炭(ω(Fe)=3%in Fe-Biochar);(6)每一季水稻插秧前,一次性施加1500 kg·hm-2、ω(Fe)=5%的铁基生物炭(ω(Fe)=5%in Fe-Biochar)。结果表明:(1)施用生物炭、铁粉和铁基生物炭土壤钝化调理剂可以增加水稻产量,显著降低籽粒重金属Cd含量;(2)施用铁基生物炭可以显著增加水稻根表铁膜Fe含量,同时显著增加水稻根表铁膜固定的Cd量,抑制重金属Cd向籽粒的运输累积。综合考虑施用成本和钝化效果,对于Cd污染稻田,建议施用1500 kg·hm-2、ω(Fe)=3%的铁基生物炭材料。 相似文献
994.
Lina Gan Kezhi Li Hejingying Niu Yue Peng Jianjun Chen Yuandong Huang Junhua Li 《Frontiers of Environmental Science & Engineering》2021,15(4):70
995.
城市环境经营是城市经营重要组成部分,文章从城市环境、城市环境经营的内涵出发,对成都市环境经营的战略层次、目标层次、策略层次和操作层次进行了系统的实证研究,并就目前存在问题,提出了相关建议。 相似文献
996.
Homayon Ahmad Panahi Alireza Feizbakhsh Rozita Abdolahi Fard Elham Moniri 《毒物与环境化学》2013,95(8):1279-1289
Quantitative analysis of cadmium in environmental samples was achieved with a polymeric sorbent synthesized by copolymerization of N,N-dimethylacrylamide and allyl glycidyl ether/iminodiacetic acid as chelating monomers with N,N′-methylenebisacrylamide as cross-linker. The polymer was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis, and scanning electron microscopy. The sorption capacity of the functionalized sorbent was 70 mg g?1. The equilibrium sorption data of Cd(II) on polymeric sorbent were analyzed using Langmuir, Freundlich, Temkin, and Redlich–Peterson models. Based on equilibrium adsorption data, the constants at pH 4.2 and 20 °C were determined for the first three as 0.33 (L mg?1), 17.5 (mg g?1) (L mg?1)1/n, and 12.9 (J mol?1). Recovery of 94% of the metal ion was obtained with 0.5 mol L?1 nitric acid as an eluting agent. 相似文献
997.
Th. Eikmann S. Michels V. Makropoulos Th. Krieger H. J. Einbrodt K. Tsomi 《毒物与环境化学》2013,95(1):461-466
An investigation was undertaken to study the exposure of children in areas with different air pollution and of adults working in three different plants (lead processing, battery plant, oil refinery) using arsenic in urine as a biological parameter. The arsenic excretion of the children are in agreement with the air pollution in the investigated areas. The workers in the lead processing plant are found to have the highest urine excretion values of the three worker collectives. The mean excretion values is nearly ten times higher than that found in the normal population. 相似文献
998.
对5块钢筋混凝土板(分别为未加固、采用有机胶或无机胶粘贴碳纤维加固、采取或不采取防火保护措施)进行标准火灾试验,得出了不同种类的胶粘剂和是否采取防火保护措施对高温下碳纤维加固钢筋混凝土板的破坏形态、跨中变形、耐火极限等的影响。试验结果表明:即使未采取任何防火保护措施,无机胶粘贴碳纤维加固钢筋混凝土板仍具有较好的耐火性能;未采取防火保护措施的情况下,有机胶粘贴碳纤维加固钢筋混凝土板的耐火性能比较差;有机胶粘贴碳纤维加固钢筋混凝土板,采取适当的防火保护措施后,可有效降低碳纤维粘贴层的温度,从而保证碳纤维与混凝土的粘结强度。 相似文献
999.
In view of the widespread use of pesticides in agriculture and its associated toxic effects on environment and human beings, the fate of these chemicals in soil is of major concern. The pesticide adsorption process is one of the major factors affecting its persistence and movement in the soil. With a view of studying the fate of malathion in soil, the adsorption of this insecticide was studied on three Indian soils by using batch equilibrium method. To carry out the adsorption study, a new simple, sensitive, and rapid method was developed, based on microwave-assisted alkaline hydrolysis of insecticide to the dimethyl dithiophosphate and its subsequent reaction with copper(I) perchlorate in acetonitrile. On mixing the reagents, a yellow color developed, which was stable for 120?min and was measured at 419?nm. The adsorption of malathion was studied by using Freundlich's adsorption equation and n f values were observed less than 1 in all the soils. The leaching behavior of the insecticide was studied in terms of ground ubiquity score, which was below 1.8, classifying malathion as non-leacher pesticide, and hence it is not hazardous. 相似文献
1000.
Cheng Xu 《国际发展与全球生态学杂志》2013,20(1):54-62
Although sustainable development has already been promulgated as one of its fundamental strategies by the national government since 1993, sustainable development, as an exotic new paradigm characteristic of profound philosophical and ethical thinking initiated in developed countries, is still not familiar to the Chinese people. Fortunately, in parallel to the evolution of sustainable agriculture, mainly in developed countries, since the beginning of the 1980s, Chinese agricultural scientists and technicians have already innovated their own unique form of Chinese Ecological Agriculture (CEA), on the basis of traditional agriculture that has been sustained for more than 4000 years. The basic principle of CEA emphasizes the obeying of both ecological rules and economic rules, as well as the approach of systematics and ecological engineering exactly corresponding to those adopted by sustainable development. The major difference between the two is that CEA has already been executed on a very large scale and has served as an effective and popularized way to implement sustainable agriculture in most parts of China. Also, as an active way of intensifying agriculture in terms of more inputs of skills, knowledge and labour, CEA is contributing much to all-round rural development throughout China. 相似文献