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671.
672.
我国铁路危险货物办理站安全分析与对策 总被引:3,自引:1,他引:2
危险货物运输的源头是危险货物办理站 ,研究危险货物办理站的安全管理及存在的问题 ,具有现实意义和社会影响 ,对铁路行车安全和危货安全承运及保管至关重要。笔者通过实践和调查 ,阐述了目前我国铁路危险货物办理站安全运输中存在的主要问题 ,指出了危险货物办理站现有问题产生的原因 ,并提出了我国危险货物办理站问题解决的对策。 相似文献
673.
John G. Orthoefer Wellington Moore Dale Kraemer Freda Truman Walden Crocker You Yen Yang 《Environment international》1981,5(4-6)
Groups of strain A mice were exposed to diesel exhaust by inhalation and diesel particulate by intraperitoneal injection. The animals were exposed from seven to eight weeks and then sacrificed 26–30 weeks postexposure. Other animals were exposed for up to seven months by the inhalation route. Some animals were promoted using urethane at a dose below which tumors would occur. There was no increase in incidence of pulmonary adenomas in the animals exposed to either diesel exhaust or diesel particulate over the control animals. In the animals which were promoted using urethane at a low dose, there was a significant increase in pulmonary adenomas. Diesel particulate was found in the lungs and bronchial lymph nodes of animals exposed to diesel exhaust 26–30 weeks after cessation of exposure. 相似文献
674.
C. Le Caignec C. Gicquel M. C. Gubler C. Guyot M. C. You A. Laurent M. Joubert N. Winer A. David J. M. Rival 《黑龙江环境通报》2004,24(3):165-168
Beckwith–Wiedemann syndrome (BWS) is an overgrowth syndrome associated with congenital malformations and tumour predisposition. BWS results from variable mutations or epigenetic modifications of imprinted genes in the 11p15 chromosomal region. We present a fetus with mild general overgrowth and bilateral enlarged echogenic kidneys with loss of the corticomedullary differentiation in which prenatal diagnosis of BWS was suspected. The rest of the fetal anatomy and the amniotic fluid volume appeared normal. After termination of the pregnancy, molecular analysis confirmed the diagnosis of BWS by showing an isolated hypermethylation of the H19 gene. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
675.
以小型三柱塞泵为动力,利用两套旋转水射流同时对钢管内外表面进行清洗,清洗喷头的移动和被清洗件的替换动作,由三柱塞泵驱动的液压油缸及其牵引的钢丝绳操作,系统仅有单一动力装置。旋转接头采用胶状体拦截固体颗粒,利用悬浮安装的O 型圈密封压力;可在压力12MPa 以下,输送磨料浆液,每分钟300 转时,寿命可达1000 小时。清洗液可以进行加热,并过滤循环使用。该方法已在煤矿单体液压支柱的清洗作业中得到使用,清洗速度达到每小时(40~60)根缸筒或活塞柱。 相似文献
676.
677.
介绍了流动式二氧化硫快速遥测系统的原理和测试方法,对该系统应用于遥测大气二氧化硫的空浓度分布,不的二氧化硫排放量和沉降量,烟羽的水平扩散参数σy和抬升高度△H进行了研究。 相似文献
678.
In spite of progress achieved in the research of environmental impact assessment (EIA), the problem of weight distribution for a set of parameters has not as yet, been properly solved. This paper presents an approach of objective weighting by using a procedure of P
ij
principal component-factor analysis (P
ij
PCFA), which suits specifically those parameters measured directly by physical scales. The P
ij
PCFA weighting procedure reforms the conventional weighting practice in two aspects: first, the expert subjective judgment is replaced by the standardized measure P
ij
as the original input of weight processing and, secondly, the principal component-factor analysis is introduced to approach the environmental parameters for their respective contributions to the totality of the regional ecosystem. Not only is the P
ij
PCFA weighting logical in theoretical reasoning, it also suits practically all levels of professional routines in natural environmental assessment and impact analysis. Having been assured of objectivity and accuracy in the EIA case study of the Chuansha County in Shanghai, China, the P
ij
PCFA weighting procedure has the potential to be applied in other geographical fields that need assigning weights to parameters that are measured by physical scales. 相似文献
679.
利用废碱性电池制备得到尖晶石结构的锰锌铁氧体Mn0.6Zn0.4Fe2O4(MZF),利用原位聚合制备得到硅包覆的磁性纳米复合物MZF@SiO2(MZFS),采用浸渍法制备得到集磁分离、吸附与类Fenton催化活性于一体的CeO2/MZFS磁性吸附剂,并对其形貌和磁性能等进行了表征.结果表明,CeO2/MZFS对水中盐酸四环素(TH)表现出良好的吸附性能,160 min吸附过程可达平衡,TH的去除率达到95%.吸附过程可用准二级动力学方程描述,化学吸附为速控步骤;Freundlich等温吸附模型能较好地描述该吸附过程,热力学计算结果表明,CeO2/MZFS对TH的吸附是以物理吸附为主的自发吸热过程;利用红外光谱初步揭示了吸附机制.吸附TH后的CeO2/MZFS可利用其非均相类Fenton催化活性以H2O2作为再生剂进行原位再生,6次循环使用后,CeO2/MZFS对TH仍能保持较高的平衡吸附量.研究结果可为抗生素废水的治理提供理论指导和技术支持. 相似文献
680.
Yanyang Liu Bin Men Aibin Hu Qingliang You Guiying Liao Dongsheng Wang 《环境科学学报(英文版)》2020,32(4):395-407
In this work, we proposed a green and cost-effective method to prepare a graphene-based hyper-cross-linked porous carbon composite (GN/HCPC) by one-pot carbonization of hyper-cross-linked polymer (HCP) and glucose. The composite combined the advantages of graphene (GN) and hyper-cross-linked porous carbon (HCPC), leading to high specific surface area (396.93 m2/g) and large total pore volume (0.413 cm3/g). The resulting GN/HCPC composite was applied as an adsorbent to remove 2,4-dichlorophenol (2,4-DCP) from aqueous solutions. The influence of different solution conditions including pH, ionic strength, contact time, system temperature and concentration of humic acid was determined. The maximum adsorption capacity of GN/HCPC composite (calculated by the Langmuir model) could reach 348.43 mg/g, which represented increases of 43.6% and 13.6% over those of the as-prepared pure GN and HCPC, respectively. The Langmuir model and pseudo-second-order kinetic model were found to fit well with the adsorption process. Thermodynamic experiments suggested that the adsorption proceeded spontaneously and endothermically. In addition, the GN/HCPC composite showed high adsorption performance toward other organic contaminants including tetracycline, bisphenol A and phenol. Measurement of the adsorption capability of GN/HCPC in secondary effluent revealed a slight decrease over that in pure water solution. This study demonstrated that the GN/HCPC composite can be utilized as a practical and efficient adsorbent for the removal of organic contaminants in wastewater. 相似文献