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201.
本文根据部队官兵需要,明确了重新研制07A系列军用制式皮鞋的重要意义,并逐一说明了07A系列常服皮鞋、礼服皮鞋的产品特点。  相似文献   
202.
采用磁场-铋膜电极伏安法测定废水中痕量Pb2+.铋和铅同时沉积在电极表面形成铋膜电极,为Pb2+的测定提供了一个无汞环境.在高浓度Fe3+存在时,外加磁场促进了Pb2+在电极上的沉积.在磁感应强度0.6 T、Fe3+浓度0.09 mol/L、Bi3+浓度10 μmol/L、沉积电位-0.8 V、沉积时间60 s的最佳实验条件下,该方法对Pb2+的仪器检测灵敏度为4.61μA/(μmol·L-1),线性范围为0.01~1.00μmol/L,检出限为8.5×10-4μtxmol/L.  相似文献   
203.
此文叙述了转向螺母锻模块液态模锻工艺及特点,对该工艺及模具设计作了较详细的分析研究。  相似文献   
204.
建立了一套以层次分析、聚类与模糊隶属函数相结合,以及专家评分等评价方法为基础的评价指标体系,从经济效益、环境效益、社会效益3个方面对燃煤电厂脱硫石膏资源化水平进行评价分析.该评价体系将理论与实践、定性与定量相结合,具有严格性和精确性,为燃煤电厂提高脱硫石膏资源化水平提供参考.  相似文献   
205.
Thirty-three air samples were collected by high-volume samplers from May 2007 to June 2008 in the coastal area of southwest Taiwan and analyzed for total suspended particulates (TSP) and polycyclic aromatic hydrocarbons (PAHs). Concentrations of TSP and total PAHs ranged from 40.4 to 251 μg m(-3) and 1.86-56.4 ng m(-3), respectively. Except for joss paper burning during the religious celebration of Ghost Month, which resulted in the highest concentration of PAHs in the summer of 2007, a seasonal variation in total PAH concentration was observed over this study period, with the highest concentrations in winter and the lowest in summer. Because of the geographical and climatic characteristics of the sampling site, monsoon activities modulate the seasonal variations of PAHs. Diagnostic ratios showed that PAHs in the atmosphere of the Kaohsiung coastal area arose predominantly from vehicle emissions (mainly from diesel exhaust), joss paper burning, and coal/wood combustion. The results of hierarchical cluster analysis (HCA) and principal component analysis (PCA) indicated that the sampling days could be divided into three groups and that the major source identification of PAHs was the same as the identification by diagnostic ratios. In addition, the results of HCA and PCA suggest that the samples collected with a prevailing northerly or northeasterly wind direction contain both local emissions and those from neighboring sources. On the other hand, the cases related to westerly or northwesterly winds indicated that local emission was the major source for the sampling site.  相似文献   
206.
Although prey-detecting and searching abilities of predatory leeches of rhynchobdellid or the Erpobdelliformes of arhynchobdellid species have been studied in the past, hirudiniformes leeches are rarely mentioned. In this study, we investigated the chemosensory ability for prey-detecting and searching in Whitmania laevis, a hirudiniformes species that mainly preys on freshwater snails, and examined if such ability aided in their prey selection. Five sympatric snail species, i.e., apple snail Pomacea canaliculata, thiarid snail Thiara tuberculata, viviparid snail Sinotaia quadrata, ear pond snail Radix auricularia swinhoei and tadpole snail Physa acuta were used as prey. Our results showed that W. laevis has the chemosensory ability to detect the waterborne odors of snails. However, they follow the snails by their mucus trails, and not by the odor that the snails leave in the water. Of these five snail species, W. laevis only followed the trails of the thiarid snails, ear pond snails and tadpole snails, and did not show a different response to the trails produced by snails of different sizes. Our results suggest that W. laevis can use waterborne odors to detect the existence of prey. They rely on mucus trails to follow their preferred prey, but do not distinguish between snails of a preferred size by their mucus trails. In addition, when following the trail of a preferred snail, W. laevis exhibits a newly described searching behavior, i.e., head tapping, and may use it to locate a snail trail and increase its probability of finding the trail-laying snail nearby.  相似文献   
207.
Environmental Science and Pollution Research - Local questionnaire surveys were conducted to collect representative activity data for calculation of annual emissions from residential combustion in...  相似文献   
208.
赖耀富  赖诚 《四川环境》1993,12(4):33-34
肉联厂废水具有高生物降解性,其水质及排放量随季节变化很大,一般的小型肉联厂不能承担传统的处理方法,本文所述工程为应用厌氧接触发酵-稳定塘工艺,以及用新型过滤材料,取得了显著的效果,为处理小型肉联厂废水提供了一个良好的范例。  相似文献   
209.
安康“83.8”洪水灾害及防汛工作简析   总被引:2,自引:2,他引:0  
来天成  郝宗刚 《灾害学》1991,6(3):55-60
本文对安康“83.8”洪水灾害形成的机理及人为因素进行论述,并对洪水造成的灾害和灾后的教训及作法作了阐述。  相似文献   
210.
Amine-basedcarbon-capture technologies have been shown to be energetically expensive and to cause significant environmental and epidemiological impacts due to their volatility.Bicarbonate formation from carbon dioxide's reaction with water has been suggested as an effective alternative for capturing CO_2;however,the thermodynamics of this reaction are not well understood.This study experimentally determined the equilibrium constant of sodium bicarbonate(Na HCO_3)decomposition to sodium,water,and carbon dioxide;the study also compared the equilibrium constant to theoretical calculations.Using a combination of experimentation and thermodynamic relationships,the unitless equilibrium constants of the forward and reverse reactions were calculated accurately(error±9%and±4%,respectively).Equilibrium data were calculated using enthalpy and entropy values of each component of Na HCO_3decomposition at temperatures ranging from 25 to 155°C respectively.These results offer more data essential to optimizing Na HCO_3use in environmentally friendly nextgeneration CO_2-capture technologies.  相似文献   
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