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901.
Environmental Science and Pollution Research - The Three Gorges Dam’s construction and industrial transfer have resulted in a new air pollution pattern with the potential to threaten the...  相似文献   
902.
Inkjet printing of metal nanoparticles is an attractive method for front-side metallization of silicon solar cells. It is owing to noncontact, low-cost, low-waste, and simple process. In this work, we proposed the ink-jet printing and electroless technology to fabricate the seed layer and electrode layer, respectively. Furthermore, we used electroplating method to increase the electrode conductivity. In this way, the energy conversion efficiency up to 12.22% without AR coating can be obtained on 100?×?100 mm c-Si cell.  相似文献   
903.
In this study, field measurements were conducted to estimate and characterize the atmospheric emission levels and profiles of polychlorinated biphenyls (PCBs) from multiple industrial thermal processes. The emission levels and profiles of PCBs from five types of thermal processes at twenty-three plants were studied and compared with eight processes reported in our previous studies. Correlation analysis was preformed to identify a marker congener for emission of ΣPCB. A significant correlation was observed between congener CB-118 and ΣPCB (R2 = 0.65 and p < 0.01), which suggests that CB-118 is a good marker congener for emission of ΣPCB. The profiles of PCBs emitted from the thirteen thermal processes were compared, and this information could be used for studying source–receptor relationships and identifying the specific sources of PCBs. To prioritize the sources for control, the concentrations of PCBs from thirteen industrial thermal sources were compared. The PCB concentrations from secondary zinc smelting and thermal wire reclamation were about one to three order magnitude higher than those of other sources, which suggests that these two sources be given priority in PCB source control. Finally, the atmospheric emission factors of PCBs from the thirteen industrial sources were summarized, and these data will be useful for developing an integrated emission inventory of PCBs.  相似文献   
904.
Surface water quality and its natural and anthropogenic controls in the Xiangjiang River were investigated using multivariate statistical approaches and a comprehensive observation dataset collected from 2004 to 2008. Cluster analysis (CA) grouped the 15 different sampling stations into five clusters with similar hydrochemistry characteristics and pollution levels. Four principal components (PCs), nutrients, heavy metals, natural components, and organic components, were extracted from the entire dataset. Comparison of the different regional characteristics of these four PCs revealed a decreasing trend for heavy metals and an increasing trend for organic factor on an annual scale, and the seasonal trend was only observed for natural factor. We also conducted analysis of variance (ANOVA) in combination with principal component analysis (PCA) to quantify the relative contribution of spatial and temporal variations to each of the four PCs. The results revealed that 62% of the contributions from the spatial sites were responsible for variations in heavy metals, while 83% of the contributions from the sampling time were responsible for natural variations observed. However, no significant spatial or temporal contributions were found to be responsible for the nutrient and organic variations. Finally, some suggestions regarding water management were put forward based on the current status and future trends of surface water quality in the Xiangjiang River.  相似文献   
905.
The treatment and disposal of sewage sludge are significant environmental problems in China. The reuse of sewage sludge for fuel could be an effective solution. The aim of this study was to characterize the behavior of sludge-derived fuel during combustion by a thermogravimetric method. The combustion profiles obtained showed four obvious weight loss regions. The results of dynamics analysis showed that first-order reactions together with Arrhenius’ law explained reasonably well the different stages of weight loss in the samples. Three temperature regions (162–327 °C, 367–445 °C, and 559–653 °C for sawdust and 162–286 °C, 343–532 °C, and 609–653 °C for coal) in each derivative thermogravimetry (DTG) curve corresponded well with the Arrhenius equation. The reactivity of sludge was lower than that of samples containing sawdust, but higher than that of coal-containing samples. These data demonstrate that sludge-derived fuel has better combustion characteristics than sludge, sawdust, or coal.  相似文献   
906.
A gas standard mixture containing 22 chlorinated hydrocarbons in high purity nitrogen was prepared using a two-step weighing method and a gasifying apparatus developed in-house. The concentration of each component was determined using a gas chromatograph with flame ionization detection (GC/FID). Linear regression analysis of every component was performed using the gas standard mixture with concentrations ranging from 1 to 10 μmol/mol, showing the complete gasification of volatile organic compound (VOCs) species in a selected cylinder. Repeatability was also examined to ensure the reliability of the preparation method. In addition, no significant difference was observed between domestic treated and imported treated cylinders, which were conducive to reduction of the cost of raw materials. Moreover, the results of stability testing at different pressures and long-term stability tests indicated that the gas standard at 1 μmol/mol level with relative expanded uncertainties of 5% was stable above 2 MPa for a minimum of 12 months. Finally, a quantity comparison was conducted between the gas standard and a commercial gas standard from Scott Specialty Gases (now Air Liquide America Specialty Gases). The excellent agreement of every species suggested the favorable accuracy of our gas standard. Therefore, this reference material can be applied to routine observation of VOCs and for other purposes.  相似文献   
907.
908.
汽车尾气中多环芳烃(PAHs)成分谱图研究   总被引:35,自引:9,他引:26  
采集并测定了不同型号、油品、里程数的汽车尾气中14种多环芳烃,对分析结果归一化处理后确定其多环芳烃成分谱图.研究表明,汽车在30rmin内排放的14种PAHs总浓度为41.53~121.1μg/m3;其中苯并(a)蒽(BaA)浓度最大,占总量的33.3%;萘(Naph)、苯并(ghi) (Bghip)、茚(1,2,3-cd)芘(In)分别为16.8%、12.9%和12.1%.相同里程数的柴油车排放PAHs总量大于汽油车;除BaA和Naph,柴油车主要排放苊(Ac)、芴(Fluor)、Bghip和In,而汽油车主要排放Bghip、In、苯并(k)荧蒽(BkF).柴油车排放3环PAHs的量大于汽油车,但5~6环PAHs的排放量小于汽油车;随着汽车里程数的增加,PAHs(特别是荧蒽(Flur)、芘(Py)、苯并(a)芘(BaP)、Bghip)的排放总量增加.  相似文献   
909.
介绍了基于“静态气化清灰原理”的我国自主研制的静态清灰袋式除尘技术,分析了它的技术经济优势,并对其应用于600 M研燃煤机组锅炉烟气除尘进行了实例分析,最后结合袋式除尘行业发展态势、国家环保政策导向及静态清灰袋式除尘技术的优势,对静态清灰袋式除尘技术的产业化推广应用前景进行了分析和预测.  相似文献   
910.
本文讨论了低热通量条件下消防员防护服装热防护性能的测试原理和测试步骤。通过测试。分析了低热通量条件下消防员防护服装热防护性能的各种影响因素。  相似文献   
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