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601.
以废旧印刷线路板非金属分离物为前躯体,经热解、成型、炭化和水蒸汽活化制备粒状活性炭.研究了热解温度对残碳收率的影响,煤焦油配比对成型碳强度的影响,活化反应条件对活性炭烧蚀率、比表面积和碘吸附值的影响.结果表明,随着热解温度的提高残碳收率下降;随着煤焦油配比增大,成型碳的强度呈现先增大后减少的趋势,成型碳机械强度最大时的...  相似文献   
602.
Fine particles associated with haze pollution threaten the health of over 400 million people in China. Owing to excellent non-destructive fingerprint recognition characteristics, Raman and surface-enhanced Raman scattering (SERS) are often used to analyze the composition of fine particles to determine their physical and chemical properties as well as reaction mechanisms. However, there is no comprehensive Raman spectral library of fine particles. Furthermore, various studies that used SERS for fine-particle composition analysis showed that the uniqueness of the SERS substrates and different excitation wavelengths can produce a different spectrum for the same fine-particle component. To overcome this limitation, we conducted SERS experiments with a portable Raman spectrometer using two common SERS substrates (silver (Ag) foil and gold nanoparticles (Au NPs)) and a 785 nm laser. Herein, we introduced three main particle component types (sulfate-nitrate-ammonium (SNA), organic material, and soot) with a total of 39 chemical substances. We scanned the solid Raman, liquid Raman, and SERS spectra of these substances and constructed a fine-particle reference library containing 105 spectra. Spectral results indicated that for soot and SNA, the differences in characteristic peaks mainly originated from the solid-liquid phase transition; Ag foil had little effect on this difference, while the Au NPs caused a significant red shift in the peak positions of polycyclic aromatic hydrocarbons. Moreover, with various characteristic peak positions in the three types of spectra, we could quickly and correctly distinguish substances. We hope that this spectral library will aid in the future identification of fine particles.  相似文献   
603.
Nanoscale bismuth oxyiodide (nano-BiOI) is widely studied and applied in environmental applications and biomedical fields, with the consequence that it may be deposited into aquatic environments. However, the impact of nano-BiOI on aquatic ecosystems, especially freshwater microalga, remains limited. Herein, the nano-BiOI was synthesized and its response mechanism towards microalga Chlamydomonas reinhardtii was evaluated. Results showed that a low concentration of nano-BiOI (5 mg/L) could stimulate algal growth at the early stage of stress. With the increase in concentration, the growth rate of algal cells was inhibited and showed a dose effect. Intracellular reactive oxygen species (ROS) were significantly induced and accompanied by enhanced lipid peroxidation, decreased nonspecific esterase activity, and significantly upregulated glutathione S-transferase activity (GST) activity. Mineral nutrient metabolism analysis showed that nano-BiOI significantly interfered with the mineral nutrients of the algae. Non-targeted metabolomics identified 35 different metabolites (DEMs, 22 upregulated, and 13 downregulated) under 100 mg/L BiOI stress. Metabolic pathway analysis demonstrated that a high concentration of nano-BiOI significantly induced metabolic pathways related to amino acid biosynthesis, lipid biosynthesis, and glutathione biosynthesis, and significantly inhibited the sterol biosynthesis pathway. This finding will contribute to understanding the toxicological mechanisms of nano-BiOI on C. reinhardtii.  相似文献   
604.
以云南省1961-2011年的滑坡泥石流灾害和逐日降水观测数据为基础,采用相关分析和小波变换分析方法,研究了云南滑坡泥石流与强降水变化的相关性特征和多时间尺度特征。结论为:近51年来云南滑坡泥石流活动频次呈现出逐步增长的趋势,云南滑坡泥石流与强降水的变化具有显著的相关关系,与暴雨的相关性最高,其次为大暴雨和大雨。云南滑坡泥石流与强降水变化表现出十分明显的多时间尺度变化特征。滑坡泥石流与强降水的变化均存在有6年的特征时间尺度变化,在6年的特征时间尺度上,云南滑坡泥石流的变化一般是相同或滞后于强降水的变化。  相似文献   
605.
山区铁路沿线暴雨泥石流预报的研究   总被引:40,自引:4,他引:40  
泥石流发生是灾害性降雨过程和流域内不稳定的松散物产状与制约水、沙输移的河沟条件所决定的。解决泥石流预报中的时、空因素,可以通过每小时接收卫星云图的信息分析决定。对某一流域内能否发生泥石流的预报,则由降雨条件函数和地面环境动态函数组合的量级决定。本研究对铁路三个预报试验区、黄河水利委员会三个水土保持科学试验站的大量观测试验资料进行了统计分析,完善了“山区铁路暴雨泥石流中短期预报的研究”专题中提出的泥  相似文献   
606.
系统地阐述了中子辐射防护服的设计依据、结构、式样及使用效果。表明这是一种能有效地屏蔽热中子和中能中子的防护器具,可用于许多场所。  相似文献   
607.
云南极端霜冻气候事件的气候特征及环流背景分析   总被引:2,自引:0,他引:2  
陶云  段旭  任菊章  何群 《灾害学》2012,(2):43-48
利用云南124个气象站逐日最低气温和天气现象(霜)资料,计算最低气温低于-5℃的站点数占全省总站数的比例,定义站点比例超出25%的霜冻事件为云南极端霜冻气候事件。分析了云南极端霜冻气候事件的气候特征及环流背景。结果表明,云南极端霜冻事件发生前气温偏低,云量偏多;霜冻发生时夜间晴朗,辐射散热强烈,气温再度下降。这种霜冻属于混合霜冻或称为平流辐射霜冻。极端霜冻气候事件发生的主要原因之一是高空冷平流与底层冷高压控制下夜间晴空辐射冷却降温。发生时空气湿度较发生前小,空气相对干燥。  相似文献   
608.
This paper analyzes the air quality impacts of coal-fired power plants in the northern passageway of the West-East Power Transmission Project in China. A three-layer Lagrangian model called ATMOS, was used to simulate the spatial distribution of incremental sulfur dioxide (SO2) and coarse particulate matter (PM10) concentrations under different emission control scenarios. In the year 2005, the emissions from planned power plants mainly affected the air quality of Shanxi, Shaanxi, the common boundary of Inner Mongolia and Shanxi, and the area around the boundary between Inner Mongolia and Ningxia. In these areas, the annually averaged incremental SO2 and PM10 concentrations exceed 2 and 2.5 microg/m3, respectively. The maximum increases of the annually averaged SO2 and PM10 concentrations are 8.3 and 7.2 microg/m3, respectively, which occur around Hancheng city, near the boundary of the Shaanxi and Shanxi provinces. After integrated control measures are considered, the maximum increases of annually averaged SO2 and PM10 concentrations fall to 4.9 and 4 microg/m3, respectively. In the year 2010, the areas affected by planned power plants are mainly North Shaanxi, North Ningxia, and Northwest Shanxi. The maximum increases of the annually averaged SO2 and PM10, concentrations are, respectively, 6.3 and 5.6 microg/m3, occurring in Northwest Shanxi, which decline to 4.4 and 4.1 microg/m3 after the control measures are implemented. The results showed that the proposed power plants mainly affect the air quality of the region where the power plants are built, with little impact on East China where the electricity will be used. The influences of planned power plants on air quality will be decreased greatly by implementing integrated control measures.  相似文献   
609.
含碳气溶胶研究进展:有机碳和元素碳   总被引:20,自引:0,他引:20  
含碳气溶胶是我国大气区域性复合型污染的重要物种,对全球气候变化、辐射强迫、能见度、环境质量、人类健康等会产生重要影响.主要从含碳气溶胶来源及成因、环境影响、样品采集及测试等方面对国内外相关研究进行了评述,讨论了有机碳和元素碳研究中存在的关键和难点问题,并对其发展前景进行了展望.  相似文献   
610.
浙江省畜牧业发展的生态环境问题及其控制对策   总被引:22,自引:1,他引:22  
系统地论述了浙江省畜牧业发展的生态环境问题,分析了畜禽污染的现状和趋势,提出了一整套消除畜牧公害,促进畜牧业可持续发展的对策和措施 。  相似文献   
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