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81.
温度、氨对鲢、鳙、草、鲤鱼的影响   总被引:7,自引:0,他引:7       下载免费PDF全文
为制定热排放标准的需要,用动态实验和静态实验方法研究了热冲击与氨对鲢、鳙、草、鲤鱼的急性和亚急性效应。结果表明:选择温度与起始致死温度(TL50)值随着驯化温度的升高而增大,鳙鱼对热冲击的反应较敏感。氨对鲢、鳙、鲤鱼的急性毒性(96h)LC50值分别为0.38、0.30、0.66mgNH3/L(非离解氨)。水温升高5℃,鲤鱼的(96h)LC50。值从0.66mgNH3/L下降到0.44mgNH3/L,热冲击明显提高了氨对鲤鱼的毒性。氨对鲤鱼的亚急性毒性结果表明,鳃、肝组织出现了病理改变。以上室内实验结果可作为评价监测热污染水质的科学依据。  相似文献   
82.
温州临江垃圾焚烧发电厂飞灰的性质研究   总被引:1,自引:0,他引:1  
研究了温州临江垃圾焚烧发电厂生活垃圾焚烧产生飞灰的物理和化学性质。飞灰为含水率低、颗粒尺寸集中在43~175μm之间的灰色粉末,主要由Si、Al、Ca、Mg、Fe、Na、K、C和S元素组成。飞灰中Pb、Cd的浸出浓度在酸性条件下都不同程度地高于我国危险废物鉴别标准的允许浓度,其中Pb的浸出浓度在pH值1.06~13.69条件下远远超标,碱性条件下浸出毒性比酸性条件下小。矿物组成主要为石英(SiO2)、赤铁矿αFe2O3、钙长石CaO.Al2O3.2SiO2、钙铝黄长石2CaO.Al2O3.SiO2、KCl、NaCl、CaCO、PbO、TiO2、ZnCO3等,溶解盐含量高达19.5%,化学反应活性较强,热稳定性较差。  相似文献   
83.
李昌厚  陈颖  李思成 《火灾科学》2014,23(4):195-202
高层建筑发生火灾后,火灾烟气会在多种驱动力的作用下从着火房间迅速蔓延扩散至整栋建筑,严重威胁建筑内人员的生命安全。因此,控制建筑内烟气蔓延是建筑消防安全的一项重要内容。该文对热浮力、烟囱效应和室外风作用下建筑内火灾烟气输运规律进行分析,较系统地总结了这三种驱动力作用下火灾烟气输运的国内外研究成果,指出了以往研究的一些不足之处。根据国内外相关工作的研究进展及当前需要,对今后高层建筑火灾烟气输运规律的主要研究内容提出了几点展望。  相似文献   
84.
• Cu and Cr can be mostly incorporated into CuFexAlyCr2xyO4 with a spinel structure. • Spinel phase is the most crucial structure for Cu and Cr co-stabilization. • Compared to Al, Fe and Cr are easier to be incorporated into the spinel structure. • ‘Waste-to-resource’ by thermal process at attainable temperatures can be achieved. Chromium slag usually contains various heavy metals, making its safe treatment difficult. Glass-ceramic sintering has been applied to resolve this issue and emerged as an effective method for metal immobilization by incorporating heavy metals into stable crystal structures. Currently, there is limited knowledge about the reaction pathways adopted by multiple heavy metals and the co-stabilization functions of the crystal structure. To study the Cu/Cr co-stabilization mechanisms during thermal treatment, a simulated system was prepared using a mixture with a molar ratio of Al2O3:Fe2O3:Cr2O3:CuO= 1:1:1:3. The samples were sintered at temperatures 600–1300°C followed by intensive analysis of phase constitutions and microstructure development. A spinel phase (CuFexAlyCr2xyO4) started to generate at 700°C and the incorporation of Cu/Cr into the spinel largely complete at 900°C, although the spinel peak intensity continued increasing slightly at temperatures above 900°C. Fe2O3/Cr2O3 was more easily incorporated into the spinel at lower temperatures, while more Al2O3 was gradually incorporated into the spinel at higher temperatures. Additionally, sintered sample microstructures became more condensed and smoother with increased sintering temperature. Cu / Cr leachability substantially decreased after Cu/Cr incorporation into the spinel phase at elevated temperatures. At 600°C, the leached ratios for Cu and Cr were 6.28% and 0.65%, respectively. When sintering temperature was increased to 1300°C, the leached ratios for all metal components in the system were below 0.2%. This study proposes a sustainable method for managing Cu/Cr co-exist slag at reasonable temperatures.  相似文献   
85.
86.
以工业废弃物粉煤灰和当地粘土为主要原料,十二烷基苯磺酸钠为发泡剂,采用发泡注浆法制备轻质莫来石耐火材料,研究了烧结温度对耐火材料晶相的影响以及发泡剂的种类、添加量和浆料固含量对轻质耐火材料常温物理性能的影响。结果表明,适当的烧结温度可改善耐火材料的晶相,同时对制品的孔隙率也有一定影响。选择适宜的发泡剂及添加量,在一定的浆料固含量范围内,可以制备容重小,孔隙率高,导热系数小,机械强度适中的轻质耐火材料。  相似文献   
87.
The radiant heat flux from a pool fire is frequently calculated using the solid flame model, where the flame envelope is approximated as a stationary cylinder whose surface emits thermal radiation at a constant rate. Radiant heat flux calculations using the solid flame model assume the target to be at a given elevation, typically at ground level, and to have an unobstructed view of the fire. The presence of obstacles (e.g., walls, buildings, etc.) or terrain features that would create shaded areas and provide shielding of a target from the fire is typically neglected in these calculations: this is a conservative approach, but it is not accurate. This paper presents a methodology to utilize the solid flame model to calculate the heat flux to a target while taking into account the presence of an obstruction between the target and the fire. The shielded solid flame method can quantitatively account for the presence of obstacles as a passive mitigation measure and allows project developers or designers to optimize their facility layout to meet safety requirements. The methodology presented in this paper uses the same correlations found in currently used solid flame models (e.g., LNGFIRE3), therefore, it remains consistent with current regulatory requirements for LNG facilities in the U.S.  相似文献   
88.
Web spiders are considered to have expanded their habitats from dim to bright environments during the evolutionary history. Because they are sedentary predators exposed to the sun, they may have developed a suite of adaptive traits to cope with thermal stress. We examined the critical thermal maximum, spectral reflectance of solar energy by the body surface, and surface–volume ratio (SVR) for 11 spider species. Analysis of the four genera having a pair of species inhabiting both bright and dim environments showed that species in bright environments exhibited higher lethal temperatures, but spectral reflectance and SVR did not differ. Independent contrasts using the 11 species indicated that critical thermal maximum was positively correlated with spectral reflectance and spectral reflectance was negatively correlated with SVR. These results suggest that physiological tolerance to high temperatures and a biophysical mechanism to reduce heat gain evolved jointly during the history of habitat expansion in araneoid spiders.  相似文献   
89.
Accurate experimental data on the thermo-physical properties of CO2-mixtures are pre-requisites for development of more accurate models and hence, more precise design of CO2 capture and storage (CCS) processes. A literature survey was conducted on both the available experimental data and the theoretical models associated with the transport properties of CO2-mixtures within the operation windows of CCS. Gaps were identified between the available knowledge and requirements of the system design and operation. For the experimental gas-phase measurements, there are no available data about any transport properties of CO2/H2S, CO2/COS and CO2/NH3; and except for CO2/H2O(/NaCl) and CO2/amine/H2O mixtures, there are no available measurements regarding the transport properties of any liquid-phase mixtures. In the prediction of gas-phase viscosities using Chapman–Enskog theory, deviations are typically <2% at atmospheric pressure and moderate temperatures. The deviations increase with increasing temperatures and pressures. Using both the Rigorous Kinetic Theory (RKT) and empirical models in the prediction of gas-phase thermal conductivities, typical deviations are 2.2–9%. Comparison of popular empirical models for estimation of gas-phase diffusion coefficients with newer experimental data for CO2/H2O shows deviations of up to 20%. For many mixtures relevant for CCS, the diffusion coefficient models based on the RKT show predictions within the experimental uncertainty. Typical reported deviations of the CO2/H2O system using empirical models are below 3% for the viscosity and the thermal conductivity and between 5 and 20% for the diffusion coefficients. The research community knows little about the effect of other impurities in liquid CO2 than water, and this is an important area to focus in future work.  相似文献   
90.
选取35台装机容量30万千瓦以上大型火电机组,进行了为期2年的监测。总结出大型火电机组二氧化硫排放规律,对大型火电机组燃煤含硫量、脱硫设施脱硫效率和二氧化硫排放浓度三者间的关系进行了统计分析,建立了线性回归方程,进而对燃用不同含硫量燃煤的火电机组执行不同排放标准时,配套脱硫设施需要达到的脱硫效率进行了预测。  相似文献   
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