共查询到20条相似文献,搜索用时 15 毫秒
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Steven J. Page 《Aerosol science and technology》2013,47(4):249-267
Small scale laboratory pulverizing experiments were performed on humidified coal material sieved to size 6.35 mm (0.250 in) and below to eliminate effects due to inherent planes of weakness (cleats or joints). Experimental factors studied include the coal seam proximate analysis constituents, the breakage-in duced electrostatic field of airborne dust, and the specific airborne dust generated. Results of these pulverizing experiments show that only coals below 1-2% air dry loss (ADL) moisture content are in a highly charged state after pulverization and that the amount of charging decreases rapidly with increasing ADL up to 1-2%. This appears to have a direct effect on the specific dust generation characteristics of coals. However, each coal may have its own characteristic dust charge and generation signature. Underground dust samples obtained in coal seams with inherent moisture contents ranging from 0.5 to 4.5% suggest that significant particle agglomeration exists for the 0.5% inherent moisture coal but not the coals with moisture > 1.3% inherent moisture, in agreement with the laboratory tests. 相似文献
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The results of the thermal analysis of brown coals from the Mugunsk coal strip mine (Irkutsk oblast) are reported. The number and sequence of the elementary steps of reactions occurring in coals on heating were determined. 相似文献
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Heat-shielding glasses have been produced using dust from electric filters as the colorant agent. The introduction of such pigment makes it possible to obtain glasses with different spectral parameters. 相似文献
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Howard H. D. Lee 《Journal of the American Ceramic Society》1990,73(8):2261-2265
The ability of mercury porosimetry in characterizing particle packing and pore structures of dense ceramic green compacts is evaluated. Differences in intrusion spectra between the dry-pressed and slip-cast compacts demonstrate the utility of mercury porosimetry for particle-packing analysis. Of the voids embedded in the matrix, only those at or extending to the matrix surface are detectable. Intrusion—extrusion spectra show hysteresis, but otherwise do not provide added insight into bulk defect structure. 相似文献
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锦州石化公司某催化装置再生烟气粉尘含量高,烟机无法长周期运行,本文对该装置剂耗、粉尘长时间居高不下的现象进行了分析。同时利用2009年装置停产大修时机,对三、四旋系统进行了改造,使装置剂耗、烟机入口粉尘浓度下降,烟机运转平稳。 相似文献
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以巴丹吉林沙漠为主体的中国北部沙漠是我国北方地区两大粉尘源之一.利用包含详细粉尘活动过程的MATCH-DEAD模式系统,分别对2000,2001和2002年春季(3~5月)亚洲大陆在有、无中国北部沙漠区条件下的大气粉尘状况进行了数值实验研究,通过对比分析了中国北部沙漠区对亚洲粉尘含量的贡献.结果表明:(1)下垫面状况与粉尘释放关系密切,下垫面的改善对粉尘的释放有明显的抑制作用.(2)中国北部沙漠区释放的粉尘主要影响黄土高原、中国东南部、日本、韩国等地,但对于我国华北地区特别是北京地区的粉尘气溶胶含量贡献较小.(3)中国北部沙漠区释放的粉尘粒子在垂直高度上主要分布在3.5 km以下;在源地粒子集中分布在近地面,在粉尘源区下游粒子集中分布在垂直高度为1~2 km范围内.(4)在源地粒径较大的粒子优势较大,而在下游地区中等粒径的粒子(2.5~5.0μm)优势最大. 相似文献
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The new model describing the gaseous transport through graphite gaskets is based on the assumption of a flow in the transition regime through nano‐scale capillaries, using the Maxwellian wall‐slip boundary condition for rarefied gases. Together with an earlier published model describing the liquid transport in graphite gaskets, it enables the characterization of fugitive emissions of volatile organic compounds from fluid‐charged flange joints in chemical and petrochemical plants as a function of medium properties, pipe pressure, and gasket stress. Additionally, combination of the models allows predicting the emission rates of gases by experiments with liquids as the emitting fluid. Finally, recommendations are made to improve the gaskets with respect to their sealing performance towards gases. 相似文献
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对常温常压下滑动弧等离子体放电分解二甲醚(DME)制氢进行了研究,探讨了进气流量、电极间距、放电电压、电极形状和水/DME摩尔比以及添加的空气量对滑动弧等离子体DME转化制氢的影响。结果表明,当进气流量由43 mL·min-1增加到76 mL·min-1时,DME转化率从58.9%下降至50.6%,H2收率从26.9%下降至19.7%。随着电极间距由2 mm增加到4 mm、放电电压由11.2 kV增加到17.1kV时,DME转化率和H2收率增加,制氢能耗降低。电极最宽处有5mm平滑的竖直部分、上端电极长度50 mm,弧度23o的2#电极对DME放电反应最有利;添加水蒸汽和适量的空气对DME分解制氢反应有利,当水/DME摩尔比为2.3,添加空气的体积分数为25.8%时,DME转化率最大为74.1%,氢气的收率最大为43.4%。 相似文献
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Measurements to characterize inhalable aerosol exposure are subject to random error even after sources of systematic error have been eliminated. For a fixed aerosol sampler geometry the random errors are due to the variability of measured and unmeasured parameters including ambient variables, quantification technique, and operation parameters. In this discussion we apply a multi-component error estimation model to size selective aerosol sampling with the well-known Institute of Occupational Medicine (IOM) inhalable aerosol sampler. Random errors due to typical variations in sampler flow control, timing, and mass determination were small, being approximately 3%. Similarly, random errors due to variations in wind velocity were reasonably small at approximately 10%. However, the bias introduced by wind velocity was notable, ranging from peak values of 17 to 27% depending on aerosol mass median aerodynamic diameter and geometric standard deviation. This modeling indicated that the combined influence of variations in sampler flow control, timing, mass determination, and ambient wind velocity on IOM performance appeared to be less than approximately 10%; however, bias at moderate wind velocities was shown to be important for the IOM sampler as suggested by other studies. The effects of sampler placement, angle of incidence of ambient wind velocity on the sampler, and head orientation of the exposed person are unknown at this time and need additional research. 相似文献
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The flow field inside a cylindrical mixing vessel was visualized by electrical resistance tomography (ERT), a non‐intrusive measurement technique. Six tomography planes, each containing 16 sensing electrodes, measured the mixing time in the agitation of pseudoplastic fluid exhibiting yield stress. The effects of various parameters such as impeller types, impeller speed, fluid rheology, power consumption, Reynolds number, and absence of baffles on the mixing time were investigated. The Maxblend impeller was able to improve the mixing performance of non‐Newtonian fluids in a batch reactor. The mixing quality could be further enhanced by decreasing the xanthan gum concentration and using baffles in the mixing vessel. 相似文献
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Don J. Roth Michael J. Verrilli Richard E. Martin Laura M. Cosgriff 《Journal of the American Ceramic Society》2005,88(8):2164-2168
An ultrasonic guided wave scan system was used to non-destructively monitor damage over time and position in a C/enhanced SiC sample that was creep tested to failure at 1200°C in air at a stress of 69 MPa (10 ksi). The use of the guided wave scan system for mapping evolving oxidation profiles (via porosity gradients resulting from oxidation) along the sample length and predicting failure location was explored. The creep-rupture tests were interrupted for ultrasonic evaluation every two hours until failure at ∼17.5 cumulative hours. 相似文献
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粉煤灰代矿粉拌制沥青混凝土路面的试验与应用 总被引:1,自引:0,他引:1
Yang Ying xin 《粉煤灰综合利用》1999,(1)
用粉煤灰取代矿粉拌制沥青混合料,进行室内性能试验,进而用于铺筑沥青砼路面,取得了满意的结果。 相似文献
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Using Singular Value Decomposition to Characterize Protein–Protein Interactions by In‐cell NMR Spectroscopy
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Subhabrata Majumder Christopher M. DeMott Dr. David S. Burz Dr. Alexander Shekhtman 《Chembiochem : a European journal of chemical biology》2014,15(7):929-933
Distinct differences between how model proteins interact in‐cell and in vitro suggest that the cytosol might have a profound effect in modulating protein–protein and/or protein–ligand interactions that are not observed in vitro. Analyses of in‐cell NMR spectra of target proteins interacting with physiological partners are further complicated by low signal‐to‐noise ratios, and the long overexpression times used in protein–protein interaction studies may lead to changes in the in‐cell spectra over the course of the experiment. To unambiguously resolve the principal binding mode between two interacting species against the dynamic cellular background, we analyzed in‐cell spectral data of a target protein over the time course of overexpression of its interacting partner by using single‐value decomposition (SVD). SVD differentiates between concentration‐dependent and concentration‐independent events and identifies the principal binding mode between the two species. The analysis implicates a set of amino acids involved in the specific interaction that differs from previous NMR analyses but is in good agreement with crystallographic data. 相似文献
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以烧结灰水浸渣为原料、酸性硫脲溶液为浸出剂,采用超声强化法研究了超声波功率、颗粒尺寸、浸出时间、硫脲浓度、反应温度对银浸出率的影响,在此基础上采用响应曲面法(RSM)优化设计银浸出实验,获得烧结灰中提银的最佳工艺条件和二阶多项式模型. 结果表明,在超声波功率400 W、颗粒尺寸75~96 ?m、浸出时间90 min、硫脲浓度22 g/L、反应温度50℃条件下,银浸出率的模型预测值为96.15%,实测值为95.7%,相对误差为0.45%,可用该模型预测烧结灰提取银过程. 相似文献
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煤矿井下抽采的瓦斯是一种清洁能源,全国每年瓦斯抽放量约有20亿m3,其中绝大部分直接排空,这不仅造成了资源的浪费,而且也加剧了环境的污染。研究表明利用瓦斯发电,不但可以实现资源的有效利用,而且还能带来明显的经济效益和环保效益,对煤矿瓦斯抽采产生积极推动作用,可以有效减少煤矿瓦斯灾害的威胁。 相似文献