共查询到20条相似文献,搜索用时 70 毫秒
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(一)概况建材非金属矿地质经常要分析测试大量的各种硅酸盐岩石试样,其主要成份SiO_2、Fe_2O_3和Al_2O_3是必测项目.按常规方法,试样经碱熔酸化蒸干脱硅,重量法定SiO_2,容量法定Fe_2O_3和Al_2O_3.此法虽准确可靠,但流程长,工作量大,耗材多.光度法能克服以上缺点,只是苦于朗伯——比尔定律适应范围有限,长期不能用于高含量领域.笔者为解决这一问题进行了初步探索性实验. 相似文献
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本文对变色酸分光光度法测钛的多种影响因素进行了选择实验,并用选定的条件对玻璃中钛进行测定。结果表明,在选定条件下,测定玻璃中钛含量能达到较高的准确度和精密度。 相似文献
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BaO—ZnO—La2O3—B2O3系统玻璃结构的研究 总被引:1,自引:0,他引:1
ZnO-La2O3-B2O3玻璃具有高折射、低色散的特点。但该系统玻璃容易析晶失透,常需加入一些高价金属氧化物,如V2O5,Nb2O5等。本研究通过加入BaO,提高了该系统的玻璃形成能力。研究表明,加入少量的BaO,使玻璃网络中〔BO4〕和〔ZnO4〕数量上升,非桥氧数量下降,玻璃网络趋于稳定,玻璃形成能力提高。实验表明,在BaO-ZnO-La2O3-B2O3玻璃网络中Zn^2+离子的配位与BaO 相似文献
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采用传统工艺制备出B_2O_3引入量分别为0,5.6,11.2,16.8g的SiO_2-Al_2O_3-BaO-CaO-B_2O_3固体氧化物燃料电池(SOFC)封接玻璃,并通过傅里叶红外光谱仪(FTIR)、高温显微镜(HSM)、X射线衍射仪(XRD)、热膨胀仪、电化学工作站及扫描电镜(SEM)等手段,系统研究了B_2O_3引入量对SOFC封接玻璃结构与封接性能(润湿性和玻璃粉烧结性、玻璃特征温度以及玻璃析晶所产生的热膨胀系数变化、玻璃-陶瓷的电性能和封接界面稳定性)的影响.结果表明:随着B_2O_3引入量的增加,SOFC封接玻璃结构中的[BO_3]含量不断增加,[SiO_4]含量不断减少;SOFC封接玻璃封接性能的变化规律取决于其结构的变化,其中B_2O_3引入量分别为11.2,16.8g的玻璃性能满足实际SOFC封接玻璃的要求,可用于实际SOFC单电池的封接. 相似文献
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《Planning》2015,(24)
针对煤矸石酸浸提铝工艺中AlCl_3·6H_2O的结晶问题,采用静态法测定了25、50、70℃时AlCl_3·6H_2O在Fe(Ⅲ)-KCa-Cl-H_2O体系中的溶解度。结果表明:在KCl-FeCl_3-H_2O、CaCl_2-FeCl_3-H_2O和CaCl_2-KCl-H_2O体系中,AlCl_3·6H_2O的溶解度均随着温度的升高而有所增大;而在所测溶液浓度范围内(0~1mol/L),固定其中一种溶液的浓度,AlCl_3·6H_2O的溶解度随着另一溶液浓度的增大皆不断减小,这是由氯离子的加入产生的同离子效应导致的。通过比较溶解度数据发现,溶液浓度是影响AlCl_3·6H_2O溶解度的主要因素,温度对AlCl_3·6H_2O溶解度的影响可忽略,这为AlCl_3·6H_2O的工业结晶过程的设计和优化提供了理论依据。 相似文献
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建立了一种电感耦合等离子体质谱法(ICP-MS)测定玻璃固化体中铯含量的方法。该方法从ICP-MS的背景控制、内标物选择、质谱干扰等方面进行了优化。试验结果表明,该方法检出限为0.18mg/kg,相对标准偏差(n=12)为0.48%~4.11%,加标回收率为98%~102%,可用于玻璃固化体中铯含量的测定。 相似文献
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Efficiency and energy requirements for the transformation of organic micropollutants by ozone, O3/H2O2 and UV/H2O2 总被引:1,自引:0,他引:1
The energy consumptions of conventional ozonation and the AOPs O3/H2O2 and UV/H2O2 for transformation of organic micropollutants, namely atrazine (ATR), sulfamethoxazole (SMX) and N-nitrosodimethylamine (NDMA) were compared. Three lake waters and a wastewater were assessed. With p-chlorobenzoic acid (pCBA) as a hydroxyl radical (•OH) probe compound, we experimentally determined the rate constants of organic matter of the selected waters for their reaction with •OH (kOH,DOM), which varied from 2.0 × 104 to 3.5 × 104 L mgC−1 s−1. Based on these data we calculated •OH scavenging rates of the various water matrices, which were in the range 6.1-20 × 104 s−1. The varying scavenging rates influenced the required oxidant dose for the same degree of micropollutant transformation. In ozonation, for 90% pCBA transformation in the water with the lowest scavenging rate (lake Zürich water) the required O3 dose was roughly 2.3 mg/L, and in the water with the highest scavenging rate (Dübendorf wastewater) it was 13.2 mg/L, corresponding to an energy consumption of 0.035 and 0.2 kWh/m3, respectively. The use of O3/H2O2 increased the rate of micropollutant transformation and reduced bromate formation by 70%, but the H2O2 production increased the energy requirements by 20-25%. UV/H2O2 efficiently oxidized all examined micropollutants but energy requirements were substantially higher (For 90% pCBA conversion in lake Zürich water, 0.17-0.75 kWh/m3 were required, depending on the optical path length). Energy requirements between ozonation and UV/H2O2 were similar only in the case of NDMA, a compound that reacts slowly with ozone and •OH but is transformed efficiently by direct photolysis. 相似文献
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Catalytic incineration is one of the cost-effective technologies to deal with unwanted volatile organic compounds (VOCs). Catalytic incineration of styrene over a MnO/Fe2O3 catalyst was carried out in a bench scale catalytic incinerator. Three kinetic models, the power-rate law, the Mars and van Krevelen model and the Langmuir-Hinshelwood model were used to analyze the results. A differential reactor design was used for best fit of kinetic models in this study. The results show that the Langmuir-Hinshelwood model may be feasible to describe the catalytic incineration of styrene. This suggests that the chemical adsorption of either O2 molecules or O atoms is important in the process of catalytic incineration of styrene. 相似文献
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O3/H2O2艺去除饮用水中2-MIB的效能与机制 总被引:1,自引:0,他引:1
以2-甲基异莰醇(MIB)为嗅味物质的代表物,采用过氧化氢/臭氧氧化(O3/H2O2)工艺去除水中嗅味物质,考察了O3/H2O2工艺对水中2一MIB的去除效能与主导作用机制。研究表明,投加H2O2显著提高了单独0,氧化对2-MIB的去除效能,H2O2与O3最佳物质的量比为0.3:1,且2-MIB去除效果随pH值的升高而升高。叔丁醇对2-MIB的去除表现出显著的抑制作用,在O3氧化2-MIB过程中,除O3分子氧化2-MIB外,O3在水中自分解产生的强氧化性的羟基自由基(HO·)也具有协同氧化作用。不同浓度的天然有机物(NOM)对2-MIB去除效果的影响不同,较低浓度的NOM促进了2-MIB的去除,但随着其浓度的升高,2-MIB去除率明显降低。O3/H2O2工艺对水中2-MIB表现出良好的去除效果,是强化去除水中2-MIB等致臭微量有机物的重要工艺。 相似文献