印尼油砂尾砂制取半水石膏研究

印尼油砂的尾砂矿中含有约80%的钙盐,利用其丰富的钙含量将其合成二水石膏,进一步合成半水石膏。分别考察反应温度,二水石膏质量分数,氯化钠质量分数和溶液p H值,最终确定反应温度为96℃,二水石膏质量分数为15%,氯化钠质量分数为15%,溶液p H=5为反应适宜条件。得到的石膏经过X射线衍射和电镜扫描确定反应基本完成,晶体为长条六棱柱状,为半水石膏理想形态。     

Characterization of four petrologic end members from Alberta oil sands and comparison between different mines and sampling times

The current research was performed on four petrologic end members samples from Syncrude's North Mine collected in 2012 (NM12), i.e. marine clay (MC), marine sand (MS), estuarine clay (EC), and estuarine sand (ES). The mineralogical compositions of the four petrological end members were determined using X‐ray diffraction (XRD), quantitative XRD (QXRD), elemental analysis, and particle size distribution (PSD) measurements. Bulk samples from the four petrologic end members, after bitumen removal, were mainly composed of clay minerals (kaolinite, illite, chlorite, and mixed‐layer expandable clays) and non‐clay minerals such as quartz, carbonates, feldspars, and traces of TiO₂ minerals, gypsum, and pyrite. Bulk samples of the clay end members were composed of significantly higher amounts of clay minerals and lower amounts of quartz compared with the bulk samples of the sand end members. XRD analysis of oriented preparations (air dried‐54 % RH and ethylene glycolated) of the < 0.2 μm fractions of the four end members showed that interstratified illite‐smectite of high (～30 %) and low (～10 %) expandability were observed only in clay‐rich end members, i.e. NM12‐EC and MC, respectively. Kaolinite‐smectite was only found in the < 0.2 μm fraction of the NM12‐MC with an expandability between 5 and 10 %. Interstratification of illite‐smectite was observed in the < 0.2 μm fraction of NM09‐MC and EC samples but the expandability was only 10 % for both fractions. However, kaolinite‐smectite was not found in the same fraction for NM09‐MC and EC. ES and EC had the highest and lowest bitumen contents, respectively, for the NM12, NM09, and AM10 samples.     

用模糊控制的人造水晶单片机温度控制系统

人造水晶生长过程中，温度直接决定晶体的质量。文章介绍了由51系列单片机组成的温度控制系统硬件、软件的组成及控制方法，着重讨论了如何实现模糊控制；在接口8155的输出位，用软件方法实现PWM输出，控制双向晶闸管单位时间内输出完整的正弦波个数的方法来调节温度。     

石英砂岩含水层快速施工

介绍在刘庄煤矿副井石英砂岩含水层施工中,综合机械化配套、施工方法和劳动组织,为该类地层快速施工积累了成功的实践经验。     

Ionic liquids used as QCM coating materials for the detection of alcohols

Six imidazolium-based ionic liquids (ILs) were synthesized and employed as sensing materials coated on quartz crystal microbalance for the detection of organic vapors. Acetone, ethanol, dichloromethane, benzene, toluene and hexane were selected as representatives for common environmental pollutants, and good linear responses from 0 to 100% of concentrations were observed. The halogen-anion-containing imidazolium ILs-coated sensors showed fast response, excellent reversibility, and considerable sensitivity and selectivity towards alcohols, and the selective factors were up to 30 times for ethanol versus other VOCs. The existence of water vapor reduced the frequency response of the sensor, but a good linear relationship remained.     

Cavitation in Liquid Helium Observed in a Flow Due to a Vibrating Quartz Fork

A quartz fork vibrating at high amplitude is used to study cavitation in He I and He II along the saturated vapor pressure (SVP) curve and at slightly elevated pressures. Cavitation is observed as a breakdown of the resonance response at critical velocity when slowly sweeping the frequency of the drive across the resonance and confirmed by visual observation of a bubble occurring in He II in the space between the prongs of the fork. On decreasing the temperature from 4.2 K along the SVP curve the critical velocity slowly increases from about 0.4 m/s to 1 m/s, until a steep increase up to about 2 m/s occurs within about 20 mK just below the superfluid transition. We discuss our results, including the measured dependence of the critical velocity versus overpressure at fixed bath temperature.      

Three characterization techniques coupled with adsorption for studying the nanoporosity of supported films and membranes

Three characterization techniques are described for studying the open nanoporosity, i.e. the open free volume, the microporosity, the mesoporosity and the thickness variation of thin deposited films during gas adsorption and condensation. They are all based on the coupling of the sorption of a probe gaseous molecule at room temperature and a physical characterization tool of thin deposited films: the quartz crystal microbalance, ellipsometry and X-ray reflectometry, giving the mass uptake, the refractive index variation and the electronic density variation, respectively, of the film due to the adsorbate intrusion inside the open free volume and pores. The film thickness evolution during the sorption can also be followed by the two last techniques. These techniques are complementary because each one can bring specific properties and can validate the results of another one. Both static and dynamic measurements can be carried out to characterize the porosity, the contraction or the swelling of the film and the penetration rate of the gas.     

Thermo-oxidative characterization and kinetics of tar sands

In this research, non-isothermal kinetics and thermal analysis of Gerçü? tar sand sample is studied by DSC (differential scanning calorimeter) and TG/DTG (thermogravimetry). Experiments were performed using three different mesh size (20-35, 35-50 and >50) of sample. Differential scanning calorimeter (DSC) curves revealed three reaction regions in the temperature range of 20-600 °C. On the other hand, thermogravimetry (TG/DTG) curves of tar sand samples at different particle sizes demonstrated three stages of weight loss. Two different kinetic models (Coats & Redfern and Arrhenius) were used to determine the kinetic parameters of the samples and it was observed that the average activation energy values were between 17.5 and 26.6 kJ/mol, for reaction region-II and 126.2-160.1 kJ/mol for reaction region-III, respectively. In order to see the contribution of each region to the overall reactivity of the tar sand sample, weighted mean apparent activation energy of the samples are also determined.     

Ammonia thermal decomposition on quartz and stainless steel walls

Ammonia has been proposed as a promising solution for hydrogen carriers as well as clean fuels. However, the reaction kinetics is still not robust in many engineering applications, where the deviation is mainly caused by the surface reactions of ammonia on the wall. To examine the ammonia surface reaction on engineering materials, in the present study, the thermal decomposition of ammonia is systematically investigated in uniformly heated quartz/SUS304 tubular flow reactors with the prescribed heating length. A decrease in the inner diameter of the quartz tubular reactor leads to an increase in the ammonia thermal decomposition rate, showing that the thermal decomposition reaction occurs even on quartz surfaces, which is usually believed to be inert. The thermal decomposition on the SUS304 reactor surface starts from as low as 700 K, indicating it is much more reactive than the quartz surface. One-step surface reaction models of ammonia for quartz/SUS304 surfaces are proposed, with which the reaction rates are estimated based on the experimental data. The inner surface of the SUS304 tubular reactor after the thermal decomposition experiments is examined by X-ray photoelectron spectroscopy. The formation of iron nitride on SUS304, which in turn facilitates ammonia thermal decomposition, reveals the positive feedback between ammonia decomposition and nitriding. Moreover, the present one-step surface reaction on stainless steel has been validated by measuring ammonia distributions in the preheat zone of NH₃/O₂/N₂ premixed flame impinging on a stainless steel plate through a two-photon absorption laser-induced fluorescence (TALIF) technique.     

饮用水处理中不同滤料除氨氮效果及需氧量研究

对比研究了活性无烟煤、活性炭、石英砂以及无烟煤4种滤料过滤去除饮用水中氨氮的效果及其与需氧量的关系。试验结果表明,当氨氮低于2 mg/L时,4种滤料过滤都能够有效去除氨氮,水中溶解氧逐渐耗尽;当氨氮浓度高于2 mg/L时,4种滤料的去除率均有所下降,但相比石英砂和无烟煤而言,活性无烟煤和活性炭过滤能够更有效地去除氨氮。纯氧曝气能够将溶解氧浓度提高到25 mg/L,从而大幅度改善4种滤料对氨氮的去除效果;活性无烟煤和活性炭过滤可将大部分氨氮转化为硝酸盐,但石英砂和无烟煤过滤则会发生亚硝酸盐积累现象。在活性无烟煤和活性炭过滤去除氨氮过程中,氨氮去除量与溶解氧的平均比例为1∶4.25,略低于理论值。这种定量关系对于生物过滤去除氨氮工艺的设计和运行具有指导意义。