提高熔融石英匣钵质量的研究

从原料配方、细度、颗粒级配及装烧等工艺入手．研究了提高熔融石英匣钵质量的途径。结果表明：通过提高巨钵中熔融石英含量，增加租颗粒比例．采用还原焰隧道窑反装匣体带瓷坯一次烧成工艺、可使其使用寿命由原来的10-15次提高到40-50次。     

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.      

Wire electrochemical discharge machining (WECDM) of quartz glass with titrated electrolyte flow

Electrochemical discharge machining (ECDM) is a promising technique with great potential for application to machining non-conductive brittle materials. In this study, wire electrochemical discharge machining (WECDM) was applied to processing quartz glass with electrolyte supplied in titrated flow. During WECDM, under surface tension and gravity, the electrolyte flows down in droplets, over the graphite auxiliary electrode and brass wire, producing oxygen and hydrogen bubbles, respectively. The fluid inside the droplet forms eddies on the two sides of the quartz, removing chips and electrolysis resultants. Rapid replenishment of electrolyte to constant concentration can ensure even distribution of current density and a stable insulation gas film can thus be formed. Experimental results show that quartz glass processed by WECDM with titrated electrolyte flow yielded long straight slits of small mean width. In addition, with the electrolyte supplied in droplets, less electrolyte is consumed in the process. The proposed droplet titration approach to WECDM of quartz glass incurs less cost and pollution, making it both cost effective and environmental friendly.     

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.     

Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

The effects of a dilute (ionic strength = 5 × 10⁻³ M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 μg/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ∼3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.     

绿泥石膜对胡尖山地区长6储层孔隙的影响

绿泥石膜是鄂尔多斯盆地胡尖山地区延长组长6油层组储集岩中最常见的粘土矿物之一。根据铸体薄片和X衍射分析得出：绿泥石膜形成于早成岩时期,该层段孔隙度随着绿泥石膜含量的增加而增大,对该地区储层孔隙度具有建设性作用。这种作用主要体现在抑制石英次生加大、增加颗粒间抗压实强度、抑制压溶以及挤占碳酸盐岩胶结物生长空间三个方面。     

The influence of oxidation reduction potential and water treatment processes on quartz lamp sleeve fouling in ultraviolet disinfection reactors

Ultraviolet (UV) disinfection systems are incorporated into drinking water production facilities because of their broad-spectrum antimicrobial capabilities, and the minimal disinfection by-product formation that generally accompanies their use. Selection of an optimal location for a UV system within a drinking water treatment facility depends on many factors; a potentially important consideration is the effect of system location on operation and maintenance issues, including the potential for fouling of quartz surfaces. To examine the effect of system location on fouling, experiments were conducted at a groundwater treatment facility, wherein aeration, chlorination, and sand filtration were applied sequentially for treatment. In this facility, access to the water stream was available prior to and following each of the treatment steps. Therefore, it was possible to examine the effects of each of these unit operations on fouling dynamics within a UV system. Results indicated zero-order formation kinetics for the fouling reactions at all locations. Increases in oxidation reduction potential, caused by water treatment steps such as aeration and chlorination, increased the rate of sleeve fouling and the rate of irradiance loss within the reactor. Analysis of metals in the sleeve foulant showed that calcium and iron predominate, and relative comparisons of foulant composition to water chemistry highlighted a high affinity for incorporation into the foulant matrix for both iron and manganese, particularly after oxidizing treatment steps. Fouling behavior was observed to be in qualitative agreement with representations of the degree of saturation, relative to the metal:ligand combinations that are believed to comprise a large fraction of the foulants that accumulate on the surfaces of quartz jackets in UV systems used to treat water.     

某复杂多金属矿低尾化综合利用技术研究

矿产资源在选矿过程中产生的大量尾矿,既是资源的浪费,又是环境污染源。因此,开展低尾化乃至无尾化综合利用研究,最大程度提高资源利用率是未来矿产资源开发、利用的必由之路。本文在研究国内某复杂多金属矿综合利用时,通过分析所含矿物的基因属性、赋存状态以及嵌布关系,先后进行了钽铌精矿、方解石精矿、锂精矿、云母精矿、长石精矿、石英精矿共计6个产品的选别回收,实现了除少量泥质、铁屑之外的全产品、无尾化综合利用技术路线,可为以后同类型复杂多金属矿的综合回收提供思路借鉴。     

Kinetics of photocatalytic reduction of Pb(II) on nanocrystalline TiO2 coatings: A quartz crystal microbalance study

Pb(II) is a highly toxic substance, exposure to which can cause various diseases. To better understand the application of TiO₂ as a photocatalyst for removing Pb(II) from wastewater, quartz crystal microbalance (QCM) technique was employed to in situ investigate the reduction behavior of Pb(II) on nanocrystalline TiO₂ coatings under N₂. The processes of Pb(II) reduction at various concentrations of HCOOH and in the presence of different organic additives were monitored, and the corresponding kinetics was proposed. The obtained results showed that the kinetics of Pb(II) reduction on TiO₂ coatings was closely related to the organic additives. The HCOOH showed a higher efficiency for Pb(II) reduction in comparison with other organic additives, and the reduction-rate constant reached 0.54 × 10⁻³ s⁻¹ which was two times higher than that exhibited in the presence of C₂H₅OH. QCM measurement provides an useful method for monitoring the reduction process of Pb(II) on TiO₂ coatings.