溶剂蒸溶法对书写时间判定的初步尝试

本文针对圆珠笔字迹相对书写时间的鉴定,参照溶剂提取法,提出一种新的实验技术——溶剂蒸溶法.该方法以检样纸张作为展开板,以乙醇蒸气作为展开剂,通过测定圆珠笔油墨在纸张上的扩散程度来判定圆珠笔字迹的相对书写时间.

确定文件形成时间的几种新方法

本文概要介绍了判断书写时间技术在八、九十年代的重要进展，并介绍了几种确定文件形成时间的新方法：热分析法、Ｘ光电子能谱法、显微分光光度法、溶剂蒸溶法。

Liquid dehumidification-assisted evaporative supercooling method for ice slurry production

Due to the fact that the conventional ice slurry production system using supercooled water suffers from ice block and depends heavily on electric power,a novel ice slurry production system is proposed.The new system consists of two major parts：the evaporative supercooling process and the liquid dehumidification process.The classical diffusion-control equation is improved by introducing an impact factor into the simulation analysis in the evaporative supercooling process.Meanwhile,experiments are carried out by adopting the particle analyzer to detect the radii and the velocities of the droplets,and an infrared camera to examine the temperature profile of the physical process.It is found that the theoretical conclusion agrees well with the experimental results.Compared with the conventional system,the new system can alleviate the burden on electric power and raise efficiency.These improvements are essentially attributed to the reutilization of the inner waste heat generated from the system itself.

Solubility and phase diagrams of hydroxyl manganese chloride

In the course of the basic research on the ammonia-evaporation reaction of manganese monoxide （MnO）, hydroxyl manganese chloride （Mn2（OH）3Cl） was found. The solubility and phase diagrams of the hydroxyl manganese chloride were investigated. The aqueous thermostat and vibrating bed were used to determine the solubility of hydroxyl manganese chloride in water, ammonium chloride and manganese chloride system, and the phase diagrams of multicomponent system were drawn. The research results indicate that hydroxyl manganese chloride has been produced in laboratory and is in favor of the solid-liquid separation at high temperature.

Structure-Property Relationships and Models of Controlled Drug Delivery of Biodegradable Poly (D, L-lactic acid) Microspheres

An oil-in-water (O/W) solvent evaporation method was used to prepare biodegradable microspheresbased on poly(D,L-lactic acid) (PLA). Nifedipine, a hydrophobic drug, was chosen as a model molecule in the studyof drug entrapment and release. Effect of preparation conditions on the size, morphology, drug loading, and releaseprofiles of micropheres was investigated. Based on in vitro release experimental findings, a diffusion/dissolutionmodel was presented for quantitative description of the resulting release behaviors and drug release kinetics fromPLA microspheres analyzed. The mathematical models were used to predict the effect of microstructure on theresulting drug release. It provided an approach to determine the suitable structure parameters for microspheres toachieve desired drug release behaviors.

Ordered mesoporous Cu-ZnO-Al_2O_3 adsorbents for reactive adsorption desulfurization with enhanced sulfur saturation capacity

To enhance sulfur adsorption and reactive activity, ordered mesoporous Cu-ZnO-Al2O3 adsorbents were prepared by a novel one-pot evaporation-induced self-assembly strategy using P123 as a structure-directing agent and ethanol as the solvent for reactive adsorption desulfurization. The metal oxide precursor molecules around P123 micellized, and self-assembly simultaneously occurred during evaporation from an ethanol solution at 60 °C, leading to the formation of the p6 mm hexagonal symmetry mesoporous structure. Characterization results prove that the Cu-ZnO-Al2O3 adsorbents possess an ordered mesoporous structure with high thermal stability, large surface area（386–226 m2/g）, large pore volume（0.60–0.46 cm3/g）, and good dispersion of ZnO and Cu, which is beneficial for transforming S-compounds to ZnO. The sulfur saturation capacity of the ordered-mesoporous-structure Cu-ZnO-Al2O3 adsorbents is larger（49.4 mg/g） than that of the unordered mesoporous structure（13.5 mg/g）.

Enrichment of Semi-Volatile Organic Acids from Aqueous Solutions by Multiple-Effect Membrane Distillation

Multiple-effect membrane distillation （MEMD） process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation （AGMD） module with the function of internal heat recovery. Aqueous solutions of glyoxylic acid, glycolic acid, lactic acid, pyrnvic acid, malonic acid and glutaric acid were used as model feed. For a feed of 1% （mass fraction）, each acid could be enriched for 8--20 times, which depended on the surface tension of the concentrate. The operation performance of MEMD process was characterized by permeation flux J, performance ratio PR and acid rejection rate R. The effects of cold feed-in temperature, heated feed-in temperature, feed-in volumetric flow rate and feed-in concen- tration on MEMD performance were experimentally evaluated. Maximum values of J, PR and R were 4.8 L/（h-m2）, 9.84 and 99.93%, respectively. Moreover, MEMD process demonstrated a fairly good stability in a long-term experiment lasting for 30 d when aqueous solution of 4% （mass fraction） lactic acid was used as a feed.

Fouling evaluation on membrane distillation used for reducing solvent in polyphenol rich propolis extract

Membrane distillation(MD) has not been widely studied in the concentrate of phenolic rich solution in comparison to osmotic distillation. In this work, the potential of MD to reduce solvent in the polyphenol rich propolis extract was further investigated. Polyvinylidene fluoride(PVDF) membranes were engineered with the smaller pore size for the less hydrophobic surface in order to avoid wetting, allowing only the solvent vapor to be transferred from the warm feed into the cold permeate. All the membranes exhibited more than 95% rejection of phenolic and flavonoid compounds. Although the hydrophilic membranes exhibited less fouling, they displayed a lower flux than the hydrophobic membrane due to the hindrance in the wetted pores. The hydrophobic membrane was seriously fouled by the phenolic acid as shown in the Fourier transform infrared spectroscopy spectrum. Pore plugging occurred on these hydrophobic membranes as confirmed in the scanning electron microscope images.

Recovery of copper sulfate after treating As-containing wastewater by precipitation method

The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2：1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide. The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4：1 and copper arsenite was reduced by SO2 at 60℃ for 1 h. The white powder was gained after the arsenious acid solution was evaporated and cooled. Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air. The results show that red residue is Cu3（SO3）2·2H2O and the white powder is As2O3. The leaching rate of Cu reaches 99.00% when the leaching time is 1.5 h, molar ratio of H2SO4 to Cu is 1.70, H2SO4 concentration is 24% and the leaching temperature is 80 ℃. The direct recovery rate of copper sulfate is 79.11% and the content of CuSOa·5H2O is up to 98.33% in the product after evaporating and cooling the copper sulfate solution.

Gradient Step Method to Predict the Ozone Solubility in Water

In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7. The ozone concentration on gas phase is continually increased after the saturation is reached. The method proposed is faster than conventional method （isocratic method）. The solubility from the gradient method is compared with that values obtained from correlations founded in the literature.

Salt－Water Dynamics in Soils：IV．Changes of Ionic Composition in Soil Profiles During Water Evaporation and Infiltration

Through a simulation test carried out with soil columns (61.8 cm in diameter), the changes of ioniccomposition in soil profile during the processes of water evaporation and infiltration were studied. Underevaporation conditions, ions moving upward with fresh groundwater were mainly Cl￣-, SO, Ca￣(2+), andNa￣+. When the mineralized groundwater took part in the salt accumulation, the ionic composition in soilswas close to that in ground water supplemented. Under rainfall infiltration conditions, the salt-leaching roleoccurred mainly in the top soil. With the decrease of total salt content, NO and Cl￣- reduced rapidly, SOdecreased slowly, but HCO had a little change only. Among cations, Na￣+ and Ca￣(2+) contents lowered atthe same speed, and Mg￣(2+) decreased slowly.

Bioavailability Improvement of SLMs Based Erythromycin Ethyl Succinate using Stearic Acid-Myrj-52-based SLM＇s

Solid lipid microparticles of erythromycin ethyl succinate were prepared using solvent evaporation method to improve its bioavailability and efficacy. The solvent was allowed to evaporate after which the various entrapments were determined; the best entrapment was used in the in vivo studies to determine the bioavailability and efficacy. This study was done with albino mice. The best entrapment obtained was 83% with a loading capacity of 2.9% （Batch D） and was used in comparison with the unformulated drug to check for the in vivo efficacy. The results show higher efficacy with the formulated drug than with the pure drug both in vitro and in vivo. The in vitro test results were better despite that some enzymes which need to act on the solid lipid microparticles were not present in the in vitro assay and could lead to a reduction in the release of the drugs. In conclusion, there was improvement in efficacy, and hence bioavailability.

A New Procedure to Solve the Non-Linear Reaction-Diffusion Equation

1 INTRODUCTIONThe concentration distribution of reactant in porouscatalyst pellet not only is the basis of calculating theeffectiveness factor,but also has a great significancein investigating the reaction and mass transfer in thecatalyst pellet.In principle,the concentration distri-bution and the effectiveness factor of a catalyst pelletcan be obtained by solving the reaction-diffusion equation.However,most of the differential equations haveno analytical solution except for some simple cases.The previous investigators have made great efforts to calculate the effectiveness factors of catalysts.They first obtained asymptotic solutions of effective-ness factor in the cases of the Thiele modulus φ→Oand φ→oo by means of perturbation method,thensynthesized the information of the asymptotic solu-

Synthesis and characterization of polyfunctional aziridine/polyester microcapsules by multiple emulsion-solvent evaporation method

Polyfunctional aziridine/polyester microcapsules as control-release waterborne cross-linker were synthesized by multiple emulsion-solvent evaporation method. The results show that,a lower surface free energy with shell polyester is more favourable for the formation of microcapsules. Full encapsulating microcapsules are synthesized with the polyester with a surface free energy of 34.5 mJ/m2. Shell-to-core feeding mass ratio has a significant influence on the morphology and core content of the resulting microcapsules. Well defined spherical microcapsules with uniform shell thickness and core content at around 22% are produced at a shell-to-core mass ratio of 1:1. When 2.5% of colloid stabilizer is used,hollow spherical microcapsules are obtained. A high solvent evaporation rate results in wrinkling and porosity of the microcapsules,and an evaporation rate equivalent to solvent elimination in about 2 h provides a uniform rate of surface hardening. The characterization of the microcapsules by SEM and FTIR demonstrates that polyfunctional aziridine is encapsulated at the centre of the microcapsule. The microcapsules synthesized can be broken at a high shear rate.

Salt-Water Dynamics in Soils: II. Effect of Precipitation on Salt-Water Dynamics

Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensiometers. The results show that in the profile of whole silty loam soil, the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water; and in the profile with an intercalated bed of clay or with a thick upper layer of clay, the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil. In case of soil water being supplemented by precipitation, the evaporation of groundwater in the soil columns reduced, resulting in a great decline of salt accumulation from soil profile to surface soil. The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer. The direct infiltration depth of precipitation was less than 1 m in general, but water pressure transfer could go up to groundwater surface directly.

Separation of Lactic Acid from Diluted Solution by Hybrid Short Path Evaporation and Reactive Distillation

This work describes the separation and purification of lactic acid from diluted solution by HSPE （hybrid short path evaporation） and RD （reactive distillation） as coupled process. The results showed that it is possible to increase lactic acid concentration up to 4.7 times higher than the raw material concentration.

Optimized water vapor permeability of sodium alginate films using response surface methodology

The water vapor permeability （WVP） of films is important when developing pharmaceutical applications. Films are frequently used as coatings, and as such directly influence the quality of the medicine. The optimization of processing conditions for sodium alginate films was investigated using response surface methodology. Single-factor tests and Box-Behnken experimental design were employed. WVP was selected as the response variable, and the operating parameters for the single-factor tests were sodium alginate concentration, carboxymethyl cellulose （CMC） concentration and CaClz solution immersion time. The coefficient of determination （R2） was 0.97, indicating statistical significance. A minimal WVP of 0.389 8 g-mm/（m^2.h.kPa） was achieved under the optimum conditions. These were found to be a sodium alginate concentration, CMC concentration and CaCl2 solution immersion time at 8.04%, 0.13%, and 12 min, respectively. This provides a reference for potential applications in manufacturing film-coated hard capsule shells.

The preparation of high concentration alkaline silica sol with the method of vacuum distillation

High concentration alkaline silica sol has been prepared by the method of vacuum distillation, which shows that the stable and high concentration silica sol can be obtained under conditions as follows： 70℃, vacuum degree of 0.095Mpa and dispersant of SDS. The experimental results show that the sol particles size decreases with mass concentration first and then increase, sol viscosity increases with mass concentration during the concentrating process. The TEM method was used to study the dispersion behavior of sol particles, its result showed that sol particles dispersed more uniformly after concentrating process than before concentrating distinctly. It could be concluded that the disperse degree of alkaline silica sol could be increased by addition of right dispersant. The dispersion mechanism of dispersant in alkaline silica sol was also discussed.

Effects of curing age on compressive and tensile stress-strain behaviors of ecological high ductility cementitious composites

To obtain the design parameters of the structure made by ecological high ductility cementitious composites(Eco-HDCC),the effects of curing age on the compressive and tensile stress-strain relationships were studied.The reaction degree of fly ash,non-evaporable water content and the pH value in pore solution were calculated to reveal the mechanical property.The results indicate that as the curing age increases,the peak compressive strength,peak compressive strain and ultimate tensile strength of Eco-HDCC increase.However,the ultimate compressive strain and ultimate tensile strain of Eco-HDCC decrease with the increase in curing age.Besides,as the curing age increases,the reaction degree of fly ash and non-evaporable water content in Eco-HDCC increase,while the pH value in the pore solution of Eco-HDCC decreases.Finally,the simplified compressive and tensile stress-strain constitutive relationship models of Eco-HDCC with a curing age of 28 d were suggested for the structure design safety.

LSER-based modeling vapor pressures of(solvent+salt) systems by application of Xiang-Tan equation

The study deals with modeling the vapor pressures of(solvent + salt) systems depending on the linear solvation energy relation(LSER) principles. The LSER-based vapor pressure model clarifies the simultaneous impact of the vapor pressure of a pure solvent estimated by the Xiang-Tan equation, the solubility and solvatochromic parameters of the solvent and the physical properties of the ionic salt. It has been performed independently two structural forms of the generalized solvation model, i.e. the unified solvation model with the integrated properties(USMIP) containing nine physical descriptors and the reduced property-basis solvation model. The vapor pressure data of fourteen(solvent + salt) systems have been processed to analyze statistically the reliability of existing models in terms of a log-ratio objective function. The proposed vapor pressure approaches reproduce the observed performance relatively accurately, yielding the overall design factors of 1.0643 and1.0702 for the integrated property-basis and reduced property-basis solvation models.