复方降脂保肝速溶颗粒的成型工艺研究

目的:优化复方降脂保肝速溶颗粒的成型工艺。方法:分别以吸湿率、成型率、溶化率、崩解时限为考察指标,采用多指标综合评分的方法,通过单因素考察和正交试验分别对稀释剂、崩解剂、增溶剂的种类和用量进行优化。结果:优化的成型工艺为干膏粉与稀释剂乳糖的配比为2∶3,增溶剂十二烷基硫酸钠用量为2%,崩解剂交联羧甲基纤维素钠用量为1%。验证试验结果显示,优化后所制颗粒溶化率为97.3%,成型率为89.2%,崩解时限为36 s,吸湿率为10.3%,颗粒休止角为33.3°,有效成分水飞蓟宾含量为1.03 mg/g(RSD≤3.60%,n=3)。结论:该成型工艺合理、可行、稳定,可为该制剂的生产提供科学依据。

小儿补肾固表颗粒成型工艺研究

目的优选小儿补肾固表颗粒最佳成型工艺。方法将干膏粉与6种辅料分别按同一比例湿法制粒,以颗粒吸湿率、成型率、溶化率为指标,优选辅料种类。根据干膏得率、一日服用量和口感,确定辅料用量。按相应方法测定3批成品的水分、休止角、堆密度和临界相对湿度。结果小儿补肾固表颗粒最佳成型工艺为:按干膏粉与蔗糖粉1∶0. 68混匀,以88%(ml/ml)乙醇搅拌,用一号筛制粒,70℃干燥,即得。测得3批成品水分分别为4. 7%、3. 3%、3. 6%,休止角分别为36. 9°、35. 0°、36. 3°,堆密度分别为0. 52、0. 53、0. 52 g/ml、临界相对湿度分别为67. 0%、68. 0%、68. 0%。结论优选的小儿补肾固表颗粒成型工艺简便可行,为其中试生产和新制剂报批提供依据。

猪皮不溶性胶原的特性研究

探讨了猪皮不溶性胶原的可溶化率和可溶化物的结构,分别比较了猪皮和牛皮两种试样。由于动物的年龄不同,胶原的性质变化显著,不溶性胶原在pH7.5、60℃水中加热时,4个月龄猪皮和幼牛皮在1h可溶化60%,22h可溶化90%,但1年龄猪皮和成牛皮可溶化率减少30%～40%。用20℃2mol/L氯化钙或45℃1mol/L尿素使其溶化时的可溶化率也有类似的现象。不溶性胶原用胃蛋白酶处理后,由于动物年龄差异引起的可溶化率差别明显减小,猪皮80%以上,牛皮60%以上可溶化。这种可溶化物的SepHarosecl-4B凝胶过滤图谱与胃蛋白酶未处理区比较,显示α成分的比例显著增加,而且猪皮的这种变化较牛皮更大。

复方芪丹颗粒成型工艺研究

目的:研究复方芪丹颗粒的最佳成型工艺。方法:采用单因素实验,以颗粒的成型率、吸湿率和溶化率为评价指标,筛选出其处方中加入辅料的种类、配比及最佳的成型工艺条件。结果:确定最佳成型工艺条件为:药粉和乳糖1∶1.5配比,用5%PVP的90%乙醇液为粘合剂制软材,14目筛制粒,50℃干燥,整粒。结论:优选得到的工艺稳定可行。

Temperature variation and solution treatment of high strength AA7050

Temperature variation and solution treatment of high strength aluminum alloy were investigated with temperature data acquisition system,microstructural observation,mechanical properties test,electrical conductivity measurement and differential scanning calorimetry（DSC） analysis.Specimens with two dimensions were employed in the experiment.The results indicate that the specimens with large size undergo low solution temperature and short time,giving rise to the reduction of hardening precipitates.The optimized solution treatments for specimens with dimensions of 25 mm×25 mm×2.5 mm and 70 mm×60 mm×20 mm are（480 ℃,30 min） and（480 ℃,90 min）,respectively.The densities of GP zones and η＇ phases of the small specimen are higher than those of the large specimen,which is consistent with the properties of the alloys.

Chemical dissolution resistance of anodic oxide layers formed on aluminum

Chemically resistant anodic oxide layers were formed on pure aluminum substrates in oxalic acid-sulphuric acid bath.Acid dissolution tests of the obtained anodic layers were achieved in accordance with the ASTM B 680-80 specifications：35mL/L 85% H3PO4＋20g/L CrO3 at 38℃.Influence of oxalic acid concentration,bath temperature and anodic current density on dissolution rate and coating ratio was examined,when the sulphuric acid concentration was maintained at 160g/L.It was found that chemically resistant and compact oxide layers were produced under low operational temperature （5℃） and high current densities （3A/dm^2）.A beneficial effect was observed concerning the addition of oxalic acid （18g/L）.The morphology and the composition of the anodic oxide layer were examined by scanning electron microscopy （SEM）,atomic force microscopy （AFM） and glow-discharge optical emission spectroscopy （GDOES）.

Conversion of coal gangue into alumina, tobermorite and TiO_2-rich material

A large amount of coal gangue from coal mining and processing is regarded as waste and usually stockpiled directly. In order to recycle the valuable elements from the coal gangue, an integrated process is proposed. The process consists of three steps: 1concentrating alumina from the coal gangue via activation roasting followed by alkali leaching of Si O2 which produces alumina concentrate for alumina extraction by the Bayer process; 2) synthesizing tobermorite whiskers from the filtrated alkali liquo containing silicate via a hydrothermal method and reusing excess caustic liquor; and 3) enriching titanium component from the Baye process residue by sulfuric acid leaching. Alumina concentrate with 69.5% Al_2O_3 and mass ratio of alumina to silica(A/S) of 5.9pure 1.1 nm tobermorite whisker and TiO_2-rich material containing 33% TiO_2 are produced, respectively, with the optimal parameters Besides, the actual alumina digestion ratio of alumina concentrate reaches 80.4% at 270 oC for 40 min in the Bayer process.

Pressure leaching of bismuth sulfide concentrate containing molybdenum and tungsten in alkaline solution

The leaching results of bismuth sulfide concentrate containing molybdenum and tungsten in air-H2O2-NaOH system, pressure-O2-Na2CO3 system and pressure-O2-NaOH system were investigated. The results show that the extraction of molybdenum, tungsten and sulfur goes up with the increase of NaOH concentration, oxygen partial pressure and reaction time. The extraction of molybdenum and tungsten also rises up with temperature, but the leaching ratio of sulfur increases initially to a peak of 98% at 150℃ and then decreases with the increase of temperature. Under the optimal conditions, the extraction of molybdenum, tungsten and sulfur is more than 95.6%, 93.8% and 96.0%, respectively, and the main phases of residue are Bi2O3 and Fe2O3. Therefore, the method of pressure leaching in alkaline solution is provided as an effective separation of molybdenum, tungsten and sulfur from bismuth and a beneficial pretreatment for consequent process.

Dissolution rate determination of alumina in molten cryolite-based aluminum electrolyte

Determination of dissolution rate of alumina is one of the classical problems in aluminum electrolysis. A novel method which can measure the dissolution rate of alumina was presented. Effect of factors on dissolution rate of alumina was studied intuitively and roundly using transparent quartz electrobath and image analysis techniques. Images about dissolution process of alumina were taken at an interval of fixed time from transparent quartz electrobath of double rooms. Gabor wavelet transforms were used for extracting and describing the texture features of each image. After subsampling several times, the dissolution rate of alumina was computed using these texture features in local neighborhood of samples. Regression equation of the dissolution rate of alumina was obtained using these dissolution rates. Experiments show that the regression equation of the dissolution rate of alumina is y=-0.000 5x^3＋0.024 0x^2-0.287 3x＋ 1.276 7 for Na3AIF6-AIF3-Al2O3-CaF2-LiF- MgF2 system at 920 ℃.

Alkaline extraction characteristics of steelmaking slag batch in NH_4Cl solution under environmental pressure

In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective extraction yield and conversion ratio was systemically focused on. The results show that alkaline earth metal conversion ratio is changed with leaching time and NH4CI concentration by first order exponential, and the maximum conversion for calcium keeps about 68% at 120 min in 0.4 mol/L NH4C1 solution, while leaching temperature and particle size have a linear effect on conversion ratio. Selective extraction yield of calcium is more than 93%, and the value of Mg is less than 5%. Apparent layer bands of silicon and calcium appear in the surface area through morphology detection of slag after leaching, and the case for 38-75 μm slag batch is more obvious than 75 150 μm slag and slag with larger particle size when leaching in 0.4 mol/L NH4Cl solution for 90 rain at 60 ℃.

Effect of ferrite content on dissolution kinetics of gibbsitic bauxite under atmospheric pressure in NaOH solution

The dissolution property of high-ferrite gibbsitic bauxite and the effect of ferrite content on the dissolution kinetics of gibbsitic bauxites in sodium hydroxide solution under atmospheric pressure from 50 to 90 °C were systematically investigated.The dissolution property of high-ferrite gibbsitic bauxite is increased by increasing the dissolution temperature and the Na OH concentration or decreasing the particle size of bauxite,which is easy to dissolve under atmospheric pressure.The kinetic equations of gibbsitic bauxites with different ferrite contents during the dissolution process at different temperatures for different times were established,and the corresponding activation energies were calculated.The ferrite in the gibbsitic bauxite reduces the dissolution speed and increases the activation energy of dissolution,the diffusion process of which is the rate-controlling step.

Silica-alumina molar ratio and some factors effect on the synthesis of zeolites from fly ash

In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, which is hydrothermally treated at about 104 ℃, and the liquid/solid ratio was controlled at 6：1. In order to control Si/Al molar ratio, SiO2 or Al2O3 powers were added to the fly ash. The results of XRD and SEM show that the alkali melted can activate fly ash and eliminate its quartz and mullite, along with the improvement of Si/Al molar ratio and alkalinity. In addition, zeolite Na-A changes into sodalite gradually, and nepheline is the synthesized intermediate product. Those results were discussed on the basis of a formation mechanism of zeolite from fly ash.

Supercritical Carbon Dioxide Extraction of Andrographolide from Andrographis paniculata： Effect of the Solvent Flow Rate, Pressure, and Temperature

Andrographis paniculata Nees has been extensively used for traditional medicine and help against fever dysentery, diarrhoea, inflammation, and sore throat. In this study, andrographolide, the main component of this plant was extracted from the leaves of A. paniculata using supercritical carbon dioxide. The operating pressures were varied from 7.50 to 20MPa, the temperatures were varied from 30℃ to 60℃, and the flow rates were varied from 0.5 to 4ml.min^-1. The best extraction condition occurred at 10MPa, 40℃, and a flow rate of 2ml.min^-1 for a 3g sample of A. paniculata ground-dried leaves. The measured extraction rate was found to be about 0.0174g of andrographolide per gram of andrographolide present in the leaves per hour of operation. The future studies must focus on the interaction between the various operating parameters such as temperature, pressure, and flow rate of supercritical carbon dioxide.

Permeability variation characteristics of coal after injecting carbon dioxide into a coal seam

A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after injection of carbon dioxide into the coal seam. Sihe, Yuwu, and Changcun mines were used as research sites. Scanning electron microscopy and permeability instruments were used to measure coal properties such as permeability and surface structure of the coal samples at different pH values of carbon dioxide solution and over different timescales. The results show that the reaction between minerals in coal and carbonate solution exhibit positive and negative aspects of permeability-the dissolution reaction between carbonate minerals in coal and acid solution improves the conductivity of coal whilst, on the other hand, the clay minerals in the coal （mainly including montmorillonite, illite and kaolinite） exhibit expansion as a result of ion exchange with the H~ in acid solution, which has a negative effect on the per- meability of the coal. The permeability of coal samples increased at first and then decreased with immer- sion time, and when the soaking time is 2-3 months the permeability of the coal reached a maximum. In general, for coals with permeabilities less than 0.2 mD or greater than 2 roD, the effect on the permeabil- ity is low： when the permeability of the coal is in the range 0.2-2 mD, the effect on the permeability is highest. Research into permeability change characteristics can provide a theoretical basis for carbon diox- ide injection under different reservoir permeability conditions and subsequent drainage.

Absorption Rate of CO_2 into MDEA Aqueous Solution Blended with Piperazine and Diethanolanline

Absorption rate of CO2 into aqueous solution of N-methyldiethanolamine (MDEA) blended with diethanolamine (DEA) and piperazine (PZ) was studied and a kinetic model was established. It is shown that homogeneous activation mechanism could explain this absorption process. The absorption rate coefficients of carbon dioxide into MDEA aqueous solution blended with DEA, PZ or DEA+PZ were compared with each other. The results demonstrated that the different activation effect of DEA, PZ and DEA+PZ on the carbon dioxide absorption comes from the difference in CO2 combination rate, transport of PZ and DEA to MDEA and the regeneration rate of PZ and DEA.

Kinetics of nickel leaching from roasting-dissolving residue of spent catalyst with sulfuric acid

Sulfuric acid leaching process was applied to extract nickel from roasting-dissolving residue of a spent catalyst, the effect of different parameters on nickel extraction was investigated by leaching experiments, and the leaching kinetics of nickel was analyzed. The experimental results indicate that the effects of particle size and sulfuric acid concentration on the nickel extraction are remarkable; the effect of reaction temperature is mild; while the effect of stirring speed in the range of 400-1 200 r/min is negligible. Decreasing particle size or increasing sulfuric acid concentration and reaction temperature, the nickel extraction efficiency is improved. 93.5% of nickel in residue is extracted under suitable leaching conditions, including particle size （0.074-0.100） mm, sulfuric acid concentration 30% （mass fraction）, temperature 80 ~C, reaction time 180 min, mass ratio of liquid to solid 10 and stirring speed 800 r/min. The leaching kinetics analyses shows that the reaction rate of leaching process is controlled by diffusion through the product layer, and the calculated activation energy of 15.8 kJ/mol is characteristic for a diffusion controlled process.

Preparation and characterization of new sealing glasses based on Li_(2)O-NiO-P_(2)O_(5) system

A series of glass are synthesized via a melt quenching technique based on the Li_(2)O-Ni O-P_(2)O_(5) system.The concentration of nickel oxide varies from 5%to 15%in molar fraction.XRD pattern verifies the amorphous nature of prepared glass samples with 5%,and 10%nickel oxide in molar fraction.While Li_(3)P and Ni_(2)P_(4)O_(12)phases are precipitated with a high nickel content up to 15%in molar fraction.As nickel is substituted for lithium,a systematic increase in glass transition temperature(T_(g))and glass softening temperatures(T_(s))is observed.This is greatly related to the increased structure,coherence in the glass network.Structural investigation showed that Ni_(2+) spectra are present in both octahedral and tetrahedral sites.Physical properties such as glass density((2.38±0.1)-(2.46±0.1)g/cm^(3)),and molar volume((42.28±0.1)-(39.15±0.1)cm^(3)/mol)are examined.The NiO/Li_(2)O replacements led to a decrease in the dissolution rate of the resultant amorphous materials from 1.53×10^(-5)to 3.20×10^(-6)g/(cm^(2)·min).Thermal expansion coefficients CTE of the glasses are diverse from 157×10^(-7) to 96×10^(-7)℃^(-1) over the temperature range of 25-250℃.The prepared glasses are expected to be useful as a low-temperature sealing material.

Effects of Surfactant on Zinc Recovery by Solvent Extraction during Leaching in HCl-FeCl_3 Solution

The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aqueous FeCl_3-HCl-tetrachloroethylene system.Through the measurements of surface tension and viscosity of thesphalerite Slurry modified with different surfactants, it isconcluded that sodium dodecyl sulfonate in the concentration rang Of0.05 to 0.2 g·L^-1 can improve the viscosity of sphalerite slurry inthe water, decrease the surface tension of Leaching solution, preventthe aggregation of ore particles, and give very high zinc extraction.

Impacts of Secondary Aerosols on a Persistent Fog Event in Northern China

The chemistry version of the Weather Re- search and Forecasting model （WRF/Chem） was coupled with the anthropogenic emission inventory of David Streets to investigate the impacts of secondary aerosols on a persistent fog event from 25 to 26 October 2007, in Northem China. The spatial distribution of the simulated fog is consistent with satellite observations, and the time-height distributions of the simulated boundary layer where the fog formed are also in good agreement with these observations. The sensitivity studies show that the secondary aerosols of SO4, NO3, and NH4 formed from gaseous precursors of SO2, NOx, and NH3 had substantial impacts on the formation processes and microphysical structure of the fog event. The decrease of the secondary aerosols obviously reduced the liquid water path and column droplet number concentration of the fog below the 1-km layer, and the corresponding area-averaged liquid water path and droplet number concentration of the fog decreased by 43% and 79%, respectively. The concentra- tions of NOx and NO3 were found to be extremely high in this case. The concentration of interstitial aerosol NO3 was much higher than the SO4 and NH4, but the concentration of SO4 was highest in the cloud-borne aerosols. The average activation ratios for SO4, NO3, and NH4 were 34%, 31%, and 30%, respectively, and the maximum ra- tios reached 62%, 86%, and 55% during the fog episode.