磷石膏预处理pH值对其制备免烧胶凝材料的影响

为探究磷石膏预处理pH值对磷石膏及磷石膏制备免烧胶凝材料的影响,明确免烧胶凝材料抗压强度与磷石膏预处理pH值的关系,以自制的激发剂对磷石膏进行预处理,将预处理后的磷石膏与水泥(干料质量比为4∶1)混合制备免烧胶凝材料。结果表明:在100 g磷石膏中加入200 mL激发剂,预处理24 h后,磷石膏晶体出现了择优取向;随着预处理pH值的增大,磷石膏的微观结构越有利于后续免烧胶凝材料强度的提高。综合考虑,选择最佳预处理pH值为9,此时所制得的免烧胶凝材料的微观结构最致密,几乎所有的磷石膏颗粒都被水泥的水化产物包裹,其7 d、28 d和浸水后的抗压强度均满足普通烧结砖MU10强度要求。

HPLC测定烧烫伤凝胶中蒽醌类成分的含量

目的:建立烧烫伤凝胶(黄连,黄柏,大黄等)中5种蒽醌成分的含量测定方法。方法:采用HPLC法,伊利特-C18柱,以甲醇-1%磷酸溶液(80∶20),流速:1.0 mL/m in,检测波长:430 nm。结果:该方法使样品中5种蒽醌类成分得到良好的分离,且线性关系良好。大黄素、大黄酚、大黄酸、大黄素甲醚、芦荟大黄素的平均回收率及RSD分别为98.0%,1.3%;97.1%,1.8%;97.8%,1.5%;97.4%,1.7%;96.7%,1.2%。结论:本法专属性强,灵敏度高,重现性好,适于该制剂中蒽醌类成分的分离与测定。

中药烧烫伤凝胶的研制及质量控制

目的制备中药烧烫伤凝胶,并建立质量控制方法。方法以1．5％卡波姆940作为凝胶基质, 以三乙醇胺为中和剂,采用高效液相色谱法测定盐酸小檗碱含量,并进行了稳定性考察和皮肤 刺激性实验。结果盐酸小檗碱含量测定线性范围为26．64-133．20μg／mL,r=0．9997,平均回收率 为96．77％,RSD为1．6％,制剂稳定性良好,对皮肤无刺激作用。结论本制剂制备工艺简便,性质稳定, 质量可控,适用于医院制剂。

中药烧烫伤凝胶质量标准的色谱研究

建立烧烫伤凝胶的色谱（TLC和HPLC）质量标准．采用薄层色谱法（TLC）对烧烫伤凝胶中黄连、黄柏、大黄、黄芩进行了定性鉴别，并用高效液相色谱法（HPLC）对烧烫伤凝胶中有效成分盐酸小檗碱进行含量测定．盐酸小檗碱含量测定的线性范围为26．64-133．20μg／mL，r=0．9997，平均回收率为96.77％，RSD为1．6％．定性鉴别和含量测定方法简便可靠，重复性好，可有效的控制烧烫伤凝胶的质量．

注射成型塑胶件常见问题分析

主要介绍家电类产品中塑胶件的常见表面缺陷,以便在设计阶段防止缺陷,缩短开发周期,节约开发成本。

Synthesis and Conductivity of Oxyapatite Ionic Conductor La10-xVx（SiO4）6O3＋x

Apatite-lanthanum silicate has attracted considerable interest in recent years due to its high oxide ion conductivity.In this paper,V-doped samples La10-xVx(SiO4) 6O3+x(0≤x≤1.5) were prepared by sol-gel method and the influences of V-dopant content on calcining temperature and conductivity were reported.The samples were characterized by thermal analysis(TG-DSC) ,X-ray diffraction(XRD) and scanning electron micrograph(SEM) . The apatite was obtained at 800°C,a relatively low temperature in comparison to 1500°C with the conventional solid-state method.The ceramic pellets sintered at 1200°C for 5 h showed a higher relative density than La9.33Si6O26 pellets sintered at 1400°C for 20 h.The conductivities of samples were measured by electrochemical impedance spectroscopy.The conductivity was improved with the increase of V-dopant content on La site.

Sol-gel auto-combustion synthesis of K_xNa_(1-x)NbO_3 nanopowders and ceramics: Dielectric and piezoelectric properties

The KxNa1-xNbO3 nanopowders with cubic-like morphology and an average size of about 50 nm were synthesized by sol-gel auto-combustion method.And then,the ceramics were prepared and the phase transition,microstructure and electrical properties of the KxNa1-xNbO3 ceramics were investigated.Pure perovskite phases of the KxNa1-xNbO3 ceramics were confirmed by XRD patterns and the K0.50Na0.50NbO3 ceramics show the coexistence of orthorhombic and monoclinic structures.SEM micrographs show that all samples have bimodal grain size distributions and the number of the small grains decrease with increasing K+content in the bimodal grain size distribution system.The K0.50Na0.50NbO3 ceramics with the uniform grain size and the maximum density show excellent electrical properties withεr=467.40,tanδ=0.020,d33=128 pC/N and kp=0.32 at the room temperature,demonstrating that the properties of the K0.50Na0.50NbO3 powers prepared by sol-gel auto-combustion are excellent and the ceramics are promising lead-free piezoelectric materials.

Preparation and Application of the Sol–Gel Combustion Synthesis-Made CaO/CaZrO_3 Sorbent for Cyclic CO_2 Capture Through the Severe Calcination Condition

Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis （SGCS） method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% （by volume） C02. The mass ratio of CaO to CaZr03 as 8：2 （designated as CasZr2） was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area （SA） ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.

Grain Growth Kinetics of BaTiO3 Nanocrystals During Calcining Process

BaTiO3 nanocrystals were synthesized by sol-gel method using barium acetate （Ba（CH3COO2） and tetrabutyl titanate （Ti（OC4H9）4） as raw materials. Xerogel precursors and products were characterized by means of thermogravimetric/differential scanning calorimetry （TG/DSC）, X-ray diffraction （XRD） and transmission electron microscope （TEM）. The influence of the calcination temperature and duration on the lattice constant, the lattice distortion, and the grain size of BaTiO3 nanocrystals was discussed based on the XRD results. The grain growth kinetics of BaTiO3 nanocrystals during the calcination process were simulated with a conventional grain growth model which only takes into account diffusion, and an isothermal model proposed by Qu and Song, which takes into account both diffusion and surface reactions. Using these models, the pre-exponential factor and the activation energy of the rate constant were estimated. The simulation results indicate that the isothermal model is superior to the conventional one in describing the grain growth process, implying that both diffusion and surface reactions play important roles in the grain growth process.

Structural and Magnetic Properties of Chemically Synthesized Pd-Modified NiFe2O4 Nanoparticles

Magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. Magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe2O4.

Application of FTIR to analysis chemical structure of soot aerosol emitted from lump-coal combustion in fixed bed

The objectives of this work are to study the primary chemical structure of soot aerosol derived from lump-coal combustion in different experimental conditions in fixed bed. A laboratory-scale movable fixed bed, water-cooled soot aerosol collection system, and electric reactor have been designed and used in the process. Three kinds of coals, sized at 3-5 ram, have been heated in the experiments. Fourier Transform Infrared Spectroscopy （FTlR） has been employed to test functional groups of soot aerosol samples. Infrared spectra from 400 to 4000 cm^ -1 and semiquantitative analysis have been employed. The results of experiments show that contents of hydrogen-bonded are increased, contents of unsaturated hydrocarbons are increased, and contents of aromatic hydrocarbons are decreased with temperature increase; contents of hydrogen-bonded and unsaturated hydrocarbons are increased first and decreased late, and contents of aromatic hydrocarbons are decreased with gases residence time extension; the contents of hydrogen bonded and unsaturated hydrocarbons derived from soot aerosol samples are higher than those from original coal samples in lower-volatile coals, and the contents of aromatic hydrocarbons derived from soot aerosol samples are lower than those from original coals; and contents of hydrogen-bonded are decreased, contents of unsaturated hydrocarbons are increased, and contents of aromatic hydrocarbons are decreased with a increase.

Effects of transport on aerosols over the eastern slope of the Tibetan Plateau:synergistic contribution of Southeast Asia and the Sichuan Basin

The aerosol optical properties and chemical components of PM2.1(particulate matter with a diameter of 2.1μm or less)were investigated at Mount Gongga on the eastern slope of the Tibetan Plateau from April 2012 to December 2014.The annual mean aerosol optical depth(AOD)was 0.35±0.23,and the?ngstr?m exponent was 1.0±0.38.The AOD exhibited higher values in summer and winter,but lower values in spring and autumn.Dividing the observational periods into dry and wet seasons,the authors found that the concentrations of K^+,elemental carbon,secondary inorganic aerosols,and primary and secondary organic carbon in the dry(wet)season were 0.29(0.21),0.88(0.60),7.4(4.5),7.5(5.1),and 3.9(12)μg m?3,respectively.Combined with trajectory analysis,the authors found that higher concentrations of K^+,elemental carbon,and primary organic carbon indicated the effects of biomass burning from Southeast Asia during the dry season.However,the oxidation of volatile organic compounds was the main source of aerosols during the wet season,which originated from the Sichuan Basin.

Optimization of the Doped Ablator Layers for the Plastic Ignition Capsule

The paper investigates theoretically the optimization of the doped ablator layers for the plastic ignition capsule. The high-resolved one-dimensional implosion simulations show that the inner pure CFI layer of the Si-doped design is excessively preheated by the hard x-ray, leading to the unstable ablator-fuel interface compared to the Ge-doped capsule. This is because that the Si K-shell absorption edge （1.8 keV） is higher than the Ge L-edge （1.3 keV）, and Si dopant makes more hard x-ray penetrate through the doped ablator layers to preheat the inner pure CH layer. So an optimization of the doped ablator layers （called ＂Si/Ge capsule＂） is performed： an Si-doped CH layer is placed next to the outer pure CH layer to keep the high implosion velocity; next to the Si-doped layer is a thin Ge-doped layer, in order to absorb the hard x-ray and protect the inner undoped CH-layer from excessively preheating. The simulations show that the Si/Ge capsule can effectively improve hydrodynamic stability at the ablator-fuel interface while keeping the high implosion velocity.

Effect of electrolyzed oxidizing water and hydrocolloid occlusive dressings on excised burn-wounds in rats

Objective: To study the efficacy of electrolyzed oxidizing water ( EOW ) and hydrocolloid occlusive dressings in the acceleration of epithelialization in excised burn-wounds in rats.Methods: Each of the anesthetized Sprague-Dawley rats (n = 28) was subjected to a third-degree burn that covered approximately 10% of the total body surface area. Rats were assigned into four groups: Group Ⅰ ( no irrigation), Group Ⅱ (irrigation with physiologic saline), Group Ⅲ ( irrigation with EOW ) and Group Ⅳ ( hydrocolloid occlusive dressing after EOW irrigation). Wounds were observed macroscopically until complete epithelialization was present, then the epithelialized wounds were examined microscopically. Results: Healing of the burn wounds was the fastest in Group Ⅳ treated with hydrocolloid occlusive dressing together with EOW. Although extensive regenerative epidermis was seen in each Group, the proliferations of lymphocytes and macrophages associated with dense collagen deposition were more extensive in Group Ⅱ, Ⅲ and IV than in Group Ⅰ. These findings were particularly evident in Group Ⅲ and Ⅳ.Conclusions: Wound Healing may be accelerated by applying a hydrocolloid occlusive dressing on burn surfaces after they are cleaned with EOW.