Preparation and Characterization of CeO_2 Superfine Powder

The CeO_2 superfine powder was prepared by the co-precipitation method, using the industrial grade Ce_2(CO_3)_3 and NH_4HCO_3 as starting material and precipitating reagent, respectively. The precipitated precursons and the calcinated products were characterized by the thermogravimetric analysis/thermoanalysis (TGA/DTA), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The results show that using NH_4HCO_3 as a precipitating reagent, the precipitate decomposed full as it was heated to 360 ℃. The CeO_2 superfine powder formed by calcinating the precipitate belongs to a cubic CaF_2-type structure and has the first mean particle diameter 140 nm and second mean particle diameter 630 nm. The CeO_2 powder particles aggregate and grow with raising the calcination temperature.

Effect of Superfine Grinding on Physicochemical Properties, Antioxidant Activity and Phenolic Content of Red Rice ( <i>Oryza sativa</i>L.)

Red rice gains popularity as a functional crop owing to its high polyphenols content and antioxidant activity. However, active components are discarded in common milling. Superfine ground technology was employed in this paper. To evaluate the influence of superfine ground processing on the physicochemical properties and functional effect of red rice (Oryza sativa L.), four powders with the size of 156.74 μm, 69.53 μm, 26.35 μm, and 10.68 μm were prepared by superfine grinding technology in this paper. Results showed that the size was smaller for red rice powders, greater for the bulk density (from 0.624 g/ml to 0.745 g/ml), and smaller for the angle of repose (from 74.67&deg;to 61.41&deg;) and slide (from 38.99&deg;to 26.42&deg;). The values of water solubility index, water holding capacity and enzymatic digestibility by α-amylase significantly increased with the decreasing particle size (P < 0.05). In addition, antioxidant activity and phenolic content were enhanced by superfine ground. These results indicated that superfine ground would improve the physicochemical and functional properties of red rice, which was helpful to promote the overall quality and healthy effect of foods containing red rice.

Protective effects of Purendan superfine powder on retinal neuron apoptosis in a rat model of type 2 diabetes mellitus

This study sought to investigate the effects of Purendan superfine powder comprised of Momordica charantia, Radix Ginseng, and Radix Salviae Miltiorrhiae on neuronal apoptosis and expression of bcl-2, bax, and caspase-3, which are retinal apoptosis-associated factors in rats with diabetes mellitus induced by continuous intraperitoneal injection of streptozotocin. The results showed that Purendan superfine powder could upregulate the expression of bcl-2 protein and mRNA, and downregulate the expression of bax and caspase-3 in the retina of diabetes mellitus rats. In addition, Purendan superfine powder was shown to reduce the number of apoptotic neurons. Our experimental findings indicate that Purendan superfine powder can inhibit neuronal apoptosis in the retina of diabetes mellitus rats and has protective effects on diabetic retinopathy.

In Vivo Histocompatibility Evaluation of Polyurethane Membrane Modified by Superfine Silk-fibroin Powder

In this study, a novel polyurethane membrane, modified by superfine silk-fibroin powder, was prepared for small-diameter vascular grafting. Scanning electron microscopy, transmission electron microscopy, and histological examination were applied to evaluate histocompatibility of this polyurethane membrane. The polyurethane membrane was compared with polytetrafluoroethylene material. A pseudomembrane and gap formed between polytetrafluoroethylene and the surrounding tissues, and no cells infiltrated or grew into the polytetrafluoroethylene material. On the contrary, superfine silk-fibroin powder/polyurethane blend membrane merged tightly with the surrounding tissues without gaps, and cells infiltrated and grew into the material. Moreover, the negative effects of superfine silk-fibroin powder/polyurethane blend membrane on cells were less than those of its polytetrafluoroethylene counterpart. Our findings indicated that the superfine silk-fibroin powder/polyurethane blend membrane has better histocompatibility than polytetrafluoroethylene membrane. It is concluded that the superfine silk-fibroin powder/polyurethane blend membrane is a promising biomaterial for small-diameter prosthesis.

NEAR RAPID DIRECTIONAL SOLIDIFICATION AND ITS SUPERFINE MICROSTRUCTURE

This paper briefly reviews the recent research on the near rapid directional solidification and microstructure superfining. The morphology transitions and the corresponding mechanical properties are presented. The critical velocities relevant to the morphology transitions are comprehensively given. Meanwhile the solidification characteristics near absolute stability limit are studied.It can be clearly seen that the superfine microstructures possess extremely better properties compared with the conventional microstructures.

Preparation of Superfine-Cemented Carbide by Spark Plasma Sintering

92WC-8Co puwder mixture with superfine-tungsten carbide was respectively sintered by spark plasma sintering（ SPS ） and sintering isostutic pressure （SIP）. Complete dense samples with 200 nm WC grains and 94.2HRA hardness were prepared by spark plasma sintering at 1 150 ℃ and under 4.5 kN for 5 minutes. SIP was carried out at 1 400 ℃ for 30 minutes with a result of 300-400 nm WC grains and 93 HRA hardness. The results show that sintering temperature is greatly decreased by SPS, sintering time is largely shortened and WC grain growth is effectively retarded. Micropores and drawb（wks in superfine-cemented carbide made by SPS are greatly declined, which is very useful to improving nwehanical properties.

Discussion on the Application of LS-DYNA in Superfine Grinding of Wheat Bran

Superfine grinding, involving the fragmentation mechanism of wheat bran cell tissue, is being employed by milling industry. In order to determine the effect of wheat bran cell tissue on the fragmentation mechanism when using superfine grinding,a technical scheme of the nonlinear finite element numerical simulation method based on LS-DYNA is proposed in this paper.The physiological characteristics of wheat bran structural layers including outer pericarp, intermediate layer and aleurone layer are examined first, and then the mechanical properties of wheat bran structural layers and their effects on the super fine grinding process are analyzed. Secondly, the explicit time integration algorithm of LS-DYNA is introduced, and the application feasibility of LS-DYNA in the analysis of wheat bran superfine grinding mechanism is discussed. Finally, the specific application of LS-DYNA in the determination of grinding form and load, the selection and design of the grinding media and the selection of grinding temperature are discussed in detail in the process of superfine grinding for wheat bran cell tissue. The above research provides a theoretical basis for selecting and developing the equipment and technology suitable for wheat bran superfine grinding, and lays a theoretical foundation for enhancing the quality and efficiency of wheat bran superfine grinding.

Packing Density Improvement through Addition of Limestone Fines, Superfine Cement and Condensed Silica Fume

Adoption of a low water/powder (W/P) ratio is the key to improve the strength and durability of concrete, which relies on a high packing density because fresh concrete requires excess water to offer flowability. To obtain a high packing density, powders with different particle sizes, including limestone fines (LSF), superfine cement (SFC), condensed silica fume (CSF), were added to the cement paste and the resulting packing densities were measured directly by a newly-developed wet packing test. Results demonstrated that addition of powders with a finer size would more significantly improve the packing density but the powders should be at least as fine as 1/4 of the OPC to effectively improve the packing density. Packing density and voids ratio relationship showed that a small increase in packing density can significantly decrease the voids ratio, which could allow the W/P ratio to be reduced to improve the strength and durability of the concrete without compromising the flowability.

Mathematical Index for Evaluating Disperse Dyes Levelness of Superfine Polyester Fabric

The dyeing deference between the superfine and the con-ventional polyester fabric is discussed. The major threefactors affecting the level dyeing property of superfinepolyester-initial adsorption rate, desorption rate andinterface migration rate of dyestuffs at 70℃ are studied.The levelness improves considerably with decreased ini-tial adsorption rate, increased desorption rate and inter-face migration rate. And then a mathematical indexbased on them is established. The evaluation to dispersedyes resulting from it corresponds with their perfor-mance during industrial process. As new definitions, ini-tial adsorption rate and desorption rate of dyestuffs arefirstly introduced.

STUDY ON NYLON 6/SUPERFINE RUBBER PARTICLES COMPOSITES VIA IN SITU POLYMERIZATION

Two highly cross-linked superfine styrene-butadiene rubber particles, one with 1 wt% of carboxyl groups and theother without such groups having particle sizes of 130-150 nm and 80-100 nm respectively, were used to prepare nylon6/rubber composites via in situ polymerization. It was found that carboxylic styrene-butadiene dispersed uniformly in nylonmatrix and there was strong interfacial interaction because of the graft polymer formed by the reaction of nylon with carboxylgroup of the rubber, resulting in considerably improved impact strength with almost unchanged tensile strength. However,the addition of styrene-butadiene without carboxyl groups showed intensive agglomeration of the rubber particles and weakinterfacial interactions, and the toughness of the materials was improved slightly. The crystallization and rheological behavior of the composites were also discussed.

The Feasibility of Basalt Rock Powder and Superfine Sand as Partial Replacement Materials for Portland Cement and Artificial Sand in Cement Mortar

The research gap on the feasibility of basalt rock powder(BRP)and superfine sand(SS)in preparation of cement mortar is significant.This study examines probable changes occurred in the modified cement mortar due to incorporation of certain quantity of basalt rock powder and superfine sand in mixture proportion.The cement mortar included Portland cement,artificial sand and water as principal mixture constituents.Then,basalt rock powder and superfine sand were added as partial replacement materials for Portland cement and artificial sand respectively.Therefore,replacement percentages were 10%,15%,20%,25%and 30%when the basalt rock powder replaced Portland cement and in case the artificial sand was replaced by superfine sand,10%,20%,30%,40%and 50%.Then,the strength indexes such as flexural strength,compressive strength,ultrasonic pulse velocity and dynamic elastic modulus were investigated.The results show that the presence of basalt rock powder in mixture proportion increased the flexural and compressive strengths of cement mortar however the cement mortar that contained superfine sand illustrated inadequate mechanical performance as flexural and compressive strengths decreased remarkably.Moreover,when basalt rock powder and superfine sand were included together in mixture proportion,the cement mortar’s mechanical performance declined compared to that of the reference cement mortar.Despite the fact that basalt rock powder and superfine sand weakened the cement mortar’s mechanical properties,it was found that they can be added into the cement mortar as partial replacement of Portland cement and artificial sand in the following ratios:from 10%to 25%when basalt rock powder replaces Portland cement and from 10%to 20%when artificial sand is replaced by superfine sand.

Effect of Serum from Overfatigue Rats on JNK/c-Jun/HO-1 Pathway in Human Umbilical Vein Endothelial Cells and the Intervening Effect of Tongxinluo(通心络)Superfine Powder

Objective:To cultivate human umbilical vein endothelial cells (HUVECs) in the serum of overfatigue rats with the intervention of Tongxinluo (通心络) superfine powder (TXLSP).By examining the variation of the activity of JNK/c-Jun/HO-1 pathway,the possible mechanisms of vascular endothelial dysfunction under overfatigue conditions and the intervening effect of TXLSP were explored.Methods:The HUVECs were randomly divided into the normal control group,the model group,the SP600125 (a specific antagonist of JNK)gro...

A novel method for fast and continuous preparation of superfine titanium dioxide nanoparticles in microfluidic system

Previously we had developed a microfluidic system that can be easily fabricated by bending a stainless-steel tube into large circular loops.In this study,a fast and continuous preparation method for superfine TiO_(2) nanoparticles(TiO_(2)-NPs)was developed for the aforementioned microfluidic system.The proposed method can yield anatase TiO_(2) in 3.5 min,in contrast to the traditional hydrothermal reaction method,which requires hours or even days.Different reaction conditions,such as reaction temperature(120-200℃),urea concentration(20-100 g/L),and tube length(5-20 m)were investigated.X-ray diffraction and Brunauer-Emmett-Teller analysis indicate that the as-prepared TiO_(2)-NPs have crystalline sizes of 4.1-5.8 nm and specific surface areas of 250.7-330.7 m^(2)/g.Transmission electron microscopy images show that these TiO_(2)-NPs have an even diameter of approximately 5 nm.Moreover,because of their small crystalline sizes and large specific surface areas,most of these as-prepared TiO_(2)-NPs exhibit considerably better absorption and photocatalytic performance with methylene blue than commercial P5 TiO_(2) does.

Observation of changes in the number of myocardial capillaries in rabbits after treatment of acute myocardial infarction by Tongxinluo superfine powder

OBJECTIVE: To investigate the effects of Tongxinluo superfine powder on cardiac function, infarct size and the number of myocardial capillaries in a rabbit model of acute myocardial infarction.METHODS: A total of 32 New Zealand white rabbits were randomly divided into four groups: sham operation group, model group, treatment group,and pre-treatment, the experiment of pre-treatment group was performed 6 weeks early than the treat) group,The four groups use a unified modeling technique. An acute myocardial infarction model was established through external application of70% ferric chloride on the coronary artery. After 7 d,electrocardiogram, ultrasonography of cardiac function, micro-computed tomography, pathology and other data were collected.RESULTS: In the treatment and pre-treatment groups, ejection fraction, left ventricular short axis shortening rate, left ventricular end-systolic diameter and cardiac output significantly improved, the number of capillaries significantly increased, and infarct size significantly decreased. In addition, the results suggest that the value of intra-ventricular pressure and the situation of electrocardiogram also changed to different degrees with the increasing of treatment of cycle.CONCLUSION: Tongxinluo superfine powder can protect the myocardium, improve the blood supply of the myocardium and reduce the degree of myocardial injury, during acute stage of myocardial infarction.

Detailed in-furnace measurements with reburning of superfine pulverized coal in high CO_(2)concentration

This paper presents detailed measurements of gaseous species during the reburning process with high CO_(2)concentration in a bench-scale furnace.Superfine pulverized coal,with the average particle size below or around 20μm,is used as the reburning fuel.The data of flue gas concentration(NOx,HCN,NH_(3),CH_(4),O_(2),CO,CO_(2)etc.)is obtained in order to reveal the intrinsic connection between NOx emissions and other influential gaseous species at different positions of the furnace.The finding concludes that the advantage of superfine pulverized coal with regard to NO reduction is more efficient in homogeneous stage rather than heterogeneous stage.Meanwhile,the evolution of HCN and CH_(4)agrees well with each stage of NO reduction,which indicates that these gaseous species are favorable for NO abatement.Eventually,oxygen consumption rate for superfine pulverized coal is relatively faster,conducive to strengthen both homogeneous and heterogeneous NO reduction under CO_(2)reburning condition.

A New Method for Improving Strength and Plasticity of Steel Wire

Specially designed wire-drawing equipment with multiple electropulse generator was introduced. The influences of multiple electropulses processing on the microstructure and properties of the hardened steel wire were investigated. Samples treated by direct current under the same current density as that in multiple electropulses processing were carried out for contrast analysis. The results show that the optimized parameters of multiple electropulses processing will be facilitated to increase the nucleation rate and slow down the growth rate of recrystallized grains. Consequently, massive superfine grains of micro and sub-micro scale could be found in the steel wire. Thereby, the elongation was significantly enhanced with a relatively small strength reduction in comparison with as-received cold-drawing steel wires. Outstanding mechanical properties of steel wire were obtained.

Influences of four processing methods on main nutritional components of foxtail millet: A review

Foxtail millet, originated from China and now cultivated worldwide, is a kind of high dietary fiber whole grain food, and has a high level of vitamins and proteins. Furthermore, foxtail millet has many positive effects on the adjuvant treatment of diabetes, cancer, and cardiovascular diseases because of the abundance in polyphenols. Nonetheless, foxtail millet has poor processing characteristics due to the absence of gluten, restricting the development of foxtail millet products. Studies have demonstrated that heat-moisture treatment, extrusion, superfine grinding, and microbial fermentation are promising methods to improve the processing qualities of foxtail millet. Heat-moisture treatment is helpful to increase the content of resistant starch but has less influence on other components, further reduce the GI value of foxtail millet. The extrusion has positive effects on improving the solubility of foxtail millet starch and increasing the contents of polyunsaturated fatty acid, linoleic and linolenic acids, and adverse effects on reducing the solubility of foxtail millet proteins and causing losses of nutrients due to Maillard reaction. Superfine grinding can reduce the particle size of foxtail millet to obtain a better mouthfeel of foxtail millet products. The superfine foxtail millet flour has better solubility, higher freeze-thaw stability, and lower gelatinization temperature. Microbial fermentation contributes positively to reducing the molecular weight and retrogradation value of foxtail millet starch, degrading rapidly digested starch, and improving the digestibility of foxtail millet protein. This paper briefly introduced the effects of different processing methods on foxtail millet nutrients, aiming to provide references for increasing the variety and improving the quality of foxtail millet products.

钛酸钡锶复盐超微陶瓷粉末制备以及粉末结构测定

本文首次报道采用简单低耗的有机介质化学共沉淀法,制备超微陶瓷粉末钛酸钡锶复盐(Ba_xSr(1-x)TiO_3)。由扫描电镜观测其平均粒径在0.45μm以下。由X-粉晶衍射图得到,该复盐粉末属于BaTiO_3(四方)与SrTiO3(立方)的混晶。

Wool characteristics of crossbred Baghdadi wild ram and Iran native sheep

Twenty mid side wool samples of crossbred sheep were collected and their characteristics were determined. Data analyzed by SAS software and Duncan’s multiple range tests was used for comparison of mean wool characteristics. Average fleece weight, yield, wool diameter, Fine fiber and staple length were: 431.59 ± 38.95 gr, 65.14%, 14.24 ± 0.67 μm, 48.67 ± 5.59, and 43.65 ± 4.15 mm respectively. Mean fleece weight was significantly affected (p 1 and F2 generation 11.84 ± 0.58, 16.27 ± 0.72 μm respectively. There were effective differences among ages (12.55 ± 0.74, 14.47 ± 0.58 and 13.11 ± 0.64 μm for 1, 2 and 3 yr old respectively). Wool diameter of younger animals, males and F1 was so fine (12.55, 12.87 and 11.84 μm respectively). Staple length of F2 crosses was significantly longer than F1 crosses (p 1 was significantly finer than F2, but length and down fiber percentage was less than second generation. As wild sheep shed his fiber in winter, the first filial crosses also shed their fibers from the end of winter to early spring. Shedding was seldom observed in F2 generations. It seems likely that wool from crossbred sheep could be used for those applications for which cashmere is suitable. This study indicates that, such crossbred sheep have a superfine wool and could be used in pure or blend for textile industry.