Control of N-nitrosodimethylamine(NDMA)in drinking water could be achieved by removing its precursors as one practical way.Herein,superfine powdered activated carbons with a diameter of about 1μm(SPACs)were successfu...Control of N-nitrosodimethylamine(NDMA)in drinking water could be achieved by removing its precursors as one practical way.Herein,superfine powdered activated carbons with a diameter of about 1μm(SPACs)were successfully prepared by grinding powdered activated carbon(PAC,D50=24.3μm)and applied to remove model NDMA precursors,i.e.ranitidine(RAN)and nizatidine(NIZ).Results fromgrain diameter experiments demonstrated that the absorption velocity increased dramatically with decreasing particle size,and the maximum increase in k2 was 26.8-folds for RAN and 33.4-folds for NIZ.Moreover,kinetic experiments explained that rapid absorption could be attributed to the acceleration of intraparticle diffusion due to the shortening of the diffusion path.Furthermore,performance comparison experiments suggested that the removal of RAN and NIZ(C_(0)=0.5 mg/L)could reach 61.3%and 60%,respectively,within 5 min,when the dosage of SAPC-1.1(D_(50)=1.1μm)was merely 5 mg/L,while PAC-24.3 could only eliminate 17.5%and 18.6%.The adsorption isotherm was well defined by Langmuir isotherm model,indicating that the adsorption of RAN/NIZ was a monolayer coverage process.The adsorption of RAN or NIZ by SAPC-1.1 and PAC-24.3 was strongly pH dependent,and high adsorption capacity could be observed under the condition of pH>pk_(a)+1.The coexistence of humic acid(HA)had no significant effect on the adsorption performance because RAN/NIZ may be coupled with HA and removed simultaneously.The coexistence of anions had little effect on the adsorption also.This study is expected to provide an alternative strategy for drinking water safety triggered by NDMA.展开更多
A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder...A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder has a higher H(?) and lower σ,than one made up of spherical Fe_O_4.展开更多
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 a...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.展开更多
Phosphorous slag （PHS）, ground granulated blast-furnace slag （GGBS） and fly ash （FA） were used as replacements of Portland cement to modify the microstruc^xe of recycled aggregate concrete （RAC）. A new manufac...Phosphorous slag （PHS）, ground granulated blast-furnace slag （GGBS） and fly ash （FA） were used as replacements of Portland cement to modify the microstruc^xe of recycled aggregate concrete （RAC）. A new manufacturing method named ＂W3T4＂ was proposed to improve the performances of interracial transition zone （ITZ） between recycled aggregate and mortar. The mechanical properties and the durability of RAC were tested, which show that this new manufacturing method improves the properties of RAC, and the GGBS with finest size makes a great contribution to the performance of RAC due to its better filling effect and much earlier pozzolanic reaction. Combined with GGBS, the effects of PHS on the retardation of setting time can be alleviated and the synergistic effect helps to make a more compact RAC. For the RAC with 25% of the recycled aggregate （RA） replacement and 10% PHS ＋ 10% GGBS additives, the compressive strength increases by 25.4%, but the permeability decreases by 64.3% with respect to the reference concrete made with nature aggregates. The micro-mechanisms of these improvements were investigated by the scanning electron microscope （SEM）. The SEM images show that the new manufacturing method, adding superfine pozzolanic powders and super-plasticizer benefits, makes a much denser ITZ in RAC.展开更多
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 th...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°to 61.41°) and slide (from 38.99°to 26.42°). 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.展开更多
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...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.展开更多
In this paper, statistical optimization method was used to optimize the flash-spinning process conditions. Ultra-high molecular weight polyethylene （UHMWPE） superfine fiber was fabricated by flash-spinning method us...In this paper, statistical optimization method was used to optimize the flash-spinning process conditions. Ultra-high molecular weight polyethylene （UHMWPE） superfine fiber was fabricated by flash-spinning method using UHMWPE as the fiberforming polymer, 1, 2-dichloroethane as the main solvent. The important parameters of the flash-spinning were filtered by Plackett-Burman experimental design based on the single factor experiments. After determining the best regions of the fiber properties, the optimum level of the important parameters were determined by Box-Behnken design. The results of the design showed that the important parameters influencing on the properties of the flash.spinning fiber were spinning temperature, spinning pressure, and spinning solution concentration. The optimum technical parameters were： spinning temperature 186. 4 ~C, spinning pressure 6. 16 MPa, spinning solution concentration 3.06 %. The highest combination property of the flash-spinning fiber was 86.39 under this condition.展开更多
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 histologi...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.展开更多
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 N...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.展开更多
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 cri...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.展开更多
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 ...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.展开更多
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 whe...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.展开更多
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 ob...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.展开更多
In this paper,a kind of composite microtube,which is made from superfine silk powder and polyurethane,reinforced by polyster and spandex tubular fabrics,was examined.The cross-section of composite microtubes were micr...In this paper,a kind of composite microtube,which is made from superfine silk powder and polyurethane,reinforced by polyster and spandex tubular fabrics,was examined.The cross-section of composite microtubes were microporous,and micropores were uniform distributed,the inner surface was relatively smooth.The results showed that the wall thickness of composite microtubes increased,which led to the strength,the breaking work and the initial modulus incresead;that the spandex content increased brought about the initial modulus and the breaking work decreased,but the breaking extension and the breaking load were firstly increased and then decreased;and all the mechanical properties decreased as the SFSP content increased.展开更多
The infiltration casting process for producing aluminum foam includes three steps： preparing precursor using NaCI particles, infiltrating molten aluminum and cleaning NaCI precursor. Defects occur during the preparat...The infiltration casting process for producing aluminum foam includes three steps： preparing precursor using NaCI particles, infiltrating molten aluminum and cleaning NaCI precursor. Defects occur during the preparation of aluminum foam with superfine open-cell structure, and influence the pore structure and performance of aluminum foam materials. The types of the defect and their forming mechanisms are analyzed in this paper. The defects include point defects and linear metal defects, and are caused by the defects in salt precursor and the insufficient infiltration of molten aluminum into precursor. With the choice of proper precursor preparation method and infiltration process parameters, the complete aluminum foam with superfine pores could be achieved.展开更多
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...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.展开更多
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...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.展开更多
A superfine slag powder (SP) made from granulated blast furnace slag incorporating activators by using special millingtechnique, was used as supplementary cementitious material in high performance concrete (HPC), repl...A superfine slag powder (SP) made from granulated blast furnace slag incorporating activators by using special millingtechnique, was used as supplementary cementitious material in high performance concrete (HPC), replacing part ofthe mass of normal Portland cement. The effects of the SP on the workability, mechanical and crack self-healingproperties of HPC were studied. The hydration process and microstructure characteristics were investigated by X-raydiffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The crack self-healing capacitywas evaluated by Brazilian test. The test results indicate that the SP has especially supplementary effect on waterreducing and excellent property of better control of slump loss. The concrete flowability increases remarkably withthe increase of SP replacement level in the range of 20% to 50%. The compressive and splitting tensile strengthsof HPC containing SP are higher than the corresponding strength of the control concrete at all ages. The crackself-healing ability is highly dependent on SP content of HPC.展开更多
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 pre...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.展开更多
The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twi...The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twice,and broken wall cooking machine processing.The particle size distribution,free polyphenols,bound polyphenols and antioxidant activity of whole fruit pulp prepared by the three kinds of pulverization methods were discussed.The results showed that the particle size distribution of the whole fruit pulp by wet superfine grinding was more concentrated compared with the broken-wall cooking machine processing,and the total phenols dissolution rate of the navel orange whole pulp was increased by 6.9%,and the total flavonoid dissolution rate was increased by 13.5%.The results also suggested that wet superfine grinding twice could improve 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging activity of polyphenols in the whole fruit pulp,wet superfine grinding once and wet superfine grinding twice also could obviously enhance the reducing power and iron reduction ability of polyphenols in the whole fruit pulp.In conclusion,wet superfine grinding could increase both the polyphenol content and antioxidant activity of navel orange whole fruit pulp,it can be used as a pretreatment processing method for preparing navel orange whole fruit pulp.展开更多
基金supported by the Key Technology Research and Development Program of Shandong(No.2020CXGC011406)the National Natural Science Foundation of China(No.22076091)the State Key Joint Laboratory of Environment Simulation and Pollution Control,China(No.21L01ESPC).
文摘Control of N-nitrosodimethylamine(NDMA)in drinking water could be achieved by removing its precursors as one practical way.Herein,superfine powdered activated carbons with a diameter of about 1μm(SPACs)were successfully prepared by grinding powdered activated carbon(PAC,D50=24.3μm)and applied to remove model NDMA precursors,i.e.ranitidine(RAN)and nizatidine(NIZ).Results fromgrain diameter experiments demonstrated that the absorption velocity increased dramatically with decreasing particle size,and the maximum increase in k2 was 26.8-folds for RAN and 33.4-folds for NIZ.Moreover,kinetic experiments explained that rapid absorption could be attributed to the acceleration of intraparticle diffusion due to the shortening of the diffusion path.Furthermore,performance comparison experiments suggested that the removal of RAN and NIZ(C_(0)=0.5 mg/L)could reach 61.3%and 60%,respectively,within 5 min,when the dosage of SAPC-1.1(D_(50)=1.1μm)was merely 5 mg/L,while PAC-24.3 could only eliminate 17.5%and 18.6%.The adsorption isotherm was well defined by Langmuir isotherm model,indicating that the adsorption of RAN/NIZ was a monolayer coverage process.The adsorption of RAN or NIZ by SAPC-1.1 and PAC-24.3 was strongly pH dependent,and high adsorption capacity could be observed under the condition of pH>pk_(a)+1.The coexistence of humic acid(HA)had no significant effect on the adsorption performance because RAN/NIZ may be coupled with HA and removed simultaneously.The coexistence of anions had little effect on the adsorption also.This study is expected to provide an alternative strategy for drinking water safety triggered by NDMA.
文摘A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder has a higher H(?) and lower σ,than one made up of spherical Fe_O_4.
文摘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.
基金Project(51178417)supported by the National Natural Science Foundation of ChinaProject(2012R10025)supported by the Qianjiang Talent Plan of Zhejiang Province,China+2 种基金Project(2012HY006B)supported by the Marine Cross-Guide Research Funds of Zhejiang University,ChinaProject(2013FZA4015)supported by the Fundamental Research Funds for the Central Universities,ChinaProject supported by the Department of Construction of Zhejiang Province,China
文摘Phosphorous slag （PHS）, ground granulated blast-furnace slag （GGBS） and fly ash （FA） were used as replacements of Portland cement to modify the microstruc^xe of recycled aggregate concrete （RAC）. A new manufacturing method named ＂W3T4＂ was proposed to improve the performances of interracial transition zone （ITZ） between recycled aggregate and mortar. The mechanical properties and the durability of RAC were tested, which show that this new manufacturing method improves the properties of RAC, and the GGBS with finest size makes a great contribution to the performance of RAC due to its better filling effect and much earlier pozzolanic reaction. Combined with GGBS, the effects of PHS on the retardation of setting time can be alleviated and the synergistic effect helps to make a more compact RAC. For the RAC with 25% of the recycled aggregate （RA） replacement and 10% PHS ＋ 10% GGBS additives, the compressive strength increases by 25.4%, but the permeability decreases by 64.3% with respect to the reference concrete made with nature aggregates. The micro-mechanisms of these improvements were investigated by the scanning electron microscope （SEM）. The SEM images show that the new manufacturing method, adding superfine pozzolanic powders and super-plasticizer benefits, makes a much denser ITZ in RAC.
文摘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°to 61.41°) and slide (from 38.99°to 26.42°). 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.
文摘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.
基金Key Project of Chinese Ministry of Education( No. 208005)Instructional Technology Project of National Textile andApparel Council, China ( No.2009076)Application Fundamental and Advanced Technology Research Proposal Project of Tianjin, China(No.10 JCYBJC03100)
文摘In this paper, statistical optimization method was used to optimize the flash-spinning process conditions. Ultra-high molecular weight polyethylene （UHMWPE） superfine fiber was fabricated by flash-spinning method using UHMWPE as the fiberforming polymer, 1, 2-dichloroethane as the main solvent. The important parameters of the flash-spinning were filtered by Plackett-Burman experimental design based on the single factor experiments. After determining the best regions of the fiber properties, the optimum level of the important parameters were determined by Box-Behnken design. The results of the design showed that the important parameters influencing on the properties of the flash.spinning fiber were spinning temperature, spinning pressure, and spinning solution concentration. The optimum technical parameters were： spinning temperature 186. 4 ~C, spinning pressure 6. 16 MPa, spinning solution concentration 3.06 %. The highest combination property of the flash-spinning fiber was 86.39 under this condition.
基金supported by a grant from the 973 Programof Ministry of Science and Technology of China(No.2009CB526400)
文摘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.
文摘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.
文摘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.
基金Funded by the Science Foundation of Shanghai , China ( No.0152nm046)
文摘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.
基金Supported by National Natural Science Foundation-Henan Joint Fund Key Support Project(No.U1604254)Open Subject of National Engineering Laboratory of Wheat&Corn Further Processing(No.NL2017010)
文摘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.
文摘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.
基金State Natural Sciences Fundgrant number:50873079+1 种基金National Major Foudamental Research Program of Chinagrant number:2009CB526402
文摘In this paper,a kind of composite microtube,which is made from superfine silk powder and polyurethane,reinforced by polyster and spandex tubular fabrics,was examined.The cross-section of composite microtubes were microporous,and micropores were uniform distributed,the inner surface was relatively smooth.The results showed that the wall thickness of composite microtubes increased,which led to the strength,the breaking work and the initial modulus incresead;that the spandex content increased brought about the initial modulus and the breaking work decreased,but the breaking extension and the breaking load were firstly increased and then decreased;and all the mechanical properties decreased as the SFSP content increased.
文摘The infiltration casting process for producing aluminum foam includes three steps： preparing precursor using NaCI particles, infiltrating molten aluminum and cleaning NaCI precursor. Defects occur during the preparation of aluminum foam with superfine open-cell structure, and influence the pore structure and performance of aluminum foam materials. The types of the defect and their forming mechanisms are analyzed in this paper. The defects include point defects and linear metal defects, and are caused by the defects in salt precursor and the insufficient infiltration of molten aluminum into precursor. With the choice of proper precursor preparation method and infiltration process parameters, the complete aluminum foam with superfine pores could be achieved.
基金supported by National Natural Science Foundation of China(Nos.51776123,51806140,and 51704194)the Shanghai Sailing Plan(No.19YF1418000)。
文摘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.
文摘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.
基金The research work presented in this paper was conducted with partial support from the Foundation for University Key Teacher by the Ministry of EducationThe first author also gratefully acknowledges the financial support from NSFC (No. 59908007) t
文摘A superfine slag powder (SP) made from granulated blast furnace slag incorporating activators by using special millingtechnique, was used as supplementary cementitious material in high performance concrete (HPC), replacing part ofthe mass of normal Portland cement. The effects of the SP on the workability, mechanical and crack self-healingproperties of HPC were studied. The hydration process and microstructure characteristics were investigated by X-raydiffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The crack self-healing capacitywas evaluated by Brazilian test. The test results indicate that the SP has especially supplementary effect on waterreducing and excellent property of better control of slump loss. The concrete flowability increases remarkably withthe increase of SP replacement level in the range of 20% to 50%. The compressive and splitting tensile strengthsof HPC containing SP are higher than the corresponding strength of the control concrete at all ages. The crackself-healing ability is highly dependent on SP content of HPC.
文摘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.
基金Supported by National Key R&D Program(2017YFD0400701)~~
文摘The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twice,and broken wall cooking machine processing.The particle size distribution,free polyphenols,bound polyphenols and antioxidant activity of whole fruit pulp prepared by the three kinds of pulverization methods were discussed.The results showed that the particle size distribution of the whole fruit pulp by wet superfine grinding was more concentrated compared with the broken-wall cooking machine processing,and the total phenols dissolution rate of the navel orange whole pulp was increased by 6.9%,and the total flavonoid dissolution rate was increased by 13.5%.The results also suggested that wet superfine grinding twice could improve 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging activity of polyphenols in the whole fruit pulp,wet superfine grinding once and wet superfine grinding twice also could obviously enhance the reducing power and iron reduction ability of polyphenols in the whole fruit pulp.In conclusion,wet superfine grinding could increase both the polyphenol content and antioxidant activity of navel orange whole fruit pulp,it can be used as a pretreatment processing method for preparing navel orange whole fruit pulp.
