bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis of Vertically Loaded Cylindrical Ti Implants
Authors: Sojic Ljiljana Tihacek , Lemic Aleksandra Milic , Subic Aleksandar , Yang Jie , Grubor Dragan
Published: March 2013

The following study was conducted in order to evaluate the effects of height, width and design variations on the stress distribution of vertically loaded, cylindrical titanium implants using finite element analysis (FEA). Three groups of cylindrical titanium TPS surface implants (Premium, Sweden & Martina, Italy) inserted into mandible segments were analysed. The three Premium implants in the first group were of different length (10.0, 11.5 and 13.0 mm) but possessed the same diameter of 3.80 mm. The second group consisted of three Premium implants with the same length of 11.5 mm but with different diameters (3.30, 3.80 and 4.25 mm). In the last group two different implant designs were compared, one featuring platform switching and a straight emergence profile and the other without platform switching. Overall, eight implant-bone samples were analyzed and the resulting stress distributions during vertical loading were obtained. For all eight samples, maximum stress values were found in the area of the implant neck and the stress values decreased in the apical direction. The higher stress values in the second group were detected in the implant with smaller diameter. It was noted that the implant with platform switching experienced lower stresses than the one without platform switching. Changes in length did not have any significant effect on the stress distribution. Under a vertical occlusal load, an implant with a larger diameter and with platform switching had the most favorable stress distribution throughout the implant structure and the adjacent bone tissue.
Experimental Investigation of Characteristics of Passive Safety Elements
Authors: Tanaskovic Jovan , Miskovic Zarko , Lucanin Vojkan , Mitrovic Radivoje
Published: March 2013

Development of passive safety elements is a key component in the design and manufacture of railway vehicles. Proper functioning of these elements is of great importance and has a direct influence on the safety of passengers, goods and vehicles. Different types of railway vehicles require absorption elements of different geometries and absorption power. Over the last twelve years, new types of absorption elements have been investigated in Serbia. Research has begun on steel tubes and square cross-sections, which absorb energy based on the principles of folding tubes. Research progressed to seamless tubes with circular cross sections on the basis of two methods of energy absorption: expansion and shrinkage of the tube. The best characteristics were obtained using the shrinking method. The most recent research was based on shrinking tubes in combination with folding tubes in parallel operation. This combined method was chosen as the resulting absorber has higher absorption power with smaller dimensions, which is a key consideration given the available and very limited space for the mounting of the absorber behind the buffer. Experimental investigation of the combined absorber through a scale model was conducted on a Zwick Roell HB250 material testing machine at the Faculty of Mechanical Engineering, University of Belgrade. The recorded parameters showed a gradual increase in force values, a decrease in maximal force values at the start of the folding process, and a significant increase in the absorbed energy compared to the shrinking or folding process alone.
Analysis of Deep Groove Ball Bearing Design for Assembly
Authors: Mitrovic Radivoje , Subic Aleksandar , Atanasovska Ivana
Published: March 2013

This paper presents a comprehensive analysis of the assembly processes for single-row ball bearings. There are two different types of assembly processes, which depend on ball numbers and ball bearing ring designs. In the case of deep groove ball bearings, assembly is usually undertaken through slight deformation of the outer ring to increase clearance for insertion of the final ball. As a result, the outer ring takes an elliptical instead of a circular shape and requires deformation to be below a critical level to avoid fracture. Causal analysis of outer ring fracture during assembly is the main goal of the presented analysis, based on the expressions of the Theory of Elasticity for the thin ring exposed to bending, as well as Finite Element Analysis (FEA). The theoretical and numerical results have been verified by experimental testing.
Inhibition of Serum PON Arylesterase Activity by Different Inhibitors and Correlation Analysis
Authors: Zhang Zhixin , Zhang Shi Xiu , Mu Xiao Jing , Chen Yun Yun , Ji Jin Gou , Wu Juan
Published: March 2013

In the assay of serum PON arylesterase activity using phenyl acetate as a substrate, a number of other serum hydrolases can catalyze the substrate hydrolysis, and so bring high background activity signal. EDTA and 2-hydroxyquinoline (2-HQ) were PON inhibitors. Based on this property, background activity can be determined by adding EDTA or 2-HQ just prior to adding the substrate (phenyl acetate). The specific serum PON activity was obtained by subtracting the background activity from the total serum arylesterase activity. The correlation of the background signals based on different inhibitors and the correlation of the specific serum PON activity were investigated, respectively. The inhibition consistency was analyzed. The correlation analysis of PON activity-age was performed.
Indirect Spectrophotometric Determination of Methimazole Using Phenanthroline-Fe(II)
Authors: Wen Xin Rong , Tu Chang Qing
Published: March 2013

A novel method for the indirect determination of methimazole by spectrophotometry using phenanthroline-Fe(Ⅱ) has been established.The results showed that in acid medium, Fe(Ш) could be reduced to Fe(Ⅱ) by hydrosulfuryl(-SH) in methimazole molecule,and then using phenanthroline as chromogenic reagent of Fe(Ⅱ), and the content of methimazole was determinated indirectly through determinating the content of Fe(Ⅱ) by spectrophotometry. The various effect factors on the determination of methimazole by spectrophotometry using phenanthroline-Fe(Ⅱ) were investigated in detail.The maximum absorption wavelength of chromogenic system was 509 nm, good linear relationship was obtained between the absorbance and the concentration of methimazole in the range of 0.0016～0.0064 mg/mL,the equation of the linear regression was A = 0.1942 + 64.598ρ (mg•mL-1),with a linear correlation coefficient was 0.9995.This proposed method had been applied to determinate of methimazole in real pharmaceutical,and the results agreed well with those obtained by pharmacopoeial method.
Modification of Activated Carbon and its Application on Adsorption of UDMH Gas
Authors: Wang Huan Chun , Gou Xiao Li , Lv Xiao Meng
Published: March 2013

Two kinds of modified activated carbons were prepared by dipping with Zn(NO3)2 solution and by reducing in the atmosphere of N2 at high temperature respectively, which were characterized by FTIR,DSC,SEM and EDS. The surface structure was strongly changed in the process, along with the changes of chemical functional groups. The results of adsorption experiments revealed that the adsorbent capacities of UDMH gas at room temperature were enhanced obviously by modification compared with the raw activated carbon, especially dipped by transition metal solution. The mechanism probably involved was also discussed.
Study on Extraction of Natural Black Soya Bean Peptide and Antioxidant Activity
Authors: Zhang Yan Fang , Xiao Chun Ling , Jia Xin , Li Qiong Jie , Xue Yuan Yuan , Chai He Qing
Published: March 2013

With black beans as raw materials, different factors on natural black beans peptide yield influence, and through the establishment of DPPH • system, OH • system, reducing power system measurement for the determination of different concentration of black soya bean peptide oxidation stability. The results showed that the liquid material ratio 17.5,leaching 42°C,extracting 55 min, black beans peptide extraction is 2.386 mg/g. Black beans peptide in various system all have certain oxidative stability, in the concentration of 0.04mg/ml to 74.05% clearance of DPPH• , in 0.06mg/ml concentration of OH•clearance rate is 80.48%, 0.08 mg/ml concentrations reduction force is 0.745, and in these three system natural black beans peptide oxidation stability are better than those of contrast VC is strong .
Study on Synthesis of (s)-3-(t-Butyldimethylsilyloxy)-7,7-Dichloro-2,2-Dimethyloctanoic Acid
Authors: Wang Xiao Ji , Liu Dong Wang , Tang Lin Jun , Zhang Jian Ting , Li Yang
Published: March 2013

(s)-3-(t-butyldimethylsilyloxy)-7,7-dichloro-2,2-dimethyloctanoic acid (9), a segment of the new cyclodepsipeptide lyngbyabellin A[1] (14) , which exhibits moderate cytotoxycity against human cancer cell lines, was synthesized through six steps. The key stereoselective synthesis of (9) was achieved by the enantioselective aldol reaction developed by Kiyooka[2].
Energy-Level Splitting of Cs2NaYCl6 Crystal Doped with Praeseodymium
Authors: Duan Mei Ling , Li Jin Hong , Yang Xiao Feng
Published: March 2013

The 91×91 complete energy matrix of 4f2 configuration ion praeseodymium in octahedral cubic crystal field has been constructed based upon the combination of Racah’s group-theoretical consideration with Slater’s wavefunctions. The energy levels of praseodymium (Pr3+) in hexachloride elpasolite crystals Cs2NaYCl6 have been calculated. The calculated results display a good agreement with the experimental values, which implies that the complete energy matrix method can be received as a recommendable tool to perform a theoretical analysis to the doped crystal.
The Preparation and Research of the Aerogel-Type Wood Composite Material
Authors: Li Xiu Rong , Fu Yun Lin , Jiang Tao , Sun Jing , Xie Zhi Hua , Li De Hua
Published: March 2013

The aerogel-type wood is prepared under crafts of dissolution of wood materials by 1 - propenyl -3- methylimidazolium ionic liquid and followed supercritical drying process. And then, cellulose fibers as supporting frame with incomplete three-dimensional cross-linked network are reformed after dissolution of aerogel-based timber. The reformed cellulose fibers possess microstructure that similar with light wood, stable chemical and physical properties, dry density of 0.221 g/cm3 and porosity over 87%. Additionally, the novel wood-based material achieved by green chemical treatment can continue to fix and store carbon absorbed during the growth stage of trees, and will also play a certain significance in areas of low-carbon and environmental protection.
The Effect of KHCO3 on Photosynthesis of Eggplant Seedlings
Authors: Li Ying Chang , Hao Jian Jun
Published: March 2013

The low concentration of CO2 in the atmosphere is one of the main factors to restrict photosynthesis of C3 plants. The effect of KHCO3 on photosynthesis of eggplant seedlings was studied in order to improve photosynthesis of C3 plants. The results showed that KHCO3 could significantly enhance the photosynthetic rate of eggplant seedlings. 500mg/L KHCO3 was the most optimal concentration to improve photosynthetic rate of eggplant seedlings. KHCO3 could increase light saturation point, CO2 saturation point, carboxylase efficiency and lower CO2 compensate point of eggplant seedlings. KHCO3 could improve stomatal conductance and electron transport activity. There was phosphoenolpyruvate carboxylase (PEPC) in leaves of eggplant seedlings, but PEPC activity was low. KHCO3 could improve ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity and PEPC activity. From impact factors, HCO3- could enhance photosynthetic rate. K+ could raise stomatal conductance of eggplant seedlings. HCO3- could improve activity of PEPC . Both HCO3- and K+ could increase Rubisco activity.
Synthesis and In Vitro Anti-Breast Cancer Activity of Trametenolic Acid B Derivatives
Authors: Ding Ming Ruo , Zhang Qiao Yin , Hu Fang , Huang Nian Yu , Wang Jun Zhi
Published: March 2013

Six compounds were synthesized from the lanostane-type tetracyclic triterpenoid of trametenolic acid B with the aim of obtaining more active compounds, which were characterized by NMR, IR, ESI-MS and elemental analysis. Their cytotoxic activities were evaluated against the breast cancer cell line MD-AMB-231. The compound 3b exhibited the best anti-proliferative effect than trametenolic acid B and other derivatives with the IC50 of 17.78 µM.
Synthesis of Ropivacaine under Ultrasound Irradiation
Authors: Li Sai , Fu Xiao Bin , Liu Li , Lan Nuo , Meng Weng Qi , Zhang Jing Zheng , Cui Wen , Liu Yi
Published: March 2013

Ropivacaine hydrochloride was synthesized from 2-pipecolic acid by successive reaction with SOCl2 and 2,6-dimethylaniline at 40°C under ultrasonic irradiation to give (S)-N-(2,6-dimethylphenyl)-piperidin-2-carboxamide (4), and 4 was reacted with 1-bromopropane at 50°C for 1 h under ultrasonic irradiation. The effect of reaction solvent, temperature and time under ultrasonic irradiation were investigated. Compared with conventional methods, the main advantages of the present procedure are milder conditions, shorter reaction time and higher yields. The total yield was 63.1%, [α]25 D= – 6.7°(c = 2, H2O).
The Application of Ultrasonic Instead of Sulfur Dioxide in Processing of Strawberry Wine
Authors: Jiang Ming Zhu , Wang Wen Bo , Wei Yan Mei , Ma Yong Kun
Published: March 2013

Using fresh strawberry fruits as materials, the impact of using ultrasound to sterilize the process of strawberry wine was studied in this paper. In the experiment, the effects of different ultrasonic frequency, ultrasonic time and ultrasonic temperature in processing of strawberry wine were studied respectively. The results indicated that the treatment with supersonic procession of 40°C, 60min and 120W could get the best pH value of strawberry wine; the treatment with supersonic procession of 40°C, 45min, 80W could get the best total acidity value; the treatment with supersonic procession of 30°C, 45min, 120W could get the best Vc content value; the treatment with supersonic procession of 40°C, 45min, 100W could get the best sensory score of strawberry wine; treated with supersonic procession of 40°C, 30min, 100W, the microbic quantity of strawberry wine could be get the lowest value. Among them, ultrasonic power had a more significant effect on the pH and total acidity of strawberry wine, as well as ultrasonic temperature on the content of Vc and ultrasonic time on the sensory evaluation and microbial quantity.
The Influences of Aerobic and Anaerobic Conditions on PHB and Glycerin Yields in the Process of Lignin Degradation by Pseudomonas stutzeri P156
Authors: Wang Zhi , Qin Wei Zi , Bao Shuai Shuai , Chen Xiong , Zhang Feng Lian , Li Dong Sheng
Published: March 2013

The effects of aerobic and anaerobic conditions on polyhydroxybutyrate (PHB) and glycerin yields during the course of lignin degradation were studied with Pseudomonas stutzeri P156. The lignin degradation rate was 22.5% and 15%, respectively, under aerobic and anaerobic condition. However, the gradation rate/biomass (YL/X) was nearly no differences that diversified from 0.9% to 3%. In addition, the maximal anaerobic yield of PHB and glycerin yield was 0.42 g/g and 56.3 ug/ml, which was 176.6% and 36.7% higher than that under aerobic condition, respectively. Interestingly to point out, anaerobic lignin degradation rate was decreased by 33.3% relative to the aerobic one, but lignin content did decreased by 15% at the cost of higher yields of PHB and glycerin, which suggested biosyntheses of PHB and glycerin could balance the redox potential under anaerobic condition, facilitate lignin degradation by Pseudomonas stutzeri P156, persistently, and meet the process demands of straw-based anaerobic methane fermentation.
The Study of Eleutheroside on Immunological Function of Aging Rats
Authors: Yang Ping , Jia Qiao , Meng Xian Jun
Published: March 2013

Objective: a study on effect of eleutheroside on the immunological function of aging model rats, exploring its immune mechanism of delaying aging.Method : Eleutheroside of different concentration after the effect of aging model rats ,calculating the cardiac index ,determination of T- lymphocyte proliferation faction by MTT colorimetric , determination the concentration of the IL-2, IL-6 and TNF-α by double antibody sandwich ELISA method. Result : Eleutheroside can improve the immune function of aged rats and have the centration-dependent .Conclusion: Eleutheroside can improve the immune function of the aged rats and delay the immune senescence.
Isolation and Identification of Thermostable Lactase-Producing Bacillus coagulans T242
Authors: Qian Fang , Jiang Shu Juan , Liu Tao , Mu Guang Qing
Published: March 2013

Lactase from the thermophilic bacteria has the good characteristics of heat-stability, high production and low pollution, and can effectively solve people’s problem of “lactose intolerance”. In the present work, a thermostable lactase-producing strain was isolated from the fermenting sample in fermenting tank of a spice factory in Chinese city of Dalian. Base on morphological observation, physiological and biochemical tests and molecular identification, the thermostable lactase-producing strain T242 was identified as Bacillus coagulans. Moreover, investigation revealed that lactase from Bacillus coagulans T242 is an intracellular lactase hydrolyzing lactose into glucose and galactose inside of the bacterial cell, and the optimum approach for releasing lactase was the treatment with lysozyme followed by high concentration of NaCl.
Rapid Spectrophotometric Determination of Hypothermia Protection Activity of Sericin Peptides on Lactobacillus bulgaricus
Authors: Zhou Yan Fu , Wu Jin Hong , Wang Shao Yun , Guo Xiao Qing , Wang Zheng Wu
Published: March 2013

Sericin peptides have a high proportion of hydrophilic amino acid residues, which are considered to protect cells from freezing stress due to the maintenance of water in the cells. In this paper, the hypothermia protection effect of sericin peptides was studied by reading optical density of cells at 600 nm, which was detailedly optimized to be a direct and practical spectrophotometric method. The survival rate of Lactobacillus bulgaricus after frozen storaged with addition of 0.1 mg/mL sericin peptides was close to that of 10% (v/v) glycerol (p > 0.05). The survival rate of 5 mg/mL sericin peptides was up to 64.17%.
Hemagglutination Characterization of Lectins from Four Traditional Chinese Medicines
Authors: Yuan Hui Jun , Yang Ai Mei , Gong Hui Ling , Hu Jing , Bao Jing Ting , Yuan Yi Jun
Published: March 2013

Hemagglutination titer of crude lectin from four traditional chinese medicine was detected. Lectins from Radix Polygalae and Saxifraga stolonifera agglutinated red blood cells of rabbit, rat and chook potently. Heteropappus hispidus (Thunb.) Less lectin also agglutinated the three kinds of red blood cells, but hemagglutination titer was lower. Hemagglutination effect of Lepisorus waltonii (Ching) Ching lectin only appeared in rat red blood cells.
Expression of Recombinant Human Cytomegalovirus Fusion Proteins pp150-pp65 Fragments and its Application
Authors: Jin Yu Fen , Li Yan Lei , Hua Yan , Zhang Xiao Gang , Yu Ting
Published: March 2013

Objective To evaluate the effectiveness of prokaryotic expression of fusion proteins pp150-pp65 of human cytomegalovirus (hCMV) for its application as antigen, the fusion protein of pp150-pp65 were expressed in prokaryotic expression system and purified by Ni-NTA affinity chromatography column for preparing the colloidal gold kit. Methods Using DNA from HCMV strain as template, the genes encoding pp150 and pp65 protein fragment were amplified by PCR technique, respectively. After confirmed by DNA sequence analysis, the recombinant plasmid pET28a-pp150-pp65 was transformed into E.Coil.BL21(DE3) and induced to express with IPTG. The expressed fusion protein was characterized by SDS-PAGE and western blot after purified, then we used the purified fusion protein to develop combined detection kit of IgM/IgG antibody against HCMV (colloidal gold method) with Beijing Innovita Bio-tech Co., Ltd for detecting the samples, compared with the imported kits (ELISA). Results The gene of fusion fragment pp150-pp65 was correctly amplified and the recombinant vector was successfully constructed. The purified protein with the molecular weight of 45KD had good antigenicity by western blot. The protein was subjected to assay with an ELI SA capture kit in its specific and sensitive assay based on colloidal gold nanoparticles, testing of 600 serum samples indicated that this kit had a sensitivity of 92.7%;, specificity of 83.1%, crude consistency o f 90.2%, compared to the imported HCMV-IgG kit; the sensitivity of the kit was 88.1%, specificity was 89.2%, coarse consistency was 88.5%, compared to the imported HCMV-IgM kit; Conclusion In this experiment, the HCMV antigen with high purity and specificity (pp150-pp65 recombinant protein) was prepared effectively through genetic engineering technology. Compared to imported reagents, the colloidal gold kit consisting of fusion protein in a capture assay had high sensitivity and specificity. Preliminary clinical use warrants further development and use of this kit. Furthermore, it provides a technological basis for detection of HCMV in different stages of clinical infection.
Optimization of the Fusion Expression of Chicken β-Defensin Gal-3 in E Coli
Authors: Wang Hui Yan , Liu Lei , Mo Suo , Liu Huan , He Yuan Xin , Li Yan , Jiang Yong
Published: March 2013

The expression level of chicken β-defensin Gal-3 was influenced by lactose concentration, induction time and initial cell density, and IPTG induction was used as a control. The optimal parameters of various factors were confirmed. the optimal parameters with lactose induction was 37°C of culture temperature, 2 g/L of joining lactose final concentration when the recombinant strain growth density A600 achieved 0.8 and induction maintained 3 hours, the production of fusion protein reached the highest level. This study provides a good experimental basis for the large production of Gal-3.
The Interaction of Cytotoxic Sm (III) Complex of Plumbagin with Bovine Serum Albumin
Authors: Tan Ming Xiong , Luo Xu Jian , Gu Yun Qiong , Lu Gong Cong
Published: March 2013

Plumbagin (PLN) is isolated from Plumbago Zeylanica, an anticancer Traditional Chinese Medicine. The interaction between cytotoxic complex [Sm (PLN)3(H2O)2]H2O and bovine serum albumin (BSA) is investigated by fluorescence, synchronous fluorescence, and UV-vis spectra. It is observed that Sm(III) complex can reduce the fluorescence intensity of BSA by the way of static quenching.
Absorbability of Active Carbon Influencing the Haze in Clarified Apple Juice
Authors: Yi Xin Xin , Wang Fang , Pang Mei Xia , Tan Feng , Qi Jing Hua
Published: March 2013

The relationship of adsorption characteristic about active carbon and the haze in clarified apple juice was investigated. Particle size and addition and adsorption temperature of active carbon were studied.0.18mm particle size with the biggest specific surface area and 0.075mm particle size with the widest microspore distribution of active carbon lowered the turbidity and contents of haze active protein and that of haze active phenolics. Contents of haze active protein and that of haze active phenolics in apple juice were decreased by increasing the adding amounts of active carbon. High temperature of adsorption showed the positive relationship with volume of haze active phenolic and the negative relationship with volume of haze active protein. Particle size of active carbon with 0.18mm or 0.075mm and addition of 15g/kg and adsorption temperature with 50°C are chosen in reducing the haze in apple juice. Absorbability of active carbon has great effects on the haze of apple juice.
Optimization of Ultrasonic Extraction of Total Flavonoids from Litchi (Litchi chinensis Sonn.) Seed by Response Surface Methodology
Authors: Lin Li Jing , Huang Xiao Bing , Li Ji Hua , Zhou Yao Min , Tang Yong Fu , Ran Xu
Published: March 2013

The ultrasonic technology was applied to optimize the processing parameters of extraction of flavonoids from litchi seed using the response surface methodology. The Box–Behnken design was used to analyze the effect of independent variables including extraction temperature (X1), methanol concentration (X2) and extraction time (X3) on the yield of total flavonoids as the dependent variable(Y). The analysis of variance (ANOVA) indicated that three independent variables, their quadratic terms and interaction terms showed a significant effect on yield of total flavonoids (YTF) except the interaction between X1and X2. A mathematical model with high determination coefficient was constructed, according to which the optimal extraction conditions were determined as follows: extraction temperature 70°C, methanol concentration 68%, extraction time 70 min. Under the above-mentioned condition, the experimental value of YTF was 3.55 g catechin equivalent per 100 g of dry (g CE/100 g ), which agreed with the predicted value perfectly, demonstrating the response surface model was suitable in optimizing the extraction of flavonoids from litchi seed.
NBO Analysis the Chlorine Anion Recognition Mechanism of the Urea-Based Involving Iodine and Fluorine Derivation Functional Molecular Material
Authors: Liu Yan Zhi , Liu Yan , Yuan Kun , Zhu Yuan Cheng
Published: March 2013

The recognition mechanism of the urea-based non-involving fluorine (A) and involving fluorine (B) derivation receptors for the chlorine anion (Cl-) was discussed by using the density function B3LYP method. The results showed that recognition mechanism was performed by using four coordination weak bonds, which include two N-H…Cl hydrogen bonds and two C-I…Cl halogen bonds. The calculated interaction energies (ΔECP) with basis set super-position error (BSSE) correction of the two systems are -121.78 and -179.71 kJ•mol-1, respectively. So, the urea-based involving fluorine derivation receptor (B) presents the better recognition capable for the Cl-. Natural bond orbital theory (NBO) analysis has been used to investigate the electronic behavior and property of the N-H…Cl hydrogen bonds and two blue-shift C-I…Cl halogen bonds in the A…Cl- and B…Cl- recognition systems, respectively.
Research of Preparation Factors on Magnetic Cassava Starch Microspheres
Authors: Lan Ping , Feng Yu Xian , Chen A Ming , Qiao Lei Lei , Lan Li Hong , Liao An Ping
Published: March 2013

Magnetic cassava starch microspheres have been prepared by means of the method of precipitation magnetization, cassava starch as raw material adsorbing or embedding Fe3O4, many influence factors on magnetic cassava starch iron rate such as pH, reaction time, stirring speed, ratio of Fe+3 to Fe+2, reaction temperature also investigated in this paper. On the base above research, we preliminary got the optimal conditions on the synthesis of magnetic cassava starch microspheres.
Rheological Properties of Fresh Jujube Pulp
Authors: Zong Wei , Cao Yi Heng
Published: March 2013

The rheological behavior of fresh jujube pulp with different concentration (30%-50%) was studied at a wide range of temperature (20°C-60°C) and homogenization pressure (0M-25MPa)in this paper. The result shown particle of fresh jujube pulp decreases with homogenization pressure, viscosity increased with concentration increase but decreases with temperature increase. Besides, the viscosity of fresh jujube correlated remarkably with its soluble solids content and pulp particles size.
Study on Ultrasonic Assisted - Precipitation Method Combined Purification of Tea Saponin
Authors: Wu Yu Qiong , Man Wei Dong
Published: March 2013

Commercial crude tea saponin as raw material, ultrasonic assisted extraction technology of tea saponin was investigated. Five influence factors of ethanol concentration, extraction temperature, extraction time, solid-liquid ratio, ultrasonic power on the extraction of tea saponin were studied in detail. Orthogonal experiment through the single factor experiment design, the experimental results show that the optimum operating conditions for the ethanol concentration of 80%, solid-liquid ratio 1: 40, extraction temperature 40°C, ultrasonic power of 300W, ultrasonic extraction time 45 minutes. Under the optimum conditions obtained tea saponin extract with ethanol- acetone precipitation method is further purified, tea saponin content increased from 52.1% to 93.6%. The result indicated that the purity of the tea saponin could be effectively improved through the ultrasonic assisted- precipitation combined method.
Simultaneous Determination of Four Herbicide and Pesticide Residues in Chinese Green Tea Using QuEChERS Purification Procedure and UPLC-MS/MS Analysis
Authors: Wang Su Fang , Zhang Shou Jie , Dong Chun Hong , Wang Guo Qing , Guo Jun Feng , Sun Wu Yong
Published: March 2013

A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg-1and 5 μg•kg-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg-1spiking levels range from 77.4% to 95.3%. TheSupersSuperscript textcript textrelative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.
Analysis and Study of the Structural Characteristics of Ultrafine Stirred Mill
Authors: Li Hui Juan , Yan Hong Wei , Lu Hui Shan , Gao Qiang
Published: March 2013

In recent years, due to the ultra-fine powder is widely used in various industries of the national economy. And corresponding to domestic and foreign have developed a variety of ultra-fine grinding equipment, including stirring mill, which is considered the most potential for development of an ultra-fine grinding equipment. This is brought to its unique working principle and structure characteristics. This paper introduces the stirred mill work principle as well as the history of the development of the stirred mill both at home and abroad, which analysis of the structural characteristics of stirred mill. And it puts forward the directions of the stirred mill in the future research.
Explosion Simulation for Petrochemical Plant with Water Spray
Authors: Yuan Ji Wu , Zhao Xiang Di , Wang Zheng
Published: March 2013

Traditional assessment techniques can't predict the explosion with effects of water spray system. A method of explosion simulation which based on FLACS software for Petrochemical plant with water spray were used for simulating the explosion risk of a coal gasification company’s plant. Simulation results indicate that the water spray system can significantly weaken the devices exploded consequences. This method can be used for fire protection system design and optimization of layout for petrochemical plants.
Material Choice of Rotating Seal Joint of the Device Yellow Phosphorus Extraction from Phosphorus Sludge at Moderate Temperature
Authors: Li Zhi Lin , Jiang Ying Xiang , Li Gui Zhen
Published: March 2013

This paper introduces the process of yellow phosphorus extraction from phosphorus sludge at moderate temperature and existing problems of the device. It is necessary to design the rotating seal joint of the device again. According to materials physical and chemical properties, the paper expounded materials choice of rotating seal joint parts.
Air and Wet Air Oxidation of 9Cr-3Co-3W Creep Resistant Ferritic Steel at 650 °C
Authors: Tang Shan , Tang Xi , Xiang Z.D.
Published: March 2013

The new experimental creep resistant ferritic steel of the 9Cr-3Co-3W type was oxidised at 650 °C in air and wet air. The oxidation kinetics was measured by intermittent weight measurement. The scales formed were analysed using techniques of XRD, SEM and EDS. The results showed that the oxidation rate was more than a magnitude faster in wet air than in air. The oxidation kinetics in air obeyed the parabolic rate law of oxidation only in a limited oxidation period of up to 1726 h whereas it did not follow any power rate law of oxidation in wet air. The steel cannot form a protective Cr2O3 scale either in air or in wet air at 650 °C. Instead, the scale formed in air consisted of an outer (Fe0.6Cr0.4)2O3 layer and an inner Cr-rich (Fe,Cr)2O3 layer containing Cr2O3 particles, but in wet air it consisted of an outer Fe3O4 layer and an inner (Fe,Cr)3O4 layer.
Effect of Rare Elements on Corrosion Behavior of SPCC in CSP
Authors: Zhou Yan Feng , Qiu Wei Jian , Li Wei Xiao , Xie Jiang
Published: March 2013

The corrosion process of rare earth (RE) SPCC steel and SPCC steel in CSP in 3.5% NaCl solutions was investigated by SEM, EDS, XRD and polarization curve measurements. The results show that grain refinement can be obtained, the inclusions will be formed, and the electrochemical corrosion of microscopic region is weakened and therefore the corrosion resistance of SPCC steel could be improved by addition of RE. The rust layer of RE treated steel generated in the solution is more compact, the α-FeOOH content in rust layer is higher, and the content of activated γ-FeOOH and β-FeOOH is smaller, which are helpful to protect the steel. It also shows that current densities of SPCC steel is lower and the corrosive tendency will decrease with the addition of RE, which also makes the corrosion resistance of steel improved.
Optimization of Liquid Steel Flow in an Industrial Tundish
Authors: Tong Qiu Fang , Wu Zhong Hua , Mujumdar Arun S.
Published: March 2013

A computational fluid dynamic (CFD) model was developed to study the fluid flow phenomena taking place in an industrial tundish. Numerical results showed spatial distributions of the velocity vectors, the residence time and fields of turbulence kinetic energy. Selected computer simulation results were validated with experimental data. The effect of the impact pad and interior dams on the hydrodynamics of liquid steel flow were studied numerically and optimized to reduce the fraction of dead volume zones and augment nonmetallic inclusions to float into the slag. A novel design of a turbo-stopper was proposed and its function to decelerate the ladle shroud jet and direct the flow back to reduce slag entrapment was discussed. Such numerical results improved our understanding of the hydrodynamics of liquid steel flow in the tundish and contribute to an optimized operation.
Research on the Process of High Silicon Aluminum Alloy in MEDM
Authors: Hu Fu Qiang , Sun Jian Fei , Wei Jun Qi , Zhang Yong , Jia Yan Dong , Zhao Yue Rui , Liu Ting Yi
Published: March 2013

Because of the high content of Si, traditional machining can hardly machine micro and small structures. While there is almost no microscopic force in the process of micro-electrical discharge milling (MEDM), so it has great advantages. In the process of MEDM for high silicon aluminum (Si-Al) alloy, the impacts of electrical parameters on processing time, the trend and degree of electrode wear are researched. The Al-50wt%Si alloy made by spray forming (SF) and casting forming (CF) and electrode of copper and tungsten are adopted to do the research. Related processing laws are summarized. A micro-3D structure was made by using appropriate parameters based on the experiment and research.
Simulation of Dynamic Recrystallization for Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy in β Processed Using Cellular Automaton
Authors: Wang Ke Lu , Lu Shi Qiang , Li Xin , Dong Xian Juan
Published: March 2013

The cellular automaton (CA) method coupling fundamental metallurgical principles was used to simulate the dynamic recrystallization (DRX) behavior of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy in β processed. Using physically based rules for the simulation of nucleation and growth phenomena of dynamically recrystallized grains. The effects of hot deformation temperature and true strain on the DRX characteristic of the alloy during β processed was studied, and the results compared with experiments. The predictions show very good agreement with the experimental results for the alloy.
Research on Band Microstructure and Annealing Process of CrMo Steel Used for Precision Ball Screw
Authors: Ding Xia , Yan Ye , Wang Qian , Li Bao Min , Li Mu Sen
Published: March 2013

The band microstructure has an adverse effect on the comprehensive mechanics performance of Cr-Mo steel used for ball screw. This paper dealt with the different annealing processes combined with the forming mechanism of the banded structure. It shows that the annealing with long time can basically eliminate the band microstructure.
The Study on the Fabrication of Nano-Structured Steel by Cold Rolling and Annealing of Martensite
Authors: Xu Guang , Yang Jing , Xiong Tao , Deng Peng , Cao Long Fei
Published: March 2013

Sub-nano structured steel was obtained by cold rolling and annealing martensite microstructure for a plain carbon steel. The mean grain size is several hundreds nanometer. The steel has very high strength and also good total elongation.
Cluster Structures and Evolution in Liquid Al-Pb Alloys
Authors: Yang Ning , Sun Yong , Zhang Hui
Published: March 2013

Molecular dynamics (MD) simulations was used to investigate the structures and evolution of atom clusters in liquid Al-Pb alloys. Pair correlation functions and chemical short-rang-order (CSRO) parameters indicate that inhomogeneous atoms are prone to be repulsed while Al-Al and Pb-Pb clusters are easy to emerge. The Voronoi analysis shows that the main coordination number around Al atoms and polyhedron index vary with Pb increasing. The main coordination number abruptly decrease from 11 to 9 when the Pb atomic percentage range from 30% - 40% , proving that Al-Al and Pb-Pb clusters are prone to be separated.
Research on MRT3-BA Steel in Macro Inclusions
Authors: Wang Shuo Ming , Wang Jian Xing , Gao Ju
Published: March 2013

The research about the macro-inclusions of three processes: BOF→ LF→ CC, BOF→ RH→ CC and BOF→ LF→ RH→ CC, shows that: The types of inclusion are SiO2-Al2O3-CaO-TiO2-MnO, SiO2 and SiO2-Al2O3. The content of SiO2-Al2O3- CaO-TiO2-MnO in the three processes are 34.2%、23.5% and 27%; The content of SiO2 are 24.4%、47% and 27%; The content of SiO2-Al2O3 are 26.8%、17.6% and 9%. Large inclusion>300μm takes up 69.8%~85% of the total inclusion in billet in three technological processes, and the inclusion, containing K and Na, is the most; slag entrapment in mould is really serious. Considering the cleanliness and cost, the better technological process of MRT3-BA stamping steel is BOF→ RH→ CC.
Study of Micro-Inclusion of Grade 45 Steel
Authors: Xiao Bu Qing , Li Sheng Fu , Tian Xiao Tao , Wang Jian Xing
Published: March 2013

According to the production process of grade 45 steel(120tBOF→slag refining→ CC), some system analysis are introduced to research on the type composition and quantity of micro-inclusions, and the effect of slag washing production process on the cleanliness of casting slab is evaluated. The results of the study show that: The content of T[O] is 48.75ppm in normal slab, The content of T[O] is 56.2ppm in head slab, The content of T[O] is 49.2ppm in compound casting slab.The main types of micro-inclusion in slab are MnS inclusion and Al2O3 inclusion. The quality of micro-inclusions is 14.32/mm2 in the normal slab, the quality of micro-inclusions is 17.68 /mm2 in the head slab, the quality of micro-inclusions is 27.94 /mm2 in the compound casting. In the normal slab, the average total volume ratio of micro-inclusions is 0.0458%. The particle size of micro-inclusions is smaller. The particle size of less than 10μm in micro-inclusions is the largest and is about 80%.
Adsorption of Cu (II) on Thiourea Impregnated Gelatin Microspheres
Authors: Yu Li Li , Yao Lin
Published: March 2013

In this study, we describe a novel adsorbent, thiourea impregnated gelatin microspheres(TIGM) which were synthesized from thiourea impregnated gelatin by inverse suspension polymerization with glutaraldehyde as crosslinker. With the aim to investigate the absorption kinetics of Cu(II) on TIGM, the absorption equilibrium, the effects of temperature on the absorption was fully discussed. It was found that this adsorbent is effective for the removal of Cu(II) from aqueous solutions. Results of the experiments presented that the thiourea was uniformly dispersed in microspheres mainly through chemical bonds, and the adsorption isotherms of Cu(II) on TIGM fits well both with the classical Freundlich equation and the Langmuir equation. It was also suggested that the adsorption rate of Cu (II) was faster at higher temperature, and the amount of the adsorption also increases with the increasing of temperature. According to the research, the maximal adsorption capacity is obtained when pH is 5 to 9, and the adsorption kinetics of Cu(II) onto TIGM could be described by pseudo-first-order rate mode.
Study on the Large Inclusions in 20g Steel
Authors: Zhu Li Guang , Wang Ruo Si , Du Cheng Liang
Published: March 2013

According to the production process of 20g steel(120t BOF→ LF→ CC), some system analysis are introduced to research on the content of T[O] and [N] and the type, source, composition and quantity of micro inclusions in refining process, pouring process and casting billet. The results of the study show: in billet, the main type of large inclusions is CaO-SiO2-Al2O3-MgO complex inclusion of sulfur contained. The content of large inclusions is 14.5mg/10kg in normal billet. The content of large inclusions is 33.14mg/10kg in compound casting billet which is 1.29 time than normal billet.The content of large inclusions whose particle size is more than 300μm in billet is 8.39mg/10kg, and make up 87% of the total. The content of large inclusions whose particle size is 140-300μm in billet is 2.29mg/10kg, and make up 15.79% of the total. The content of large inclusions whose particle size is 80-140μm in billet is 3.82mg/10kg, and make up 26.35% of the total. Unsteady casting plays an important role in the steel cleanliness.
Curing Reaction Kinetics of Epoxy/MWCNT-P Composites
Authors: Sun Li Jiao , Huang Ya , Chen Xiao Ting
Published: March 2013

The effects of the functionalized multi-walled carbon nanotubes (MWCNT-P) on the curing behavior of a diglycidyl ether of bisphenol-A epoxy (DGEBA) in the presence of 4,4'-methylenedianiline were investigated by non-isothermal differential scanning calorimetry. Activation energy (Ea) was obtained through Kissinger and Ozawa methodsItalic text respectively, and reaction order(n) was educed by Crane equation. The results showed that the addition of MWCNT-P enhanced the cure reaction of DGEBA with 4,4'-methylenedianiline, compared with pure epoxy system, epoxy containing MWCNT-P exhibited a lower activation energy. Both systems presented the same reaction orders, which indicated MWCNT-P did not change the auto-catalytic cure reaction mechanism of the epoxy resin.
Dielectric and Infrared Properties of Plasma Sprayed Nano β-SiC/ Al2O3 Agglomerate Composite Absorbing Coatings
Authors: Yuan Xiao Jing , Zha Bai Lin , Wang Han Gong
Published: March 2013

In this paper, the nano-β-SiC/Al2O3 composite absorbing coatings produced by plasma spraying technology were reported. Where, β-SiC phase dissipates in the boundary of Al2O3 grains. Then, the relationship between microstructure and dielectric properties was built. Some results are shown as follows: with increasing of flatten ratio of particle and pores, the microwave reflectivity coefficient of composite absorbing coatings decreases and ranges to low frequency. And, there exists a threshold value, about 30wt% of nano β-SiC, the microwave reflectivity coefficient of composite absorbing coatings can reach to -8 dB. The infrared properties of β-SiC/ Al2O3composite absorbing coatings with experiment is about 0.6~0.8, respectively.
Interfacial Debonding Force and Shear Strength of Sugar Palm (Arenga pinnata) Fiber Reinforced Composites by Pull-Out Test
Authors: Khor L.S. , Zulkiflle Leman , Lee C. H.
Published: March 2013

An experimental investigation was performed to understand the pulling out behaviour of sugar palm (Arenga pinnata) fibers from unsaturated polyester (UP) composites. The effect of embedded length on the fiber-matrix interface was studied. Fibers were treated with UP and phenol formaldehyde (PF). Untreated fibers were used as the control. Single fiber pull-out tests were carried out for 360 specimens to determine the debonding force and interfacial shear strength (IFSS). Significant increase in debonding force of untreated fiber and UP-impregnated fiber was observed from embedded length of 2 mm to 3 mm. However, no significant increase was observed for the embedded length of more than 3 mm. Debonding force showed remarkable improvement with ascending order of untreated fibers, PF-impregnated fibers, and UP-impregnated fibers. The optimum embedded lengths of untreated fibers and UP fibers were determined. Additional finding showed that the interfacial shear strength decreased as the embedded length increased. However, UP-impregnated fibers showed the highest IFSS value, followed by PF fibers and untreated fibers. Analysis using Scanning Electron Microscope (SEM) was also included to justify the result.
Preparation and Electrochemical Properties of Poly(p-Chloroaniline)
Authors: Zhang Chun Yu , Niu Hai Jun , Zhang Lin , Bai Xu Duo
Published: March 2013

Polymerization of p-chloroaniline (CA) was achieved electrochemically in aqueous solution containing H2SO4 as supporting electrolyte. The films were obtained by applying sequential linear potential scan rate 20mV/s between -0.5 to 1.5V versus Ag/AgCl electrode. The polymer was characterized by UV-visible and FT-IR spectroscopy. We observed the morphologies of PCA films through the scanning electronic microscope (SEM), showing island protruding structure. The Tafel curves showed that PCA can be used as anti-corrosion material.
The Computer Simulation of the Acid-Base Titration
Authors: Huang Xue Zheng , Liu Yang Tao , Zhang Lei
Published: March 2013

The mathematical model on acid-base titration was established by using analytical chemistry theory; therefore the author designed a program to solve the model by using of Visual Basic language. The program can not only calculate the pH Value of the acid-base titration solution, choose the appropriate indicator, calculate the endpoint error and judge the feasibility of the titration, but also can draw the curve of the acid-base titration.
Research on the Adsorption Abilities and Mechanism of the Grafted Composite Adsorption Material PEI/SiO2 towards p-Nitrophenol
Authors: Du Rui Kui , An Fu Qiang
Published: March 2013

Functional macromolecule polyethyleneimine (PEI) is grafted onto the surface of silica gel particles with the “graft to” method using γ-chloropropyl trimethoxy silane as coupling agent, and the grafted composite adsorption material PEI/SiO2 is prepared. The adsorption abilities and mechanism of PEI/SiO2 towards p-nitrophenol are also studied. The results show that PEI/SiO2 possesses very strong adsorption ability for p-nitrophenol by hydrogen bond interaction. The adsorption amount can reach to 78.6mg•g−1. The adsorption is physical adsorption of a monomolecular layer and conforms to the Freundlich adsorption model. The pH and temperature have great influence on the adsorption capacity. As sodium hydroxide solution is used as eluent, and the adsorbed phenol is eluted easily from PEI/SiO2.