bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Behaviour of Zink Electrode in an Neutral Environment at Polarization with Industrial Alternating Current
Authors: Bitursyn S.S. , Bayeshov A.B. , Sarbaeva M.
Published: September 2013

The article deals with the process of electrochemical dissolution of zinc polarization by alternating current of 50 Hz frequency in a solution of sodium sulfate. The influence of various parameters on the current efficiency of zinc dissolution was considered: the current density on the titanium and zinc electrodes, electrolyte concentration, duration of electrolysis and temperature of electrolyte. It was shown that at change of current density on the titanium electrode from 10 kA/m2 up to 70 kA/m2 current efficiency of zinc dissolution increases (55%), and further down. At change of current density of zinc electrode from 200 A/m2 to 800 A/m2, electrolysis time from 0.25 to 2.0 hours and increase of temperature from 20°C to 80°C the current efficiency of dissolution decreases and with increasing concentrations of sodium sulphate increases to 90%. Based on the results shown it is possible to create a waste-free synthesis of zinc compounds from environmental harmful residues of zinc metal by electrochemical technology.
Estimation of Calorific Value of Coals Using BP and Elman Neural Networks
Authors: Zhang Hong Liang , Hao Zhen Da , Kong Xiang Ming , Li Wei
Published: September 2013

Coal quality analysis is an important part in the fuel management of power system. The coal calorific value (CCV) is the basis to appraisal of coals heat balance calculation, coal consumption, heat efficiency and improving of heat utilization. There exist many methods on estimation of CCV. Artificial neural networks have many advantages in this area. This paper described the network structure, the mathematical model and the algorithm flow of BP neural network (BPNN) and Elman neural network (ENN) which are both used for the CCV estimation. Results show that both BPNN and ENN can well reflect the non-linear relationship between CCV and other factors of coal quality. And ENN is more accurate to predict CCV, with smaller absolute error.
Study on Mechanical Property of Polylactic Acid Toughened by Polyacrylate Microsphere
Authors: Song Xiao Li , Chen Ying , Xu Yu Zhi , Wang Chun Peng
Published: September 2013

Polyacrylate microsphere with different core/shell ratio (mass ratio) were prepared by semi-continuous seed emulsion copolymerization using butyl acrylate (BA) and methyl methacrylate (MMA) as main monomers，which were used to toughen polylactic acid (PLA) after drying. The effect of core/shell ratio of polyacrylate toughening agent (ACR) on mechanical properties of PLA was studied. The results showed that when adding 8wt%ACR, the impact strength and elongation at break of PLA were both first increased and then decreased as increasing of core/shell ratio, while the tensile strength loss of PLA was little changed. It is found that the impact strength was increased about 24% than that of neat PLA as well as the elongation at break was increased from 2% to 12% when the ratio was 7/3, which was the best ratio.
Electrochemical Polymerization of Variamine Blue Film at Glassy Carbon Electrode and its Electrochemical Behavior
Authors: Li Guo Bao , Liu Cheng , Sui Wei Ping , Yang Qiu Xia
Published: September 2013

Variamine blue (VB) polymer coatings can be obtained by electrochemical polymerization at glassy carbon electrode. The electrochemical behavior of this stable polymer film at glassy carbon electrode was investigated by cyclic voltammetry. The surface coverage, Γ,the charge transfer coefficient, α , and the charge transfer constant, ks, for electron transfer between VB and glassy carbon electrode were calculated as 9.0×́10-5 mol·cm-2, 0.47, 2.97 s-1 respectively. This VB polymer coatings modified electrode shows good electrocatalytic activity toward ascorbic acid (AA), uric acid (UA). It can be used in simultaneous determination of AA and UA in a mixture.
Using Reversible Addition-Fragmentation Chain Transfer Polymerization to Synthesize Well-Defined Polymer
Authors: Bian Shou Juan , Fu Ying Juan , Qin Meng Hua
Published: September 2013

As an effective and versatile tool for production of functional polymer, RAFT polymerization has been successfully applied to the polymerization of block copolymers and other polymers of complex architectures with precisely controlled structure, molecular weight, and polydispersity. It has the ability to control polymerization of most monomers and has fine compatibility with reaction conditions. The present article summarized some of the features of the RAFT process, and reviewed the recent advances in the production of green polymers.
Effect about Axial Vibration on Solution Viscosities of PS/Supercritical CO2
Authors: Li Bing , Zhou Nan Qiao
Published: September 2013

In this paper, a technology of determining the melt viscosity of a polystyrene(PS)/supercritical CO2solution using a linear capillary tube die mounted on a foaming dynamic extruder is presented. CO2was injected into the dynamic extrusion barrel. Single-phase PS/CO2solutions were formed using a microcellular extrusion system and phase separation was prevented by maintaining a high pressure in the capillary tube die. Bymeasuring the pressure drop through the die, the viscosity of PS/CO2, solutions was determined. The dynamic extruder foaming apparatus was developed and using it to study the effects of CO2content and vibration on viscosity of PS/CO2solution. The blow agents and vibration can plastic the polymer viscosity. A theoretical model based on the generalized Cross-Carreau model was proposed to describe the shear-thinning behavior of PS/CO, solutions at various shear rates. The zeroshearviscosity was modeled using a generalized Arrhenius equation to accommodate the effects of temperature, pressure, CO2content, and vibration.
Ageing Effect on Steady Rheological Behavior in Oilfield Water of Water-Soluble, Hydrophobically Associating Polymer
Authors: Zhu Yue Jun , Zhang Jian , Jing Bo , Tan Ye Bang
Published: September 2013

The effect of ageing time on the macromolecular composition and conformation on intermolecular entanglement and crosslinking was investigated for a water-soluble, hydrophobically associating polymer (WSHAP), by steady-flow and oscillatory experiments at reservoir temperature (65 °C). The measurement of rheological properties was carried out with changing sample properties such as shear stress, shear rate and storage time. Moreover, for the investigated samples, the mathematical interpretation of relationship between the modulusGand the shear rate γ according to the Ostwald de Waele (power law) model, was carried out. Energy of viscous flow (Ea) has also been determined and discussed.
Silica-Supported Phosphotungstic Acid as Green Heterogeneous Catalyst for α-Pinene Polymerization
Authors: Cao Song , Zeng Wei , Wang Shuo , Zhang Tai Shun , Liu Zu Guang , Xie Xiong Min
Published: September 2013

Phosphotungstic acid supported over silica catalysts were prepared, characterized and tested. The results show that silica-supported phosphotungstic acid with 50 wt% of loading amount indicates excellent catalytic performance for the polymerization ofα-pinene. It is also found that the products are easily separated from reaction mixture and the silica-supported phosphotungstic acid catalysts are low-corrosive. Hence, a clean and environmentally friendly heterogeneous catalyst forα-pinene polymerization is reported.
Study of the Volatile Constituents in Atractlodesm acrocephala Koidz by Gas Chromatography–Mass Spectrometry and Combined Chemometric Methods
Authors: Xie Xian Zhen , Huang Lan Fang , Feng Xiao Liang , Wang Yu Lin
Published: September 2013

A method for the study of the volatile components in Atractlodesm acrocephala Koidz from different sources with combined chemometrics methods was developed. After the volatile components in Atractlodesm acrocephala Koidz from two different locations were detected by GCMS, the qualitative and quantitative analysis of the volatile components of Atractlodesm acrocephala Koidz from Tiantai was conducted with SFA. Then, the common peak in Atractlodesm acrocephala Koidz sample from Xinan was extracted with orthogonal projection method. Among the identified components, there were 37 components coexisting in the studied samples although the relative content of each component showed difference to some extent. The obtained results can provide useful information for the developing of fingerprint of Atractlodesm acrocephala Koidz. It also can be used to compare the sameness and differences of Atractlodesm acrocephala Koidz from different sources and for quality control of Atractlodesm acrocephala Koidz.
Molecular Simulation of Solution Process of Organic Molecules in Polyethylene Membranes
Authors: Liu Qing Zhi , Yang Deng Feng , Yue Ya Juan , Geng Zhen Bo , Hu Yang Dong
Published: September 2013

The dissolution process of benzene, toluene and ethylbenzene in amorphous polyethylene (PE) membrane was studied in this paper, and the solubility coefficients of the above organic molecules were analyzed and calculated by molecular dynamics simulation. The results showed: the solubility coefficient decreased with increasing molecular weights of organic molecules in the same temperature, and it also decreased with increasing temperature for the same organic molecule. Distribution of density field and energy field for organic molecules in PE were obtained. From the density distribution, the concentrated adsorbed area of the three kinds of molecules is clearly seen, which located at the more loose place in polyethylene membrane. From the energy distribution, it showed thehot spots of the organic molecules, which were the location that the organic molecules were most easily absorbed. The adsorption capacities of benzene, toluene and ethyl benzene in polyethylene membrane decreased in turn.
Mechanical Properties of Poly(lactic acid) / Thermoplastic Starch Blends Crosslinked by Gamma Radiation
Authors: Kalapakdee Siriruck , Pongprayoon Thirawudh , Hemvichian Kasinee , Suwanmala Phiriyatorn , Kangsumrith Wararat
Published: September 2013

This research aims to determine the influences of radiation-induced crosslinking on the mechanical properties of polymer blends between poly (lactic acid) (PLA) and thermoplastic starch (TPS). PLA and TPS were mixed at different ratios (90:10, 80:20, 70:30, 60:40) in the presence of a crosslinking agent using a twin screw extruder. The blends were compression molded into films. The film samples were irradiated by gamma radiation at different doses. Gel fraction was used to determine crosslinking efficiency. Results showed that gamma radiation was able to induce crosslinking for PLA/TPS blends. The gel fraction and mechanical properties decreased with increasing TPS content. The optimum ratio of PLA:TPS with the maximum gel fraction and mechanical properties was 90:10 and the optimum dose was 40 kGy by gamma radiation.
Research Progress of Conductive Polymer Material
Authors: Han Zhi Jia , Shen Sheng Fei , Li Zai Yuan
Published: September 2013

The research of conductive polymer material has received the widespread attention and development. This article has introduced the classification and preparation methods of conductive polymer materials, conductive mechanism, application and research progress in various fields.
Performance Characterization of a Novel Flame Retardant Material Poly(lactic acid-co-melamine)
Authors: Xiong Jin Feng , Huo Jing Pei , Peng Pai , Wang Zhao Yang
Published: September 2013

Directly starting from D,L-lactic acid (LA) and melamine (MA), poly (lactic acid-co- melamine) [P(LA-co-MA)] as a kind of potential polymeric flame retardant is synthesized via melt polycondensation. The properties of P(LA-co-MA) s at different molar feed ratios are characterized by XRD, DSC and TGA. Most decomposition temperatures of P(LA-co-MA) s are higher than these of homopolymer poly (D,L-lactic acid) (PDLLA). For the char yield, all copolymers have higher char yield than PDLLA. Furthermore, the more MA in the feed content, the higher char yield.
Synthesis, Characterization of 2',7'-dibromo-2,3,6,7-tetraethoxy-9,9'-spirobifluorene
Authors: Qi Chun Hua , Lei Xiao Long , Sun Xiao Xia , Hu Yu
Published: September 2013

A simple and efficient synthetic procedure of 2',7'-dibromo-2,3,6,7-tetraethoxy-9,9'-spirobi [fluoren has been developed. The new monomer of 2',7'-dibromo-2,3,6,7-tetraethoxy-9,9'-spirobi [fluoren has been synthesized in high yields over five steps from readily available starting materials. The new monomer has good solubility in organic solvents such as chloroform, methylene chloride, tetrahydrofuran, ethyl acetate and so on.
Study on the Role of Surfactants to Aqueous Two-Phase Synthesizing CPAM
Authors: Cao Ya Feng , Qu Mei Jun , Tan Feng Zhi , Liu Zhao Li , Li Yuan
Published: September 2013

In this paper,cationic polyacrylamide (CPAM) was synthesized by using aqueous two-phase polymerization. The Role of surfactants to aqueous two-phase synthesizing CPAM was studied, including the effect of the type,the composition and the concentration of the surfactants. The results showed that non-ionic surfactants had a better stabilizing impact on the polymer aqueous two-phase system. And the effect of the compound surfactant was better than that of a single surfactant. Take the chemical compound of Tween80 and OP10 as the polymerization auxiliaries, the optimum reaction condition of synthesis were as follows:wTween80:ѡOP10=1.5,w=1.6%, 50°C.In this process conditions, the distribution coefficient was the most appropriate in the continuous phase, the total monomer conversion rate and the intrinsic viscosity number of the product reached the maximum.
Synthesis and Properties of Thermo- and pH-Sensitive Poly[(Sodium Humate)-(N-Isopropylacrylamide)-(Acrylic Acid)] Intelligent Hydrogel
Authors: Zhou Xiao Mi , Sun Xiao Ran , Li Guang Yue
Published: September 2013

A novel intelligent hydrogel of poly(Humic acid - Nisopropylacrylamide - Acrylic acid) (P(NIPAAm-HA-AA)) was prepared at 70°C by inverse suspension polymerization. The reactions include uses N,N-methylene-bis-acrylamide (MBA) as a cross-linking agent, ammonium persulfate (KPS) as an initiator, cyclohexane as a continuous phase and span-65 as dispersant. The influence such as concentration of monomers and cross-linking agent, mole fraction of span-65 in mixed monomers, and temperature of polymerization on the property of resulting P(NIPAAm-HA-AA) hydrogels was investigated in detail. Fourier transform infrared (FTIR) demonstrated that NIPAAm, HA and AA was synthetized successfully. The results showed that the swelling ratio (SR) of modified hydrogel was improved significantly with the dosage of NIPAAm. It was also observed that the thermosensitive and pH sensitive characteristics was strongly affected by concentrations of NIPAAm. At last, we choose NIPAAm: HA=0.3.
Study on the Properties of the PVA/SF Blend Membranes
Authors: Wang Shu , Liu Zu Lan , Chen Li Man , Jiang Yu Chun , Jia Yi Ru , Huang Yong Xiang , Zhang Yuan Song
Published: September 2013

Polyvinyl alcohol/silk fibroin blend membrane obtained by adding different components of polyols to the ternary solvent of CaCl2 / C2H5OH / H2O ,makes up for the brittleness of sf and increases its potential properties.Electronic microscope,strength tester and other equipments are used to text the structure and performances of blend membrane. The tests of performances such as moisture content rate,loss rate in hot water, the tensile strength and elongation at break shows that: the blend membrane added by glycerol improves in thermal and mechanical performance to some extent.
Synthesis and Properties of Polyacrylate Emulsion Modified by Pentaerythritol Tetraacrylate
Authors: Jiao Li Yong , Yuan Gang , Qi Yun Peng , Li Lin Lin
Published: September 2013

A crosslinking core-shell structured polyacrylate emulsion polymer was synthesized by semi-batch seeded emulsion polymerization with methyl methacrylate and butyl acrylate as main monomers, and pentaerythritol tetraacrylate as a cross-linking agent. Chemical structure and micro morphology structure of the obtained polymer emulsion particles were characterized by Fourier transform infrared spectra (FTIR) and transmission electron microscope (TEM), respectively. Influences of cross-linking agent content on water resistance, thermal property, and mechanical property of the emulsion films were investigated. Compared to the film of the unmodified polyacrylate emulsion, water absorption capacity of modified polyacrylate emulsion film with 1.0% PET4A declined to 4.7%, tensile strength at break increased from 1.35MPa to 3.03MPa, and elongation at break increased to 171.7%; 5%,10% and 50% weight loss temperature of the modified emulsion increased 17°C,32°C and 45°C, respectively.
Decontamination of Dichlorvos by Hydrogen Peroxide
Authors: Li Zhan Guo , Wang Wei Qin , Xi Hai Ling , Zhao Hong Jie
Published: September 2013

H2O2 aerosol was used to oxidize dichlorvos vapor. 80.7% of dichlorvos, with the initial concentration of 90.9 mg/m3, was decontaminated when the H2O2 concentration kept in the range of 110~130 mg/m3 within 60 min. According to the oxidation products, analyzed by GC-MS, the decontamination reaction mechanism was discussed. Radical chain reaction is the main decontamination mechanism. H2O2 is dissociated to HOO-, which can induce the formation of ·OH. The double bond in dichlorvos molecule is attacked by ·OH to form molecule radical, which is further oxidized to 1,1-dichloro ethoxy dimethyl phosphate, 1,1,1-trichloro-2-hydroxyl-ethyl dimethyl phosphate, dimethyl phosphite, dimethyl phosphate, trimethyl phosphate, methyl phosphate, dichloro acetaldehyde, oxalic acid, CH2Cl2, CHCl3, parts of which are mineralized to phosphoric acid, CO2, H2O and chloridion.
Effect of Fe2+ on Ascorbic Acid - Methionine Pattern is Formed by the Reaction of Aroma Compounds
Authors: Liu Di , Shao Yu , Yang Xiao Hong
Published: September 2013

By solid phase microextraction - Gas Chromatography - mass spectrometry (SPME-GC-MS) technique against acid and methionine bad blood (ASA-Met) model of the reaction products were identified, studied the effect of Fe2+ on the formation of flavor compounds in the model reaction. 27 flavour compounds of furan, pyrazine, thiophene, sulfur and other compounds, were identified, of which, sulfur-containing compounds such as aliphatic cyclic sulfides, sulfide, pyrazine is the main flavor components. Fe2+ was added to the model in the system, on one hand the about adding some sulfur compounds yield, pyrazine compounds significantly increase; on the other hand, Thiophenes significantly reduced compounds or even disappear. This shows that in the model reaction, Fe2+ promotes the thermal degradation of Met, at the same time, suggesting that Fe2+ as oxidant to promote NH3, NH3 and H2S to generate competitive reaction and ASA degradation products formed compounds containing nitrogen, resulting in reduced Thiophenes compounds yield.
Extraction and Analysis of the Chemical Constituents of Volatile Oil from Albizia Bark
Authors: Song Yan , Wu Hai Yan , Yang Xiao Hong
Published: September 2013

Objective: To study the chemical constituents of volatile Albizia bark. Methods: the volatile chemical components of Albizia bark extract by water vapor distillation, gas chromatography - mass spectrometry method for the separation and identification of its composition and relative content. Results and conclusion: 25 chemical compounds were identified. The main chemical constituents of volatile oil in Albizia bark is 1,1-diethoxy-Ethane (23.972%), Ethyl Acetate (23.260%), Linalol (10.334%), 2-ethoxy-Butane (4.934%), D-Limonene (4.512%), L-π pinene (3.803%), Terpineol (3.126%), Ocimene (3.031%), Ethylbenzene (2.621%), Benzothiazole (2.199%), (E) -Ocimene (1.755%), Terpinolen (1.516%), Cedrene (1.471%), N-phenyl-1-Naphthalenamine (1.451%), 1-ethoxy-Pentane (1.418%), Terpinen (1.162%), o-Cymene (1.129%) et.
Biosorption of Iron (III) from Aqueous Solution Using Pleurotus ostreatus Spent Mushroom Compost as Biosorbent
Authors: Kamarudzaman Ain Nihla , Chia Chay Tay , Ab Jalil Mohd Faizal , Abdul-Talib Suhaimi
Published: September 2013

The ability of Pleurotus ostreatus spent mushroom compost for the biosorption of Iron (III) from aqueous solutions was investigated. The study was conducted in batch experiments under varying operating conditions. The optimum Iron (III) biosorption was achieved at an initial pH ranging from 4 to 5, contact time of 10 minutes and initial Iron (III) concentration of 50 mg/L using half-saturation constant of 0.4 g biosorbent dosages. The results indicated that the Iron (III) biosorption onto Pleurotus ostreatus spent mushroom compost were well fitted with the Langmuir isotherm model and a second-pseudo order kinetic model.
Effect of Plant Compound Curcumin on the Expression of a-Synuclein in Hippocampal Neurons of APPswe/PS1dE9 Double Transgenic Mice
Authors: Lin Xiao , Yu Li
Published: September 2013

In this study, we aim to investigate the effect of curcumin on the expression of a-synuclein in the APPswe/PS1dE9 double transgenic mice. APPswe/PS1dE9 double transgenic mice were used as AD (Alzheimer's disease) model and fed with different concentrations of curcumin every day for 6 months, then immunohistochemistry method were used to detect the expression of a-synuclein in hippocampus of mice. The expression of a-syn in hippocampal neuron was decreased significantly after treated with 0.16g/kg to 1.0g/kg curcumin, the change was apparent in dose-dependent manner (P<0.05). a-synuclein pay an important role in the genesis and development of Alzheimer's disease and decreased level of a-synuclein might contribute to the neuroprotective effect of Curcumin, which may become a new target for the prevention and treatment of Alzheimer's disease.
Studies on Forsythin Uptake Kinetics by Everted Rat Gut Sac Model
Authors: Cheng Jin , Di Liu Qing , Bi Xiao Lin
Published: September 2013

Our aim was to investigate the uptake kinetics of forsythin in the small intestine and analyze the factors that affect absorption. Methods. A simple and convenient method was established by HPLC to detect forsythin. To characterize forsythin uptake kinetics in different sacs, three different forsythin concentrations, P-glycoprotein inhibitor verapamil hydrochloride and Tween-80 were assayed by the everted rat gut sac model. Results. Forsythin could be absorbed in the whole intestine, the data had concentration and time dependence, and ka had no significant differences (P>0.05) at three concentrations (10, 20, and 40μg*mL-1). The results showed linear correlation between the forsythin absorption in sac contents and the incubation time from 0~90min. Forsythin absorbed dose order in rat small intestine is ileum>jejunum>duodenum. The permeability increased when forsythin was perfused with Tween-80, but P-gp inhibitor verapamil hydrochloride didn't has this effect. Conclusion. The absorption of forsythin in the small intestine is first-order process. The absorption mechanism is inferred the passive diffusion. Forsythin is not the substrate of P-gp.
Preliminary Researches on Influence of Several Kinds of Plants Including Ajuga Ciliata Bunge on Activity of Cholinesterase from Pig Serum
Authors: Chen Kang Jie , Zhao Gan , Wu Shao Cong , Zhuang Qin Chuan , Qian Fang
Published: September 2013

Leaf extract of Plantago asiatica L. could inhibit the activity of cholinesterase slightly. Leaf extract of Iuicium verum and Reineckea carnea showed no effects on the activity of cholinesterase respectively. Leaf extract of Quercifilix zeylanica (Houtt.) Cop. could activate the activity of cholinesterase slightly. Leaf extract of Asparaguscochinchinensis(Lour.) Merr, Patrinia villosa Juss., Teucrium viscidum Bl., Aregelia spertabilis could activate the activity of cholinesterase evidently.Especially the leaf extract of Ajuga ciliata Bunge could activate the activity of cholinesterase markedly, with the activity being twice as the original one.Otherwise, stem extract of Euphorbia tirucalli could also activate the activity of cholinesterase evidently.
The Effects of Strains Inoculation Amount on the Degree of Hydrolysis of Fermented Tilapia Scraps Mixed with Soybean Meal
Authors: Wang Yun , Hong Peng Zhi , Yang Ping , Liu Huan Ming , Hong Wei , Wu Pei Heng
Published: September 2013

Mixed strains were used to increase the hydrolysis degree of materials during fermenting. Tilapia scraps and soybean meal were mixed by 1:1 and Bacillus subtilis, yeast and lactic acid bacteria were added. The optimal quantity of strains was determined by hydrolysis degree through single factor experiments and orthogonal experiments. After all, The molecular weight distribution of raw material and products was analyzed by high performance size exclusion chromatography (HPSEC). The results showed that the optimum conditions were as follows: the inoculation amount of Bacillus subtilis, the yeast and the lactic acid bacteria was 0.6‰, 0.06‰ and 0.0015‰, respectively. And the hydrolysis degree of materials increased from 10.3% to 27.3%. The hydrolysis degree of materials increased markedly by adding mixed strains.
Selective Adsorption and Pre-Concentration of Morin by Molecularly Imprinted Polymers with Chitosan Beads as Functional Matrix
Authors: Zhang Hai Hui , Xu Fei Fei , Duan Yu Qing , Zhang Can , Yan Yong Sheng , Sun Gui Bo , Sun Xiao Bo
Published: September 2013

To separate and enrich morin, a molecularly imprinted polymer (MIP) was synthesized on chitosan by surface molecular imprinting technique and characterized with Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results showed that MIP possessed better selectivity and recognition for morin in a mixture than that of non-imprinted polymer (NIP). The saturated adsorption amount of MIP was 8.0 mg/g, which was 4-fold than that of NIP, and the recovery in the elution step was 94.87% and 10.97% for MIP and NIP, respectively. These findings indicate MIP could realize the separation and pre-concentration of morin in real sample and may be used for solid phase extraction (MIP-SPE) protocol.
Simultaneous Determination of the Residues of 25 Sex Hormones in Aquatic Products by HPLC-ESI MS/MS
Authors: Yu Hui Juan , Zhang Shan Shan , Feng Bing , Huang Dong Mei , Li Bing
Published: September 2013

A high performance liquid chromatography-tandem mass spectrometric method had been established for simultaneous determination of 25 sex hormones. The hormones were extracted by ethyl acetate and ethyl acetate-tert-butyl methyl ether (1/1, v/v) after enzymatic hydrolysis, followed by an LC-C18 cartridge for cleanup, then were quantified by HPLC-ESI MS/MS with internal standards. Limits of quantification were 1-2 μg.kg-1, average recoveries were 92-113 %, and the R.S.D. was 6-10 %.
Study on Immobilization of Tannase
Authors: He Shun Rong , Wu Xin Ying , Qiu Shu Yi , Huang Xing , Li Fu Li , Feng Ji Ying
Published: September 2013

In this paper,tannase was immobilized by the method of the pre cross-linking,embedding and re cross-linking.The orthogonal design is carried out on the basis of single factor,by which the optimum conditions of the immobilized tannase was selected out ,the optimum pre cross-linking and re cross-linking concentration of glutaraldehyde is 0.3%(v/v )and 0.4%(v/v),respectively,the pre cross-linking temperature is 30°C and the re cross-linking time is 1.0h.in addition,the optimum catalytic temperature is 50°C and the optimum catalytic pH is 5.0,and compered with the free tannase ,the temperature and the pH stability of immobilized tannase improved markedly.
Simultaneous Determination of Oleanolic Acid and Ursolic Acid in Leaves of Paulownia by HPLC
Authors: Xing Ya Li , Bi Liang Wu , Zhao Zhen Dong , Xia Tian Juan
Published: September 2013

A quick and accurate HPLC method has been developed for the simultaneous quantification of two bioactive triterpenes, ursolic acid and oleanolic acid in Paulownia leaves. The samples were analyzed on a Shim-pack ODS-CLC (M) (4.6 mm × 250 mm, 5 μm) column kept at 21 °C, using the methanol and aqueous phase containing 0.05%phosphoric acid with the volumetric ratio of 91.7:8.3 as the mobile phase at a flow rate of 0.6 mL/ min, and the detection wavelength was set at 210 nm. The method was validated and applied to the simultaneous quantification of the two triterpenes in Paulownia leaf extract. The standard curves were established in the range of 0.44 ~ 8.75 μg for oleanolic acid and 0.92 ~ 18.37 μg for ursolic acid. The contents of oleanolic acid and ursolic acid in leaves of Paulownia were determinated using the HPLC method and the contents were 3.87 mg/g and 13.61 mg/g, respectively.
Optimization, Modeling and Antibacterial Activity of Extraction from Fructus Alpinia Oxyphylla
Authors: Wang Dan , Chen Wen Xue , Hu Yue Ying , Peng Mei Fang
Published: September 2013

Substances from Fructus Alpinia Oxyphylla (AOF) were extracted by using solvent extraction. In accordance with central composited design of response surface methodology system, the extracts were analyzed for the index which is the criteria formula of multiplying OD value by the yield. The optimum conditions obtained were extraction temperature of 60°C, liquid-solid ratio of 9mL/g, and solvent density of 80%. According to Ficks second law of diffusion, experimental parameters of K (rate constant), Ea (activation energy), Gs (effective diffusion coefficient) were gained, which represents a good agreement between the model simulation and the results of the actual process. The results can provide the valuable theory basis for the technical design and further research of extraction process. Antibacterial activities of the extraction were shown through MIC of which represents a significant effect.
Rapid Determination of Amygdalin and its Novel Degradation Product in Plasma of Mice by SPE-HPLC
Authors: Wang Chen Xi , Li Yu Ping , Chang Jun , Zhou Bin , Han Xiao , Wu Jiang Tao , Sun Li Zhen
Published: September 2013

Amygdalin was catalytic degraded by extracellular enzymes mixture fromAspergillus nigerand a novel product, phenyl-(3,4,5-trihydroxy-6-methyl-tetrahydro-pyran-2-yloxy)-acetonitrile (PTMT), with high antitumor activity was identified and purified. To measured the Pharmacokinetic of amygdalin and its products, a simple and rapid SPE-HPLC method was set up. The analysis was performed on an Agilent HPLC system with a C18 ODS column (250 × 4.6 mm i.d.) by gradient elution with 0.05% formic acid in water and 0.05% formic acid in acetonitrile as the gradient mixtures. The flow rate was 1ml/min, the detection wavelength was 215 nm and the column temperature was kept at 25°C. The HPLC assay was carried out within 9 min. The retention times of amygdalin, mandelonitrile, prunasin, PTMT andbenzaldehyde were 3.14, 5.93, 6.82, 7.35 and 8.33 min, respectively. The mean absolute recoveries of three analysts were over 98%. The limit of detection and limit of quantification for were 0.02 and 0.04 μg/ml for amygdalin and benzaldehyde, 0.03 and 0.05 μg/ml for mandelonitrile, and 0.03 and 0.04 μg/ml for prunasin and PTMT.
Research Progress on Adhesion Mechanism of Marine Organism
Authors: Chen Shuang Kou , Zhu Jian Fang , Huang Wen Zhang , He Bai , Xiang Li Jun , Zhou Tai Gang
Published: September 2013

Marine adhesion organism includes biological mucosa such as marine bacteria, diatom, etc. and large adhesion organism such as mussel, barnacle, etc. Researches and analysis on adhesion mechanism of adhesion organism show that adhesion marine bacteria in biological mucosa will secrete protein-containing Polysaccharide polymer (PAVE) which can adhere to all kinds of surfaces. The reason is that in these secretions there is 3, 4-dihydroxyphenylalanine (DOPA) which is very viscous. Analysis on mussel, a large adhesion organism, shows that it is of super viscosity, which may result from its special molecular structure and the interaction way with substrates, and interstrand crosslink mediated by DOPA. DOPA plays an important role in this process. For marine bacteria and mussel, their viscosity is correlated with the generation and cross-linking of DOPA. On one hand, DOPA can enhance the viscosity of adhesion organism; on the other hand, it can improve the internal cohesion through cross-linking.
Construction of Yeast Strain Capable of Co-Fermenting Pentose and Hexose by Protoplast Fusion
Authors: Guo Jin Ling , Gong Da Chun , Li Zhi Jun , Zheng Zhou
Published: September 2013

Saccharomyces cerevisiae R40 and Pachysolen tannophilus P01 were used as the parental strain to construct an engineering strain capable of co-fermenting pentose and hexose by protoplast fusion. A fusant F202 was obtained through inactivating parental protoplasts, screening with YPX solid medium and high glucose liquid medium, ethanol production capacity detecting and identification with PCR-SSR technique. Subsequently, the fermentation performance and genetic stability of F202 was studied. The maximum ethanol production capacity from glucose was 1.47 ml/100 ml with a sugar and alcohol conversion rate 47% which was 11% higher than the parental strain P01. By fermenting xylose the ethanol concentration could achieve to 0.58 ml/100 ml with a sugar and alcohol conversion rate 12%. An ethanol concentration of 1.2 ml/100 ml was obtained by fermenting the mixture of xylose and glucose (mass ratio 1:2). Moreover, no decrease in ethanol yield after 8 generations propagation suggested fustant 202 possessed good genetic stability.
Optimization for Purification Technology of Platycodins by Macroreticular Resin
Authors: Jin Xue Yuan , Liu Hong , Zhu San Fu
Published: September 2013

In order to purify the platycodins from Platycodon grandiflorum, AB-8 macroporous resin was used to test. Based on single factor experiments, orthogonal test was used to optimum the purification conditions. Adsorption pH, adsorption temperature, adsorption time and platycodins concentration were as factors and adsorption capacity was as index. The results were as follows: adsorption pH 6.0, adsorption temperature 40°C, adsorption tim110min, platycodins concentration 2.0mg/mL were the optimization conditions.The adsorption quantity reached at 39.1mg/g. So AB-8 macroporous resin was a suitable resin for purify the platycodins from Platycodon grandiflorum.
Spectrophotometric Determination of Trace Ruthenium by its Catalytic Effect on Oxidation of Switzerland Pigment with KIO4
Authors: Chen Su Ping , Zhou Zhi Rong , Cai Cheng Jie , Fang Yan Ling , Fu Zhi Cheng , Chen Dan
Published: September 2013

A spectrophotometric method for the determination of ruthenium (III) is described, based on its catalytic effect on the oxidation reaction of switerland pigment with potassium periodate in 0.016 mol/L of hydrogen chloride medium and in the presence of OP emulsifier (p-iso-octyl phenoxy polyethoxy ethanol) at 100 °C. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 608 nm for the catalytic reaction of switerland pigment. The calibration curve for the recommended method was linear in the concentration range over 0.041.0 μg/L and the detection limit of the method for Ru (III) is 0.012 μg/L. The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 100.48 kJ/mol. The relative standard deviation for the determination of ruthenium (III) at the concentration of 0.02 μg/25 mL is calculated to be 2.3 % (n=11). In combination with distilled separation, the method has been successfully applied for the determination of trace ruthenium (III) in some ores and metallurgy proucts with the relative standard deviations (RSD) over 2.9 %3.8 % and the recovery over 98.2 %-103.6 %.
Continuous Flow Synthesis of Coumarin
Authors: Chen An Bang , Li Xin , Zhou Yang Zhi , Huang Ling Ling , Fang Zheng , Gan Hai Feng , Guo Kai
Published: September 2013

Flow chemistry, as a rapidly emerging technology, is exploited to provide a safe and scalable route for the pharmaceutically interesting coumarin. Here, a continuous flow approach for the generation of coumarin is reported, which relies on the two connected coil reactors design. The synthesis of coumarin has been performed successfully in high conversion on small scale and can be scaled up substantially.
Determination of the Malachite Green in Sediment by High Performance Liquid Chromatography with Fluorescence Detection
Authors: Deng Jian Chao , Yang Xian Qing , Li Lai Hao , Cen Jian Wei , Hao Shu Xian , Wei Ya , Xin Shao Ping
Published: September 2013

A new method of determination of malachite green (MG) in sediment has been developed by high performance liquid chromatography with fluorescence detection (HPLC-FLD). It is based on use of a deoxidation reaction which converts malachite green (MG) into LMG in the process of extraction. The sediment samples were extracted with a solution of formic acid and acetonitrile. Clean up and isolation was performed on MCX solid phase extraction (SPE) column. Chromatographic separation was achieved by using C18column with an isocratic mobile phase consisting of acetonitrile and ammonium acetate buffer (0.05 M, pH 4.5) (80:20, v/v). High performance liquid chromatography with fluorescence detector (λex=265 nm and λem=360 nm) was used for the determination of LMG. The recovery values of MG in sediment samples fortified with MG were determined by measuring the amount of MG in the samples, after carrying out deoxidation reaction with potassium borohydride, which converts the MG into LMG. Under the optimized conditions, the average recoveries of MG from sediment at three levels (1.0, 10 and 50 μg/kg) were 85.0% (range from 80.8 to 87.6%). Relative standard deviations (RSD) of recoveries at all fortification levels were less than for 9.57% for MG. The method detection limit obtained for MG was 0.5 μg/kg.
Effect of Alkaline Pretreatment on Cellulosic Structural Changes of Paulownia
Authors: Deng Yao Jie , Lv Yuan Cai , Cheng Jia Qi , Chen Yuan Cai
Published: September 2013

Four different concentrations of alkaline solution for pretreatment of Paulownia biomass were comparatively studied. The extracted celluloses were characterized using Fourier Transform Infrared spectra (FTIR) for changes of the chemical group, as well as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM). The four samples were untreated biomass, treated with 2%, 4% and 6%peroxide alkaline, and thena comparison between alkaline and dilute acid pretreatment on those indexes were conducted. FTIR spectra results suggested that NaOH could mainly work on lignin of the raw material while the dilute acid work on hemicellulose. The CrI of acid pretreatment and alkaline pretreatment increased to 0.5467 and 0.6395 respectively comparing with the value of 0.4347 of raw material. The XRD results suggested that both of them could act on amorphous region firstly. The SEM micrographs showed the visual structure changes of this progress. The results of enzyme hydrolysis showed 93.3% and 90.6% of the potential glucose and xylose were recovered in the pretreated biomass at 6% NaOH that proved the effects of the NaOH on cellulose structural.
The New Wheat MDH-GOAT Enzyme Complex and its Application for Quantitative Determination of Glutamate Concentration
Authors: Saniyam Ibragimova , Gukkengeimer Elena , Riger Nataliya , Kulbaeva Gulzat , Gilmanov Murat
Published: September 2013

The quantitative determination of glutamate is very important for diagnostic of many diseases of the nervous system, severity of stroke of the brain and also for determination glutamate in the food stuffs [1,2]. To the present days for quantitative determination of glutamate is wide used to the enzyme preparation of glutamate dehydrogenase (GDh) from bovine liver. However the application of GDh has the next serious disadvantages: high lability of this preparation and many substances strong change the activity of GDh. For example there are nucleotides, amino acid, steroid and metal ions. As the results the application of GDh preparation dont give reliable determination of quantity of glutamate. Thus there is the high necessity to propose another enzyme preparation for quantitative determination of glutamate without above mentioned disadvantages. In this reason we propose absolutely new enzyme preparation for this aim. In the laboratory of the enzyme structure and regulation of the Institute of the molecular biology and biochemistry of the Ministry of the education and science of the Republic of Kazakhstan was discovered the new enzyme complex (EC), which consists of malate dehydrogenase (MDh) and glutamate-oxaloacetate aminotransferase (GOAT) and used it for quantitative determination of glutamate concentration [3].
Comparison Study of Experimental and Simulation in the Glucose Isomerisation Process in a Fixed-Bed Reactor
Authors: Rahman N. Abd. , Hussain Mohd Azlan , Md.Jahim Jamaliah
Published: September 2013

Production of fructose from glucose isomerisation process using commercial immobilized glucose isomerase (IGI) was conducted in a fixed-bed bioreactor. A semi-empirical kinetic model based on the mechanism of the glucose isomerisation process has been proposed. The values of maximum rate of reaction, Vm ,g L-1 min-1 are (1.82, 1.86, 1.93 and 0.37), for Michaelis-Menten constant Km, g L-1 the values are (1.04, 1.11, 1.24 and 0.35). In this modified model, known as MM3 the variation of temperature, pH, and initial substrate concentration, feed flow rates have been taken into account. The validation of the models with experimental data was checked in terms of AAE and R2. The values of correlation coefficient, R2 (> 0.95) indicated that MM3 model was well fitted to the experimental data.
Green Ester Lubricants Based on Rapeseed Acid and their Lubricity
Authors: Liao De Zhong , He Jie Yu , Mao Li Xin , Xu Yi Xue
Published: September 2013

Several complex esters were synthesized from phthalic anhydride, neopentyl glycol and rapeseed acid. Their rheological properties, biodegradability and tribological properties were measured. It was found that the complex esters have a wide viscosity range of 126~325mm2/s at 40°C with viscosity indices about 127~143, and solidifying points lower than-38°C. The maximum non seizure load of a complex ester with degree of polymerization 1.42 is as high as 735 N, with a wear scar diameter of 0.41mm, superior to mineral oil. The biodegradation rates are higher than 73%, and the thermal stability is good. So these complex esters are a class of green synthetic ester oils with excellent properties.
Determination of Imidacloprid, Acetamiprid, Thiabendazole and Carbendazim Residues in Edible Fungi by HPLC
Authors: Lin Ling , Yang Chun Liang , Peng Zheng , Wang Ming Yue , Zeng Zong Qiang , Guo Hong Bin
Published: September 2013

A method was developed for simultaneous determination of imidacloprid,acetamiprid, thiabendazole and carbendazim in lentinus edodes, straw mushroom and oyster mushroom by HPLC. Acetonitrile was edded in the sample for extraction solvent, the sample was purified by NH2 solid phase extraction cartridge,then detected by HPLC.The results showed that a good linearity in the range of 0.05~5.0μg/mL with the linear correlation coefficients of 0.9991~0.9997, the detection limits of imidacloprid, acetamiprid, thiabendazole and carbendazim were respectively 0.002 mg/kg,0.005mg/kg, 0.003 mg/kg and 0.003 mg/kg.Tests for recovery were made by addition of four pesticidess standards at three different concentration levels (0.1, 0.5 and 1.0 mg/kg) to the blank sample.The mean recovery rates were 86.0%~105.0% , the relative standard deviations were less than 3.5%.The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.
A Validated Chiral HPLC Method for the Enantiomeric Separation of Melphalan HCl
Authors: Gao Li Ping , Li Wen Juan , Wang Xin Ping
Published: September 2013

A new and accurate chiral HPLC method was developed for the determination of Melphalan HCl, L-Phenylalanine, 4-bis (2-chloroethyl) amino hydrochloride an anti-cancer chemotherapy drug and its potential impurity namely D-Phenylalanine, 4-bis (2-chloroethyl) amino hydrochloride ( D-enantiomer) in bulk substance. HPLC separation was carried out by reverse phase chromatography on Crownpak CR (+) (5μm, 4.0x150mm) with a mobile phase composed of perchloric acid (pH 4.0): methanol in the ratio of 90:10. Melphalan and its potential impurities were baseline resolved in the optimized method. The pH of perchloric acid solution in the mobile phase has played a key role in achieving chromatographic resolution between the enantiomers and in enhancing chromatographic efficiency. The developed method was completely validated and proved to be robust. The validated method yielded good results regarding specificity, precision, linearity, accuracy, robustness, sensitivity. Melphalan HCl sample solution is found to be stable for at least 60hrs at room temperature. The proposed method was found to be suitable and accurate for quantitative determination of Melphalan HCl and its D-enantiomer in bulk substance.
Effect of Al Content Addition on Microstructure of Mg-9Zn-xAl Alloy
Authors: Li Chun , Lei Jie , Zhou Chun Sheng , Li Yuan Dong , Liu Yan Feng , Yuan Xun Feng
Published: September 2013

Microstructure of Mg-9Zn-xAl (x=2,4,6) magnesium alloy was prepared by traditional casting, SIM casting and isolated treatment. The effect of Al content addition on microstructure of Mg-9Zn-xAl was investigated. Results show that Compared with traditional casting, grain size is refined by self-inoculation method casting. Grain size of Mg-9Zn-xAl (x=2,4,6) is 88μm,76μm and 69μm respectively at traditional casting, and is 49.5μm,42μm,35.6μm respectively at SIM casting. With Al content increase, the isolated island-like secondary phase change into semi-continuous network and continuous network, and combination between Magnesium and alloy element decrease accumulation of magnesium atom on the primary phase, so that the growth of the primary phase is prevented.
Manufacturing Technology of Space Optical Materials
Authors: Chen Ya
Published: September 2013

In this paper, the performance comparison between glass ceramics (Zerodur) and silicon carbide (SiC) which are two kinds of common materials used for space optical reflector is carried out, and several lightweight structure forms are analyzed. The oval plane reflector is applied in ultra-low temperature environment of space, take this kind of reflector as an example, its lightweight structure is optimized by CAD, then through finite element analysis, deformation of the planar lightweight mirror is 0.014λ (rms) in gravity condition, and deformation is 0.002λ (rms) in ultra-low temperature of-150 degrees environment. The actual lightweight processing is controled by the CNC system in a graphical way, and using chemical method to eliminate the stress and micro crack generated during processing, its final surface shape precision reaches 0.022λ (rms). Finally, this paper introduces the manufacture method of novel silicon carbide (SiC), and analyzes the current situation and development trends of the spatial lightweight reflector manufacturing technology.
Investigation of Parameters Relevant to Microcellular Foam Injection Molding
Authors: Deng Luo Hong , Chen Zai Liang , Wang Fei
Published: September 2013

The paper is proposed that we can use single factor experiment method and range analysis method to investigate four technological parameters (Melt temperature, Weight loss, Injection time and Gas content) of the technological parameters in the process of microcellular foam injection molding. By investigating the rules and degree which are obtained from the factors influence on bubbles morphology, it is actually meaningful that we can control and improve the bubbles morphology for improving the capability of Microcellular Foam Injection Molding materials.