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Preparation of CS-CMC Bipolar Membrane and its Application in Electro-generated FeO_4^(2-)

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Chinese Chemical Letters 2006年第11期17卷 1527-1530页

作者： yu xi REN Zhen chen Ri Yao chen xi ZHEN Ya Ming GENG College of Chemistry and Materials Science Experiment Center Fujian Normal University Fuzhou 350007

CS-CMC bipolar membrane was prepared and the cross-section photograph of CS-CMC BM was observed by SEM. FT-IR spectrum indicated that CS-CMC BM contained -N=CRH2^＋ and -COO^- functional groups. The charge density of -N--CRH2^＋ in CS membrane was about 14.13 mmol/g and the charge density of -COO in CMC membrane was about 9.01 mmol/g. The electrochemistry properties of CS-CMC BM were also studied. CS-CMC BM not only can effectively stop FeO4^2- from diffusing into the cathode chamber, but also plays an important role in the supply of OH＂ consumed during the electro-generated FeO4^2- process.

关键词： Bipolar membrane (BM) cylinder electrolysis bath carboxymethylcellulose (CMC),chitosan (CS) ferrate (FeO4^2-) colloid titration.

Chemoenzymatic synthesis of α2–3-sialylated carbohydrate epitopes

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Science China Chemistry 2011年第1期54卷 117-128页

作者： HUANG ShengShu yu Hai chen xi Department of Chemistry University of California One Shields Avenue Davis California 95616 USA

Sialic acids are common terminal carbohydrates on cell *** with internal carbohydrate structures,they play important roles in many physiological and pathological *** order to obtain α2–3-sialylated oligosaccharides,a highly efficient one-pot three-enzyme synthetic approach was *** *** α2–3-sialyltransferase (PmST1) involved in the synthesis was a multifunctional enzyme with extremely flexible donor and acceptor substrate *** acceptors,including type 1 structure (Galβ1–3GlcNAcβProN3),type 2 structures (Galβ1–4GlcNAcβProN3 and 6-sulfo-Galβ1– 4GlcNAcβProN3),type 4 structure (Galβ1–3GalNAcβProN3),type 3 or core 1 structure (Galβ1–3GalNAcβProN3) and human milk oligoscaccharide or lipooligosaccharide lacto-N-tetraose (LNT) (Galβ1–3GlcNAcβ1–3Galβ1–4GlcβProN3),were chemically *** were then used in one-pot three-enzyme reactions with sialic acid precursor ManNAc or ManNGc,to synthesize a library of naturally occurring β2–3-linked sialosides with different internal sugar *** sialylated oligosaccharides obtained are valuable probes for their biological studies.

关键词： carbohydrate chemoenzymatic synthesis sialic acid sialylation sialyltransferase

Two-dimensional magnetic resonance neurography in neurotmesis of the left sciatic nerve A case report

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Neural Regeneration Research 2010年第14期5卷 1113-1116页

作者： Zhongjun Hou xiaojun yu xi Li Yaotang chen Department of Gamma Knife Second Affiliated Hospital Guangzhou Medical University Guangzhou 510260 Guangdong Province China

Magnetic resonance neurography （MRN） is used to determine traumatic changes within nervous trunks. A 21-year-old male was treated for neurotmesis of the left sciatic nerve. At 41 days after micro-neurosurgery, two-dimensional MRN （2-D MRN） was performed with plain and contrast scans in the left injured sciatic nerve. More than 2 years after trauma, 2-D MRN images were collected to re-examine the left sciatic nerve. Results from the first 2-D MRN examination revealed a swollen left sciatic nerve. Furthermore, TlWl revealed a local nodule with slightly high intensity, and T2WI revealed hyperintensity. The nodule was significantly enhanced. Upon 2-D MRN re-examination more than 2 years after injury, the injured left sciatic nerve trunk was thinner, and the nodule margin in the left sciatic trunk was clearer. The supero-inferior diameter was enlarged by 2 mm compared with previous films. The degree of enhancement became weaker in the nodule. 2-D MRN revealed continuity, traumatic neuroma, and atrophy of the injured sciatic nerves in detail. Thin-slice technique was crucial for this method, as well as fat-suppressed and blood flow-suppressed imaging.

关键词： Two-dimensional magnetic resonance neurography neurotmesis traumaticneuroma sciatic nerve peripheral nerve injury neural regeneration

Plasticity and microstructure evolution of W-CeO2 rods with different short-duration pulse currents

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Rare Metals 2017年第12期36卷 981-986页

作者： Wen-Guang Zhu Jian-Can Yang Jie Cao Lin Huang yu-chen xi Zuo-Ren Nie School of Materials Science and Engineering Beijing University of Technology Beijing 100124 China

To improve the formability of W-rare earth electrode, the influence of high-energy pulse on the plasticity property of W-CeOrods was investigated. The effects of current density(J), pulse width(tw), frequency(f), and strain rate on the plasticity of W-CeOrods were discussed in detail. Results of tensile tests show that the W-CeOrods applied with the electrical pulses obtain a maximum percentage total elongation at fracture(9.65 %), increased by118.7 % compared to that without pulses. This is owing to both the heat effect and the interaction of current between dislocations and rare earth additions. Electron back scattered diffraction(EBSD)-generated grain boundary(GB) maps suggest that the length of low-angle grain boundaries composed of high-density dislocations decreases after deformation while applying the pulse current. This demonstrates that the short-duration pulsed current enhances the mobility of dislocations. Scanning electron microscopy(SEM) images of the rods after deformation with the pulse current show that the long fiber-shaped additions become discontinuous,which could reduce the stress concentration and hinder the crack propagation.

关键词： Pulse current Plasticity W-CeO_2 rod Lowangle grain boundary

NUMERICAL RESEARCH ON WATER GUIDE BEARING OF HYDRO-GENERATOR UNIT USING FINITE VOLUME METHOD

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Journal of Hydrodynamics 2007年第5期19卷 635-642页

作者： PENG yu-cheng chen xi-yang ZHANG Ke-wei HOU Guo-xiang School of Energy and Power. Engineering Huazhong University of Science and Technology Wuhan 430074 China School of Traffic Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

With the consideration of the geometry of tilting pad journal bearing, a new form of the Reynolds equation was derived in this article. The film thickness, the squeeze motion of the journal and the rotation motion of the pad were explicitly contained in the equation. Based on this equation, together with the equilibrium equation of pad pivot, the water guide bearing used in the Gezhouba 10 F hydro-generator unit was numerically researched. The new Reynolds equation for the lubricating film was solved using Finite Volume （FV） discretization, Successive Over-Relaxation （SOR） iteration method and C＋＋ code are included. According to the numerical solution, and the stability of the film and the influences of the film thickness, the journal squeeze effect and the pad rotation effect on film force were discussed. The results indicate that the squeeze effect can not be neglected, although the rotation effect is negligible for both low-speed and high-speed bearings, so the computing time could be greatly reduced.

关键词： hydro-generator unit Reynolds equation,tilting pad journal bearing Finite Volume (FV) method

In vitro biocompatibility evaluation of silk-fibroin/ polyurethane membrane with cultivation of HUVECs

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Frontiers of Materials Science 2014年第1期8卷 63-71页

作者： Mei ZHOU Wei-Ci WANG Yong-Gui LIAO Wen-Qi LIU Miao yu chen-xi OUYANG Department of Vascular Surgery Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China

In order to investigate the in vitro biocompatibility of a novel polyurethane （PU） membrane modified by incorporation of superfine silk-fibroin powder （SFP）, which was prepared for small-diameter vascular grafts, with the cultivation of human umbilical vein endothelial cells （HUVECs）, PU and SFP were mixed with the ratios of 9：1, 7：3, 5：5, 3：7 （PU：SFP） to make four composite materials. Unmodified PU and polytetrafluoroethylene （PTFE） were added as control groups. CCK-8 assay was used to evaluate the cytotoxicity of these biomaterials. Data were processed using SPSS, and P〈 0.05 was considered to be statistically significant. Adherence and spreading of HUVECs on the surface of specimens was observed using direct contact cultivation. The toxicity ratings of the novel composites were grade 0-1, which is in the acceptable range. In all the experimental groups except control, SFP/PU with ratio of 1：9 had the least cytotoxicity property, and more content of SFP in the composite showed no improvement of the biocompatibility. HUVECs strongly attached to and grew on the surface of the biomaterials, and proliferated rapidly. The proliferation ability increased with increased proportion of SFP; however the cell quantity on the surface of the materials decreased when the proportion of SFP was equal to or larger than that of PU in the composite. It is concluded that this novel material has excellent cellular affinity with no cytotoxicity to HUVECs. Adding SFP gives PU better biocompatibility, while further research on optimum blend ratios is still needed.

关键词： polyurethane (PU) silk-fibroin (SF) small diameter vascular graft biocompatibility human umbilical vein endothelial cell (HUVEC)

NUMERICAL STUDY OF CAVITATION ON THE SURFACE OF THE GUIDE VANE IN THREE GORGES HYDROPOWER UNIT

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Journal of Hydrodynamics 2010年第5期22卷 703-708页

作者： PENG yu-cheng chen xi-yang CAO Yan HOU Guo-xiang School of energy and Power Engineering Huazhong University of Science and Technology Wuhan 430074 China College of Electronic Information Engineering Wuhan Polytechnic Wuhan 430074 China School of Traffic Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Large-area erosions such as rust and obvious cavitation were found on the surface of the guide vane in Three Gorges hydropower units. A numerical explanation of the cavitation is given in this article. At first, based on the characteristic performance curves of the prototype hydro-turbine supplied by ALSTOM together with the actual operating conditions, an operating point is chosen for numerical analysis using the Reynolds-Averaged Navier-Stokes （RANS） equations. The flow passages from the inlet of the spiral case to the outlet of the draft tube are included in the computational domain. The results show that the static pressure on the guide vane surface is much higher than the critical pressure of cavitation. Secondly, a tiny protrusion on the guide vane surface is considered and the problem is simplified to a 2-D problem to study the local detailed flow near the guide vane surface. The protrusion is 0.5 mm in height and is 5.0 mm in width. On the basis of the results of RANS simulations, the 2-D problem is studied using the Large Eddy Simulation （LES）. It is shown that there exists a region in which the static pressure reaches a level below the vapor pressure of the water. Thirdly, a cavitation model is included for the 0.5 mm protrusion case and another tiny pit case, with a tiny pit 0.3 mm in depth and 1.0 mm in width. The results show that vapor bubble exists at the protrusion entrance and the pit exit as the low pressure regions.

关键词： cavitation guide vane numerical analysis

Oncogenic Wnt3a is a promising sensitive biomarker for monitoring hepatocarcinogenesis

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Hepatobiliary & Pancreatic Diseases International 2023年第3期22卷 263-269页

作者： Min Yao Jian-Jun Wang xi-yu chen Wen-Li Sai Jie Yang De-Feng Wang Li Wang Deng-Fu Yao Research Center of Clinical Medicine Affiliated Hospital of Nantong UniversityNantong 226001China Department of Immunology Medical School of Nantong UniversityNantong 226001China Nantong Health College of Jiangsu Province Nantong 226016China Department of Molecular Biology Life Science School of Nantong UniversityNantong 226019China Research Center for Intelligence Information Technology of Nantong University Nantong 226019China

Background:The effective treatment for hepatocellular carcinoma(HCC)depends on early ***,the abnormal expression of Wnt3a as the key signaling molecule in the Wnt/β-catenin pathway was found in HCC cells and could be released into the *** this study,we used rat model of hepatocarcinogenesis to dynamically investigate the alteration of oncogenic Wnt3a and to explore its early monitor value for ***:Sprague-Dawley rats(SD)were fed with diet 2-fluorenylacetamide(2-FAA,0.05%)for inducing hepatocarcinogenesis,and grouped based on liver morphological alteration by Hematoxylin&Eosin(H&E)staining;rats fed with normal chow were used as normal control(NC).Total RNA and protein were purified from rat *** expressed genes(DEGs)or Wnt3a m RNA,cellular distribution,and Wnt3a protein levels were analyzed by whole genome microarray with signal logarithm ratio(SLR log 2 cy5/cy3),immunohistochemistry,and enzyme-linked immunosorbent assay,***:Models of rat hepatocarcinogenesis were successfully established based on liver histopathological H&E *** were divided into the cell degeneration(r Deg),precancerosis(r Pre-C)and HCC(r HCC)*** numbers of the up-and down-regulated DEGs with SLR≥8 were 55 and 48 in the r Deg group,268 and 57 in the r Pre-C group,and 312 and 201 in the r HCC group,*** altered genes were involved in cell proliferation,signal transduction,tumor metastasis,and *** with the NC group,Wnt3a m RNA was increased by 4.6 folds(P<0.001)in the r Deg group,7.4 folds(P<0.001)in the r Pre-C group,and 10.4 folds(P<0.001)in the r HCC group;the positive rates of liver Wnt3a were 66.7%(P=0.001)in the r Deg group,100%(P<0.001)in the r Pre-C group,and 100%(P<0.001)in the r HCC group,***,there were significant differences of liver Wnt3a(P<0.001)or serum Wnt3a(P<0.001)among different ***:Overexpression of Wnt3a was associated with rat hepa

关键词： Hepatocarcinogenesis Dynamic expression Monitoring Model

Differences between two methods to derive a nonlinear Schrödinger equation and their application scopes

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Chinese Physics B 2024年第2期33卷 421-429页

作者：陈羽西张恒段文山 College of Physics and Electronic Engineering Northwest Normal UniversityLanzhou 730070China

The present paper chooses a dusty plasma as an example to numerically and analytically study the differences between two different methods of obtaining nonlinear Schrödinger equation(NLSE).The first method is to derive a Korteweg–de Vries(KdV)-type equation and then derive the NLSE from the KdV-type equation,while the second one is to directly derive the NLSE from the original *** is found that the envelope waves from the two methods have different dispersion relations,different group *** results indicate that two envelope wave solutions from two different methods are completely *** results also show that the application scope of the envelope wave obtained from the second method is wider than that of the first one,though both methods are valuable in the range of their corresponding application *** is suggested that,for other systems,both methods to derive NLSE may be correct,but their nonlinear wave solutions are different and their application scopes are also different.

关键词： dusty plasmas nonlinear waves particle-in-cell simulation