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Growth and Chemical Thermodynamics Analysis of SiC Film on Si Substrate by Heating Polystyrene/Silica Bilayer Method

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Chinese Journal of Chemical Physics 2008年第2期21卷 151-155页

作者： yun Li yu-xia wang Zheng Chen Jian-wen wang You-ming Zou Department of Material Science and Engineering University of Science and Technology of China Hefei 230026 China

SiC films were prepared by modified heating polystyrene/silica bilayer method on Si（111） substrate in normal pressure flowing Ar ambient at 1300℃ . The films were investigated by Fourier transform infrared absorption, X-ray diffraction, and scanning electron microscopy measurements. The chemical thermodynamics process is discussed. The whole reaction can be separated into four steps. The carburizing of SiO is the key step of whole reaction. The main reaction-sequence is figured out based on Gibbs free energy and equilibrium constant. Flowing Ar is necessary to continue the progress of whole reaction by means of carrying out accumulating gaseous resultants. The film is very useful for application in a variety of MOS-based devices for its silica/SiC/Si（111） structure, in which the silica layer can be removed thoroughly by the standard RCA cleaning process.

关键词： Thin film Heat treatment Silicon carbide Chemical thermodynamics Silicon monoxide

Growth Kinetics of Silicon Carbide Film Prepared by Heating Polystyrene/Si（111）

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Chinese Journal of Chemical Physics 2009年第1期22卷 102-106页

作者： Jian-wen wang yu-xia wang Zheng Chen You-ming Zou Department of Materials Science and Engineering University of Science and Technology of China Hefei 230025 China

SiC films were prepared by heating polystyrene/Si（111） in normal pressure argon atmosphere at different temperatures. The films were investigated by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared absorption measurements. The thicknesses of SiC films were calculated from FTIR spectra. The growth kinetics of the growth process of SiC films were investigated as well. The thicknesses of the SiC films grown for 1 h with increasing growth temperatures have different trends in the three temperature ranges： increasing slowly （1200-1250 ℃）, increasing quickly （1250- 12.70 ℃）, and decreasing （1270-1300 ℃）. The apparent activation energies of the growth process of SiC films in the three ranges were calculated to be 122.5,522.5, and -127.5 J/mol respectively. Mechanisms of the different growth processes were discussed. The relation between film thicknesses and growth temperatures indicated that the growth process was a 2D mechanism in the first range and 3D mechanism in the second range. In the third range, the thicknesses of SiC films were decreased by the volatility of Si and C atoms.

关键词： Thin films Silicon carbide Fourier transform infrared absorption Growth kinetics

Effect of SO_2 on the performance of Ag-Pd/Al_2O_3 for the selective catalytic reduction of NOx with C_2H_5OH

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Journal of Environmental Sciences 2006年第5期18卷 973-978页

作者： XIE Shu-xia yu yun-bo wang Jin HE Hong State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The influence of SO2 on the performance of Ag-Pd/Al2O3 for the selective catalytic reduction （SCR） of NOx with C2H5OH was investigated experimentally. The activity test results suggest that Ag-Pd/Al2O3 shows a small activity loss in the presence of SO2 when using C2H5OH as a reductant. In situ DRIFTS spectra show that the activity loss originates from the formation of surface sulphate species on the Ag-Pd/Al2O3. The surface sulphate species formation inhibits the formation of nitrate, whereas hardly changes the partial oxidation of C2H5OH. Compared with the NOx reduction by C3H6, an obvious suppression of the surface sulphate species formation was observed by DRIFTS experiment when using C2H5OH as a reductant. This phenomenon reveals the better catalytic performance and strong SO2 tolerance of Ag-Pd/Al2O3-C2H50H system.

关键词： sulphate SCR nitrate enolic species isocyanate reaction mechanism

The impacts of infectious complications on outcomes in acute pancreatitis: a retrospective study

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Military Medical Research 2021年第1期8卷 37-47页

作者： Xun Jiang Ji-yu Shi xia-yu wang Yong Hu yun-Feng Cui Tianjin Medical University Tianjin 300041China Department of Surgery Tianjin Nankai HospitalNankai Clinical School of Medicine122 Sanwei RoadNankai districtTianjin 300110China

Background: The occurrence of infectious complications characterizes the more severe forms of acute pancreatitis(AP) and is associated with high mortality. We investigated the effects of infection at different sites in patients with AP, including those with necrotizing pancreatitis(NP).Methods: We conducted a retrospective analysis of 285 patients who met the inclusion criteria for AP and were admitted to Tianjin Nankai Hospital between January 2016 and September 2019. According to the source of the culture positivity during hospitalization, patients were divided into four groups: sterile group(n=148), pancreatic infection group(n=65), extrapancreatic infection group(n=22) and combined infection group(n=50). The source of infection, microbiology, biochemical parameters and prognostic indicators were ***: In terms of baseline characteristics, the four groups were similar in age, sex, aetiology, previous pancreatitis and diabetes. Compared with the severity of the disease in the other groups, the APACHE II scores(9.91±4.65, 9.46±5.05, respectively) and organ failure rate(40.9% and 50%, respectively)were higher in the extrapancreatic infection group and the combined infection group(P<0.05). The frequency of surgical intervention and hospitalization time in patients with NP complicated with extrapancreatic infection was greatly increased(P<0.05). Regarding the primary outcome, patients in the combined infection group had longer hospital stays(68.28±51.80 vs. 55.58±36.24, P<0.05) and higher mortality(24.0% vs. 9.2%, P<0.05) than patients in the pancreatic infection group. In addition, patients in the extrapancreatic infection group also showed high intensive care utilization(59.1%) and mortality rates(18.2%). Among the 137 AP patients with infection complications, 89 patients exhibited multidrug-resistant(MDR) microorganisms, and the mortality rate of patients with MDR bacterial infection was higher than that of patients with non-MDR bacterial infection(24.7

关键词： Acute pancreatitis Infectious complications Extrapancreatic infection Mortality

Research and development of advanced structured packing in a rotating packed bed

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Chinese Journal of Chemical Engineering 2022年第9期35卷 178-186页

作者： Zhi-Guo yuan yu-xia wang You-Zhi Liu Dan wang Wei-Zhou Jiao Peng-Fei Liang Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China

As the core component of the rotating packing bed,packing is a place for efficient gas–liquid mixing and mass *** this paper,a 3D structured packing composed of a mesh structure and a support structure was *** mesh structure is a ring-shaped mesh surrounded by triangular meshes,which is stable in structure and can achieve a high degree of dispersion and aggregation of the liquid *** support structure is composed of ring-shaped structural units arranged at a certain angle along the axial direction,which can enhance the turbulence of the airflow while constructing regular gas-phase *** steel meshes of different diameters and supporting structures are alternately combined to form 3D packing,which is loaded in a layered cross-flow rotating packing *** results show that under the same operating conditions,the mass transfer performance of 3D packing and wire mesh packing are equivalent,and both are better than pall ring ***,the pressure drop of 3D packing is significantly lower than that of pall ring packing and wire mesh *** design and implementation of packing the development presented in this paper can be used to develop special structured packing for rotating bed,which can further improve the performance of rotating packed bed(RPB).

关键词： Rotating packed bed 3D printed packing 3D modeling Mass transfer Pressure drop Gas–liquid channel

A{Tb_(2)Fe_(3)}Pyramid Single-Molecule Magnet with Ferromagnetic Tb-Fe Interaction

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Chinese Journal of Chemistry 2019年第4期37卷 373-377页

作者： Han Li Xixi Meng Mengmeng wang yu-xia wang Wei Shi Peng Cheng College of Chemistry Key Laboratory of Advanced Energy Materials Chemistry(MOE)and Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Nankai UniversityTianjin 300071China

The influence of magnetic interactions to the magnetization dynamics was well experimentally studied in a 3d-4f single-molecule magnet(SMM)[Tb^(Ⅲ)_(2)Fe^(Ⅲ)_(3)(μ5-O)L_(2)(NO_(3))_(4)Cl](1,H_(4)L=N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylene diamine)and its diamagneticion-diluted *** ferromagnetic coupling between Tb^Ⅲand Fe^Ⅲions and SMM behavior of 1 were observable,which proved clearly that the magnetic interaction between 3d-4f spin carriers has also an excessive impact on fine-tuning the magnetization dynamic behaviors of 3d-4f complexes.

关键词： A{Tb_(2)Fe_(3)}Pyramid Single-Molecule Magnet Ferromagnetic Tb-Fe Interaction magnetization dynamic behaviors

Purification and characterization of a novel antifungal protein from Bacillus subtilis strain B29

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第4期10卷 264-272页

作者： Jing LI Qian YANG Li-hua ZHAO Shu-mei ZHANG yu-xia wang xiao-yu ZHAO Department of Life Science and Engineering Harbin Institute of Technology Harbin 150001 China Institute of Microbiology of Heilongjiang Academy of Sciences Harbin 150010 China Heilongjiang University Press Harbin 150040 China

An antifungal protein was isolated from a culture of Bacillus subtilis strain B29. The isolation procedure comprised ion exchange chromatography on diethylaminoethyl （DEAE）-52 cellulose and gel filtration chromatography on Bio-Gel P-100. The protein was absorbed on DEAE-cellulose and Bio-Gel P-100. The purified antifungal fraction was designated as B29I, with a molecular mass of 42.3 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）, pl value 5.69 by isoelectric focusing （IEF）-PAGE, and 97.81% purity by high performance liquid chromatography （HPLC）. B291 exhibited inhibitory activity on mycelial growth in Fusarium oxysporum, Rhizoctonia solani, Fusarium moniliforme, and Sclerotinia sclerotiorum. The 50% inhibitory concentrations （IC50） of its antifungal activity toward Fusarium oxysporum and Rhizoctonia solani were 45 and 112 μmol/L, respectively. B29I also demonstrated an inhibitory effect on conidial spore germination of Fusariurn oxysporum and suppression of germ-tube elongation, and induced distortion, tumescence, and rupture of a portion of the germinated spores.

关键词： Bacillus subtilis Antifungal protein Purification

A novel terbium complex using oxadiazole derivative as a neutral ligand:Synthesis and properties

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Chinese Chemical Letters 2007年第5期18卷 573-576页

作者： yu Liu Kong Qiang Xing Ji Yong Deng Mei xiang Zhu xia yu wang Wei Guo Zhu College of Chemistry Xiangtan University Xiangtan 411105 China Department of Chemistry Qiongzhou University Wuzhishan 572200 China

A novel terbium complex using 1,3,4-oxadiazole derivative as a neutral ligand was synthesized and characterized. Its thermal stability and photoluminescent properties were studied. The strong emission peaked at 546 nm with a full width at half maximum of 5 nm was observed in the pure terbium complex film under excitation of 328 nm light, which is attributed to the characteristic emission of terbium ion. The good thermal stability and intense sharp emission of this terbium complex display its potential application in electroluminescence devices.

关键词： rerbium complex 1,3,4-Oxadiazole Synthesis Photoluminescence

Reliability analysis of carbon fiber rod-reinforced umbilical cable under tension using an improved sampling method

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Petroleum Science 2024年第4期21卷 2769-2778页

作者： yu Zhang Hong-yu Zhang Ran xia Si-Ao Jiang Fang wang College of Safety and Ocean Engineering China University of Petroleum China Academy of Aerospace Aerodynamics China Aerospace Science and Technology Group College of Engineering Science and Technology Shanghai Ocean University

The umbilical cable is a vital component of subsea production systems that provide power, chemical agents, control signals et al., and its requirement for reliability is exceedingly high. However, as the umbilical cable is a composite structure comprising multiple functional units, the reliability analysis of such cables involves numerous parameters that can impact calculation efficiency. In this paper, the reliability analysis of a new kind of umbilical cable with carbon fiber rod under tension is analyzed. The global dynamic analytical model is first established to determine the maximum tension load, then the local analytical model of umbilical cable including each unit are constructed by finite element method(FEM). Based on the mechanical analytical model, the reliability of umbilical cable under tension load is studied using response surface method(RSM) and Monte Carlo method. During the calculation process, a new tangent plane sampling method to calculate the response surface function(RSF) is proposed in this paper, which could make sampling points faster come close to the RSF curve, and it is proved that the calculation efficiency increases about 33% comparing with traditional method.

关键词： Umbilical cable Carbon fiber rod Failure analysis Response surface method Reliability