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Factors influencing particle agglomeration during solid-state sintering

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Acta Mechanica Sinica 2012年第3期28卷 711-719页

作者： Chao Wang shao-hua chen State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences100190 BeijingChina

Discrete element method （DEM） is used to study the factors affecting agglomeration in three-dimensional copper particle systems during solid-state sintering. A new parameter is proposed to characterize agglomeration. The effects of a series of factors are studied, including particle size, size distribution, inter-particle tangential viscosity, tem- perature, initial density and initial distribution of particles on agglomeration. We find that the systems with smaller particles, broader particle size distribution, smaller viscos- ity, higher sintering temperature and smaller initial density have stronger particle agglomeration and different distribu- tions of particles induce different agglomerations. This study should be very useful for understanding the phenomenon of agglomeration and the micro-structural evolution during sin- tering and guiding sintering routes to avoid detrimental ag- glomeration.

关键词： Solid-state sintering Discrete element simula-tion. Agglomeration. Densification

Mini-review:Is alcohol consumption associated with gastroesophageal reflux disease?

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第6期11卷 423-428页

作者： shao-hua chen Jie-wei WANG You-ming LI Department of Gastroenterology the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Gastroesophageal reflux disease(GERD) is one of the most common disorders with an increasing incidence and *** consumption may be a risk factor for GERD;however,the relationship remains to be fully *** results of different studies are diverse and *** investigations concerning this matter are inappropriate and further well-designed prospective studies are needed to clarify the effect of alcohol on GERD.

关键词： Alcohol Gastroesophageal reflux disease Motility Acid

Inflammatory bowel disease unclassified

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第4期12卷 280-286页

作者： Ning ZHOU Wei-xing chen shao-hua chen cheng-fu XU You-ming LI Department of Gastroenterology the First Affiliated Hospital College of Medicine Zhejiang University Hangzhou 310003 China

Objective:Inflammatory bowel diseases (IBDs) are idiopathic,chronic,and inflammatory intestinal *** two main types,ulcerative colitis (UC) and Crohn's disease (CD),sometimes mimic each other and are not readily *** purpose of this study was to present a series of hospitalized cases,which could not initially be classified as a subtype of IBD,and to try to note roles of the terms indeterminate colitis (IC) and inflammatory bowel disease unclassified (IBDU) when such a dilemma ***:Medical records of 477 patients hospitalized due to IBD,during the period of January 2002 to April 2009,were retrospectively studied in the present *** available previous biopsies from endoscopies of these patients were ***:Twenty-seven of 477 IBD patients (5.7%) had been initially diagnosed as having *** them,23 received colonoscopy and histological examinations in our hospital.A total of 90% (9/10) and 66.7% (4/6) of patients,respectively,had a positive finding via wireless capsule endoscopy (CE) and double-balloon enteroscopy (DBE).The barium-swallow or small bowel follow-through (SBFT) was performed on 11 *** changes were observed under computer tomographic (CT) scanning in 89.5% (17/19) of *** treatment strategies were employed for all ***:Our data indicate that IBDU accounts for 5.7% of initial diagnoses of *** definition of IBDU is valuable in clinical *** those who had no clear clinical,endoscopic,histological,or other features affording a diagnosis of either UC or CD,IBDU could be used parenthetically.

关键词： Inflammatory bowel disease unclassified Ulcerative colitis Crohn’s disease Subtype Diagnosis

Citric acid reduces the decline in P300 amplitude induced by acute alcohol consumption in healthy adults

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第5期13卷 395-401页

作者： Wei-xing chen Chuan-qin XU shao-hua chen Gen-yun XU huai-zhuang YE Department of Gastroenterology the First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310003China Department of Public Health School of MedicineZhejiang UniversityHangzhou 310003China

Event-related potential (ERP) is a reliable neuroelectric measure of brain activity that helps to confirm the assessment of mental status and cognitive impairment. Many studies have reported that alcoholics show a significantly lower ERP P300 amplitude than the norm. In the present study, ERP P300 waves were measured to evaluate the effect of citric acid on cognitive function during excessive alcohol consumption in healthy adults. Five volunteers were selected through clinical interview, physical examination, and psychiatric assessment for participation in this study. In a double-blind placebo-controlled before-after design, each subject was treated with 5 ml/kg body weight alcohol, 5 ml/kg body weight alcohol and 1 mg citric acid, or a placebo on three separate occasions, one week apart. ERP P300, blood biochemical indicators, blood alcohol concentrations (BACs) and acetaldehyde concentrations were assessed. Repeated measure analysis of variance (ANOVA) with a within-subjects factor was used to evaluate differences in blood biochemical indicators, BACs, blood acetaldehyde concentrations, and ERP P300 in the three sessions of assessments. Several blood biochemical indicators showed significant differences between treatments, including the levels of cholinesterase (CHE), total bile acid (TBA), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and glycylproline dipeptidyl aminopeptidase (GPDA). BACs after consumption of alcohol alone or citric acid with al- cohol were significantly higher compared to those after placebo treatment (P<0.05). There were no significant dif- ferences in blood acetaldehyde concentrations between the treatments. The P300 amplitudes on the frontal (Fz), central (Cz), and parietal (Pz) regions of the scalp after consumption of alcohol were significantly lower than those after consumption of the placebo or citri

关键词： Ethanol Citric acid Event-related potential (ERP) P300 Cognitive function Acetaldehyde

g-C3N4/SnS2 Heterostructure： a Promising Water Splitting Photocatalyst

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Chinese Journal of Chemical Physics 2017年第1期30卷 36-42,I0001页

作者： shao-hua chen Jia-jun Wang Jing huang Qun-xiang Li Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics University of Science and Technology of China Hefei 230026 China Tianjin Key Laboratory of Structure and Performance for Functional Molecules Key Laboratory of Inorganic-Organic Hybrid Functional Materials Chemistry Ministry of EducationCollege of Chemistry Tianjin Normal University Tianjin 300387 China School of Materials and Chemical Engineering Anhui Jianzhu University Hefei 230601 China

Graphite-like carbon nitride （g-C3N4） based heterostrutures has attracted intensive attention due to their prominent photocatalytic performance. Here, we explore the g-CaN4/SnS2 coupling effect on the electronic structures and optical absorption of the proposed g-CaN4/SnS2 heterostructure through performing extensive hybrid functional calculations. The obtained geometric structure, band structures, band edge positions and optical absorptions clearly reveal that the g-C3N4 monolayer weakly couples to SnS2 sheet, and forms a typical van der Waals heterojunction. The g-C3N4/SnS2 heterostructure can effectively harvest visible light, and its valence band maximum and conduction band minimum locate in energetically favorable positions for both water oxidation and reduction reactions. Remarkably, the charge transfer from the g-C3N4 monolayer to SnS2 sheet leads to the built-in interface polarized electric field, which is desirable for the photogenerated carrier separation. The built-in interface polarized electric field as well as the nice band edge alignment implys that the g-CaN4/SnS2 heterostructure is a promising g-CaN4 based water splitting photocatalyst with good performance.

关键词： First-principles calculation Coupling effect Optical absorption Band edge alignment Water splitting

Novel flexible broadband microwave absorptive fabrics coated with graphite nanosheets/polyurethane nanocomposites

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Progress in Natural Science:Materials International 2012年第4期22卷 288-294页

作者： Miao-miao Yu shao-hua chen Zhe Zhou Mei-fang Zhu State Key Laboratory for Modification of Chemical Fiber and Polymer Materials College of Materials Science and EngineeringDonghua University

Graphite nanosheets (GNS) were prepared by surfactant assisted ultrasonication from expanded graphite (EG) and followed by coating onto vinylon fabrics with water-borne polyurethane (WPU). The morphology of GNS and GNS/polyurethane (PU) coatings was characterized by field emission scanning electron microscope (FESEM), and the structure of GNS was studied by fourier transform infrared (FTIR) spectroscopy. Electromagnetic (EM) parameters indicated that GNS is a kind of dielectric loss material, in which little magnetic loss is found. Reflection loss (RL) results showed that both GNS content and coated thickness had great influences on the microwave absorption. For the fabric coated with GNS/PU nanocomposites (30/100 by weight, wet thickness of 0.39 mm for dry areal density in 130g/m2 ), RL values exceeding 5dB could be obtained in the frequency range of 10.7-18GHz, while 10dB in 12.7-18GHz, and a minimum value of 28dB at 15.2GHz. These GNS/PU coated fabrics are light and flexible with much thin and low-cost coated layer, and showed great potential in radar camouflaging and electromagnetic interference application.

关键词： Microwave absorption Graphite nanosheets Water-borne polyur-ethane Ultrasonication Coated fabrics

Growth of AgBr/Ag_(3)PO_(4) Heterojunction on Chitosan Fibers for Degrading Organic Pollutants

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Advanced Fiber Materials 2020年第5期2卷 246-255页

作者： Si-wei Xiong Yan Yu Pei Wang Man Liu shao-hua chen Xian-ze Yin Luo-xin Wang hua Wang College of Materials Science and Engineering State Key Laboratory of New Textile Materials and Advanced Processing TechnologyWuhan Textile UniversityWuhan 430073People’s Republic of China Sichuan Textile Science Research Institute Chengdu 610072People’s Republic of China

Using Fiber as the based material for photocatalyst particles is favorable for their recovery,thereby avoiding the photocatalyst particles cause secondary pollution to water *** this work,the AgBr and Ag_(3)PO_(4) photocatalyst particles were loaded onto the surface of chitosan fiber(CF)via chelation and in situ anion-exchange *** photocatalytic results illustrated that the AgBr/Ag_(3)PO_(4)/CF composites displayed the best photocatalytic performance when the mass ratio of Ag_(3)PO_(4) and AgBr onto the CF was approximately 1:0.15,their degradation rate can reach 98.1%for the methyl orange(MO)solution,this value far exceeded those of pure CF,AgBr/CF composites,and Ag_(3)PO_(4)/CF ***,the AgBr/Ag_(3)PO_(4)/CF composites also shown excellent durability,after the fifth cycle,they still maintained a decolorization rate of 86.4%for the MO solution,while the Ag_(3)PO_(4)/CF composites maintained a decolorization rate of only 70.7%.Based on these results,we consider that the AgBr/Ag_(3)PO_(4)/CF composites have high practical interest in environmental remediation.

关键词： AgBr Ag_(3)PO_(4) Chitosan fiber Photocatalytic degradation

Design methodology of an osculating cone waverider with adjustable sweep and dihedral angles

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第9期21卷 770-782页

作者： shao-hua chen Jun LIU Wei huaNG Feng DING Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China

When considering the practical engineering application of a waverider,the on-design and off-design aerodynamic characteristics of the design conditions,especially the lift-to-drag ratio and the stability,deserve *** to recently studies,the planform and rear sight shape of a waverider are closely related to the above aerodynamic ***,the planform leading-edge profile curve used to design the planform shape of a vehicle is applied to designing an osculating cone *** key parameters concerned in planform and rear sight shape,namely the plan view sweep angle of the leading edge and the dihedral angle of the underside are introduced to the waverider design *** parameter is inserted in the control curve ***,a parameterization scheme is put forward for the free adjustment of the sweep angle along the leading ***,three examples are generated for verification and *** the verification process based on the inviscid flow field of one case,the influences of the sweep and dihedral angles on the lift-to-drag ratio and the lateral static stability are evaluated,and meaningful results are *** on these results,we can conclude that,considering the maximum lift-to-drag ratio,the sweep angle plays a role on the lift-to-drag ratio only at subsonic and trans/supersonic speed as a negligible effect is observed at hypersonic speeds,whereas the dihedral angle is seem to produce a relevant difference at hypersonic *** the lateral static stability,the dihedral angles have more influence on the waverider than the sweep angles.

关键词： Osculating cone waverider Planform leading-edge profile curve Sweep and dihedral angles Lift-to-drag ratio Lateral static stability

Helicobacter pylori and Crohn's disease: A retrospective single-center study from China

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World Journal of Gastroenterology 2013年第28期19卷 4576-4581页

作者： Zun Xiang Yi-Peng chen Yue-Fang Ye Kui-Fen Ma shao-hua chen Lin Zheng Yi-Da Yang Xi Jin Department of Gastroenterology the First Affiliated Hospital College of Medicine Zhejiang University Department of Gastroenterology the Affiliated Hospital College of Medicine Hangzhou Normal University Department of Pharmacy the First Affiliated Hospital College of Medicine Zhejiang University Department of Infectious Disease the First Affiliated Hospital College of Medicine Zhejiang University

AIM: To investigate the association between Helicobacter pylori (H. pylori ) infection and the prevalence of Crohn's disease (CD). METHODS: Subjects were selected from patients admitted the gastrointestinal (GI) department at The First Affiliated Hospital School of Medicine (Zhejiang University)for abdominal pain, hematochezia, diarrhea and other GI symptoms between January 2008 and September 2012. CD was diagnosed by endoscopy and biopsy. H. pylori infection was detected by a 14 C-urea breath test and culturing of the biopsy sample. Demographic, anthropometric and serologic data were collected for each patient. H. pylori infection rate was compared between CD and control groups, followed by a subgroup analysis based on extent and severity of CD. Student's t , Mann-Whiney U , and χ 2 tests were used to analyze the data. RESULTS: A total of 447 patients were analyzed, including 229 in the CD group and 248 in the control group. There were no significant differences in age, sex, and rates of hypertension or diabetes. However, the CD group showed significantly higher rates of smoking history (34.9% vs 18.1%), alcohol intake (17.4% vs 8.1%), white blood cell count (9.7 ± 2.9 × 10 9 /L vs 4.3 ± 0.9 × 10 9 /L), and C-reactive protein (36.3 ± 20.8 mg/L vs 5.5 ± 2.3 mg/L) but lower body mass index (24.5 ± 2.0 kg/m 2 vs 26.0 ± 2.2 kg/m 2 ) than the control group. The H. pylori infection rate in the CD group was 27.1%, significantly lower than that of 47.9% in the control group. Furthermore, the H. pylori infection rates in patients with colonic, small intestine, ileocolonic and extensive CD were 31.1%, 28.9%, 26.8% and 25.9% respectively, all of which were significantly lower than in the control group. Finally, the H. pylori infection rates in patients with remission, moderate and severe CD were 34.3%, 30.7% and 22.0% respectively, which were also significantly lower than in the control group. CONCLUSION: Lower H. pylori infection in CD patients suggests a correlation between

关键词： Crohn’s disease Helicobacter pylori Urea breath test Biopsy Pathogenesis Inflammatory bowel disease Bacteria