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Instability of single-walled carbon nanotubes conveying Jeffrey fluid

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Chinese Physics B 2021年第4期30卷 328-332页

作者： bei-Nan jia Yong-Jun jian School of Mathematical Science Inner Mongolia UniversityHohhot 010021China

We report instability of the single-walled carbon nanotubes(SWCNT) filled with non-Newtonian Jeffrey *** objective is to get the influences of relaxation time and retardation time of the Jeffrey fluid on the vibration frequency and the decaying rate of the amplitude of carbon *** elastic Euler-Bernoulli beam model is used to describe vibrations and structural instability of the carbon nanotubes.A new vibration equation of an SWCNT conveying Jeffrey fluid is first derived by employing Euler-Bernoulli beam equation and Cauchy momentum equation taking constitutive relation of Jeffrey fluid into *** complex vibrating frequencies of the SWCNT are computed by solving a cubic eigenvalue problem based upon differential quadrature method(DQM).It is interesting to find from computational results that retardation time has significant influences on the vibration frequency and the decaying rate of the ***,the vibration frequency decreases and critical velocity increases with the retardation *** is to say,longer retardation time makes the SWCNT more stable.

关键词： single-walled carbon nanotubes Jeffrey fluid relaxation time retardation time

Surface modification of apatite-wollastonite glass ceramic by synthetic coupling agent

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Frontiers of Materials Science 2014年第2期8卷 157-164页

作者： Qin LONG Da-Li ZHOU Xiang ZHANG jia-bei ZHOU College of Chemical Engineering Sichuan University Chengdu 610065 China College of Materials Science and Engineering Sichuan University Chengdu 610064 China Gannan Medical University Ganzhou 341000 China

In this study, lysine was introduced into the surface of apatite-wollastonite glass ceramic （AW-GC） to improve its cytocompatibility by two steps reaction procedure. Firstly, lysine connected to N-β-（aminoethyl）-y-aminopropyl trimethoxy silane （A-1120） by covalent binding of amide group. Secondly, the lysine-functionalized A-1120 was deposited on the surface of AW-GC through a silanization reaction involving a covalent attachment. FTIR spectra indicated that lysine had been immobilized onto the surface of AW-GC successfully. Bioactivity of the surface modified AW-GC was investigated by simulated body fluid （SBF）, and the in vitro cytocompatibility was evaluated by coculturing with human osteosarcoma cell MG63. The results showed that the process of hydroxyapatite layer formed on the modified material was similar to AW-GC while the mode of hydroxyapatite deposition was changed. The growth of MG63 cells showed that modifying the AW-GC surface with lysine enhances the cell adhesion and proliferation.

关键词： surface modification apatite-wollastonite glass ceramic (AW-GC) lysine silane coupling agent cytocompaUbility

Inflammatory myofibroblastic tumor of the pancreatic neck misdiagnosed as neuroendocrine tumor:A case report

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World Journal of Gastroenterology 2023年第20期29卷 3216-3221页

作者： jia-bei Liu Qian-Biao Gu Peng Liu Department of Radiology The First Affiliated Hospital of Hunan Normal UniversityHunan Provincial People’s HospitalChangsha 410005Hunan ProvinceChina Department of Radiology The First Affiliated Hospital of Hunan Normal University(Hunan Provincial People’s Hospital)Changsha 410005Hunan ProvinceChina

BACKGROUND Inflammatory myofibroblastic tumor(IMT)is a relatively rare *** global incidence of IMT is less than 1%.There is no specific clinical *** usually occurs in the lungs,but the pancreas is not the predilection *** SUMMARY We present a case of a male patient,51 years old,who was diagnosed with a pancreatic neck small mass on ultrasound one year ago during a physical *** he had no clinical symptoms and the mass was relatively small,he did not undergo ***,the mass was found to be larger on review,and he was referred to our *** the primal clinical diagnosis was pancreatic neuroendocrine tumor,the patient underwent surgical ***,the case was confirmed as pancreatic IMT by postoperative *** Pancreatic IMT is relatively rare and easily *** can better understand and correctly diagnose this disease by this case report.

关键词： Inflammatory myofibroblastic tumor Diagnosis Imaging Pancreas Case report

H_∞ Robust Control of DC-AC Interfaced Microsource in Microgrids

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International Journal of Automation and computing 2013年第1期10卷 73-78页

作者： Chun-Xia Dou Fang Zhao Xing-bei jia Dong-Le Liu Institute of Electrical Engineering Yanshan University

This paper focuses on the direct current-alternating current （DC-AC） interfaced microsource based H∞ robust control strategies in microgrids. It presents detail of a DC-AC interfaced microsource model which is connected to the power grid through a controllable switch. A double loop current-regulated voltage control scheme for the DC-AC interface is designed. In the case of the load disturbance and the model uncertainties, the inner voltage and current loop are produced based on the H∞ robust control strategies. The outer power loop uses the droop characteristic controller. Finally, the scheme is simulated using the Matlab/Simulink. The simulation results demonstrate that DC-AC interfaced microsource system can supply high quality power. Also, the proposed control scheme can make the system switch smoothly between the isolated mode and grid-connected mode. 更多

关键词： Microgrid DC-AC interfaced microsource H∞ robust control f-v droop characteristic smooth switching

Phase-field numerical simulation of three-dimensional competitive growth of dendrites in a binary alloy

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China Foundry 2018年第1期15卷 44-50页

作者： Li Feng Ya-long Gao Chang-sheng Zhu Guo-sheng An Xin Deng bei-bei jia School of Materials and Engineering Lanzhou University of Technology State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology School of Computer and Communication Lanzhou University of Technology

The normal vector of migration direction in the solid-liquid interface of dendrites was used to describe the phase-field governing equation. By using the three angles formed by the normal vector for the migration direction of the dendritic growth interface and the coordinate axes of the simulation region, the authors expressed the interfacial anisotropy equation, and built a phase-field model for the competitive growth of multiple grains. Taking a Al-2%mole-Cu binary alloy as an example, the competitive growth of multiple grains during isothermal solidification was simulated by applying parallel computing techniques. In addition, the phase field simulation results were verified by the experimental method. The simulation results show that the competitive growth of equiaxed dendrite is divided into two types: the first occurs during the process of competitive growth, the tips of primary dendrite on different grains taking part in the competition stop growing in their optimal growth direction; the second also occurs during competitive growth, the tips of primary dendrite which participate in the competition on different grains never stop growing in their optimal growth direction. The dendritic morphologies of the first competition growth type are divided into two types. Primary dendrites of grains taking part in the competition stop growing in their optimal growth direction and the competition plane enlarges when neither one wins the competition. However, when one wins the competition, the primary dendrites of grains with superiority go through the blocking grains and continue to grow in their optimal growth direction. The primary dendrites of inferior grains stop growing in their optimal growth direction and then instead grow in those areas without obstacles. The dendritic morphology of the second competition-growth type is shown to be the deformation of primary dendrites, which are mainly represented as the deflection and bending observed from different views. Compar

关键词： dendrite Al-Cu binary alloy competitive growth dendritic morphology

Mechanically exfoliated MoS_(2) nanosheets decorated with SnS_(2) nanoparticles for high-stability gas sensors at room temperature

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Rare Metals 2021年第6期40卷 1536-1544页

作者： jia-bei Liu Jin-Yong Hu Can Liu Yu-Ming Tan Xiang Peng Yong Zhang School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411105China

Due to its unique physical,chemical and surface electronic properties,molybdenum disulfide(MoS_(2))nanosheets open up a new avenue for nitrogen dioxide(NO2)detection at room ***,the gas sensing properties of pure MoS_(2) nanosheets are inevitably degenerated by the adsorption of atmospheric oxygen,which results in weak stability for MoS_(2)-based gas *** surface defects and constructing heterojunctions may be effective strategies to improve the gas sensing properties of MoS_(2) *** this work,we design a novel nanocomposite based on MoS_(2) nanosheets decorated with tin disulfide(SnS_(2))nanoparticles(MoS_(2)/SnS_(2))via combining the mechanical exfoliation method with the facile hydrothermal *** experimental results indicate that,after surfaces decoration with SnS_(2) nanoparticles,the as-prepared gas sensor based on MoS_(2)/SnS_(2) nanocomposites exhibits reliable long-term stability with the maximum response value drift of less than 3%at room ***,the MoS_(2)/SnS_(2) sensor also possesses desirable gas sensing properties upon NO_(2) at room temperature,such as high sensitivity,rapid response/recovery speed(28 s/3 s,5×10^(-6) NO_(2)),satisfactory selectivity,favorable repeatability and *** improved gas sensing properties of MoS_(2)/SnS_(2) nanocomposites can be attributed to the unique electronic properties of MoS 2 nanosheets with the fewer layers structure and the competitive adsorption effect of SnS_(2) *** work elucidates that SnS_(2) nanoparticles serving as an effective antioxidative decoration can promote the stability of MoS_(2) nanosheets,providing a promising approach to achieve high-stability NO2 gas sensors at room temperature.

关键词： Mechanically exfoliated MoS2 nanosheets MoS_(2)/SnS_(2)nanocomposites NO2 sensing properties Room-temperature detection

Recombinant adenovirus containing hyper-interleukin-6 and hepatocyte growth factor ameliorates acute-on-chronic liver failure in rats

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World Journal of Gastroenterology 2016年第16期22卷 4136-4148页

作者： Dan-Dan Gao jia Fu Bo Qin Wen-Xiang Huang Chun Yang bei jia Chongqing Key Laboratory of Infectious Diseases and Parasitic Diseases Department of Infectious Diseases The First Affiliated Hospital of Chongqing Medical University

AIM: To investigate the protective efficacy of recombinant adenovirus containing hyper-interleukin-6 (Hyper-IL-6, HIL-6) and hepatocyte growth factor (HGF) (Ad-HGF-HIL-6) compared to that of recombinant adenovirus containing either HIL-6 or HGF (Ad-HIL-6 or Ad-HGF) in rats with acute-on-chronic liver failure (ACLF).METHODS: The recombinant adenoviruses containing HIL-6 and/or HGF were constructed. We established an ACLF model, and rats were randomly assigned to control, model, Ad-GFP, Ad-HIL-6, Ad-HGF or Ad-HGF-HIL-6 group. We collected serum and liver tissue samples to test pathological changes, biochemical indexes and molecular biological ***: Attenuated alanine aminotransferase, prothrombin time, high-mobility group box 1 (HMGB1), endotoxin, tumour necrosis factor (TNF)-α and interferon-γ were observed in the Ad-HGF-, Ad-HIL-6- and Ad-HGF-HIL-6-treated rats with ACLF. Likewise, reduced hepatic damage and apoptotic activity, as well as reduced HMGB1 and Bax proteins, but raised expression of Ki67 and Bcl-2 proteins and Bcl-2/Bax ratio were also observed in the Ad-HGF-, Ad-HIL-6- and Ad-HGF-HIL-6-treated rats with ACLF. More significant changes were observed in the Ad-HGF-HIL-6 treatment group without obvious side effects. Furthermore, caspase-3 at the protein level decreased in the Ad-HIL-6 and Ad-HGF-HIL-6 treatment groups, more predominantly in the latter ***: This study identifies that the protective efficacy of Ad-HGF-HIL-6 is more potent than that of Ad-HGF or Ad-HIL-6 in ACLF rats, with no significant side effects.

关键词： Acute-on-chronic liver failure Recombinant adenovirus Hyper-interleukin-6 Hepatocyte growth factor Inflammatory cytokines

Dynamic Mechanical Characteristics and Damage Evolution Model of Granite

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Journal of beijing Institute of Technology 2018年第2期27卷 302-311页

作者： Shuaifeng Wu Yingqi Wei Hong Cai bei jia Dianshu Liu China Institute of Water Resources and Hydropower Research Beijing 100038China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China

By using the technique of the split Hopkinson pressure bar（ SHPB）,impact tests at different stress wavelengths（ 0. 8-2. 0 m） and strain rates（ 20-120 s^（-1）） were conducted to study the dynamic mechanical properties and damage accumulation evolution lawof granite. Test results showthat the dynamic compressive strength and strain rate of granite have a significantly exponential correlation;the relationship between peak strain and strain rate is approximately linear,and the increase of wavelengths generally makes the level of peak strain uplift. The multiple-impacts test at a lowstrain rate indicates that at the same wavelength,the cumulative damage of granite shows an exponential increasing form with the increase of strain rate; when keeping the increase of strain rate constant and increasing the stress wavelength,the damage accumulation effect of granite is intensified and still shows an exponential increasing form; under the effect of multiple impacts,the damage development trend of granite is similar overall,but the increase rate is accelerating. Therefore the damage evolution model was established on the basis of the exponential function while the physical meaning of parameters in the model was determined. The model can reflect the effect of the wave parameters and multiple impacts. The validity of the model and the physical meaning of the parameters were verified by the test,which further offer a reference for correlational research and engineering application for the granite.

关键词： split Hopkinson pressure bar(SHPB) stress wave parameter dynamic mechanical property damage model

Neuroprotective effects of electroacupuncture on early- and late-stage spinal cord injury

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Neural Regeneration Research 2015年第10期10卷 1628-1634页

作者： Min-fei Wu Shu-quan Zhang jia-bei Liu Ye Li Qing-san Zhu Rui Gu Department of Orthopedics Bethune Second Hospital of Jilin University Department of Orthopedics Tianjin Nankai Hospital Department of Orthopedics China-Japan Union Hospital Jilin University

Previous studies have shown that the neurite growth inhibitor Nogo-A can cause secondary neural damage by activating Rho A. In the present study, we hypothesized that electroacupuncture promotes neurological functional recovery after spinal cord injury by inhibiting Rho A expression. We established a rat model of acute spinal cord injury using a modification of Allen＇s method. The rats were given electroacupuncture treatment at Dazhui（Du14）, Mingmen（Du4）, Sanyinjiao（SP6）, Huantiao（GB30）, Zusanli（ST36） and Kunlun（BL60） acupoints with a sparsedense wave at a frequency of 4 Hz for 30 minutes, once a day, for a total of 7 days. Seven days after injury, the Basso, Beattie and Bresnahan（BBB） locomotor scale and inclined plane test scores were significantly increased, the number of apoptotic cells in the spinal cord tissue was significantly reduced, and Rho A and Nogo-A m RNA and protein expression levels were decreased in rats given electroacupuncture compared with rats not given electroacupuncture. Four weeks after injury, pathological tissue damage in the spinal cord at the site of injury was alleviated, the numbers of glial fibrillary acidic protein- and neurofilament 200-positive fibers were increased, the latencies of somatosensory-evoked and motor-evoked potentials were shortened, and their amplitudes were increased in rats given electroacupuncture. These findings suggest that electroacupuncture treatment reduces neuronal apoptosis and decreases Rho A and Nogo-A m RNA and protein expression at the site of spinal cord injury, thereby promoting tissue repair and neurological functional recovery.

关键词： nerve regeneration spinal cord injury electroacupuncture locomotion Rho A Nogo-A glial fibrillary acidic protein neurofilament 200 neural regeneration