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Study on power generations and dynamic responses of the bistable straight beam and the bistable L-shaped beam

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Science China(Technological Sciences) 2018年第9期61卷 1404-1416页

作者： YAO MingHui ma Li ZHANG wei Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures College of Mechanical EngineeringBeijing University of Technology

In this paper, a simplified model of the bistable piezoelectric cantilever beam with magnets is established, and the potential energy of the bistable system is analyzed. We have proposed the bistable L-shaped beam structure, which has the same geometry dimensions of the bistable straight beam in the first time. The comparative study on power generations and dynamic responses of the bistable straight beam and the bistable L-shaped beam plays an important role in exploring excellent piezoelectric *** experiment structure includes the base layer and the piezoelectric layer. The harmonic excitation is given to the *** analysis results show that the potential energy function of the system has two obvious steady potential wells. In addition, the depth of the upper potential well is different from that of the lower potential well when the gravity potential energy is considered. Experimental results demonstrate that the power generation for the straight beam is better than that of the horizontally placed L-shaped beam when the excitation amplitude is 450 m V. There is the existence that the energy harvesting capacity of the bistable L-shaped beam is better than that of the bistable straight beam when the excitation amplitude is 400 m ***, the power generation of the bistable L-shaped beam with the upper potential well is obviously better than that of the bistable L-shaped beam with the lower potential well. In addition, comparing with the straight beam, the dynamic response of the bistable L-shaped beam is more complex when the external excitation frequency is changed. It is also observed that the distance between the magnets has the obvious influence on the dynamic response of the bistable system. It is very effective to select the appropriate distance between the magnets to improve the power generation of the bistable energy harvester under the fixed excitation conditions.

关键词： bistable straight beam bistable L-shaped beam power generation dynamic response

Deep learning for complex chemical systems

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National Science Review 2023年第12期10卷 8-10页

作者： wei Li Guoqiang Wang jing ma Institute of Theoretical and Computational Chemistry Key Laboratory of Mesoscopic Chemistry of Ministry of Education School of Chemistry and Chemical Engineering Nanjing University

Modern experimental techniques and theoretical simulations extended the research scope of complex chemical processes in functional molecules/materials innovation. Quantum chemistry (QC)-level simulations of macromolecules and condensed-phase systems need machine learning (ML) or deep learning (DL)[1]to decrease computational costs, which traditionally increases exponentially with system size. To guide rational design and optimize synthetic processes,

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A Taint Analysis Framework Applied to Android Applications in the Packed State

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China Communications 2023年第3期20卷 336-346页

作者： Shouying Bai Lu ma Huan ma wei Liu National Computer Network Emergency Response Technical Team/Coordination Center of China Beijing 100029China

In recent years,Android applications have caused personal privacy leaks *** order to analyze the malicious behavior,taint analysis technology can be used to track the API call chain,build a control-flow graph of function,and determine whether there is a security ***,with the continuous escalation of offensive and defensive confrontation of source code,more and more applications use reinforcement technology to prevent security practitioners from performing reverse analysis,therefore it is impossible to analyze function-behavior from the source ***,we design a framework of taint analysis that applied to the Android applications,which automatically unpacks the Android APKs,restores the real source code of the App,performs taint analysis,and generates a control-flow graph of *** tests showed that the system can cope with the current mainstream reinforcement technology and restore the real Dex file ***,compared with the number of nodes before packing,the generated control-flow graph had an explosive increase,which effectively assisted manual analysis of App with the privacy leakage behaviors.

关键词： privacy disclosure unpacked technology taint analysis

Phase thermal stability and mechanical properties analyses of(Cr,Fe,V)–(Ta,W)multiple-based elemental system using a compositional gradient film

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International Journal of Minerals,Metallurgy and materials 2020年第10期27卷 1379-1387页

作者： Qiu-wei Xing Jiang ma Yong Zhang Beijing Advanced Innovation Center of materials Genome Engineering State Key Laboratory of Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China

High-entropy alloys(HEAs)generally possess complex component combinations and abnormal *** traditional methods of investigating these alloys are becoming increasingly inefficient because of the unpredictable phase transformation and the combination of many *** development of compositionally complex materials such as HEAs requires high-throughput experimental methods,which involves preparing many samples in a short *** we apply the high-throughput method to investigate the phase evolution and mechanical properties of novel HEA film with the compositional gradient of(Cr,Fe,V)-(Ta,W).First,we deposited the compositional gradient film by ***,the mechanical properties and thermal stability of the(Cr0.33Fe0.33V0.33)x(Ta0.5W0.5)100−x(x=13-82)multiplebased-elemental(MBE)alloys were *** the deposited wafer was annealed at 600℃for 0.5 h,the initial amorphous phase was transformed into a body-centered cubic(bcc)structure phase when x=*** were observed on the film surface when x was 72 and ***,the highest hardness of as-deposited films was found when x=18,and the maximum hardness of annealed films was found when x=33.

关键词： high-throughput fabrication hard coating thermal resistance mechanical property phase stability high-entropy alloys

The diagnostic value of tenascin-C in acute aortic syndrome

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Journal of Geriatric Cardiology 2024年第3期21卷 359-368页

作者： Ming ma wei CHEN Hai-Long CAO Jun PAN Qing ZHOU Xin-Long TANG Dong-jin WANG Department of Thoracic and Cardiovascular Surgery Nanjing Drum Tower Hospital Clinical College of Nanjing Medical UniversityNanjingChina Department of Thoracic and Cardiovascular Surgery Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingChina Department of Thoracic surgery Kunshan Hospital of Traditional Chinese MedicineJiangsuChina

OBJECTIVES Misdiagnosis of acute aortic syndrome(AAS)significantly increases ***-C(TN-C)is an extracellular matrix glycoprotein related to cardiovascular *** elevation of TN-C in AAS and whether it can discriminate suddenonset of acute chest pain in Chinese remains *** We measured the plasma concentration of TN-C by ELISA in a cohort of 376 patients with chest or back *** to discriminate AAS from acute coronary syndrome(ACS)were compared and *** From October 2016 to September 2021,376 undiagnosed patients with chest or back pain were enrolled.166 of them were finally diagnosed as AAS,100 were ACS and 110 without cardiovascular diseases(NCV).TN-C was significantly elevated in AAS at 18.18 ng/mL(IQR:13.10–27.68)compared with 7.51 ng/mL(IQR:5.67–11.38)in ACS(Pmance of TN-C was superior to D-dimer and *** The concentration of serum TN-C in AAS patients was significantly higher than that in ACS patients and ***-C could be a new biomarker to distinguish AAS patients in the early stage after symptoms onset from other pain diseases.

关键词： acute cardiovascular elevated

Protective effect of oat bran extracts on human dermal fibroblast injury induced by hydrogen peroxide

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第2期14卷 97-105页

作者： Bing FENG Lai-ji ma jin-jing YAO Yun FANG Yan-ai MEI Shao-min wei School of Chemical and material Engineering Jiangnan University R&D Center Shanghai Jahwa United Co.Ltd. Department of Physiology and Biophysics School of Life SciencesFudan University

Oat contains different components that possess antioxidant properties; no study to date has addressed the antioxidant effect of the extract of oat bran on the cellular level. Therefore, the present study focuses on the investi- gation of the protective effect of oat bran extract by enzymatic hydrolysates on human dermal fibroblast injury induced by hydrogen peroxide （H2O2）. Kjeldahl determination, phenol-sulfuric acid method, and high-performance liquid chromatography （HPLC） analysis indicated that the enzymatic products of oat bran contain a protein amount of 71.93%, of which 97.43% are peptides with a molecular range from 438.56 to 1301.01 Da. Assays for 1,1-diphenyl-2-picrylhydrazyl （DPPH） radical scavenging activity indicate that oat peptide-dch extract has a direct and concentration-dependent antioxidant activity. 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） colorimetric assay and the TdT-mediated digoxigenin-dUTP nick-end labeling （TUNEL） assay for apoptosis showed that administration of H2O2 in human dermal fibroblasts caused cell damage and apoptosis. Pre-incubation of human dermal fibroblasts with the Oatp for 24 h markedly inhibited human dermal fibroblast injury induced by H2O2, but ap- plication oat peptides with H2O2 at same time did not. Pre-treatment of human dermal fibroblasts with Oatp significantly reversed the H2O2-induced decrease of superoxide dismutase （SOD） and the inhibition of malondialdehyde （MDA）. The results demonstrate that oat peptides possess antioxidant activity and are effective against H2O2-induced human dermal fibroblast injury by the enhanced activity of SOD and decrease in MDA level. Our results suggest that oat bran will have the potential to be further explored as an antioxidant functional food in the prevention of aging-related skin injury.

关键词： Oat bran Extraction Antioxidant Human dermal fibroblasts Cell injury

Dipeptide： from gel to chiral crystal

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Science Bulletin 2017年第23期62卷 1555-1556页

作者： Hongchao ma Yanhui wei State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology College of Chemical Engineering China University of Petroleum (East China) Qingdao 266580 China Institute of Biomedical materials and Engineering College of Chemistry and Chemical Engineering Qingdao University Qingdao 266071 China

Crystallization in gel media is an important strategy for the growth of organic, inorganic and protein crystals, The suppression of sedimentation, convection currents and nucleation afforded by the viscous property of gel media are beneficial for obtaining crystals with improved physical properties such as fewer defects, better optical auality, and larger size.

关键词： Dipeptide from gel to chiral crystal

Influence factors of two dimensional position map on photomultiplier detector block designed by quadrant sharing technique

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Nuclear Science and Techniques 2011年第4期22卷 224-229页

作者： wei Qingyang WANG Shi ma Tianyu ma Fei DAI Tiantian XU Tianpeng WU Zhaoxia jin Yongjie LIU Yaqiang Key Laboratory of Particle & Radiation Imaging (Tsinghua University) Ministry of Education Department of Engineering Physics Tsinghua University Beijing 100084 China

The position decoding accuracy and the spatial resolution of positron emission tomography detectors are greatly influenced by the performance of the two-dimensional position map,including the gain uniformity of photomultiplier tube (PMT),the baseline offset of the PMT signals and the accuracy of analogue to digital converter (ADC).In this work,a PMT-quadrant sharing detector was *** data acquisition platforms are employed to conduct the influence factors on the two-dimensional position map performances,one was that the waveforms of the PMT signals were scanned by the sequence acquisition mode based on the oscilloscope of LeCroy waveRunner 204MXi-A,and another was a self-developed high speed ADC data acquisition *** show that the event decoding positions were concentrated on the PMT with higher gain,the position map was distorted at the baseline offset of signal,and the cross-line artifacts were caused by the insufficient ADC sampling bit for a larger size position *** the parameters need be adjusted properly to stabilize a real system,and the flexible oscilloscope platform can be used to design the detector block and the other platform with high ADC ***,the electrical circuit with a proper ADC accuracy adjusts the PMT gains and baseline offsets.

关键词：光电倍增管三维位置影响因素共享技术地图设计正电子发射断层扫描象限

Efficacy and safety of endoscopic submucosal tunnel dissection for superficial esophageal squamous cell carcinoma and precancerous lesions

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World Journal of Gastroenterology 2018年第26期24卷 2878-2885页

作者： jin Wang Xiao-Nan Zhu Lin-Lin Zhu wei Chen Yi-Han ma Tao Gan jin-Lin Yang Department of Gastroenterology and Hepatology West China Hospital of Sichuan University State Key Laboratory of Biotherapy and Cancer Center Sichuan University Department of General Practice West China Hospital of Sichuan University

AIM To evaluate the clinical outcomes of patients who underwent endoscopic submucosal tunnel dissection(ESTD) for esophageal squamous cell carcinoma(ESCC) and precancerous *** ESTD was performed in 289 patients. The clinical outcomes of the patients and pathological features of the lesions were retrospectively *** A total of 311 lesions were included in the analysis. The en bloc rate, complete resection rate, and curative resection rate were 99.04%, 81.28%, and 78.46%, respectively. The ESTD procedure time was 102.4 ± 35.1 min, the mean hospitalization time was 10.3 ± 2.8 d, and the average expenditure was 3766.5 ± 846.5 dollars. The intraoperative bleeding rate was 6.43%, the postoperative bleeding rate was 1.61%, the perforation rate was 1.93%, and the postoperative infection rate was 9.65%. Esophageal stricture and positive margin were severe adverse events, with an incidence rate of 14.79% and 15.76%, respectively. No tumor recurrence occurred during the follow-up period. CONCLUSION ESTD for ESCC and precancerous lesions is feasible and relatively safe, but for large mucosal lesions, the rate of esophageal stricture and positive margin is high.

关键词： Superficial esophageal squamous cell carcinoma Endoscopic submucosal tunnel dissection Efficiency Safety Esophageal stricture