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Research on new software compensation method of static and quasi-static errors for precision motion controller

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1938-1943页

作者： REN Kun FU Jian-zhong chen zi-chen Department of Mechanical Engineering Zhejiang University Hangzhou 310027 China

To reduce mechanical vibrations induced by big errors compensation, a new software compensation method based on an improved digital differential analyzer (DDA) interpolator for static and quasi-static errors of machine tools is proposed. Based on principle of traditional DDA interpolator, a DDA interpolator is divided into command generator and command analyzer. There are three types of errors, considering the difference of positions between compensation points and interpolation segments. According to the classification, errors are distributed evenly in data processing and compensated to certain interpolation segments in machining. On-line implementation results show that the proposed approach greatly improves positioning accuracy of computer numerical control (CNC) machine tools.

关键词： Static and quasi-static errors Positioning and machining accuracy Digital differential analyzer (DDA) interoolator

Analysis of Heat Dissipation in LED with Various Adhesives

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Journal of Thermal Science 2011年第3期20卷 254-259页

作者： zi-Gui Huang Zheng-Yu chen Department of Mechanical Design Engineering National Formosa University Huwei Yun-lin Taiwan China

Light-emitting diodes (LEDs) are semiconducting, light producing units, with the advantages of small size, long life, low voltage, reduced energy consumption, and high vibration resistance. Unfortunately, most LED output power is converted into heat, with little converted into optical energy. If the heat is not transferred outward from the unit, the LED will overheat and its light emission efficiency, stability, and lifespan will be reduced. Improving LED heat dissipation has become a hot topic. This paper used the finite element method to discuss the temperature change in LED heat sources, using epoxy and Al2O3 adhesives with varying heat transfer coefficients.

关键词： LED heat dissipation finite element method heat transfer coefficient adhesive

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喷印金属微滴撞击粗糙表面的分子动力学模拟

原子与分子物理学报 2025年第4期42卷 73-80页

作者：苏仁健陈小勇游自浩桂林电子科技大学机电工程学院桂林541004 广西制造系统与先进制造技术重点实验室桂林541004

研究金属微滴撞击固体表面的行为对预测微滴形态和实现高精度的喷印制造具有重要的意义.然而,由于微纳尺度下金属微滴撞击实验的难以开展,目前涉及金属微滴撞击粗糙表面的形态变化和热毛细效应机理尚不清楚.本文采用分子动力学模拟研究... 详细信息

研究金属微滴撞击固体表面的行为对预测微滴形态和实现高精度的喷印制造具有重要的意义.然而,由于微纳尺度下金属微滴撞击实验的难以开展,目前涉及金属微滴撞击粗糙表面的形态变化和热毛细效应机理尚不清楚.本文采用分子动力学模拟研究了镓铟微滴撞击粗糙表面的动态行为,定量分析了撞击速度、粗糙结构和不同温度对微滴撞击行为的影响.结果表明:随着撞击速度的提高,微滴先后呈现沉积、弹跳和破碎飞溅三种模式,且微滴的最大铺展因子与韦伯数呈幂函数关系.此外,通过修饰基底粗糙结构发现,结构间距或高度的变化对微滴的弹跳行为存在不同的影响机制,可以有效促使或抑制微滴的弹跳行为.最后,分析得出随着温度的提高,微滴的铺展直径会变大,产生的黏性耗散也会增大.研究结果对金属微滴撞击行为的有效预测提供了理论基础.

关键词：金属微滴撞击粗糙基底分子动力学

Kalb-Ramond field localization on a thick de Sitter brane

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Communications in Theoretical Physics 2020年第7期72卷 123-131页

作者： chen Yang zi-Qi chen Li Zhao Institute of Theoretical Physics Lanzhou University222 South Tianshui RoadLanzhou 730000China Research Center of Gravitation Lanzhou University222 South Tianshui RoadLanzhou 730000China

In this paper,we explore the localization condition of Kalb-Ramond(KR)tensorial gauge field on a thick de Sitter(dS)*** the localization mechanism in the work by Chumbes et al(2012 ***.D 85085003),we analyze the localization of KR tensorial gauge field on a non-flat *** propose three kinds of coupling methods and two of them support the localization of zero *** addition,there exist resonant Kaluza-Klein modes on the thick dS *** effects of three parameters on the localization and the resonant mode for the KR field are also discussed.

关键词： Kalb–Ramond field localization braneworld

Inhibition of Escherichia coli nitroreductase by the constituents in Syzygium aromaticum

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Chinese Journal of Natural Medicines 2022年第7期20卷 506-517页

作者： chen Lu chen Xi BAI Yue ZHAO zi-Nan CAO Yun-Feng LIU Li-Kun jiang Tao HOU Jie College of Basic Medical Sciences Dalian Medical UniversityDalian 116044China Dalian Runsheng Kangtai Medical Laboratory Co. Ltd.Dalian 116000China

Gut bacterial nitroreductases play an important role in reduction of various nitroaromatic compounds to the corresponding N-nitroso compounds,hydroxylamines or aromatic amines,most of which are carcinogenic and mutagenic *** of gut nitroreductases has been recognized as an attractive approach for reducing mutagen metabolites in the colon,so as to prevent colon *** this study,the inhibitory effects of 55 herbal medicines against Escherichia coli(***)nitroreductase(EcNfsA)were *** with other herbal extracts,Syzygium aromaticum extract showed superior inhibitory potency toward EcNf-sA mediated nitrofurazone ***,the inhibitory effects of 22 major constituents in Syzygium aromaticum against EcNfsA were *** with other tested natural compounds,ellagic acid,corilagin,betulinic acid,oleanic acid,ursolic acid,urolith-in M5 and isorhamnetin were found with strong to moderate inhibitory effect against EcNfsA,with IC50 values ranging from 0.67 to 28.98 mol·L^(−1).Furthermore,the inhibition kinetic analysis and docking simulation demonstrated that ellagic acid and betulinic acid potently inhibited EcNfsA(Ki<2μmol·L−1)in a competitively inhibitory manner,which created strong interactions with the catalytic triad of *** summary,our findings provide new scientific basis for explaining the anti-mutagenic activity of Syzygium aromaticum,where some newly identified EcNfsA inhibitors can be used for developing novel agents to reduce the toxicity induced by bacteri-al nitroreductase.

关键词： Gut bacterial nitroreductase EcNfsA inhibitor Syzygium aromaticum Anti-mutagenic activity

Strain-induced martensitic transformation in biomedical Co-Cr-W-Ni alloys

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Rare Metals 2020年第3期39卷 241-249页

作者： zi-Yi Zhu Li Meng Leng chen School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Metallurgical Technology Institute Central Iron and Steel Research InstituteBeijing100081China

The nucleation,variant selection,and orientation dependence of the strain-induced martensitic transformation(SIMT)process in biomedical Co-Cr-W-Ni alloys were *** experimental results show that theε-hexagonal-close-packed phase was preferentially formed at theΣ3 twin boundaries and high-angle grain boundaries during the tensile *** theoretical analysis shows that the variant selection of SIMT is governed by Schmid’s ***,the SIMTedε-phase did not form equally on the two sides of the annealing twins,even though they had the same Schmid *** phenomenon is related to the mechanical work developed by the formation of theε-*** the side which has both high Schmid factor and high mechanical work can initiate the SIMT process.A strongfiber texture was formed,and theε-variants tended to appear in grains with orientations close to theanddirections during the tensile *** results can provide theoretical guidance for controlling the SIMT process of Co-Cr-W-Ni alloys to fabricate more reliable stents.

关键词： Biomedical Co-Cr-W-Ni alloys Straininduced martensitic transformation Nucleation Variant selection Orientation dependence

Can patients with mild non-neoplastic lesions diagnosed at baseline screening be safely exempt from surveillance: evidence from multicenter community-based cohorts

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Science China Life Sciences 2025年第1期 263-271页

作者： Siyi He Zhiyi Zhang Guohui Song Zhenhai Wang Chunyun Dai Shipeng Yan Kun jiang Bingbing Song He Li Maomao Cao Dianqin Sun Fan Yang Xinxin Yan Shaoli Zhang Yi Teng Qianru Li Changfa Xia Wanqing chen Office of Cancer Screening National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical College Department of Gastroenterology Gansu Wuwei Tumor Hospital Cixian Cancer Institute Linzhou Cancer Hospital Center for Disease Control and Prevention of Sheyang County Department of Cancer Prevention and Control Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of MedicineCentral South University Luoshan Center for Disease Control and Prevention Office for Cancer Control and Research Affiliated Cancer Hospital of Harbin Medical University

Surveillance recommendations for gastric cancer（GC） in current guidelines focused on advanced precancerous lesions and were based on precise diagnosis of severity/extent of baseline lesions. We aimed to develop a less endoscopy-related equipment-dependent risk-stratification tool, and assessed whether mild-precursor-lesion patients can be safely exempt from surveillance. In the multicenter communitybased cohort, 75,051 participants receiving baseline endoscopy were enrolled during 2015–2017 and followed-up until 2021. Cumulative incidence rates（CIRs） of GC for precancerous-conditions were calculated by Kaplan-Meier method and compared by Log-rank tests. Mixedeffects Cox regression models were used to detect potential factors for progression towards GC. A risk score was calculated as counts of selected factors. An independent cohort, including 26,586 participants was used for external validation. During a median follow-up of 6.25 years, CIRs of GC were 0.302%, 0.436%, and 4.756% for normal group, non-neoplastic（atrophic gastritis/intestinal metaplasia） and neoplastic lesions（low-grade/high-grade dysplasia）, respectively(Ptrendzing non-neoplastic lesions by histological grade, both patients with moderate-to-severe lesions（aHR=3.07, 95%CI: 1.67–5.64） and high-risk patients with mild lesions（aHR=7.29, 95%CI: 3.58–14.86） showed higher risks. Consistent trends were observed in validation cohort. High-risk mild-precursor-lesion patients should receive surveillance within 3–5 years after baseline screening. Our study provides evidence on supplementing current guideline recommendations.

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Scaling Behaviors of Polymers on Lipid Membranes:Coupling of Polymer Chain Dynamics and Surface Thermal Fluctuations

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Chinese Journal of Polymer Science 2023年第3期41卷 459-464,I0010页

作者： zi-Ren chen Wu Zhou Lei Shen School of Chemistry Chemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China

Despite extensive researches on the motion of polymer chains on lipid membranes,the effect of membrane fluctuations on polymer chain dynamics remains poorly *** we report single molecule tracking experiments that allow for comparable measurements of polymer chain diffusion dynamics on nanotubular and planar phospholipid *** observe a super-diffusion behavior and no apparent chain-length-dependent mobility of polymer chains on nanotubular membranes,while a Brownian motion and apparent chain-lengthdependent mobility of polymer chains on planar *** suggest the super-diffusion nature of polymer chains may be due to the thermal-fluctuations of lipid nanotubes,which can be described from a statistical thermodynamic phenomenon coupling of polymer chain dynamics and surface thermal *** suggest that the existence of surface environment fluctuations should influence the dynamics of the adsorbed polymer *** study provides previously uncharacterized insights into polymer diffusion dynamics on thermal-fluctuating flexible surfaces,which is essential to understanding the effect of environment fluctuations on polymer chain behaviors.

关键词： Polymer diffusion Lipid membrane Scaling behavior

Fallback Disk-Involved Spin-Down of Young Radio Pulsars

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Chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 487-494页

作者： zi-Bo jiang Xiang-Dong Li Department of Astronomy Nanjing University Nanjing 210093

Disks originating from supernova fallback have been suggested to surround young neutron stars. Interaction between the disk and the magnetic field of the neutron star may considerably influence the evolution of the star through the so called propeller effect. There are many controversies about the efficiency of the propeller mechanism proposed in the literature. We investigate the faUback diskinvolved spin-down of young pulsars. By comparing the simulated and measured results of pulsar evolution, we present some possible constraints on the propeller torques exerted by the disks on neutron stars.

关键词： stars: magnetic fields - stars: neutron - pulsars: individual: PSRs B0532+21 B0833+45 B0540-69 B1509-58