检索结果-南通市图书馆

维普期刊数据库

A High precision Software co.pensation Algorithm for Silico. Piezoresistive Pressure Sensor

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2019年第4期28卷 748-753页

作者： WU Tianshu CHEN Shuyu WU Peng NIE Shaozhong co.lege of co.puter Science Chongqing University chongqing Chuanyi Automation co. Ltd.

There are generally zero drift, sensitivity drift and nonlinear error in silico. piezoresistive pressure sensors due to the inherent characteristics of semico.ductor materials. It is necessary to co.pensate and co.rect the errors produced so as to meet the requirements of measurement accuracy. In order to further improve the co.pensation precision, based on the research of various basic software co.pensation methods, a surface fitting co.pensation algorithm based on least square method is designed, and the software is implemented on the Visual Basic platform. The experimental results show that the zero drift, sensitivity drift and nonlinear error is effectively eliminated, and the output precision of the sensor is greatly improved.

关键词： High precision co.pensation algorithm Least square method Surface fitting

Towards Friction Stir Remanufacturing of High‑Strength Aluminum co.ponents

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2023年第1期36卷 91-102页

作者： Xiangchen Meng Yuming Xie Xiaotian Ma Mingyang Liang Xiaoyang Peng Shiwei Han Lei Kan Xin Wang Sihao Chen Yongxian Huang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China chongqing Tiema Industries Group co. Ltd.Chongqing 630050China The Sixth Military Representative Ofce of the Army Installment Station in chongqing Chongqing 400042China Shanghai Spacefight precision Machinery Institute Shanghai 201600China

Volumetric defects in high-strength aluminum alloy co.ponents were repaired via friction stir remanufacturing(FSR).Various co.sumable pins made of AA7075-T6 were *** diameters of the co.sumable pins afected material fow,which ensured that the materials at the repairing interface were forged to metallurgical *** angles determined load transfer besides material fow,which afected the fracture of the pins before the dwelling *** repaired co.ponents were achieved when the co.ical angle of the co.sumable pin was 1°larger than that of the volumetric *** ultimate tensile strength and elongation of the repaired co.ponents reached 445.9 MPa and 9.6%,*** design criteria of the co.sumable pin in the FSR was established,which provided valuable references to repair volumetric defects in high-strength aluminum co.ponents.

关键词： Aluminum alloy Defects Friction stir welding Interfaces Microstructures Mechanical properties

Deep Learning-Based Automatic Detection and Evaluation on co.crete Surface Bugholes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

co.puter Modeling in Engineering & Sciences 2022年第5期131卷 619-637页

作者： Fujia Wei Liyin Shen Yuanming Xiang Xingjie Zhang Yu Tang Qian Tan School of Management Science and Real Estate Chongqing UniversityChongqing400044China CMCU Engineering co. Ltd.Chongqing400039China

co.crete exterior quality is one of the important metrics in evaluating co.struction project *** the defects affecting co.crete exterior quality,bughole is one of the most co.mon imperfections,thus detecting co.crete bughole accurately is significant for improving co.crete exterior quality and co.sequently the quality of the whole *** paper presents a deep learning-based method for detecting co.crete surface bugholes in a more objective and automatic *** bugholes are identified in co.crete surface images by Mask *** evaluation metric is developed to indicate the scale of co.crete *** proposed approach can detect bugholes in an instance level automatically and output the mask of each bughole,based on which the bughole area ratio is automatically calculated and the quality grade of the co.crete surfaces is *** demonstration,a total of 273 raw co.crete surface images taken by mobile phone cameras are co.lected as a *** test results show that the average precision(AP)of bughole masks is 90.8%.

关键词： Defect detection engineering co.crete quality deep learning instance segmentation

Extending the Lifetime of co.per-beryllium Alloys as Plastic Injection High-end Needle Valve Mold Nozzle Tips Through a Heat-treatment-based Microstructure Optimization Approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2023年第3期38卷 665-668页

作者：孟晓敏 ZHAO Dong MAJID Shaker chongqing 2D Materials Institute Chongqing 400701China Chengdu Lianyu precision Machinery co. Ltd.Chengdu 611730China Lehrstuhl Für Physikalische Chemie II Universitat Erlangen-NürnbergEgerlandstraBe 391058ErlangenGermany

The relationship between the microstructure and the practical performance of two different co.per-beryllium alloys including their lifetime has been ***,two valves made of two different alloys with very similar co.positions and the same heat treatment methods were investigated by various standard techniques including metallography,X-ray diffraction,chemical co.position,microhardness,and thermal co.ductivity *** both alloys experienced the same heat-treatment processes,they revealed different thermal and mechanical properties due to the minor difference in their chemical *** alloy providing a longer lifetime (40%more) as the tip had a higher thermal co.ductivity of 280.3 W(m·K)^(-1) (about two times that of the other alloy).Regarding the metallography images and the measured thermal co.ductivity values of the alloys,the extended lifetime of the nozzle with the optimum performance is ascribed to its biphasic microstructure and the minor grain boundaries and interfacial thermal *** important difference in the chemical co.position was investigated in this study.

关键词： crystal structure grain boundaries metals and alloys thermal properties needle valve

维普期刊数据库

Study on influence of key blasthole parameters on tunnel overbreak

在线全文

学校读者我要写书评

暂无评论

Underground Space 2023年第2期9卷 76-90页

作者： Zi-qiang Li Zheng Li Wei-wei Huang Xuan-ming Ding Hang Zhang School of Civil Engineering and Architecture Chongqing University of Science&TechnologyChongqing 401331China Key Laboratory of New Technology for co.struction of Cities in Mountain Area Ministry of EducationChongqing UniversityChongqing 400045China chongqing City co.struction Investment(Group)co. Ltd.Chongqing 400023China School of Civil Engineering Chongqing University400045China

To determine the influence of key blasthole parameters on tunnel overbreak during blasting co.struction,an intelligent detection sys-tem for tunnel blasting co.struction is independently *** the key blasthole parameters and overbreak of a typical section of a single line tunnel under the co.dition of Class V surrounding rock are analyzed and *** actual data obtained is co.pared with the results of numerical simulations and theoretical *** results are as follows:(1)Quantitative analysis is performed based on the blasthole angle,opening position,and charge mass by the self-developed intelligent detection equipment for blasthole parameters,which can be used to guide the drilling *** scanning equipment for outline excavation can be used to image the actual excavation section in real-time and has the advantages of high precision and fast speed;(2)Tunnel overbreak can be regarded as co.sisting of two parts:the surrounding rock damage caused by the blasting load,and the co.lapse of the surrounding rock caused by the blasthole opening *** parameter of the peripheral hole will affect the tunnel overbreak;however,the key parameter is the blasthole opening position;(3)The distributions of the tunnel overbreak volume obtained with the theoretical analysis,finite element simulation,and measurements are basically *** the co.dition of Class V surrounding rock,the overbreak of this single line tunnel can reach 14.1–78.2 *** meet the specification requirements,the opening position and co.struction accuracy of the peripheral hole should be strictly co.trolled.

关键词： Tunnel blasting Blasthole parameters Tunnel overbreak Surrounding rock damage Smooth surface blasting

Dynamic recrystallization behavior and co.ncidence site lattice evolution in thermal deformation of 316H stainless steel used in nuclear systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第9期30卷 1862-1872页

作者： Le-li Chen Rui Luo Pei Gao Tian-wei Yin Hui-xia Hao Dong-hua Sheng Tian Liu Heng-nan Ding Yu Cao Bao-sen Zhang Xiao-nong Cheng School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina Technical Management Department Jiangsu Yinhuan Precision Steel Tube Co.Ltd.Yixing 214200JiangsuChina co.lege of Materials Science and Engineering Chongqing UniversityChongqing 400045China School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167JiangsuChina

The hot deformation behavior of 316H stainless steel used in the 4th-generation nuclear systems was investigated by thermal co.pression tests at 1000–1150 C and 0.01–10 s^(-1).It was found that true stress firstly increased and then decreased with the increasing strain rate with a threshold of 1 s^(-1).Electron backscatter diffraction was used to analyze the microstructure *** dynamic recrystallization(DDRX)was the dominant dynamic recrystallization(DRX)mechanism,while co.tinuous dynamic recrystallization(CDRX)was the supplementary *** happened before CDRX and provided additional nucleation sites for the *** grain boundaries(R3)appeared in DRX grains due to growth *** the length fraction of R3 increased,the co.ncidence site lattice(CSL)boundary transition began to occur,forming R9 and *** the occurrence of full DRX,the growth and annexation of DRX grains were easy to be promoted,in which progress both equiaxed grains and CSL boundaries *** ideal deformation microstructure with fine and uniform DRX grains,which was acco.panied by a high length fraction of CSL boundaries,appeared at 1000℃–0.01 s^(-1),1050℃–0.01–0.1 s^(-1),1100℃–0.1–1 s^(-1) and 1150℃–1–10 s^(-1).That is,the deformation co.ditions mentioned above were the preferable thermal forming parameters for 316H stainless steel in actual productions.

关键词： 316H stainless steel Thermal co.pression Microstructure Dynamic recrystallization co.ncidence site

Three-dimensional parametric co.tact analysis of planetary roller screw mechanism and its application in grouping for selective assembly

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第1期19卷 53-72页

作者： Huilin HE Peitang WEI Huaiju LIU Xuesong DU Rui HU Genshen LIU Yajun WU State Key Laboratory of Mechanical Transmission for Advanced Equipment Chongqing UniversityChongqing 400044China Taiyuan Heavy Machinery Group co. Ltd.Taiyuan 030024China

The planetary roller screw mechanism(PRSM)is a novel precision transmission mechanism that realizes the co.version between linear and rotary *** co.tact characteristics of helical surfaces directly determine PRSM’s performance in load-carrying capacity and transmission ***,studying the co.tact characteristics of PRSM forms the fundamental basis for enhancing its transmission *** this study,a three-dimensional parametric analysis method of co.tact characteristics is proposed based on the PRSM meshing principle and PyVista(a high-level API to the Visualization Toolkit).The proposed method co.siders the influence of machining errors among various thread *** effects of key machining errors on co.tact positions and axial clearance,as well as their sensitivities,are *** excellent solution accuracy,this method exhibits higher calculation efficiency and stronger robustness than the analytical and numerical meshing *** influence of nominal diameter and pitch errors of the screw,roller,and nut on the axial clearance follows a linear relationship,whereas flank angle errors have negligible effects on the axial *** co.responding influence co.fficients for these three machining errors on the axial clearance are 0.623,0.341,and *** variations in co.tact positions caused by individual errors are *** angle errors and roller diameter errors result in linear displacements of the co.tact points,whereas pitch errors cause the co.tact points to move along the arc of the roller *** on the proposed threedimensional parametric co.tact characteristics analysis method,the Fuzzy C-Means clustering algorithm co.sidering error sensitivity is utilized to establish a co.ponent grouping technique in the selective assembly of critical PRSM co.ponents,ensuring the rational and co.sistent clearances based on the given co.ponent’s machining *** study provides effective guidance for analyzing co.ta

关键词： planetary roller screw mechanism(PRSM) co.tact position axial clearance machining error grouping for selective assembly

Enhancing microseismic/aco.stic emission source localization accuracy with an outlier-robust kernel density estimation approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第7期34卷 943-956页

作者： Jie Chen Huiqiong Huang Yichao Rui Yuanyuan Pu Sheng Zhang Zheng Li Wenzhong Wang State Key Laboratory of co.l Mine Disaster Dynamics and co.trol Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Central South UniversityChangsha 410083China chongqing City co.struction Investment Group co. Ltd.Chongqing 400023China co.l Geological Exploration Institute of Gansu Lanzhou 730000China

Monitoring sensors in co.plex engineering environments often reco.d abnormal data,leading to significant positioning *** reduce the influence of abnormal arrival times,we introduce an innovative,outlier-robust localization method that integrates kernel density estimation(KDE)with damping linear co.rection to enhance the precision of microseismic/aco.stic emission(MS/AE)source *** approach systematically addresses abnormal arrival times through a three-step process:initial location by 4-arrival co.binations,elimination of outliers based on three-dimensional KDE,and refinement using a linear co.rection with an adaptive damping *** validate our method through lead-breaking experiments,demonstrating over a 23%improvement in positioning accuracy with a maximum error of 9.12 mm(relative error of 15.80%)—outperforming 4 existing *** under various system errors,outlier scales,and ratios substantiate our method’s superior *** blasting experiments also co.firm the practical applicability,with an average positioning error of 11.71 m(relative error of 7.59%),co.pared to 23.56,66.09,16.95,and 28.52 m for other *** research is significant as it enhances the robustness of MS/AE source localization when co.fronted with data *** also provides a practical solution for real-world engineering and safety monitoring applications.

关键词： Microseismic source/aco.stic emission(MS/AE) Kernel density estimation(KDE) Damping linear co.rection Source location Abnormal arrivals

维普期刊数据库

Mechanical behaviors of extruded Mg alloys with high Gd and Nd co.tent

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2021年第4期31卷 591-598页

作者： Yuling Xu Shiwei Wang Yuye Wang Li Chen Lixiang Yang Lu Xiao Li Yang Norbert Hort chongqing Academy of Science and Technology Shanghai Spaceflight precision Machinery Institute Mag IC-Magnesium Innovation Center Helmholtz-Zentrum Geesthacht co.lege of Materials Science and Engineering Chongqing University

The influence of alloying elements and heat treatment on the microstructure and mechanical behaviors of extruded Mg–Gd–Nd ternary alloys was investigated in this study. The grain sizes dramatically decreased after extrusion, and the particles which distributed in Mg matrix had great effect on the grain size. The grain sizes of extruded alloys decreased from 26 to 5 μm with the alloying co.tent increasing. The mechanical test results show that both Gd and Nd had positive effect on the hardness, yield strength and Young’s modulus. The ultimate tensile strength(UTS) was enhanced by Gd co.tent, decreased with Nd co.tent. The elongation of alloys was lower with higher alloying elements. Those extruded alloys were aged for 200 h in 200℃. The Young’s moduli were decreased by ageing treatment. co.bined with microstructure study, the part of the reinforcement which identified as Mg5(Gd/Nd) was dissolved in Mg matrix. Nd element obviously has influence on the solubility of Gd in Mg alloys.

关键词： Wrought Mg alloy Mechanical properties Rare earth element