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杨房沟水电站高拱坝大体积混凝土温控措施研究

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四川水力发电 2022年第4期41卷 10-14页

作者：叶劲松刘晓龙李雷刚中国水利水电第七工程局有限公司四川成都610213

高拱坝大体积混凝土施工过程中的温度控制为其重中之重。为解决大体积混凝土在其硬化过程中水泥水化热在块体内产生的温度变化带来的应变和应力、继而引发的温度裂缝问题,需要采取强有力的施工措施控制混凝土的温度变化。阐述了杨房沟... 详细信息

高拱坝大体积混凝土施工过程中的温度控制为其重中之重。为解决大体积混凝土在其硬化过程中水泥水化热在块体内产生的温度变化带来的应变和应力、继而引发的温度裂缝问题,需要采取强有力的施工措施控制混凝土的温度变化。阐述了杨房沟水电站从混凝土原材料、出机口温度、混凝土入仓、浇筑、养护及通水冷却等环节进行的全过程有效控制,使混凝土温控相关的各项指标满足设计要求,控制水平优秀,所取得的经验对同类工程具有推广和借鉴意义。

关键词：高拱坝大体积混凝土杨房沟水电站温度控制措施研究

Study of the Judder Characteristics of Friction Material for an Automobile Clutch and Test Verification

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Chinese Journal of Mechanical Engineering 2023年第2期36卷 352-364页

作者： Zhengfeng Yan Hangsheng li Hairui Lei Maoqing Xie leigang Wang School of Automotive and Transportation Engineering Hefei University of TechnologyHefei 230009China Allways Friction Material(Kunshan)Co.Ltd Suzhou 215332China School of Materials Science&Engineering Jiangsu UniversityZhenjiang 212013China Zhejiang Tieliu Clutch Co.Ltd. Hangzhou 311101China

The friction judder characteristics during clutch engagement have a significant influence on the NVH of a *** this research,the judder characteristics of automobile clutch friction materials and experimental verification are ***,considering the stick-slip phenomenon in the clutch engagement process,a detailed 9-degrees-of-freedom(DOF)model including the body,each cylinder of the engine,clutch and friction lining,torsional damper,transmission and other driveline parts is established,and the calculation formula of friction torque in the clutch engagement process is ***,the influence of the friction gradient characteristics on the amplification or attenuation of the automobile friction judder is analyzed,and the corresponding stability analysis and the numerical simulation of different friction gradient values are carried out with MATLAB/Simulink ***,judder bench test equipment and a corresponding damping test program are developed,and the relationship between the friction coefficient gradient characteristics and the system damping is *** a large number of tests,the evaluation basis of the test is *** research results show that the friction lining with negative gradient characteristics of the friction coefficient will have a judder *** the friction gradient value is less than-0.005 s/m,the judder signal of the measured clutch cannot be completely attenuated,and the judder phenomenon *** the friction gradient is greater than-0.005 s/m,the judder signal can be significantly suppressed and the system connection tends to be stable.

关键词： Clutch friction lining Judder Friction coefficient gradient Damping Bench test

Reliability analysis based on a novel density estimation method for structures with correlations

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Chinese Journal of Aeronautics 2017年第3期30卷 1021-1030页

作者： Baoyu li leigang ZHANG Xuejun ZHU Xiongqing YU Xiaodong MA College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China China Academy of Launch Vehicle Technology Beijing 100076 China

Estimating the Probability Density Function（PDF） of the performance function is a direct way for structural reliability analysis,and the failure probability can be easily obtained by integration in the failure ***,efficiently estimating the PDF is still an urgent problem to be *** existing fractional moment based maximum entropy has provided a very advanced method for the PDF estimation,whereas the main shortcoming is that it limits the application of the reliability analysis method only to structures with independent *** in fact,structures with correlated inputs always exist in engineering,thus this paper improves the maximum entropy method,and applies the Unscented Transformation（UT） technique to compute the fractional moments of the performance function for structures with correlations,which is a very efficient moment estimation method for models with any *** proposed method can precisely estimate the probability distributions of performance functions for structures with ***,the number of function evaluations of the proposed method in reliability analysis,which is determined by UT,is really *** examples are employed to illustrate the accuracy and advantages of the proposed method.

关键词： Fractional moment Maximum entropy Probability density function Reliability analysis Unscented transformation

Redistribution of C and N Atoms in High Nitrogen Martensitic Stainless Steel During Cryogenic Treatment

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Acta Metallurgica Sinica(English Letters) 2022年第4期35卷 591-595页

作者： Xin Cai Xiaoqiang Hu leigang Zheng Dianzhong li University of Chinese Academy of Sciences Beijing 100049China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The redistribution of C and N atoms during cryogenic treatment is crucial for the microstructure evolution and properties of high nitrogen martensitic ***,the distinct redistribution behavior of C and N atoms in a martensitic stainless steel with 0.3 wt%C and 0.5 wt%N after cryogenic treatment were investigated by the atom probe *** clusters begin to form after cryogenic treatment at-60℃and gradually increase with the decrease of cryogenic treatment *** Mo–N and Cr–N pairs are homogeneously distributed in the matrix even after cryogenic treatment at-120℃,and then form enrichment phenomenon when the cryogenic temperature is deeply lowered to-190℃.It is found that the distinct redistributions of C and N atoms are associated with the different interaction energy between substitutional atoms and *** stronger interaction between Cr,Mo atoms and N delays the segregation of N during the cryogenic ***,the mechanical properties results confirmed that the deep lower cryogenic treatment is a promising method to improve the hardness and strength in the high nitrogen martensitic stainless steel.

关键词： Interstitial atom Cryogenic treatment Martensitic stainless steel Atom probe tomography

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龙门式自动化焊接专机的柔性化设计

机床与液压 2011年第18期39卷 12-14页

作者：冯宝林李雷刚时张杰王美玲胡晓娟牛晓庆王丹中国科学院合肥研究院先进制造技术研究所江苏常州213164 常州佳卓特种车辆有限公司江苏常州213017

针对多种尺寸特种车辆底盘的焊点多、焊缝短以及焊接设备要具有对这些底盘焊接的通用性,设计一款具有柔性可调底盘的自动化焊接设备。该焊接设备由龙门架、翻转机构和焊接机械手三大部分组成;由PLC进行运动控制,由光电编码器进行位置检... 详细信息

针对多种尺寸特种车辆底盘的焊点多、焊缝短以及焊接设备要具有对这些底盘焊接的通用性,设计一款具有柔性可调底盘的自动化焊接设备。该焊接设备由龙门架、翻转机构和焊接机械手三大部分组成;由PLC进行运动控制,由光电编码器进行位置检测;采用触屏式人机界面,可方便快捷地设置和修改工艺参数。实践证明:该焊接设备可较好地解决特种车辆底盘焊接焊点多、焊缝短、焊缝姿态多、底盘尺寸种类多的难题。

关键词：特种车辆底盘多尺寸龙门架焊接专机柔性设计

Enhancement Mechanism of Cerium in 316LN Austenitic Stainless Steel During Creep at 700 ℃

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Acta Metallurgica Sinica(English Letters) 2023年第3期36卷 507-512页

作者： Renxian Yang Xin Cai leigang Zheng Xiaoqiang Hu Dianzhong li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Effect of cerium(Ce)on creep strength and microstructure of 316LN austenitic stainless steel(316LN steel)at 700℃/150 MPa was investigated by scanning electron microscopy(SEM),scanning transmission electron microscopy(STEM)and thermodynamic *** of 0.032 wt%Ce to 316LN steel results in a prominent increase in creep life from 313 to 556 *** enriches in titanium nitride nanoparticles,increases slightly the activity and diffusion coefficient of Mo,and facilitates the formation of fine and dense intragranular Laves phase *** the creep strength is remarkably enhanced by Ce addition in 316LN steel through the intragranular Laves phase precipitation *** reveals a new insight into the improvement effect of rare earth(RE)elements such as Ce on creep strength of austenitic stainless steels,which inspired the design of RE-microalloying heat-resistant steels.

关键词： 316LN austenitic stainless steel Rare earth Creep Laves phase Precipitation strengthening

Full-length transcriptome sequencing analysis reveals differential skin color regulation in snakeheads fish Channa argus

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Aquaculture and Fisheries 2024年第4期9卷 590-596页

作者： leigang Mao Yongan Zhu Jiaren Yan Longgang Zhang Shuren Zhu li An Qinglei Meng Zhishan Zhang Xirong Wang College of Fisheries and life Science Shanghai Ocean UniversityShanghai201306China Shandong Freshwater Fisheries Research Institute Jinan250017China

Albinism is a genetic disorder caused by a series of genetic abnormalities that result in a decrease in *** yellow snakehead fish(GCAS)has been discovered while the Channa argus(CAS)breeding,but the genetic mechanism that causes its albinism is not *** sequencing and comparison of CAS and GCAS skin using Oxford Nanopore Technologies(ONT)technology to elucidate the molecular mechanisms of snakehead albinism.27.1 G clean reads and 26,198 full-length non-redundant sequences were generated via ONT ***,8079 new transcripts and 7231 genes were identified by comparing and analyzing redundant removed transcripts and known reference genome *** results of DEGs analysis showed that a total of 59 transcripts were differentially expressed in the two groups,including 22 up-regulated transcripts and 37 down-regulated *** causative genes associated with albinism have been identified,including TYR(Tyrosinase)and SOX10(SRY-box transcription factor 10)(tyrosinase synthesis and metabolism),S-100(S100 calcium binding protein A1)(melanin production),NLRC3(NLR family CARD domain containing 3)(disease immunity)are significantly down-regulated in GCAS,while RhoGEFs expression(melanin synthesis)is *** interaction analysis revealed that GAPDH(Glyceraldehyde-3-phosphate dehydrogenase)is the top hub gene in the regulation of skin color in *** addition,the skin of snakehead fish is regulated by metabolic(GAPDH),immune[Tumor protein p53(TP53),C-X-C motif chemokine ligand 8(CXCL8),SRC proto-oncogene,non-receptor tyrosine kinase(SRC),CD274]and neural[Notch receptor 1(NOTCH1),C-X-C motif chemokine ligand 12(CXCL12)]related genes to achieve differences in skin *** findings in understanding the process by which albinism in fish develops.

关键词： Albinism Channa argus Nanopore-based RNA sequencing Melanin

Identifying neutral allele Sb at pollen-sterility loci in cultivated rice with Oryza rufipogon origin

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Chinese Science Bulletin 2009年第19期54卷 3813-3821页

作者： SHI leigang liU XiangDong liU Bo ZHAO XingJuan WANG Lan li JinQuan LU YongGen Guangdong Provincial Key Laboratory of Plant Molecular Breeding College of Agriculture South China Agricultural University Guangzhou 510642 China

Pollen sterility is commonly found in the intra-specific hybrids of indica and japonica rice,which is one of the main constrains for the utilization of heterosis between indica and *** loci controlling the pollen sterility of F1 between indica and japonica have been identified from previous *** alleles at each locus are potential to overcome the F1 pollen sterility associated with the ***,exploitation and utilization of neutral alleles are of significant *** present research was based on fine mapping of the F1 pollen-sterility gene Sb and the abundant genetic diversity of Oryza rufipogon *** to Gaozhou,Guangdong Province(referred to as Gaozhou wild rice).Crosses were made using Taichung65(with the genotype of SbjSbj and referred to as E1) and its near-isogenic line of F1 pollen sterility gene Sb(with the genotype of SbiSbi,E2) as female parents,and 12 different accessions of Gaozhou wild rice as male parents.F1 pollen fertility was examined to identify the materials having the neutral alleles at the F1 pollen-sterility *** of 4 molecular markers tightly linked with the Sb locus was analyzed in the F2 populations derived from the F1s carrying the neutral *** pollen fertility related to the 3 genotypes of the molecular markers was also checked by statistical test to determine whether it was consistent with the *** results showed that the pollen fertility of two F1s from one accession of Gaozhou wild rice(GZW099) with E1 and E2 was(89.22±1.07)% and(85.65±1.05)%,*** of them were fertile and showed no significant difference by *** of the 3 genotypes of the 4 molecular markers followed the expected Mendelian ratio(1:2:1) in the F2 *** was no significant difference for the averaged pollen fertility of the plants related to the 3 genotypes,suggesting that no interaction exists between the alleles at the Sb locus in GZW099 and Taichung65 or ***

关键词：遗传学等位基因稻子杂交

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Photon-counting distributed free-space spectroscopy

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light(Science & Applications) 2021年第11期10卷 2207-2216页

作者： Saifen Yu Zhen Zhang Haiyun Xia Xiankang Dou Tengfei Wu Yihua Hu Manyi li Mingjia Shangguan Tianwen Wei lijie Zhao Lu Wang Pu Jiang Chengjun Zhang lixing You leigang Tao Jiawei Qiu School of Earth and Space Science University of Science and Technology of China230026 HefeiChina School of Atmospheric Physics Nanjing University of Information Science&Technology210044 NanjingChina Hefei National Laboratory for Physical Sciences at the Microscale 230026 HeifeiChina Changcheng Institute of Metrology&Measurement Aviation Industry Corporation of China100095 BeijingChina State Key Laboratory of Pulsed Power Laser Technology National University of Defense Technology230037 HefeiChina State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen University361102 XiamenChina Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences200050 ShanghaiChina

Spectroscopy is a well-established nonintrusive tool that has played an important role in identifying and quantifying substances,from quantum descriptions to chemical and biomedical *** exist in accurate spectrum analysis in free space,which hinders us from understanding the composition of multiple gases and the chemical processes in the atmosphere.A photon-counting distributed free-space spectroscopy is proposed and demonstrated using lidar technique,incorporating a comb-referenced frequency-scanning laser and a superconducting nanowire single-photon *** is suitable for remote spectrum analysis with a range resolution over a wide *** an example,a continuous field experiment is carried out over 72 h to obtain the spectra of carbon dioxide(CO_(2))and semi-heavy water(HDO,isotopic water vapor)in 6 km,with a range resolution of 60 m and a time resolution of 10 *** to the methods that obtain only column-integrated spectra over kilometer-scale,the range resolution is improved by 2-3 orders of magnitude in this *** CO_(2)and HDO concentrations are retrieved from the spectra acquired with uncertainties as low as±1.2%and±14.3%,*** method holds much promise for increasing knowledge of atmospheric environment and chemistry researches,especially in terms of the evolution of complex molecular spectra in open areas.

关键词： spectroscopy holds dioxide