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Communications in Theoretical Physics 2024年第1期76卷 1-6页

作者： Engui Fan yanxi zhang School of Mathematical Sciences and Key Laboratory of Mathematics for Nonlinear Science Fudan UniversityShanghai200433China Tianjin Xinhua High School No.99 machang RoadTianjin300204China

In this paper,we address interesting soliton resolution,asymptotic stability of N-soliton solutions and the Painleve asymptotics for the Kundu-Eckhaus(KE)equation with nonzero boundary conditions iq_(t)+q_(xx)-2(l|q|^(2)-1)q+4β^(2)(lql^(4)-1)q+4iβ(lql^(2))_(x)q=0,q(x,0)=q_(0)(x)-±1,x→±∞.The key to proving these results is to establish the formulation of a Riemann-Hilbert(RH)problem associated with the above Cauchy problem and find its connection with the RH problem of the defocusing NLS *** the■-steepest descent method and the results of the defocusing NLS equation,we find complete leading order approximation formulas for the defocusing KE equation on the whole(x,t)half-plane including soliton resolution and asymptotic stability of N-soliton solutions in a solitonic region,Zakharov-Shabat asymptotics in a solitonless region and the Painlevéasymptotics in two transition regions.

关键词： defocusing Kundu-Eckhaus equation Riemann-Hilbert problems steepest descent method soliton resolution asymptotic stability Painleve transcendents

A scheme to fix multiple solutions in amplitude analyses

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Chinese Physics C 2024年第5期48卷 8-22页

作者：高原宁荣天泽杨振伟张辰佳张艳席 School of Physics Peking UniversityBeijing 100871China

Decays of unstable heavy particles usually involve the coherent sum of several amplitudes,like in a multiple slit *** amplitude analysis techniques have been widely used to resolve these amplitudes for better understanding of the underlying *** special cases where two spin-1/2 particles and two(pseudo-)scalar particles are present in the process,multiple equivalent solutions are found owing to intrinsic symmetries in the summed probability density *** this study,the problem of multiple solutions is discussed,and a scheme to overcome this problem is proposed by fixing some free *** are generated to validate the strategy.A new approach to align the helicities of initial-and final-state particles in different decay chains is also introduced.

关键词： amplitude analysis multiple solutions helicity formalism

Detecting the single chiral molecule during the reaction

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中国科学:材料科学(英文版) 2023年第8期66卷 3377-3378页

作者： Juejun Wang Zepeng zhang Shurui Ji yanxi zhang Wenjing Hong College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005China The Institute of Flexible Electronics(IFE Future Technologies)Xiamen UniversityXiamen 361005China

Detecting an individual molecule during the chemistry dynamics is essential for capturing accurate information about the chemical process in the time domain,which could be achieved by precisely forming single-molecule junctions between two electrodes and reading out the variation in electrical signals[1–3],but has yet to penetrate the stereochemistry *** is a crucial pursuit of chirality chemistry to develop effective asymmetric synthesis methodologies and reveal the physicochemical mechanisms[4,5].And the key obstacle lies in achieving in situ detection of chiral intermediates in reactions[6].Chirality is a fundamental molecular property arising from the structure asymmetry,with two mirror-image forms known as *** to similar signals of enantiomeric isomers,it is a great challenge to distinguish chiral species and the process of their configurational transformation in single-molecule *** then comes up with a question—how to detect chirality changes in stereochemistry.

关键词： chiral isomers mirror

煤矿岩巷TBM掘进随掘地震信号特征及其应用

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工矿自动化 2024年第6期50卷 46-53,60页

作者：党保全郭立全张延喜任永乐李圣林淮河能源集团煤业分公司通防地质技术部安徽淮南232000 安徽理工大学地球与环境学院安徽淮南232001 淮河能源集团煤业分公司谢桥煤矿安徽淮南236221 福州华虹智能科技股份有限公司福建福州350003

随掘地震超前探测技术可实现探掘平行,为巷道快速智能掘进场景下实时、精准地质保障提供了可能。随掘震源产生的是复杂、变频、连续信号,信号特征认知直接影响数据处理与成像精度,而目前针对岩巷全断面掘进机(TBM)随掘地震信号特征的认... 详细信息

随掘地震超前探测技术可实现探掘平行,为巷道快速智能掘进场景下实时、精准地质保障提供了可能。随掘震源产生的是复杂、变频、连续信号,信号特征认知直接影响数据处理与成像精度,而目前针对岩巷全断面掘进机(TBM)随掘地震信号特征的认知仍不清晰,且暂时还没有针对性开展过信号处理与成像研究工作。针对上述问题,以谢桥煤矿瓦斯治理巷TBM随掘地震超前探测试验为例,分析了刀盘先导信号与岩壁接收信号的时间域、频率域及时频域特征:岩巷TBM随掘地震信号中不同振幅能量成分比例呈现金字塔形,但分布随机,不对称程度较高;机械运转信号能量较大,刀盘先导信号强度是岩壁接收信号的200倍左右;频率域变频特征明显;机械运转信号基础频率较低,刀盘先导信号频率成分主要集中在10~80 Hz与150~200 Hz,主频为36.99 Hz,岩壁接收信号频率成分主要集中在50~200 Hz,主频为137.97 Hz;刀盘先导信号较岩壁接收信号时频域能量团分布更为规则,多次震源激发现象明显,能量团之间的差异性特征表明了多次震源激发时振幅能量与持续时间的随机性。利用脉冲化算法与绕射叠加偏移成像方法对岩巷TBM随掘地震信号进行数据处理与成像试验,结果表明:(1)脉冲化等效单炮记录与利用常规震源得到的超前探测单炮记录特征一致性较强,同相轴清晰且连续性较好,可满足现场探测分析需要。(2)对探测范围内岩体情况的超前预报结果与实际揭露情况一致,说明岩巷TBM随掘地震超前探测可提供有效地质保障。

关键词：煤矿岩巷掘进随掘地震超前探测随掘地震信号全断面硬岩掘进机刀盘先导信号岩壁接收信号绕射叠加偏移成像

Heavy flavour physics and CP violation at LHCb:Aten-year review

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Frontiers of physics 2023年第4期18卷 1-69页

作者： Shanzhen Chen Yiming Li Wenbin Qian Zhihong Shen Yuehong Xie Zhenwei Yang Liming zhang yanxi zhang Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Nuclear Physics and Technology&School of Physics Peking UniversityBeijing 100871China Key Laboratory of Quark and Lepton Physics of Ministry of Education&Institute of Particle Physics Central China Normal UniversityWuhan 430079China Department of Engineering Physics&Center for High Energy Physics Tsinghua UniversityBeijing 100084China

Heavy flavour physics provides excellent opportunities to indirectly search for new physics at very high energy scales and to study hadron properties for deep understanding of the strong *** LHCb experiment has been playing a leading role in the study of heavy flavour physics since the start of the LHC operations about ten years ago,and made a range of high-precision measurements and unexpected discoveries,which may have far-reaching implications on the field of particle *** review highlights a selection of the most influential physics results on CP violation,rare decays,and heavy flavour production and spectroscopy obtained by LHCb using the data collected during the first two operation periods of the *** upgrade plan of LHCb and the physics prospects are also briefly discussed.

关键词： LHCb flavour physics CP vioation

Online Monitoring of Welding Status Based on a DBN Model During Laser Welding

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Engineering 2019年第4期5卷 671-678页

作者： yanxi zhang Deyong You Xiangdong Gao Seiji Katayama Guangdong Provincial Welding Engineering Technology Research Center Guangdong University of TechnologyGuangzhou 510006China Joining and Welding Research Institute Osaka UniversityOsaka 567-0047Japan

In this research,an auxiliary illumination visual sensor system,an ultraviolet/visible(UVV)band visual sensor system(with a wavelength less than 780 nm),a spectrometer,and a photodiode are employed to capture insights into the high-power disc laser welding *** features of the visible optical light signal and the reflected laser light signal are extracted by decomposing the original signal captured by the photodiode via the wavelet packet decomposition(WPD)*** captured signals of the spectrometer mainly have a wavelength of 400-900 nm,and are divided into 25 sub-bands to extract the spectrum features by statistical *** features of the plume and spatters are acquired by images captured by the UVV visual sensor system,and the features of the keyhole are extracted from images captured by the auxiliary illumination visual sensor *** on these real-time quantized features of the welding process,a deep belief network(DBN)is established to monitor the welding status.A genetic algorithm is applied to optimize the parameters of the proposed DBN *** established DBN model shows higher accuracy and robustness in monitoring welding status in comparison with a traditional back-propagation neural network(BPNN)*** effectiveness and generalization ability of the proposed DBN are validated by three additional experiments with different welding parameters.

关键词： Online monitoring Multiple sensors Wavelet packet decomposition Deep belief network

Computer-assisted preoperative planning for proximal humeral fractures by minimally invasive plate osteosynthesis

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Chinese Medical Journal 2014年第18期127卷 3278-3285页

作者： Chen yanxi zhang Kun Qiang Minfei Li Haobo Dai Hao Department of Orthopaedic Trauma East Hospital Tongji UniversitySchool of Medicine Shanghai 200120 China

Background Accurate and precise preoperative planning can provide information instrumental for performing less invasive articular fracture surgery. The purpose of this study was to determine that computer-assisted preoperative planning （CAPP） has the potential to improve efficiency and time in the operating room. Methods Sixty-four patients with proximal humeral fractures were treated using locking plates by minimally invasive plate osteosynthesis （MIPO） with CAPP. The time needed for virtual segmentation, reduction, and fixation of the fracture fragments were recorded. Intra and interobserver reliabilities were analyzed using the intraclass correlation coefficient. The clinical function was analyzed using Constant Score and radiology. Results The mean total time required for CAPP of two-part, three-part, and four-part proximal humeral fractures were （13.63±1.38） minutes, （23.14±2.18） minutes, and （39.61±3.01） minutes, respectively. The intra and interobserver reliabilities for all variables were high, ranging from 0.785 to 0.992. The mean operation time was （50.1±6.7） minutes. Fifty- two patients were followed up with an average time of 34.2 months. The mean Constant Score of the injury side was （82.5 ± 9.9）. Three of the fifty-two patients had four complications. Conclusion The application of CAPP was efficient and reliable, and provided excellent clinical and radiographic outcomes for the treatment of proximal humerus fractures by MIPO.

关键词： proximal humerus fractures computer-aided design preoperative planning minimally invasive plate osteosynthesis imaging, three-dimensional

The regulatory role of m^(6)A modification in the maintenance and differentiation of embryonic stem cells

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Genes & Diseases 2024年第5期11卷 126-139页

作者： Jin zhang Lingling Tong Yuchen Liu Xiang Li Jiayi Wang Ruoxin Lin Ziyu Zhou Yunbing Chen yanxi Chen Yirong Liu Di Chen Center for Reproductive Medicine of the Second Affiliated Hospital Center for Regeneration and Cell Therapy of Zhejiang University-University of Edinburgh Institute(ZJU-UoE Institute)Zhejiang University School of MedicineZhejiang UniversityHangzhouZhejiang 310003China Zhejiang University-University of Edinburgh Institute(ZJU-UoE Institute) Zhejiang University School of MedicineZhejiang UniversityHangzhouZhejiang 310003China College of Materials and Chemical Engineering Minjiang UniversityFuzhouFujian 350108China National Key Laboratory of Biobased Transportation Fuel Technology HainingZhejiang 314400China

As the most prevalent and reversible internal epigenetic modification in eukaryotic mRNAs,N6-methyladenosine(m^(6)A)post-transcriptionally regulates the processing and metabolism of mRNAs involved in diverse biological processes.m^(6)A modification is regulated by m^(6)A writers,erasers,and *** evidence suggests that m^(6)A modification plays essential roles in modulating the cell-fate transition of embryonic stem *** investigation of embryonic stem cell maintenance and differentiation is critical for understanding early embryonic development,which is also the premise for the application of embryonic stem cells in regenerative *** review highlights the current knowledge of m^(6)A modification and its essential regulatory contribution to the cell fate transition of mouse and human embryonic stem cells.

关键词： Cell-fate transition Embryonic stem cell Epigenetic modification m^(6)A modification Post-transcriptional regulation

The Structure and Size-effect of Calcium Modified Lead Titanate Nanocrystal,Pb_(0.85)Ca_(0.15)TiO_3

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Chemical Research in Chinese Universities 1999年第2期15卷 66-70页

作者： FU Honggang QIANG Liangsheng XU Chongquan ZHAN Zhiqian zhang Xin YU Haitao zhang yanxi HUANG Li Department of Applied Chemistry Harbin University of TechnologyHarbin150001 School of Chemistry and Engineering Heilongjiang UniversityHa rbin150080 La b.of Enha nce d Oil Recovery Rate of Institution of E.and D. Daqing163712

ＩｎｔｒｏｄｕｃｔｉｏｎＰＴＣｉｓａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｆｅｒｒｏｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｏｆｍｏｄｉｆｉｅｄｌｅａｄｔｉｔａｎａｔｅ，ｗｈｉｃｈｃａｎｍａｋｅｔｈｅｔｅｔｒａｇｏｎａｌ／ｃｕｂｉｃ... 详细信息

ＩｎｔｒｏｄｕｃｔｉｏｎＰＴＣｉｓａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｆｅｒｒｏｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｏｆｍｏｄｉｆｉｅｄｌｅａｄｔｉｔａｎａｔｅ，ｗｈｉｃｈｃａｎｍａｋｅｔｈｅｔｅｔｒａｇｏｎａｌ／ｃｕｂｉｃａｘｉａｌｒａｔｉｏｏｆｌｅａｄｔ...

关键词： PTC15 Nanocrystal Crystal structure Size effect Crystal structure, Size effect

基于熔池图像不变矩特征的激光-MIG复合焊接根部驼峰在线检测方法

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中国激光 2023年第12期50卷 72-80页

作者：黄宇辉范西岸张艳喜高向东广东工业大学广东省焊接工程技术研究中心广东广州510006

根部驼峰缺陷是激光-MIG复合焊接(MIG焊,熔化极惰性气体保护焊)中常出现的焊接缺陷之一,因该缺陷出现在焊件背部,所以在焊接过程中不易被发现。为检测根部驼峰缺陷,采用高速摄像机捕捉焊接图像。对预处理后的图像进行阈值分割得到熔池... 详细信息

根部驼峰缺陷是激光-MIG复合焊接(MIG焊,熔化极惰性气体保护焊)中常出现的焊接缺陷之一,因该缺陷出现在焊件背部,所以在焊接过程中不易被发现。为检测根部驼峰缺陷,采用高速摄像机捕捉焊接图像。对预处理后的图像进行阈值分割得到熔池轮廓图像,通过局部形态学处理进一步获取熔池二值化图像。提取二值化图像的四组归一化不变矩,并采用滑动均值法进行降噪处理,进而获得不变矩特征。建立动态调整学习率算法的一维卷积神经网络模型,以熔池尾部图像的四组归一化不变矩及其滑动均值作为输入。通过9150个连续焊缝样本检测值和实际值的比较,验证了该网络模型具有良好的检测能力。该方法可应用于封闭式的平板对接焊,通过采集激光-MIG复合焊接中焊件表面信号,对无法直接观察的背部驼峰缺陷进行检测。

关键词：激光技术神经网络激光-MIG复合焊根部驼峰熔池图像图像不变矩