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基于水文环境的鱼雷自导作用距离预估方法研究

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舰船科学技术 2024年第6期46卷 181-185页

作者：李永胜邓剑晶杨向锋肖霖中国船舶集团有限公司第七〇五研究所陕西西安710075 水下信息与控制重点实验室陕西西安710075

水声传播特性受海洋环境的水文条件影响严重,具有非常显著的时变和空变特性,直接制约着鱼雷自导性能。基于波束追踪(Bellhop)声场计算方法,综合考虑信道特性、装备自身特性和目标特性,建立鱼雷自导作用距离预估模型,提出鱼雷工作深度选... 详细信息

水声传播特性受海洋环境的水文条件影响严重,具有非常显著的时变和空变特性,直接制约着鱼雷自导性能。基于波束追踪(Bellhop)声场计算方法,综合考虑信道特性、装备自身特性和目标特性,建立鱼雷自导作用距离预估模型,提出鱼雷工作深度选择方法,可为鱼雷探测能力评估、作战规划、作战参数选择等提供技术手段。通过仿真和实航试验结果,分析水文环境对鱼雷自导作用距离的影响,验证了预估模型的准确性,研究成果可用于指导鱼雷作战使用,并为研究鱼雷自导环境适应性问题提供参考。

关键词：鱼雷自导作用距离预估 Bellhop 环境适应性水声传播

Design and performance of a high-speed and low-noise preamplifier for SiPM

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Nuclear Science and Techniques 2023年第11期34卷 93-102页

作者： xi‑yang wang Hong‑Yu Zhang De‑Qing Fang wan‑Bing He xiao‑Long wang Qi‑Bin Zheng Shi‑Ming Zou Key Laboratory of Nuclear Physics and Ion‑beam Application(MOE)and Institute of Modern Physics Fudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China Laboratory of Radiation Detection and Medical Imaging and School of Health Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China

Considering the R&D for upgrading the K^(0)_(L) andμdetectors in the Belle II experiment using a scintillator and silicon pho-tomultiplier(SiPM),we designed a compact high-speed and low-noise *** preamplifier demonstrated a good gain stability,bandwidth of 426 MHz,baseline noise level ofσ≈0.6 mV,dynamic range of up to170 mV of the input signal amplitude,good time resolution of 20 ps,and it can be comprehensively applied to *** pole-zero-cancelation in the preamplifier reduces both the rise and fall times of the SiPM signal,which can significantly improve the time resolution and reduce the pile-up when using a large SiPM or an array of *** combinations of the preamplifier and several types of SiPMs demonstrated time resolutions better than 50 ps for most cases;when the number of detected photons was larger than 60,a time resolution of approximately 25 ps was achieved.

关键词： Silicon photomultiplier High-speed amplifier Low noise High time resolution

不平整跑道激励下飞机起落架随机响应及可靠性分析

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振动工程学报 2024年第3期37卷 497-504页

作者：张莹金峥嵘贾万涛刘小川许勇西北工业大学数学与统计学院陕西西安710129 中国飞机强度研究所陕西西安710065

采用非线性二自由度系统构建了飞机起落架模型,通过时域噪声刻画了不平整跑道对飞机起落架系统的随机激励,并引入路面不平度系数描述了跑道的不平整程度;基于飞机起落架模型响应的概率密度函数及其统计量,开展了不平整跑道对飞机起落架... 详细信息

采用非线性二自由度系统构建了飞机起落架模型,通过时域噪声刻画了不平整跑道对飞机起落架系统的随机激励,并引入路面不平度系数描述了跑道的不平整程度;基于飞机起落架模型响应的概率密度函数及其统计量,开展了不平整跑道对飞机起落架系统影响规律的研究。应用随机可靠性分析方法以及人体振动舒适性理论,通过建立安全域和舒适域与系统响应之间的关系,分析了起落架模型在不同路面不平度系数下的可靠性,并对乘客舒适性进行了评价。研究结果表明:路面不平度系数越大,系统状态变量的波动越剧烈,系统的可靠性和舒适性与路面不平度系数呈一定的负相关性;在路面不平度系数较小的情况下,系统平均首次穿越时间以及舒适性受随机扰动的影响更加显著。

关键词：飞机起落架随机响应可靠性跑道不平整

Five commonly used traditional Chinese medicine formulas in the treatment of ulcerative colitis:A network meta-analysis

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World Journal of Clinical Cases 2024年第22期12卷 5067-5082页

作者： Zhi-Hui Zhao Yi-Hang Dong xin-Qi Jiang Jing wang wan-Li Qin Zhang-Yi Liu xiao-Qing Zhang Yu-Jie Wei School of Life Sciences Beijing University of Chinese MedicineBeijing 102488China School of Acupuncture-Moxibustion and Tuina Beijing University of Chinese MedicineBeijing 102488China

BACKGROUND Currently,traditional Chinese medicine(TCM)formulas are commonly being used as adjunctive therapy for ulcerative colitis in *** meta-analysis,a quantitative and comprehensive analytical method,can systematically compare the effects of different adjunctive treatment options for ulcerative colitis,providing scientific evidence for clinical *** To evaluate the clinical efficacy and safety of commonly used TCM for the treatment of ulcerative colitis(UC)in clinical practice through a network *** Clinical randomized controlled trials of these TCM formulas used for the adjuvant treatment of UC were searched from the establishment of the databases to July 1,*** that met the inclusion criteria were screened and evaluated for literature quality and risk of bias according to the Cochrane 5.1 *** methodological quality of the studies was assessed using ReviewManager(RevMan)5.4,and a funnel plot was constructed to test for publication *** 1.16 statistical software was used to perform statistical analysis of the treatment measures and derive the network relationship and ranking diagrams of the various intervention *** A total of 64 randomized controlled trials involving 5456 patients with UC were included in this *** adjuvant treatment of UC using five TCM formulations was able to improve the clinical outcome of the *** treatment with Baitouweng decoction(BTWT)showed a significant effect[mean difference=36.22,95%confidence interval(CI):7.63 to 65.76].For the reduction of tumor necrosis factor in patients with UC,adjunctive therapy with BTWT(mean difference=−9.55,95%CI:−17.89 to−1.41),Shenlingbaizhu powder[SLBZS;odds ratio(OR)=0.19,95%CI:0.08 to 0.39],and Shaoyao decoction(OR=−23.02,95%CI:−33.64 to−13.14)was *** decoction was more effective than BTWT(OR=0.12,95%CI:0.03 to 0.39),SLBZS(OR=0.19,95%CI:0.08 to 0.39),and xi Lei powder(OR=0.34,95%CI:0.13 to 0.81)i

关键词： Network meta-analysis Traditional Chinese medicine Ulcerative colitis Mesalazine Treatment

The Strongly Simple Cycles with Given Rotation Pairs of an Interval Map

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Acta Mathematica Sinica,English Series 2007年第1期23卷 37-40页

作者： Tai xiang SUN Hong Jian xi xiao Yan ZHANG Department of Mathematics Cuangxi University. Nanning 530004 P. R. China Department of Mathematics Guangxi College of Finance and Economics. Nanning 530004 P. R. China Department of Mathematics Guangxi University Nanning 530004. P. R. China

In this paper, we introduce the notion of the strongly simple cycles with some rotation pair for interval maps and prove that, if an interval map has a cycle with given rotation pair, then it, has a strongly simple cy... 详细信息

关键词： interval map strongly simple cycle rotation pair

Potentiation of the lateral habenula-ventral tegmental area pathway underlines the susceptibility to depression in mice with chronic pain

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Science China(Life Sciences) 2024年第1期67卷 67-82页

作者： Chun-Kui Zhang Pan wang Yuan-Yuan Ji Jian-Shuai Zhao Jun-xiang Gu xian-xia Yan Hong-Wei Fan Ming-Ming Zhang Yu Qiao xiao-Die Liu Bao-Juan Li Ming-Hui wang Hai-Long Dong Hao-Hong Li Peng-Cheng Huang Yun-Qing Li Wu-Gang Hou Jin-Lian Li Tao Chen Department of Anatomy and K.K.Leung Brain Research Centre Fourth Military Medical UniversityXi’an 710032China Beijing Institute of Basic Medical Sciences Beijing 100850China Key Laboratory of Ministry of Public Health for Forensic Science Xi’an Jiaotong UniversityXi’an 710061China Department of Anesthesiology Xijing HospitalFourth Military Medical UniversityXi’an 710032China Department of Neurosurgery the Second Affiliated Hospital of Xian Jiaotong UniversityXi’an 710004China School of Biomedical Engineering Fourth Military Medical UniversityXi’an 710032China Affiliated Mental Health Centre and Hangzhou Seventh People’s Hospital Zhejiang University School of MedicineHangzhou 310013China The MOE Frontier Research Center of Brain&Brain-machine Integration Zhejiang University School of Brain Science and Brain MedicineHangzhou 310058China Department of Neurology The First Affiliated Hospital of Nanchang UniversityNanchang 330006China Department of Anatomy School of MedicineNorthwest UniversityXi’an 710069China

Chronic pain often develops severe mood changes such as ***,how chronic pain leads to depression remains elusive and the mechanisms determining individuals’responses to depression are largely *** we found that depression-like behaviors could only be observed in 67.9%of mice with chronic neuropathic pain,leaving 32.1%of mice with depression *** determined that the spike discharges of the ventral tegmental area(VTA)-projecting lateral habenula(LHb)glutamatergic(Glu)neurons were sequentially increased in sham,resilient and susceptible mice,which consequently inhibited VTA dopaminergic(DA)neurons through a LHbGlu-VTAGABA-VTADA ***,the LHbGlu-VTADA excitatory inputs were dampened via GABAB receptors in a pre-synaptic *** of LHb-VTA pathway largely affected the development of depressive symptoms caused by chronic *** study thus identifies a pivotal role of the LHb-VTA pathway in coupling chronic pain with depression and highlights the activity-dependent contribution of LHbGlu-to-VTADA inhibition in depressive behavioral regulation.

关键词： chronic pain depression lateral habenula ventral tegmental area dopamine susceptibility

Precision Balance Method for Cupped Wave Gyro Based on Cup-bottom Trimming

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Chinese Journal of Mechanical Engineering 2012年第1期25卷 63-70页

作者： TAO Yi xi xiang xiao Dingbang TAN Yingqi CUI Hongjuan WU Xuezhong College of Mecha tronics Engineering and Automation National University of Defense TechnologyChangsha 410073China Wuhan Ordnance N.C.O.Academy Wuhan 430075China Department of Mechatronics Engineering Zhuhai CollegeJilin UniversityZhuhai 519041China

The mechanical balance process is the key process to eliminate the quadrature error and improve the performance of the cupped wave gyro. The conventional mechanical balance method for cupped wave gyro based on cup-wall trimming requires high control accuracy of trimming quantity, which increases the production cost and decreases the fabrication efficiency in large extent. However, it is hard to reach the high balance accuracy with the natural frequency split of mHz grade by using the conventional method. In this paper, the lumped mass dynamic model of the cupped wave gyro is built by discretization method, and the effects of different position trimming on the natural frequency are analyzed. It is pointed out that trimming off a tiny quantity of material from cup-wall causes large variation of the natural frequency is the main reason for the low accuracy of the conventional mechanical balance method. Then, a precision balance method for cupped wave gyro based on cup-bottom trimming is presented and the entire procedures of this method are given. The static balance process and dynamic balance process of the precision balance method are simulated by the finite element software. The simulation result shows that the precision balance method based on cup-bottom trimming brings less additional natural frequency split in the static balance process, minimizes the natural frequency split to mHz grade and rectify the angle of mode offset to 0.1° grade in the dynamic balance process, furthermore, the method decreases the requirement for control accuracy of trimming quantity evidently. The research work provides references for structure optimization design and balance process plan of the cupped wave gyro.

关键词： cupped wave gyro precision balance trimming modal analysis natural frequency split

Ensuring the Correctness of Regular Expressions: A Review

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International Journal of Automation and computing 2021年第4期18卷 521-535页

作者： Li-xiao Zheng Shuai Ma Zu-xi Chen xiang-Yu Luo College of Computer Science and Technology Huaqiao UniversityXiamen 361021China State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100191China

Regular expressions are widely used within and even outside of computer science due to their expressiveness and ***, regular expressions have a quite compact and rather tolerant syntax that makes them hard to understand, hard to compose,and error-prone. Faulty regular expressions may cause failures of the applications that use them. Therefore, ensuring the correctness of regular expressions is a vital prerequisite for their use in practical applications. The importance and necessity of ensuring correct definitions of regular expressions have attracted extensive attention from researchers and practitioners, especially in recent years. In this study, we provide a review of the recent works for ensuring the correct usage of regular expressions. We classify those works into different categories, including the empirical study, test string generation, automatic synthesis and learning, static checking and verification,visual representation and explanation, and repairing. For each category, we review the main results, compare different approaches, and discuss their advantages and disadvantages. We also discuss some potential future research directions.

关键词： Regular expressions correctness string generation learning static checking verification visualization repairing

A new error-controllable method for smoothing the G01 commands

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Chinese Journal of Aeronautics 2019年第7期32卷 1756-1771页

作者： Min wan wan-Jing xiNG yang LIU Qun-Bao xiao Wei-Hong ZHANG School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an710072China State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXian710072China

In real machining, the tool paths are composed of a series of short line segments, which constitute groups of sharp corners correspondingly leading to geometry discontinuity in tangent. As a result, high acceleration with high fluctuation usually occurs. If these kinds of tool paths are directly used for machining, the feedrate and quality will be greatly reduced. Thus, generating continuous tool paths is strongly desired. This paper presents a new error-controllable method for generating continuous tool path. Different from the traditional method focusing on fitting the cutter locations, the proposed method realizes globally smoothing the tool path in an error-controllable way. Concretely, it does the smoothing by approaching the newly produced curve to the linear tool path by taking the tolerance requirement as a constraint. That is, the error between the desired tool path and the G01 commands are taken as a boundary condition to ensure the finally smoothed curve being within the given tolerance. Besides, to improve the smoothing ability in case of small corner angle, an improved local smoothing method is also proposed by symmetrically assigning the control points to the two adjacent linear segments with the constrains of tolerance and G3 continuity. Experiments on an open five-axis machine are developed to verify the advantages of the proposed methods.

关键词： Energy approximation method Error-controllable global smoothing method G3 continuity Local smoothing method Quasi-uniform quintic Bspline curve