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干涉配合紧固件应力波安装枪研制

机械科学与技术 2009年第6期28卷 799-802页

作者：刘剑曹增强王晶西北工业大学机电学院西安710072

介绍了采用应力波安装干涉配合紧固件的原理,并结合工程应用对干涉配合紧固件的应力波安装枪结构进行了设计,研制成功新型手提式应力波安装枪。试验表明新研制的安装枪重量轻、后坐力小,能够满足工程需要,为应力波安装方法的应用奠定了... 详细信息

介绍了采用应力波安装干涉配合紧固件的原理,并结合工程应用对干涉配合紧固件的应力波安装枪结构进行了设计,研制成功新型手提式应力波安装枪。试验表明新研制的安装枪重量轻、后坐力小,能够满足工程需要,为应力波安装方法的应用奠定了基础。

关键词：紧固件干涉配合应力波安装枪

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干涉配合紧固件安装的数值模拟

机械科学与技术 2009年第4期28卷 527-531页

作者：王晶曹增强刘剑西北工业大学西安710072

采用有限元方法对传统干涉配合紧固件强迫安装方法和应力波安装方法的安装过程进行了数值模拟,分析了两种安装方法的加载特点,研究了采用不同加载时结构的应力应变,得到不同安装方法可以安装的最大干涉量。对两种安装方法的安装质量进... 详细信息

采用有限元方法对传统干涉配合紧固件强迫安装方法和应力波安装方法的安装过程进行了数值模拟,分析了两种安装方法的加载特点,研究了采用不同加载时结构的应力应变,得到不同安装方法可以安装的最大干涉量。对两种安装方法的安装质量进行了对比,从理论上证明了应力波安装方法的优越性。

关键词：干涉配合紧固件安装有限元数值模拟

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TC4钛合金构件电磁铆接极限间隙量研究

材料科学与工艺 2021年第3期29卷 26-32页

作者：杨宝惠曹增强左杨杰西北工业大学机电学院西安710072 四川大学空天科学与工程学院成都610065

维修中拆卸原铆钉将导致钉孔间隙明显增大,进而直接影响维修后铆接构件性能。为了实现大间隙量下钛合金铆接构件的有效维修,本文通过试验对TC4钛合金构件电磁铆接极限间隙量进行了研究,并评估了铆接构件拉剪性能。结果表明:电磁铆接通... 详细信息

维修中拆卸原铆钉将导致钉孔间隙明显增大,进而直接影响维修后铆接构件性能。为了实现大间隙量下钛合金铆接构件的有效维修,本文通过试验对TC4钛合金构件电磁铆接极限间隙量进行了研究,并评估了铆接构件拉剪性能。结果表明:电磁铆接通过绝热剪切成形的方式,能有效实现大间隙量下钛合金构件的干涉铆接;随着钉孔间隙量的增加,镦头直径和高度均呈现出近线性递减,尽管钉杆成形后直径明显增大,但干涉量却减小;拉剪试验中,试件分别发生拉弯和剪切失效,拉脱性能对钉孔间隙量不敏感,但试件剪切屈服强度和失效强度均随着钉孔间隙量的增加而明显提高;对于4 mm钛合金铆钉,建议极限钉孔直径为4.3 mm。

关键词：钛合金电磁铆接工艺参数拉脱性能剪切性能

Zeros of Complete Symmetric Polynomials over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1772-1788页

作者： cao Wei School of Mathematics and Statistics Minnan Normal UniversityZhangzhou 363000China

Wan and Zhang(2021) obtained a nontrivial lower bound for the number of zeros of complete symmetric polynomials over finite fields,and proposed a problem whether their bound can be *** this paper,the author improves Wan-Zhang's bound from three *** proposed results are based on the estimates related to the number of certain permutations and the value sets of non-permutation polynomials associated to the complete symmetric *** the author believes that there are still possibilities to improve the bounds and hence Wan-Zhang's bound.

关键词： Complete symmetric polynomial finite field permutation polynomial value set

Pt nanodendrites with a PtIr alloy surface structure exhibit excellent stability toward acidic hydrogen evolution reaction

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Nano Research 2024年第6期17卷 4844-4849页

作者： Chang Liu Zongnan Wei Minna cao Rong cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

The development of effective and stable electrocatalysts for the hydrogen evolution reaction(HER)in acidic electrolytes is a significant *** this work,homogeneous Pt nanodendrites(Pt NDs)with a PtIr shell were successfully synthesized by a two-step wet chemical *** open three-dimensional(3D)dendritic structure exhibited exceptional electrocatalytic characteristics,exposing as many active sites as ***,by alloying Ir with Pt on the surface,catalytic activity was greatly enhanced while ensuring extremely high *** surface-enriched platinum nanodendritic catalysts(Pt@PtIr NDs)outperformed the control samples and the commercial *** acidic HER test,Pt@PtIr NDs had a lower overpotential(22 mV)than Pt NDs(26 mV)and commercial Pt/C(31 mV)at 10 mA/cm^(2),and the activity of Pt@PtIr NDs remained consistent even after undergoing a continuous durability test for at least 168 h,which was much superior to the performance of commercial Pt/C(10 h)under identical test *** study revealed that the application of 3D Pt dendritic metal alloys may offer a chance for the development of enhanced electrocatalysts in acidic HER.

关键词： Pt nanodendrites iridium high stability hydrogen evolution reaction alloy

Quantitative phase imaging based on holography:trends and new perspectives

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Light(Science & Applications) 2024年第7期13卷 1235-1277页

作者： Zhengzhong Huang Liangcai cao Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In 1948,Dennis Gabor proposed the concept of holography,providing a pioneering solution to a quantitative description of the optical *** 75 years of development,holographic imaging has become a powerful tool for optical wavefront measurement and quantitative phase *** emergence of this technology has given fresh energy to physics,biology,and materials *** holography(DH)possesses the quantitative advantages of wide-field,non-contact,precise,and dynamic measurement capability for *** has unique capabilities for the propagation of optical fields by measuring light scattering with phase *** offers quantitative visualization of the refractive index and thickness distribution of weak absorption samples,which plays a vital role in the pathophysiology of various diseases and the characterization of various *** provides a possibility to bridge the gap between the imaging and scattering *** propagation of wavefront is described by the complex *** complex-value in the complex-domain is reconstructed from the intensityvalue measurement by camera in the ***,we regard the process of holographic recording and reconstruction as a transformation between complex-domain and real-domain,and discuss the mathematics and physical principles of *** review the DH in underlying principles,technical approaches,and the breadth of *** conclude with emerging challenges and opportunities based on combining holographic imaging with other methodologies that expand the scope and utility of holographic imaging even *** multidisciplinary nature brings technology and application experts together in label-free cell biology,analytical chemistry,clinical sciences,wavefront sensing,and semiconductor production.

关键词： holographic phase precise

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干涉配合弹性强化机理分析

航空学报 2018年第4期39卷 230-238页

作者：张岐良曹增强李红梅向聪刘平中国工程物理研究院总体工程研究所绵阳621900 西北工业大学机电学院西安710072

鉴于基于支撑效应(SE)的干涉配合疲劳强化理论具有内在的局限性,通过引入弹簧模型(SM)研究了干涉配合的强化机理,以期获得更全面的认识并促进干涉配合技术的应用。首先,分析了支撑效应理论的不足之处,提出了经典理论难以解释的多个问题... 详细信息

鉴于基于支撑效应(SE)的干涉配合疲劳强化理论具有内在的局限性,通过引入弹簧模型(SM)研究了干涉配合的强化机理,以期获得更全面的认识并促进干涉配合技术的应用。首先,分析了支撑效应理论的不足之处,提出了经典理论难以解释的多个问题;然后,介绍了弹簧模型的基本思想及其求解结果,从弹性变形的角度对以上疑难问题作出了解释;最后,借助弹簧模型给出了干涉量的优化方法,并得到了最佳干涉量的解析表达式。弹簧模型的计算结果表明:干涉配合存在一种动态的弹性强化机制,在交变外载作用下结构组件的弹性变形及接触的自动调节作用,是被连接件传载幅值得以降低的原因;干涉量的选取不仅要考虑结构尺寸和材料,同时还应结合实际的载荷条件。

关键词：干涉配合弹簧模型强化机理疲劳应力幅

Dynamic Setting Method of Assessment Indicators for Power Curves of Renewable Energy Sources Considering Scarcity of Reserve Resources

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 101-114页

作者： Minghao cao Jilai Yu the Department of Electrical Engineering Harbin Institute of TechnologyHarbinChina

With the increasing proportion of renewable energy sources(RESs)in power grid,the reserve resource(RR)scarcity for correcting power deviation of RESs has become a potential ***,the power curve of RES needs to be more rigorously *** RR scarcity varies during different time periods,so the values of assessment indicators should be dynamically *** assessment indicators in this paper include two aspects,i.e.,deviation exemption ratio and penalty ***,this paper proposes a method for dynamically calculating the supply capacity and RR cost,primarily taking into account the operating status of thermal units,forecast information of RES,and load ***,after clarifying the logical relationship between the degree of RR scarcity and the values of assessment indicators,this paper establishes a mapping function between *** on this mapping function,a dynamic setting method for assessment indicators is *** the future,RES will generally be equipped with battery energy storage systems(BESSs).Reasonably utilizing BESSs to reduce the power deviation of RESs can increase the expected income of ***,this paper proposes a power curve optimization strategy for RESs considering self-owned *** case study demonstrates that the dynamic setting method of assessment indicators can increase the revenue of RESs while ensuring that the penalty fees paid by RESs to the grid are sufficient to cover the RR ***,the power curve optimization strategy can help RESs further increase income and fully utilize BESSs to reduce power deviation.

关键词： Renewable energy battery energy storage system(BESS) power curve assessment reserve service parameter setting

Bioinspired Closed-loop CPG-based Control of a Robotic Manta for Autonomous Swimming

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Journal of Bionic Engineering 2024年第1期21卷 177-191页

作者： Yiwei Hao Yonghui cao Yingzhuo cao Xiong Mo Qiaogao Huang Lei Gong Guang Pan Yong cao School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Unmanned Vehicle Innovation Center Ningbo Institute of NPUNingbo 315103China Key Laboratory of Unmanned Underwater Vehicle Technology of Ministry of Industry and Information Technology Xi'an 710072China

Fish in nature exhibit a variety of swimming modes such as forward swimming,backward swimming,turning,pitching,etc.,enabling them to swim in complex scenes such as coral *** is still difficult for a robotic fish to swim autonomously in a confined area as a real ***,we develop an untethered robotic manta as an experimental platform,which consists of two flexible pectoral fins and a tail fin,with three infrared sensors installed on the front,left,and right sides of the head to sense the surrounding *** generate multiple swimming modes of the robotic manta and online switching of different modes,we design a closed-loop Central Pattern Generator(CPG)controller based on distance information and use a combination of phase difference and amplitude of the CPG model to achieve stable and rapid adjustment of yaw *** verify the autonomous swimming ability of the robotic manta in complex scenes,we design an experimental scenario with a concave *** experimental results show that the robotic manta can achieve forward swimming,backward swimming,in situ turning within the concave obstacle,and finally exit from the area safely while relying on the perception of external obstacles,which can provide insight into the autonomous exploration of complex scenes by the biomimetic robotic ***,the swimming ability of the robotic manta is verified by field tests.

关键词： Biomimetic robotic manta Central Pattern Generator Closed-loop control Backward swimming