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Modal disturbance investigation of rod-shaped ultrasonic motor using bending vibrations

ZHANG Jiantao, ZHU Hua, ZHAO Chunsheng

《机械工程前沿（英文）》 2008年第3卷第3期页码 343-347 doi: 10.1007/s11465-008-0058-6

摘要： Modal disturbance of a rod-shaped ultrasonic motor using bending vibrations can cause problems such as low motor efficiency, instability, and poor control. In this paper, a dynamic analysis model of a stator is created on the basis of the finite element method (FEM) and Hamilton principle. The modal frequency sensitivities of the stator to the structure parameters are investigated by modal analysis. Accordingly, the structure parameters of the stator are modified to separate working modes from disturbance modes. A rod-shaped ultrasonic motor stator is fabricated, and the experimental results of its amplitude frequency response characteristics show that the purpose of modal separation is achieved. The frequency separation between working modes and disturbance modes is more than 2 kHz. The validity of the method is verified.

关键词： Hamilton principle disturbance separation frequency separation dynamic analysis

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Function and principle innovative design of mechanical products based on TRIZ/FA

YUAN Feng, WANG Tai-yong, NIE Hui-juan

《机械工程前沿（英文）》 2006年第1卷第3期页码 350-355 doi: 10.1007/s11465-006-0031-1

摘要： Function and principle innovation is the ultimate innovation of a product. To achieve Function and principle innovation design of mechanical products, a new process model of function and principle solving is proposed, based on TRI

关键词： TRI principle solving product principle innovation ultimate innovation

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Principle of maximum entropy for reliability analysis in the design of machine components

Yimin ZHANG

《机械工程前沿（英文）》 2019年第14卷第1期页码 21-32 doi: 10.1007/s11465-018-0512-z

摘要： We studied the reliability of machine components with parameters that follow an arbitrary statistical distribution using the principle of maximum entropy (PME). We used PME to select the statistical distribution that best fits the available information. We also established a probability density function (PDF) and a failure probability model for the parameters of mechanical components using the concept of entropy and the PME. We obtained the first four moments of the state function for reliability analysis and design. Furthermore, we attained an estimate of the PDF with the fewest human bias factors using the PME. This function was used to calculate the reliability of the machine components, including a connecting rod, a vehicle half-shaft, a front axle, a rear axle housing, and a leaf spring, which have parameters that typically follow a non-normal distribution. Simulations were conducted for comparison. This study provides a design methodology for the reliability of mechanical components for practical engineering projects.

关键词： machine components reliability arbitrary distribution parameter principle of maximum entropy

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General Optimal Trajectory Planning: Enabling Autonomous Vehicles with the Principle of Least Action

Heye Huang,Yicong Liu,Jinxin Liu,Qisong Yang,Jianqiang Wang,David Abbink,Arkady Zgonnikov,

《工程（英文）》 doi: 10.1016/j.eng.2023.10.001

摘要： This study presents a general optimal trajectory planning (GOTP) framework for autonomous vehicles (AVs) that can effectively avoid obstacles and guide AVs to complete driving tasks safely and efficiently. Firstly, we employ the fifth-order Bezier curve to generate and smooth the reference path along the road centerline. Cartesian coordinates are then transformed to achieve the curvature continuity of the generated curve. Considering the road constraints and vehicle dynamics, limited polynomial candidate trajectories are generated and smoothed in a curvilinear coordinate system. Furthermore, in selecting the optimal trajectory, we develop a unified and auto-tune objective function based on the principle of least action by employing AVs to simulate drivers’ behavior and summarizing their manipulation characteristics of “seeking benefits and avoiding losses.” Finally, by integrating the idea of receding-horizon optimization, the proposed framework is achieved by considering dynamic multi-performance objectives and selecting trajectories that satisfy feasibility, optimality, and adaptability. Extensive simulations and experiments are performed, and the results demonstrate the framework’s feasibility and effectiveness, which avoids both dynamic and static obstacles and applies to various scenarios with multi-source interactive traffic participants. Moreover, we prove that the proposed method can guarantee real-time planning and safety requirements compared to drivers’ manipulation.

关键词： Autonomous vehicle Trajectory planning Multi-performance objectives Principle of least action

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工程项目供应链的委托-代理模型分析

吴育华,张庆民

《中国工程科学》 2008年第10卷第5期页码 75-78

摘要：

从委托代理理论出发，对基于集成化供应链的委托-代理模型的一般形式进行讨论。在此基础上，结合工程项目集成化供应链中委托方和代理方的特点构建了工程项目供应链单期委托-代理模型和多阶段工程项目供应链声誉模型。

关键词：委托-代理模型激励模型声誉模型随机行走

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铁路隧道建设理念和设计原则

王梦恕,张梅

《中国工程科学》 2009年第11卷第12期页码 4-8

摘要：

铁路隧道的建设正处于前所未有的大发展时期，笔者在总结大量工程成功经验和失败教训的基础上提出了铁路隧道建设的基本理念：隧道必须建成遗产工程；隧道必须进行科学的风险评估；隧道建设必须合理工期、合理造价、合理合同、合理施工方案和设计原则；隧道必须进行信息化施工。提出了单双线隧道选择、隧道纵坡及辅助导洞设置、支护结构设计以及快速施工等隧道设计原则。隧道建设的理念和设计原则可指导今后铁路隧道的规划、设计和施工。

关键词：铁路隧道建设理念设计原则

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非饱和土的塑性体应变与剪应变的相互作用原理

王靖涛

《中国工程科学》 2007年第9卷第11期页码 11-15

摘要：

将岩土塑性体应变与剪应变的相互作用原理拓展到了非饱和土领域。除了塑性体应变与剪应变的相互作用外，在非饱和土中出现了两类新的相互作用，吸力-塑性体应变和孔隙气压力-塑性体应变。吸力具有二重性质，其对塑性体应变作用包括两个相反的方面。基于吸力性质，阐明了非饱和土的一些独特的性质，诸如有效应力参数的物理涵义，吸力对体积变化和前期固结压力的影响和湿陷机理等。另外，应用拓展的塑性体应变与剪应变相互作用原理，从理论上证明了非饱和土的临界状态线是存在的和唯一的，以及它与应力历史无关。

关键词：塑性体应变与剪应变的相互作用原理非饱和土基质吸力有效应力原理

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Conceptual design of compliant mechanisms using level set method

Shi-kui CHEN, Michael Yu WANG

《机械工程前沿（英文）》 2006年第1卷第2期页码 131-145 doi: 10.1007/s11465-006-0018-y

摘要： We propose a level set method-based framework for the conceptual design of compliant mechanisms. In this method, the compliant mechanism design problem is recast as an infinite dimensional optimization problem, where the design variable is the geometric shape of the compliant mechanism and the goal is to find a suitable shape in the admissible design space so that the objective functional can reach a minimum. The geometric shape of the compliant mechanism is represented as the zero level set of a one-higher dimensional level set function, and the dynamic variations of the shape are governed by the Hamilton-Jacobi partial differential equation. The application of level set methods endows the optimization process with the particular quality that topological changes of the boundary, such as merging or splitting, can be handled in a natural fashion. By making a connection between the velocity field in the Hamilton-Jacobi partial differential equation with the shape gradient of the objective functional, we go further to transform the optimization problem into that of finding a steady-state solution of the partial differential equation. Besides the above-mentioned methodological issues, some numerical examples together with prototypes are presented to validate the performance of the method.

关键词： splitting minimum dimensional optimization Hamilton-Jacobi topological

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Practice and principle of traditional Chinese medicine for the prevention and treatment of COVID-19

《医学前沿（英文）》 doi: 10.1007/s11684-023-1040-8

摘要： Traditional Chinese medicine (TCM) has played an important role in the prevention and treatment of coronavirus disease 2019 (COVID-19) epidemic in China. The integration of Chinese and Western medicine is an important feature of Chinese COVID-19 prevention and treatment. According to a series of evidence-based studies, TCM can reduce the infection rate of severe acute respiratory syndrome coronavirus 2 in high-risk groups. For patients with mild and moderate forms of COVID-19, TCM can relieve the related signs and symptoms, shorten the period of nucleic-acid negative conversion, and reduce conversion rate to the severe form of the disease. For COVID-19 patients with severe and critical illnesses, TCM can improve inflammatory indicators and blood oxygen saturation, shorten the hospital stay, and reduce the mortality rate. During recovery, TCM can improve patients’ symptoms, promote organ function recovery, boost the quality of patients’ life, and reduce the nucleic-acid repositive conversion rate. A series of mechanism research studies revealed that capability of TCM to treat COVID-19 through antiviral and anti-inflammatory effects, immune regulation, and protection of organ function via a multicomponent, multitarget, and multipathway approach.

关键词： traditional Chinese medicine COVID-19 SARS-CoV-2 clinical evidence-based study mechanism integrated traditional Chinese and Western medicine

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宜万铁路岩溶隧道防排水原则及技术研究

王秀英,谭忠盛,王梦恕,张民庆

《中国工程科学》 2010年第12卷第8期页码 107-112

摘要：

宜万铁路岩溶隧道地质条件复杂、岩溶形态多样，高压富水溶腔段是岩溶隧道治理的重点和难点。在对充填型溶腔进行富水分级的基础上，制定岩溶隧道的防排水原则。对于可以排放的溶腔，研究总结了使岩溶水的排放得到合理控制的总体方案和安全保障方案。对于采用“以堵为主”原则进行处理的高压富水充填岩溶，研究总结了相应的全断面帷幕注浆技术、隧道周边超前预注浆技术，并提出了外堵内固周边注浆新技术，在保证安全的前提下极大地加快了施工进度。宜万铁路岩溶隧道的结构防排水按照“因地制宜、堵排结合、多道防线”的原则进行。

关键词：岩溶隧道防排水原则注浆技术

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Design Method and Numerical Control Machining Principle for an Arbitrary n-polygon Noncircular Section

WU Yi-jie, LENG Hong-bin

《机械工程前沿（英文）》 2006年第1卷第1期页码 71-75 doi: 10.1007/s11465-005-0005-8

摘要：

By analyzing the structure characteristics of arbitrary n-polygon noncircular sections, mathematical formulas among the characteristic parameters were set up, and a theorem for designing this kind of sections was deduced by mathematical induction method. Based on the mechanistic transmission principle, the control theorems for the numerical control (NC) grinding of arbitrary n-polygon noncircular sections and the control model for the multicoordinate motion were built. A feed rate selfadjusting method was proposed to uniform the grinding speed with the changes of sectional curvature. Then, an NC machine tool for grinding n-polygon noncircular sections was developed. The test results of the grinded parts showed that the section profiles accorded with the design demands: the roughness was less than 0.32 ?m and the dimensional accuracy was within 8 ?m. The results prove that the proposed theorems and method can effectively direct the design and manufacture of the polygonal noncircular connection.

关键词： manufacture multicoordinate characteristic polygonal noncircular mechanistic transmission

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工程项目生态系统概念与原理研究

周红,成虎,徐鹏富

《中国工程科学》 2006年第8卷第10期页码 94-98

摘要：

依据生态学和应用生态学的基本概念和原理，结合工程项目系统的特征，提出了工程项目生态系统的概念。采用对比分析法对工程项目生态系统的层次结构、原则、组成进行了具体的分析。工程项目生态系统的演化、平衡和生命系统一样，是个非线性的耗散结构,其演化和平衡满足逻辑斯谛模型。

关键词：工程项目生态系统概念原理

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Treating wastewater under zero waste principle using wetland mesocosms

Safaa M. Ezzat, Mohammed T. Mohammed T.

《环境科学与工程前沿（英文）》 2021年第15卷第4期 doi: 10.1007/s11783-020-1351-9

摘要： Abstract • Smart wetland was designed to treat wastewater according to zero waste principle. • The system included a dynamic roughing filter, Cyperus papyrus (L.) and zeolite. • It removed 98.8 and 99.8% of chemical and bacterial pollutants in 3 days. • The effluent reused to irrigate a landscape and the sludge recycled as fertilizer. • The plant biomass is a profitable resource for antibacterial and antioxidants. The present investigation demonstrates the synergistic action of using a sedimentation unit together with Cyperus papyrus (L.) wetland enriched with zeolite mineral in one-year round experiment for treating wastewater. The system was designed to support a horizontal surface flow pattern and showed satisfactory removal efficiencies for both physicochemical and bacteriological contaminants within 3 days of residence time. The removal efficiencies ranged between 76.3% and 98.8% for total suspended solids, turbidity, iron, biological oxygen demand, and ammonia. The bacterial indicators (total and fecal coliforms, as well as fecal streptococci) and the potential pathogens (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) showed removal efficiencies ranged between 96.9% and 99.8%. We expect the system to offer a smart management for every component according to zero waste principle. The treated effluent was reused to irrigate the landscape of pilot area, and the excess sludge was recycled as fertilizer and soil conditioner. The zeolite mineral did not require regeneration for almost 36 weeks of operation, and enhanced the density of shoots (14.11%) and the height of shoots (15.88%). The harvested plant biomass could be a profitable resource for potent antibacterial and antioxidant bioactive compounds. This could certainly offset part of the operation and maintenance costs and optimize the system implementation feasibility. Although the experiment was designed under local conditions, its results could provide insights to upgrade and optimize the performance of other analogous large-scale constructed wetlands.

关键词： Wastewater dynamic roughing filter Cyperus papyrus (L.) zeolite zero waste

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论岩土塑性体应变与剪应变的相互作用原理

王靖涛

《中国工程科学》 2006年第8卷第9期页码 24-29

摘要：

对岩土塑性变形过程中体应变与剪应变的相互作用原理的内涵做了深入的阐述，特别对塑性体应变和剪应变之间的相互作用方式，塑性体应变对抗剪能力的直接控制作用，剪缩和剪胀发生的条件，应力路径相关性是这种相互作用的综合体现及实例验证，临界状态是塑性和弹性体应变都保持不变的纯粹剪切变形过程等方面进行了论证；根据这个相互作用原理，在理论上证明了空间临界状态线的存在性和唯一性以及它与应力是无关的。

关键词：岩土塑性体变形和剪应变的相互作用原理岩土本构关系压硬性剪胀性

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《网络安全法（草案二次审议稿）》第27条修改建议——以网络服务提供者协助解密义务为中心

崔聪聪,李欲晓,韩松

《中国工程科学》 2016年第18卷第6期页码 34-38 doi: 10.15302/J-SSCAE-2016.06.007

摘要：

网络服务提供者协助解密义务，隐含着公权力（侦查权）与私权利（通信秘密权、隐私权）之间的冲突。用户的非公开信息应该在可控、可追溯基础上，遵循必要性原则和比例原则，综合考虑执法成本，司法机关经由法律确定网络服务提供者履行协助解密义务获取，进而达到社会治理管控、公众安宁生活与网络服务提供者营业自由的综合效益最大化目标，避免落入公权力严重侵犯私权利的情形或者出现政府失效的无序状态。

关键词：协助解密义务必要性原则比例原则可控、可追溯救济措施