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机床结构传递函数的辨识方法 被引量:2
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作者 徐燕申 Minis I E Magrab E B 《天津大学学报》 EI CAS CSCD 1991年第3期66-72,共7页
从闭环切削系统的解耦阐明机床结构传递函数的辨识方法,对切削和非发削状态作了比较。实验表明两种状态下结构传递函数是有差别的,原因在于动载和静载条件不同,使得机床结构间的接触刚度和接触徂尼发生变化。还讨论了结构有效动柔度的... 从闭环切削系统的解耦阐明机床结构传递函数的辨识方法,对切削和非发削状态作了比较。实验表明两种状态下结构传递函数是有差别的,原因在于动载和静载条件不同,使得机床结构间的接触刚度和接触徂尼发生变化。还讨论了结构有效动柔度的计算方法,以左刃和右刃切削为例,分析了切削力方向变化对结构有效传递函数的影响。 展开更多
关键词 机术结构 传递函数 辨识
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MATHEMATICAL MODEL OF SELF-REPAIRING FLIGHT CONTROL 被引量:2
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作者 王永 詹训慧 +1 位作者 吴刚 胡寿松 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期178-183,共6页
The most prospective method for certain structural failures and damages that cannot employ redundancy is self-repairing techniques, to ensure especially the maximum flight safety. Based on the characters of self-repai... The most prospective method for certain structural failures and damages that cannot employ redundancy is self-repairing techniques, to ensure especially the maximum flight safety. Based on the characters of self-repairing aircraft, this paper states some basic assumptions of the self-repairing aircraft, and puts forward some special new conceptions concerning the self-repairing aircraft: control input, operating input, command input, repair input and operating and control factor as well as their relationships. Thus it provides a simple and reliable mathematical model structure for the research on the self-repairing control of the aircraft. 展开更多
关键词 SELF-REPAIRING flight control mathematical model operating and control factor
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Simulation and analysis of resin flow in injection machine screw 被引量:2
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作者 Ling-feng LI Samir MEKID 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第3期338-345,共8页
A method with simulation and analysis of the resin flow in a screw is presented to ease the control of some problems that may affect the efficiency and the quality of the product among existing screws in an injection ... A method with simulation and analysis of the resin flow in a screw is presented to ease the control of some problems that may affect the efficiency and the quality of the product among existing screws in an injection machine. The physical model of a screw is established to represent the stress, the strain, the relationship between velocity and stress, and the temperature of the cells. In this paper, a working case is considered where the velocity and the temperature distributions at any section of the flow are obtained. The analysis of the computational results shows an ability to master various parameters depending on the specifications. 展开更多
关键词 SCREW PLASTICITY Velocity distribution Temperature distribution
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Self-organized evolution of mechanism kinetic scheme based on axiomatic design 被引量:1
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作者 冯毅雄 Tan Jianrong Wei Zhe Hao He 《High Technology Letters》 EI CAS 2007年第4期373-378,共6页
The self-organized evolution technology of the mechanism kinetic scheme based on axiomatic design is presented. This technology tries to express the constraints between kinetic mechanisms briefly in a semantic form wh... The self-organized evolution technology of the mechanism kinetic scheme based on axiomatic design is presented. This technology tries to express the constraints between kinetic mechanisms briefly in a semantic form which is more familiar to the designers. Through the mapping process between the kinetic chain unit and the unit instance, the evolution from abstract unit to concrete engineering instance is achieved. The subdivision of unit coupling semantics is studied, and the evolution of semantics is finished. Also, the semantic constraints evolution of unit coupling semantics is described. The product structure models with function and assembly meanings are constructed based on the kinematic chain unit and unit coupling. It provides a basis to realize the inheritance and transfer of constraint information from conceptual design to design for assembly (DFA). As the engineering practice result shows, the method can help the engineers express their And the automation, recursion and design intension more clearly and naturally in a high semantic level. visualization of the mechanism kinetic scheme design are realized 展开更多
关键词 mechanism kinetic scheme SELF-ORGANIZATION EVOLUTION axiomatic design
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Structural design, analysis and performance evaluation of a novel planar parallel robot: theory and experiment
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作者 Ding Qinyong (丁庆勇) Sun Lining +1 位作者 Liu Xinyu Ji Junhong 《High Technology Letters》 EI CAS 2005年第3期229-234,共6页
The structural design, analysis and experimental verification of a novel planar parallel robot that includes parallelogram linkages are reported in this paper. A design methodology combining finite element analysis (... The structural design, analysis and experimental verification of a novel planar parallel robot that includes parallelogram linkages are reported in this paper. A design methodology combining finite element analysis (FEA) and flexible dynamics is employed in the analysis. The appropriate natural frequencies of robot throughout workspaee are predicted, and the effects of payload, flexibility of joints, cross section and orientations of robot on the natural frequency are analyzed by simulation. Extensive structural vibration experiments with the completed manipulator confirm the predicted structural vibration characteristics throughout the workspace. The experiment also proves the robot's performance under a fuzzy self-tuning PI controller. 展开更多
关键词 parallel robot structural analysis finite element analysis (FEA) natural frequency fuzzy PI control
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Theoretical and Technological Aspects on the Inverse Structure in the Fields of High Speed Electric Machines
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作者 Mircea Ignat Teodora Paraschiv Ioan Cristinel Haraguta 《Journal of Energy and Power Engineering》 2012年第3期456-462,共7页
The paper presents the design and technological aspects on the high speed electrical machines which include the mechanical radial and axial strees because of the centrifugal forces. It presents a reverse structure wit... The paper presents the design and technological aspects on the high speed electrical machines which include the mechanical radial and axial strees because of the centrifugal forces. It presents a reverse structure with outlet rotor and inlet stator that have high speed 20.000 rpm-24.000 rpm and power 1 kW for the pecific of the ventilanting centrifugal fan domain. This unconventional type of machine is not still in the phase of specific tests. 展开更多
关键词 Asyncrone machine CAGE high speed magnetic circuit mechanical stress motor reverse structure.
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Fabrication and Characterization of NEMS
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作者 JIAO Ji-wei YANG Heng LI Tie LI Xin-xin WANG Yue-lin 《Optoelectronics Letters》 EI 2007年第2期91-94,共4页
We proposed a called“nano-fabrication based on MEMS technology”approach to realize the typical nano-electro- mechanical structures,such as integrated nano probe,ultrathin cantilever,silicon nano wire,and doubly clam... We proposed a called“nano-fabrication based on MEMS technology”approach to realize the typical nano-electro- mechanical structures,such as integrated nano probe,ultrathin cantilever,silicon nano wire,and doubly clamped nano beam, to demonstrate the feasibility and advantages.We also introduced the characterization of nano structures based on laser vibrometer and piezoresistive effect,the latter method was first time applied to investigate a doubly daped nanobeam with a thickness of about 200 nm. 展开更多
关键词 NEMS 纳米级结构 制造 特征 MEMS技
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Instability mechanism and control technology of soft rock roadway affected by mining and high confined water 被引量:12
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作者 Li Guichen Jiang Zuohan +3 位作者 Lv Chuangxin Huang Chao Chen Gui Li Mingyuan 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第4期573-580,共8页
Based on deformation and failure characteristics of the second belt conveyor roadway at level II of Zhuxianzhuang coal mine, laboratory experiments, numerical calculation and field test were adopted to analyze the com... Based on deformation and failure characteristics of the second belt conveyor roadway at level II of Zhuxianzhuang coal mine, laboratory experiments, numerical calculation and field test were adopted to analyze the composition and microstructure of mudstone, the law of mudstone hydration and its strength weakening induced by water, the characteristics of surrounding rock deformation and failure under the action of confined water. Results showed that montmorillonite clay minerals accounted for as much as 76% of mudstone, with a large number of pores existing in the microstructure. Besides, as the molecular structure of montmorillonite changed, mudstone microstructure damage occurred with the macroscopic manifestation of its theological instability. Weakening degree of confined water on residual strength of mudstone was almost 50%. The instability mechanism of soft rock roadway caused by high confined water is that surrounding rock circulates the process of "fracture-seepage-mud ding-closed" twice, which weakens its strength and leads to roadway instability. A combined support technology, namely the, "high-toughness sealing layer + hollow grouting cables + full-length anchoring bolts with deep borehole" was proposed. Based on field observation, the soft rock roadway was controlled effectively, which also verified the effectiveness of new control technology for surrounding rock. 展开更多
关键词 High confined water Soft rock roadway Instability mechanism Control technology
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The Use of MCRD Technique in Mode Shapes Extraction
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作者 Ahmed. A. Elshafey Mahmoud R. Haddara H. Marzouk 《Journal of Civil Engineering and Architecture》 2010年第7期26-33,共8页
The random decrement technique is an averaging technique that can be used to extract the free decay response of the structure from its random stationary vibratory response. The free decay response can then be used to ... The random decrement technique is an averaging technique that can be used to extract the free decay response of the structure from its random stationary vibratory response. The free decay response can then be used to identify the vibratory characteristics of the structure. The main advantage of the technique is that the identification of the parameters of the structure is achieved without previous knowledge of the excitation forces. This paper extends the random decrement technique to obtain the mode shapes of the structure using the concept of a multichannel random decrement technique (MCRD). This technique is based on extracting simultaneous random decrement records from measurements made at several points on the structure. The method is very efficient and simple. Numerical examples are solved and compared with the exact mode shapes extracted using classical modal analysis. An excellent agreement between the extracted modes shapes using the MCRD and those obtained from the classical modal analysis techniques is achieved. The vibration of an offshore structure excited by white noise excitation is used to illustrate the method. 展开更多
关键词 Mode shapes multichannel random decrement free decay
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Minimizing of the only-insertion insdel systems
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作者 闵勇 金小刚 +1 位作者 苏先创 彭博 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第10期1021-1025,共5页
A more recent branch of natural computing is DNA computing. At the theoretical level, DNA computing is powerful. This is due to the fact that DNA structure and processing suggest a series of new data structures and op... A more recent branch of natural computing is DNA computing. At the theoretical level, DNA computing is powerful. This is due to the fact that DNA structure and processing suggest a series of new data structures and operations, and to the fact of the massive parallelism. The insertion-deletion system (insdel system) is a DNA computing model based on two genetic operations: insertion and deletion which, working together, are very powerful, leading to characterizations of recursively enumerable lan- guages. When designing an insdel computer, it is natural to try to keep the underlying model as simple as possible. One idea is to use either only insertion operations or only deletion operations. By helping with a weak coding and a morphism, the family INS4^7DEL0^0 is equal to the family of recursively enumerable languages. It is an open problem proposed by Martin-Vide et al. on whether or not the parameters 4 and 7 appearing here can be replaced by smaller numbers. In this paper, our positive answer to this question is that INS2^4DEL0^0 can also play the same role as insertion and deletion. We suppose that the INS2^4DEL0^0 may be the least only-insertion insdel system in this situation. We will give some reasons supporting this conjecture in our paper. 展开更多
关键词 DNA computing Insdel Only insertion
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Mechanism of Structural Transformation of China's Technology Export
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作者 陈晓华 黄先海 刘慧 《China Economist》 2011年第4期83-96,共14页
Extending Long's (2001) two-sector model into a three-sector model, this paper constructs a new framework for analysing the evolution mechanism of the structure of technology exports. The authors also have applied ... Extending Long's (2001) two-sector model into a three-sector model, this paper constructs a new framework for analysing the evolution mechanism of the structure of technology exports. The authors also have applied an adjusted Hausman model to measure the structure of exported technology at China's provincial level regions. Upon this foundation, approaching the subject from its domestic and international impact factors, this paper empirically tests the motives driving the structural transformation of China's technology export. The conclusions are: (1) the structure of China's technology export has improved significantly in recent years, but not as highly as measured by Rodrik (2006) et al. (2) The dynamic mechanism of the structure of China's technology export differs from that of the other developing countries. At national and regional levels, the mounting physical capital stock is the fundamental driving force, but with obvious decreasing marginal utility. (3) Excessive unskilled labor in the capital production sector in the central and western regions, and excessively low export prices in the eastern regions have caused negative effects of the skilled labor in the western region and unskilled labor in the eastern region on local structure of technology export. 展开更多
关键词 technical structure of exports physical capital unskilled labor skilled labor
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PRCA: A highly efficient computing architecture
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作者 Luo Xingguo 《Engineering Sciences》 EI 2014年第4期38-47,共10页
Applications can only reach 8 %~15 % of utilization on modern computer systems. There are many obstacles to improving system efficiency. The key root is the conflict between the fixed general computer architecture and... Applications can only reach 8 %~15 % of utilization on modern computer systems. There are many obstacles to improving system efficiency. The key root is the conflict between the fixed general computer architecture and the variable requirements of applications. Proactive reconfigurable computing architecture(PRCA) is proposed to improve computing efficiency. PRCA dynamically constructs an efficient computing architecture for a specific application via reconfigurable technology by perceiving requirements,workload and utilization of computing resources. Proactive decision support system(PDSS),hybrid reconfigurable computing array(HRCA) and reconfigurable interconnect(RIC) are intensively researched as the key technologies. The principles of PRCA have been verified with four applications on a test bed. It is shown that PRCA is feasible and highly efficient. 展开更多
关键词 PRCA efficient computing CHALLENGES
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Distributed Cooperative Mechanism and Application for Monitoring of Urban Subway Construction
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作者 冯建中 白林燕 胡振琪 《Journal of Donghua University(English Edition)》 EI CAS 2006年第6期25-28,32,共5页
In this paper, combining the technologies of Computer Supported Cooperative Work (CSCW), Workflow and Network, the authors aim to organize virtual distributed cooperative work environment (VDCWE) and expound the r... In this paper, combining the technologies of Computer Supported Cooperative Work (CSCW), Workflow and Network, the authors aim to organize virtual distributed cooperative work environment (VDCWE) and expound the running mechanism of cooperative workflow and design its algorithm for monitoring of urban subway construction. And then a prototype system was built based on the above,capable of supporting user analyzing, dealing with and managing data of monitoring, and real-timely releasing corresponding information, providing interactive virtual and distributed coordination meet-environment, dynami-cally and transparently, in favor of clients' interoperaiility and solving practicing problems, and so on. 展开更多
关键词 CSCW work flow cooperative work MODEL CISMUSC.
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Research on Network Security Algorithm based on ZigBee Technology
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作者 XiaoleiWu 《International Journal of Technology Management》 2014年第8期164-166,共3页
Paper study the MAC layer security mechanism and data frame structure in ZigBee protocol, improve the algorithm for random Fuzzing test technology, and test method of attack fusion boundary, structure of Fuzzing and t... Paper study the MAC layer security mechanism and data frame structure in ZigBee protocol, improve the algorithm for random Fuzzing test technology, and test method of attack fusion boundary, structure of Fuzzing and the node clone, proposed a ZigBee routing protocol for the MAC layer security comprehensive detection algorithm. Fuzzing test show that the testing algorithm can not only greatly improve the test efficiency in Fuzzing, more than the structure of Fuzzing is increased by 50% in path coverage. 展开更多
关键词 ZigBee protocol Fuzzing test boundary scan test
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Multidimensional CAE methods for car body structure optimization
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作者 Men Yongxin Ma Fangwu +2 位作者 Zhu Zhenying Zhang Jiyou Yuan Liantai 《Engineering Sciences》 EI 2012年第6期38-42,66,共6页
The computer aided engineering(CAE) analysis technique has become one of the most important means in modern automobile development due to its remarkably computing capability.With the development of CAE bussiness softw... The computer aided engineering(CAE) analysis technique has become one of the most important means in modern automobile development due to its remarkably computing capability.With the development of CAE bussiness software and intensive research on automotive development process,the CAE technique,which was only used as an auxiliary validation tool in the later product development in the past,is gradually used in each stage of product development now.Furthermore,accurate and fast analysis data can be supplied effectively.Especially in current CAE application, based on some optimization technologies such as sensitivity,feature and topology,the parametric design gradually enables a CAE engineer to be free from the condition which a convention analysis usually lags behind a design,and makes it be parallel to or even anterior to the design.Under the circumstance,the CAE resources can be maximized in each project development department,thereby promoting the project progress and quality,and creating a new philosophy of 'analysis-driven design'. 展开更多
关键词 BIW MODAL STIFFNESS SFE PARAMETERIZATION sensitivity topological optimization structural adhesive
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Research on the Multimedia Data Mining and Classification Algorithm based on the Database Optimization Techniques
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作者 Hu Xiu 《International Journal of Technology Management》 2015年第11期58-60,共3页
In this research article, we analyze the multimedia data mining and classification algorithm based on database optimization techniques. Of high performance application requirements of various kinds are springing up co... In this research article, we analyze the multimedia data mining and classification algorithm based on database optimization techniques. Of high performance application requirements of various kinds are springing up constantly makes parallel computer system structure is valued by more and more common but the corresponding software system development lags far behind the development of the hardware system, it is more obvious in the field of database technology application. Multimedia mining is different from the low level of computer multimedia processing technology and the former focuses on the extracted from huge multimedia collection mode which focused on specific features of understanding or extraction from a single multimedia objects. Our research provides new paradigm for the methodology which will be meaningful and necessary. 展开更多
关键词 Data Mining Classification Algorithm Database Optimization Multimedia Source.
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Application of Norms Models with Vectoral System in Construction Projects
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作者 Vladimir Krizaic 《Journal of Civil Engineering and Architecture》 2014年第6期722-728,共7页
Normization, i.e., the system of norms is a structure that defines the group of elements containing the norm values for the requirements of a certain resource. Resources comprise of materials, machines and labor. All ... Normization, i.e., the system of norms is a structure that defines the group of elements containing the norm values for the requirements of a certain resource. Resources comprise of materials, machines and labor. All the requirements of the measure units of the resources are given statically and with the discrete data. Thus, every slight change in the expense list item reference causes a change in norm and our norm is not flexible and features a discrepancy with the real life situations. In order to achieve a higher level of preciseness and to speed up the technological processes of planning and norming the engines of a company that lead to the regulation of the system, the discrete elements of the working (time-related) norms should be replaced by the dynamic ones. This is made possible through setting up norms models that in turn can be presented by formulae in the vectoral system. The use and implementation of the new technologies in terms of production, computer science and cybernetics provides for upgrading the norm requirements. New working tasks in turn require a new norm standardization, which can be applied to the hydrodemolition of concrete constructions by means of water robots that use high pressure water jets. 展开更多
关键词 Norms models water robots model standardization norm Erlang distribution.
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Parameters and Trajectory Overall Optimization Design of the Combined Cycle Engine Reusable Launch Vehicle 被引量:1
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作者 CUI Naigang ZHAO Lina +1 位作者 HUANG Rong WEI Changzhu 《Aerospace China》 2016年第4期14-20,共7页
Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research... Reusable launch vehicle is an important way to realize fast,cheap and reliable space transportation.A combined cycle engine system provides a more efficient and flexible form of power.The investigation on the research status of the combined cycle engine technology,including basic principle,research programs and classification of structure is firstly discussed in this paper.Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design.Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms,in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles. 展开更多
关键词 Reusable launch vehicle Combined cycle engine Bilevel hierarchical Integrated Parameters/trajectory overall optimization
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Adhesive bonding of composite aircraft structures:Challenges and recent developments 被引量:7
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作者 PANTELAKIS Sp. TSERPES K.I. 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第1期2-11,共10页
In this review paper,the challenges and some recent developments of adhesive bonding technology in composite aircraft structures are discussed.The durability of bonded joints is defined and presented for parameters th... In this review paper,the challenges and some recent developments of adhesive bonding technology in composite aircraft structures are discussed.The durability of bonded joints is defined and presented for parameters that may influence bonding quality.Presented is also,a numerical design approach for composite joining profiles used to realize adhesive bonding.It is shown that environmental ageing and pre-bond contamination of bonding surfaces may degrade significantly fracture toughness of bonded joints.Moreover,it is obvious that additional research is needed in order to design joining profiles that will enable load transfer through shearing of the bondline.These findings,together with the limited capabilities of existing non-destructive testing techniques,can partially explain the confined use of adhesive bonding in primary composite aircraft structural parts. 展开更多
关键词 adhesive bonding fracture toughness finite element analysis
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Application of computer-assisted surgery techniques in the management of zygomatic complex fractures 被引量:2
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作者 Xiao Zhang Chao-Ying Han +6 位作者 Min-Jia Dai Jin-Long Chen Xiao-Hui Zheng Jie Long Wei Tang Wei-Dong Tian Lei Liu 《Chinese Journal of Traumatology》 CAS CSCD 2018年第5期281-286,共6页
Patients suffering from zygomatic complex fractures always present facial deformity and dyslunctions, and thereafter develop psychological and physiological problems. It is really hard to get an ideal prog- nosis for ... Patients suffering from zygomatic complex fractures always present facial deformity and dyslunctions, and thereafter develop psychological and physiological problems. It is really hard to get an ideal prog- nosis for the zygomatic complex fractures because of the complicated anatomical structures. Computer- assisted surgery techniques, as the new emerging auxiliary methods, can optimize the surgical protocol, predict operation outcomes, and improve the accuracy and quality of the operation. Meanwhile the postoperative complications can be reduced effectively. This review aims to provide a comprehensive overview of the application of computer-assisted surgery techniques in the management of zygomatic complex fractures. 展开更多
关键词 Zygomatic complex fractures Computer-assisted surgical techniques ACCURACY REDUCTION
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