摘要：In Magnetic Resonance Imaging(MRI)guided intervention procedures,the flexibility and reliability of the mammary gland fixation device are important indicators for cnsuring the quality of *** paper presents a bionic flexible fixation system for MRI-guided breast biopsy,and establishes a mathematical model of the palm-type curved plate and a breast compression *** bending angle,eccentricity,and tightening stroke of the palm-type curved plate are considered the main influencing *** bending angle and eccentricity of the bionic palm-type curved plate and flexible fingers are optimized,and a prototype of the breast fixation system is *** experimental results show that when the external force is 10 N,the average repetitive accuracy of four lesion points is 0.71 mm,0.60 mm,0.63 mm,and 0.68 mm,*** the pressures are 8 N,10 N,and 12 N,the thickness of the compressed tissue is 76.27 mm,72.8 mm and 68.73 mm,*** has good repetitive accuracy and is compatible with the concept of flexible fixation that reduces the uncomfortable feeling of the human *** propose that by optimizing the flexible tightening mechanism,it is feasible to properly control the external compression force to effectively reduce the compression pain for patients while guaranteeing the tightening reliability in breast biopsy.

摘要：According to the water balance principle, the expression of the phreatic table is established by considering evaporation and considering evaporation ＆ drainage respectively. The law of phreatic table variation under the combined effects of considering evaporation ＆ drainage is obtained. Based on Newton-Raphson iterarive method, calculation and analysis programs are done to solve the first order implicit differential equation of the sewer drainage calculation considering phreatic evaporation. The calculation results show： after considering phreatic evaporation, in the need of reducing the same height of phreatic, the sewer spacing is appropriately larger than the case which didn＇t consider the affection of phreatic evaporation; the phreatic drop speed in both effects of evaporation and drainage is faster than the case of just considering the drainage effect. Phreatic evaporation has a great influence to the subgrade sewer distance, phreatic evaporation needs to be considered in the subgrade drainage design.

摘要：Multidisciplinary design optimization （MDO） is widely employed to enhance turbomachinery compo- nents efficiency. The aim of this work is to describe a complete tool for the aero-mechanical design of a radial in- flow turbine and a centrifugal compressor. The high rotational speed of such machines and the high exhaust gas temperature （only for the turbine） expose blades to really high stresses and therefore the aerodynamics design has to be coupled with the mechanical one through an integrated procedure. The described approach employs a fuUy 3D Reynolds Averaged Navier-Stokes （RANS） solver for the aerodynamics and an open source Finite Element Analysis （FEA） solver for the mechanical integrity assessment. Due to the high computational cost of both these two solvers, a meta model, such as an artificial neural network （ANN）, is used to speed up the optimization design process. The interaction between two codes, the mesh genera- tion and the post processing of the results are achieved via in-house developed scripting modules. The obtained results are widely presented and discussed.

摘要：According to the chemiluminescence reaction mechanism of nitric oxide(NO)and ozone(O_(3)),a new cylindrical total reflection S-type optical cavity design for rapid detection of NO gas is *** optical cavity model is based on the total reflection S-type structure on the inner wall of the *** software ZEMAX was used to simulate the optical path of the model,and software FLUENT was used to simulate and verify the *** comparative analysis showed that the chemiluminescence collection efficiency of the S-type optical cavity collection path was 36.6%,and the gas reaction and mixing in the S-type optical cavity model was more sufficient,and the reaction mixing stability error was 0.049,which was 2 times higher than the traditional stability *** model is simple in structure and meets the new national *** provides a practical idea of design for the real-time exhaust gas detection.

摘要：Emulating periodic main wing movement of a bird for generating lift and thrust remains a significant challenge in developing a robotic *** sequences of main wing motion are comprised of flapping,folding,bending,and *** this paper,we concentrate on the flapping and folding motion,and design two wing mechanisms based on a 4-bar linkage structure:one is only for Flapping Motion(FM)and the other is for simultaneous Flapping and Folding Motion(FFM)during a wing *** derive relationships between length and angle of links to analyze kinematic characteristics of the mechanisms and conduct an optimization to select the length parameters of links that allow maximization of the flapping *** run a simulation to confirm the performance of the optimized parameters by examining physical properties,and fabricate two wing mechanisms *** particular,the folding motion is achieved without using an additional *** measurements to investigate a lift profile of each mechanism and their quantitative comparison of the performance of both types confirm the benefits of the folding motion in the perspectives of wing frequency and *** expect that our kinematic formulation,design procedures,and comparative measurement results can help develop a wing mechanism to create a truly biomimetic robotic bird.

摘要：According to the requirements of a solar dish-Brayton system,a centrifugal compressor stage with a minimum total pressure ratio of 5,an adiabatic efficiency above 75% and a surge margin more than 12% needs to be designed.A single stage,which consists of impeller,radial vaned diffuser,90° crossover and two rows of axial stators,was chosen to satisfy this *** achieve the stage performance,an impeller with a 6:1 total pressure ratio and an adiabatic efficiency of 90% was designed and its preliminary geometry came from an in-house one-dimensional *** vaned diffuser was applied downstream of the *** rows of axial stators after 90° crossover were added to guide the flow into axial *** jet-wake flow,shockwave and boundary layer separation coexisted in the impeller-diffuser region,optimization on the radius ratio of radial diffuser vane inlet to impeller exit,diffuser vane inlet blade angle and number of diffuser vanes was carried out at design ***,an optimized centrifugal compressor stage fulfilled the high expectations and presented proper *** simulation showed that at design point the stage adiabatic efficiency was 79.93% and the total pressure ratio was *** surge margin was 15%.The performance map including 80%,90% and 100% design speed was also presented.

摘要：An attempt is made in the present study to obtain the relationships among process parameters and physical dimensions of AA6063 aluminium alloy coating on IS2062 mild steel obtained through friction surfacing and their impact on strength and ductility of the coating. Factorial experimental design technique was used to investigate and select the parameter combination to achieve a coating with adequate strength and ductility. Spindle speed, axial force and table traverse speed were observed to be the most significant factors on physical dimensions. It was observed that the thickness of the coating decreased as the coating width increased. In addition, the width and thickness of the coatings are higher at low and high torques. At intermediate torque values, when the force is high, the width of the coating is high, and its thickness is thin; and when the force is low, the width and thickness are low. The interaction effect between axial force(F)-table traverse speed(Vx) and spindle speed(N)-table traverse speed(Vx) produced an increasing effect on coating width and thickness, but other interactions exhibited decreasing influence. It has also been observed that sound coatings could be obtained in a narrow set of parameter range as the substrate-coating materials are metallurgically incompatible and have a propensity to form brittle intermetallics.

摘要：From the perspectives of engineering （CE）, computer concurrent supported cooperative work （CSCW）, product lifecycle management （PLM）, to collaborative supply chain and service network, collaborative systems engineering （CSE） has been extended and enriched in many research efforts. CSE is not just a technique or method but also a fundamental business philosophy and strategy.

摘要：The metal powder direct and rapid prototyping technology is one of the most developing methods in the laser rapid prototyping technique. The coaxial powder delivery system is the key technique. The purpose of this paper is to introduce a new type of coaxial powder delivery system and simulate the metal powder and shield gas flow in the powder nozzle. 2-D and 3-D model of the new coaxial powder delivery system are established. Then gas-solid two-phase flow model and the k-ε turbulent model are selected to simulate the flow of metal powder in powder nozzle. The Euler-Lagrange method is used in the simulating computation. The results show that the new coaxial powder delivery system has stable performance, uniform powder flux, high cooling efficiency, and long useful life.

摘要：This review paper summarizes constructal design progress performed by the authors for eight types of heat sinks with ten performance indexes being taken as the optimization objectives,respectively,by combining the methods of theoretical analysis and numerical *** eight types of heat sinks are uniform height rectangular fin heat sink,non-uniform height rectangular fin heat sink,inline cylindrical pin-fin heat sink(ICPHS),plate single-row pin fin heat sink(PSRPHS),plate inline pin fin heat sink(PIPHS),plate staggered pin fin heat sink(PSPHS),single-layered microchannel heat sink(SLMCHS)with rectangular cross sections and double-layered microchannel heat sink(DLMCHS)with rectangular cross sections,*** the ten performance indexes are heat transfer rate maximization,maximum thermal resistance minimization,minimization of equivalent thermal resistance which is defined based on the entransy dissipation rate(equivalent thermal resistance for short),field synergy number maximization,entropy generation rate minimization,operation cost minimization,thermo-economic function value minimization,pressure drop minimization,enhanced heat transfer factor maximization and efficiency evaluation criterion number maximization,*** optimal constructs of the eight types of heat sinks with different constraints and based on the different optimization objectives are compared with each *** results indicated that the optimal constructs mostly are different based on different optimization objectives under the same boundary *** optimization objective should be suitable chosen based on the focus when the constructal design for one heat sink is *** results obtained herein have some important theoretical significances and application values,and can provide scientific bases and theoretical guidelines for the thermal design of real heat sinks and their applications.