摘要：A flexure hinge is a major component in designing compliant mechanisms that o ers unique possibilities in a wide range of application fields in which high positioning accuracy is required. Although various flexure hinges with di erent configurations have been successively proposed, they are often designed based on designers' experiences and inspirations. This study presents a systematic method for topological optimization of flexure hinges by using the level set method. Optimization formulations are developed by considering the functional requirements and geometrical constraints of flexure hinges. The functional requirements are first constructed by maximizing the compliance in the desired direction while minimizing the compliances in the other directions. The weighting sum method is used to construct an objective function in which a self-adjust method is used to set the weighting factors. A constraint on the symmetry of the obtained configuration is developed. Several numerical examples are presented to demonstrate the validity of the proposed method. The obtained results reveal that the design of a flexure hinge starting from the topology level can yield more choices for compliant mechanism design and obtain better designs that achieve higher performance.

摘要：t In this paper an overall scheme of the task management system of ternary optical computer （TOC） is proposed, and the software architecture chart is given. The function and accomplishment of each module in the system are described in general. In addition, according to the aforementioned scheme a prototype of TOC task management system is implemented, and the feasibility, rationality and completeness of the scheme are verified via running and testing the prototype.

摘要：Prosthesis implantation and fat transplantation are common breast *** general,prosthesis implantation alone does not achieve a realistic enough appearance,and fat transplantation alone is difficult to achieve in the correct *** date,no reports have focused on methods of combining fat with implanted prostheses for breast *** a newly designed bionic ink(i.e.,polyether F127 diacrylate(F127DA)&poly(ethylene glycol)diacrylate(PEGDA))and projection-based three-dimensional bioprinting(PBP),we report the development of a new method for printing porous *** was used to improve the printing precision of the prosthesis by increasing the gel point of F127DA and reducing the impact of external *** compression modulus of the printed prosthesis was very close to that of prostheses currently used in clinical practice and to that of natural ***,stromal vascular fraction gel(SVF-gel),a human fat extract,was injected into the pores of the synthesized prostheses to prepare a prosthesis mixed with adipose *** were implanted subcutaneously in nude mice to observe their biological *** 14 and 28 days of observation,the prosthesis showed good biocompatibility,and adipose tissues grew well in and around the *** result shows that a porous prosthesis containing pre-placed adipose tissues is a promising breast reconstruction material.

摘要：Based on frequency response and convex optimization,a novel optimal control system was developed for chemical *** feedforward control is designed to improve the tracking performance of closed loop chemical *** parametric model is not required because the system directly utilizes the frequency response of the loop transfer function,which can be measured *** particular,the extremal values of magnitude and phase can be solved according to constrained quadratic programming optimizer and convex *** examples show the effectiveness of the *** design method is simple and easily adopted in chemical industry.

摘要：A fire water monitor driven by worm gear with bevel gear was designed based on the theoretical calcula-tions. The classification and features of fire water monitor were elaborated, and the design of whole structure andkey components of fire water monitor were discussed. Moreover, the jet characteristics and the influence factors onthe jet performances were also investigated in details. The simulation results approximately agree with the expecta-tion effect, which reflects the rationality of the design. The relevant analysis can provide some guidance for thedesign and optimization of fire water monitor.

摘要：For the first-order integrating processes with long delay, a Modified Smith Predictor (MSP) was analyzed when the control signal saturated. If the MSP controller has no anti-windup scheme, the saturation effectively chops off the control input resulting in performance deterioration. Thus, a simple and effective anti-windup scheme, without an additional parameter, is designed for the MSP. Simulation results illustrate that the proposed method may achieve good performance under the nominal and model uncertainty cases.

摘要：Due to the wide railway network and different characteristics of many earthquake zones in china,considering the running safety performance of trains(RSPT)in the design of high-speed railway bridge structures is very *** this study,in order to provide the seismic design and evaluation measure of the bridge structure based on the RSPT,a calculation model of RSPT on bridge under earthquake was established,and the track surface response measure when the derailment coefficient reaches the limit value was calculated by referring to 15 commonly used ground motion(GM)intensity *** on the coefficient of variation of the limit value obtained from multiple GM samples,the optimal measures were ***,the limit value of bridge seismic response based on RSPT with different train speeds and structural periods was determined.

摘要：The influence of brazing temperature and brazing time on the microstructure and shear strength ofγ-TiAl/GH536 joints brazed with Ti-Zr-Cu-Ni-Fe-Co-Mo filler was investigated using SEM,EDS,XRD and universal testing *** show that all the brazed joints mainly consist of four reaction layers regardless of the brazing temperature and brazing *** thickness of the brazed seam and the average shear strength of the joint increase firstly and then decrease with brazing temperature in the range of 1090-1170℃and brazing time varying from 0 to 20 *** maximum shear strength of 262 MPa is obtained at 1150℃for 10 *** brittle Al3NiTi2 and TiNi3 intermetallics are the main controlling factors for the crack generation and deterioration of joint *** fracture surface is characterized as typical cleavage fracture and it mainly consists of massive brittle Al3NiTi2 intermetallics.

摘要：In recent decades,the application of seismic metamaterials to protect civil infrastructures being free of the damage of earthquakes has been attracting extensive ***,the proposed locally resonant seismic metamaterials provide the probability of isolating the low-frequency seismic wave using a small-size isolation ***,in previous studies,the energy absorption properties of locally resonant seismic metamaterials remain one of the least understood aspects of *** from the fascinating energy absorption characteristic of negative Poisson ratio(NPR)metamaterial,we creatively design a new seismic metamaterial structure by assembling the locally resonant seismic metamaterial and NPR metamaterial,to isolate seismic *** sound cone technique combining the transmission spectrum is employed to identify the surface wave from the hybrid *** generation mechanism of frequency bandgap and the isolation effectiveness of the proposed seismic metamaterial are discussed in *** results indicate that the generation of ultra-low and ultra-wide frequency bandgap with the range of 0.65 Hz–18.9 Hz is attributed to the locally resonant and energy absorption of the proposed seismic metamaterial structure and the excellent isolation effect is achieved by transforming the surface wave into the bulk *** frequency bandgap narrows as the distance increases between each *** addition,the mechanical properties of the NPR bearing,such as the Poisson ratio,mass density,and elastic modulus,have remarkable impact on the frequency bandgap,especially on the upper bound *** practical engineering,the NPR bearing with a low Poisson ratio,small mass density,and high elastic modulus is suggested for the design of the NPR locally resonant seismic metamaterial *** domain analysis for the practical seismic wave verifies that the proposed seismic metamaterial has a promising application in isolating ultra-low and ultra-wi

摘要：Developing efficient platinum(Pt)-based electrocatalysts is enormously significant for fuel ***,we report an integrated electrocatalyst of ultralow-Pt alloy encapsulated into nitrogen-doped nanocarbon architecture for efficient oxygen reduction *** hybrid Pt-based catalyst achieves a mass activity of 3.46 A mg^(-1)_(pt)the potential of 0.9 V *** with a negligible stability decay after 10,000 *** importantly,this half-cell activity can be expressed at full cell level with a high Pt utilization of 10.22 W mg^(-1)_(Pt cathode)and remarkable durability after 30,000 cycles in *** and theoretical investigations reveal that a highly strained Pt structure with an optimal Pt-0 binding energy is induced by the incorporation of Co/Ni into Pt lattice,which would account for the improved reaction *** synergistic catalysis due to nitrogen-doped nanocarbon architecture and active Pt component is responsible for the enhanced catalytic ***,the strong metal-support interaction and optimized hydrophilic properties of nanocarbon matrix facilitate efficient mass transport and water *** work may provide significant insights in designing the low-Pt integrated electrocatalysts for fuel cells and beyond.