摘要：Three vaned diffusers, designed to have high negative incidence (-8°) at the design operating point, are studied experimentally. The overall performance (efficiency and pressure ratio) are measured at three rotational speeds, and flow angles before and after the diffuser are measured at the design rotational speed and with three mass flow rates. The results are compared to corresponding results of the original vaneless diffuser design. Attention is paid to the performance at lower mass flows than the design mass flow. The results show that it is possible to improve the performance at mass flows lower than the design mass flow with a vaned diffuser designed with high negative incidence. However, with the vaned diffusers, the compressor still stalls at higher mass flow rates than with the vaneless one. The flow angle distributions after the diffuser are more uniform with the vaned diffusers.

摘要：This paper explores the design of leg morphology in a six-legged *** by nature,where animals have different leg morphology,we examined how the difference in leg morphology influences behaviors of the *** this end,a systematic search was conducted by scanning over the parameter space consisting of default angles of leg joints of the six-legged robot,with two main objectives:to maximize the kinematic flexibility and walking performance of the *** show that(1)to have a high kinematic flexibility with both the torso and swing legs,the femur segment should tilt downwards by 5°-10°and the tibia segment should be vertically downwards or with a slight inward tilt;(2)to achieve relatively energy-efficient and steady walking,the tibia segment should be approximately vertically downwards,with the femur segment tilting upwards to lower the torso *** results of this study suggest that behaviors of legged robots can be passively enhanced by careful mechanical design choices,thereby leading to more competent legged machines.

摘要：Mini turbo-pumps having a diameter smaller than 100mm are employed in many fields;automobile radiator pump,ventricular assist pump,cooling pump for electric devices,washing machine pump and so ***,the needs for mini turbo-pumps would become larger with the increase of the application of it for electrical *** is desirable that the mini turbo-pump design is as simple as possible due to restriction to make precise *** the design method for the mini turbo-pump is not established because the internal flow condition for these small-sized fluid machineries is not clarified and conventional theory is not conductive for small-sized *** types of rotors with different outlet angles are prepared for an experiment and a numerical *** performance tests are conducted with these rotors in order to investigate the effect of the blade outlet angle on performance and internal flow condition of mini *** is clarified from the experimental results that head of the mini turbo-pump increases and maximum efficiency flow rate shifts to larger flow rate according to the increase of the blade outlet angle,however the maximum efficiency decreases with the increase of *** the present paper,the performance of the mini turbo-pump is shown and the internal flow conditions are clarified with the results of the experiment and the numerical flow ***,the effects of the blade outlet angle on the performance are investigated and high performance design with simple structure for the mini turbo-pump would be considered.

摘要：Nanozymes, nanomaterials with enzyme-like characteristics,are emerging as novel artificial enzymes (Gao et al., 2007;Manea et al., 2004;Yan, 2018). They are superior to natural enzymes in many ways, such as higher stability, lower cost in preparation, and better robustness toward harsh environments (Wei and Wang, 2013).

摘要：This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device （VAD） in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.

摘要：As the architecture,engineering,and construction(AEC)industry is marching into the sustainable and low-carbon era,the performance of architecture has drawn more attention than *** technology has made quantified analysis of architectural performance possible and,therefore,directly enables architects and engineers to incorporate performance analysis into the design work *** is argued that performance-based and performancedriven architectural designs differ in that the latter involves computer-aided optimization technique so that the performance can be used as the criteria to truly“drive”the *** paper starts with a brief introduction of performance issues in architectural design,followed by a review of the evolution of performance-based architectural *** concept of performance-driven architectural design is presented,and some design projects and research work are *** driving engine,i.e.,optimization technique,and its application in architectural design is *** to making performance-driven design a common practice are explained,and a schematic of integrated performance-based/driven architectural design software is proposed.

摘要：Design method for large stone porous asphalt mixtures （LSPM） was analyzed to avoid the early distresses of semi-rigid asphalt pavements. Based on stone-to-stone skeleton structure concept, processes of LSPM gradation design was given. The gradation composite design for LSPM shows that the LSPM nominal maximum size （ N MS） should be larger than 26.5 mm, and the NMS sieve passing percentage should be greater than 50%. Through experiments and calculations on the volume properties of the aggregate, the range of aggregate gradation curve of LSPM was given. In terms of asphalt binder＇s normalized test results, MAC-70 and SBS modified asphalt were selected as the asphalt binders. The applicability of large scale Marshall Method and gyratory compaction method to shape specimens was investigated. Based on the asphalt mixture performance evaluation, the optimum asphalt content range （3.1%-3.6%）, the bitumen film＇s thickness range （13-16 μm） and the air void range （13%-18 %） were recommended. Finally, LSPM was tested by the laboratory performance tests including rutting resistance test, fatigue test and water stability test. The theoretic and practical analysis shows that LSPM has a good performance on water permeability, rutting resistance and reflection crack resistance.

摘要：In this paper, we present an investigation on the tracking performances of feedback control as a function of reference signals. We use multi-objective optimal designs of feedback controls as a fair basis for comparing different control designs, and examine step, ramp, and periodic signals at various frequencies. Through comparing the tracking performances of controls designed with different reference signals,we find that the controls designed with ramp signals perform better in tracking step and ramp references than those designed with step signals. To track periodic signals, we find that the controls designed with periodic signals at the same frequency generally provide the best performance, and those designed with step and ramp signals perform comparably.

摘要：To accurately launch laser, a fast-steering mirror(FSM) with flexure hinge is designed. First, actuators, angle sensors and flexure hinge were designed or selected respectively according to requirements of vehicle track-launch system. Then, the servo control system with two closed loops was projected after fine manufacturing and assembling. Finally, the pointing precisions of FSM on the static and vibrancy platforms were tested. The results show that the designed FSM with pointing error range on the static platform is less than 0.9″, and less than 44.5″ on the vibrancy shaker, which can meet the requirements of vehicle track-launch system application.

摘要：To improve the transmission accuracy and stiffness of the ball cycloid reducer, the authors developed a novel cycloid ball reducer, which uses a full complement ball as its gear teeth. Ceramic balls are used to get better performance in severe working conditions. A simple synthesis method was also found to determine the raceway forms and compute the contact forces among the balls and raceways. The Contact Stress Analysis (CSA) computer program was used to optimize the design of the reducer. In this paper, the following topics are covered: (1) Study of the geometry of the raceways. (2) Analyses of the principal curvature of the raceways are also accomplished. In addition, the modification of the raceway is put forward. (3) The contact forces and the reducer efficiency are evaluated. (4) Study of the performance of ceramic balls used in the CBR. A reducer using the above design technique was tested and the performances show that the reducer has high precision and rigidity. An increase of more than 50 percent transmission power was realized in the new gearing.