摘要：A cylindrical negative Poisson's ratio(CNPR) structure based on two-dimensional double-arrow negative Poisson's ratio(NPR)structure was introduced in this paper. The CNPR structure has excellent stiffness, damping and energy absorption performances,and can be applied as spring, damper and energy absorbing components. In this study, the CNPR structure was used as a jounce bumper in vehicle suspension, and the load-displacement curve of NPR jounce bumper was discussed. Moreover, the influences of structural parameters and materials on the load-displacement curve of NPR jounce bumper were specifically researched. It came to the conclusion that only the numbers of cells and layers impact the hardening displacement of NPR jounce bumper. And all parameters significantly affect the structure stiffness at different displacement periods. On the other hand, the load-displacement curve of NPR jounce bumper should be in an ideal region which is difficult to be achieved applying mathematical optimization method. Therefore, a parametric design strategy of NPR jounce bumper was proposed according to the parametric analysis results. The design strategy had two main steps: design of hardening displacement and design of stiffness. The analysis results proved that the proposed method is reliable and is also meaningful for relevant structure design problem.

摘要：The self-dissipation and attenuation capacity of materials play an important role in realizing efficient electromagnetic absorption,in this case,the roles of macroscopic composition and micro-structure should be emphasized simultaneously in the reasonable design of microwave *** that,Fe_(3)N alloy embedded in two-dimensional porous carbon composites were fabricated via facile sol-gel and sacrificial template ***,the magnetic/dielectric materials combination and porous structure introduction are conductive to the optimization of impedance matching property,as result of the enhancement of microwave absorption *** addition,sufficient magnetic loss capacity,strong conductivity as well as polarization attenuation bring about the outstanding microwave absorbing performance with an effective absorption bandwidth of 6.76 GHz and a minimum reflection loss value of-65.6 d *** is believed that this work not only lay a foundation to achieve microwave response materials in a wide frequency range,but also emphasize the significant role of the component selection and structural design.

摘要：A co-design scheme of event-triggered sampling mechanism and active fault tolerant control(FTC) is developed. Firstly,a fault diagnosis observer is designed to estimate both the fault and the state simultaneously by using the event-triggered sampled output. Some H∞constraints between the estimation errors and the event-triggered sampling mechanism are established to ensure the estimation accuracy. Then, based on the constraints and the obtained fault information, an event-triggered detector and a static fault tolerant controller are co-designed to guarantee the stability of the faulty system and to reduce the sensor communication ***, the problem of the event detector and dynamic FTC co-design is also investigated. Simulation results of an unstable batch reactor are finally provided to illustrate the effectiveness of the proposed method.

摘要：In this paper, a composite control scheme for macro-micro dual-drive positioning stage with high accel- eration and high precision is proposed. The objective of control is to improve the precision by reducing the influence of system vibration and external noise. The positioning stage is composed of voice coil motor （VCM） as macro driver and piezoelectric actuator （PEA） as micro driver. The precision of the macro drive positioning stage is improved by the com- bined PID control with adaptive Kalman filter （AKF）. AKF is used to compensate VCM vibration （as the virtual noise） and the external noise. The control scheme of the micro drive positioning stage is presented as the integrated one with PID and intelligent adaptive inverse control approach to compensate the positioning error caused by macro drive positioning stage. A dynamic recurrent neural networks （DRNN） based inverse control approach is proposed to offset the hysteresis nonlinearity of PEA. Simulations show the positioning precision of macro-micro dual-drive stage is clearly improved via the proposed control scheme.

摘要：Much research effort has been devoted to economic design of X ＆ S control charts,however,there are some problems in usual *** the one hand,it is difficult to estimate the relationship between costs and other model parameters,so the economic design method is often not effective in producing charts that can quickly detect small shifts before substantial losses occur;on the other hand,in many cases,only one type of process shift or only one pair of process shifts are taken into consideration,which may not correctly reflect the actual process *** improve the behavior of economic design of control chart,a cost ＆ loss model with Taguchi＇s loss function for the economic design of X ＆ S control charts is embellished,which is regarded as an optimization problem with multiple statistical *** optimization design is also carried out based on a number of combinations of process shifts collected from the field operation of the conventional control charts,thus more hidden information about the shift combinations is mined and employed to the optimization design of control *** the same time,an improved particle swarm optimization（IPSO） is developed to solve such an optimization problem in design of X ＆ S control charts,IPSO is first tested for several benchmark problems from the literature and evaluated with standard performance *** results show that the proposed algorithm has significant advantages on obtaining the optimal design parameters of the *** proposed method can substantially reduce the total cost（or loss） of the control charts,and it will be a promising tool for economic design of control charts.

摘要：For the gray attributes of the equipment program and its difficulty to carry out the quantitative assessment of the equipment program information, the gray relation projection method is simply reviewed. Combining the super-data envelopment analysis（DEA） model and the gray system theory, a new super-DEA for measuring the weight is proposed, and a gray relation projection model is established to rank the equipment programs. Finally, this approach is used to evaluate the equipment program. The results are verified valid and can provide a new way for evaluating the equipment program.

摘要：The beginning of the history of stealth technology can trace back to the later period of the Second World *** prototype of a jet-powered flying wing,Horten Ho 229,flew on March 1,1944,designed by Walter Horten&Reimar *** Horten visualized the use of charcoal dust to absorb radar electromagnetic waves(EMWs).

摘要：The compressed ready-only-memory （ROM） file system （CramFS） has been widely used in Linux-based devices. However, it is a read-only filesystem which can not meet the requirement of today＇s smart mobile devices because most of them require updating the software on the air （OTA）. This paper presents a design and implementation of write-enabled CramFS which only introduces minor architecture changes and very limited space filesystems also proves the feasibility of this solution. cost. The performance benchmark with other popular write-enabled

摘要：作为目前最有前景的绿氢生产方式,电解水技术被研究者广泛关注.其中,电催化析氧反应(oxygen evolution reaction,OER)作为电解水的半反应,由于其缓慢的四电子转移步骤而成为电解水器件的能量瓶颈.高效的OER催化电极设计是解决该问题的有效方式.本文分析了OER催化剂中氧原子介导的电子重排与活性位点配位不对称性之间的构效关系.通过自发氧化还原反应,将镍离子引入到泡沫镍(NF)表面的FeWO_(4)中,以此破坏FeWO_(4)晶格中FeO_(6)八面体的对称性,并基于此调节Fe位点的电子结构.结构调控促进了钨酸盐适度重构成为具有高OER活性的羟基氧化物.在碱性环境中,具有不对称配位Fe位点的Fe_(0.53)Ni_(0.47)WO_(4)/NF自支撑电极在10 mA cm^(-2)的电流密度下,可获得170 mV的超低过电势,并在1000 mA cm^(-2)的高电流密度下可维持稳定500 h.这种新型OER催化电极为高活性电催化系统的设计提供了新的见解.

摘要：设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片的结构重构,包括粗糙表面、氧空位以及结晶Fe-MOF和非晶Fe–B之间的面内异质结.面内异质结调节铁位点的d带中心以降低OER/HER能垒.优化的Fe–B/FeMOF/IF在10 m A cm^(-2)下驱动OER和全解水,分别仅需1.44和1.53 V.水分解系统在500 m A cm^(-2)下工作100小时以后的结构变化和性能衰减可忽略不计.该工作为异质结构界面的工程提供了启示,并促进了先进电催化剂的合理设计.