摘要：Splitting water under large current density is essential for efficient large-scale production and commercial utilization of ***,the performance of the available electrocatalysts for hydrogen evolution reaction(HER)is far from satisfactory under large current density in alkaline *** we report a remarkably active and durable electrocatalyst,long and dense MoS2/Ni3S2 co-axial heterostructure nanowires on nickel foam(NF).Notably,it requires only 182 and 200 mV overpotential to achieve large current density of 500 and 1000 mA cm^-2,respectively,in alkaline solution,which are far superior to those of Pt/C-NF(281 and 444 mV)and the reported best non-noble metal catalysts(191 and 220 mV).The physical origin for this extraordinary HER performance is analyzed,which provides a useful guide for structure design of electrocatalysts to further improve their performance.

摘要：This paper proposes the current search (CS) metaheuristics conceptualized from the electric current flowing through electric networks for optimization problems with continuous design variables. The CS algorithm possesses two powerful strategies, exploration and exploitation, for searching the global optimum. Based on the stochastic process, the derivatives of the objective function is unnecessary for the proposed CS. To evaluate its performance, the CS is tested against several unconstrained optimization problems. The results obtained are compared to those obtained by the popular search techniques, i.e., the genetic algorithm (GA), the particle swarm optimization (PSO), and the adaptive tabu search (ATS). As results, the CS outperforms other algorithms and provides superior results. The CS is also applied to a constrained design of the optimum PID controller for the dc motor speed control system. From experimental results, the CS has been successfully applied to the speed control of the dc motor.

摘要：This study investigates the current situation of the film and television education in primary and secondary schools in China. The purpose is to find out the problems existing in the current film and television education in primary and secondary schools, and give improvement measures. A questionnaire was designed in this study and teachers in 89 primary and secondary schools in Liaocheng City, Shandong Province filled in the questionnaires. A total of 355 valid questionnaires were collected. This study analyzed the survey data, and drawn a series of conclusions about the current situation of film and television education in primary and secondary schools on the basis of data analysis. Based on the results of the survey, some suggestions are given to provide reference for the development of film and television education in primary and secondary schools.

摘要：To miniaturize a very low level dc current amplifier and to improve its output response speed, the switched capacitor negative feedback circuit (SCNF), instead of the conventionally used high-ohmage resistor, is presented in this paper. In our system, a switched capacitor filter (SCF) and an offset controller are also used to decrease vibrations and offset voltage at the output of the amplifier using SCNF. The theoretical output voltage of the very low level dc current amplifier using SCNF is obtained. The experimental results show that the unnecessary components of the amplifier’s output are much decreased, and that the response speed of the amplifier with both the SCNF and SCF is faster than that using high-ohmage resistor.

摘要：This paper presents a method for designing a class of countermeasures for DPA attacks based on attenuation of current variations. In this class of countermeasures, designers aim at decreasing the dynamic current variations to reduce the information that can be extracted from the current consumption of secure microsystems. The proposed method is based on a novel formula that calculates the number of current traces required for a successful DPA attack using the characteristics of the microsystem current signal and the external noise of the measurement setup. The different stages of the proposed method are illustrated through designing an example current flattening circuit. Meanwhile validity and applicability of the proposed formula is verified by comparing theoretical results with those obtained experimentally for the example circuit. The proposed formula not only estimates the required level of attenuation for a target level of robustness defined by design requirements, it also predicts the effectiveness of a countermeasure using simulation results therefore dramatically reducing the time to design of secure microsystems.

摘要：An application of the current search (CS), one of the most efficient metaheuristic optimization search techniques, to design the PIDA (proportional-integral-derivative-accelerated) controllers is proposed in this paper. The CS is applied to search for the optimum PIDA controller’s parameters. The obtained controllers are tested against nine benchmark systems collected by ?sstr?m and H?gglund considered as the hard-to-be-controlled plants and an automatic voltage regulator (AVR) system. As results, the optimum PIDA controllers can be successfully obtained by the CS and the responses of controlled systems are very satisfactory.

摘要：In the field of analog VLSI design, current conveyors have reasonably established their identity as an important circuit design element. In the literature published during the past few years, numerous application have been reported which are based on a variety of current conveyors. In this paper, an oscillator circuit has been proposed. This oscillator is designed using a single positive type second generation current controlled current conveyor (CCCII+). A CCCII has parasitic input resistance on it’s current input node. This resistance could be exploited to reduce circuit complexities. Thus in this accord, a novel oscillator circuit is proposed which utilizes the parasitic resistance of the CCCII+ along with a few more passive components.

摘要：A high power buck-boost switch-mode LED driver delivering a constant 350 mA with a power efficient current sensing scheme is presented in this paper. The LED current is extracted by differentiating the output capacitor voltage and maintained by a feedback. The circuit has been fabricated in a standard 0.35 μm AMS CMOS process. Measurement results demonstrated a power-conversion efficiency over 90% with a line regulation of 8%/V for input voltage of 3.3 V and current output between 200 mA and 350 mA.

摘要：Basing on the state variable method, a block diagram of the current-mode biquad active circuit was proposed, whose integrators were realized using three kinds of active elements such as operational amplifier, second generation current conveyors and operational transconduc-tance amplifiers-electric capacity. The characteristics of each circuit were analyzed.

摘要：The synthetic making test has been widely used in evaluating the break ability of high-voltage circuit breaker. However, the test research and application are still inadequate, especially in the condition of rated voltage. According to the realistic conditions of test stations in China, a control device based on pre-arcing current detection and phase control is proposed in this paper. A sample of the control device made up of DSP TMS320LF2407A is fabricated, in which the CPLD MAX7064 is used to transmit signals for EMC design. It can be applied in full voltage synthetic making test at a level of 126kV/63kA. The test results show that, it is accurate to control the making phase of the applied voltage, whether the closing is demanded at voltage peak or zero.