摘要：The development of low-cost,highly active platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)is crucial for widespread applications of fuel *** effective approach lies in alloying Pt with non-noble transition metals to modulate the physicochemical state of the Pt ***,fundamental challenges remain in understanding the structure-performance relationship due to the complexity of composition,crystal type,and surface structure during the alloying *** this study,we synthesized a series of PtCo bimetallic solid solutions with varying ratios using a liquid-phase synthesis *** exploiting the characteristics of solid solutions,the resulting PtCo bimetallic alloy maintains the face-centered cubic crystal structure of pure platinum,minimizing the complexities introduced during alloying and facilitating mechanism ***,under controlled alloy composition and crystal structure,we investigated the dependence of the electrocatalytic activity for the oxygen reduction reaction on the surface strain of the platinum *** S-PtCo-SNPs cathode designed accordingly endows both proton exchange membrane fuel cell(PEMFC)(2.08 W cm^(−2) at 4 A cm^(−2))and Zn-air battery(ZAB)(143.1 mW cm^(−2) at 214.5 mA cm^(−2))with outstanding performance.

摘要：Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect *** this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser *** results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in *** experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus ***,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.

摘要：Machine learning (ML) has been widely used todesign and develop new materials owing to its low computational cost and powerful predictive capabilities. In recentyears, the shortcomings of ML in materials science have gradually emerged, with a primary concern being the scarcity ofdata. It is challenging to build reliable and accurate ML modelsusing limited data. Moreover, the small sample size problemwill remain long-standing in materials science because of theslow accumulation of material data. Therefore, it is importantto review and categorize strategies for small-sample learningfor the development of ML in materials science. This reviewsystematically sorts the research progress of small-samplelearning strategies in materials science, including ensemblelearning, unsupervised learning, active learning, and transferlearning. The directions for future research are proposed, including few-shot learning, and virtual sample *** importantly, we emphasize the significance of embedding material domain knowledge into ML and elaborate on thebasic idea for implementing this strategy.

摘要：This paper considers the frequency-quadrupling three-cavity gyroklystrons with successive frequency-doubling in each *** cavities of 225 GHz frequency-quadrupling gyroklystron are designed with the scattering matrices method and the possible operating mode are *** the point-gap theory,the starting currents of the possible operating modes and the potential parasitic modes in the output cavity are calculated. The optimal operating mode is proposed under consideration of the mode competition and the power capacity of the cavity.

摘要：This paper proposes a novel robust design method for the sense mode of a MEMS vibratory gyroscope based on fuzzy reliability and Taguchi design. The principles of fuzzy reliability and Taguchi design are both introduced and described in detail. Experimental results demonstrate that the signal to noise ratio of the robust design scheme is better than those of the other experimental *** the full temperature range from -40 to 80°C, the temperature sensitivities of phase margin, gain margin, sensitivity margin,the maximum amplitude of open loop system, bandwidth of closed loop system, and the performance function of the robust design system are all smaller than those of the original design system. Meanwhile, the temperature sensitivity of the bandwidth of the robust design system is improved to 126 from 1075 ppm/°C. Moreover, the bias drift over the full temperature range of the robust design system is improved to 61°/h from 179°/h.

摘要：An aeroelastic two-level optimization methodology for preliminary design of wing struc- tures is presented, in which the parameters for structural layout and sizes are taken as design vari- ables in the first-level optimization, and robust constraints in conjunction with conventional aeroelastic constraints are considered in the second-level optimization. A low-order panel method is used for aerodynamic analysis in the first-level optimization, and a high-order panel method is employed in the second-level optimization. It is concluded that the design of the abovementioned structural parameters of a wing can be improved using the present method with high efficiency. An improvement is seen in aeroelastic performance of the wing obtained with the present method when compared to the initial wing. Since these optimized structures are obtained after consideration of aerodynamic and structural uncertainties, they are well suited to encounter these uncertainties when they occur in reality.

摘要：Molybdenum-based catalysts have demonstrated significant potential in the electrocatalytic hydrogen evolution reaction(HER).However,the limited exposure of active sites and strong hydrogen adsorption result in suboptimal ***,a Mo_(2)N±MoSe_(2) heterojunction is prepared on carbon cloth(MNS/CC)to enhance the *** strong electronic interaction between Mo_(2)N and MoSe_(2),combined with the lower work function of Mo_(2)N,creates an intrinsic electric field at the heterojunction interface,which markedly improves charge transfer ***,the optimized electronic structure of Mo sites further enhances charge transfer and intrinsically catalytic activity in *** a result,MNS/CC requires overpotentials of mere 65 and 210 mV to achieve current densities of 20 mA cm^(−2) and 1 A cm^(−2),respectively,with a Tafel slope of only 96 mV dec−***,MNS/CC maintains stable operation at 1 A cm^(−2) for 240 h without significant *** results offer insights into the design of non-precious metal-based electrocatalysts for industrial hydrogen production.

摘要：This paper reports the simulation of an electron gun. The effects on the beam quality of some parameters on the beam quality were studied and optimal choices were identified. It gives numerical beam qualities for a common electrostatic triode gun, and the dependencies on design parameters such as electrode geometries and bias voltages to these electrodes are shown. An electron beam of diameter 5 mm with energy of 5 keV was assumed for the simulation process. Some design parameters were identified as variable parameters in the presence of space charge. These parameters are the inclination angle of emission electrode, the applied voltage to the focusing electrode, the gap width between the emission electrode and the focusing electrode and the diameter of the focusing electrode. The triode extraction system is designed and optimized by using CST software （for Particle Beam Simulations）. The physical design of the extraction system is given in this paper. From the simulation results, it is concluded that the inclination angle of the emission electrode is optimized at 22.5°, the applied voltage to the focusing electrode was optimized and found to be Vfoc =-600 V, the optimal separation distance （gap between emission electrode and focusing electrode） is 4 mm, and the optimal diameter of the emission electrode is 14 mm. Initial results for these efforts aimed at emittance improvement are also given.

摘要：This paper focuses upon the novel optical conical scanning imaging working mode design for small *** kind of satellite employs only one inclined optical camera achieving wide-swath imaging via a rotational motion about the nadir axis either by the camera or by the *** working modes are designed,i.e.,high-speed rotational mode,low-speed rotational mode,and variable-speed rotational *** the high-speed and low-speed working modes,the camera rotates at a constant speed and the corresponding angular velocity is derived under the consideration of guaranteed coverage and minimized *** improve the system performance,an enhanced working mode taking advantages of both the high-speed rotational mode and lowspeed rotational mode is *** in this variable-speed rotational mode,the camera rotates slowly to get high-quality pictures when it works,while it rotates rapidly to reduce the energy consumption and save the storage during which period the camera is turned off to minimize the *** these working modes are illustrated in detail,and numerical simulation tests are conducted to validate their effectiveness.

摘要：Recently, it has been demonstrated that memristors can be utilized as logic operations and memory elements. In this paper, we present a novel circuit design for complementary resistive switch（CRS）-based stateful logic operations. The proposed circuit can automatically write the destructive CRS cells back to the original states. In addition, the circuit can be used in massive passive crossbar arrays which can reduce sneak path current greatly. Moreover, the steps for CRS logic operations using our proposed circuit are reduced compared with previous circuit designs. We validate the effectiveness of our scheme through Hspice simulations on the logic circuits.