摘要：Wireless millirobots engineered to infiltrate intricate vascular networks within living organisms,particularly within constricted and confined spaces,hold immense promise for the future of medical ***,with their multifaceted and intricate designs,some robots often grapple with motion and functionality issues when confronted with tight spaces characterized by small cross-sectional *** this study,drawing inspiration from the high aspect ratio and undulating swimming patterns of snakes,a millimeter-scale,snake-like robot was designed and fabricated via a combination of extrusion-based four-dimensional(4D)printing and magnetic-responsive intelligent functional inks.A sophisticated motion control strategy was also developed,which enables the robots to perform various dynamic movements,such as undulating swimming,precise turns,graceful circular motions,and coordinated cluster movements,under diverse magnetic field *** a potential application,the snake robot can navigate and release drugs in a model coronary intervention vessel with tortuous channels and fluid *** novel design and promising applications of this snake robot are invaluable tools in future medical surgeries and interventions.

摘要：To obtain the peak response at 532nm, narrow-band response GaA1As photocathodes with two GaAIAs ac- tive layers of different aluminum compositions are designed in consideration of the maximum absorptivity and quantum efficiency. The transmission-mode and the corresponding reflective-mode photocathodes are grown by metalorganic chemical vapor deposition. The results indicate that the peak response and the cut-off wavelength occur at 532nm for the two kinds of photocathodes respectively. The response of the reflection-mode photoeath- ode is an order of magnitude higher than that of the transmission-mode photocathode, whereas the better growth quality and the thicker second GaAIAs active layer can improve the transmission-mode response.

摘要：A new type of V-shaped photonic crystal fiber with elliptical air-holes is proposed to realize simultaneous high bire- fringence and nonlinearity at a wavelength of 1.55 μm. The full vector finite element method was adopted to investigate its characteristics, including birefringence, nonlinearity, and dispersion. The PCF exhibited a very high birefringence of 2.89x10-2 and very high nonlinear coefficient of 102.69 W-1 .km 1. In particular, there were two zero-dispersion wave- lengths （ZDWs） in the visible （X： 640-720 nm and Y： 730-760 nm） and near-infrared regions （X： 1050-1606 nm and Y： 850-1500 nm）. The combination of high birefringence and nonlinearity allowed the PCF to maintain the polarization state and generate a broadband super continuum, with potential applications in nonlinear optics.

摘要：We design a novel X-ray image detector by lens coupling a Gd2O2S：Tb intensifying screen with a high performance low-light-level （L^3, which often means luminescence less than 10^-3 Lux） image intensifier. Different coupling effects on imaging performance between zoom lens and fix-focus lens are analyzed theoretically. In experiment, for designing a detector of 15-inch visual field, the system coupled by zoom lens is of 12.25-lp/cm resolution, while the one with fix-focus lens is 10 lp/cm. The superiority of zoom lens is validated. It is concluded that zoom lens preserves the image information better than fix-focus lens and improves the imaging system＇s performance in this design, which is referential to the design of other optical imaging systems.

摘要：Synchronization control is a kernel technique of the laser range-gated(LRG) imaging system which controls the synchronization of the pulsed laser and the ICCD camera *** can achieve range gating effectively and improve the resolution of image *** control circuits which are composed of discrete components have a poor performance of anti-interference,and the transmitting signal has a bad delay which affects the conventional circuit's precision and stabilization *** solve these problems,a range-gated synchronization control circuit is *** circuit,which takes the advantages of FPGA's high compact and flexibility,uses the phase-locking-loop(PLL) to multiply the global clock *** design improves the precision and stabilization greatly,makes the precision up to a nanosecond level and provides a real-time selection of the values of pulse width and *** results indicate that this circuit has a high precise and stable range-gated pulse.

摘要：Fast charge transfer and anti-photocorrosion are two crucial factors for developing efficient, durable photoanodes for photoelectrochemical （PEC） cells. Reduced graphene oxide （RGO） is a promising photoanode element that can provide both of these. In this study, we elucidated the roles of RGO in the charge transfer and surface passivation of photoanodes by the precise design of a RGO-wrapped photoanode and examination of its PEC properties. Arrays of hetero-nanorods （HNRs） with three different designs were fabricated as photoanodes using RGO, CdSe nanoparticles （NPs）, and ZnO nanorods （NRs） as building blocks. CdSe@ZnO HNRs were prepared by decorating ZnO NRs with CdSe NPs. Finite-element analysis and experimental studies demonstrated that in the CdSe@ZnO HNRs, if only the ZnO NRs were wrapped by RGO, the conductivity between CdSe and ZnO was enhanced by RGO to shuttle charges. If RGO only surrounded the outside of the CdSe@ZnO HNRs, the corrosion was slowed owing to the passivation effect of RGO, which increased the electron lifetime of the photoanode. If both CdSe and ZnO were fully wrapped by RGO, the advantages of the two aforementioned cases were both obtained. RGO-wrapped CdSe@ZnO HNRs with position-controlled designs are promising photoanode materials with a high PEC efficiency, and the developed synthesis process can be applied to explore the design and fabrication of next-generation photoanodes using RGO as a buildin~ block.

摘要：Electrochemical CO_(2) reduction reaction (CO_(2) RR) offers a practical solution to current global greenhouse effect by converting excessive CO_(2) into value-added chemicals or fuels. Noble metal-based nanomaterials have been considered as efficient catalysts for the CO_(2) RR owing to their high catalytic activity, long-term stability and superior selectivity to targeted products. On the other hand, they are usually loaded on different support materials in order to minimize their usage and maximize the utilization because of high price and limited reserve. The strong metal-support interaction (MSI) between the metal and substrate plays an important role in affecting the CO_(2) RR performance. In this review, we mainly focus on different types of support materials (e.g., oxides, carbons, ligands, alloys and metal carbides) interacting with noble metal as electrocatalysts for CO_(2) RR. Moreover, the positive effects about MSI for boosting the CO_(2) RR performance via regulating the adsorption strength, electronic structure, coordination environment and binding energy are presented. Lastly, emerging challenges and future opportunities on noble metal electrocatalysts with strong MSI are discussed.

摘要：The geometric,electronic and optical properties of the graphene-like gallium nitride(GaN) monolayer paired with WS_2 or WSe_2 were studied systematically using the first-principles *** interacts with WS2 or WSe_2 via van der Waals interaction and all the most stable configurations of these two nanocomposites exhibit direct band gap ***,the type-Ⅱ heterojunctions are formed because the conduction band minimums and valence band maximums are respectively contributed by WS_2(or WSe_2) and *** imaginary parts of the dielectric function and the absorption spectra of the heterostructures were also calculated and the relatively improved optical properties were observed because of the new interband *** addition,the band offsets as well as the intrinsic electric fields resulting from the interlayer charge transfer indicate that the electron-hole pairs recombination can be effectively inhibited,which is conducive for the photocatalysis ***,the band gaps of the heterostructures can be modulated by applying biaxial strains and even shift away the conduction band edge potential from the H^+/H_2potential in a certain range,which further enhances the photocatalyst *** results indicate that GaN/WS2 or GaN/WSe_2 nanocomposites are good candidate materials for photocatalyst or photoelectronic applications.

摘要：具有强光学非线性和高稳定性的非线性光学(NLO)有机材料因其潜在的广泛应用而备受关注.本研究中,我们设计并系统地研究了具有超强二阶非线性光学响应的一种新型NLO查尔酮衍生物—1-(4-甲氧基苯基)-3-(4-乙氧基苯基)-2-丙烯基-1-酮(DMPO).合成得到的这种新设计的DMPO仅在5天内即可快速生长出尺寸为10×5×4 mm^(3)的DMPO单晶.这些DMPO晶体由中性有机分子组成,它们在较宽的波段600–1800 nm范围具有高透明性,还拥有适度的光学带隙(2.51 eV),并展现出卓越的抗潮解性能.重要的是,DMPO实测的二次谐波产生(SHG)响应高达基准材料4-(4-二甲氨基苯乙烯基)甲基吡啶对甲苯磺酸盐(DAST)的1.86倍,证实了DMPO具有优良的宏观二阶光学非线性性质.因此,DMPO是集多种优点于一身的一种有机NLO新材料,可广泛应用于NLO领域.

摘要：有机集成化光电子器件兼具了小型化和多功能性的优势,如集成了有机发光和紫外探测的有机发光紫外探测器件(OLED-UVOPDs).这种器件中的有机光电材料的设计仍然面临重大的挑战.在本文中,以蒽为π桥,腈基苯为受体,三苯胺(TPA)和二甲基三苯胺(2mTPA)分别为给体,设计并合成了两种可用于OLED-UVOPD器件的蓝色发光分子,TPA-AN和2mTPA-AN.它们的发光峰分别位于474和488 nm处,荧光量子产率为51.1%和46.6%.通过单载流子器件计算得到其电子迁移率分别为3.96×10^(-5)和6.63×10^(-7)cm^(2)V^(-1)s^(-1).基于TPA-AN的OLED器件表现出强的蓝光发射,最大亮度为43,110 cd m^(-2),最大外量子效率(EQE)为8.1%.它们在OLED-UVOPD集成器件中表现出优异的性能,紫外探测率分别为7.18×10^(11)和2.85×10^(12)Jones,最大EQE分别为8.7%和5.9%.