摘要：设计钛基金属有机骨架(MOF)实现高效光催化CO_(2)还原具有重要意义但仍极具挑战.本文发展了一种新的一步原位水蚀刻方法制备超细Pd纳米颗粒/多级孔Ti-MOFs高效光催化剂,其中水刻蚀在形成多级孔结构的同时也为Pd的锚定提供了丰富位点,进而在光还原的作用下一步实现Pd纳米颗粒在MOFs表面和内部的负载.得益于多级孔结构和超细Pd颗粒负载,Pd/hMUV-10在350℃光照下的CO产率高达65.9 mmol g^(-1)h^(-1),比目前最先进的MOF基催化剂高出约两个数量级,并超过大多数已报道的无机半导体基催化剂.在200℃相对温和的条件下,CO的产率也达到3.36 mmol g^(-1)h^(-1).在350℃的连续循环测试中,催化剂活性几乎没有衰减.理论计算表明,Pd负载可增强对CO_(2)的吸附和降低CO_(2)还原能垒,从而实现高效光热CO_(2)还原.本文所报道的Pd/hMUV-10催化剂有望在工业CO_(2)捕获和转化中得到应用.

摘要：Space nuclear power system is the key technology for deep space exploration missions in the future, especially for space base building-up. This paper evaluates several typical latest space nuclear reactor system （SNRS） designs, and finds that most of their weights are heavier than necessary. From the point of weight-control, the SA4 design is the best but its design is more complex than others. A newly designed SNRS, based on the SAFE400 model, uses annular fuel and has better performance, with a fuel mass lower than that of the SAFE400 prototype by 18.75%. Meanwhile, different from former opinions, the delay neutron fractions of SNRS are not constant and change with the different SNRS designs. Therefore, designs of SNRS not to count the delayed neutron fracture or directly to consider it as 0.00677 are not appropriate.

摘要：The all traditional electrical resistance tomography (ERT) sensors have a static structure, which cannot satisfy the intelligent requirements for adaptive optimization to ERT sensors that is subject to flow pattern changes during the real-time detection of two-phase flow. In view of this problem, an adaptive ERT sensor with a dynamic structure is proposed. The electrodes of the ERT sensor are arranged in an array structure, the flow pattern recognition technique is introduced into the ERT sensor design and accordingly an ERT flow pattern recognition method based on signal sparsity is proposed. This method uses the sparse representation of the signal to express the sampling voltage of the ERT system as a sparse combination and find its sparse solution to achieve the classification of different flow patterns. With the introduction of flow identification information, the sensor has an intelligent function of adaptively and dynamically adapting the sensor structure according to the real-time flow pattern change. The experimental results show that the sensor can automatically identify four typical flow patterns: core flow, bubble flow, laminar flow and circulation flow with recognition rates of 91%, 93%, 90% and 88% respectively. For different flow patterns, the dynamically optimized sensor can significantly improve the quality of ERT image reconstruction.

摘要：Owing to the fact that the LED drive circuit must have constant output current control,we propose a controlled current driver with a high precision for the white light *** discrete constant current settings are available and may be selected at the supply voltage from 2.9 V to 4.4 V,which is up to 1 *** autozero transconductance amplifier is proposed,which effectively improves the precision,reduces the offset voltage and the *** variation in the ratio of the external resistor current to the LED load current is less than 2.3%,when the LED load current changes from 200 mA to 800 mA.

摘要：在红外波段模拟章鱼皮肤变色功能的柔性材料在智能热管理、柔性显示和自适应伪装等领域具有广泛的应用前景.本文利用液态金属颗粒和柔性弹性体模拟头足纲变色动物皮肤中的色素细胞和真皮基质,开发了一种通过机械变形调控红外反射/辐射性能的“全柔性红外变色皮肤”.在等轴拉伸作用下,液态金属颗粒会伴随弹性体基体发生延展/收缩变形,从而改变其外形、尺寸和表面形貌,实现对材料红外反射率和发射率的动态调控,以达到动态伪装效果.实验证明,集成了液态金属颗粒/弹性体复合材料的柔性多步态机器人能够在运动过程中迅速改变体色,并且在高次数循环中展现出优异的机械稳定性.本研究为未来设计新型红外发射率动态可调材料与器件提供了材料和物理基础.

摘要：A novel dual-emitter vacuum Compton detector （D-VCD） with higher gamma ray detecting efficiency is proposed. The emitters are made of Ta A1 clad metal. The gamma ray sensitivity is studied by Monte Carlo simulation using the MCNP code. A comparison between calculations and results measured by using the 1.25 MeV gamma ray of Co-60 is also performed. Experimental sensitivities for two sample D-VCDs with the same materials and structures are 1.92×10^-20 and 2.02×10^-20·cm^2/MeV separately, which are consistent with the simulation result of 1.98×10^-20·cm^2/MeV and are 4 times higher than that of VCD with a single Fe emitter. According to the simulation results, in a gamma energy range from 0.5 to 3 MeV, the maximum sensitivity variance for the D-VCD is less than 15%, and less than 5% in a range from 1 to 2 MeV in particular. The novel D-VCD is applicable to the detection of intense pulse gamma rays.

摘要：A large dual-polarization microstrip reflectarray with China-coverage patterns in two operating bands is *** sufficiently compensate for the spatial phase delay differences in two operating bands separately,a three-layer rectangular patch element is addressed,which is suitable for the large dual-polarization *** to the complexly shaped areas and high gain requirements,there are more than 25000 elements in the reflectarray,making it difficult to design,due to more than 150000 optimization ***,the discrete fast Fourier transform(DFFT)and the inverse DFFT are used to establish a one-to-one relationship between the aperture distribution and the far field,which lays a foundation for optimizing the shaped-beam *** intersection approach,based on the alternating projection,is used to obtain the desired reflection phases of all the elements at some sample frequencies,and a new method for producing a suitable initial solution is proposed to avoid undesired local *** validate the design method,a dual-polarization shaped-beam reflectarray with 7569 elements is fabricated and *** measurement results are in reasonable agreement with the simulation ***,for the large broadband reflectarray with the minimum differential spatial phase delays in the operating band,an approach for determining the optimal position of the feed is *** simultaneously find optimal dimensions of each element in two orthogonal directions,we establish a new optimization model,which is solved by the regular polyhedron ***,a dual-band dual-polarization microstrip reflectarray with 25305 elements is designed to cover the continent of *** results show that patterns of the reflectarray meet the China-coverage requirements in two operating bands,and that the proposed optimization method for designing large reflectarrays with complexly shaped patterns is reliable and efficient.

摘要：Ionic electroactive polymers （IEAPs） are a category of intelligent soft materials exhibiting large displacement under electric excitation, based on inner ion or solvent transport. Due to their unique advantages such as flexibility, low driving voltage, large bending displacement and aquatic-environment adaptability, IEAPs have been documented as very promising actuators for the applications in bionic robots. This review presents an analysis to the current research status of IEAPs exploited in bionic robots. According to the specific bionic parts, those robots are divided into four classes： imitation of fins, limbs, joints and trunks. Their dimension, weight, voltage amplitude, frequency and maximum speed were summarized to show the optimum design range. The results show that the approach velocity of the current robots were higher （〉 35 mm· s-1） when the robot weighted 60 g - 180 g and the body was 90 mm - 130 mm long. For voltage from 1 V - 3 V and frequencies from 0.7 Hz - 1.2 Hz, the speed was relatively higher （〉 35 mm·s-1）.To some extent, the maximum speed decreases when the area of the IEAP material used in bionic robot increases. For underwater circumstances, IEAP materials are most suitable for designing bionic robots swimming with Body and/or Caudal Fin （BCF）. This review provides important guidance for the design of lEAP bionic robots.

摘要：The electrochemical dissolution and passivation of laser additive manufactured Ti6Al4V were investigated through Tafel polarization,potentiostatic polarization and AC impedance *** results show that the solution treatment−aging(STA)process aggravates the element micro-segregation compared to the annealing process,leading to varied Al and V contents of the phases from different *** is proven that either Al-rich or V-rich condition can highly affect the electrochemical dissolution behaviors due to thermodynamical instability caused by element *** dissolution rate in the metastable passivation process is controlled by the stability of the produced film that is affected by phases distribution,especially the difficult-to-dissolve *** then,the dissolution rate of the phases in the transpassivation region is consistent with the rank in the activation process because the dense film is not capable of being *** to the annealed sample,the higher dissolution rate of the STA sample is beneficial to the electrochemical machining(ECM)of Ti6Al4V.

摘要：In order to meet the requirement of network synthesis optimization design for a micro component, a three-level information frame and functional module based on web was proposed. Firstly, the finite element method （FEM） was used to analyze the dynamic property of coupled-energy-domain of virtual prototype instances and to obtain some optimal information data. Secondly, the rough set theory （RST） and the genetic algorithm （GA） were used to work out the reduction of attributes and the acquisition of principle of optimality and to confirm key variable and restriction condition in the synthesis optimization design. Finally, the regression analysis （RA） and GA were used to establish the synthesis optimization design model and carry on the optimization design. A corresponding prototype system was also developed and the synthesis optimization design of a thermal actuated micro-pump was carded out as a demonstration in this paper.