摘要：The 60-GHz traveling-wave tube （TWT） prevails nowadays as the amplifier for the satellite communication and electronic countermeasures. The folded waveguide （FW） is a promising all-metal slow-wave structure （SWS） for the 60-GHz TWT with advantages of robust performance, fine heat dissipation, considerable power and bandwidth. A novel FW periodically loaded with rectangular grooves is analyzed for the purpose of gaining higher power and gain. The rf characteristics are investigated by numerical simulation, and the nonlinear large- signal performance of such a TWT is analyzed by a 3I） particle-in-cell code MAGIC. Compared with normal circuits, relatively higher continuous-wave power （40-56 W） and similar bandwidth （5 GHz） are predicted by simulation. Meanwhile, the designed operation voltage is 10.5 kV, which keeps the low-voltage advantage of the popular helix TWT competitor. The novel FW will favor the design of a broadband and high-power 60-GHz TWT

摘要：We present a design of an acoustic levitator consisting of three pairs of opposite transducer *** orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in *** changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully ***,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical *** design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.

摘要：An optimized transducer prototype with a sandwich structure vibrated longitudinally is proposed for a transmitter in acoustic logging, especially in acoustic logging while drilling, 5y taking account of drilling environments with high temperature and pressure, as well as strong collar drilling vibration during the drilling process. Aimed to improve the transmitting performance, numerical and experimental studies for the transducer optimization are conducted. The impact of location and length of the piezoelectric stack on resonance characteristics arid effective electromeehanical coupling coefficient is calculated and analyzed. Admittance and transmitting performance of the proposed transducer are measured in laboratory experiments, and the results are compared with simulated ones. It is shown that the newly proposed transducer has higher transmitting performance with lower resonance frequencies. This work provides theoretical and experimental bases for transducer designing and acoustic wave measurements in acoustic logging, especially in acoustic logging while drilling.

摘要：A method of designing an E-plane power combiner composed of two quarter-arc bent rectangular waveguides is proposed for sub-THz and THz waves. The quarter-arc bent-waveguide power combiner has a simple geometry which is easy to design and fabricate. By HFSS codes, the physical mechanism and performance of the power combiner are analyzed, and the relationship between the output characteristics and the structure/operating parameters is given. Simulation results show that our power combiner is suitable for the combining of two equalpower and reversed-phase signals, the bandwidth of the combiner is wide and can be adjusted by the radius of the quarter-arc, and the isolation performance of the combiner can be improved by adding thin film resistive septa at the junction of two quarter-arc bent waveguides. Meanwhile, an approximate method based on the analytic geometrical analysis is given to design this power combiner for different frequency bands.

摘要：Ultrashort pulses complicate the frequency conversion in a nonlinear crystal, where group velocity mismatch becomes the main obstacle due to dispersion. We present a design for group velocity compensated second harmonic generation in a modulated nonlinear structure, embedded in a liquid crystal box. In this structure, nonlinear crystals act as sources of signal and liquid crystals compensate for group velocity mismatch originating from nonlinear crystals. There are the advantages of the flexible, controllable birefringence of liquid crystals. Meanwhile, a method calculating the parameters of this type of structure is presented. To make it clear, an example is provided. Furthermore, the structure can also be shaped as a waveguide to support integration into other optical devices, applicable to all-optical processing systems.

摘要：Traditional research in automated negotiation is focused on negotiation protocol and *** paper studies automated negotiation from a new point of view, proposes a novel concept, namely negotiating agent, and discusses its significance in construction of automated negotiation system, with an abstract model formally described and the architecture designed, which supports both goal-directed reasoning and reactive response. A communication model was proposed to construct interaction mechanism used by negotiating agents, in which the negotiation language used by agents is *** communication model and the language are defined in a way general enough to support a wide variety of market mechanisms, thus being particularly suitable for flexible applications such as electronic business. The design and expression of the negotiation ontology is also discussed. On the base of the theoretical model of negotiating agent, negotiating agent architecture and negotiating agent communication model (NACM) are explicit and formal specifications for the agents negotiating in an E-business environment; especially, NACM defines the negotiation language template shared among all agents formally and explicitly. The novelty of the communication model is twofold.

摘要：基于迈克尔·波特的价值链理论模型构建中国城市创意指数,包括7个1级指标和18个2级指标.采用变异系数加权法和TOPSIS(technique for order preference by similarity to ideal solution)分析法对中国20个城市的数据进行实证研究,分析影响城市创意水平发展的驱动因素.结果表明,评价指标体系中,经济资本、人力资本、文化资本、技术资本、产业资本、环境资本和制度资本7个影响因素与创意城市的发展呈正相关,其中文化资本和产业资本是最重要的影响因素.根据各指标影响程度的差异化,指出创意城市发展所面临的挑战,提出加强文化建设、发展创意产业、重视创意人才的培养、营造创意氛围和改善制度环境等建议,以提升城市创意竞争力.

摘要：本文就目前高职高专艺术设计专业课程体系教材中所面临的经典且实用理论较为匮乏、课程内容凝练不足、学科整合力度不够、实训环节较为薄弱等现状,提出以艺术设计专业教材的建设为例,在教材建设上要适度增加精辟理论指导,突出高职高专艺术类教材特质的实用性、操作性、先进性、整体性及创造性,并就建设中出现的相关注意问题提出了应对策略。

摘要：This paper develops fuzzy H∞ filter for state estimation approach for nonlinear discretetime systems with multiple time delays and unknown bounded disturbances. We design a stable fuzzy H∞ filter based on the Takagi-Sugeno (T-S) fuzzy model, which assures asymptotic stability and a prescribed H∞ index for the filtering error system. Sufficient condition for the existence of such a filter is established by solving the linear matrix inequality (LMI) problem. The LMI problem can be efficiently solved with global convergence using the interior point algorithm. Simulation exanples are provided to illustrate the design procedure of the proposed method.

摘要：对大规模交直流网络下的高压直流控制保护系统进行参数优化设计,是保证灵活交流输电系统暂态性和稳定性良好的重要手段。目前由于实时仿真技术的网络节点受限、费用高等缺点,使其不适合此规模网络的试验和设计任务。文中基于ABB公司高压直流控制保护系统硬件结构特点和MACH2(modular advanced control for HVDC and SVC)系统运作机理,提出了等价实时离线仿真的实现原理和方法,使离线仿真达到实时仿真的效果;通过与实际工控机运行结果进行比对,验证了其有效性;同时对工程用高压直流控制中的电流控制功能进行了等价实时仿真。仿真结果分析表明,基于所提出的等价实时仿真原理和方法,利用商业通用的离线仿真软件,可高效地进行高压直流控制保护系统优化设计。