摘要：Satellite launch vehicle lies at the cross-road of multiple challenging technologies and its design and optimization present a typical example of multidisciplinary design and optimization（MDO） *** complexity of problem demands highly effi-cient and effective algorithm that can optimize the *** heuristic approach（HHA） based on meta-heuristics is applied to the optimization of air launched satellite launch vehicle（ASLV）.A non-learning random function（NLRF） is proposed to con-trol low-level meta-heuristics（LLMHs） that increases certainty of global solution,an essential ingredient required in product conceptual design phase of aerospace *** empirical study is performed to evaluate the performance advan-tages of proposed approach over popular non-gradient based optimization *** of ASLV encompasses aerodynamics,propulsion,structure,stages layout,mass distribution,and trajectory modules connected by multidisciplinary feasible design *** approach formulates explicit system-level goals and then forwards the design optimization process entirely over to *** distinctive approach for launch vehicle system design relieves engineers from tedious,iterative task and en-ables them to improve their component level *** is an impetus on vehicle performance and cost,and so it is considered as the core of vehicle design ***,gross launch mass is to be minimized in HHA.

摘要：Monodisperse aerosols are essential in many applications, such as filter testing, aerosol instrument calibration, and experiments for validating models. This paper describes the design principle, construction, and performance of a monodisperse-aerosol generation system that comprises an atomizer, virtual impactor, microcontroller-based isokinetic probe, wind tunnel, and velocity measurement device. The size distribution of the produced monodisperse aerosols was determined by an optical particle counter. The effects of atomizer characteristics, the rates of minor and major flow, and solution criteria were investigated. It was found that all these parameters affect the generation of monodisperse aerosol. Finally, the expected geometric standard deviation （〈1.25） of monodisperse aerosol particles was obtained with the most suitable atomizer for 10% oleic acid in ethyl alcohol solution with 5%-15% minor flow, where the ratio between the nozzle-to-probe distance and acceleration-nozzle-exit diameter was 0.66. The con- structed monodisperse-aerosol-generation system can be used for instrumental calibration and aerosol research.

摘要：An optimal control method for seismic-excited building structures with multiple time delays is investigated in this paper. The system state equation with multiple time delays is discretized and transformed into a standard discrete form without any explicit time delay by a particular augmenting for state variables. A time-delay controller is then designed based on this standard equation using the discrete optimal control method. Effectiveness of the proposed controller is demonstrated by numerical simulations. Simulation results indicate that a very small time delay may result in the instability of the control system if it is not compensated in the control design. Time delay may be compensated effectively by the proposed controller, in the mean time, an effective control may be obtained. The proposed controller is valid for both small and large time delays.

摘要：In this study, a reactive distillation column in which chemical reaction and separation occur simultaneously is applied for the synthesis of tert-amyl ethyl ether （TAEE） from ethanol （EtOH） and tert-amyl alcohol （TAA）. Pervaporation, an efficient membrane separation technique, is integrated with the reactive distillation for enhancing the efficiency of TAEE production. A user-defined Fortran subroutine of a pervaporation unit is developed, allowing the design and simulation of the hybrid process of reactive distillation and pervaporation in Aspen Plus simulator. The performance of such a hybrid process is analyzed and the results indicate that the integration of the reactive distillation with the pervaporation increases the conversion of TAA and the purity of TAEE product, compared with the conventional reactive distillation.

摘要：Aspect-oriented modeling can uncover potential design faults, yet most existing work fails to achieve both separation and composition in a natural and succinct way. This study presents an aspect-oriented modeling and analysis approach with hierarchical Coloured Petri Nets(HCPN). HCPN has sub-models and well-defined semantics combining a set of submodels. These two characteristics of HCPN are nicely integrated into aspect oriented modeling. Submodels are used to model aspects while the combination mechanism contributes to aspects weaving. Furthermore, the woven aspect oriented HCPN model can be simulated and analyzed by the CPN Tools. A systematic web application case study is conducted. The results show the system original properties are satisfied after weaving aspects and all design flaws are revealed. As such, the approach can support web application design and analysis in an aspect-oriented fashion concisely and effectively.

摘要：This paper deals with a bi-extrapolated subgradient projection algorithm by intro- ducing two extrapolated factors in the iterative step to solve the multiple-sets split feasibility problem. The strategy is intend to improve the convergence. And its convergence is proved un- der some suitable conditions. Numerical results illustrate that the bi-extrapolated subgradient projection algorithm converges more quickly than the existing algorithms.

摘要：As a β stabilizing element in Ti-based alloys,the effect of Mo on phase constitution,microstructure,mechanical and shape memory properties was *** compositions of Ti-xMo-3Sn alloys(where x=2,4,6,at.%) were prepared by arc melting.A binary composition of Ti-6 Mo alloy was also prepared for ***-xMo-3Sn alloys show low hardness and high ductility with 90% reduction in thickness while Ti-6 Mo alloy shows high hardness,brittle behavior,and poor *** emission scanning electron microscopy(FESEM) reveals round morphology of athermal ω(ωath) *** presence of ωath phase is also confirmed by X-ray diffraction(XRD)in both as-cast and solution-treated and quenched *** optical microscopy(OM) and FESEM show that the amount of martensite forming during quenching decreases with an increase in Mo content,which is also due to β→ω *** hardness trends reinforce the presence of ωath *** shape memory effect(SME) of 9% is the highest for Ti-6 Mo-3Sn *** SME is trivial due to ωath phase formation;however,the increase in SME is observed with an increase in Mo content,which is due to the reverse transformation from ωath and the stress-induced martensitic *** addition,a new and very simple method was designed and used for shape memory effect measurement.

摘要：为了去除不定积分环节产生的直流偏置项,提出了一种基于"一次移动平均法"的改进积分算法。利用一个整数周期的积分信号值构成一个集合,计算出集合的算术平均值作为瞬时直流偏置,将原积分信号减去该直流偏置,最终可得到无直流偏置项的积分信号。为实时更新直流偏置,在每个时钟上升沿将一个积分信号的新采样值加入集合尾部,并去除集合首部的数值点,从而确保集合长度维持固定值并能实时反映出最新的直流偏置。以FPGA为信号处理平台,采用Modelsim仿真和实验测试相结合的方法验证了该算法的可行性。该方法已成功用于电磁式微陀螺仪的滑模控制器之中。同已有方法相比,该积分算法复杂度低、实时性好、易于实现。

摘要：Developing novel electrode materials for li-thium-ion batteries （LIBs） with rapid charge/discharge cap- ability and high cycling stability remains a big challenge to date. Herein, we demonstrate the design and synthesis of ul- trathin MoS2 nanosheets in-situ grown on sponge-like carbon nanospheres by a simple diffusion-controiled process. The unique sponge-like carbon nanosphere core can be used as ＂reservoir＂ of electrolyte by adsorbing to shorten the ion- diffusion path, and meanwhile as ＂elastomer＂ to alleviate the structural change of the MoS2 nanosheets during the charge/ discharge processes. Furthermore, the vertical ultrathin MoS2 nanosheets with broadened interlayer space greatly enrich the electrochemical active sites. Consequently, the as-obtained MoS2/C nanospheres exhibit increased specific capacities at various rates with superior cycling stability compared to the MoS2/C floccules. It is reckoned that the present concept can be extended to other electrode materials for achieving high- rate and stable LIBs.

摘要：The catalyst function was achieved in two regions in an oxygen permeation membrane reactor： H2 dissociated and reacted with lattice oxygen or oxygen ions to form H20 near the membrane surface. The H20 formed could react with the residual CH4 away from the membrane surface area.