摘要：The hoist bracket links the rescue hoist with the helicopter cabin, and its structure design greatly affects the operation convenience and safety of the hoistman and lifeguard in the rescue process with a *** paper firstly builds the force model of the hoist and bracket, and gives five kinds of typical working conditions as the design ones of the bracket. Then this paper puts forward a design process of the hoist bracket based on the topology optimization and strength analysis with the 3D modeling and finite element analysis. This design process can make the bracket's structure lightweight by achieving the optimal material layout under the conditions of maximizing the static stiffness or minimizing the compliance of the bracket. And this improves the dynamic performance of the helicopter, and reduces the fuel consumption and cost under the strength constraints. Finally,taking the design of the hoist bracket used in a rescue helicopter as an example, this paper illustrates the proposed model and method. The analysis results show that the mass of the hoist bracket decreases by 12.5% while the static stiffness of the hoist bracket is achieved. The optimization design results meet the strength requirements of the hoist.

摘要：Resistive Plate Chamber （RPC） modules will be used as one part of the cosmic muon veto system in the Daya Bay reactor neutrino experiment. A total of 189 RPC modules will cover the three water pools in the experiment. To achieve track reconstruction and high efficiency, each module consists of 4 layers, each of which contains two sizes of bare chambers. The placement of bare chambers is reversed in different layers to reduce the overlapping dead areas. The module efficiency and patch emciency were studied both in simulation and test of the data analysis. 143 modules have been constructed and tested. The preliminary study shows that the module and patch 3 out of 4 layers efficiency reaches about 98%.

摘要：The dewatering of fine, flotation cleaned coals from Huaibei and Xuzhou (bituminous) and Yongcheng (anthracite) were studied. The supernatant and filter cake were examined to determine the rate and extent of flocculation and dewatering. A starch-based filter aid was used to increase flocculation and dewatering rates. The filtration constant, K, and compression index, s, of the Yongcheng slurry were measured under various conditions. A designed experiment was performed to determine optimum conditions for dewatering. The results showed that the filter aid enhanced flocculation and coagulation of the fine cleaned coal slurry, enhanced the structure of the filter cake and promoted dewatering of the cake. Moisture content in the cake was reduced to 17% after vacuum filtration.

摘要：A novel simplified method is presented to design FIR filter with controllable center frequency. The properties of transfer curves for all-phase filters are illustrated under 3 windowing conditions. By combining single-window all-phase filter design steps and double phase-shift combination, a series of design formulas for point-pass filter, notch filter, band-pass filter and band-stop filter are derived, thus the design computation complexity is greatly reduced. Experiments prove that the center frequency of all the filters can be accurately specified at arbitrary position by adjusting frequency parameters m and λ.

摘要：在诸多交互式软件系统中,包括软件开发工具及基于万维网的工具,性能问题是至关重要的.然而在软件开发过程中,性能问题并未得到足够的重视.主要目的是展示一种有效方法,使得经过细致设计后交互式软件有满意的性能.展示如何应用软件性能工程方法于交互式软件工具开发中,特别注重在设计阶段的性能估算及其在决定实现方案时之效果.除了源于软件性能工程的严格的量化估算方法,提出性能亦可半量化或非量化方法进行有效而经济的估算.基于结果的描述,最终建议为源于软件性能工程方法学中苛求采用系统环境参数进行细化定量性能估算未必是惟一手段.演示了在软件工具开发早期阶段中一种用以评估性能的基于分析和实验的有效综合途经.希望能反映出了良好的实验计算机科学之本质.

摘要：Although different from modernity or post- modernity,post- modernism,as the discourse strategy of the intellectuals is inevitably related to power discourse in the respect of self- consciousness and the artistic and cultural self-construction. Due to its historical consciousness,it is inseparable from ideology,and as discourse construction,post-modernism belongs to the field of ideology. Foucault puts forward that discourse analysis should connect to social,political and cultural factors and that discourse derives from the operation of the power mechanism. T he deconstruction of the post- modernist art brings about the inevitable political context of its discourse. Post-modernism deviates from the discourse system of the dom inant power and is marginalized at the same time.

摘要：A design of polarization-maintaining retro-reflectors （PMRRs） for folded-path applications is proposed and analyzed. The prism-based scheme enables the output light, which is parallel to the input, to have an identical state of polarization. The principle of the design is theoretically verified, and the related error is analyzed due to possible manufacturing imperfection. The maximum spatial angle error is ±2.75°. The effect on the extinction ratio and insertion loss is also discussed, which further proves the design＇s feasibility in practical applications.

摘要：This paper is concerned with the reliable H∞ filtering problem against sensor failures for a class of discrete-time systems with sector-bounded nonlinearities. The resulting design is that the filtering error system is asymptotically stable and meets the prescribed H∞ norm constraint in normal case as well as in sensor failure case. Sufficient conditions for the existence of the filter are obtained by using appropriate Lyapunov functional and linear matrix inequality (LMI) ***, in order to reduce the design conservativeness and get better performance, we adopt the slack variable method to realize the decoupling between the Lyapunov matrices and the system dynamic matrices. A numerical example is provided to demonstrate the effectiveness of the proposed designs.

摘要：Lorenz systems family unifying Lorenz system, Chen system and L system is a typical chaotic *** this paper, we consider impulsive control Lorenz chaotic systems family with time-varying impulse intervals. Byestablishing an effective tool of a set of inequalities, we analyze the asymptotic stability of impulsive control Lorenzsystems family and obtain some new less conservative conditions. Based on the stability analysis, we design a novelimpulsive controller with time-varying impulse intervals. Illustrative examples are provided to show the feasibility andeffectiveness of our method. The obtained results not only can be used to design impulsive control for Lorenz systemsfamily, but also can be extended to other chaotic systems.

摘要：The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and *** order to analyze the effects of key parameters of tine furrow openers on soil properties(soil bulk density,soil water-stable aggregates(WSA),and soil disturbance)of the surface soil layer of 0-10 cm and surface straw disturbance,the tine furrow openers with different structural parameters,including cutting edge thickness,cutting edge curve,penetration clearance angle and rake angle,were designed and tested under no-till *** test and single factor test were performed to analyze the effects of different *** showed that the rake angle,cutting edge thickness and cutting edge curve had significant effects on cross-sectional area of furrow(Af)and disturbance of surface straw;the rake angle had a significant effect on soil bulk *** types and operating depth had significant effects on soil disturbance caused by tine furrow *** concave type tine furrow opener produced the lowest soil disturbance and soil bulk density of seed furrow,the highest surface straw disturbance and the greatest content of WSA(>0.5 mm).With increasing rake angles of tine furrow opener,the width of seedbed(Wsb)and the Af decreased first and then increased,respectively,while the width of soil throw(Wst)and the height of ridge(Hr)*** Wsb and Af created by tine furrow opener with 60°rake angle were significantly lower than that with others,*** tine furrow opener with rake angle ranged from 45°to 60°created the lowest soil bulk *** the penetration clearance angle increased,the content of WSA(>0.5 mm)decreased,but the effect of penetration clearance angle on the content of WSA(<0.5 mm)was not *** cutting edge thickness(<2 mm)had no significant effects on soil properties of *** study could provide a reference for optimal design of the tine fu