摘要：Vectored non-covalent interactions—mainly hydrogen bonding and aromatic interactions—extensively contribute to(bio)-organic self-assembling processes and significantly impact the physicochemical properties of the associated ***,vectored non-covalent interaction-driven assembly occursmainly along one-dimensional(1D)or three-dimensional(3D)directions,and a two-dimensional(2D)orientation,especially that of multilayered,graphene-like assembly,has been reported *** this present research,by introducing amino,hydroxyl,and phenyl moieties to the triazine skeleton,supramolecular layered assembly is achieved by vectored non-covalent *** planar hydrogen bonding network results in high stability,with a thermal sustainability of up to about 330°C and a Young’s modulus of up to about 40 *** introducing wrinkles by biased hydrogen bonding or aromatic interactions to disturb the planar organization,the stability ***,the intertwined aromatic interactions prompt a red edge excitation shift effect inside the assemblies,inducing broad-spectrum fluorescence covering nearly the entire visible light region(400–650 nm).We show that bionic,superhydrophobic,pillar-like arrays with contact angles of up to about 170°can be engineered by aromatic interactions using a physical vapor deposition approach,which cannot be realized through hydrogen *** findings show the feasibility of 2D assembly with engineerable properties by modulating vectored non-covalent interactions.

摘要：笔者从钢琴艺术的社会大众化发展现状出发,设计、发放了调查问卷,通过回收后对结果的统计及逐项分析,发现城市学琴儿童的启蒙时间早,持续状况以及各个年龄段人群对钢琴益处的认知度均呈现出逐步增长的趋势。本文分为三个部分:第一部分为城市钢琴艺术大众化发展的现状;第二部分论述城市钢琴艺术大众化的推进误区;第三部分针对当前钢琴艺术大众化发展的误区,探析解决这些问题的策略。

摘要：Aiming at determining the thermal contact resistance of ball screws,a new analytical method combining the minimum excess principle with the MB fractal theory is proposed to estimate thermal contact resistance of ball screws considering microscopic fractal characteristics of contact *** minimum excess principle is employed for normal stress ***,the MB fractal theory is adopted for thermal contact *** effectiveness of the proposed method is validated by self-designed *** comparison between theoretical and experimental results demonstrates that thermal contact resistance of ball screws can be obtained by the proposed *** this basis,effects of fractal parameters on thermal contact resistance of ball screws are ***,effects of the axial load on thermal contact resistance of ball screws are also *** conclusion can be drawn that the thermal contact resistance decreases along with the fractal dimension D increase and it increases along with the scale parameter G increase,and thermal contact resistance of ball screws is retained almost constant along with axial load increase before the preload of the right nut turns into zero in *** application of the proposed method is also conducted and validated by the temperature measurement on a self-designed test bed.

摘要：To ameliorate the disadvantages of imaging system coupled with imaging fiber bundle, a method by adding square aperture microlens arrays at both entrance and exit ends of the imaging fiber bundle is proposed to increase the system's coupling efficiency. The expressions for solving the parameters of both ends' microlens units are deducted particularly. The microlens arrays used for an infrared imaging fiber bundle with the single fiber diameter of 100 μm and core diameter of 70 μm are designed by this method. The simulation results show that compared with the system without microlens arrays, the fill factor of the imaging fiber bundle coupled microlens arrays system is increased from 44.4% to more than 90%, and the coupling efficiency is doubled too. So the design method is correct, and the introduction of microlens arrays into imaging fiber bundle coupled system is feasible and superior.

摘要：在结构振动控制中,为了最大限度发挥吸振器的耗能减振作用,需要寻找吸振器的最优参数,即最优频率比、最优阻尼比和最优质量比,使得结构在不同的频率激励下获得最好的减振效果。本文将基于进化算法的多目标优化技术与多属性决策方法联合运用,针对主系统存在阻尼的减振系统,研究了动力吸振器的优化和决策问题。对于多目标优化问题,采用改进的非支配解排序的多目标进化算法(NSGA Ⅱ),求出Pareto最优解,由这些Pareto最优解构成决策矩阵,使用客观赋权的信息熵方法对最优解的属性进行权值计算,然后用逼近理想解的排序方法(TOPSIS)进行多属性决策(MADM)研究,对Pareto最优解给出排序。文中给出了4个设计参数、3个目标函数的动力吸振器优化设计算例。

摘要：We demonstrate a simple and controllable way to synthesize large-area, few-layer graphene on iron substrates by an optimized chemical vapor deposition （CVD） method using a mixture of methane and hydrogen. Based on an analysis of the Fe-C phase diagram, a suitable procedure for the successful synthesis of graphene on Fe surfaces was designed. An appropriate temperature and cooling process were found to be very important in the synthesis of highly crystalline few-layer graphene. Graphene-based field-effect transistor （FET） devices were fabricated using the resulting few-layer graphene, and showed good quality with extracted mobilities of 300-1150 cm2/（V.s）.

摘要：基于分枝定界方法,研究了环肋圆柱壳静水压力作用下,考虑强度和稳定性约束时重量最轻的混合变量优化设计问题,讨论了强度约束和稳定性约束以及材料、几何参数对优化结果的影响。该方法能够有效求解环肋圆柱壳的混合优化问题,计算量小,精度高;环肋圆柱壳经优化后,壳板的重量比例大约是70%,肋骨重量占30%,并且随壳体的长径比(L/R)变化不大。环肋圆柱壳的优化中,肋骨的应力约束是主要约束,肋骨应力已经非常接近许用应力标准,其他应力、局部和总体失稳压力还有一定的储备。

摘要：动力吸振器被广泛用于船舶、飞机和汽车等工业领域。在结构振动控制中,为了最大限度地发挥吸振器的耗能减振作用,需要寻找吸振器的最优参数,即最优频率比、最优阻尼比和最优质量比,使得结构在不同的频率激励下获得最好的减振效果。文章将基于进化算法的多目标优化技术与多属性决策方法联合运用,针对主系统存在阻尼的减振系统,研究了动力吸振器的优化和决策问题。对于多目标优化问题,采用改进的非支配解排序的多目标进化算法(NSGAII),求出Pareto最优解,由这些Pareto最优解构成决策矩阵,使用客观赋权的信息熵方法对最优解的属性进行权值计算,然后用逼近理想解的排序方法(TOPSIS)进行多属性决策(MADM)研究,对Pareto最优解给出排序。文中给出了4个设计参数、3个目标函数的动力吸振器优化设计算例。

摘要：To correctly capture spatial targets from cluttered and motive celestial background,a new Multi-Target Capture algorithm was proposed,which is a comparative difference algorithm based on the combination of centroid extraction and despun registration of efficient ***,this algorithm was applied in an image processing system based on the DSP featuring high speed and high *** procedures of image processing are as follows:first,label efficient points in the frame and extract their centroids;second,make appropriate despun registration,according to the reference rotation angles provided by Space Robot position system;third,translate and register centroid coordinates of efficient points in reference frames and get the registration points according to the principle that there are the most same centroid coordinates of efficient points when completely registered;finally,eliminate the same background points by using comparative difference *** result shows that this image processing system can meet the needs of the whole system.

摘要：激波管作为动态压力校准装置,其产生的阶跃压力幅值大小,以及平台时间是对阶跃压力进行测量校准的重要指标。基于理想情况下,选择管腔内气体介质为空气,通过理论分析得到了使得阶跃平台时间最长的高低压腔长度比优化设计方案。在考虑由实际激波管管腔内的黏性所导致的激波衰减情况时,通过仿真方式对理论结果进行误差分析,得到理想情况下与实际的偏差度。结果表明,在有黏情况下压力幅值随距离增加而逐渐减小,同时入射激波的马赫数在底端面附近呈线性衰减,衰减系数随马赫数增加而增大,而在入射激波马赫数相同时,低压腔越长,底端面附近位置处的衰减系数越小。同时利用仿真结论对实验测量计算马赫数结果进行修正,减小底端面位置处的真实值与实验计算值之间的误差。