Biomimetic fabrication and characterization of an artificial rice leaf surface with anisotropic wetting

In nature,rice leaves exhibit special anisotropic sliding capabilities.Although researchers have succeeded in fabricating artificial rice leaf structures and realizing the wettability function of the leaf surface,these methods used to date are complex and do not allow the fabrication of surfaces with large area.Herein,we adopted a simple technology—two steps soft transfer to fabricate biomimetic rice leaf.The fabricated surface well reproduced the structures of the rice leaf surface and exhibited a static superhydrophobic property similar to that of the real rice leaf surface.In terms of its dynamic wettability,it clearly exhibited an anisotropic sliding property.Systematic measurements showed that the sliding angles parallel and perpendicular with the vein direction were 25° and 40°,respectively.The method was simple and reliable,without the need for expensive instruments and complex technologies,which could be used for the rapid fabrication of large-area artificial rice leaf surfaces.We believe that the artificial rice leaf surface fabricated by this method has great potential applications in biomimetic functional surfaces,microfluidics,and so on.     

人体前臂组织各向异性的人体通信信道模型

人体前臂是一个近似的圆柱体结构,由组织包裹组成。这些组织有的各向同性,如皮肤,脂肪;有的各向异性,如肌肉等。它们对人体电流信号的传播与分布有着极大的影响,特别是肌肉组织。应用麦克斯韦方程,结合人体组织特性和准静态条件下的边界条件,在柱坐标系下建立了基于人体组织特性的信道模型。用该模型,结合人体组织各向特性的电参数(肌肉),在MATLAB2010a上分别计算出具有组织特性的信道模型和不具有组织特性的信道模型的结果。然后与在人体右前臂测量得到的数据相比较,发现加入组织特性的信道模型的增益曲线与实验数据保持高度一致,模型的平均误差比各向同性的信道模型误差下降了2%,最大误差也下降了3%,进一步降低了模型的失真率。     

利用Z型载流导线列阵构成的新型磁晶格

提出两种新型的磁表面微囚禁列阵来构成一维和二维的磁晶格，计算了载流导线和偏磁场形成的磁场强度、梯度和曲率分布．研究表明这些磁表面微囚禁列阵微阱中心的磁场存在非零最小值，可以用来作成一维和二维的磁晶格，实现多维BEC列阵，甚至是光子晶体．     

带频道负荷的频道分配问题的图论模型

在无线电网络中,邻近的地理区域内用同一个频道的用户过多就会引起无线电通信的拥塞．增加频道负荷约束,限制同一时间内用相同频道的用户数量来控制这一现象．给出了带有负荷频道约束的私人移动无线电网络的图表示,推广了顶点染色的概念,得到了此问题的有关理论结果．     

Quantum coherence and entanglement with ultracold atoms in optical lattices

At nanokelvin temperatures, ultracold quantum gases can be stored in optical lattices, which are arrays of microscopic trapping potentials formed by laser light. Such large arrays of atoms provide opportunities for investigating quantum coherence and generating large-scale entanglement, ultimately leading to quantum information processing in these artificial crystal structures. These arrays can also function as versatile model systems for the study of strongly interacting many-body systems on a lattice.     

L1中弱强迫非线性迷向方程

我们证明了L1中非线性迷向方程弱解的存在性,在一些条件下,得到了正则性结果.     

多涂层各向异性短纤维复合材料热弹性解

建立了包含任意层同轴圆柱壳体模型,并得到了热载荷作用下的空间轴对称控制方程.利用局部/总刚度矩阵方程方法,在假定材料的性质与温度无关的情形下获得了具有任意涂层正交各向异性单向短纤维复合材料的热弹性解析解.相比于经典的弹性力学方法--根据界面应力和位移连续联立方程组求解,所用方法极大地减少了未知量的个数,便于计算机编程.最后,针对具体的算例,给出了多涂层单向短纤维增强复合材料在热载荷作用下的位移场和应力场,分析了纤维体积含量Vf对复合材料位移和应力分布的影响.     

可控氧流冶金

总结可控氧流冶金的原理、特点、方法,介绍可控氧流冶金在金属熔体的无污染脱氧以及从溶解于离子熔体中的氧化物提取有价金属方面的研究状况,认为可控氧流冶金有利于创建全新的绿色冶金新技术。     

Collective behavior of coupled map lattices with different scales of local coupling

In this paper, I present a numerical study on the collective behavior of one-dimensional coupled map lattices with the nearest coupling to different scales for the whole system. Using the maximum Lyapunov exponent as a tool for subsystem and return mapping, I observed several basic patterns of collective behavior and investigated the contrasts between the different scales. To study the mechanism, the system under entirely random perturbations was investigated using the Monte Carlo method and the contrast with the deterministic approach is given. The results show that the response to a random input is complicated and involves the correlation of different signals and taking into consideration the dynamic properties of the system itself.     

Optical polymer thin films with isotropic and anisotropic nano-corrugated surface topologies

Light reflection from computer monitors, car dashboards and any other optical surface can impair the legibility of displays, degrade transmission of optical components and in some cases may even pose safety hazards. Antireflective coatings are therefore widely used, but existing antireflection technologies often perform sub-optimally or are expensive to implement. Here we present an alternative approach to antireflection coatings, based on an extension of our photo-aligning and photo-patterning technology for liquid-crystal displays (LCDs) and liquid-crystal polymer films with smooth surfaces to optical polymer films with controlled surface topologies. Nano- and micro-corrugated topologies are shown to result from optically induced monomer phase-separation on the polymer surfaces. The properties of the resulting films make them suitable high-performance and low-cost antireflection coatings for optical components of virtually any size, shape and material. Moreover, the approach can be used to form a wide range of other functional polymer thin films with isotropic as well as anisotropic topologies. For example, films can be produced whose optical birefringence exceeds that of the birefringence of the polymer material itself. These new films can also be used as diffractive thin films, diffusers, and directional reflectors which preserve light polarization, or as substrates for aligning liquid crystals to produce bright, low-power-consumption LCDs with integrated optical functions and memory.     

板面为各向异性面的横观各向同性拉伸板的精化理论

基于板面为各向异性面的横观各向同性弯曲板的精化理论,对板面为各向异性面的横观各向同性拉伸板进行了分析和研究。不作任何预先假设,利用横观各向同性弹性理论和Elliott-Lodge通解,获得了由板中面上的位移和横向正应变表示的位移场和应力场。根据Lur’e方法和边界条件获得了板面受横向载荷的精化方程,略去高阶项后获得了板的近似控制微分方程。将各向同性材料常数代入到方程中,得到的精化理论与各向同性拉伸板的精化理论一致。     

板面为各向异性面的横观各向同性弯曲板的精化理论

在板面为各向同性面的横观各向同性板精化理论的基础上,对板面为各向异性面的横观各向同性板进行了研究,并推导出其精化理论。根据横观各向同性弹性理论和Elliott-Lodge通解,在不作任何预先假设的条件下,获得了由板中面上的位移和转角表示的位移场和应力场,根据Lur’e方法和边界条件获得了板面受横向载荷的精化方程,略去高阶项后获得可直接应用的近似控制微分方程。令所有物理量与x2或x3无关,得出的精化理论分别与横观各向同性梁和各向同性梁的精化理论一致。     

各向异性半平面与各向同性半平面的周期焊接问题

利用平面弹性复变方法和解析函数边值问题的基本理论，研究了各向异性半平面与各向同性半平面的周期焊接问题，并得出应力分布封闭形式的解     

Sobolev方程的各向异性有限元的高精度分析

利用具有各向异性特征的双线性元和双二次元对Sobolev方程进行Calerkin逼近,摆脱了对网格剖分满足正则性条件的要求,同时,利用积分恒等式技巧,得到了与传统方法相同的超逼近结果。     

Rayleigh衰落信道下基于LDPC码的自适应发射分集技术

将低密度校验码（low desity parity codes,LDPC）应用于一种简单的发射分集技术（space—time block codes,STBC）及自适应STBC,推导出LDPC码在与STBC级联并采用自适应功率分配算法时的译码方法,通过计算机仿真研究了其在Rayleigh衰落信道下的性能．采用发射分集技术可以提供分集增益,提高了系统的性能,而利用由接收端反馈的信道状态信息,可以在发射端采用自适应功率分配算法,使LDPC—STBC的系统性能有进一步的改善．另外,在相似的译码复杂度下,给出了LDPC．STBC与turbo-STBC的性能比较．     

用FDTD法分析各向异性介质填充矩形波导的截止特性

给出用时域有限差分(FDTD)法分析各向异性介质填充波导问题的差分格式,实例计算了磁各向异性介质完全填充矩形波导TE模各模式的截止波数,计算结果与理论值吻合较好;分析了磁各向异性介质和电各向异性介质填充对矩形波导TE模和TM模主模归一化截止波数的影响。     

P-Q阀可控液压系统单元的计算机控制

为适应复杂液压系统的压力、速度变化要求,通过对电液比例压力-流量复合阀(P-Q阀)的特性分析,研究以P-Q阀为核心元件,搭建与负载相适应的可控液压系统单元.该液压系统单元采用模糊PID控制策略,实现不同负载和不同速度的变化.仿真结果表明可控液压系统单元可满足工作状态要求.