Anisotropic Hybrid Hydrogels with Superior Mechanical Properties Reminiscent of Tendons or Ligaments

Mimicking the hierarchically anisotropic structure and excellent mechanical properties of natural tissues, such as tendons and ligaments, using biomaterials is challenging. Despite recent achievements with anisotropic hydrogels, limitations remain because of difficulties in achieving both structural and mechanical characteristics simultaneously. A simple approach for fabricating hybrid hydrogels with a hierarchically anisotropic structure and superior mechanical properties that are reminiscent of tendons or ligaments is proposed. Alginate–polyacrylamide double‐network (DN) hydrogels incorporated with high aspect ratio mesoporous silica microparticles are stretched and fixed via subsequent drying and ionic crosslinking to achieve multiscale structures composed of an anisotropically aligned polymer network embedded with aligned microparticles. The mechanical properties of hydrogels can be further controlled by the degree of stretching, quantities, and functional groups of inorganic microparticles, and types of crosslinking cations. The subsequent reswelling results in a high water content (>80%) similar to that of natural tendons while high strength, modulus, and toughness are maintained. The optimized anisotropic hybrid hydrogel exhibits a tensile modulus of 7.2 MPa, strength of 1.3 MPa, and toughness of 1.4 MJ m^?3 even in the swollen state, which is 451‐, 27‐, and 2.2 times higher than that observed in the non‐swollen tough DN hydrogel. This study suggests a new strategy for fabricating anisotropic hydrogels with superior mechanical properties to develop new biomaterials for artificial tendons or ligaments.     

引入加权系数的交直流混合微电网潮流计算

在下垂控制的交直流混合微电网潮流计算过程中,存在雅可比矩阵对角线元素为零值而无法求解的情况。针对上述现象,文中提出引入加权系数的改进潮流计算算法,对F(k)和F(k+1)引入加权系数,构造误差平方和函数以求解最佳权重值,通过第k+1次迭代与第k次迭代之间的关系求出第k+1次迭代的解,重复上述过程直至结果收敛。通过IEEE30节点算例证明了改进算法的正确性和有效性,并将其用于下垂控制的交直流混合微电网潮流计算。     

新型III-V族变形微盘硅基混合激光器

文章中,我们设计了一种连接一个Si的输出波导的新型III-V族变形微盘硅基混合激光器,并通过BCB键合技术以及标准光刻将其制备。相比于传统圆形微盘激光器,该激光器实现了激光从硅波导的定向发射以及单纵模输出。实验上,在连续电流操作下,我们获得了0.31 mW的输出功率以及27 dB的边模抑制比。     

基于氧化石墨烯功能材料提高PEDOT:PSS电极性研究

基于聚(3,4-乙烯二氧噻吩)-聚苯乙烯磺酸(PE DOT:PSS)/氧化石墨烯(GO)混合溶液,利用旋涂法制 备了高电导率透明阳极,并采用硫酸(H₂SO₄)浸渍处理的方式,使其导电特性进一步 增强。采用最佳方式 处理的PEDOT:PSS/GO混合薄膜在厚度为40 nm时,其方阻为80 Ω/□,在550 nm时的透过率达到87.7％。 基于表面形貌的AFM图,吸收光谱和拉曼光谱,在少量氧化石墨烯掺杂和硫酸处理后,PSS －和PEDOT⁺链 相分离,使得PEDOT:PSS的结构发生了变化,提高了混合薄膜的电导率。与ITO和纯PEDOT: PSS分 别作为阳极的OLED器件相比,采用优化的PEDOT:PSS/GO混合薄膜作为阳极时的OLED器件具有 最低 的启亮电压和最高的电流效率,其最大亮度是纯PEDOT:PSS作为阳极的OLED的1.7倍。较高 的透过率, 电导率和HOMO能级,尤其是表面形貌的改变都有利于PEDOT:PSS/GO阳极OLED器件性能的改善 。     

Hybrid prioritized multiple access protocols for bank LANs

Bank communication networks support four classes of traffic: Alarm, BSC, SNA and IP traffic, with each class of traffic having different priority requirements. In this paper, a framework for the design of multiple access protocols which are capable of handling the above priority classes is introduced. Furthermore, a hybrid multiple access protocol that has been designed according to the proposed framework is presented and evaluated by means of extensive simulation results. The proposed protocol, is applicable to a broad range of prioritized LANs. Copyright © 2004 John Wiley & Sons, Ltd.     

混合进制复制生成序列的相关函数

介绍了以混合进制码为复制信息,用平移复制生成多复数值序列的方法,讨论了复制生成序列的性质和复制生成序列的相关函数,给出了两个生成序列的互相关函数值恒为零的条件,最后给出了一个复制信息的选取准则,根据这个准则可以得到一个两两之间互相关函数值恒为零的序列族.     

复杂散射环境中MoM与UTD混合方法的PO扩展

本文提出利用物理光学PO可扩展MoM UTD的应用范围 .理论和数值结果表明 ,PO电流的引入抛开了MoM UTD混合中的镜像原则 ,使散射体扩展到任意复杂面 ,以及很好地解决了线天线距离弯曲曲面较近的情况下UTD技术的缺陷 .另外 ,本文指出适当比例的PO区域仍可以较准确地求解MoM区域的电流和阻抗特性 ,使得本文方法变得简单有效 ;这为快速有效地分析复杂电大目标的电磁兼容问题提出了一条新的切实可行的途径     

Performance Monitoring and Assessment of Embedded HW/SW Systems

Performance assessment of embedded HW/SW systems built with various types of VLSI components, i.e. heterogeneous multi-processor architectures, is important to help the development of complex real-time applications. To design such a tool, two issues must be solved: the gathering of relevant information simultaneously on several components without disturbing the application behavior, display of the performance results in a way that can be easily interpreted by designers. This paper presents a significant solution for the two above issues. We first describe what the goal for designers is and what kind of applications are concerned. Then we describe the principle of collecting an event trace and the technique to evaluate the selected performance indexes. The monitoring technique, based on a specific ASIC, is non-intrusive and allows our tool to capture real-time event occurrences from software tasks, and even from hardware functions implemented in ASICs. Each event is automatically time-stamped, collected and processed in real-time to evaluate the performance indexes selected by the designer. We also describe the display tool which clearly shows the results to the designer according to different representations. This technique and the associate real-time performance analyzer are integrated in a complete development process based on the MCSE methodology.     

Integrated sizing and scheduling of wind/PV/diesel/battery isolated systems

In this paper we address the optimal sizing and scheduling of isolated hybrid systems using an optimization framework. The hybrid system features wind and photovoltaic conversion systems, batteries and diesel backup generators to supply electricity demand. A Mixed-Integer Linear Programming formulation is used to model system behavior over a time horizon of one year, considering hourly changes in both the availability of renewable resources and energy demand. The optimal solution is achieved with respect to the minimization of the levelized cost of energy (LCOE) over a lifetime of 20 years. Results for a case study show that the most economical solution features all four postulated subsystems.     

Statistical optimization of a DC-RF hybrid plasma flow system for in-flight particle treatment

There are many input parameters to control a DC-RF hybrid plasma flow system, such as total gas flow rate, central gas flow rate, swirl gas ratio, RF power and DC power. Furthermore, the interactive effects among these parameters should be considered. In the present study, statistical analysis using simple linear model is conducted to clarify the effects of the input parameters and their interactions on the outputs such as particle residence time and average temperature in a DC-RF hybrid plasma flow system. The thermofluid characteristics of a DC-RF hybrid plasma flow are compared with those of an RF plasma flow. It is shown that the plasma characteristics are changed drastically by adding even small DC power. Furthermore, controllability is also improved by optimizing the operating conditions of a DC-RF hybrid plasma flow system.