Unusual Two-Step Assembly of a Minimalistic Dipeptide-Based Functional Hypergelator

Self-assembled peptide hydrogels represent the realization of peptide nanotechnology into biomedical products. There is a continuous quest to identify the simplest building blocks and optimize their critical gelation concentration (CGC). Herein, a minimalistic, de novo dipeptide, Fmoc-Lys(Fmoc)-Asp, as an hydrogelator with the lowest CGC ever reported, almost fourfold lower as compared to that of a large hexadecapeptide previously described, is reported. The dipeptide self-assembles through an unusual and unprecedented two-step process as elucidated by solid-state NMR and molecular dynamics simulation. The hydrogel is cytocompatible and supports 2D/3D cell growth. Conductive composite gels composed of Fmoc-Lys(Fmoc)-Asp and a conductive polymer exhibit excellent DNA binding. Fmoc-Lys(Fmoc)-Asp exhibits the lowest CGC and highest mechanical properties when compared to a library of dipeptide analogues, thus validating the uniqueness of the molecular design which confers useful properties for various potential applications.     

CF/ABS树脂复合材料制备工艺对导电性能的影响及对屏蔽性能的理论预测

本文研究了使用溶剂法、密炼机和开炼机混炼碳纤维填充ABS树脂复合材料的导电性能,得到了纤维填充量与复合材料电阻率的关系,对其导电机理进行了分析.通过比较,发现纤维长径比是决定复合材料导电性能的重要因素,其它如纤维在基体中的分布也对复合材料导电性能有影响.最后对复合材料的屏蔽性能进行了理论计算.     

Analysis and comparison of two-dimensional permanent-magnet arrays for planar motor

This paper investigates three kinds of permanent-magnet arrays used in planar motors with polarity centers distributed in the lattices of a matrix. The magnetic field of every kind of magnet array is analyzed by analytical methods. First, we give a Laplace equation of magnetic scalar potential and a series of boundary conditions. Then, we derive the analytical expressions of magnet field strength and magnet flux density in the air gap of each kind of magnet array by the method of separation of variables. Finally, we compare the three types of magnet arrays on the basis of the analytical solutions.     

多信道光纤环形网络结构分析

本文对多信道光纤环形网络结构进行了详细分析，推导出环网内平均路经长度和最大直径计算公式，并分析了最佳多信道光纤环网结构。     

关于不确定的对称组合系统的稳定化控制器与观测器的设计

本文研究了不确定的对称组合系统的稳定化控制器与观测器的设计问题，给出一种设计稳定化控制器与观测器的方法，在这种设计方法中，使给定的带有不确定性的对称组合系统稳定的状态反馈增益矩阵和观测器增益矩阵可由低阶代数Ｒｉｃｃａｔｉ方程的解导出。     

拉西瓦高拱坝岩体力学、工程地质研究成果综述

拉西瓦水电站高拱坝建基岩体工程地质、岩体力学研究是中国水电顾问集团2004年度专题科研成果之一“高混凝土拱坝建基岩体工程地质、岩体力学综合研究”的主要成果,其重点内容为岩体风化、卸荷、岩体质量级别的定量划分、河谷应力场分带、建基岩体主要岩体力学参数研究,坝肩抗滑稳定、开挖后综合检测验证等;在理论探讨、方法实践、预测验证和创新尝试等方面取得了一定成果,具有一定的社会、经济效益。     

关于不确定对称组合系统的稳定化

研究不确定对称组合系统的二次稳定化问题,给出这类系统可二次稳定的一些充分条件 及计算反馈控制律的方法.这些条件的检验和反馈控制律的计算都由两个低阶系统关于相应 问题的求解来完成.     

管线用钢氢致裂纹(HIC)影响因素分析

研究了管线用钢的化学成分和金相组织对钢的氢致裂纹(HIC)性能的影响。研究认为,带状组织和马氏体含量对HIC性能有很大影响,S含量及Cep对HIC有不同程度影响。含有少量Cu、Ni的钢更适合在酸性环境下使用。     

基于弹塑性有限单元法的齿轮轴数值模拟

基于弹塑性有限单元法的一般原理,建立了齿轮轴热处理的热力耦合分析模型,对12Cr齿轮轴热处理工艺中温度、应力以及相变的分布情况进行了模拟,研究了加热规范的成形性,并与实际结果比较证实本模型的有效性,为有限单元法在热处理工艺模拟中的应用奠定了一定基础。     

Physically-based modeling,simulation and rendering of fire for computer animation

We give an up-to-date survey on techniques and methods for fire simulation in computer graphics. Physically-based method prevails over traditional non-physical methods for realistic visual effect. In this paper, we explore visual simulation of fire-related phenomena in terms of physically modeling, numerical simulation and visual rendering. Firstly, we introduce a physical and chemical coupled mathematical model to explain fire behavior and motion. Several assumptions and constrains are put forward to simplify their implementations in computer graphics. We then give an overview of present methods to solve the most complicated processes in numerical simulation: velocity advection and pressure projection. In addition, comparisons of these methods are also presented respectively. Since fire is a participating medium as well as a visual radiator, we discuss techniques and problems of these issues as well. We conclude by addressing several open challenges and possible future research directions in fire simulation.