Studied on a novel human keratinocyte membrane delivery system in vitro

The culture of keratinocytes on flexible membranes has been proposed as a means to simplify, accelerate and improve the efficiency with which proliferating cells are delivered to full thickness or non-healing skin defects. The purpose of this article was to study the ability of chitosan-gelatin manbranes to facilitate the growth of human keratinocytes. The membranes with different chitosan contents were studied. The surface properties of chitosan-gelatin membranes were investigate by SEM, and water contact angle test. The mechanical property of the membranes was tested. Data implied that gelatin could make the membranes more flexible and hydrophilic than chitosan membranes, which may regulate the seeded cells behavior. Loading human keratinocytes on chitosan-gelatin membranes, cells attachment, spread, and growth were investigated by light microscopy, SEM, and MTT test. The results suggested that the adhesion and proliferation of keratinocytes seeded on chitosan-gelatin membranes were same as on tissue culture plate, in which gelatin could modify the interaction between keratinocytes and chitosan membranes. Therefore, chitosan-gelatin membrane is a good candidate for keratinocytes delivery system.     

包装图形设计在包装商品中的作用

从事商品包装设计的设计师们都知道，包装设计具有双重性，即艺术性与商品性。而从销售包装设计的角度来看艺术性是隶属于商品性的，两者的融合才是一件完美的销售包装设计。包装设计表达语言与及其它方面设计相比具有一定的共性，也存在着一定差异。它是一种视觉传达设计，由于文化传达的方式，内容和媒体的不同，因而有其表达特点。     

Alumina‐Supported CoFe Alloy Catalysts Derived from Layered‐Double‐Hydroxide Nanosheets for Efficient Photothermal CO2 Hydrogenation to Hydrocarbons

A series of novel CoFe‐based catalysts are successfully fabricated by hydrogen reduction of CoFeAl layered‐double‐hydroxide (LDH) nanosheets at 300–700 °C. The chemical composition and morphology of the reaction products (denoted herein as CoFe‐x) are highly dependent on the reduction temperature (x). CO₂ hydrogenation experiments are conducted on the CoFe‐x catalysts under UV–vis excitation. With increasing LDH‐nanosheet reduction temperature, the CoFe‐x catalysts show a progressive selectivity shift from CO to CH₄, and eventually to high‐value hydrocarbons (C₂₊). CoFe‐650 shows remarkable selectivity toward hydrocarbons (60% CH₄, 35% C₂₊). X‐ray absorption fine structure, high‐resolution transmission electron microscopy, Mössbauer spectroscopy, and density functional theory calculations demonstrate that alumina‐supported CoFe‐alloy nanoparticles are responsible for the high selectivity of CoFe‐650 for C₂₊ hydrocarbons, also allowing exploitation of photothermal effects. This study demonstrates a vibrant new catalyst platform for harnessing clean, abundant solar‐energy to produce valuable chemicals and fuels from CO₂.     

全内螺纹塑件3种注射模设计

分析了带有全内螺纹结构的硬质塑料零件的特点,设计了手工脱模、螺纹自动旋转脱模、滑块脱模的3种模具结构.     

实时三维超声心动图中二尖瓣的提取

二尖瓣的复杂结构和不规则运动特性使得自动提取非常困难,因而依据二尖瓣解剖形状的先验知识,采用人机交互方式构造符合二尖瓣生理形状的柱状区域,把该区域作为测地活动轮廓模型的区域约束项,在levelset框架下对二尖瓣进行分割提取。该方法通过对大量三维超声瓣膜进行实验,取得了良好的分割效果,能够直接准确提取三维心脏二尖瓣。     

某深基坑土钉墙支护位移控制的设计与观测

针对一开挖深度为12.6m深基坑土钉墙锚喷支护过程中的位移问题,本文在按稳定控制进行设计的基础上,采用FLAC3D三维快速拉格朗日差分程序,基于莫尔-库伦破坏准则和理想弹塑性模型,对基坑外土体的下沉和墙后土体的水平位移采用数值计算方法进行了变形控制设计,并对基坑开挖边坡水平位移和沉降量进行了现场观测。结果表明,现场水平位移和沉降量监测值与设计值较为接近。本文进行的土钉墙位移控制设计方法可为相关的深基坑支护工程提供参考。     

基于AOP的Web系统事务管理的应用研究

面向方面的程序设计（Aspect—Oriented Programming,AOP）是在继承OOP基础之上进行改进而来的一种创新的软件设计方法,通过引入方面概念,将应用程序中的核心业务逻辑同其提供支持的通用服务分离开来,从而降低代码之间的耦合度,增加程序的灵活性和可重用性。通过简介AOP在事务处理中的应用,介绍了Spring框架和AOP相结合的事务处理方法。通过采用Spring的AOP框架,使系统的核心业务逻辑和事务管理逻辑分开,从而系统的藕合性大大降低且易于扩展,面向方面编程提高了系统的模块性。     

Adaptive backstepping‐based control design for uncertain nonlinear active suspension system with input delay

This paper addresses the control problem of adaptive backstepping control for a class of nonlinear active suspension systems considering the model uncertainties and actuator input delays and presents a novel adaptive backstepping‐based controller design method. Based on the established nonlinear active suspension model, a projector operator–based adaptive control law is first developed to estimate the uncertain sprung‐mass online, and then the desirable controller design and stability analysis are conducted by combining backstepping technique and Lyapunov stability theory, which can not only deal with the actuator input delay but also achieve better dynamics performances and safety constraints requirements of the closed‐loop control system. Furthermore, the relationship between the input delay and the state variables of this vehicle suspension system is derived to present a simple and effective method of calculating the critical input delay. Finally, a numerical simulation investigation is provided to illustrate the effectiveness of the proposed controller.     

具有理想对比度的一般存取结构可视密码方案

本文提出了一种基于取反运算可获得理想对比度的可视密码方案,适用于一般存取结构可以实现秘密图像无失真地恢复,并且没有像素扩展。该方案应用了简单的布尔运算实现了传统可视密码方案中单纯的叠加运算无法实现的功能。     

基于智能代理的网络监测系统

提出了一个基于智能代理的网络监测系统,智能代理采用模糊逻辑方法对连接数据库中的为数据进行初步处理,把不能处理的连接信息交给管理员,根据管理员的反馈,修改访问控制策略库和模糊非法饲库,并把非法连接记录下来。