14 resultados para J J C Smart

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Password authentication has been adopted as one of the most commonly used solutions in network environment to protect resources from unauthorized access. Recently, Lee–Kim–Yoo [S.W. Lee, H.S. Kim, K.Y. Yoo, Improvement of Chien et al.'s remote user authentication scheme using smart cards, Computer Standards & Interfaces 27 (2) (2005) 181–183] and Lee-Chiu [N.Y. Lee, Y.C. Chiu, Improved remote authentication scheme with smart card, Computer Standards & Interfaces 27 (2) (2005) 177–180] respectively proposed a smart card based password authentication scheme. We show that these two schemes are both subject to forgery attacks provided that the information stored in the smart card is disclosed by the adversary. We also propose an improved scheme with formal security proof.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

栉孔扇贝是我国北方一种重要的贝类养殖品种。自1997年以来爆发的栉孔扇贝大规模死亡,给地区经济造成了重大损失并且已经严重威胁着扇贝养殖业的健康发展。然而,到目前为止,对扇贝免疫防御分子机理的了解还很少,深入研究扇贝免疫应答的分子机制是认识和了解病害发生和实现病害控制的重要途径。本研究采用了EST大规模测序和3’RACE的方法,从栉孔扇贝cDNA文库中克隆到一个凝集素基因CfLec-2,并对功能进行了研究。 CfLec-2 cDNA全长708bp,5’非翻译区(Untranslated Region, UTR)含有59bp,3’非翻译区含有163bp,具有典型的多聚腺苷酸加尾信号序列AATAAA和多聚腺苷酸尾巴,开放阅读框(Open Reading Frame, ORF )含有486bp,编码162个氨基酸残基,该多肽的理论分子量为16.8 kDa,等电点为4.54。利用SignalP分析,发现其信号肽的剪切位置在VEA-QSL之间。经BLASTP比对分析可知,CfLec-2基因编码的蛋白与人的Brevican,Anguilla japonica的C-type lectin-1和C-type lectin-2, Rattus norvegicus的CD23有较高的相似性,其中与Brevican的一致性有37%。Clustal W多序列比对发现该多肽具有标准长型C型凝集素所必须的6个保守半胱氨酸和相对保守的糖识别位点。用SMART(Small Modular Architecture Research Tool)软件分析发现其具有一个保守的糖识别结构域(Carbohydrate-recognition Domain, CRD),氨基酸序列上第49、125、141、149位置上的半胱氨酸参与形成糖识别结构域,而位于N末端的第21和32位上的两个半胱胺酸形成额外的一个二硫键,位于115、116和117上的Glu、Pro、Asp则构成了糖识别位点。 将编码CfLec-2成熟肽段的cDNA序列克隆进pET32a(+)载体中,并在大肠杆菌Rosetta-gami(DE3)中重组表达CfLec-2。重组蛋白利用其具有的His tag纯化并复性后发现CfLec-2可以凝集溶血葡萄球菌,且凝集过程不需要钙离子的参与。并且,CfLec-2对大肠杆菌TOP10F’有微弱的抑菌活性,对溶壁微球菌、溶血葡萄球菌和鳗弧菌则没有抑菌活性。这一结果说明,CfLec-2可能不仅参与对入侵微生物的识别过程,而且可能作为效应分子起到了直接杀灭入侵微生物的作用。 本研究发现CfLec-2具有和以前在栉孔扇贝报道的CFLec-1完全不同的功 能,说明栉孔扇贝利用不同的凝集素来识别不同的病原,同时也暗示栉孔扇贝中可能有更多不同功能的凝集素有待发现。研究结果丰富和发展了海水无脊椎动物免疫学的内容,对进一步了解扇贝固有免疫的机制,实现养殖扇贝疾病防治具有重要参考价值。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The laser-solidified microstructural and compositional characterization and phase evolution during tempering at 963 K were investigated using an analytical transmission electron microscope with energy dispersive X-ray analysis. The cladded alloy, a powder mixture of Fe, Cr, W, Ni, and C with a weight ratio of 10:5:1:1:1, was processed with a 3 kW continuous wave CO2 laser. The processing parameters were 16 mm/s beam scanning speed, 3 mm beam diameter. 2 kW laser power, and 0.3 g/s feed rate. The coating was metallurgically bonded to the substrate, with a maximum thickness of 730 mu m, a microhardness of about 860 Hv and a volumetric dilution ratio of about 6%. Microanalyses revealed that the cladded coating possessed the hypoeutectic microstructure comprising the primary dendritic gamma-austenite and interdendritic eutectic consisted of gamma-austenite and M7C3 carbide. The gamma-austenite was a non-equilibrium phase with extended solid solution of alloying elements and a great deal of defect structures, i.e. a high density of dislocations, twins, and stacking faults existed in gamma phase. During high temperature aging, in situ carbide transformation occurred of M7C3 to M23C6 and M6C. The precipitation of M23C6, MC and M2C carbides from austenite was also observed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文以对热工模具进行失效分析的基础上,利用激光熔覆技术,在5CrMnMo基础上设计并制备强韧兼备的抗高温磨损涂层。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文从裂纹顶端位错运动的简化模型估计形成塑性区所消耗的功;从而计算临界裂纹扩展力。由于Ⅰ型加载和Ⅱ型加载的应力状态有所不同,裂纹顶端塑性功耗也会不一样。基于上述思想,考虑了小范围屈服的K_(Ⅰc)和K_(Ⅱc)的关系,得出K(Ⅱc)>K(Ⅰc)的结论,符合实验结果;并就K(Ⅱc)/K(Ⅰc)的比值与材料性能和温度的关系作了讨论。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

利用OM、SEM、TEM研究了Fe-Cr-C-W-Ni激光熔覆涂层熔覆态及其高温时效态的微观组织结构。结果表明激光熔覆层组织细小,具有强韧两相组成(奥氏体和M_7C_3碳化物)的微观结构特征,高温时效处理组织中有M_(23)C_6、M_6C、M_2C等新碳化物形成。显微硬度和冲击磨损实验证实了激光熔覆态和峰值时效态熔覆层均具有良好的力学性能。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

<正>内向整流型钾离子通道(Kir,inwardlyrectifyingpotassium)在细胞激活、细胞内外钾离子K~+的动态平衡、胰岛素分泌等细胞生理过程中起重要作用。而细胞内各种不同因素和第二信使对Kir的调控则是实现其不同生理功能的途径。已有实验结果表明,4,5二磷酸磷脂酰肌醇(PIP2,phosphatidylinositol4,5-bisphosphate)与Kir相互作用的强弱决定了Kir对各种调控因素的响应程度。根据Kir2.1与Kir3.1胞内C-末端X-ray

Relevância:

20.00% 20.00%

Publicador:

Resumo:

c="http://img3.douban.com/mpic/s1281493.jpg" border="0" alt="" hspace="8" width="102" height="144" align="left" />MicrosoftVisualC十十6.0作为Microsoft Visual Studio的重要组成部分,包含了迄今为止功能最为强大的基于Windows的应用框架,在同类产品中处于领先地位。VisualC十十6.0是Microsoft迄今为止最全面、最完善的程序开发工具,为了适应各种编程风格,该软件提供了各种各样的辅助工具,在发挥编程能力和提高灵活性方面达到了空前的水平。与以往VisualC十十的各种版本相比较,VisualC十十6.0在编程环境、程序语言技术等方面做了许多改进,从而使VisualC十十更加适合专业程序员快速进行应用程序的开发。

本书内容丰富、图文并茂,是一本适合各种读者学习VisualC十十6.0的优秀参考书。

目 录
第一章 VisualC十十6.0简介及安装
1.1VisualC十十6.0新特性
1.2viSualC十十6.0开发环境简介
1.3如何学习使用VisualC十十6.0
1.4VisualC十十6.0的安装
第二章 走进C十十的世界
2.1类和对象的简介
2.2继承和多态性――一个具体的例子
2.3内嵌对象
2.4在栈中申请对象
2.5全程对象的申请
2.6对象之间的相互关系――指针数据成员
2.7this指针的使用
2.8对指针的引用
2.9友元类和友元函数
2.10静态类成员
2.11重载运算符
2.12从代码中分离出类定义
2.13匈牙利表示法
第三章 VisualC十十6.0的编程环境
3.1VisualC十十6.0主窗口
3.2VisualC十十6.0工具栏
3.3VisualC十十6.0菜单栏
3.4项目与项目工作区
3.5资源与资源编辑器
第四章 编一个最简单的VC十十程序
4.1什么是AppWizard?
4.2迎接你的第一个AppWizard程序
4.3“Iamaprogrammer.”在哪儿?
第五章 程序框架入门
5.1一个简化过的程序框架
5.2WinMain():第一个动作
5.3登记窗口类
5.4创建一个窗口
5.5显示窗口
5.6显示出那条消息
5.7窗口类与窗口对象
第六章 消息循环
6.1在消息循环中兜圈子
6.2对事件做出响应:WindowFun()
6.3响应不同的消息
6.4现在你还跟得上吗?
6.5设备界面进行交互
第七章 精通程序框架
7.1WinMain()函数在哪儿?
7.2应用程序框架和源文件
7.3工具条、状态条和打印等选项
7.4程序的控制流程
第八章 使用classWizard编程
8.1使用ClassWizard添加消息处理函数
8.2classWizard功能介绍
8.3传送鼠标消息
8.4保存鼠标绘图的信息
第九章 视图与文档
9.1Document-View模式
9.2从视图中分离出文档
9.3保存文档
9.4再访MyProg2.cpp
第十章 对象连接与嵌入(OLE)及其自动化
10.1公共对象模式(COM)
10.2类厂(classfactory)
10.3OLE自动化
10.4IDispatch接口
第十一章 动态连接库(DLLs)
11.1为什么使用DLL
11.2传统的DLL
11.3MFC库DLL
11.4MyProg4A――编写自己的类库扩展DLL
11.5MyProg4B――使用MFC库扩展DLL
11.6资源访问
第十二章 图形设备接口
12.1设备环境类
12.2GDI对象
12.3Windows的颜色映射
12.4映射方式
12.5字体
12.6MyProg3例程序
12.7MyProg3B程序
12.8MyPr0g3C例程序――使用CScrollView
第十三章 对话框
13.1在状态条上显示对话控件的帮助信息
13.2利用Fi1eOpen通用对话框打开多个文件
13.3定制通用文件对话框
13.4扩展和缩减一个对话框
13.5显示一个模式或无模式对话框
13.6编写定制的DDX/DDV例程
第十四章 剖析工具Spy十+
14.1窗体
14.2消息
14.3进程与线程
第十五章 代码调试
15.1TRACE
15.2调试框架
15.3自我诊断
15.4调试代码的作用
15.5用Dump()显示对象的信息
15.6检查内存

Relevância:

20.00% 20.00%

Publicador:

Resumo:

More and more piezoelectric materials and structures have been used for structure control in aviation and aerospace industry. More efficient and convenient computation method for large complex structure with piezoelectric actuation devices is required. A load simulation method of piezoelectric actuation is presented in this paper. By this method, the freedom degree of finite element simulation is significantly reduced, the difficulty in defining in-plane voltage for multi-layers piezoelectric composite is overcome and the transfer computation between material main direction and the element main direction is simplified. The concept of simulation load is comprehensible and suitable for engineers of structure strength in shape and vibration control, thereby is valuable for promoting the application of piezoelectric material and structures in practical aviation and aerospace fields.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A process of laser cladding Ni-CF-C-CaF2 mixed powders to form a multifunctional composite coatingd on gamma-TiAl substrate was carried out. The microstructure of the coating was examined using XRD, SEM and EDS. The coating has a unique microstructure consisting of primary dendrite or short-stick TiC and block Al4C3 carbides reinforcement as well as fine isolated spherical CaF2 solid lubrication particles uniformly dispersed in the NiCrAlTi (gamma) matrix. The average microhardness of the composite coatings is approximately HV 650 and it is 2-factor greater than that of the TiAl substrate. (C) 2008 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Negabinary is a component of the positional number system. A complete set of negabinary arithmetic operations are presented, including the basic addition/subtraction logic, the two-step carry-free addition/subtraction algorithm based on negabinary signed-digit (NSD) representation, parallel multiplication, and the fast conversion from NSD to the normal negabinary in the carry-look-ahead mode. All the arithmetic operations can be performed with binary logic. By programming the binary reference bits, addition and subtraction can be realized in parallel with the same binary logic functions. This offers a technique to perform space-variant arithmetic-logic functions with space-invariant instructions. Multiplication can be performed in the tree structure and it is simpler than the modified signed-digit (MSD) counterpart. The parallelism of the algorithms is very suitable for optical implementation. Correspondingly, a general-purpose optical logic system using an electron trapping device is suggested. Various complex logic functions can be performed by programming the illumination of the data arrays without additional temporal latency of the intermediate results. The system can be compact. These properties make the proposed negabinary arithmetic-logic system a strong candidate for future applications in digital optical computing with the development of smart pixel arrays. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)00803-X].

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fluorescence of Tm3+/Er3+ codoped bismuth-silica (BS) glasses and the sensitization of Ce3+ are investigated. It shows that Ce3+ codoping with Tm3+/Er3+ in BS glasses results in a quenching of Tm3+ ion emission from F-3(4) to the H-3(6) level. Consequently, the 1.47 mu m emission occurs after the population inversion between the H-3(4) and F-3(4) levels. Furthermore, the codoped glasses show the broad emission spectra over the whole S and C bands with full-width at half-maximum (FWHM) up to about 119nm, as it combines 1.55 mu m emission band of Er3+ with 1.47 mu m emission band of Tm3+ under 800nm excitation.