关于IC卡燃气表技术难点的研究

对IC卡燃气表目前存在的问题给出较详细的说明和讨论,并从开发者的角度分析了IC卡燃气表的技术难点,重点给出了涉及IC卡燃气表的数据安全、精确计量以及阀门控制等方面的技术解决思路.     

基于DS18B20的温度测量装置的设计

介绍了由数字温度传感器DS18820和Freescale公司的MC68HC908GP32单片机组成的温度测量装置,可以实现对温度的测量和显示等功能．阐述了其系统结构、硬件原理图、工作时序和软件实现方法,并总结了在M68HC08系列单片机中使用DS18820的注意点．     

A deterministic construction of irregular LDPC codes

In order to solve high encoding complexities of irregular low-density parity-check (LDPC) codes, a deterministic construction of irregular LDPC codes with low encoding complexities was proposed. And the encoding algorithms were designed, whose complexities are linear equations of code length. The construction and encoding algorithms were derived from the effectively encoding characteristics of repeat-accumulate (RA) codes and masking technique. Firstly, the new construction modified parity-check matrices of RA codes to eliminate error floors of RA codes. Secondly, the new constructed parity-check matrices were based on Vandermonde matrices, this deterministic algebraic structure was easy for hardware implementation. Theoretic analysis and experimental results show that, at a bit-error rate of 10×10⁻⁴, the new codes with lower encoding complexities outperform Mackay’s random LDPC codes by 0.4–0.6 dB over an additive white Gauss noise (AWGN) channel. Foundation item: Supported by the National Natural Science Foundation of China(60496315, 60572050)     

肝大部切除前后热休克处理对热休克蛋白、酸性磷酸酶和碱性磷酸酶活性影响的分析

综合了磷酸酶的原位复性电泳、体视学分析、比色分析等方法分析①切除大白鼠大部分肝后的肝再生期间,②热休克处理大白鼠（４６℃、３０ｍｉｎ）恢复８ｈ,再切除大部分肝后的肝再生期间,③切除大部分肝恢复４ｈ,再热休克处理（４６℃、３０ｍｉｎ）后的肝再生期间热休克蛋白（ＨＳＣ７０／ＨＳＰ６８）、酸性磷酸酶（ＡＣＰ）和碱性磷酸酶（ＡＫＰ）动态变化的资料,从６个方面比较分析了ＨＳＣ７０／ＨＳＰ６８,ＡＣＰ和ＡＫＰ在肝再生中的相互关系及对肝再生的可能作用     

偶64～68Ge同位素的对相变及其演化

应用唯象核芯加两准粒子模型的一种微观实现(sdIBM-2 2q．P．)方案并考虑到实验单粒子能量,较成功地再现了偶^64-68Ge核的基态带、β带、γ带和部分高自旋态能谱．基于唯象模型和微观方案求出了s玻色子不拆对和一个d玻色子发生拆对顺排所需要的最小能量值．该阈值明确指认：随着中子数的增加,偶Ge同位素可能发生从^54Ge核的两准质子顺排态向^68Ge核的两准中子顺排态的演化;揭示了偶Ge同位素对相变对象转移的演化过程．     

嵌入式Web Server中TCP/IP协议的实现

介绍了单片机MC68HC908AP64与以太网控制芯片RTL8019AS的硬件接口电路实现,以及在AP64中如何运用嵌入式Internet的基本理论实现一个瘦TCP/IP协议栈,并且应用瘦TCP/IP协议栈实现嵌入式Web Server。通过该系统可以将家电的控制信号转化成因特网上的信息进行传输,从而实现对设备的远程控制。     

MC68HC705P6A在电梯门安全保护光幕装置中的应用

本文介绍了MC68HC705P6A单片机在电梯门安全保护光幕中的应用,以及电梯门安全保护光幕的工作原理,电路设计和软件设计.     

Role of Sam68 as an adaptor protein in signal transduction

Sam68, the substrate of Src in mitosis, belongs to the family of RNA binding proteins. Sam68 contains consensus sequences to interact with other proteins via specific domains. Thus, Sam68 has various proline-rich sequences to interact with SH3 domain-containing proteins. Moreover, Sam68 also has a C-terminal domain rich in tyrosine residues that is a substrate for tyrosine kinases. Tyrosine phosphorylation of Sam68 promotes its interaction with SH2 containing proteins. The association of Sam68 with SH3 domain-containing proteins, and its tyrosine phosphorylation may negatively regulate its RNA binding activity. The presence of these consensus sequences to interact with different domains allows this protein to participate in signal transduction pathways triggered by tyrosine kinases. Thus, Sam68 participates in the signaling of T cell receptors, leptin and insulin receptors. In these systems Sam68 is tyrosine phosphorylated and recruited to specific signaling complexes. The participation of Sam68 in signaling suggests that it may function as an adaptor molecule, working as a dock to recruit other signaling molecules. Finally, the connection between this role of Sam68 in protein-protein interaction with RNA binding activity may connect signal transduction of tyrosine kinases with the regulation of RNA metabolism.Received 16 July 2004; received after revision 12 August 2004; accepted 18 August 2004     

页岩声发射RA值及其分形特征的试验研究

对页岩进行常规三轴压缩条件下的声发射试验,得到其声发射RA值时间序列,并利用MATLAB编程计算其关联维数,得到分形维数与时间的耦合关系,采用分形理论对其进行分析,以研究页岩在常规三轴压缩破坏过程中的微观机制及其分形特征。结果表明:1)页岩在常规三轴压缩破坏过程中的裂纹为张剪复合裂纹,并以剪切裂纹为主,张裂纹主要出现在峰值强度前后,并且随着围压的升高,张裂纹数量明显减少,这说明围压能够抑制张裂纹的产生。2)页岩声发射RA值在时域上具有自相似特征,具有分形特征,其分形维数演化模式为:上升—突降—波动。3)声发射RA值的分形维数在初期上升,表明岩石内部先是微小裂纹无序扩展,并融合贯通成破裂面,此时分形维数突降,表明裂纹沿破裂面有序地扩展,岩石产生宏观裂纹,预示着岩石即将发生破坏,因此可以将分形维数的首次突降作为岩体失稳破坏的前兆。