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881.
Xiao Ling Yu Zu-yu Yang Chao Zhu Hua-yue Du Yu-min College of Resource Environmental Science Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2004,9(2):247-251
0 IntroductionChitosanisadeacetylatedderivativeofchitin ,containinginitsstructure glucosamineandacetylglucosamine joinedthroughβ (1→ 4 )linkages.ItisinsolubleinwaterandcommonorganicsolventsbutsolubleatapHunder 6 .5acidicmedia.Duetoitsexcellentbiodegradableandbiocompatiblecharacter,chi tosanhasbeenexaminedextensivelyinthepharmaceuticalindus tryforitspotentialinthedevelopmentofdrugdeliverysys tems[1 ,2 ] .Gelatinisabiodegradablepolymerofwidesafety ,pro ducedfromcollagen ,themostabundantprote… 相似文献
882.
ZHAO Wei HU Ke KIMOTO Akitsu MIZUYAMA Takahisa . Institute of Environmental Science Beijing Normal University Beijing China . College of Earth Sciences Jilin University Changchun Jilin China . Laboratory of Erosion Control Graduate School of Agriculture Kyoto University Kyoto Japan 《武汉大学学报:自然科学英文版》2004,9(4):527-532
0 IntroductionManystudieshavebeendoneonthesedimentdischargeinMt.Tanakami .Thosestudiesconcerntheamountofsedi mentsandfewdiscussionsabouttheprocessonly .Andthesedi mentyieldmechanismindevastatedslopeinMt.Tanakamiisnotfullyunderstood.Inordertorecordthewholeprocessofsoilero sionfromthebeginningofprecipitation ,totheendofsedimentmovement,asimulatingexperimentbyusingartificialrainiscon ducted .Basedonthisexperiment,andbyfurthercomparingwiththepreviousdataofsedimentsinthisarea,somebasicdataaboutc… 相似文献
883.
Leaching Mechanism of Complicated Antimony-Lead Concentrate and Sulfur Formation in Slurry Electrolysis 总被引:1,自引:0,他引:1
Anodic reaction mechanism of complicated antimony-lead concentrate in slurry electrolysis was investigated by the anodic polarization curves determined under various conditions. The main reactions on the anode are the oxidations of FeCln^(2-n) . Though the oxidation of jamesonite particle on the anode can occur during the whole process, it is less. With the help of mineralogy studies and relevant tests, the leaching reaction mechanism of jameson[to and gudmundite during slurry electrolysis was ascertained. Because of the oxidation reaction of FeCl3 produced by antimony-lead concentrate itself, the non-oxidation complex acid dissolution of jameson[re, the oxidation complex acid dissolution of gudmundite, and the oxidation of air carried by stirring, the leaching ratio of antimony reaches about 35% when HCl-NH4Cl solution is used to leach antimony-lead concentrate directly. So when the theoretical electric quantity is given to oxidation of antimony in slurry electrolysis, all of antimony, lead and iron containing in antimony-lead concentrate, are leached. The formation of sulfur is through the directly redox reaction of Fe^3 and jameson[re. The S^2- in jamesonite is oxidized into S^0 , and forms the crystals of sulfur again on the spot. The redox reaction of Fe^3 and H2S formed by non-oxidative acid dissolution of jamesonite is less. 相似文献
884.
本文提出一种安全可靠的多媒体传输方案 ,将多媒体编码过程与认证过程相结合 ,信道编码过程与加密过程相结合 ,既实现了对多媒体敏感区域的认证功能 ,又实现了对整个数据流的加密保护 .其中 ,认证过程对敏感数据进行数字签名 ,并将此签名嵌入敏感区域 ,它可以检测出恶意篡改或传输错误 ;信道编码加密过程是将纠错编码与混沌流密码相结合 ,同时具有纠错功能和加密功能 .理论分析可见 ,认证和加密过程都与编码过程相结合 ,计算复杂度低 ,而且保持了信道编码的容错能力 .实验结果表明 ,此方案具有较高的安全性 ,适合多媒体数据的安全传输 . 相似文献
885.
开发了一种新型的埋入式光纤曲率传感器 ,以结构的曲率变形对传感器的输出光强实现强度调制 .对传感器的静态和动态特性作了分析 ,提出了该传感器的传感机理 ,对传感器的结构作了改进 .将此传感器埋入树脂基复合材料板内部 ,测量板的弯曲变形 .可利用此曲率传感器组成准分布式传感系统检测智能结构的形状变化 . 相似文献
886.
多传感器机器人数据采集与融合系统研究 总被引:1,自引:1,他引:1
根据多传感器机器人控制器数据采集量大、数据融合算法复杂、系统实时性强的特点 ,提出了基于ADμC812和TMS32 0F2 0 6的双CPU结构的机器人信息采集与数据融合系统结构 .介绍了该系统的硬件组成、基本工作原理以及接口电路 ,并给出了ADμC812子系统程序流程图 . 相似文献
887.
阐述了在PowerBuilder的应用程序中 ,实现嵌入电子邮件的一般原理、方法及具体的程序实现 ,使PowerBuilder应用程序能够访问与MAPI兼容的电子邮件系统 .该邮件应用的特点在于能在应用软件系统中自动发送和接收电子邮件 ,同时还能获得地址薄的信息 .该邮件应用模块可挂接在任意PowerBuilder应用软件中 ,具有一定实用价值 . 相似文献
888.
This paper considers the use of polar codes to enable secure transmission over parallel relay channels.By exploiting the properties of polar codes over parallel channels, a polar encoding algorithm is designed based on Channel State Information(CSI) between the legitimate transmitter(Alice) and the legitimate receiver(Bob).Different from existing secure transmission schemes, the proposed scheme does not require CSI between Alice and the eavesdropper(Eve). The proposed scheme is proven to be reliable and shown to be capable of transmitting information securely under Amplify-and-Forward(AF) relay protocol, thereby providing security against passive and active attackers. 相似文献
889.
Masking is one of the most commonly used Side-Channel Attack(SCA) countermeasures and is built on a security framework, such as the ISW framework, and ensures theoretical security through secret sharing.Unfortunately, the theoretical security cannot guarantee practical security, because several possible weaknesses may exist in the actual implementation. These weaknesses likely come from the masking schemes or are introduced by the implementation methods. Finding the possible weakness of the masking scheme is an interesting and important issue for real applications. In this paper, the possible weaknesses for masking schemes in FieldProgrammable Gate Array(FPGA) design are discussed. It was found that the combinational circuit is the key to the security of masking schemes. The Toggle Count(TC) method and its extension are utilized to evaluate the security of masking schemes in the design phase and the implementation phase separately. Comparing different logic-level simulators for the Xilinx FPGA platform, the behavioral and post-translate simulations are considered as the analysis method in the design phase, while the post-map and the post-route simulations are used to find the weakness during the implementation phase. Moreover, a Standard Delay Format(SDF) based improvement scheme is proposed to significantly increase the effectiveness of the TC model. 相似文献
890.
The phenomenon of cooperation is prevalent in both nature and human society. In this paper a simulative model is developed to examine how the strategy continuity influences cooperation in the spatial prisoner’s games in which the players migrate through the success-driven migration mechanism. Numerical simulations illustrate that the strategy continuity promotes cooperation at a low rate of migration, while impeding cooperation when the migration rate is higher. The influence of strategy continuity is also dependent on the game types. Through a more dynamic analysis, the different effects of the strategy continuity at low and high rates of migration are explained by the formation, expansion, and extinction of the self-assembled clusters of “partial- cooperators” within the gaming population. 相似文献