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云计算；侧信道攻击；信息泄露；多执行体架构；虚拟机切换；虚拟机迁移 1

交换机 1

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Low crosstalk switch unit for dense piezoelectric sensor networks

Lei QIU, Shenfang YUAN,

《机械工程前沿（英文）》 2009年第4卷第4期页码 401-406 doi: 10.1007/s11465-009-0047-4

摘要： Structural health monitoring (SHM), on the basis of piezoelectric (PZT) sensors and lamb wave method, is efficient in estimating the state of monitored structures. Furthermore, to monitor large-scale structures, dense piezoelectric sensor networks are required, which usually contain many piezoelectric sensor pairs called actuator-sensor channels. In that case, considering the few data acquisition channels especially in the data acquisition board with a high sampling rate and limited quantity of signal amplifiers used in an integrated computer system, a switch unit is adopted to switch to different channels. Because of the high frequency and power of the lamb wave excitation signal, there exists a crosstalk signal in the switch unit. A large crosstalk signal is mixed into the response signal so that the on/off-line signal processing task is difficult to achieve. This paper first analyzes the crosstalk signal phenomenon, describes its production mechanism, and proposes a method to reduce it. Then a 24-switch channel low crosstalk switch unit based on a digital I/O board PCI7248 produced by Adlink technology is developed. An experiment is implemented to validate it. Its low crosstalk characteristics make it promote the real application of the SHM based active lamb wave method. Finally, a general software program based on LabVIEW software platform is developed to control this switch unit.

关键词： structural health monitoring (SHM) piezoelectric (PZT) sensor networks switch unit crosstalk signal

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Synthesis and properties of tetrathiafulvalene-porphyrin assemblies

Meijiang LI, Rui HUANG, Changzhi WU, Hujin ZUO, Guoqiao LAI, Yongjia SHEN

《化学科学与工程前沿（英文）》 2011年第5卷第4期页码 422-428 doi: 10.1007/s11705-011-1124-x

摘要： Two donor-σ-acceptor molecular systems incorporating tetrathiafulvalene (TTF) and tetraphenylporphyrin (TPP) units, TTF-TPP ( ) and TTF-TPP-TTF ( ), were synthesized. Both and and their synthetic intermediates have been characterized by H nuclear magnetic resonance ( H NMR) and mass spectrography (MS). Their ultraviolet and visible spectroscopy (UV-Vis) and cyclic voltammetry (CV) showed negligible intramolecular charge transfer interaction in their ground states. Their fluorescence intensity was strongly quenched compared with TPP, which implied the photoinduced electron transfer occurred from the TTF unit to the TPP unit in the excited state. On the other hand, their fluorescence intensity could be modulated by sequential oxidation of the TTF unit using chemical methods, which exhibited their potential application in fluorescence molecular switch.

关键词： tetrathiafulvalene tetraphenylporphyrin dyad triad fluorescence molecular switch

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Generation and repair of AID-initiated DNA lesions in B lymphocytes

null

《医学前沿（英文）》 2014年第8卷第2期页码 201-216 doi: 10.1007/s11684-014-0324-4

摘要：

Activation-induced deaminase (AID) initiates the secondary antibody diversification process in B lymphocytes. In mammalian B cells, this process includes somatic hypermutation (SHM) and class switch recombination (CSR), both of which require AID. AID induces U:G mismatch lesions in DNA that are subsequently converted into point mutations or DNA double stranded breaks during SHM/CSR. In a physiological context, AID targets immunoglobulin (Ig) loci to mediate SHM/CSR. However, recent studies reveal genome-wide access of AID to numerous non-Ig loci. Thus, AID poses a threat to the genome of B cells if AID-initiated DNA lesions cannot be properly repaired. In this review, we focus on the molecular mechanisms that regulate the specificity of AID targeting and the repair pathways responsible for processing AID-initiated DNA lesions.

关键词： class switch recombination somatic hypermutation activation-induced deaminase DNA repair genomic instability

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Microbial mediated arsenic biotransformation in wetlands

Si-Yu Zhang, Paul N. Williams, Jinming Luo, Yong-Guan Zhu

《环境科学与工程前沿（英文）》 2017年第11卷第1期 doi: 10.1007/s11783-017-0893-y

摘要： Distribution and behavior of arsenic in wetland are summarized. Macro-scale and micro-scale processes in wetland are reviewed. Microbes act as the switch in determining wetland as a source or sink of arsenic. Environmental factors affecting arsenic microbial biotransformation are summarized. Arsenic (As) is a pervasive environmental toxin and carcinogenic metalloid. It ranks at the top of the US priority List of Hazardous Substances and causes worldwide human health problems. Wetlands, including natural and artificial ecosystems (i.e. paddy soils) are highly susceptible to As enrichment; acting not only as repositories for water but a host of other elemental/chemical moieties. While macro-scale processes (physical and geological) supply As to wetlands, it is the micro-scale biogeochemistry that regulates the fluxes of As and other trace elements from the semi-terrestrial to neighboring plant/aquatic/atmospheric compartments. Among these fine-scale events, microbial mediated As biotransformations contribute most to the element’s changing forms, acting as the ‘switch’ in defining a wetland as either a source or sink of As. Much of our understanding of these important microbial catalyzed reactions follows relatively recent scientific discoveries. Here we document some of these key advances, with focuses on the implications that wetlands and their microbial mediated transformation pathways have on the global As cycle, the chemistries of microbial mediated As oxidation, reduction and methylation, and future research priorities areas.

关键词： Arsenic Wetland Microbes Switch

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新型弧焊电源及其智能控制

黄石生,薛家祥,余文松,陈延明

《中国工程科学》 2000年第2卷第4期页码 70-74

摘要：

重点介绍了弧焊逆变器新的发展方向--软开关相移PWM控制技术，给出了一个具体的电路实例和试验结果；分析了弧焊逆变器动态过程的仿真技术和模糊逻辑控制方法，为新型弧焊逆变器的研制提供了一种新思路。

关键词：弧焊逆变器软开关动态过程仿真模糊控制

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交换式以太网NC建模与实时性能分析

王晓欣,刘鲁源,刘昆,马津艳

《中国工程科学》 2006年第8卷第6期页码 55-59

摘要：

交换式以太网的实时性能分析是工业以太网研究领域的一个热点课题，目前还没有一个有效的数学模型来对其进行描述。通过对典型交换机结构的分析，应用网络微积分理论建立了交换机的服务曲线模型，该模型将交换机中的数据流分为实时数据和非实时数据，并得到了最大延迟值和最大缓存需求值等，最大延迟为交换机的实时应用提供了理论边界值，最大缓存需求值为在实时工业环境中的交换机构建提供了理论参考。

关键词：网络微积分交换机到达曲线服务曲线延迟

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关于下一代网络的体系结构

李国杰

《中国工程科学》 2002年第4卷第8期页码 40-43

摘要：

归纳了对下一代网络的共识与分歧，分析了产生分歧的原因，提出应重视网络体系结构研究，包括重新认识边缘论（end-to-end argument）、光通信与分组交换技术的融合、UNI模式向NNI模式的过渡，同时要关注网络结构和动力学规律的基础研究。

关键词：网络体系结构光通信分组交换 UNI NNI 网络动力学

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具有容错结构的高可用计算机双系统研究

金士尧,胡华平,李宏亮

《中国工程科学》 1999年第1卷第3期页码 46-50

摘要：

为了确保高的可用性，在重大工程实践中往往采用具有容错结构的计算机双系统。双系统处理得到两个结果的异同性，历来是研究双系统容错的技术重点和难点。文章在双系统可用性分析、结果判错与选择、以及双工切换技术方面都有突破性的进展，并在重点工程中得以实现，取得显著效果。

关键词：可用性双工系统故障判别率切入成功率

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基于IP骨干网的虚拟专用网理论与实现

李秀忠

《中国工程科学》 2002年第4卷第3期页码 84-91

摘要：

讨论了虚拟专用网（VPN），尤其是IP-VPN的相关方面。在此基础上分析了IP-VPN的虚拟专用路由网（VPRN）和虚拟专用局域网（VPLS）两种类型。着重讨论了VPRN的两种实现机制——边界网关协议/多协议标记交换（BGP/MPLS）和虚拟路由器（VR），并进行了比较。实现了一种VPLS——虚拟局域网（VLAN）。最后从理论上探讨了基于网络的VPN的服务质量（QoS）并提出了一种VPN QoS的实现途径。

关键词：虚拟专用路由网（VPRN）虚拟专用局域网段（VPLS）边界网关协议/多协议标记交换（BGP/MPLS）虚拟路由器（VR）最坏情况加权公平排队（WF²Q）随机早期检测（RED）

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基于切换和迁移多执行体架构虚拟机的云侧信道攻击防御技术 Regular Papers

Chao YANG, Yun-fei GUO, Hong-chao HU, Ya-wen WANG, Qing TONG, Ling-shu LI

《信息与电子工程前沿（英文）》 2019年第20卷第5期页码 731-748 doi: 10.1631/FITEE.1800526

摘要：云中不同租户的虚拟机共存为以信息泄露为目标的侧信道攻击创造了便利条件。然而，当前绝大多数防御技术都存在通用性或兼容性问题，无法在真实环境下实现快速部署。作为云系统固有功能之一，虚拟机迁移机制可通过在服务器之间迁移虚拟机，限制租户共存，从而提供一种具有应用前景的防御思路。本文首先建立一个统一的攻击模型，攻击者关注的目标是有效侧信道攻击。设计了一种包含多执行架构虚拟机的新型云系统：Driftor。对于其中每个虚拟机，同一时刻有且仅有一个执行体处于运行状态，并通过代理提供服务，以此降低可能泄漏的信息量。为模拟虚拟机迁移机制，系统将在虚拟机不同执行体之前周期性切换运行状态，同时通过真实迁移操作加强防御效果。为解决CIRCUIT-SAT求解迁移问题时的弱扩展性，本文提出一种类贪婪算法，通过逐渐扩展必须迁移的虚拟机子集搜索可行解。实验结果表明，Driftor能有效防御快速侧信道攻击，且针对真实云应用的防御开销较小。

关键词：云计算；侧信道攻击；信息泄露；多执行体架构；虚拟机切换；虚拟机迁移

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标题作者时间类型操作

Low crosstalk switch unit for dense piezoelectric sensor networks

Lei QIU, Shenfang YUAN,

期刊论文

Synthesis and properties of tetrathiafulvalene-porphyrin assemblies

Meijiang LI, Rui HUANG, Changzhi WU, Hujin ZUO, Guoqiao LAI, Yongjia SHEN

期刊论文

Generation and repair of AID-initiated DNA lesions in B lymphocytes

null

期刊论文