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Lipschitz非线性系统；动态输出反馈控制；事件触发控制；全局渐近稳定 1

NNI 1

UNI 1

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

产权模式评价 1

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切入成功率 1

到达曲线 1

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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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Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of

Leijing Liu, Hao Zhang, Bo Xiao, Yang Liu, Bin Xu, Chen Wang, Shanpeng Wen, Erjun Zhou, Gang Chen, Chan Im, Wenjing Tian

《化学科学与工程前沿（英文）》 2021年第15卷第1期页码 127-137 doi: 10.1007/s11705-020-1936-7

摘要： Effects of a benzotriazole (BTA)-based small molecule, BTA2, as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7):[6,6]-phenyl-C -butyric acid methyl ester (PC BM) organic solar cells (OSCs) were investigated by optical simulation of a transfer matrix model (TMM), photo-induced charge extraction by linearly increasing voltage (photo-CELIV) technique, atomic force microscope (AFM), and the Onsager–Braun model analysis. BTA2 is an A A D A A -type non-fullerene small molecule with thiazolidine-2,4-dione, BTA, and indacenodithiophene as the terminal acceptor (A ), bridge acceptor (A ), and central donor (D), respectively. The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum. The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2, resulting in more photogenerated excitons in the ternary OSCs. The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs. AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor, which is disadvantageous to charge carrier transport. The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs, the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.

关键词： third component organic solar cells charge carrier generation charge carrier recombination bimolecular recombination

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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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Multi-class dynamic network traffic flow propagation model with physical queues

Yanfeng LI, Jun LI

《工程管理前沿（英文）》 2017年第4卷第4期页码 399-407 doi: 10.15302/J-FEM-2017041

摘要： This paper proposes an improved multi-class dynamic network traffic flow propagation model with a consideration of physical queues. Each link is divided into two areas: Free flow area and queue area. The vehicles of the same class are assumed to satisfy the first-in-first-out (FIFO) principle on the whole link, and the vehicles of the different classes also follow FIFO in the queue area but not in the free flow area. To characterize this phenomenon by numerical methods, the improved model is directly formulated in discrete time space. Numerical examples are developed to illustrate the unrealistic flows of the existing model and the performance of the improved model. This analysis can more realistically capture the traffic flow propagation, such as interactions between multi-class traffic flows, and the dynamic traffic interactions across multiple links.

关键词： first-in-first-out (FIFO) multi-class traffic physical queues traffic flow modeling

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A survey of instantaneous poles for a class of two-degree-of-freedom spherical mechanisms

Soheil ZARKANDI

《机械工程前沿（英文）》 2014年第9卷第4期页码 344-353 doi: 10.1007/s11465-014-0320-z

摘要：

This paper is a detailed exploration of instantaneous poles for a class of two-degree-of-freedom (two-DOF) spherical mechanisms (SMs) with seven links or bars. For two-DOF SMs, the secondary instantaneous poles (the ones which cannot be found by direct inspection) must lie on the specified great circles. For many of these mechanisms, however, some of these great circles cannot be obtained by a direct application of Aronhold-Kennedy theorem. This paper presents geometrical and analytical techniques to locate these unknown great circles for three topologies of seven-bar two-DOF SMs.

关键词： spherical mechanisms instantaneous poles Aronhold-Kennedy theorem great circles pencil of meridian

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Unified cycle model of a class of internal combustion engines and their optimum performance characteristics

Shiyan ZHENG

《能源前沿（英文）》 2011年第5卷第4期页码 367-375 doi: 10.1007/s11708-011-0170-x

摘要： The unified cycle model of a class of internal combustion engines is presented, in which the influence of the multi-irreversibilities mainly resulting from the adiabatic processes, finite-time processes and heat leak loss through the cylinder wall on the performance of the cycle are taken into account. Based on the thermodynamic analysis method, the mathematical expressions of the power output and efficiency of the cycle are calculated and some important characteristic curves are given. The influence of the various design parameters such as the high-low pressure ratio, the high-low temperature ratio, the compression and expansion isentropic efficiencies etc. on the performance of the cycle is analyzed. The optimum criteria of some important parameters such as the power output, efficiency and pressure ratio are derived. The results obtained from this unified cycle model are very general and useful, from which the optimal performance of the Atkinson, Otto, Diesel, Dual and Miller heat engines and some new heat engines can be directly derived.

关键词： internal combustion engine irreversibility power output efficiency optimization

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Statistical analysis of recombination properties of the boron-oxygen defect in p-type Czochralski silicon

Nitin NAMPALLI,Tsun Hang FUNG,Stuart WENHAM,Brett HALLAM,Malcolm ABBOTT

《能源前沿（英文）》 2017年第11卷第1期页码 4-22 doi: 10.1007/s11708-016-0442-6

摘要： This paper presents the application of lifetime spectroscopy to the study of carrier-induced degradation ascribed to the boron-oxygen (BO) defect. Specifically, a large data set of p-type silicon samples is used to investigate two important aspects of carrier lifetime analysis: ① the methods used to extract the recombination lifetime associated with the defect and ② the underlying assumption that carrier injection does not affect lifetime components unrelated to the defect. The results demonstrate that the capture cross section ratio associated with the donor level of the BO defect ( ) vary widely depending on the specific method used to extract the defect-specific recombination lifetime. For the data set studied here, it was also found that illumination used to form the defect caused minor, but statistically significant changes in the surface passivation used. This violation of the fundamental assumption could be accounted for by applying appropriate curve fitting methods, resulting in an improved estimate of (11.90±0.45) for the fully formed BO defect when modeled using the donor level alone. Illumination also appeared to cause a minor, apparently injection-independent change in lifetime that could not be attributed to the donor level of the BO defect alone and is likely related to the acceptor level of the BO defect. While specific to the BO defect, this study has implications for the use of lifetime spectroscopy to study other carrier induced defects. Finally, we demonstrate the use of a unit-less regression goodness-of-fit metric for lifetime data that is easy to interpret and accounts for repeatability error.

关键词： Czochralski silicon boron-oxygen defect injection dependent lifetime spectroscopy goodness-of-fit repeatability error

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深圳城市供水系统产权结构重组模式及评价

肖文,欧阳芳锐,王先甲

《中国工程科学》 2004年第6卷第7期页码 48-52

摘要：

提出了城市供水系统产权结构重组的两种基本模式，运用制度经济学和管理学理论，提出产权结构模式评价的指标与方法，分析了这两种产权结构模式的特性和在这两种模式下不同利益主体的行为与利益关系的变化特点及优缺点，并提出了缓解劣势的手段与方法。

关键词：城市供水产权结构产权重组产权模式评价

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Highlights in agri-product quality and safety

Guanghong ZHOU

《农业科学与工程前沿（英文）》 2018年第5卷第3期页码 289-290 doi: 10.15302/J-FASE-2018236

摘要：

关键词： valign= top class= J_zhaiyao

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The advances of Sino-German new materials

Rongbiao Wang

《化学科学与工程前沿（英文）》 2018年第12卷第3期页码 327-328 doi: 10.1007/s11705-018-1748-1

摘要：

关键词： valign= top class= J_zhaiyao

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Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

《机械工程前沿（英文）》 2020年第15卷第1期页码 66-80 doi: 10.1007/s11465-019-0570-x

摘要： The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to construct 2D rotational degrees of freedom (DOF), a platform with 2-dimension revolute joints is proposed first. Based on the constraint screw theory, the feasible limbs that can be connected in the platform are synthesized. In order to provide constant rotational axis for the platform, a class of redundant limbs are designed. A class of redundant 2R1T parallel spindle heads is obtained by connecting the redundant limbs with the platform and the redundant characteristics are verified by the modified Grübler-Kutzbach criterion. The corresponding 5-axis collaborative manipulators are presented by constructing a 2-DOF series translational bottom moving platform. The inverse kinematics and the orientation workspace as well as the decoupling characteristics of this type of 2R1T parallel spindle heads are analyzed. The results show that these manipulators have large 2D rotational angles than the traditional A3/Z3 heads and can be potentially used in the application of multi-axis machine tools and the 3D printers.

关键词： parallel mechanism redundant mechanism large rotational angles machine tools 2R1T spindle head collaborative manipulator

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Evaluation of transmissibility for a class of nonlinear passive vibration isolators

Z. K. PENG, Z. Q. LANG, G. MENG

《机械工程前沿（英文）》 2012年第7卷第4期页码 401-409 doi: 10.1007/s11465-012-0349-9

摘要：

In this study, the concept of Output Frequency Response Functions (OFRFs) is applied to represent the transmissibility of nonlinear isolators in frequency domain. With the OFRFs estimated from numerical simulation responses, an explicit analytical relationship between the transmissibility and the nonlinear characteristic parameters is derived for a wide class of nonlinear isolators that have nonlinear anti-symmetric damping characteristics and a comprehensive pattern about how the nonlinear damping characteristic parameters might affect the force and displacement transmissibility is built for the vibration isolators. The results reveal that it is reasonable to analyze the force and displacement transmissibility of the nonlinear isolators by simply investigating the fundamental harmonic components of the force and displacement outputs of the nonlinear isolators, and the introduction of a nonlinear anti-symmetric damping into vibration isolators can significantly suppress both the force and displacement transmissibility over the resonant frequency region, but has almost no effect on the transmissibility at non-resonant regions. These conclusions are of significant importance in the analysis and design of the nonlinear vibration isolators with nonlinear anti-symmetric damping.

关键词： nonlinear vibration volterra series Output Frequency Response Functions (OFRFs) nonlinear damping vibration isolator

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reference tracking control design for a class of nonlinear systems with time-varying delays

Mei-qin LIU,Hai-yang CHEN,Sen-lin ZHANG

《信息与电子工程前沿（英文）》 2015年第16卷第9期页码 759-768 doi: 10.1631/FITEE.1500053

摘要： This paper investigates the trajectory tracking control for a class of nonlinear systems with timevarying delays by virtue of Lyapunov-Krasovskii stability theory and the linear matrix inequality (LMI) technique. A unified model consisting of a linear delayed dynamic system and a bounded static nonlinear operator is introduced, which covers most of the nonlinear systems with bounded nonlinear terms, such as the one-link robotic manipulator, chaotic systems, complex networks, the continuous stirred tank reactor (CSTR), and the standard genetic regulatory network (SGRN). First, the definition of the tracking control is given. Second, the performance analysis of the closed-loop system including this unified model, reference model, and state feedback controller is presented. Then criteria on the tracking controller design are derived in terms of LMIs such that the output of the closed-loop system tracks the given reference signal in the sense. The reference model adopted here is modified to be more flexible. A scaling factor is introduced to deal with the disturbance such that the control precision is improved. Finally, a CSTR system is provided to demonstrate the effectiveness of the established control laws.

关键词： H∞ reference tracking Nonlinear system State feedback control Time-varying delays Unified model

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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