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工程饱和介质中漩涡光的调制不稳定性 Review

D.G. Pires, N.M. Litchinitser

《工程（英文）》 2022年第17卷第10期页码 31-43 doi: 10.1016/j.eng.2022.04.022

摘要：

光束在水下环境、雾、云或生物组织等混浊介质中的传播在科学和技术中有着越来越重要的应用，包括生物成像、水下和自由空间通信技术。虽然这些应用在传统上依赖于常规的线性偏振高斯光束，但光具有许多未被发掘的自由度，如自旋角动量（SAM）和轨道角动量（OAM）。本文提出了具有“旋转”自由度的复杂光束在工程化非线性胶体介质中的非线性光-物质相互作用。利用变分法和摄动法，我们考虑了非圆柱光学涡旋、椭圆光学涡旋和高阶贝塞尔光束在时间上的积分（HOBBIT），来预测这些光束演化的动力学行为和稳定性。这些结果可应用于许多强散射环境下涉及光透射的情况。

关键词： Optical vortex Orbital angular momentum Modulation instability Turbid media

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Combustion instability detection using the wavelet detail of pressure fluctuations

JI Junjie, LUO Yonghao

《能源前沿（英文）》 2008年第2卷第1期页码 116-120 doi: 10.1007/s11708-008-0019-0

摘要： A combustion instability detection method that uses the wavelet detail of combustion pressure fluctuations is put forward. To confirm this method, combustion pressure fluctuations in a stoker boiler are recorded at stable and unstable combustion with a pressure transducer. Daubechies one-order wavelet is chosen to obtain the wavelet details for comparison. It shows that the wavelet approximation indicates the general pressure change in the furnace, and the wavelet detail magnitude is consistent with the intensity of turbulence and combustion noise. The magnitude of the wavelet detail is nearly constant when the combustion is stable, however, it will fluctuate much when the combustion is unstable.

关键词： comparison wavelet approximation pressure transducer general pressure consistent

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海底不稳定性研究进展及展望

高伟健,李伟

《中国工程科学》 2023年第25卷第3期页码 109-121 doi: 10.15302/J-SSCAE-2023.03.010

摘要：

海底不稳定性及次生海底地质灾害广泛存在于海洋之中，对海岸港口设施、海洋钻井平台、海底管道光缆等海底基础建设颇具威胁。但目前对海底不稳定性的成因机制与主控因素仍知之甚少，为加深对海底不稳定性的认识，本文回顾了海底不稳定性研究进展，梳理了海底不稳定性及次生海底地质灾害的主要类别、全球分布情况和地球物理识别特征，归纳了目前海底不稳定性研究的定量分析方法，进一步分析了其成因机制、控制因素及工程地质灾害风险，探讨了海底陆坡失稳演化过程试验模拟技术的适用范畴与技术瓶颈。最后，从海底不稳定性的致灾机理研究、多源数据智能分析和海底失稳立体监测3 个维度提出了未来海底不稳定性研究的发展方向与对策建议，以期为海底不稳定性的模拟、预测和预警等工作提供指导性建议。

关键词：海底不稳定性；海底地质灾害；成因机制；风险评估；不稳定性分析

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基于双正交复序列的高效扩频调制方法

史小红

《中国工程科学》 2012年第14卷第3期页码 108-112

摘要：

提出了一种采用双正交复序列的高效扩频调制与解调方法（DoCS）。输入数据比特流被分割为长度为M的组，每组的M比特作为输入码字，从2M-2个长度为L的DoCS序列中选择一条序列进行发送，被选中的序列以QPSK方式调制在载波上，实现扩频通信。文中还提出了一种前向相位校正(FPC)方法来解决该系统中收发两端的载波同步问题。

关键词：调制与解调技术高效扩频调制前向相位校正双正交码

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A driving pulse edge modulation technique and its complex programming logic devices implementation

Xiao CHEN,Dong-chang QU,Yong GUO,Guo-zhu CHEN

《信息与电子工程前沿（英文）》 2015年第16卷第12期页码 1088-1098 doi: 10.1631/FITEE.1500111

摘要： With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insulated gate bipolar transistors (IGBTs). By modulating the density and width of the pulse trains, without regulating the hardware circuit, the slope of the gate driving voltage is controlled to change the switching speed. This technique is used in the driving circuit based on complex programmable logic devices (CPLDs), and the switching voltage spike of IGBTs can be restrained through software, which is easier and more flexible to adjust. Experimental results demonstrate the effectiveness and practicability of the proposed method.

关键词： Driving pulse edge modulation Switching voltage spike Complex programmable logic device (CPLD) Active gate drive

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表面张力作用下柱形胶体的弹性失稳

黄殿武,乔玲,汪时机

《中国工程科学》 2007年第9卷第4期页码 50-54

摘要：

采用弹性理论研究了圆柱形胶体在表面张力作用下的弹性失稳问题；利用能量泛函变分的方法导出了发生弹性失稳的非经典边界条件，得到了失稳的判据方程。分析判据方程发现，弹性失稳与圆柱体的半径、内禀尺度和失稳波长相关。

关键词：柱形胶体弹性失稳内禀尺度表面效应

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Cannabidiol prevents depressive-like behaviors through the modulation of neural stem cell differentiation

《医学前沿（英文）》 2022年第16卷第2期页码 227-239 doi: 10.1007/s11684-021-0896-8

摘要： Chronic stress impairs radial neural stem cell (rNSC) differentiation and adult hippocampal neurogenesis (AHN), whereas promoting AHN can increase stress resilience against depression. Therefore, investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs. The nonpsychoactive phytocannabinoid cannabidiol (CBD) has been shown to be effective against depression. However, whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown. Here, by using the chronic restraint stress (CRS) mouse model, we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions. Moreover, transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process. The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte, which was partly mediated by the modulation of the FoxO signaling pathway. These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.

关键词： cannabidiol depression radial neural stem cells neurogenesis

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Underlying mechanism of the hydrothermal instability of Cu

Nadeen Al-Janabi,Abdullatif Alfutimie,Flor R. Siperstein,Xiaolei Fan

《化学科学与工程前沿（英文）》 2016年第10卷第1期页码 103-107 doi: 10.1007/s11705-015-1552-0

摘要： Water induced decomposition of Cu (BTC) (BTC= benzene-1,3,5-tricarboxylate) metal-organic framework (MOF) was studied using dynamic water vapour adsorption. Small-angle X-ray scattering, Fourier transform infrared spectroscopy and differential scanning calorimetry analyses revealed that the underlying mechanism of Cu (BTC) MOF decomposition under humid streams is the interpenetration of water molecules into Cu-BTC coordination to displace organic linkers (BTC) from Cu centres.

关键词： hydrothermal stability metal-organic framework (MOF) open metal sites (OMSs) dynamic water vapour adsorption

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Mechanisms and impacts of chromosomal translocations in cancers

null

《医学前沿（英文）》 2012年第6卷第3期页码 263-274 doi: 10.1007/s11684-012-0215-5

摘要：

Chromosomal aberrations have been associated with cancer development since their discovery more than a hundred years ago. Chromosomal translocations, a type of particular structural changes involving heterologous chromosomes, have made a critical impact on diagnosis, prognosis and treatment of cancers. For example, the discovery of translocation between chromosomes 9 and 22 and the subsequent success of targeting the fusion product BCR-ABL transformed the therapy for chronic myelogenous leukemia. In the past few decades, tremendous progress has been achieved towards elucidating the mechanism causing chromosomal translocations. This review focuses on the basic mechanisms underlying the generation of chromosomal translocations. In particular, the contribution of frequency of DNA double strand breaks and spatial proximity of translocating loci is discussed.

关键词： DNA double strand breaks chromosomal translocations genomic instability spatial proximity carcinogenesis

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病理状态下肠道微生态的调节

王玉兰, 王保红, 吴俊芳, 江向洋, 唐惠儒, Ole H. Nielsen

《工程（英文）》 2017年第3卷第1期页码 83-89 doi: 10.1016/J.ENG.2017.01.013

摘要：

人类微生态是寄居在人体中的微生物聚集体，且主要存在于胃肠道(GIT) 中。肠道微生态随着人体发育而演化，并在人类健康和疾病中起着重要作用。近年来，由于微生态会影响宿主代谢、生理学和免疫系统发育，而且微生态紊乱可能导致许多疾病，其越来越受到人们的关注。肠道微生态可能与恶性肿瘤有一定联系，如胃癌和结直肠癌；也可能与其他一些疾病有关，如非酒精性脂肪肝(NAFLD)、被称为工业化世界“生活方式疾病”的肥胖和糖尿病、冠心病以及中枢神经系统紊乱。虽然分子技术革命为我们更准确地研究肠道微生态提供了必要的工具，但是我们需要更精确地阐明其与某些人类疾病病理变化的关系，明确微生态在不同疾病中的作用是新的治疗策略发展的基础。本文概述了肠道微生态对人类健康的重要影响以及调整肠道菌群结构的潜在用途，如菌群移植用于治疗耐药艰难梭菌(C. difficile) 的感染。通过微生态干预调整肠道区域以改善人类健康的概念虽刚刚兴起，但其治疗意义显著。因此，抑制有害菌、促进有益菌可能会保护人类健康，并且这些努力将为探索发展更加合理的治疗方案打下基础。

关键词：肠道菌群疾病菌群调节

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p-Cresyl sulfate promotes the formation of atherosclerotic lesions and induces plaque instability by

null

《医学前沿（英文）》 2016年第10卷第3期页码 320-329 doi: 10.1007/s11684-016-0463-x

摘要：

Coronary atherosclerosis is a major complication of chronic kidney disease. This condition contributes to the increased mortality in dialysis patients. p-Cresyl sulfate (PCS) is a prototype of protein-bound uremic toxins that cannot be efficiently removed through routine dialysis procedures. In the present study, ApoE^−/− mice that underwent 5/6 nephrectomy were randomly divided into two groups, namely, vehicle-treated group (n = 20) and PCS-treated group (n = 20). Mice were sacrificed for en face and immunohistological analyses after 8 or 24 weeks of high-fat diet. Rat aortic vascular smooth muscle cells (VSMCs) were treated with phosphate buffer solution or 500 µmol/L PCS for in vitro evaluation. PCS-treated mice were observed to suffer increased atherosclerotic lesions after eight weeks of PCS administration. Moreover, 24 weeks of PCS administration also markedly increased the vulnerability index of aortic plaques. PCS was also observed to facilitate the migration and proliferation of VSMCs during the progression of the disease. Moreover, PCS disturbed the balance between matrix metalloproteinases and tissue inhibitor of metalloproteinases within the plaques. Thus, PCS played a vital role in promoting atherogenesis and disturbing the stability of formed plaques probably by targeting VSMCs.

关键词： p-cresyl sulfate atherosclerosis plaque stability vascular smooth muscle cell

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Dynamic modulation performance of ferroelectric liquid crystal polarization rotators and Mueller matrix

Song ZHANG, Lelun WANG, Anze YI, Honggang GU, Xiuguo CHEN, Hao JIANG, Shiyuan LIU

《机械工程前沿（英文）》 2020年第15卷第2期页码 256-264 doi: 10.1007/s11465-019-0573-7

摘要： A ferroelectric liquid crystal polarization rotator (FLCPR) has been widely used in polarization measurement due to its fast and stable modulation characteristics. The accurate characterization of the modulation performance of FLCPR directly affects the measurement accuracy of the instrument based on liquid crystal modulation. In this study, FLCPR is accurately characterized using a self-developed high-speed Stokes polarimeter. Strong linear and weak circular birefringence are observed during modulation processes, and all the optical parameters of FLCPR are dependent on driving voltage. A dual FLCPR-based Mueller matrix polarimeter is designed on the basis of the Stokes polarimeter. The designed polarimeter combines the advantages of the high modulation frequency of FLCPR and the ultrahigh temporal resolution of the fast polarization measurement system in the Stokes polarimeter. The optimal configuration of the designed polarizer is predicted in accordance with singular value decomposition. A simulated thickness measurement of a 24 nm standard SiO thin film is performed using the optimal configuration. Results show that the relative error in thickness measurement caused by using the unsatisfactory modulation characteristics of FLCPR reaches up to −4.34%. This finding demonstrates the importance of the accurate characterization of FLCPR in developing a Mueller matrix polarizer.

关键词： ferroelectric liquid crystal polarization rotator (FLCPR) dual liquid crystal Mueller matrix polarizer design and optimization

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Frequency-controlable sine signal based on PWM and its implementation on FPGA

Lianzhen HUANG, Jiangang LI, Dongjun ZHANG

《机械工程前沿（英文）》 2012年第7卷第3期页码 322-328 doi: 10.1007/s11465-012-0312-9

摘要：

A sine generation method that the different frequent sine signals can be generated by the different Pulse-Width Modulation (PWM) signals generated by Field-Programmable Gate Array (FPGA) through low-pass filter of fixed parameters was proposed. The method just takes a few FPGA resources and was proved feasible by the theory. The experiment results and theory analysis tally.

关键词： Pulse-Width Modulation (PWM) Field-Programmable Gate Array (FPGA) frequency controllable

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Analysis and design of pulse frequency modulation dielectric barrier discharge for low power applications

Tang-tang GUO,Xing-liang LIU,Shi-qiang HAO,Chi ZHANG,Xiang-ning HE

《信息与电子工程前沿（英文）》 2015年第16卷第3期页码 249-258 doi: 10.1631/FITEE.1400185

摘要： For low power dielectric barrier discharge (DBD) used in small-size material treatment or portable devices, highstep transformer parasitic capacitance greatly influences the performance of the resonant converter as it is of the same order of magnitude as the equivalent capacitance of DBD load. In this paper, steady-state analysis of the low power DBD is presented, considering the inevitable parasitic capacitance of the high-step transformer. The rectifier-compensated first harmonic approximation (RCFHA) is applied to linearize the equivalent load circuit of DBD at low frequency and the derived expressions are accurate and convenient for the analysis and design of the power supply. Based on the proposed linear equivalent load circuit, the influence of transformer parasitic capacitance on the key parameters, including the frequency range and the applied electrode voltage, is discussed when the power is regulated with pulse frequency modulation (PFM). Also, a design procedure is presented based on the derived expressions. A prototype is constructed according to the design results and the accuracy of the design is verified by experimental results.

关键词： Dielectric barrier discharge Rectifier-compensated first harmonic approximation Parasitic capacitance Power converter design

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Aerodynamic stability evolution tendency of suspension bridges with spans from 1000 to 5000 m

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0980-z

摘要： Aerodynamic instability owing to aerostatic and flutter-related failures is a significant concern in the wind-resistant design of long-span suspension bridges. Based on the dynamic characteristics of suspension bridges with spans ranging from 888 to 1991 m, we proposed fitted equations for increasing spans and base frequencies. Finite element models of suspension bridges with increasing span from 1000 to 5000 m were constructed. The structural parameters were optimized to follow the fitted tendencies. To analyze the aerodynamic instability, streamlined single-box section (SBS), lattice truss section (LTS), narrow slotted section (NSS), and wide slotted section (WSS) were considered. We performed three-dimensional (3-D) full-mode flutter analysis and nonlinear aerostatic instability analysis. The flutter critical wind speed continuously decreases with span growth, showing an unlimited approaching phenomenon. Regarding aerostatic instability, the instability wind speed decreases with span to approximately 3000 m, and increases when the span is in the range of 3000 to 5000 m. Minimum aerostatic instability wind speed with SBS or LTS girder would be lower than observed maximal gust wind speed, indicating the probability of aerostatic instability. This study proposes that suspension bridge with span approximately 3000 m should be focused on both aerostatic instability and flutter, and more aerodynamic configuration optimistic optimizations for flutter are essential for super long-span suspension bridges with spans longer than 3000 m.

关键词： suspension bridge super long-span finite element model aerodynamic instability aerodynamic configuration