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Petroleum Science 2024年第2期21卷 1369-1384页

作者： Chong-Zheng Sun Yu-Xing Li Hui Han xiao-yi geng xiao Lu College of Energy Storage Technology Shandong University of Science and TechnologyQingdao 266590ShandongChina College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety China University of PetroleumQingdao 266580ShandongChina

Liquid hydrogen storage and transportation is an effective method for large-scale transportation and utilization of hydrogen energy. Revealing the flow mechanism of cryogenic working fluid is the key to optimize heat exchanger structure and hydrogen liquefaction process(LH2). The methods of cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the falling film flow characteristics with the effect of co-current gas flow in LH2spiral wound heat *** results show that the flow rate of mixed refrigerant has a great influence on liquid film spreading process, falling film flow pattern and heat transfer performance. The liquid film of LH2mixed refrigerant with column flow pattern can not uniformly and completely cover the tube wall surface. As liquid flow rate increases, the falling film flow pattern evolves into sheet-column flow and sheet flow, and liquid film completely covers the surface of tube wall. With the increase of shear effect of gas-phase mixed refrigerant in the same direction, the liquid film gradually becomes unstable, and the flow pattern eventually evolves into a mist flow.

关键词： Hydrogen liquefaction Spiral wound heat exchanger Flow pattern transition Falling film flow

Simulation Research on a SVPWM Control Algorithm for a Four-Leg Active Power Filter

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Journal of China University of Mining and Technology 2007年第4期17卷 590-594页

作者： ZHOU Juan WU xiao-jie geng yi-wen DAI Peng School of Information and Electrical Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

In this paper the topology of a four-leg shunt active-power filter (APF) is given. The APF compensates har-monic and reactive power in a three-phase four-wire system. The scheme adopted for control of the four-leg active power filter,a 3-Dimensional Pulse Width Modulation (PWM) technique,is presented. The theoretical deduction of a space vector PWM (SVPWM) algorithm is given in this paper. The paper also analyzes the distribution of the volt-age-space vector of the four-leg converter in αβγ coordinates and describes methods to determine the location of the voltage-space vector and to calculate duration time. Finally,the algorithm is implemented in simulation; the results show that the total harmonic distortion (THD) of the three phase-current waveforms is reduced. The neutral wire current,after compensation,is about 0 A showing that the topology of the four-leg shunt APF is feasible and the proposed scheme is effective.

关键词： three-phase four-wire system shunt active power filter 3-Dimensional space vector PWM

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IPSec虚拟专用网络服务质量研究与仿真

计算机仿真 2009年第8期26卷 137-142页

作者：肖耿毅桂林师范高等专科学校物理与信息技术系广西桂林541001

IPSec虚拟专用网在使用IPSec的加密、认证和封装等功能后,将会导致其服务质量(QoS)明显下降。为研究加密和认证这两个影响最大的因素,分析了目前IPSec虚拟专用网常用的加密算法和认证算法对QoS的影响,利用OPNET仿真工具建立了IPSec虚拟... 详细信息

IPSec虚拟专用网在使用IPSec的加密、认证和封装等功能后,将会导致其服务质量(QoS)明显下降。为研究加密和认证这两个影响最大的因素,分析了目前IPSec虚拟专用网常用的加密算法和认证算法对QoS的影响,利用OPNET仿真工具建立了IPSec虚拟专用网的仿真模型,把不同组合的常用加密算法和认证算法对QoS的影响分别进行仿真,并对仿真结果做了对比分析。结果表明,在隧道方式下,采用ESP/DES/MD5算法组合的IPSec_F irewall_VPN1的QoS性能最好,而加密对QoS的影响较大。今后在网络运行过程中,可以参考仿真优化结果提高网络安全和服务质量,按需求,灵活选择,使运行达到最佳的效果。

关键词：虚拟专用网服务质量加密认证仿真

基于SPCSE与WKELM的网络入侵检测方法研究

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计算机仿真 2022年第6期39卷 425-429页

作者：肖耿毅桂林师范高等专科学校数学与计算机技术系广西桂林541199

网络入侵检测系统是用于保护系统免受非法攻击的重要网络防御工具,网络入侵行为复杂的、冗长的特征严重影响网络入侵的检测效果。现提出一种基于稀疏主成分空间嵌入与加权核极限学习机的网络入侵检测方法。为了有效约简网络入侵数据的特... 详细信息

网络入侵检测系统是用于保护系统免受非法攻击的重要网络防御工具,网络入侵行为复杂的、冗长的特征严重影响网络入侵的检测效果。现提出一种基于稀疏主成分空间嵌入与加权核极限学习机的网络入侵检测方法。为了有效约简网络入侵数据的特征,提出一种基于稀疏主成分的特征约简的降维算法,即稀疏主成分空间嵌入算法(SPCSE)。同时,为了改进极限学习机的检测效果,提出一种加权核极限学习机算法(WKELM),它采用核函数代替包含激活函数的加权极限学习机隐层随机特征映射,有利于提高算法的非线性处理能力和鲁棒性。仿真结果显示加权核极限学习机对于网络入侵的检测精度95%,极限学习机对于网络入侵的检测精度92%,而提出的网络入侵检测方法对于网络入侵的检测精度达到98.5%,表明提出的网络入侵检测方法对于网络入侵的检测结果优于传统极限学习机以及加权核极限学习机。

关键词：稀疏主成分空间嵌入加权核极限学习机网络入侵检测

A promising approach for quantifying focal stroke modeling and assessing stroke progression:optical resolution photoacoustic microscopy photothrombosis

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Neural Regeneration Research 2025年第7期20卷 2029-2037页

作者： xiao Liang Xingping Quan xiaorui geng Yujing Huang Yonghua Zhao Lei Xi Zhen Yuan Ping Wang Bin Liu Faculty of Health Sciences University of MacaoMacao Special Administrative RegionChina Center for Cognitive and Brain Sciences University of MacaoMacao Special Administrative RegionChina Department of Biomedical Engineering Southern University of Science and TechnologyShenzhenGuangdong ProvinceChina State Key Laboratory of Quality Research in Chinese Medicine Institute of Chinese Medical SciencesUniversity of MacaoTaipaMacao Special Administrative RegionChina Department of Emergency Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina

To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral ***,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly *** this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed *** observed the molding process in mice of different ages and presented age-dependent vascular embolism ***,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a *** imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.

关键词： age-dependent cerebral cortex ischemic stroke mouse model optical coherence tomography angiography photoacoustic microscopy photothrombosis vascular imaging

Carbon-supported CeNCl as an efficient catalyst for CO_(2)cycloaddition

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Nano Research 2025年第1期18卷 157-163页

作者： Li Liu Lingling Zhang Xiang Chu Baokang geng Huilin Wang Zongxiang Li xiao Wang Shuyan Song Hongjie Zhang School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Sinocare Incorporation Changsha 410221China Department of Chemistry Tsinghua UniversityBeijing 100084China

The cycloaddition reaction of CO_(2)with epoxide not only effectively reduces the concentration of CO_(2)in the atmosphere,but also has excellent industrial application value and up to 100%atom utilization,but there are difficulties in separation and recovery of traditional homogeneous catalysts,harsh reaction conditions of traditional heterogeneous catalysts,and activation of CO_(2)*** this paper,an easily synthesized heterogeneous catalyst CeNCl/C was used to catalyze the cycloaddition reaction of CO_(2)with styrene oxide,with a high yield of 92.7%,a high selectivity of 96.7%,a turnover numbers(TON)value of 349,and a good stability demonstrated in six cycle tests(equivalent to 216 h of testing).Through comprehensive studies,it was shown that CeNCl/C contains Lewis acid-base centers as active centers,which can effectively reduce the energy barrier required for ring opening of the reaction substrate,enhance the adsorption and activation of CO_(2),and promote the formation of intermediates,which led to the acquisition of excellent catalytic activity.

关键词： CO_(2)cycloaddition heterogeneous catalysis CeNCl Lewis acid/base

Design of a CMOS Distributed Power Amplifier with Gradual Changed Gain Cells

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Chinese Journal of Electronics 2018年第6期27卷 1158-1162页

作者： ZHANG ying LI Zeyou YANG Hua geng xiao ZHANG yi College of Electronic and Optical Engineering College of Microelectronics Nanjing University of Posts and Telecommunications National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology Nanjing University of Posts and Telecommunications

A non-uniform Distributed power amplifier(DPA) is designed and implemented in a 0.18μm CMOS technology. The gradual changed gain cells work with the tapered on-chip inductors to construct non-uniform artificial transmission lines, which improves the output power and efficiency in a wide frequency band while maintaining good input and output impedance matching. The proposed DPA achieves 9 dB average associated gain from 1 to 17.2 GHz, and the input return loss is less than--9 dB while the output return loss is less than-8.5 dB in the desired frequency band. The output power at 1 dB Output compression point(OP1 dB) is more than 7.8 dBm in the frequency band of 2-16 GHz, and the peak power-added efficiency is 6.2% with the OP1 dB12.6 dBm at 4 GHz.

关键词： Distributed amplifier Impedance matching Power added efficiency Artificial transmission line

Non-volatile constituents and pharmacology of Chimonanthus: A review

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Chinese Journal of Natural Medicines 2019年第3期17卷 161-186页

作者： SHU Ren-geng WAN yi-Li WANG xiao-Min School of Pharmacy Jiangxi University of Traditional Chinese Medicine School of Pharmacy China Pharmaceutical University School of Life Science Jiangxi University of Traditional Chinese Medicine

Chimonanthus plants widely distributed in southern area of China, which have a long history of edibles and medicine. Phytochemical investigations have shown that Chimonanthus produced 143 non-volatile constituents, including alkaloids, flavonoids, terpenoids, coumarins and others, which exhibit significant anti-oxidant, anti-bacterial, anti-cancer, anti-inflammatory, antihyperglycemic, antihyperlipidemic and other biological activities. On the basis of systematic reviewing of literatures, this article overviews the non-volatile constituents and pharmacology of Chimonanthus from domestic and foreign over the last 30 years(until June 2018), and may provide a useful reference for the further development of Chimonanthus.

关键词： Chimonanthus Non-volatile constituents Pharmacology Review

On the properties of the Rational Function Spectrum describing waves near islands and reefs in South China Sea

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Journal of Hydrodynamics 2021年第5期33卷 879-888页

作者： yi-geng Wang Zhi Zong Li Zhou xiao-long Liu Xue-kang Gu School of Naval Architecture Dalian University of TechnologyDalian 116024China China Ship Scientific Research Center Wuxi 214082China

On-site measurements show that water waves near islands and reefs in South China Sea exhibit different properties of wave energy distributions with regard to wave frequencies,among which the most prominent factor is the interplay of swells arising from the West Pacific Ocean and the local wind *** also show that the breaking waves continuously appear,containing more energy in high frequency components,and the nonlinear characteristics of the waves are important in adjusting the energy *** properties may explain the large discrepancies between the well-accepted wave spectra(for example the P-M spectrum,Neumann spectrum,ITTC spectrum etc.)and the measured wave spectra near islands and reefs in South China ***,a new Rational Function Spectrum is proposed in this paper to describe waves near islands and reefs which turns out to show satisfactory *** well captures wave power distributions in the form of single and double peaks,at low-and high-frequency regions,as well as nonlinear scale power *** on the investigation of the measured data near an island in South China Sea,the relation between the parameters used in the Rational Function Spectrum and the statistical parameters of water waves(significant wave height and wave period)is *** is noted that the wave properties at low-and high-frequencies are controlled by the local wind velocities at the wave growth stage,but remain constant at the wave decay *** parameter peak frequency is only dependent on the wave period corresponding to the maximum wave *** parameter spectral peak is determined from the wave height and the wave *** relations help to clarify the physical meanings of the parameters used in the Rational Function Spectrum,and thus provide an alternative spectral form to describe random waves near islands and reefs.

关键词： Rational Function Spectrum double peak near islands and reefs swell nonlinear

Recent Progress and Applications of HfO_(2)-Based Ferroelectric Memory

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Tsinghua Science and Technology 2023年第2期28卷 221-229页

作者： xiao Liu Xiangshun geng Houfang Liu Minghao Shao Ruiting Zhao yi Yang Tian-Ling Ren Beijing National Research Center for Information Science and Technology(BNRist) School of Integrated CircuitsTsinghua UniversityBeijing 100084China

The discovery of ferroelectricity in hafnium oxide (HfO_(2)) based thin films in 2011 renewed the interest inferroelectrics. These new ferroelectrics possess completely different crystal morphology with conventional perovskiteferroelectrics, and present more robust ferroelectric properties upon aggressive scaling and compatibility withstandard integrated circuit fabrication processes. In this article, we give a brief introduction to the conventionalferroelectric memories, then review the basic properties, recent progress, and memory applications of theseHfO_(2)-based ferroelectrics.

关键词： ferroelectric memory non-volatile memory hafnium oxide fluorite structure material