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A comprehensive review on microchannel heat sinks for electronics cooling

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International Journal of Extreme Manufacturing 2024年第2期6卷 133-162页

作者： Zhi-Qiang Yu Mo-Tong li Bing-Yang cao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084People’s Republic of China

The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device *** the development of micro-machining technologies,the microchannel heat sink(MCHS)has become one of the best ways to remove the considerable amount of heat generated by high-power *** has the advantages of large specific surface area,small size,coolant saving and high heat transfer *** paper comprehensively takes an overview of the research progress in MCHSs and generalizes the hotspots and bottlenecks of this *** heat transfer mechanisms and performances of different channel structures,coolants,channel materials and some other influencing factors are ***,this paper classifies the heat transfer enhancement technology and reviews the related studies on both the single-phase and phase-change flow and heat *** comprehensive review is expected to provide a theoretical reference and technical guidance for further research and application of MCHSs in the future.

关键词： microchannel heat sink thermal management of electronics microscale heat transfer heat transfer enhancement

Investigating Optical Transport Network Performance:A Recurrence Plot Approach

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China Communications 2024年第5期21卷 166-176页

作者： Sun Xiaochuan cao Difei Wei Biao li Zhigang li Yingqi College of Artificial Intelligence North China University of Science and TechnologyTangshan 063210China Hebei Key Laboratory of Industrial Intelligent Perception Tangshan 063210China

In future optical transport networks,lightpath performance analysis is of great practical significance for fully automated *** general,the quality of transmission(QoT)of lightpaths,measured by optical quality factor or optical signal-to-noise ratio,has a complex time-varying process,along with the interactions of the other lightpath state parameters(LSPs),such as transmit power,chromatic dispersion,polarization mode *** studies are mostly focused on lightpath QoT estimation,but ignoring lightpath-level data *** this case,our article proposes a novel lightpath performance analysis method considering recurrence plot(RP)and cross recurrence plot(CRP).Firstly,we give a detailed interpretation on the recurrence patterns of LSPs via a qualitative 2-D RP representation and its quantitative *** can potentially enable the accurate and fast lightpath failure detection with a low computational *** the other hand,CRP is devoted to modeling the relationships between lightpath QoT and LSPs,and the correlation degree is determined by a geometric mean of multiple indexes of cross recurrence quantification *** the view of application,such CRP analysis can provide the effective knowledge sharing to guarantee more credible QoT *** experiments on a real-world optical network dataset have clearly demonstrated the effectiveness of our proposal.

关键词： CRP analysis lightpath QoT optical transport networks RP analysis

Coupled Cross-Flow/in-line Vortex-Induced Vibration Responses of a Catenary-Type Riser Subjected to Uniform Flows

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Journal of Ocean University of China 2024年第5期23卷 1202-1212页

作者： li Xiaomin cao Xi li Fuheng YANG Zhiwen College of Engineering Ocean University of ChinaQingdao 266404China College of Hydrodynamic Engineering Tianjin Research Institute for Water Transport EngineeringM.O.TTianjin 300456China

A three-dimensional numerical scheme was developed to investigate the vortex-induced vibration(VIV)of a catenary-type riser(CTR)in the in-line(IL)and cross-flow(CF)*** using the vector form intrinsic finite element method,the CTR was discretized into a finite number of spatial particles whose motions satisfy Newton’s second *** Van der Pol oscillator was used to simulate the effect of vortex *** coupling equations of structural vibration and wake oscillator were solved using an explicit central differential *** numerical model was verified with the published *** VIV characteristics of the CTR subjected to uniform flows,including displacement,frequency,standing wave,traveling wave,motion trajectory,and energy transfer,were studied *** numerical results revealed that the multimode property occurs in the CF-and IL-direction VIV responses of the *** increase in the flow velocity has slight effects on the maximum VIV *** to structural nonlin-earity,the double-frequency relationship in the CF and IL directions is rarely ***,the vibration trajectories display the shape of an inclined elliptical ***,the negative energy region is inconspicuous under the excitation of the uniform flow.

关键词： vortex-induced vibration vector form intrinsic finite element catenary-type riser wake oscillator equation

Cadherin-18 loss in prospermatogonia and spermatogonial stem cells enhances cell adhesion through a compensatory mechanism

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Zoological Research 2024年第5期45卷 1048-1060页

作者： Xiao-Xiao li Dan-Chen Zhang Yan Wang Jian wen Xing-Ju Wang Yu-Lu cao Ru Jiang Jia-Rui li Yi-Nuo li He-He liu wen-Hai Xie Zheng-Feng Xu Ping Hu Kang Zou Germline Stem Cells and Microenvironment Lab College of Animal Science and TechnologyNanjing Agricultural UniversityNanjingJiangsu 210095China Stem Cell Research and Translation Center Nanjing Agricultural UniversityNanjingJiangsu 210095China School of life Sciences and Medicine Shandong University of TechnologyZiboShandong 255000China Department of Prenatal Diagnosis Women’s Hospital of Nanjing Medical UniversityNanjing Maternity and Child Health Care HospitalNanjingJiangsu 210004China

Extracellular membrane proteins are crucial for mediating cell attachment,recognition,and signal transduction in the testicular microenvironment,particularly germline stem *** 18(CDH18),a type Ⅱ classical cadherin,is primarily expressed in the nervous and reproductive ***,we investigated the expression of CDH18in neonatal porcine prospermatogonia(ProSGs)and murine spermatogonial stem cells(SSCs).Disruption of CDH18 expression did not adversely affect cell morphology,proliferation,self-renewal,or differentiation in cultured porcine ProSGs,but enhanced cell adhesion and prolonged cell *** analysis indicated that the down-regulation of CDH18 in ProSGs significantly up-regulated genes and signaling pathways associated with cell *** further elucidate the function of CDH18 in germ cells,Cdh18 knockout mice were generated,which exhibited normal testicular morphology,histology,*** analysis showed increased expression of genes associated with adhesion,consistent with the observations in porcine *** interaction of CDH18withβ-catenin and JAK2 in both porcine ProSGs and murine SSCs suggested an inhibitory effect on the canonical Wnt and JAK-STAT signaling pathways during CDH18 ***,these findings highlight the crucial role of CDH18 in regulating cell adhesion in porcine ProSGs and mouse *** this regulatory mechanism provides significant insights into the testicular niche.

关键词： Extracellular signal Fertility Quiescency Wnt signaling pathway

A Novel CCA-NMF Whitening Method for Practical Machine Learning Based Underwater Direction of Arrival Estimation

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Journal of Beijing Institute of Technology 2024年第2期33卷 163-174页

作者： Yun Wu Xinting li Zhimin cao School of Physics and Electronic Engineering Northeast Petroleum UniversityDaqing 163318China

Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical *** to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based DOA estimation methods trained on simulated Gaussian noised array data cannot be directly applied to actual underwater DOA estimation *** order to deal with this problem,environmental data with no target echoes can be employed to analyze the non-Gaussian ***,the obtained information about non-Gaussian components can be used to whiten the array *** on these considerations,a novel practical sonar array whitening method was ***,based on a weak assumption that the non-Gaussian components in adjacent patches with and without target echoes are almost the same,canonical cor-relation analysis(CCA)and non-negative matrix factorization(NMF)techniques are employed for whitening the array *** the whitened array data,machine learning based DOA estimation models trained on simulated Gaussian noised datasets can be used to perform underwater DOA estimation *** results illustrated that,using actual underwater datasets for testing with known machine learning based DOA estimation models,accurate and robust DOA estimation performance can be achieved by using the proposed whitening method in different underwater con-ditions.

关键词： direction of arrival(DOA) sonar array data underwater disturbance machine learn-ing canonical correlation analysis(CCA) non-negative matrix factorization(NMF)

Efficient simulation of spatially correlated non-stationary ground motions by wavelet-packet algorithm and spectral representation method

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 799-814页

作者： Ji Kun cao Xuyang Wang Suyang wen Ruizhi College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100022China Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

Although the classical spectral representation method(SRM)has been widely used in the generation of spatially varying ground motions,there are still challenges in efficient simulation of the non-stationary stochastic vector process in *** first problem is the inherent limitation and inflexibility of the deterministic time/frequency modulation *** difficulty is the estimation of evolutionary power spectral density(EPSD)with quite a few *** tackle these problems,the wavelet packet transform(WPT)algorithm is utilized to build a time-varying spectrum of seed recording which describes the energy distribution in the time-frequency *** time-varying spectrum is proven to preserve the time and frequency marginal property as theoretical EPSD will do for the stationary *** the simulation of spatially varying ground motions,the auto-EPSD for all locations is directly estimated using the time-varying spectrum of seed recording rather than matching predefined EPSD *** the constructed spectral matrix is incorporated in SRM to simulate spatially varying non-stationary ground motions using efficient Cholesky decomposition *** addition to a good match with the target coherency model,two numerical examples indicate that the generated time histories retain the physical properties of the prescribed seed recording,including waveform,temporal/spectral non-stationarity,normalized energy buildup,and significant duration.

关键词： non-stationarity time-varying spectrum wavelet packet transform(WPT) spectral representation method(SRM) response spectrum spatially varying recordings

Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

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High Voltage 2024年第1期9卷 137-149页

作者： Ruoyu Han Yuchen cao Yakun liu Xi Chen Ting li Chen li Pengfei li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijingChina Department of Electrical Engineering Shanghai Jiaotong UniversityShanghaiChina Beijing Institute of Astronautical System Engineering BeijingChina Aerospace Research Institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the *** paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed *** visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical *** results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal *** transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate *** inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive *** addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion *** information reveals two different plasma states of main discharge arc channel and adjacent surface electrical *** correspondence of the physical mechanism of electrical explosion and optical radiation is *** images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism *** research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

Atomic layer deposition in advanced display technologies:from photoluminescence to encapsulation

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International Journal of Extreme Manufacturing 2024年第2期6卷 65-82页

作者： Rong Chen Kun cao Yanwei wen Fan Yang Jian Wang Xiao liu Bin Shan State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiPeople’s Republic of China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiPeople’s Republic of China

Driven by the growing demand for next-generation displays,the development of advanced luminescent materials with exceptional photoelectric properties is rapidly accelerating,with such materials including quantum dots and phosphors,***,the primary challenge preventing the practical application of these luminescent materials lies in meeting the required durability *** layer deposition(ALD)has,therefore,been employed to stabilize luminescent materials,and as a result,flexible display devices have been fabricated through material modification,surface and interface engineering,encapsulation,cross-scale manufacturing,and *** addition,the appropriate equipment has been developed for both spatial ALD and fluidized ALD to satisfy the low-cost,high-efficiency,and high-reliability manufacturing *** strategic approach establishes the groundwork for the development of ultra-stable luminescent materials,highly efficient light-emitting diodes(LEDs),and thin-film ***,this significantly enhances their potential applicability in LED illumination and backlighted displays,marking a notable advancement in the display industry.

关键词： atomic layer deposition display luminescent encapsulation

Large Eddy Simulation of Vertical Structure and Size Density of Deep Layer Clouds

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Advances in Atmospheric Sciences 2024年第8期41卷 1629-1642,1668-1670页

作者： Bangjun cao Xianyu YANG Jun wen Qin HU Ziyuan ZHU School of Atmospheric Sciences Chengdu University of Information TechnologyChengdu 610225China Institute for Geophysics and Meteorology University of CologneCologne 50923Germany

In a convective scheme featuring a discretized cloud size density, the assumed lateral mixing rate is inversely proportional to the exponential coefficient of plume size. This follows a typical assumption of-1, but it has unveiled inherent uncertainties, especially for deep layer clouds. Addressing this knowledge gap, we conducted comprehensive large eddy simulations and comparative analyses focused on terrestrial regions. Our investigation revealed that cloud formation adheres to the tenets of Bernoulli trials, illustrating power-law scaling that remains consistent regardless of the inherent deep layer cloud attributes existing between cloud size and the number of clouds. This scaling paradigm encompasses liquid, ice, and mixed phases in deep layer clouds. The exponent characterizing the interplay between cloud scale and number in the deep layer cloud, specifically for liquid, ice, or mixed-phase clouds, resembles that of shallow convection,but converges closely to zero. This convergence signifies a propensity for diminished cloud numbers and sizes within deep layer clouds. Notably, the infusion of abundant moisture and the release of latent heat by condensation within the lower atmospheric strata make substantial contributions. However, this role in ice phase formation is limited. The emergence of liquid and ice phases in deep layer clouds is facilitated by the latent heat and influenced by the wind shear inherent in the middle levels. These interrelationships hold potential applications in formulating parameterizations and post-processing model outcomes.

关键词： deep layer cloud cloud spatial structure cloud size density large eddy simulation