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Fluid Dynamics & Materials Processing 2022年第1期18卷 131-144页

作者： Zhenggang Zhan Han Chen Yanyi Zhang Ruilin Cheng Gang Deng PowerChina Guiyang Engineering Co. Ltd.Guiyang550081China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing100038China Key Laboratory of Construction and Safety of Hydraulic Engineering of Ministry of Water Resources China Institute of Water Resources and Hydropower ResearchBeijing100038China

The factors influencing the permeability coefficient of gravelly soils used for the development of embankment dams(core wall)are analyzed.Such factors include(but are not limited to)soil size,anisotropy,density and boundary effects.A review of the literature is conducted and new directions of research are proposed.In such a framework,it is shown that gravelly soil with controlled density and vertical stress should be used to optimize the measurement of the vertical and horizontal permeability coefficients,respectively.

关键词： Wide-grading gravelly soil core wall materials permeability coefficient test method

Fault Location Detection of Transmission Lines in Noise Environments Based on Random Matrix Theory

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CSEE Journal of Power and Energy Systems 2022年第4期8卷 1233-1241页

作者： Jun An Zihan deng Haipeng Chen gang Mu Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of Education(Northeast Electric Power University)Jilin 132012.Jilin ProvinceChina

Fault detection and location are critically significant applications of a supervisory control system in a smart grid.The methods,based on random matrix theory(RMT),have been practiced using measurements to detect short circuit faults occurring on transmission lines.However,the diagnostic accuracy is infuenced by the noise signal in the measurements.The relationship between mean eigenvalue of a random matrix and noise is detected in this paper,and the defects of the Mean Spectral Radius(MSR),as an indicator to detect faults,are theoretically determined,along with a novel indicator of the shifting degree of maximum eigenvalue and its threshold.By comparing the indicator and the threshold,the occurrence of a fault can be assessed.Finally,an augmented matrix is constructed to locate the fault area.The proposed method can effectively achieve fault detection via the RMT without any influence of noise,and also does not depend on system models.The experiment results are based on the IEEE 39-bus system.Also,actual provincial grid data is applied to validate the effectiveness of the proposed method.

关键词： Fault detection maximum eigenvalue noise random matrix theory smart grid

Density fluctuations in intermediate-energy heavy-ion collisions

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Nuclear Science and Techniques 2022年第5期33卷 1-7页

作者： Cong Liu Xian-Gai deng Yu-gang Ma Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China

Within the framework of the isospin-dependent quantum molecular dynamics model,we simulate^(129)Xe+^(119)Sn collisions in an incident energy range of 20 to 190MeV/nucleon and discuss the liquid-gas phase transition with density fluctuations.For comparison,we also extract the effective Fisher parameter τ_(eff),multiplicity of intermediate-mass fragments(IMFs),and information entropy.It is found that the Fisher parameter and maximum information entropy of collisions have peak values at E_(beam)=50-80 MeV/nucleon.In addition,the maximum multiplicity of IMFs has a plateau around 70 MeV/nucleon.For higher-order density moments in a larger central region of[-5,5]^(3) fm^(3) in the collision system,a maximum plateau also appears as function of beam energy at energies exceeding 70 MeV/nucleon.These observables,which are consistent with each other,indicate a liquid-gas phase transition around 70 MeV/nucleon for the^(129)Xe+^(119)Sn system.

关键词： Heavy-ioncollisions Liquid-gasphase transition IQMD Density moment Intermediatemass fragment Informationentropy Fisher-lawparameter

Enhance hydrates formation with stainless steel fiber for high capacity methane storage

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Chinese Journal of Chemical Engineering 2022年第10期50卷 435-443页

作者： Zhixia deng Shuanshi Fan Yanhong Wang Xuemei Lang gang Li School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640China Guangdong Engineering Technology Research Center of Advanced Insulating Coating Zhuhai 519175China Institute of Modern Industrial Innovation South China University of TechnologyZhuhai 519175China Key Laboratory of Fuel Cell Technology of Guangdong Province Guangzhou 510640China

In order to realize efficient gas storage of hydrate,stainless steel fiber(SSF)was added to 0.03%(mass)sodium dodecyl sulfate(SDS)solution for gas storage experiment.SSF can not only improve the problem that hydration heat cannot be removed effectively in the hydration process,but also improve gas storage speed and gas storage by increasing hydrate nucleation sites.Under the experimental conditions(273.2 K,5-9 MPa),the peaks of temperature rise in SDS+SSF systems were found to become much smaller than those in SDS systems.The maximum gas storage rate and the maximum methane uptake of SSF+SDS system reached 9.89-24.90 cm^(3)·g^(-1)·min^(-1) and 178.65-200.89 cm^(3)·(g H_(2)O)-1,respectively.Compared with the surfactant SDS solution without SSF,they increased by 10.47%-33.22%and 9.16%-25.36%,respectively.The effect of SSF length on gas storage performance was studied.Due to the continuous thermal conduction network,longer SSF showed a higher gas storage capacity and methane uptake rate compared with shorter SSF.At the same time,compared with other metal fillers,SSF+SDS not only had excellent gas storage performance,but also the amount of SSF(0.1 g·ml^(-1))was only 7.6%of foamed aluminum,and the volume gas storage density was increased by 145.4%.The use of stainless steel fiber made the best use of the thermal conductivity of metal,reduced the amount of metal used,and improved the volume density and mass density of gas storage.

关键词： Methane Stainless steelfiber Gas storagecapacity Hydrate Gas storagerate Heat transfer

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

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Frontiers in Energy 2022年第6期16卷 943-955页

作者： Shun SANG Chen ZHANG Jianwen ZHANG gang SHI Fujin deng School of Electrical Engineering Nantong UniversityNantong 226019China Key Laboratory of Control of Power Transmission and Conversion of the Ministry of Education Shanghai Jiao Tong UniversityShanghai 200240China School of Electrical Engineering Southeast UniversityNanjing 210096China

This paper investigates and discusses the interaction stability issues of a wind farm with weak grid connections,where the wind turbines(WTs)are controlled by a new type of converter control strategy referred to as the voltage source(VS)control.The primary intention of the VS control method is to achieve the high-quality inertial response capability of a single WT.However,when it is applied to multiple WTs within a wind farm,its weakgrid performance regarding the stability remains concealed and needs to be clarified.To this end,a frequency domain model of the wind farm under the VS control is first developed.Based on this model and the application of a stability margin quantification index,not only the interactions between the wind farm and the weak grid but also those among WTs will be systematically assessed in this paper.A crucial finding is that the inertial response of VS control has negative impacts on the stability margin of the system,and the dominant instability mode is more related to the interactions among the WTs rather than the typical grid-wind farm interaction.Based on this knowledge,a stabilization control strategy is then proposed,aiming for stability improvements of VS control while fulfilling the demand of inertial responses.Finally,all the results are verified by time-domain simulations in power systems computer aided design/electromagnetic transients including DC(PSCAD/EMTDC).

关键词： weak grids voltage source(VS)control wind turbine(WT) stabilization control wind farm inertial response

Event-triggered consensus control of heterogeneous multi-agent systems: model-and data-based approaches

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Science China(Information Sciences) 2023年第9期66卷 151-167页

作者： Xin WANG Jian SUN Fang deng gang WANG Jie CHEN School of Automation Beijing Institute of Technology National Key Lab of Autonomous Intelligent Unmanned Systems Beijing Institute of Technology Chongqing Innovation Center Department of Control Science and Engineering Tongji University

This article addresses the model-and data-based event-triggered consensus of heterogeneous leader/follower multi-agent systems(MASs). A dynamic periodic transmission protocol is developed to alleviate the communication and computational burden, where the followers can interact locally with neighbors to approach the dynamics of the leader. Capitalizing on a discrete-time looped-functional, a model-based consensus condition for the closed-loop MASs is derived as linear matrix inequalities(LMIs), along with a design method for obtaining distributed event-triggered controllers and the associated triggering parameters.Upon collecting noise-corrupted state-input measurements in offline open-loop experiments, a data-based leader/follower MAS representation is derived and employed to address the data-driven consensus control problem without explicit MAS models. This result is subsequently generalized to guarantee an H∞-consensus control performance. Finally, a simulation example is given to corroborate the efficiency of the proposed distributed triggering scheme and the data-driven consensus controller.

关键词： data-driven control multi-agent system consensus looped-functional LMI

Purifying chylous plasma by precluding triglyceride via carboxylated polyethersulfone microfiltration membrane

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Chinese Journal of Chemical Engineering 2022年第9期35卷 130-139页

作者： Yang Liu Qiu Han Guiliang Li Haibo Lin Fu Liu Gang Deng Dingfeng Lv Weijie Sun Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 315000China University of Chinese Academy of Sciences Beijing 100049China The Ningbo Central Blood Station Ningbo 315099China Department of Blood Transfusion Ningbo First HospitalNingbo 315010China

Precluding the excessive lipoproteins from plasma rapidly and effectively is highly needed for biomedical detection and reducing plasma product scrap in blood donation stations.The current centrifugation procedure is high-cost and time-consuming.Herein,we fabricated an anionic microfiltration polyethersulfone(PES)membrane modified by interface swelling and implanting of acrylic acid(AA)for screening out large particle lipoprotein chylomicron(CM)and adsorbing cationic very low-density lipoproteins(VLDL).To improve the separation efficiency,a two-stage filtration through carboxylated polyethersulfone microfiltration membranes with the mean pore size of 0.45 and 0.22μm respectively were conducted.Attenuated total reflection Fourier transform infrared technique(ATR-FTIR),water contact angle(WCA),Zeta potential and scanning electron microscope(SEM)were employed to characterize the modified membrane.To test the effectiveness of this membrane,plasma flux and concentration variation of plasma components were examined to study the purification effectiveness.Furthermore,the hemocompatibility of modified membranes was tested to confirm its practicability on bloodcontacting materials.The carboxylated polyethersulfone microfiltration membrane shows its promising potential application to purify chylous plasma.

关键词： Chylous plasma Chylomicrons Very low-density lipoproteins Carboxylated polyethersulfone microfiltration membrane

Serum folate status among blood donors in south-central China

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Journal of Innovative Optical Health Sciences 2022年第2期15卷 42-48页

作者： Yan Ma Huan deng Mingdi He Ru Yang gang Shen Wuhan Blood Center-Huazhong University of Science and Technology United Hematology Optical Imaging Center Hubei Institute of Blood Transfusion Wuhan Blood Center WuhanHubei 430030P.R.China Wuhan Blood Center-Huazhong University of Science and Technology United Hematology Optical Imaging Center Britton Chance Center for Biomedical Photonics School of Optical and Electronic Information-Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology 430074 P.R.China

Folate deficiency has been confirmed to be related to various diseases.Unfortunately,there are few reports on the folate status of Chinese adults.This study aims to evaluate the serum folate status of blood donors in south-central China.In this study,248 blood donors were included.The information on subjects was collected by a brief questionnaire concerning alcohol consumption habits,smoking habits,fruit and vegetable consumption and physical activity.The serum folate concentration was measured by electrochemiluminescence immunoassay.The geometric mean serum folate concentration was 13.4 nmoll-1(95%CI,12.7-14.1).The prevalence of serum folate concentrations below 6.8 nmoll-1 was 5.2%(95%CI,2.5-8.0).There were significant differences in serum folate concentrations with respect to sex(p-values<0.05),age(p-values<0.05),fruit and vegetable consumption(p-values<0.05),and alcohol consumption habits(p-values<0.05).The concentration of serum folate increased with age(p-values<0.05)and fruit and vegetable consumption(p-values<0.05).Individuals with an age of 30 years or younger were nearly 3.5 times as likely as those aged over 30 years to have an insufficient level of serum folate(OR=3.48;95%CI:1.01-11.99).An age of 30 years or younger was a risk factor for folate deficiency.Most blood donors had sufficient serum folate concentrations in south-central China.National surveys of folate status should be implemented in China.

关键词： Serum folate folate status folate de¯ciency blood donors folate concentrations

Range-spread target detector via coherent energy accumulation and block thresholding denoising

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Journal of Systems Engineering and Electronics 2021年第4期32卷 873-880页

作者： ZHANG Yunjian PAN Pingping deng Zhenmiao WU gang School of Electronics and Communication Engineering Sun Yat-sen UniversityGuangzhou 510275China Jiuquan Satellite Launch Center Dunhuang 736200China

A range-spread target(RST)detector is proposed for wideband radar.The detector,referred to as a conjugate multiplication and block thresholding(CMBT)detector,is simple for implementation in existing radar systems and has the advantage of minor calculation.First,the target energy of adjacent stretched echoes is coherently accumulated via conjugate multiplication and Fourier transform operations.It is noted that conjugate multiplication of two complex Gaussian distributed noise is complex double Gaussian distributed,leading to a signal to noise ratio(SNR)loss.Subsequently,considering the sparsity and clustering characteristics of the conjugate multiplication amplitude spectrum(CMAS),the block thresholding method is adopted for denoising,where the noise and cross-terms are adaptively smoothed,and the signal terms can be basically preserved.Finally,numerical simulation results for both synthetic and real radar data validate the effectiveness of the proposed detector,comparing with the conventional integration detector(ID),the spatial scattering density(SSD)detector,and waveform entropy(WE)and waveform contrast(WC)based detectors.

关键词： wideband radar detection range-spread target conjugate multiplication block thresholding denoising

Synthesis, performance and structure characterization of glyoxal-monomethylolurea-melamine (G-MMU-M) co-condensed resin

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中国化学工程学报:英文版 2023年第7期59卷 92-104页

作者： Haixiang Liu Jun Zhang Chunlei Dong gang Zhu Guanben Du Shuduan deng Yunnan Key Laboratory of Wood Adhesives and Glue Products Southwest Forestry UniversityKunming 650224China

In order to reduce the formaldehyde emission of formaldehyde-based wood adhesive from the source,it is aimed to develop a novel co-condensed resin of glyoxal-monomethylolurea-melamine(G-MMU-M).A series of G-MMU-M resins with various formulations of raw materials were successfully prepared.The basic properties and bonding performance of the G-MMU-M resins were determined.Furthermore,the structures of resins were characterized by FTIR,^(13)C NMR,XPS,and ESI-MS.The results show that the prepared G-MMU-M resin remains stable for 30 d,meanwhile,the dry and wet bonding strength of the plywoods bonded with the resins,solid content and viscosity are influenced greatly by the addition amount of melamine and MMU/G molar ratio.The G-MMU-M resins with MMU/G molar ratio of 0.9:1.0 and 8% melamine exhibit the highest dry and bonding strength of 1.98 MPa and 1.27 MPa,increased by 34% and 63%,respectively,in comparison with glyoxal-monomethylolurea(G-MMU)resin.In the G-MMU-M resins,there were four main oligomers including M—CH(—^(+)CH-MMU)-O-MMU,M-CH(—CH_(2)OH)-MMU-O-MMU,M—CH(—OH)—^(+)CH-MMU-O-MMU,and M—CH(—^(+)CH-MMU)-MMU-p-G.

关键词： Wood adhesive Glyoxal-monomethylolurea-melamine Synthesis Chemical reaction Measurement Structure