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Hybrid MMC with Low Voltage Operations and DC Fault Ride-through Capabilities Based on Auxiliary Full-bridge Converter

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CSEE Journal of Power and Energy Systems 2022年第3期8卷 864-871页

作者： Xibei Zhao Jiangping ding Jianzhong Xu Jinsha yuan State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University(NCEPU)Beijing102206China

The hybrid modular multilevel converter(MMC)based on half-bridge sub-modules(HBSMs)and full-bridge submodules(FBSMs)can operate at low DC voltages and clear DC side fault ***,the costs and power losses are much higher in hybrid *** auxiliary full-bridge converter(AFC)is designed to reconstruct the converter structure in the arm level,and the HBSMs output capacitor voltage through the AFC can attain similar capabilities to hybrid *** operational principle of the auxiliary full-bridge converter is discussed,and the low voltage operation and non-blocking fault ride through control are verified in a two-terminal DC network *** economic analysis,the power loss of the AFC is similar to a HBSM MMC but the total investment is lower than a hybrid MMC,making the AFC a promising solution to improve the existing HBSM converter with more controllability.

关键词： DC fault fault ride through hybrid MMC low voltage operation

Chlorine-free emission disposal of spent acid etchant in a three-compartment ceramic membrane reactor

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Chinese Journal of Chemical Engineering 2020年第1期28卷 271-278页

作者： Fanglu yuan Lele Cui Peipei ding Wenheng Jing State Key Laboratory of Materials-Oriented Chemical Engineering National Engineering Research Center for Special Separation MembraneCollege of Chemical EngineeringNanjing Tech UniversityNanjing 211800China

Electrochemical technologies for the on-site treatment of spent acid etchant have received great attention due their ease of operation and economic benefits. On the other hand, a large amount of Cl2 is generated during the electrolysis process, which leads to potential environmental risks. In the present work, a novel threecompartment ceramic membrane flow reactor, including a cathode chamber, an anode chamber, and a gas absorption chamber was developed. The three chambers were divided by an Al2O3 ceramic membrane and a breathable hydrophobic anode diffusion electrode(ADE). The Cl2 evolution onset potential of the ADE was increased to 1.19 V from 1.05 V of the graphite felt, effectively inhibiting the chlorine evolution reaction(CER).The anode-generated Cl2 diffused into the gas absorption chamber through the ADE and was eventually consumed by the H2O2 adsorbent. Cu could be recovered without emitting chlorine due to the special structure of reactor. The current efficiency of copper precipitation and cathode reduction from Cu2+to Cu+reached 97.7%at a working current of 150 m A. These results indicated that the novel membrane reactor had high potential for application in the copper recovery industry.

关键词： Spent acid etchant Chlorine evolution reaction Anode diffusion electrode Three-compartment reactor Ceramic membrane

Successful endovascular treatment with long-term antibiotic therapy for infectious pseudoaneurysm due to Klebsiella pneumoniae:A case report

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World Journal of Clinical Cases 2020年第24期8卷 6529-6536页

作者： Tie-Hao Wang Ji-Chun Zhao Bin huang Jia-Rong Wang ding yuan Department of Vascular Surgery West China HospitalSichuan UniversityChengdu 610000Sichuan ProvinceChina

BACKGROUND Infectious common femoral artery pseudoaneurysm caused by Klebsiellapulmonary infection is a relatively infrequent entity but is potentially life andlimb threatening. The management of infectious pseudoaneurysm *** SUMMARY We reported a 79-year-old man with previous Klebsiella pneumoniae pulmonaryinfection and multiple comorbidities who presented with a progressive pulsatemass at the right groin and with right lower limb pain. Computed tomographyangiography showed a 6 cm × 6 cm × 9 cm pseudoaneurysm of the right commonfemoral artery accompanied by occlusion of the right superficial femoral arteryand deep femoral artery. He underwent endovascular treatment (EVT) withstent–graft, and etiology of infectious pseudoaneurysm was confirmed. Then, 3-mo antibiotic therapy was given. One-year follow-up showed the stent–graft waspatent and complete removal of surrounding *** The femoral artery pseudoaneurysm can be caused by Klebsiella pneumoniaederiving from the pulmonary infection. Moreover, this unusual case highlights theuse of EVT and prolonged antibiotic therapy for infectious pseudoaneurysm.

关键词： Infectious pseudoaneurysm Common femoral artery Klebsiella pneumoniae Antibiotic therapy Endovascular treatment Case report

Persistent fast kink magnetohydrodynamic waves detected in a quiescent prominence

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Science China(Physics,Mechanics & Astronomy) 2022年第3期65卷 122-130页

作者： Dong Li Jianchao Xue ding yuan Zongjun Ning Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China CAS Key Laboratory of Solar Activity National Astronomical ObservatoriesBeijing 100101China Institute of Space Science and Applied Technology Harbin Institute of TechnologyShenzhen 518055China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China

Small-scale, cyclic, transverse motions of plasma threads are usually seen in solar prominences, which are often interpreted as magnetohydrodynamic(MHD) waves. Here, we observed small-scale decayless transverse oscillations in a quiescent prominence, and they appear to be omnipresent. The oscillatory periods of the emission intensity and a proxy for the line-of-sight Doppler shift are about half period of the displacement oscillations. This feature agrees well with the fast kink-mode waves in a flux tube. All the moving threads oscillate transversally spatially in phase and exhibit no significant damping throughout the visible segments, indicating that the fast kink MHD waves are persistently powered and ongoing dissipating energy is transferred to the ambient plasma in the quiet corona. However, our calculations suggest that the energy taken by the fast kink MHD waves alone can not support the coronal heating on the quiet Sun.

关键词： the Sun corona prominence magnetohydrodynamic(MHD)waves

Effect of the surface properties of an activated coke on its desulphurization performance

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Mining Science and Technology 2009年第6期19卷 769-774页

作者： ZHANG Xiang-lan ZHANG Yan ding Fang-sheng huang Qi-jiang LI yuan School of Chemical and Environmental Engineering China University of Mining ＆ Technology Beijing 100083 China

Commercial coke was modified by H2O2 and/or NH3.H2O to obtain an activated coke containing additional oxygen functional groups and/or nitrogen functional groups. The aim of the modification was to enhance the SO2 adsorption capacity of the activated coke. Several techniques, including total nitrogen content measurements, SO2 adsorption, XPS and FTIR analysis, were used to characterize the coke samples. The XPS and FTIR spectra suggest the existence of -CONH2 groups in the H2O2 plus ammonia modified coke. The SO2 adsorption capacity of an activated coke increases slightly with an increase in H2O2 concentration during the modification process. The desulphurization performance of a modified coke is considerably enhanced by increasing the treatment temperature during ammonia modification. The amount of nitrogen in a coke modified by H2O2 plus NH3.H2O is the highest, and the SO2 adsorption capacity of the coke is also the highest (89.9 mg/gC). The NH3.H2O (only) modified sample has lower nitrogen content and lower desulphurization capacity (79.9 mg/gC). H2O modification gives the lowest SO2 adsorption capacity (28.9 mg/gC). The H2O2 pre-treatment is beneficial for the introduction of nitrogen onto the surface of a sample during the following ammonia treatment process.

关键词： activated coke surface property desulphurization property

Ex vivo revascularization of renal artery aneurysms in a patient with solitary kidney: A case report

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World Journal of Clinical Cases 2019年第16期7卷 2401-2405页

作者： Xi-Yang Chen Ji-Chun Zhao Bin huang ding yuan Yi Yang Department of Vascular Surgery West China Hospital of Sichuan University

BACKGROUND Multiple renal artery aneurysms (RAAs) involving multiple branches in a solitary kidney are rare and present a major challenge to *** vivo or in situ repair combined with renal artery revascularization is the classical procedure for these complicated cases,which are not suitable for endovascular *** choice of bypass graft remains controversial because of the risk of aneurysmal degeneration for autologous *** SUMMARY A 39-year-old female patient presented with left lumbar pain for more than 3 *** tomography angiography showed congenital absence of the right kidney and three left RAAs involving multiple distal *** patient met the criteria for surgical repair due to symptoms of threatened *** to the anatomy and location of multiple RAAs,ex vivo revascularization with saphenous vein graft (SVG) was *** the 3-year follow-up,computed tomography angiography demonstrated the aneurysmal degeneration of the Yshaped *** patient remained asymptomatic and follow-up ultrasound showed no continuous growth of SVG *** SVG aneurysm in RAA revascularization causes us to reflect on the choice of graft,especially for solitary kidney patients.

关键词： Renal artery aneurysm Bypass Ex vivo repair Aneurysmal degeneration Case report

Adjustable ion energy barrier for reliable memristive neuromorphic systems

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Science China Materials 2024年第11期67卷 3759-3760页

作者： Tianci huang Zuqing yuan School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China

With the rapid development of artificial intelligence and the processing of large-scale data,the demand for low-power and high-speed computing has become increasingly crucial[1].Neuromorphic computing,which mimics the neural structure of the human brain,offers a promising solution to overcome the limitations of traditional von Neumann architecture[2,3].

关键词： overcome limitations barrier

Strain concentration factor of heterogeneous materials and analytical influence functions based on Eshelby tensor

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Theoretical & Applied Mechanics Letters 2024年第4期14卷 306-313页

作者： Shanqiao huang Zifeng yuan HEDPS Center for Applied Physics and TechnologyDepartment of Mechanics and Engineering SciencePeking UniversityBeijing 100871China State Key Laboratory for Turbulence and Complex Systems Peking UniversityBeijing 100871China

In this manuscript,Eshelby tensor is employed to assess the strain concentration that arises in the matrix phase at the interface,offering precise values and locations of maximum strain under specific loading conditions for both spherical and cylindrical *** compared to numerical simulation results,the analytical predictions grounded in the Eshelby tensor exhibit satisfactory *** an analytical calculation method based on Eshelby tensor for the elastic strain influence functions of reduced-order homogenization(ROH)method is developed and adopted on particle-reinforced and fibrous composites,presenting its feasibility and advantage on off-line stage calculation of ROH *** error analyses between analytical and numerical results are *** numerical results also exhibit the necessity of finer interface partitioning to obtain the response on micro-scale with higher resolution.

关键词： Eshelby tensor Strain concentration Composite structures Reduced-order-homogenization Influence functions

Al-enabled properties distribution prediction for high-pressure die casting Al-Si alloy

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Advances in Manufacturing 2024年第3期12卷 591-602页

作者： Yu-Tong Yang Zhong-yuan Qiu Zhen Zheng Liang-Xi Pu ding-ding Chen Jiang Zheng Rui-Jie Zhang Bo Zhang Shi-Yao huang Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing211816People’s Republic of China Xi’an Jiaotong-Liverpool University Suzhou215000JiangsuPeople’s Republic of China Materials Academy JITRI Suzhou215100JiangsuPeople’s Republic of China Key Laboratory for Light-weight Materials Nanjing University of Science and TechnologyNanjing210009People’s Republic of China College of Materials Science and Engineering Chongqing UniversityChongqing400044People’s Republic of China Collaborate Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083People’s Republic of China Chongqing Millison Technologies Inc. Chongqing401321People’s Republic of China

High-pressure die casting(HPDC)is one of the most popular mass production processes in the automotive industry owing to its capability for part ***,the nonuniform distribution of mechanical properties in large-sized HPDC products adds complexity to part property ***,a methodology for property prediction must be *** characterization,simulation technologies,and artificial intelligence(AI)algorithms were ***,an image recognition technique was employed to construct a temperature-microstructure characteristic model for a typical HPDC Al7Si0.2Mg ***,a porosity/microstructure-mechanical property model was established using a machine learning method based on the finite element method and representative volume element model ***,the computational results of the casting simulation software were mapped with the porosity/microstructure-mechanical property model,allowing accurate prediction of the property distribution of the HPDC Al-Si *** AI-enabled property distribution model developed in this study is expected to serve as a foundation for intelligent HPDC part design platforms in the automotive industry.

关键词： Artificial intelligence(AI) Properties prediction High-pressure die-casting(HPDC) Image recognition Machine learning