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Rapidly modifying microstructure and mechanical properties of AA7150 Al alloy processed with electropulsing treatment

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Journal of Materials Science & Technology 2021年第36期95卷 172-179页

作者： kai Chen Lihua zhan Wenfang Yu College of Mechanical and Electrical Engineering of Central South University Changsha 410083China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Light Alloy Research institute of Central South University Changsha 410083China

Studies show that the proper solid solution treatment(SST)is a key step in the precipitation strengthening of AA7150 Al *** the superior characteristics of the fully dissolved phase,it has major drawbacks,including high consumption of energy and low ***,electropulsing treatment(EPT)has been proposed to study dissolved precipitations and modify microstructures of AA7150 Al alloy faster than conventional *** have been conducted in the present article,and the obtained results show that EPT can promote the rapid dissolution of theη’phase at relatively low temperatures in only 20 ***,the strength and ductility of electropulsed samples decrease *** with conventional SST,EPT accelerates recrystallization and obtains relatively fine grains after 20 and 50 s electric ***,as the EPT time increases,the corresponding non-uniform local heating and the electron force promote dislocation generation and annihilation.

关键词： AA7150 Al alloy Electropulsing treatment Rapid dissolution Recrystallization Dislocation

intelligent Mining Technology for an Underground Metal Mine Based on Unmanned Equipment

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Engineering 2018年第3期4卷 381-391页

作者： Jian-guo Li kai zhan BGRiMM Technology Group Beijing 100160 China

This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technolo- gies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole （DTH） drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining： the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technol- ogy is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China＇s mining industry.

关键词： Underground Autonomous Communication Navigation intelligent

Daifan San intervenes in forkhead box P3 and the interleukin(iL)-23/iL-17A signaling pathway to help prevent and treat primary biliary cirrhosis

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Journal of Traditional Chinese Medicine 2020年第4期40卷 571-583页

作者： zhan kai Xu Yan Han Mengling Cheng Liangbin The Second Clinical College of Guangzhou University of Chinese Medicine Guangzhou 510000China Department of internal Medicine Hubei Rongjun HospitalWuhan 430079China Department of Hepatology the Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510000China Department of Hepatology Hubei Provincial Hospital of Chinese MedicineWuhan 430061China

OBJECTiVE:To investigate the mechanism by which Daifan San(DFS)prevents and treats primary biliary cirrhosis(PBC)via the forkhead box P3(FoxP3)and interleukin(iL)-23/iL-17A signaling ***:Ninety C57BL/6 mice were randomly divided into the control,model,DFS low-dose,DFS middle-dose,DFS high-dose and ursodeoxycholic acid(UDCA)groups(n=15 per group).A mouse model of PBC was induced using polyinosinic polycytidylic acids(poly i:C).Lymphocyte subset expression in the peripheral blood was analyzed via flow *** inflammatory cytokines and antimitochondrial autoantibody(AMA)levels were detected via enzyme-linked immunosorbent *** expressions and location of typeⅠcollagen,typeⅢcollagen,cytokeratin 19 and FoxP3 in the liver tissue were evaluated via ***3,iL-23 and iL-17 expressions in the peripheral blood and liver tissue were evaluated via real-time polymerase chain reaction and western ***:iL-17,iL-23,iL-8,iL-33,TNF-α,and AMA expressions were significantly increased in the model group and decreased in the DFS and UDCA ***,Treg cell and FoxP3 expressions were significantly decreased in the model group and increased in the DFS and UDCA *** iL-23/iL-17A signaling pathway was closely correlated with chronic inflammation of the bile duct in PBC and functional deletion of Treg cells,leading to reduced FoxP3 levels and mediating the loss of tolerance in ***:DFS may delay the occurrence and relieve the symptoms of PBC by downregulating iL-23/iL-17A signaling pathway expression and upregulating FoxP3 expression.

关键词： Liver cirrhosis,biliary interleukin-23 interleukin-17 Signal transduction FoxP3 protein,mouse Daifan San

Electro-optic 3D snapshot of a laser wakefield accelerated kilo-ampere electron bunch

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Light(Science & Applications) 2024年第5期13卷 823-834页

作者： kai Huang zhan Jin Nobuhiko Nakanii Tomonao Hosokai Masaki Kando Kansai institute for Photon Science(KPSi) National Institutes for Quantum Science and Technology(QST)KyotoJapan. Laser Accelerator R&D Innovative Light Sources DivisionRIKEN SPring-8 CenterHyogoJapan. SANKEN Osaka UniversityOsakaJapan

Laser wakefield acceleration,as an advanced accelerator concept,has attracted great attentions for its ultrahigh acceleration gradient and the capability to produce high brightness electron *** three-dimensional(3D)density serves as an evaluation metric for the particle bunch quality and is intrinsically related to the applications of an *** its significance,this parameter has not been experimentally measured in the investigation of laser wakefield *** report on an electro-optic 3D snapshot of a laser wakefield electron bunch at a position outside the *** 3D shape of the electron bunch was detected by simultaneously performing optical transition radiation imaging and electro-optic *** 3D structures to a few micrometer levels were reconstructed using a genetic *** electron bunch possessed a transverse size of less than 30 *** current profile shows a multi-peak *** main peak had a duration of1 *** maximum electron 3D number density was~9×10^(21)m^(-3).This research demonstrates a feasible way of 3D density monitoring on femtosecond kilo-ampere electron bunches,at any position of a beam transport line for relevant applications.

关键词： laser acceleration field

GNSS vulnerabilities:simulation,verification,and mitigation platform design

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Geo-Spatial information Science 2013年第3期16卷 149-154页

作者： Xin ZHAO Xingqun zhan kai YAN School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

This paper introduces the design and construction of global navigation satellite systems(GNSS)vulnerability simulation,verification,and mitigation *** platform contains five modules:simulation of the signal-in-space environment,simulation of the vulnerabilities in the space segment,signal quality monitoring and data processing,vulnerability assessment and validation,and integrated *** provides a set of integrated simulations of different types of interference in the GNSS signal propagation domain,including electromagnetic interference,atmospheric disturbances,multipath,and interference in the inter-satellite *** paper focuses on the design of the main system modules and testing through an experimental *** results demonstrate both the effectiveness and realism of the modules and overall platform.

关键词： GNSS vulnerability spoofing jamming ionosphere delay multipath effect

Microstructural evolution and aging behavior of Mg-4.5Y-2.5Nd-1.0Gd-0.5Zr alloys with different Zn additions

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Rare Metals 2021年第8期40卷 2188-2196页

作者： Zheng Tian Qiang Yang kai Guan zhan-Yi Cao Jian Meng Key Laboratory of Automobile Materials of Ministry of Education Department of Materials Science and EngineeringJilin UniversityChangchun130025China State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

Microstructures and mechanical properties of Mg-4.5 Y-2.5 Nd-1.0 Gd-0.5 Zr-xZn(x=0,0.5,1.0,and 1.5;wt%)alloys under as-cast and peak-aged states were investigated in this *** results indicate that the intermetallic phase components are closely dependent on Zn *** as-cast state,the dominant eutectic phase is Mg5 RE in the alloys with 0 wt%and 0.5 wt%Zn additions while Mg5 RE,18 R-and 14 H-LPSO(long period stacking ordered)phases in the alloys with 1.0 wt%and1.5 wt%Zn *** solution and peak-aging,the highest strength and hardness were obtained on the alloy with 0.5 wt%Zn *** electron microscopy(TEM)characterizations revealed that there are denser and finer precipitates on basal(β’)and prismatic(γ’)planes,***,the excellent mechanical performance of the alloy with 0.5 wt%Zn addition is mainly due to precipitation strengthening and grain boundary strengthening.

关键词： Magnesium alloy intermetallic phase Precipitates Mechanical property

Synthesis and mesomorphic properties of bent-shaped molecule with low bent-angle central core and long alkylthio tail

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Chinese Chemical Letters 2011年第9期22卷 1111-1114页

作者： Xiao Dong Li Mao Sheng zhan kai Wang School of Material Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China

Two homologous series of bent-shaped molecules composed of low bent-angle naphthalene central core and long alkoxy tail or alkylthio tail, N（1,7）-n-OPiMB and N（1,7）-n-SP1MB （n = 20, 22）, respectively, were synthesized. The mesomorphic properties were investigated by differential scanning calorimetry （DSC）, polarizing optical microscopy （POM） and X-ray diffraction （XRD）. Compared to the direct transition from the isotropic phase to the chiral B4 phase examined in N（1,7）-n-OPiMB, N（1,7）-n-SPiMB exhibited a rare iso-Ncol-Colh-B4 phase sequence. The combination of the asymmetric low bent-angle 1,7-naphathalene central core and the flexible long alkylthio tail is considered to play an important role in the formation of such a novel phase sequence.

关键词： Bent-shaped Liquid crystal Alkylthio tail Mesomorphic behaviour

Container introspection: Using External Management Containers to Monitor Containers in Cloud Computing

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Computers, Materials & Continua 2021年第12期69卷 3783-3794页

作者： Dongyang zhan kai Tan Lin Ye Haining Yu Hao Liu School of Cyberspace Science Harbin Institute of TechnologyHarbin150001China Temple University Philadelphia19122USA City University of Hong Kong Kowloon Tong518057Hong Kong Qianxin Technology Group Co. Ltd.Beijing100000China

Cloud computing plays an important role in today’s internet environment,which meets the requirements of scalability,security and reliability by using virtualization *** technology is one of the two mainstream virtualization *** lightweight,high deployment efficiency make container technology widely used in large-scale cloud *** container technology has created huge benefits for cloud service providers and tenants,it cannot meet the requirements of security monitoring and management from a tenant ***,tenants can only run their security monitors in the target container,but it is not secure because the attacker is able to detect and compromise the security *** this paper,a secure external monitoring approach is proposed to monitor target containers in another management *** management container is transparent for target containers,but it can obtain the executing information of target containers,providing a secure monitoring *** monitors running inside management containers are secure for the cloud host,since the management containers are not *** implement the transparent external management containers by performing the one-way isolation of processes and *** process one-way isolation,we leverage Linux namespace technology to let management container become the parent of target *** mounting the file system of target container to that of the management container,file system one-way isolation is *** with the existing host-based monitoring approach,our approach is more secure and suitable in the cloud environment.

关键词： Container introspection management container external approach one-way isolation

Long-term surface water changes and driving cause in Xiong'an,China:from dense Landsat time series images and synthetic analysis

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Science Bulletin 2018年第11期63卷 708-716页

作者： Chunqiao Song Linghong Ke Hang Pan Shengan zhan kai Liu Ronghua Ma Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China Department of Geography University of CaliforniaLos AngelesLos AngelesCA 90095United States School of Earth Sciences and Engineering Hohai UniversityNanjing 211100China Department of Geographic information Science Nanjing UniversityNanjing 210023China

China＇s government statement recently reported the plan of constructing Xiong＇an New Area, which aims to phase out some extra capital functions from Beijing and to explore an innovative urban development mode with the priority in eco-environmental protection. The New Area is located in the semi-arid North China Plain （NCP） and is home to NCP＇s largest natural freshwater wetland, Baiyangdian Lake. A comprehensive realization of surface water dynamics would be crucial for policy-makers to outline a sustainable environment development strategy for New Area. in this study, we used a total of 245 time slices of cloud-free Landsat images to document the continuous changes of water bodies within Xiong＇an City dur- ing 1984-2016 and to provide detailed evidence of water presence and persistency states and changes under the influences of climate change and human actions. Our results reveal that the New Area water body areas varied dramatically during the past 33 years, ranging from 0.44 km^2 in April 1988 to 317.85 km^2 in February 1989. The change of surface water area was not characterized by a monotonically decreasing tendency. The evolution processes can be divided into four sub-stages： the first extreme desiccation in mid-1980s, the wet stage with the most extensive inundation areas and strong inter-annual fluctuations from late-1988 to late 1999, another desiccation stage in early 2000s, and the overall recovering stage between 2007 and 2016. We also mapped the maximum water inundation extents and frequencies of all-season, pre-wet season （February-May） and post-wet season （September-December） for the 33 years and different sub-periods. Although there is good agreement between time series of surface water area evolution in the New Area and station-based precipitation and evaporation variations, multipie lines of evidences reviewed in previous research indicate that the degraded Baiyangdian Lake was also tightly associated with human activities from various aspects, inc

关键词： Xiong'an New Area Surface water Baiyangdian Lake Remote sensing Climate change Landsat