期刊文献+
共找到36篇文章
< 1 2 >
每页显示 20 50 100
Enhancing layered perovskite ferrites with ultra-high-density nanoparticles via cobalt doping for ceramic fuel cell anode
1
作者 Shuo Zhai Rubao Zhao +9 位作者 Hailong Liao Ling Fu Senran Hao Junyu Cai yifan wu Jian Wang Yunhong Jiang Jie Xiao Tao Liu Heping Xie 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期39-48,共10页
Nanoparticles anchored on the perovskite surface have gained considerable attention for their wide-ranging applications in heterogeneous catalysis and energy conversion due to their robust and integrated structural co... Nanoparticles anchored on the perovskite surface have gained considerable attention for their wide-ranging applications in heterogeneous catalysis and energy conversion due to their robust and integrated structural configuration.Herein,we employ controlled Co doping to effectively enhance the nanoparticle exsolution process in layered perovskite ferrites materials.CoFe alloy nanoparticles with ultra-high-density are exsolved on the(PrBa)_(0.95)(Fe_(0.8)Co_(0.1)Nb_(0.1))2O_(5+δ)(PBFCN_(0.1))surface under reducing atmosphere,providing significant amounts of reaction sites and good durability for hydrocarbon catalysis.Under a reducing atmosphere,cobalt facilitates the reduction of iron cations within PBFCN_(0.1),leading to the formation of CoFe alloy nanoparticles.This formation is accompanied by a cation exchange process,wherein,with the increase in temperature,partial cobalt ions are substituted by iron.Meanwhile,Co doping significantly enhance the electrical conductivity due to the stronger covalency of the Cosingle bondO bond compared with Fesingle bondO bond.A single cell with the configuration of PBFCN_(0.1)-Sm_(0.2)Ce_(0.8)O_(1.9)(SDC)|SDC|Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF)-SDC achieves an extremely low polarization resistance of 0.0163Ωcm^(2)and a high peak power density of 740 mW cm^(−2)at 800℃.The cell also shows stable operation for 120 h in H_(2)with a constant current density of 285 mA cm^(−2).Furthermore,employing wet C_(2)H_(6)as fuel,the cell demonstrates remarkable performance,achieving peak power densities of 455 mW cm^(−2)at 800℃and 320 mW cm^(−2)at 750℃,marking improvements of 36%and 70%over the cell with(PrBa)_(0.95)(Fe_(0.9)Nb_(0.1))_(2)O_(5+δ)(PBFN)-SDC at these respective temperatures.This discovery emphasizes how temperature influences alloy nanoparticles exsolution within doped layered perovskite ferrites materials,paving the way for the development of high-performance ceramic fuel cell anodes. 展开更多
关键词 Solid oxide fuel cell ANODE Ethane fuel NANOPARTICLE EXSOLUTION Layered perovskite Ferrites
下载PDF
Multimode Design and Analysis of an Integrated Leg-Arm Quadruped Robot with Deployable Characteristics
2
作者 Fuqun Zhao yifan wu +4 位作者 Xinhua Yang Xilun Ding Kun Xu Sheng Guo Xiaodong Jin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期41-61,共21页
To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of... To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of the legarm chain. When the robot performs a task, reconfigurable configuration and mode switching can be achieved using this joint. In contrast from traditional quadruped robots, this robot can stack in a designated area to optimize the occupied volume in a nonworking state. Kinematics modeling and dynamics modeling are established to evaluate the mechanical properties for multiple modes. All working modes of the robot are classified, which can be defined as deployable mode, locomotion mode and operation mode. Based on the stability margin and mechanical modeling, switching analysis and evaluation between each mode is carried out. Finally, the prototype experimental results verify the function realization and switching stability of multimode and provide a design method to integrate and perform multimode for quadruped robots with deployable characteristics. 展开更多
关键词 Quadruped robot Multimode design Mode switching Locomotion Operation
下载PDF
In Situ Deposition of Drug and Gene Nanoparticles on a Patterned Supramolecular Hydrogel to Construct a Directionally Osteochondral Plug
3
作者 Jiawei Kang Yaping Li +7 位作者 Yating Qin Zhongming Huang yifan wu Long Sun Cong Wang Wei Wang Gang Feng Yiying Qi 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期341-359,共19页
The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,sp... The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair. 展开更多
关键词 Osteochondral regeneration Oriented hydrogel Kartogenin miRNA-26a
下载PDF
Design and Analysis of a Novel Shoulder Exoskeleton Based on a Parallel Mechanism 被引量:2
4
作者 Lianzheng Niu Sheng Guo +2 位作者 Majun Song yifan wu Haibo Qu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第2期261-278,共18页
Power-assisted upper-limb exoskeletons are primarily used to improve the handling efficiency and load capacity.However,kinematic mismatch between the kinematics and biological joints is a major problem in most existin... Power-assisted upper-limb exoskeletons are primarily used to improve the handling efficiency and load capacity.However,kinematic mismatch between the kinematics and biological joints is a major problem in most existing exoskeletons,because it reduces the boosting effect and causes pain and long-term joint damage in humans.In this study,a shoulder augmentation exoskeleton was designed based on a parallel mechanism that solves the shoulder dislocation problem using the upper arm as a passive limb.Consequently,the human–machine synergy and wearability of the exoskeleton system were improved without increasing the volume and weight of the system.A parallel mechanism was used as the structural body of the shoulder joint exoskeleton,and its workspace,dexterity,and stiffness were analyzed.Additionally,an ergonomic model was developed using the principle of virtual work,and a case analysis was performed considering the lifting of heavy objects.The results show that the upper arm reduces the driving force requirement in coordinated motion,enhances the load capacity of the system,and achieves excellent assistance. 展开更多
关键词 Upper limb exoskeleton Parallel mechanism Human–machine compatibility DYNAMICS
下载PDF
Novel Radiation-Adjustable Heating Terminal Based on Flat Heat Pipe Combined with Air Source Heat Pump
5
作者 yifan wu Hongli Sun +3 位作者 Mengfan Duan Borong Lin Hengxin Zhao Chaohung Liu 《Engineering》 SCIE EI CAS CSCD 2023年第1期192-207,共16页
The electrification of building heating is an effective way to meet the global carbon target. As a clean and sustainable electrified heating technology, air-source heat pumps (ASHPs) are widely used in areas lacking c... The electrification of building heating is an effective way to meet the global carbon target. As a clean and sustainable electrified heating technology, air-source heat pumps (ASHPs) are widely used in areas lacking central heating. However, as a major component of space heating, heating terminals might not fit well with ASHP in order to achieve both intermittency and comfort. Therefore, this study proposes a novel radiation-adjustable heating terminal combined with an ASHP to achieve electrification, intermittency, and better thermal comfort. Radiant terminals currently suffer from three major problems: limited maximum heating capacity, inability to freely adapt, and difficulty with combining them with ASHPs. These problems were solved by improving the structural design of the novel terminal (Improvement A–E). Results showed that the maximum heating capacity increased by 23.6% and radiation heat transfer ratio from 10.1% to 30.9% was provided for users with the novel terminal. Further, new flat heat pipe (FHP) design improved stability (compressor oil return), intermittency (refrigerant thermal inertia), and safety (refrigerant leakage risk) by reducing the length of exposed refrigerant pipes. Furthermore, a new phased operation strategy was proposed for the novel terminal, and the adjustability of the terminal was improved. The results can be used as reference information for decarbonizing buildings by electrifying heating terminals. 展开更多
关键词 Novel heating terminal Air-source heat pump Structural impr ovement design Maximum heating capacity Rapid adjustability Room temperature distribution
下载PDF
A graphene-enhanced high-barrier and fast-curing film for deep in situ condition preserved coring in coal seams
6
作者 Dongsheng Yang Zhiyu Zhao +4 位作者 yifan wu Liangyu Zhu Jingli Lu Tao Liu Heping Xie 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第11期1365-1376,共12页
Scientific research on deep in situ resources is highly important to the theory and technology system construction for deep in-situ resource exploitation.To obtain high-condition preserved core samples,it is vital to ... Scientific research on deep in situ resources is highly important to the theory and technology system construction for deep in-situ resource exploitation.To obtain high-condition preserved core samples,it is vital to maintain the original material,humidity and luminous flux information inside the core.Therefore,this study proposes a research and development strategy for a high-toughness and highbarrier sealing film based on the molecular structure design and filler synergistic enhancement via a deep solid-state sealing film using in situ substance preservation(ISP),in situ moisture preservation(IMP)and in situ light preservation(ILP)coring principles.A graphene/epoxy composite sealing film with a high barrier,high strength and high toughness was developed.The oxygen permeability of the film was 0.23 cm^(3)/(m^(2)·d),the water vapor permeability was 1.26 g/(m^(2)·d),and the light transmittance was 0.The tensile strength reached 15.4 MPa,and the toughness was 5242.9 kJ/m^(3).The results from the film substance and moisture preservation performance verification experiments showed that the sealing film had an excellent sealing effect on small molecules,such as water,alkanes and even ions,which further verified that the sealing film greatly contributed to the maintenance and preservation of deep in-situ resource reserves and abundance. 展开更多
关键词 ISP-IMP-ILP-coring Graphene/epoxy resin composites Sealing film
下载PDF
“Guidezilla”extension catheter combined with balloon technique for treating pulmonary artery stenosis caused by Takayasu arteritis
7
作者 yifan wu Jinzhi Wang +5 位作者 Zhihui Fu Min Liu Wanmu Xie Xincao Tao Qiang Huang Zhenguo Zhai 《Journal of Interventional Medicine》 2023年第4期198-201,共4页
Takayasu arteritis(TA)is a rare systemic vasculitis of the aorta and its primary branches,which usually occurs in young women.Due to its insidious onset and lack of specific symptoms,this disease can be easily misdiag... Takayasu arteritis(TA)is a rare systemic vasculitis of the aorta and its primary branches,which usually occurs in young women.Due to its insidious onset and lack of specific symptoms,this disease can be easily misdiagnosed or missed.Approximately 50%of the patients having TA with pulmonary artery involvement develop pulmonary hypertension(PH).The 3-year survival rate among patients with TA-related PH is lower than that among patients with TA alone.Early balloon pulmonary angioplasty(BPA)can improve the clinical symptoms and survival of patients with stable TA.To the best of our knowledge,this is the first case reported in the English literature in which a“Guidezilla”catheter was used during BPA to treat stenosis and occlusion of the pulmonary artery caused by Takayasu arteritis(TA). 展开更多
关键词 Takayasu arteritis Pulmonary hypertension Balloon pulmonary angioplasty Guidezilla catheter
下载PDF
过渡金属原子对掺杂g-CN单层作为高效氮电催化剂性能 被引量:2
8
作者 黄斌 吴亦凡 +3 位作者 陈碧波 钱勇 周耐根 李能 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第7期1160-1167,共8页
由于氨是药物、肥料和树脂等领域的基础,氨合成一直广受关注.工业中主要通过Haber-Bosch反应制备氨,反应需要在高温高压下进行.因此,探索其它氨合成技术对减轻能源消耗和缓解温室效应具有重大意义.在溶液条件下,采用水作为氢质子源,电... 由于氨是药物、肥料和树脂等领域的基础,氨合成一直广受关注.工业中主要通过Haber-Bosch反应制备氨,反应需要在高温高压下进行.因此,探索其它氨合成技术对减轻能源消耗和缓解温室效应具有重大意义.在溶液条件下,采用水作为氢质子源,电化学还原氮合成氨方法受到了极大关注.然而,大多数电催化剂难以活化氮气分子且电催化氮气还原过程中存在副反应竞争,因此,研发高效的电催化材料仍然是一个重要研究领域.研究人员探索了多种电催化材料,其中,双原子对催化剂成为电催化领域的研究热点.与单原子催化剂相比,双原子对催化剂不仅具有低配位的金属原子,而且可以通过调节额外分散的金属原子来改善多数电催化反应性能.作为一种新型碳氮材料,二维g-CN具有高表面积、多孔结构以及出色的光学活性和热力学稳定性,可以与金属原子对良好地适配,是一种有潜力的基底材料.然而,目前有关金属双原子对负载在g-CN单层上作为电催化剂催化N_(2)分子还原性能尚不清楚.本文采用密度泛函理论计算研究了N_(2)分子在过渡金属原子对(TM=Sc~Zn)掺杂g-CN单层上的吸附和活化,根据吉布斯自由能详细地研究了电催化合成氨的电化学机理.计算发现,在Fe_(2)@CN和Co_(2)@CN催化剂上,其决速步骤的自由能变化分别为0.47和0.78 eV.对于Fe_(2)@CN,N_(2)电还原反应机制遵循末端路径,而在Co_(2)@CN上,其还原过程为末端或混合路径.由于Co_(2)@CN对析氢反应的抑制效果较好,因此该电催化材料体系极具竞争力.相比于Co_(2)@CN,Fe_(2)@CN具有较好的氮气活化性能,但选择性较差.另外,N_(2)分子与Fe_(2)@CN和Co_(2)@CN之间存在电荷的接受-给予过程,这在活化惰性N_(2)分子中氮原子间的三键上起到了关键作用.第一性原理分子动力学模拟结果表明,Fe_(2)@CN和Co_(2)@CN表现出较高的结构稳定性.因此,本文深入探讨了过渡金属原子对掺杂g-CN单层催化剂上的氮气还原效率及机制,为合理设计该系列的高效、低成本电催化剂提供理论依据. 展开更多
关键词 原子对催化剂 石墨氮化碳单层 氮还原反应 二维材料 密度泛函理论
下载PDF
Sustained delivery of vascular endothelial growth factor mediated by bioactive methacrylic anhydride hydrogel accelerates peripheral nerve regeneration after crush injury 被引量:3
9
作者 Wanlin Xu yifan wu +3 位作者 Hao Lu Yun Zhu Jinhai Ye Wenjun Yang 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第9期2064-2071,共8页
Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration ... Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves. 展开更多
关键词 bioactive material controlled release crush injury HYDROGEL muscle function nerve regeneration peripheral nerve sciatic function index vascular endothelial growth factor VASCULARIZATION
下载PDF
Electrochemical CO_(2) mineralization for red mud treatment driven by hydrogen-cycled membrane electrolysis 被引量:2
10
作者 Heping Xie Yunpeng Wang +6 位作者 Tao Liu yifan wu Wenchuan Jiang Cheng Lan Zhiyu Zhao Liangyu Zhu Dongsheng Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第3期14-23,共10页
CO_(2)mineralization as a promising CO_(2)mitigation strategy can employ industrial alkaline solid wastes to achieve net emission reduction of atmospheric CO_(2).The red mud is a strong alkalinity waste residue produc... CO_(2)mineralization as a promising CO_(2)mitigation strategy can employ industrial alkaline solid wastes to achieve net emission reduction of atmospheric CO_(2).The red mud is a strong alkalinity waste residue produced from the aluminum industry by the Bayer process which has the potential for the industrial CO_(2)large scale treatment.However,limited by complex components of red mud and harsh operating conditions,it is challenging to directly mineralize CO_(2)using red mud to recover carbon and sodium resources and to produce mineralized products simultaneously with high economic value efficiently.Herein,we propose a novel electrochemical CO_(2)mineralization strategy for red mud treatment driven by hydrogen-cycled membrane electrolysis,realizing mineralization of CO_(2)efficiently and recovery of carbon and sodium resources with economic value.The system utilizes H_(2)as the redox-active proton carrier to drive the cathode and anode to generate OH^(-) and H^(+) at low voltage,respectively.The H^(+) plays as a neutralizer for the alkalinity of red mud and the OH^(-) is used to mineralize CO_(2)into generate highpurity NaHCO_(3)product.We verify that the system can effectively recover carbon and sodium resources in red mud treatment process,which shows that the average electrolysis efficiency is 95.3%with highpurity(99.4%)NaHCO_(3)product obtained.The low electrolysis voltage of 0.453 V is achieved at10 mA·cm^(-2) in this system indicates a potential low energy consumption industrial process.Further,we successfully demonstrate that this process has the ability of direct efficient mineralization of flue gas CO_(2)(15%volume)without extra capturing,being a novel potential strategy for carbon neutralization. 展开更多
关键词 CO_(2)mineralization Red mud ELECTROLYSIS Waste treatment Flue gas
下载PDF
Effect of ionic liquids on stability of O/W miniemulsion for application of low emission coating products 被引量:1
11
作者 Yiyang Kong Binjie Hu +1 位作者 Yanqing Guo yifan wu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第1期196-201,共6页
Room temperature ionic liquids(RTILs) are non-volatile organic salts. They may replace conventional coalescing agents in latex coating thus reducing volatile organic compounds(VOCs) emission as well as improving perfo... Room temperature ionic liquids(RTILs) are non-volatile organic salts. They may replace conventional coalescing agents in latex coating thus reducing volatile organic compounds(VOCs) emission as well as improving performance of latex coating products such as better thermal stability, conductivity, and antifouling property. The formation of latex coating containing RTILs can be achieved by encapsulation of RTILs inside particles via miniemulsion polymerization. In this study, the role of RTILs and its concentration on stability of miniemulsion during storage and polymerization were investigated. It has been found that, above a critical concentration(10 wt%), adding more RTILs to oil phase may weaken miniemulsion stability during storage as well as polymerization. Such observations were consistent with the zeta potential measurement for miniemulsions prepared at the similar conditions. The results obtained here would be a useful guideline for the development of new waterborne coating products with desirable functions and particle sizes. 展开更多
关键词 室温离子液体 乳液稳定性 产品应用 低辐射镀膜 挥发性有机化合物 乳胶涂料 聚合形成 临界浓度
下载PDF
A preliminary experiment of determining the geopotential difference using two hydrogen atomic clocks and TWSTFT technique 被引量:1
12
作者 Kuangchao wu Ziyu Shen +3 位作者 Wenbin Shen Xiao Sun Chenghui Cai yifan wu 《Geodesy and Geodynamics》 2020年第4期229-241,共13页
General relativity theory(GRT)concludes that a precise clock ticks at different running rates if it is under the influence of different geopotentials.Therefore,by comparing the running rates of clocks at arbitrary two... General relativity theory(GRT)concludes that a precise clock ticks at different running rates if it is under the influence of different geopotentials.Therefore,by comparing the running rates of clocks at arbitrary two stations,the geopotential difference between them can be determined.In this study,with the help of two hydrogen atomic clocks(noted as H-masers),using the two-way satellite time and frequency transfer(TWSTFT)technique,we carried out experiments of the geopotential difference determination at the China Aerospace Science&Industry Corporation(CASIC),Beijing.Here the ensemble empirical mode decomposition(EEMD)method is adopted to remove periodic signals included in the original observations.Finally,the clock-comparison-determined geopotential difference in the experiments is determined.Results show that the difference between the geopotential difference determined by GRT and that determined by measuring tape is about 1316.1±931.0 m2s-2,which is equivalent to 134.3±95.0 m in height,and in consistence with the stability of the H-masers applied in the experiments(at the level of10-15/day).With the rapid improvement of atomic clocks’accuracy,the geopotential determination by accurate clocks is prospective,and it is promising to realize the unification of the world vertical height system(WVHS). 展开更多
关键词 Hydrogen atomic clock TWSTFT technique EEMD method GEOPOTENTIAL
下载PDF
An Early Warning Model of Financial Distress Prediction Based on Logistic-AHP-BP Neural Network Model 被引量:1
13
作者 yifan wu 《经济管理学刊(中英文版)》 2018年第2期184-194,共11页
Ever since the appearance of"Implementation Measures for Suspending and Terminating the Listing of Loss-making Companies"in 2001,the delisting system has emerged.However,the proportion of delisted companies ... Ever since the appearance of"Implementation Measures for Suspending and Terminating the Listing of Loss-making Companies"in 2001,the delisting system has emerged.However,the proportion of delisted companies in China has never exceeded 1% each year.The number of delisted companies in the security market is far less than the number of companies with financial distress.The capital market lacks a good delisting system and investors lack risk identification capabilities.Financial risk is directly related to delisting risk.Therefore,an early warning model of financial distress prediction for China.s stock market can provide guidance to stakeholders such as listed companies and capital markets.This paper first explains the immature delisting system of China.s capital market and the overall high risk of listed companies.financial distress.Then,the paper further elaborates previous research on financial distress prediction model of listed companies and analyzes the advantages and disadvantages of different models.This paper chooses the Analytic Hierarchy Process(AHP)to screen out the main factors that affect the risk of financial distress.The main factors are included in Logistic regression model and BP neural network model for predicting financial distress of listed companies.The overall effect of two models are assessed and compared.Finally,this paper proposes policy implications according to empirical results. 展开更多
关键词 FINANCIAL DISTRESS Risk of Delisting LOGISTIC Regression BP NEURAL Network Model
下载PDF
Observation of blobs using a gas puff imaging diagnostic on the HL-2A tokamak
14
作者 袁金榜 袁博达 +11 位作者 许敏 余羿 聂林 柯锐 王占辉 龚少博 吴婷 吴一帆 龙婷 王华杰 刘灏 乐伟 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第8期12-17,共6页
A gas puff imaging(GPI) diagnostic has been developed and applied to measure edge plasma turbulence on the HL-2A tokamak.The principle and experimental setup of GPI are described.GPI is applied to investigate blobs in... A gas puff imaging(GPI) diagnostic has been developed and applied to measure edge plasma turbulence on the HL-2A tokamak.The principle and experimental setup of GPI are described.GPI is applied to investigate blobs in the edge and scrape-off layer.Statistical characterizations of GPI line emission intensity are calculated, including the probability density functions(PDFs),skewness, and kurtosis of the intensity, which are found to be consistent with measurements by Langmuir probes.Besides, the track of blob motions is recorded by time sequence of individual frames.The characteristics of the original images and the relatively high-frequency(>10 kHz)/low-frequency(1–10 kHz) component images are illustrated.The observation of the blob’s structures and high-speed motions proves the success and high performance of the GPI diagnostic. 展开更多
关键词 GAS PUFF IMAGING DIAGNOSTIC statistical characterization BLOB motions
下载PDF
Formation and destruction of striation plasmas in helium glow discharge at medium pressures
15
作者 朱海龙 黄琪翔 +2 位作者 吴一繁 李昱瑞 任克昌 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第5期176-182,共7页
The striation plasmas are usually generated within a positive column of glow discharge,where rich and complex physical interactions are involved,especially,in the medium or high pressures.Along these lines,our work ai... The striation plasmas are usually generated within a positive column of glow discharge,where rich and complex physical interactions are involved,especially,in the medium or high pressures.Along these lines,our work aims to thoroughly investigate the formation and destruction of helium striation plasmas at kPa level pressures.The characteristics of the helium striation plasmas,and especially the optical emission properties are explored.The emission lines of 706.52 nm and391.44 nm related to the energetic electrons and the high-energy metastable helium atoms respectively,were focused on in this work.The formation of striation plasmas in a helium glow discharge,is mainly associated with the instability originating from the stepwise ionization of high-energy metastable state atoms,Maxwellization of the electron distribution functions and gas heating.Additionally,the destruction effect of helium striation plasmas is of great significance when a small amount of nitrogen or oxygen is mixed into the discharge plasmas.The reduction of the mean electron energy and the consumption of the high-energy metastable helium atoms are considered as the underlying reasons for the destruction of striation plasmas. 展开更多
关键词 striation plasmas medium pressures atomic emission spectroscopy helium discharge metastable atoms ionization wave
下载PDF
A Rigid Nanoplatform for Precise and Responsive Treatment of Intracellular Multidrug-Resistant Bacteria
16
作者 Shaoqi Qu Xiaoyong Huang +4 位作者 Xiangbin Song yifan wu Xiaowei Ma Jianzhong Shen Kui Zhu 《Engineering》 SCIE EI CAS 2022年第8期57-66,共10页
Antibiotic treatment failure against life-threatening bacterial pathogens is typically caused by the rapid emergence and dissemination of antibiotic resistance.The current lack of antibiotic discovery and development ... Antibiotic treatment failure against life-threatening bacterial pathogens is typically caused by the rapid emergence and dissemination of antibiotic resistance.The current lack of antibiotic discovery and development urgently calls for new strategies to combat multidrug-resistant(MDR)bacteria,especially those that survive in host cells.Functional nanoparticles are promising intracellular drug delivery systems whose advantages include their high biocompatibility and tunable surface modifications.Inspired by the fact that the rigidity of nanoparticles potentiates their cellular uptake,rigidity-functionalized nanoparticles(RFNs)coated with bacteria-responsive phospholipids were fabricated to boost endocytosis,resulting in the increased accumulation of intracellular antibiotics.Precise delivery and high antibacterial efficacy were demonstrated by the clearing of 99%of MDR bacteria in 4 h using methicillin-resistant Staphylococcus aureus(MRSA)and pathogenic Bacillus cereus as models.In addition,the subcellular distribution of the RFNs was modulated by altering the phospholipid composition on the surface,thereby adjusting the electrostatic effects and reprograming the intracellular behavior of the RFNs by causing them to accurately target lysosomes.Finally,the RFNs showed high efficacy against MRSA-associated infections in animal models of wound healing and bacteremia.These findings provide a controllable rigidity-regulated delivery platform with responsive properties for precisely reprograming the accumulation of cytosolic antibiotics,shedding light on precision antimicrobial therapeutics against intracellular bacterial pathogens in the future. 展开更多
关键词 Antibiotic Bacteria Mesoporous silica PHOSPHOLIPID RIGIDITY
下载PDF
Determination of the orthometric height difference based on optical fiber frequency transfer technique
17
作者 Anh The Hoang Ziyu Shen +4 位作者 Wen Bin Shen Chenghui Cai Wei Xu An Ning yifan wu 《Geodesy and Geodynamics》 CSCD 2021年第6期405-412,共8页
The development of remote frequency transfer techniques,especially the appearance of optical clocks with unprecedented stability,has prompted geoscientists to study their applications in geodesy.Using remote frequency... The development of remote frequency transfer techniques,especially the appearance of optical clocks with unprecedented stability,has prompted geoscientists to study their applications in geodesy.Using remote frequency transfer technique,by frequency comparison of two optical clocks at two points P and Q connected by optical fibers,one can measure the signal’s frequency shift between them,and the geopotential difference between them can be determined based on the gravity frequency shift equation.Given the orthometric height of P,the orthometric height of Q can be determined.Since the present stability of the optical clock has achieved 1×10^(-18) or better and comparing the frequency transfer via optical fiber provides stability at 10^(-19) level,the optical clock network enables determining the orthometric height at centimeter-level.This study provides a formulation to determine the height diffe rence at one-centimeter level between two points on the ground based on the optical fiber frequency transfer technique. 展开更多
关键词 Optical fiber frequency transfer(OFFT) Optical fiber Frequency transfer GEOPOTENTIAL
下载PDF
Shape Sensing of Thin Shell Structure Based on Inverse Finite Element Method
18
作者 Zhanjun wu Tengteng Li +4 位作者 Jiachen Zhang yifan wu Jianle Li Lei Yang Hao Xu 《Structural Durability & Health Monitoring》 EI 2022年第1期1-14,共14页
Shape sensing as a crucial component of structural health monitoring plays a vital role in real-time actuation and control of smart structures,and monitoring of structural integrity.As a model-based method,the inverse... Shape sensing as a crucial component of structural health monitoring plays a vital role in real-time actuation and control of smart structures,and monitoring of structural integrity.As a model-based method,the inverse finite element method(iFEM)has been proved to be a valuable shape sensing tool that is suitable for complex structures.In this paper,we propose a novel approach for the shape sensing of thin shell structures with iFEM.Considering the structural form and stress characteristics of thin-walled structure,the error function consists of membrane and bending section strains only which is consistent with the Kirchhoff–Love shell theory.For numerical implementation,a new four-node quadrilateral inverse-shell element,iDKQ4,is developed by utilizing the kinematics of the classical shell theory.This new element includes hierarchical drilling rotation degrees-of-freedom(DOF)which enhance applicability to complex structures.Firstly,the reconstruction performance is examined numerically using a cantilever plate model.Following the validation cases,the applicability of the iDKQ4 element to more complex structures is demonstrated by the analysis of a thin wallpanel.Finally,the deformation of a typical aerospace thin-wall structure(the composite tank)is reconstructed with sparse strain data with the help of iDKQ4 element. 展开更多
关键词 Structural health monitoring inverse finite method Kirchhoff–Love shell theory composite tank shape sensing
下载PDF
Bioinformatics Analysis of DNA-binding Response Regulator PhoP in Vibrio alginolyticus
19
作者 yifan wu Junlin WANG +3 位作者 Fuyuan ZENG Weijie ZHANG Xing XIAO Huanying PANG 《Asian Agricultural Research》 2022年第3期42-46,61,共6页
[Objectives]To amplify the DNA-binding response regulator PhoP in Vibrio alginolyticus and analyze its sequence characteristics and subunit structure.[Methods]According to the sequence of the DNA-binding response regu... [Objectives]To amplify the DNA-binding response regulator PhoP in Vibrio alginolyticus and analyze its sequence characteristics and subunit structure.[Methods]According to the sequence of the DNA-binding response regulator PhoP in V.alginolyticus,a pair of specific primers was designed for PCR amplification,and the bioinformatics of the sequence amplified was analyzed.Using MEGA 5.0 software,the phoP phylogenetic tree was constructed by the neighbor-joining method.Using SWISS-MODEL software,the three-dimensional structural model of the PhoP subunit was simulated.[Results]The full-length phoP gene was 732 bp,encoding a total of 243 amino acids.The predicted theoretical molecular weight of the protein is about 27.67 kD,and the isoelectric point is 5.09.The prediction results of protein subcellular localization,SignalP 4.0,TMHMM Server 2.0 and SoftBerry-Psite show that PhoP is located in the cytoplasm,and is stable and hydrophobic;there is a signal peptide cleavage site between amino acids 29 and 30,and there is no transmembrane region.The amino acid sequence contains one Asn-glycosylation site,one protein kinase C phosphorylation site,seven casein kinase II phosphorylation sites,one tyrosine kinase phosphorylation site,three myristoylation sites,and seven C-terminal microbody targeting signal sites.The PhoP of V.alginolyticus has high homology with that of Vibrio campbellii.The PhoP subunit of V.alginolyticus has similar configuration to the single-subunit RegX3 protein of Mycobacterium tuberculosis.[Conclusions]This study has a positive effect on the prevention and control of vibriosis and the improvement of the current aquatic economic animal breeding environment. 展开更多
关键词 Vibrio alginolyticus Gene cloning PHOP Bioinformatics analysis
下载PDF
Preparation and acoustic properties of high-temperature acoustic emission sensor based on La_(3)Ga_(5)SiO_(14) crystal
20
作者 Jingxiang Si Changhong Yang +3 位作者 Rui Guo yifan wu Xiujuan Lin Shifeng Huang 《Journal of Advanced Dielectrics》 2024年第1期25-32,共8页
With the rapid development of modern industries,the high-temperature piezoelectric sensors that can work in extreme environments are in great demand.In this work,langasite(La_(3)Ga_(5)SiO_(14),LGS),as a high-temperatu... With the rapid development of modern industries,the high-temperature piezoelectric sensors that can work in extreme environments are in great demand.In this work,langasite(La_(3)Ga_(5)SiO_(14),LGS),as a high-temperature piezoelectric crystal with stable electro-elastic performance,is used as core element,and air and porous Al_(2)O_(3) are selected as backing layers respectively to prepare two kinds of high-temperature acoustic emission(AE)sensors.The detection sensitivities at 25–500℃ are analyzed by the ball falling test and Hsu–Nielsen experiment.Under the condition of 25–500℃,the received amplitude signals by both sensors are maintained above 90 dB stimulated by the ZrO_(2) ceramic ball dropping.In the Hsu–Nielsen experiment,as the temperature rising from 25℃ to 500℃,the signal amplitude of sensor with air backing layer decays from 447 mV to 365 mV,while the signal amplitude varies from 270 mV to 203 mV for the sensor with porous Al_(2)O_(3) backing layer.Signiffcantly,compared with the bandwidth of the air-backing sensor(37–183 kHz),the sensor with porous Al_(2)O_(3) backing layer broadens bandwidth to 28–273 kHz.These results show that both these AE sensors have strong and stable response ability to AE signals at high-temperature of 500℃.Therefore,piezoelectric AE sensor based on LGS has great potential application in the ffeld of high-temperature structural health monitoring. 展开更多
关键词 La_(3)Ga_(5)SiO_(14) acoustic emission sensor sensitivity structural health monitoring
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部