检索结果-南通市图书馆

A note on the collapsing geometry of hyperkahler four manifolds

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2019年第11期62卷 2195-2210页

作者： Shouhei Honda Song Sun ruobing zhang Mathematical Institute Tohoku UniversitySendai 980-8578Japan Department of Mathematics University of California at BerkeleyBerkeleyCA 94720USA Department of Mathematics Stony Brook UniversityStony BrookNY 11790USA

We make some observations concerning the one-dimensional collapsing geometry of four-dimensional hyperk?hler metrics.

关键词： hyperkahler metrics collapsing K3 manifold

Interaction between plasma jet and silicone rubber covered by porous inorganic contaminants:Surface hydrophobicity or hydrophilicity?

在线全文

学校读者我要写书评

暂无评论

High Voltage 2022年第6期7卷 1023-1033页

作者： Shuang Li Jianjun Li Yongqiang Fu ruobing zhang Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenChina

The variation of surface hydrophobicity of silicone rubber materials covered with porous inorganic pollution layer under the action of atmospheric pressure plasma jet presents some new features,which have important engineering applications in the field of outdoor insulation of power *** of the plasma with the polluted silicone rubber is studied and surface hydrophobicity is *** results show that the exposure of plasma greatly accelerates the transfer of low molecular weight siloxanes(LMWs)in the pollution ***,the surface hydrophobicity is determined by the LMWs contents and the exposure *** acceleration effects of plasma during and after plasma exposure are proposed,their influence on surface hydrophobicity is analysed and related mechanisms are *** addition,the competing influence of plasmainduced acceleration of the transfer of LMWs towards the surface and plasmaoxidation of LMWs on surface hydrophobicity is discussed.

关键词： rubber inorganic acceleration

Plasma jet array treatment to improve the hydrophobicity of contaminated HTV silicone rubber

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第10期19卷 75-82页

作者： ruobing zhang Qianting HAN Yan XIA Shuang LI Laboratory of Advanced Technology of Electrical Engineering and Energy Graduate School at Shenzhen Tsinghua University Shenzhen 518055 People＇s Republic of China

An atmospheric-pressure plasma jet array specially designed for HTV silicone rubber treatment is reported in this paper. Stable plasma containing highly energetic active particles was uniformly generated in the plasma jet array. The discharge pattern was affected by the applied voltage. The divergence phenomenon was observed at low gas flow rate and abated when the flow rate *** of the plasma plume is close to room temperature which makes it feasible for temperature-sensitive material treatment. Hydrophobicity of contaminated HTV silicone rubber was significantly improved after quick exposure of the plasma jet array, and the effective treatment area reached 120 mm？×？50 mm（length？×？width）. Reactive particles in the plasma accelerate accumulation of the hydrophobic molecules, namely low molecular weight silicone chains, on the contaminated surface, which result in a hydrophobicity improvement of the HTV silicone rubber.

关键词： atmospheric-pressure plasma jet plasma jet array hydrophobicity HTV silicone rubber

Interfacial bonding enhancement of the RTV recoating with sandwiched contaminant by plasma jet

在线全文

学校读者我要写书评

暂无评论

High Voltage 2019年第4期4卷 345-348页

作者： Shanshan Wang Shuang Li Jianjun Li ruobing zhang Hui Liu Division of Energy and Environment Graduate School at ShenzhenTsinghua UniversityShenzhen518055People's Republic of China State Grid Shandong Electric Power Research Institute JinanPeople's Republic of China

Room temperature vulcanised(RTV)silicone rubber is widely used in electrical power system,applied to the glass or porcelain insulator surface to enhance *** coatings get contaminated after long-term operation and need to be *** accumulate and embed into the surface of base RTV coating,forming a hard-to-remove inorganic transition *** sandwiched contaminant layer destroys the adhesion between original and reapplied silicone rubber coating ***’study innovatively reports a method to enhance interfacial bond properties of the RTV recoating with sandwiched contaminant layer,by using an atmospheric-pulsed discharge plasma jet(APPJ)for surface *** boiling test and 180-degree peel test were conducted to evaluate interfacial bond properties *** electron microscopy(SEM)was applied to observe the cross-section of recoating interface,while Fourier-transform infrared spectroscopy(FTIR)to detect chemical changes of contaminant layer,giving out microscopic and theoretical explanation.

关键词： coating sandwich rubber

A large-scale cold plasma jet: generation mechanism and application effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第4期26卷 1-8页

作者：崔伟胜张若兵 Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055People’s Republic of China

Atmospheric pressure cold plasma jets(APCPJs) typically exhibit a slender, conical structure,which imposes limitations on their application for surface modification due to the restricted treatment area. In this paper, we introduce a novel plasma jet morphology known as the large-scale cold plasma jet(LSCPJ), characterized by the presence of both a central conical plasma jet and a peripheral trumpet-like diffuse plasma jet. The experimental investigations have identified the factors influencing the conical and the trumpet-like diffuse plasma jet, and theoretical simulations have shed light on the role of the flow field and the electric field in shaping the formation of the LSCPJ. It is proved that, under conditions of elevated helium concentration, the distributions of impurity gas particles and the electric field jointly determine the plasma jet’s morphology. High-speed ICCD camera images confirm the dynamic behavior of plasma bullets in LSCPJ, which is consistent with the theoretical analysis. Finally, it is demonstrated that when applied to the surface treatment of silicone rubber, LSCPJ can achieve a treatment area over 28 times larger than that of APCPJ under equivalent conditions. This paper uncovers the crucial role of impurity gases and electric fields in shaping plasma jet morphology and opens up the possibility of efficiently diversifying plasma jet generation effects through external electromagnetic fields. These insights hold the promise of reducing the generation cost of plasma jets and expanding their applications across various industrial sectors.

关键词： diffuse plasma jet flow field electric field surface treatment

Hydrophobicity changes of polluted silicone rubber introduced by spatial and dose distribution of plasma jet

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2022年第4期24卷 53-60页

作者： Shuang LI Xinzheng GUO Yongqiang FU Jianjun LI ruobing zhang Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments Shenzhen International Graduate School(SIGS)Tsinghua UniversityShenzhen 518055People's Republic of China

The hydrophobicity of polluted silicone rubber was improved rapidly under plasma jet *** is an important phenomenon of the interaction between the plasma jet and the porous surface,and shows a wide application prospect in the power *** this process,the spatial characteristics and dose of plasma jet are very ***,the variation of hydrophobicity of polluted silicone rubber under plasma jet treatment was studied,and the spatial characteristics and dose of plasma jet on polluted silicone rubber were also investigated in the *** results show that the surface property(hydrophilic or hydrophobic)depended on the dose of plasma applied to the *** effective treated area was a circle,and the contact angles changed along the radial direction of the *** was attributable to the diffusion of plasma bullets on the surface and the distribution of plasma *** plasma dose could be characterized by the energy density of the plasma applied on the *** the increase of plasma dose,the surface contact angles first increased rapidly and then decreased gradually.

关键词： plasma jet polluted silicone rubber hydrophobicity plasma dose energy density spatial distribution

Dielectric barrier discharge-based defect engineering method to assist flash sintering

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2023年第5期12卷 1046-1057页

作者： Xinhao Zhao Nianping Yan Yueji Li Zikui Shen Rongxia Huang Chen Xu Xuetong Zhao Xilin Wang ruobing zhang Zhidong Jia Guangdong Engineering Technology Research Center of Power Equipment Reliability in Complicated Coastal Environments Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China State Grid Jiangxi Electric Power Research Institute Nanchang 330096China School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China Institute of Materials China Academy of Engineering PhysicsMianyang 621907China fSchool of Electrical Engineering Chongqing UniversityChongqing 400044China

Oxygen vacancy OV plays an important role in a flash sintering (FS) process. In defect engineering, the methods of creating oxygen vacancy defects include doping, heating, and etching, and all of them often have complex processes or equipment. In this study, we used dielectric barrier discharge (DBD) as a new defect engineering technology to increase oxygen vacancy concentrations of green billets with different ceramics (ZnO, TiO_(2), and 3 mol% yttria-stabilized zirconia (3YSZ)). With an alternating current (AC) power supply of 10 kHz, low-temperature plasma was generated, and a specimen could be treated in different atmospheres. The effect of the DBD treatment was influenced by atmosphere, treatment time, and voltage amplitude of the power supply. After the DBD treatment, the oxygen vacancy defect concentration in ZnO samples increased significantly, and a resistance test showed that conductivity of the samples increased by 2–3 orders of magnitude. Moreover, the onset electric field (E) of ZnO FS decreased from 5.17 to 0.86 kV/cm at room temperature (RT);while in the whole FS, the max power dissipation decreased from 563.17 to 27.94 W. The defect concentration and conductivity of the green billets for TiO_(2) and 3YSZ were also changed by the DBD, and then the FS process was modified. It is a new technology to treat the green billet of ceramics in very short time, applicable to other ceramics, and beneficial to regulate the FS process.

关键词： flash sintering(FS) ZnO dielectric barrier discharge(DBD) oxygen vacancy OV defect engineering

Investigation of spectral bandwidth of BBO-I phase matching non-collinear optical parametric amplification from visible to near-infrared

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2008年第Z1期1卷 101-108页

作者： Bo LIU ruobing zhang Huagang LIU Jing MA Chen ZHU Qingyue WANG College of Precision Instrument and Opto-electronics Engineering Key Laboratory of Optoelectronics Information and Technical Science Tianjin University

Laser sources which have high power, short time duration and are broadly tunable are needed for the application of ultra-fast lasers. Femtosecond optical parametric amplification(OPA) is one of the most important techniques to produce broadly tunable and several femtosecond laser pulses. To obtain an extremely short pulse, the femtosecond OPA should adequately support a large spectral bandwidth. Ultra-broadband type-I phase matching OPA based on BBO was theoretically investigated. The achromatic phase matching(APM) technology was introduced to femtosecond OPA, and a broadband phase matching condition was given when the signal beams were angularly *** methods were presented to choose the optimized non-collinear angle and angular dispersion. Effects of non-collinear angle and rate of angular dispersion to the parametric bandwidth were also discussed. The results indicate that a proper non-collinear angle of the noncollinear optical parametric amplifier(NOPA) and getting signal beams dispersed at the right rate in nearinfrared conditions can increase the parametric bandwidth dramatically.

关键词： nonlinear optics broadband femtosecond optical parametric amplification (OPA) angular dispersion group velocity matching

Femtosecond laser microstructuring of nickel foil

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2010年第1期8卷 38-40页

作者：贾威周彬李珣柴路章若冰王清月 Ultrafast Laser Laboratory School of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityKey Laboratory of Opto-Electronic Information Technical ScienceMinistry of Education of China

We observe the morphological change and grain structure of Ni foil when it is ablated with femtosecond laser pulses. Scanning electron microscopy and field emission transmission electron microscopy are used to study the nature of the morphology and grain structure of nickel foil and determine the essential features. The results indicate that there are many random uanostructures in the center of the ablated region composed of nanocrystalline grains as well as some core-shell structures phase explosion and extremely high cooling rate are the for the formation of surface nanostructures. The observed morphologies seem to suggest that most probable physical mechanisms responsible

关键词： Crystal microstructure Field emission Grain size and shape Morphology Nanostructures Nickel alloys Pulsed laser applications Scanning electron microscopy Surface chemistry Transmission electron microscopy