检索结果-南通市图书馆

Spatial distribution of metal emissions in supernova remnant 3C 397 viewed with Chandra and XMM

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 267-270页

作者： JIANG Bing & chen Yang department of astronomy,nanjing university,nanjing 210093.china 1. department of astronomy Nanjing University Nanjing 210093 China

We present X-ray equivalent width imaging of 3C 397 for Mg Heα,Si Heα,S Heα,and Fe Kα complex lines with Chandra and XMM-Newton *** images revealed that the heavier the element is,the smaller the extent of the element distribution *** Mg emission is evidently enhanced in the southeastern blow-out region,well along the radio boundary there,and appears to partially envelope the eastern Fe *** bilateral hat-like Si line-emitting structures are along the northern and southern borders,roughly symmetric with respect to the south-east-northwest elongation *** S line-emitting shell is located just inside the northern radio and IR shell,indicating a layer of reversely shocked sulphur in the ejecta.A few enhanced Fe features are basically aligned along the diagonal of the rectangular shape of the SNR,which implicates an early asymmetric SN explosion.

关键词： ISM 3C 397 G41.1-0.3 X-ray supernova remnants

An MSX infrared analysis of the superbubble around the giant HII region NGC3603

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 271-273页

作者： WANG Jia & chen Yang department of astronomy,nanjing university,nanjing 210093.china 1. department of astronomy Nanjing University Nanjing 210093 China

Using the MSX mid-infrared observations,we reveal a 100pc-scale superbubble surrounding the giant HII region *** suggest that the diffuse surrounding infrared emission in bands A,C,and D is dominated by that of PAH and the emission in band E is dominated by that of dust *** fitted dust temperature is consistent with heating by the central cluster's UV *** derived gas-to-dust mass ratio for the bubble shell is of order 102.

关键词： superbubble HII region cluster PAH dust

Molecular dynamics simulation study of nitrogen vacancy color centers prepared by carbon ion implantation into diamond

在线全文

学校读者我要写书评

暂无评论

Nanotechnology and Precision Engineering 2024年第3期7卷 71-78页

作者： Wei Zhao Zongwei Xu pengfei Wang Hanyi chen State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China department of Modern Physics University of Science and Technology of ChinaHefei 230026China

Nitrogen vacancy(NV)color centers in diamond have useful applications in quantum sensing andﬂuorescent *** can be gen-erated experimentally by ion implantation,femtosecond lasers,and chemical vapor ***,there is a lack of studies of the yield of NV color centers at the atomic *** the molecular dynamics simulations described in this paper,NV color centers are pre-pared by ion implantation in diamond with pre-doped nitrogen and subsequent *** differences between the yields of NV color centers produced by implantation of carbon(C)and nitrogen(N)ions,respectively,are *** is found that C-ion implantation gives a greater yield of NV color centers and superior location *** effects of different pre-doping concentrations(400–1500 ppm)and implantation energies(1.0–3.0 keV)on the NV color center yield are analyzed,and it is shown that a pre-doping concentra-tion of 1000 ppm with 2 keV C-ion implantation can produce a 13%yield of NV color centers after 1600 K annealing for 7.4 ***,a brief comparison of the NV color center identiﬁcation methods is presented,and it is found that the error rate of an analysis utiliz-ing the identify diamond structure coordination analysis method is reduced by about 7%compared with conventional identiﬁcation+methods.

关键词： NV color center Ion implantation Molecular dynamics(MD)simulation Yield enhancement

The inversion of the real kinematic properties of coronal mass ejections by forward modeling

在线全文

学校读者我要写书评

暂无评论

Research in astronomy and Astrophysics 2011年第2期11卷 237-244页

作者： You Wu 1 and Peng-Fei chen 1,2 1 department of astronomy,nanjing university,nanjing 210093.china 2 Key Lab of Modern Astron.and Astrophys.,Ministry of Education,nanjing 210093.china department of astronomy Nanjing University Nanjing 210093 China Key Lab of Modern Astron. and Astrophys. Ministry of Education Nanjing 210093 China

Kinematic properties of coronal mass ejections （CMEs） suffer from projection effects,and it is expected that the real velocity should be larger and the real angular width should be smaller than the apparent *** attempts have been taken to correct the projection effects,which however led to an inflated average velocity probably due to the biased choice of CME *** order to estimate the overall influence of the projection effects on the kinematic properties of the CMEs,we perform a forward modeling of real distributions of CME properties,such as the velocity,the angular width,and the latitude,by requiring their projected distributions to best match *** a matching is conducted by Monte Carlo *** to the derived real distributions,we found that （1） the average real velocity of all non-full-halo CMEs is about 514 km s-1,and the average real angular width is about 33°,in contrast to the corresponding apparent values of 418 km s-1 and 42.7° in observations;（2） For the CMEs with the angular width in the range of 20°-120°,the average real velocity is 510 km s-1 and the average real angular width is 43.4°,in contrast to the corresponding apparent values of 392 km s-1 and 52° in observations.

关键词： Sun: coronal mass ejections (CMEs) -- methods: statistical -- methods:numerical

Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

在线全文

学校读者我要写书评

暂无评论

High Voltage 2024年第1期9卷 137-149页

作者： Ruoyu Han Yuchen Cao Yakun Liu Xi chen Ting Li chen Li pengfei Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijingChina department of Electrical Engineering Shanghai Jiaotong UniversityShanghaiChina Beijing Institute of Astronautical System Engineering BeijingChina Aerospace Research Institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the *** paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed *** visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical *** results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal *** transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate *** inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive *** addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion *** information reveals two different plasma states of main discharge arc channel and adjacent surface electrical *** correspondence of the physical mechanism of electrical explosion and optical radiation is *** images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism *** research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

MALDI coupled with laser-postionization and trapped ion mobility spectrometry contribute to the enhanced detection of lipids in cancer cell spheroids

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 464-468页

作者： Jing chen Peisi Xie pengfei Wu Yu He Zian Lin Zongwei Cai Ministry of Education Key Laboratory of Analytical Science for Food Safety and Biology Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food SafetyCollege of ChemistryFuzhou UniversityFuzhou 350116China department of Chemistry State Key Laboratory of Environmental and Biological AnalysisHong Kong Baptist UniversityHong KongChina College of Forestry Nanjing Forestry UniversityNanjing 210018China

Cancer cell spheroids(CCS) are a valuable three-dimensional cell model in cancer studies because they could replicate numerous characteristics of solid tumors. Increasing researches have used matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI) to investigate the spatial distribution of endogenous compounds(e.g., lipids) in CCS. However, only limited lipid species can be detected owing to a low ion yield by using MALDI. Besides, it is still challenging to fully characterize the structural diversity of lipids due to the existence of isomeric/isobaric species. Here, we carried out the initial application of MALDI coupled with laser-postionization(MALDI-2) and trapped ion mobility spectrometry(TIMS) imaging in HCT116 colon CCS to address these challenges. We demonstrated that MALDI-2 is capable of detecting more number and classes of lipids in HCT116 colon CCS with higher signal intensities than MALDI. TIMS could successfully separate numerous isobaric/isomeric species of lipids in CCS. Interestingly, we found that some isomeric/isobaric species have totally different spatial distributions in colon CCS. Further MS/MS imaging analysis was employed to determine the compositions of fatty acid chains for isomeric species by examining disparities in signal intensities and spatial distributions of product ions. This work stresses the robust ability of TIMS and MALDI-2 imaging in analyzing endogenous lipids in CCS, which could potentially become powerful tools for future cancer studies.

关键词： Matrix-assisted laser desorption/ionization(MALDI) Mass spectrometry imaging MALDI coupled with laser-postionization Trapped ion mobility spectrometry Cancer cell spheroids

Dimension and measure theoretic entropy of a subshift in symbolic space

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第14期42卷 1193-1196页

作者： chen Ercai and XIONG Jincheng1. department of astronomy, nanjing university, Nangjing 210093. china 2. department of Mathematics, South china Normal university, Guangzhou 510631, china department of astronomy Nanjing University Nangjing China department of Mathematics South China Normal University Guangzhou China

1 Definitions and resultsWITH the development of the theory of dynamical systems and fractal geometry, one provedthat symbolic dynamics is a powerful tool to study chaos and fractals. It is useful to study thefractal characteristics of symbolic dynamics. In the present note we shall point out the relationbetween the dimension and measure theoretic entropy of any subshift in symbolic space. Weprove here that the Bowen’s formula for Hausdorff dimension holds without Markov struc-ture. A variational principle for dimension is obtained.

关键词： symbolic space subshift measure theoretic entropy dimension.

A UNIFIED MODEL FOR SOLAR FLARES

在线全文

学校读者我要写书评

暂无评论

南京大学学报(自然科学) 1999年第4期 496-499页

作者： chen pengfei Fang cheng Ding Mingde Tang Yuhua (department of astronomy,nanjing university,210093.nanjing,PRC) departmentofastronomy NanjingUniversity210093NanjingPRC

We performed 2.5-dimensional numerical simulation for two cases,one with the the reconnection point at a high altitude,the other with the reconnection point at a low *** the high-altitude case,the bright loop appears to rise for a long time,with its two footpoints separating and the field lines below the bright loop shrinking,which are all typical features of two-ribbon *** the low-altitude case,the bright loops cease rising only a short time after the impulsive phase of the reconnection and then become rather stable,which shows a large similarity to the compact *** results imply that the two types of solar flares,i.e.,the two-ribbon flares and the compact ones,might be unified into the same magnetic reconnection model,where the height of the reconnection point leads to the bifurcation.

关键词： Sun:flares-MHD-Sun:magnetic fields

Heme oxygenase 1 linked to inactivation of subchondral osteoclasts in osteoarthritis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang university-Science B(Biomedicine & Biotechnology) 2024年第6期25卷 513-528页

作者： Miao CHU Guangdong chen Kai chen pengfei ZHU Zhen WANG Zhonglai QIAN Huaqiang TAO Yaozeng XU Dechun GENG department of Orthopedics the First Affiliated Hospital of Soochow UniversitySuzhou 215006China department of Orthopedics Yixing People’s HospitalYixing 214200China department of Orthopedics Hai’an People’s HospitalHai’an 226600China department of Orthopedics Suzhou Kowloon HospitalShanghai Jiao Tong University School of MedicineSuzhou 215028China

Osteoarthritis(OA)is a chronic progressive osteoarthropathy in the *** activation plays a crucial role in the occurrence of subchondral bone loss in early ***,the specific mechanism of osteoclast differentiation in OA remains *** our study,gene expression profiles related to OA disease progression and osteoclast activation were screened from the Gene Expression Omnibus(GEO)***2R and Funrich analysis tools were employed to find differentially expressed genes(DEGs).Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses demonstrated that chemical carcinogenesis,reactive oxygen species(ROS),and response to oxidative stress were mainly involved in osteoclast differentiation in OA subchondral ***,fourteen DEGs that are associated with oxidative stress were *** first ranked differential gene,heme oxygenase 1(HMOX1),was selected for further *** results showed that osteoclast activation in the pathogenesis of OA subchondral bone is accompanied by the downregulation of *** was revealed to inhibit osteoclastogenesis by targeting HMOX1 and upregulating the expression of antioxidant protein in ***,carnosol was found to alleviate the severity of OA by inhibiting the activation of subchondral osteoclasts in *** research indicated that the activation of osteoclasts due to subchondral bone redox dysplasia may serve as a significant pathway for the advancement of *** HMOX1 in subchondral osteoclasts may offer novel insights for the treatment of early OA.

关键词： Osteoclast Oxidative stress Osteoarthritis(OA) Heme oxygenase 1(HMOX1) Carnosol