检索结果-南通市图书馆

Temporal and Spectral Characteristics of Persistent Emission and Special Bursts of Magnetar SGR J1935+2154 Based on Insight-HXMT

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期24卷 225-233页

作者： Xue-Feng Lu li-Ming Song Ming-Yu Ge Shuang-Nan Zhang Jin-Lu Qu Ce Cai Cong-Zhan liu cheng-kui li Yu-Cong Fu Ying-Chen Xu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China College of Physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal UniversityShijiazhuang 050024China Department of Astronomy Beijing Normal UniversityBeijing 100875China

In October 2022,the magnetar SGR J1935+2154 entered the active outburst *** the episode,the InsightHXMT satellite carried out a long observation that lasted for 20 *** than 300 bursts were detected,and a certain amount of persistent radiation signals were also *** paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT *** the same time,the burst phase distribution characteristics,spectral lag results of burst,the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are *** found that there is no significant delay feature during different energy bands for the bursts of SGR J1935+*** observed zero-lag burst does not have a unique *** time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the *** also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.

关键词： radiation mechanisms:general dense matter magnetic fields

Analysis of Bright Source Hardness Ratios in the 4 yr Insight-HXMT Galactic Plane Scanning Survey Catalog

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第2期24卷 154-170页

作者： Chen Wang Jin-Yuan liao Ju Guan Yuan liu cheng-kui li Na Sai Jing Jin Shuang-Nan Zhang Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Astronomy School of Physics and TechnologyWuhan UniversityWuhan 430072China WHU-NAOC Joint Center for Astronomy Wuhan UniversityWuhan 430072China

We conduct a statistical analysis of the hardness ratio(HR)for bright sources in the 4 yr Galactic Plane Scanning Survey catalog of *** on the stable(variable)flux F_(s)(F_(v))or spectrum S_(s)(S_(v))of each source,the bright sources are classified into three groups:F_(v)&S_(v),F_(v)&S_(s),and F_(s)&_(s).Our study of the HR characteristics in different types of sources reveals that accretion-powered neutron star(NS)low-mass X-ray binaries(LMXBs)exhibit softer energy spectra than NS high-mass X-ray binaries(HMXBs),but harder energy spectra than black hole binaries in most *** difference is probably due to their different magnetic field ***,Fv&Sv LMXBs tend to be harder than Fv&Ss LMXBs below 7 keV,while the opposite is true for *** results suggest that LMXBs may dominate unclassified sources,and NS binaries are likely to be the primary type of X-ray binaries with ambiguous compact *** comparing the HR of transient sources in their outburst and low-flux states,it is found that the averaged HR of four sources in the two states are roughly comparable within *** also investigate the spatial properties of the three groups and find that Fv&Sv sources are mainly located in the longitude of-20°

关键词： catalogs-surveys-methods data analysis-X-rays general

Two Types of Compact UHF Antennas for Partial Discharge Measurement

在线全文

学校读者我要写书评

暂无评论

高电压技术 2008年第11期34卷 2305-2310页

作者： JIN Zhuo-rui SUN Cai-xin cheng Chang-kui li Jian State Key Laboratory of Power Transmission Equipment ＆ System Security and New Technology Department of High Voltage and Insulation Engineering Chongqing University Chongqing 400044 China

To investigate the partial discharge (PD) online monitoring of transformers by ultra-high-frequency (UHF) approaches,high-qualified UHF antennas are focused on as one key technique. The size of UHF sensor used for PD UHF online monitoring in transformer is excessively large,therefore,it is not convenient for internal installation of transformer. Two types of compact UHF antennas with small sizes,a Hilbert fractal antenna and a small loop antenna are presented. PD experiments of three typically artificial insulation defects are executed and both antennas are used for PD measurement. The spectra of power via frequency of detected PD signals are analyzed and compared. The experimental results show that the Hilbert fractal antenna and small loop antenna are qualified for PD online UHF monitoring.

关键词：超高频天线局部放电测量方法电压

Troy: Efficient Service Deployment for Windows Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第1期33卷 313-322页

作者： Deyu ZHANG Yu XIE Mucong XU En cheng Xiaoyan kui Bangwen HE Yunhao li School of Computer Science and Engineering Central South University

The modern university computer lab and kindergarden through 12th grade classrooms require a centralized solution to efficiently manage a large number of desktops. The existing solutions either bring virtualization overhead in runtime or requires loading a large image over 30 GB leading to an unacceptable network latency. In this work, we propose Troy which takes advantage of the differencing virtual hard disk techniques in Windows *** such, Troy only loads the modifications made on one machine to all other machines. Troy consists of two modules that are responsible to generate an initial image and merge a differencing image with its parent image, respectively. Specifically, we identify the key fields in the virtual hard disk image that links the differencing image and the parent image and find the modified blocks in the differencing images that should be used to replace the blocks in the parent image. We further design a lazy copy solution to reduce the I/O burden in image merging. We have implemented Troy on bare metal machines. The evaluation results show that the performance of Troy is comparable to the native implementation in Windows, without requiring the Windows environment.

关键词： Runtime Image synthesis Merging Loading Metals Hard disks Virtualization

同方期刊数据库

Highly selective electrosynthesis of 3,4-dihydroisoquinoline accompanied with hydrogen production over three-dimensional hollow CoNi-based microarray electrocatalysts

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2509-2519页

作者： Yu Xin liyu Chen Yingwei li kui Shen Guangdong Provincial Key Lab for Green Chemical Product Technology School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China State Key Laboratory of Pulp and Paper Engineering School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

Electrocatalytic oxidation reaction of biomass-based derivatives is an excellent candidate to replace water oxidation for obtaining both value-added products and hydrogen(H_(2)),but the exploration of competent electrocatalysts is still highly ***,two new types of three-dimensional self-supported hollow microarrays containing CoNi layered double hydroxide(CoNi-LDH)and N-doped carbon nanosheets decorated with CoNi alloyed nanoparticles(CoNi-NC)on carbon cloth(CC)are prepared,which are further used as efficient electrocatalysts for tetrahydroisoquinoline(THIQ)electrooxidation and hydrogen evolution reaction(HER),*** demonstrate that the Co-modulated electronic environment for Ni(II)/Ni(Ⅲ)redox-looping in CoNi-LDH is the main factor to boost the selectivity of 3,4-dihydroisoquinoline(DHIQ)for the indirect electrooxidation process of *** functional theory(DFT)calculations reveal that the Ni(Ⅲ)/Co(Ⅲ)dual sites of CoNi-LDH exhibit enhanced adsorption for THIQ but poorer adsorption for DHIQ compared to pure Co(Ⅲ)or Ni(Ⅲ).Therefore,the Ni(Ⅲ)/Co(Ⅲ)dual sites can effectively inhibit the peroxidation of DHIQ to isoquinoline(IQ)over CoNi-LDH,thus improving the selectivity of DHIQ to nearly 100%,much higher than that of its pure Ni ***,CC@CoNi-NC can deliver high HER activity with low overpotential(40 mV@10 mA·cm^(-2))and high exchange current density(3.08 mA·cm^(-2)).Impressively,the assembled flow-cell device with CC@CoNi-LDH anode and CC@CoNi-NC cathode only requires low cell voltage and electricity consumption of 1.6 V and 3.50 kWh per cubic meter of H_(2)(@25 mA·cm^(-2)).

关键词： highly selective electrosynthesis dihydroisoquinolines hydrogen evolution reaction metal-organic frameworks hollow microarrays

Relationship between structure and microwave dielectric properties of li_(3)Mg_(4)Nb_(1-x)Ta_(x)O_(8)ceramics

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

Journal of Materiomics 2024年第1期10卷 245-252页

作者： Chongsheng Wu kui liu Honglan Lai Fang Xu School of Mechanical and Electrical Engineering Chengdu University of TechnologyChengduSichuan610059China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu610054China State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang621010China

Herein,the sintering behavior and dielectric properties of Ta5+-doped li3Mg4NbO8 ceramics were investigated by solid-phase reactions in combination with first-principles *** particular,li_(3)Mg_(4)Nb_(0.96)Ta_(0.04)O_(8)illustrates the best dielectric properties after sintering at 1,175℃withεr=13.71±0.20,Q×f=(132,112±2,391)GHz(increased by 25%)andτf=(25.07±1.36)×10^(−6)℃^(−1).The non-intrinsic factors reflect that a small amount of Ta^(5+)doping produces a secondary phase,increased densification,and grain size,all of which optimize the dielectric *** dominant intrinsic factors indicate that the increase in bond ionicity,the greater polarization of Ta^(5+),and the blueshift of the Raman characteristic peak all lead to an increase inε*** increase in lattice energy and the decrease in the damping behavior of the Nb/Ta-O bond vibrations lead to an increase in Q×*** weakening of the Nb/TaO_(6) octahedral distortion leads to an optimization ofτ*** modified li_(3)Mg_(4)Nb_(0.96)Ta_(0.04)O_(8) ceramics have promising applications in microwave communications.

关键词： First-principles li_(3)Mg_(4)NbO_(8),dielectric properties Lattice vibration

Predictors of functional independence, quality of life, and return to work in patients with burn injuries in China's Mainland

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

Burns & Trauma 2016年第4期4卷 273-283页

作者： Dan Tang Cecilia W.P.li-Tsang Ricky K.C.Au Xia Shen kui-cheng li Xian-feng Yi lin-rong liao Hai-yan Cao Ya-nan Feng Chuan-shun liu Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHung HomHong Kong Special Administrative RegionChina Guangdong Provincial Work Injury Rehabilitation Hospital GuangzhouChina Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHung HomHong Kong Special Administrative RegionChina Department of Physiotherapy Guangdong Provincial Work Injury Rehabilitation HospitalGuangzhouChina Department of Occupational Therapy Guangdong Provincial Work Injury Rehabilitation HospitalGuangzhouChina Department of Burn Surgery and Burn Rehabilitation Guangdong Provincial Work Injury Rehabilitation HospitalGuangzhouChina

Background:Burn injury may be associated with long-term rehabilitation and disability,while research studies on the functional performance after injuries,quality of life(QOL),and abilities to return to work of burn patients are *** outcomes are related not just to the degree and nature of injuries,but also to the socio-economical background of the *** study aimed to identify the factors which might affect burn patients’abilities to reintegrate back to the society based on a sample in China's ***:A retrospective study was conducted to collect data of demographic characteristics,medical data about burn injuries,physical and psychological status,and self-perceived QOL at the initial phase and upon discharge from a rehabilitation hospital,timing of rehabilitation,and duration of rehabilitation *** hundred fifteen patients with burn injuries were recruited in the *** linear regression and logistic regression were used to obtain a model to predict the functional abilities and the perceived QOL at discharge and their changes during rehabilitation,as well as the post-injury work status within 6 months after ***:The functional performance at discharge and its change were significantly predicted by the functional abilities and QOL at the admission,duration of treatment,timing of rehabilitation,payer source,and total body surface area *** perceived QOL at discharge and its change were significantly predicted by the baseline QOL at admission and duration of *** significant predictors of work status within 6 months post-discharge included age,education,payer source,total body surface area burned,perceived QOL,and bodily pain at ***:The present study identified a number of factors affecting the rehabilitation outcomes of people with burn *** of these predictors may help clinicians assess the rehabilitation potential of burn survivors and assist in resource

关键词： Burns Functional independence Quality of life Return to work Predictors Rehabilitation

The Year-scale X-Ray Variations in the Core of M87

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

Research in Astronomy and Astrophysics 2023年第6期23卷 203-211页

作者： Yu-lin cheng Fei Xiang Heng Yu Shu-Mei Jia Xiang-Hua li cheng-kui li Yong Chen Wen-cheng Feng Department of Astronomy Yunnan UniversityKunming 650091China Department of Astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China

The analysis of light variation of M87 can help us understand the disk *** the past decade,M87 has experienced several short-term light variabilities related to *** also find that there are year-scale X-ray variations in the core of *** light variability properties are similar to *** re-analyzing 56Chandra observations from 2007 to 2019,we distinguish the“non-flaring state”from“flaring state”in the light *** removing flaring state data,we identify four gas clumps in the nucleus and all of them can be well fitted by the clumpy-ADAF *** average mass accretion rate is~0.16M⊙yr^(-1).We analyze the photon index(Γ)-flux(2-10 keV)correlation between the non-flaring state and flaring *** the non-flaring states,the flux is inversely proportional to the photon *** the flaring states,we find no obvious correlation between the two *** addition,we find that the flare always occurs at a high mass accretion rate,and after the luminosity of the flare reaches the peak,it will be accompanied by a sudden decrease in *** results can be explained as that the energy released by magnetic reconnection destroys the structure of the accretion disk,thus the luminosity decreases rapidly and returns to normal levels thereafter.

关键词： X-rays:galaxies galaxies:clusters:individual(M87) accretion accretion disks

GRB 190530A:From Precursor,Prompt Emission to Afterglow all Originated from Synchrotron Radiation

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第6期22卷 22-32页

作者： Hui-Ya liu Xiang-Gao Wang li-Ping Xin Zi-Min Zhou liang-Jun Chen Bing li Yuan-Gui Yang Qi Luo cheng-kui li Shao-lin Xiong ling-Jun Wang Xu-Hui Han li-Ming Song Jian-Yan Wei En-Wei liang Shuang-Nan Zhang Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China GXU-NAOC Center for Astrophysics and Space Sciences Nanning 530004China CAS Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physics and Electronic Information Huaibei Normal UniversityHuaibei 235000China

GRB 190530A was jointly observed by the High Energy X-ray Telescope of the Hard X-ray Modulation Telescope(Insight-HXMT/HE)and the Ground-Based Wide-Angle Camera network(GWAC-N)with the extremely large field of *** triggered by Insight-HXMT/HE and Fermi/GBM,we observed the optical emission of GRB 190530A,using the 30 cm telescope of GWAC(GWAC-F30)to search and locate its *** observation of the late afterglow of GRB 190530A was made with the 2.16 m telescope at Xinglong *** this paper,we make a detailed exploration of the origin of GRB *** the prompt emission,a“double-tracking”pattern is presented both for the low-energy spectral indexαand the peak energy Epin the Band function with Insight-HXMT/HE and Fermi/GBM data;the results of GRB 190530A are consistent with the Amati and Yonetoku correlations;the spectral lag(τ)versus energy(E)can be estimated withτ=-3.0±0.06+(0.17±0.03)*** synchrotron radiation can account for the origin of GRB190530A prompt emission ***αand Epof the precursor are essentially the same as that of the main prompt emission,implying that they have the same *** the afterglow,it can be described with the external forward shock model in ISM circumburst *** summary,from precursor,prompt emission to afterglow of GRB 190530A all originated from synchrotron radiation.

关键词： (stars)gamma-ray burst:individual(GRB 190530A)-(stars)gamma-ray burst general-virtual observatory tools