检索结果-南通市图书馆

Small glitches: the role of strange nuggets?

Research in Astronomy and Astrophysics 2016年第3期16卷 91-98页

作者： xiao-yu lai Ren-Xin Xu School of Physics Xinjiang University Xinjiang Astronomical Observatory Chinese Academy of Sciences School of Physics Peking University Kavli Institute for Astronomy and Astrophysics Peking University

Pulsar glitches, i.e. the sudden spin-ups of pulsars, have been detected for most known *** mechanism giving rise to this kind of phenomenon is uncertain, although a large data set has been *** the framework of the starquake model, based on Baym ＆ Pines, the glitch sizes（the relative increases of spin-frequencies during glitches） △Ω/Ω depend on the released energies during glitches, with less released energies corresponding to smaller glitch sizes. On the other hand, as one of the dark matter candidates,our Galaxy might be filled with so called strange nuggets（SNs） which are relics from the early *** this case collisions between pulsars and SNs are inevitable, and these collisions would lead to glitches when enough elastic energy has been accumulated during the spin-down process. The SN-triggered glitches could release less energy, because the accumulated elastic energy would be less than that in the scenario of glitches without SNs. Therefore, if a pulsar is hit frequently by SNs, it would tend to have more small glitches, whose values of ？？/？ are smaller than those in the standard starquake model（with larger amounts of released energy）. Based on the assumption that in our Galaxy the distribution of SNs is similar to that of dark matter, as well as on the glitch data in the ATNF Pulsar Catalogue and Jodrell Bank glitch table, we find that in our Galaxy the incidences of small glitches exhibit tendencies consistent with the collision rates between pulsars and SNs. Further testing of this scenario is expected by detecting more small glitches（e.g.,by the Square Kilometre Array）.

关键词： pulsars -- glitches -- quark-cluster stars -- strange nuggets

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A note on the discovery of a 2M_⊙ pulsar

引用

Research in Astronomy and Astrophysics 2011年第6期11卷 687-691页

作者： xiao-yu lai Ren-Xin Xu School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China

It is conventionally thought that the state equation of dense matter softens and thus cannot result in high maximum mass if pulsars are quark stars and that a recently discovered 2M⊙ pulsar （PSR J1614–2230） may make pulsars unlikely to be quark stars. However, this standard point of view would be revisited and updated if quark clustering could occur in cold quark matter because of the strong coupling be- tween quarks at realistic baryon densities in compact stars. It can be argued that the state equation of clustered quark matter stiffens to support compact stars with maxi- mum mass Mmax 2M⊙. In this brief note, it is demonstrated that large parameter space ranges are allowed for Mmax 2M⊙ in a Lennard-Jones model of clustered quark matter and the newly measured highest mass of PSR J1614–2230 would be meaningful for constraining the number of quarks inside a single quark-cluster to be Nq ≤ 103.

关键词： dense matter — elementary particles — pulsars: general — stars: neutron

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rotating Massive Strangeon Stars and X-Ray Plateau of Short GRBs

引用

Research in Astronomy and Astrophysics 2024年第3期24卷 47-57页

作者： Xi-Yan Yang xiao-yu lai Wei-Wei Tan Ren-Xin Xu School of Physics and Optoelectronic Engineering Yangtze UniversityJingzhou 434023China Research Center for Astronomy Hubei University of EducationWuhan 4300205China Key Laboratory of Quark and Lepton Physics Central China Normal UniversityMinistry of EducationWuhan 430079China School of Physics Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

Strangeon stars,which are proposed to describe the nature of pulsar-like compact stars,have passed various observational *** maximum mass of a non-rotating strangeon star could be high,which implies that the remnants of binary strangeon star mergers could even be long-lived massive strangeon *** study rigidly rotating strangeon stars in the slowly rotating approximation,using the Lennard-Jones model for the equation of *** can significantly increase the maximum mass of strangeon stars with unchanged baryon numbers,enlarging the mass-range of long-lived strangeon *** spin-down after merger,the decrease of radius of the remnant will lead to the release of gravitational *** into account the efficiency of converting the gravitational energy luminosity to the observed X-ray luminosity,we find that the gravitational energy could provide an alternative energy source for the plateau emission of X-ray *** fitting results of X-ray plateau emission of some short gamma-ray bursts suggest that the magnetic dipole field strength of the remnants can be much smaller than that of expected when the plateau emission is powered only by spin-down luminosity of magnetars.

关键词： dense matter-(stars) pulsars general-(stars) gamma-ray burst general

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Merging strangeon stars

引用

Research in Astronomy and Astrophysics 2018年第2期18卷 125-134页

作者： xiao-yu lai yun-Wei yu En-Ping Zhou yun-Yang Li Ren-Xin Xu School of Physics and Mechanical & Electrical Engineering Hubei University of Education Xinjiang Astronomical Observatory Chinese Academy of Sciences Institute of Astrophysics Central China Normal University School of Physics Peking University Kavli Institute for Astronomy and Astrophysics Peking University

The state of supranuclear matter in compact stars remains puzzling, and it is argued that pul- sars could be strangeon stars. What would happen if binary strangeon stars merge？ This kind of merger could result in the formation of a hyper-massive strangeon star, accompanied by bursts of gravitational waves and electromagnetic radiation （and even a strangeon kilonova explained in the paper）. The tidal polarizability of binary strangeon stars is different from that of binary neutron stars, because a strangeon star is self-bound on the surface by the fundamental strong force while a neutron star by the gravity, and their equations of state are different. Our calculation shows that the tidal polarizability of merging bi- nary strangeon stars is favored by GW170817. Three kinds of kilonovae （i.e., of neutron, quark and strangeon） are discussed, and the light curve of the kilonova AT 2017gfo following GW170817 could be explained by considering the decaying strangeon nuggets and remnant star spin-down. Additionally, the energy ejected to the fireball around the nascent remnant strangeon star, being manifested as a gamma-ray burst, is calculated. It is found that, after a prompt burst, an X-ray plateau could follow in a timescale of 102 - 103 s. Certainly, the results could be tested also by further observational synergies between gravitational wave detectors （e.g., Advanced LIGO） and X-ray telescopes （e.g., the Chinese HXMT satellite and eXTP mission）, and especially if the detected gravitational wave form is checked by peculiar equations of state provided by the numerical relativistical simulation.

关键词： stars: neutron -- pulsars: general -- X-rays: stars -- gravitational waves

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Merging strangeon stars Ⅱ:the ejecta and light curves

引用

Research in Astronomy and Astrophysics 2021年第10期21卷 86-96页

作者： xiao-yu lai Cheng-Jun Xia) yun-Wei yu Ren-Xin Xu Department of Physics and Astronomy Hubei University of EducationWuhan 430205China Research Center for Astronomy Hubei University of EducationWuhan 430205China School of Information Science and Engineering NingboTech UniversityNingbo 315100China Institute of Astrophysics Central China Normal UniversityWuhan 430079China School of Physics Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

The state of supranuclear matter in compact stars remains puzzling,and it is argued that pulsars could be strangeon *** consequences of merging double strangeon stars are worth exploring,especially in the new era of multi-messenger *** develop the"strangeon kilonova"scenario proposed in Paper I,we make a qualitative description about the evolution of ejecta and light curves for merging double strangeon *** the hot environment of the merger,the strangeon nuggets ejected by tidal disruption and hydrodynamical squeezing would suffer from evaporation,in which process particles,such as strangeons,neutrons and protons,are *** into account both the evaporation of strangeon nuggets and the decay of strangeons,most of the strangeon nuggets would turn into neutrons and protons,within dozens of milliseconds after being *** evaporation rates of different particles depend on temperature,and we find that the ejecta could end up with two components,with high and low opacity *** high opacity component would be in the directions around the equatorial plane,and the low opacity component would be in a broad range of angular *** bolometric light curves show that the spin-down power of the long-lived remnant would account for the whole emission of kilonova AT2017gfo associated with GW170817,if the total ejected mass 10^(-3)M⊙.The detailed picture of merging double strangeon stars is expected to be tested by future numerical simulations.

关键词： dense matter equation of state pulsars:general

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Supernova neutrinos in a strangeon star model

引用

Research in Astronomy and Astrophysics 2017年第9期17卷 39-50页

作者： Mao yuan Ji-Guang Lu Zhi-Liang Yang xiao-yu lai Ren-Xin Xu Department of Astronomy Beijing Normal UniversityBeijing 100875China School of Physics Peking UniversityBeijing 100871China School of Physics and Engineering Hubei University of EducationWuhan 430205China Kavli Institute for Astronomy and Astrophysics at Peking University Beijing 100871China

The neutrino burst detected during supernova SN 1987A is explained in a strangeon star model, in which it is proposed that a pulsar-like compact object is composed of strangeons （strangeon： an abbreviation for ＂strange nucleon＂）. A nascent strangeon star＇s initial internal energy is calculated, with the inclusion of pion excitation （energy around 1053 erg, comparable to the gravitational binding energy of a collapsed core）. A liquid-solid phase transition at temperature - 1 - 2 MeV may occur only a few tens of seconds after core collapse, and the thermal evolution of a strangeon star is then modeled. It is found that the neutrino burst observed from SN 1987A can be reproduced in such a cooling model.

关键词： stars neutron -- supernovae individual (SN 1987A)- neutrinos

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The optical/UV excess of X-ray-dim isolated neutron star Ⅱ.Nonuniformity of plasma on a strangeon star surface

引用

Research in Astronomy and Astrophysics 2018年第7期18卷 81-92页

作者： Wei-Yang Wang Yi Feng xiao-yu lai yun-Yang Li Ji-Guang Lu Xuelei Chen Ren-Xin Xu Key Laboratory of Computational Astrophysics National Astronomical ObservatoriesChinese Academy ofSciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Hubei University of Education Wuhan 430205China Key Laboratory of Radio Astronomy Chinese Academy of SciencesBeijing 100101China Center for High Energy Physics Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

Several X-ray-dim isolated neutron stars （XDINSs）, also known as the Magnificent Seven, exhibit a Planck-like soft X-ray spectrum. In the optical/ultraviolet （UV） band, there is an excess of radiation compared to an extrapolation from the X-ray spectrum. However, the majority exhibits ＂spec- tral deviations＂： the fact that there is more flux at longer wavelengths makes spectra deviate from the Rayleigh-Jeans law. A model of bremsstrahlung emission from a nonuniform plasma atmosphere is proposed in the regime of a strangeon star to explain the optical/UV excess and its spectral devi- ation as well as X-ray pulsation. The atmosphere is on the surface of strangeon matter, which has negligible emission, and is formed by the accretion of ISM-fed debris disk matter moving along the magnetic field lines to near the polar caps. These particles may spread out of the polar regions which makes the atmosphere non-uniform. The modeled electron temperatures are ~ 100 - 200 eV with radi- ation radii Ropt ~ 5 - 14km. The spectra of five sources （RX J0720.4-3125, RX J0806.4-4123, RX J1308.6＋2127, RX J1605.3＋3249, RX J1856.5-3754） from optical/UV to X-ray bands can be fitted well by the radiative model, and exhibit Gaussian absorption lines at ~ 100 - 500 eV as would be expected. Furthermore, the surroundings （i.e., fallback disks or dusty belts） of XDINSs could be tested by future infrared/submillimeter observations.

关键词： X-rays stars - stars neutron - stars individual

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic resonance imaging： a valuable method for diagnosing chronic lumbago caused by lumbar muscle strain and monitoring healingprocess

引用

Chinese Medical Journal 2013年第13期126卷 2465-2471页

作者： OUYANG Lin JIA Qian-xin xiao yu-hui KE lai-shun HE Ping Department of Medical Imaging People's Liberation Army 175th Hospital Affiliated Southeast Hospital of Xiamen University Zhangzhou Fujian 363000 China

Background Magnetic resonance imaging （MRI） is the most sensitive technique for evaluating the healing process and should be performed before the patients return to their exercise routines. The aim of this research was to diagnose chronic lumbago associated with lumbar muscle strain and to monitor healing process by MRI. Methods Sixty-five symptomatic cases of chronic lumbago caused by lumbar muscle strain were collected from March 2009 to October 2011. MRI was used to examine, diagnose and monitor the healing process. The control group included 65 random cases of asymptomatic volunteers. MRI methods included routine sequences of GRE TlWl, TSE T2WI and special sequences of T2-STIR-FS, combined with DWI. We compared the MRI characteristics of symptomatic cases before and after healing and with asymptomatic controls. Results The important MRI characteristics of chronic lumbago with lumbar muscle strain included：（1） The low back muscle showed edema. （2） The low back intermuscular spaces showed edema and/or fluid. （3） The low back spaces beside the spinous process showed edema and/or fluid. （4） The low back vertebral articular process fossae or transverse process fossae showed fluid. Of these image characteristics, the intermuscular space edema provided the best diagnostic sensitivity, Se=83%, with Y1=0.63, Tr=74%. The low back muscle edema provided the best diagnostic specificity, Sp=100%, with Y1=0.66, Tr=83%. And the spaces edema beside the spinous process provided the best diangnostic accuracy, Tr=86%, with YI = 0.71, Se=80%, Sp=91%. The diagnosis accurate could be improved by combining multiple MRI characteristics. The diagnostic accuracy could achieve n=93%, with Y1=0.86, Se=100% and Sp=86% when two characteristics were combined. After rehabilitation care, the edema disappeared on the repeated MRI. Conclusions MRI may well be a useful diagnostic method for lumbago with lumbar muscle strain. Combining routine sequences with T2-STIR-FS and DWI sequences could demon

关键词： psoas muscles," sprains and strains," magnetic resonance imaging muscular-skeletal image

来源：

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

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： xiao Xiang Feng Gao yu-Gui Peng Peng Wu Zong-Lin Li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of Lxand/or Ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Epstein-Barr virus positive post-transplant lymphoproliferative disorder with significantly decreased T-cell chimerism early after transplantation:A case report

引用

World Journal of Radiology 2024年第10期16卷 600-607页

作者： Qing-Na Guo Hai-Sheng Liu Lin Li Dian-Ge Jin Ji-Min Shi xiao-yu lai Li-Zhen Liu Yan-Min Zhao Jian yu Yan-yuan Li Fang-Quan yu Zhe Gao Jiao Yan He Huang Yi Luo Yi-Shan Ye Bone Marrow Transplantation Center The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003Zhejiang ProvinceChina Department of Hematology The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050035Hebei ProvinceChina Liangzhu Laboratory Zhejiang University Medical CenterHangzhou 310003Zhejiang ProvinceChina Department of Pathology First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003Zhejiang ProvinceChina Department of Hematology Jinhua People’s HospitalJinhua 321000Zhejiang ProvinceChina

BACKGROUND Post-transplant lymphoproliferative disorder(PTLD)is a rare but highly fatal complication occurring after allogeneic hematopoietic cell transplantation(allo-HCT)or solid organ transplantation(SOT).Unlike SOT,PTLD after allo-HCT usually originates from the donor and is rarely accompanied by a loss of donor *** SUMMARY We report a case of Epstein-Barr virus positive PTLD manifesting as diffuse large B-cell lymphoma(DLBCL)with significantly decreased T-cell chimerism early after allo-HCT.A 30-year-old patient with acute myeloid leukemia underwent unrelated allo-HCT after first complete *** 3 mo after transplantation,the patient developed cervical lymph node enlargement and gastric lesions,both of which were pathologically suggestive of ***,the patient experienced a significant and persistent decrease in T-cell chimerism.A partial remission was achieved after chemotherapy with single agent rituximab and subsequent R-CHOP combined *** The loss of T-cell chimerism and the concomitant T-cell insufficiency may be the cause of PTLD in this patient.

关键词： Post-transplant lymphoproliferative disorder T-cell chimerism Epstein-Barr virus T cell function Case report

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：