检索结果-南通市图书馆

The Bright Single Pulse Emission from PSR B1133+16

Research in Astronomy and Astrophysics 2024年第4期24卷 253-261页

作者： Jun Tan Zhi-Gang Wen Zhen wang Xue-Feng Duan hong-guang wang Na wang Vishal Gajjar Jian-Ping Yuan Rai Yuen Wen-Ming Yan Jian-Ling Chen Wei Han Hui wang Cheng-Bing Lyu Ai-Jun Dong Maths and Information Technology School Yuncheng UniversityYuncheng 044000China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China Space Science Laboratory University of CaliforniaBerkeley 94710USA Department of Physics and Electronic Engineering Yuncheng UniversityYuncheng 044000China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550025China

We have conducted a comprehensive investigation into the bright single pulse emission from PSR B1133+16using the Giant Metrewave Radio *** time resolution data(61μs)were obtained at a center frequency of 322 MHz with a bandwidth of 32 MHz over a continuous observation period of 7.45 hr.A total of 1082 bright pulses were sporadically detected with peak flux densities ranging from 10 to 23 times stronger than the average pulse ***,no giant pulse-like emission with a relative pulse energy larger than 10 and extremely short duration was detected,indicating that these bright pulses cannot be categorized as giant pulse *** majority of these bright pulses are concentrated in pulse phases at both the leading and trailing windows of the average pulse profile,with an occurrence ratio of approximately *** pulse energy distribution for all individual pulses can be described by a combination of two Gaussian components and a cutoff power-law with an index of α=-*** updated nulling fraction of 15.35%±0.45% was determined from the energy *** emission of individual pulses follows a log-normal distribution in peak flux density *** is imperative that regular phase drifting in bright pulse sequence is identified in both the leading and trailing components for the first *** physical mechanisms are discussed in detail to provide insights into these observations.

关键词： (stars:)pulsars:general (stars:)pulsars:individual(PSR B1133+16) methods:observational methods:data analysis

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

Circular Polarization of Fast Radio Bursts in the Curvature Radiation Scenario

引用

Research in Astronomy and Astrophysics 2022年第7期22卷 206-213页

作者： Hao Tong hong-guang wang School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China

The curvature radiation is applied to the explanation of the circular polarization of fast radio bursts(FRBs).Significant circular polarization is reported in both apparently non-repeating and repeating *** radiation can produce significant circular polarization at the wing of the radiation *** the curvature radiation scenario,in order to see significant circular polarization in FRBs,(1) more energetic bursts,(2) bursts with electrons having higher Lorentz factor,and(3) a slowly rotating neutron star at the center are *** rotational period of the central neutron star may explain why some FRBs have high circular polarization,while others do *** possible difference in refractive index for the parallel and perpendicular components of electric field,the position angle may change rapidly over the narrow pulse window of the radiation *** position angle swing in FRBs may also be explained by this non-geometric origin,besides that of the rotating vector model.

关键词： stars:magnetars (stars:)pulsars:general polarization

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

Periodicity in fast radio bursts due to forced precession by a fallback disk

引用

Research in Astronomy and Astrophysics 2020年第9期20卷 210-214页

作者： Hao Tong Wei wang hong-guang wang School of Physics and Electronic Engineering Guangzhou UniversityGuangzhou 510006China School of Physics and Technology Wuhan UniversityWuhan 430072China WHU-NAOC Joint Center for Astronomy Wuhan UniversityWuhan 430072China

Recently,a 16-day periodicity in a fast radio burst was *** propose that this 16-day periodicity may be due to forced precession of the neutron star by a fallback *** the rotation axis is misaligned with respect to the normal direction of the disk plane,the neutron star will *** eccentricity of the neutron star may be due to rotation or strong magnetic field,or similar *** found that the 16-day period may be understood using typical masses of the fallback *** observations and information about the neutron star rotation period may help to discriminate different *** possible precession observations in pulsars,magnetars and fast radio bursts may be understood together considering forced precession by a fallback disk.

关键词： accretion fast radio burst stars:magnetar 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

Applications of Extended Hyperbolic Function Method for Quintic Discrete Nonlinear SchrSdinger Equation

引用

Communications in Theoretical Physics 2007年第3期47卷 474-478页

作者： ZHAO hong HAN Ji-guang wang Wei-Tao AN hong-Yong School of Physical Science and Information Engineering Liaocheng University Liaocheng 252059 China

By using the extended hyperbolic function method, we have studied a quintic discrete nonlinear Schrodinger equation and obtained new exact localized solutions, including the discrete bright soliton solution, dark soliton solution, bright and dark soliton solution, alternating phase bright soliton solution, alternating phase dark soliton solution, and alternating phase bright and dark soliton solution, if a special relation is bound on the coefficients of the equation.

关键词： extended hyperbolic function method quintic discrete nonlinear Schr6dinger equation discretesolitons alternating phase

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

Use of digital subtraction angiography for assessment of digital replantation

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第3期13卷 209-212页

作者： Liu-hong wang guang-qiang ZHANG Department of Radiology the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China

Objective: To assess the blood flow of the proper digital artery using digital subtraction angiography (DSA) in the early stage after replantation. Methods: From January 2006 to October 2010, 27 anastomosed arteries in 27 replanted digits were included in the study. The patients included nine males and four females. The patients received DSA at 48 to 96 h after digital replantation. Based on DSA image, the blood flow was classified into normal, slow-running, and flow-stopping types. The patients with normal digital blood flow were given continuous routine treatments; the patients with slow-running flow were given the conservative treatments, such as release of the tight dressings, removal of stitches, keeping warm, the use of massage, and the use of anticoagulants and anti-inflammatory drugs; the patients with flow-stopping received immediate surgical re-exploration. Results: In this series, 23 digits in 11 patients showed a normal blood flow, and these digits all survived. In one of 13 patients, two digits which displayed slow-running flow also survived after conservative treatments. In two of 13 patients, two digits showed flow stopping, with one surviving and one failing after re-exploration and arterial revision. Conclusions: The DSA can be used to assess the blood flow of the proper digital artery in the early stage after replantation. It provides essential information for salvaging the replanted finger.

关键词： Digital subtraction angiography Proper digital artery Replantation Blood flow

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

Study of a high-temperature and high-pressure FBG sensor with Al_2O_3 thin-wall tube substrate

引用

Optoelectronics Letters 2008年第4期4卷 260-263页

作者： ZHOU hong QIAO Xue-guang wang hong-liang FENG De-quan wang Wei Optical Fiber Sensing Laboratory Xi＇an Petroleum University Xi ＇an 710065 China

A fiber Bragg grating(FBG) high-temperature and high pressure sensor has been designed and fabricated by using the Al2O3 thin-wall tube as a *** test results show that the sensor can withstand a pressure range of 0-45 MPa and a temperature range of -10-300 ℃,and has a pressure sensitivity of 0.0426 nm/MPa and a temperature sensitivity of 0.0112 nm /

关键词：光纤布拉格光栅传感器高温高压三氧化二铝薄壁管光学传感器

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

Radio Phase-Resolved Spectra of the Conal-Double Pulsar B1133+16

引用

Chinese Journal of Astronomy and Astrophysics 2007年第6期7卷 789-802页

作者： Jian-Ling Chen hong-guang wang Wan-Hai Chen Hui Zhang Yi Liu Center for Astrophysics Guangzhou University Guangzhou 510006 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Based on dividing the profile into a number of absolute phase intervals, the phaseresolved spectra （PHRS） are derived from published time-aligned average profiles at radio frequencies over two decades for the classic conal-double pulsar B1133＋16. The relative spectral index, defined as the difference between the spectral indices of a reference and the given arbitrary phase interval, is obtained by power-law fit at each phase interval. The derived phase-resolved spectra show an ＂M-like＂ shape, of which the leading part and trailing part are approximately symmetrical. The basic feature of the PHRS is that the spectrum first flattens then steepens as the pulse phase sweeps from the profile center to the profile edges. The PHRS provide a coherent explanation of the major features of profile evolution of B 1133＋ 16, namely, the pulse width shrinkage with increasing frequency and the frequency evolution of the relative intensity between the leading and trailing conal components, and the bridge emission. The PHRS may be an indicator for emission spectral variation across the pulsar magnetosphere. Possible mapping from PHRS to emission-location-dependent spectral variation is presented, and some intrinsic mechanisms are discussed.

关键词： pulsars individual (B 1133+ 16) -- method data analysis

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

Traditional surgical planning of liver surgery is modified by 3D interactive quantitative surgical planning approach： a single-center experience with 305 patients

引用

Hepatobiliary & Pancreatic Diseases International 2017年第3期16卷 271-278页

作者： Xue-Dong wang hong-guang wang Jun Shi Wei-Dong Duan Ying Luo Wen-Bin Ji Ning Zhang Jia-hong Dong Department of Hepatobiliary Surgery Beijing Tsinghua Changgung Hospital Medical Center Tsinghua University Beijing 102218 China Hospital and Institute of Hepatobiliary Surgery Chinese PLA General Hospital Beijing 100853 China

BACKGROUND： Decision making and surgical planning are to achieve the precise balance of maximal removal of target lesion, maximal sparing of functional liver remnant volume, and minimal surgical invasiveness and therefore, crucial in liver surgery. The aim of this prospective study was to validate the accuracy and predictability of 3D interactive quantitative surgical planning approach （IQSP）, and to evaluate the impact of IQSP on traditional surgical plans based on 2D images. METHODS： A total of 305 consecutive patients undergoing hepatectomy were included in this study. Surgical plans were created by traditional 2D approach using picture archiving and communication system （PACS） and 3D approach using IQSP respectively by two groups of physicians who did not know the surgical plans of the other group. The two surgical plans were submitted to the chief surgeon for selection before operation. The specimens were weighed. The two surgical plans were compared and analyzed retrospectively based on the operation results. RESULTS： The two surgical plans were successfully developed in all 305 patients and all the 3D IQSP surgical plans were selected as the final decision. Total 278 patients successfully underwent surgery, including 147 uncomplex hepatectomy and 131 complex hepatectomy. Twenty-seven patients were withdrawn from hepatectomy. In the uncomplex group, the two surgical plans were the same in all 147 patients and no statistically significant difference was found among 2D calcu- lated resection volume （2D-RV）, 3D IQSP calculated resection volume （IQSP-RV） and the specimen volume. In the complex group, the two surgical plans were different in 49 patients （49/131, 37.4%）. According to the significance of differences, the 49 different patients were classified into three grades. No statistically significant difference was found between IQSP-RV and specimen volume. The coincidence rate of territory analy- sis of IQSP with operation was 92.1% （93/101） for 101 patients of

关键词： precision quantitative surgical planning reconstruction hepatectomy

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

An Annular Gap Acceleration Model for γ-ray Emission of Pulsars

引用

Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 496-502页

作者： Guo-Jun Qiao Ke-Jia Lee Bing Zhang hong-guang wang Ren-Xin Xu Department of Astronomy Peking University Beijing 100871 Department of Physics University of Nevada Las Vegas Nevada 89154 USA Center for Astrophysics Guangzhou University Guangzhou 510400

If the binding energy of the pulsar＇s surface is not so high （the case of a neutron star）, both negative and positive charges will flow out freely from the surface of the star. An annular free flow model for 7-ray emission of pulsars is suggested. It is emphasized that：（1） Two kinds of acceleration regions （annular and core） need to be taken into account. The annular acceleration region is defined by the magnetic field lines that cross the null charge surface within the light cylinder. （2） If the potential drop in the annular region of a pulsar is high enough （normally the case for young pulsars）, charges in both the annular and the core regions could be accelerated and produce primary gamma-rays. Secondary pairs are generated in both regions and stream outwards to power the broadband radiations. （3） The potential drop grows more rapidly in the annular region than in the core region. The annular acceleration process is a key process for producing the observed wide emission beams. （4） The advantages of both the polar cap and outer gap models are retained in this model. The geometric properties of the 7-ray emission from the annular flow are analogous to that pre-sented in a previous work by Qiao et al., which match the observations well. （5） Since charges with different signs leave the pulsar through the annular and the core regions respectively, the current closure problem can be partially solved.

关键词： pulsars: general - pulsars: - radiation mechanisms: non-thermal - stars:neutron - elementary particles

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

Recovering the pulse profiles and polarization position angles of some pulsars from interstellar scattering

引用

Research in Astronomy and Astrophysics 2012年第5期12卷 529-539页

作者： Abdujappar Rusul Ali Esamdin Alim Kerim Dilnur Abdurixit hong-guang wang Xiao-Ping Zheng School of Physics Science and Technology Xinjiang University Urumqi 830046 China Xinjiang Astronomical Observatory Chinese Academy of Sciences Urumqi 830011 China Xinjiang University-National Astronomical Observatory Joint Center for Astrophysics Urumqi 830046 China Department of Physics Guangzhou University Guangzhou 510006 China The Institute of Astrophysics Huazhong Normal University Wuhan 430079 China

Interstellar scattering causes broadening and distortion in the mean pulse profiles and polarization position angle （PPA） curves of pulsars, especially pulse profiles observed at lower frequencies. This paper implements a method to recover the pulse profiles and PPA curves of five pulsars which have obvious scattered pulse pro- files at lower frequency. It reports a simulation to show the scattering and descatter- ing of pulse profiles and PPA curves, and as a practical application the lower frequency profiles and PPA curves of PSR 1356-60, PSR 1831-03, PSR 1838＋04, PSR 1859＋03 and PSR 1946＋35 are obtained. It is found that the original pulse profiles and PPA curves can be recovered.

关键词： stars pulsar-interstellar medium

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

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：