期刊文献+
共找到16篇文章
< 1 >
每页显示 20 50 100
Design and assembly of a nested imaging X-ray telescope for the Hot Universe Baryon Surveyor mission
1
作者 Jun Yu Ruohui Xian +8 位作者 Xiaoqiang Wang Yifan Wang Zhanshan Wang Wei Zhang Yibo Cai Jing Yang Xi Lu Wei Wang Wei Cui 《Astronomical Techniques and Instruments》 CSCD 2024年第3期157-165,共9页
The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progres... The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process. 展开更多
关键词 Nested x-ray telescope Thermal glass slumping telescope assembly In situ measurement
下载PDF
Status of the Hard X-ray Modulation Telescope Project 被引量:2
2
作者 LU Fangjun 《空间科学学报》 CAS CSCD 北大核心 2014年第5期544-546,共3页
The Hard X-ray Modulation Telescope(HXMT) is China's first astronomical satellite.It will perform a broad band(1–250 keV) scan survey and do pointed observations of X-ray sources to study their spectra and multi-... The Hard X-ray Modulation Telescope(HXMT) is China's first astronomical satellite.It will perform a broad band(1–250 keV) scan survey and do pointed observations of X-ray sources to study their spectra and multi-wavelength temporal properties. The pre-flight models of the satellites have been finished, and the flight models are in production. The expected launch date of HXMT is in late 2015. 展开更多
关键词 HARD x-ray MODULATION telescope(HXMT) Astronomical satellite Active GALACTIC NUCLEI
下载PDF
Calibration of X-ray telescope prototypes at PANTER 被引量:1
3
作者 Ying-Yu Liao Zheng-Xiang Shen +11 位作者 Jun Yu Qiu-Shi Huang Bin Ma Zhong Zhang Xiao-Qiang Wang Kun Wang Chun Xie Vadim Burwitz Gisela Hartner Marlis-Madeleine La Caria Carlo Pelliciari Zhan-Shan Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第12期199-206,共8页
We report on a ground X-ray calibration of two X-ray telescope prototypes at the PANTER X-ray Test Facility, operated by the Max-Planck-Institute for Extraterrestrial Physics, in Neuried, Germany.The X-ray telescope p... We report on a ground X-ray calibration of two X-ray telescope prototypes at the PANTER X-ray Test Facility, operated by the Max-Planck-Institute for Extraterrestrial Physics, in Neuried, Germany.The X-ray telescope prototypes were developed by the Institute of Precision Optical Engineering(IPOE)of Tongji University, in a conical Wolter-I configuration, using thermal glass slumping technology.Prototype #1 with three layers and Prototype #2 with 21 layers were tested to assess the prototypes’ onaxis imaging performance. The measurement of Prototype #1 indicates a Half Power Diameter(HPD) of 82′′ at 1.49 keV. As for Prototype #2, we performed more comprehensive measurements of on-axis angular resolution and effective area at several energies ranging from 0.5–10 keV. The HPD and effective area are111′′ and 39 cm^2 at 1.49 keV, respectively, at which energy the on-axis performance of the prototypes is our greatest concern. 展开更多
关键词 x-ray telescopes thermal slumping technology x-ray calibration PANTER
下载PDF
In-Orbit Calibration and Data Analysis of China's First Grazing Incidence Focusing X-Ray Pulsar Telescope
4
作者 LV Zhengxin MEI Zhiwu +10 位作者 DENG Loulou LI Liansheng SHI Yongqiang CHEN Jianwu ZUO Fuchang LIU Ke WANG Chunyu ZHANG Jianfu MO Yanan WANG Shuyan ZHAO Yuan 《Aerospace China》 2017年第3期3-10,共8页
The grazing incidence focusing X-ray pulsar telescope(iFXPT), as the main payload of the X-ray Pulsar Navigation Test Satellite(XPNAV-1), will have great significance on China's space scientific exploration and X-... The grazing incidence focusing X-ray pulsar telescope(iFXPT), as the main payload of the X-ray Pulsar Navigation Test Satellite(XPNAV-1), will have great significance on China's space scientific exploration and X-ray pulsar navigation. With PSR B0531+21(Crab Pulsar) as the observation target, the pulsar profile has been recovered based on the data obtained by iFXPT, realizing the main objective of "observing" PSR B0531+21 for the first time in China. This payload mainly consists of the Wolter-I X-ray optics, silicon drift detector, magnetic deflector, electronics, high-energy particle shield and high-stability structures. Currently, the iFXPT, with its good in-orbit performance, has obtained a considerable observation data. The effective area, sensitivity and energy response have been calibrated both on ground and in-orbit, demonstrating a high degree of consistency. Meanwhile, the in-orbit observation data and information for pulsar navigation has also been analyzed simultaneously. As a result, the feasibility of the exploration scheme and the performance of the telescope have been fully validated. 展开更多
关键词 x-ray pulsar navigation satellite focusing x-ray telescope in-orbit observation profile folding timing residual
下载PDF
The High Energy X-ray telescope (HE) onboard the Insight-HXMT astronomy satellite 被引量:12
5
作者 CongZhan Liu YiFei Zhang +30 位作者 XuFang Li XueFeng Lu Zhi Chang ZhengWei Li AiMei Zhang YongJie Jin HuiMing Yu Zhao Zhang MinXue Fu YiBao Chen JianFeng Ji YuPeng Xu JingKang Deng RenCheng Shang GuoQing Liu FangJun Lu ShuangNan Zhang YongWei Dong TiPei Li Mei Wu YanGuo Li HuanYu Wang BoBing Wu YongJie Zhang Zhi Zhang ShaoLin Xiong Yuan Liu Shu Zhang HongWei Liu YiJung Yang Fan Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2020年第4期20-34,共15页
The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector pl... The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments. 展开更多
关键词 x-ray telescope HXMT calibration scintillation DETECTOR
原文传递
The Low Energy X-ray telescope (LE) onboard the Insight-HXMT astronomy satellite 被引量:10
6
作者 Yong Chen WeiWei Cui +24 位作者 Wei Li Juan Wang YuPeng Xu FangJun Lul YuSa Wang TianXiang Chen DaWei Han Wei Hu Yi Zhang Jia Huo YanJi Yang MaoShun Li Bo Lu ZiLiang Zhang TiPei Li ShuangNan Zhang ShaoLin Xiong Shu Zhang RongFeng Xue XiaoFan Zhao Yue Zhu YuXuan Zhu HongWei Liu YiJung Yang Fan Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2020年第4期49-61,共13页
The Low Energy X-ray telescope(LE) is one of the three main instruments of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT). It is equipped with Swept Charge Device(SCD) sensor arrays with a total geometrical... The Low Energy X-ray telescope(LE) is one of the three main instruments of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT). It is equipped with Swept Charge Device(SCD) sensor arrays with a total geometrical area of 384 cm^2 and an energy band from 0.7 to 13 ke V. In order to evaluate the particle induced X-ray background and the cosmic X-ray background simultaneously, LE adopts collimators to define four types of Field Of Views(FOVs), i.e., 1.6°×6°, 4°×6°, 50°-60°×2°-6 oand the blocked ones which block the X-ray by an aluminum cover. LE is constituted of three detector boxes(LEDs) and an electric control box(LEB) and achieves a good energy resolution of 140 e V@5.9 ke V, an excellent time resolution of 0.98 ms, as well as an extremely low pileup(<1%@18000 cts/s). Detailed performance tests and calibration on the ground have been performed,including energy-channel relation, energy response, detection efficiency and time response. 展开更多
关键词 LE x-ray telescope SCD COLLIMATORS
原文传递
Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite 被引量:19
7
作者 Shuang-Nan Zhang TiPei Li +116 位作者 FangJun Lu LiMing Song YuPeng X u CongZhan Liu Yong Chen XueLei Cao QingCui Bu Zhi Chang Gang Chen Li Chen TianXiang Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong Yuan Yuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan Can Gungor ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge Ou JinLu Qu Na Sai RenCheng Shang GuoHong Shen Liang Sun Ying Tan Lian Tao YouLi Tuo Chen Wang ChunQin Wang GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BaiYang Wu BoBing Wu Mei Wu GuangCheng Xiao ShaoLin Xiong LinLi Yan JiaWei Yang Sheng Yang YanJi Yang QiBin Yi Bin Yuan AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang ShenYi Zhangs Shu Zhang Tong Zhang WanChang Zhang Wei Zhang WenZhao Zhang Yi Zhang YiFei Zhang YongJie Zhang Yue Zhang Zhao Zhang Zhi Zhang ZiLiang Zhang HaiSheng Zhao XiaoFan Zhao ShiJie Zheng JianFeng Zhou YuXuan Zhu Yue Zhu RenLin Zhuang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2020年第4期2-19,共18页
As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray as... As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 Me V. It was designed to perform pointing, scanning and gamma-ray burst(GRB)observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed.Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results. 展开更多
关键词 X-and γ-ray telescopes and instrumentation neutron stars black holes x-ray binaries γ-ray bursts
原文传递
Space solar telescope in soft X-ray and EUV band 被引量:4
8
作者 CHEN Bo LIU Zhen +4 位作者 YANG Lin GAO Liang HE Fei WANG XiaoGuang NI QiLiang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2009年第11期1806-1809,共4页
In this paper we have reviewed our achievements in soft X-ray and extreme ultraviolet (EUV) optics. Up to now, the research system of soft X-ray and EUV optics has been established, including light sources, detectors,... In this paper we have reviewed our achievements in soft X-ray and extreme ultraviolet (EUV) optics. Up to now, the research system of soft X-ray and EUV optics has been established, including light sources, detectors, calibrations, optical testing and machining of super smooth mirrors, and fabrications of multilayer film mirrors. Based on our achievements, we have developed two types of solar space telescopes for the soft X-ray and EUV space solar observations. One is an EUV multilayer normal incident telescope array including 4 different operation wavelength telescopes. The operation wavelengths of the EUV telescope are 13.0, 17.1, 19.5 and 30.4 nm. The other is a complex space solar telescope, which is composed of an EUV multilayer normal incident telescope and a soft X-ray grazing incident telescope. The EUV multilayer normal incident telescope stands in the central part of the soft X-ray grazing incident telescope. The normal incident telescope and the grazing incident telescope have a common detector. The different operation wavelengths can be changed by rotating a filter wheel. 展开更多
关键词 space solar telescope soft x-ray EUV OPTIC
原文传递
Design and verification of the HXI collimator on the ASO-S mission 被引量:1
9
作者 Deng-Yi Chen Yi-Ming Hu +11 位作者 Tao Ma Yang Su Jian-Feng Yang Jian-Ping Wang Guang-Zhou Xu Xian-Kai Jiang Jian-Hua Guo Yong-Qiang Zhang Yan Zhang Wei Chen Jin Chang Zhe Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第6期241-252,共12页
A space-borne hard X-ray collimator,comprising 91 pairs of grids,has been developed for the Hard X-ray Imager(HXI).The HXI is one of the three scientific instruments onboard the first Chinese solar mission:the Advance... A space-borne hard X-ray collimator,comprising 91 pairs of grids,has been developed for the Hard X-ray Imager(HXI).The HXI is one of the three scientific instruments onboard the first Chinese solar mission:the Advanced Space-based Solar Observatory(ASO-S).The HXI collimator(HXI-C)is a spatial modulation X-ray telescope designed to observe hard X-rays emitted by energetic electrons in solar flares.This paper presents the detailed design of the HXI-C for the qualification model that will be inherited by the flight model.Series tests on the HXI-C qualification model are reported to verify the ability of the HXI-C to survive the launch and to operate normally in on-orbit environments.Furthermore,results of the X-ray beam test for the HXI-C are presented to indirectly identify the working performance of the HXI-C. 展开更多
关键词 Solar observation ASO-S x-ray telescope the collimator VERIFICATION
下载PDF
Epidemiologic Features, Radiological Findings and Clinical Outcomes of 19 Patients with COVID-19 in a Single Center in Beijing, China 被引量:1
10
作者 Lan Song Zhenchen Zhu +8 位作者 Ruijie Zhao Pengchang Li Duxue Tian Tiekuan Du Yan Xu Qiwen Yang Wei Cao Wei Song Zhengyu Jin 《Chinese Medical Sciences Journal》 CAS CSCD 2021年第2期85-96,共12页
Objective To describe the epidemiologic,clinical,laboratory,and radiological characteristics and prognoses of COVID-19 confirmed patients in a single center in Beijing,China.Methods The study retrospectively included ... Objective To describe the epidemiologic,clinical,laboratory,and radiological characteristics and prognoses of COVID-19 confirmed patients in a single center in Beijing,China.Methods The study retrospectively included 19 patients with nucleic acid-confirmed SARS-CoV^2 infection at our hospital from January 20 to March 5,2020.The final follow-up date was March 14,2020.The epidemiologic and clinical information was obtained through direct communication with the patients or their family members.Laboratory results retrieved from medical records and radiological images were analyzed both qualitatively by two senior chest radiologists as well as quantitatively via an artificial intelligence software.Results We identified 5 family clusters(13/19,68.4%)from the study cohort.All cases had good clinical prognoses and were either mild(3/19)or moderate(16/19)clinical types.Fever(15/19,78.9%)and dry cough(11/19,57.9%)were common symptoms,Two patients received negative results for more than three consecutive viral nucleic acid tests.The longest interval between an initial CT abnormal finding and a confirmed diagnosis was 30 days.One patient's nucleic acid test turned positive on the follow-up examination after discharge.The presence of radiological abnormalities was non-specific for the diagnosis of COVID-19.Conclusions COVID-19 patients with mild or no clinical symptoms are common in Beijing,China.Radiological abnormalities are mostly non-specific and massive CT examinations for COVID-19 screening should be avoided.Analyses of the contact histories of diagnosed cases in combination with clinical,radiological and laboratory findings are crucial for the early detection of COVID-19.Close monitoring after discharge is also recommended. 展开更多
关键词 CORONAVIRUS SARS-CoV-2 COVID-19 tomography x-ray computed follow-up
下载PDF
Microsurgical Treatment of Occupying-space Lesions of Brainstem
11
作者 Yu-guangLiu YuLi +3 位作者 MengLiu Wan-dongSu Xin-gangLi Shu-ganZhu 《Chinese Medical Sciences Journal》 CAS CSCD 2004年第2期96-96,共1页
关键词 ADOLESCENT Adult ASTROCYTOMA Brain Diseases Brain Neoplasms Brain Stem Female follow-up Studies HEMATOMA Humans Magnetic Resonance Imaging Male MICROSURGERY Middle Aged Tomography x-ray Computed
下载PDF
Scientific objectives of the Hot Universe Baryon Surveyor(HUBS) mission 被引量:1
12
作者 Joel Bregman Renyue Cen +51 位作者 Yang Chen Wei Cui Taotao Fang Fulai Guo Edmund Hodges-Kluck Rui Huang Luis C.Ho Li Ji Suoqing Ji Xi Kang Xiaoyu Lai Hui Li Jiangtao Li Miao Li Xiangdong Li Yuan Li Zhaosheng Li Guiyun Liang Helei Liu Wenhao Liu Fangjun Lu Junjie Mao Gabriele Ponti Zhijie Qu Chenxi Shan Lijing Shao Fangzheng Shi Xinwen Shu Lei Sun Mouyuan Sun Hao Tong Junfeng Wang Junxian Wang Q.Daniel Wang Song Wang Tinggui Wang Weiyang Wang Zhongxiang Wang Dandan Xu Haiguang Xu Heng Xu Renxin Xu Xiaojie Xu Yongquan Xue Hang Yang Feng Yuan Shuinai Zhang Yuning Zhang Zhongli Zhang Yuanyuan Zhao Enping Zhou Ping Zhou 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2023年第9期134-178,共45页
The Hot Universe Baryon Surveyor(HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectr... The Hot Universe Baryon Surveyor(HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectroscopy and large field of view,the HUBS mission will be uniquely qualified to measure the physical and chemical properties of the hot gas in the interstellar medium, the circumgalactic medium, the intergalactic medium, and the intracluster medium. These measurements will be valuable for two key scientific goals of HUBS, namely to unravel the AGN and stellar feedback physics that governs the formation and evolution of galaxies, and to probe the baryon budget and multi-phase states from galactic to cosmological scales. In addition to these two goals, the HUBS mission will also help us solve some problems in the fields of galaxy clusters, AGNs, difuse X-ray backgrounds, supernova remnants, and compact objects. This paper discusses the perspective of advancing these fields using the HUBS telescope. 展开更多
关键词 x-ray telescopes Galactic halo x-ray sources
原文传递
In-orbit performance of HE onboard Insight-HXMT in the first 5 years
13
作者 Xu-Fang Li Cong-Zhan Liu +10 位作者 Yi-Fei Zhang Xiao-Bo Li Zheng-Wei Li Xue-Feng Lu Zhi Chang Ming-Yu Ge Juan Zhang Yu-Peng Xu Fang-Jun Lu Li-Ming Song Shuang-Nan Zhang 《Radiation Detection Technology and Methods》 CSCD 2023年第1期3-14,共12页
Purpose The high-energy X-ray telescope(HE),one of the three main payloads of the Insight-HXMT mission,is composed of eighteen NaI(Tl)/CsI(Na)phoswich detectors,where NaI(Tl)serves as the primary detector covering 20... Purpose The high-energy X-ray telescope(HE),one of the three main payloads of the Insight-HXMT mission,is composed of eighteen NaI(Tl)/CsI(Na)phoswich detectors,where NaI(Tl)serves as the primary detector covering 20–250 keV,and CsI(Na)is used as an active shield detector to suppress the background of NaI(Tl)and also serves as an all-sky gammaray burst monitor covering 0.2–3MeV.In this paper,we review the in-orbit performance of HE in the first 5 years since Insight-HXMT was launched on June 15,2017.Methods The major performances we concern include the gain and energy resolution of NaI(Tl)and CsI(Na)detectors,the performance of pulse shape discriminator(PSD)and system dead time.In this work,we investigate these performances mainly using the data of blank-sky observations and the data when the telescope is in earth occultation.Results The overall performance of HE/NaI(Tl)is very stable in the first 5 years,whereas the gain of HE/CsI(Na)shows a continuously increasing trend and should be calibrated regularly.Conclusion In general,HE is still in good health and well-calibrated status after five-year’s operation.The in-orbit performance of HE has no significant deviation from expectation.HE is expected to be in operation healthily for another several years of extended mission life. 展开更多
关键词 Insight-HXMT Hard x-ray telescope Scintillation detector In-orbit
原文传递
Investigation of natural contamination layer growth on optical substrates 被引量:1
14
作者 Li Jiang Qiu-Shi Huang +8 位作者 Igor V.Kozhevnikov Yi-Yun Yao Jiang-Tao Feng Yu-Fei Feng Bin Ma Hong-Fei Jiao Hong Chen Zhong Zhang Zhan-Shan Wang 《Chinese Physics C》 SCIE CAS CSCD 2018年第11期107-119,共13页
The surface contamination layer on mirrors can cause significant degradation of the optical performance, which is widely observed in applications, particularly in the fabrication of X-ray focusing telescopes. In this ... The surface contamination layer on mirrors can cause significant degradation of the optical performance, which is widely observed in applications, particularly in the fabrication of X-ray focusing telescopes. In this paper, we study the natural contamination layer arising from adsorption precipitation of hydrocarbons or other organic and water molecules in the absence of any external factor. Temporal evolution of the layer formed on super-smooth fused silica, borosilicate glass, and silicon substrates is studied by X-ray reflectometry, atomic force microscopy, and transmission electron microscopy for a one-year period after surface cleaning. The general characteristics of adhesion layer growth are established and discussed. The reconstructed dielectric constant profiles demonstrate that an increase in the adhesion layer thickness, deposited mass and density over time obeys power laws with extremely small exponents. Therefore, the adhesion layer growth is rapid immediately after surface cleaning, with a - 1 nm thick layer formed within the first day on all three substrates studied, while the layer density is low (- 1 g/cm^3). The layer growth on the fused silica and silicon substrates became very slow in the succeeding days, with only a 1.4-1.5 nm thick layer and 1.2-1.3 g/cm^3 density after one year of storage in air. At the same time, the adhesion layer growth on the glass substrate showed unexpected acceleration about two months after cleaning, so that the layer thickness reached - 2.2 nm after one year of storage. The reason for this effect, which is connected with leaching of the glass, is discussed briefly. 展开更多
关键词 x-ray telescope surface contamination surface dynamics x-ray reflectometry inverse problem
原文传递
Splenosis simulating an intrahepatic mass 被引量:1
15
作者 晁明 徐宏伟 《Chinese Journal of Traumatology》 CAS 2004年第1期62-64,共3页
关键词 Biopsy Needle Diagnosis Differential follow-up Studies Humans LAPAROTOMY Liver Diseases Liver Neoplasms Male Middle Aged Risk Assessment SPLENOSIS Tomography x-ray Computed Ultrasonography Doppler
原文传递
Hemiparesis in carotid cavernous fistulas (CCFs): a case report and review of the literature 被引量:1
16
作者 王慧晓 白如林 +2 位作者 黄承光 卢亦成 张光霁 《Chinese Journal of Traumatology》 CAS 2004年第5期317-320,共4页
Carotid-cavernous fistulas (CCFs) are abnormal arteriovenous anastamoses between the carotid artery and the cavernous sinus. These fistulas may be classified by cause (spontaneous or traumatic), flow velocity (high or... Carotid-cavernous fistulas (CCFs) are abnormal arteriovenous anastamoses between the carotid artery and the cavernous sinus. These fistulas may be classified by cause (spontaneous or traumatic), flow velocity (high or low), or pathogenesis (direct or indirect). The most commonly adopted classification is that described by Barrow based on arterial supply. Traumatic CCFs are almost always direct shunts between the internal carotid artery (ICA) and the cavernous sinus. General features of CCFs, which may be apparent with any lesion, including bruit, headache, loss of vision, altered mental status and neurological deficits. Some fistulae may present primarily with hemorrhage before any evaluation can be performed. However, hemiparesis has been rarely observed. Only a literature review of Murata et al reported a case of hemiparesis caused by posttraumatic CCF, in which the fistula resulted in venous hypertension and subsequent brainstem congestion. While in our case, cerebral infarction was caused by total steal of the blood flow. The patient recovered after occlusion of the fistula with a detachable balloon. 展开更多
关键词 ADULT Balloon Occlusion Carotid-Cavernous Sinus Fistula Cerebral Angiography Craniocerebral Trauma follow-up Studies Humans MALE PARESIS Recovery of Function Risk Assessment Severity of Illness Index Tomography x-ray Computed Treatment Outcome Wounds Nonpenetrating
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部