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Survey on the Magnetic Structure of the Neutral Sheets in Earth's Magnetotail
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作者 XIAO Chao SHEN Chao +3 位作者 CHENG Guosheng ZHANG Hua ZHANG Ting CARR C M 《空间科学学报》 CAS CSCD 北大核心 2016年第6期837-848,共12页
Based on the multipoint magnetic observations of Cluster from 2001 to 2004,the magnetic field structure in magnetotail Neutral Sheet(NS) is statistically surveyed.The results are as follows.In NS,a cubic function is s... Based on the multipoint magnetic observations of Cluster from 2001 to 2004,the magnetic field structure in magnetotail Neutral Sheet(NS) is statistically surveyed.The results are as follows.In NS,a cubic function is selected to reveal the relation between y(GSM) and positional parameter z.The relation between y and magnetic field values indicates that the magnetic field is weak at midnight region and strengthens gradually at the duskside and dawnside.The relation between y and curvature radius is expressed by a quadratic function.And R_c of flattened CS is less than that of the normal CS.B_y determines the orientation of MFLs' configuration.The polar angle of the curvature vector is affected by the NS configuration.In addition,the correlation between the polar angle of the curvature vector and z is higher.The polar angle of the normal of the osculating plane is uncertain in the center area.The relation between the azimuthal angles of the curvature vector(the normal of the osculating plane) and y is negatively correlated.An empirical model applied to yz plane of the three-dimensional structure of the magnetic field lines in the NS are developed,and it is represented as a function of the positional parameter y.Finally,the current density is also statistically surveyed. 展开更多
关键词 Magnetic structure statistical survey Neutral sheet Developing model
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Statistics of Chinese Oil-gas Production Petroleum Drilling and Geophysical Survey
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《China Oil & Gas》 CAS 1998年第1期61-61,共1页
关键词 Statistics of Chinese Oil-gas Production Petroleum Drilling and Geophysical survey
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A Preliminary Study on the Calculating Method for the Evolution of Siltation and Erosion of Tidal Flat Based on GIS 被引量:1
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作者 杜景龙 郜昂 +3 位作者 杨世伦 张文祥 赵华云 李鹏 《Marine Science Bulletin》 CAS 2005年第1期45-53,共9页
T he estuary and coast is an area where the land and the sea interact and a place in which human beings frequently move about so that understanding and controlling the change and development modes of the coastal landf... T he estuary and coast is an area where the land and the sea interact and a place in which human beings frequently move about so that understanding and controlling the change and development modes of the coastal landform plays a vital part in exploiting and protecting coastal resources. A model is the generalization and abstraction of objective things. This paper summarizes four methods for the landform development of the tidal shore and underwater delta, mainly discusses the model’s structural elements, and presents their specific application on the basis of the authors’ case study. With the application of the profile model, the dynamic change of coastal landform can be clearly seen by contrasting the different profiles of different years. Through the shrinking, expanding and transformation of the isobath, plane model is used to study the macro-change of the shoal and the coastal landform. Speed model is an efficient means to analyze the trend of erosion and deposition and the local change in a great area of the sea. Statistical survey model is a static analysis, which can be used to establish the relationship between the erosion and deposition of the shoal and the altitude and slope of survey spot. 展开更多
关键词 p rofile model p lane model speed model statistical survey model Yangtze Estuary
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Is There an Improvement of Antibiotic Use in China? Evidence from the Usage Analysis of Combination Antibiotic Therapy for Type Ⅰ Incisions in 244 Hospitals 被引量:4
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作者 周文娟 罗桢妮 +3 位作者 唐昌敏 邹晓旭 赵露 方鹏骞 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2016年第5期772-779,共8页
The improvement of antibiotic rational use in China was studied by usage analysis of combination antibiotic therapy for type Ⅰ incisions in 244 hospitals. Five kinds of hospitals, including general hospital, maternit... The improvement of antibiotic rational use in China was studied by usage analysis of combination antibiotic therapy for type Ⅰ incisions in 244 hospitals. Five kinds of hospitals, including general hospital, maternity hospital, children's hospital, stomatological hospital and cancer hospital, from 30 provinces were surveyed. A systematic random sampling strategy was employed to select outpatient prescriptions and inpatient cases in 2011 and 2012. A total of 29 280 outpatient prescriptions and 73 200 inpatient cases from 244 hospitals in each year were analyzed. Data were collected with regards to the implementation of the national antibiotic stewardship program(NASP), the overall usage and the prophylactic use of antibiotic for type Ⅰ incisions. Univariate analysis was used for microbiological diagnosis rate before antimicrobial therapy, prophylactic use of antibiotics for typeⅠincision operation, and so on. For multivariate analysis, the use of antibiotics was dichotomized according to the guidelines, and entered as binary values into logistic regression analysis. The results were compared with the corresponding criteria given by the guidelines of this campaign. The antibiotic stewardship in China was effective in that more than 80% of each kind of hospitals achieved the criteria of recommended antibiotics varieties. Hospital type appeared to be a factor statistically associated with stewardship outcome. The prophylactic use of antibiotics on type Ⅰ incision operations decreased by 16.22%(P〈0.05). The usage of combination antibiotic therapy for type Ⅰ incisions was also decreased. Region and bed size were the main determinants on surgical prophylaxis for type Ⅰ incision. This national analysis of hospitals on antibiotic use and stewardship allows relevant comparisons for bench marking. More efforts addressing the root cause of antibiotics abuse would continue to improve the rational use of antibiotics in China. 展开更多
关键词 antibiotics Antibiotic outpatient inpatient incision usage multivariate surveyed statistically addressing
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Candidate members of star clusters from LAMOST DR2
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作者 Bo Zhang Xiao-Yan Chen +10 位作者 Chao Liu Li Chen Li-Cai Deng Jin-Liang Hou Zheng-Yi Shao Fan Yang Yue Wu Ming Yang Yong Zhang Yong-Hui Hou Yue-Fei Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第8期1197-1208,共12页
In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification: selection along the stellar ... In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification: selection along the stellar track in the colormagnitude diagram, i.e., photometric identification, and selection from the distribution of radial velocities, i.e. the kinematic identification. We find that the radial velocities from the LAMOST data are very helpful in the membership identification. The mean probability of membership is 40% for the sample selected with radial velocity. With these 24 star clusters, we investigate the performance of the radial velocity and metallicity estimated with the LAMOST pipeline. We find that the systematic offsets in radial velocity and metallicity are 0.85 ± 1.26 km s-1and-0.08 ± 0.04 dex, with dispersions of 5.47+1.16-0.71 km s-1and 0.13+0.04-0.02 dex, respectively. Finally, we propose that the photometrically-selected candidate members of the clusters covered by the LAMOST footprint should be assigned higher priority so that more candidate stars can be observed. 展开更多
关键词 open clusters and associations: general—stars: statistics—catalogs—surveys—methods: data analysis
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Interview with Professor Danny Pfeffermann
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作者 Lyu Ni Kai Tan 《Statistical Theory and Related Fields》 2018年第2期219-221,共3页
An interview with Professor Danny Pfeffermann is conducted during the conference of SmallArea Estimation 2018 (SAE 2018), an international conference held between June 16 and 18at East China Normal University, Shangha... An interview with Professor Danny Pfeffermann is conducted during the conference of SmallArea Estimation 2018 (SAE 2018), an international conference held between June 16 and 18at East China Normal University, Shanghai, China. SAE 2018 is also a celebration of ProfessorPfeffermann’s 75th birthday. Our interview consists of eight questions, which focus on Professor Pfeffermann’s personal education background, research motivations, contributions to thedevelopment of statistics, opinions on big data and data science, and his future plan. Professor Pfeffemann used interesting examples to express his opinions on the future development ofstatistics. 展开更多
关键词 INTERVIEW small area estimation survey and official statistics
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