检索结果-南通市图书馆

Nighttime electron density enhancements at middle and low latitudes in East Asia

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

Science China Earth Sciences 2015年第4期58卷 551-561页

作者： ZHANG YanYan liU liBo CHEN YiDing liU Jing YU You li ming Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences

Nighttime enhancements in ionospheric electron density at mid- and low-latitudes are investigated by using the critical frequency of the F2-1ayer （foF2） data measured from ionosonde stations at Okinawa （26.3°N, 127.8°E, Geomagnetic 15.3°N）, Yamagawa （31.2°N, 130.6°E, Geomagnetic 20.4°N）, Kokubunji （35.7°N, 139.5°E, Geomagnetic 25.5°N）, and Wakkanai （45.4°N, 141.7°E, Geomagnetic 35.4°N） in East Asia during several solar cycles. The results show that there are obvious seasonal and solar activity dependencies of the nighttime electron density enhancements. The enhancements are termed pre-midnight enhancement and post-midnight enhancement, according to the local time when the enhancement appeared. The former has a higher occurrence probability in summer months than in winter months. In contrast, the latter has a larger occurrence probability in winter months than in summer months. Moreover, the nighttime enhancements in electron density are more likely to occur at lower solar activity. These seasonal and solar activity variations of the nighttime enhancements in electron density can be explained in terms of the combined effects of downward plasma flux from the plasmasphere and the neutral winds.

关键词： nighttime electron density enhancements critical frequency of the F2-1ayer seasonal and solar activity dependencies vertical equivalent winds

在线全文

学校读者我要写书评

暂无评论

某院互联网医院云药房运行模式和成效分析

中国处方药 2024年第1期22卷 52-54页

作者：李明张枫艳王素梅复旦大学附属中山医院青浦分院上海201700

目的探讨互联网医院云药房药学服务模式在患者就医诊疗过程中带来的作用。方法收集互联网医院云药房2022年12月1日~2023年3月31日处方1897张,对患者的年龄、科室分布、退药情况、配送地址、就医成本等情况进行分析。结果互联网医院云药... 详细信息

目的探讨互联网医院云药房药学服务模式在患者就医诊疗过程中带来的作用。方法收集互联网医院云药房2022年12月1日~2023年3月31日处方1897张,对患者的年龄、科室分布、退药情况、配送地址、就医成本等情况进行分析。结果互联网医院云药房建设后,患者药物配送率达89.72%,节约了患者的就医成本。结论互联网医院云药房药学服务模式可方便患者诊疗,节约患者就诊成本,还可以促进医疗资源合理分配和药学服务模式延伸的发展。

关键词：互联网医院云药房作用药品配送运行成效

High-precision high-voltage detuning system for HIAF-SRing electron target

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2023年第5期34卷 125-138页

作者： Kai-ming Yan ming-Rui li Yun-Bin Zhou Xiao-ming Ma Jin-Bin Shangguan Zhong-Kui Huang Xiao-Jun Wang Mei-Tang Tang Jie Gao Hou-Ke Huang Da-Qin Gao li-Jun Mao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The development of a detuning system for the precision control of electron energy is a major challenge when electron targets are used in ion-storage ***,a high-precision,high-voltage,detuning system was developed for the electron target of a high-intensity heavy-ion accelerator facility-spectrometer ring(HIAF-SRing)to produce accurate electron-ion relative energies during *** system consists of auxiliary,and high-voltage detuning power *** front stage of the auxiliary power supply adopts an LCC resonant converter operating in the soft-switching state and an LC filter for a sinusoidal waveform output in the *** detuning power supply is a high-voltage pulse amplifier(HVPA)connected with a high-voltage DC(HVDC)module in *** this paper,the design and development of the detuning system are described in detail,and the test bench is *** test results demonstrated that the detuning system conforms to the technical specifications of the dielectronic recombination(DR)***,a Fe15+DR spectrum was measured using the detuning *** experimental data demonstrated a good experimental resolution and verified the reliability and feasibility of the design.

关键词： detuning system Storage ring Dielectronic recombination

Reduction behavior of hematite in the presence of coke

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第11期23卷 1244-1251页

作者： Ze-hong Wang Guo-feng li Yong-sheng Sun ming-zhao He College of Resources and Civil Engineering Northeastern University Shenyang 110819 China College of Mining Engineering North China University of Science and Technology Tangshan 063009 China CITIC Pacific Mining Management Pty Ltd. 45 St. Georges Terrace Perth WA6000 Australia

The reduction kinetics of hematite in the presence of coke as a reductant was studied via isothermal and non-isothermal thermodynamic analyses. The isothermal reduction of hematite was conducted at a pre-determined temperature ranging from 1423 to 1573 K. The results indicated that a higher reduction temperature led to an increased reduction degree and an increased reduction rate. The non-isothermal reduction of hematite was carried out from room temperature to 1573 K at various heating rates from 5 to 15 K·min^（-1）. A greater heating rate gave a greater reduction rate but decreased reduction degree. With an increase in temperature, both the reduction rate and the reduction degree increased at a smaller rate when the temperature was less than 1150 K, and they increased at a higher rate when the temperature was greater than 1150 K before completion of the reduction reaction. Both the isothermal and the non-isothermal reduction behaviors of hematite were described by the Avrami–Erofeev model. For the isothermal reduction, the apparent activation energy and pre-exponential factor were 171.25 kJ ·mol^（-1） and 1.80 × 10~5 min^（-1）, respectively. In the case of non-isothermal reduction, however, the apparent activation energy and pre-exponential factor were correlated with the heating rate.

关键词： hematite ore reduction reduction kinetics coke

自体牙骨移植材料修复牙槽骨缺损的应用效果研究

在线全文

学校读者我要写书评

暂无评论

中国实用口腔科杂志 2024年第1期17卷 74-79页

作者：郭子君丁铭李雅冬中国人民解放军陆军特色医学中心口腔科重庆400042 重庆医科大学附属第一医院口腔科重庆400042

目的研究自体牙骨移植材料结合引导骨再生术(guided bone regeneration,GBR)在修复牙槽骨缺损中的临床效果。方法选择2020年1月至2021年10月于重庆医科大学附属第一医院口腔科就诊的需行GBR修复牙槽骨缺损的患者82例。依照随机数表法... 详细信息

目的研究自体牙骨移植材料结合引导骨再生术(guided bone regeneration,GBR)在修复牙槽骨缺损中的临床效果。方法选择2020年1月至2021年10月于重庆医科大学附属第一医院口腔科就诊的需行GBR修复牙槽骨缺损的患者82例。依照随机数表法分为研究组(42例)和对照组(40例)。研究组患者在种植术中将自体牙骨移植材料植入牙槽骨缺损处,对照组患者在种植术中将Bio-Oss?骨粉植入牙槽骨缺损处。比较两组患者的种植成功率、骨组织指标(颊舌侧骨板宽度、边缘骨吸收量)、种植体稳定性值(implant stability quotient,ISQ)及不良反应发生率。结果术后1年研究组和对照组患者种植成功率的比较,差异无统计学意义(χ^(2)=0.186,P=0.735);两组患者术前及术后即刻的颊舌侧骨板宽度比较,差异均无统计学意义(均P> 0.05);研究组术后12个月的颊舌侧骨板宽度大于对照组,差异有统计学意义(t=3.872,P=0.005);研究组术后12个月的边缘骨吸收量低于对照组,差异有统计学意义(t=-3.030,P=0.039);术后6个月研究组ISQ高于对照组,差异有统计学意义(t=2.996,P=0.017);两组不良反应发生率的比较,差异无统计学意义(χ^(2)=0.076,P=0.532)。结论自体牙骨移植材料与Bio-Oss?骨粉修复牙槽骨缺损均能获得较高的治疗成功率。相比Bio-Oss?骨粉,自体牙骨移植材料能有效增加术后牙槽骨宽度,延缓种植体边缘骨吸收,获得更好的种植体稳定性,具有较高的生物安全性,值得在临床上进一步推广。

关键词：自体牙骨移植材料口腔种植临床效果

Comparison of two Bayesian-point-estimation methods in multiple-source localization

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2018年第6期37卷 11-17页

作者： li Qianqian ming Pingshou YANG Fanlin ZHANG Kai WU Ziyin College of Geomatics Shandong University of Science and Technology Qingdao 266590 China State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Submarine Geosciences State Oceanic Administration Hangzhou 310012 China

Environmental uncertainty represents the limiting factor in matched-field localization. Within a Bayesian framework, both the environmental parameters, and the source parameters are considered to be unknown variables. However, including environmental parameters in multiple-source localization greatly increases the complexity and computational demands of the inverse problem. In the paper, the closed-form maximumlikelihood expressions for source strengths and noise variance at each frequency allow these parameters to be sampled implicitly, substantially reducing the dimensionality and difficulty of the inversion. This paper compares two Bayesian-point-estimation methods： the maximum a posteriori（MAP） approach and the marginal posterior probability density（PPD） approach to source localization. The MAP approach determines the sources locations by maximizing the PPD over all source and environmental parameters. The marginal PPD approach integrates the PPD over the unknowns to obtain a sequence of marginal probability distribution over source range or *** Carlo analysis of the two approaches for a test case involving both geoacoustic and water-column uncertainties indicates that：（1） For sensitive parameters such as source range, water depth and water sound speed, the MAP solution is better than the marginal PPD solution.（2） For the less sensitive parameters, such as,bottom sound speed, bottom density, bottom attenuation and water sound speed, when the SNR is low, the marginal PPD solution can better smooth the noise, which leads to better performance than the MAP *** the source range and depth are sensitive parameters, the research shows that the MAP approach provides a slightly more reliable method to locate multiple sources in an unknown environment.

关键词： source localization Bayesian-point-estimation method uncertain environment

Comparative study of microbial community structure in different filter media of constructed wetland

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第1期22卷 127-133页

作者： ming li Qiaohong Zhou Min Tao Ying Wang lijuan Jiang Zhenbin Wu State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China Graduate University of Chinese Academy of Sciences Beijing 100039 China School of Resource & Environmental Engineering Wuhan University of Technology Wuhan 430070 China

Comparisons of microbial community structure, in eight filter media of zeolites, anthracite, shale, vermiculite, ceramic filter media, gravel, steel slag and bio-ceramic, were undertaken by analyzing the phospholipid fatty acid （PLFA） composition. A total of 20 fatty acids in the range of C18to C20 were determined but only 13 PLFAs were detected in steel slag. They consist of saturated fatty acids, branched fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. The variation of fatty acids was revealed in the relative proportions of these fatty acids in different media. The aerobic prokaryotes were the predominant group in all media. The PLFA composition showed significant differences among the eight different media by Tukey＇s honestly test. It was found that steel slag was significantly different in the microbial community as compared to other filter media, probably due to its alkaline effluent. Steel slag alone is probably not a good choice of substratum in constructed wetlands. The principle components analysis （PCA） showed that zeolites, bio-ceramic, shale and vermiculite had a similar microbial community structure while steel slag and ceramic filter media were distinct from other media.

关键词： microbial community structure phospholipid filter media biomarkers constructed wetland steel slag

在线全文

学校读者我要写书评

暂无评论

井下铲运机无人驾驶系统发展及5G应用

有色金属（矿山部分） 2024年第2期76卷 1-5,25页

作者：李铭刘伟宋岳汶曹彪王湖鑫矿冶科技集团有限公司北京100160 金属矿山智能开采技术北京市重点实验室北京102600 北京北矿智能科技有限公司北京100070

铲运机无人驾驶是智能矿山建设的重要组成部分,为了实现高海拔高寒地区井下无人采矿,通过梳理国内外铲运机无人驾驶系统发展现状,分析铲运机自主行驶系统相关理论和关键技术,从地下铲运机轨迹偏差预测技术、自主行驶多偏差控制技术和防... 详细信息

铲运机无人驾驶是智能矿山建设的重要组成部分,为了实现高海拔高寒地区井下无人采矿,通过梳理国内外铲运机无人驾驶系统发展现状,分析铲运机自主行驶系统相关理论和关键技术,从地下铲运机轨迹偏差预测技术、自主行驶多偏差控制技术和防碰撞预测与控制技术等方面进行了归纳总结。以西藏华泰龙矿为例,采用最新网络通信技术5G,建设了5G+铲运机无人驾驶系统。对铲运机无人驾驶系统在高海拔高寒地区的发展具有重要意义。

关键词：智能矿山井下铲运机无人驾驶 5G应用高海拔高寒地区

design and calibration of a new high-definition three-dimensional laparoscopic system

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2015年第1期16卷 79-84页

作者： Jia TANG li-qiang WANG Bo YUAN Hong JIANG Qi-ming ZHU State Key Laboratory of Modern Optical Instrumentation Optical Engineering Department Zhejiang University Hangzhou 310027 China

We present a high-definition （HD） 3D laparoscopic system including a dual channel optical system, two cameras, a camera control unit （CCU）, and an HD 3D monitor. This laparoscopic system is capable of outputting dual high-definition videos and providing vivid 3D images. A modified pinhole camera model is used for camera calibration and a new method of depth measurement to improve precision. The average error of depth measurement measured by experiment （about 1.13 mm） was small in proportion to the large range in distance of the system （10-150 mm）. The new method is applicable to any calibrated binocular vision system.

关键词： Dual optical channels Three dimensional Camera calibration Pinhole model depth measurement Laparoscopicsystem