期刊文献+
共找到17,172篇文章
< 1 2 250 >
每页显示 20 50 100
EAST中快离子Dα诊断光电检测系统的设计 预览
1
作者 刘冬梅 骆凡 +5 位作者 常加峰 黄娟 熊魁 周峰 岳长喜 李智成 《核聚变与等离子体物理》 CAS CSCD 北大核心 2019年第3期215-220,共6页
设计了具有高时间和空间分辨率EAST快离子Dα的光电检测系统,它由16路光电倍增管(PMT)和电流放大器(采用蓝宝石材料代替传统印刷板电路)构成。为了使快离子Dα(FIDA)信号在中性束注入时能从其他光源的在同一光谱范围内的谱线中检测出来... 设计了具有高时间和空间分辨率EAST快离子Dα的光电检测系统,它由16路光电倍增管(PMT)和电流放大器(采用蓝宝石材料代替传统印刷板电路)构成。为了使快离子Dα(FIDA)信号在中性束注入时能从其他光源的在同一光谱范围内的谱线中检测出来,系统参数设计为整体光子-电压增益5.0×10^9、电流放大器增益106V/A、-3dB带宽500kHz。实验结果表明,该光电检测系统可以很好的检测到快离子Dα(FIDA)信号,并有助于从Dα光的多普勒偏移光谱推断快离子特性。 展开更多
关键词 EAST 光电检测系统 快离子Dα信号 电流放大器
在线阅读 下载PDF
晕电流作用下EAST上偏滤器靶板的可靠性研究 预览
2
作者 张洋 覃世军 +2 位作者 曹磊 陈大龙 姚达毛 《核聚变与等离子体物理》 CAS CSCD 北大核心 2019年第3期221-226,共6页
通过建立晕电流峰值分布的高斯混合模型,结合靶板结构的极限状态方程,利用Monte Carlo方法开展了晕电流作用下EAST上偏滤器靶板的可靠性研究。研究结果表明,在晕电流作用下,EAST上偏滤器靶板具有极高的可靠性。这一结果为EAST上偏滤器以... 通过建立晕电流峰值分布的高斯混合模型,结合靶板结构的极限状态方程,利用Monte Carlo方法开展了晕电流作用下EAST上偏滤器靶板的可靠性研究。研究结果表明,在晕电流作用下,EAST上偏滤器靶板具有极高的可靠性。这一结果为EAST上偏滤器以及CFETR的可靠性研究提供了参考。 展开更多
关键词 EAST 晕电流 偏滤器 可靠性
在线阅读 下载PDF
TZM材料的热吸收率分析
3
作者 訾鹏飞 李磊 +1 位作者 曹磊 姚达毛 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2019年第8期2413-2417,共5页
钛锆钼合金(TZM)作为面对等离子体材料(PFM)将会继续在实验型先进超导托卡马克(EAST)中大量使用。利用深圳大学的电子枪设备分别对轧制态及锻造态的TZM进行了热吸收率的测试并对相关结果进行了分析。结果显示,轧制态及锻造态的TZM的热... 钛锆钼合金(TZM)作为面对等离子体材料(PFM)将会继续在实验型先进超导托卡马克(EAST)中大量使用。利用深圳大学的电子枪设备分别对轧制态及锻造态的TZM进行了热吸收率的测试并对相关结果进行了分析。结果显示,轧制态及锻造态的TZM的热吸收率均在0.7左右,并且这个数值不会受到冷却效果及材料温度的影响而产生变化。这一结果将对判断TZM在使用中的安全性有巨大帮助,同时对EAST的远期升级及CFETR的建设都具有重要的参考价值。 展开更多
关键词 热吸收率 钛锆钼合金 面对等离子体材料 EAST
EAST快速极紫外光谱仪波长的原位标定及其应用 预览
4
作者 姚黎明 张凌 +8 位作者 许棕 杨秀达 吴承瑞 张睿瑞 杨飞 吴振伟 姚建铭 龚先祖 胡立群 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2019年第8期2645-2650,共6页
介绍了东方超环(experimental advanced supereonducting tokamak, EAST)托卡马克上的两套快速极紫外(EUV)光谱仪系统波长的原位标定方法、结果及其应用。这两套谱仪均为掠入射平场谱仪,时间分辨均为5 ms·frame -1 。两套谱仪分别... 介绍了东方超环(experimental advanced supereonducting tokamak, EAST)托卡马克上的两套快速极紫外(EUV)光谱仪系统波长的原位标定方法、结果及其应用。这两套谱仪均为掠入射平场谱仪,时间分辨均为5 ms·frame -1 。两套谱仪分别工作在20~500和10~130 的波段范围,由步进电机控制探测器在焦平面上移动实现整个观测波段上的波长扫描。利用这两套谱仪系统观测极紫外波段光谱,计算EAST中低-高Z杂质离子特征线辐射强度随时间的演化,监测和研究等离子体中杂质的行为。高Z杂质尤其是钨、钼等金属元素,发出的EUV波段光谱的构成非常复杂,准确识谱对谱仪精确的波长测量能力以及谱分辨能力要求很高,因此精确的波长标定是识别钨、钼等高Z杂质谱线以及研究它们行为的最关键的技术之一。利用EAST等离子体中类氢到类铍的低、中Z杂质的特征谱线以及它们的二阶甚至三阶谱线,结合谱仪系统的色散能力,对这两套快速极紫外光谱仪的波长进行了精确的原位标定。用于波长标定的杂质谱线有O Ⅷ 18.97 , O Ⅶ 21.60 , C Ⅵ 33.73 , Li Ⅲ 113.9 , Li Ⅲ 135.0 , Li Ⅱ 199.28 , Ar ⅩⅤ 221.15 , He Ⅱ 256.317 , He Ⅱ 303.78 , Ar ⅩⅥ 353.853 及C Ⅳ 384.174 等。利用波长标定的结果对观测到的EUV光谱进行谱线识别,两套谱仪观测到的绝大多数谱线波长与美国技术标准局(National Institute of Standards and Technology, NIST)数据库的标准波长相差分别小于0.08和0.03 。开发了谱仪波长原位标定程序模块,将这个模块内嵌到谱仪数据实时上传的交互式软件中,实现了全谱数据以及特征谱线强度随时间演化数据的实时处理和上传。同时利用开发的全谱分析交互式软件以及EAST上的数据查看软件,最终实现了快速EUV谱仪自采数据的准实时分析、读取和查看。 展开更多
关键词 EAST托卡马克 极紫外波段(EUV)光谱仪 波长标定 钨光谱
在线阅读 下载PDF
Meridional Displacement of the East Asian Upper-tropospheric Westerly Jet and Its Relationship with the East Asian Summer Rainfall in CMIP5 Simulations 预览
5
作者 Yuhan YAN Chaofan LI Riyu LU 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第11期1203-1216,共14页
As the first leading mode of upper-tropospheric circulation in observations, the meridional displacement of the East Asian westerly jet (EAJ) varies closely with the East Asian rainfall in summer. In this study, the i... As the first leading mode of upper-tropospheric circulation in observations, the meridional displacement of the East Asian westerly jet (EAJ) varies closely with the East Asian rainfall in summer. In this study, the interannual variation of the EAJ meridional displacement and its relationship with the East Asian summer rainfall are evaluated, using the historical simulations of CMIP5 (phase 5 of the Coupled Model Intercomparison Project). The models can generally reproduce the meridional displacement of the EAJ, which is mainly manifested as the first principal mode in most of the simulations. For the relationship between the meridional displacement of the EAJ and East Asian rainfall, almost all the models depict a weaker correlation than observations and exhibit considerably large spread across the models. It is found that the discrepancy in the interannual relationship is closely related to the simulation of the climate mean state, including the climatological location of the westerly jet in Eurasia and rainfall bias in South Asia and the western North Pacific. In addition, a close relationship between the simulation discrepancy and intensity of EAJ variability is also found: the models with a stronger intensity of the EAJ meridional displacement tend to reproduce a closer interannual relationship, and vice versa. 展开更多
关键词 EAST ASIAN WESTERLY jet MERIDIONAL TELECONNECTION EAST ASIAN rainband model simulation
在线阅读 下载PDF
EAST运动斯塔克效应诊断的信号处理分析系统设计 预览
6
作者 刘冬梅 侯效龙 +5 位作者 刘春 符佳 吕波 吴振伟 万宝年 胡雷 《核电子学与探测技术》 CAS 北大核心 2019年第3期325-330,共6页
运动斯塔克效应诊断利用光弹调制偏振测量技术可将偏振角的空间方向的测量转化为对二倍频信号强度比值的求取.为精准、快速地获取二倍频信号幅值,设计了基于FPGA的运动斯塔克效应诊断数字频谱分析系统,系统采用高速ADC采集运动斯塔克效... 运动斯塔克效应诊断利用光弹调制偏振测量技术可将偏振角的空间方向的测量转化为对二倍频信号强度比值的求取.为精准、快速地获取二倍频信号幅值,设计了基于FPGA的运动斯塔克效应诊断数字频谱分析系统,系统采用高速ADC采集运动斯塔克效应信号后送入FPGA,以EP2AGX125型FPGA为核心进行快速傅里叶变换获得信号频谱,求取二倍频分量的幅值进而计算出偏振角.经仿真与实验测试,该系统的测量精度好于5%,工作周期小于10 ms,满足MSE诊断信号处理要求. 展开更多
关键词 EAST 运动斯塔克效应诊断 傅里叶变换 FPGA
在线阅读 下载PDF
Recent Progress in Studies of the Variabilities and Mechanisms of the East Asian Monsoon in a Changing Climate 预览
7
作者 Wen CHEN Lin WANG +4 位作者 Juan FENG Zhiping WEN Tiaojiao MA Xiuqun YANG Chenghai WANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第9期887-901,共15页
Located in a monsoon domain,East Asia suffers devastating natural hazards induced by anomalous monsoon behaviors.East Asian monsoon(EAM)research has traditionally been a high priority for the Chinese climate community... Located in a monsoon domain,East Asia suffers devastating natural hazards induced by anomalous monsoon behaviors.East Asian monsoon(EAM)research has traditionally been a high priority for the Chinese climate community and is particularly challenging in a changing climate where the global mean temperature has been rising.Recent advances in studies of the variabilities and mechanisms of the EAM are reviewed in this paper,focusing on the interannual to interdecadal time scales.Some new results have been achieved in understanding the behaviors of the EAM,such as the evolution of the East Asian summer monsoon(EASM),including both its onset and withdrawal over the South China Sea,the changes in the northern boundary activity of the EASM,or the transitional climate zone in East Asia,and the cycle of the EASM and the East Asian winter monsoon and their linkages.In addition,understanding of the mechanism of the EAM variability has improved in several aspects,including the impacts of different types of ENSO on the EAM,the impacts from the Indian Ocean and Atlantic Ocean,and the roles of mid-to high-latitude processes.Finally,some scientific issues regarding our understanding of the EAM are proposed for future investigation. 展开更多
关键词 EAST ASIAN summer MONSOON EAST ASIAN winter MONSOON CHANGING CLIMATE MONSOON onset and withdrawal transitional CLIMATE zone different types of ENSO
在线阅读 下载PDF
基于改进EAST算法的舰船目标检测研究 预览
8
作者 蒋丽婷 《信息技术》 2019年第12期99-103,共5页
针对可见光遥感图像待检测目标较小、尺度多样,检测困难问题,文中提出一种基于改进EAST的舰船检测方法。文中检测算法将使用单个神经网络以端到端的方式实现斜矩形框预测,并采用多尺度特征融,改进后,预测速度达到17FPS,准确率提升5.35%... 针对可见光遥感图像待检测目标较小、尺度多样,检测困难问题,文中提出一种基于改进EAST的舰船检测方法。文中检测算法将使用单个神经网络以端到端的方式实现斜矩形框预测,并采用多尺度特征融,改进后,预测速度达到17FPS,准确率提升5.35%,在小目标检测性能上表现良好,对多尺度目标检测具有较好鲁棒性。 展开更多
关键词 遥感图像 EAST 舰船检测 多尺度特征 小目标检测
在线阅读 下载PDF
EAST液态锂试验测试平台磁体系统的MATLAB辅助设计
9
作者 胡乐星 杨庆喜 +3 位作者 宋云涛 宋伟 左桂忠 胡建生 《机械设计》 CSCD 北大核心 2019年第3期19-23,共5页
为了设计一套液态锂台面试验测试平台磁体系统,并保证磁体线圈的安全稳定运行,采用了MATLAB对其进行辅助设计,并对计算结果进行了校核计算。通过对线圈产生的磁场及其电参数和水参数的计算,可知:线圈的安匝数、线圈半径等对线圈磁场的... 为了设计一套液态锂台面试验测试平台磁体系统,并保证磁体线圈的安全稳定运行,采用了MATLAB对其进行辅助设计,并对计算结果进行了校核计算。通过对线圈产生的磁场及其电参数和水参数的计算,可知:线圈的安匝数、线圈半径等对线圈磁场的分布、冷却水的流速及平台的综合成本具有显著的影响。计算结果对于磁体线圈的参数设计,以及冷却水泵和电源的选型具有重要的指导意义。 展开更多
关键词 EAST 液态锂限制器 测试平台 亥姆霍兹线圈
EAST新型下偏滤器冷却结构传热性能数值模拟 预览
10
作者 徐厚昌 李磊 +5 位作者 姚达毛 周自波 曹磊 许铁军 韩乐 訾鹏飞 《核聚变与等离子体物理》 CAS CSCD 北大核心 2019年第2期127-133,共7页
为实现EAST装置超400s长脉冲高约束模、10MW加热功率下的稳态运行,需对现有的下碳偏滤器进行升级改造,拟采用钨串结构水冷却系统,热通量控制在水冷钨铜第一壁材料允许的稳态的10MW·m-2。在对下钨偏滤器的冷却结构传热性能进行数值... 为实现EAST装置超400s长脉冲高约束模、10MW加热功率下的稳态运行,需对现有的下碳偏滤器进行升级改造,拟采用钨串结构水冷却系统,热通量控制在水冷钨铜第一壁材料允许的稳态的10MW·m-2。在对下钨偏滤器的冷却结构传热性能进行数值模拟仿真研究的基础上,研究了多种以钨串单元为基础的冷却结构,提出了一种新型下钨偏滤器水冷结构设计,并建立了满足传热要求的EAST装置新型下钨偏滤器单元结构模型。 展开更多
关键词 EAST 等离子体 钨偏滤器 水冷 传热分析
在线阅读 下载PDF
EAST柔性机械手臂体数据采集系统设计 预览
11
作者 刘武常 杨婵娟 《自动化技术与应用》 2019年第5期92-95,共4页
柔性机械手由机械臂体和执行器组成,在EAST装置的正常运行与维护中作用重大,该设备臂体需达到定位精度高及耐高温的要求,据此本文完成了位姿数据采集系统的设计,该系统主要采用磁线性编码器芯片和倾角传感器芯片,实现了臂体姿态的精确定... 柔性机械手由机械臂体和执行器组成,在EAST装置的正常运行与维护中作用重大,该设备臂体需达到定位精度高及耐高温的要求,据此本文完成了位姿数据采集系统的设计,该系统主要采用磁线性编码器芯片和倾角传感器芯片,实现了臂体姿态的精确定位,与上位机通过CAN总线方式实现数据交换,可在高温环境下正常工作(115℃),系统整体控制过程及读取传感器信号主要由主控芯片完成,为采集电机的外表温度,结合温度传感器Pt100设计了调理电路,通过对高温、定位和姿态方面进行试验,结果表明该系统准确性较高且耐高温,满足设计的要求。 展开更多
关键词 柔性机械手 EAST 磁线性编码器 传感器
在线阅读 下载PDF
中国东部南北样带森林生态系统蒸腾与蒸散比值估算
12
作者 任小丽 路倩倩 +2 位作者 何洪林 张黎 牛忠恩 《地理学报:英文版》 SCIE CSCD 2019年第11期1807-1822,共16页
The ratio of transpiration to evapotranspiration (T/ET) is a key parameter for quantifying water use efficiency of ecosystems and understanding the interaction between ecosystem carbon uptake and water cycling in the ... The ratio of transpiration to evapotranspiration (T/ET) is a key parameter for quantifying water use efficiency of ecosystems and understanding the interaction between ecosystem carbon uptake and water cycling in the context of global change.The estimation of T/ET has been paid increasing attention from the scientific community in recent years globally.In this paper,we used the Priestly-Taylor Jet Propulsion Laboratory Model (PT-JPL) driven by regional remote sensing data and gridded meteorological data,to simulate the T/ET in forest ecosystems along the North-South Transect of East China (NSTEC) during 2001-2010,and to analyze the spatial distribution and temporal variation of T/ET,as well as the factors influencing the variation in T/ET.The results showed that:(1) The PT-JPL model is suitable for the simulation of evapotranspiration and its components of forest ecosystems in Eastern China,and has relatively good stability and reliability.(2) Spatial distribution of T/ET in forest ecosystems along NSTEC was heterogeneous,i.e.,T/ET was higher in the north and lower in the south,with an averaged value of 0.69;and the inter-annual variation of T/ET showed a significantly increasing trend,with an increment of 0.007/yr (p<0.01).(3) Seasonal and inter- annual variations of T/ET had different dominant factors.Temperature and EVI can explain around 90%(p<0.01) of the seasonal variation in T/ET,while the inter-annual variation in T/ET was mainly controlled by EVI (53%,p<0.05). 展开更多
关键词 The North-South TRANSECT of East China (NSTEC) forest ECOSYSTEMS ratio of TRANSPIRATION to EVAPOTRANSPIRATION (T/ET) water use efficiency (WUE)
透平膨胀机控制系统设计 预览
13
作者 付贤政 袁恺 《淮南师范学院学报》 2019年第2期107-109,共3页
氦透平膨胀机是氦制冷机的关键部件,它的工作效率以及稳定性直接影响氦制冷机的各项性能指标。EAST托卡马克装置低温系统中原有四台俄罗斯透平制动性能较差,故障率高,严重影响着低温系统的稳定性。通过调研,从捷克PBS公司购买一台透平... 氦透平膨胀机是氦制冷机的关键部件,它的工作效率以及稳定性直接影响氦制冷机的各项性能指标。EAST托卡马克装置低温系统中原有四台俄罗斯透平制动性能较差,故障率高,严重影响着低温系统的稳定性。通过调研,从捷克PBS公司购买一台透平代替原有的透平D。文章主要完成了新透平控制系统的设计以及运行调试,为后续透平的更换奠定了基础。 展开更多
关键词 先进实验超导托卡马克 低温系统 透平膨胀机
在线阅读 下载PDF
Calculation of the heat flux in the lower divertor target plate using an infrared camera diagnostic system on the experimental advanced superconducting tokamak 预览
14
作者 Zhi-Xue Cui Xin Li +3 位作者 Shuang-Bao Shu Jia-Rong Luo Mei-Wen Chen Yu-Zhong Zhang 《核技术:英文版》 SCIE CAS CSCD 2019年第6期63-69,共7页
During the discharging of Tokamak devices, interactions between the core plasma and plasma-facing components (PFCs) may cause exorbitant heat deposition in the latter. This poses a grave threat to the lifetimes of PFC... During the discharging of Tokamak devices, interactions between the core plasma and plasma-facing components (PFCs) may cause exorbitant heat deposition in the latter. This poses a grave threat to the lifetimes of PFCs materials. An infrared (IR) diagnostic system consisting of an IR camera and an endoscope was installed on an Experimental Advanced Superconducting Tokamak (EAST) to monitor the surface temperature of the lower divertor target plate (LDTP) and to calculate the corresponding heat flux based on its surface temperature and physical structure, via the finite element method. First, the temperature obtained by the IR camera was calibrated against the temperature measured by the built-in thermocouple of EAST under baking conditions to determine the true temperature of the LDTP. Next, based on the finite element method, a target plate model was built and a discretization of the modeling domain was carried out. Then, a heat conduction equation and boundary conditions were determined. Finally, the heat flux was calculated. The new numerical tool provided results similar to those for DFLUX;this is important for future work on related physical processes and heat flux control. 展开更多
关键词 EAST DIVERTOR TARGET PLATE INFRARED CAMERA Heat FLUX Finite element analysis
在线阅读 下载PDF
Concentration and Characterization of Colored Dissolved Organic Matter in the Surface Microlayer and Subsurface Water of the Yellow Sea and the East China Sea 预览
15
作者 ZHANG Jing ZHAO Junjie +1 位作者 YANG Guipeng LIU Weifeng 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第2期383-393,共11页
The distribution and chemical properties of colored dissolved organic matter(CDOM)in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated.The input of freshwater and biological act... The distribution and chemical properties of colored dissolved organic matter(CDOM)in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated.The input of freshwater and biological activities had an evident influence on the CDOM levels(characterized by the light absorption coefficient at the wavelength of 355 nm a355)in the study area.The spatial distribution of CDOM levels displayed a gradually decreasing trend from the coastal waters(0.37m^-1)to the open sea(0.18m^-1).The spectral slope ratio(the slope ratio SR defined as S275-295:S350-400)during the cruise was correlated with salinity,and exhibited a large variation from inshore(average of 2.515)to offshore sites(average of 5.327)compared with the distribution of a355.The values of SR were related to CDOM molecular weight(MW).The a355,SR,and chlorophyll a in 37 samples collected from the surface microlayer were significantly correlated with those in the corresponding subsurface water samples,implying a strong exchange action between the microlayer and bulk water.The a355 and SR of CDOM exhibited significant microlayer enrichment,with mean enrichment factors(EFs)of 1.72 and 1.62,respectively. 展开更多
关键词 COLORED dissolved organic matter(CDOM) absorption coefficient SPECTRAL SLOPE ratio YELLOW SEA East China SEA
在线阅读 下载PDF
Nationwide seroprevalence, spatial distribution and risk factors of Leishmania in Jordan
16
作者 Mohammad MObaidat Amira ARoess 《亚太热带生物医学杂志:英文版》 CAS 2019年第6期227-231,共5页
Objective:To explore the seroprevalence,spatial distribution and risk factors for Leishmania seropositivity in Jordan.Methods:Blood samples from 872 apparently healthy participants were randomly selected from 11 gover... Objective:To explore the seroprevalence,spatial distribution and risk factors for Leishmania seropositivity in Jordan.Methods:Blood samples from 872 apparently healthy participants were randomly selected from 11 governorates in Jordan and tested for anti-Leishmania K39 IgG.Risk factors(animal ownership and agriculture practices)and demographic data were also collected using pre-tested and validated questionnaire.Results:Overall,2.52% of participants were seropositive for Leishmania spp.Participants living in the Jordan Valley plateau had significantly greater odds(adjusted odds ratio= 3.70,95% CI 1.37-9.93)of seropositivity than those living in the Highlands after adjustment for age.Conclusions:This study supports the intermittent reports of cutaneous leishmaniasis outbreaks in the Jordan Valley.Vector control measures in the Jordan Valley should be considered,including insecticide treated bed nets,sugar baits and using flowering plants to attract and trap Phlebotomus papatasi sand flies.Active surveillance in the Jordan Valley is also recommended in light of this and other reports. 展开更多
关键词 ZOONOTIC Emerging PATHOGENS One Health Middle East and North Africa
Improvements in Long-Lead Prediction of Early-Summer Subtropical Frontal Rainfall Based on Arctic Sea Ice 预览
17
作者 XING Wen HUANG Fei 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期542-552,共11页
Seasonal prediction of East Asia(EA) summer rainfall, especially with a longer-lead time, is in great demand, but still very challenging. The present study aims to make long-lead prediction of EA subtropical frontal r... Seasonal prediction of East Asia(EA) summer rainfall, especially with a longer-lead time, is in great demand, but still very challenging. The present study aims to make long-lead prediction of EA subtropical frontal rainfall(SFR) during early summer(May-June mean, MJ) by considering Arctic sea ice(ASI) variability as a new potential predictor. A MJ SFR index(SFRI), the leading principle component of the empirical orthogonal function(EOF) analysis applied to the MJ precipitation anomaly over EA, is defined as the predictand. Analysis of 38-year observations(1979-2016) revealed three physically consequential predictors. A stronger SFRI is preceded by dipolar ASI anomaly in the previous autumn, a sea level pressure(SLP) dipole in the Eurasian continent, and a sea surface temperature anomaly tripole pattern in the tropical Pacific in the previous winter. These precursors foreshadow an enhanced Okhotsk High, lower local SLP over EA, and a strengthened western Pacific subtropical high. These factors are controlling circulation features for a positive SFRI. A physical-empirical model was established to predict SFRI by combining the three predictors. Hindcasting was performed for the 1979-2016 period, which showed a hindcast prediction skill that was, unexpectedly, substantially higher than that of a four-dynamical models’ ensemble prediction for the 1979-2010 period(0.72 versus 0.47). Note that ASI variation is a new predictor compared with signals originating from the tropics to mid-latitudes. The long-lead hindcast skill was notably lower without the ASI signals included, implying the high practical value of ASI variation in terms of long-lead seasonal prediction of MJ EA rainfall. 展开更多
关键词 East Asia SUBTROPICAL FRONTAL rainfall long-lead seasonal PREDICTION Arctic sea ice Physical-empirical model
在线阅读 下载PDF
Middle East respiratory syndrome coronavirus in pediatrics: a report of seven cases from Saudi Arabia
18
作者 Sarah H. Alfaraj Jaffar A. Al-Tawfiq +1 位作者 Talal A. Altuwaijri Ziad A. Memish 《医学前沿:英文版》 CAS CSCD 2019年第1期126-130,共5页
Infection with Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012 as an important respiratory disease with high fatality rates of 40%—60%. Despite the increased number of cases over subsequent ye... Infection with Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012 as an important respiratory disease with high fatality rates of 40%—60%. Despite the increased number of cases over subsequent years, the number of pediatric cases remained low. A review of studies conducted from June 2012 to April 19, 2016 reported 31 pediatric MERS-CoV cases. In this paper, we present the clinical and laboratory features of seven patients with pediatric MERS. Five patients had no underlying medical illnesses, and three patients were asymptomatic. Of the seven cases, four (57%) patients sought medical advice within 1-7 days from the onset of symptoms. The three other patients (43%) were asymptomatic and were in contact with patients with confirmed diagnosis of MERS-CoV. The most common presenting symptoms were fever (57%), cough (14%), shortness of breath (14%), vomiting (28%), and diarrhea (28%). Two (28.6%) patients had platelet counts of < 150 ×10^9/L, and one patient had an underlying end-stage renal disease. The remaining patients presented with normal blood count, liver function, and urea and creatinine levels. The documented MERS-CoV Ct values were 32 38 for four of the seven cases. Two patients (28.6%) had abnormal chest radiographic findings of bilateral infiltration. One patient (14.3%) required ventilator support, and two patients (28.6%) required oxygen supplementation. All the seven patients were discharged without complications. 展开更多
关键词 Middle East RESPIRATORY SYNDROME CORONAVIRUS MERS-CoV pregnancy PEDIATRICS
Development Optimization for a Typical Carbonate Reservoir in the Middle East 预览
19
作者 Wei Chenji Yang Jian +2 位作者 Liu Shuangshuang Li Zhengzhong Lou Yuankeli 《中国油气:英文版》 CAS 2019年第1期29-36,共8页
Belt and Road initiative is a very important strategy for Chinese companies to cooperate with foreign ones.The Middle East is a region that contains abundant oil and gas resources. Meanwhile, many countries in the Mid... Belt and Road initiative is a very important strategy for Chinese companies to cooperate with foreign ones.The Middle East is a region that contains abundant oil and gas resources. Meanwhile, many countries in the Middle East support and join in the Belt and Road initiative. Since oil and gas resources are of vital significance for Chinese industry,the cooperation in oil and gas with countries in the Middle East is an important part in ’Belt and Road’ initiative. CNPC began its overseas business from the year 1993 and now it keeps cooperating with many countries in the Middle East. UAE has a large amount of oil and gas reserves and after evaluation, CNPC became the shareholder of ADNOC Onshore and gained 8% of the stocks.In order to improve the development effect, ADNOC appointed several international oil companies as asset leaders for four assets. As a reward, each asset leader can have more income and less tax. As a result, CNPC decided to compete for NEB asset leader with other international oil companies. After analyzing the current development plan, our group conducted the optimization scheme for NEB asset that can help improve the current situation and enhance oil recovery.The optimization scheme is divided into three steps. First is the establishment of effective drainage system.Second is to control water cut and GOR. Third is to enhance oil recovery factor based on first two steps. After discussion with the research group of ADNOC, they admitted that our strategy can solve the problems. Finally, CNPC obtained the asset leader, and has more impact on UAE oil and gas industry since then. 展开更多
关键词 MIDDLE East CARBONATE Reservoir NEB ASSET LEADER
在线阅读 下载PDF
A review of Acanthamoeba keratitis in the Middle East and Iran
20
作者 Mohammad Hossein Feiz Haddad Azar Shokri +1 位作者 Habib Habibpour Seyede Manizhe Heidar Nejadi 《急性病杂志(英文版)》 2019年第4期133-141,共9页
Acanthamoeba keratitis, a vision-threatening disease, is caused by a free-living amoeba of genus Acanthamoeba. Amoeba is widely distributed all around the world. Several cases of Acanthamoeba keratitis have been repor... Acanthamoeba keratitis, a vision-threatening disease, is caused by a free-living amoeba of genus Acanthamoeba. Amoeba is widely distributed all around the world. Several cases of Acanthamoeba keratitis have been reported from the Middle East and Iran as well. The infection is mainly caused by inappropriate use of contact lens;therefore, it is more common among lens wearers. The number of reported cases worldwide is increasing annually due to the increasing number of contact lens wearers for medical or cosmetic reasons. It is known that early diagnosis and treatment can reduce consequent damages, while the delay in these processes will deteriorate the vision. Nowadays contact lens wearing, surgery and use of corticosteroids are known to predispose to Acanthamoeba keratitis, and it was also believed that trauma was the main cause. Increasing public knowledge about Acanthamoeba infection, inquiring the history of patients, clinical signs and laboratory findings can be helpful to early diagnosis and better treatment. Regardless of the increasing knowledge of diagnosis and treatment, this disease is still a challenge. Considering the long curative time, and insufficient efficacy of available treatments, it seems that the prevention is more important than the treatment. This review aimed to explain Acanthamoeba keratitis in the Middle East and Iran from the aspects of epidemiology, diagnosis, and therapeutic treatment. 展开更多
关键词 ACANTHAMOEBA KERATITIS DIAGNOSIS THERAPY MIDDLE EAST Iran
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈