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Science China Earth Sciences 2009年第10期52卷 1661-1672页

作者： yang yafen CHEN ChuXin School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China

The neutral wind dynamo contributes significantly to the ionospheric electrodynamics, and the variation of the neutral winds thus affects the ionosphere. Here we study the effects of the seasonal variation of the winds in a realistic Earth main field. The two-dimensional ionospheric dynamo equation is expressed in the framework of a revision of the International Geomagnetic Reference Field (IGRF) under the assumptions of equipotential field lines and conservation of current. A revision of IGRF and typical uniform conductance are used to isolate the effects of the seasonal variation of the winds. Our results show that the potential and the currents in solstice seasons are much different from those in equinox seasons. The gradients of the potential are steeper in solstice seasons than in equinox sea- sons, and similarly the shell currents are stronger in solstice seasons, due to the stronger neutral winds, than in equinox seasons. Correspondingly, the Birkeland currents in solstice seasons are 2-3 times larger than those in equinox seasons, and that the Birkeland currents are much stronger in winter than in summer. Consequently, this suggests that the couplings between North and South Hemi-spheres are much stronger in solstice seasons than in equinox seasons, and likewise they are stronger in winter than in summer.

关键词： neutral winds seasonal variation shell currents Birkeland currents coupling realistic Earth main field

Dipole tilt controls bow shock location and flaring angle

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Science China Earth Sciences 2017年第1期60卷 198-206页

作者： LU JianYong YUAN HuanZhi WANG Ming yang yafen Institute of Space Weather College of Math & StatisticsNanjing University of Information Science & Technology National Center for Space Weather China Meteorological Administration

The dipole tilt angle has beenfound to affect Earth's bow *** work presents a quantitative relationship between the dipole tilt angle and the bow shock location and flaring *** collected a large data set of bow shock crossings from four different satellites(IMP 8,Geotail,Magion 4,and Cluster),including some recent crossings obtained during *** results from a statistical analysis demonstrate that:(1)the subsolar standoff distance increases but the flaring angle decreases with increasing dipole tilt angle;(2)when the dipole tilt angle changes sign from negative to positive,the dayside bow shock moves toward Earth and the shift can be as much as 2.29 R_E,during which the flaring angle increases;and(3)the shape of bow shock in the northern and southern hemispheres *** the northern hemisphere bow shock,with increasing positive/negative dipole tilt angle,the flaring angle increases/*** for the southern hemisphere,the trend is the opposite;with increasing positive/negative dipole tilt angle,the flaring angle decreases/*** results are helpful for future bow shock modeling that needs to include the effects of dipole tilt angle.

关键词： Bow shock Dipole tilt Solar wind-magnetosphere coupling

Research on process-induced effect in 14-nm FinFET gate formation and digital unit optimization design

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Journal of Semiconductors 2024年第12期45卷 88-93页

作者： yafen yang Hang Xu Tianyang Feng Jianbin Guo David Wei Zhang School of Microelectronics Fudan UniversityShanghai 200433China Jiashan Fudan Institute Jiaxing 314100China

The advanced fin-shaped field-effect transistor(FinFET)technology offers higher integration density and stronger channel control capabilities,however,more complex process effects are also introduced which have significant influence on device *** address these issues,we complete a design-technology co-optimization(DTCO)focused on FinFET,including both process-induced effect during gate formation and corresponding digital unit optimization *** 14 nm Fin-FET complementary metal oxide semiconductor(CMOS)technology is used to illustrate the sensitivity of transistor perfor-mance to process-induced effect,specifically the poly pitch effect(PPE)and cut poly effect(CPE).Predictive technology com-puter aided design(TCAD)simulations have been carried out to evaluate the transistor performance in *** on the results,optimizations in digital unit design is *** delay of the digital unit inverter is decreased by 0.7%,and the rise delay is decreased by 2.1%.For multiple selector(MUX2NV),the delay decreases by 4.64%for rise and 3.56%for drop,respec-tively.

关键词： FinFET TCAD process-induced effect digital unit optimization design

Analysis of the air-sea heat exchange during the El Nino event in 1983

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Acta Oceanologica Sinica 1990年第4期9卷 513-526页

作者： Zhu yafen and yang Dasheng Geophysics Department,Peking University,Beijing,China China

In this paper,by using the ECMWF objective analysed data as well as CAC and NOAA grid point data of 1981 and 1983,the sensible and latent heat fluxes at the air and sea boundary surface within the range of 45°E-75°W, 35°N-35°S over the Pacific and the Indian Ocean are calculated. The purpose is to analyse the different revealing features during the mature stage and at the end of the 1982 -1983 El Nino event and to compare the difference of the features between thd El Nino and the normal. The result shows that the air and sea heat exchange west of the dateline over the central tropical Pacific during the EJ Nino period is more intense than that of the normal. However,the fluxes of the sensible and latent heat on the sea surface with strong warming of SSTneat by and on the south side of the equator east of 170°W are low and even negative,and the patterns of the sensible and latent heat fluxes over the Indian Ocean during the year of 1983 are similer to that of normal. Spatial patterns of the sensible heat ,the latent heat,SST,OLR and the wind speed exhibit large anomalies during the El Nino event. The corresponding relationships of the spatial distribution of the streng exchange of heat fluxes with regions of high SST and action convection or negative anomalies of OLR are relatively complicated. But the region of maximum air and sea heat exchange is in good coincidence with that of high value of the Vs. The strong heat exchange is weakened with the declining and the finishing of the El Nino event in the central tropical Pacific.

关键词： heat Analysis of the air-sea heat exchange during the El Nino event in 1983 Nino El

Research on the framework of e-government body of knowledge

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Journal of Library Science in China 2015年 225-226页

作者： yafen yang 不详

It has been more than 20 years since the concept of'e-government'was first ***,due to the sophisticated research object and external theoretical reference,it is difficult to establish a scientific,systematic and logical theory system of e-government which can be accepted by most *** far,it has been hard to get a comprehensive,unified and rational grasp of

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Flexible biomimetic olfactory neurons based on organic heterojunction

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Journal of Semiconductors 2024年第12期45卷 80-86页

作者： Tianyang Feng Jialin Meng Hang Xu yafen yang Tianyu Wang Hao Zhu Qingqing Sun David Wei Zhang Lin Chen School of Microelectronics Fudan UniversityShanghai 200433China School of Integrated Circuits Shandong UniversityJinan 250100China National Integrated Circuit Innovation Center Shanghai 201203China

Simulating the human olfactory nervous system is one of the key issues in the field of neuromorphic ***-tory neurons interact with gas molecules,transmitting and storing odor information to the olfactory center of the *** order to emulate the complex functionalities of olfactory neurons,this study presents a flexible olfactory synapse transistor(OST)based on pentacene/C8-BTBT organic *** modulating the interface between the energy bands of the organic semiconductor layers,this device demonstrates high sensitivity(ppb level)and memory function for NH3 ***-cal synaptic behaviors triggered by NH_(3) pulses have been successfully demonstrated,such as inhibitory postsynaptic currents(IPSC),paired-pulse depression(PPD),long-term potentiation/depression(LTP/LTD),and transition from short-term depression(STD)to long-term depression(LTD).Furthermore,this device maintains stable olfactory synaptic functions even under differ-ent bending conditions,which can present new insights and possibilities for flexible synaptic systems and bio-inspired elec-tronic products.

关键词： olfactory neurons organic transistor gas-modulated flexible electronic device

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国内外移动政务发展研究

情报资料工作 2011年第6期32卷 35-40页

作者：杨雅芬北京大学信息管理系北京100871

文章分析了移动政务及其相关因素、应用分类,并根据地理区域的不同对世界各地较为成功的移动政务项目进行简要的统计和分析,进而概述了国内外移动政务的发展状况,在此基础上进一步分析基于SMS技术的移动政务应用。

关键词：移动政务 SMS 发展研究

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电子政务服务质量评价研究及启示

情报资料工作 2013年第6期34卷 69-74页

作者：杨雅芬北京大学信息管理系北京100871

文章分析了服务质量的概念界定、理论流派以及评价模式,之后从公共服务质量评价、公众满意度评价、政府网站质量评价等方面对现有研究进行了分析和论述,从而提出电子政务服务质量评价研究的一些启示,以期为后续研究提供有益的借鉴。

关键词：电子政务服务质量评价

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电子政务知识体系框架研究

中国图书馆学报 2015年第2期41卷 29-40页

作者：杨雅芬杭州电子科技大学经济学院

本文从概念界定、文献综述、构建思路、构建过程等方面对电子政务知识体系进行分析总结,认为:为了更好地理解电子政务,有必要对电子政务已有的学术成果进行分析与整合,以便从中提炼出一个具有内在逻辑结构的电子政务知识体系,并建立起... 详细信息

本文从概念界定、文献综述、构建思路、构建过程等方面对电子政务知识体系进行分析总结,认为:为了更好地理解电子政务,有必要对电子政务已有的学术成果进行分析与整合,以便从中提炼出一个具有内在逻辑结构的电子政务知识体系,并建立起适合的知识体系框架。研究采用"逻辑起点论"与"问题系统论"两种方法论,最终提出一个由基本概念、基本理论、基本原理和规律、技术理论知识、管理服务理论知识五个模块构成的电子政务知识体系框架,每个模块中的知识内容来源于电子政务问题研究者的各种思想和观点。通过该电子政务知识体系框架,人们能够更好地把握电子政务各种属性和关系的内在联系,进一步审视当前电子政务研究的状态和效果,同时也对电子政务的实践活动起到一定的指导和借鉴作用。图4。表2。参考文献25。

关键词：电子政务知识体系知识框架

ADVANCE　IN　RESEARCH　ON　THE　HAZARDS　FROM　FUTURE　SEALEVEL　RISE　IN　THE　CHINA＇S　COASTAL　AREA

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Natural Disaster Reduction in China 1996年第3期 125-131页

作者： yang Guishan and Shi yafen(Naming institute of Geography and Limnology, Chinese Academy of Sciences, Naming210008, China )

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关键词： SEAL