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Search Results: 1 - 10 of 129197 matches for " Zhang Yi-Chi "
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Snow Cover Depletion Curve in Kaidu River Basin,Tianshan Mountains

LI Bao-lin,ZHANG Yi-chi,ZHOU Cheng-hu,

资源科学 , 2004,
Abstract: 根据遥感数据获得的雪盖消融曲线是输入到融雪径流模型中一个最重要的参数,云是影响积雪解译精度的主要因素.该文采用美国国家水文遥感中心(NOHRSC)基于NOAA/AVHRR数据通道1、2、3和4数据的theta算法,区分雪、云与陆地、水体,并将该期影像及其前一段时间内影像通过镶嵌取theta的最大值,从而既起到去云的作用,也实现对云下覆信息有效的插补.研究区受云的影响十分严重,镶嵌影像时段的长短对云的去除影响很大.10天镶嵌和30天镶嵌影像受云的影像仍然十分明显,长序列镶嵌影像(使用该期及其前期所有影像镶嵌)的雪盖消融曲线受云的影响较小,可以作为SRM等融雪径流模型比较准确的输入参数.研究区从3月中旬到4月末积雪融化迅速,到了5月份,尤其是6月和7月积雪分布范围很小且比较稳定.研究区内可划分为6个高程带,其中高程带C和D积雪变化对径流影响最为显著.各高程带积雪覆盖率一般在3月中旬达到最大值,高程带A、B内的积雪基本上在4月中旬融化完毕,高程带C和D积雪5月份基本融化完毕,而海拔较高的高程带E和F积雪要到5月或6月积雪消融才停止并保持稳定.
An Iterative Procedure for Optimizing the Performance of the Fuzzy-Neural Job Cycle Time Estimation Approach in a Wafer Fabrication Factory
Toly Chen,Yi-Chi Wang
Mathematical Problems in Engineering , 2013, DOI: 10.1155/2013/740478
Effect of Electrode Surface Modification by Sulfide on QCM Based Protein Biosensor  [PDF]
Yu-Cheng Lin, Yi-Chi Chen, Liang-Yu Chen
Optics and Photonics Journal (OPJ) , 2013, DOI: 10.4236/opj.2013.32B071

The rapid development of surface sensitive biosensor technologies requires optimum control of surface modification to provide reliable and reproducible results. With the aim to assemble a quartz crystal microbalance (QCM)-based protein biosensor, we focus our attention on sulfide receptor and its integration with the surface of the electrode. Here, we present different surface modification processing time to allow sulfide molecules to be immobilized to gold coated sensor for QCM sensing. The optimum surface modification processing time is also obtained by bovine serum albumin (BSA) binding measurement.

Hydrological Response of Runoff to Climate Variation in Kaidu Catchment

ZHANG Yi-chi,LI Bao-lin,CHENG Wei-ming,ZHANG Xue-ren,ZHANG Yi-chi,LI Bao-lin,CHENG Wei-ming,ZHANG Xue-ren,

资源科学 , 2004,
Abstract: With recent comprehensive investigation of TaLimu river, the response of runoff to climate variation of KaiDu river, an important source of TaLimu river, has been a research focus for many scientists. Because a few human activities happened in KaiDu catchment, the variation of runoff is mainly caused by climate change, especially in yearly and seasonal temporal scale. KaiDu catchment is located in the middle of TianShan mountain in XinJiang municipality and has only one meteorological station and one hydrological station within the range of 19012km2. On the large spatial-temporal scale or in the case of data absence, researchers often divide runoff, precipitation and temperature series per ten years into several periods, then acquire the rule of runoff response to climate though comparing the changes of natural elements between difference periods. Obviously, it is impossible for natural elements to take substaintial changes every ten years, it is reasonable to partition the periods of series according to the varition feature of natural elements. In this paper, Mann-Kendall test and Mann-Whitney test is applied to detection the monotonic trends and step trends of yearly and seasonal runoff, precipitation and temperature series from 1958 to 2000 and take the changes point of trends feature as the boundary of periods.The analysis result show that spring runoff is stable in past 45a, other seasonal runoff and yearly runoff are much smaller during 1974 and 1986 than other periods and show significant monotonic increasing trends after 1987. Yearly average temperature during 1975 and 1988 is lower than other periods and average temperature in summer take step increase after 1977. Precipitation show great spatial differences: upstream area has more precipitation than middle-stream area, yearly precipitation decreased after 1973 and aestival precipitation during 1977 and 1988 is fewer than other periods in upstream area, both yearly and aestival precipitation of middle-stream area increased after 1987. By comparing the variation of runoff, precipitation and temperature on the base of runoff periods partition, it is found that climate variation in summer is key reason for runoff change in summer, autumn and winter, precipitation directly influences the runoff but temperature does it through glacier wastage, precipitation has more weight than temperature in influencing runoff change. The reduction of glacier wastage during 1974 and 1986 make the decrease percentage of runoff greater than precipitation, and the augment of glacier wastage during 1986 and 2000 make the increase percentage of runoff greater than precipitation.
Analysis on the Characteristics of Annual Runoff in Hotan Catchment

WU Yi,CHENG Wei-ming,REN Li-liang,ZHANG Yi-chi,ZHANG Xue-ren,

自然资源学报 , 2006,
Abstract: The runoff of a catchment is affected comprehensively by human activities and natural conditions such as soil,vegetation,climate,etc.Therefore streamflow represents the characteristics of determinacy as well as stochasticism.Researches on runoff characteristics are beneficial for the sustainable utilization of water resources,water conservancy planning and agricultural develop-ment. The study area of this paper is Hotan catchment,which is located in the Tarim River Basin in southern Xinjiang,with an area of 48 870km2.The Hotan River is of great importance to ecosystem and society in Taklimakan Desert,because it is the only river that traverses the desert.The paper analyzed the intra-annual distribution and annual variation of runoff in the catchment according to observed data.Some indexes,including the coefficient of nonuniformity,the degree of concentration and the time of concentration,were used to analyze the intra-annual distribution of runoff;the methods of Kendall rank test and periodgram were used to analyze the trend and period of multi-annual runoff. The results show that due to the impacts of runoff-supplying sources,the intra-annual nonuniformity is very high,being more than 75% of the annual total runoff in summer.The coefficient of nonuniformity and the degree of concentration are much bigger than the normal,and the computed time of concentration is in accordance with the time of the observed maximum monthly runoff.The streamflow concentrated in some period of time could possibly arise the conflicts between water usage and supply,which will restrict the sustainable development of agricultural production and the socioeconomy.The Hotan River Basin is supplied by the glaciers and snow mountains,so the statistic of annual runoff Cv is small which indicates that the variation of annual runoff is weak.The annual precipitation,temperature and human activities exert impacts on the variation of runoff.The precipitation influences the runoff directly,in the past 40 years,the precipitation in the Hotan catchment presented an increasing trend.Under the background of global warming,the snow line on the mountains is hoisting and the glacier is shrinking.And with the development of agriculture,the irrigation water requirement is increasing constantly.Owning to the effect of these factors,the runoff in Hotan catchment presents a weak declining trend.The result of periodical analysis is that the annual runoff has no obvious periodicity.
Dependence of loading time on control parameters in a standard vapour-loaded magneto-optical trap

Zhang Yi-Chi,Wu Ji-Zhou,Li Yu-Qing,Ma Jie,Wang Li-Rong,Zhao Yan-Ting,Xiao Lian-Tuan,Jia Suo-Tang,

中国物理 B , 2011,
Abstract: Loading time is one of the most important dynamic characteristics of a magneto-optical trap. In this paper, we primarily report on a detailed experimental study of the effects of some magneto-optical trap control parameters on loading time, including the background vacuum pressure, the magnetic field gradient, and the intensities of trapping and repumping lasers. We compare the results with previous theoretical and experimental results, and give qualitative analysis. These experimental investigations offer some useful guidelines to control the loading time of magneto-optical traps. The controllable loading time achieved is helpful to enhance the signal-to-noise ratio of photoassociation spectroscopy, which is remarkably improved from 7 to 28.6.
An Exploration of the Limits of the Maxwell-Boltzmann Distribution
Yi-Chi Yvette Wu,L. H. Ford
Physics , 2014,
Abstract: Selected aspects of the Maxwell-Boltzmann for molecular speeds are discussed, with special attention to physical effects of the low speed and high speed limits. We use simple approaches to study several topics which could be included in introductory courses, but are usually only discussed in more advanced or specialized courses.
Research on improve the SNR of ultracold cesium molecule rovibronic spectrum via best optimization parameter control

Zhang Yi-Chi,Wu Ji-Zhou,Ma Jie,Zhao Yan-Ting,Wang Li-Rong,Xiao Lian-Tuan,Jia Suo-Tang,

物理学报 , 2010,
Abstract: Ultracold atom photoassociation spectroscopy is significant for studying the long-range molecular potential energy structure. The signal-noise ratio of ultracold Cesium Molecule photoassociation Rovibronic Spectrum is one of the indicators as a measure of detection technology which directly affect the distinguishing ability and detection sensitivity of the spectra. We obtain an long-range ultracold cesium molecular hyperfine rovibration spectra by modulating the fluorescence spectroscopy. We find that demodulation parameters have a significant impact to the signal-noise ratio of spectra by studying the demodulation parameters such as integration time and sensitivity, which show nonlinear relation with the ratio. We achieve the optimal control of the signal-noise ratio for spectrum according to our experiment, which laid an important foundation for further studying the long-range state rovibration level of ultracold cesium molecule.
Clinical Manifestation of EUGOGO Classification in Graves'Orbitopathy

曾 鹏,余 韵,范淑贤,李梓敬,张一弛,廖韵如,胡玉新,王 梅
,YU Yun,FAN Shu-xian,LIZ i-jing,ZHANG Yi-chi,LIAO Yun-ru, HU Yu-xin,WANG Mei

- , 2018, DOI: A
Abstract: 【目的】分析甲状腺相关眼病(GO)以欧洲甲状腺相关眼眶病专家组(EUGOGO)标准分级的临床特 征。【方法】回顾性收集2010年1月-2016年12月于中山大学孙逸仙纪念医院内分泌与眼科明确诊断为GO的 110例病例,记录其病史、眼部检查,分别按照EUGOGO标准、NOSPECS标准进行GO严重程度的分级,按照临床 活动度评分(CAS)进行GO炎症活动度的分级,并对这些指标进行综合性分析。【结果】本研究共收集110例患 者211眼。患者年龄平均47.4(S=12.8)岁,其中具有吸烟史27例。甲状腺疾病病史平均24.7(S=42.5)月。GO病 史平均10.4(S=23.1)月。眼球突出度平均19.1(S=3.1)mm。按照EUGOGO标准:轻度25例(22.7%),中-重度56 例(50.9%),威胁视力病例包括压迫性视神经病变(DON)或角膜破坏29例(26.4%)。临床活动度CAS评分≥3分 者(活动)47例(42.7%),CAS评分<3分者(不活动)63例(57.3%)。而按照NOSPECS分级系统评估, 2级2例 (1.8%), 3级9例(8.2%), 4级69例(62.7%), 5级6例(5.5%), 6级24例(21.8%)。所有病例中,74例(67.3%)接受 全身激素治疗;15例(13.6%)接受眼眶放射治疗; 4例(3.6%)接受手术治疗(眼眶减压术, 3例;斜视手术, 1例)。 【结论】GO患者非活动性病例略多于活动性病例,中-重度病例与威胁视力的病例占多数。目前国内按照EU? GOGO推荐的治疗方法进行治疗的病例较少,对GO临床治疗方案尚不统一,因而需要进一步探索适合我国国情 治疗GO的研究
Applied Neural Intelligence to Modeling, Control, and Management of Human Systems and Environments
Toly Chen,P. Balasubramaniam,Quek Hiok Chai,Yi-Chi Wang
Applied Computational Intelligence and Soft Computing , 2012, DOI: 10.1155/2012/595041
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