Detecting spatio-temporal changes of arable land and construction land in the Beijing-Tianjin corridor during 2000–2015     

Guo  Liying  Di  Liping  Tian  Qing 《地理学报(英文版)》2019,29(5):702-718

Journal of Geographical Sciences - Rapid peri-urbanization has become a new challenge for sustainable urban-rural development worldwide. To clarify how unprecedented urban sprawl at the...  相似文献   

A photometric study of a new short period eclipsing sdB binary NSVS 07826147     

Zhu Liying  Qian Shengbang 《Astrophysics and Space Science》2010,329(1-2):107-112

NSVS?07826147 and NSVS?04818255 were suspected as possible eclipsing sdB binary systems by Kelley and Shaw. In order to investigate the short period eclipsing sdB binaries, we have listed them as our observing targets and began to monitor it from March 2009. Till now, we have obtained four complete CCD light curves and 16 high precise times of light minimum of NSVS?07826147. All light curves show strong reflection and a very narrow eclipse, which implies that NSVS?07826147 should be a new short period eclipsing sdB binary. For the system NSVS?04818255, no eclipse character was found in the light curves according to our observations. However, we found that a star near NSVS?04818255 is a close binary system with a period of about 0.32498 days. Up to now, only seven short period eclipsing sdB binary systems have been found, including NSVS?07826147. With the new precise epochs obtained by us, the new period of this system is derived as 0.16177046(5) days, which can be used to predict the epochs of light minimum. Furthermore, the light curves of NSVS?07826147 are analyzed using the Wilson–Van Hamme code and the testing photometric solutions are presented and discussed.  相似文献   

忻州市“12121”气象声讯服务发展状况分析     

刘丽英  杨勇  王文祥  郭定选  蒋云盛  康晋伟 《山西气象》2009,(2):44-46

山西省结合忻州市“12121”发展状况,通过分析提高拨打率的三大因素,明确了如何充分地利用气象声讯服务平台的优势,向广大用户及时提供内容丰富、专业性强、贴近百姓生活的气象信息,使“12121”气象声讯服务项目具有较强的市场竞争能力和持续发展能力,产生显著的社会效益和经济效益。  相似文献   

L波段探空数据接收机的常见问题和使用技巧     

韦振华  韦丽英  黎洁波 《气象研究与应用》2010,32(2):41-43

就使用GTC2型L波段探空数据接收机过程中出现的几个常见问题进行阐述和分析,提出了解决问题的办法,以及在应急状态下接收机的使用技巧。  相似文献   

Another Record: Ocean Warming Continues through 2021 despite La Ni?a Conditions     

Lijing CHENG  John ABRAHAM  Kevin E. TRENBERTH  John FASULLO  Tim BOYER  Michael E. MANN  Jiang ZHU  Fan WANG  Ricardo LOCARNINI  Yuanlong LI  Bin ZHANG  Zhetao TAN  Fujiang YU  Liying WAN  Xingrong CHEN  Xiangzhou SONG  Yulong LIU  Franco RESEGHETTI  Simona SIMONCELLI  Viktor GOURETSKI  Gengxin CHEN  Alexey MISHONOV  Jim REAGAN 《大气科学进展》2022,39(3):373-385

The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (O...  相似文献   

基于KNN的地基可见光云图分类方法   总被引：1，自引：0，他引：1       下载免费PDF全文

朱彪  杨俊  吕伟涛  陈丽英  马颖  姚雯  张义军 《应用气象学报》2012,23(6):721-728

云图的自动分类是实现地基云自动化观测的技术保障。该文探讨了一种先将云图分为积状云、层状云和卷云3大类的分类方案,通过对3大云类和晴空这4种天空类型的纹理特征、颜色特征和形状特征进行分析,选取了21个特征参量,并采用K最近邻分类器 (K-Nearest Neighbor,KNN), 在不同的K取值情况下对这几类天空类型进行了分类识别。结果表明:新的分类方案是可行的,且当纹理特征、颜色特征和形状特征结合使用时获取了比单独利用纹理特征、颜色特征和形状特征以及它们两两组合时更好的识别效果。当K=7且使用21个特征参量时,KNN算法对积状云、层状云、卷云和晴空的识别最好, 识别正确率分别为91.1%,74.4%,70.0%和100.0%,平均正确率为83.9%。  相似文献   

Effects of water chemistry and concentrations of dissolved organic matter on its fluorescence characteristics and molecular conformation     

Yi Mei  Liying Wang  Fengchang Wu 《中国地球化学学报》2009,28(4):413-420

Previous studies showed that water chemistry and concentrations of dissolved organic matter (DOM) could affect its molecular conformation and binding characteristics with hydrophobic organic contaminants (HOCs). However, the conformational change of DOM resultant from water chemistry and concentrations of DOM was not extensively investigated; therefore, the contradictory reports regarding the binding property with HOCs were available in literature. In this study, the effects of ionic strength, pH and DOM concentrations on the fluorescence properties of two humic acids (HA), namely Fluka HA and Amherst HA, were investigated by three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM) and steady-state fluorescence polarization (FP) techniques. The results not only corroborated previous observations obtained by other investigators, but revealed some new information about the fluorescence properties and molecular conformation of the humic acids under different water chemistry and DOM concentration conditions, which could shed light on its binding mechanisms and binding properties with HOCs.  相似文献   

五寨县适宜栽培黄芪的气象条件分析     

马子平  溪玉香  张翠玲  郝小平  刘丽英  史云飞 《山西气象》2008,(3)

通过分析黄芪生长发育所需要气候条件和五寨县基本气候条件,总结出五寨县适宜栽培黄芪的优势以及五寨黄芪有效成份超过全国其它黄芪产区的主要原因,为今后打造五寨黄芪种植品牌提供理论根掘。  相似文献   

地震科技成果综合评价原则及方法的探讨     

孙丽英  赖松 《华南地震》1990,(3)

本文介绍一套适合于广东省地震局实际情况的评价指标体系,认为定性分析与定量评分相结合的综合评奖方法是当前较合理可行的评奖办法。  相似文献   

观音阁水库引水工程施工控制网的设计     

王丽英  贾晓堂 《测绘通报》2012,(6):64-67

结合观音阁水库引水工程,探讨特长隧洞施工控制网测量的设计,主要研究GPS在特长隧洞测量方面的应用。隧洞贯通的相关技术限差,国家有关测量规范仅规定到8 km之内。参考国内外有关案例和技术规则,进行理论上的精度估算,研究确定采用C级GPS全面网作为首级平面控制网,为以后的特长隧洞施工控制网测量提供了宝贵的经验和理论依据。  相似文献