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Improved Carrier Frequency Offset Estimation in OFDM Systems

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The Journal of China Universities of Posts and Telecommunications 2004年第Z1期11卷 33-36页

作者： liu xiao-ming liu yuan-an Wireless Communication Center Beijing University of Posts and Telecommunications Beijing 100876 P.R.China Wireless Communication Center Beijing University of Posts and Telecommunications Beijing 100876 P.R.China

A new carrier frequency offset estimation algorithm in Orthogonal Frequency Division Multiplexing (OFDM) systems is proposed. The proposed algorithm is an improvement of the Michele Morelli (M&M) algorithm. It also uses a training symbol which is divided into L>2 identical parts to estimate the carrier frequency offset, and the estimation range is ±L/2 the subcarrier spacing, but the performance of the proposed Maximum Likelihood (ML) algorithm is more robust and complex efficient than the M&M algorithm.

关键词： frequency offset estimation multipath channel OFDM

维普期刊数据库

Efficient defect-controlled photocatalytic hydrogen generation based on near-infrared Cu-In-Zn-S quantum dots

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Nano Research 2018年第3期11卷 1379-1388页

作者： xiao-yuan liu Guozhen Zhang Hao Chen Haowen Li Jun Jiang Yi-Tao Long Zhijun Ning School of Physical Science and Technology ShanghaiTech University Shanghai 201210 China Key Laboratory for Advanced Materials & School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China School of Chemistry and Materials Science Hefei National Laboratory for Physical Sciences at the Microscale and CAS Key Laboratory of Mechanical Behavior and Design of Materials (LMBD) University of Science and Technology of China (USTC) Hefei 230026 China

The development of photocatalysts that can effectively harvest visible light is essential for advances in high-efficiency solar-driven hydrogen generation. Herein, we synthesized water soluble CuInS2 （CIS） and Cu-In-Zn-S （CIZS） quantum dots （QDs） by using one-pot aqueous method. The CIZS QDs are well passivated by glutathione ligands and are highly stable in aqueous conditions. We subsequently applied these QDs as a light harvesting material for photocatalytic hydrogen generation. Unlike most small band gap materials that show extremely low efficienc36 these new QDs display remarkable energy conversion efficiency in the visible and near-infrared regions. The external quantum efficiency at 650 nm is - 1.5%, which, to the best of our knowledge, is the highest value achieved until now in the near-infrared region.

关键词： quantum dots photocatalysis hydrogen generation surface defect

Effects of raster resolution on landslide susceptibility mapping:A case study of Shenzhen

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Science China(Technological Sciences) 2008年第S2期51卷 188-198页

作者： TIAN yuan,xiao ChenChao,liu Yu & WU Lun Institute of RS and GIS,Peking University,Beijing 100871,China Peking Univ Inst RS & GIS Beijing 100871 Peoples R China

Resolution has been playing a significant role in landslide susceptibility mapping and hazard *** on geographical information system(GIS) and information model,the effects of raster resolution on landslide susceptibility mapping are studied in a central area of Shenzhen,*** factors are selected to calculate landslide susceptibility with eleven groups of different resolutions(5 to 190 m).It has been found that a finer resolution does not necessarily lead to a higher accuracy of landslide susceptibility mappings,while the result of 90 m-resolution has the best accuracy and the 150 m-resolution has the worst *** accuracy curve is in a shape of "W" along with resolution decreasing:1) The accuracy decreases from 5 to 70 m;2) and then the best accuracy appears at 90 m,which is almost the same as the mean size of landslides in study area;3) the accuracy decreases again from 110 to 150 m;4) and finally the accuracy increases from 150 to 190 *** sensitivity analysis indicates that the effects of raster resolution are mainly caused by the resolution impact on landform parameter derivation,while factors like geology and human activity are very insensitive to resolutions.A further study shows that in flat,ridge,and slope foot terrains,the susceptibility mapping result is sensitive to resolution,but in the sloping surface area the sensitivity is much less sensitive to *** last,by choosing study areas with different sizes,it has also been found that the optimal resolutions are variable due to size of study *** the study area is larger than a threshold,which is 135 km2 in this study,and the optimal resolution is almost fixed.

关键词： resolution sensitivity landslide susceptibility mapping digital elevation model(DEM) information model

维普期刊数据库

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Keep Loneliness Away

Women of China 1996年第4期 39-40页

作者： xiao yuan xiaoHONG liu

EVERYTHING changed around me. No files to read, fewer telephone calls, and the children have left home to start their own families....I am left at home, with huge amounts of time and I wonder how I will ever be able to spend all the hours." This is what many elderly people say after retiring from their work. An answer to the problem was found by a group of retired women cadres, who once worked in the field of women’s issues. They often say, "Don’t allow yourself to be tied up by loneliness.

关键词： Keep Loneliness Away

Singing the Praise of Hong Kong's Return——A Hong Kong chorus visits Beijing

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Women of China 1997年第7期 21-22页

作者： xiao yuan HONG liu

AN 82-member Hong Kong chorus recently held a concert in Beijing to express their happiness at Hong Kong’s return to China. The Hong Kong Arts Chorus entitled their concert, "When the wind sweeps through, paddy fields produce fragrance to merge both banks--hail the return of Hong Kong." The verse which the chorus had adopted as the title of their concert in Beijing comes from a well-known song on the mainland,"My Motherland." By adopting this

关键词： A Hong Kong chorus visits Beijing Singing the Praise of Hong Kong’s Return

Effort to Rebuild Happiness

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Women of China 1996年第5期 19-20页

作者： xiao yuan xiaoHONG liu

ZHANG Huan felt her life broke apart when her husband died. It was not until two years later that she pulled herself together. She adopted a positive attitude towards her life and felt ready to establish a family agai... 详细信息

关键词： Zhang Effort to Rebuild Happiness

Woman Doctor Declares War Against Hemophilia

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Women of China 1996年第4期 36-38页

作者： xiao yuan xiaoHONG liu

DANGERS of hereditary diseases are hidden in the complicated process by which life is formed. There are many who work hard to save lives and fight against such misfortune. And Doctor Zhao Cuilan is one such soldier who has chosen hemophilia as her battlefield. Hemophilia is a hereditary disease characterized by the inability of the patient’s blood to clot. When a person lacks the substance that causes blood clotting, he can bleed to death. In

关键词： Woman Doctor Declares War Against Hemophilia Zhang

Expression and immunoreactivity of HCV/HBV epitopes

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World Journal of Gastroenterology 2005年第41期11卷 6440-6444页

作者： Xin-Yu Xiong xiao liu yuan-Ding Chen Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College Kunming 650118 Yunnan Province China

AIM： To develop the epitope-based vaccines to prevent Hepatitis C virus （HCV）/Hepatitis B virus （HBV） infections. METHODS： The HCV core epitopes C1 STNPKPQRKTKRNTNRRPQD （residuals aa2-21） and C2 VKFPGGGQIVGGVYLLPRR （residuals aa22-40）, envelope epitope E GHRMAWDMMMNWSP （residuals aa315-328） and HBsAg epitope S CTTPAQGNSMFPSCCCTKPTDGNC （residuals aa124-147） were displayed in five different sites of the flock house virus capsid protein as a vector, and expressed in E. coli cells （pET-3 system）. Immunoreactivity of the epitopes with anti-HCV and anti-HBV antibodies in the serum from hepatitis C and hepatitis B patients were determined. RESULTS： The expressed chimedc protein carrying the HCV epitopes C1, C2, E （two times）, L3C1-I2E-L1C2- L2E could react with anti-HCV antibodies. The expressed chimeric protein carrying the HBV epitopes S, I3S could react with anti-HBs antibodies. The expressed chimeric proteins carrying the HCV epitopes C1, C2, E plus HBV epitope S, L3C1-I2E-L1C2-L2E-I3S could react with anti- HCV and anti-HBs antibodies. CONCLUSION： These epitopes have highly specific and sensitive immunoreaction and are useful in the development of epitope-based vaccines.

关键词： HCV HBV Epitope-based vaccine Recombinant Xmmunoreactivity

Manometric asymmetry of the anal sphincter: anatomic evidence and clinical application

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中华医学杂志(英文版) 2005年第3期000卷 35-39页

作者： xiao yuan-hong and liu GuilinDepartment of Pediatric Surgery, PLA General Hospital, Beijing 100853, China Department of Pediatric Surgery PLA General Hospital Beijing 100853 China

Background Manometric pressure asymmetry of the anal sphincter exists in the anal canal. There are reports about the anatomy of the anal sphincter, but the relationship between the configuration and the pressure asymmetry of the anal sphincter is not clear. This study is to investigate the anatomic evidence and clinical application of anal sphincter pressure asymmetry.

关键词： anus · manometry · anal sphincter · pressure · manometric asymmetry gradient · anatomy