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A possible Younger Dryas-type event during Asian monsoonal Termination 3

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Science china Earth Sciences 2006年第9期49卷 982-990页

作者： chen Shitao1, WANG Yongjin1, KONG Xinggong1, LIU Dianbing1, chenG Hai2 & R.L. Edwards2 1. College of Geography Science, nanjing normal university, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, nanjing 210097, china 2. department of Geology and Geophysics, university of Minnesota, Minneapolis MN55455, USA 1. College of Geography Science Nanjing Normal University Jiangsu Key Laboratory of Environmental Change and Ecological Construction Nanjing 210097 China 2. department of Geology and Geophysics University of Minnesota Minneapolis MN 55455 USA

Seven U-Th dates, 560 δ 18O data and microscopic sequences were measured for sta- lagmites from two high-altitude caves in Shennongjia area, Hubei Province. Variations of the de- cadal-resolution stalagmite δ 18O record from Swan Cave (1600 m elevation) reflect large spatial changes in circulation strength and precipitation of Asian monsoon. The evidence comes from a great similarity among the stalagmite δ 18O records from nanjing, Jiangsu Province; Libo, Guizhou Province and here studied area during the last deglaciation, including a part interval of Younger-Dryas event and Bolling-Allerod. A 30-year-resolution stalagmite δ 18O record from Yongxing Cave (1400 m eleva- tion), 70 km away from Swan Cave, reveals a rapid transition of Asian monsoon climate during Ter- mination 3 at about 245±5 kaBP. Based on 3 U-Th dates and about 5000 continuous annual bands, a millennial dry episode has been observed during Asian monsoonal Termination 3 from the Yongxing δ 18O profile. With respect to its structure, duration and transition, the dry reversal, as indicated by our stalagmite δ 18O record, generally agrees with the pattern of the YD event well-expressed in the Chi- nese stalagmite δ 18O records. This YD-type event is characterized by a large decrease in δ 18O value as much as 2.30‰, more than half of the δ 18O excursion between glacial/interglacial periods, and lasts 1371±59 a determined by the annual counting chronology. After this event, the monsoon climate shifted abruptly into the interglacial period within 74±4 a. Our data corroborate the view that the re- peated occurrence of YD-type event was not an “accident”, possibly resulted from the coupling of ice-sheet and oceanic/atmospheric circulations.

关键词： stalagmite, Termination 3, Asian monsoon, YD-type event, Shennongjia, Hubei Province.

Role of Peroxisome Proliferator-Activated Receptor Gamma in Glucose-induced Insulin Secretion

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Acta Biochimica et Biophysica Sinica 2006年第1期38卷 1-7页

作者： Ze-Kuan XU~(1,2),Neng-Guin chen~1,Chang-Yan MA~1,Zhuo-Xian MENG~1,Yu-Jie SUN~1,and Xiao HAN~(1*) ~1 Key Laboratory of Human Functional Genomics of Jiangsu Province,department of Biochemistry and Molecular Biology, nanjing Medical university,nanjing 210029,china ~2 department of normal Surgery,the First Affiliated Hospital of nanjing Medical university,nanjing 210029,china KeyLaboratoryofHumanFunctionalGenomicsofJiangsuProvincedepartmentofBiochemistryandMolecularBiology NanjingMedicalUniversityNanjingChina departmentofnormalSurgery theFirstAffiliatedHospitalofNanjingMedicalUniversity

Peroxisome proliferator-activated receptor (PPAR) isoforms (α and γ) are known to beexpressed in pancreatic islets as well as in insulin-producing cell *** of PPAR have been shoWn toenhance glucose-induced insulin secretion in rat pancreatic ***,their effect on insulin secretionis still *** understand the molecular mechanism by which PPAR7 exerts its effect on glucose-induced insulin secretion,we examined the endogenous activity of PPAR isoforms,and studied the PPARyfunction and its target gene expression in INS-1 *** found that:(1)endogenous PPARγ was activatedin a ligand-dependent manner in INS-1 cells;(2)overexpression of PPARy in the absence of PPARγ ligandsenhanced glucose-induced insulin secretion,which indicates that the increased glucose-induced insulin secretionis a PPARγ-mediated event;(3)the addition of both PPARγ and retinoid X receptor (RXR) ligands showed asynergistic effect on the augmentation of reporter activity,suggesting that the hetero-dimerization of PPAR7and RXR is required for the regulation of the target genes;(4)PPARs upregulated both the glucose transporter2 (GLUT2) and Cbl-associated protein (CAP) genes in INS-1 *** findings suggest an importantmechanistic pathway in which PPARγ enhances glucose-induced insulin secretion by activating the expressionof GLUT2 and CAP genes in a ligand-dependent manner.

关键词： PPARγ ligand glucose-induced insulin secretion glucose transporter 2 Cb1-associated protein

Proper holomorphic self-maps of smooth bounded Reinhardt domains in C^2

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Science china mathematics 2008年第1期51卷 93-100页

作者： chen ZhiHua~1 & PAN YiFei~(2,3+) 1 department of mathematics, Tongji university, Shanghai 200092, china 2 department of Mathematical Sciences, Indiana university-Purdue university Fort Wayne, Fort Wayne, IN 46805-1499, USA 3 School of mathematics and Information Sciences, Jiangxi normal university, Nanchang 330022, china department of mathematics Tongji University Shanghai China department of Mathematical Sciences Indiana University-Purdue University Fort Wayne Fort Wayne USA School of mathematics and Information Sciences Jiangxi Normal University Nanchang China

It is proved that every proper holomorphic self-map of a smooth bounded Reinhardt domain in C^2 is an automorphism.

关键词： Reinhardt domain proper holomorphic maps

Existence of unbiased estimate of regression parameters in simple linear EV models

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Science china mathematics 2005年第7期48卷 915-928页

作者： LIU Jixue & chen Xiru department of Statistics and Finance, university of Science and Technology of china, Hefei 230026, china department of mathematics, Graduate School of Chinese Academy of Sciences, Beijing 100049, china department of Statistics and Finance University of Science and Technology of China Hefei 230026 China department of mathematics Graduate School Chinese Academy of Sciences Beijing 100049 China

It is well known that for one-dimensional normal EV regression model X = x+ u,Y =α+βx+e, where x, u, e are mutually independent normal variables and Eu=Ee=0, the regression parameters a and β are not identifiable without some restriction imposed on the parameters. This paper discusses the problem of existence of unbiased estimate for a and β under some restrictions commonly used in practice. It is proved that the unbiased estimate does not exist under many such restrictions. We also point out one important case in which the unbiased estimates of a and β exist, and the form of the MVUE of a and β are also given.

关键词： EV regression model unbiased estimate identiflability.

Geometric double-entity model for recognizing far-near relations of clusters

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Science china(Information Sciences) 2011年第10期54卷 2040-2050页

作者： WANG KaiJun ,YAN XuanHui & chen LiFei School of mathematics and Computer Science,Fujian normal university,Fuzhou 350108,china 1. School of mathematics and Computer Science Fujian Normal University Fuzhou 350108 China

When solving many practical problems,we not only need sample labels given by a clustering algorithm,but also rely on the recognition of far-near relations of *** the difficult condition of many clusters in a high-dimensional data set,the clustering visualization methods based on dimension reductions usually produce the phenomena,e.g.,some clusters are overlapping,interlacing,or pushed away;as a result,the far-near relations of some clusters are displayed wrongly or cannot be *** existing inter-cluster distance methods cannot determine whether two clusters are far away or *** geometric double-entity model method (GDEM) is proposed to describe far-near relations of clusters,and the methods such as the relative border distance,absolute border distance and region dense degree are designed to measure far-near degrees between *** pays attention to both the absolute distance between nearest sample sets and the dense degrees of border regions of two clusters,and it is able to uncover accurately far-near relations of clusters in a high-dimensional space,especially under the difficult condition mentioned *** experimental results on four real data sets show that the proposed method can effectively recognize far-near relations of clusters,while the conventional methods cannot.

关键词： geometric double-entity model far-near relations of clusters distance between clusters partitional clustering algorithms

Mitochondrial rRNA and tRNA and hearing function

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Cell Research 2007年第03期17卷 227-239页

作者： Guangqian Xing~1 Zhibin chen~1 Xin Cao~2 ~1department of Otolaryngology,the First Affiliated Hospital of nanjing Medical university,nanjing 210029,china ~2department of Biotechnology,nanjing Medical university,nanjing 210029,china 1department of Otolaryngology the First Affiliated Hospital of Nanjing Medical University Nanjing 210029 China 1department of Otolaryngology the First Affiliated Hospital of Nanjing Medical University Nanjing 210029 China 2department of Biotechnology Nanjing Medical University Nanjing 210029 China

The human ear is a delicate sensory apparatus of hearing for normal communication,and its proper functioning is highlydependent on mitochondrial oxidative *** first mitochondrial point mutation for nonsyndromic andaminoglycoside-induced hearing loss was identified in *** then a number of inherited mitochondrial mutationshave been implicated in hearing *** of the molecular defects responsible for mitochondrial disorder-associatedhearing loss are mutations in the 12S rRNA gene and tRNA *** this review,after a short description of normal hear-ing mechanisms and mitochondrial genetics,we outline the recent advances that have been made in the identification ofdeafness-associated mitochondrial mutations,and discuss how mitochondrial dysfunction contributes to hearing loss.

关键词： mitochondrial DNA rRNA tRNA gene mutation aminoglycosides hearing loss

Preparation of Ultrafine Li4+x AlxSi1-xO4 by Sol-Gel Method and Its Ionic Conductivity

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Rare Metals 2000年第3期19卷 231-236页

作者： chen Rufen,Song Xiuqin and Liu Huating (陈汝芬) (宋秀芹) (刘华亭) department of Chemistry,Hebei normal university,Shijiazhuang 050016,china Hebei normal Univ Dept Chem Shijiazhuang 050016 Peoples R China

Solid electrolyte Li 4+ x Al x Si 1- x O 4 ( x =0～0.5) was prepared by sol gel *** powder samples were characterized by DTA TG,TEM,SEM and XRD. Ionic conductivity of the sintered sample was determined by means of A C impedance *** experimental results show that the solid solution range was 0< x ≤0.4,while the conductivity of samples rised with increasing amount of Al 2O 3 added,the maximum conductivity of Li 4.4 Al 0.4 Si 0.6 O 4 was 8.612×10 -3 S·cm -1 at 300℃.The average grain size of samples was 70 *** sample prepared by sol gel method required lower temperature and presented higher ionic conductivity compared with the samples by the conventional solid state reaction.

关键词： Li 4+ x Al x Si 1- x O 4 Sol Gel method Ionic conductivity

Analogues of Hadwiger's Theorem in Space IR^n—Sufficient Conditions for a Convex Domain to Enclose Another

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Acta Mathematica Sinica,English Series 1995年第1期11卷 12-22页

作者： Zhou Jiazu department of mathematics,Guizhou normal university,Guiyang,550001 china Li Haizhong department of mathematics,Zhengzhou university,Zhengzhou,450052 china chen Xingyue department of mathematics,Chongqing Teacher’s College,Yongchuan,632168 china 贵州师范大学数学系贵州贵阳郑州大学数学系河南郑州重庆师范高等专科学校数学系重庆

We estimate the kinematic measure of one convex domain moving to another under the group G of rigid motions in IR~*** first estimate the kinematic formula for the total scalar curvature ∫Rdv of the n-2 dimensional intersection submanifold D∩g *** we use Chern and Yen’s kinematic fundamental formula and our integral inequality to obtain a sufficient condition for one convex domain to contain another in IR~n(≥4).For n=4,we directly obtain another sufficient condition in IR~4.

关键词： Analogues of Hadwiger’s Theorem in Space IR~n Sufficient Conditions for a Convex Domain to Enclose Another IR

无蹼壁虎冬眠期与出眠初期肝脏比较细胞学研究

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解剖学报 1996年第3期27卷 278-283页

作者：嵇庆张锡然陈宜峰南京师范大学生物系

用形态计量学方法对无蹼壁虎冬眠期与出眠初期肝脏进行了比较细胞学研究，结果表明：１．冬眠期肝细胞内富含糖原颗粒和脂滴，线粒体和粗面内质网稀少，溶酶体较小且电子密度较低，高尔基复合体极少。出眠初期肝细胞内糖原颗粒和脂滴稀... 详细信息

用形态计量学方法对无蹼壁虎冬眠期与出眠初期肝脏进行了比较细胞学研究，结果表明：１．冬眠期肝细胞内富含糖原颗粒和脂滴，线粒体和粗面内质网稀少，溶酶体较小且电子密度较低，高尔基复合体极少。出眠初期肝细胞内糖原颗粒和脂滴稀少，线粒体和粗面内质网丰富，溶酶体较大且电子密度较高，高尔基复合体增多。２．出眠初期肝脏有明细胞和暗细胞区分。３．冬眠期肝血窦内肝细胞表面的微绒毛数目明显少于出眠初期。４．冬眠期与出眠初期胆小管内肝细胞表面微绒毛数目之间差异不显著，但冬眠期肝小管细胞内富含糖原颗粒，出眠初期肝小管细胞内富含粗面内质网。上述结果提示：１．冬眠期肝细胞处于不活跃状态，出眠初期大部分肝细胞处于活跃状态。２．出眠初期肝细胞内溶酶体功能较冬眠期活跃，细胞内消化能力明显增强。３．出眠初期肝细胞与血液之间的交换能力较冬眠期强。４．肝细胞中的脂滴是冬眠中脂肪储备的一种重要形式，其在维持冬眠期物质与能量消耗方面有重要意义。

关键词：无蹼壁虎冬眠肝脏比较细胞学