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C^*-代数中的无限正元
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作者 王琳 《青岛大学学报(自然科学版)》 CAS 2008年第2期10-13,共4页
讨论了判定C*-代数中的正元是无限元的几个等价条件,并且证明了E.Kirchkerg和M.Rordam给出的无限正元的定义在单C*-代数情形下与林华新给出的无限元定义是一致的。
关键词 C^*-代数 C^*-代数 无限正元 比较关系
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稳秩1C^*—代数的几个等价刻画
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作者 潘正君 《陕西师大学报(自然科学版)》 CSCD 1991年第2期16-18,21,共4页
引入酉分解元的概念,给出稳秩1C~*-代数的几个等价刻画,部分回答了D.Handelman的一个问题,并证明了任何稳定有限的单C~*-代数皆可嵌人到具稳秩1的C~*-代数之中。
关键词 C^*-代数 稳秩1 酉分解元
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A C-Band Monolithic GaAs PIN Diode SPST Switch
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作者 吴茹菲 张健 +1 位作者 尹军舰 张海英 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第5期879-882,共4页
A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an... A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an on-state insertion loss of less than 1.6dB and a return loss of greater than 10dB while maintaining an off-state isolation of greater than 23dB from 5.5 to 7. 5GHz. The measured 1dB power gain compression point is about 20dBm. 展开更多
关键词 C-BAND SPST switches OaAs PIN diodes
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Uniform B-C-N Ternary Monolayer from Non-Metal Filled g-C3N4 Sheet
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作者 张娜 武晓群 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第4期394-398,J0001,共6页
By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are... By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are metallic except for B4-C3N4 monolayer, which is a semiconductor with an energy band gap of 1.18 eV. In particular, the BnC-C3N4 is a ferromagnetic metal with a net magnetic moment of 0.57 μB/cell, which can be used to develop metal-free spintronic device. The calculated formation energy indicates these B-C-N ternary sheets are highly thermal stable. It presents a new route to obtain uniform B-C-N ternary sheet for electronic and spintronic applications. 展开更多
关键词 Density functional theory B-C-N ternary monolayer g-C3N4
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Adalimumab in prevention of postoperative recurrence of Crohn's disease in high-risk patients 被引量:3
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作者 Mariam Aguas Guillermo Bastida +7 位作者 Elena Cerrillo Belén Beltrán Marisa Iborra Cristina Sánchez-Montes Fernando Muoz Jesús Barrio Sabino Riestra Pilar Nos 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第32期4391-4398,共8页
AIM:To evaluate the effectiveness of adalimumab in preventing recurrence after intestinal resection for Crohn's disease in high-risk patients.METHODS:A multicenter,prospective,observational study was conducted fro... AIM:To evaluate the effectiveness of adalimumab in preventing recurrence after intestinal resection for Crohn's disease in high-risk patients.METHODS:A multicenter,prospective,observational study was conducted from June 2009 until June 2010.We consecutively included high-risk Crohn's disease patients who had undergone an ileal/ileocolonic resection.High-risk patients were defined as two or more criteria:smokers,penetrating pattern,one or more previous surgical resections or prior extensive resection.Subcutaneous adalimumab was administered 2 wk(± 5 d) after surgery at a dose of 40 mg eow,with an initial induction dose of 160/80 mg at weeks 0 and 2.Demographic data,previous and concomitant treatments(antibiotics,5-aminosalicylates,corticosteroids,immunomodulators or biologic therapies),smoking status at the time of diagnosis and after the index operation and number of previous resections(type and reason for surgery) were all recorded.Biological status was assessed with C-reactive protein,erythrocyte sedimentation rate and fecal calprotectin.One year(± 3 mo) after surgery,an ileocolonoscopy and/or magnetic resonance enterography was performed.Endoscopic recurrence was defined as Rutgeerts score ≥ i2.Morphological recurrence was based on magnetic resonance(MR) score ≥ MR1.RESULTS:Twenty-nine patients(55.2% males,48.3% smokers at diagnosis and 13.8% after the index operation),mean age 42.3 years and mean duration of the disease 13.8 years were included in the study.A mean of 1.76(range:1-4) resections previous to adalimumab administration and in 37.9% was considered extensive resection.51.7% had previously received infliximab.Immunomodulators were given concomitantly to 17.2% of patients.Four of the 29(13.7%) developed clinical recurrence,6/29(20.7%) endoscopic recurrence and 7/19(36.8%) morphological recurrence after 1-year.All patients with clinical recurrence showed endoscopic and morphological recurrence.A high degree of concordance was found between clinical-endoscopic recurrence(k = 0.76,P < 0.001) and clinical-morphological recurrence(k = 0.63,P = 0.003).Correlation between endoscopic and radiological findings was good(comparing the 5-point Rutgeerts score with the 4-point MR score,a score of i4 was classified as MR3,i3 as MR2,and i2-i1 as MR1)(P < 0.001,r s = 0.825).During follow-up,five(17.2%) patients needed adalimumab dose intensification(40 mg/wk);Mean time to intensification after the introduction of adalimumab treatment was 8 mo(range:5 to 11 mo).In three cases(10.3%),a biological change was needed due to a worsening of the disease after the dose intensification to 40 mg/wk.One patient suffered an adverse event.CONCLUSION:Adalimumab seems to be effective and safe in preventing postoperative recurrence in a selected group of patients who had undergone an intestinal resection for their CD. 展开更多
关键词 Crohn's disease Postoperative recurrence Prevention Tumor necrosis factor alpha agents Adalimumab
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Broadband MMIC Power Amplifier for C-X-Ku-Band Applications
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作者 张书敬 杨瑞霞 +2 位作者 张玉清 高学邦 杨克武 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第6期829-832,共4页
A three-stage MMIC power amplifier operating from 6to 18GHz is fabricated using 0.25μm A1GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor(PHEMT).The amplifier isfully monolithic,with all matching,bi... A three-stage MMIC power amplifier operating from 6to 18GHz is fabricated using 0.25μm A1GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor(PHEMT).The amplifier isfully monolithic,with all matching,biasing,and DC block circuitry included on the chip.Thepower amplifier has an average power gain of 19dB over 6~18GHz.At operation frequenciesfrom 6 to 18GHz,the output power is above 33.3dBm,and the maximum output power of the MMICis 34.7dBm at 10Ghz.The input return loss is less than-10db and the out-put return is lessthan-6dB over operating frequency.This power amplifier has,to our knowledge,the best powergain flatness reported at C-X-Ku-band applications. 展开更多
关键词 High electron mobility transistors Monolithic microwave integrated circuits Semiconducting gallium arsenide
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Synthesis and Crystal Structure of Bis(nitrate)- bis(N,N'-dimethyl-N,N'-dibenzenyl-urea)uranyl(Ⅱ) 被引量:1
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作者 ZHU Li-Ming LI Bao-Long② CAO Zheng-Bai ZHANG Yong (College of Chemistry and Chemical Engineering, Suzhou University, Suzhou 215006, China) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2003年第5期521-524,共4页
The new uranyl complex UO2(NO3)2[PhN(CH3)C(O)(CH3)NPh]2 was synthesized and its crystal structure has been determined by single-crystal X-ray diffraction. Crystal data: C30H32N6O10U, triclinic, space group P with a = ... The new uranyl complex UO2(NO3)2[PhN(CH3)C(O)(CH3)NPh]2 was synthesized and its crystal structure has been determined by single-crystal X-ray diffraction. Crystal data: C30H32N6O10U, triclinic, space group P with a = 7.772(1), b = 9.267(1), c = 12.644(1) ? a = 68.246(8), b = 73.871(9), g = 84.99(1)o, V = 812.4(2) ?, Mr = 874.65, Z = 1, Dc = 1.788 g/cm3, F(000) = 426, m = 5.062 mm-1, the final R = 0.022 and wR = 0.059 for 3571 observed reflections (I > 2s(I)). The central uranyl ion is coordinated by six oxygen atoms, two from the carbonyl groups of N,N-dimethyl-N,N-dibenzenyl-urea molecules and the other four from two nitrate groups. 展开更多
关键词 substituted urea uranyl complex synthesis crystal structure
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Study on the ultraviolet-visible spectral feature of tobacco leaves by pattern recognition
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作者 RUAN Chun-sheng XU Chang-liang +5 位作者 ZHANG Ge FAN Jing LI Yu-zhong WANG Xiao-xia FANG Li CHEN Sui-yun 《Journal of Life Sciences》 2009年第9期34-42,53,共10页
In order to differentiate regions, varieties, and parts of tobacco leaves, two pattern recognition methods through pattern classification modeling were developed based on the comprehensive information of ultraviolet-v... In order to differentiate regions, varieties, and parts of tobacco leaves, two pattern recognition methods through pattern classification modeling were developed based on the comprehensive information of ultraviolet-visible spectroscopy (UV-VIS) by employing one-way analysis of variance (ANOVA1) and wave range random combination (WRRC) technology from MATLAB. This proposed classification method has never been reported previously and the instrument and operation for this method is much more convenient and efficient than previous reported classification methods. The result of this paper demonstrated that the spectral features extracted by ANOVAI and WRRC methods could be used to differentiate tobacco leaves with different patterns. The ANOVAI method had a training recognition rate range of 75.00-87.50%,4 and a validation recognition rate range of 57.14-100%. The WRRC method had a training recognition rate range of 75.00-94.12% and a validation recognition rate range of 66.67-100%. The ANOVAI method is more convenient and efficient in model developing, while the WRRC method utilizes fewer model variables and is more robust. 展开更多
关键词 Nicotiana tabacum ultraviolet-visible spectroscopy (UV-VIS) pattern recognition spectral feature DIFFERENTIATION
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Hapseeker:A C++ Program for Analyzing Haplotype
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作者 谌平 郑伟 王留阳 《Agricultural Science & Technology》 CAS 2009年第3期1-2,6,共3页
The C++ program: Hapseeker was developed to analyze DNA or RNA sequence, besides, Hapseeker could be used to identify haplotype, calculate frequency of each haplotype as well as find variable site quickly. Moreover, H... The C++ program: Hapseeker was developed to analyze DNA or RNA sequence, besides, Hapseeker could be used to identify haplotype, calculate frequency of each haplotype as well as find variable site quickly. Moreover, Hapseeker had many advantages such as simple operation, rapid running speed and high accuracy. 展开更多
关键词 Hapseeker Hapseeker C Variable site
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SELECTION OF NEW EPITOPES FROM MONOVALENT DISPLAYED PHAGE OCTAPEPTIDE LIBRARY
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作者 李全喜 王琰 +4 位作者 李竞 王雅明 徐建军 王力民 董志伟 《Chinese Medical Sciences Journal》 CAS CSCD 1998年第1期1-8,共8页
A library of 2 ×107 random octapeptides was constructed by use of phagemid-based monovalent phage display system. The randomly synthesized degenerated oligodeoxyribonucleotides (oligos ) were fused to the truncat... A library of 2 ×107 random octapeptides was constructed by use of phagemid-based monovalent phage display system. The randomly synthesized degenerated oligodeoxyribonucleotides (oligos ) were fused to the truncated g Ⅲ (p230-p403). Sequence analysis of 11 randomly chosen clones suggested that the degenerated inserts and its deduced amino acid (aa) sequences are randomly distributed. The library was used to select binding peptides to the monoclonal antibody (mAb) 9E10, which recognizes a continuous decapeptide epi- tope of denatured human c-myc protein. After four to five rounds of panning, most of the eluted clones could bind to 9E10. Sequence analysis of the selected positive clones indicated that the binding sequences could fall into two classes, one class (clone 1) shares a consensus motif, ISE x x L, with c-myc decapeptide; and the sequences of the other class are entirely different. The binding of both classes to 9E10 could be specifically inhibited by free c-myc decapeptide. The immunogenicity of the phage peptide was further investigated by construction of multivalent displayed phage peptides and immunization of animals with or without adjuvant. ELISA and competitive ELISA showed that anti-serum from both mice and rabbit immunized with either clone could bind to the original antigen, c-myc decapeptide. These results denote that in spite of the dissimilarity of the selected peptides with c-myc decapeptide, they are capable of inducing similar immune respones in vivo, thus actually mimicking the antigen epitope. 展开更多
关键词 monovalent phage display peptide library epitope mimicry
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Cuntz代数的可遗传C*-子代数
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作者 刘树冬 方小春 魏常果 《数学学报(中文版)》 SCIE CSCD 北大核心 2009年第5期969-974,共6页
本文讨论了Cuntz代数的可遗传C^*-子代数.给出了Cuntz代数的在同构意义下所有的可遗传C^*-子代数,完整解答了Cuntz代数上的矩阵代数的同构问题,并讨论了某些纯无限单的C^*-代数的可遗传C^*-子代数.
关键词 Cuntz代数 纯无限C^*-代数 可遗传C^*-子代数
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Reaction kinetics and phase behavior in the chemoselective hydrogenation of 3‐nitrostyrene over Co‐N‐C single‐atom catalyst in compressed CO_(2)
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作者 Dan Zhou Leilei Zhang +5 位作者 Wengang Liu Gang Xu Ji Yang Qike Jiang Aiqin Wang Jianzhong Yin 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第9期1617-1624,共8页
Single‐atom catalysts(SACs)have demonstrated excellent performances in chemoselective hydrogenation reactions.However,the employment of precious metals and/or organic solvents compromises their sustainability.Herein,... Single‐atom catalysts(SACs)have demonstrated excellent performances in chemoselective hydrogenation reactions.However,the employment of precious metals and/or organic solvents compromises their sustainability.Herein,we for the first time report the chemoselective hydrogenation of 3‐nitrostyrene over noble‐metal‐free Co‐N‐C SAC in green solvent—compressed CO2.An interesting inverted V‐curve relation is observed between the catalytic activity and CO2 pressure,where the conversion of 3‐nitrostyrene reaches the maximum of 100%at 5.0 MPa CO2(total pressure of 8.1 MPa).Meanwhile,the selectivities to 3‐vinylaniline at all pressures remain high(>99%).Phase behavior studies reveal that,in sharp contrast with the single phase which is formed at total pressure above 10.8 MPa,bi‐phase composed of CO2/H_(2)gas‐rich phase and CO2‐expanded substrate liquid phase forms at total pressure of 8.1 MPa,which dramatically changes the reaction kinetics of the catalytic system.The reaction order with respect to H_(2)pressure decreases from~0.5 to zero at total pressure of 8.1 MPa,suggesting the dissolved CO2 in 3‐nitrostyrene greatly promotes the dissolution of H_(2)in the substrate,which is responsible for the high catalytic activity at the peak of the inverted V‐curve. 展开更多
关键词 Single‐atom catalyst Co‐N‐C CO2 Phase behavior Chemoselective hydrogenation 3‐Nitrostyrene
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某些C*-代数上的2-局部映射
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作者 于静 方小春 范庆斋 《数学进展》 CSCD 北大核心 2009年第3期289-294,共6页
讨论了单C*代数上的2-局部等距的线性;在证明某些C*代数上的2-局部自同构是线性的同时,根据C*代数的K-理论,给出了满足此结果的C*代数例子.
关键词 2-局部等距 2-局部自同构 C^*- 代数
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Bivariate genome-wide association study suggests that the DARC gene influences lean body mass and age at menarche
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作者 HAI Rong ZHANG Lei +7 位作者 PEI YuFang ZHAO LanJuan RAN Shu HAN YingYing ZHU XueZhen SHEN Hui TIAN Qing DENG HongWen 《Science China(Life Sciences)》 SCIE CAS 2012年第6期516-520,共5页
Lean body mass (LBM) and age at menarche (AAM) are two important complex traits for human health. The aim of this study was to identify pleiotropic genes for both traits using a powerful bivariate genome-wide asso... Lean body mass (LBM) and age at menarche (AAM) are two important complex traits for human health. The aim of this study was to identify pleiotropic genes for both traits using a powerful bivariate genome-wide association study (GWAS). Two stud- ies, a discovery study and a replication study, were performed. In the discovery study, 909622 single nucleotide polymor- phisms (SNPs) were genotyped in 801 unrelated female Han Chinese subjects using the Affymetrix human genome-wide SNP array 6.0 platform. Then, a bivariate GWAS was performed to identify the SNPs that may be important for LBM and AAM. In the replication study, significant findings from the discovery study were validated in 1692 unrelated Caucasian female subjects One SNP rs3027009 that was bivafiately associated with left arm lean mass and AAM in the discovery samples (P=7.26x10-6) and in the replication samples (P=0.005) was identified. The SNP is located at the upstream of DARC (Duffy antigen receptor for chemokines) gene, suggesting that DARC may play an important role in regulating the metabolisms of both LBM and AAM. 展开更多
关键词 bivariate genome-wide association study age at menarche lean body mass DARC gene
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Roles of flanking sequences in the binding between unimolecular parallel-stranded G-quadruplexes and ligands
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作者 GAI Wei YANG QianFan +8 位作者 XIANG JunFeng SUN HongXia SHANG Qian LI Qian JIANG Wei GUAN AiJiao ZHANG Hong TANG YaLin XU GuangZhi 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第3期731-740,共10页
G-quadruplexes attract more and more attention in recent years.Numerous small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug developmen... G-quadruplexes attract more and more attention in recent years.Numerous small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug development.As a motif existed in physiological condition,flanking sequences are an important part of G-quadruplexes but the study on the impact of flanking sequences on (G-quadruplex)-ligand binding is rarely reported.In this paper,the effects of flanking sequences on binding affinity between a series of unimolecular parallel-stranded G-quadruplex sequences derived from c-myc oncogene promoter (termed as c-myc G-quadruplexes) and their ligands are discussed in detail.The results showed that the flanking sequences on c-myc G-quadruplexes play key roles in (G-quadruplex)-ligand interaction.When a c-myc G-quadruplex is bound to its ligands,the flanking sequences might form a binding cavity above the terminal G-quartet,which could provide a suitable site for ligands to dock in.Moreover,the bases on flanking sequences could interact with ligand through π-π stacking,and finally form a sandwich-stacking mode (terminal G-quartet,ligand and bases on the flanking sequence).This mode could stabilize the (G-quadruplex)-ligand complex effectively and enhance the binding affinity dramatically.However,flanking sequences are also found to exhibit steric hindrance effect which could impede the (G-quadruplex)-ligand binding. 展开更多
关键词 G-QUADRUPLEX flanking sequences interaction mechanism C-MYC cyanine dye
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Single-molecule-force spectroscopy study of the mechanism of interactions between TSP-1 and CD47
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作者 PAN Yan Gang WANG Feng +2 位作者 LIU Yan Hou YANG Yong-Guang WANG Hong Da 《Science China Chemistry》 SCIE EI CAS 2014年第12期1716-1722,共7页
The 4N1K peptide,which is derived from the C-terminal domain of thrombospondin-1(TSP-1),is usually used as a functional mimic peptide for TSP-1.Knowledge about the interaction force of 4N1K/CD47 is important in explai... The 4N1K peptide,which is derived from the C-terminal domain of thrombospondin-1(TSP-1),is usually used as a functional mimic peptide for TSP-1.Knowledge about the interaction force of 4N1K/CD47 is important in explaining how TSP-1 affects the biological effect of CD47.Here we used a single-molecule force spectroscopy(SMFS)technique to explore the interaction of 4N1K/CD47 on both normal and oxidative human red blood cells(h RBCs)at single-molecule level.There was no interaction force between 4N1K and CD47 on normal h RBCs;however,we did find 4N1K-bound CD47 on oxidative h RBCs.We also detected interaction forces for 4N1K/CD47ex(extracellular domain of human CD47),and 4N1K/oxidative CD47ex.The interaction forces of 4N1K/CD47ex were almost consistent with those of 4N1K/oxidative CD47ex at the same loading rate.These results suggest that the conformational change of CD47 is critical for 4N1K-CD47 interaction on oxidative h RBCs. 展开更多
关键词 TSP-1 CD47 h RBCs single-molecule force spectroscopy
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C_∞ Compactness for Minimal Submanifolds in the Unit Sphere 被引量:1
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作者 徐森林 梅加强 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2003年第2期191-198,共8页
In this paper we study the C3 compactness for minimal submanifolds in the unit sphere. We obtain two compactness theorems. As an application, we prove that there is a positive number δ(n), such that if the square of ... In this paper we study the C3 compactness for minimal submanifolds in the unit sphere. We obtain two compactness theorems. As an application, we prove that there is a positive number δ(n), such that if the square of the length of the second fundamental form of a minimal subrnanifold in the unit sphere is less than 2n/3+δ(n), it must be totally geodesic or diffeomorphic to a Veronese surface. 展开更多
关键词 minimal submanifold totally geodesic compactness theorem.
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