期刊文献+
共找到424篇文章
< 1 2 22 >
每页显示 20 50 100
水平共形映射和调和Morphism 被引量:1
1
作者 莫小欢 《数学年刊(A辑)》 CSCD 北大核心 1996年第4期443-450,共8页
本文建立了Riemann流形之间水平共形映射之能量密度的基本公式.作为应用,得到了水平共形映射是水平相似映射的充要条件;分类了欧氏空间的开子集之间所有具有全测地纤维的水平共形映射;最后导出了由调和morphism的度量形变产生的水... 本文建立了Riemann流形之间水平共形映射之能量密度的基本公式.作为应用,得到了水平共形映射是水平相似映射的充要条件;分类了欧氏空间的开子集之间所有具有全测地纤维的水平共形映射;最后导出了由调和morphism的度量形变产生的水平共形映射力调和motphism的等价条件.因而改进和推广了Baird-Eells,Gudmundsson以及Baird的相应结果. 展开更多
关键词 水平共形映射 调和morphism 黎曼流形
下载PDF
到欧氏空间的调和Morphisms的分类
2
作者 傅吉祥 《数学年刊(A辑)》 CSCD 北大核心 1999年第3期361-364,共4页
本文使用了流形几何的方法,分类了从IR^m中开子集U到IR^n的水平相似的调和morphisms,作为推论,给出了Gudmundsson与Sigurdsson关于复欧氏空间的连通开子集之间的全纯调和morphisms的完全分类定理[8]的一个简单证明。
关键词 水平共形映射 调和morphism 分类 欧氏空间
下载PDF
Alteration of ERβ gene Rsal polymorphism may contribute to reduced fertilization rate and embryonic developmental competence
3
作者 Qiu-Fang Zhang Huai-Liang Feng +4 位作者 Lan Zhao Ping Liu Li Li Jie Yan Jie Qiao 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第2期317-321,共5页
This paper aims to determine the possible role of estrogen receptor-β (ERβ) gene Rsal polymorphism on sperm fertility and early embryonic development in humans. Three groups of Chinese men were recruited: in vitr... This paper aims to determine the possible role of estrogen receptor-β (ERβ) gene Rsal polymorphism on sperm fertility and early embryonic development in humans. Three groups of Chinese men were recruited: in vitro fertilization (IVF) group, including 374 couples who underwent conventional IVF; intracytoplasmic sperm injection (ICSI) group, including 294 couples who underwent an ICSI procedure using ejaculated sperm; and azoospermic group, consisting of 197 couples who underwent ICSI using either testis or epididymis sperm. Rsal polymorphism in the ERβ gene was detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism technique; fertilization and high-quality embryo rates were evaluated for each group. In each group, no significant differences were found in the overall rates of fertilization and high-quality embryos among GG, AG and AA genotypes. However, the proportion of cycles possessing a satisfactory high-quality embryo rate with the AA genotype was significantly lower than that in the wild-type GG genotype from each group. These results demonstrated that sperm possessing the ERβ RsalA genotype may have reduced fertilization ability and decreased early embryonic developmental potential, which could directly or indirectly contribute to the low fertilization rate and early embryonic developmental arrest in some cases. 展开更多
关键词 embryo development estrogen receptor-β gene FERTILIZATION intracytoplasmic sperm injection in vitro fertilization poly-morphism
下载PDF
Peroxisome Proliferator-activated Receptor-γ2 Pro12Ala and C-689T Polymorphisms and Haplotypes Affect the Profiles of Coronary Heart Disease in Diabetic Chinese People
4
作者 黎简平 程龙献 +1 位作者 何美安 邬堂春 《South China Journal of Cardiology》 CAS 2008年第1期1-9,共9页
Objectives Peroxisome proliferator-activated receptor-γ2(PPARγ2) variant Pro12Ala was demonstrated with risk of coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM). Another variant C-689T in the p... Objectives Peroxisome proliferator-activated receptor-γ2(PPARγ2) variant Pro12Ala was demonstrated with risk of coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM). Another variant C-689T in the promoter was reported with lower receptor activity but lack of reports on association between C-689T and CHD or T2DM. Methods A total of 351 subjects without CHD and T2DM (controls) and 125 patients with CHD and T2DM (cases) were enrolled in our case-control study. Polymerase chain reaction-restricted fragments length polymorphism (PCR-RFLP) was used to detect Pro12Ala and C-689T polymorphisms. And effects on CHD merged with T2DM of the two polymorphisms were analyzed in individual and haplotype analyses. Results In the study, Pro12Pro, Pro12Ala and Ala12Ala genotype frequencies were 92.9%, 6.8% and 0.3% in controls; 92.8%, 7.2% and 0.0% in cases respectively whilst CC, CT and TT genotype frequencies were 93.4%, 6.3% and 0.3% in controls; 92.8%, 7.2% and 0.0% in cases respectively. Pro12Ala and C-689T polymorphisms were in strong linkage disequilibrium (D'=0.81, P=0.000) and the observed haplotype frequency of Pro-C, Pro-T, Ala-C and Ala-T was 0.957, 0.006, 0.008 and 0.028 respectively. No significant associations were detected between the two polymorphisms and CHD merged with T2DM in either individual or haplotype analyses. In subjects with obesity [body mass index (BMI)≥25 kg/m^2], we found that both Pro12Ala and C-689T polymorphisms were associated with BMI. In haplotype analyses, we found that Pro12Ala and C-689T haplotypes had associations with systolic blood pressure in total population, with BMI, waist circle and total cholesterol(TC) in obesity subgroup and with fasting blood glucose and TC in males. Conclusions PPARγ2 Pro12Ala and C-689T polymorphisms and haplotypes affect the profiles of CHD merged with T2DM in Chinese Han people. 展开更多
关键词 peroxisome proliferator-activated receptor-γ2 coronary heart disease type 2 diabetes mellitus poly-morphism HAPLOTYPE
下载PDF
H pylori seropositivity and cytokine gene polymorphisms 被引量:5
5
作者 Yasuaki Saijo Eiji Yoshioka +4 位作者 Tomonori Fukui Mariko Kawaharada Fumihiro Sata Hirokazu Sato Reiko Kishi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第33期4445-4451,共7页
AIM: To investigate whether the pro- and anti-inflammatory cytokine gene polymorphisms, IL1B-511C/T, IL1B-31C/T, IL6-634C/G, TNF-1031T/C, TNF-857C/T, and IL10-1082A/G, interact with smoking and drinking habits to infl... AIM: To investigate whether the pro- and anti-inflammatory cytokine gene polymorphisms, IL1B-511C/T, IL1B-31C/T, IL6-634C/G, TNF-1031T/C, TNF-857C/T, and IL10-1082A/G, interact with smoking and drinking habits to influence infection with H pylori.METHODS: The subjects were 410 Japanese transit company employees. C-reactive protein and conventional cardiovascular risk factors were evaluated. Serum anti-H pylori antibodies were measured. The genotypes of IL1B-511C/T, IL1B-31C/T, IL6-634C/G, TNF-1031T/C, TNF-857C/T, and IL10-1082A/G polymorphisms were determined by allelic discrimination using fluorogenic probes and a 5′nuclease assay.RESULTS: In gender- and age-adjusted logistic analyses, the subjects with TNF-857T/T had a significantly lower odds ratio (OR) for H pylori seropositivity (reference -857C/C; OR = 0.15, 95% CI: 0.03-0.59, P = 0.007). After stratification according to smoking and drinking status, among never-smokers, the subjects with IL1B-511C/T had a significantly lower OR (reference -511C/C; OR = 0.30, 95% CI: 0.10-0.90, P = 0.032). Among drinkers in the 1-5 times/wk category, the subjects with IL1B-511T/T had a significantly lower OR (reference C/C; OR = 0.38, 95% CI: 0.16-0.95, P = 0.039), and the subjects with IL1B-31C/T and T/T had a significantly higher OR (reference C/C; C/T: OR = 2.59, 95% CI, P = 0.042: 1.04-6.47; C/C: OR = 3.17, 95% CI: 1.23-8.14, P = 0.017). Among current smokers, the subjects withIL6-634C/G had a significantly higher OR (reference C/C; OR = 2.28, 95% CI: 1.13-4.58, P = 0.021). However, the interactions terms between the aforementioned genotypes and lifestyles were not statistically significant.CONCLUSION: Contrary to previous findings, the results herein suggest that the TNF-857T/T genotype may be protective against chronic infection with H pylori. Drinking and smoking habits may influence the effect of cytokine gene polymorphisms. Further studies are required to clarify the effects of the pro- and anti-inflammatory cytokine polymorphisms and gene-environmental interactions on H pylori infection. 展开更多
关键词 细胞活素类 细胞 基因 医学研究
下载PDF
Linear Functional Equations and Twisted Polynomials
6
作者 Moumouni Djassibo Woba 《Journal of Applied Mathematics and Physics》 2024年第4期1459-1471,共13页
A certain variety of non-switched polynomials provides a uni-figure representation for a wide range of linear functional equations. This is properly adapted for the calculations. We reinterpret from this point of view... A certain variety of non-switched polynomials provides a uni-figure representation for a wide range of linear functional equations. This is properly adapted for the calculations. We reinterpret from this point of view a number of algorithms. 展开更多
关键词 Functional Equations Twisted Polynomials RINGS morphismS Euclidian Division
下载PDF
Preservation of Quasi-isomorphisms of Complexes
7
作者 Zhong Kui LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2012年第12期2489-2500,共12页
We consider the preservation property of the homomorphism and tensor product functors for quasi-isomorphisms and equivalences of complexes. Let X and Y be two classes of R-modules with Ext〉I(X,Y) = 0 for each objec... We consider the preservation property of the homomorphism and tensor product functors for quasi-isomorphisms and equivalences of complexes. Let X and Y be two classes of R-modules with Ext〉I(X,Y) = 0 for each object X ∈ X and each object Y ∈ Y. We show that if A,B ∈ C^(R) are X-complexes and U, V ∈ Cr(R) are Y-complexes, then U V Hom(A, U) Hom(A, Y); A B Hom(B, U) Hom(A, U). As an application, we give a sufficient condition for the Hom evaluation morphism being invertible. 展开更多
关键词 Quasi-isomorphism equivalence derived functor Gorenstein homological dimension Hom evaluation morphism
原文传递
高血压药物基因多态性分析对安徽皖南地区高血压患者个体化治疗的参考价值
8
作者 万淑君 张梦莹 +4 位作者 陈其雷 钟民 朱小龙 张莺莺 吕坤 《中国临床药理学与治疗学》 CAS CSCD 北大核心 2024年第1期68-75,共8页
目的:分析皖南地区高血压患者β受体阻滞剂、血管紧张素受体拮抗剂(ARB)、血管紧张素转换酶抑制剂(ACEI)、钙离子拮抗剂及利尿剂药物基因多态性分布频率,为高血压药物基因检测工作和个性化用药提供理论依据。方法:搜集2021年7月至2023年... 目的:分析皖南地区高血压患者β受体阻滞剂、血管紧张素受体拮抗剂(ARB)、血管紧张素转换酶抑制剂(ACEI)、钙离子拮抗剂及利尿剂药物基因多态性分布频率,为高血压药物基因检测工作和个性化用药提供理论依据。方法:搜集2021年7月至2023年4月皖南医学院弋矶山医院839例高血压住院患者药物基因检测信息,分析各基因位点分布频率。结果:ACE(I/D)I/I、I/D及D/D基因型频率分别为42.1%、46.0%、11.9%;肾上腺素能受体β1(ADRB1)(1165G>C)G/G、G/C及C/C基因型频率分别为8.3%、40.0%、51.6%;血管紧张素Ⅱ受体1(AGTR1)(1166A>C)A/A、A/C及C/C基因型频率分别为90.2%、9.8%、0.0%;CYP2C9*3(1075A>C)*1/*1、*1/*3及*3/*3基因型频率分别为91.3%、8.7%、0.0%;CYP2D6*10(100C>T)*1/*1、*1/*10及*10/*10基因型频率分别为25.0%、36.6%、38.4%;CYP3A5*3(6986A>G)*1/*1、*1/*3及*3/*3基因型频率分别为7.0%、39.0%、54.0%;钠尿肽前体蛋白A(NPPA)(2238T>C)T/T、T/C及C/C基因型频率分别为97.9%、2.1%、0.0%。此外,皖南地区多个药物相关基因位点基因型分布频率与中国其他地区存在统计学差异(P<0.05)。结论:皖南地区高血压药物相关基因位点基因型分布频率具有一定偏向性,且与中国其他地区相比存在统计学差异,提示开展高血压药物基因多态性检测对皖南地区高血压药物个体化应用具有一定指导意义。 展开更多
关键词 高血压药物 药物代谢酶基因 药物作用靶点基因 基因多态性 个体化用药
下载PDF
Single Nucleotide Polymorphism Identification in Polyploids: A Review, Example, and Recommendations 被引量:16
9
作者 Josh Clevenger Carolina Chavarro +2 位作者 Stephanie A. Pearl Peggy Ozias-Akins Scott A. Jackson 《Molecular Plant》 SCIE CAS CSCD 2015年第6期831-846,共16页
Understanding the relationship between genotype and phenotype is a major biological question and being able to predict phenotypes based on molecular genotypes is integral to molecular breeding. Whole- genome duplicati... Understanding the relationship between genotype and phenotype is a major biological question and being able to predict phenotypes based on molecular genotypes is integral to molecular breeding. Whole- genome duplications have shaped the history of all flowering plants and present challenges to elucidating the relationship between genotype and phenotype, especially in neopolyploid species. Although single nucleotide polymorphisms (SNPs) have become popular tools for genetic mapping, discovery and appli- cation of SNPs in polyploids has been difficult. Here, we summarize common experimental approaches to SNP calling, highlighting recent polyploid successes. To examine the impact of software choice on these analyses, we called SNPs among five peanut genotypes using different alignment programs (BWA-mem and Bowtie 2) and variant callers (SAMtools, GATK, and Freebayes). Alignments produced by Bowtie 2 and BWA-mem and analyzed in SAMtools shared 24.5% concordant SNPs, and SAMtools, GATK, and Freebayes shared 1.4% concordant SNPs. A subsequent analysis of simulated Brassica napus chromosome 1A and 1C genotypes demonstrated that, of the three software programs, SAMtools performed with the highest sensitivity and specificity on Bowtie 2 alignments. These results, however, are likely to vary among species, and we therefore propose a series of best practices for SNP calling in polyploids. 展开更多
关键词 GENOMICS homeolog next-generation sequencing (NGS) PEANUT polyptoid single nucleotide poly-morphism (SNP)
原文传递
Some Properties of Morphisms in Effect Algebras 被引量:4
10
作者 ZHANG Jian Cheng WANG Guo Jun 《Journal of Mathematical Research and Exposition》 CSCD 2009年第2期219-226,共8页
In the present paper the properties of morphisms in effect algebras are discussed. The conditions for the morphisms in effect algebras to be join-preservation and meet-preservation are given. From the categorical poin... In the present paper the properties of morphisms in effect algebras are discussed. The conditions for the morphisms in effect algebras to be join-preservation and meet-preservation are given. From the categorical point of view, some properties of ideals, filters and congruence relations under morphisms are obtained. 展开更多
关键词 effect algebra effect morphism IDEAL CONGRUENCE adjoint functor.
下载PDF
The Automorphism Group of Green Algebra of 9-Dimensional Taft Hopf Algebra 被引量:1
11
作者 Ruju Zhao Chengtao Yuan Libin Li 《Algebra Colloquium》 SCIE CSCD 2020年第4期767-798,共32页
Let H3 be the 9-dimensional Taft Hopf algebra,let r(H3)be the corresponding Green ring of H3,and let Aut(R(H3))be the automorphism group of Green algebra R(H3)=R■Zr(H3)over the real number fieldR.We prove that the qu... Let H3 be the 9-dimensional Taft Hopf algebra,let r(H3)be the corresponding Green ring of H3,and let Aut(R(H3))be the automorphism group of Green algebra R(H3)=R■Zr(H3)over the real number fieldR.We prove that the quotient group Aut(R(H3))/T1 is isomorphic to the direct product of the dihedral group of order 12 and the cyclic group of order 2,where T1 is the isomorphism class which contains the identity map and is isomorphic to a group G={(c,d)∈R^(2)∣∣(c,d)≠(−1/3,−1/6)}with multiplication given by(c1,d1)⋅(c2,d2)=(c1+c2+2c1c2−4d1d2+2c1d2+2d1c2,d1+d2−2c1c2−2d1d2+4c1d2+4d1c2). 展开更多
关键词 auto morphism group Green ring Green algebra 9-dimensional Taft Hopf algebra
原文传递
Automorphism Groups of Some Finite p-Groups 被引量:1
12
作者 Heguo Liu Yulei Wang 《Algebra Colloquium》 SCIE CSCD 2016年第4期623-650,共28页
The automorphism group of G is determined, where G is a nonabelian p-group given by a central extension as 1→Zpm→G→Zp×…×Zp→1 such that its derived subgroup has order p.
关键词 generalized extraspecial p-group symplectic space orthogonal space auto-morphism central extension
原文传递
(n,d)-(Ext)-phantom态射与(n,d)-环
13
作者 余君丽 张春霞 《中山大学学报(自然科学版)(中英文)》 CAS CSCD 北大核心 2024年第1期154-165,共12页
引入了(n,d)-phantom态射与(n,d)-Ext-phantom态射的概念.利用它们,给出了(n,d)-环、n-遗传环以及n-正则环的一系列新刻画.
关键词 (n d)-phantom态射 (n d)-Ext-phantom态射 n-凝聚环 (n d)-环 n-遗传环
下载PDF
循环纯phantom态射
14
作者 魏敏敏 赵仁育 《吉林大学学报(理学版)》 CAS 北大核心 2024年第2期249-255,共7页
通过引入循环纯phantom态射的概念,给出循环纯phantom态射的一些等价刻画,证明每个R-模都有核为循环纯内射模的满的循环纯phantom覆盖,并讨论循环纯phantom预覆盖在环变换下的传递性.
关键词 循环纯 循环纯phantom态射 预覆盖
下载PDF
Harmonic polynomial morphisms between Euclidean spaces
15
作者 唐梓洲 《Science China Mathematics》 SCIE 1999年第6期570-576,共7页
Two non-existence theorems on harmonic polynomial morphisms between Euclidean spaces have been
关键词 HARMONIC morphism NONSINGULAR MULTILINEAR map isoparametric polynomial.
原文传递
Finite morphisms of projective and K■hler manifolds
16
作者 Thomas PETERNELL 《Science China Mathematics》 SCIE 2008年第4期685-694,共10页
In this paper we study finite morphisms of projective and compact K■hler manifolds, in particular,positivity properties of the associated vector bundle,deformation theory and ramified endomorphisms.
关键词 FINITE morphism deformation GALOIS covering ample vector BUNDLE Fano manifold
原文传递
Bernstein theorem for harmonic morphisms from (N + 1)-sphere to N- manifold
17
作者 DONG YuxinDepartment of Mathematics, Hangzhou University, Hangzhou 310028, China 《Chinese Science Bulletin》 SCIE EI CAS 1997年第1期11-14,共4页
morphism. Harmonic morphisms may be characterized as harmonic mappings which are horizontally weakly conformal. In recent years a substantial progress has been made in the field of harmonic morphism, for example, refs... morphism. Harmonic morphisms may be characterized as harmonic mappings which are horizontally weakly conformal. In recent years a substantial progress has been made in the field of harmonic morphism, for example, refs. [ 3—7]. In ref. [4], Baird and Wood proved the following: (ⅰ) Any non-constant harmonic morphism from (S^3, g_(can)) to a Riemann 展开更多
关键词 harmonic morphism HOPF FIBRATION geodesic.
原文传递
Frobenius morphisms and stable module categories of repetitive algebras
18
作者 DENG BangMing WAN JinKui 《Science China Mathematics》 SCIE 2008年第2期169-184,共16页
Let k be the algebraic closure of a finite field F_q and A be a finite dimensional k-algebra with a Frobenius morphism F.In the present paper we establish a relation between the stable module category of the repetitiv... Let k be the algebraic closure of a finite field F_q and A be a finite dimensional k-algebra with a Frobenius morphism F.In the present paper we establish a relation between the stable module category of the repetitive algebra of A and that of the repetitive algebra of the fixed-point algebra A^F.As an application,it is shown that the derived category of A^F is equivalent to the subcategory of F-stable objects in the derived category of A when A has a finite global dimension. 展开更多
关键词 FROBENIUS morphism REPETITIVE algebra STABLE MODULE CATEGORY derived CATEGORY
原文传递
The morphism induced by Frobenius push-forward
19
作者 LI LingGuang 《Science China Mathematics》 SCIE 2014年第1期61-67,共7页
Let X be a smooth projective curve of genus g 2 over an algebraically closed field k of characteristic p>0,and F:X→X(1)the relative Frobenius morphism.Let M s X(r,d)(resp.M ss X(r,d))be the moduli space of(resp.se... Let X be a smooth projective curve of genus g 2 over an algebraically closed field k of characteristic p>0,and F:X→X(1)the relative Frobenius morphism.Let M s X(r,d)(resp.M ss X(r,d))be the moduli space of(resp.semi-)stable vector bundles of rank r and degree d on X.We show that the set-theoretic map S ss Frob:M ss X(r,d)→M ss X(1)(rp,d+r(p-1)(g-1))induced by[E]→[F(E)]is a proper morphism.Moreover,the induced morphism S s Frob:M s X(r,d)→M s X(1)(rp,d+r(p-1)(g-1))is a closed immersion.As an application,we obtain that the locus of moduli space M s X(1)(p,d)consisting of stable vector bundles whose Frobenius pull backs have maximal Harder-Narasimhan polygons is isomorphic to the Jacobian variety Jac X of X. 展开更多
关键词 FROBENIUS morphism stable vector bundle moduli space stratification
原文传递
On the Construction of p-Harmonic Morphisms and Conformal Actions
20
作者 Xiao Huan MO Li Bing HUANG Yuan Zheng ZHANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2007年第8期1475-1484,共10页
We produce p-harmonic morphisms by conformal foliations and Clifford systems. First, we give a useful criterion for a foliation on an m-dimensional Riemannian manifold locally generated by conformal fields to produce ... We produce p-harmonic morphisms by conformal foliations and Clifford systems. First, we give a useful criterion for a foliation on an m-dimensional Riemannian manifold locally generated by conformal fields to produce p-harmonic morphisms. By using this criterion we manufacture conformal foliations, with codimension not equal to p, which are locally the fibres of p-harmonic morphisms. Then we give a new approach for the construction of p-harmonic morphisms from R^m/{0} to R^n. By the well-known representation of Clifford algebras, we find an abundance of the new 2/3 (m + 1)-harmonic morphism Ф: R^m/{0} → R^n where m = 2κδ(n - 1). 展开更多
关键词 p-harmonic morphism Clifford system homogeneous function conformal field
原文传递
上一页 1 2 22 下一页 到第
使用帮助 返回顶部