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Visible Light Catalyzed Reductive Cross-Coupling of α-CF_(3)-alkyl Bromide and Alkynyl Bromide
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作者 Yiqiang Tian Yi Li Chun Zhang 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第20期2479-2484,共6页
Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis.Here,we introduce the development of a visible-light catalytic direct reduction coupling reaction between α-CF_(3)... Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis.Here,we introduce the development of a visible-light catalytic direct reduction coupling reaction between α-CF_(3)-alkyl bromides and alkynyl bromides to access valuable organic frameworks.Our research confirms the excellent compatibility of this reaction with various functional groups,which could be used to modify the substrate with biologically active molecular fragments.Mechanistic investigations,including control experiments,fluorescence quenching studies,and light-switching experiments,have provided insights into the reaction mechanism.This study paves the way for the application of visible-light catalysis in diverse synthetic transformations,offering a sustainable and efficient approach to organic synthesis. 展开更多
关键词 Visiable light catalysis C-C bond formation reductive cross-coupling Trifluoromethyl group Alkynyl group Radicals Organohalides PHOTOCHEMISTRY
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Some infinite dimensional representations of reductive groups with Frobenius maps 被引量:3
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作者 XI NanHua 《Science China Mathematics》 SCIE 2014年第6期1109-1120,共12页
In this paper,we construct certain irreducible infinite dimensional representations of algebraic groups with Frobenius maps.In particular,a few classical results of Steinberg and Deligne&Lusztig on complex represe... In this paper,we construct certain irreducible infinite dimensional representations of algebraic groups with Frobenius maps.In particular,a few classical results of Steinberg and Deligne&Lusztig on complex representations of finite groups of Lie type are extended to reductive algebraic groups with Frobenius maps. 展开更多
关键词 infinite dimensional representation reductive group induced module
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Catalytic HgCl_2-Samarium System Induced Reductive Coupling of Nitriles with Nitro Compounds
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作者 JiMingZHANG YongMinZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第2期97-100,共4页
The intermolecular coupling of a nitro group with a cyano group mediated by a Sm(Hg) amalgam prepared from metal samarium powder and catalytic mercury dichloride was studied.
关键词 Mercury dichloride SAMARIUM reductive coupling nitro group cyano group amidine.
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CONJUGACY CLASSIFICATION CARTAN SUBGROUPS OF L-GROUPS
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作者 侯自新 《Chinese Science Bulletin》 SCIE EI CAS 1992年第1期6-8,共3页
Let G be a connected complex reductive algebraic groups. The dual group ~LG^0 of G is an algebraic group whose simple root system π~v is the dual of the simple root system π of G and whose characteristic lattice is ... Let G be a connected complex reductive algebraic groups. The dual group ~LG^0 of G is an algebraic group whose simple root system π~v is the dual of the simple root system π of G and whose characteristic lattice is just the dual lattice X_*(T) of the characteristic lattice X~*(T)of G, where T is a given maximal torus of G and the simple root system π corresponds to a Borel subgroup B containing T. For the detail of the definition of a dual group see Ref. [1]. 展开更多
关键词 reductive group L-group CARTAN subgroup.
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丹参酮IIA衍生物的合成 被引量:2
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作者 姚连琦 秦立玙 +1 位作者 李雯 刘德龙 《现代生物医学进展》 CAS 2018年第2期205-209,共5页
目的:丹参酮IIA是中药丹参的脂溶性成分,具有抗肿瘤、抗氧化、抗心脑血管疾病等多种生理活性。本文拟对其进行结构改造以获得活性更好的丹参酮IIA衍生物。方法:首先,以丹参酮IIA为原料,通过Vilsmeier反应在其16-位引入醛基,再与醋酸胺... 目的:丹参酮IIA是中药丹参的脂溶性成分,具有抗肿瘤、抗氧化、抗心脑血管疾病等多种生理活性。本文拟对其进行结构改造以获得活性更好的丹参酮IIA衍生物。方法:首先,以丹参酮IIA为原料,通过Vilsmeier反应在其16-位引入醛基,再与醋酸胺进行还原胺化反应,以较高收率得到16-位胺甲基取代的丹参酮IIA衍生物。接着,对其氨基进行修饰,得到10个不同N-取代的丹参酮IIA衍生物。同时考察反应温度、反应溶剂和反应时间等条件对还原胺化反应的影响,确定最佳反应条件。结果:通过1H-NMR、13C-NMR以及LC-MS对所有产物结构进行了确认。还原胺化反应的最佳反应条件为:以1,2-二氯乙烷为溶剂,温度保持40℃,反应时间为2h。结论:反应步骤简单、条件温和、产率较高,是合成16-位取代的丹参酮IIA衍生物的理想方法。 展开更多
关键词 丹参酮IIA 衍生物 还原胺化 胺甲基 合成
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代数几何和表示论的一些新进展
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作者 刘文飞 余世霖 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2023年第6期948-962,共15页
双有理几何在双有理等价意义下对射影代数簇及其推广射影偶进行分类,是代数几何中的一个主要研究方向.代数几何与表示论具有不可分割的紧密联系,辛奇点就是同时涉及到这两个领域的一个重要研究课题.本文在对双有理几何中的基本概念进行... 双有理几何在双有理等价意义下对射影代数簇及其推广射影偶进行分类,是代数几何中的一个主要研究方向.代数几何与表示论具有不可分割的紧密联系,辛奇点就是同时涉及到这两个领域的一个重要研究课题.本文在对双有理几何中的基本概念进行简短的介绍后,探讨了典范体积的分布及应用,该不变量在射影偶的有界性问题上发挥关键作用.介绍了辛奇点的形变及量子化,及其在表示论中的应用. 展开更多
关键词 对数一般型偶 有界性 典范体积 辛奇点 形变 半单群 约化群 幂零轨道 Harish-Chandra模 量子化 轨道方法
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约化群对约化型齐性空间的真作用
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作者 王瑜 李天增 《周口师范学院学报》 CAS 2010年第5期6-9,共4页
研究了约化群对约化型齐性空间G/H作用的真不连续性,通过实例G=SL(n,R),H=SL(m,R),L=SL(2,R)验证了L对齐性空间G/H作用是真不连续的.
关键词 约化群 约化型的齐性空间 真不连续
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Non-naturally reductive Einstein metrics on Sp(n) 被引量:1
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作者 Zhiqi CHEN Huibin CHEN 《Frontiers of Mathematics in China》 SCIE CSCD 2020年第1期47-55,共9页
We prove that Sp(2k+l)admits at least two non-naturally reductive Einstein metrics which are Ad(Sp(k)×Sp(k)×Sp(l))-invariant ifk<1.It implies that every compact simple Lie group Sp(n)for n≥4 admits at le... We prove that Sp(2k+l)admits at least two non-naturally reductive Einstein metrics which are Ad(Sp(k)×Sp(k)×Sp(l))-invariant ifk<1.It implies that every compact simple Lie group Sp(n)for n≥4 admits at least 2[(n-1)/3]non-naturally reductive left-invariant Einstein metrics. 展开更多
关键词 EINSTEIN METRIC non-naturally reductive METRIC RIEMANNIAN manifold Lie group
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The decomposition of permutation module for infinite Chevalley groups 被引量:1
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作者 Xiaoyu Chen Junbin Dong 《Science China Mathematics》 SCIE CSCD 2021年第5期921-930,共10页
Let G be a connected reductive group defined over F_q, the finite field with q elements. Let B be a Borel subgroup defined over F_q. In this paper, we completely determine the composition factors of the induced module... Let G be a connected reductive group defined over F_q, the finite field with q elements. Let B be a Borel subgroup defined over F_q. In this paper, we completely determine the composition factors of the induced module M(tr) = kG ■tr(where tr is the trivial B-module) for any field k. 展开更多
关键词 reductive group abstract representation permutation module flag variety
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群作用在复几何中的一些运用
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作者 GUAN Daniel 《Chinese Quarterly Journal of Mathematics》 2023年第3期254-275,共22页
In this article,we give a further survey of some progress of the applications of group actions in the complex geometry after my earlier survey around 2020,mostly related to my own interests.
关键词 Invariant structure Homogeneous space Fiber bundles Hermitian manifolds reductive Lie group Compact manifolds Chern class Co-homogeneity one Kahler manifolds
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On Some Recent Progress in Complex Geometry-the Area Related to Homogeneous Manifolds 被引量:1
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作者 GUAN Daniel 《Chinese Quarterly Journal of Mathematics》 2020年第2期111-144,共34页
In this article,we give a survey of some progress of the complex geometry,mostly related to the Lie group actions on compact complex manifolds and complex homogeneous spaces in the last thirty years.In particular,we e... In this article,we give a survey of some progress of the complex geometry,mostly related to the Lie group actions on compact complex manifolds and complex homogeneous spaces in the last thirty years.In particular,we explore some works in the special area in Di erential Geometry,Lie Group and Complex Homogeneous Space.Together with the special area in nonlinear analysis on complex manifolds,they are the two major aspects of my research interests. 展开更多
关键词 Invariant structure Homogeneous space Complex torus bundles Hermitian manifolds reductive Lie group Compact manifolds Ricci form Locally conformal Kahler manifolds
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GL_(2)(C)的一些不可约表示
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作者 陈晓煜 赖元旭 李支泽 《上海师范大学学报(自然科学版)》 2023年第3期295-302,共8页
设G=GL_(2)(C),并且B是G的标准Borel子群,并且CG,CB分别是群G和群B的在复数域C上的群代数.对于任意B的特征标θ,定义G的离散诱导模M(θ)=CG×CB^(θ).证明了当θ是反支配权时,M(θ)是个不可约表示.由此给出了一类GL_(2)(C)全新的、... 设G=GL_(2)(C),并且B是G的标准Borel子群,并且CG,CB分别是群G和群B的在复数域C上的群代数.对于任意B的特征标θ,定义G的离散诱导模M(θ)=CG×CB^(θ).证明了当θ是反支配权时,M(θ)是个不可约表示.由此给出了一类GL_(2)(C)全新的、无限维的不可约表示. 展开更多
关键词 简约群 朴素诱导模 Bruhat分解
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NEW NON-NATURALLY REDUCTIVE EINSTEIN METRICS ON Sp(n)
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作者 Shaoxiang ZHANG Huibin CHEN Shaoqiang DENG 《Acta Mathematica Scientia》 SCIE CSCD 2021年第3期887-898,共12页
In this paper, we consider a class of left invariant Riemannian metrics on Sp(n),which is invariant under the adjoint action of the subgroup Sp(n-3) × Sp(1) × Sp(1) × Sp(1).Based on the related formulae... In this paper, we consider a class of left invariant Riemannian metrics on Sp(n),which is invariant under the adjoint action of the subgroup Sp(n-3) × Sp(1) × Sp(1) × Sp(1).Based on the related formulae in the literature, we show that the existence of Einstein metrics is equivalent to the existence of solutions of some homogeneous Einstein equations. Then we use a technique of the Gr?bner basis to get a sufficient condition for the existence, and show that this method will lead to new non-naturally reductive metrics. 展开更多
关键词 Einstein metric non-naturally reductive metric compact Lie group symplectic group
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Spherical Tropical Geometry:a Survey of Recent Developments
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作者 Kiumars KAVEH Christopher MANON 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2018年第3期454-465,共12页
This is a survey of some recent results on spherical tropical geometry.
关键词 Tropical geometry reductive group action spherical variety Grbner theory
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大豆对SO_2的适应性反应 被引量:29
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作者 钱永常 余叔文 《植物生理学报(0257-4829)》 CSCD 1991年第3期232-238,共7页
受一定浓度SO_2熏气的大豆幼苗出现可见伤害以后,在继续熏气的过程中可见伤害程度不再进一步发展,表现出一定的适应性。与此相联系,膜透性增加和TTC还原力下降这两个SO_2伤害指标也得到一定程度的恢复,SO_2熏气使游离氨基酸含量增加,随... 受一定浓度SO_2熏气的大豆幼苗出现可见伤害以后,在继续熏气的过程中可见伤害程度不再进一步发展,表现出一定的适应性。与此相联系,膜透性增加和TTC还原力下降这两个SO_2伤害指标也得到一定程度的恢复,SO_2熏气使游离氨基酸含量增加,随着熏气时间延长,增加的游离氨基酸含量回到对照水平,提示受扰乱的代谢过程有所恢复。低浓度SO_2预处理提高了大豆对高浓度SO_2的抗性,与抗氧化有关的巯基(-SH)含量显著增加,超氧物歧化酶(SOD)活性也有所增强,同工酶谱分析显示有SOD同工酶带的酶量增加或新带出现。 展开更多
关键词 大豆 二氧化硫 适应性反应
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A Characterization of Linearly Semisimple Groups
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作者 Amelia ALVARE Z Pedro SANCHO Carlos SANCHO 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第1期185-192,共8页
Let G -- Spec A be an affine K-group scheme and A = (w ∈ A* : dimK A*-w 〈 ∞, dimK w. A* 〈 ∞}. Let (-, -) : A* × A → K, (w, w) := tr(ww), be the trace form. We prove that G is linearly reductiv... Let G -- Spec A be an affine K-group scheme and A = (w ∈ A* : dimK A*-w 〈 ∞, dimK w. A* 〈 ∞}. Let (-, -) : A* × A → K, (w, w) := tr(ww), be the trace form. We prove that G is linearly reductive if and only if the trace form is non-degenerate on A*. 展开更多
关键词 Linearly reductive group trace form Pontrjagin's duality
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HOLOMORPHIC HARMONIC ANALYSIS ON COMPLEX REDUCTIVE GROUPS
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作者 安金鹏 钱敏 王正栋 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期560-572,共13页
The authors define the holomorphic Fourier transform of holomorphic functions on complex reductive groups, prove some properties such as the Fourier inversion formula, and give some applications. The definition of the... The authors define the holomorphic Fourier transform of holomorphic functions on complex reductive groups, prove some properties such as the Fourier inversion formula, and give some applications. The definition of the holomorphic Fourier transform makes use of the notion of K-admissible measures. The authors prove that K-admissible measures are abundant, and the definition of holomorphic Fourier transform is independent of the choice of K-admissible measures. 展开更多
关键词 Complex reductive group Fourier transform holomorphic representation
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AC1及AC3对白内障形成中晶状体氧化还原物质及硒含量的变化 被引量:2
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作者 黄莉莉 贾维红 张昌颖 《生物化学杂志》 CSCD 1989年第5期385-389,共5页
观察了AC1和AC3对抗亚硒酸钠性白内障形成过程中晶状体的脂类过氧化作用,非蛋白质疏基水平及硒含量。结果表明,亚硒酸钠组大鼠,在晶状体混浊出现前已发生脂类过氧化作用及硒含量的明显增加,非蛋白质巯基含量的显著降低,并持续至核混浊期... 观察了AC1和AC3对抗亚硒酸钠性白内障形成过程中晶状体的脂类过氧化作用,非蛋白质疏基水平及硒含量。结果表明,亚硒酸钠组大鼠,在晶状体混浊出现前已发生脂类过氧化作用及硒含量的明显增加,非蛋白质巯基含量的显著降低,并持续至核混浊期;而同时接受AC1或AC3的大鼠,晶状体非蛋白质巯基水平初期降低,然后逐渐恢复至正常。AC1可有效的对抗亚硒酸钠所致的脂类过氧化作用增加,而AC3的对抗效应需一定剂量及时程,两者对晶状体硒含量均无明显影响。 展开更多
关键词 白内障 亚硒酸钠 AC1 AC3
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关于约化李代数结构常数的一个公式
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作者 董道珍 《河南大学学报(自然科学版)》 CAS 1998年第4期10-12,共3页
使用分析的方法得约化李代数结构常数适应的一个公式,这就是Ci=∑nj=1j≠i(-1)jCjjiδ(j,i)=0,i=1,…n.这里Cjji是结构常数:δ(j,i)的值,当1,…i^,…,j,i,j+1…n是偶排列时... 使用分析的方法得约化李代数结构常数适应的一个公式,这就是Ci=∑nj=1j≠i(-1)jCjjiδ(j,i)=0,i=1,…n.这里Cjji是结构常数:δ(j,i)的值,当1,…i^,…,j,i,j+1…n是偶排列时为1,否则为-1。 展开更多
关键词 李代数 约化李代数 结构常数
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糖基亚苄基NaBH_3 CN-HCl选择性开环过程中乙酰基迁移现象的研究
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作者 秦致辉 蔡孟深 李中军 《有机化学》 SCIE CAS CSCD 北大核心 2001年第3期214-217,共4页
用NaBH3CN HCl/Et2 O对 3 O 乙酰基 4,6 O 亚苄基 β D 吡喃半乳糖乙硫苷 (2 )进行还原开环 ,发现有乙酰基迁移至 2 位的产物生成 ;进一步的实验表明 ,室温条件下 ,NaBH3CN与
关键词 还原开环 乙酰基迁移 氰硼氢化钠 3-O-2酰基-4 6-O-亚苄基-β-D-吡喃半乳糖乙硫苷
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