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吡啶C(3)位的选择性三氟甲硫基化和二氟甲硫基化反应

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有机化学 2022年第10期42卷 3423-3424页

作者：陈峰卿凤翎中国科学院上海有机化学研究所中国科学院有机氟化学重点实验室上海200032

作为分子结构修饰的重要手段,向分子中引入氟原子或含氟基团可以显著改善母体分子原有的理化特性和生物活性.由于具有大的亲脂性和电负性等特性,三氟甲硫基(scf_(3))的引入可以提高药物的脂溶性、化学和代谢稳定性.二氟甲硫基(scf_(2)H... 详细信息

作为分子结构修饰的重要手段,向分子中引入氟原子或含氟基团可以显著改善母体分子原有的理化特性和生物活性.由于具有大的亲脂性和电负性等特性,三氟甲硫基(scf_(3))的引入可以提高药物的脂溶性、化学和代谢稳定性.二氟甲硫基(scf_(2)H)中含有酸性氢,可以与酶等物质形成氢键,从而增加含二氟甲硫基药物与生物体的相互作用.

关键词：电负性甲硫基三氟甲硫基化氟原子亲脂性脂溶性 scf 生物活性

Maximization of the sum of the trace ratio on the Stiefel manifold, II: Computation

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Science China Mathematics 2015年第7期58卷 1549-1566页

作者： ZHANG LeiHong LI RenCang Department of Applied Mathematics Shanghai University of Finance and Economics Department of Mathematics University of Texas at Arlington

Abstract The necessary condition established in Part I of this paper for the global maximizers of the maximization problem max V tr(VTAV)/tr(VTBV)+tr(VTCV)over the Stiefel manifold{V∈Rm×l |VTV=Il}(lscf)iteration for computing a maximizer.In this part,we analyze the global and local convergence of the scf iteration,and show that the necessary condition for the global maximizers is fulfilled at any convergent point of the sequences of approximations generated by the scf iteration.This is one of the advantages of the scf iteration over optimization-based methods.Preliminary numerical tests are reported and show that the scf iteration is very efficient by comparing with some manifold-based optimization methods.

关键词：最大化问题迭代计算歧管迹线局部收敛迭代优化 scf 试验报告

Predictive approach of heterogeneous catalysis

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National Science Review 2018年第5期5卷 633-635页

作者： Jean-Marie Basset Jérémie D.A.Pelletier King Abdullah University of Science and Technology

‘Predictive catalysis’ or ‘catalysis by design’ has recently advanced heterogeneous catalysis by using the conceptual tool of surface fragments [1] such as ‘surface organometallic fragments’(SOMF)or ‘surface coordination fragments’(scf) to achieve and understand a presumed catalytic cycle (see Fig. 1).One or several fragments of the molecule

关键词： scf CR CO EXAFS

Genome-wide Analysis of Kelch Repeatcontaining F-box Family

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Journal of Integrative Plant Biology 2007年第6期49卷 940-952页

作者： Yujin Sun Xiaofan Zhou Hong Ma Department of Biology and the Huck Institutes of Life Sciences Intercollege Graduate Program in Cell and Developmental Biology The Pennsylvania State University University Park PA 16802 USA

The ubiquitin-dependent protein degradation pathway plays diverse roles in eukaryotes. Previous studies indicate that both F-box and Kelch motifs are common in a variety of organisms. F-box proteins are subunits of E3 ubiquitin ligase complexes called scfs （SKP1, Cullinl, F-box protein, and Rbxl）; they have an N-terminal F-box motif that binds to SKP1 （S-phase kinase associated protein）, and often have C-terminal protein-protein interaction domains, which specify the protein substrates for degradation via the ubiquitin pathway. One of the most frequently found protein interaction domains in F-box proteins is the Kelch repeat domain. Although both the F-box and Kelch repeats are ancient motifs, Kelch repeats-containing F-box proteins （KFB） have only been reported for human and Arabidopsis previously. The recent sequencing of the rice genome and other plant genomes provides an opportunity to examine the possible evolution history of KFB. We carried out extensive BLAST searches to identify putative KFBs in selected organisms, and analyzed their relationships phylogenetically. We also carried out the analysis of both gene duplication and gene expression of the KFBs in rice and Arabidopsis. Our study indicates that the origin of KFBs occurs before the divergence of animals and plants, and plant KFBs underwent rapid gene duplications.

关键词： Arabidopsis thaliana F-box motif Kelch repeats Kelch repeats-containing F-box proteins scf SKP1 like.

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二倍体马铃薯中scf;复合体的组分分析

生物技术通报 2022年

作者：高蒙李富婷魏湛林张赛行白如仟尚轶马玲云南师范大学生命科学学院云南师范大学能源与环境科学学院

自交不亲和（Self-incompatibility,SI）广泛存在于开花植物中，是防止近交促进杂交的一种途径，可有效维持物种的基因型多样性。车前科、茄科、蔷薇科等植物中的自交不亲和类型属于典型的配子体型自交不亲和（gametophytic selfincompa... 详细信息

自交不亲和（Self-incompatibility,SI）广泛存在于开花植物中，是防止近交促进杂交的一种途径，可有效维持物种的基因型多样性。车前科、茄科、蔷薇科等植物中的自交不亲和类型属于典型的配子体型自交不亲和（gametophytic selfincompatibility,GSI）。在GSI植物的杂交过程中，花粉管中的scf;复合体（Skp1/Cullin1/F-box）作为E3泛素连接酶，参与了花粉对异我型S-核糖核酸酶（S-RNase）的降解过程，是维持杂交亲和的关键因子。本研究通过整理GSI植物scf;复合体的研究进展，借助同源比对、进化树及蛋白序列分析等生物信息学分析手段，对二倍体马铃薯中scf;复合体的各个组分进行了初步分析，并对各组分基因的表达量和蛋白互作情况进行分析，最终确定了马铃薯花粉管中的scf;复合体可能是由Soltu.DM.06G001040,Soltu.DM.11G004330,Soltu.DM.06G022320以及相应的SLF蛋白组成的。

关键词： scf 复合体配子体型自交不亲和马铃薯

Spatial-temporal variability of snow cover over the Amur River Basin inferred from MODIS daily snow products in recent decades

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Research in Cold and Arid Regions 2020年第6期12卷 418-429页

作者： XiaoLin Lu WanChang Zhang ShuHang Wang Bo Zhang QuanFu Niu JinPing Liu Hao Chen HuiRan Gao Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Engineering Laboratory for Lake Pollution Control and Ecological Restoration Chinese Research Academy of Environmental ScienceBeijing 100012China Lanzhou University of Technology LanzhouGansu 730050China University of Chinese Academy of Sciences Beijing 100049China

MODIS snow products MOD10A1\MYD10A1 provided us a unique chance to investigate snow cover as well as its spatial-temporal variability in response to global changes from regional and global perspectives.By means of MODIS snow products MOD10A1\MYD10A1 derived from an extensive area of the Amur River Basin,mainly located in the Northeast part of China,some part in far east area of the former USSR and a minor part in Republic of Mongolia,the reproduced snow datasets after removal of cloud effects covering the whole watershed of the Amur River Basin were generated by using 6 different cloud-effect-removing algorithms.The accuracy of the reproduced snow products was evaluated with the time series of snow depth data observed from 2002 to 2010 within the Chinese part of the basin,and the results suggested that the accuracies for the reproduced monthly mean snow depth datasets derived from 6 different cloud-effect-removing algorithms varied from 82%to 96%,the snow classification accuracies(the harmonic mean of Recall and Precision)was higher than 80%,close to the accuracy of the original snow product under clear sky conditions when snow cover was stably accumulated.By using the reproduced snow product dataset with the best validated cloud-effect-removing algorithm newly proposed,spatial-temporal variability of snow coverage fraction(scf),the date when snow cover started to accumulate(SCS)as well as the date when being melted off(SCM)in the Amur River Basin from 2002 to 2016 were investigated.The results indicated that the scf characterized the significant spatial heterogeneity tended to be higher towards East and North but lower toward West and South over the Amur River Basin.The inter-annual variations of scf showed an insignificant increase in general with slight fluctuations in majority part of the basin.Both SCS and SCM tended to be slightly linear varied and the inter-annual differences were obvious.In addition,a clear decreasing trend in snow cover is observed in the region.Trend analysis(at 10%significance level)sh

关键词： MODIS scf SCS SCM Amur River Basin cloud effect removal

Lending a hand to asymmetric trifluoromethylthiolation:enantioselective[2,3]-sigmatropic rearrangement of sulfonium ylides

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Science China Chemistry 2017年第12期60卷 1565-1566页

作者： Guoliang Mao Lei Chen Congyang Wang Provincial Key Laboratory of Oil&Gas Chemical Technology College of Chemistry and Chemical EngineeringNortheast Petroleum UniversityDaqing 163318China Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The introduction of a trifluoromethanesulfenyl group(scf3)into organic molecules can,in principle,significantly enhance the cell-membrane permeability,metabolic stability and bioavailability because of its high lipophilicity and intrinsic electron-withdrawing properties.As a consequence,tremendous efforts have been made to develop diverse trifluoromethylthiolation protocols by using either

关键词： scf Lending a hand to asymmetric trifluoromethylthiolation:enantioselective sigmatropic rearrangement of sulfonium ylides

Electronic structure and photoelectron spectrum Assignment of allene

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Chinese Journal of Chemistry 1993年第5期11卷 406-411页

作者： WANG,Zhi-Zhong YANG,Ming YANG,Zhong-Zhi Institute of Theoretical Chemistry and State Key Laboratory of Computational Theoretical Chemistry,Jilin University,Changchun,Jilin 130023 Institute of Theoretical Chemistry and State Key Laboratory of Computational Theoretical Chemistry Jilin University Changchun Jilin 130023

In this paper a series of ab initio scf and configuration calculations were reported for the ground state and excited states X^2E, A^2E,~2B_2 and ~2A_1 of allene.For ground state X^2E Jahn- Teller distorsion was discussed and a twisted angle of 50° and a torsional barriers of 0.21—0.51 eV were derived.Based on calculated results,the experimental photoelectron spectrum of allene has been assigned.

关键词： scf Electronic structure and photoelectron spectrum Assignment of allene Cl

Vocalization during copulation behavior in greater horseshoe bats,Rhinolophus ferrumequinum

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Chinese Science Bulletin 2013年第17期58卷 2179-2184页

作者： LIU Ying METZNER Walter FENG Jiang Jilin Key Laboratory of Animal Resource Conservation and Utilization Northeast Normal University Department of Integrative Biology & Physiology University of California

Vocal communication plays an important role for individual recognition and male-female interaction during mating in greater horseshoe bats,especially in respect to mate fidelity,which ensures that the bats can maintain a stable social organization.Few studies,however,have addressed the calling behavior during copulating in bats.Here,we initially report the copulation vocalizations and behaviors of both male and female greater horseshoe bats.During copulation,the male assumed a dorsal position and arched his back,arming around the female using his feet and thumbs.The male repeatedly produced very short constant frequency(scf) syllables with high intensity and repetition rate(male 1:16.48±4.8 ms,male 2:17.79±4.03 ms) when he tried to insert the penis into the female,and then long syllables(male 1:42.08±12.67 ms,male 2:43.02±11.44 ms) after penile insertion.The female bats sometime refused the male bats in the early phase of copulations as emitting noise bursts and broad-band vocalizations,but kept silence during actual copulation.We also found that the scf copulation calls of one male remained stable peak frequencies on different copulation days although its echolocation call frequency varied each day.Moreover,different male individuals maintained their own "private frequency" in the scf copulation calls.Therefore,we predicted that the scf copulation calls may serve as an indicator for female greater horseshoe bats to recognize the mating males in order to maintain mate fidelity because horseshoe bats exhibit sexual segregation before mating.Our results stipulate further studies on mating system and copulation strategies in polygynous bats.Such work may also aid in promoting the preservation of greater horseshoe bats.

关键词：交配行为菊头蝠发声回声定位叫声铁恒定频率 scf 个人识别