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991.
高等教育要适应世界潮流和时代变化,本科教育须进一步提高实践教学的比重,加强理论教学与实践教学相结合,完善协同育人机制。结合学科发展和企业发展需求,中山大学化学学院与金发科技股份有限公司(简称金发科技)共同建设大学生实践教学基地。本文以中山大学-金发科技本科实践教学基地为例,探讨大学生校外实践基地建设过程中遇到的问题以及实践基地的建设内容与成果体会。 相似文献
992.
993.
Li Xiang Yao Dongbao Zhou Junxiang Zhou Xiang Sun Xianbao Wei Bing Li Chengxu Zheng Bin Liang Haojun 《中国科学:化学(英文版)》2020,63(1):92-98
Signal amplification is an important issue in DNA nanotechnology and molecular diagnostics. In this work, we report a strategy for the catalytic self-assembly of spherical nucleic acids(SNAs) programmed by two-layer cascaded DNA circuits through integrating an entropy-driven catalytic network, a catalytic hairpin assembly circuit, and a facile SNA assembly-based reporter system. This integrated system could implement ~100,000-fold signal amplification in the presence of 1 p M of input target.Possessing powerful amplification ability of nucleic acid signal, our strategy should be of great potential in fabricating more robust dynamic networks to be applied for signal transduction, DNA computing, and nucleic acid-based diagnostics. 相似文献
994.
995.
Cephalotanins A–D,Four Norditerpenoids Represent Three Highly Rigid Carbon Skeletons from Cephalotaxus sinensis 下载免费PDF全文
Dr. Jin‐Biao Xu Dr. Yao‐Yue Fan Prof. Dr. Li‐She Gan Dr. Yu‐Bo Zhou Prof. Dr. Jia Li Prof. Dr. Jian‐Min Yue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14648-14654
Four polycyclic norditerpenoids, cephalotanins A–D ( 1 – 4 ) representing three unprecedented carbon skeletons with highly rigid ring systems, were isolated from Cephalotaxus sinensis and structurally characterized by a combination of various methods. Compounds 1 and 2 are new skeletal norditerpenoid trilactones, while 3 and 4 are two norditerpenoids featuring different new carbon skeletons. Biosynthetic pathways for 1 – 4 were proposed by involving diverse and very fascinating chemical events with the coexisting cephalotane troponoids as the precursors. Compound 1 exhibited good NF‐κB inhibition with an IC50 value of 4.12±0.61 μΜ. 相似文献
996.
Copper‐Catalyzed Reaction Cascade of Thiophenol Hydroxylation and S‐Arylation through Disulfide‐Directed C−H Activation 下载免费PDF全文
Prof. Dr. Dawei Wang Xin Yu Wei Yao Wenkang Hu Chenyang Ge Prof. Dr. Xiaodong Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(16):5543-5546
Copper‐catalyzed thiophenol C?H activation is described. Through an initial attempt to conduct C‐arylation with arylboronic acid, a rather surprising sequential C?H activation and S‐arylation was discovered. Mechanistic investigation revealed the disulfide intermediate as the key component in directing C?H oxidation. The overall reaction proceeded under mild conditions with molecular oxygen as the oxidant. Discovery of disulfide as the directing group provides a potential new direction for catalytic C?H functionalization under mild conditions. 相似文献
997.
998.
Four Zn(II) complexes, [Zn L 2(SO4)]n ( 1 ), [Zn L 4(H2O)2]?2(NO3)?4EtOH ( 2 ), [Zn L 2Cl2]? L ( 3 ), and [Zn L 2Br2]? L ( 4 ) ( L = uniconazole), were synthesized using a hydrothermal method and characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal XRD. Complex 1 formed a one‐dimensional polymer chain. However, complexes 2 ‐ 4 were obtained as zero‐dimensional mononuclear coordination compounds. The antifungal activities of these complexes were then evaluated against four selected fungi using the mycelial growth rate method. The resulting data indicate that all complexes show better antifungal activities than their ligands and mixtures. In addition, the interactions between the metal salts of complexes 1 ‐ 4 and uniconazole seem to be synergistic. Furthermore, the polymer chain structure of complex 1 significantly enhanced the bioactivity, especially against Botryosphaeria ribis ( I ). Density functional theory (DFT) calculations were carried out to help explain the enhanced bioactivity after the formation of Zn(II) complexes. The resulting data show that the HOMO–LUMO energy gaps of complexes 1 ‐ 4 (0.0578, 0.0946, 0.1053, and 0.1245 eV) are smaller than that of the free ligand (0.1247 eV) and correlate with the antifungal activity of the zinc complexes. 相似文献
999.
In this paper, the singular value decompositions of anti-symmetric matrices and anti-bisymmetric matrices are presented, and a class of parameterized inverse singular value problem for anti-bisymmetric matrices is solved. Numerical examples which confirm our theory are presented. 相似文献
1000.