维普中文期刊产品整合服务
13篇 您的检索式:作者名="Dafa"
    题名 作者 年代 出处 被引量
1The First OCCCO Pentadentate Chelates:Osmium Mediated Stepwise Oxidations of Terminal Alkynes by Pyridine N-Oxide显示文摘of main observation and conclusion Oxygen atom transfer reactions between alkynes and heteroarene N-oxides are currently mediated by transition metal,such as gold,ruthenium or rhodium,but they have never been catalyzed by osmium.Herein,we report stepwise oxidations of terminal alkynes mediated by an osmium carbolong complex,using pyridine N-oxide as the oxidant,yielding novel aldehyde-or carboxylic acid-coordinated osmapentalyne derivatives selectively.The mechanism was illustrated by density functional theory calculations,providing a new route for oxygen atom transfer between heteroarene N-oxides and alkynes.Jianfeng Lin Qiannan Xu Xinlei Lin Yuhui Hua Dafa Chen Yonghong Ruan Hong Zhang Haiping Xia 2020Chinese Journal of Chemistry2020,38,11:4
2The research and application of spray cooling technology in Shanghai Expo显示文摘Huang Chen Ye Dafa Zhao Huizhong 2011Applied Thermal Engineering2011,31,17:1
3Mesoporous alumina catalytic material prepared by grafting wide-pore MCM-41 with an alumina multilayer显示文摘Landau M V Dafa E Kaliya M L Sen T Herskowitz M 0,,1:1
4Experimental measurement of bipartite entanglement using parameterized quantum circuits显示文摘Entanglement in quantum systems plays a crucial role in various quantum information tasks. Measuring entanglement has been an important issue in both experiments and theories. In this work, we use parameterized quantum circuits(PQCs) to diagonalize density matrices of quantum states and obtain entanglement by only measuring the diagonal elements. With this method, full quantum state tomography can be bypassed, greatly reducing the number of measurements. A comprehensive characterization of entanglement was performed by using Rényi entropy and partially transposed moments. Mutual information, calculated from entropy is also used to characterize dynamical quantum phase transitions. We experimentally demonstrated the method on a four-qubit nuclear magnetic resonance quantum simulator. Our results agree with the theoretical descriptions. The measurement complexity of our PQC-based method grows linearly with the number of diagonal elements in the density matrix, a square root reduction over the full quantum tomography. The proposed method can have great potential in quantum systems with a large number of particles.Shunzhong Xue Yulei Huang Dafa Zhao Chao Wei Jun Li Ying Dong Jiancun Gao Dawei Lu Tao Xin Gui-Lu Long 2022Science China(Physics,Mechanics & Astronomy)2022,65,8:0
5Enhancement of Sister Chromatid Exchanges in Peripheral Blood Lymphocytes of Thyroid Cancer Patients in Vitro显示文摘Kontou Maria Dafa Evagelia Trivizaki Antoniou M. Elsa Iordanidou Lydia Lialiaris S. Theodore 2015Journal of Pharmacy and Pharmacology2015,3,4:0
6海淘吹的是什么风?显示文摘冰岛的鱼肝油、德国的净水器、葡萄牙的手帕纸、巴西的蜂胶、越南的榴莲饼干等等,以往这些只能在国外使用到的商品,现在国人不出国就能通过海淘获得。Panda Dafa 2017现代广告2017,0,14:0
7Experimental and theoretical evidences for the formation of transition metal complexes with five coplanar metal-carbonσbonds显示文摘Theσbond is an important concept in chemistry,and the metal-carbon(M-C)σbond in particular is a central feature in organometallic chemistry.Synthesis of stable complexes with five coplanar M-Cσbonds is challenging.Here,we describe the synthesis of two different types of stable complexes with five coplanar M-Cσbonds,and examine the stability of such complexes which use rigid conjugated carbon chains to chelate with the metal center.Density functional theory(DFT)calculations show that the M-Cσbonds in these complexes have primarily a covalent character.Besides theσnature,there are also aπconjugation component among the metal center and carbons,which causes delocalization.This work expanded the coplanar M-Cσbonds to five.Yuhui Hua Ming Luo Zhengyu Lu Hong Zhang Dafa Chen Haiping Xia 2023National Science Review2023,10,12:0
8Formal[2+1]Cycloadditions of a Metallacyclopentadiene Unit with Alkynes:Constructing Tetracyclic Conjugated Frameworks with Bridgehead Metals显示文摘Comprehensive Summary Metallacyclopentadienes play a vital role in transition-metal mediated and catalyzed cycloaddition reactions of alkynes.Though versatile reactions of metallacyclopentadienes with alkynes have been disclosed,[2+1]cycloadditions of metallacyclopentadienes and alkynes have never been discovered.In present work,we report the formal[2+1]cycloadditions of a metallacyclopentadiene unit with a broad scope of commercial alkynes,providing a facile strategy to construct tetracyclic conjugated compounds.The deuterated experiment indicates a metal vinylidene intermediate has been involved in[2+1]cycloaddition.Moreover,the electrophilic substitution reaction of the tetracyclic conjugated compound with the aid of density functional theory(DFT)calculated Fukui functions is investigated.Zhenwei Chu Jinhua Li Dafa Chen Zhengyu Lu Weiran Meng Ming Luo Haiping Xia 2023Chinese Journal of Chemistry2023,41,16:0
9A One-Pot Strategy for the Synthesis of β-Substituted Rhoda-and Irida-Carbolong Complexes显示文摘Comprehensive Summary Starting from an organic multiyne,three steps are normally needed for the preparation of non-βphosphonium functionalized rhodaand irida-carbolong complexes.Herein,a one-pot strategy,by mixing a multiyne,a nucleophile,and Rhcl(CO)(PPh_(3))_(2)/AgBF_(4)or[Ir(CH:CN)(CO)(PPh_(3))_(2)]BF_(4),was developed to achieve a series ofβfunctionalized rhoda-and irida-carbolong complexes.Theβ-substituents in these complexes can be various C-,N-and O-centered groups,dependent on the nucleophiles used.This strategy provides a new convenient route to construct carbolong complexes,which is important for the further development of carbolong chemistry.Binbin Xu Wei Mao Chengcheng Wu Jinhua Li Zhengyu Lu Ming Luo Liu Leo Liu Lingling Mao Dafa Chen Haiping Xia 2022Chinese Journal of Chemistry2022,40,15:0
10Construction of a Metallacyclopentadiene Ring through the Attack of Carbanions to M≡C Bond Followed by C—H Activation显示文摘Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an osmapentalyne with benzyl carbanions,was developed.The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond,followed by C—H activation to form the five-membered osmacyclopentadiene ring.Most of the reactions were carried out at room temperature,the substituents on the aromatic rings of benzyl carbanions are diverse,and the resulting products contain an Os—H bond,representing a novel type of 10C-carbolong complexes.This work provides a new convenient route to construct metallacyclopentadienes,which is expected to further promote the development of such a type of substances.Chun Tang Shengjie Zhang Zhengyu Lu Qian Li Ming Luo Dafa Chen Haiping Xia 2024Chinese Journal of Chemistry2024,42,3:0
11Carbolong Chemistry: Planar CCCCX-Type (X = N, O, S) Pentadentate Chelates by Formal [3+1] Cycloadditions of Metalla-Azirines with Terminal Alkynes显示文摘Three-membered unsaturated rings have been widely utilized in organic synthesis due to their inherent highly strained structures.Although much research has been applied to ring-expansion reactions of such strained ring systems,pathways other than[3+2]cycloadditions have rarely been observed in their reactions with alkynes,and to date,no[3+1]cycloadditions of isolated three-membered unsaturated rings with alkynes have been reported.Here we demonstrate an unprecedented[3+1]cycloaddition in which a fused metalla-azirine is used as a template to generate a series of planar CCCCX-type(X=N,O,S)pentadentate carbolong complexes 3–6.A series of substituted alkynes was tested for further exploration of the scope and mechanism for the[3+1]cycloaddition reactions.Complexes 3–6 represent rare examples of planar pentadentate complexes that assemble fourπ-conjugated fused rings by one bridgehead atom.These novel complexes are thermally stable in air and absorb ultraviolet,visible,and near-infrared light,and thus are potentially applicable in photoelectric devices and pharmaceuticals.Ming Luo Yuhui Hua Kaiyue Zhuo Lipeng Long Xinlei Lin Zhihong Deng Zhenyang Lin Hong Zhang Dafa Chen Haiping Xia 2021CCS Chemistry2021,3,2:0
12New Passenger Services in Railway Stations Based on Mode Group Diversity Multiplexing Optical Fiber Communications显示文摘Dafa Loum 2012Journal of Civil Engineering and Architecture2012,6,10:0
13A New Approach of Asphalt Quality Control: Inducting Online Supervision at Production Plant显示文摘Msc. Egli Dafa Dr. Nissim Dafa 2016材料科学与工程(中英文B版)2016,6,4:0
返回顶部 每页显示:
共1页 首页 上一页 第1页 下一页 末页 /1 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费