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Theoretical Study on the Dissociation of Ligands in the Rhodium and Iridium Complexes Containing 1,1,1,5,5,5-Hexafl uo roacetylaceto nato

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Chinese Journal of Chemistry 2013年第3期31卷 421-429页

作者： Xiufang Ma Yanhua Lei zhaoxu chen Institute of Theoretical and Computational Chemistry Key Laboratory of Mesoscopic Chemistry of MOE School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210093 China Institute of Molecular Engineering and Applied Chemistry Anhui University of Technology Ma' anshan Anhui 243002 China

Functionalization of the inert C-H bonds of unsaturated molecules by transition metal complex is an important means to form new C-C bonds. The functionalization is usually initiated by the ligand dissociation of a complex. In this paper we employ both ab initio and density functional methods to explore the influence of central metals, conformation, solvent and protonation on the ligand dissociation of the （hfac-O,O）2M（L）（py） complexes [M=Rh（Ⅲ） or Ir（Ⅲ）, hfac-O,O=k^2-O,O-1,1,1,5,5,5-hexafluoroacetylacetonato, L = CH3, CH3CO2, （CH3CO）2CH, CH30 or OH, py=pyridine]. We demonstrate that ligand pyridine dissociates more easily than the ＂L＂ ligands un-der study in aprotic solvent and gas phase and the dissociation of pyridine is more facile in the trans-conformation than in the cis-isomer. These phenomena are rationalized based on electronic structure and molecular orbital inter-actions. We show that solvation only slightly stabilizes the complexes and does not change the ligand dissociation ordering. In particular, we show that pyridine is no longer the labile ligand in protic media. Instead, the oxy-gen-containing ligands （apart from those like hfac that form a cyclic structure with the central metal） that coordinate to the central metal via oxygen atom become the labile ones. Finally our calculations indicate that hfac is a stable ligand, even in protic media.

关键词： C-H activation protonation conformatiom bond dissociation energy

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Convergence History of the Songliao and Jiamusi Blocks in the Eastern End of Central Asian Orogenic Belt: Evidence from Detrital Zircons of Late Paleozoic Sedimentary Rocks

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Acta Geologica Sinica(English Edition) 2019年第5期93卷 1417-1433页

作者： chen zhaoxu LIU Yongjiang GUAN Qingbin College of Earth Sciences Jilin UniversityChangchunJilin 130061China Key Lab of Submarine Geosciences and Prospecting Techniques MOEInstitute for Advanced Ocean StudyCollege of Marine GeosciencesOcean University of ChinaQingdaoShandong 266100China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong 266237China

Central Asian Orogenic Belt(CAOB) is one of the largest accretionary orogenic belts in the world. The eastern segment of CAOB is dominated by Paleozoic Paleo Asian Ocean tectonic regime, Mesozoic Paleo-Pacific tectonic regime and Mongolian-Okhotsk tectonic regime. The Songliao and Jiamusi blocks are located in the easternmost part of the CAOB and are the key region to solve the problem about overprinting processes of multiple tectonic regimes. It is generally believed that the Mudanjiang Ocean between the two blocks was finally closed in the Mesozoic, but the Paleozoic magmatism also developed along the Mudanjiang suture zone, while on both sides of the suture zone, there were comparable Paleozoic strata, indicating that the two blocks had converged during the Paleozoic, and the evolution history of the two blocks in the Late Paleozoic remains controversial. The Carboniferous-Permian terrestrial strata mainly developed in Binxian, Wuchang and Tieli on Songliao Block, Baoqing and Mishan on Jiamusi Block. Samples from the Songliao and Jiamusi blocks in the Late Carboniferous-Early Permian and Late Permian are collected for comparative analysis. The LAICP-MS zircon U-Pb dating results show that the maximum depositional age of Middle Permian Tumenling Formation and Late Permian Hongshan Formation in Songliao Block is ~260 Ma, while that of Tatouhe Formation and Carboniferous strata in Jiamusi Block are ~290 Ma and ~300 Ma, respectively, which supports the previous stratigraphic division scheme. The age peaks of ~290-300 Ma, ~400 Ma, ~500 Ma appeared in the Late Carboniferous to Early Permian strata of Jiamusi Block and the Middle Permian strata of Songliao Block. The age peak of ~500 Ma in the Middle Permian strata of Songliao Block may come from the Cambrian basement, Mashan Complex, of Jiamusi Block, while the age peaks of ~420-440 Ma in the Carboniferous strata of Jiamusi Block may come from the Silurian magmatic arc in Zhangguangcai Range in the eastern margin of So

关键词： Detrital zircon Permian stratum Jiamusi Block Songliao Block Central Asian Orogenic Belt

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Efficiency evaluation of government investment for air pollution control in city clusters:A case from the Beijing-Tianjin-Hebei areas in China

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Frontiers of Engineering Management 2023年第4期10卷 612-624页

作者： Siqi YANG Li ZHANG zhaoxu chen Nan LI School of Information Management Beijing Information Science and Technology UniversityBeijing 100096China Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen361021China Xiamen Key Laboratory of Urban Metabolism Institute of Urban EnvironmentChinese Academy of SciencesXiamen361021China University of the Chinese Academy of Sciences Beijing100049China

Air pollution poses a significant threat to human health,particularly in urban areas with high levels of industrial *** China,the government plays a crucial role in managing air quality through the Air Pollution Prevention and Control Action *** government provides direct financial support and guides the investment direction of social funds to improve air *** government investment has led to improvements in air quality across China,concerns remain regarding the efficiency of such large-scale *** address this concern,we conducted a study using a three-stage data envelopment analysis(DEA)-Malmquist model to assess the efficiency of government investment in improving air quality in *** analysis revealed regional disparities and annual dynamic ***,we focused on the Beijing-Tianjin-Hebei areas as a case study,as the investment primarily targeted industrial activities in urban areas with the goal of improving living conditions for urban *** results demonstrate significant differences in investment efficiency between *** exhibits relatively high investment efficiency,while cities in Hebei Province require *** identified scale inefficiency,which refers to the ratio of air pollutant reduction to financial investment,as the main factor contributing to regional ***,we found that increasing the total investment scale can help mitigate this ***,our study observed positive but fluctuating annual changes in investment efficiency within this city cluster from 2014 to ***-combined technical efficiency,which represents the investment strategy,is the main obstacle to improving yearly investment ***,in addition to promoting investment strategies at the individual city level,it is crucial to enhance coordination and cooperation among cities to improve the investment efficiency of the entire city *** the efficiency of gover

关键词： investment efficiency government investment air pollution control three-stage DEA-Malmquist model

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Ultralow-Energy-Barrier H_(2)O_(2)Dissociation on Coordinatively Unsaturated Metal Centers in Binary Ce-Fe Prussian Blue Analogue for Efficient and Stable Photo-Fenton Catalysis

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Energy & Environmental Materials 2023年第6期6卷 427-435页

作者： Wenting Zheng Hui Guo Changqing Zhu Cailiang Yue Wenlei Zhu Fuqiang Liu zhaoxu chen State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Institute of Theoretical and Computational Chemistry Key Laboratory of Mesoscopic Chemistry of MOESchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

The low intrinsic activity of Fenton catalytic site and high demand for light-energy input inhibit the organic-pollution control efficiency of photo-Fenton ***,through structural design with density functional theory(DFT)calculations,Ce is predicted to enable the construction of coordinatively unsaturated metal centers(CUCs)in Prussian blue analogue(PBA),which can strongly adsorb H_(2)O_(2)and donate sufficient electrons for directly splitting the O-O bond to *** a substitution-co-assembly strategy,binary Ce-Fe PBA is then prepared,which rapidly degrades sulfamethoxazole with the pseudo-first-order kinetic rate constant exceeding reported values by 1-2 orders of ***,the photogenerated electrons reduce Fe(Ⅲ)and Ce(Ⅳ)to promote the metal valence cycle in CUCs and make sulfamethoxazole degradation efficiency only lose 6.04%in 5 ***,by introducing rare earth metals into transition metal-organic frameworks,this work guides the whole process for highly active CUCs from design and construction to mechanism exploration with DFT calculations,enabling ultrafast and stable photo-Fenton catalysis.

关键词： Ce substitution coordinatively unsaturated metal centers photo-Fenton Prussian blue analogue

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Data-Driven Fault Detection for Nonlinear System:the Implicit Model Approach 36

Data-Driven Fault Detection for Nonlinear System:the Implici...

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第36届中国控制会议

作者： chen zhaoxu FANG Huajing KE Zhiwu TAO Mo Science and Technology on Thermal Energy and Power Laboratory Wuhan Second Ship Design and Research Institute Huazhong University of Science and Technology

ISBN: (纸本)9781538629185

The catastrophic failures of complex industrial process besides the causing negative social impacts have highlighted the issue of system ***-based and data-based fault diagnosis have been researched for *** of the approaches used to fault diagnosis have significant advantages and *** has been proved both in theory and practice that modelbased and data-based approaches cannot replaced each *** this big data era,it is necessary to develop an alternative approach which starts from data,aims at specific mechanism realization and is capable of handling dynamic system *** alternative approach we called implicit model approach（IMA） may provide new thoughts and methods to handle the issue of system *** this paper,based on IMA,we propose a fault detection algorithm for nonlinear *** nonlinear system is represented as Takagi-Sugeno fuzzy *** obtain every residual function in each operating *** overall residual function is obtained by parallel distributed *** validate the proposed algorithm on Tennessee-Eastman process.

关键词： data-driven T-S fuzzy model fault detection subspace identification

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Oroclines in the Central Asian Orogenic Belt

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National Science Review 2023年第2期10卷 17-19页

作者： Yongjiang Liu Wenjiao Xiao Yongfei Ma Sanzhong Li A.Yu.Peskov zhaoxu chen Tong Zhou Qingbin Guan Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Lab of Submarine Geoscience and Prospecting TechniquesCollege of Marine Geosciences Ocean University of China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology National Key Laboratory of Ecological Security and Sustainable Development in Arid Areas Xinjiang Research Center for Mineral Resources Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences College of Earth Sciences Institute of Disaster Prevention Kosygin Institute of Tectonics and Geophysics Far East Branch Russian Academy of Sciences

The term ’orocline’ was first proposed by Carey [1] to describe the structure as ’an orogenic system which has been flexed in plane to a horse-shoe or elbow shape’;it usually emphasizes that a previous straight mountain belt or tectonic units have been bended *** the orocline has been used to describe any curved mountain belt regardless of its original shape [2].

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Carbon nitride with encapsulated nickel for semi-hydrogenation of acetylene: pyridinic nitrogen is responsible for hydrogen dissociative adsorption

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Science China Chemistry 2018年第8期61卷 1014-1019页

作者： Teng Fu Tao Wang Hongfang Sun Yida Xu Zhen Dong Xiangke Guo Luming Peng Yan Zhu zhaoxu chen Weiping Ding Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical Engineering Nanjing University

A new mechanism of catalyst has been demonstrated in this article. With the interaction between carbon nitride(CN) and encapsulated nickel, the CN in the catalyst has been endowed with new active sites for the adsorption and activation of hydrogen while nickel itself is physically isolated from the contact with reactive molecules. For the selective hydrogenation of acetylene in large amount of ethylene, the catalyst shows excellent ethylene selectivity than the nickel catalyst itself, which is almost totally unselective. Meanwhile, the CN itself is inactive for the reaction. The results of characterization demonstrate that pyridinic nitrogen doped in the carbon matrix should be the active sites for hydrogen dissociative adsorption. The theoretical calculations further confirm the results and provide with the detail in the electron transfer between nickel and CN in the catalyst. The current results supply a new concept for design of high performance catalyst.

关键词： carbon nitride nickel selective hydrogenation acetylene pyridinic nitrogen

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Discovery of Two Families of VSb-Based Compounds with V-Kagome Lattice

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Chinese Physics Letters 2021年第12期38卷 44-49页

作者： Yuxin Yang Wenhui Fan Qinghua Zhang zhaoxu chen Xu chen Tianping Ying Xianxin Wu Xiaofan Yang Fanqi Meng Gang Li Shiyan Li Lin Gu Tian Qian Andreas PSchnyder Jian-gang Guo Xiaolong chen Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Max-Planck-Institut für Festkörperforschung Heisenbergstrasse 1D-70569 StuttgartGermany State Key Laboratory of Surface Physics Department of PhysicsFudan UniversityShanghai 200438China School of Materials Tsinghua UniversityBeijing 100084China Songshan Lake Materials Laboratory Dongguan 523808China

We report the structure and physical properties of two newly discovered compounds AV_(8)Sb_(12)and AV_(6)Sb_(6)(A=Cs,Rb),which have C_(2)(space group:Cmmm)and C_(3)(space group:R3 m)symmetry,*** basic Vkagome unit appears in both compounds,but stacking ***_(2)Sb_(2) layer is sandwiched between two V_(3)Sb_(5)layers in AV_(8)Sb_(12),altering the V-kagome lattice and lowering the symmetry of kagome layer from hexagonal to *** AV_(6)Sb_(6),the building block is a more complex slab made up of two half-V_(3)Sb_(5)layers that are intercalated by Cs cations along the *** property measurements demonstrate that both compounds are nonmagnetic metals,with carrier concentrations at around 10^(21)cm^(-3).No superconductivity has been observed in CsV_(8)Sb_(12)above 0.3 K under in situ pressure up to 46 *** to CSV_(3)Sb_(5),theoretical calculations and angle-resolved photoemission spectroscopy reveal a quasi-two-dimensional electronic structure in CsV_(8)Sb_(12)with C_(2)symmetry and no van Hove singularities near the Fermi *** findings will stimulate more research into V-based kagome quantum materials.

关键词： symmetry Lattice hexagonal

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四唑互变异构反应的密度泛函理论(DFT)研究

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化学学报 1999年第11期57卷 1206-1212页

作者：肖鹤鸣陈兆旭南京理工大学化学系南京210094

运用11种密度泛函理论方法对四唑互变异构反应进行了计算研究.结果表明,B3LYP-DFT法与从头算的优化几何和能量最为吻合;在6-31G^(?)基组下B3LYP计算的IR频率与MP2/6311G^(?)计算结果相差很小;用未经校正的B3LYP计算频率求得的产物(2H-四... 详细信息

运用11种密度泛函理论方法对四唑互变异构反应进行了计算研究.结果表明,B3LYP-DFT法与从头算的优化几何和能量最为吻合;在6-31G^(?)基组下B3LYP计算的IR频率与MP2/6311G^(?)计算结果相差很小;用未经校正的B3LYP计算频率求得的产物(2H-四唑)的热力学性质与实测结果也完全一致;由此推荐B3LYP-DFT法适合于对四唑化合物作系统研究.

关键词：互变异构密度泛函理论四唑异构化反应

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四唑及其衍生物的理论研究 (8) 硝氨四唑衍生物的从头算

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化学学报 1998年第12期56卷 1198-1206页

作者：陈兆旭肖鹤鸣南京理工大学化学系南京210094

运用从头计算法,在HF/6-31G水平下,全优化计算了7种硝氨四唑衍生物的分子几何和电子结构.结果表明,标题物的四唑环近似为平面构型;2H式中性分子的芳香性大于相应的1H式异构体.5-硝氨-1H四唑分子内氢键使硝氨基与环共面;其余标题物中硝... 详细信息

运用从头计算法,在HF/6-31G水平下,全优化计算了7种硝氨四唑衍生物的分子几何和电子结构.结果表明,标题物的四唑环近似为平面构型;2H式中性分子的芳香性大于相应的1H式异构体.5-硝氨-1H四唑分子内氢键使硝氨基与环共面;其余标题物中硝氨基与环垂直.不同水平下的总能量计算表明,标题物中电子相关效应显著;1H式中性分子较2H式的能量高,5-硝氨四唑负离子在三个负离子中最稳定.根据电荷分布阐明了四唑环质子化位置和标题物与金属的配位方式.此外还计算了各标题物的红外光谱及热力学性质.

关键词：硝氨四唑分子几何红外光谱四唑衍生物从头算

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