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Low Valent Palladium Clusters: Synthesis, Structures and Catalytic Applications

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Chinese Journal of Chemistry 2020年第12期38卷 1897-1908页

作者： Qian Liu liang zhao Kkey laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084China

Ay one of the most common transition metal catalysts,mononuclear palladium catalysts have been develped systematcally and a widely recognizedcatalytic mechanism featured with a pd/Pd catalytic cycle for a palladium center has been ***,recent research works have revealed thatpalladium clusters may also be catalysts or catalyti intermediates involved in the catalytic *** major discovery brings new perspectives for adeep and comprehensive understanding of the PRd-catalyzed reaction *** with the latest advances in the field of organometllicchemistry,we here highlight the synthesis,structures,and catalytic reactivities of palladium custer *** reviw discusses severalwel-defined syntheticstrategies and diversepalladum cluster-based catalytic systems in detail,to provide insights into the rational design of promisingpalladium cluster catalysts and the effective search for appropriate synthetic methods.

关键词： palladium catalytic cluster

Gradient Estimates for p-Laplacian Lichnerowicz Equation on Noncompact Metric Measure Space

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Chinese Annals of Mathematics,Series B 2020年第3期41卷 397-406页

作者： liang zhao Ming SHEN Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Mathematics and Computer Science Fuzhou UniversityFuzhou 350116China

In this paper, the authors obtain the gradient estimates for positive solutions to the weighted p-Laplacian Lichnerowicz equation △p,fu + cuσ= 0 on noncompact smooth metric measure space, where c is a nonnegative constant, and p, σ(1 < p≤2, σ≤p-1) are real constants. Moreover, by the gradient estimate, they can get the corresponding Liouville theorem and Harnack inequality.

关键词： p-Laplacian Positive solutions Liouville theorem

Liouville Type Theorems for Nonlinear p-Laplacian Equation on Complete Noncompact Riemannian Manifolds

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Chinese Annals of Mathematics,Series B 2023年第3期44卷 379-390页

作者： Guangyue HUANG liang zhao Department of Mathematics Henan Normal UniversityXinxiangHenan453007China School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing210016China

In this paper,the authors study the gradient estimates for positive weak solutions to the following p-Laplacian equation△_(p)u+au^(σ)=0 on complete noncompact Riemannian manifold,where a,σare two nonzero real constants with p≠*** the gradient estimate,they can get the corresponding Lionville *** the other hand,by virtue of the Poincare inequality,they also obtain a Liouville theorem under some integral conditions with respect to positive weak solutions.

关键词： p-Laplacian Liouville theorem Positive weak solution

Removal and transformation of dissolved organic matter in secondary effluent during granular activated carbon treatment

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第7期9卷 994-1003页

作者： liang-liang WEI Qing-liang zhao Shuang XUE Ting JIA State Key Laboratory of Urban Water Resources and Environments （SKL UWRE） School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

This paper focused on the removal and transformation of the dissolved organic matter （DOM） in secondary effluent during the granular activated carbon （GAC） treatment. Using XAD-8/XAD-4 resins, DOM was fractionated into five classes： hydrophobic acid （HPO-A）, hydrophobic neutral （HPO-N）, transphilic acid （TPI-A）, transphilic neutral （TPI-N） and hydrophilic fraction （HPI）. Subsequently, the water quality parameters of dissolved organic carbon （DOC）, absorbance of ultraviolet light at 254 nm （UV-254）, specific ultraviolet light absorbance （SUVA） and trihalomethane formation potential （THMFP） were analyzed for the unfractionated and fractionated water samples. The results showed that the order of the DOC removal with respect to DOM fractions was observed to be HPI〉HPO-A〉HPO-N〉TPI-A〉TPI-N. During the GAC treatment, the THMFP of the unfractionated water samples decreased from 397.4 μg/L to 176.5 μg/L, resulting in a removal efficiency of 55.6%. The removal order of the trilaalomethanes （THMs） precursor was as follows： HPO-A〉TPI-A〉TPI-N〉HPO-N〉HPI. By the GAC treatment, the specific THMFP of HPO-A, TPI-A, TPI-N and the original unfractionated water samples had a noticeable decrease, while that of HPO-N and HPI showed a converse trend. The Fourier transform infrared （FTIR） results showed that the hydroxide groups, carboxylic acids, aliphatic C-H were significantly reduced by GAC treatment.

关键词： Dissolved organic matter (DOM) Fractionation Trihalomethane formation potential (THMFP) Specific THMFP Fourier-transform infrared (FTIR)

On-Machine Measurement of the Straightness and Tilt Errors of a Linear Slideway Using a New Four-Sensor Method

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 122-132页

作者： Lei zhao Kai Cheng Hui Ding liang zhao School of Mechatronics Engineering Harbin Institute of Technology College of Engineering Design and Physical Sciences Brunel University

Although there are some multi-sensor methods for measuring the straightness and tilt errors of a linear slideway, they need to be further improved in some aspects, such as suppressing measurement noise and reducing *** this paper, a new four-sensor method with an improved measurement system is proposed to on-machine separate the straightness and tilt errors of a linear slideway from the sensor outputs, considering the influences of the reference surface profile and the zero-adjustment values. The improved system is achieved by adjusting a single sensor to di erent positions. Based on the system, a system of linear equations is built by fusing the sensor outputs to cancel out the e ects of the straightness and tilt errors. Three constraints are then derived and supplemented into the linear system to make the coe cient matrix full rank. To restrain the sensitivity of the solution of the linear system to the measurement noise in the sensor outputs, the Tikhonov regularization method is utilized. After the surface profile is obtained from the solution, the straightness and tilt errors are identified from the sensor outputs. To analyze the e ects of the measurement noise and the positioning errors of the sensor and the linear slideway, a series of computer simulations are carried out. An experiment is conducted for validation, showing good consistency. The new four-sensor method with the improved measurement system provides a new way to measure the straightness and tilt errors of a linear slideway, which can guarantee favorable propagations of the residuals induced by the noise and the positioning errors.

关键词： Multi-sensor method Straightness error Tilt error On-machine measurement Linear slideway Error separation technique

Coupling pinch analysis and rigorous process simulation for hydrogen networks with light hydrocarbon recovery

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Chinese Journal of Chemical Engineering 2021年第12期34卷 141-148页

作者： Minbo Yang Xiao Feng liang zhao Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi'an 710049China Key Laboratory of Advanced Control and Optimization for Chemical Processes East China University of Science and TechnologyMinistry of EducationShanghai 200237China

In refineries,some hydrogen-rich streams contain considerable light hydrocarbons that are important raw materials for the chemical *** hydrogen networks with light hydrocarbon recovery can enhance the reuse of both hydrogen and light *** work proposes an automated method for targeting hydrogen networks with light hydrocarbon recovery.A pinch-based algebraic method is improved to determine the minimum fresh hydrogen consumption and hydrogen sources fed into the light hydrocarbon recovery unit *** process simulation is conducted to determine the mass and energy balances of the light hydrocarbon recovery *** targeting procedures are developed through combination of the improved pinch method and rigorous process *** hybrid method is realized by coupling the Matlab and Aspen HYSYS platforms.A refinery hydrogen network is analyzed to illustrate application of the proposed *** integration of hydrogen network with light hydrocarbon recovery further reduces fresh hydrogen requirement by463.0 m^(3)·h^(-1) and recovers liquefied petroleum gas and gasoline of 1711.5 kg·h^(-1) and 643 kg·h^(-1),respectively.A payback period of 9.2 months indicates that investment in light hydrocarbon recovery is economically attractive.

关键词： Hydrogen Light hydrocarbon recovery Pinch technology Simulation Systems engineering

Upper mantle seismic anisotropy beneath a convergent boundary:SKS waveform modeling in central Tibet

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Science China Earth Sciences 2014年第4期57卷 759-776页

作者： zhao liang zhao Ming LU Gang State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences

This study used SKS waveforms from the International Deep Profiling of Tibet and the Himalayas(INDEPTH) III dataset and a new 2D method for modeling seismic waves in anisotropic media to construct an image of anisotropic structures beneath central Tibet.A preferred model revealed three-segment anisotropic structures in the upper mantle beneath the study *** modeling demonstrated that the anisotropy was mainly generated by the lithosphere but not the asthenosphere,and that an anisotropic model with a flatter axis of symmetry provides a more consistent interpretation of the observations than models having steeply dipping symmetry axes.A relatively low velocity zone may underlie or intermingle with the anisotropic structures in the northern portion of the *** tests also indicate that variations in the elastic constants and depth extent of the anisotropy assumed by the calculations do not affect the general conclusions,although trade-offs exist among certain model *** modeling results suggest that the complex seismic structures in central Tibet were associated with underthrusting of the Indian lithosphere beneath the Asian lithosphere;the inferred flat symmetry axis of the anisotropy was likely generated during this collision *** this were not the case,the inherited anisotropy would exhibit a steeply dipping axis of symmetry,parallel to the direction of underthrusting.

关键词： waveform modeling spectral element method upper mantle anisotropy central Tibet

Existence and Convergence of Solutions for Nonlinear Elliptic Systems on Graphs

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Communications in Mathematics and Statistics 2024年第4期12卷 735-754页

作者： Jinyan Xu liang zhao School of Mathematical Sciences Key Laboratory of Mathematics and Complex Systems of MOEBeijing Normal UniversityBeijing 100875People’s Republic of China

We consider a kind of nonlinear systems on a locally finite graph G=(V,E).We prove via the mountain pass theorem that this kind of systems has a nontrivial ground state solutionwhich depends on the parameterλwith some suitable assumptions on the ***,we pay attention to the concentration behavior of these solutions and prove that asλ→∞,these solutions converge to a ground state solution of a corresponding Dirichlet ***,we also provide some numerical experiments to illustrate our results.

关键词： Nonlinear elliptic system Locally finite graph Ground state solution

Gradient Estimates for a Nonlinear Parabolic Equation with Diffusion on Complete Noncompact Manifolds

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Chinese Annals of Mathematics,Series B 2015年第1期36卷 57-66页

作者： liang zhao Zongwei MA Department of Mathematics Nanjing University of Aeronautics and Astronautics College of Mathematics Physics and Information Engineering Jiaxing University

The authors obtain some gradient estimates for positive solutions to the following nonlinear parabolic equation:αu/αt=△u-b(x,t)u~σ on complete noncompact manifolds with Ricci curvature bounded from below,where 0<... 详细信息

关键词： Gradient estimates Positive solutions Harnack inequality