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A versatile synthetic strategy towards rare earth based metal-organic frameworks

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Science ch.na chemistry 2025年

作者： Quan Shi Yun-Hao Xu Ming-Hui ch.n Peng Zhao Wen-Bo Deng Ji xiong Kai Guo Ya-Qing Feng Bao Zhang School of chemical Engineering and Technology Tianjin University Tianjin Collaborative Innovation Center of chemical Science and Engineering Guangdong Laboratory chemistry & Fine chemical Industry Jieyang Center

Rare earth metal-organic frameworks (RE-MOFs) have drawn wide attention owing to diverse network structures and various application ***,due to the unpredictable formation of the nodes,it is still challenging to design novel RE-MOFs.A novel versatile strategy was developed employing a RE-acetate complex (RE2(ch3COO)6·4H2O) as a precursor to construct RE-MOFs.2D RE-MOFs (RE-DBP) and 3D RE-MOFs (RE-TCPP) could be obtained by using dicarboxylic porphyrin ligands H2DBP and tetracarboxylic porphyrin ligands H2TCPP,*** RE-MOFs were further synthesized to verify the universality of the *** crystalline RE-MOFs could also be prepared at room temperature via the developed strategy,which could significantly promote large-scale preparation and practical application of *** proof of the concept,the performance of porphyrin-based RE-MOFs was investigated in the photocatalytic cycloaddition of CO2with *** the RE-DBP(Co) MOFs,Tb-DBP(Co) exhibited the best photocatalytic performance,which was also greater than that of the corresponding 3D MOF Tb-TCPP(Co) due to the optimal 2D structure and thus the accelerated photogenerated charge separation and transfer *** work not only provides a novel versatile strategy to design and develop RE-MOFs,but also proposes a promising approach for the potential bulk production of RE-MOFs at room temperature.

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Synthesis and Catalyzing Behavior of Olefin Polymerization of cis-Cyclopentene Bridged Titanocenes

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ch.nese chemical Letters 2000年第11期11卷 979-980页

作者： Li, JS xiong, ch Ma, YQ Li, J ch.n, X nankai Univ Inst Elementoorgan Chem Tianjin 300071 Peoples R China Tianjin normal Univ Dept Chem Tianjin 300070 Peoples R China

Two cis-cyclopentene bridged titanocenes have been synthesized. Two homogeneous Ziegler catalysts prepared by activation of synthesized compounds with methylalumoxane are active for ethylene polymerization reactions.

关键词： cis Ti Synthesis and Catalyzing Behavior of Olefin Polymerization of cis-Cyclopentene Bridged Titanocenes

Two-way coupling model for shock-induced laminar boundary-layer flows of a dusty gas

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Acta Mech.nica Sinica 2005年第6期21卷 557-563页

作者： Boyi Wang Yi xiong A.n. Osiptsov LnM Institute of Mechanics Chinese Academy of SciencesBeijing 100080 China Institute of Mech.nics Moscow State University119899 Moscow Russia

The present paper describes a numerical two-way coupling model for shock-induced laminar boundary-layer flows of a dust-laden gas and studies the transverse migration of fine particles under the action of Saffman lift force. The governing equations are formulated in the dilute twophase continuum framework with consideration of the finiteness of the particle Reynolds and Knudsen numbers. The full Lagrangian method is explored for calculating the dispersedphase flow fields （including the number density of particles） in the regions of intersecting particle trajectories. The computation results show a significant reaction of the particles on the two-phase boundary-layer structure when the mass loading ratio of particles takes finite values.

关键词： Shock wave Dusty gas Two-phase boundary layer Two-way coupling numerical modeling

Estimating rock properties using sound signal dominant frequencies during diamond core drilling operations

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Journal of Rock Mech.nics and Geotechnical Engineering 2019年第4期11卷 850-859页

作者： ch.Vijaya Kumar Harsha Vardhan ch.S.n.Murthy n.C.Karmakar Department of Mining Engineering National Institute of Technology KarnatakaSurathkalIndia Indian Institute of Technology (BHU) VaranasiIndia

In many engineering applications such as mining,geotechnical and petroleum industries,drilling operation is widely *** drilling operation produces sound by-product,which could be helpful for preliminary estimation of the rock ***,determination of rock properties is very difficult by the conventional methods in terms of high accuracy,and thus it is expensive and *** this context,a new technique was developed based on the estimation of rock properties using dominant frequencies from sound pressure level generated during diamond core drilling ***,sound pressure level was recorded and sound signals of these sound frequencies were analyzed using fast Fourier transform (FFT).Rock drilling experiments were performed on five different types of rock samples using computer numerical control (CnC) drilling mach.ne BMV 45 *** simple linear regression analysis,mathematical equations were developed for various rock properties,*** compressive strength,Brazilian tensile strength,density,and dominant frequencies of sound pressure *** developed models can be utilized at early stage of design to predict rock properties.

关键词： Rock properties Sound pressure level Fast Fourier transform (FFT) Sound signal Core drilling Dominant frequencies

A Learning-based Control Framework for Fast and Accurate Manipulation of a Flexible Object

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Journal of Bionic Engineering 2024年第4期21卷 1761-1774页

作者： Junyi Wang Xiaofeng xiong Silvia Tolu Stanislav n.Gorb Department of Electrical and Photonics Engineering Technical University of DenmarkAnker Engelunds Vej 101Kongens LyngbyZealand2800Denmark SDU Biorobotics Mærsk Mc-Kinney Møller InstituteUniversity of Southern Denmark(SDU)Campusvej 55Odense MFunen5230Denmark Department Functional Morphology and Biomech.nics Zoological InstituteUniversity of KielAm Botanischen Garten 1–9D-24118KielSchleswig-HolsteinGermany

This paper presents a learning-based control framework for fast(3 times of others).Besides,motion tracking errors are greatly reduced to 13.29 and 22.36 of constant impedance control by the OIAC of the proposed *** ad... 详细信息

This paper presents a learning-based control framework for fast(nd accurate manipulation of a flexible object,i.e.,whip *** framework consists of a motion planner learned or optimized by an algorithm,Online Impedance Adaptation Control(OIAC),a sim2real mech.nism,and a visual feedback *** experimental results show that a soft actor-critic algorithm outperforms three Deep Reinforcement Learning(DRL),a nonlinear optimization,and a genetic algorithm in learning generalization of motion *** can greatly reduce average learning trials(tond maximize average rewards(to>3 times of others).Besides,motion tracking errors are greatly reduced to 13.29 and 22.36 of constant impedance control by the OIAC of the proposed *** addition,the trajectory similarity between simulated and physical whips is *** presented framework provides a new method integrating data-driven and physics-based algorithms for controlling fast and accurate arm manipulation of a flexible object.

关键词： Deep reinforcement learning Deformable object manipulation Variable impedance control Sim2real Visual tracking

Can a dam type of an alpine lake be derived from lake geometry?A negative result

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Journal of Mountain Science 2021年第3期18卷 614-621页

作者： Adam EMMER Vojtěch CURIn University of Graz Institute of Geography and Regional ScienceCascade|The Mountain Processes and Mountain Hazards GroupGraz 8010Austria Czech Academy of Sciences Prague 16500Czechia Global ch.nge Research Institute Czech University of Life Sciences PragueFaculty of Environmental SciencesBrno 60300Czechia

Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is *** a consequence,numerous region-and nation-wide GLOF assessment studies have been published *** studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by ***,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual *** lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mech.nism(dam overtopping/dam breach)and thus GLOF *** this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam *** dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the *** only promising results are obtained for extreme values(selected bins)of the *** instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed ***,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra.

关键词： Alpine lake High mountain lake GLOFs Glacial lake Moraine-dammed Bedrock-dammed negative result Cordillera Blanca

nonstationary fuzzy forecasting of wind and wave climate in very long-term scales

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Journal of Ocean Engineering and Science 2018年第2期3卷 144-155页

作者： ch.n.Stefanakos E.Vanem SInTEF Ocean Department of Energy and TransportPostboks 4762 TorgardenTrondheim NO-7465Norway DnV GL Group Technology and ResearchP.O Box 3001322HøvikNorway

Global climate ch.nge may have serious impact on human activities in coastal and other *** ch.nge may affect the degree of storminess and,hence,ch.nge the wind-driven ocean wave *** may affect the risks associated with maritime activities such as shipping and offshore oil and ***,there is a recognized need to understand better how climate ch.nge will affect such ***,such understanding comes from future projections of the wind and wave climate from numerical climate models and from the stochastic modelling of such *** work investigates the applicability of a recently proposed nonstationary fuzzy modelling to wind and wave climatic *** to this,fuzzy inference models(FIS)are coupled with nonstationary time series modelling,providing us with less biased climatic *** long-term datasets for an area in the north Atlantic Ocean are used in the present study,namely nORA10(57 years)and ExWaCli(30 years in the present and 30 years in the future).Two distinct experiments have been performed to simulate future values of the time series in a climatic *** assessment of the simulations by means of the actual values kept for comparison purposes gives very good results.

关键词： Fuzzy time series Wind and wave data Forecasting nonstationary Ocean wind and wave climate

Coverless Video Steganography Based on Frame Sequence Perceptual Distance Mapping

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Computers, Materials & Continua 2022年第10期73卷 1571-1583页

作者： Runze Li Jiaohua Qin Yun Tan neal n.xiong College of Computer Science and Information Technology Central South University of Forestry&TechnologyChangsha410004China Department of Mathematics and Computer Science Northeastern State UniversityTahlequah74464OKUSA

Most existing coverless video steganography algorithms use a particular video frame for information *** methods do not reflect the unique sequential features of video carriers that are different from image and have poor *** propose a coverless video steganography method based on frame sequence perceptual distance *** this method,we introduce Learned Perceptual Image Patch Similarity(LPIPS)to quantify the similarity between consecutive video frames to obtain the sequential features of the *** we establish the relationship map between features and the hash sequence for information *** addition,the MongoDB database is used to store the mapping relationship and speed up the index match.ng speed in the information hiding *** results show that the proposed method exhibits outstanding robustness under various noise *** with the existing methods,the robustness to Gaussian noise and speckle noise is improved by more than 40%,and the algorithm has better practicability and feasibility.

关键词： Coverless steganography frame sequence perception distance

Reversible Data Hiding in Encrypted Images Based on Adaptive Prediction and Labeling

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Computers, Materials & Continua 2022年第11期73卷 3613-3628页

作者： Jiaohua Qin Zhibin He Xuyu Xiang neal n.xiong College of Computer Science and Information Technology Central South University of Forestry&TechnologyChangsha410004China Department of Mathematics and Computer Science Northeastern State UniversityTahlequah74464OKUSA

Recently,reversible data hiding in encrypted images(RDHEI)based on pixel prediction has been a hot ***,existing schemes still employ a pixel predictor that ignores pixel ch.nges in the diagonal direction during prediction,and the pixel labeling scheme is *** solve these problems,this paper proposes reversible data hiding in encrypted images based on adaptive prediction and ***,we design an adaptive gradient prediction(AGP),which uses eight adjacent pixels and combines four scanning methods(i.e.,horizontal,vertical,diagonal,and diagonal)for *** can adaptively adjust the weight of the linear prediction model according to the weight of the edge attribute of the pixel,which improves the prediction ability of the predictor for complex *** the same time,we adopt an adaptive huffman coding labeling scheme,which can adaptively generate huffman codes for labeling according to different images,effectively improving the scheme’s embedding performance on the *** experimental results show that the algorithm has a higher embedding *** embedding rate on the test image Jetplane is 4.2102 bpp,and the average embedding rate on the image dataset Bossbase is 3.8625 bpp.

关键词： Reversible data hiding adaptive gradient prediction huffman coding embedding capacity