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Decorating Covalent Organic Frameworks with High-density Chelate Groups for Uranium Extraction

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Chemical Research in Chinese Universities 2022年第2期38卷 433-439页

作者： QIN Xudong TANG Xiaohui MA Yu XU Hong XU Qing yang weiting GU Cheng State Key Laboratory of Luminescent Materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of TechnologyGuangzhou 510640P.R.China Key Laboratory of Advanced Materials of Tropical Island Resources Ministry of EductionSchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228P.R.China CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research Institute(SARI)Chinese Academy of Sciences(CAS)Shanghai 201210P.R.China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084P.R.China Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of TechnologyGuangzhou 510640P.R.China

The extraction of uranium from aqueous solution is highly desirable for sustaining the increasing demand for environmental safety and nuclear fuel.Herein,we report a strategy using a two-step covalent modification for the synthesis of covalent organic frameworks(COFs)with high-density amidoxime chelate groups at periphery.The introduction of dense amidoxime groups plays a pivotal role in uranium adsorption.The resulting COF exhibits strong affinity with the distribution coefficient of 5.2×104 mL/g and a high adsorption capacity of 319.9 mg/g.The strategy could be expanded to identify and remove different contaminants by introducing special functional groups.

关键词： Two-step post-synthetic modification High-density amidoxime Uranium adsorption

Face-directed Strategy for the Construction of Polyoxovanadate-based Metal-Organic Tetrahedra

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Chemical Research in Chinese Universities 2023年第6期39卷 954-959页

作者： CHEN Huiping GONG Yaru CHU Qiangqiang PANG Xiao HUANG Xiaojing TIAN Xudong yang weiting PAN Qinhe SU Zhongmin WANG Xinlong Key Laboratory of Advanced Materials of Tropical Island Resources Ministry of EducationSchool of ScienceHainan UniversityHaikou 570228P.R.China School of Chemical Engineering and Technology Hainan UniversityHaikou 570228P.R.China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012P.R.China

Polyoxometalate-based metal-organic polyhedra(MOPs)were of particular concern because of the various exquisite building blocks and the suitable constructional characteristics.To further understand the design and particularity of polyoxovanadate-based MOPs,(NH_(2)Me)_(8){[V_(6)O_(6)(OCH_(3))_(9)(C_(6)H_(5)PO_(3))]_(4)·(BPT)_(4)}·2DMF(HNU-74)and(NH_(2)Me)12{[V_(6)O_(6)(OCH_(3))_(9)(C_(6)H_(5)PO_(3))]4·(HBCBAIP)_(4)}(SO_(4))_(2)·MeOH·DMF(HNU-75)were constructed by a face-directed synthesis strategy.Both structures were assembled with four secondary building units as vertexes and four organic ligands served as faces.Different from HNU-74,HNU-75 showed a carboxyl group free during the coordination process,resulting in the pore channels being blocked and the free carboxyl group linking outwards,paving the way for the formation of the 3D structure.Due to the pore channels of HNU-74,the adsorption of I2 was studied and the adsorption capacity was 148 mg/g.

关键词： Metal-organic polyhedron Face-directed strategy Tetrahedral structure Iodine adsorption

TSCND:Temporal Subsequence-Based Convolutional Network with Difference for Time Series Forecasting

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Computers, Materials & Continua 2024年第3期78卷 3665-3681页

作者： Haoran Huang weiting Chen Zheming Fan MOE Research Center of Software/Hardware Co-Design Engineering East China Normal UniversityShanghai200062China

Time series forecasting plays an important role in various fields, such as energy, finance, transport, and weather. Temporal convolutional networks (TCNs) based on dilated causal convolution have been widely used in time series forecasting. However, two problems weaken the performance of TCNs. One is that in dilated casual convolution, causal convolution leads to the receptive fields of outputs being concentrated in the earlier part of the input sequence, whereas the recent input information will be severely lost. The other is that the distribution shift problem in time series has not been adequately solved. To address the first problem, we propose a subsequence-based dilated convolution method (SDC). By using multiple convolutional filters to convolve elements of neighboring subsequences, the method extracts temporal features from a growing receptive field via a growing subsequence rather than a single element. Ultimately, the receptive field of each output element can cover the whole input sequence. To address the second problem, we propose a difference and compensation method (DCM). The method reduces the discrepancies between and within the input sequences by difference operations and then compensates the outputs for the information lost due to difference operations. Based on SDC and DCM, we further construct a temporal subsequence-based convolutional network with difference (TSCND) for time series forecasting. The experimental results show that TSCND can reduce prediction mean squared error by 7.3% and save runtime, compared with state-of-the-art models and vanilla TCN.

关键词： Difference data prediction time series temporal convolutional network dilated convolution

Durable poly(binaphthyl-co-p-terphenyl piperidinium)-based anion exchange membranes with dual side chains

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Journal of Energy Chemistry 2024年第2期89卷 324-335,I0008页

作者： weiting Gao Xuelang Gao Qiugen Zhang Aimei Zhu Qinglin Liu Department of Chemical&Biochemical Engineering Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryThe College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 790-784South Korea

Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological structure and forming unblocked ion pathways in AEMs for fast ion transport.Fluorination of side chains can further enhance phase separation due to the superhydrophobic nature of fluorine groups.However,their electronic effect on the alkaline stability of side chains and membranes is rarely reported.Here,fluorine-containing and fluorine-free side chains are introduced into the polyaromatic backbone in proper configuration to investigate the impact of the fluorine terminal group on the stability of the side chains and membrane properties.The poly(binaphthyl-co-p-terphenyl piperidinium)AEM(QBNp TP)has the highest molecular weight and most dimensional stability due to its favorable backbone arrangement among ortho-and meta-terphenyl based AEMs.Importantly,by introducing both a fluorinated piperidinium side chain and a hexane chain into the p-terphenyl-based backbone,the prepared AEM(QBNp TP-QFC)presents an enhanced conductivity(150.6 m S cm^(-1))and a constrained swelling at 80℃.The electronic effect of fluorinated side chains is contemplated by experiments and simulations.The results demonstrate that the presence of strong electro-withdrawing fluorine groups weakens the electronic cloud of adjacent C atoms,increasing OH^(-)attack on the C atom and improving the stability of piperidinium cations.Hence QBNp TP-QFC possesses a robust alkaline stability at 80℃(95.3%conductivity retention after testing in 2 M Na OH for 2160 h).An excellent peak power density of 1.44 W cm^(-2)and a remarkable durability at 80℃(4.5%voltage loss after 100 h)can be observed.

关键词： Anion exchange membranes Backbone structure Fluorinated side chain Alkaline stability

A multi-responsive luminescent sensor towards Fe_(3+) and acetone based on a Cd-containing metal–organic framework

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Chinese Chemical Letters 2016年第4期27卷 497-501页

作者： Ting Wang Qing-Hui Liu Ying Gao Xiu-Yun yang weiting yang Song Dang Zhong-Ming Sun Changchun University of Science & Technology School of Chemistry and Environmental Engineering State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences College of Physics Jilin University

A Cd-containing metal–organic framework（Cd L）, formula as {[Cd_3（L）_2（H_2O）_6] 1.5DMF}, has been synthesized under solvothermal condition by the reaction of 4,40,400-（methylsilanetriyl）tribenzoic acid（H_3L） and Cd^（2＋）ion. Single-crystal X-ray diffraction reveals that Cd L displays a three-dimensional framework with 2-fold interpenetration and DMF molecules locate in the void space of the channels. A topological analysis of the framework indicates Cd Lisa 3,4-connected pto net. The photoluminescence properties of Cd L are systematically studied in detail. Impressively, Cd L shows excellent detection performance towards Fe^（3＋）ion and acetone in the sensing experiments, which undoubtedly demonstrates the great potential of Cd L as a highly selective multi-responsive luminescent sensor for the detection of organic solvents and metal ions.

关键词： Metal–organic framework Fluorescent probe Multi-responsive sensor Luminescent quenching

Heterometallic zinc uranium oxyfluorides incorporating imidazole ligands

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Chinese Chemical Letters 2015年第6期26卷 641-645页

作者： Xiao-Xiao Liu Yuan Wang Wan-Guo Tian weiting yang Zhong-Ming Sun Changchun University of Science & Technology School of Chemistry and Environmental Engineering State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences

Two heterometallic uranium oxyfluorides with hybrid networks were hydrothermally synthesized by incorporating two imidazoles, 1-（biphenyl-4-yl）-lH-imidazole （bpi） and 1,4-di（1H-imidazol-l-yl）ben- zene （dib）, formulated as Zn（bpi）2（UO2）2（H2O）F6 （1） and Zn（dib）（UO2）F4-0.5H20 （2）. Compound 1 consists of chains of edge-sharing UO2F5 and UO2F4（H20） pentagonal bipyramids, which are linked by Zn（bpi）2 moieties to form the sheet structure with decorated bpi. While in compound 2, sheets of edge- sharing dimers of UO2F5 pentagonal bipyramids and ZnF3N2 polyhedra are linked by dib, creating a pillared three-dimensional framework. The two compounds represent the few examples of heterometallic uranium oxyfluorides incorporating organic ligands. The syntheses, structure as well as the IR spectra, UV-vis spectra and luminescent properties of the bimetallic uranium oxyfluorides are studied.

关键词： Uranium Imidazole Crystal structure Luminescence

Layered and three-dimensional uranyl–organic assemblies with 4,4′-oxidiphthalic acid

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Chinese Chemical Letters 2016年第3期27卷 325-329页

作者： Dai Wu Ying Gao Wan-Guo Tian Yun-Hui Li weiting yang Zhong-Ming Sun School of Chemistry and Environmental Engineering Changchun University of Science & Technology Changchun 130022 China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

Hydrothermal reactions of uranyl nitrate and 4,4＇-oxidiphthalic acid（H4L） resulted in the formation of three new uranyl-organic framework materials,namely（NH4）2[（UO2）3（L）2]·5H2O（1）,（NEt4）[（UO2）3（H2O）（L）（HL）]（2） and（UO2）7（H2O）2（phen）4（L）2（HL）2（3）（NEt4 = tetraethylammonium,phen = 1,10-phenanthroline）.These three structures all comprise common uranyl pentagonal bipyramids.In 1,UO7polyhedra are linked by hexadentate ligands to form a 3D framework with 1D channels,in which are located NH4^＋ ions and water molecules.While in 2,the organic ligands adopt pentadentate and hexadentate coordination modes,ligating UO7 units to create a layered structure with channels filled by NEt4^＋ ions.For 3,uranyl square bipyramids are also accommodated together with pentagonal bipyramids,which are linked by tetradentate carboxylate ligands to produce the layered assembly.Phen molecules also coordinate to the uranyl centers to build up the structure.Luminescent studies indicate that 2 and 3 exhibit the characteristic uranyl emission.

关键词： Uranyl–organic assemblies Carboxylates Structures Luminescence

Parameter calibration of the tensile-shear interactive damage constitutive model for sandstone failure

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1153-1174页

作者： Yun Shu Zheming Zhu Meng Wang weiting Gao Fei Wang Duanying Wan Yuntao Wang MOE Key Laboratory of Deep Earth Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu610065China Tianfu Engineering-oriented Numerical Simulation & Software Innovation Center Chengdu620107China

The tensile-shear interactive damage(TSID)model is a novel and powerful constitutive model for rock-like materials.This study proposes a methodology to calibrate the TSID model parameters to simulate sandstone.The basic parameters of sandstone are determined through a series of static and dynamic tests,including uniaxial compression,Brazilian disc,triaxial compression under varying confining pressures,hydrostatic compression,and dynamic compression and tensile tests with a split Hopkinson pressure bar.Based on the sandstone test results from this study and previous research,a step-by-step procedure for parameter calibration is outlined,which accounts for the categories of the strength surface,equation of state(EOS),strain rate effect,and damage.The calibrated parameters are verified through numerical tests that correspond to the experimental loading conditions.Consistency between numerical results and experimental data indicates the precision and reliability of the calibrated parameters.The methodology presented in this study is scientifically sound,straightforward,and essential for improving the TSID model.Furthermore,it has the potential to contribute to other rock constitutive models,particularly new user-defined models.

关键词： Damage constitutive model Parameter calibration Rock modeling Sandstone Dynamic impact load Tensile-shear interactive damage(TSID)model

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铁路车站咽喉区道岔自动分组方法研究

铁道学报 2023年第6期45卷 9-15页

作者：陈维亚杨伟婷石晓琪鲁佳琪中南大学交通运输工程学院湖南长沙4100752 中南大学轨道交通大数据湖南省重点实验室湖南长沙410075

咽喉区道岔分组不仅是运用利用率计算法查定铁路车站咽喉通过能力的必要步骤,还是车站进路选择、股道运用等行车技术作业的关键环节。为解决当前自动分组方法不能有效解决复杂咽喉区非水平方向布置道岔的分组问题,将咽喉区道岔分组问题... 详细信息

咽喉区道岔分组不仅是运用利用率计算法查定铁路车站咽喉通过能力的必要步骤,还是车站进路选择、股道运用等行车技术作业的关键环节。为解决当前自动分组方法不能有效解决复杂咽喉区非水平方向布置道岔的分组问题,将咽喉区道岔分组问题抽象为有向图中点的归属问题,构建咽喉有向图模型和道岔分组有向图模型,设计二阶段法对模型求解。第一阶段识别平行进路,目标是基于咽喉有向图运用DFS算法识别并生成平行进路对全集;第二阶段为判断道岔归属,目标是基于进路判断法及道岔坐标设计初分、调整、检验等计算步骤判断道岔归属并生成道岔组。以某个布置复杂的技术站咽喉为例,对本文所提出方法进行检验,结果表明该方法能够快速准确地实现咽喉道岔自动分组,有利于铁路数字化设计和智能化生产管理。

关键词：铁路车站道岔自动分组二阶段法有向图深度优先搜索算法