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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 1031-1044页

作者： Si YUAN Yue WU qinyan xing Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil Engineering Tsinghua University

This paper presents a strategy for computation of super-convergent solutions of multi-dimensional problems in the finite element method （FEM） by recursive application of the one-dimensional （1D） element energy projection （EEP） technique. The main idea is to conceptually treat multi-dimensional problems as generalized 1D problems, based on which the concepts of generalized 1D FEM and its consequent EEP formulae have been developed in a unified manner. Equipped with these concepts, multi-dimensional problems can be recursively discretized in one dimension at each step, until a fully discretized standard finite element （FE） model is reached. This conceptual dimension-by- dimension （D-by-D） discretization procedure is entirely equivalent to a full FE discretization. As a reverse D-by-D recovery procedure, by using the unified EEP formulae together with proper extraction of the generalized nodal solutions, super-convergent displacements and first derivatives for two-dimensional （2D） and three-dimensional （3D） problems can be obtained over the domain. Numerical examples of 3D Poisson＇s equation and elasticity problem are given to verify the feasibility and effectiveness of the proposed strategy.

关键词： three-dimensional(3D)problem generalized one-dimensional(1D)finiteelement method (FEM) dimension-by-dimension(D-by-D) super-convergence elementenergy projection(EEP)

杆件轴向受迫振动的Galerkin有限元EEP法自适应求解

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应用数学和力学 2019年第9期40卷 945-956页

作者：邢沁妍杨青浩陆琛宇杨杏清华大学土木工程系土木工程安全与耐久教育部重点实验室

基于单元能量投影(element energy projection,EEP)法自适应分析在杆件静力问题以及离散系统运动方程组中所取得的成果,以直杆轴向受迫振动为例,研究并建立了一种在时间域和一维空间域同时实现自适应分析的方法.该方法在时间和空间两个... 详细信息

基于单元能量投影(element energy projection,EEP)法自适应分析在杆件静力问题以及离散系统运动方程组中所取得的成果,以直杆轴向受迫振动为例,研究并建立了一种在时间域和一维空间域同时实现自适应分析的方法.该方法在时间和空间两个维度都采用连续的Galerkin有限元法(finite element method,FEM)进行求解,根据半离散的思想,由空间有限元离散将模型问题的偏微分控制方程转化为离散系统运动方程组,对该方程组进行时域有限元自适应求解;然后再基于空间域超收敛计算的EEP解对空间域进行自适应,直至最终的时空网格下动位移解答的精度逐点均满足给定误差限要求.文中对其基本思想、关键技术和实施策略进行了阐述,并给出了包括地震波输入下的典型算例以展示该法有效可靠.

关键词：受迫振动时空有限元自适应 Galerkin法单元能量投影

Superconducting Single-Layer T-Graphene and Novel Synthesis Routes

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Chinese Physics Letters 2019年第9期36卷 46-63页

作者： qinyan Gu Dingyu xing Jian Sun National Laboratory of Solid State Microstructures School of Physics and Collaborative Innovation Center of Ad vanced MicrostructuresNanjing UniversityNanjing 210093

Single-layer superconductors are ideal materials for fabricating superconducting nano ***,up to date,very few single-layer elemental superconductors have been predicted and especially no one has been successfully synthesized ***,using crystal structure search techniques and ab initio calculations,we predict that a single-layer planar carbon sheet with 4-and 8-membered rings called T-graphene is a new intrinsic elemental superconductor with superconducting critical temperature(Tc)up to around 20.8 *** importantly,we propose a synthesis route to obtain such a single-layer T-graphene,that is,a T-graphene potassium intercalation compound(C4 K with P4/mmm symmetry)is firstly synthesized at high pressure(>11.5 GPa)and then quenched to ambient condition;and finally,the single-layer T-graphene can be either exfoliated using the electrochemical method from the bulk C4 K,or peeled off from bulk T-graphite C4,where C4 can be obtained from C4 K by evaporating the K ***,we find that the calculated Tc of C4 K is about 30.4 K at 0 GPa,which sets a new record for layered carbon-based *** present findings add a new class of carbon-based *** particular,once the single-layer T-graphene is synthesized,it can pave the way for fabricating superconducting devices together with other 2 D materials using the layer-by-layer growth techniques.

关键词： red Superconducting Single-Layer T-Graphene and Novel Synthesis Routes Graphene

Flocculation behaviors of a novel papermaking sludge-based flocculant in practical printing and dyeing wastewater treatment

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Frontiers of Environmental Science & Engineering 2021年第5期15卷 283-293页

作者： Kangying Guo Baoyu Gao Jie Wang Jingwen Pan qinyan Yue xing Xu Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityQingdao266237China

In our previous studies,several papermaking sludge-based flocculants(PSBFs)were synthesized from wood pulp papermaking *** structure-activity relationships of the PSBFs have been investigated in simulated dye wastewater treatment,but their efficiencies in practical printing and dyeing wastewater(PPDW)treatment are ***,an PSBF was prepared,and its performance is discussed in comparison to polyaluminium chloride(PAC)and polyacrylamide(PAM)in PPDW *** PSBF was used in three ways:as an independent flocculant,as a PAC aid,or used to treat the effluent of the PAC *** results indicated that adding PSBF alone produced similar color and chemical oxygen demand(COD_(Cr))removals as the PAC system alone,but PSBF performed better than PAC when the pH of PPDW was higher than *** PSBF as a PAC aid improved the color,COD_(Cr)and turbidity removals,but the elimination efficiencies were slightly lower than those of the PAC+PAM ***,when PSBF was used as a flocculant to treat the effluent of the PAC system(PAC→PSBF),the effluent qualities were *** with the PAC system,the color and COD_(Cr)removals of PAC→PSBF system increased by 16.21%and 13.26%,*** excitation and emission matrix fluorescence results indicated that PSBF removed tryptophan-like pollutants more efficiently than *** the pH requirements of the subsequent bioreactor treatment in practice,the PAC→PSBF system were also investigated at the PPDW pH level of *** maximum removal efficiencies of color,COD_(Cr)and turbidity were 90.17%,32.60%and 82.50%,respectively.

关键词： Practical wastewater treatment Commercial coagulant/flocculant Secondary coagulation-flocculation process Chemical oxygen demand Coagulation-flocculation mechanism

Novel cationic polyamidine:Synthesis,characterization,and sludge dewatering performance

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Journal of Environmental Sciences 2017年第1期29卷 305-314页

作者： Bo Guo Huan Yu Baoyu Gao Sen Zhang qinyan Yue xing Xu Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityJinan 250100China. Shandong Institute of Metrology Jinan 250014China

In this study,a new and facile route was employed for synthesis of polyamidine with abundant cations and attractive five-membered ringlike structural unit.N-vinylformamide and acrylonitrile copolymerized firstly to form intermediates,and the intermediates were processed with hydrochloric acid to produce polyamidine.A series of polymerization conditions（*** time,temperature and dosage of initiator） were optimized through productivity,viscosity and cationic degree as *** analysis illustrated that the amidinization process could reduce the size of spaces between molecular and created compact structure,which would contribute to good flocculation performance and high ***-IR,XPS and NMR spectra presented a rather clear structure of polyamidine.34.3%of sludge was sedimentated through the flocculation of polyamidine in the early *** contrast,only 6.8%of sludge was sedimentated by *** moisture content in dehydrated floc could be reduced to 77.7%when 60 mg/L polyamidine was *** results demonstrated that the polyamidine showed a great potential in the practical application of sludge dewatering.

关键词： Polyamidine Synthesis Characterization Sludge dewatering

Carbon-based single atom catalyst: Synthesis, characterization, DFT calculations

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Chinese Chemical Letters 2022年第2期33卷 663-673页

作者： Yanan Shang Xiaoguang Duan Shaobin Wang qinyan Yue Baoyu Gao xing Xu Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityJi’nan 250100China School of Chemical Engineering and Advanced Materials The University of AdelaideAdelaideSA 5005Australia

Carbon-based single-atom catalysts(SACs) with atomic sizes of active sites have become the promising candidates for a variety of catalytic systems because of their high atom utilization, and unique electronic structures. Different types of single-atom sites can be fabricated via multiple preparation strategies, which would demonstrate distinct different coordination configurations and electronic features, and ultimately affected the structure-catalysis relationship of SACs in targeted reactions. As a result, it is necessary to identify the active sites of SACs and understand the structure-catalysis relationship of SACs at the atomic scale. In this review, a variety of preparation strategies of carbon-based SACs were documented. Then, the recent development on versatile characterization techniques and computational achievements were summarized regarding in understanding the electronic and geometric characteristics of carbon-based ***, major challenges and development directions concerning single-atom sites identification and advanced tools development are discussed to shed light on future research of carbon-based SACs.

关键词： Single atom Synthesis DFT calculations Characterization Catalysis

Application and mechanism of polysaccharide extracted from Enteromorpha to remove nano-ZnO and humic acid in coagulation process

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Frontiers of Environmental Science & Engineering 2018年第3期12卷 129-136页

作者： Jianzhang Sun Baoyu Gao Yuanxia Luo Moxi Xue xing Xu qinyan Yue Yan Wang Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and Engineering Shandong University Jinan 250100 China

Enteromorpha polysaccharide （Ep） extracted from alga a novel green coagulant aid for nanoparticles （NPs） and heavy metal ions removal and the structure of EP was intensively studied in this study. The integration of Ep with polyaluminum chloride （PAC-Ep） coagulants exhibited higher coagulation performance than that of the polyaluminum chloride （PAC） because of the negatively charged NPs suspension and humic aid （HA） solution. Significant high removal efficiencies of dissolved organic matter （94.1%）, turbidity （99.3%） and Zn ions （69.3%） were achieved by the PAC-Ep coagulants. The dual-coagulation properties of PAC-Ep for different pollutants was based on multiple mechanisms, including （i） AI^3＋ charge neutralization; （ii） hydroxy aluminum hydroxyl bridging formed polynuclearhydroxy complexes bridge and sweep colloidal particles; （iii） adsorption and bridging of Ep chain for the NPs and heavy metal ions. Results indicated that the destabilization of colloid was induced by the coexisting HA and higher removal was achieved as ions adsorption was enhance in the presence of HA complexation. On the basis of that, the extraction of polysaccharide is a promising candidate for its high coagulation performance in water treatment.

关键词： Algal ExtractionEnteromorpha polysaccharide IH-^13C nuclear magnetic resonance (NMR)Fourier transform infrared (FTIR)X-ray photoelectron spectroscopy (XPS)Coagulation mechanism

Adsorptive removal of phosphate by the bimetallic hydroxide nanocomposites embedded in pomegranate peel

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Journal of Environmental Sciences 2020年第5期32卷 189-198页

作者： Muhammad Akram xing Xu Baoyu Gao qinyan Yue Shang Yanan Rizwan Khan Muhammad Ali Inam Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityQingdao 266200China Department of Chemical Engineering Quaid-e-Awam University of EngineeringScience and Technology(QUEST)Naiuabshah 67480SindfiPakistan Institute of Environmental Sciences and Engineering(IESE) School of Civil and Environmental Engineering(SCEE)National University of Sciences and Technology(NUST)H-12 CampusIslamabad 44000Pakistan

This study aimed to fabricate new and effective material for the efficiency of phosphate *** types of adsorbent materials,the zirconium hydroxides embedded in pomegranate peel(Zr/Peel)and zirconium-lanthanum hydroxides embedded in pomegranate peel(Zr-La/Peel)were *** electronic microscopy(SEM),x-ray photoelectron spectroscopy(XPS)and x-ray diffraction(XRD)were evaluated to give insight into the physicochemical properties of these ***-La/Peel exceeded the adsorption efficiency of Zr/Peel adsorbents in batch adsorption experiments at the same pH *** peel as a host can strive to have a strong"shielding effect"to increase the steadiness of the entrenched Zr and La *** and Zr are hydroxide metals that emit many hydrogen ions during the hydrolysis reaction,which contribute to protonation and electrostatic *** highest adsorption capacity of La-Zr/Peel for phosphate was calculated to be40.21 mg/g,and pseudo second-order equation is very well fitted for kinetic *** adsorption efficiency was reduced by an increase of *** the background of coexisting Cl-,little effect on adsorption efficiency was observed,while adsorption capacities were reduced by almost 20-30%with the coexistence of SO42-,NO3-and humic acid(HA).

关键词： Bimetallic hydroxides Pomegranate peel Phosphate Adsorption

An enhanced coagulation using ferric chloride and poly-ferric chloride coagulant assisted by polyamidine:Performance and mechanisms

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Chinese Chemical Letters 2023年第12期34卷 300-304页

作者： Bo Guo Sen Zhang xing Xu Baoyu Gao Qian Li qinyan Yue Shandong Institute of Metrology Ji'nan 250014China Shandong Key Laboratory of Water Plution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityJi'nan 250100China

The deterioration of water caused by industrial production is a thorny *** the problem cogently through innovative coagulationstrategies has been recognized of important practical *** this work,a simple enhanced coagulation by using ferric chloride(FC)and poly-ferric chloride(PFC)coupled with polyamidine(PA)were tried to remove the toxic *** results shown that PA addition could obviously enhance coagulation performances of the iron-based *** synergic coagulation process and mechanism were studied and discussed in detail based on the coagulation behaviors,flocs properties,removal eficiency and zeta *** and PFC remove organics mainly through charge neutralization and adsorption-bridging,resulting in a good purification *** PA with a higher charge density showed better purification performance due to enhanced charge *** is worth mentioning that the addition of PA could make the coagulants adapt to a wider pH range,and remove the toxic organics more *** is to say,the practical adaptability of the coagulant was *** work thus provides a simple strategy to effectively purify wastewater and further improve the water safety.

关键词： Coagulation erformance Polyamidine Ferric hloride Poly-ferric chloride

Composite topological nodal lines penetrating the Brillouin zone in orthorhombic AgF_(2)

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npj Computational Materials 2019年第1期5卷 694-701页

作者： Dexi Shao Huaiqiang Wang Tong Chen Pengchao Lu qinyan Gu Li Sheng Dingyu xing Jian Sun National Laboratory of Solid State Microstructures and Department of Physics Nanjing University210093 NanjingChina Collaborative Innovation Center of Advanced Microstructures 210093 NanjingChina

It has recently been found that nonsymmorphic symmetries can bring many exotic band ***,based on symmetry analysis,we predict that materials with time-reversal symmetry in the space group of Pbca(No.61)possess rich symmetry-enforced band crossings,including nodal surfaces,fourfold degenerate nodal lines and hourglass Dirac loops,which appear in triplets as ensured by the cyclic permutation *** take Pbca AgF_(2) as an example in real systems and studied its band structures with ab initio ***,in the absence of spin-orbit coupling(SOC),besides the above-mentioned band degeneracies,this system features a nodal chain and a nodal armillary sphere penetrating the Brillouin zone(BZ).While with SOC,we find a new configuration of the hourglass Dirac loop/chain with the feature traversing the BZ,which originates from the splitting of a Dirac loop confined in the ***,guided by the bulk-surface correspondence,we calculated the surface states to explore these bulk nodal *** evolution of these interesting nodal phenomena traversing the BZ under two specific uniaxial strains is also discussed.

关键词： nodal symmetry Brillouin