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A novel method for synthesis of styryl phosphonate monoester and its application in La(Ⅲ) extraction

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Journal of Rare Earths 2020年第6期38卷 649-656页

作者： Kaihua Huang yun Jia Shuai Wang Jia Yang Hong zhong College of Chemistry and Chemical Engineering Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese ResourcesCentral South UniversityChangsha 410083China

Herein,styryl phosphonate monoester(SPE) was synthesized and first introduced as rare earth *** solvent extraction of lanthanum(Ⅲ) from nitrate solution using styryl phosphonate mono-isooctyl ester(SPE108),di-2-ethylhexyl phosphoric acid(D2 EHPA) and 2-ethylhexyl phosphonic acidmono-2-ethylhexyl ester(EHEHPA) as extractants was *** effects of experimental parameters including equilibrium time,extractant concentration,aqueous pH,phase ratio and salt concentration on the extraction process were *** results indicate that the extraction ability and capacity of the extractants follow the order:SPE108> D2 EHPA> ***’s more,the extraction process is less affected by ammonium sulfate in the aqueous phase with *** results of the separation between lanthanum and adjacent lanthanides(Ce,Pr,Nd,Sm) show that SPE108 can separate lanthanides efficiently at low *** extraction mechanism of SPE108 is proved to be similar to D2 EHPA,and the density functional theory(DFT) calculation results infer that SPE108 exhibits superior extraction ability due to its strong electron-accepting ability.

关键词： Styryl phosphonate monoester Rare earth Extraction Extractant

Supervised Contrastive Learning with Term Weighting for Improving Chinese Text Classification

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Tsinghua Science and Technology 2023年第1期28卷 59-68页

作者： Jiabao Guo bo Zhao Hui Liu Yifan Liu Qian zhong School of Cyber Science and Engineering Wuhan UniversityWuhan 430000China

With the rapid growth of information retrieval technology,Chinese text classification,which is the basis of information content security,has become a widely discussed *** view of the huge difference compared with English,Chinese text task is more complex in semantic information ***,most existing Chinese text classification approaches typically regard feature representation and feature selection as the key points,but fail to take into account the learning strategy that adapts to the ***,these approaches compress the Chinese word into a representation vector,without considering the distribution of the term among the categories of *** order to improve the effect of Chinese text classification,a unified method,called Supervised Contrastive Learning with Term Weighting(SCL-TW),is proposed in this *** contrastive learning makes full use of a large amount of unlabeled data to improve model *** SCL-TW,we calculate the score of term weighting to optimize the process of data augmentation of Chinese ***,the transformed features are fed into a temporal convolution network to conduct feature *** verifications are conducted on two Chinese benchmark *** results demonstrate that SCL-TW outperforms other advanced Chinese text classification approaches by an amazing margin.

关键词： Chinese text classification Supervised Contrastive Learning(SCL) Term Weighting(TW) Temporal Convolution Network(TCN)

Comparative study on pyrolysis of bamboo in microwave pyrolysis-reforming reaction by binary compound impregnation and chemical liquid deposition modified HZSM-5

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Journal of Environmental Sciences 2020年第8期32卷 186-196页

作者： Haoran Du Zhaoping zhong bo Zhang Kun Shi Zhaoying Li Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education Southeast UniversityJiangsu 210096China

The deactivation of catalyst is a significant reason for its limited application during the catalytic fast pyrolysis(CFP)*** reduce the coke formation,binary compound impregnation(BCI)and chemical liquid deposition(CLD)were used to modify HZSM-5 *** the same time,the self-designed microwave reactor separated the pyrolysis of bamboo and catalytic upgrading of primary vapor,which made the catalytic effect more *** results indicated that CLD used TiO 2 deposition to cover external acid sites,while BCI by phosphorus-nickel could cover and partly destroy superficial acid sites through two different *** the scope of the loaded amount studied,the yield of aromatic hydrocarbons in the oil phase increased at first and then decreased,while the coke formation reduced ***(benzene,toluene and xylene),the most valuable product in bio-oil,drastically increased by 39.1%and 22.6%respectively over the CLD and BCI modified *** the catalytic performance as well as cost,CLD over HZSM-5 has more advantages in the CFP process to upgrade bio-oil.

关键词： Bamboo Modified HZSM-5 Microwave Binary compound impregnation Chemical liquid deposition

Rh single atoms embedded in CeO_(2) nanostructure boost CO_(2) hydrogenation to HCOOH

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Chinese Journal of Chemical Engineering 2022年第3期35卷 62-69页

作者： bo Wu Xing Yu Min Huang Liangshu zhong Yuhan Sun CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

CO_(2)hydrogenation to value-added chemicals is a promising pathway to solve CO_(2)-relevant environmental problems but still remains a great ***,we report a CeO_(2)nanostructure supported Rh single atoms(Rh-SAs/CeO_(2))catalyst and was used for the efficient CO_(2)hydrogenation to *** Rh-SAs/CeO_(2)exhibited high catalytic activity with turnover numbers(TON)up to 221 at 200℃,which was 4-fold to that of CeO_(2)supported Rh nanoparticles(Rh-NPs/CeO_(2)).Moreover,HCOOH selectivity for Rh-SAs/CeO_(2)reached 85%,much higher than that of Rh-NPs/CeO_(2)(46%).Mechanism studies revealed that Rh single atoms in the Rh-SAs/CeO_(2)with high metal atoms utilization efficiency not only provided abundant active sites to promote the catalytic activity,but also suppressed the decomposition of HCOOH to CO and benefited the formation of HCOOH.

关键词： CO_(2)hydrogenation Selectivity Single-atom catalysts(SACs) Rh HCOOH

Hysteretic behavior of cambered surface steel tube damper:Theoretical and experimental research

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Frontiers of Structural and Civil Engineering 2023年第4期17卷 606-624页

作者： Jiale LI yun ZHOU Zhiming HE Genquan zhong Chao ZHANG Department of Civil Engineering Guangzhou UniversityGuangzhou 510006China Department of Civil&Transportation Engineering Guangdong University of TechnologyGuangzhou 510006China

A novel cambered surface steel tube damper(CSTD)with a cambered surface steel tube and two concave connecting plates is proposed *** steel tube is the main energy dissipation component and comprises a weakened segment in the middle,a transition segment,and an embedded *** is believed that during an earthquake,the middle weakened segment of the CSTD will be damaged,whereas the reliability of the end connection is *** and experimental studies are conducted to verify the effectiveness of the proposed *** for the initial stiffness and yield force of the CSTD are ***,two CSTD specimens with different steel tube thicknesses are fabricated and tested under cyclic quasi-static *** result shows that the CSTD yields a stable hysteretic response and affords excellent energy dissipation.A parametric study is conducted to investigate the effects of the steel tube height,diameter,and thickness on the seismic performance of the *** with equalstiffness design steel tube dampers,the CSTD exhibits better energy dissipation performance,more stable hysteretic response,and better uniformity in plastic deformation distributions.

关键词： cambered surface steel tube damper energy dissipation capacity finite element model hysteretic performance parametric study

A characteristic modeling method of error-free compression for nonlinear systems

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Control Theory and Technology 2021年第3期19卷 375-383页

作者： Bin Meng yun-bo Zhao Jing-Jing Mu Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control EngineeringBeijingChina Department of Automation University of Science and Technology of ChinaBeijingChina China Aerospace Science and Technology Corporation BeijingChina

The existence of error when compressing nonlinear functions into the coefficients of the characteristic model is known to be a key issue in existing characteristic modeling approaches,which is solved in this work by an error-free compression *** first define a key concept of relevant states with corresponding compressing methods into their coefficients,where the coefficients are continuous and bounded and the compression is ***,we give the conditions for decoupling characteristic modeling for MIMO systems,and sequentially,we establish characteristic models for nonlinear systems with minimum phase and relative order two as well as the flexible spacecrafts,realizing the equivalence in the characteristic model ***,we explicitly explain the reasons for normalization in the characteristic model theory.

关键词： Characteristic modeling Relevant states Error-free compression Flexible spacecraft Normalization

Porous carbon/Fe composites from waste fabric for high-efficiency electromagnetic wave absorption

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Journal of Materials Science & Technology 2022年第31期126卷 266-274页

作者： Jin-bo Cheng Hai-bo Zhao Ai-Ning Zhang Yan-Qin Wang Yu-zhong Wang Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) State Key Laboratory of Polymer Materials EngineeringNational Engineering Laboratory for Eco-Friendly Polymer Materials(Sichuan)College of ChemistrySichuan UniversityChengdu 610064China

Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation ***,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave *** this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high ***,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon ***,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption ***,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 *** work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.

关键词： Up recycling Microwave absorption Waste fabrics Thin thickness

ANTI-PLANE SHEAR CRACK IN A FUNCTIONALLY GRADIENT PIEZOELECTRIC MATERIAL

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Acta Mechanica Solida Sinica 2002年第2期15卷 140-148页

作者： Hu Keqiang zhong Zheng Jin bo Tongji Univ Dept Engn Mech & Technol Shanghai 200092 Peoples R China

The main objective of this paper is to study the singular natureof the crack-tip stress and electric displacement field in afunctionally gradient piezoelectric medium having materialcoefficients with a discontinuous derivative. The problem isconsidered for the simplest possible loading and geometry, namely,the anti-plane shear stress and electric displacement in -plane oftwo bonded half spaces in which the crack is parallel to theinterface.

关键词： functionally gradient material piezoelectric material stress intensityfactors electric dis- placement intensity factors

Left-definite boundary conditions of Sturm-Liouville problems when the interval shrinks to a point

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Applied Mathematics(A Journal of Chinese Universities) 2011年第1期26卷 29-37页

作者： GAO yun-lan WANG zhong WU Hong-you Department of Mathematics Inner Mongolia University of Technology Huhhot 010051 China Department of Mathematics ZhaoQing University Zhaoqing 526061 China Department of Mathematics Northern Illinois University DeKalb IL60115 USA

On the condition that the interval of the problem shrinks to a point, we investigated the separated boundary conditions Sα,β of left-definite Sturm-Liouville problem, and answered the following question： Is there a co ∈ J such that Sα,β is always left-definite or semi-left-definite for the Sturm-Liouville equation for each c ∈ （a, co）？

关键词： Left-definite Sturm-Liouville problem semi-left-definite Sturm-Liouville problem separatedboundary condition.