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Exploiting Unlabeled Data for Neural Grammatical Error Detection

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Journal of Computer Science & Technology 2017年第4期32卷 758-767页

作者： zhuo-ran Liu Yang Liu School of Software Beihang University Beijing 100191 China State Key Laboratory of Intelligent Technology and Systems Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Department of Computer Science and Technology Tsinghua University Beijing 100084 China Jiangsu Collaborative Innovation Center for Language Competence Xuzhou 221009 China

Identifying and correcting grammatical errors in the text written by non-native writers have received increasing attention in recent years. Although a number of annotated corpora have been established to facilitate data-driven grammatical error detection and correction approaches, they are still limited in terms of quantity and coverage because human annotation is labor-intensive, time-consuming, and expensive. In this work, we propose to utilize unlabeled data to train neural network based grammatical error detection models. The basic idea is to cast error detection as a binary classification problem and derive positive and negative training examples from unlabeled data. We introduce an attention-based neural network to capture long-distance dependencies that influence the word being detected. Experiments show that the proposed approach significantly outperforms SVM and convolutional networks with fixed-size context window.

关键词： unlabeled data grammatical error detection neural network

Classification of anti-symmetric solutions to the fractional Lane-Emden system

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Science China Mathematics 2023年第4期66卷 723-744页

作者： Congming Li ran zhuo School of Mathematical Sciences and CMA-Shanghai Shanghai Jiao Tong UniversityShanghai 200240China School of Mathematics and Statistics Huanghuai UniversityZhumadian 463000China

We study the anti-symmetric solutions to the Lane-Emden type system involving fractional Laplacian(-△)^(s)(0 详细信息

We study the anti-symmetric solutions to the Lane-Emden type system involving fractional Laplacian(-△)^(s)(0

关键词： Lane-Emden system fractional Laplacian maximum principle Liouville type theorems existence

Liouville type theorems for Schrdinger systems

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Science China Mathematics 2015年第1期58卷 179-196页

作者： zhuo ran LI Feng Quan Department of Mathematical Sciences Yeshiva University School of Mathematical Sciences Dalian University of Technology

We study positive solutions to the following higher order SchrSdinger system with Dirichlet boundary conditions on a half space： where a is any even number between 0 and n. This PDE system is closely related to the integral system where G is the corresponding Green＇s function on the half space. More precisely, we show that every solution to （0.2） satisfies （0.1）, and we believe that the converse is also true. We establish a Liouville type theorem the non-existence of positive solutions to （0.2） under a very weak condition that u and v are only locally integrable. Some new ideas are involved in the proof, which can be applied to a system of more equations.

关键词： Schrodinger systems poly-harmonic operators Dirichlet boundary conditions method of movingplanes in integral forms Kelvin transforms monotonicity rotational symmetry non-existence

l^(2) Decoupling for Certain Surfaces of Finite Type in R^(3)

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Acta Mathematica Sinica,English Series 2023年第8期39卷 1442-1458页

作者： zhuo ran LI Ji Qiang ZHENG School of Mathematics and Statistics Yancheng Teachers UniversityYancheng 224002P.R.China Institute of Applied Physics and Computational Mathematics P.O.Box 8009Beijing 100088P.R.China

In this article,we establish an 2 decoupling inequality for the surface F_(4)^(2):={(ξ1,ξ2,ξ_(1)^(4)+ξ_(2)^(4)):(ξ1,ξ2)∈[0,1]^(2)}associated with the decomposition adapted to finite type geometry from our previous work[Li,Z.,Miao,C.,Zheng,J.:A restriction estimate for a certain surface of finite type in R^(3).*** ***.,27(4),Paper No.63,24 pp.(2021)].The key ingredients of the proof include the so-called generalized rescaling technique,an l^(2) decoupling inequality for the surfaces{(ξ1,ξ2,φ1(ξ1)+ξ42):(ξ1,ξ2)∈[0,1]^(2)}with φ1 being non-degenerate,reduction of dimension arguments and induction on scales.

关键词： Decoupling inequality finite type reduction of dimension arguments induction on scales

Challenges and Recent Developments of Photoflow-Reversible Deactivation Radical Polymerization(RDRP)

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Chinese Journal of Polymer Science 2021年第9期39卷 1069-1083页

作者： zhuo-ran Zhong Yi-Nan Chen Yang Zhou Mao Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China

Photo-controlled reversible-deactivation radical polymerizati on(photo-RDRP)has been investigated as a"green"and spatiotem-porally controlling pathway for polymer *** the combination of photo-RDRP and flow chemistry has offered opportunities to increase light intensity and enable uniform light irradiation,problems associated with flow approaches still remain for photoflow-RDRP,which has hindered merging flow polymerization with other cutting-edge ***,we summarize challenges and recent achievements in photoflow-RDRP including the development of(a)droplet/slug-flow to regulate reside nee time distribution,(b)mixing techniques to tailor polymer,(c)polymerization in duced self-assembly,and(d)computer-aided *** hope this work will provide in formative knowledge to people in related fields and stimulate novel ideas to promote polymer synthesis in both academia and industry.

关键词： Controlled radical polymerization RDRP Photopolymerization Flow chemistry Flow polymerization

L^(2)Schrödinger Maximal Estimates Associated with Finite Type Phases in R^(2)

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Acta Mathematica Sinica,English Series 2024年第11期40卷 2809-2839页

作者： zhuo ran LI Jun Yan ZHAO Teng Fei ZHAO Department of Mathematics Taizhou UniversityTaizhou225300P.R.China School of Mathematical Sciences Zhejiang Normal UniversityJinhua321004P.R.China School of Mathematics and Physics University of Science and Technology BeijingBeijing100083P.R.China

In this paper,we establish Schrödinger maximal estimates associated with the finite type phaseФ(ξ_(1),ξ_(2)):=ξ_(1)^(m)+ξ_(2)^(m),where m≥4 is an even ***[12],we prove an L2 fractal restriction estimate associated with the surface{(ξ_(1),ξ_(2),Ф(ξ_(1),ξ_(2))):(ξ_(1),ξ_(2)∈[0,]^(2)}as the main result,which also gives results on the average Fourier decay of fractal measures associated with these *** key ingredients of the proof include the rescaling technique from[16],Bourgain-Demeter’sℓ^(2)decoupling inequality,the reduction of dimension arguments from[17]and induction on *** notice that our Theorem 1.1 has some similarities with the results in[8].However,their results do not cover *** arguments depend on the positive definiteness of the Hessian matrix of the phase function,while our phase functions are degenerate.

关键词： Pointwise convergence finite type decoupling reduction of dimension arguments

Microstructure and formation mechanism of SHS joining between C_f/Al composites and TiAl intermetallic with Al–Ni–CuO interlayer

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Rare Metals 2015年第1期34卷 17-21页

作者： zhuo-ran Li Guang-Jie Feng Kai Xu Xiang-Long Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

In this study, it was reported a novel approach for joining Cf/A1 composites and TiA1 intermetallic by self- propagating high-temperature synthesis （SHS）. Mixed powders of 14A1-2Ni-3CuO were used as the SHS inter- layer, and differential thermal analysis test of A1-Ni-CuO interlayer was conducted to analyze the exothermic char- acteristic. Sound joint was got by SHS joining under the conditions of 600 ℃, 30 min, and 5 MPa. The joint was characterized by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and X-ray diffrac- tion （XRD）. TiA13 and NiA13 are, respectively, formed in the TiA1/interlayer and Cf/A1/interlayer interfaces. Reac- tion products of Ni2Al3, NiAl3, A1203, and Cu were observed in the interlayer. And the formation mechanism of SHS joining was investigated.

关键词： SHS Joining Microstructure Formationmechanism A1-Ni-CuO interlayer

Effects of Joining Conditions on Microstructure and Mechanical Properties of C_f/Al Composites and TiAl Alloy Combustion Synthesis Joints

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 405-413页

作者： Guang-Jie Feng zhuo-ran Li Rui-Hua Liu Shi-Cheng Feng State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

Cf/Al composites and TiAl alloy were joined by combustion synthesis in different joining conditions. Effects of additive Cu, joining temperature and holding time on joint microstructure and shear strength were characterized by employing DTA, SEM, EDS, XRD and shear test. Results show that the additive Cu in the Ti-Al-C interlayer could significantly decrease the reaction temperature owing to the emergence of Al--Cu eutectic liquid. Reaction degree of the interlayer was influenced by joining temperature and holding time. Due to the barrier action of formed TiAl3 layer, reaction rate of Ti and Al was determined by the atoms diffusion. The reaction between Ti and AI was more sensitive to the joining temperature rather the holding time. The joints shear strength was influenced by joining condition directly. The maximum shear strength of CS joints was 25.89 MPa at 600 ℃ for 30 rain under 5 MPa. Interface evolution mechanism of the CS joint was analyzed based on the experimental results and phase diagram.

关键词： C/Al composite TiAl alloy Combustion synthesis Interface microstructure Formationmechanism

Microstructure evolution and formation mechanism of laser-ignited SHS joining between Cf/Al composites and TiAl alloys with Ni-Al-Ti interlayer

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Rare Metals 2017年第9期36卷 746-752页

作者： Guang-Jie Feng zhuo-ran Li Shi-Cheng Feng Wei-Jie Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

In this study, Cf/Al composites and TiAl alloys were joined by a new method named laser-ignited selfpropagating synthesis（SHS）. Mixed powders of 63.0Ni-31.9Al-5.1Ti（wt%） were used as joining *** joint was got. The microstructure evolution and formation mechanism of the SHS joint were investigated by scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS） and X-ray diffraction（XRD）. Results show that localized melting occurs on both sides. One γ-Ni（0.35）Al（0.30）Ti（0.35） and two Ni-Al reaction layers form,respectively, in the TiAl/interlayer and Cf/Al/interlayer interfaces. The combustion of Ni-Al-Ti interlayer begins with the sharp reaction of Ni and Al. The interlayer product is a eutectic organization of NiAl and Al-rich γ.

关键词： SHS Joining Microstructure Formationmechanism Ni-Al-Ti interlayer