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Heintze-Karcher Inequality for Anisotropic Free Boundary Hypersurfaces in Convex Domains

数学研究（英文） 2024年第3期57卷 243-258页

作者： Xiaohan Jia Guofang Wang Chao Xia xuwen zhang School of Mathematics Southeast UniversityNanjing 211189China Mathematisches Institut Universität FreiburgErnst-Zermelo-Str.1Freiburg 79104Germany School of Mathematical Science Xiamen UniversityXiamen 361005China

In this paper,we prove an optimal Heintze-Karcher-type inequality for ani-sotropic free boundary hypersurfaces in general convex *** equality is achieved for anisotropic free boundary Wulff shapes in a convex *** appl... 详细信息

关键词： Heintze-Karcher's inequality constant mean curvature free boundary surface capil-lary surface convex cone

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Selective and Coverage Multi-head Attention for Abstractive Summarization 2

Selective and Coverage Multi-head Attention for Abstractive ...

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2019 2nd International Conference on Computer Information Science and Artificial Intelligence, CISAI 2019

作者： zhang, xuwen Liu, Gongshen School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai200240 China

Although the Transformer model has outperformed traditional sequence-To-sequence model in a variety of natural language processing (NLP) tasks, it still suffers from semantic irrelevance and repetition for abstractive text summarization. The main reason is that the long text to be summarized is usually composed of multi-sentences and has much redundant information. To tackle this problem, we propose a selective and coverage multi-head attention framework based on the original Transformer. It contains a Convolutional Neural Network (CNN) selective gate, which combines n-gram features with whole semantic representation to obtain core information from the long input sentence. Besides, we use a coverage mechanism in the multi-head attention to keep track of the words which have been summarized. The evaluations on Chinese and English text summarization datasets both demonstrate that the proposed selective and coverage multi-head attention model outperforms the baseline models by 4.6 and 0.3 ROUGE-2 points respectively. And the analysis shows that the proposed model generates the summary with higher quality and less repetition. © Published under licence by IOP Publishing Ltd.

关键词： Semantics

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Considerations in testing treatment effects on transient event driven health status changes measured by patient reported outcomes

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STATISTICS IN MEDICINE 2019年第29期38卷 5497-5511页

作者： Liu, Jingyuan Legg, Jason C. Mo, May zhang, xuwen Xiamen Univ Sch Econ Wang Yanan Inst Studies Econ Dept StatMOE Key Lab Econometr 422 Siming South Rd Xiamen 361005 Fujian Peoples R China Xiamen Univ Fujian Key Lab Stat Sci 422 Siming South Rd Xiamen 361005 Fujian Peoples R China Amgen Inc Global Biostat Sci Newbury Pk CA USA

Many treatments and drugs are intended to reduce the occurrence of negative events of interest, control the severity of the events, accelerate recovery from the events, or a combination of these effects. While assessing the clinical effect is typically the primary objective of a trial, testing the treatment effect on the health status of patients based on patient reported outcome (PRO) can be a useful component in determining the value of a treatment. Analysis of PROs in this setting, however, face the following challenges: the PRO value immediately after the event occurrence is often not captured, and the effect of the event on health status measured by the PRO is transient as subjects recover over time. Therefore, traditional statistical methods used to assess treatment effects suffer from low power for PROs. In this manuscript, we apply a kernel smoothing technique to estimate before- and after-event PRO values. We also propose new test outcomes based on observed and estimated PRO values and evaluate tests that focus on the tail distributions. We demonstrate that the tail distribution tests using the new outcomes can achieve high power under certain conditions.

关键词： maximum sequential difference modified area under curve patient reported outcome tail distribution test

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Side-Chain-Functionalized Poly(indacenodithiophene-alt-benzothiadizole)s as Stretchable High-Mobility Semiconductors with Improved Elasticity

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MACROMOLECULES 2024年第2期57卷 528-538页

作者： Zhao, Bin Pei, Dandan Shi, Yibo zhang, xuwen zhang, Bo Deng, Yunfeng Han, Yang Geng, Yanhou Tianjin Univ Collaborat Innovat Ctr Chem Sci & Engn Tianjin Sch Mat Sci & Engn Tianjin 300072 Peoples R China Tianjin Univ Tianjin Key Lab Mol Optoelect Sci Tianjin 300072 Peoples R China Collaborat Innovat Ctr Chem Sci & Engn Tianjin Tianjin 300072 Peoples R China BOE Technol Grp Co Ltd BOE Technol Innovat Ctr Beijing 100176 Peoples R China Tianjin Univ Joint Sch Natl Univ Singapore Int Campus Fuzhou 350207 Peoples R China Tianjin Univ Int Campus Fuzhou 350207 Peoples R China

To regulate the mechanical properties of poly(indacenodithiophene-alt-benzothiadizole) (IDT-BT), a high-mobility polymer semiconductor with high ductility but inferior elasticity (plastic deformation onset strain (PdOS) < 10%), triisopropylsilyl (TIPS), hydroxyl (OH), and 2-ureido-4[1H]-pyrimidone (UPy) groups were introduced into its side chain ends. The incorporation of bulky and neutral TIPS groups led to slightly increased ductility but had no obvious influence on the elasticity of the polymer. The presence of OH groups resulted in enhanced elasticity without sacrificing ductility. However, high-content (20 mol %) OH-functionalized side chains were necessary to improve PdOS to above 30% due to the weak and dynamic nature of formed hydrogen bonds. In contrast, incorporating a small amount of UPy groups, capable of forming strong quadruple hydrogen bonds, in side chains could significantly improve the elasticity of the polymer. A PdOS of above 40%, along with a crack onset strain of similar to 100% and decent hole mobility of similar to 0.6 cm(2) V(-1)s(-1), was demonstrated for polymer UPy-5% that contained 5 mol % UPy-functionalized side chains. Because of excellent elasticity, UPy-5% films displayed stable mobility against cyclic stretching, releasing up to 500 cycles at a tensile strain of 30%.

关键词： Deformation Elasticity Nucleic acid structure Polymers Thin films

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ISAR Imaging Based on Block Sparse Smoothed L0 Norm Recovery Algorithm 2

ISAR Imaging Based on Block Sparse Smoothed L0 Norm Recovery...

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2019 2nd International Conference on Advanced Algorithms and Control Engineering, ICAACE 2019

作者： Feng, Junjie zhang, xuwen Wang, Yonghui School of Electrical Engineering Liupanshui Normal University Liupanshui GUIZHOU553004 China College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing211106 China

In order to obtain high resolution inverse synthetic aperture radar (ISAR) sparse images, a block sparse signal recovery ISAR imaging algorithm is proposed by considering the cluster characteristics of target in this paper. Firstly, the ISAR sparse imaging model is established, the imaging is converted to L0 norm optimization problem. Secondly, one negative exponential function sequence is used as smoothed function to approach the block L0 norm. Finally, the revised step is added to ensure solving the optimization problem along the steepest descent gradient direction and the cost function is updated for the next loop. Simulation results verify the proposed algorithm is effective. © Published under licence by IOP Publishing Ltd.

关键词： Inverse synthetic aperture radar

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Isothermal Stage Kinetics of Direct Coal Liquefaction for Shenhua Shendong Bituminous Coal

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ENERGY & FUELS 2015年第11期29卷 7526-7531页

作者： Jiang, Hongbo Wang, Xiuhui Shan, Xiangen Li, Kejian zhang, xuwen Cao, Xueping Weng, Huixin E China Univ Sci & Technol Res Inst Petr Proc Shanghai 200237 Peoples R China Natl Engn Lab Direct Coal Liquefact Shanghai 201108 Peoples R China

To study the direct coal liquefaction in the isothermal stage of Shenhua Shendong bituminous coal, the direct coal liquefaction with an iron-based catalyst was carried out in a 0.01 ton/day continuous tubular facility in the temperature range of 445-465 degrees C, with hydrogenated anthracene and wash oil as the solvent. An eight-lump kinetic model of the isothermal stage was proposed, and the kinetic parameters were estimated. The result showed that, in the isothermal stage, the oil was mainly obtained from pre-asphaltene and asphaltene (PAA) rather than from coal directly. The model was valid for the isothermal stage of direct coal liquefaction.

关键词： TEMPERATURE RANGE Mentoring Coal liquefaction absorbent oil kinetic model stream stage Kinetic parameters bituminous coal

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The order and disorder of higher education system 6

The order and disorder of higher education system

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6th International Conference on Information Management and Technology, CIMTECH 2021

作者： zhang, xuwen Chi, Jingming Song, Jing Graduate School of Education Dalian University of Technology Dalian China Liaoning Police College Dalian China

ISBN: (纸本)9781450385015

Higher education system is not only a complex nonlinear system, but also a complex adaptive system;Order and disorder is one of the most important concepts, the system works from disorderly to orderly is also an adaptive result. In this paper, the characteristics of higher education system are analyzed from the point of view of complex adaptive system, and the order and disorder existing in higher education system and the transformation between them are analyzed by combining the theory of dissipative structure in complexity science and the thought of synergetics, in order to understand the operation law of higher education system more clearly. © 2021 ACM.

关键词： Adaptive systems

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Quinoidal-Diketopyrrolopyrrole-Based Low-Bandgap n-Type Conjugated Polymers via Direct Arylation Polycondensation: Chalcogen Effects on Structures and Properties

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MACROMOLECULES 2024年第19期57卷 9006-9016页

作者： Rao, Mei Wang, Pai Shi, Yibo zhang, xuwen Han, Yang Deng, Yunfeng Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Mol Optoelect Sci Tianjin 300072 Peoples R China Tianjin Univ Key Lab Organ Integrated Circuits Minist Educ Tianjin 300072 Peoples R China Collaborat Innovat Ctr Chem Sci & Engn Tianjin Tianjin 300072 Peoples R China

Low-bandgap conjugated polymers (CPs) with strong absorption in the short-wave infrared region usually show ambipolar characteristics. Herein, three low-bandgap CPs, that is, PQF, PQT, and PQS, with unipolar n-type transport behavior were synthesized via direct arylation polycondensation (DArP) with quinoids based on terchalcogenophene-flanked diketopyrrolopyrrole (DPP) derivatives as C-Br monomers and less electron-rich (E)-1,2-bis (3,4-difluorothien-2-yl) ethene (4FTVT) as a C-H monomer, and the chalcogen effects on the isomerism of the quinoids and the properties of the resultant CPs were investigated. Thiophene-flanked DPP-containing quinoids are the mixtures of (E, E), (E, Z), and (Z, Z) isomers, while the sole (E, E) isomer is found in furan-flanked DPP-based quinoids and (Z, Z) isomer is dominant in the quinoids based on selenophene-flanked DPP. The quinoidal monomers are stable to undergo DArP. All three CPs show lower bandgaps of similar to 1.1 eV and unipolar n-type transport behavior with field-effect electron mobility (mu e) above 0.1 cm2 V-1 s(-1). Among them, the polymer PQF, comprising furan-flanked DPP, exhibits the highest mu e of 0.21 cm2 V-1 s(-1), possibly attributed to the simple chain conformation. This study provides a strategy to design low-bandgap unipolar n-type polymer semiconductors.

关键词： n-type conjugated polymers quinoidal structures low bandgap direct arylation polycondensation chalcogen effect

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Kinetics of naphthalene catalytic hydrogenation under high temperature and high pressure

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PETROLEUM SCIENCE AND TECHNOLOGY 2020年第3期38卷 266-270页

作者： Bie, Shiquan Jiang, Hongbo Wang, Wei Shu, Geping zhang, xuwen Wang, Hongxue Gao, Shansong East China Univ Sci & Technol Res Inst Petr Proc 130 Meilong Rd Shanghai Peoples R China East China Univ Sci & Technol Int Joint Res Ctr Green Energy Chem Engn Shanghai Peoples R China China Shenhua Coal Liquid & Chem Shanghai Res Ins Natl Engn Lab Direct Coal Liquefact Shanghai Peoples R China

The catalytic hydrogenation reaction of naphthalene was carried out on the Ni-Mo/Al2O3 catalyst by using a constant-temperature fixed-bed reactor with the temperature ranging from 315 degrees C to 400 degrees C and pressure ranging from 12 to 20 MPa. The model of naphthalene catalytic hydrogenation was proposed based on the Langmuir-Hinshelwood-Hougen-Watson competitive adsorption theory, and the model parameters were estimated. The results show that the hydrogenation reaction of naphthalene to tetralin is fast, and tetralin tends to form trans-decalin, while there is no direct conversion between trans-decalin and cis-decalin. The reaction activation energy of naphthalene to tetralin is the smallest.

关键词： Catalytic hydrogenation high temperature and high pressure kinetics naphthalene Ni-Mo Al2O3

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C-H/C-H Oxidative Direct Arylation Polycondensation to Isoindigo-Based n-Type Conjugated Polymers

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MACROMOLECULES 2024年第9期57卷 4158-4166页

作者： Shi, Yibo zhang, xuwen Wang, Tianzuo Rao, Mei Han, Yang Deng, Yunfeng Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Key Lab Organ Integrated Circuits Minist Educ Tianjin 300072 Peoples R China Tianjin Univ Tianjin Key Lab Mol Optoelect Sci Key Lab Organ Integrated Circuits Minist Educ Tianjin 300072 Peoples R China Collaborat Innovat Ctr Chem Sci & Engn Tianjin Tianjin 300072 Peoples R China Tianjin Univ Joint Sch Natl Univ Singapore & Tianjin Univ Int Campus Fuzhou 350207 Peoples R China

Two high molecular weight conjugated polymers (CPs), i.e., poly[N,N '-bis(4-tetradecyloctadecyl)-7,7 '-difluoroisoindigo-alt-2,2 '-bithiazole] (P2FI2Tz) and poly[N,N '-bis(4-tetradecyloctadecyl)-5,5 ',7,7 '-tetrafluoroisoindigo-alt-2,2 '-bithiazole] (P4FI2Tz), were synthesized via C-H/C-H oxidative direct arylation polycondensation (Oxi-DArP) using PdCl2/CuCl/Cu(OAc)(2) as catalytic system and chlorobenzene as solvent. Both polymers are unipolar n-type semiconductors with electron mobility (mu(e)) > 0.2 cm(2) V-1 s(-1), attributed to their low-lying highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbital (LUMOs), which are -6.01/-3.69 and -6.24/-3.82 eV for P2FI2Tz and P4FI2Tz, respectively. P2FI2Tz was also synthesized via C-Br/C-H direct arylation polycondensation (DArP) and Stille polycondensation. The resultant polymers P2FI2Tz-D and P2FI2Tz-S showed slightly lower mu(e) compared to Oxi-DArP-made polymer (P2FI2Tz-O1) with a similar molecular weight. Notably, Oxi-DArP is much faster and more efficient than DArP and Stille polycondensation. P2FI2Tz with a number-average molecular weight (M-n) above 40 kDa, was obtained in 9 h of Oxi-DArP, significantly shorter than 24 h with DArP and Stille polycondensation. P2FI2Tz with a M-n as high as 191 kDa could be synthesized via Oxi-DArP by extending the polymerization time to 16 h. Our results prove Oxi-DArP to be an efficient protocol to synthesize polymer semiconductors. This is also the first comparative study on three methods, i.e., Oxi-DArP, DArP, and Stille polycondensation.

关键词： Condensation Diffraction Monomers Organic reactions Polymers

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