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On solitary *** 2 A unified perturbation theory for higher-order waves

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Acta Mechanica Sinica 2005年第6期21卷 515-530页

作者： Theodore Yaotsu Wu xinlong wang Wendong Qu California Institute of Technology Pasadena CA 91125 U.S.A. Fellow Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China State Key Laboratory of Modern Acoustics and Institute of Acoustics Nanjing University Nanjing 210093 China California Institute of Technology Pasadena CA 91125 U.S.A PIMCO Newport Beach CA 92660 U.S.A.

A unified perturbation theory is developed here for calculating solitary waves of all heights by series expansion of base flow variables in powers of a small base parameter to eighteenth order for the one-parameter family of solutions in exact form, with all the coefficients determined in rational numbers. Comparative studies are pursued to investigate the effects due to changes of base parameters on （i） the accuracy of the theoretically predicted wave properties and （ii） the rate of convergence of perturbation expansion. Two important results are found by comparisons between the theoretical predictions based on a set of parameters separately adopted for expansion in turn. First, the accuracy and the convergence of the perturbation expansions, appraised versus the exact solution provided by an earlier paper [1] as the standard reference, are found to depend, quite sensitively, on changes in base parameter. The resulting variations in the solution are physically displayed in various wave properties with differences found dependent on which property （e.g. the wave amplitude, speed, its profile, excess mass, momentum, and energy）, on what range in value of the base, and on the rank of the order n in the expansion being addressed. Secondly, regarding convergence, the present perturbation series is found definitely asymptotic in nature, with the relative error δ （n）（the relative mean-square difference between successive orders n of wave elevations） reaching a minimum, δm at a specific order, n = n both depending on the base adopted, e.g. nm,α= 11-12 based on parameter α （wave amplitude）, nm,δ = 15 on δ （amplitude-speed square ratio）, and nm.ε= 17 on ε （ wave number squared）. The asymptotic range is brought to completion by the highest order of n = 18 reached in this work.

关键词： Solitary waves on water Unified perturbation theory Base functions Base parameters Asymptotic representation

Multiscale analysis of heart beat interval increment series and its clinical significance

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Chinese Science Bulletin 2009年第20期54卷 3784-3789页

作者： HUANG XiaoLin NING XinBao wang xinlong Key Laboratory of Modern Acoustics Institute of Biomedical Electronic Engineering Nanjing University Nanjing 210093 China Key Laboratory of Modern Acoustics and Institute of Acoustics Nanjing University Nanjing 210093 China

Analysis of multiscale entropy(MSE) and multiscale standard deviation(MSD) are performed for both the heart rate interval series and the interval increment *** the interval series,it is found that,it is impractical to discriminate the diseases of atrial fibrillation(AF) and congestive heart failure(CHF) unambiguously from the healthy.A clear discrimination from the healthy,both young and old,however,can be made in the MSE analysis of the increment series where we find that both CHF and AF sufferers have significantly low MSE values in the whole range of time scales investigated,which reveals that there are common dynamic characteristics underlying these two different *** addition,we propose the sample entropy(SE) corresponding to time scale factor 4 of increment series as a diag-nosis index of both AF and CHF,and the reference threshold is *** indication that this index can help discriminate sensitively the mild heart failure(cardiac function classes 1 and 2) from the healthy gives a clue to early clinic diagnosis of CHF.

关键词：多尺度间隔临床意义充血性心力衰竭心脏小型企业时间尺度临床诊断

Mechanism and kinetics study on removal of Iron from phosphoric acid by cation exchange resin

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Chinese Journal of Chemical Engineering 2019年第5期27卷 1050-1057页

作者： Xinke Leng Yanjun Zhong Dehua Xu xinlong wang Lin Yang School of Chemical Engineering Sichuan University

Iron element is one of the main impurities in wet-process phosphoric acid and it has a significant impact on the subsequent phosphorus chemical products. This paper studied the feasibility of using Sinco-430 cation exchange resin for iron removal from phosphoric acid. The specific surface area and the total exchange capacity of resin were 8.91 m2·g-1 and 5.18 mmol·g-1, respectively. The sorption mechanism was determined by FTIR and XPS and the results indicated that iron was combined with-SO3 H in resin. The removal process was studied as a function of temperature, H3 PO4 content and mass ratio between resin and solution. The unit mass of resin to remove iron was 0.058 g·g-1 resin when the operating parameters were T = 50 ℃, H3 PO4 content = 27.61 wt%and S/L = 0.1, respectively. Kinetics study demonstrated that pseudo-second-order reaction model fits this study best and the calculated activation energy of overall reaction is 29.10 kJ·mol-1. The overall reaction process was mainly controlled by pore diffusion.

关键词： Purification of wet-process phosphoric acid Cation exchange resin Kinetics models Diffusion models

Influence of Curing Accelerators on the Imidization of Polyamic Acids and Properties of Polyimide Films

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Journal of Wuhan University of Technology(Materials Science) 2016年第5期31卷 1137-1143页

作者：徐勇 ZHAO Anlu wang xinlong XUE Hui LIU Feilong School of Chemical Engineering Nanjing University of Science & Technology Nanjing 210094 China

In order to lower the imidization temperature of polyamic acids（PAA）, the catalytic activities of the curing agents p-hydroxybenzoic acid（PHA）, quinoline（QL）, benzimidazole（BI）, benzotriazole（BTA）, triethylamine（Et_3N） and 1, 8-diazabicyclo [5.4.0]undec-7-ene（DBU） were investigated in the process of thermal imidization of PAA. In addition, the effect of these various curing agents on the thermal stabilities and mechanical properties of the resultant polyimide（PI） films was determined. Quinoline was found to be an effective curing accelerator in the use of two-step method for synthesizing PI. Due to its moderate base strength, low steric crowding effect and moderate boiling point, quinoline could not only accelerate PAA to achieve imidization completely at 180 ℃, but also maintain the mechanical properties and thermal stability of the ordinary PI film. Any residual quinoline could be removed from PI films by heating at 250 ℃ for 4 h.

关键词： polyimide film curing accelerator quinoline low temperature imidization

DenseCL:A simple framework for self-supervised dense visual pre-training

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Visual Informatics 2023年第1期7卷 30-40页

作者： xinlong wang Rufeng Zhang Chunhua Shen Tao Kong The University of Adelaide Australia Zhejiang University China Tongji University China ByteDance AI Lab. China

Self-supervised learning aims to learn a universal feature representation without *** date,most existing self-supervised learning methods are designed and optimized for image *** pre-trained models can be sub-optimal for dense prediction tasks due to the discrepancy between image-level prediction and pixel-level *** fill this gap,we aim to design an effective,dense self-supervised learning framework that directly works at the level of pixels(or local features)by taking into account the correspondence between local ***,we present dense contrastive learning(DenseCL),which implements self-supervised learning by optimizing a pairwise contrastive(dis)similarity loss at the pixel level between two views of input *** to the supervised ImageNet pre-training and other self-supervised learning methods,our self-supervised DenseCL pretraining demonstrates consistently superior performance when transferring to downstream dense prediction tasks including object detection,semantic segmentation and instance ***,our approach significantly outperforms the strong MoCo-v2 by 2.0%AP on PASCAL VOC object detection,1.1%AP on COCO object detection,0.9%AP on COCO instance segmentation,3.0%mIoU on PASCAL VOC semantic segmentation and 1.8%mIoU on Cityscapes semantic *** improvements are up to 3.5%AP and 8.8%mIoU over MoCo-v2,and 6.1%AP and 6.1%mIoU over supervised counterpart with frozen-backbone evaluation protocol.

关键词： Self-supervised learning Visual pre-training Dense prediction tasks

Effects of dry-wet cycles on the mechanical properties of sandstone with unloading-induced damage

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Journal of Mountain Science 2024年第10期21卷 3474-3486页

作者： NAN Gan ZHANG Jiaming LUO Yi wang xinlong HU Zhongyi Faculty of Engineering China University of Geosciences(Wuhan)Wuhan 430074China

Sandstone is the fundamental material in various engineering and construction ***,the mechanical integrity of sandstone can be compromised by initial unloading damage resulting from activities such as engineering ***,this degradation is further exacerbated under periodic dry-wet environmental *** study investigated the effects of dry-wet cycles and unloading on the mechanical properties of jointed fine sandstone using uniaxial and triaxial compression *** tests were performed on rock samples subjected to varying unloading degrees and different numbers of dry-wet *** results demonstrate that with an increase in the unloading degree from 0%to 70%,there is a corresponding decrease in peak stress ranging from 10%to 33%.Additionally,the cohesion exhibits a reduction of approximately 20%to 25%,while the internal friction angle experiences a decline of about 3.5%to 6%.These findings emphasize a significant unloading ***,the degree of peak stress degradation in unloading jointed fine sandstone diminishes with an increase in confining pressure,suggesting that confining pressure mitigates the deterioration caused by dry-wet ***,as the number of dry-wet cycles increases,there is a notable decline in the mechanical properties of the sandstone,evidencing significant dry-wet *** the Drucker Prager criterion,this study establishes a strength criterion and fracture criterion,denoted as σ_(1)(m,n) and K_(T)^(Ⅱ)(m, n), to quantify the combined impacts of dry-wet cycles and unloading on jointed fine sandstone,which provides a comprehensive understanding of its mechanical behavior under such conditions.

关键词： Unloading Dry-wet cycle Jointed fine sandstone Strength criterion fracture criterion Mechanical properties

The Current State and Progress of Mpox Vaccine Research

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China CDC weekly 2024年第7期6卷 118-125页

作者： xinlong wang Zhixia Gu Shugui Sheng Rui Song Ronghua Jin Beijing Key Laboratory of Emerging Infectious Diseases Institute of Infectious DiseasesBeijing Ditan HospitalCapital Medical UniversityBeijingChina National Center for Infectious Diseases Beijing Ditan HospitalCapital Medical UniversityBeijingChina

On July 23,2022,the World Health Organization(WHO)declared the monkeypox(mpox)outbreak a“Public Health Emergency of International Concern.”Since 2022,outbreaks of mpox in many countries around the world have primarily resulted in fatalities among immunocompromised individuals,such as untreated HIV/AIDS *** the eradication of smallpox was declared by the WHO in 1980,the global vaccination against smallpox has been gradually *** also stopped routine smallpox vaccination in *** protective effect of the smallpox vaccine has decreased over time due to aging and declining immunity in those who were *** individuals,timely vaccination against smallpox is an effective means of protection against ***,due to safety concerns with the smallpox vaccine and the limitations of current mpox vaccines,there is no vaccine that is safe,effective,and has low side effects applied in clinical *** article provides a comprehensive review of the development of mpox virus(MPXV)vaccines,their application in special populations,and the current state of vaccine research,considering the etiology,transmission,and prevention of the ***,as an effective method of epidemic prevention,can provide long-term immune protection and effectively reduce the severity of ***,as there is no licensed specific MPXV vaccine available globally,the vaccines currently used for mpox prevention are mostly smallpox *** smallpox vaccines can offer some degree of protection against mpox by activating cross-protection in the body.

关键词： prevention routine protective

Synthesis and characterization of two novel coordination polymers based on the rigid 1H-1,2,3-triazole-4,5-dicarboxylic acid ligand

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Science China Chemistry 2010年第10期53卷 2177-2182页

作者： Gang Yuan KuiZhan Shao DongYing Du xinlong wang ZhongMin Su NE Normal Univ Fac Chem Inst Funct Mat Chem Changchun 130024 Peoples R China

Two novel three-dimensional (3-D) coordination polymers, [Pb(HTDA)]n (1) and [Co5(TDA)2(H2TDA)2(H2O)8]n (2) [H3TDA = 1H-1,2,3-triazole-4,5-dicarboxylic acid], have been prepared by hydrothermal reactions and characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction. Compound 1 is constructed from rod-shaped secondary building units (SBUs) and exhibits a 3-D network with (410·65)(410·63·82) topology. Compound 2 is built up from ligands bridging three different cobalt ions and exhibits a 3-D network with (4·82)3(4·82·103) topology. In addition, the thermal stabilities of the two compounds, the photoluminescence properties of compound 1 and the magnetic properties of compound 2 have been studied.

关键词： coordination polymer hydrothermal reaction 1H-1 2 3-triazole-4 5-dicarboxylic acid secondary building units transition metal

In situ construction of Co/N/C-based heterojunction on biomass-derived hierarchical porous carbon with stable active sites using a Co-N protective strategy for high-efficiency ORR,OER and HER trifunctional electrocatalysts

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Journal of Energy Chemistry 2021年第3期30卷 626-638页

作者： Xuehui Lv Zuoxu Xiao Haoyuan wang xinlong wang Lulu Shan Fuling wang Chuangyu Wei Xiangjie Tang Yanli Chen College of Science School of Materials Science and EngineeringChina University of Petroleum(East China)Qingdao 266580ShandongChina

The facile designs and fabrication of noble metal-free electrocatalysts are highly required to achieve multifunctional catalytic activity with excellent stability in Zn-air batteries,fuel cells and water splitting ***,a heterostructure engineering is applied to construct the high performance Co,Ncontaining carbon-based multifunctional electrocatalysts with the feature of isotype(i.e.n-n type Co_(2)N_(0.67)-BHPC)and anisotype(i.e.p-n type Co_(2)O_(3)-BHPC)heterojunctions for ORR,OER and *** nn type Co_(2)N_(0.67)-BHPC,in which biomass(***)-derived hierarchical porous carbon(BHPC)incorporated with nonstoichiometric active species Co_(2)N_(0.67),is fabricated by using an in situ protective strategy of macrocyclic central Co-N_(4) from CoTPP(5,10,15,20-tetrakis(phenyl)porphyrinato cobalt)precursor through the intermolecularπ-πinteractions between CoTPP and its metal-free analogue H_(2) ***,an unprotected strategy of macrocyclic central Co-N_(4) from CoTPP can afford the anisotype Co_(2)O_(3)-BHPC p-n *** as-prepared n-n type Co_(2)N_(0.67)-BHPC heterojunction exhibited a higher density of Co-based active sites with outstanding stability and more efficient charge transfer at the isotype heterojunction interface in comparison with p-n type Co_(2)O_(3)-BHPC ***,for ORR,Co_(2)N_(0.67)-BHPC exhibits the more positive onset and half-wave potentials of 0.93 and 0.86 V ***,respectively,superior to those of the commercial 20 wt%Pt/C and most of Cobased catalysts reported so *** drive a current density of 10 mA cm^(-2),Co_(2)N_(0.67)-BHPC also shows the lower overpotentials of 0.34 and 0.21 V *** for OER and HER,***,the Zn-air battery equipped with Co_(2)N_(0.67)-BHPC displays higher maximum power density(109 mW cm^(-2))and charge-discharge cycle ***,the anisotype heterojunction Co_(2)O_(3)-BHPC as trifunctional electrocatalyst reveals evidently photoelectroc

关键词： Anisotype heterojunction Isotype heterojunction Multifunctional catalyst Biomass-derived Prophyrin