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Modification of nanometer calcium carbonate for water-borne architectural coatings

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Journal of China University of Mining and Technology 2008年第1期18卷 76-81页

作者： WANG xun-qiu jiang Deng-gao School of Chemical Engineering Zhengzhou University Zhengzhou Henan 450002 China

A kind of modifier was synthesized to modify the surface of nanometer calcium carbonate （abbreviated as nano-CaCO3）, which is used in architectural coatings. The modification technology of the nano-CaCO3 was studied through orthogonal experimental methods. The factors studied were rotation speed, modifier dosage, emulsification temperature, emulsification time and heat aging time after emulsification. Optimized conditions for modification of the surface were： rotation speed 16000 r/min; modifier dosage 3%; emulsification temperature 75 ℃; emulsification time 60 min and aging time 40 min. The modified nano-CaCO3 was also studied by size-distribution measurements, transmission electron microscopy, infrared spectroscopy and thermal analysis. The results show that the size distribution of the modified nano-CaCO3 is uniform and that there are chemi-sorption and physi-sorption between the nano-CaCO3 and the modifier. Compared to traditional architectural coatings without nano-CaCO3, the nanometer composite coatings are obviously improved in respect to dirt resistance, scrub resistance, thixotropy, water resistance, alkalinity resistance and aging resistance.

关键词： nanometer calcium carbonate surface modification modifier architectural coatings

Structural performance of a façade precast concrete sandwich panel enabled by a bar-type basalt fiber-reinforced polymer connector

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Frontiers of Structural and Civil Engineering 2023年第1期17卷 122-137页

作者： Junqi HUANG Qing jiang xun CHONG Xianguo YE Caihua LIU School of Civil and Hydraulic Engineering Hefei University of TechnologyHefei 230009China Anhui Civil Engineering Structures and Materials Laboratory Hefei 230009China

In this study,a novel diagonally inserted bar-type basalt fiber reinforced polymer(BFRP)connector was proposed,aiming to achieve both construction convenience and partially composite behavior in precast concrete sandwich panels(PCSPs).First,pull-out tests were conducted to evaluate the anchoring performance of the connector in concrete after exposure to different ***,direct shear tests were conducted to investigate the shear performance of the *** the test on the individual performance of the connector,five façade PCSP specimens with the bar-type BFRP connector were fabricated,and the out-of-plane flexural performance was tested under a uniformly distributed *** investigating parameters included the panel length,opening condition,and boundary *** results obtained in this study primarily indicated that 1)the bar-type BFRP connector can achieve a reliable anchorage system in concrete;2)the bar-type BFRP connector can offer sufficient stiffness and capacity to achieve a partially composite PCSP;3)the boundary condition of the panel considerably influenced the out-of-plane flexural performance and composite action of the investigated façade PCSP.

关键词： precast concrete sandwich panel basalt fiber reinforced polymer pull-out performance shear performance out-of-plane flexural performance

Block Copolymer Colloidal Particles with Unique Structures through Three-dimensional Confined Assembly and Disassembly

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Chinese Journal of Polymer Science 2019年第8期37卷 744-759页

作者： jiang-ping Xu Jin-Tao Zhu Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of Education Hubei Key Laboratory of Materials Chemistry and Service Failure School of Chemistry and Chemical Engineering Huazhong University of Science and Technology (HUST) Wuhan 430074 China State Key Laboratory of Materials Processing and Mold Technology HUST Wuhan 430074 China

Structured block copolymer(BCP) particles have gained increasing attention due to their potential applications in separation,catalysis, controlled release, and other fields. Three-dimensional(3D) confined assembly has been proved as a facile yet robust approach for generating BCP particles with controllable shapes and internal structures. In this feature article, we summarized the preparation of structured polymeric particles through 3D confined self-assembly of BCPs. The effects of interfacial interactions, degree of confinement,and additives on the shape and internal structure of BCP microparticles were comprehensively discussed. In addition, we highlighted the recent progress in using disassembly as a route to synthesize colloidal particles with unique structures. Two strategies were introduced in this part:(a) disassembling the discrete domains resulted in mesoporous microparticles;(b) disassembling the continuous domains led to the dissociation of microparticles into micelle-like nano-objects. The applications of the structured colloidal particles in photonic crystals,controlled release, and directed growth of inorganic materials were also presented. Finally, we discussed the current challenges and future opportunities in this promising area.

关键词： Block copolymers Self-assembly Confinement Polymer particles Nano-objects

Adaptive synchronization of a class of fractional-order complex-valued chaotic neural network with time-delay

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Chinese Physics B 2021年第12期30卷 248-253页

作者： Mei Li Ruo-xun Zhang Shi-ping Yang College of Physics Hebei Normal UniversityShijiazhuang 050024China Department of Computer Science North China Electric Power UniversityBaoding 071003China College of Primary Education Xingtai UniversityXingtai 054001China

This paper is concerned with the adaptive synchronization of fractional-order complex-valued chaotic neural networks(FOCVCNNs)with *** chaotic behaviors of a class of fractional-order complex-valued neural network are ***,based on the complex-valued inequalities of fractional-order derivatives and the stability theory of fractional-order complex-valued systems,a new adaptive controller and new complex-valued update laws are proposed to construct a synchronization control model for fractional-order complex-valued chaotic neural ***,the numerical simulation results are presented to illustrate the effectiveness of the developed synchronization scheme.

关键词： adaptive synchronization fractional calculus complex-valued chaotic neural networks time-delay

Statistical properties of fatigue damage of Gaussian random loadings

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航空动力学报 2014年第3期29卷 596-603页

作者： CHENG Hong-wei TAO Jun-yong CHEN xun jiang Yu Science and Technology on Integrated Logistics Support Laboratory College of Mechatronic Engineering and AutomationNational University of Defense Technology

Firstly,the fatigue damages associated with the random loadings were always deemed as highcycle or very-high-cycle fatigue problems,and based on Chebyshev theorem,the number of rainflow cycles in a given time interval could be recognized as a constant by neglecting its ***,the randomness of fatigue damage induced by the distribution of rainflow cycles was *** to central limit theorem,the fatigue damage could be assumed to follow Gaussian distribution,and the statistical parameters:mean and variance,were derived from Dirlik's ***,the proposed method was used to a simulate Gaussian random loading and the measured random loading from an *** with observed results were carried out *** the first example,the relative errors of the proposed method are 2.29%,3.52%and 1.16%for the mean,standard deviation and variation coefficient of fatigue damage,*** the second example,these relative errors are 11.70%,173.32%and 18.20%,and the larger errors are attributable to non-stationary state of the measured loading to some extent.

关键词： random loading fatigue damage rainflow counting probability density function rainflow cycle range

A spherical parameterization approach based on symmetry analysis of triangular meshes

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 1009-1017页

作者： Jian-ping HU Xiu-ping LIU Zhi-xun SU Xi-quan SHI Feng-shan LIU School of Mathematical Sciences Dalian University of Technology Dalian 116024 China Department of Applied Mathematics and Theoretical Physics Delaware State University Dover DE 19901 USA

We present an efficient spherical parameterization approach aimed at simultaneously reducing area and angle dis-tortions. We generate the final spherical mapping by independently establishing two hemisphere parameterizations. The essence of the approach is to reduce spherical parameterization to a planar problem using symmetry analysis of 3D meshes. Experiments and comparisons were undertaken with various non-trivial 3D models, which revealed that our approach is efficient and robust. In particular, our method produces almost isometric parameterizations for the objects close to the sphere.

关键词： Triangular mesh Spherical parameterization Symmetry analysis

Improved positioning algorithm based on two step least square in NLOS environments

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 58-63页

作者： WU Shi-xun LI Ji-ping-yin LIU Shou Department of Electronics and Communication Engineering Central China Normal University Wuhan 430079 China

Non-line-of-sight （NLOS） propagation is a major source of error for accurate time-of-arrival （TOA） location estimation. The two-step least square （LS） method, which does not need any information about the distribution of the NLOS error, has been studied in related researches to provide efficient location estimation of the mobile terminal （MT）. By observing the estimation of the error covariance matrix in the two-step LS method, this paper finds that the measured distances are more suitable than the initial estimated distances by maximum likelihood （ML） algorithm in NLOS environments. Moreover, by making use of the geometry relations among fixed terminals （FTs）, some measured distances which are corrupted by big NLOS errors may be reduced. Further, an iteration method can be adopted to further improve the performance of the algorithm. Accordingly, an improved algorithm based on the two-step LS method is proposed. Simulation results demonstrate that the improved algorithm has better performance than the two-step LS method and converges more quickly. Meanwhile, it is robust in different NLOS environments.

关键词： NLOS propagation TOA least square position algorithm maximum likelihood

The Weyl’s Theorem and Its Perturbations in Semisimple Banach Algebra

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Acta Mathematica Sinica,English Series 2021年第5期37卷 675-688页

作者： Ying Ying KONG Li Ning jiang Yan xun REN School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081P.R.China

Denote a semisimple Banach algebra with an identity e by *** paper studies the Fredholm,Weyl and Browder spectral theories in a semisimple Banach algebra,and meanwhile considers the properties of the Fredholm element,the Weyl element and the Browder ***,for a∈A,we give the Weyl’s theorem and the Browder’s theorem for a,and characterize necessary and sufficient conditions that both a and f(a)satisfy the Weyl’s theorem or the Browder’s theorem,where f is a complex-valued function analytic on a neighborhood ofσ(a).In addition,the perturbations of the Weyl’s theorem and the Browder’s theorem are investigated.

关键词： Semisimple Banach algebra Fredholm element Browder element Weyl’s theorem perturbation

Clinical manifestations of respiratory syncytial virus infection and the risk of wheezing and recurrent wheezing illness:a systematic review and meta‑analysis

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World Journal of Pediatrics 2023年第11期19卷 1030-1040页

作者： Ming‑Yue jiang Yu‑ping Duan xun‑Liang Tong Qiang‑Ru Huang Meng‑Meng Jia Wei‑Zhong Yang Lu‑Zhao Feng School of Population Medicine and Public Health Chinese Academy of Medical Sciences and Peking Union Medical College#9 Dong Dan San TiaoDongcheng DistrictBeijing 100730China Department of pulmonary and critical care medicine Beijing Hospital/National Gerontology Center/Institute of GerontologyChinese Academy of Medical SciencesBeijing 100730China State Key Laboratory of Respiratory Health and Multimorbidity Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Key Laboratory of Pathogen Infection Prevention and Control(Peking Union Medical College) Ministry of EducationBeijingChina

Background Respiratory syncytial virus(RSV)infection in infants is a global health *** aimed to investigate the common manifestations of RSV infection by age group and human development index(HDI)level and to assess its association with the development of wheezing and recurrent wheezing *** We searched the literature published between January 1,2010 and June 2,2022 in seven *** included common manifestations and long-term respiratory outcomes of RSV infection in ***-and fixed-effect models were used to estimate the effect size and their 95%confidence *** analysis was conducted by age and HDI *** review was registered in PROSPERO(CRD42022379401).Results The meta-analysis included 47 *** top five manifestations were cough(92%),nasal congestion(58%),rhinorrhea(53%),shortness of breath(50%),and dyspnea(47%).The clinical symptoms were most severe in *** our analysis,compared to very high and high HDI countries,fewer studies in medium HDI countries reported related manifestations,and no study in low HDI countries reported *** RSV-infected infants were more likely to develop wheezing than the non-infected infants[odds ratio(OR),3.12;95%CI,2.59–3.76]and had a higher risk of developing wheezing illnesses after recovery(OR,2.60;95%CI,2.51–2.70).Conclusions Cough and shortness of breath are common manifestations of RSV *** attention should be given to infants and areas with low HDI *** current findings confirm an association between RSV infection and wheezing or recurrent wheezing illness.

关键词： Clinical manifestations infants infection Recurrent wheezing Respiratory syncytial virus infection Wheezing