检索结果-南通市图书馆

Environmental Simulation Experiments of 3D-C/SiC Composites with Different PyC Interfacial Layers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2003年第z1期19卷 77-80页

作者： ning dong Yongdong XU Laifei CHENG Litong ZHANG State Key Laboratory of Solidification Northwestern Polytechnical University Xi′an 710072 China State Key Laboratory of Solidification Northwestern Polytechnical University Xi′an 710072 China State Key Laboratory of Solidification Northwestern Polytechnical University Xi′an 710072 China State Key Laboratory of Solidification Northwestern Polytechnical University Xi′an 710072 China

A series of 3D-C/SiC composites with different pyrolytic carbon (PyC) interracial layers (about 20～300 nm thick)were prepared by chemical vapor infiltration. Simulation experiments at different temperatures were performed byexposing C/SiC specimens in single and coupling gases partial pressure atmospheres, namely, O2, H2O vapor andmolten salt (Na+) vapor. It suggested that at intermediate temperature range (about 600～800℃) a dramatic effectof PyC thickness on the weight and strength change of C/SiC was shown, which was mainly influenced by O2 partialpressure; at high temperature range (about 1200～1300℃) the effect was not obvious relatively, which might beinfluenced by H2O vapor partial pressure; and finally at very high temperature range (＞1500℃) the molten saltvapor was the factor of most possibility affecting the weight change of C/SiC.

关键词： C/SiC, Interfacial layer, Simulation experiment

Epitaxial Growth of Multi-structure SnO_2 by Chemical Vapor Deposition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 946-950页

作者： dong-ning He Peter Hodgson Wei-Min Gao Agricultural Product Processing Research Institute Chinese Academy of Tropical Agricultural Sciences Institute for Frontier Materials Deakin University Centre of Excellence in Engineered Fibre Composites(CEEFC) Faculty of HealthEngineering and SciencesUniversity of Southern Queensland

The nanowire and whisker heterostructures of tin dioxide were fabricated by the chemical vapor deposition *** was demonstrated that various structures of tin oxide can be obtained by controlling the thickness of gold layer and the partial pressure of source vapor at growing sites.12.5 and 25 nm thicknesses are preferable for the epitaxial growth of nanowires and heterostructure through vapor–liquid–solid mechanism,*** tin dioxide whiskers with core-shell structure were fabricated by vapor–solid ***,the influences of various factors on the tin dioxide growth are also discussed.

关键词： Nanostructure Heterostructure Tin dioxide Chemical vapor deposition Carbothermal method

Promotional effect of cobalt doping on catalytic performance of cryptomelane-type manganese oxide in toluene oxidation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第4期126卷 263-274页

作者： ning dong Mengyue Chen Qing Ye Dan Zhang Hongxing Dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceSchool of Environmental and Chemical EngineeringFaculty of Environment and LifeBeijing University of TechnologyBeijing 100124China R&D Department of Atmospheric Prevention and Control Technology Guangdong Suncere Technology Co.Ltd.Guangzhou 510220China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Environmental Chemical EngineeringSchool of Environmental and Chemical EngineeringFaculty of Environment and LifeBeijing University of TechnologyBeijing 100124China

The cryptomelane-type manganese oxide (OMS-2)-supported Co (x Co/OMS-2;x=5,10,and15 wt.%) catalysts were prepared via a pre-incorporation *** as-prepared materials were used as catalysts for catalytic oxidation of toluene (2000 ppmV).Physical and chemical properties of the catalysts were measured using the X-ray diffraction (XRD),Fourier transform infrared spectroscopic (FT-IR),scanning electron microscopic (SEM),X-ray photoelectron spectroscopy (XPS),and hydrogen temperature-programmed reduction (H_(2)-TPR)*** all of the catalysts,10Co/OMS-2 performed the best,with the T90%,specific reaction rate at 245℃,and turnover frequency at 245℃ (TOFCo) being 245℃,1.23×10^(-3)moltoluene/(gcat·sec),and 11.58×10^(-3)sec-1for toluene oxidation at a space velocity of 60,000mL/(g·hr),*** excellent catalytic performance of 10Co/OMS-2 were due to more oxygen vacancies,enhanced redox ability and oxygen mobility,and strong synergistic effect between Co species and OMS-2 ***,in the presence of poisoning gases CO_(2),SO_(2)or NH_(3),the activity of 10Co/OMS-2 decreased for the carbonate,sulfate and ammonia species covered the active sites and oxygen vacancies,*** the activation treatment,the catalytic activity was partly *** good low-temperature reducibility of 10Co/OMS-2 could also facilitate the redox process accompanied by the consecutive electron transfer between the adsorbed O_(2)and the cobalt or manganese *** the oxidation process of toluene,the benzoic and aldehydic intermediates werefirst generated,which were further oxidized to the benzoate intermediate that were eventually converted into H_(2)O and CO_(2).

关键词： Cryptomelane-type manganese oxide Cobalt doping Volatile organic compound Toluene oxidation

An investigation on catalytic performance and reaction mechanisms of Fe/OMS-2 for the oxidation of carbon monoxide, ethyl acetate, and toluene

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第2期34卷 258-268页

作者： ning dong Mengyue Chen Qing Ye Dan Zhang Hongxing Dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceSchool of Environmental and Chemical EngineeringFaculty of Environment and LifeBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Environmental Chemical EngineeringSchool of Environmental and Chemical EngineeringFaculty of Environment and LifeBeijing University of TechnologyBeijing 100124China

The octahedral molecular sieve(OMS-2)-supported Fe( xFe/OMS-2: x = 1, 3, 5, and 10) catalysts were prepared using the pre-incorporation method. Physicochemical properties of the as-synthesized materials were characterized by means of various techniques, and their catalytic activities for CO, ethyl acetate, and toluene oxidation were evaluated. Among all of the samples, performed the best, with the reaction temperature required to achieve 90% conversion( T 90%) being 160 ℃ for CO oxidation, 210 ℃ for ethyl acetate oxidation, and 285 ℃ for toluene oxidation. Such a good catalytic performance of 5Fe/OMS-2 was associated with its high(Mn^(3+) + Mn^(2+)) content and adsorbed oxygen species concentration, and good lowtemperature reducibility and lattice oxygen mobility as well as strong interaction between Fe and OMS-2. In addition, catalytic mechanisms of the oxidation of three pollutants over the 5Fe/OMS-2 catalyst were also studied. It was found that CO, ethyl acetate or toluene was first adsorbed, then the related intermediates were formed, and finally the formed intermediates were completely converted into CO_(2) and H_(2)O.

关键词： Cryptomelane-type OMS-2 Supported iron catalyst CO oxidation Volatile organic compound oxidation Toluene oxidation

Duplication of 19q (13.2-13.31) associated with comitant esotropia: A case report

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第20期9卷 5526-5534页

作者： Yue-Lan Feng ning-dong Li Department of Ophthalmology National Center for Children's HealthBeijing Children’s HospitalCapital Medical UniversityBeijing 100045China Department of Ophthalmology First Hospital Affiliated to Baotou Medical CollegeBaotou 014010Inner Mongolia Autonomous RegionChina

BACKGROUND Comitant esotropia is the most common form of *** is caused by heterogeneous environmental and genetic risk *** pure duplication of the long arm of chromosome 19 is a rare *** 8 patients with partial trisomy of the long arm of chromosome 19q have been reported to ***,we describe a girl with pure duplication of 19q,who was diagnosed with congenital esotropia,microcephaly,and gallbladder *** SUMMARY The patient was diagnosed with esotropia when she was *** Krimsky method showed+50 prism diopters in the primary gaze *** additional abnormal findings were observed following slit lamp and fundus examination,but the features of the full-field electroretinogram showed a decreased amplitude and increased implicit *** resonance imaging showed ventriculomegaly with thinning of the corpus callosum and splenium in her brain.A 4.42 Mb mosaic duplication within 19q13.2-q13.31 region(chr19:39,343,725 to 43,762,586)was detected by microarray comparative genomic *** Strabismus is reported in many live borns with pure duplication of *** important clinical characteristic indicates that the candidate genes fundamental for this phenotype may be narrowed to genes within the 19q13.3-q13.31 *** were two candidate genes observed that may contribute to the comitant esotropia phenotype,namely XRCC1(19:43,543,311)and SMG9(19:43,727,991).

关键词： Duplication 19q Esotropia Strabismus XRCC1 SMG9 Case report

Doubling Algorithm for Nonsymmetric Algebraic Riccati Equations Based on a Generalized Transformation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2018年第6期10卷 1327-1343页

作者： Bo Tang Yunqing Huang ning dong School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and EngineeringKey Laboratory of Intelligent Computing and Information Processing of Ministry of EducationXiangtan UniversityXiangtan 411105HunanChina School of Science Hunan City UniversityYiyang 413000HunanChina School of Science Hunan University of TechnologyZhuzhou 412000HunanChina

We consider computing the minimal nonnegative solution of the nonsymmetric algebraic Riccati equation with *** is well known that such equations can be efficiently solved via the structure-preserving doubling algorithm(SDA)with the shift-and-shrink transformation or the generalized Cayley *** this paper,we propose a more generalized transformation of which the shift-and-shrink transformation and the generalized Cayley transformation could be viewed as two special ***,the doubling algorithm based on the proposed generalized transformation is presented and shown to be ***,the convergence result and the comparison theorem on convergent rate are *** numerical experiments show that the doubling algorithm with the generalized transformation is efficient to derive the minimal nonnegative solution of nonsymmetric algebraic Riccati equation with M-matrix.

关键词： Shift-and-shrink transformation generalized Cayley transformation doubling algorithm nonsymmetric algebraic Riccati equation

Chaotic Particle Swarm Optimization Algorithm Parametric Identification of Bouc-Wen hysteresis Model for Piezoelectric Ceramic Actuator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chaotic Particle Swarm Optimization Algorithm Parametric Ide...

Broadband Source Ranging in Shallow Water Using the Ω-Interference Spectrum

第25届中国控制与决策会议

作者： ning dong Hongjuan Li Xiangdong Liu Key Laboratory for Intelligent Control & Decision of Complex Systems Beijing Institute of Technology School of Automation Beijing Institute of Technology

ISBN: (纸本)9781467355339

A chaotic particle swarm optimization (CPSO) algorithm is proposed by introducing chaos state into the original Particle Swarm Optimization (PSO) which aims to solving the flaws of easy plunging into local optimum and losing search ability in the last period for the fast particle velocity decrease. CPSO algorithm takes advantage of the ergodicity, randomicity, and regularity of chaos to make chaotic searching for the global extremun at the same time with the particle swarm optimization. This algorithm synthesizes the high efficiency of global optimization of PSO algorithm and the ergodicity and randomicity of local search of chaotic algorithm. This paper utilizes aforementioned algorithm to identify the Bouc-Wen hysteresis model for piezoelectric ceramic actuators (PCA). The experimental results show that the model identified by CPSO algorithm has better performance than that by PSO algorithm.

关键词： Chaotic Particle Swarm Optimization Bouc-Wen Identification Piezoelectric Ceramic Actuator

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第6期27卷 110-113页

作者： ZHAO Zhen-dong WANG ning GAO Da-Zhi WANG Hao-Zhong College of Information Science and Engineering Ocean University of China Qingdao 266100

The concept of the waveguide invariant is revisited and a simple relationship between the range of source and the quasi-period of the acoustic interference spectrum in the frequency domain （Ω-interference spectrum） is derived. Then a method for a broadband source ranging in shallow water using a single receiver and a broadband guide source, requiring no modeling and no knowledge about the ocean environment, is proposed. The method is validated by simulation and verified with the experimental data.

关键词： Methods Broadband Source Ranging Ω-Interference Spectrum

Corrosion mechanism of Zn-Al-Mg-coated steel in simulated polluted marine atmosphere

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第9期31卷 2294-2307页

作者： Pei-dong ning Li-yuan Xiao Jin Wang Qian-qian Liu Kui Xiao Research Institute JISCO Hongxing Iron and Steel Co.Ltd.Jiayuguan735100GansuChina Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China

The corrosion behaviour of zinc–aluminium–magnesium-coated steel in a simulated polluted marine atmospheric environment was ***,an indoor ageing acceleration test was carefully designed by simulating a polluted marine *** objective was to in-depth investigate the corrosion mechanism of Zn–Al–Mg-coated steel exposed to a simulated polluted marine *** experiments were carried out by scanning electron microscopy for micro-morphological characterization,X-ray diffraction,electrochemical impedance spectroscopy and electrodynamic polarization curves for the aged *** analysis of the results obtained after an indoor accelerated ageing test shows that Zn–Al–Mg coatings generate insoluble Zn_(5)Cl_(2)(OH)_(8)·H_(2)O and Zn_(4)SO_(4)(OH)_(6)during the corrosion process,which hinders the diffusion of corrosive substances into the substrate,and the insoluble substances are structurally dense and thus inhibit further ***,this effectively inhibits the occurrence of further corrosion,and thus,Zn–Al–Mg coating can significantly extend the service life of Zn–Al–Mg-coated steel.

关键词： Zn-Al-Mg-coated steel Electrochemical impedance spectroscopy Polarization curve Atmospheric corrosion Marine atmosphere