检索结果-南通市图书馆

Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 194-203页

作者： WANG Zhen LI Huajian HUANG Fali YANG Zhiqiang WEN Jiaxin SHI Henan Railway engineering research Institute China Academy of Railway Science Corporation LimitedBeijing 100081China State Key Laboratory for Track Technology of High-Speed Railway Beijing 100081China

In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMC)are prepared by taking the manufactured sand lithology(tuff,limestone,basalt,granite),stone powder content(0,5%,10%,15%)and concrete strength grade(C60,C80,C100)as *** evolution of mechanical properties of HMC and the correlation between cubic compressive strength and other mechanical properties are *** to river sand,manufactured sand enhances the cubic compressive strength,axial compressive strength and elastic modulus of concrete,while its potential microcracks weaken the flexural strength and splitting tensile strength of *** powder content displays both positive and negative effects on mechanical properties of HMC,and the stone powder content is suggested to be less than 10%.The empirical formulas between cubic compressive strength and other mechanical properties are proposed.

关键词： manufactured sand concrete railway mechanical property lithology stone powder content

A new approach to regulate the photoelectric properties of two-dimensional SiC materials:first-principles calculation on B-N co-doping

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2020年第3期16卷 205-210页

作者： ZHANG Chun-hong ZHANG Zhong-zheng YAN Wan-jun Mathematics and Physics Institute Anshun UniversityAnshun 561000China Avionics and Information Network engineering Center Anshun UniversityAnshun 561000China Electronic Information engineering Institute Anshun UniversityAnshun 561000China

This paper describes a new approach to regulate the photoelectric properties of two-dimensional SiC *** first-principles pseudo-potential plane wave method is used to calculate the geometric structure,electronic structure and optical properties of two-dimensional(2D)SiC co-doped by the adjacent elements of C-Si(such as B and N).The results show that:after B-N co-doping,the supercell lattices of 2D SiC are observed obviously deformation near the doped ***,the band structures of 2D SiC co-doped by B-N become *** the impurity level enters the forbidden band,the band gap decreases,and the distribution of density of states near the Fermi level changes *** calculation of optical properties shows that the ability to absorb electromagnetic waves of 2D SiC has been enhanced obviously in the low energy range after B-N *** reason is originated from the transition of the 2p state of B and *** the same time,the static dielectric constant increases and the peak of reflectivity *** above results indicate that the optoelectronic properties of 2D SiC can be modulated by co-doping B-N.

关键词： dimensional properties calculation

Mesoporous Ti-Mo Mixed Oxides Catalyzed Transformation of Carbohydrates into 5-Hydroxymethylfurfural

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2017年第1期19卷 26-32页

作者： Zhang Qiuyun Wei Fangfang Luo Dan Ma Peihua Zhang Yutao School of Chemistry and Chemical engineering Anshun University Anshun 561000 Special and Key Laboratory of Functional Materials and Resource Chemistry of Guizhou Provincial Education Department Anshun University Anshun 561000 School of Chemistry and Chemical engineering Guizhou University Guiyang 550025

Mesoporous Ti-Mo mixed oxides were prepared via a facile approach using stearic acid as the template, and were characterized using XRD FT-IR, nitrogen adsorption-desorption isotherm and TEM techniques. The catalytic activity of the prepared mesoporous Ti-Mo mixed oxides was first evaluated for the dehydration of fructose to 5-hydroxymethylfurfural(HMF), and a 50.3% yield of HMF was obtained within 60min at 120℃. Moreover, moderate yields of HMF could also be achieved from glucose and sucrose. The mesoporous catalyst could be simply separated from the reaction mixture after termination of the reaction and reused five times with no significant loss of catalytic activity.

关键词： mesoporous catalyst solid acid heterogeneous catalysis carbohydrate 5-hydroxymentylfurfural(HMF)

A Novel Design Strategy for Temperature-Responsive IPN Hydrogels Based on a Copolymer of Acrylamide and N-(1,1-Dimethyl-3-Oxobutyl)-Acrylamide

在线全文

学校读者我要写书评

暂无评论

Advances in Chemical engineering and Science 2018年第4期8卷 255-270页

作者： Yu Wang Huifang Xia Jun Zhao Xiuqin Cai Shengke Chen Bengxiu Li School of Chemistry and Materials Sciences Guizhou Education University Guiyang China anshun engineering research centre of concrete admixture Anshun China School of Chemistry and Materials Science Weinan Normal University Weinan China GuizhouTiejinahengfa New Material Technology Co. Ltd. Anshun China

A methology is described for the synthesis of novel temperature-responsive interpenetrating polymer network (IPN) hydrogels with poly(2-acrylamido- 2-methylpropane sulfonic acid) (PAMPS) as a tightly crosslinked 1st network, temperature-responsive poly(acrylamide-co-N-(1,1-dimethyl-3-oxobutyl)- acrylamide) (P(AM-co-DAAM)) with low cost as a lossely crosslinked 2nd network. The structure and morphology of the IPN hydrogels were characterized by FTIR, TGA and SEM, and the results indicated that PAMPS network introduced P(AM-co-DAAM) hydrogels have large, thermally stable and interconnected porous network. The properties of the IPN hydrogels, which include: swelling capacity, equilibrium swelling/deswelling ratio, temperature- responsive behavior, and the dwelling kinetics as specific temperature, were investigated carefully. Results showed that the obtained IPN hydrogels displayed a controllable equilibrium swelling/deswelling behavior and possessed remarkable thermosensitivity. In addition, the results also indicate that the incorporation of the hydrophobic groups DAAM has a big effect on the LCST of the IPN hydrogels. Consequently, these novel temperature-responsive IPN hydrogels with low cost and slow-releasing performance would be promising for potential applications, such as environmental catalysis, water treatment, and agriculture.

关键词： Temperature-Responsive Hydrogel Interpenetrating Polymer Network Equi-librium Swelling Ratio Slow-Releasing Performance

High-efficiency trace Na extraction from crystal quartz ore used for fused silica-——A pretreatment technology

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第10期24卷 1075-1086页

作者： Min Lin Zhen-yu Pei Yuan-yuan Liu Zhang-jie Xia Kang Xiong Shao-min Lei En-wen Wang School of Resources and Environmental engineering Wuhan University of Technology School of Resources and Environmental engineering Anshun University

Trace Na sources, extraction dynamics of trace Na, and influences of calcination temperature on quartz lattice, fluid inclusions, and muscovite were studied in detail herein for trace Na extraction from the quartz ore with water leaching at 90℃. Experimental results suggested that the trace Na sources included quartz lattice, fluid inclusions, and muscovite. The extraction rate of the trace Na in quartz ores can reach 31.0wt% after calcination at 900℃ for 5 h and water leaching at 90℃ for 24 h. The extraction process consisting of the dissolution of unfree Na and diffusion of free Na was dominated by calcination temperature. Calcination at 900℃ for 5 h was effective for extraction of the trace Na in fluid inclusions and muscovite. The extraction of the trace Na was mainly affected by the decrepitation of fluid inclusions when the calcination temperature ranged from 400 to 600℃ and by the damage of muscovite when the calcination temperature ranged from 600 to 900℃. Based on the extraction rates at different calcination temperatures, approximately 20.1wt% of the trace Na occurred in fluid inclusions, approximately 10.9wt% existed in muscovite, and 69.0wt% mainly occurred in quartz lattice.

关键词： trace sodium extraction quartz ore fluid inclusion muscovite decrepitation calcination water leaching

Macro-mechanics and Microstructure of Nanomaterial-modified Geopolymer concrete: A Comprehensive Review

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 204-214页

作者： WANG Tao FAN Xiangqian GAO Changsheng QU Chiyu The National Key Laboratory of Water Disaster Prevention Nanjing Hydraulic Research InstituteNanjing 210024China Southern Marine Science and engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China School of Water Conservancy and Transportation Zhengzhou UniversityZhengzhou 450001China

We have described in detail the effects of nano-SiO_(2),nano-CaCO_(3),carbon nanotubes,and nano-Al_(2)O_(3) on geopolymer concrete from the perspectives of macro mechanics and *** existing research results show that the mechanism of nano-materials on geopolymer concrete mainly includes the filling effect,nucleation effect,and bridging effect,the appropriate amount of nano-materials can be used as fillers to reduce the porosity of geopolymer concrete,and can also react with Ca(OH)2 to produce C-S-H gel,thereby improving the mechanical properties of geopolymer *** optimum content of nano-SiO_(2) is between 1.0%and 2.0%.The optimum content of nano-CaCO_(3) is between 2.0%and 3.0%.The optimum content of carbon nanotubes is between 0.1%and 0.2%.The optimum content of nano-Al_(2)O_(3) is between 1.0%and 2.0%.The main problems existing in the research and application of nanomaterial-modified geopolymer concrete are summarized,which lays a foundation for the further application of nanomaterial in geopolymer concrete.

关键词： nanomaterials low carbon geopolymer concrete macro-mechanics microstructure

Effects of temperature change on elastic behavior of steel beams with semi-rigid connections

维普期刊数据库评论

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 Central South University 2010年第4期17卷 845-851页

作者：蔡建国冯健韩运龙 Key Laboratory of concrete and Prestressed concrete Structures Ministry of Education Southeast University engineering research Center for Prestress of Jiangsu Province Southeast University

Based on the nonlinear displacement-strain relationship,the virtual work principle method was used to establish the nonlinear equilibrium equations of steel beams with semi-rigid connections under vertical uniform loads and temperature *** the non-uniform temperature distribution across the thickness of beams,the formulas for stresses and vertical displacements were *** the basis of a flowchart for analysis of the numerical example,the effect of temperature change on the elastic behavior of steel beams was *** is found that the maximal stress is mainly influenced by axial temperature change,and the maximal vertical displacement is principally affected by temperature *** the effect of temperature gradients on the maximal vertical displacement decreases with the increase of rotational stiffness of *** the maximal stress and vertical displacement decrease with the increase of rotational stiffness of *** can be concluded that the effects of temperature changes and rotational stiffness of joints on the elastic behavior of steel beams are ***,the influence of rotational stiffness becomes smaller when the rotational stiffness is larger.

关键词： steel beams semi-rigid connections stress displacement stiffness elastic behavior temperature change virtual work principle

Elastic stability of shallow pin-ended parabolic arches subjected to step loads

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2010年第1期17卷 156-162页

作者：陈耀冯健 Key Laboratory of concrete and Prestressed concrete Structures of Ministry of Education Southeast University engineering research Center for Prestress of Jiangsu Province Southeast University

Buckling could be induced when shallow arches were subjected to vertical step loads. In-plane static and dynamic buckling of shallow pin-ended parabolic arches with a horizontal cable was investigated. Based on the equations of motion derived from Hamilton's principle, nonlinear equilibrium equations and static buckling equilibrium equations were deduced. Through the pseudo-static analysis, approximate solutions to the lower and upper dynamic buckling loads under step loads were obtained, for shallow parabolic arches. The results show that dynamic buckling and snap-through buckling are impossible when modified slenderness ratio λλs, where λc and λs denote critical slenderness ratios of bucking and snap-through buckling, respectively; effects of the stiffness of the horizontal cable on the dynamic buckling are significant; and the dynamic buckling loads under a equivalent central concentrated step load are lower than the loads under a distributed load appreciably.

关键词： shallow parabolic arch step load dynamic buckling modified slenderness ratio stiffness ratio

Strength and thermal behavior of low weight foam geopolymer using circulating fluidized bed combustion fly ash

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2015年第9期22卷 3633-3640页

作者：刘泽邵宁宁秦俊峰孔凡龙王春雪王栋民 research Institution of concrete and Eco-materials School of Chemical and Environmental Engineering China University of Mining & Technology

A comparative study of the influence of elevated temperature on foam geopolymer using circulating fluidized bed combustion fly ash（CFA） was reported. Foam geopoymers were prepared with different amounts of foam agent and different Si O2/Al2O3 molar ratios of 3.1, 3.4, and 3.8. The mechanical, thermo-physical properties and microstructure of the foam geopolymers before and after exposure to elevated temperature of 800, 1000, and 1200 ℃ were investigated. The specimen with Si O2/Al2O3 molar ratio of 3.8 exhibits the highest compressive strength, better microstructure and dimension stability before and after firing. Carnegeite, nepheline, and zeolite crystalline phases appearing after exposure may contribute to the good post-exposure strength. Low weight foam geopolymer using CFA can increase strength and maintain higher stability as high as 1000 ℃.

关键词： foam geopolymer circulating fluidized bed combustion fly ash thermal analysis microstructure strength

Direct synthesis of ordered mesoporous ZSM-5 zeolites from in situ crystallization of carbonaceous SBA-15

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2017年第12期60卷 1588-1595页

作者： Fangfang Wei Qiuyun Zhang Hong Wu Changyan Cao Weiguo Song School of Chemistry and Chemical engineering Anshun UniversityAnshun 561000China Key Laboratory of Functional Materials and Resource Chemistry of Guizhou Provincial Education Department Anshun UniversityAnshun 561000China College of Chemistry and Material engineering Liupanshui Normal UniversityLiupanshui 553004China Beijing National Laboratory of Molecular Sciences Laboratory of Molecular Nanostructure and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

Two types of ordered mesoporous ZSM-5 zeolites with different mesopores were synthesized by a two-step method. First, carbonaceous SBA- 15 was produced by in situ carbonization of SBA- 15/P 123 composite. Then the obtained SBA- 15/C composite was transformed into crystallized mesoporous ZSM-5 by impregnation TPAOH followed by steam-assisted crystallization. The final calcined samples synthesized with typical SBA-15/P 123 precursor showed a wormlike morphology with the mean mesopore size of 4.6 nm, while samples synthesized with the addition of trimethylbenzene as swelling agent in the precursor exhibited the morphology of microsphere with the mesopore size of about 9.5 nm. Both two types of mesoporous ZSM-5 zeolites exhibited large surface area and mesopore structure. The steam-assisted crystallization （SAC） was performed with lower consumption of solvents. This two-step method may also be suitable for synthesizing other ordered mesoporous zeolites used as catalysts in some catatytic processes.

关键词： mesoporous zeolites ZSM-5 in situ carbonization steam-assistant crystallization