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福建柏材用型优树选择 被引量:3
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作者 黄树军 沈秋水 +3 位作者 周宗哲 荣俊冬 陈礼光 郑郁善 《亚热带农业研究》 2015年第2期101-105,共5页
在收集福建省不同区域57株福建柏材用型优树的基础上,分析林龄组、立地类型、区域对优树选择的影响。结果表明,林龄组、立地类型、区域均影响福建柏材用型优树选择;不同林龄组胸径、树高、材积年均生长量均存在极显著差异,中龄林生长快... 在收集福建省不同区域57株福建柏材用型优树的基础上,分析林龄组、立地类型、区域对优树选择的影响。结果表明,林龄组、立地类型、区域均影响福建柏材用型优树选择;不同林龄组胸径、树高、材积年均生长量均存在极显著差异,中龄林生长快速,适宜在中龄林选择;立地条件以较肥沃(Ⅱ类)为佳;引种要注意不同区域的选择,注意种源对环境的适应性和抗耐性。综合来看,福建柏材用型优树选择应注意区域种源的选择,选优适宜在中林龄、Ⅱ类立地评选。 展开更多
关键词 福建柏 材用型 优树选择 指标
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An XML-based approach to represent generic bill of materials
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作者 邱福生 刘文剑 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第3期402-407,共6页
To solve the difficulty in describing the generic bill of material (GBOM) with the conventional tabular structure in a relational database system,a novel XML-based approach is presented to represent GBOM. It can repre... To solve the difficulty in describing the generic bill of material (GBOM) with the conventional tabular structure in a relational database system,a novel XML-based approach is presented to represent GBOM. It can represent and maintain one generic structure that encompasses all variants of a product. With the combination of product-oriented notation,this approach further gives a high degree of flexibility to support the user in the product variant specification task. The generic BOM system is then introduced for the particular product variant,and a prototype system has been developed. It is indicated that the presented approach is feasible. 展开更多
关键词 XML generic BOM REPRESENTATION product variant
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Feasibility of developing composite action between concrete and cold-formed steel beam
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作者 S.O.Bamaga M.Md.Tahir +6 位作者 T.C.Tan S.Mohammad N.Yahya A.L.Saleh M.Mustaffar M.H.Osman A.B.A.Rahman 《Journal of Central South University》 SCIE EI CAS 2013年第12期3689-3696,共8页
Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction in... Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction industry due to their light mass, ductility by economic cold forming operations, favorable strength-to-mass ratio and other factors. The utilization of cold formed steel sections with concrete as composite can hugely reduce the construction cost. However, the use of cold formed steel members in composite concrete beams has been very limited. A comprehensive review of developments in composite beam with cold formed steel sections was introduced. It was revealed that employing cold-formed steel channel section to replace reinforcement bars in conventional reinforced concrete beam results in a significant cost reduction without reducing strength capacity. The use of composite beam consisting of cold-formed steel open or close box and filled concrete could also reduce construction cost. Lighter composite girder for bridges with cold-formed steel of U section was introduced. Moreover, types of shear connectors to provide composite action between cold-formed steel beam and concrete slab were presented. However, further studies to investigate the effects of metal decking on the behavior of composite beam with cold-formed steel section and introduction of ductile shear connectors were recommended. 展开更多
关键词 cold formed steel BEAM composite shear connection thin-wall composite girder
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Experimental and Computational Investigation of Hybrid FRP Bonded-Reinforced Concrete Beams under Cyclic Loading 被引量:1
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作者 Hasan Nikopour M. Nehdi P. Broumand 《Journal of Civil Engineering and Architecture》 2012年第3期322-333,共12页
Although several experimental and numerical studies have been carried out on the shear capacity of RC beams retrofitted by carbon or glass fibre-reinforced polymers, there has been little work on hybrid FRP sheet appl... Although several experimental and numerical studies have been carried out on the shear capacity of RC beams retrofitted by carbon or glass fibre-reinforced polymers, there has been little work on hybrid FRP sheet applications, particularly under cyclic loading. In the present research, five RC beams were constructed, and four of which were retrofitted using various schemes of FRP sheets. All beams were subjected to quasi-static cyclic loading in an attempt to represent the effect repetitive loading. The ultimate load, and deflection response at mid-span of the beams were measured and compared with predictions of a computational model based on finite element analysis. Experimental results demonstrated that hybrid applications of FRP sheets can improve the shear performance of retrofitted RC beams and increase the ultimate strain of the FRP sheets at failure. The results of the computational model were in reasonable agreement with the corresponding experimental results. 展开更多
关键词 BEAMS reinforced concrete fibre-reinforced polymer shear strength finite element method.
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Wet-spinning assembly of nitrogen-doped graphene film for stable graphene-polyaniline supercapacitor electrodes with high mass loading 被引量:1
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作者 Xingyuan Chu Tieqi Huang +6 位作者 Yueqi Hu Ruilin Dong Jingyang Luo Shengying Cai Weiwei Gao Zhen Xu Chao Gao 《Science China Materials》 SCIE EI CSCD 2020年第10期1889-1897,共9页
Graphene-polyaniline(GP)composites are promising electrode materials for supercapacitors but possessing unsatisfied stability,especially under high mass loading,due to the low ion transmission efficiency and serious p... Graphene-polyaniline(GP)composites are promising electrode materials for supercapacitors but possessing unsatisfied stability,especially under high mass loading,due to the low ion transmission efficiency and serious pulverization effect.To address this issue,we propose a scalable method to achieve highly wettable GP electrodes,showing excellent stability.In addition,our results demonstrate that the performance of electrodes is nearly independent of the mass loading,indicating the great potential of such GP electrodes for practical devices.We attribute the remarkable performance of GP to the delicate precursor of nitrogen doped graphene film assembled by wet-spinning technology.This report provides a strategy to promote the ion penetrating efficiency across the electrodes and deter the pulverization effect,aiming at the practical GP supercapacitor electrodes of high mass loading. 展开更多
关键词 SUPERCAPACITOR GRAPHENE POLYANILINE nitrogen doping stability mass loading
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Preparation of Li_4Ti_5O_(12) submicrospheres and their application as anode materials of rechargeable lithium-ion batteries 被引量:9
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作者 ZHANG Ai, ZHENG ZongMin, CHENG FangYi, TAO ZhanLiang & CHEN Jun Key Laboratory of Advanced Energy Materials Chemistry, Ministry of Education College of Chemistry, Nankai University, Tianjin 300071, China 《Science China Chemistry》 SCIE EI CAS 2011年第6期936-940,共5页
We report on the preparation of spinel Li4Ti5O12 submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12 submicrospheres are synthesized with three steps of... We report on the preparation of spinel Li4Ti5O12 submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12 submicrospheres are synthesized with three steps of the hydrolysis of TiCl4 to form rutile TiO2, the hydrothermal treatment of rutile TiO2 with LiOH to prepare an intermediate phase of LiTi2O4+δ, and the calcinations of LiTi2O4+δ to obtain spinel Li4Ti5O12. The as-prepared products are investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The diameters of Li4Ti5O12 submicrospheres with novel hierarchical microstructures are about 200–300 nm with the assembly of 20–30 nm nanoparticles. The electrochemical properties of Li4Ti5O12 submicrospheres are measured by galvanostatical discharge/charge test and cyclic voltammetry (CV). The as-prepared Li4Ti5O12 display excellent discharge/charge rate and cycling capability. A high discharge capacity of 174.3 mAh/g is obtained in the first discharge at 1 C rate. Meanwhile, there is only tiny capacity fading with nearly 100% columbic efficiency in the sequential 5–50 cycles. Moreover, lithium-ion diffusion coefficient in Li4Ti5O12 is calculated to be 1.03 × 10-7 cm2/s. The present results indicate that the as-prepared Li4Ti5O12 submicrospheres are promising anode candidates of rechargeable Li-ion batteries for high-power applications. 展开更多
关键词 LI4TI5O12 TiO2 TICL4 anode material lithium-ion battery
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