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综合管廊共构段基坑回填施工工艺及质量控制措施 被引量:6
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作者 胡平 《工程质量》 2020年第9期66-70,共5页
北京大兴国际机场配套基础设施首创性地将"高铁、轻轨、高速公路、城市道路、地下综合管廊"以共构共廊形式规划建设在一起。以北京大兴国际机场高速公路地下综合管廊高架共构段为依托,根据基坑不同区域针对性地采用素填土、... 北京大兴国际机场配套基础设施首创性地将"高铁、轻轨、高速公路、城市道路、地下综合管廊"以共构共廊形式规划建设在一起。以北京大兴国际机场高速公路地下综合管廊高架共构段为依托,根据基坑不同区域针对性地采用素填土、级配砂石、低等级混凝土等回填材料,介绍基坑回填主要施工工艺及相应质量问题,并给出相应的控制措施,取得了良好效果。 展开更多
关键词 综合管廊 共构段 基坑回填 施工工艺
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深圳市前海地下道路工程共构段抗拔桩抗浮系数的研究与应用 被引量:3
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作者 丁小峰 黄伟强 方四宝 《建筑施工》 2016年第10期1460-1462,共3页
通过深圳前海地下道路工程抗拔桩设计抗浮系数的研究,选择了抗浮总安全系数法和相对应的施工技术。经过实际施工检验,取得较好的使用效果,验证了抗浮总安全系数法的科学、合理性,为类似工程提供了有益的参考。
关键词 深圳前海地下道路工程 共构段 抗拔桩抗浮 总安全系数 施工技术
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北京新机场线共构段下部结构模板调运统筹设计
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作者 刘佳杰 张星 《山西建筑》 2019年第4期109-110,共2页
通过对施工现场模板调运进行统筹设计,确定了合理的模板调运计划,确保能在要求工期内完工的前提下,根据各工序的施工特点和所需时间,通过合理的调运安排充分利用现场模板,以减小模板的成本。
关键词 共构段 下部结 模板设计 调运统筹
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Influence of Preparation Conditions on Structural Stability of Ordered Mesoporous Carbons Synthesized by Evaporation-induced Triconstituent Co-assembly Method 被引量:1
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作者 游波 杨俊 +3 位作者 雍国平 刘少民 谢卫 苏庆德 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第3期365-372,I0004,共9页
Various ordered mesoporous carbons (OMCs) have been prepared by evaporation-induced trieonstituent co-assembly method. Their mesostructural stability under different carbon content, aging time and acidity were conve... Various ordered mesoporous carbons (OMCs) have been prepared by evaporation-induced trieonstituent co-assembly method. Their mesostructural stability under different carbon content, aging time and acidity were conveniently monitored by X-ray diffraction, transmission electron microscopy, and N2 sorption isotherms techniques. The results show mesostruetural stability of OMCs is enhanced as the carbon content increases from 36% to 46%, further increasing carbon content deteriorates the mesostructural stability. Increasing aging time from 0.5 h to 5.0 h make the mesostructural stability go through an optimum (2.0 h) and gradually reduce framework shrinkage of the OMCs. Highly OMCs can only be obtained in the acidity range of 0.2-1.2 mol/L HC1, when the acidity is near the isoelectrie point of silica, the resulting OMCs have the best mesostructure stability. Under the optimum condition, the carbon content of 46%, aging time of 2.0 h, and 0.2 mol/L HCl, the resulting OMCs have the best mesostrueture stability and the highest BET surface areas of 2281 m2/g. 展开更多
关键词 Triblock copolymer Mesostructural stability SELF-ASSEMBLY Ordered mesoporous carbon
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Comparison of Node Architectures for Elastic Optical Networks with Waveband Conversion 被引量:1
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作者 张平 李巨浩 +3 位作者 郭秉礼 何永琪 陈章渊 邬贺铨 《China Communications》 SCIE CSCD 2013年第8期77-87,共11页
In Elastic Optical Networks(EONs)with flexible bandwidth allocation,the blocking probability is high because of spectral contention.Similar to the functionality of wavelength conversion in Wavelength-Division-Multiple... In Elastic Optical Networks(EONs)with flexible bandwidth allocation,the blocking probability is high because of spectral contention.Similar to the functionality of wavelength conversion in Wavelength-Division-Multiplexing(WDM)networks,waveband conversion has been proposed to solve spectral contention in EONs.In this paper,we discuss the design of node architectures for an EON with waveband conversion.Four node architectures with shared Tuneable Waveband Converters(TWBCs)are proposed,and their blocking performances are evaluated by simulation.Simulation results show that the blocking probability of a node is significantly improved by waveband conversion.The sharing efficiency of waveband converters is also investigated.Simulation results show that at the same blocking rate,the node architecture with converters shared per node can save more than 20% waveband converters compared with that of the one with converters shared per link. 展开更多
关键词 EON TWBC node architecture blocking probability
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Self-assembly and chemical processing of block copolymers:A roadmap towards a diverse array of block copolymer nanostructures 被引量:3
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作者 WYMAN Ian LIU GuoJun 《Science China Chemistry》 SCIE EI CAS 2013年第8期1040-1066,共27页
Block copolymers can yield a diverse array of nanostructures.Their assembly structures are influenced by their inherent structures,and the wide variety of structures that can be prepared especially becomes apparent wh... Block copolymers can yield a diverse array of nanostructures.Their assembly structures are influenced by their inherent structures,and the wide variety of structures that can be prepared especially becomes apparent when one considers the number of routes available to prepare block copolymer assemblies.Some examples include self-assembly,directed assembly,coupling,as well as hierarchical assembly,which can yield assemblies having even higher structural order.These assembly routes can also be complemented by processing techniques such as selective crosslinking and etching,the former technique leading to permanent structures,the latter towards sculpted and the combination of the two towards permanent sculpted structures.The combination of these pathways provides extremely versatile routes towards an exciting variety of architectures.This review will attempt to highlight destinations reached by LIU Guojun and coworkers following these pathways. 展开更多
关键词 block copolymers SELF-ASSEMBLY chemical processing CROSSLINKING
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Triblock copolymer-assisted construction of 20 nm-sized ytterbium-doped TiO_2 hollow nanostructures for enhanced solar energy utilization efficiency 被引量:2
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作者 Lin Cheng Xuefeng Xu +8 位作者 Yuyan Fang Yan Li Jiaxi Wang Guojia Wan Xueying Ge Liangjie Yuan Keli Zhang Lei Liao Quan Yuan 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第5期850-857,共8页
Rare-earth doped titania single-crystalline hollow nanoparticles of 20 nm are constructed via a simple sol-gel process. Amphiphilic ABA tri-block copolymers played a key role in assisting the formation of hollow struc... Rare-earth doped titania single-crystalline hollow nanoparticles of 20 nm are constructed via a simple sol-gel process. Amphiphilic ABA tri-block copolymers played a key role in assisting the formation of hollow structure, for which a hollow nanostructure growth mechanism is proposed. By introducing rare earth into the synthesis process, the as-prepared nanoparticles exhibit near-infrared light absorption properties. Photo-decomposition efficiency of Orange II azo dye can be successfully evaluated when using Yb3+-doped Ti O2 hollow nanoparticles as photocatalysts; it is more than two times higher than the pure Ti O2 hollow nanoparticles. The hollow nanostructured Yb3+-doped Ti O2 samples are exploited as photoanodes in N719- sensitized solar cells and prove able to improve the photoelectric conversion efficiency by measuring the solar cell parameters of dye-sensitized solar cells(DSSCs) under simulative sunlight. 展开更多
关键词 rare earth hollow nanostructure TITANIA SINGLE-CRYSTALLINE COPOLYMER
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Nanophase separation and structural evolution of block copolymer films: A "green" and "clean" supercritical fluid approach
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作者 Tandra Ghoshal 《Nano Research》 SCIE EI CAS CSCD 2015年第4期1279-1292,共14页
Thin films of block copolymers (BCPs) are widely accepted as potentially important materials in a host of technological applications including nano- lithography. In order to induce domain separation and form well-de... Thin films of block copolymers (BCPs) are widely accepted as potentially important materials in a host of technological applications including nano- lithography. In order to induce domain separation and form well-defined structural arrangements, many of these are solvent-annealed (i.e. solvent swollen) at moderate temperatures. The use of solvents can be challenging in industry from an environmental point of view as well as having practical/cost issues. However, a simple and environmentally friendly alternative to solvo-thermal annealing for the periodically ordered nanoscale phase separated structures is described herein. Various asymmetric polystyrene-b-poly(ethylene oxide) (PS-b-PEO) thin films were annealed in a compressible fluid, supercritical carbon dioxide (scCO2), to control nanodomain orientation and surface morphologies. For the first time, periodic well defined, hexagonally ordered films with sub-25 nm pitch size were demonstrated using a supercritical fluid (SCF) process at low temperatures and pressures. Predominant swelling of PEO domains in scCO2 induces nanophase separation, scCO2 serves as green alternative to the conventional organic solvents for the phase segregation of BCPs with complete elimination of any residual solvent in the patterned film. The depressurization rate of scCO2 following annealing was found to affect the morphology of the films. The supercritical annealing conditions could be used to define nanoporous analogues of the microphase separated films without additional processing, providing a one-step route to membrane like structures without affecting the ordered surface phase segregated structure. An understanding of the BCP self- assembly mechanism can be realized in terms of the deviation in glass transition temperature, melting point, viscosity, interaction parameter and volume fraction of the constituent blocks in the scCO2 environment. 展开更多
关键词 block copolymer supercritical CO2 SELF-ASSEMBLY SWELLING NANOPORES
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