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Aeroelastic modeling of wind loading on a cable-net supported glass wall 被引量:1
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作者 Zhifu Gu Letian Yang Yan Li Bin Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第3期409-415,共7页
Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and a... Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and analyzed. In order to design a glass wall under wind loading, the "wind- vibration factor" is estimated and discussed. In fact, the mech- anism of wind acting on the wall is commonly known not only as positive pressure, but also as negative pressure caused by the flow separation on the corners of the building. Due to the diffidence in the mechanism of wind acting, two typi- cal response cases are classified. The results show that the dynamic response of the structure caused by the negative pressure is stronger than that of the positive pressure case. To determine the aerodynamic wind loading on a flexible part of structure on a building, wind tunnel study may be useful and play an important role. 展开更多
关键词 Wind tunnel study Cable-net supported glasswall - Wind-vibration factor Aeroelastic model
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DEVELOPING EXPERT DECISION SUPPORT SYSTEM WTH VP-EXPERT AND LOTUS 1-2-3 IN RE-BLENDING BY USE
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作者 舒航 杨鹏 《Journal of China University of Mining and Technology》 1994年第2期104-111,共8页
An expert decision support system (EDSS) for multi-bins balance and contro1 of orequality in production ore bins of some large-scale open pit iron mine in China has been developed byexpert svitem tool software VP-EXPE... An expert decision support system (EDSS) for multi-bins balance and contro1 of orequality in production ore bins of some large-scale open pit iron mine in China has been developed byexpert svitem tool software VP-EXPERT and integration software LOTUS 1-2-3 in this paper. Itis known by practicing that a medium-scale EDSS constructed on microcomputer is completcly, feaasible by means of VP-EXEPERT to construct knowledge base system (KBS), LOTUS 1-2-3 tomake decision support system (DSS) and link them with BAT. 展开更多
关键词 VP-EXPERT LOTUS 1-2-3 ore-blending expert System decision support system expert decision support system
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Study on Support Vector Machine Based on 1-Norm
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作者 潘美芹 贺国平 +2 位作者 韩丛英 薛欣 史有群 《Journal of Donghua University(English Edition)》 EI CAS 2006年第6期148-152,共5页
The model of optimization problem for Support Vector Machine(SVM) is provided, which based on the definitions of the dual norm and the distance between a point and its projection onto a given plane. The model of impro... The model of optimization problem for Support Vector Machine(SVM) is provided, which based on the definitions of the dual norm and the distance between a point and its projection onto a given plane. The model of improved Support Vector Machine based on 1-norm(1-SVM) is provided from the optimization problem, yet it is a discrete programming. With the smoothing technique and optimality knowledge, the discrete programming is changed into a continuous programming. Experimental results show that the algorithm is easy to implement and this method can select and suppress the problem features more efficiently. Illustrative examples show that the 1-SVM deal with the linear or nonlinear classification well. 展开更多
关键词 1- SVM best separating plane feature suppression feature selection.
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EXACT SOLUTION FOR RECTANGULAR SLAB WITH THREE EDGES SIMPLY-SUPPORTED AND OTHER FREE
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作者 YU TENGHAIDepartment of Mathematics 《内江师范学院学报》 1996年第2期1-7,共7页
In this paper,we give all-sided pastic analysis of the rectangular slab with three edges simply-supported and other free.Here we discuss the following four cases:(1)The uniformly distributedload over the area a slab.(... In this paper,we give all-sided pastic analysis of the rectangular slab with three edges simply-supported and other free.Here we discuss the following four cases:(1)The uniformly distributedload over the area a slab.(2).A concentrated load act at midpoint of free edges slab.(3)A concen-trated load act at the center a slab.(4)The line load act along free edge of slab. 展开更多
关键词 The RECTANGULAR SLAB with three EDGES simply - supportED and OTHER free have wide the use value. But up to now only find the EXACT solution that a concentrated load act at midpoint of free edye a slab. The EXACT solution of OTHER support force
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A Novel Way to Prepareγ-A1_2O_3 Supported SO_4^(2-)/ZrO_2 Solid Superacid Catalysts for n-Butane Isomerization
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作者 Ting LEI Yi TANG +2 位作者 Wei Ming HUA Jin Suo XU Zi GAO (Department of Chemistry, Fudan University, Shanghai 200433) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第1期89-92,共4页
Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts wer... Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts were enhanced significantly j The activity of the most active sample. 60%SZ/Al_2O3-P, was even about 2 times more active than that of the SZ catalyst. 展开更多
关键词 SO_4^(2-)/ZrO_2 n-Butane Isomerization γ-A1_2O_3 supported superacid catalysts.
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NEW SOLID BASE DERIVED FROM AIPO4-5 SUPPORTED KF
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作者 Jian Hua ZHU Qin Hug XU Hideshi HATTORI(Chemistry Department, Nanjing University.Nanjing 210093,China.)(Centre for Advanced Research of Energy Technology, Hokkaido University,Sapporo 060.Japan) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第7期671-674,共4页
Dispersion of KF on AlPO4-5 molecular sieve created basic sites and caused 1654 cm- band of bidentate carbonate in CO2 adsorption.After pre-treated above 823K. 5%KF/AlPO4-5exhibited basic catalytic activity in the iso... Dispersion of KF on AlPO4-5 molecular sieve created basic sites and caused 1654 cm- band of bidentate carbonate in CO2 adsorption.After pre-treated above 823K. 5%KF/AlPO4-5exhibited basic catalytic activity in the isomerization of butenes at 273K. and the activity increasedwith the pre-treatment temperature up to 923K. 展开更多
关键词 NEW SOLID BASE DERIVED FROM AIPO4-5 supportED KF
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载体晶面诱导的Pt-Sn合金及其丙烷脱氢研究
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作者 刘雅楠 郑天赐 +2 位作者 宋远飞 翁少霞 李殿卿 《现代化工》 CAS CSCD 北大核心 2024年第9期103-108,113,共7页
针对传统浸渍过程中Sn与氧化铝载体易于形成铝酸锡络合物,在反应过程中Pt-Sn合金结构易偏析的问题,利用Al_(2)O_(3)择优暴露晶面诱导效应构筑稳定的Pt-Sn/Al_(2)O_(3)有序合金催化剂。通过丙烷脱氢性能评价发现,棒状r-Al_(2)O_(3)负载的... 针对传统浸渍过程中Sn与氧化铝载体易于形成铝酸锡络合物,在反应过程中Pt-Sn合金结构易偏析的问题,利用Al_(2)O_(3)择优暴露晶面诱导效应构筑稳定的Pt-Sn/Al_(2)O_(3)有序合金催化剂。通过丙烷脱氢性能评价发现,棒状r-Al_(2)O_(3)负载的Pt-Sn催化剂形成了均匀且结构稳定的有序合金结构。在560℃时,丙烷初始转化率达68%,丙烯选择性大于97%,远高于其他氧化铝载体负载的Pt-Sn催化剂。利用SEM、STEM和CO-IR等对系列催化剂结构进行表征,结果表明,Pt-Sn/r-Al_(2)O_(3)中形成了隔离且电子富集的Pt物种,从而促进了C—H的活化及丙烯的脱附。 展开更多
关键词 载体晶面诱导 丙烷脱氢 Pt-Sn合金 贵金属减量化
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Investigation on Porosity and In-plane Water Permeability of Nonwoven Geotextiles
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作者 魏取福 贺福敏 迟景魁 《Journal of China Textile University(English Edition)》 EI CAS 1998年第2期51-54,共4页
Nonwoven geotextiles have been widely used as drains orfilters in many civil engineerings.The hydraulic charac-teristics of geotextiles are the basic function in these ap-plications.The in-plane permeability of nonwov... Nonwoven geotextiles have been widely used as drains orfilters in many civil engineerings.The hydraulic charac-teristics of geotextiles are the basic function in these ap-plications.The in-plane permeability of nonwoven geo-textiles was discussed in this paper.The results of in-plane permeability coefficient of nonwoven geotextilesfrom measurement were analyzed. 展开更多
关键词 GEOTEXTILE NONWOVEN GEOTEXTILE in - plane per-meability.
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基于支持向量机的棒-板空气间隙击穿电压预测方法及其应用 被引量:15
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作者 邱志斌 阮江军 +1 位作者 黄道春 舒胜文 《电工技术学报》 EI CSCD 北大核心 2017年第19期220-228,共9页
空气间隙的击穿电压与放电起始前的电场分布特征存在多维非线性关系。为了实现空气间隙的击穿电压预测,以电场特征集作为输入,以间隙在加载电压下是否击穿作为输出,采用支持向量分类机建立击穿电压预测模型。针对极不均匀电场空气间隙... 空气间隙的击穿电压与放电起始前的电场分布特征存在多维非线性关系。为了实现空气间隙的击穿电压预测,以电场特征集作为输入,以间隙在加载电压下是否击穿作为输出,采用支持向量分类机建立击穿电压预测模型。针对极不均匀电场空气间隙的击穿特性受电晕影响的问题,提出两种修正方法:通过增加受电晕影响的训练样本数据,提高预测模型的泛化性能;或基于"电晕云"的思想进行二次电场计算及特征量提取,对预测模型的输入特征进行修正。采用修正后的模型对极不均匀电场下棒-板间隙的工频击穿电压及棒-板长空气间隙的操作冲击放电电压进行预测,预测值与试验值吻合良好。该方法有利于减少试验次数,降低试验成本。 展开更多
关键词 -板空气间隙 极不均匀电场 击穿电压 支持向量机 电场特征量 电晕层
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基于LBP-TOP特征的微表情识别 被引量:15
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作者 卢官明 杨成 +2 位作者 杨文娟 闫静杰 李海波 《南京邮电大学学报(自然科学版)》 北大核心 2017年第6期1-7,共7页
微表情是一个人试图隐藏内心真实情感却又不由自主流露出的不易被察觉的面部表情。与一般面部表情相比,微表情最显著的特点是持续时间短、强度弱,往往难以有效识别。文中提出了一种基于LBP-TOP(Local Binary Pattern from Three Orthogo... 微表情是一个人试图隐藏内心真实情感却又不由自主流露出的不易被察觉的面部表情。与一般面部表情相比,微表情最显著的特点是持续时间短、强度弱,往往难以有效识别。文中提出了一种基于LBP-TOP(Local Binary Pattern from Three Orthogonal Planes)特征和支持向量机(Support Vector Machine,SVM)分类器的微表情识别方法。首先,采用LBP-TOP算子来提取微表情特征;然后,提出一种基于ReliefF与局部线性嵌入(Locally Linear Embedding,LLE)流形学习算法相结合的特征选择算法,对提取的LBP-TOP特征向量进行降维;最后,使用径向基函数(Radial Basis Function,RBF)核的SVM分类器进行分类,将测试样本图像序列的微表情分为5类:高兴、厌恶、压抑、惊讶、其他。在CASME Ⅱ微表情数据库上采用"留一人交叉验证"(Leave-One-Subject-Out Cross Validation,LOSO-CV)的方式进行了实验,可得到58.98%的分类准确率。实验结果表明了该算法的有效性。 展开更多
关键词 微表情 LBP-TOP 局部线性嵌入 RELIEFF 支持向量机
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隧道径向锚钉-斜交锚杆复合支护技术研究 被引量:4
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作者 陈洪凯 梁丹 +1 位作者 董平 唐红梅 《地下空间与工程学报》 CSCD 北大核心 2016年第3期754-760,共7页
基于长短锚杆组合支护理论,提出了一种隧道径向锚钉-斜交锚杆复合支护技术,该技术可提高支护结构的整体抗力,有利于缩小围岩塑性区半径,增加锚杆处于稳定围岩区的长度。为进一步研究锚钉和锚杆的组合长度,将隧道围岩划分为A、B和C三区,... 基于长短锚杆组合支护理论,提出了一种隧道径向锚钉-斜交锚杆复合支护技术,该技术可提高支护结构的整体抗力,有利于缩小围岩塑性区半径,增加锚杆处于稳定围岩区的长度。为进一步研究锚钉和锚杆的组合长度,将隧道围岩划分为A、B和C三区,并把锚杆作用在围岩体内的剪应力简化为环向边界应力,运用厚壁圆筒弹塑性理论推导了锚钉和锚杆组合长度计算式。实例分析表明,0.8m(锚钉)和3.8m(锚杆)的组合长度可以使隧道塑性区半径降低28%,锚固盲区减小88.8%。可见,在隧道长短锚杆组合支护理论中,该计算方法对围岩锚固体长度参数设计有一定指导意义。 展开更多
关键词 隧道工程 径向锚钉-斜交锚杆复合支护技术 理论推导 岩体结构面
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Yield Increasing and Quality Improving Effects of Smash-ridging Method("4453" Effects) and Its Potential in Benefiting the Nation and the People 被引量:4
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作者 韦本辉 《Agricultural Science & Technology》 CAS 2014年第10期1767-1769,共3页
Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating "... Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating "4453" effects, as fol ows: "Four increases" include to increase loosen soil quantity in cultivation layers, soil nutri-ents use, "water pool" in soils, and "oxygen pool" in soils. Four reductions are to reduce soil erosion, carbon emission, salt content and heavy metal in soils. Five resistances refer to improve crop resistance capacity in terms of drought, high tem-perature, lower temperature, disease and lodging. Three improvements indicate to enhance photosynthetic efficiency over 10%, yield in 10%-30% and quality over 5%. lt is researched that without additional chemical fertilizer, yield could increase by 10% by labor force, animal, tractor or smash-ridging machine. What’s more, by smash-ridging cultivation, the depth can be 20 times or higher compared with tractor cultivation, with looser soils. lt is estimated that if smash-ridging cultivation is applied once in agricultural lands in China, present soil layers can be twice as deep as present. Specifical y, the thickness of loose soil-layers could be extended from 10-18 cm at present to 25-35 cm, and natural rainfal would increase by 40 bil ion cm3. After vitalization of soil nutrients, chemical fertilizer would decrease by 7 bil ion kg, and the increased c rops would feed more than 300 mil ion population as per yield at 7 50 kg/hm2. 展开更多
关键词 Smash-ridging technology Extension nationwide lncrease range in 10%-30% supporting more 300 mil ion population"4453" effects Development potential
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Wullf-Ros等周不等式 被引量:1
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作者 孙宝磊 何俊秀 姚纯青 《西南师范大学学报(自然科学版)》 CAS 北大核心 2015年第12期22-26,共5页
通过讨论平面卵形区域K+tW的支持函数的一些性质,证明了Wullf-Ros等周不等式,同时给出了WullfRos等周亏格的几个下界估计值.
关键词 平面卵形区域 Wullf-Ros等周亏格 Ros等周不等式 支持函数 下界
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基于双等沉面的柔性桩承式路堤荷载-沉降分析 被引量:6
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作者 赵明华 张承富 刘长捷 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2021年第1期1-9,共9页
为了建立能充分考虑桩承式路堤各组成部分之间协调变形特性的理论方法,基于柔性桩-桩承式路堤的变形机理,提出了路堤-桩-土协调变形的双等沉面荷载传递模型.首先,该模型基于路堤中的等沉面以及桩承式路堤的变形特点,在桩底以下一定深度... 为了建立能充分考虑桩承式路堤各组成部分之间协调变形特性的理论方法,基于柔性桩-桩承式路堤的变形机理,提出了路堤-桩-土协调变形的双等沉面荷载传递模型.首先,该模型基于路堤中的等沉面以及桩承式路堤的变形特点,在桩底以下一定深度处,引入一个与路堤中相似的等沉面.其次,考虑到现有土柱模型的不足,引入能考虑内外土柱间相对位移对摩擦因数的影响的土柱模型.介于上、下等沉面之间的路堤、桩、土,通过彼此的协调变形影响等沉面处的应力,从而影响路堤的总体沉降和桩土应力比.最后,将本文计算结果和复合模量法计算结果与实测结果进行对比,结果表明:与实测值相比,复合模量法计算沉降值的相对误差为19.4%,本文计算沉降值的相对误差为9.6%,本文计算的桩土应力比相对误差为9.91%,证明了本文理论方法是合理的. 展开更多
关键词 桩基 -结构物相互作用 双等沉面 桩承式路堤 土拱效应 桩土应力比
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甲烷干重整及金属-载体相互作用 被引量:8
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作者 史健 祝星 +2 位作者 李孔斋 魏永刚 王华 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2020年第6期1407-1418,共12页
CO 2和CH 4均是温室气体的重要成员并且数量可观,其资源化利用对于应对气候变化和能源危机具有重要意义。甲烷干重整是经典转化方式之一,将CO 2“供氧”还原反应和CH 4“需氧”氧化反应结合起来并相互转化,其产物合成气(H 2和CO)可用于... CO 2和CH 4均是温室气体的重要成员并且数量可观,其资源化利用对于应对气候变化和能源危机具有重要意义。甲烷干重整是经典转化方式之一,将CO 2“供氧”还原反应和CH 4“需氧”氧化反应结合起来并相互转化,其产物合成气(H 2和CO)可用于费-托合成碳氢化合物液态燃料。近年来,干重整已经成为能源环境领域热点之一,在重整新工艺和催化剂设计策略方面取得了重要进展,推动了高活性和高稳定性催化剂和新工艺研发。详细综述了甲烷干重整工艺和催化剂的研究成果,重点介绍了干重整工艺新发展和催化剂功能设计,结合Ni-载体相互作用、双金属协同效应、界面效应、单原子催化等新策略对干重整工艺中的基础科学问题进行了探讨,并对干重整技术现有难点和未来发展方向进行了展望。 展开更多
关键词 甲烷干重整(DRM) 化学链 催化剂 金属-载体相互作用 界面效应
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含支撑板结构的管-翅式换热器胀接工艺仿真 被引量:5
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作者 蒋祥荣 李凯 +1 位作者 李大永 彭颖红 《塑性工程学报》 CAS CSCD 北大核心 2015年第4期93-98,共6页
基于LS-DYNA软件平台建立换热器胀接工艺的仿真模型,研究包含支撑板结构的大型管-翅式换热器的胀接工艺过程。分析了胀接过程中翅片的变形及支撑板的存在对翅片的影响,对胀接工艺参数进行了优化,同时分析了胀接前后换热管内径的变化。... 基于LS-DYNA软件平台建立换热器胀接工艺的仿真模型,研究包含支撑板结构的大型管-翅式换热器的胀接工艺过程。分析了胀接过程中翅片的变形及支撑板的存在对翅片的影响,对胀接工艺参数进行了优化,同时分析了胀接前后换热管内径的变化。结果表明,胀接过程中,与支撑板右侧相邻的翅片受到的轴向挤压力最大,危险性最高;适当增加翅片间隙可有效避免胀接过程中翅片的损坏;此外,变形区管壁材料的流动使得胀接后换热管内径略大于模具外径。 展开更多
关键词 胀接成形 -翅式换热器 支撑板 翅片损伤 换热管内径
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硫酸盐-冻融循环下自感应水泥砂浆的耐久及压敏性能 被引量:1
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作者 李一凡 王社良 +3 位作者 徐晋 白娇娇 全晓旖 徐卫锋 《硅酸盐通报》 CAS 北大核心 2022年第3期777-786,共10页
为提升寒冷地区建筑结构的实时损伤监测效果,研究了硫酸盐-冻融循环作用下采用短切碳纤维与铁尾矿作为导电材料制备的自感应水泥砂浆的耐久与压敏性能。利用质量损失、相对动弹性模量及抗压强度损失为依据探讨耐久性能变化规律,以电阻... 为提升寒冷地区建筑结构的实时损伤监测效果,研究了硫酸盐-冻融循环作用下采用短切碳纤维与铁尾矿作为导电材料制备的自感应水泥砂浆的耐久与压敏性能。利用质量损失、相对动弹性模量及抗压强度损失为依据探讨耐久性能变化规律,以电阻率变化率-压应力的相关关系反映硫酸盐-冻融循环作用下压敏性能发展规律并解释其导电机理,并采用平均应力敏感系数评价硫酸盐-冻融循环作用下压敏性能稳定性。结果表明,碳纤维体积掺量为0.4%、铁尾矿替代率为30%(质量分数)组合掺入水泥砂浆时,其耐久性能与压敏性能均达到较高水平,但硫酸盐-冻融循环造成的孔洞与裂缝会导致铁尾矿碳纤维水泥砂浆电阻率变化率-压应力呈一阶指数衰减关系,可采用Plane模型来反映平均应力敏感系数衰减程度与冻融循环次数、铁尾矿替代率之间良好的相关关系。 展开更多
关键词 铁尾矿 短切碳纤维 硫酸盐-冻融循环 压敏性能 应力敏感系数 plane模型
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蝶形钢索-拱桥的几个设计参数分析 被引量:1
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作者 岳永强 丁洁民 +2 位作者 陈鸿鸣 杨辉柱 陆秀丽 《结构工程师》 2005年第3期1-5,共5页
本工程是某学校校区内一座钢索-拱桥,本文分析了影响该结构的几个参数,首先本文比较了圆弧形和抛物线形拱轴线对整个结构的受力、变形、周期和振型的影响,以及竖向荷载和竖向刚度分配的影响;同时本文还分析了索与拱平面的夹角和拱与水... 本工程是某学校校区内一座钢索-拱桥,本文分析了影响该结构的几个参数,首先本文比较了圆弧形和抛物线形拱轴线对整个结构的受力、变形、周期和振型的影响,以及竖向荷载和竖向刚度分配的影响;同时本文还分析了索与拱平面的夹角和拱与水平面夹角的关系及其对整个结构的影响;再者本文分析了桥面支座形式对整个结构的影响。 展开更多
关键词 参数分析 拱桥 钢索 设计 蝶形 抛物线形 刚度分配 竖向荷载 结构 拱轴线 圆弧形 水平面 夹角 校区 工程 受力 振型
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Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams 被引量:61
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作者 Jinhua Wang Bin Yu +4 位作者 Hongpu Kang Guofa Wang Debing Mao Yuntao Liang Pengfei Jiang 《International Journal of Coal Science & Technology》 EI 2015年第2期97-162,共66页
Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mi... Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology & Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows: 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as "low gas content, high gas emission", are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed. 展开更多
关键词 Ultra-thick coal seams Top-coal caving mining Large mining height Mining method - Mining equipment Roadway support Safety guarantee
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Effect of temperature difference load of 32 m simply supported box beam bridge on track vertical irregularity 被引量:5
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作者 Kaize Xie Jun Xing +3 位作者 Li Wang Chunxiang Tian Rong Chen Ping Wang 《Journal of Modern Transportation》 2015年第4期262-271,共10页
In order to study the effect of temperature difference load (TDL) along the vertical direction of a simply supported beam bridge section on the vertical irregularity, a rail-bridge-piers calculation model was establ... In order to study the effect of temperature difference load (TDL) along the vertical direction of a simply supported beam bridge section on the vertical irregularity, a rail-bridge-piers calculation model was established. Taking 32 m simply supported box beam bridge which is widely used in the construction of pas- senger dedicated line in China as an example, influences of the temperature variation between the bottom and top of the bridge, temperature curve index, type of temperature gradient, and beam height on track vertical irregularity were analyzed with the model. The results show that TDL has more effects on long wave track irregularity than on short one, and the wavelength mainly affected is approxi- mately equal to the beam span. The amplitude of irregu- larity caused by TDL is largely affected by the temperature variation, temperature curve index, and type of temperature gradient, so it is necessary to monitor the temperaturedistribution of bridges in different regions to provide accurate calculation parameters. In order to avoid the irregularity exceeding the limit values, the height of 32, 48, and 64 m simply supported box beam bridges must not be less than 2.15, 3.2, and 4.05 m, respectively. 展开更多
关键词 Simply supported beam bridge Temperaturegradient Vertical irregularity - Beam height
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