期刊文献+
共找到24,105篇文章
< 1 2 250 >
每页显示 20 50 100
基于Open-GL组件技术的采矿模拟系统 被引量:6
1
作者 贾明涛 潘长良 +1 位作者 王李管 侯林惠 《中南工业大学学报》 CSCD 北大核心 2003年第1期11-15,共5页
冬瓜山铜矿是目前国内发现的埋深最大、有岩爆倾向的缓倾斜厚度大的铜矿床,为了安全、高效生产,开发一套综合矿床开采模型对该矿山进行管理、调度、分析、控制及模拟.作者对其中的一个子系统“采矿过程动态模拟系统”的技术开发进行了研... 冬瓜山铜矿是目前国内发现的埋深最大、有岩爆倾向的缓倾斜厚度大的铜矿床,为了安全、高效生产,开发一套综合矿床开采模型对该矿山进行管理、调度、分析、控制及模拟.作者对其中的一个子系统“采矿过程动态模拟系统”的技术开发进行了研究.其过程是:通过系统分析,利用Open-GL图形库开发了适用于Delphi的通用三维图形环境及基本图元组件;分析并建立了开采轮数与开采步数之间的数学关系式;根据矿体项、底板倾角设定合理的单元块尺寸,以便既能精确模拟矿体边界形态,又能减少系统处理工作量,提高系统运行效率;运用时钟组件实现模拟过程的动态效果.利用这些技术,开发了一个采矿过程动态模拟系统.实践结果表明,该系统运行效果良好. 展开更多
关键词 组件技术 采矿模拟系统 open-GL 图形库 冬瓜山铜矿 矿床开采
在线阅读 下载PDF
Application of open-pit and underground mining technology for residual coal of end slopes 被引量:10
2
作者 CHE, Zhaoxue YANG, Hong 《Mining Science and Technology》 EI CAS 2010年第2期266-270,共5页
Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining tech... Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized. 展开更多
关键词 integrated open-pit and underground mining end-slope resource recovery economic benefit surface coal mine
在线阅读 下载PDF
Dispersion compensation in an open-loop all-optical chaotic communication system 被引量:3
3
作者 刘慧杰 任斌 冯久超 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第4期138-144,共7页
The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber tr... The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber transmission under strong injection conditions. The performances of fiber links composed of two types of fiber segments in different dispersion compensation maps are compared by testing the quality of the recovered message with different bit rates and encrypted by chaotic modulation (CM) or chaotic shift keying (CSK). The result indicates that the performance of the pre-compensation map is always worst. Two types of symmetrical maps are identical whatever the encryption method and bit-rate of message are. For the transmitting and the recovering of message of lower bit rate (1 Gb/s), the post-compensation map is the best scheme. However, for the message of higher bit rate (2.5 Gb/s), the parameters in communication system need to be modified properly in order to adapt to the high-speed application. Meanwhile, two types of symmetrical maps are the best scheme. In addition, the CM method is superior to the CSK method for high-speed applications. It is in accordance with the result in a back-to-back configuration system. 展开更多
关键词 chaotic communication dispersion compensation semiconductor lasers strong injection open-loop configuration
在线阅读 下载PDF
Remote open-path laser-induced breakdown spectroscopy for the analysis of manganese in steel samples at high temperature 被引量:1
4
作者 Minchao CUI Yoshihiro DEGUCHI +4 位作者 Zhenzhen WANG Seiya TANAKA Min-Gyu JEON Yuki FUJITA Shengdun ZHAO 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第3期52-59,共8页
A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the rel... A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the relatively simple configuration and optics were employed to measure the steel samples at a remote distance and a hot sample temperature. The system has obtained a robustness for the deviation of the sample position because of the open-path and alloptical structure. The measurement was carried out at different sample temperatures by placing the samples in a muffle furnace with a window in the front door. The results show that the intensity of the spectral lines increased as the sample temperature increased. The influence of the sample temperature on the quantitative analysis of manganese in the steel samples was investigated by measuring ten standard steel samples at different temperatures. Three samples were selected as the test sample for the simulation measurement. The results show that, at the sample temperature of 500 ℃, the average relative error of prediction is 3.1% and the average relative standard deviation is 7.7%, respectively. 展开更多
关键词 REMOTE open-path LIBS steel MANGANESE SAMPLE temperature QUANTITATIVE ANALYSIS
在线阅读 下载PDF
Open-circuit voltage analysis of p-i-n type amorphous silicon solar cells deposited at low temperature 被引量:1
5
作者 Ni Jian Zhang Jian-Jun Cao Yu Wang Xian-Bao Li Chao Chen Xin-Liang Geng Xin-Hua Zhao Ying 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第8期403-407,共5页
This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125℃. We find that poor quality p-a-Si... This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125℃. We find that poor quality p-a-SiC:H films under regular conditions lead to a restriction of open circuit voltage although the band gap of the i-layer varies widely. A significant improvement in open circuit voltage has been obtained by using high quality p-~SiC:H films optimized at the "low-power regime" under low silane flow rates and high hydrogen dilution conditions. 展开更多
关键词 amorphous silicon solar cell low temperature open-circuit voltage
在线阅读 下载PDF
Stability analysis of the sliding process of the west slope in Buzhaoba Open-Pit Mine 被引量:1
6
作者 Ning Fang Ji Changsheng Garmondyu E.Crusoe Jr. 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第5期869-875,共7页
To study the stability of the west slope in Buzhaoba Open-Pit Mine and determine the aging stability coefficient during slide mass development, the deformation band of the west slope and the slide mass structure of th... To study the stability of the west slope in Buzhaoba Open-Pit Mine and determine the aging stability coefficient during slide mass development, the deformation band of the west slope and the slide mass structure of the 34,600 profile are obtained on the basis of hydrology, geology, and monitoring data.The residual thrust method is utilized to calculate the stability coefficients, which are 1.225 and 1.00 under sound and transfixion conditions, respectively. According to the rock damage and fragmentation and the principle of mechanical parameter degradation, the mechanical models of the slide mass development of the hard and soft rock slopes are established. An integrated model for calculating the slope stability coefficient is built considering water, vibration, and other external factors that pertain to the structural plane damage mechanism and the generating mechanism of the sliding mass. The change curve of the stability coefficient in the slide mass development is obtained from the relevant analyses,and afterwards, the stability control measures are proposed. The analysis results indicate that in the cracking stage of the hard rock, the slope stability coefficient decreases linearly with the increase in the length Lbof the hard rock crack zone. The linear slope is positively correlated to rock cohesion c. In the transfixion stage of the soft rock, the decrease speed of the stability coefficient is positively correlated to the residual strength of the soft rock. When the slope is stable, the stability coefficient is in a quadratic-linear relationship with the decreased height Dh of the side slope and in a linear relationship with anchoring force P. 展开更多
关键词 open-pit mine Side slope Sliding process Aging stability Crack zone
在线阅读 下载PDF
调度自动化OPEN-3000系统显示异常的分析处理
7
作者 徐珊 《无线互联科技》 2015年第2期143-145,共3页
OPEN-3000系统是电网监控及调度人员监视和控制电网的主要技术手段。文章深入分析了一次因OPEN-3000系统显示异常而导致监控员无法监视电网运行状态的问题,并提出具体解决方法,为更全面掌握OPEN-3000系统,更好地维护系统积累了经验,同... OPEN-3000系统是电网监控及调度人员监视和控制电网的主要技术手段。文章深入分析了一次因OPEN-3000系统显示异常而导致监控员无法监视电网运行状态的问题,并提出具体解决方法,为更全面掌握OPEN-3000系统,更好地维护系统积累了经验,同时也提高了系统运行的可靠性。 展开更多
关键词 open-3000系统 显示异常 Qt控件 字体文件库
在线阅读 下载PDF
OPEN-3000调度自动化系统的研究
8
作者 向荣 《通讯世界》 2014年第11期97-99,共3页
本文主要结合具体工程实例来介绍OPEN-3000调度自动化系统内容,并探讨了南瑞科技OPEN-3000系统的硬件配置及应用,从而为我国的电力行业的发展提供一定的保障,仅供参考。
关键词 open-3000 调度自动化 研究
在线阅读 下载PDF
Open-loop frequency response for a chaotic masking system
9
作者 黄显高 Yu Pei 黄伟 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第12期2894-2901,共8页
In this paper, a new numerical simulation approach is proposed for the study of open-loop frequency response of a chaotic masking system. Using Chua's circuit and the Lorenz system as illustrative examples, we have s... In this paper, a new numerical simulation approach is proposed for the study of open-loop frequency response of a chaotic masking system. Using Chua's circuit and the Lorenz system as illustrative examples, we have shown that one can employ chaos synchronization to separate the feedback network from a chaotic masking system, and then use numerical simulation to obtain the open-loop synchronization response, the phase response, and the amplitude response of a chaotic masking system. Based on the analysis of the frequency response, we have also proved that changing the amplitude of the exciting (input) signal within normal working domain does not influence the frequency response of the chaotic masking system. The new numerical simulation method developed in this paper can be extended to consider the open-loop frequency response of other systems described by differential or difference equations. 展开更多
关键词 open-LOOP frequency response chaotic masking system
在线阅读 下载PDF
Open-MUSIC:基于度量学习与特征子空间投影的电磁目标开集识别算法 被引量:1
10
作者 杨柳 利强 邵怀宗 《电子学报》 EI CAS CSCD 北大核心 2022年第6期1310-1318,共9页
在越来越复杂的电磁频谱环境中,要想实现对频谱资源的管控,首先要判断发送信号的辐射源是否是己方已知的.针对此问题,本文提出了一种基于计算特征子空间投影比值的算法Open-MUSIC(MUltiple SIgnal Classification),通过神经网络获得已... 在越来越复杂的电磁频谱环境中,要想实现对频谱资源的管控,首先要判断发送信号的辐射源是否是己方已知的.针对此问题,本文提出了一种基于计算特征子空间投影比值的算法Open-MUSIC(MUltiple SIgnal Classification),通过神经网络获得已知类特征表示;进而得到已知类特征矩阵的两个正交子空间;以特征在两个子空间内的投影比值为指标,对辐射源信号样本是否为已知做判决.在3个数据集上的仿真表明,Open-MUSIC算法的性能在电磁数据集上较其他方法提升了3%以上. 展开更多
关键词 开集识别 特征子空间分解 中心损失 投影
在线阅读 下载PDF
MIS-TLIF与OPEN-TLIF治疗单节段腰椎管狭窄的疗效比较 被引量:1
11
作者 麻光喜 杨益宇 许兵 《浙江临床医学》 2022年第4期560-563,共4页
目的探讨微创经椎间孔腰椎椎体间融合术(MIS-TLIF)与开放性TLIF(OPEN-TLIF)治疗单节段腰椎管狭窄的临床疗效。方法回顾性分析单节段腰椎管狭窄患者103例,随访过程中失访4例,根据不同的手术方式分为MIS-TLIF组(50例)和OPEN-TLIF组(49例)... 目的探讨微创经椎间孔腰椎椎体间融合术(MIS-TLIF)与开放性TLIF(OPEN-TLIF)治疗单节段腰椎管狭窄的临床疗效。方法回顾性分析单节段腰椎管狭窄患者103例,随访过程中失访4例,根据不同的手术方式分为MIS-TLIF组(50例)和OPEN-TLIF组(49例)。比较两组患者的围手术期指标、手术疗效及术后并发症发生情况。在术前、术后3个月及术后1年,采用视觉模拟评分法(VAS)对两组患者进行疼痛程度评估,采用Oswestry功能障碍指数(ODI)问卷表评估腰部功能活动情况,采用日本骨科协会评估治疗分数(JOA)评估腰背部及下肢功能。术后1年应用CT平扫+二三维重建获取患者的椎间隙后高度和节段性脊柱前弯的影像学参数,并进行组间比较。结果两种术式的手术疗效比较,差异无统计学意义(P>0.05)。MIS-TLIF组的手术时间、术后卧床时间、术后住院时间均短于OPEN-TLIF组,术中出血量、术后引流量均少于OPEN-TLIF组,术后并发症总发生率低于OPEN-TLIF组,差异均有统计学意义(P<0.05)。术前、术后3个月及术后1年,两组的VAS评分、ODI指数及JOA评分比较,差异均无统计学意义(P>0.05)。术后1年两组患者的椎间隙后高度、节段性脊柱前弯角度比较,差异均无统计学意义(P>0.05)。结论MIS-TLIF是治疗单节段腰椎管狭窄的有效手段,具有手术时间短、术中出血量和术后引流量少、住院时间短、术后并发症发生率低的优势,能够有效改善患者腰椎功能,恢复椎间隙后高度和节段性前弯。 展开更多
关键词 微创经椎间孔腰椎椎体间融合术 开放性椎间孔腰椎椎体间融合术 单节 段腰椎管狭窄
在线阅读 下载PDF
A BLIND RANDOMIZED CROSS -OVER TRIAL COMPARING BETAXOLOL WITH TIMOLOL IN OPEN-ANGLE GLAUCOMA AND OCULAR HYPERTENSION
12
作者 H.Moham-mad-Rabie J.Rajavi M.Rahmati-kamel 《国际眼科杂志》 CAS 2003年第1期1-1,共1页
Purpose: To compare the short-term efficacy and side effects of betaxolol and timoloi in treatment of primary open angle glaucoma or ocular hypertension. Methods: Fourteen patients with newly diagnosed early primary o... Purpose: To compare the short-term efficacy and side effects of betaxolol and timoloi in treatment of primary open angle glaucoma or ocular hypertension. Methods: Fourteen patients with newly diagnosed early primary open angle glaucoma or ocular hypertension were included.Each patient received 0.5% timoloi and 0.5% betaxolol twice daily for four weeks in two phases. Between two courses of treatment there was four weeks wash out period. At the end of study the effect of these two drugs on intraocular pressure, mean arterial blood pressure,pulse rate,basic tear secretion and ocular symptoms were evaluated and statistically analyzed,using wilcoxon and chi-squar test.RESULTS:The study was performed on fourteen patients with baseline IOP of 26.7 ±1.5 mmHg.After four weeks treatmem,timoiol and betax-olol reduced IOP by 7.8±1.2mmHg or 29% and 6.1±1.3mmHg or 23%, respectively (P<0.001). The difference between two groups was significant(P<0.001). Mean arterial blood pressure was reduced with betaxolol and 展开更多
关键词 开角型青光眼 眼内高压 倍他洛尔 噻吗洛尔 疗效 比较研究 盲法随机交叉试验
在线阅读 下载PDF
A Method for Constructing Open-Domain Chinese Entity Hypernym Hierarchical Structure
13
作者 CAI Hongbo CHEN Hong LIU Shen 《ZTE Communications》 2017年第1期49-54,共6页
Entity relation is an essential component of some famous knowledge bases,such as Freebase,Yago and Knowledge Graph,while the hyponymy plays an important role in entity relations that show the relationship between the ... Entity relation is an essential component of some famous knowledge bases,such as Freebase,Yago and Knowledge Graph,while the hyponymy plays an important role in entity relations that show the relationship between the more general terms(hypernyms)and the more specific instances of the terms(hyponyms).In this paper,we present a comprehensive scheme of open-domain Chinese entity hypernym hierarchical construction.Some of the most important unsupervised and heuristic approaches for building hierarchical structure are covered in sufficient detail along with reasonable analyses.We experimentally evaluate the proposed methods and compare them with other baselines.The result shows high precision of our method and the proposed scheme will be further improved with larger scale corpora. 展开更多
关键词 ENTITY hypernym hierarchization APRIORI Algorithm SUFFIX hypernym open.domain
在线阅读 下载PDF
Experiments on an Open-Loop Cycle Carbon Dioxide Refrigeration System
14
作者 徐雷 蒋彦龙 +1 位作者 郑小漪 蔡玉飞 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第4期452-460,共9页
An open loop cycle carbon dioxide(CO2)refrigeration system is established,and the cooling performances of high-pressure CO2 under different storage conditions(25℃,30℃,and 35℃)are investigated.Moreover,the experimen... An open loop cycle carbon dioxide(CO2)refrigeration system is established,and the cooling performances of high-pressure CO2 under different storage conditions(25℃,30℃,and 35℃)are investigated.Moreover,the experimental mass flow rates of CO2 are compared with the theoretical values at different conditions and refrigeration capacities.The results indicate that the storage condition of CO2 has a significant impact on the refrigeration performance,and the mass flow rate of CO2 increases with the increasing storage temperature in a given refrigeration capacity. 展开更多
关键词 CO2 open loop cycle refrigeration system mass flow rate storage condition
在线阅读 下载PDF
饱和软黏土中回型沉垫基础竖向承载特性研究
15
作者 刘润 许泽伟 +1 位作者 陈广思 梁超 《岩土力学》 北大核心 2025年第2期381-388,共8页
随着海上风电装机总量逐渐增加,适用于海洋软土地基区域的坐底式海上风电安装平台逐渐得到推广使用。该平台通过支撑结构坐于沉垫基础顶面,沉垫基础再将集中荷载均匀分布到海底地基中,为整个风电安装平台提供支撑。但传统的未开孔沉垫... 随着海上风电装机总量逐渐增加,适用于海洋软土地基区域的坐底式海上风电安装平台逐渐得到推广使用。该平台通过支撑结构坐于沉垫基础顶面,沉垫基础再将集中荷载均匀分布到海底地基中,为整个风电安装平台提供支撑。但传统的未开孔沉垫基础在长时间坐底条件下,基础底部土体会产生固结,并与基础紧密吸附在一起,增大基础回收或迁移难度,因此提出了一种新的中心开孔回型沉垫基础结构形式。为探究饱和软黏土中回型沉垫基础竖向承载特性,开展了离心机竖向承载力试验,结合有限元数值分析方法,研究开孔率和土体归一化强度对竖向极限承载力的影响。结果表明:当土体归一化强度小于2时,美国石油协会(American Petroleum Institute,简称API)规范低估了基础竖向承载力;当土体归一化强度大于2时,高估了基础承载力;随着开孔率的增大,竖向极限承载力逐渐减小,但不能依据API规范简单地采用有效面积对开孔沉垫基础进行线性折减;提出了以开孔率和土体归一化强度为变量的回型沉垫基础竖向极限承载力计算公式,为实际工程提供参考。 展开更多
关键词 沉垫基础 竖向承载力 开孔率 离心机试验
在线阅读 下载PDF
明渠交汇口水动力及掺混特性研究进展
16
作者 曾诚 周婧 +4 位作者 李凯 付毅成 周婕 蔡雷 王玲玲 《水利水电科技进展》 北大核心 2025年第1期10-17,共8页
针对明渠交汇区域内水流结构的复杂情况,从明渠交汇口汇流比、交汇角度、床面高差和其他影响因素的角度,综述了明渠交汇口分离区、剪切层、二次环流等很多特有的水动力及掺混特性的研究进展,梳理了物理模型试验、数值模拟研究和实地观... 针对明渠交汇区域内水流结构的复杂情况,从明渠交汇口汇流比、交汇角度、床面高差和其他影响因素的角度,综述了明渠交汇口分离区、剪切层、二次环流等很多特有的水动力及掺混特性的研究进展,梳理了物理模型试验、数值模拟研究和实地观测成果,总结了水动力及掺混特性的研究现状。基于目前存在的主要问题,未来应重点研究人工智能算法的应用,植被、密度差、潜流带对掺混特性的影响以及挟沙水流交汇问题中的冲刷淤积影响。 展开更多
关键词 明渠交汇口 水动力 掺混 影响因素
在线阅读 下载PDF
新型开口肋正交异性钢桥面板疲劳性能对比试验研究
17
作者 徐秀丽 钱思博 +6 位作者 李洪涛 吴冲 王仁贵 李琦 丁兴国 李枝军 李雪红 《土木工程学报》 北大核心 2025年第3期50-67,共18页
为从根本上改善正交异性钢桥面板疲劳性能,文章提出3种新型开口肋正交异性钢桥面板结构,分别为L肋-横隔板开大槽口、L肋-横隔板开钥匙孔、球扁钢肋-横隔板开苹果孔。为探究新型开口肋正交异性钢桥面板疲劳性能优越性及其疲劳易损部位,... 为从根本上改善正交异性钢桥面板疲劳性能,文章提出3种新型开口肋正交异性钢桥面板结构,分别为L肋-横隔板开大槽口、L肋-横隔板开钥匙孔、球扁钢肋-横隔板开苹果孔。为探究新型开口肋正交异性钢桥面板疲劳性能优越性及其疲劳易损部位,设计包括双面焊闭口U肋和3种新型开口肋正交异性钢桥面板结构的4个足尺模型,进行疲劳加载对比试验。通过组合式监测方法,捕捉关键细节疲劳裂纹的产生和扩展状态。试验结果表明:1000万次疲劳加载后,闭口U肋和大槽口桥面板的疲劳性能薄弱部位均为纵肋与顶板连接部位顶板焊趾;1200万次疲劳加载后,钥匙孔桥面板疲劳性能薄弱部位为横隔板与顶板连接焊缝顶板焊趾,苹果孔桥面板仍未产生疲劳裂纹。闭口U肋疲劳裂纹起裂于顶板与纵肋连接焊缝焊趾,分别沿着焊趾或者垂直、斜交于焊缝扩展;大槽口桥面板疲劳裂纹起始位置与闭口U肋相同,沿顶板焊趾扩展;钥匙孔桥面板疲劳裂纹起裂于顶板与横隔板连接焊缝顶板焊趾,并沿焊趾绕着横隔板扩展。新型开口肋结构可显著降低各疲劳易损细节的应力水平及横隔板面外变形,其中钥匙孔桥面板与苹果孔桥面板在顶板与纵肋连接处应力幅仅为闭口U肋的6.39%和11.12%,苹果孔桥面板开口处应力幅及面外变形较闭口U肋分别降低了42%和34%;相同加载条件下,苹果孔桥面板的疲劳寿命最高,其次为钥匙孔桥面板,二者均表现出优异的抗疲劳性能。 展开更多
关键词 桥梁工程 开口肋正交异性钢桥面板 足尺模型 疲劳试验 疲劳裂纹
在线阅读 下载PDF
空间网格空腹夹层板结构创新与实践最新进展
18
作者 陈红鸟 杨瑛 +4 位作者 田鹏刚 周正荣 陈靖 魏艳辉 马克俭 《应用力学学报》 北大核心 2025年第1期1-20,共20页
为了解决大跨度空腹网架结构抗剪刚度不足的问题,贵州大学马克俭教授于20世纪90年代创新地提出了空腹夹层板结构。通过减小竖杆的高宽比,使之形成“超短柱”,即剪力键,利用剪力键连接上、下肋协同受力,从而使空腹夹层板结构具有较大的... 为了解决大跨度空腹网架结构抗剪刚度不足的问题,贵州大学马克俭教授于20世纪90年代创新地提出了空腹夹层板结构。通过减小竖杆的高宽比,使之形成“超短柱”,即剪力键,利用剪力键连接上、下肋协同受力,从而使空腹夹层板结构具有较大的剪切刚度,其整体力学特性介于密肋井字楼盖与空腹网架之间。系统回顾了空腹夹层板结构的发展历程,介绍了该结构的组成和分类,总结了该结构的几何和力学特点,归纳了现有的理论分析方法与技术规程、结构优势及工程应用案例,尤其是2010年以后的工程实践进展;最后,对空腹夹层板结构体系的应用前景进行展望。空腹夹层板结构具有大跨度灵活划分空间、节约层高、降低结构自重、节省建筑用材、空腹可穿越管线等诸多优势,在全国30个省(市、自治区)的实际工程应用面积已达300余万平方米,节约建设资金超过2亿元。空腹夹层板结构体系的理论及实践创新体现了新时代的科技自立自强,采用多高层大跨度空腹夹层板楼盖结构可节约土地资源,对促进我国生态文明建设有重要意义。 展开更多
关键词 钢筋混凝土 空腹夹层板 大跨度结构 多高层建筑 网格结构
在线阅读 下载PDF
从脑白质病神经血管单元探讨开通玄府法内涵
19
作者 吴巍 黄世敬 +1 位作者 杨戈 潘菊华 《长春中医药大学学报》 2025年第2期127-131,共5页
通过对脑白质病神经血管单元与玄府理论的归纳和分析,发现脑玄府与脑白质病神经血管单元在结构和功能上呈现出一定的相关联性,并且脑白质病神经血管单元及其功能障碍与脑白质病不同阶段脑玄府开阖功能受损具有相似性。开通玄府法可应用... 通过对脑白质病神经血管单元与玄府理论的归纳和分析,发现脑玄府与脑白质病神经血管单元在结构和功能上呈现出一定的相关联性,并且脑白质病神经血管单元及其功能障碍与脑白质病不同阶段脑玄府开阖功能受损具有相似性。开通玄府法可应用在脑白质病各个阶段的治疗中,且开通玄府法具有维护脑神经血管单元和促进神经功能康复的作用。脑白质病神经血管单元稳态可以阐述开通玄府法的内涵,并为脑白质病的中医治疗提供了新思路。 展开更多
关键词 脑白质病 神经血管单元 稳态 开通玄府法
在线阅读 下载PDF
图像识别智能放煤含矸率高精度预测研究(Ⅰ)--煤流表面含矸率
20
作者 王家臣 杨胜利 +3 位作者 李良晖 安博超 宋世雄 王雨兵 《煤炭学报》 北大核心 2025年第1期150-165,共16页
图像识别智能放煤是实现智能化综放开采的重要技术之一,其核心在于通过监测煤流含矸率控制放煤口开闭。而井下低照度环境、煤岩块体的不规则形状及堆积叠压等因素是制约煤流含矸率预测的主要难题。针对煤流表面含矸率,构建了不同照度条... 图像识别智能放煤是实现智能化综放开采的重要技术之一,其核心在于通过监测煤流含矸率控制放煤口开闭。而井下低照度环境、煤岩块体的不规则形状及堆积叠压等因素是制约煤流含矸率预测的主要难题。针对煤流表面含矸率,构建了不同照度条件下的煤岩图像数据库,研究了照度及煤岩种类对图像分割性能的影响,开发了综放开采“放-运”全过程高仿真实验平台,提出了基于多照度融合与光流场优化的复杂场景下煤流表面投影面积含矸率高精度识别方法。其次,探讨了不同投影角度和投影方式对煤岩块体二维形态学特征提取的影响,明确了不同维度形态学特征之间的量化关系,构建了“尺寸+形状”特征融合的煤岩块体体积预测模型,用于合理预测煤流表面体积含矸率。最后,结合实验室和现场数据验证了所提方法的有效性。研究表明:随着照度的增大,2种煤岩组合形式的识别精度均先增大后稳定,并略有下降。通过合理设置照度(比如17730 lx),煤+泥岩复杂组合的mAP@0.5由88.7%(3180 lx)提升至92.3%。通过引入多照度融合和光流场分析,可进一步提升复杂场景下的煤流表面投影面积含矸率识别精度和算法适应性。合理选择光源波长,可以放大煤岩块体相对漫反射率差异,增加煤岩块体图像特征区分度。合理的图像投影方式也有利于不规则形状煤岩块体投影面积预测,预测偏差由60%降低至10%以下。通过引入形状特征辅助体积预测模型,体积预测精度显著提高,决定系数由仅考虑尺寸特征模型的0.9416提升至0.9692。 展开更多
关键词 综放开采 智能放煤 含矸率 煤流 煤岩形态
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部