首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   35篇
  免费   2篇
  国内免费   3篇
工业技术   40篇
  2023年   4篇
  2022年   2篇
  2020年   2篇
  2019年   1篇
  2018年   4篇
  2016年   4篇
  2015年   1篇
  2014年   2篇
  2011年   4篇
  2010年   3篇
  2008年   2篇
  2007年   1篇
  2006年   2篇
  2005年   3篇
  2004年   2篇
  2003年   1篇
  2002年   2篇
排序方式: 共有40条查询结果,搜索用时 15 毫秒
31.
说明了软件可视化在可视化技术领域的地位和它的内涵 ,讨论了软件可视化系统的构成要素 ,概述了软件可视化系统的实现策略。  相似文献   
32.
The double tearing mode(DTM)in a high βN(βN>1.5)discharge with internal transport barrier on EAST was investigated.A 15 kHz tearing mode(TM)(m≥3,n=3)appears at outer q=2 surface at first,which is stable in the highβN phase.Then a 2 kHz TM(m=2,n=1)occurs at inner q=2 surface.Soon after,high βN collapsed with the crash of ELM,and DTM formed during the collapse of βN.The positions of the two islands of the DTM are consistent with the q=2 surface.The temperature fluctuations are the strongest between the two magnetic islands.A statistical analysis of high βN discharges operating with the reversed magnetic shear configuration in the EAST 2015-2018 campaign revealed the existence of the DTM in many discharges.During the DTM phase,all βN are reduced by 10%-30% within 0.1 s.However,there are two different βN behaviors thereafter-with and without βN recovery.Studying the physical mechanism of βN recovery during the DTM phase will benefit steady-state operation with reversed shear configurations in the future.  相似文献   
33.
建立精确的宽幅钢箱梁桥有限元模型对此类结构的动力性能评估与结构设计有着重要的意义。建立了宽幅钢箱梁桥精细三维有限元模型,对宽幅钢箱梁桥不同施工阶段开展基于环境激励作用下的模态测试,采用随机子空间法与峰值拾取法识别桥梁的前十二阶模态,基于模态识别结果采用响应面法对桥梁有限元模型进行修正,详细分析了桥梁铺装层、邻跨等效质量对桥梁模态的影响。分析结果表明:建立的有限元模型具有较高的精度;铺装层会显著降低桥梁各阶自振频率,邻跨等效质量对桥梁的横向与扭转频率有显著的影响。  相似文献   
34.
对精细化管理的发展与概念进行了介绍,并在分析城市桥梁施工管理相关特点的基础上,提出了城市桥梁施工精细化管理的原则,同时从员工、进度、质量等方面总结了城市桥梁施工精细化管理的具体措施,最后指出精细化管理是城市桥梁施工管理未来发展的必然趋势。  相似文献   
35.
刘海庆  杨凌辉  任永杰  邾继贵 《红外与激光工程》2016,45(11):1117002-1117002(6)
提出了一种基于正交柱面成像相机的大尺寸三维坐标测量方法。正交柱面成像相机由一个正交柱面成像光学系统和两个正交放置的线阵CCD组成,它们分别被用来检测被测点的水平角和垂直角。一个相机决定了两个角度,两个相机交汇,即可实现被测点的三维坐标测量。所提出的方法在精密坐标测量特别是动态位置跟踪方面具有突出的优势。一个灵活的内参标定方法被用来标定正交柱面成像相机,内参标定后相机在水平方向和垂直方向角度测量误差的均值分别为1.85和2.16。另外,双相机的外参标定也被介绍,外参标定后系统的坐标测量精度优于0.52 mm。实验结果表明:所提出的三维坐标测量方法有效,具有良好的测量精度。  相似文献   
36.
A millimeter wave solid state source—far infrared laser combined interferometer system (MFCI) consisting of a three-channel 890 GHz hydrogen cyanide (HCN) laser interferometer and a three-channel 340 GHz solid state source interferometer (SSI) is developed for real-time line-integrated electron density feedback and electron density profile of the EXL-50 spherical tokamak device. The interferometer system is a Mach–Zehnder type, with all probe-channels measured vertically, covering the plasma magnetic axis to the outermost closed magnetic plane. The HCN laser interferometer uses an HCN laser with a frequency of 890 GHz as a light source and modulates a 100 kHz beat signal by a rotating grating, giving a temporal resolution of 10 μs. The SSI uses two independent 340 GHz solid-state diode sources as the light source, the frequency of the two sources is adjustable, and the temporal resolution of SSI can reach 1 μs by setting the frequency difference of the two lasers at 1 MHz. The main optical path of the two interferometers is compactly installed on a set of double-layer optical platform directly below EXL-50. Dual optical path design using corner cube reflectors avoids the large support structures. Collinear the probe-beams of two wavelengths, then the phase error caused by vibration can be compensated. At present, the phase noise of the HCN Interferometer is 0.08 rad, corresponding to a line-integrated electron density of 0.88 × 1017 m−2, one channel of measuring result was obtained by the MFCI system, and the highest density measured is about 0.7 × 1019 m−2.  相似文献   
37.
The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak, including the blob detection rate Nb,size δb,lifetime τb and radial velocity vr,b.The blob properties in L-mode and I-mode are similar, and those in ELM-free H-mode are different to them. The blob Nbis smaller while τbis larger in H-mode. The experimental blob sizeδband velocity scalings vr,bb show a good agre...  相似文献   
38.
高凝油井电伴热优化计算   总被引:4,自引:0,他引:4  
针对潍北油田疃3块原油高凝、高含蜡、井筒举升高能耗等导致的井筒举升难题,根据传热学基本原理和两相流理论,建立了井筒电热杆加热数学模型,利用设计的优化计算软件,得到了疃3块3口高凝油井的电加热方式、电加热深度及电加热功率。针对恒功率电伴热系统存在的缺陷,提出了一种新的电伴热优化方法,即电热杆长度、下入位置及加热点分布优化计算,并以疃3块3-X1井为例进行了优化研究。结果表明,恒功率电伴热优化后3口井的加热深度由原来800 m变为448~492 m,人工补充热量由最初的8 kW降至3.69~5.56 kW,降幅达30.5%~53.88%。对电伴热段进行均匀分段,适当增加分段数,可有效降低井筒举升能耗。将油井3-X1的加热段均匀分为10段,每段长度为45 m时,人工补充热量为4.25 kW,与恒功率电伴热系统相比,井筒举升能耗进一步降低23.6 %。  相似文献   
39.
An internal transport barrier (ITB) can be formed on EAST in exploring high-parameter operation. Previous studies show that safety factor (q) profiles, Shafranov shift and magnetohydrodynamic behaviors could be helpful in ITB formation by suppressing anomalous transport. Recently, electron density evolution with high resolution demonstrates that fishbone could be dominant in electron density ITB formation and sustainment. The power threshold is low in the fishbone condition and the electron density profile is determined by traits of fishbone. Simulation shows that the low-k ion mode is suppressed by fishbone. Direct measurement of turbulence in the inner region shows that the internal kink mode could sustain an electron temperature ITB by suppressing the trapped electron mode. The multi-scale interaction between the kink mode and turbulence by current could be key in sustaining high-electron-temperature long-pulse operation.  相似文献   
40.
利用软X射线、中子注量检测诊断系统和偏振干涉仪(Polarimeter-interferometer,POINT)约束下的平衡反演算法(Equilibrium Fitting Algorithm,EFIT),对东方超环(Experimental Superconducting Tokamak,EAST)等离子体在离子回旋共振频率波(Ion Cyclotron Resonance Frequency wave,ICRF)在轴沉积加热下的锯齿周期,锯齿幅度,q=1面处等离子体压强梯度,q=1面的半径的变化情形进行了研究。研究发现,在轴沉积情况下,加入ICRF可以对锯齿起致稳作用(延长锯齿周期),锯齿周期与ICRF功率呈正相关;锯齿周期随着ICRF的加入或者ICRF功率的变化趋势,与锯齿幅度和q=1面处等离子体压强梯度变化趋势大体上一致;要改变q=1面半径,ICRF的功率可能需要到0.8 MW以上;在ICRF功率占比更高的加热条件下,锯齿周期和q=1面半径随着ICRF功率变化更敏感;EAST中ICRF产生的快离子和导致的q=1面半径的变化可能对锯齿行为有一定的影响。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号