基于图像测量的花键套端面尺寸检测     

许贤泽  陈少阳  刘盼盼  乐意 《测绘信息与工程》2015,40(1)

设计了一套基于图像测量技术的花键套端面尺寸检测系统,采用高分辨率工业相机获取零件图像信息,使用相机标定技术标定相机参数,以校正光学系统导致的零件图像畸变,通过图像处理技术处理并分析图像,得到图像特征尺寸信息,最后采用分区域标定像素当量的方法得到零件实际尺寸.使用该检测系统与三坐标测量仪检测系统进行对比实验,实验结果显示,该系统尺寸检测结果与三坐标测量仪检测结果比照相差不超过10 μm.每个零件检测时间不超过20 s,速度远远快于平均检测时间需约2 min的三坐标测量仪检测方法,因此在满足检测精度的基础上大大提高了检测速度,实现了花键套尺寸批量检测.  相似文献   

Distribution of CMEs with Different Angular Widths and Comparison with the Phase of Sunspot Number in the 23rd Solar Cycle     

MENG Wei-juan  LE Gui-ming  LIN Zhao-xiang  ZHANG Yong  YANG Xing-xing 《Chinese Astronomy and Astrophysics》2014

The variation of the number of coronal mass ejections (CMEs) with different angular widths in the period of 1996-2008 is analyzed statistically in this paper, together with a comparison of the feature of time variation between the number of CMEs with some typical angular widths and the number of sunspots.  相似文献   

Retrieval of balanced fields: an optimal control method   总被引：1，自引：0，他引：1  

FRANÇOIS-XAVIER LE DIMET  MOHAMED OUBERDOUS 《地球，A辑:动力气象学与海洋学》1993,45(5):449-461

  相似文献   

Lateglacial landform associations at Jæren (SW Norway) and their glaci-dynamic implications     

STÅLE RAUNHOLM  HANS PETTER SEJRUP  EILIV LARSEN 《Boreas: An International Journal of Quaternary Research》2003,32(3):462-475

The Jæren lowland is located on the southwestern coast of Norway between a mountainous region in the east and the offshore Norwegian Channel in the west. During the Last Glacial Maximum, Jæren was in an intermediate position between an ice stream following the Norwegian Channel northwards, and westward flowing inland ice. The dynamic behaviour of the inland ice and the interaction with the ice stream are examined by means of geomorphological analysis of digital terrain models and sedimentological investigations. SW-trending drumlins were formed at Jæren below tributary ice from the inland, feeding into the Norwegian Channel Ice Stream. The presence of Rogen moraine in the central part of Jæren indicates a frozen substratum prior to their formation, and this suggests a transition to cold-based ice between the tributaries. The deglaciation of the Norwegian Channel at about 15 ka BP resulted in an unstable ice front for the inland ice sheet. The formation of Rogen moraine may be explained by a dynamic advance resulting in extensional flow and fracturing of the frozen substratum between the tributaries. The dynamic advance was followed by an early deglaciation of the coastal areas as evidenced by shallow marine sediments. Deformation of the shallow marine sand indicates a glacial readvance through the valleys formerly acting as tributaries to the ice stream.  相似文献   

Valence state partitioning of V between pyroxene‐melt: Effects of pyroxene and melt composition,and direct determination of V valence states by XANES. Application to Martian basalt QUE 94201 composition     

J. M. KARNER  J. J. PAPIKE  S. R. SUTTON  C. K. SHEARER  P. BURGER  G. McKAY  L. LE 《Meteoritics & planetary science》2008,43(8):1275-1285

Abstract— Experiments on a Martian basalt composition show that D_v augite/melt is greater than D_v pigeonite/melt in samples equilibrated under the same fO₂ conditions. This increase is due to the increased availability of elements for coupled substitution with the V³⁺ or V⁴⁺ ions, namely A1 and Na. For this bulk composition, both A1 and Na are higher in concentration in augite compared with pigeonite; therefore more V can enter augite than pigeonite. Direct valence state determination by XANES shows that the V³⁺ and V⁴⁺ are the main V species in the melt at fO₂ conditions of IW‐1 to IW+3.5, whereas pyroxene grains at IW‐1, IW, and IW+1 contain mostly V³⁺. This confirms the idea that V³⁺ is more compatible in pyroxene than V⁴⁺. The XANES data also indicates that a small percentage of V²⁺ may exist in melt and pyroxene at IW‐1. The similar valence of V in glass and pyroxene at IW‐1 suggests that V²⁺ and V³⁺ may have similar compatibilities in pyroxene.  相似文献   

Partially Fused Granite Blocks from Mt. Elephant, Victoria, Australia     

LE MAITRE  R. W. 《Journal of Petrology》1974,15(2):403-412

Petrological and chemical evidence is presented to show thatsmall patches of brown glass found in blocks of granite eruptedin basaltic scoria at Mt. Elephant are the result of the partialfusion of biotite and quartz. The glass has moderate SiO₂ (63–66per cent), high AI₂O₃ (17.5–19 per cent), high FeO (3.8–5.2per cent) and very high K₂O (7.0–7.8 per cent) relativeto Na₂O (3.3–3.7 per cent) and is similar in compositionto many high K alkali syenites and trachytes.  相似文献   

考虑流固耦合效应的单桩式海上风电机组结构响应模拟     

乐可定  郁冶  赵兰浩  牟凯龙 《海洋工程》2023,41(5):37-47

针对海上风电整机系统,建立了一体化流固耦合分析方法。在模拟过程中,采用浸入边界法解决风机叶片旋转引起的静动干涉问题,利用改进的守恒式 level set（简称 ICLS）方法捕捉海浪自由面,并使用交错迭代法求解流固耦合方程。通过构建 “风机—塔架—基础”一体化流固耦合数值模拟方法,能够在一次仿真计算中实现海上风电整机系统的全过程数值模拟,准确求解多荷载耦合作用下“风机—塔架—基础”的整体结构动力响应。以某单桩式海上风电工程为例,验证了本方法能够实现对海上风电整体系统的一体化分析。  相似文献   

城市水利工程对京杭大运河无锡段水位影响分析          下载免费PDF全文

朱骊  乐峰  张建平  贾小网  秦建国 《水文》2014,34(4):92-96

根据京杭大运河无锡段历年河流水位与降水量的关联,结合城市水利工程,分析了京杭大运河无锡段水位变化规律。重点研究了2003年前后水位变化的形成机制,推求出水利工程和气候条件下水位的变化特点,总结了城市水利工程对京杭大运河流向产生的影响。为本地区研究城市水利工程影响下河流水位变化情况及防汛应用提供了数据支持。  相似文献   

秋季太湖水下光场结构及其对水生态系统的影响   总被引：3，自引：1，他引：2  

黄昌春  李云梅  孙德勇  乐成峰  伍蓝  王利珍  王鑫 《湖泊科学》2009,21(3):420-428

水生态系统中光能的分配很大程度上决定了水生态系统的结构和功能,利用2007年11-12月太湖水体光学特性和组分浓度数据,对秋季太湖水下光场结构特征和水体组分光竞争能力的表征光学量(漫衰减系数、平均余弦)和影响因素(吸收系数比重)进行了分析研究.结果表明,秋季太湖水下辐照度呈现单峰分布,最高值为583nm左右:根据Kd可将黄质和非色素物质主导程度的强弱分为弱、较强、强三个等级;Kd(PAR)平均值为4.61±1.54m-1,水体真光层厚度平均值为1.11±0.35m;太湖水下光场的光能主要分布在青光和黄绿光波长范围内,约占总能量的60%,蓝光和红光波长范围内的能量约占30%,这样的光谱结构有利于铜绿微囊藻和斜生栅藻的生长.  相似文献   

广西大瑶山地区加里东期石英脉型金矿：上木水金矿白云母Ar-Ar年龄约束          下载免费PDF全文

李忠阳  党院  乐兴文 《高校地质学报》2018,24(5):637

石英脉型金矿是广西大瑶山地区主要的金矿床类型之一,但一直没有高精度的年龄数据约束其成矿时代。论文首次 对大瑶山南部广西苍梧县上木水石英脉型金矿中的热液白云母进行39Ar/40Ar年龄法测年,获得坪年龄为（432.6 ± 3.2）Ma,相应 的等时线年龄为（428.2 ± 7.2）Ma,反等时线年龄为（425.3 ± 6.6）Ma,表明其成矿时代为加里东期。这一数据进一步证明 大瑶山南部的古龙-夏郢环形成矿区主要以加里东期矿化为主,除了与加里东期岩浆岩有关的斑岩-矽卡岩型钨多金属矿化 外,还存在石英脉型金矿。同时,位于大瑶山中部沿区域性大黎断裂分布的六岑-桃花-古袍金矿田的石英脉型金矿时代仍 然不明确,还需要进一步的高精度测年数据来约束。  相似文献