定位壳级进模设计

根据定位壳的工艺特点,采用单侧载体1模1件成形,增加了侧整形、侧切边、侧弯曲和精冲小孔等工序,对级进模各子模的上、下模结构进行了优化组合,使材料利用率大于25%。生产实践证明:模具结构合理,工艺性好,生产可靠,满足了企业的生产要求。

基于霍夫变换和Canny算子的表壳中心定位方法

为实现手表壳中心定位,搭建了一套单目机器视觉系统,并基于该系统的硬件条件,编写相应的图像处理程序。在对手表壳外形轮廓的物理特征和图像特征进行分析后,确定了表壳中心定位算法的操作流程。通过图像预处理提取有用特征信息,并利用Canny算子提取出完整的手表壳轮廓。在此基础上,利用霍夫变换检测轮廓的中心圆,从而获取其中心点的坐标信息。通过实验对该表壳中心定位方法进行准确率验证,结果表明:手表壳中心定位方法能够满足工业生产要求,具有一定的实用性。

用于多品种“面销定位”桥壳的清洗托运小车研制

为解决多品种"面销定位"桥壳的清洗问题,本文结合多品种桥壳的定位、清洗特点以及所用步进输送方式,通过带安装孔车体组件、左销定位组件、平面定位组件、右销定位组件及加工配置方法的设计,不仅拓宽了该托运小车应用范围,满足了多品种桥壳的清洗使用需求,而且在其桥壳品种变换时,满足了实际生产时的"省时、省力"变换所需,且结构新颖,运行平稳,简单实用,易于制作,且具有可推广的应用价值。

Deformation caused by the 2011 eastern Japan great earthquake monitored using the GPS single-epoch precise point positioning technique

Crustal deformation can provide constraints for studying earthquake rupture and shock wave transmission for the Mw9.0 eastern Japan great earthquake. Using the single- epoch precise point positioning （PPP） method and the appropriate positioning flow, we process GPS data from six IGS （International GNSS Service） sites （e.g., MIZU, TSK2, USUD, MTKA, AIRA and KSMV） located in Japan and obtain the positioning results with centimeter scale precision. The displacement time series of the six sites are analyzed using the least squares spectral analysis method to estimate deformations caused by the Mw9.0 mainshock and the Mw7.9 aftershock, and the cumulative displacements after 1 day. Mainshock displacements at station MIZU, the nearest site to the mainshock in the North （N）, East （E）, and Up （U） directions, are -1.202 m, 2.180 m and -0.104 m, respectively, and the cumulative deformations after 1 day are -1.117 m, 2.071 m and -0.072 m, respectively. The displacements at station KSMV, the nearest site to the Mw7.9 aftershock in the N, E and U directions, are -0.032 m, 0.742 m and -0.345 m, respectively. The other sites obviously experienced eastern movements and subsidence. The deformation vectors indicate that the horizontal displacements caused by the earthquake point to the epicenter and rupture. Elastic bounds evidently took place at all sites. The results indicate that the crustal movements and earthquake were part of a megathrust caused by the Pacific Plate sinking under the North American Plate to the northeast of Japan island arc.

Regional Tectonic Deformation Background and Medium- and Short-Term Precursors to the Minle-Shandan Earthquakes1

Using GPS observations of horizontal movement from 2001 to 2003 and the cross-fault mobile short-levelling data of 1988～2003, and with the aid of the improved negative dislocation model and the time-varying curve of strain intensity ratio of fault deformation, the regional tectonic deformation background and medium- and short-term precursors related to the preparation of the Minle-Shandan earthquakes of M S6.1 and M S5.8 on October 25, 2003 are investigated. The results reveal that, under the background of the wide-range deformation adjustment, short-term relaxation and recovery caused by the Kunlun Mountains earthquake of M S8.1, the hypocenters of the earthquakes are located on the north edge of the shear stress enhancement zone between the compressional locked segments of block boundary fault, a place which may represent an accelerated strain accumulation. An obvious anomaly of strain intensity ratio appeared in short-levelling measurements crossing over the fault at the Shihuiyaokou site, the closest to the epicenters, 3 months before the occurrence of the earthquakes. In addition, the variation in number of anomalies from 10-odd days to months before the earthquakes in the entire monitoring area and the anomaly concentration and local enhancement relative to near source in the 3 months before the earthquakes are regarded to be precursors to the two events.

GPS Observation and Study on Recent Crustal Movement in the Northeastern Area of Pamir,Xinjiang

Calculation of repeated observation data at the densified GPS monitoring network in northeastern area of Pamir together with data from IGS stations in the periphery of the area yielded the movement rate of more than 40 GPS station sites in the area, and, hence, the recent crustal deformation rate pattern and time series of fiducial GPS stations in the area were obtained. The result indicates that the principal movement direction of the GPS station sites is NNW, basically diagonal to the strike of Tianshan fold belt, i.e. a normal compression occurs in the Tianshan region. The movement pattern near Jiashi and its southwestern zone is some different from that of station sites in their surrounding areas, indicating a certain relation of tectonic deformation in Jiashi area to seismic activity during last years. The movement rate of station sites in the periphery of Tarim basin less varies and its direction is basically consistent. It indicates less or basically no deformation within Tarim basin.

Crustal Movement in the Northern Part of North China Associated with Zhangbei Earthquake

Crustal Deformation Monitoring Center, China Seismological Bureau, Tianjin 300180, China Crustal deformation in the northern part of North China associated with Zhangbei earthquake is analyzed using GPS data collected during 1992, 1996 and 1999, precise re-leveling data collected during 1992, 1998 and 2000, and INSAR result (September 22, 1997～May 6, 1998). The results indicate: ① The vertical deformation is not remarkable since 1992. The vertical crustal deformation in the central and northern part of North China in recent 10 years is of inheritance. The scope of the significant deformation is 15km×15km with a magnitude of 250mm when the event occurred. ② The horizontal deformation is not remarkable in any unit of North China. ③ Before and after the event (1992～1996 and 1996～1999), there is kinematic change of horizontal motion between different units. The activity mode along Yinshan tectonic zone changed from relative static state to left-lateral strike slip; The dominant extensional movement along Shanxi rift zone changed to right-lateral strike slip; Yanshan tectonic zone changed from left-lateral strike-slip with extension to left-lateral strike slip; Yanshan-Hebei transitional zone formed before the event disappeared after the event. ④ The scale of the deformation is closely related to the physical property of media and geological structure environment. Further analysis indicates that ① Zhangbei earthquake does not mean that the earthquake activity begins to be strengthened in North China; ② The crustal movement is normal at present; ③ Next stronger earthquake in North China might be located in Yanshan tectonic zone, especially at its both ends, and Shanxi tectonic zone.

Discussion on Characteristics of Crustal Deformation along the Zhangjiakou-Bohai Sea Seismotectonic Zone

The Zhangjiakou-Bohai Sea fault zone located in the northern part of the North China region is a seismotectonic zone controlling the present-day strong earthquake activities. Under the effect of regional principal compressive stress with the direction of NEE-SWW, a series of NE-trending active tectonic zones have developed, which form a group of conjugated shear fracturing systems and control the occurrence of the present-day strong earthquakes. The feature of crustal deformation around this fault zone is studied in the paper. The long-term crustal deformation pattern from GPS measurements exhibits a relatively complete left-lateral strike-slip movement along the active fault zone. However, studies on crustal deformation by stages indicate that a series of NE-trending large-scale anomalous gradient zones have appeared along the Zhangjiakou-Bohai Sea fault zone before moderately strong earthquakes. They are represented respectively by the activities of the Tangshan-Hejian, the Sanhe-Laishui and the Yanhuai-Shanxi seismotectonic zones. This may indicate the occurrence of med-term precursors to moderately strong earthquakes along Zhangjiakou-Bohai Sea zone. The results in the paper show that the crustal deformation pattern before strong earthquake reveals the information of strain status in the deep seismogenic zone, while the chaotic pattern after the occurrence of strong earthquake represents the adjustment of the covering strata.