凸缘断面型钢多工位在线尺寸测量

研制了一种凸缘断面型钢的多工位轧件尺寸在线测量系统 ,测量精度可达 0 .0 1mm。该系统用于型钢轧制的闭环尺寸控制 ,借助于带人工智能的控制软件 ,可以明显提高型钢轧制的尺寸精度。用于轧制 H2 0 0mm× 10 0 mm铅质模拟轧件时 ,轧件的腰部厚度尺寸偏差可以从标准要求的± 1.0 mm提高至± 0 .1mm之内。用于 60 kg/m重轨的冷定径精轧 ,轨高的尺寸偏差可从± 0 .5 mm提高至± 0 .

SJ34型车刀量角仪车刀几何角度测量方法研究

简介SJ34型车刀量角仪,根据SJ34型车刀量角仪的结构特点,提出测量工位概念,运用几何分析拓展了SJ34型车刀量角仪的测量范围,据此提出相关的间接测量计算公式,借鉴电子仪器的标定理念,在车刀几何角度测量方法中引入标定测量。并通过数据对比,来证明相关间接测量计算公式的正确性。

SJ25型车刀量角仪车刀几何角度测量方法研究

简介SJ25型车刀量角仪,根据SJ25型车刀量角仪的结构特点,提出测量工位概念,运用几何分析拓展了SJ25型车刀量角仪的测量范围,据此提出相关的间接测量计算公式,借鉴电子仪器的标定理念,在车刀几何角度测量方法中引入标定测量。并通过数据对比,来证明相关间接测量计算公式的正确性。

NEW MODEL OF THEODOLITE INDUSTRIAL MEASURING SYSTEM

Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision of the TIMS has been considered so low that the TIMS isnt applied to some precise measurements.The error in self locating TIMS is a main factor which affects the precision of the TIMS.A new model of the TIMS is given out in this paper,and it can eliminate the error in self locating the TIMS.The new model is not only investigated and analyzed theoretically but also verified by the real measured data.

Design of High Precision Horizontal Control Network for Large-Scale Hydropower Project

A new solution of combination network of GPS and high precise distance measurements with EDM is proposed. Meanwhile, it’s inadvisable only using GPS network without distance measurements. Three schemes: terrestrial network, GPS network and combination network are discussed for horizontal control network design of Xiangjiaba Dam in view of precision, reliability, coordinate and outlay in detail.

Injection molding of micro patterned PMMA plate

A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 minx213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 ram. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate （PMMA） was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

Prediction Research of Deformation Modulus of Weak Rock Zone under In-situ Conditions

Weak rock zone (soft interlayer, fault zone and soft rock) is the highlight of large-scale geological engineering research. It is an important boundary for analysis of rock mass stability. Weak rock zone has been formed in a long geological period, and in this period, various rocks have undergone long-term consolidation of geostatic stress and tectonic stress; therefore, under in-situ conditions, their density and modulus of deformation are relatively high. Due to its fragmentary nature, once being exposed to the earth's surface, the structure of weak rock zone will soon be loosened, its density will be reduced, and its modulus of deformation will also be reduced significantly. Generally, weak rock zone can be found in large construction projects, especially in the dam foundation rocks of hydropower stations. These rocks cannot be eliminated completely by excavation. Furthermore, all tests nowadays are carried out after the exposure of weak rock zone, modulus of deformation under in-situ conditions cannot be revealed. In this paper, a test method explored by the authors has been introduced. This method is a whole multilayered medium deformation method. It is unnecessary to eliminate the relatively complete rocks covering on weak rock zone. A theoretical formula to obtain the modulus of deformation in various mediums has also been introduced. On-site comparative trials and indoor deformation modulus tests under equivalent density conditions have been carried out. We adopted several methods for the prediction researches of the deformation modulus of weak rock zone under in-situ conditions, and revealed a fact that under in-situ conditions, the deformation modulus of weak rock zone are several times higher than the test results obtained after the exposure. In a perspective of geological engineering, the research findings have fundamentally changed peoples' concepts on the deformation modulus of weak rock zone, provided important theories and methods for precise definition of deformation modulus of deep weak rock zone under cap rock conditions, as well as for reasonable engineering applications.

Low impedance nature of 12 acupoints on the limbs,and the unexpected dependence on limb angle

OBJECTIVE: To better understand the working mechanism of acupuncture, we investigated the skin electrical impedance distribution around acupoints, and the impedance changes at 12 original acupoints bilaterally after bending the limbs.METHODS: We measured the skin electrical impedance in three study subjects in the frequency range of 40 to 10 k Hz using the four-electrode method with a sharp probe and a large reference electrode.A measurement matrix of 7 mm × 7 mm with spacing of 2.0(or 3.0) mm was measured to obtain 2 D impedance mapping of acupoints. The impedance spectra of 12 original acupoints were measured at the 0° position and the 90° position.RESULTS: The electrical impedance of some acupoints, such as Yangchi(TE 4), was 16 times lower than that of the surrounding area, showing a recognizable small central area of low impedance with a diameter of less than 4 mm. In contrast, other acupoints, such as Laogong(PC 8), had an electrical impedance that was not significantly different from that of the surrounding area. When the limb was bent from a straight position(0o) to a vertical position(90o), the electrical impedance of the 12 original acupoints showed varied trends, either increasing or decreasing by a factor of up to ten times, or remaining at the same level.CONCLUSION: Not all acupoints tested show the property of low impedance, which might be related to the varied depth of the openings of superficial collaterals. The unexpected dependence of acupoint impedance on limb angle is a novel discovery, which implies that the channel paths are located in interstitial structures in the limbs. It might be possible to determine an optimized limb position for each particular acupuncture treatment in clinical practice.