回转曲面测量技术

针对回转体曲面，提出了一种利用三坐标测量机和回转工件台，在工件连续转动过程中，让测头沿母线运动，在圆柱坐标系中进行测量的方法．该方法具有测头的运动简单、安全、可靠性高、效率高等优点．论述了其工作原理、圆柱坐标的提取以及一些关键技术，包括测头系统的作用半径标定、转台回转轴线位置确定、被测零件的自动定心技术等．研制了由三坐标测量机、回转工件台、测头回转体和非接触激光三角法测头组成的实验系统，对易碎石膏零件进行测量，精度可以达到0．02mm．     

三角法光学非接触测量头应用中的关键技术

光学非接触测头在其实际应用中，有一系列问题需要解决．为此，对三角法测量头的灵敏度与特性标定、工件的倾斜与颜色的影响、光束功率与引起的温升、测头的位置找正、测头系统的作用半径标定等应用中的关键技术进行了实验研究，提出了误差补偿、提高调整和标定精度以提高光学非接触测头使用精度的方法。     

圆度测量的误差分离及数据处理

详细推导出三测头误差分离原理用于测量工件圆度误差的数学公式；论述用滑动平均法和数字滤波法对采样数据作处理，可有效地抑制干扰信号，提高信噪比；通过对比实验证明上述方法对提高测量精度有明显效果。     

回转式激光线扫描测量仪

提出一种基于线结构光的回转式视觉测量系统,首先介绍系统的组成和工作原理,建立了线结构光测头的数学模型,并用该系统对测头进行标定;然后确定转台的回转中心,实现了将测头二维测量值向被测物体三维坐标的转换;最后,给出了实际测量结果,此系统能一次性完整测量任意工件的外表面,测量精度优于0．07mm。     

薄孔壁厚和小孔径测量系统

由于相邻孔壁厚度的测量根据进刀量进行计算时精度很低，故提出了一种应用电容传感器对2个微小孔间相邻孔壁进行精密测量的系统．基于非接触式电容测孔传感器，研究了测头的电场边缘效应影响及保护环的宽度选择，设计了电容瞄准测孔传感器的测头对相邻小孔中心定位，利用电容差动测厚传感器测量孔壁，系统由1个瞄准测孔传感器和2个差动测厚传感器及三通道测量电路组成，处理数据后直接显示孔径和孔间壁厚．系统属非接触测量，无需修正测头及工件变形误差，实验证明，测量精度为0．5μm，     

应用在线整定广义最小方差多项式权值的测头控制方法

在曲面工件的高精度、高效率自动扫描测量过程中,为了提高测头自动跟踪扫瞄控制的精度和平稳性,提出了基于在线整定多项式权值的广义最小方差(OSPW_GMV)控制方法.该方法的主要思想是根据在线估计的被控对象参数及OSPW_GMV的输出,在线调整多项式的权值,实现测头自动跟踪扫瞄的控制.实验结果证明,使用具有高跟踪精度和强鲁棒性的OSPW_GMV控制器,可使测头跟踪过程的误差小于0.1mm的跟踪要求,且每次运算时间与广义最小方差控制器相差不大,因此该控制方法在一些实时性及控制精度要求较高的精密检测场合,有较好的应用价值.     

基于图像处理技术的工件长度在线测量

针对轧钢厂加热钢锭传输线,提出了一种工件长度在线测量方法.利用CCD摄像机对生产线上工件的图像信息进行远距离采集.考虑到实时在线检测要求算法简单计算速度快,在对图像信息进行边缘噪声滤除的基础上,利用图像灰度的梯度算子提取工件边缘特征,并进行边缘识别,从而实现工件长度的在线测量.为补偿摄像镜头的非线性影响,进行了二次多项式拟合处理,以提高测量精度.同时,介绍了实时在线测长系统的组成和功能,并对其测量速度和精度进行了实际测试分析,结果表明,被测工件长度在400~1 200 mm之间,运行速度不高于5 m/s时,测量误差低于0.4%.     

三坐标测量机测头的校正方法和误差分析

三坐标测量机的测头是坐标测量机的关键部件,主要用来触测工件表面。为确保测量机的测量精度和测量效率,现通过对三坐标测量机测量系统接触式测头结构特点的分析,并对测头校正时所产生的误差进行分析探讨,提出了测头直径有效的校正和使用方法,从而获得最佳的有效工作长度和测针刚性,提高了测量精度。     

随机取样示波器时间测量电路的设计

随机取样实际上是以触发点为参考基准进行取样、存储和再现信号。如何精确测量触发脉冲与第一个采样脉冲之间的时间，以及如何利用它摆正各次触发后采集的样品数据在时间轴上的位置并正确重显被测信号，是随机示波器设计的重点。本文对高等效采样率的随机采术数字示波器的“时间内插电路”作了分析和设计。     

一种在线测量圆柱工件直径的方法

介绍一种快速、精确的在线测量圆柱工件直径的方法—V型座测经法.对测量原理和误差进行了分析,指出在顶角为60°的V型座测量椭圆度较小的圆柱工件时,随机一次测量结果即可视为其平均直径,测量误差已可忽略。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.