阿根廷Φ139.7mm套管探伤缺陷的解剖分析

中原油田所用的阿根廷套管大量不合格，对其进行无损探伤和解剖分析后发现，主要缺陷是折叠和大型非金属夹杂物。     

A Narrowing-based Instantiation Rule for Rewriting-based Fold/Unfold Transformations

In this paper we show how to transfer some developments done in the field of functionallogic programming (FLP) to a pure functional setting (FP). More exactly, we propose a complete fold/unfold based transformation system for optimizing lazy functional programs. Our main contribution is the definition of a safe instantiation rule which is used to enable effective unfolding steps based on rewriting. Since instantiation has been traditionally considered problematic in FP, we take advantage of previous experiences in the more general setting of FLP where instantiation is naturally embedded into an unfolding rule based on narrowing. Inspired by the so called needed narrowing strategy, our instantiation rule inherits the best properties of this refinement of narrowing. Our proposal optimizes previous approaches (that require more transformation effort) defined in the specialized literature of pure FP by anticipating bindings on unifiers used to instantiate a given program rule and by generating redexes at different positions on instantiated rules in order to enable subsequent unfolding steps. As a consequence, our correct/complete technique avoids redundant rules and preserves the natural structure of programs.     

塔北隆起张性构造带形成机制与油气关系

塔北隆起张性构造带分布于隆起轴部的轮台断隆上,主要为早期断裂受喜马拉雅运动早期的左旋扭动在浅层派生的北西-南东向张性构造.断裂在平面上呈左行雁列展布,在剖面上为小型地堑组合,部分断裂向深部与先存断裂联合形成负反转构造.与断裂相伴的褶皱构造沿断裂走向分布,且受断裂活动控制.塔北隆起张性构造带位于极有利的构造部位,具有良好的油气远景.     

热轧板冷弯开裂分析

采用扫描电子显微镜和光学显微镜观察了热轧板在冷弯过程中开裂试样的断口形貌并进行了成分分析。发现裂纹内存在氧化铁且呈断续分布，裂纹两侧基体内存在着内氧化颗粒且其显微组织也有差异。分析表明，热轧板冷弯开裂是由热轧折叠缺陷造成的，但不影响整批材料的性能。实际使用中只要切除缺陷部位，即可正常使用。     

Statistical analysis of distribution patterns of coal seams in fold zones in Northwest China

The mechanisms for rock bursts occurrences in fold zones are complex, and the redistribution of in-situ stresses is closely related to the complexity of the structures. Analysis of the geomorphology of fold structures and changes of coal thickness can help identify zones prone to rock bursts to improve safety and productivity in coal mines. This study investigated the distribution characteristics of fold structures in coal seams in fold zones in four mines in northwest China. Geometrical characteristics of fold structures in coal seams and changes of coal thickness were analysed, based on comprehensive evaluation indexes,such as the length–width ratio of folds, interlimb angle, ratio P1 of projected width of fold limbs to that of the hinge zone, curvature ratio P2, the maximum curvature and amplitude. The statistical analysis of the four coal mines shows that the length–width ratio of folds changed from 0.78 to 2.03 and the maximum curvature of cross sections of folds was less than 0.04. The curvature ratio of cross section of a fold in the structure was no more than 1.4 and the interlimb angles of cross sections of 89% of folds were larger than 150°. Gentle fold structures were dominant and the specific geological morphologies were domes or basins. The isopleth of coal thickness above the coal mines showed a fluctuation trend similar to the contour line of the floor of coal seams. The coal thickness in an anticline area was smaller than that in the neighboring syncline area. Therefore, the overall variation of coal thickness in the mining areas was likely to have a relation with the direction of the regional principal stress.     

Preparation of fluorine-doped tin oxide (SnO2:F) film on polyethylene terephthalate (PET) substrate

Fluorine-doped tin oxide (FTO), one of the most popular transparent conductive oxide (TCO) materials, coated on glass has been used in various applications including many new-generation solar cells. However, there is a lack of reporting when it comes to FTO coated on flexible transparent substrate. For this paper, spray pyrolysis technique was used to have FTO firstly coated on to a brass substrate, which was then dissolved away after cementing an upper flexible transparent polyethylene terephthalate (PET) substrate, finally leaving high quality FTO film on PET substrate. Their structural, electrical, optical and flexible properties were investigated. The lowest resistivity was 7.6 × 10^− 4 Ω cm, which is as good as conventional FTO deposited on glass. Their fold ability could be significantly improved to transcend commercial ITO/PET only by increasing the pretreating time of the brass substrate.     

龙首山直沟门岩体特征及构造环境

直沟门岩体(年龄374±38Ma)侵入于华北板块西缘的龙首山岩群,主要由花岗岩、二长花岗岩 等岩性组成。根据野外产状和岩相学特征可划分为3个单元,从早到晚依次为:直沟门单元、湾湾圈单 元和马路湾单元。岩体的w(SiO2)65.94%～75.18%,w(K2O)2.36%～4.35%,w(Na2O)3.53%～ 5.47%,总体上w(Na2O)≈w(K2O)。随w(SiO2)增大w(CaO),w(TFeO),w(MgO)减少,所有岩 石均具铝弱过饱和,ANKC=1.01～1.09,岩浆类型属钙碱性系列,σ=1.99～2.64,皮可克指数为55.6。 Li,Cs,Rb质量分数较低,而Ba,Sr较高,从早到晚大体存在Rb/Sr减少,而Sr,Ba,Co和Ba/K增加。 湾湾圈和马路湾单元在ΣREE((152.11～171.94)×10-6),ΣLREE/ΣHREE(24.81～26.92),δEu (0.91～1.10)以及配分模式等方面是相似的,与其相比,直沟门单元的ΣREE(46.62×10-6),ΣLREE/ ΣHREE(3.52)低,而δEu(1.60)高。w(La)与w(La)/w(Sm)大体存在正相关,δEu,ΣREE与DI变化 也相一致。直沟门岩体形成于祁连造山带碰撞阶段之后,属后碰撞花岗岩。在w(CaO)/w(Na2O)对 w(Al2O3)/w(TiO2)图上,与拉克伦褶皱带后碰撞花岗岩的投影区相近。直沟门岩体的岩浆可能源自 祁连褶皱带下冲火山岩。     

离合器内齿轮包挤压成形工艺及实验研究

研究了在离合器上使用的圆柱直齿内齿轮的加工工艺,与当前使用的冷挤压法成形工艺的比较表明,该工艺克服了冷挤压成型齿时载荷大,模具凸模磨损严重,使用寿命短的缺陷,解决了直接冷挤压成形内齿轮中的产品质量一致性不够好的问题,得到了齿形饱满,端面平整的内齿轮,而且成形内齿与预挤分开,使带齿模具凸模寿命可得到延长,具有生产实用化的前景。     

Characteristics of dynamically formed oxide films on molten aluminium

Abstract

The characteristics of oxide films formed within a short time of pouring were investigated using samples prepared via the oxide–metal–oxide sandwich (OMO) technique. Surfaces of the OMO sandwiches were studied using scanning electron microscopy. The thickness of the folds of oxide films was examined and compared with previously obtained values for Al–7Si–0··4Mg and Al–5Mg alloys. Results showed that the thicknesses of oxide films formed in pure aluminium and Al-7Si- 0.4Mg alloy are very close and in the range 100-500 nm.     

Detecting and quantifying envelope singularities in the plane

The mathematical envelopes of families of both rigid and non-rigid moving shapes play a fundamental role in a variety of problems from very diverse application domains, from engineering design and manufacturing to computer graphics and computer assisted surgery. Geometric singularities in these envelopes are known to induce malfunctions or unintended system behavior, and the corresponding theoretical and computational difficulties induced by these singularities are not only massive, but also well documented. We describe a new approach to detect and quantify the envelope singularities induced by 2-dimensional shapes of arbitrary complexity moving according to general non-periodic and non-singular planar affine motions. Our approach, which does not require any envelope computations, is reframing the problem in terms of “fold points” and “fold regions” in the neighborhood of geometric singularities, and we show that the existence of these fold points is a necessary condition for the existence of singularities. We establish a mathematically well defined duality between the 2-dimensional Euclidean space in which the motion takes place and a 2+1 spacetime domain. Based on this duality, we recast the problem of detecting and quantifying geometric singularities into inherently parallel tests against the original geometric representation in the 2-dimensional Euclidean space. We conclude by discussing the significance of our results, and the extension of our approach to 3-dimensional moving shapes.