基于模糊聚类的可重构制造工艺规划方法

可重构制造是未来解决批量加工中高效、低成本与生产柔性之间矛盾的新型制造模式,建立与可重构机床设计紧密联系的零件族加工工艺方案对实现可重构制造具有重要意义。首先建立面向零件族的加工信息矩阵,进而形成零件的加工工序单元序列及工序单元顺序矩阵;依据零件可并行加工的方位组合,基于模糊聚类多层次分析法,将零件间相似的工序单元序列组配成工序段序列,再由零件间相似的工序段序列创成出零件工艺方案;最终通过零件间工艺方案的模糊聚类相似度计算,得到零件族中零件间最为相似的加工工艺方案,实现零件间加工工艺的快速转换。以某汽车变速箱体零件族的加工为例,验证了该方法的可行性。     

浅谈飞机起落架外筒零件的数控加工

本文从数控加工技术的特点、内容及工艺流程出发,以歼击机起落架的关键零件外筒为例,分析了该零件的材料特点,并针对影响外筒加工质量的因素作分析,将常规加工方法与数控加工有效结合,重点对数控加工工艺流程设计进行了探讨。     

某发动机双层结构预旋喷嘴精密焊接研究

本文介绍了某发动机双层结构多叶片的预旋喷嘴的研制过程,该零件由内、外两层钣金成型形筒体、内加强筋以及60个钣金叶片组合焊接而成,结构复杂,加工难度大。该零件首次采用钣金成型壳体,筒壁上采用激光切割方法加工叶型孔,其在组件上装配精度和变形控制我们还没有掌握,需要在首件研制时进行摸索。为此我们采用高精度的筒体成型工艺和高精密的激光切割技术,加上合理的装配、焊接工装,上述工艺的成功应用,大大提高了零件的加工精度和质量,为钣金件双层多叶片类零件的加工工艺提供许多可借鉴的地方。     

轴套类零件的数控工艺及夹具设计

本文以某轴套类零件为例,根据其结构特点进行工艺分析,确定合理加工路线,并设计其夹具结构,充分体现数控车削加工的优势.     

论大型薄壁件车加工变形质量控制

以某发动机上的某大型薄壁件为研究对象,在数控立车设备上,通过设计专用车加工夹具控制零件变形、选用专用机夹刀具,编制数控加工程序,选择合理的切削参数,控制零件加工中的变形,保证零件从研制到批产的过渡,稳定了工序加工质量,提高了加工效率,解决大型整体薄壁鼓筒类零件加工瓶颈问题,有效地促进大型钛合金薄壁件加工工艺技术水平的进步和提升。     

大型薄壁整体环形火焰筒加工工艺的研究

某发动机火焰筒外环为整体结构有别于其它型号发动机的分段焊接式火焰筒,它5段型面呈锥度组成的薄壁环形件,沿型面壁厚1.2±0.05。在零件5段外壁上分布7000余个φ1.2～φ1.8径向小孔及大孔。零件的毛料重量36.18kg（ρ=8.28g/cm3）,成品零件净重6.7kg,该材料为变形高温合金GH3536,由于其难切削特性且该零件较高、壁厚极薄,数控车加工时易让刀产生振纹,造成零件质量超差。本文从生产实际情况出发,从工艺路线、切削参数、加工方法等方面进行分析及试验研究,为新型号薄壁机匣类整体环形火焰筒的研制提供可借鉴的工艺方法。     

带侧孔筒形件注塑模设计

筒座零件有四个侧孔,成型难度大,为了设计较为合理的成型模具,对筒座零件进行了工艺分析和模具主要结构设计,包括分型面的设计、浇注系统的设计、脱模机构设计、合模导向机构的设计、排气系统和温度调节系统的设计等。最后绘制了筒座注塑模具装配图。     

某型机外涵承力环精益加工研究

本文以某型航空发动机外涵承力环为典型零件,介绍了腐蚀工艺、热处理工艺在钛合金材料中的应用,介绍了缩短钛合金零件加工周期的方法,同时还介绍了在数控加工中利用层铣刀提高数控铣加工效率的技术。根据腐蚀工艺和热处理工艺的工艺特点,通过调整加工余量的方式,改变热处理工艺和腐蚀工艺的工艺顺序,从而杜绝了零件的半精加工工序,缩短了零件的工艺路线,提高了零件的加工效率,缩短了零件的加工周期。解决了钛合金零件冗长的工艺路线的问题,为今后钛合金零件的加工技术提供参考。     

基于模板工艺的参数化工艺设计技术研究与实现

针对烟草机械产品的系列化和参数化特点,对参数化工艺设计技术进行了研究和实现。通过对零件分类建立模板工艺,并对其进行参数化,即在模板工艺与零件参数之间建立参数关系,以实现参数化驱动生成零件加工工艺。该技术已在某企业的CAPP系统中实现,显著提高了工艺设计的效率和工艺规范性。     

面向非回转体类零件制造单元研究

为了解决非转体类零件中一些零件加工复杂,生产效率低。经常需要使用专用的工夹量具。采用成组技术把非回转体类零件分类成组,通过建立零件族,设计出零件族的典型工艺,进而建立非回转体类零件的制造单元,在制作单元内完成零件的加工过程,这样有利于使用非回转体类零件的成组的工夹量具,能提高非回转体类零件的生产效率和加工质量。     

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.     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

A computer generator for randomly layered structures

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

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。     

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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