插齿刀变位系数约束条件与计算流程

变位系数计算是插齿刀设计的重要工作.讨论了插齿刀变位系数选取原则以及应当满足不产生齿顶变尖、被切齿轮齿根过渡曲线干涉、根切和顶切等4个的约束条件.给出了新刀设计的最大变位系数和根据刃磨到最后刀齿仍有必要强度所允许的最小变位系数计算公式,编制了插齿刀变位系数计算机辅助运算流程,使插齿刀设计简单快速且便于判断设计的可行性.     

NGW型行星齿轮传动设计中的几个计算问题

行星齿轮传动与普通定轴轮系齿轮传动相比较,具有多方面的优越性。然而行星齿轮传动一般均为变位齿轮传动,设计计算工作量十分浩繁,其中尤以几何参数的计算为最,这也是行星齿轮传动不易推广应用的一个原因。本文对NGW型行星齿轮传动进行了分析,就以下三个计算问题列出了它们的简捷计算方法和计算公式: 一、太阳轮、行星轮和内齿圈的配齿数方法; 二、用查曲线圈方法计算角度变位齿轮传动的几何参数; 三、在内啮合角度变位齿轮传动的几何参数和几何尺寸计算中,引入了“齿顶延长系数”的概念,并在分析插齿加工的特点的基础上,引出了包括内、外啮合、滚切、插切齿轮的统一的设计用几何尺寸计算公式。最后还附有设计计算实例。     

渐开线少齿差内齿轮副的优化设计及其图形的自动显示

采用优化设计方法来解决渐开线少齿差行星传动中内齿轮副几何参数的合理选择问题。该优化模型的目标函数为内齿轮副的啮合效率，设计变量为外、内齿抡的变位系数Ｘ＿１、Ｘ＿２和齿顶高系数ｈ＊＿ｎ．以保证一定的重合度、齿顶厚以及避免各种几何干涉为约束条件。优化方法为复合形法。最后，还编制了自动绘图程序，以便借助计算机自动显示和绘制内齿副的啮合图。     

非标准复合齿轮插齿刀设计方法

研究加工不等齿厚的非标准参数渐开线齿形,与非渐开线齿形复合的锁闭齿轮插齿刀刀齿的排列、刀具齿数的选择以及刀具设计的基本方法,介绍用限制区域选择插齿刀变位系数的新方法,并给出刀具齿顶后角与侧螺旋角的关系曲线,为插齿刀参数的选择提供依据,结果表明,采用上述方法设计非标准复合齿轮插齿刀,可简化计算和提高设计效率。     

渐开线直齿圆柱齿轮参数的测量与计算

本文阐述了渐开线直齿圆柱齿轮齿顶圆直径的测量与齿轮模数、变位系数、压力角等参数的确定方法和步骤.     

内平动齿轮传动几何参数的优化设计

为了解决内平动齿轮传动设计中几何参数,特别是变位系数确定困难、计算过程繁琐和计算结果精度不高等问题,探讨渐开线少齿差行星齿轮传动优化设计的方法,采用机械优化设计理论,运用CAD建立了内平动齿轮传动变位系数和啮合角的优化求解数学模型,在优化软件LINGO平台上编程实现了计算过程的自动化和几何参数的优化,得到了一齿差和二齿差内平动齿轮传动变位系数和啮合角的最优值,并结合工程实例,验证了该方法的优越性.计算结果表明:一齿差内齿轮副最小啮合角为53.2°,二齿差最小啮合角为39.3°;一齿差内齿轮副的外齿轮最好采用标准齿轮,内齿轮采用变位系数为0.577的正变位,二齿差内齿轮副的内、外齿轮均须采用正变位,有时变位系数大于1.     

渐开线齿形链机构的啮合机理

基于齿轮齿条机构的啮合理论，研究了渐开线齿形链机构的啮合机理．分析了渐开线齿形链轮和链条的啮合状态，得出了变位系数的求解公式，发现变位系数与齿数和节距有关，并给出了变位系数的变化曲线．对渐开线齿形链轮的根切状态进行了研究，求解了不发生根切的最小齿数．研究了渐开线链轮的最小变位系数和唯一变位系数，发现链轮节距为9．525mm时，最小齿数应为17．基于包络原理和坐标变换公式，确定了渐开线齿廓和齿根圆之间过渡曲线的方程．求解变位系数和最小齿数的方法可适用于所有节距的齿形链机构．     

渐开线少齿差行星传动的变位系数的选择

目的 解决渐开线少齿差行星传动变位系数的最佳选择方法。方法 采用齿廓建干涉条件Ｇｓ向不发生齿廓干涉条件的临界值ｅ逼近,结果,推导出选择变位系数的公式,并通过实例证明了该方法的正确性,结论利用该方法得到的变位系数,可以增大重合度,减小机构尺寸、提高传动质量。     

非圆齿轮齿廓数值计算的研究

提出了一种简单准确的非圆齿轮齿廓的数值算法．该方法从齿廓形成原理和过程出发，将非圆齿轮齿廓的计算转化成了求非圆齿轮节曲线的法向等距线和插齿刀齿廓的交点过程，因此只需要给出非圆齿轮节曲线、插齿刀参数和插齿数据，就可以非常迅速准确地计算出非圆齿轮，其中包括齿顶、工作齿廓、过渡曲线和齿根曲线的全部齿廓数据．同时，它还可以检查非圆齿轮是否发生根切或齿顶变尖等设计缺陷，为非圆齿轮的测量和线切割加工提供了准确的齿廓曲线数据．目前，该方法已经成功地应用于非圆齿轮齿廓线切割的加工中，并取得了良好的效益．     

内齿轮干涉的简易计算

内齿轮在重型机械及工程机械中应用很广.内啮合传动与外啮合传动相比较,它的特点是:尺寸紧凑、重迭系数较大、接触应力小、润滑性能好等;但是,当内齿轮付的齿数及有关参数选择不当时,会发生内齿轮特有的干涉现象,本文着重介绍内齿轮渐开线干涉、齿面重迭干涉、插刀退刀干涉的简易计算法,运用比较方便.不论标准齿轮、变位齿轮;不论标准齿高、短齿或花键齿,均可很快判断其是否会发生干涉现象.     

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.     

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.     

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。     

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.