平面二包环面蜗轮的特征建模

在环面蜗杆螺旋线解析几何方程的建模和平面包络环面蜗杆三维实体构建的基础上，分析讨论了平面二次包络环面蜗轮的几何特征，应用蜗杆特征模型，采用有限次数逻辑运算逼近方法完成平面二次包络环面蜗轮实体构建，实现了平面二次包络环面蜗轮副传动的组建．该方法简洁实用，三维实体具有真实的运动型面，能为数控加工提供精确的坐标参数，也能为平面二次包络环面蜗轮副传动的性能优化提供有用的研究方法．     

半监督平面聚类算法设计

采用以平面为原型来拟合样本的思想设计学习机,已在机器学习和数据挖掘等领域引起广泛关注,然而,如何利用少量标记样本,兼顾平面原型特点实现聚类,鲜见报道.以kPC(k-Plane Clustering)为切入点,在有标样本极端少的情况下,设计了半监督型平面聚类算法semi-kPC.考虑到L1范数较L2范数更为鲁棒的事实,在已有工作L1kPC(L1 norm kPC)的基础上,提出基于L1范数的半监督聚类方法 semi-L1kPC.从每类仅有一个已标样本出发,在人工数据集和UCI数据集上的实验表明:(1)在XOR(Exclusive OR)问题上,平面型的聚类方法的聚类准确率均显著高于k-means算法,因为k-means无法利用平面特性;(2)在引入少量监督信息后,半监督型聚类方法 semi-kPC和semi-L1kPC比其他聚类方法的聚类准确率更高;(3)采用L1范数的semi-L1kPC比semi-kPC的鲁棒性更好.     

可控二级啮合特性的蜗轮滚刀设计

圆柱蜗轮副的承载能力与蜗轮副齿面的失配方式和失配量密切相关。本文给出了失配蜗轮副齿面接触特性的计算方法,并在此基础上制定了控制齿面接触特性及对蜗轮滚刀的设计和安装参数进行优化综合的计算方法.按照本文所述方法设计的滚刀,不仅可以完全无除修磨蜗杆这一费工费时的旧工艺,得到具有良好的啮合特性和很低的误差敏感性的蜗轮副,还可以使滚刀在允许的重磨范围内使用时,除了接触区的宽度略有变化外,蜗轮副的运动平稳性和接触区位置基本保持不变.由于不修磨蜗杆,蜗轮副可以完全互换.     

1400八辊冷轧机SG—71型压下蜗轮副

太原钢铁公司第七轧钢厂的1400八辊冷轧机是从西德进口的设备,其中轧辊压下装置用的是圆柱蜗杆传动。为了自力更生地解决大型轧机压下传动蜗轮副的设计、制造问题,根据冶金部安排,由首钢、太钢和我院共同合作采用首钢—SG—71型蜗杆传动。为1400八辊轧机研制中心距760mm的新型压下蜗轮副。 我院承担进行理论研究和参数设计工作。从1976年开始进行深入的理论探讨和大量的电子计算机计算,不仅为该蜗轮副选择了最佳几何参数,而且提出了具有普遍意义的     

光激发表面等离子体波反射系数在复平面的轨迹

为了更好的理解相位型、偏振型及调制型表面等离子体波共振(SPR)传感器的工作原理和性能,采用光的电磁理论对光激发表面等离子体波时光的反射系数rp在复平面的轨迹进行了分析与研究。研究表明rp在复平面的轨迹近似在一个圆周上,从这个轨迹圆不仅可以得到反射系数的模rp和辐角φp的特性,而且可以得到rp.(φp/α)近似为一个常数的特性。这些特性非常直观地表示了相位型、偏振型及调制型SPR传感器的原理与性能,有利于SPR传感器的研究。     

虚源法研究马丢-高斯光束的传输

马丢-高斯光束是近年来被提出的一种准无衍射光束,它包括:第一类(2m+2阶)、第二类(2m+1阶)奇型马丢-高斯光束;第一类(2m阶)、第二类(2m+1阶)偶型马丢-高斯光束.马丢-高斯光束最大的特点是光学形态的多样性.因此,研究马丢-高斯光束的传输特性,使之用于实际有非常重要的意义.利用光束的可叠加原理,以第一类奇型马丢-高斯光束为例,通过定义一组虚光源,计算出了第一类奇型马丢-高斯光束在自由空间传输的积分表达式.利用类似的处理方法,还得到了另外3类马丢-高斯光束的表达式.这一组表达式为精确、定量地计算各类马丢-高斯光束的传输特性提供了方便.     

第类多模叠加态光场的不等幂次差压缩特性

利用多模不等幂次压缩态的一般理论,详细研究了第 类两态叠加多模叠加态光场的场幅幂次不等的差压缩特性(即Nj次方X压缩特性),结果发现:第 类多模叠加态在一定的条件下存在周期性变化的广义非线性二阶不等幂次Nj次方X压缩效应;发现了“奇异压缩“现象;说明这个多模叠加态光场是一种典型的多模非经典光场。     

小传动比SG-71型蜗轮副的理论研究与参数设计

本文比较系统地分析了小传动比SG-71型蜗轮副在接触线分布、根切和非工作区、齿顶变尖等方面的特点,找出了小传动比SG-71型蜗轮副难于设计的症结所在,提出了合理地选择参数的意见。实践证明,提出的理论是正确可行的。     

第Ⅱ类多模叠加态光场的不等幂次差压缩特性

利用多模不等幂次压缩态的一般理论,详细研究了第Ⅱ类两态叠加多模叠加态光场的场幅幂次不等的差压缩特性(即Nj次方X压缩特性),结果发现第Ⅱ类多模叠加态在一定的条件下存在周期性变化的广义非线性二阶不等幂次Nj次方X压缩效应;发现了"奇异压缩"现象;说明这个多模叠加态光场是一种典型的多模非经典光场.     

三环网络TL(N;1,s,s+1)超L型瓦仿真算法

提出了三环网络TL(N;1,s,s+1)的超L型瓦仿真算法,利用C#为编程工具,SQLServer2000为数据库存取中间结果,成功实现了该算法.对于任意给定的N,2≤s≤N-2这样一族三环网络可以得出超L型瓦.研究了超L型瓦形状分布特性,即由类矩形向典型超L型变化,在s的中心位置又形成类矩形,随着s的增大再逐渐变成超L型.通过分析超L型瓦得到三环网络TL(N;1,s,s+1)的直径分布特点,即具有最大值、最小值和对称性,对于任意的N,有一些s使得TL(N;1,s,s+1)紧优.     

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)

正~~