用“软铁磁极”减少永磁电机齿槽转矩的方法

针对表贴式永磁同步电机存在齿槽转矩不易削弱的问题,提出了一种采用"软铁磁极"结构降低齿槽转矩的新方法.阐述降低齿槽转矩的基本原理,并通过数学推导给出了齿槽转矩优化效果与"软铁磁极"宽度选择的一般规律.与同结构采用偏极的方法以及采用斜槽的方法进行仿真对比,针对它们的反电动势、磁通密度分布、齿槽转矩等不同方面进行仿真分析新方法所具有的优势,同时通过样机实验验证结论.结果表明,样机采用"软铁磁极"的方法时,在选取3,mm"软铁"宽度时对削弱效果最好的齿槽转矩为30,m N·m.     

基于RBF的汽车纵梁加工质量检测系统研究

针对大尺寸的汽车车架纵梁装配孔检测方式落后、效率低的问题,提出了一种基于RBF神经网络和线形结构光的汽车纵梁装配孔的机器视觉在线检测系统.利用RBF可以逼近高阶输入输出非线性系统的特性,校正摄像机成像过程中的高阶畸变,提高了系统的检测精度.该检测系统经生产现场测试,在汽车车架尺寸范围内其装配孔尺寸检测精度达到±0 1 mm,位置检测精度不大于±0 3 mm,检测时间不超过1.5 min/根,能够满足汽车车架纵梁在线检测的要求.     

一种接触网磨损的线结构光三维检测系统

接触网的磨损量是跨座式单轨交通维护中需要掌握的一个十分重要的参数.针对跨座式单轨交通接触网的特殊构造和对检测设备的要求,研究了一种基于线结构光的接触网磨损三维检测系统.该系统通过激光器与接触网之间的相对运动获取接触网的表面轮廓数据,利用光电编码器保持数据同步,最后对接触网三维重建并把测量结果实时显示.实验结果表明,该系统精度为±0.5 mm,速度可达20 km/h,可以有效实现对跨座式单轨交通接触网磨损的实时测量.     

大间隙磁力驱动轴流式血泵的电磁特性

为提高大间隙磁力传动下系统的驱动能力、传递效率和稳定性,提出三齿槽定子驱动轴流式血泵的大间隙磁力传动技术,对系统的驱动力矩和空间磁场分布电磁特性进行研究。建立三齿槽定子驱动力矩和空间磁场理论模型,利用MATLAB软件解析求解理论模型,并将解析值与ANSYS数值求解值对比,通过实验对驱动力矩和空间磁场理论模型和仿真模型进行验证。研究结果表明:驱动力矩和空间磁场数学模型正确;血泵在运行过程中稳定,连续运转过程无失步现象,系统传递效率提高;增大电流和减小主从磁极距离能提高驱动能力;主从磁极相对位置在x方向位于0 mm,y方向距离小于60 mm,z方向在±1.5 mm内,可提高系统驱动能力。该研究为大间隙磁力传动技术的可行性提供了途径和依据。     

一种航空发动机整体叶盘在线检测新技术

为了解决航空发动机整体叶盘的在线检测问题,提出了一种工业机器人整体叶盘在线检测系统.该系统以工业机器人为主执行器,携带具有通信功能的电子杠杆表采集检测数据.整体叶盘被装卡在外部旋转轴上,通过旋转定位实现整体叶盘各个盘叶的检测.系统工作前需要对机器人、电子杠杆表以及外部旋转轴的空间位置关系进行标定,并通过空间坐标系转换实现整体叶盘检测数据的还原.实验结果表明:该系统能够对整体叶盘的各项参数实现在线检测,整体检测精度达到±0.05mm.与传统整体叶盘检测方法相比较,在保证精度的前提下,该系统工作更为柔性高效,并且更加适合加工现场的在线检测要求.     

视觉引导触摸屏高精度自动贴合系统

针对传统半自动化触摸屏贴合工艺存在的诸多问题,设计一种视觉引导触摸屏高精度自动贴合系统。利用双重角点检测算法对待装配的触摸屏进行双重定位,并通过可编程逻辑控制器(PLC)对多轴控制系统进行精准操控,实现视觉引导多轴控制系统对触摸屏的贴合。实验结果表明,系统贴合精度可达±0.2 mm。该系统可自动完成触摸屏从定位到贴合的完整过程,同时可兼容多种型号触摸屏的自动贴合,摆脱了模具对生产的限制。     

气缸位置模糊控制方法的研究

针对气动位置伺服系统的非线性特征,提出了一种基于模糊控制的气缸位置控制系统.系统以计算机和压力型电气比例阀为控制核心,采用了模糊控制算法来实现气缸位置控制.模糊控制器采用了位置偏差与位置偏差变化率双输入与控制量单输出的模型.实验研究表明,系统的位置控制精度可达到±0.25 mm.该系统可以实现对气缸位置的高精度控制.     

高精度激光点扫描三维测量系统及应用

针对复杂型面刀具的设计要求和结构特点,研究开发了一种基于点采集的高精度非接触式激光扫描测量系统.系统采用高精密点式激光头,通过数据采集与扫描过程的协调控制,数据采集点间距可达5μm,可有效捕捉刀具型面的微细特征.标准试样试验结果表明,该系统的测量精度达到±10μm,整体误差小于0.375%.对直径为2 mm的精密刀具进行测量的结果表明,刀具的复杂突变表面可以得到精确再现.该系统实现了小尺寸复杂型面的高精度测量,在精密刀具等小尺寸复杂型面零件的逆向工程中具有极大的应用价值.     

基于Ansoft的内置式“一”型永磁同步电机的优化设计

设计一台电动汽车用12槽8极永磁体"一"型内置式永磁同步电机,研究该类电机齿槽转矩、空载反电势产生的机理,分析隔磁桥尺寸、永磁体嵌入深度及永磁体厚度等参数对电机齿槽转矩、空载反电势的影响。基于有限元分析软件Ansoft,以减小齿槽转矩、提高空载反电势、提高电机出力、降低噪声为目的,对该电机进行优化分析。仿真结果表明,当永磁体厚度为5.5 mm、隔磁桥宽度为4.5 mm、永磁体嵌入深度为14 mm时,电机的齿槽转矩最小、空载反电势正弦性较高、幅值较大,运行性能最优。研究成果为该类电机在电动汽车的应用奠定了一定的基础。     

基于激光位移传感器的城轨车辆轮对尺寸在线检测技术

为提高轮对尺寸测量效率及精度,提出了一种基于2D激光位移传感器的轮对尺寸在线检测技术。将2D激光位移传感器布设在轨道两侧,对经过检测区域的车轮踏面进行动态扫描,然后对采集到的数据进行坐标变换、数据融合等处理,并对处理后的踏面数据进行四阶分段曲线拟合,以实现轮缘高、轮缘厚及轮径的准确计算。为验证系统的可行性,将系统安装在实际现场进行车轮轮对尺寸在线检测,并将系统测量结果与人工测量结果进行比较。试验结果表明,系统能够完成轮对尺寸在线检测功能且检测精度高,轮缘高、轮缘厚的检测精度为±0.2 mm,轮径的检测精度为±0.5 mm。系统测量精度满足实际现场测量要求,具有较高的可行性,完全可以取代人工测量方法以提高轮对尺寸测量效率。     

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.     

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.     

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.     

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.