自动平衡补偿矢量精稳测算方法研究

自动平衡系统中配重块定位的准确性直接影响动平衡效果，如果定位不准确将导致配重块移动混乱，甚至造成平衡失败。以电磁式双配重平衡系统为研究对象，提出一种基于可编程逻辑控制器（PLC）高速采集的自动平衡配重块位置精稳测算方法，并在螺旋桨自动平衡试验台进行试验验证，实现了自动配平补偿矢量的精稳测算，结果表明在1 200 r/min的工作转速下误差不超过1步。该方法脱离了对计算机和高速数采设备的依赖，提高了控制系统的稳定性和灵活性，有利于实现自动平衡系统的轻量化设计，具有良好的工业应用价值。     

回转体静平衡的新方法

回转体的静平衡,通常采用的方法是:把回转体的轴架在同水平面内的两个平行的刀口上,让其自由滚动,当偏心重点在轴心正下方时,其会停止滚动,配重后反复试验才能平衡.本文中,作者根据杠杆平衡原理和平面力系的平衡原理,探讨了一种新方法.1 空心盘类回转体的静平衡(1)工作原理当用支点把物体支起以后,如果支点     

一种质量质心测量系统设计

稳定平台的静不平衡对系统在大过载状态下的工作性能影响很大,而精确测量稳定平台的质量质心能够将系统静不平衡量调整到最小。文章针对一般稳定平台系统的结构特点,设计了一种采用力矩平衡原理的质量质心测试系统,可以满足稳定平台精确调整静平衡的要求。     

双配重平衡头无错调控制算法研究

分析了现有的电机驱动型双配重平衡头造成错调、振荡、平衡时间长等问题的原因,提出了解决方法并将其应用到新设计的电磁驱动型双配重平衡头中。通过对双配重平衡头系统的分析,提出了配重块最优移动的准则及其判断原则。针对配重块的任意占位方式,总结出双配重平衡头无错调控制算法,并进行仿真试验验证。结果表明,该移动策略能有效地提高自动平衡品质,达到无错调、不振荡、平衡时间短的目的。     

超重力机主动平衡实验台的研制

转子质量不平衡而造成的工频振动是影响超重力机长周期运行的关键问题。为解决转子的振动问题保证机器的长周期运行,提出了利用电磁式主动平衡技术在线控制转子振动的方法。在确定了平衡平面的安装位置并计算了转子平衡所需的校正量的基础上,研制了超重力机主动平衡实验台。阐述了电磁式主动平衡系统的结构以及配重盘的驱动、自锁原理。对不平衡量为的外加载荷进行了主动平衡的实验验证。结果表明,主动平衡实验台设计是合理的,电磁式主动平衡系统可以有效的降低转子振动,为今后深入的电磁式主动平衡技术的实验研究提供保证。     

船用铜合金螺旋桨的检验要点分析

为了进一步明确对船用铜制螺旋桨的检验要求,保证船舶安全,考虑到国内外标准的要求及中国船级社的规范,并结合国内铜合金生产者的生产经验,列明了目前世界上主要船用铸造铜合金螺旋桨的成分设计和机械性能,分析了铜合金金相组织对螺旋桨性能的影响,阐述了对铜制螺旋桨进行无损探伤过程中的注意事项,并推荐一种对4叶组合式螺旋桨进行静平衡试验的替代方法．供验船人员对螺旋桨进行产品检验时参考．     

斗轮取料机配重安装

本文介绍了取料机俯仰机构配重安装维护方面的经验，取料机在运行一定年限后，俯仰配重往往不再平衡，需进行调整，本文以案例的形式介绍了其配重调整量的确定方法。     

转子自适应主动平衡算法及电磁平衡头单盘平衡试验

为了实现转子不停机平衡,研究了一种自适应主动平衡算法。基于单平面影响系数平衡方程,通过引入增益因子提高平衡迭代过程稳定性,并引入遗忘因子实现影响系数在线估计,构建了单平面在线自适应平衡算法的数学模型。为验证所提出的平衡算法的有效性,设计了一种含有永磁体的电磁圆环形主动平衡头,通过线圈电磁场与永磁体间的磁力作用驱动配重盘步进转动,依靠磁阻最小原理自锁。针对所设计的电磁平衡头,提出了一种单盘转动平衡策略,对平衡补偿量相位进行了校正。开展了不同不平衡量和转速下电主轴主动平衡试验,获得了平衡过程的时域波形、振幅下降率、平衡步数和配重盘终位置。试验结果表明:不平衡量为24.59g·cm∠180°时振幅降低42.65%,不平衡量为24.59g·cm∠285°时振幅降低37.8%;转速为2 400r·min~(-1)时振幅降低40%,转速为3 000r·min~(-1)时振幅降低60%。研究结果证明了所提出的平衡算法和装置是可行、有效的。     

应用动力学模型的高速主轴无试重动平衡方法

为解决高速主轴由于不平衡导致的振动问题,提出了一种基于动力学模型的高速主轴动平衡方法,其仅需在工作转速下采集振动响应数据,且无需停机试重.该方法通过对连续分布的不平衡量进行集中化处理,缩减不平衡响应与不平衡量之间的关系矩阵,可以在高速主轴的任意2个位置上实现双面平衡.研究结果表明,该方法能够准确地识别出等效集中的不平衡量,且所识别的由等效不平衡量引起的振动响应与原始振动响应基本一致.因此,添加配重后可使主轴各位置不平衡振动得到有效地抑制.     

推进式螺旋桨振动应力特性飞行试验与分析

根据某型飞机单发推进式螺旋桨结构与载荷特征,利用有限元分析确定桨叶振动应力危险部位,设计加装无线电遥测系统进行应变测试,并根据螺旋桨振动应力的影响因素确定飞行试验科目。测试系统装机后开展不同条件的飞行试验,获得了螺旋桨在典型工作状态下的静应力和动应力。分析表明静应力基本随高度、速度和滚转角的增大成增大趋势,但在高度5 000 m静应力随滚转角的变化趋势并不明显,动应力随速度增大明显增大,随高度和滚转角增大缓慢增大;通过Compell图和多状态频谱分析发现慢车状态1阶动频与转速2倍频接近,存在共振风险,并给出了改进建议。     

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.     

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

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to