部分时间的
- 与 部分时间的 相关的网络例句 [注:此内容来源于网络,仅供参考]
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The population distribution pattern of 15 common species belonged to bimodal, unimodal, and unstable respectively.
其峰值出现的时间均为该物种在更南部越冬地越冬的部分种群南北迁移时途经拉市海的时间。
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The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.
理论分析和试验研究表明: 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的,具有摩擦动力学的本质,任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响; 2中心轴向载荷作用下,载荷增大使球轴承的固有振动频率升高,载荷越大同样的载荷增幅引起的频率升幅减小,足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响; 3轴向和径向联合载荷作用下,径向载荷不大时球轴承振动的固有频率基本不变,但是可能引起变刚度激励的非线性振动,出现新的频峰,过大的径向载荷将使部分钢球脱离接触,使球轴承的振动和噪声呈现不稳定状态; 4润滑对球轴承的振动和噪声特性有重要的影响,良好的润滑对振动有明显的抑制作用,润滑不充分时,振动和噪声的水平会有明显增高,一定条件下还会激发接触副中的谐振,发出啸声,造成接触表面的伤害,无润滑干接触时,短时的运转就会损伤接触副表面,使振动和噪声迅速增大,并随时可能引发严重的磨损和卡滞失效;接触副润滑良好时,油膜的"刚化效应"使球轴承振动的固有频率有所提高,润滑剂中含有弥散性污浊时,振动的幅度总体升高,但弥散性污浊不会改变球轴承振动的频率特性;浙江大学博士学位论文:球轴承振动的研究 5低速时,球轴承振动的基本特征呈现不稳定状态,随着转速的提高,球轴承振动的频率特性趋于稳定,固有频率频峰升高; 6理论分析表明,干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动,振动的幅值与谐波幅值成正比,实际球轴承中钢球的分布不可能完全均匀,波纹度的激励作用会随时发生;润滑接触的分析表明,波纹度的任意谐波分量均能激励球轴承的振动; 7球轴承的几何和结构参数分析表明,球轴承尺寸越大,径向、轴向和角振动的固有频率越低;钢球中心圆直径增大,球轴承的径向和轴向振动的固有频率基本不变,角振动的固有频率有所上升,振动的幅频特性基本不变;径向游隙加大使球轴承的径向振动固有频率降低,轴向和角振动的固有频率有所升高,径向振动幅频特性的幅值升高,而轴向和角向降低;钢球的数量增多使球轴承振动的固有频率上升,幅频特性的幅值下降,径向振动的幅值下降最为明显;外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高,轴向和角振动的固有频率降低,径向幅频特性基本不变,轴向和角向幅频特性幅值升高;内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降,振动幅频特性的幅值均有升高; 8试验对比表明,传感器采用探针式安装时,由于探针接触副接触特性的影响,钡(量得到的球轴承振动信号有失真,采用专门设计和制作的试验球轴承,以固定式安装加速度计,首次测量得到了球轴承振动的真实信号,通过对振动信号的分析,验证了球轴承振动的理论模型; 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析,以样本长度的均方根值作定阶上界,FPE做判阶准则,给出的AR谱光滑,频率分辨率高,是球轴承振动分析的简便而可靠的手段; 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间,时间间隔,频率范围,同样是球轴承振动分析的可靠的手段,可用作球轴承故障诊断技术。
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Methods Proteins and peptides in CSF were separated by two-dimensional gel electrophoresis(2DE) and ultra-performance liquid chromatographer and identified by matrix assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF-MS) and electrospray ionization to study differential proteomic expression in the cerebrospinal fluid between patients with Demy- elinative disease and with other neurological diseases.
方法以中枢神经系统脱髓鞘疾病患者的脑脊液为研究对象,分别采用固相pH梯度双向凝胶电泳分离总蛋白质,凝胶经银染显色后,用图像分析软件进行比较分析、识别差异表达的蛋白质,离线应用基质辅助激光解析电离飞行时间质谱得到相应的肽指纹图谱;同时用超高压液相色谱分离酶解肽段,在线采用电喷雾四极杆飞行时间质谱鉴定肽段氨基酸序列;搜索数据库鉴定部分蛋白质。
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Third, and most importantly, note that extensionality is a theorem in standard systems of mereology , the logic of parts and wholes (for more, see the entry on mereology ).
注意到这点,我将离开时间限定词的暗示。3、最重要的,注意到外延原则是部分整体学说『merelogy,部分和整体的逻辑』的标准系统的定理(更多参考词条《 mereology 》)。
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Finally, by means of time evolution operator and numerical calculations, the time evolution of the atomic population, the atomic dipole squeezing, the time evolution of the squeezing and coherence properties of the light in the system of the two identical two-level entangled atoms interacting with the coherent optical field have been studied.
论文的第三部分工作是采用时间演化算符和数值计算方法,研究了两全同二能级纠缠原子与相干态光场相互作用过程中,原子布居、原子偶极压缩、光场的二阶相干和光场压缩性质的时间演化特性。
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In the course of time, as early perhaps as AD 150 (see Cabrol's "Origines Liturgiques" 137), the celebration of the Eucharist was combined with this purely euchological service to form one solemn act of Christian worship, which came to be called the Mass. It is to be noted that the Mass is still in two parts, the first consisting of lessons, chants, and prayers, and the second being the celebration of the Eucharist (including the Offertory, Canon, and Communion).
在这个过程中的时间,早或许正如专案150个(见cabrol的" origines liturgiques " 137 ),以庆祝圣体圣事是结合这纯粹euchological服务,以形成一个以严肃的基督教崇拜,它后来被称为地下这是需要指出的是,大众仍然是在两部分,第一部分,其中的经验教训,呼喊,并为他们祈祷,并举行第二次被庆祝圣体(包括offertory ,佳能,并交流)。
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On the one hand, because of the short action time, it is impossible to get enough time to circumvolve instruments or to circumvolve the physical fields being measured so as to scan in all directions, so the physical fields can only be measured through several instruments; on the other hand, because the physical fields are partly screened or the operator domain is too limited, the measurement directions are limited, too.
一方面,因为作用时间短,不可能有充足的时间使仪器旋转或使被测物场旋转来全方位扫描,只能固定几个方位的探头同时进行测量;另一方面,由于物体被部分遮挡或作用域小,使观测方位受到限制,也只能在测量中用少量的探头。
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A new switching scheme to the gain of variable structure control signals is proposed. The following important open problems in standard VS-MRAC and MRAC are solved by using the scheme: 1 . a prespecified transient and steady-state performance index for tracking error can be achieved without requiring any information about the plant high frequency gain sign when relative degree of modelled part of plant is one, and 2 . it is shown that as long as the performance indexes are guaranteed for the auxiliary errors, each of which in dynamics is a sub-system with relative degree one, the tracing error will converge to a small residual set in a prespecified transient time when relative degree of modelled part of plant is greater than one.
提出了一种控制增益可切换的变结构自适应律,解决了如下变结构模型参考自适应控制(包括基于调参律的模型参考自适应控制)理论研究中长期没有解决的问题:当对象建模部分相对阶为1、高频增益符号未知且存在非线性输入扰动和未建模动态等情况下,系统跟踪误差可满足预先给定的动态和稳态性能指标;当对象建模部分相对阶大于1且存在非线性输入扰动和未建模动态时,可保证系统跟踪误差在预先给定的过渡过程时间内收敛到一个残差集中; 5。
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According to the computational stability analysis conducted to the linear term time difference scheme in simple harmonic motion equation, one new semi-implicit integration scheme also is designed. By adopting a kind of revised time-explicitdifference scheme to these linear terms still included in spectral model governing equations, this defect of spectral model only partly used in semi-implicit integrating scheme, can be overcome to some degree.
以简谐振动方程中线性项时间差分格式对其计算稳定性影响为理论依据,本文设计了一种新谱模式半隐式时间积分方案,此方案通过对一般谱模式求解框架中那些隐含的线性项采用了一种显式修正的差分格式,可有效克服其国际谱模式半隐式时间求积方案实质上只是部分应用了半隐式差分格式的问题。
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The research of the thesis can be divided into four parts:Part one. The cheap raw materials, such as soluble glass, HCl, MAA were used as reactant. A aggregation SiO2 powder with network-type was prepared by controlling the ratio of material, temperature, time, mixing speed, which has smaller size than that of products sold in the market.
本论文研究工作分为四个部分:第一部分:采用价廉的水玻璃和HCL、MAA、CO2酸化体系为原料,通过材料配比、制备温度、时间、搅拌速度等工艺条件的研究,制备出比市场上销售的二氧化硅粒径更小的呈网络附聚体形态的SiO2粉体。
- 推荐网络例句
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Do you know, i need you to come back
你知道吗,我需要你回来
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Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.
1〕 杨银书,王祥生,李德昌。安徽省首次发现嗜群血蜱。
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Chapter Three: Type classification of DE structure in Sino-Tibetan languages.
第三章汉藏语&的&字结构的类型划分。