量尺寸

In com- parison with the data of the JCPDS file,the diffraction intensities of the crystal planes(hk0)become stronger and their diffractio...

随着柠檬酸加入量的增加，晶粒尺寸逐渐增加，(hk0)晶面衍射强度和衍射角偏移现象显著增强。

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。

Study on bond and diamond of diamond core drill bit for reinforced concrete;2. Also glass ceramic is used as the bond of CBN grinding wheel by examining the properties of new bond .

研究了微晶玻璃中加入低熔物、成核剂后对微晶玻璃热处理曲线、微晶量及微晶体尺寸的影响，并通过测试改性微晶玻璃的软化温度和热膨胀系数对CBN磨粒的把持强度，进而将微晶玻璃用作CBN砂轮结合剂的作用作了研究，经过在数控凸轮轴磨床上的试验证明，微晶玻璃结合剂的CBN砂轮的磨削效果很好。

The key factors for designing the tray with high liquid capacity are downcomer configuration,specifications and layout.

为了通过高液量，塔板设计的关键是降液管结构、尺寸和布置。

Elasticity plunger resume original dimension, the gap between plunger and pump barrel was increased downstroke.Leakage of sucker pump with automatic compensate gap was decreased and pump efficiency was increased upstroke, friction between plunger and pump barrel was reduced downstroke.

下冲程，弹性元件恢复原尺寸，柱塞与泵筒之间的间隙增大，从而实现上冲程减小泵漏失量，提高泵效，下冲程降低了柱塞与泵筒之间的摩阻。

At the same time, the technology of coal mining also developer quickly, compare with before mine exploitation is much more centralize, production and new building mine are increasing accretion. Because of this the character of mine size, exploitation deep, assistant exaltation and gas effuse are gradually increasing.

同时，采煤技术也迅速发展，矿井开采的集中化程度日益提高，生产和新建矿井的井型日益增大，逐渐形成井田尺寸小、开采深度大、辅助提升任务大和瓦斯涌出量增加等特点。

There are three sizes of each Epsilon drive: 2 Amp, 3 Amp and 5 Amp, with the largest drive delivering up to 37 lb-in continuous torque.

有三种尺寸的每个小量驱动器：2安培，3安培和5安培的最大提供高达37磅的连续扭矩驱动器。

In this study the distortion resistant quantity and tie piece are decided on by analyzing the stress field and the large numbers of experimental data ensuring the dimension of castings, for the distortions of lower rims and vanes are likely to occur in the solidifying process.

由于水轮机下环、叶片在凝固过程中极易产生变形，本文通过大量的实验数据及应力场分析，确定了拉筋和反变形量，并保证了铸件的尺寸精度。

The results show that dynamical ductil-ity dominated final velocity of fragments. During tube expansion, the shear fracture appears preferentially a-long the adiabatic shear bands under positive stress, so the adiabatic shear band determines the size and shapeof fragments. Though the fragmentation behaviour of medium carbon Si - Mn bainific steel is close to that ofsteel 50SiMnVB, medium carbon Si - Mn bainitic steel is an ideal candidate material for the tubular bombs be-cause it is better in dynamical ductility, which can enable the tubes to gain high speeds before fragmentation.

结果表明：材料动态塑性是决定破片最终速度的主要因素；圆管膨胀时外表面形成以剪切为主的裂纹，并向内扩展，接近内表面的绝热剪切带伴随着圆管的膨胀而扩展，并未出现失稳现象，但在正应力的作用下成为优先的断裂通道、决定破片的尺寸和形态；中碳Si-Mn贝氏体钢与50SiMnVB钢的破碎性能相近，但贝氏体钢动态塑性很更好，破碎前的膨胀量较大、更有利于提高破片初速，是弹箭比较理想的候选材料。

The I-V characteristics of the diodes with 100μm diameter indicated that as the densities of V-defects on GaN films increased from 4.1×105cm-2 to 1.03×107cm-2, the Schottky barrier height decreased from 1.44eV to 1.19eV and the reverse bias leakage current at -1V is increased sharply from 10-10A to 10-7A . Further studies on a single V-defect using conductive atomic force microscope demonstrated that the value of forward current biased at 8V at V-defect side-walls appears to be one order higher than that of plain region, indicating that the conductivity mainly occurred at the side-walls of V-defect.

实验结果发现，随著V型缺陷密度由4.1×105cm-2增加至1.03×107cm-2，在氮化镓表面蒸镀镍金属所制成直径为100μm的萧基元件之所属能障从1.44eV下降至1.19eV，而且在-1V的操作下反向偏压漏电流从10-10A急遽的攀升至10-7A；为了了解V型缺陷对厘米尺寸n-GaN萧基元件电流传导机制之影响，我们进一步的利用导电原子力显微镜(Conductive Atomic Force Microscopy， C-AFM)，特别针对单一个V型缺陷进行微观电性之量测。

The X-ray diffract was used to analyze the crystal structure of the composite. Results show that after the talc was treated with blend coupling agent, the crystal structure of talc changed, and effect Intercalation phenomenon.

通过X射线衍射分析可知，用混合偶联剂对滑石粉进行预处理后，滑石粉晶体结构发生改变，产生了插层现象，使PP／滑石粉复合材料为纳米复合材料。

An authentic Maui wedding might require the services of a 'kahu', which is a Hawaiian minister.

毛伊可能需要一个真实婚礼服务'kahu'，这是夏威夷部长。