查询词典 decrease speed

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。

Decrease speed when you are approaching a town.

你必须在接近市镇时减速。

The results indicate that, during the early storage period under short time treatment with heat air, the activities of amylase and polygalactouronase are effectively decreased; starch content reduction is inhibited; the degradation speed of pectin and the decrease speed of flesh hardness are slowed down, and the release rate of ethylene in fruit is decreased. During the later storage period, the decomposition rate of middle lamella and primary wall of the Li jujube fruit treated with heat air for a short time is delayed, exosmosis of cell contents is inhibited, and the cell structure is protected, so the storage time of Li jujube fruit is prolonged.

结果表明，梨枣采后贮前短时间热处理能有效地降低早期淀粉酶和多聚半乳糖醛酸酶活性，抑制淀粉水解，延缓果胶降解，降低乙烯释放量，延缓果肉硬度下降速度，后期能延缓果肉细胞中胶层和初生壁分解，阻止细胞内含物外渗，保护细胞的结构，从而延长了贮藏保鲜期。

With the new model and the program, steady seepage field in work period, free surface position variable law with time at upper reaches in unsteady seepage period and seepage field variable law on the condition of different seepage coefficient and water decrease speed are stimulated.

利用建立的模型和编制的程序能模拟正常运行期的稳定渗流场、非稳定渗流期上游水位变化时自由面位置随时间的变化规律以及不同的水位下降速度时渗流场的变化规律。

Theobserved strain is 10~2 times as local point strain at the same observed stress.This indicates that macroscopical symmetrical rock is quasi-brittle materialwith microcosmic heterogeneousness and its macroscopical mechanicalbehavior is the results of reciprocity and magnification between microcosmiccharacteristic, not simple sum.(4) The degree of irregularity of strain increases with the number of cycle.But degree of irregularity of transverse strain fluctuates larger at the samecycle. Moreover degree of irregularity of transverse strain is larger than that ofaxial strain. This shows that deformation and failure of rock is process ofevolvement of small crack. Small crack evolves from even and out-of-orderstatus to heterogeneous and ordinal status.(5) Ultrasonic speed decreases with the number of cycle. The decreasecourse is such: Firstly, ultrasonic speed fluctuates in a steady scope in somecycles; And then ultrasonic speed quickly decreases to a certain more smallvalue; Afterwards in succedent cycles, ultrasonic speed fluctuates about thevalue. That is to say, ultrasonic speed fluctuates and decreases at intervals ofcycles. In deformation process of rock, quantitative change and qualitativechange of its small crack evolvement carry through crosswise.(6) Strength and modulus of rock decrease with exponential function asscale of specimens increases.

同一表观应力下，局部点应变与表观应变相差可达2个数量级，表明宏观上均匀的岩石是具有细观特征的准脆性材料，其宏观力学行为是细观特征相互作用、放大的综合结果，而不是简单的叠加；(4)岩样轴向应变不均匀程度和横向应变不均匀程度随循环次数的增加渐进增大，但是在同一个循环内，横向应变离散系数随应力的变化波动较大，且同一循环级别下，横向应变不均匀程度大于轴向应变不均匀程度，表明岩石内部微裂纹的演化是岩石变形破坏的本质特征，这一演化表现为微裂纹从均匀无序分布逐渐向非均匀有序发展；(5)随循环次数的增加，所有岩样内部超声波速会出现衰减，衰减过程表现为在某几次循环内超声波速在某一相对范围内波动，然后急剧减小到某一较小值，在随后的循环内，超声波速又会保持在这一较小值附近波动，即超声波速表现为波动和急剧减小间隔形式衰减，表明从宏观看来平稳的岩石变形过程，内部结构演化过程(微裂纹发展及其相互作用)却表现为均匀量变和突发质变不断交叉进行的现象；(6)岩石强度和弹性模量随尺度增大呈指数函数规律减小。

The stude announces that their changeable regular of the center of gravity level speed in supporting phase is falling in tne first cushioning phase. When their center of gravity's vertical lines pass their heels and their knee joints go on extended contraction ,their center of gravity level speed has extended .the reason is that their angles have passed the heels and their swinging legs' kenn joints have swinging the front of their bodies. Its power originates the swinging leg's forward active swinging and the decurtation contraction of hip joints 、ankles of the supporting legs.the swinging leg shows "the calf's active backward swinging"before its landing impact,the skill affects the loss of center of gravity level speed when the swinging leg lands.they enlarge their trunks' forward-landing impact phase ,it can decrease the center of gravity level speed's loss after landing and impel the center of gravity level speed to pass the supporting spot quickly.

两人缓冲阶段身体重心水平速度变化规律是在体前缓冲阶段呈下降趋势；当身体重心垂线超过脚后跟后，在膝关节继续缓冲做退让收缩的情况下身体重心水平速度开始加大，原因是踝关节在最大缓冲时身体重心已移过支撑面及摆动腿膝关节已做体前摆动，主要动力来源于摆动腿的积极前摆和支撑腿髋、踝关节的克制性收缩；在摆动腿下压着地前期是大腿积极下压小腿随大腿的积极下压顺势向前下滑摆，在摆动腿下压着地后期表现出"小腿积极回摆"技术，对减小着地时的水平速度损失、加大向前用力都有积极影响；适当加大摆动下压着地阶段躯干的前倾角度，有利于减少着地时相的速度损失和有利于身体重心较快的移过支撑点；缩小后蹬结束后的后伸动作幅度，有利于减小腾空时间。

Through dynamic examination of electrolyses, this paper research on treatment efficiency of bipolar packed bed cell under different voltage, electrolyses time, PH value andThe experimental results show that the decompounding speed of phenol decrease with the electrolyze time increasing. With the cells voltage augment the decompounding rate of phenol increase also. But when the voltage exceed 10V, the increasing speed of decompounding rate decrease.

BPBC处理苯酚废水的实验研究结果表明，苯酚的降解速率与酚浓度呈一级反应关系，即随着实际电解时间的增加苯酚降解速率逐渐减小；随着槽电压的增大，苯酚的去除率也随之增大，但是槽电压超过10V后，苯酚去除率增加趋势减缓；在碱性条件下，pH值的变化对苯酚的去除率有一定的影响，随着pH值的增大，去除率逐渐的降低；空床流速过大时，苯酚去除率有一定的下降；投加电解质后，苯酚的去除率增加，而就投加NaCl和NaNO_3的情况下，投加等摩尔浓度的NaCl和NaNO_3，投加NaCl的效果要优于投加NaNO_3的效果；提高废水中的溶解氧有利于苯酚的去除。

The results indicate that in the synchronizing condition the MRF is unyielded, every point of MRF in the flow field has the same angular velocity. Under the slipping condition, with the increase of magnetic field or the decrease of slip speed, MRF may transfer from whole yield to partial yield. When the MRF wholly yields, the angular velocity of MRF increases nonlinearly with its radius, the non-linear distribution becomes more obvious as the magnetic intensity in the working gap increases. When the MRF partially yields, the yield region expands with the decrease of magnetic intensity or the increase of slip speed and the unyield region always reaches the driven rotor. The transfer torque of MRTD increases with the increase of the external magnetic field, but the transfer torque maintains a constant value approximately with the variation of slip speed at the same magnetic intensity.

研究结果表明，在同步工况下，传动装置流场中磁流变液未屈服，各点角速度相同；在滑差工况下，随外加磁场的增大和滑差转速的减小，磁流变液逐渐从完全屈服向部分屈服转变；磁流变液完全屈服时，磁流变液角速度随半径呈非线性增加，工作间隙中磁场越强，流场的非线性分布越明显；磁流变液部分屈服时屈服区域随外加磁场的增大而减小，随滑差转速的增大而增大，未屈服区与主动转子相连；稳态下磁流变传动装置传递的转矩随外加磁场的增加而近似呈线性增大，但在相同外加磁场下，传递转矩基本不随滑差转速改变而改变，表现出良好的恒转矩特性。

B Where the Load up/down program is not provided, the Engineer shall increase and decrease the speed in accordance with the speed increase and decrease procedure of each ship, and shall pay attention to the Load Indicator, the RPM of the Main Engine or RPM of the propeller shaft, CPP pitch, the speed

如已提供增减负荷程序，轮机员应根据速度增加和减少程序进行加减速，特别注意，负荷显示、主机转速、螺旋桨轴转速、可变螺距、船速等，避免突然加减负荷。

The results showed that, no matter mono-cropping and relay-planting, the grain SS activity of spring-sown maize and normal summer-sown maize were decreased at the early stage after anthesis, but after 40 DAA the decrease speed were slow and could maintain a high activity for a long time, which were benefit to the sucrose formation, accumulation and transportation.

结果表明，不管单作还是套作条件下增施氮肥前期春玉米和普通夏玉米籽粒SS活性略有降低，但花后40天后其活性降低慢，能长时间维持较高的值，利于蔗糖的合成、积累和转移。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。