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.

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The result showed that the content of soil carbon indices on slope cropland were lower and increased dramatically in linear pattern after the cropland were abandoned for some time. 50 years after abandonment, OC, AOC and NAOC would increase by 169%, 144% and 210% respectively, compared to the slope cropland and would be 35 %, 39 % and 33 % respectively, of t he natural Chinese arborvitae stand. The carbon pool index and carbon pool management index would sharply increased by 169% and 117%, comapared to the slope cropland would increase by 35% and 42% respectively, compared to natural Chinese arborvitae stand.

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On the landscape level, the regional landscape heterogeneity is increased and the connectivity reduced, which presents the increase of Shannon's diversity index and Evenness Index, decrease of dominance index and increase of fragmentation index. On the class level, it shows that human disturbance on landscape is intense during the past five years, anti the disturbance to artificial landscape mote intense luau that on semi-natural landscape, which means that the fragmentation index of semi-natural landscape is relatively smaller while that of the artificial landscape is larger.

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natural parameter space：自然參數(shù)空間

自然增加率 natural increase rate | 自然參數(shù)空間 natural parameter space | 自然制程界限 natural process limit

natural instincts：天性

natural increase 自然增加 | natural instincts 天性 | natural language 自然語言

natural inclinations：自然素質(zhì)

natural group design 自然組設(shè)計(jì) | natural inclinations 自然素質(zhì) | natural increase 自然增加