值
- 与 值 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 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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In this research,the indexes relating to the quality of the fried oil,including the content of the ploymers,acid value,iodine value,saponification value,peroxide value,the content of the diglyceride,oxidation stability,viscosity,were detected.The results showed that with the frying time prolonging,the content of the polymers and viscosity increased greatly,iodine value and saponification value decreased,peroxide value and acid value increased,and the content of unsaturated fatty acid reduced,a little of diglyceride produced.
在食用油煎炸过程中,对油脂品质相关的指标(包括酸值、碘值、皂化值、过氧化值、脂肪酸组成、氧化稳定性、黏度、聚合物的含量以及甘一酯、甘二酯和甘三酯的含量)进行检测,结果表明,随着煎炸时间的延长,煎炸油中的聚合物含量大大升高,黏度增大,有少量甘二酯生成,不饱和脂肪酸含量下降,碘值、皂化值降低,酸值、过氧化值升高。
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Hence, the modulus of rigidity, G, of glulam was measured by vibration test method in order to realize the shear deflection effect. The E/G values of Japanese cedar, Taiwania, Douglas-fir, and southern pine glulam were ranged form 13.2 to 14.5, 14.6 to 16.6, 12.1 to 16.6 and 16.0 to 19.1, respectively. The pure MOE was also obtained. The Ep and MOR values of glulam were ranged from 10.6 to 13.4 GPa and 48.3 to 61.9 MPa for Japanese cedar, ranged from 12.1 to 15.0 GPa and 41.8 to 58.8 MPa for Taiwania, ranged from 10.5 to 16.4 GPa and 37.2 to 65.6 MPa for Douglas-fir, ranged from 14.5 to 20.6 GPa and 70.2 to 78.48 MPa for Southern pine, respectively.
而消除剪力挠曲影响,即可得集成材之抗弯弹性模数真实值与抗弯强度,依本研究配置所得之柳杉集成材之Ep值与MOR值分别为10.6-13.4 GPa与48.3-61.9 MPa;台湾杉集成材之Ep值与MOR值分别为12.1-15.0 GPa与41.8-58.8 MPa;花旗松集成材之Ep值与MOR值分别为10.5-16.4 GPa与37.2-65.6 MPa;南方松集成材之Ep值与MOR值分别为14.5-20.6 GPa与70.2-78.4 MPa。
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Numerical simulation and shaking table tests for acceleration response of piles in liquefiable ground were performed under three earthquake events.
结果表明:三种地震输入下,自下而上沿桩-柱墩长度方向,加速度峰值放大系数变化基本一致且均出现在10~20s时段内,加速度时程曲线的形状也极其相似;压缩0.15g El Centro波输入下加速度反应在砂土层与黏土层过渡带有增大趋势、在地表则有一定程度减小,且压缩0.15g El Centro波较0.15g El Centro波输入下均偏小,0.15g El Cen-tro波输入下自下而上桩的加速度时程幅值和峰值放大系数的试验值、计算值均一直有较大幅度增大;0.5g El Centro波输入下,加速度时程幅值的计算值和试验值在桩折断位置之下一直增大、至砂土层与黏土层过渡带则大大减小,加速度峰值放大系数的试验值和计算值在砂土层与黏土层过渡带突变增大、而在地表则明显减小,且较0.15g El Centro波输入下桩的峰值放大系数要偏小。
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Because 3-valued logic has a truth more than 2-valued logic, the quantity of truth of function of 3-valued logic is more than it of 2-valued logic, and 3-valued logic has a more powerful ability to handle problems than 2-valued logic does.
由于三值逻辑比二值逻辑多一个真值,所以三值逻辑的真值函项的数量比二值逻辑的真值函项的数量大得多,所以三值逻辑才会比二值逻辑有更强的处理问题的能力。
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Burmannii, Clerodendron cyrtophyllum,Uvaria microcarpa and C.camphora were dominant in the shrub layer. The H, D, J and PIE indexes were 2.146,5.717,0.705,0.825 in arbor layer respectively, and 3.054,13.435,0.802,0.926 in shrub layer respectively.
乔木层Shannon-Winener指数H值2.146、Simpson指数D值5.717、Pielou指数J值0.705、种间相遇机率PIE值0.825;灌木层H值3.054、Simpson指数D值13.435、Pielou指数J值0.802、种间相遇机率PIE值0.926。
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Salix matsudana, Ulmus pumila, Quermus mongolica, Populus alba×P.beroliensis and Betula platyphlla are frontal 5 tree species with weight value 90.37, 90.12, 88.12, 87.55 and 86.2 respectively, were used for farmland protection forest; Acer negundo, Salix matsudana, Juniperus rigida, Fraxinus mandshurica and Ulmus pumila are frontal 5 tree species with weight value 78.14, 76.92, 75.96, 74.72 and 74.56 respectively, were used for urban protection forest; Ulmus pumila, Salix matsudana, Populus alba×P.beroliensis, Acer negundo and Larix gemelinii are frontal 5 arbor tree species with weight value 80.07, 79.07, 77.5, 72.42 and 71.67 respectively, were used for road protection forest; Salix matsudana, Populus alba×P.beroliensis, Ulmus pumila, Larixgemelinii and Betula platyphlla are frontal 5 tree species with weight value 92.37, 88.72, 86.62, 85.82 and 85.7 respectively, were used for river protection forest; Fraxinus mandshurica, Larix gemelinii, Populus alba*P.beroliensis, Ulmus pumila and Salix matsudana are frontal 5 tree species with weight value 89.61, 8.35, 87.12, 85.56 and 80.15 respectively, were used for wood forest; Cornus alba, Prunus tomentosa, Primus triloba, Syringa obalata and Sambucus williamsii are frontal 5 shrubs with weight value 82.93, 81.23, 80.85, 78.38 and 77.78 respectively, were used for landscape forest; and Acer negundo,Malus baccata, Sorbus pohuashanensis, Prunus maackii and Prunus padus are frontal 5 arbors with weight value 82, 81.52, 80.3, 79.62 and 78.9 respectively, were used for landscape forest; Prunus salicina, Prunu
根据哈尔滨地区不同林种的功能要求,给出了不同指标的期望值,通过查询系统可以得到旱柳、榆树、蒙古栎、银中杨、白桦为符合农田防护林的前五位的树种,权重值分别为90.37、90.12、88.12、87.55、86.2;糖槭、旱柳、杜松、水曲柳、榆树为符合城市防护林的前五位的树种,权重值分别为78.14、76.92、75.96、74.72、74.56;榆树、早柳、银中杨、糖槭、兴安落叶松为符合道路防护林的前五位的乔木树种,权重值分别为80.07、79.07、77.5、72.42、71.67;旱柳、银中杨、榆树、兴安落叶松、白桦为符合河岸防护林的前五位的树种,权重值分别为92.37、88.72、86.62、85.82、85.7:水曲柳、兴安落叶松、银中杨、榆树、旱柳为符合用材林的前五位的树种,权重值分别为89.61、88.35、87.12、85.56、80.15;红瑞木、毛樱桃、榆叶梅、紫丁香、接骨木为符合风景林前五位的灌木树种,权重值分别为82.93、81.23、80.85、78.38、77.78,糖槭、山丁子、花楸、山桃稠李、稠李为符合风景林前五位的乔木树种,权重值分别为82、81.52、80.3、79.62、78.9;李、杏、文冠果、山楂、野梨为符合经济林的前五位的树种,权重值分别为88.85、80.88、73.25、69.35、63.77。
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Results The sensitivity,specificity,positive predictive value,negative predictive value,Youden index,accuracy ...
结果检测血清特异性IgG的灵敏度为100·0%,特异度为97·7%,阳性预测值为97·2%,阴性预测值为100·0%,约登指数为0·977,符合率为98·7%,试验的一致率为98·5%;检测血清中总的特异性Ig灵敏度为97·1%,特异度为95·3%,阳性预测值为94·4%,阴性预测值为97·6%,约登指数为0·925,符合率为96·2%,试验的一致率为97·8%;检测唾液中特异性sIgA的灵敏度为96·2%,特异度为94·5%,阳性预测值为89·3%,阴性预测值为98·1%,约登指数为0·907,符合率为95·1%,试验的一致率为97·5%;检测粪便标本中的特异性sIgA的灵敏度为92·0%,特异度为90·2%,阳性预测值为85·2%,阴性预测值为94·9%,约登指数为0·822,符合率为90·9%,试验的一致率为98·6%,CV值均小于15%。
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First, we introduce and discuss the various methods of multivariate polynomial interpolation in the literature. Based on this study, we state multivariate Lagrange interpolation over again from algebraic geometry viewpoint:Given different interpolation nodes A1,A2 .....,An in the affine n-dimensional space Kn, and accordingly function values fi(i = 1,..., m), the question is how to find a polynomial p K[x1, x2,...,xn] satisfying the interpolation conditions:where X=(x1,X2,....,xn). Similarly with univariate problem, we have provedTheorem If the monomial ordering is given, a minimal ordering polynomial satisfying conditions (1) is uniquely exsisted.Such a polynomial can be computed by the Lagrange-Hermite interpolation algorithm introduced in chapter 2. Another statement for Lagrange interpolation problem is:Given monomials 1 ,2 ,.....,m from low degree to high one with respect to the ordering, some arbitrary values fi(i= 1,..., m), find a polynomial p, such thatIf there uniquely exists such an interpolation polynomial p{X, the interpolation problem is called properly posed.
文中首先对现有的多元多项式插值方法作了一个介绍和评述,在此基础上我们从代数几何观点重新讨论了多元Lagrange插值问题:给定n维仿射空间K~n中两两互异的点A_1,A_2,…,A_m,在结点A_i处给定函数值f_i(i=1,…,m),构造多项式p∈K[X_1,X_2,…,X_n],满足Lagrange插值条件:p=f_i,i=1,…,m (1)其中X=(X_1,X_2,…,X_n),与一元情形相似地,本文证明了定理满足插值条件(1)的多项式存在,并且按&序&最低的多项式是唯一的,上述多项式可利用第二章介绍的Lagrange-Hermite插值算法求出,Lagrange插值另一种描述是:按序从低到高给定单项式ω_1,ω_2,…,ω_m,对任意给定的f_1,f_2,…,f_m,构造多项式p,满足插值条件:p=sum from i=1 to m=Ai=f_i,i=1,…,m (2)如果插值多项式p存在且唯一,则称插值问题适定。
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Where is a partial loss of goods, merchandise, or other moveables, the measure of indemnity, subject to any express provision in the policy, is as follows:(1)Where part of the goods, merchandise or other moveables insured by a valued policy is totally lost, the measure of indemnity is such proportion of the sum fixed by the policy as the insurable value of the part lost bears to the insurable value of the whole, ascertained as in the case of an unvalued policy:(2) Where part of the goods, merchandise, or other moveables insured by an unvalued policy is totally lost, the measure of indemnity is the insurable value of the part lost, ascertained as in case of total loss:(3) Where the whole or any part of the goods or merchandise insured has been delivered damaged at its destination, the measure of indemnity is such proportion of the sum fixed by the policy in the case of the valued policy, or of the insurable value in the case of an unvalued policy, as the difference between the gross sound and damaged values at the place of arrival bears to the gross sound value:(4)"Gross value" means the wholesale price, or, if there be no such price, the estimated value, with, in either case, freight, landing charges, and duty paid beforehand; provided that, in the case of goods or merchandise customarily sold in bond, the bonded price is deemed to be the gross value.
货物、商品或者其他动产发生部分损失的,除保险单另有明文规定外,赔偿范围如下:(1)如果定值保险单承保的货物、商品或者其他动产的一部分发生全损,赔偿范围为保险单确定的保险金额中的比例部分,该比例为灭失部分的可保价值占全部可保价值的比例部分。可保价值的确定与不定值保险相同;(3)若不定值保险单承保的货物、商品或者其他动产的一部分发生全损,赔偿范围为损失部分的可保价值,可保价值的确定与全损时相同;(4)如果被保险货物或商品的全部或者一部分以受损状态运抵目的地,赔偿范围以完好毛值与受损价值的差额占完好毛值的比例计算,在定值保险单情况下,是保险单确定的金额的该比例部分,或者,在不定值保险单情况下,是可保价值的该比例部分;(5)&毛值&是指货物的批发价格,如果没有这种价格,则是货物的估计价值,不论哪一种情况,再加上已预先付讫的运费、卸货费和关税之后的价值;但是,如果货物或商品按惯例在关仓出售,那么关仓价格就视为毛值。
- 推荐网络例句
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The split between the two groups can hardly be papered over.
这两个团体间的分歧难以掩饰。
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This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.
这种做法不仅鼓励了更多的反应,而且减少跟风的可能性。
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The new PS20 solar power tower collected sunlight through mirrors known as "heliostats" to produce steam that is converted into electricity by a turbine in Sanlucar la Mayor, Spain, Wednesday.
聚光:照片上是建在西班牙桑路卡拉马尤城的一座新型PS20塔式太阳能电站。被称为&日光反射装置&的镜子将太阳光反射到主塔,然后用聚集的热量产生蒸汽进而通过涡轮机转化为电力