- 更多网络例句与无值化相关的网络例句 [注:此内容来源于网络,仅供参考]
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The properties of four factorized chi-square forms, which are used in minimization of correlated data, are studied, including their biasness and unbiasedness.
研究了关联实验数据的四种因子化形式的χ2 表达式及其极小化性质,同时讨论了极小化估计值的有偏性与无偏性。
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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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This article estimates the extreme loss distribution with extreme value theory, estimates the shape parameter with HKKP estimator, which is unbiased to small sample data, selects the right threshold by selecting smallest mean square error of the estimated cumulative distribution function and empirical cumulative distribution function and based on the extreme value theory method, this article estimates the extreme loss distribution and the p-percentile operational loss under certain believe range for Chinese commercial banks, then calculates the operational risk supervise capital.
本文利用极值理论对中国商业银行操作损失极端值分布进行估计,针对尾参数估计的来用传统Hill佑计对小样本数据容易产生偏倚的情况,提出了采用Hill佑计的改进―小样本无偏估计的HKKP佑计来估计操作损失的尾参数,针对由于阈值确定不准确导致结果偏差大的情况,采用最小化估计的累计概率分布与经验累计概率分布平均平方误差的方法确定较精确的阈值,估计出给定置信水平下操作风险损失的分位数,从而使得中国商业银行操作风险监管资本的测定成为可能。
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An unconstrained cost function is provided for the Orthogonal Space-Time Block Coded Multi-input-Multi-Output Antenna System. The global minima of the cost function are analyzed: in fact the global minima of the cost function is the normalized channel vector.
该方法主要利用了正交特性,给出了一个针对正交空时分组码MIMO系统模型的无约束代价函数,并分析了该函数的全局最小值:该无约束代价函数的最小值实际上就是实际信道的归一化矢量。
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17Mm x3mm and ψ15mmx2.5mm coin type blushless motors are respectively developed in 2005 and 2006. MIRDC expects to develop a ψ12mm x 2.5mm coin type blushless motors in 2007. Our research of the motor could assist not only Taiwan motor Industry to become the kingdom of mini motor worldwide once again, but also expect to build a new industry of micro parts in Taiwan.
期望藉由金属中心致力於金属制品高精密、微小化及高值化的制程技术研究,将薄型无刷马达技术开发逐步成熟后,将可应用於许多具有薄化需求的行动设备与装置,并期待能将本项技术与国内有兴趣的相关业者共同参与与投入,让台湾再度成为世界的小马达王国。
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By comparison with other experimental data we determined 42 energy levels of Cu and 13 energy levels of Ge. For the spectrum without experimental data for comparison, they are determined by isoelectronic sequence.
4 我们采用束箔光谱方法测量高离化态Cu和 Ge束的光谱线,与文献中的实验数据相对照,确定了 42条 Cu的谱线和 13条 Ge的谱线,对于无实验值可对照的谱线,利用理论值和实验值进行等电子序列证明。
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The results show that the optimal parameters of esterification are as follows: 4% of SO42-/ZrO2, molar ratio of methanol to litsea cubeba kernel oil 101, 68 ℃ of reaction temperature and 4 h of reaction time, the acid value decreases to 2.52 mg/g. Compared with the traditional acidic-catalyzed method, this method has the advantages of no acid proof equipment, easy to recycle catalyst and no acidic waste water emission. The optimal parameters of transesterification are as follows: 25 ℃ of reaction temperature, 0.5% of hexadecyl-trimethyl-ammonium bromide, 1% of NaOH, molar ratio of methanol to the oil 61 and 15 min of reaction time. The ester exchanging rate is 97.6%. This method adopts phase transfer catalyst and produces industry prospect, which has many advantages such as energy-saving and time-saving under room temperature.
研究结果表明,固体酸SO42-/ZrO2催化酯化反应的最佳条件为:油重4%的SO42-/ZrO2,醇油摩尔比为101,温度为68 ℃,反应时间为4 h,原油酸值降到2.52 mg/g;该法相对浓硫酸催化酯化法具有不需耐酸设备、催化剂易回收、无废水排放等优点;相转移催化酯交换反应的最佳条件为:温度为 25 ℃,0.5%的十六烷基三甲基溴化铵,油重1%的NaOH,醇油摩尔比为61,反应15 min,原油酯交换率达到97.6%;采用相转移催化技术,反应在常温下进行,大大减少了能耗,缩短了反应时间,具有的产业化前景。
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First, the geometry optimization for 1-phenyldibenzophosphole and triphenylphosphine were carried out using quantum chemical AM1 method.
用量子化学AM1方法优化了1-苯基二苯并膦和三苯基膦的几何构型,比较了两种化合物的电子结构和空间结构,发现PDBP作为羰基合成铑膦催化剂的配体要优于三苯基膦;系统研究了PDBP的合成方法,其最佳合成条件为:在无水无氧的条件下,采用二乙胺锂与溴化四苯基膦摩尔比为3,反应温度为22 ℃,反应5 h,反应后酸化, pH值为1~2,产物收率可达到85%~88%。
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Color and luster, outside hardness, fracture, acid value, saponification value, iodine value, benzene insoluble, white to light yellow, smooth and shining on surface, without obvious impurity, being hard and crispy, fracture being horse tooth structure with luster.
色泽与外观硬度、断面酸值皂化值碘值苯不溶物白色至微黄,表面光滑有光泽,无明显杂质,质硬而脆,断面呈马牙状有光泽。
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Color and luster, outside hardness, fracture, acid value, saponification value, iodine value, benzene insoluble, white to light yellow, smooth and shining on surface, without obvious impurity, being hard and crispy , fracture being horse tooth structure wi
色泽与外观硬度、断面酸值皂化值碘值苯不溶物白色至微黄,表面光滑有光泽,无明显杂质,质硬而脆,断面呈马牙状有光泽。
- 更多网络解释与无值化相关的网络解释 [注:此内容来源于网络,仅供参考]
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interlock:互锁
机床不运行16系统类用参数8901#0(FAN)设定. 0系统无相应参数. 5.互锁(INTERLOCK)信号的选择显示出"伺服初始化画面(Servo Initiate)后",按该画面提示的步骤操作,输入各 项的要求值.
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locally unbiased test:局部无偏检验
locally trivial embedding 局部平凡嵌入 | locally unbiased test 局部无偏检验 | locally uniformizing parameter 局部单值化参数
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locally uniformizing parameter:局部单值化参数
locally unbiased test 局部无偏检验 | locally uniformizing parameter 局部单值化参数 | locally uniformly convergent sequence 局部一致收敛序列
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uniformize:使一致
uniformization /单值化/ | uniformize /使一致/ | uniformly /一律地/无变化地/一样地/相同地/