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141.
在研究摩擦力驱动的接触式转动马达的基础上,本文研制了一种由声表面波驱动的非接触式转动马达.这种马达的定子选用128°YX-LiNbO3晶体,在晶体表面光刻两对叉指换能器,由叉指换能器在定子表面激发两列平行而反向传播的声表面波.定子表面铺一层流体,转子就浮在流体表面.当定子表面有两列平行而反向的声表面波传播时,流体层中就会产生平行而反向的声流,这种黏性流体的声流运动就会驱动转子运动.实验上测定了马达的角速度随驱动电压,流体层厚度以及流体运动黏性系数变化的结果.同时,我们也发现,在相同工作频率下,非接触式转动马达的阈值电压远小于接触式.  相似文献   
142.
采用流变学方法研究了双组分加成型硅橡胶的交联固化过程,并研究了反应温度对反应速率的影响.随着加成反应的进行,体系中的交联程度逐渐增加;反应温度升高,硅橡胶完全交联固化所需时间减少.  相似文献   
143.
For an upper triangular matrix ring, an explicit ladder of height $2$ of triangle functors between homotopy categories is constructed. Under certain conditions, the author obtains a localization sequence of homotopy categories of acyclic complexes of injective modules.  相似文献   
144.
145.
基于白光干涉测量色散补偿薄膜的群延迟色散   总被引:2,自引:0,他引:2  
李承帅  沈伟东  章岳光  范欢欢  刘旭 《光学学报》2012,32(10):1031003-300
为精确测量超快激光色散补偿薄膜的群延迟色散,提出了一种基于窗口傅里叶变换和样条插值去噪算法的新型白光干涉测量方案。计算机模拟表明此方法测试精度可达0.58fs2。分析了高斯噪声和光强平均效应对测试精度的影响,并使用此方法对实验制备的Gires-Tournois干涉反射镜和啁啾镜进行了测试,在宽光谱范围内测试误差小于10fs2。该方法相比其他算法可以更快速、更精确地实现薄膜相位信息的提取,具有更高的测试精度和实用性。  相似文献   
146.
In this paper we consider the contraction-proximal point algorithm: ${x_{n+1}=\alpha_nu+\lambda_nx_n+\gamma_nJ_{\beta_n}x_n,}$ where ${J_{\beta_n}}$ denotes the resolvent of a monotone operator A. Under the assumption that lim n ??? n ?=?0, ?? n ??? n ?=???, lim inf n ??? n ?>?0, and lim inf n ?? n ?> 0, we prove the strong convergence of the iterates as well as its inexact version. As a result we improve and recover some recent results by Boikanyo and Morosanu.  相似文献   
147.
We consider generalizations of Denjoy-Wolff theorem on strongly pseudo-convex domains. Beardon [3] gave a general Denjoy-Wolff theorem in hyperbolic domain in the complex plane. Our main results are generalizations of Beardon’s result in a higher dimensional setting.  相似文献   
148.
A new zinc(II) complex of N‐(piperidylthiocarbonyl)benzamide, [ZnL2], has been synthesized and characterized using elemental analysis, Fourier transform infrared and 1H NMR spectroscopies. X‐ray diffraction indicates that [ZnL2] presents a tetrahedral structure within an O2S2 donor set, which is different from analogous square planar [NiL2] and [CuL2] available in the literature. The antimicrobial activities of [ZnL2], [NiL2] and [CuL2] were evaluated against fungi and bacteria. The results show that [ZnL2] is the best for control of the studied fungi and bacteria, and its antimicrobial activity is close to that exhibited by commercial products. The relationship between the structures and antimicrobial activities of the complexes was further investigated using density functional theory calculations. It is elucidated that the increase of the polarity of carbonyl and thiocarbonyl groups determines antifungal and antibacterial activities. Moreover, the cytotoxicity of the complexes was tested against human cancer cells (hepatocellular carcinoma (SK‐Hep‐1) and breast carcinoma (MCF‐7)). The [CuL2] complex is found to be the most cytotoxic. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
149.
Although there is an increasing interest in using infrared spectroscopy for the simple, rapid, and inexpensive prediction of soil organic carbon content, few studies have used this technique to measure organic carbon chemistry. In this paper, based on both near-infrared and mid-infrared diffuse reflectance spectroscopy, we compared the use of instrumentation, spectral pretreatment, and regression method for the prediction of three parameters related to organic carbon content, one related to isotopic composition, and five related to organic carbon chemistry. A total of 140 soil samples collected from seven oriental oak forest sites across East China were used as the data set for the calibration-validation procedure. Calibrations using sample set partitioning based on joint x-y distances method significantly outperformed those using Kennard-Stone method. Compared to models using linear method (i.e., partial least squares), those using non-linear regression method (i.e., support vector machines) greatly improved the prediction precision of the alkyl-to-O-alkyl ratio and performed slightly better for the other organic carbon chemical compositions. Instrumentation had a large effect as mid-infrared models had higher average prediction accuracies than near-infrared models. We finally proposed a model using second derivative preprocessing, joint x-y distances based sample set partitioning, mid-infrared spectra, and support vector machines regression to quantify organic carbon chemistry in this study. The results are helpful for the further study of soil composition measurement.  相似文献   
150.
陈欢欢  邢进峰  丁伟航  汤小康 《应用数学》2015,37(6):451-453,521
目的 分析胸腰椎骨折后路复位短节段内固定经椎弓根Wright 液态人工骨植骨的疗效。方法 38 例胸腰椎骨折患者结合患者的经济能力分为两组,A(未植骨)组24 例单纯行后路切复椎弓根螺钉内固定术,B(植骨)组14 例一期行后路切复椎弓根螺钉内固定并经椎弓根行椎体内Wright 液态人工骨植骨术,分别随访10~27 个月,比较两组患者拆钉时伤椎前缘高度的再压缩率、Cobb角变化及伤椎影像学的变化。结果 B 组患者拆钉时伤椎前缘高度再压缩率为(5.43±2.71)%,术后Cobb 角增大为(2.03±0.51)°,与A 组(6.29±2.24)°相比差异有统计学意义(P<0.05),A 组患者术后不同程度的出现蛋壳样改变,其中2例出现断钉,1例患者出现上位椎弓根钉切割出椎体,而B 组患者未出现明显蛋壳样改变及断钉现象。结论 胸腰椎骨折后路复位短节段椎弓根钉内固定经椎弓根Wright 液态人工骨植骨能明显改善伤椎骨折的愈合,维持椎体的高度,减少蛋壳样改变及断钉等情况的发生。  相似文献   
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