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101.
环保型酸式自动滴定管的研制与应用 总被引:4,自引:0,他引:4
介绍了一种环保型酸式自动滴定管的结构、特点及使用方法。这种滴定管节省试剂,废液排放量极小,操作简单、省时,克服了常规微量滴定管精密度差、装液难、零点和滴定终点不易控制的缺点。通过数理统计方法,将环保型酸式自动滴定管与标称容量为50mL的常规酸式滴定管平行测定结果进行了比较,试验证明,该滴定分析的精密度、准确度不仅与50mL常规酸式滴定管相当,而且操作性还优于50mL常规酸式滴定管。 相似文献
102.
T. G. Liu H. Y. Cai F. L. Zhang R. A. Lessard Y. M. Zhang 《Optics and Lasers in Engineering》2001,36(4)
The principle and the method of a new automatic focusing system are presented in this paper. The system is constructed relying on the relationship between laser wave interference patterns and defocusing displacement. A CCD linear array receives interference patterns in the form of light intensity, which are converted into digital signals afterwards. Then the computer controls a stepping motor to complete auto-focusing process according to the digital results. The system has been applied in a kind of film resolution testing instrument and it shows that it has the advantage of high accuracy, high speed and wide applications. 相似文献
103.
Among the methods of quantitation commonly used in chromatography, the internal standard may be considered as the most useful and accurate; however, use of internal standards in liquid chromatography with UV and fluorometric detectors runs into considerable difficulties because the response factors may differ from each other by several orders of magnitude. Under these conditions, the search for an IS with a response factor similar to that of the analyte and adequately resolved from other peaks may prove very tedious. The deferred standard concept, already used in process and laboratory gas chromatography, is proposed as a solution; its definition, details of instrumentation, operation, and results are described in this paper. The material presented demonstrates its ability to solve this specific problem. In addition, use of the deferred standard approach is seen to save time and money. 相似文献
104.
Philippe Langlois 《BIT Numerical Mathematics》2001,41(3):515-539
A new automatic method to correct the first-order effect of floating point rounding errors on the result of a numerical algorithm is presented. A correcting term and a confidence threshold are computed using algorithmic differentiation, computation of elementary rounding error and running error analysis. Algorithms for which the accuracy of the result is not affected by higher order terms are identified. The correction is applied to the final result or to sensitive intermediate results to improve the accuracy of the computed result and/or the stability of the algorithm.This revised version was published online in October 2005 with corrections to the Cover Date. 相似文献
105.
To measure the energy spectra of low energy ions inside the International Space Station (ISS) we will expose three stacks of CR-39 plastic nuclear track detectors aligned to the three coordinate axes of the space station. The energies of cosmic ray nuclei at the stack surfaces can be determined by reconstructing the trajectories of ions stopping inside the detector material and by measuring their ranges. To measure only HZE (high charge Z and energy E) ions with charges of Z6 stopping in our experiment a special batch of CR-39 detectors with low sensitivity will be used. This detector material has been already tested by an exposure to carbon ions at the GSI accelerator in Darmstadt, Germany. 相似文献
106.
107.
支持向量机(support vector machine, SVM)具有良好的学习性能和泛化能力, 因而被广泛应用于恒星光谱分类中。然而实际应用面临的数据规模往往很大, SVM便暴露出计算量大、分类速度慢等问题。为了解决上述问题, Jayadeva等提出双支持向量机(twin support vector machine, TWSVM), 将计算时间减少至SVM的1/4。然后上述方法仅关注数据的全局特征, 对每类数据的局部特征并未关注。鉴于此, 提出基于流形模糊双支持向量机(manifold fuzzy twin support vector machine, MF-TSVM)的恒星光谱分类方法。利用流形判别分析获得数据的全局特征和局部特征, 模糊隶属度函数的引入将各类数据区别对待, 尽可能减少噪声点和奇异点对分类结果的影响。与C-SVM, KNN等传统分类方法在SDSS恒星光谱数据集上的比较实验表明了该方法的有效性。 相似文献
108.
This study proposed an automatic optical inspection (AOI) system for detection of thin-film transistor (TFT) array defects. gray level co-occurrence matrix (GLCM) and MATLAB regionprops function were used to calculate 53 TFT array defect features, which were inputted into the neural network to train the defect classifier. The images to be inspected were compared with a standard image first, in order to judge whether the TFT array samples have defects. For defective images of a TFT array, the proposed defect classifier can successfully recognize five kinds of defects in the process. According to the experimental results, the defect recognition rate of proposed system is verified to be 83.3%, which can replace manual inspection and reduce the risks of false inspections due to long duration manual work. Moreover, the proposed AOI system can improve testing efficiency and reduce manufacturing costs. 相似文献
109.
针对现有量子信息直传协议在有噪音量子信道下传输效率低及可靠性差的问题,提出了一种有效利用纠缠资源的量子安全直传通信方案.通过收发双方共享纠缠粒子作为辅助比特,采用纠缠辅助量子低密度校验码对量子态信息进行前向纠错保护,以提高系统在噪音环境下的传输可靠性.同时采用自动请求重传策略对量子态信息进行检错编码保护,当因窃听或强噪音导致译码获得的信息不正确时,则请求发端对该组信息进行编码重传操作.文中对所选用纠缠辅助量子低密度校验码在量子退极化噪音信道下的迭代译码性能进行了仿真,最后对方案的安全性进行了分析论证. 相似文献
110.
Michael Kohler Adam Krzyżak Harro Walk 《Annals of the Institute of Statistical Mathematics》2003,55(2):287-308
Regression function estimation from independent and identically distributed bounded data is considered. TheL
2 error with integration with respect to the design measure is used as an error criterion. It is shown that the kernel regression
estimate with an arbitrary random bandwidth is weakly and strongly consistent forall distributions whenever the random bandwidth is chosen from some deterministic interval whose upper and lower bounds satisfy
the usual conditions used to prove consistency of the kernel estimate for deterministic bandwidths. Choosing discrete bandwidths
by cross-validation allows to weaken the conditions on the bandwidths.
Research supported by DAAD, NSERC and Alexander von Humboldt Foundation.
The research of the second author was completed during his stay at the Technical University of Szczecin, Poland. 相似文献