共查询到20条相似文献,搜索用时 546 毫秒
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思想和方法是高中物理解题的关键。学生只有具备了解题思想,掌握了相应的解题方法,才能够快速准确地解决物理习题。高中物理解题的思想、方法主要有图像法、模型法、等效法、整体法与隔离法、守恒法、极值法等,对这些方法进行深入的探究,具有现实的理论意义和实践价值。 相似文献
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基于共振干涉法、相位法和反射回波法测量了空气和水中超声波的传播速度,比较了三种方法的优缺点,共振干涉法和相位法可测量气体和液体中的声速,反射回波法可测量液体和固体中的声速;相位法误差最小,共振干涉法误差相对较大。共振干涉法研究了示波器接收的交变电压随传播距离的变化规律,计算得空气和水中超声波的损耗系数分别为0.01381、0.01829,超声波在水中的损耗较大。使用Origin软件直线拟合,对实验结果进行分析和评价。 相似文献
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分别采用探测线圈四次90°快速翻转法、高斯计法、激磁电流断路法和激磁电流换向法对强磁场进行了测量,分析了各自的方法误差 相似文献
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光纤光栅传感信号解调技术研究进展 总被引:1,自引:0,他引:1
光纤光栅传感器是一种新型传感器,有着非常广泛的应用前景。限制光纤光栅传感器大量实际应用的主要障碍是传感信号解调,因而,光纤光栅传感信号解调是光纤光栅传感器应用的关键技术之一。本文对现有已报道的光纤光栅传感信号的解调方法进行综述,并归类为:边缘滤波法、匹配滤波法、可调谐滤波法、光源波长可调谐扫描法、射频探测法、光栅啁啾法、CCD分光仪法、干涉法。对各种方法的原理及相关改进方法进行了阐述,并对其优缺点做了比较分析,最后,对光纤光栅传感信号的解调技术发展进行了展望。 相似文献
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A. I. Trokhimets 《Journal of Applied Spectroscopy》1995,62(1):88-90
Institute of Physicoorganic Chemistry, Academy of Sciences of Belarus, 220603, Minsk, Ul. Surganova, 13, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 1, pp. 104–107, January–February, 1995. 相似文献
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F. Gandini A. Bruschi S. Cirant G. Gittini G. Granucci V. Muzzini C. Sozzi N. Spinicchia 《International Journal of Infrared and Millimeter Waves》2007,28(2):121-128
A spherical compact matched load, for high vacuum operation suited for short pulses (2 MW, 0.1 s) precise measurement has
been designed to test high power gyrotrons Bruschi, Gandini, Muzzini, Spinicchia, Cirant, Gittini, Granucci, Mellera, Nardone,
Simonetto, and Sozzi (Fusion Eng. Des. 56–57:649–654, 2001); Bruschi, Cirant, Gandini, Granucci, Mellera, Muzzini, Nardone,
Simonetto, Sozzi, and Spinicchia (Nucl. Fusion 43:1513–1519, 2003); Bruschi, Cirant, Gandini, Gittini, Granucci, Mellera,
Muzzini, Nardone, Simonetto, Sozzi, Spinicchia, Angella, and Signorelli (Development of CW and short-pulse calorimetric loads
for high power millimeter-wave Beams, 23rd Symposium on Fusion Technology, September 20–24, 2004, Venice, Italy). In order
to enhance the power handling capability of the load and to reduce the operation problems that may arise from an excessive
reflection from the load, a ray tracing code has been written to model the power distribution on the inner surface and the
pattern of the reflected radiation. The outcome of this code has been used to select a more convenient profile for the spreading
mirror of the load and to optimize a pre-load specially conceived to minimize the power reflected fraction. 相似文献
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N. K. Morozova E. I. Smirnova I. A. Karetnikov O. R. Golovanova V. G. Galstyan V. S. Zimogorskii 《Journal of Applied Spectroscopy》1996,63(4):543-547
Moscow Power Engineering Institute, 14, Krasnokazarmennaya Str., Moscow, GSP, 105835, Russia. Translated from Zhurnal Prikladnois
Spektroskopii, Vol. 63, No. 4, pp. 646–651, July–August, 1996. 相似文献
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É. S. Zolotovitskaya L. V. Glushkova T. V. Kozulya A. B. Blank 《Journal of Applied Spectroscopy》1997,64(3):410-413
A method of the atomic-emission spectrum analysis of soil has been developed for control of the accumulation of technogenic
impurities in environmental objects. A sample, after calcination at 550°C, is evaporated in an arc discharge. Spectra are
recorded by a DFS-8 spectrograph. Simultaneously, determination is made of Li, Ba, Sr, Cu, Zn, Cr, Ni, Co, Pb, Bi, Mo, V,
Ge, Ga, Y, Nb, Sn, Cd. For the majority of the elements the detection limits are lower than their percent abundance in the
crust and their maximum permissible concentrations.
Institute for Single Crystals, National Academy of Sciences of Ukraine, 60, Lenin Ave., Khar'kov, 310001, Ukraine. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 396–399, May–June, 1997. 相似文献
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ICP-AES雾化法氢化法联合测定白族产妇及新生儿发中常微量元素 总被引:2,自引:0,他引:2
本文报道用ICP-AES同时测定人发中24种元素的方法。采用10mg/ml样品,4.8mol/L盐酸溶液,用基体匹配法校正干扰,分别用雾化法和氢化法测定,用人发标准检验方法和结果的准确性。较满意地测定了Zn等18种元素。91例母婴发中的Zn、Fe、Sr、Mg、Cd、P、Ni、Se、As和Mo等元素呈显著的正相关性。 相似文献
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I. D. Lomako T. V. Smirnova A. N. Igumentsev A. A. Mel'nikov 《Journal of Applied Spectroscopy》1996,63(4):561-567
Institute of Physics of Solids and Semiconductors, Academy of Sciences of Belarus, 17, P. Brovka Str., GSP, Minsk, 220072.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 63, No. 4, pp. 667–675, July–August, 1996. 相似文献
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M. K. Samokhvalov 《Journal of Applied Spectroscopy》1995,62(3):555-558
Ul'yanovsk State Technical University, 32, Severnyi Venets St., Ul'yanovsk, 432027, Russia. Translated from Zhurnal Prikladnoi
Spektroskopii, Vol. 62, No. 3, pp. 182–185, May–June, 1995. 相似文献
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Due to the drawbacks in Support Vector Machine(SVM)parameter optimization,an Improved Shuffled Frog Leaping Algorithm(Im-SFLA)was proposed,and the learning ability in practical speech emotion recognition was improved.Firstly,we introduced Simulated Annealing(SA),Immune Vaccination(Iv),Gaussian mutation and chaotic disturbance into the basic SFLA,which bManced the search efficiency and population diversity effectively.Secondly,Im-SFLA Was applied to the optimization of SVM parameters,and an Im-SFLA-SVM method Was proposed.Thirdly,the acoustic features of practical speech emotion,such aS ridgetiness,were analyzed.The pitch frequency,short-term energy,formant frequency and chaotic characteristics were analyzed corresponding to different emotion categories,and we constructed a 144-dimensional emotion feature vector for recognition and reduced to 4-dimension by adopting Linear Discriminant Analysis(LDA) Finally,the Im-SFLA-SVM method Was tested on the practical speech emotion database,and the recognition results were compared with Shuffled Frog Leaping Algorithm optimization-SVM(SFLA-SVM)method,Particle Swarm Optimization algorithm optimization-SVM(PSo-SVM) method,basic SVM,Gaussian Mixture Model(GMM)method and Back Propagation(BP)neural network method.The experimentM resuits showed that the average recognition rate of Im-SFLA-SVM method was 77.8%,which had improved 1.7%,2.7%,3.4%,4.7%and 7.8%respectively,compared with the other methods.The recognition of fidgetiness was significantly improve,thus verifying that Im-SFLA was an effective SVM parameter selection method,and the Im-SFLA-SVM method may significantly improve the practical speech emotion recognition. 相似文献
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利用ICP-AES分析技术,通过对样品处理、元素分析谱线、酸度等因素进行试验研究,综合确定了分析条件,对铜电解液中杂质元素(Fe、Ni、Pb、Bi、Sb、Zn、As)进行了ICP-AES测定。结果表明,ICP-AES测定铜电解液中Fe、Ni、Pb、Bi、Sb、Zn和As,可以满足铜电解生产的需要,为高纯阴极铜的生产起了指导作用。 相似文献