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应用Hotelling T~2检验评价学生学习成绩的探讨 总被引:1,自引:0,他引:1
本文简述了HotellingT2检验法,并应用该法对某校学生的学习成绩进行了分析评价,发现其效果较为满意。认为对多变量资料进行分析评价需用HotellingT2检验。 相似文献
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Daimei Chen Zhongyi Jiang Jiaqing Geng Juhong Zhu Dong Yang 《Journal of nanoparticle research》2009,11(2):303-313
The nitrogen and fluorine co-doped TiO2 (N-F-TiO2) nanoparticles of anatase crystalline structure were prepared by a facile method of (NH4)2TiF6 pyrolysis, and characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), transmission
electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy etc. With
the increase of calcination temperature, (NH4)2TiF6 decomposed into TiOF2 and NH4TiOF3 at first, and then formed anatase-type TiO2 with thin sheet morphology. H3BO3 as oxygen source can promote the formation of anatase TiO2, but decrease the F content in the N-F-TiO2 materials due to the formation of volatile BF3 during the precursor decomposition. The photocatalytic activity of the obtained N-F-TiO2 samples was evaluated by the methylene blue degradation under visible light, and all the samples exhibited much higher photocatalytic
activity than P25. Moreover, the merits and disadvantages of this proposed method to prepare doped TiO2 are discussed. 相似文献
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Mechanism of mercury detection based on interaction of single-strand DNA and hybridized DNA with gold nanoparticles 总被引:1,自引:0,他引:1
Mechanisms of interaction of single-strand DNA and hybridized DNA on gold nanoparticles in the presence of Hg2+ was studied in this work. Recently the detection of Hg2+ using unmodified gold nanoparticles (AuNPs) combined with DNA is becoming a promising technique with the advantages of simplicity, cost-effectiveness and high sensitivity. However, few studies focused on the interaction of ssDNA and hybridized DNA on AuNPs to date. In the present work, we compared the interactions of different DNA probes on AuNPs using both absorption and fluorescence detection. It was found that there were only small partial dsDNA dissociated from the surface of AuNPs after hybridization in the presence of Hg2+. Moreover, we found that the aggregated AuNPs/DNA system tended to be dispersed again with increasing Hg2+ concentration up to 250 μM. Based on these results, the mechanisms of mercury detection based on interaction between DNA-conjugated gold nanoparticles were investigated. Positively charged dsDNA could bind to the surface of AuNPs and dominate the electrostatic interactions and consequently aggregation of the AuNPs/DNA system. 相似文献
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Liming Hu Shengmei Lu Fengling Yang Juhong Feng Zhaojie Liu Hansheng Xu 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2785-2790
A series of 2-phosphonoalkyl 1,2-benzisoselenazol-3(2H)-ones were designed and synthesized via reaction 2-chloroselenobenzoyl chloride with 1-hydrazinobenzyl phosphonate. The structures of all new compounds were confirmed by spectroscopic methods and microanalyses. 相似文献
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In this paper, an analytical method is proposed to construct explicitly exact and approximate solutions for nonlinear evolution
equations. By using this method, some new traveling wave solutions of the Kuramoto-Sivashinsky equation and the Benny equation
are obtained explicitly. These solutions include solitary wave solutions, singular traveling wave solutions and periodical
wave solutions. These results indicate that in some cases our analytical approach is an effective method to obtain traveling
solitary wave solutions of various nonlinear evolution equations. It can also be applied to some related nonlinear dynamical
systems. 相似文献
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Xin Zheng Chen Chen Huitao Gao Xuefeng Sun Yanbao Zhang Juhong Shi Xiaohong Han 《Biomedical chromatography : BMC》2022,36(5):e5306
Rivaroxaban is an oral anticoagulant directly inhibiting the activity of Factor Xa, which is widely used for the prophylaxis of thromboembolic disorders. Therapeutic drug monitoring (TDM) is required during therapy for individual dosage adjustment. This study aimed at developing a liquid chromatography/tandem mass spectrometry method that was suitable for rivaroxaban TDM in human plasma and urine and exploring the feasibility of urine drug monitoring in medical care. A 3 min run time of the LC–MS/MS methods was established by employing an Acquity UPLC BEH C18 (2.1 × 50 mm, 1.7 μm) column using gradient elution of 10 mmol/L ammonium acetate containing 0.1% formic acid–0.1% formic acid acetonitrile as a mobile phase at a flow rate of 0.4 ml/min with calibration ranges of 0.5–400 and 10–10,000 ng/ml for human plasma and urine, respectively. Rivaroxaban was detected on a triple quadrupole tandem mass spectrometer with an electrospray ionization source in positive ion mode. The methods showed good linearity within the calibration range. The precision and accuracy, matrix effect, extraction recovery and stability in both human matrices were all validated and meet the international guideline requirements. These validated methods were successfully applied to support the TDM of an aged patient receiving rivaroxaban for therapy. 相似文献
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由Dirichlet 级数表示的整函数f(z)在带形中有界,其系数{an}和指数 {λn}(n=1,2,... )是复数列.文中引入 φ-级 和下φ -级,讨论f(z) 具有φ -级和下φ -级的条件. 相似文献
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研究了圆对称函数的Goluzin问题.当f为圆对称函数,λ=k1(k=2,3,…)时,通过构造一个正实部函数,利用积分方法,得到了k次圆对称函数相邻系数模之差的精确估计.另外,还得到了圆对称函数的积分表示. 相似文献