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991.
A-Parseval框架小波的特征刻画 总被引:1,自引:1,他引:0
研究与伸缩矩阵A相关的Parseval框架小波(A-PFW)的特征刻画,其中伸缩矩阵A满足A~3=2I_3且A的每一列元素之和均为偶数.首先,讨论了与两个特殊伸缩矩阵B,C相关的Parseval框架小波(B-PFW,C-PFW)之间的关系,并得到C-PFW分别与两类特殊伸缩矩阵D,■相关的Parseval框架小波(D-PFW,■-PFW)之间的等价关系.其次,探讨了伪尺度函数和源于多分辨分析的A-PFW(MRA A-PFW)的特征刻画.最后,借助于维数函数,给出了A-PFW是MRA A-PFW的一个充要条件. 相似文献
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The determination method of L-phenylalanine(LPA) by fluorescence quenching was developed.The assay was based on the combination of the cucurbit[7]uril(CB[7]) with palmatine hydrochloride(PAL) reaction.In the presence of CB[7],the fluorescence of PAL was quenched by LPA which can be employed to detect LPA.Under the optimal conditions,a linear range 3.63×10-8- 9.68×10-6mol/L and a detection limit 1.27×10-8mol/L of LPA were obtained.The relative standard deviation(R.S.D) was 1.8%obtained from a series of 11 standards each containing 6.05×10-6 mol/L of LPA.This paper also discusses the mechanism of fluorescence indicator probe. 相似文献
996.
Cross-linkedβ-cyclodextrin polymer/Fe3O4 composite nanoparticles with core-shell structures were prepared via cross linking reaction on the surface of carboxymethylβ-cyclodextrin(CM-β-CD) modified Fe3O4 nanoparticles inβ-cyclodextrin alkaline solution by using epichlorohydrin as crosslinking agent.The morphology,structure and magnetic properties of the prepared composite nanoparticles were investigated by transmission electron microscopy(TEM),Fourier transform infrared(FTIR) spectrometry,X-ray diffraction(XRD) measurement,thermogravimetric analysis(TGA) and Vibrating sample magnetometry (VSM),respectively. 相似文献
997.
Yukio Ogihara 《中国化学快报》2011,22(2):181-184
A new lignan glycoside was isolated from the n-butanol extract of the roots and rhizomes of Sinopodophyllum emodi.On the basis of spectral evidences,its structure was established and named as 4,5-didemethylpodophyllotoxin 7’-O-β-D-glucopyranoside. This compound showed cytotoxicity against four human cancer cell lines(Hela,K562,SH-SY5Y and CNE) in vitro. 相似文献
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The asymmetric aza-Henry reaction of α-substituted nitroacetates and N-Boc imines was achieved with a new-type thioureaguanidine bifunctional organocatalyst.The novel transformations exhibited high diastereoselectivities,and the adducts bearing adjacent quaternary and tertiary chiral centers were generally obtained in moderate to good enantioselectivities(up to 88%ee). 相似文献
999.
MgAl and MgMAl oxides(M = Co,Ni and Cu) with a Mg:M:Al molar ratio = 4:1:1 were synthesized from the calcination of their corresponding layered double hydroxide(LDHs) precursors.Their catalytic activities were examined for the oxidation of ethylbenzene using tert-butylhydroperoxide(TBHP) as an oxidant.The oxidized product was mainly acetophenone.The catalytic activities were in the order of MgCuAl>MgNiAl~NiAl~MgCoAl~CoAl>CuAl>MgAl oxides.Reusability studies show that the catalysts are stable under the re... 相似文献
1000.
An efficient and simple method for synthesis of new hyodeoxycholic acid thiosemicarbazone derivatives under solvent-free conditions using microwave has been developed.Its main advantages are short reaction times,good conversions and the environmentally friendly nature of the process.The preliminary results indicate that some of these compounds possess inhibitory effects against E.coli. 相似文献