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191.
192.
Hideaki Sakai 《Annals of the Institute of Statistical Mathematics》1980,32(1):393-400
The effect of regularly missed observations on the estimation of parameters of an autoregressive (AR) process is investigated
by using the frequency domain method. For first order AR processes, numerical results are shown to see a behavior of variances
of the estimate due to the missed observations. In some cases, we can positively utilize the concept of missed observations
to decrease the variances if the number of observations is fixed but time instants at with the observations are made can be
changed. 相似文献
193.
Non-stereospecific ring expansions of 3-acetylbenzothiazoline sulfoxides to benzothiazines from the reaction with acetic anhydride are reported. 相似文献
194.
Teruji Tsuji Takahiro Kataoka Mitsuru Yoshioka Yuji Sendo Yasuhiro Nishitani Shoichi Hirai Takashi Maeda Wataru Nagata 《Tetrahedron letters》1979,20(30):2793-2796
The benzyl ester protecting group in β-lactam derivatives can be cleanly removed by treatment with aluminum trichloride under mild conditions, preferably in the presence of anisole, to give the corresponding free acids in high yields. 相似文献
195.
196.
197.
Case studies of the Baeyer-Villiger reaction applied to diand trifluoromethylketone derivatives and the effect of the fluoromethyl groups on the Baeyer-Villiger reaction, are described. 相似文献
198.
A convenient synthesis of 4-alkylindoles was attained by utilizing the result of a stannous chloride-effected reaction of endoperoxide of N-methoxycarbonylpyrrole with carbon nucleophiles. 相似文献
199.
200.
Mochida T Takazawa K Matsui H Takahashi M Takeda M Sato M Nishio Y Kajita K Mori H 《Inorganic chemistry》2005,44(23):8628-8641
Charge-transfer salts of branched-alkyl biferrocenes, (1',1' '-R2-1,1' '-biferrocene)[Ni(mnt)2] (1a, R = isopropyl; 2a, R = dineopentyl) and (1',1' '-R2-1,1' '-biferrocene)2[Co(mnt)2]2 (1b, R = isopropyl; 2b, R = dineopentyl), were prepared. Their valence states were investigated using X-ray crystallography and M?ssbauer spectroscopy. Complexes 1a and 1b show segregated-stack crystal structures that contain columns of acceptors, whereas structures of 2a and 2b, which contain bulky donors, are rather discrete. All of the complexes contain mixed-valent biferrocenium monocations. A two-step valence transition was found in complex 1a. The crystal contains two crystallographically independent cations: one undergoes valence localization below room temperature; the other undergoes valence localization below ca. 130 K. The former transition is derived from asymmetry of the crystal environment around the cation, whereas the latter one is caused by symmetry lowering coupled with a spin-Peierls transition (T(C) = 133.2 K) associated with the dimerization of the acceptors. This compound was found to exhibit a dielectric response based on valence tautomerization. Other complexes (1b, 2a, and 2b) show a valence-trapped state. In all complexes, charge localization was found to occur through local electrostatic interactions between the donor's cationic moiety and the acceptor's electronegative moieties. 相似文献