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81.
Takigawa A Setoguchi H Okawa M Kinjo J Miyashita H Yokomizo K Yoshimitsu H Nohara T Ono M 《Chemical & pharmaceutical bulletin》2011,59(9):1163-1168
Alkaline hydrolysis of the crude resin glycoside fraction of the leaves, stems, and roots of Calystegia soldanella ROEM. et SCHULT. (Convolvulaceae) gave four new glycosidic acids, named calysolic acids A, B, C, and D, along with one known glycosidic acid, soldanellic acid B, and three organic acids, 2S-methylbutyric, tiglic, and 2S,3S-nilic acids. The structures of the new glycosidic acids were characterized on the basis of spectroscopic data and chemical evidence. 相似文献
82.
Feroza Begum Yoshinori Namihira Tatsuya Kinjo Shubi Kaijage 《Optics Communications》2011,284(4):965-970
This paper presents a simple index-guiding square photonic crystal fiber (SPCF) where the core is surrounded by air holes with two different diameters. The proposed design is simulated through an efficient full-vector modal solver based on the finite difference method with anisotropic perfectly matched layers absorbing boundary condition. The nearly zero ultra-flattened dispersion SPCF with low confinement loss, small effective area as well as broadband supercontinuum (SC) spectra is targeted. Numerical results show that the designed SPCF has been achieved at a nearly zero ultra-flattened dispersion of 0 ± 0.25 ps/(nm·km) in a wavelength range of 1.38 μm to 1.89 μm (510 nm band) which covers E, S, C, L and U communication bands, a low confinement loss of less than 10−7 dB/m in a wavelength range of 1.3 μm to 2.0 μm and a wide SC spectrum (FWHM = 450 nm) by using picosecond pulses at a center wavelength of 1.55 μm. We then analyze the sensitivity of chromatic dispersion to small variations from the optimum value of specific structural parameters. The proposed index-guiding SPCF can be applicable in supercontinuum generation (SCG) covering such diverse fields as spectroscopy applications and telecommunication dense wavelength division multiplexing (DWDM) sources. 相似文献
83.
Dr. Wolfgang Baumann Dr. Dirk Michalik Fabian Reiß Prof. Dr. Axel Schulz Dr. Alexander Villinger 《Angewandte Chemie (International ed. in English)》2014,53(12):3250-3253
Following our interest in nitrogen chemistry, we now describe the synthesis, structure, and bonding of labile disilylated diazene, its GaCl3 adduct, and the intriguing trisilylated diazenium ion [(Me3Si)2N?N‐SiMe3]+, a dark blue and highly labile (Tdecomp>?30 °C) homoleptic cation of the type [R3N2]+. Although direct silylation of Me3Si‐N?N‐SiMe3 failed, the [(Me3Si)2N?N‐SiMe3]+ ion was generated in a straightforward two‐electron oxidation reaction from mercury(II) dihydrazide and Ag[GaCl4]. Moreover, previous structure data of Me3Si‐N?N‐SiMe3 were revised on the basis of new data. 相似文献
84.
Masashi Ban Keiko Kurokawa Rei Momose Osamu Hirota 《International Journal of Theoretical Physics》1997,36(6):1269-1288
An optimum quantum measurement that minimizes the average probability of error is considered for symmetric quantum states.
The positive operator-valued measure (POM) which satisfies the necessary and sufficient condition for the minimization of
the average probability of error is derived by using the quantum Bayes strategy. It is also shown that the mutual information
obtained in the optimum quantum measurement becomes extremum. Furthermore, an optimum quantum measurement for parameter estimation
is found for symmetric quantum states by applying the maximum-likelihood estimation. The optimum POM for the parameter estimation
has the same structure as that for the quantum state discrimination. 相似文献
85.
Thiol esters are obtained from acyl chlorides and copper-I-mercaptides in excellent yields. 相似文献
86.
We use the combinatorics of toric networks and the double affine geometric R-matrix to define a three-parameter family of generalizations of the discrete Toda lattice. We construct the integrals of motion and a spectral map for this system. The family of commuting time evolutions arising from the action of the R-matrix is explicitly linearized on the Jacobian of the spectral curve. The solution to the initial value problem is constructed using Riemann theta functions. 相似文献
87.
88.
Ono M Yamasaki T Konoshita M Ikeda T Okawa M Kinjo J Yoshimitsu H Nohara T 《Chemical & pharmaceutical bulletin》2008,56(11):1621-1624
Two new halimane-type diterpenoids, viteagnusins A and B, and three new labdane-type diterpenoids, viteagnusins C, D, and E, were isolated from the fruit of Vitex agnus-castus L. (Chasteberry, Verbenaceae) along with two known diterpenoids. Their chemical structures were determined on the basis of spectroscopic data. 相似文献
89.
In recent years, ionic liquids have attracted much attention as useful synthetic solvents. Compared with classical molecular solvents, the ionic liquids are environmentally benign reaction media. A variety of quinoline derivatives have been synthesized under ionic liquid conditions using Amberlyst‐15 as catalyst. 相似文献
90.
Reactions of 2‐Substituted Pyridines with Titanocenes and Zirconocenes: Coupling versus Dearomatisation
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Dr. Fabian Reiß Dr. Kai Altenburger Dr. Lisanne Becker Kathleen Schubert Dr. Haijun Jiao Dr. Anke Spannenberg Dr. Dirk Hollmann Dr. Perdita Arndt Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3361-3369
Reactions of group 4 metallocene sources with 2‐substituted pyridines were investigated to evaluate their coordination type between innocent and reductive dearomatisation as well as to probe the possibility for couplings. A dependence on the cyclopentadienyl ligands (Cp, Cp*), the metals (Ti, Zr), and the substrates (2‐phenyl‐, 2‐acetyl‐, and 2‐iminopyridine) was observed. While 2‐phenylpyridine is barely reactive, 2‐acetylpyridine reacts vigorously with the Cp‐substituted complexes and selectively with their Cp* analogues. With 2‐iminopyridine, in all cases selective reactions were observed. In the isolated [Cp2Ti], [Cp2Zr], and [Cp*2Zr] compounds the substrate coordinates by its pyridyl ring and the unsaturated side‐chain. Subsequently, the pyridine was dearomatised, which is most pronounced in the [Cp*2Zr] compounds. Using [Cp*2Ti] leads to the unexpected paramagnetic complexes [Cp*2TiIII(N,O‐acpy)] and [Cp*2TiIII(N,N′‐impy)]. This highlights the non‐innocent character of the pyridyl substrates. 相似文献