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991.
Two-qubit gate of combined single-spin rotation and interdot spin exchange in a double quantum dot 总被引:1,自引:0,他引:1
Brunner R Shin YS Obata T Pioro-Ladrière M Kubo T Yoshida K Taniyama T Tokura Y Tarucha S 《Physical review letters》2011,107(14):146801
A crucial requirement for quantum-information processing is the realization of multiple-qubit quantum gates. Here, we demonstrate an electron spin-based all-electrical two-qubit gate consisting of single-spin rotations and interdot spin exchange in a double quantum dot. A partially entangled output state is obtained by the application of the two-qubit gate to an initial, uncorrelated state. We find that the degree of entanglement is controllable by the exchange operation time. The approach represents a key step towards the realization of universal multiple-qubit gates. 相似文献
992.
Kenichi HaradaHiroki Horiuchi Kazuma TanabeRich G. Carter Tomoyuki EsumiMiwa Kubo Hideaki HiokiYoshiyasu Fukuyama 《Tetrahedron letters》2011,52(23):3005-3008
First asymmetric synthesis of (−)-chicanine has been accomplished in 14 steps by employing the Evans asymmetric syn-selective aldol reaction, diastereoselective hydroboration and an regioselective, intramolecular Mitsunobu etherification. The absolute configuration of (+)- and (−)-chicanine has been revised to 2R,3S,4R,5R and 2S,3R,4S,5S, respectively, through CD analysis. 相似文献
993.
To facilitate effective resource utilization, we have investigated triterpene saponins such as saikosaponin from the aerial parts of Bupleurum (B.) falcatum L., which are commonly discarded. Seven oleanene saponins were isolated from this plant; they were classified as the 13,28-epoxy type, 12-ene type, 9(11),12-diene type, and 28-acid type on the basis of their structural characteristics. For comparison, we also examined the oleanene saponins of the seeds of B. falcatum and the aerial parts of B. rotundifolium L. to obtain seven saponins and one sapogenol from the former and thirteen oleanene saponins from the latter. Several compounds obtained from them were investigated for their hepatoprotective activity and hepatotoxicity. The 13,28-epoxy type saponins had hepatoprotectivity. Ursane type showed hepatotoxicity from middle concentration. The 11,13(18)-diene type saponins did not express hepatoprotective activity. The 28-acid type saponin which has a glucosyl carboxy group showed hepatoprotective action. 相似文献
994.
El-Aasr M Fujiwara Y Takeya M Ono M Nakano D Okawa M Kinjo J Ikeda T Miyashita H Yoshimitsu H Nohara T 《Chemical & pharmaceutical bulletin》2011,59(11):1340-1343
Garlicnin A (1), a new stable, sulfur-containing compound isolated from a fraction of the acetone extracts of Allium sativum L. garlic bulbs, showed the potential to suppress tumor cell proliferation by inhibiting the polarization of M2 alternatively activated macrophages, and its structure was characterized as 3,4-dimethyl-5-(4,5-dithia-1E,7-octadiene)-tetrahydrothiophene-2-sulfoxide-S-oxide, on the basis of the results of spectroscopic analysis results. 相似文献
995.
Nine new phenylpropanoids, rashomonic acids A-D (1-4) and meehaniosides A-E (5-9), along with four known compounds were isolated from Meehania urticifolia. The structure of each new compound was elucidated based on the results of spectroscopic analyses. Compounds 3-8 showed moderate hyaluronidase inhibitory activity with IC(50) values of 183-1049 μM. 相似文献
996.
Ono M Eguchi K Konoshita M Furusawa C Sakamoto J Yasuda S Ikeda T Okawa M Kinjo J Yoshimitsu H Nohara T 《Chemical & pharmaceutical bulletin》2011,59(3):392-396
A new labdane-type diterpenoid glucoside and two new labdane-type diterpenoids were isolated from the fruit (chasteberry) of Vitex agnus-castus L. (Verbenaceae) along with 14 known compounds comprising seven labdane-type diterpenoids, one halimane-type diterpenoid, two oleanane-type triterpenoids, two ursane-type triterpenoids, one aromadendrane-type sesquiterpenoid, and one flavonoid. Their structures were characterized on the basis of spectroscopic data as well as chemical evidence. Furthermore, the antioxidative activities of the flavonoid were evaluated using five different analyses. 相似文献
997.
Takashi Kakue Mitsuo Kuwamura Yuki Shimozato Tatsuki Tahara Yasuhiro Awatsuji Kenzo Nishio Shogo Ura Toshihiro Kubota Osamu Matoba 《Optical Review》2011,18(1):180-183
We propose an in-line color digital holography that can suppress a 0th-order diffraction image and a conjugate image. This
technique reconstructs the image of an object from two holograms that are formed at two different distances from the object
for each primary color. We numerically simulated the proposed technique and confirmed that it enabled the reconstruction of
higher-quality images of an object than the Fresnel transform alone, which is the simplest reconstruction algorithm in digital
holography. The effectiveness of the proposed technique was also quantitatively shown by evaluating the reconstructed images
using root-mean-square errors. Thus, it was confirmed that the proposed technique was capable of recording and reconstructing
both three-dimensional information and color information of an object. 相似文献
998.
This paper reports the synthesis, structure, and hydrogen adsorption property of Li-doped mesoporous silica (MPS) with a 2D
hexagonal structure. The Li-doping is achieved by impregnation of the cylindrical mesopores with an ethanol solution of lithium
chloride followed by heat treatment. Detailed characterization by solid-state NMR, TG-MS, and FT-IR suggests that, during
the heat treatment, lithium chloride reacts with surface ethoxy groups (≡Si-OEt) to form ≡SiOLi groups, while ethyl chloride
is released into the gas phase. The hydrogen uptake at 77 K and 1 atm increases from 0.68 wt% for the undoped MPS to 0.81 wt%
for Li-doped MPS (Li-MPS). The isosteric heat of adsorption is 4.8 kJ mol−1, which is consistent with the quantum chemistry calculation result (5.12 kJ mol−1). The specific hydrogen adsorption on Li-MPS would be explained by the frontier orbital interaction between HOMO of hydrogen
molecules and LUMO of ≡SiOLi. These findings provide an important insight into the development of hydrogen storage materials
with specific adsorption sites. 相似文献
999.
Ozeki T Kose K Haishi T Hashimoto S Nakatsubo S Nishimura K 《Magnetic resonance imaging》2003,21(3-4):351-354
MR microscopy technique was introduced to visualize and quantify the three-dimensional structure of snowpack. Since the NMR signal from the ice was week, we looked at the air space instead filling with dodecane or aniline doped with iron acetylacetonate. Four types of snow were tested: ice spheres, large rounded poly crystals, small rounded mono-crystals and depth hoar crystals. A specific specimen-cooling system was developed to keep the temperature below 0 degrees C. In the experiments 0.5 to 2 h were necessary to accumulate the signals enough to obtain a 3D micro-image; the image matrix 128(3), voxel size (200 microm)3 or 256(3) (120 microm)3. Comparison with the 2D data using the conventional section plane method was also carried out and MR microscopy is proved to be a very useful method to visualize the microstructure of snowpack. 相似文献
1000.
Initial changes of non-traumatic osteonecrosis of femoral head in fat suppression images: bone marrow edema was not found before the appearance of band patterns 总被引:10,自引:0,他引:10
Fujioka M Kubo T Nakamura F Shibatani M Ueshima K Hamaguchi H Inoue S Sugano N Sakai T Torii Y Hasegawa Y Hirasawa Y 《Magnetic resonance imaging》2001,19(7):985-991
The present study examined initial changes in non-traumatic osteonecrosis of the femoral head (ONF) on T1- and T2-weighted MR images, and fat suppression images. The subjects were 57 renal transplant recipients (37 males and 20 females), whose median age at the time of transplantation was 31.5 years old (range, 10 to 58 years). Twelve patients developed band patterns (sign of established ONF) at an early postoperative period. Among them, 4 joints of 3 patients had a localized, faint signal abnormality in fat suppression images, where band pattern was confirmed later in T1- and T2-weighted images. In all the 57 patients, no bone marrow edema preceding to ONF was observed. Bone marrow edema would not be the cause of ONF in renal transplant patients. Early changes depicted in our fat suppression images would be useful information in the studies on pathogenesis of ONF. 相似文献