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101.
The purpose of this paper is to give a characterization of real hypersurfaces of type A0, A in a quaternionic hyperbolic space
QH
m by the covariant derivative of the second fundamental tensor.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
102.
Eunjae Jeong Sun Hee Kim In Hwan Jung Yangjun Xia Kwanghee Lee Hongsuk Suh Hong‐Ku Shim Han Young Woo 《Journal of polymer science. Part A, Polymer chemistry》2009,47(14):3467-3479
An indenofluorene‐based copolymer containing blue‐, green‐, and red light‐emitting moieties was synthesized by Suzuki polymerization and examined for application in white organic light‐emitting diodes (WOLEDs). Tetraoctylindenofluorene (IF), 2,1,3‐benzothiadiazole (BT), and 4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole (DBT) derivatives were used as the blue‐, green‐, and red‐light emitting structures, respectively. The number‐average molecular weight of the polymer was determined to be 25,900 g/mol with a polydispersity index of 2.02. The polymer was thermally stable (Td = ~398 °C) and quite soluble in common organic solvents, forming an optical‐quality film by spin casting. The EL characteristics were fine‐tuned from the single copolymer through incomplete fluorescence energy transfer by adjusting the composition of the red/green/blue units in the copolymer. The EL device using the indenofluorene‐based copolymer containing 0.01 mol % BT and 0.02 mol % DBT units ( PIF‐BT01‐DBT02 ) showed a maximum brightness of 4088 cd/m2 at 8 V and a maximum current efficiency of 0.36 cd/A with Commission Internationale de L'Eclairage (CIE) coordinates of (0.34, 0.32). The EL emission of PIF‐BT01‐DBT02 was stable with respect to changes in voltage. The color emitted was dependent on the thickness of the active polymer layer; layer (~60 nm) too thin was unsuitable for realizing WOLED via energy transfer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3467–3479, 2009 相似文献
103.
Tae Young Kim Tae Hee Lee Jong Eun Kim Rajeswari M. Kasi Chong S. P. Sung Kwang S. Suh 《Journal of polymer science. Part A, Polymer chemistry》2008,46(20):6872-6879
A nonaqueous dispersion of poly(3,4‐ethylenedioxythiophene) (PEDOT) was prepared with the use of polymeric ionic liquid (PIL) as a polymerization template and phase transfer medium. A detailed investigation was performed to understand the role of PIL in the course of polymerization and phase transfer reaction. On the basis of our findings from X‐ray photoelectric spectroscopy (XPS), we propose a mechanism by which the PIL leads to the nanostructured PEDOT colloids in various organic solvents and thus facilitating smoother surface morphologies of the PEDOT‐PIL films. In addition, the enhancement of charge transport was observed for PEDOT‐PIL complex when compared with PEDOT without PIL. Raman spectroscopy indicates that there is a reduced interaction between the charge carriers on the PEDOT and the counter ions bound to PIL, thus promoting charge carrier hopping rates. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6872–6879, 2008 相似文献
104.
105.
106.
Versatile intermediates for the synthesis of C-glycosides and oxygen heterocycles are readily available through titanium mediated methylenation of aldonolactones.Aldonolactones may be alkylated using the titanium carbene complex 2. The resulting enol ethers are of value as potential substrates for glycosidase enzymes. A high yield two step process for alkylation of these enol ethers was described. The products and procedures are relevant to the synthesis of mycotoxins, including citreoviridin and aurovertin B. 相似文献
107.
Kim HJ Kim H Alhakimi G Jeong EJ Thavarajah N Studnicki L Koprianiuk A Lough AJ Suh J Chin J 《Journal of the American Chemical Society》2005,127(47):16370-16371
Crystal structure and activation entropy data indicate that H-bond directed diaza-Cope rearrangement of chiral diimines takes place with a high degree of preorganization. CD spectroscopy and HPLC data show that there is inversion of stereochemistry for the reaction with excellent enantioselectivity. 相似文献
108.
Sec13p has been known as an endoplasmic reticulum-Golgi transport protein. Recently, it has also been shown to be required for the formation of septation in the fission yeast Schizosaccharomyces pombe. In the present study, we focused on the role of a human homolog of Saccharomyces cerevisiae SEC13, Sec13 protein during mitosis in U2OS cells. We found that the expression of Sec13 was constant throughout the cell cycle, and localized to the kinetochores at metaphase during mitosis. By using green fluorescent protein technology, we observed that Sec13 is required for evasion of mitotic arrest in response to spindle damage, leading to G1-like phase and apoptotic cell death. In addition, cells expressing exogenous Sec13 showed giant nuclei compared to endogenous ones in the absence of nocodazole. These results demonstrate that Sec13 is involved in the regulation of the metaphase/anaphase transition and may be functionally associated with mitotic machinery to maintain genomic stability during mitosis. 相似文献
109.
110.
Marten Van Dijk Dwaine Clarke Blaise Gassend G. Edward Suh Srinivas Devadas 《Designs, Codes and Cryptography》2006,39(2):253-273
We present protocols for speeding up fixed-base variable-exponent exponentiation and variable-base fixed-exponent exponentiation
using an untrusted computational resource. In the fixed-base protocols, the exponent may be blinded. In the variable-base
protocols, the base may be blinded. The protocols are described for exponentiation in a cyclic group. We describe how to extend
them to exponentiation modulo an integer where the modulus is the product of primes with single multiplicity. The protocols
provide a speedup of
over the square-and-multiply algorithm, where k is the bitlength of the exponent.
One application of the protocols is to speed up exponentiation-based verification in discrete log-based signature and credential
schemes. The protocols also allow signature verifiers to dynamically choose, for each message, the amount of work it would
like to perform to verify the signature. This results in a work-security tradeoff. We introduce a fifth protocol to perform
variable-base variable- exponent exponentiation, which also has this feature.
Our model allows the trusted resource to perform computations in its idle time. The protocols facilitate the offloading of
work to the offline stage, such that the work the trusted resource performs when it has to do an exponentiation is smaller.
Our protocols are unconditionally secure. 相似文献