排序方式: 共有50条查询结果,搜索用时 15 毫秒
1.
2.
3.
Stasko DJ Perzynski KJ Wasil MA Brodbeck JK Kirschbaum K Kim YW Lind C 《Inorganic chemistry》2004,43(13):3786-3788
The acid H(2)B(12)(OH)(12) can be isolated as a crystalline solid by protonation of the hydroxylated borane anion, B(12)(OH)(12)(2)(-). This acidic compound has low solubility in water, conducts protons in the solid state, and has thermal stability to a temperature of 400 degrees C. The conductivity mechanism is a Grotthuss mechanism with a low activation enthalpy (9-13 kcal/mol). This new acid represents an addition to the class of oxoacids, of which sulfuric and phosphoric acid are the most prominent examples. 相似文献
4.
The amino-derivatized cyclotriveratrylene analogue, triaminotrimethoxytribenzocyclononene [CTV(NH2)3(OMe)3], 1, is readily converted into triply substituted imine compounds [CTV(sal)3(OMe)3], 2, in high yield by treatment of the acid salt of 1 with a variety of substituted salicylaldehydes. Cleavage of the protecting methoxy group generates the tristridentate chelate CTV(sal)3(OH)3, 3, which is readily converted into new rim-metalated species CTV(sal)3(ONiL)3, 4a (a, L = pyrrolidine; b, L = 1-n-butyl-imidazole). Taken together, these results illustrate the remarkable synthetic flexibility that is possible for the CTV-based metal complexes by alteration of the metal, the salicylaldehyde component of the CTV ligand, or the ancillary ligands coordinated to the metal. 相似文献
5.
Patrick J. Fricke Jenna L. Stasko Dylan T. Robbins Alexander C. Gardner Jacqueline Stash Mark J. Ferraro Michael W. Fennie 《Tetrahedron letters》2017,58(48):4510-4513
Propargyl imidates derived from aromatic and aliphatic nitriles cyclize at room temperature in high yields when treated with a catalytic amount of copper (I) iodide. This 5-exo-dig process affords dihydrooxazoles which do not aromatize under the reaction conditions, and which are isolated without chromatography. Investigations of the reaction scope, subsequent functionalization of the reaction products, and preliminary mechanistic data are presented. 相似文献
6.
A new, vectorial approach to fast correlation attacks on binary memoryless combiners is proposed. Instead of individual input sequences or their linear combinations, the new attack is targeting subsets of input sequences as a whole thus exploiting the full correlation between the chosen subset and the output sequence. In particular, the set of all the input sequences can be chosen as the target. The attack is based on a novel iterative probabilistic algorithm which is also applicable to general memoryless combiners over finite fields or finite rings. To illustrate the effectiveness of the introduced approach, experimental results obtained for random balanced combining functions are presentedMost of this work was done while he was with Rome CryptoDesign Center, Gemplus, Italy 相似文献
7.
The motion of a holonomic scleronomic non-conservative mechanicalsystem with minimal dissipation is considered. As applicationsof the theory several problems are studied in detail. 相似文献
8.
A Mukherjee M Dasgupta DJ Hinde CR Morton AC Berriman RD Butt JO Newton H Timmers 《Pramana》2001,57(1):195-198
Fusion cross-sections for the 7Li + 12C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy
evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their
contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections
due to the breakup of 7Li may not be significant for 7Li + 12C reaction at energies around the barrier. 相似文献
9.
The alternating step generator is a well-known keystream generator consisting of two stop/go clocked LFSRs, LFSR1 and LFSR2, whose clocks are controlled by another LFSR, LFSR3, which is clocked regularly. A probabilistic analysis of this generator is conducted which shows that the posterior probabilites of individual bits of the first derivatives of the regularly clocked LFSR1 and LFSR2 sequences, when conditioned on a given segment of the first derivative of the keystream sequence, can be computed efficiently in a number of probabilistic models of interest. The expected values of these probabilities, for a random keystream sequence, are derived by an approximate theoretical analysis and are also verified by systematic computer experiments. It is pointed out that these posterior probabilities can be enhanced in a resynchronization scenario and thus used for a low-complexity fast correlation attack on the two LFSRs. More generally, it is argued that even without resynchronization these probabilities may be significantly different from one half for fast correlation attacks based on iterative decoding algorithms to be successful, although with incresead complexity. A related method for computing the posterior probabilities of individual bits of the LFSR3 sequence, when conditioned on both the keystream sequence and the LFSR1 and LFSR2 sequences, is also developed. As these posterior probabilities are much more different from one half, they can be used for a low-complexity fast correlation attack on LFSR3, provided that the initial states of LFSR1 and LFSR2 are previously reconstructed. 相似文献
10.