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排序方式: 共有132条查询结果,搜索用时 15 毫秒
1.
N. I. Golovina G. N. Nechiporenko G. G. Nemtsev G. P. Dolganova V. P. Roshchupkin D. B. Lempert G. B. Manelis 《Russian Journal of Applied Chemistry》2007,80(1):24-30
Methods for phase stabilization of ammonium nitrate were sought for in order to considerably expand the application area of this oxidizing agent in various-purpose self-combustible formulations, including that in a new generation of gas-generating formulations for automobile air bags. New methods for stabilization of ammonium nitrate were studied and, in particular, a search was made for organic compounds that can stabilize ammonium nitrate even at their low content. The mechanism of phase state stabilization of ammonium nitrate by compounds of this kind was examined. 相似文献
2.
3.
Zusammenfassung Bei der Einwirkung von Bromcyan auf überschüssige Anthranilsäure wird nicht N,N-Diphenyl-guanidin-o,o-dicarbonsäure (II), sondern N-(2-Ureido-benzoyl)-anthranilsäure (V) gebildet. Diese läßt sich sowohl zu 1,2,3,4-Tetrahydro-chinazolindion-(2,4) (III), als auch zu ihrem 3-(2-Carboxy-phenyl)-Derivat (VI) cyclisieren. 相似文献
4.
We present a new set of V–V rate coefficients for vibrational levels 0–5 in H2 at 300 K, measured using a stimulated Raman–spontaneous Raman pump/probe apparatus. The measured rate of the non-resonant process, H2(v = 1) + H2(v = 1) → H2(v = 0) + H2(v = 2), is consistent with the previously reported experimental value of Kreutz et al. However, semi-classical predictions of such non-resonant processes, using the identical inter-molecular potential and methodology to that given by Cacciatore and Billing, results in rates which are too slow, by a factor of approximately 3. For the “resonant” V–V process, H2(v = 1) + H2(v = 0) → H2(v = 0) + H2(v = 1), the semi-classical rate is found to be too slow by an even larger factor, of approximately 30, compared to the experimental rate, but consistent with the previously reported experimental result of Farrow and Chandler. Further, unlike the semi-classical model prediction in which the (1, 1 → 2, 0) process rate is predicted to exceed that of the (1, 0 → 0, 1) process, the experimental data shows it to be a factor of approximately 2.5 less, suggesting that semi-classical methods that treat the rotational motion classically are unsuitable for the highly anharmonic H2 molecule. The ratio of pure rotation and rotation–vibration Raman cross sections for scattering from levels 0 and 1 is also determined, with results which agree with calculations of Schwartz and LeRoy, but are somewhat larger than previous experimental results of Cureton. 相似文献
5.
B. ÁgaiK. Lempert 《Tetrahedron》1972,28(7):2069-2084
Three methods have been developed for the synthesis of N-acyl- and N-sulfonyl-aminoisoquinolinium chlorides (6) and the corresponding dipolar bases (7): (1) ring closures of N-acyl- and N-sulfonyl-N-{2-[β-(2,4-dinitranilino)vinyl]benzylidene}hydrazines(5β), (2) acylation of N-aminoisoquinolinium chloride (6a) and (3) transacylations of N-(2-isoquinolinio)-ethoxycarbonylamidate (7i). IR and NMR spectra as well as some reactions of compounds 7 are discussed. 相似文献
6.
Gyula Simig Gábor Doleschall Gyula Hornyák József Fetter Károly Lempert József Nyitrai Péter Huszthy Tibor Gizur Mária Kajtár-Peredy 《Tetrahedron》1985,41(2):479-484
Acylation of the N-substituted diethyl aminomalonates 3a–3d with diketene furnished the ring tautomers 6a–6d of the expected acetoacetyl derivatives 5. By treatment with iodine and sodium ethoxide compounds 6a–6d are smoothly converted into the β-lactam derivatives 2a–2d. Deethoxycarbonylation of the ethylene ketals 7a–7d of the latter furnishes mixtures of the corresponding diastereomeric monoesters 8 and10. The ethoxycarbonyl groups of the trans esters 8 are more reactive than those of the cis isomers 10. This permits, under appropriate conditions, selective alkaline hydrolysis and NaBH4 reduction of the trans esters 8 in the presence of the cis esters 10. Reduction of the cis ester 10c under more forceful conditions furnishes the trans hydroxymethyl derivative 11c. 相似文献
7.
8.
For a large class of separable Banach spaces we prove the following. Given a pseudoconvex open and that is locally bounded above, there is a plurisubharmonic such that . We also discuss applications of this result.
9.
The existence and uniqueness theorems for solutions in the class of analytic functions were proved for two generalized Cauchy
problems with conditions imposed on two surfaces. Using the theorems proved, implicit difference schemes are constructed for
the numerical solution. A program was designed, and the corresponding numerical calculations were performed. 相似文献
10.
A H Suter B L Lempert J R Franks 《The Journal of the Acoustical Society of America》1990,87(5):2114-2117
Many of the 9 million workers exposed to average noise levels of 85 dB (A) and above are required to wear hearing protection devices, and many of these workers have already developed noise-induced hearing impairments. There is some evidence in the literature that hearing-impaired users may not receive as much attenuation from hearing protectors as normal-hearing users. This study assessed real-ear attenuation at threshold for ten normal-hearing and ten hearing-impaired subjects using a set of David Clark 10A earmuffs. Testing procedures followed the specifications of ANSI S12.6-1984. The results showed that the hearing-impaired subjects received slightly more attenuation than the normal-hearing subjects at all frequencies, but these differences were not statistically significant. These results provide additional support to the finding that hearing protection devices are capable of providing as much attenuation to hearing-impaired users as they do to normal-hearing individuals. 相似文献