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11.
Li Zenghu 《数学物理学报(B辑英文版)》1999,19(2):121-126
The author proves a central limit theorem for the critical super Brownian motion, which leads to a Gaussian random field. In the transient case the limitingfield is the same as that obtained by Dawson (1977). In the recurrent case it is aspatially uniform field. The author also give a central limit theorem for the weightedoccupation time of the super Brownian motion with underlying dimension numberd 3, completing the results of Iscoe (1986). 相似文献
12.
C. F. Capello G. S. Parks G. E. Warren E. S. Greene und E. M. Herrick 《Fresenius' Journal of Analytical Chemistry》1936,106(7-8):281
Ohne Zusammenfassung 相似文献
13.
Richard S Herrick Christopher J Ziegler Mark Eskander Naomi McMicken 《Journal of organometallic chemistry》2003,687(1):178-184
The title compounds were prepared by heating solutions of ester protected amino acids (H-l-Ala-OEt, H-β-Ala-OEt, H-l-Val-OMe, GABA-OMe, H-l-Asp(OMe)-OMe) and glyoxal in the presence of M(CO)4(pip)2 (M=Mo, W). The resulting novel complexes, M(CO)4(dab-xxx-OR) (dab=diazabutadiene), contain an N,N′-diimine ligand and were characterized by 1H- and 13C-NMR, IR, and UV-vis measurements. The low energy band in the visible portion of the electronic spectrum is assigned to a MLCT transition and exhibits solvatochromism. The valine, alanine and aspartic ester derivatives have C2 symmetry resulting from the C2 symmetry of the ligand. The reaction of the alanine and aspartic amino esters in the presence of NEt3 produces diastereomeric mixtures caused by racemization at the amino acid α-carbon. Racemization is not observed during the formation of the valine derivatives. The crystal structures of (R,S)-Mo(CO)4(dab-asp(OMe)-OMe) (5-RS), and (S,S)-Mo(CO)4(dab-asp(OMe)-OMe) (5-SS), were determined. The structure of 5-RS confirms that racemization at the α-carbon occurred. 5-SS has C2 symmetry. 相似文献
14.
独居石微晶玻璃中玻璃相含量的红外光谱定量测定 总被引:2,自引:0,他引:2
独居石微晶玻璃由偏磷酸盐玻璃和独居石两相组成。玻璃和独居石的红外吸收谱带彼此不相重叠,且1275和616cm~(-1)谱带的吸收强度随玻璃相的含量变化而变化。两谱带的对数吸光度比值与玻璃相含量(w%)的相关系数r=0.9975,其回归方程为y=48.356 25.93x。合成独居石的IR谱中952和616cm~(-1)谱带的吸光度比值也随不同的Ce_2O_3/La_2O_3比值规律变化。其r=0.9917,回归方程为y=0.2211exp(0.0221x)。高的相关性表明IR技术可在磷酸盐微晶玻璃物相定量分析中得到实际应用。 相似文献
15.
Harvey JD Shaw JL Herrick RS Ziegler CJ 《Chemical communications (Cambridge, England)》2005,(37):4663-4665
We have synthesized the first early transition metal N-confused porphyrin complex Mo(NCTPP)(pip)2; this species is isostructural to its normal porphyrin analog Mo(TPP)(pip)2 but exhibits significant electronic differences arising from the inversion of a single pyrrolic group. 相似文献
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17.
Franklin BR Herrick RS Ziegler CJ Cetin A Barone N Condon LR 《Inorganic chemistry》2008,47(13):5902-5909
The reactions of ammonia, pyridine (py), N-methyl imidazole (N-MeIm), tetrahydrothiophene (tht), and piperidine (pip) with Re(CO) 3(H 2O) 3 (+), 1 ( + ), were investigated employing aqueous conditions under atmospheric dioxygen. The reaction of [ 1]Br in aqueous ammonia led to [Re(CO) 3(NH 3) 3]Br ([ 2]Br) as the only product isolated. For the aqueous reactions of [ 1]Br with py, N-MeIm, and tht, mixtures of products are formed because of competition between the bromide and added ligand, even when the ligand is present in excess. Substitution of the PF 6 (-) anion for Br (-) leads to the clean formation of [Re(CO) 3L 3][PF 6] ([ 3][PF 6]-[ 5][PF 6]) for py, N-MeIm, and tht, respectively, as the only products observed. Reaction of [ 1][PF 6] with pip produces the dimeric species, (pip)(CO) 3Re(micro-OH) 2Re(CO) 3(pip), 6. Reactions of [ 1]Br were also performed in methanol for comparison purposes. The reaction with pip in this solvent led to the analogous dimer, (pip)(CO) 3Re(micro-OMe) 2Re(CO) 3(pip), 7; however, reactions with py, N-MeIm, and tht gave Re(CO) 3L 2Br, 8- 10, respectively, as the only products. The crystal structures of compounds [ 2]Br- 10 are reported. 相似文献
18.
Magnus Pfaffenbach Ian Bakanas Nicholas R. O'Connor Jessica L. Herrick Richmond Sarpong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15448-15452
Divergent and enantiospecific total syntheses of the indolosesquiterpenoids xiamycins A, C, F, H and oridamycin A have been accomplished. The syntheses, which commence from (R)‐carvone, employ a key photoinduced benzannulation sequence to forge the carbazole moiety characteristic of these natural products. Late‐stage diversification from a common intermediate enabled the first syntheses of xiamycins C and F, and an unexpected one‐pot oxidative decarboxylation, which may prove general, led to xiamycin H. All synthetic intermediates and the natural products were tested for anti‐fungal activity. Xiamycin H emerged as an inhibitor of three agriculturally relevant fungal pathogens. 相似文献
19.
The complexes [M(CO)4(pyridyl‐CH=N‐CHRCO2R′)] (M = Cr, Mo; R = H, CH3, CH(CH3)2, CH2CH(CH3)2) were obtained by reaction of the Schiff bases from pyridine‐2‐carboxaldehyde and glycine, L‐alanine, L‐valine or L‐leucine esters with the norbornadiene complexes [M(CO)4(nbd)] and were characterized by IR, 1H and 13C NMR and UV‐vis spectra. The deeply colored complexes exhibit solvatochromism. 相似文献
20.
Reactions of arc-generated carbon atoms with acyl chlorides proceed by two distinct mechanistic pathways depending on the nature of the alkyl group in the substrate. Acetyl chloride affords vinyl chloride from the putative chloromethylcarbene produced by deoxygenation, whereas pivaloyl chloride gives t-butyl chloride as the predominant product via a chain reaction from the initially generated pivaloyl radical. When the alkyl group is isopropyl, both pathways are implicated. 相似文献