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71.
报道从中国南海网胰藻Hydroclathrus clathratus中分离得到3个单体化合物,经过MS,IR,1HNMR,13CNMR(DEPT),HMQC和HMBC等波谱技术鉴定为:(6R,7aS)-6-羟基-4,4,7a-三甲基-2,4,5,6,7,7a-六氢苯并呋喃-2-酮(1),1-(2-脱氧-β-D-呋喃核糖)-5-甲基-1,2,3,4-四氢嘧啶-2,4-二酮(2),尿嘧啶(3),并通过X射线单晶衍射实验确定化合物1的立体结构,其中化合物1是首次从自然界中分离得到. 相似文献
72.
5-Amino-4-cyano-8-isobutyl-7-isopropyl-6-thiocarbamoyl-2-azabicyclo[2.2.2]oct-5-en-3-thione was synthesized by the condensation of isovaleryl aldehyde with cyanothioacetamide. The structure of the product was established by X-ray crystallography. 相似文献
73.
74.
《Journal of separation science》2005,28(13):1457-1466
Comprehensive 2‐D size‐exclusion chromatography (SEC×SEC) has been realized. SEC×SEC is not a useful technique for characterizing complex polymers. However, it is potentially an elegant tool to study band‐broadening phenomena. If narrow fractions can be collected from the first dimension, the band broadening in the second dimension is only due to chromatographic dispersion. This would allow a clear distinction to be made between chromatographic band broadening (column and extra‐column) and SEC selectivity (band broadening due to sample polydispersity). In comparison with MALDI‐MS, SEC×SEC allows the study of polymers across a much broader molar‐mass range. 相似文献
75.
A new synthetic route for the preparation of the betain-like compound (CH3N)6P4F8 from (CH3NPF3)2,N-methyl-hexamethyldisilazane andN,N-dimethyl-urea has been found. The steps of this multi-stage reaction could be rationalized to a far extent.
10. Mitteilung:Kubjacek M., Utvary K., Mh. Chem.112, 305 (1981). 相似文献
76.
Kihyun Cho Jangwon Oh Taewon Lee Dongwook Shin 《Journal of Analytical and Applied Pyrolysis》2007,80(2):502-506
Aerosol flame pyrolysis deposition method was applied to deposit the oxide glass electrolyte film and LiCoO2 cathode for thin film type Li-ion secondary battery. The thicknesses of as-deposited porous LiCoO2 and Li2O–B2O3–P2O5 electrolyte film were about 6 μm and 15 μm, respectively. The deposited LiCoO2 was sintered for 2 min at 700 °C to make partially densified cathode layer, and the deposited Li2O–P2O5–B2O3 glass film completely densified by the sintering at 700 °C for 1 h. After solid state sintering process the thicknesses were reduced to approximately 4 μm and 6 μm, respectively. The cathode and electrolyte layers were deposited by continuous deposition process and integrated into a layer by co-sintering. It was demonstrated that Aerosol flame deposition is one of the good candidates for the fabrication of thin film battery. 相似文献
77.
《Arabian Journal of Chemistry》2022,15(7):103900
Emerging pharmaceutical ingredients (APIs) like sulfamethoxazole (SMX), metronidazole (MNZ) and ciprofloxacin (CIP) are biopersistent and toxic to the environment and public health. In this study, UV/TiO2 photodegradation was applied in the degradation of SMX, MNZ and CIP individually and in a mixture. For a 5 mg/L SMX solution, about 97% of SMX was degraded within 360 min, which was reduced to 80% for 80 mg/L of SMX solution at the same TiO2 dosage and photodegradation time. The maximum removals of MNZ and CIP as individual components were 100% and 89%, respectively at 600 min of photodegradation reaction time. For binary mixtures, the highest removal (100%) was achieved for MNZ and CIP ([MNZ] = [CIP] = 40 mg/L) mixture at 120 min whereas the degradations were 97% and 96% for SMX and MNZ, and SMX and CIP binary mixtures, respectively, even after 600 min of experimental time at the same concentrations. For tertiary mixture, the maximum degradation 99% was observed for (SMX = CIP] = 20 mg/L and [MNZ] = [40 mg/L) at 600 min. The observed reaction rate was 0.01085 min?1 when SMX concentration was 5 mg/L, which decreased to 0.00501 min?1 for SMX concentration of 80 mg/L, indicating decreasing of reaction rate at higher concentration. The results indicate that the UV/TiO2 process is promising to apply for the treatment of pharmaceutical wastewaters. 相似文献
78.
79.
Phase diagrams for cuprates of alkaline earth and rare earth elements are presented, covering binary to quintenary oxides and including selected solid solution series with other elements. Elementary crystal chemical data are included for identification of the occurring phases. Chemical stability is discussed with respect to the high-temperature reactions with Lewis acids like CO2, protons, etc. Particularly the occurrence of oxide carbonates is consistently pointed out as one of the possible reasons for contradictory results in phase diagrams which comprise oxides with high basicity. 相似文献
80.
N. Ya. Grigorieva 《Russian Chemical Bulletin》2005,54(4):1046-1047
High (Z)-stereoselectivity of olefination of methyl α-phenylthioalkyl and methyl α-phenylthioalkenyl ketones with methyl trimethylsilylacetate
decreases in the case of ketones containing a higher alkyl-substituent in place of the methyl group.
Dedicated to Corresponding Member of the Russian Academy of Sciences E. P. Serebryakov on the occasion of his 70th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 1020–1021, April, 2005. 相似文献