共查询到20条相似文献,搜索用时 109 毫秒
1.
结晶紫内酯(CVL)的合成方法一般是先合成无色结晶紫内酯(LCVL),然后把LCVL氧化为CVL.本文对近年来合成LCVL和LCVL氧化为CVL的方法进行了综述. 相似文献
2.
Chun Yang Gongfeng Xu Bin Liu Qinglun Wang Daizheng Liao 《Frontiers of Chemistry in China》2008,3(3):294-297
The bimetallic complex of Ni2Co(TTHA)·12H2O (TTHA = triethylene tetraminehexaacetic acid) was synthesized and characterized structurally and magnetically. The title
complex crystallizes in the triclinic space group P ī with a = 0.7316(2), b = 0.8624(2), c = 1.5041(4) nm; α = 73.38(2), β = 83.97(2), γ = 70.50(2)°. The crystal structure is built up of [Ni2(TTHA)(H2O)2]2−, Co(H2O)62+ and water molecules. The variable magnetic measurement shows that there is strong antiferromagnetic interaction between two
Ni(II) ions in [Ni2(TTHA) (H2O)2]2− with J
Ni−Ni = −141.64 cm−1, g
Ni = 2.21 and that the constant of spin-orbit coupling of Co(II) ion is −134.8 cm−1.
__________
Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis, 2007, 40(1): 6–10 [译自: 南开大学学报(自然科学版)] 相似文献
3.
CdS semiconductor nano-films were grown on ITO glass substrates by means of chemical bath deposition (CBD), with Cd(NO3)2 as Cd ion and (NH2)2CS as S ion sources. The concentration of Cd ions, deposition temperature, deposition time and post-treatment temperature
have an impact on the formation of CdS nano-films. UV-vis absorption spectrum and atomic force microscope (AFM) images indicated
that the change of concentration and post-treatment temperature may adjust the band-gap of CdS to obtain stable, homogeneous
and compact films. Formation mechanism of the crystal nucleus and CdS film was also discussed. Active sites on the surface
of ITO are critical to the formation of the crystal nucleus and a uniform and compact CdS nano-film. The active site and crystal
nucleus are formed due to the comprehensive effect of electricity, thermodynamics and chemistry.
__________
Translated from Journal of Jilin University (Science Edition), 2007, 45(1): 116–120 [译自: 吉林大学学报(自然科学版)] 相似文献
4.
The ZnO films with two-dimensional ordered macroporous structure were successfully fabricated through hydrothermal crystal
growth of ZnO on the ZnO substrate covered with a monolayer of polystyrene (PS) spheres as template. The precursor solution
of hydrothermal crystal growth of ZnO were prepared by equimolar solution of Zn(NO3)2·6H2O and hexamethylenetramine (HMT). The confinement effect of the PS spheres template on the growth of ZnO nanorods and the
influence of sodium citrate on the crystal growth of ZnO had been studied. The film surface morphology and the preferential
growth of ZnO crystal were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Also,
the photoluminescence spectrum of ZnO films had been measured, and the corresponding mechanism was discussed.
__________
Translated from Chemistry, 2007, 70 (8): 587–592 [译自: 化学通报] 相似文献
5.
铕-结晶紫缔合物分光光度法测定痕量铕 总被引:1,自引:0,他引:1
在碱性(pH10.10)条件下,铕(Ⅲ)与结晶紫形成缔合物,表观摩尔系数为=1.8×105L/(mol.cm),铕的浓度在0.15~1.2mg/l范围内遵守比耳定律,组成摩尔比为Eu∶CV=1∶2. 相似文献
6.
Huixue Ren Yanzhao Yang Jimao Lin Yinshan Qi Yeqing Zhang 《Frontiers of Chemistry in China》2008,3(2):152-156
A new synthetic method for 5-bromo-3-sec-butyl-6-methyluracil (Bromacil) using 2-bromobutane and urea as starting materials is described. The synthesis involved condensation,
cyclization and bromination with a total yield of 60%. The structure of Bromacil was determined by 1H NMR, 13C NMR and IR spectroscopy.
__________
Translated from Journal of Shandong University (Natural Science Edition), 2007, 42(7): 9–12 [译自: 山东大学学报(自然科学版)] 相似文献
7.
Xianru Pei Xiaodong Wang Shunli Zhang Jingwei Zhang Jianjun Yang Zhensheng Jin 《Frontiers of Chemistry in China》2007,2(3):265-269
Nanotube Li-Ti-O compound with high surface (198.6 m2·g−1) was prepared by a method involving the treatment of nanotube Na2Ti2O5·H2O in molten LiNO3 and characterization by means of transmission electron microscopy (TEM), energy-dispersive spectra (EDS), X-ray diffraction
(XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetry-differential thermal analysis (TG/DTG). Results show that
the nanotube Li-Ti-O compound prepared by this method involves two crystal phases: spinel Li2Ti2O4 and anatase LixTiO2 (x < 0.1). Li+ exhibits different Li1s binding energy in the two crystal phases. In ambient air, the Li-Ti-O compound adsorbs water easily,
and the chemically adsorbed water is difficult to remove below 400°C.
Translated from Chinese Journal of Inorganic Chemistry, 2006, 22(12): 2135–2139 [译自: 无机化学学报] 相似文献
8.
Yuanlin Ren Bowen Cheng Jinshu Zhang Hongjun Zang Weimin Kang Changkun Ding 《Frontiers of Chemistry in China》2008,3(3):304-308
The title compound N,N′-di(diethoxythiophosphoryl)-1,4-phenyl-enediamine was synthesized by the reaction of diethoxythiophosphoryl chloride with
p-phenylenediamine and characterized by elemental analysis, IR, and 1H NMR spectra. Its crystal structure was determined by X-ray diffraction analysis and the thermal property was studied by
TG analysis. The relative molecular weight of the title compound is 412.42. The crystal structure belongs to the orthorhombic,
Pbca space group, with a = 0.86936(16) nm, b = 1.2787(2) nm, c = 1.8897(3) nm, β = 90°, V = 2.1006(7) nm3, Z = 8, Dc = 1.304 g/cm3, μ(Mo Kα) = 0.425 mm−1, F(000) = 872, S = 1.052, the final R = 0.0628 and wR = 0.1860 for 1852 observed reflections with I>2σ(I). The X-ray diffraction analysis demonstrates that the crystal structure is centrosymmetric. The weak N-H⋯S intramolecular
hydrogen bonds were observed to link the molecules into sheets. The TG analysis shows that the title compound has good thermal
stability and char forming capability and its fire retardation for polyacrylonitrile reveals that the compound is an excellent
intumescent fire retardant.
__________
Translated from Acta Chimica Sinica, 2007, 65(18): 2034–2038 [译自: 化学学报] 相似文献
9.
The synthesis of the first two arylenealkyne conjugated macrocycles containing a long alkylene bridge via Glaser coupling of template-directed tetraacetylenes was reported. Tetraacetylene intermediates with complex structures were
constructed rapidly via quadruple Hagihara coupling of monoprotected bisacetylenes to appropriate tetraiodides and subsequent desilylation. The characterization
of such compounds was carried out by NMR, GPC and UV-Vis spectra. Unfortunately, the two compounds were not liquid crystals
and had no biaxial nematic mesophase character as expected.
__________
Translated from Chemical Journal of Chinese Universities, 2007, 28(1): 65–70 [译自: 高等学校化学学报] 相似文献
10.
Sr2CeO4/Ln3+ (Ln = Er, Ho, Tm) phosphors were synthesized with the microwave radiation method for the first time. The luminescent properties
of the samples were investigated and the up-conversion luminescence of Er3+, Ho3+ and Tm3+ doped Sr2CeO4 phosphors was observed. The spectra indicate that the energy transfer takes place from the triplet excited state of MLCT
(metal-to-ligand charge transfer) state for Sr2CeO4 (sensitizer) to the rare earth ions (activator).
__________
Translated from Journal of Hebei Normal University (Natural Science Edition), 2007, 31(2): 212–216 [译自: 河北师范大学学报 (自然科学版)] 相似文献
11.
Yingpin Li Xiaoquan Zhou Huijing Zhou Zhurui Shen Tiehong Chen 《Frontiers of Chemistry in China》2008,3(2):128-132
Manganese dioxides with various morphologies were prepared using a common hydrothermalmethod without any templates or additives.
The evolution of the morphology was accompanied by the gradual conversion of the polymorphic forms from γ-type to β-type. Meanwhile, MnO2 microspheres, urchin-like nanostructures and nanowires were successfully synthesized. The products were characterized by
X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope. The
evolution process can be explained by the Ostwald Ripening mechanism.
__________
Translated from Chinese Journal of Chinese Universities 28(7): 1223–1226 [译自: 高等学校化学学报] 相似文献
12.
The electrochemical behavior of ciprofloxacin (CFX) and its interaction with the natural calf thymus DNA (ctDNA) is studied
by using pulse difference voltammetry on a carbon electrode. CFX shows a well-defined oxidative peak at + 0.88 V. As a result
of reaction with ctDNA,the oxidative peak of CFX decreased markedly. According to the electrochemical equation deduced in
this paper, the binding constant of 1.36 × 105 (mol/L)−1 and the binding size of 1.94 (base pairs) of CFX with ctDNA were obtained by nonlinear fit analysis of the electrochemical
data. The mechanism of the interaction was explored.
__________
Translated from Journal of Zhejiang University (Science Edition), 2007, 34(3): 330–334 [译自: 浙江大学学报(自然科学版)] 相似文献
13.
ZrWMoO8 powders with different morphologies were obtained using ammonium tungstate, molybdate tungstate and zirconium tungstate as
the starting materials by dehydrating the precursor ZrWMoO7(OH)2(H2O)2. The precursor was studied by thermo-gravimetric and differential scanning calorimetry (TG-DSC). The influence of the gelling
agents (HCl, HClO4, HNO3, H2SO4 and H3PO4) on the crystallization process and crystal morphology of the products prepared was investigated by X-ray powder diffraction
(XRD), scanning electron micrograph (SEM) and X-ray fluorescence spectrometer (XRF). Results showed that the morphology of
the ZrWMoO8 particles can be simply adjusted by changing the gelling agents, and the thermal expansion coefficients of cubic ZrWMoO8 prepared in HCl solution are −3.84 × 10−6 K−1 from 100°C to 700°C.
__________
Translated from Chemical Journal of Chinese University, 2007, 28(3): 397–401 [译自: 高等学校化学学报] 相似文献
14.
Bitao Su Ke Wang Jie Bai Hongmei Mu Yongchun Tong Shixiong Min Shixiong She Ziqiang Lei 《Frontiers of Chemistry in China》2007,2(4):364-368
Fe3+-doped TiO2 composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized
by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultravioletvisible spectroscopy (UV-Vis) diffuse reflectance
spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic
activity of Fe3+/TiO2 nanoparticles under visible light irradiation. The influence of doping amount of Fe3+ (ω: 0.00%–3.00%) on photocatalytic activities of TiO2 was investigated. Results show that the size of Fe3+/TiO2 particles decreases with the increase of the amount of Fe3+ and their absorption spectra are broaden and absorption intensities are also increased. Doping Fe3+ can control the conversion of TiO2 from anatase to rutile. The doping amount of Fe3+ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The
appropriate doping of Fe3+ can markedly increase the catalytic activity of TiO2 under visible light irradiation.
__________
Translated from Journal of Northwest Normal University (Natural Science), 2006, 42(6): 55–56 [译自: 西北师范大学学报(自然科学版)] 相似文献
15.
Xiaofeng Zhang Shen Lin Xinqing Chen Jiebo Chen Liuyi Yang Minghong Luo 《Frontiers of Chemistry in China》2007,2(4):419-421
Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier
transform infrared spectrometer (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption/desorption methods. Results show that the title compound exhibits a typical mesoporous structure with the average
pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed.
__________
Translated from Journal of Fujian Normal University (Natural Science Edition), 2007, 23(2): 67–70 [译自: 福建师范大学学报 (自然科学版)] 相似文献
16.
The hydrophobic formation cationic starch (PSOAMDA) was prepared from starch (St), octadecyl acrylate (OA), acrylamide (AM)
and dimethyl diallyl ammonium chloride (DMDAAC) by means of inverse suspension polymerization with redox initiator. Water
with algae from Dianchi Lake was tested with PSOAMDA. Results show that when the molar ratio of St: AM: DMDAAC: OA is 4:8:1.5:0.6
and the reaction temperature is 40°C with a reaction time of 3 h, the monomer conversion yield, graft percentage and cationic
degree is 92.4%, 63.8% and 7.3%, respectively, and M
η = 3.26×106 g/vmol. It had been found from the flocculation of disposed water with algae from Dianchi Lake that the transparency and
COD elimination reach to 93.5% and 70.3%, respectively, with 15 mg/L PSOAMDA and at pH 6, vs. 91.3% and 69.2% obtained with
the commercial cationic polyacrylamide (PAM-C). When PSOAMDA dosage is 10–25 mg/L and the pH of aqueous solution is 6–10,
the flocculation performance is well capable of dealing with the water with algae from Dianchi Lake.
__________
Translated from Journal of Yunnan University (Natural Sciences Edition), 2007, 29(2): 177–182 [译自: 云南大学学报(自然科学版)] 相似文献
17.
Linbo Gong Shuling Gong Haiqing Dong Chunlei Zhang Yuanyin Chen 《Frontiers of Chemistry in China》2007,2(3):292-295
The reaction of 4′-hydroxy-4-methyl azobenzene (1) and 1,6-dibromohexane afforded 6-bromo-1-((4-((4-met hylphenyl)azo)phenyl)oxy)hexane (2), which further reacted with p-tert-butylcalix[4]arene to give the calix[4]arene derivative (3) whose lower rim had been modified by the azobenzene photochromic group. The structure of 3 was characterized by 1H-nuclear magnetic resonance (NMR) and electrospray ionization-mass spectrometry (ESI-MS). The fluorescence intensity of compound
3 was two to four times higher than that of compounds 1 and 2 as the azobenzene group concentration in the range of 1.6 × 10−5 to 8.0 × 10−4 mol/L, indicating that the fluorescence quantum yield of the azobenzene group had been improved through being attached to
the calix[4]arene skeleton. The liquid crystalline behavior of compound 3 was studied by polarized microscopy (POM) and differential scan calorimeter (DSC). Compound 3 exhibited the enchased texture of a smectic liquid crystal from 209.4°C to 219.5°C on heating, while 2 exhibited a liquid crystalline phase from 87.4 to 83.2°C on cooling. It was found that the calix[4]arene skeleton was a good
platform for conformation immobilization of azobenzene photochromic group and the formation of liquid crystalline.
Translated from Chinese Journal of Applied Chemistry, 2006, 23(9): 1023–1026 [译自: 应用化学] 相似文献
18.
A small molecule (GMS-SA2) with one alkyl chain and two terminal carboxyl groups was synthesized successfully by the reaction of glyceryl monostearate
(GMS) with excess succinic anhydride (SA). Then, GMS-SA2 was used as a coupling agent to condensate with polyethylene glycols (PEG) of different molecular weight or polyethylene
glycol monomethyl ether (PEGm) in the presence of stannous octoate as catalyst and diphenyl ether as azeotropic agent. The
AB2 star-shaped miktoarm copolymers were obtained successfully and were characterized by 1H-NMR, DSC, GPC, XRD, FTIR and polarizing microscopy. The results of DSC and XRD measurements indicate that the crystallization
temperature and the melting temperature of the AB2 star-shaped miktoarm copolymers are different from those of the corresponding linear PEGs, because the existing of GMS-SA2 alters their crystalline growth velocity and the perfect degree of crystals. It is very important to control the crystal
morphology of star-shaped copolymers by introducing the miktoarm into the starshaped polymers and adjusting its content in
star-shaped polymers.
__________
Translated from Chemical Journal of Chinese Universities, 2007, 28(7): 1365–1370 [译自: 高等学校化学学报] 相似文献
19.
Lei Shi Kaoshan Chen Qun Dong Jinian Fang Kan Ding 《Frontiers of Chemistry in China》2008,3(2):209-212
A water-soluble polysaccharide (CPS-0) was obtained from the root of Cudrania tricuspidata (Carr.) Bur., by hot water extraction (70°C), deproteination using enzymolysis and Sevag method, precipitation with ethanol,
and fractionation through DEAE-Sephadex A-50 chromatography. The purity of CPS-0 was determined by HPLC and the structure
was elucidated by monosaccharide composition analysis, methylation analysis, GC, GC-MS, NMR spectral (1H-NMR, 13C-NMR, HMQC), UV, IR, and elemental analysis. The CPS-0 was found to contain glucose residues only. The average repeating
unit is a decasaccharide having a backbone consisting of 1,4-linked α-D-glucopyranosyl residues to which the side chain consisting of terminal and 1,4-linked α-D-glucopyranosyl residues was attached at position 6 of the branching residues.
__________
Translated from Chemical Journal of Chinese Universities, 2007, 28(6): 1088–1091 [译自: 高等学校化学学报] 相似文献
20.
The preparation of CdSe nanospheres (ns-CdSe) and their application as electron acceptor in conjugated polymer photovoltaic
devices are reported. ns-CdSe with diameters of 5 nm were prepared through an organometallic method. The transmission electron
microscopy (TEM), ultraviolet-visible (UV-Vis) absorption and photoluminescence (PL) spectra indicate that the CdSe nanocrystals
(NCs) are monodispersed nanospheres with the first exciton absorption peak at around 625 nm and the emission peak at around
652 nm. The PL spectra of the ns-CdSe/polymer composite films show that the PL of the conjugated polymers is effectively quenched
upon the addition of ns-CdSe. Photovoltaic devices were fabricated from the composites of ns-CdSe and poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene]
(MEH-PPV) or poly(3-hexylthiophene) (P3HT). Under AM1.5 illumination (100 mW/cm2), the short circuit current (I
SC), open circuit voltage (V
OC), fill factor (FF) and energy conversion efficiency (η) reached 1.56 mA/cm2, 0.75 V, 34.5% and 0.40%, respectively for device from the ns-CdSe/MEH-PPV (15: 1 by weight) and 1.93 mA/cm2, 0.65 V, 38.4% and 0.48%, respectively for device from the ns-CdSe/P3HT (10: 1 by weight).
__________
Translated from Chemical Journal of Chinese Universities, 2007, 28(3): 596–599 [译自: 高等学校化学学报] 相似文献