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971.
In this paper,large-sized sapphire (230×210 mm,27.5 kg) was grown by SAPMAC method (sapphire growth technique with micro-pulling and shoulder-expanding at the cooled center). Dislocation peculiarity in large sapphire boule (0001) basal plane was investigated by chemical etching,scanning electron microscopy and X-ray topography method. The triangular dislocation etch pit measured is 7.6×101~8.0×102 cm-2,in which relative high-density dislocations were generated at both initial and final stages of crystal growth. The analysis of single-crystal X-ray topography shows that there are no apparent sub-grain boundaries; the dislocation lines are isolated and straight. Finally,the origins of low-density dislocation in sapphire crystal are discussed by numerical analysis method. 相似文献
972.
A MET-OH derivative,MET-OTs 1,was designed,prepared and structurally charac-terized by single-crystal X-ray diffraction. X-ray structure analysis reveals that 1 crystallizes in the monoclinic system,space group P21/c,with a=16.1178(14),b=7.5473(6),c=13.4161(11),V= 1520.3(2)3,β=111.3210(10)o,Z=4,Dc=1.421 g/cm3 and F(000)=680. 相似文献
973.
974.
利用扫描电子显微镜(SEM)和X射线能谱仪(EDS)对聚丙烯/聚氯乙烯(PP80/PVC20)二元体系,以及聚丙烯多单体接枝物[PP-g-(St-co-MMA)]/PP/PVC三元体系的相容性进行了研究。由X射线能谱微区分析得到了共混物中氯元素面分布图。对氯元素面分布进行了粒径分布统计和面积计算。实验结果表明:在PP80/PVC20共混物100份中加入6份PP-g-(St-co-MMA)增容剂时,增容效果最好;进一步增加PP-g-(St-co-MMA)含量时,PP/PVC的相容性反而降低。差示扫描量热仪(DSC)的实验结果也佐证了SEM和EDS的实验结果。 相似文献
975.
I. G. Filippova Yu. A. Simonov M. Gdanets V. Stavila 《Journal of Structural Chemistry》2005,46(6):1095-1098
The structure of tris(1,10-phenanthroline)iron(II) dinitrate dihydrate [Fe(phen)3](NO3)2·2H2O was established by X-ray diffraction analysis. The role of hydrogen bonds in crystal packing is discussed. 相似文献
976.
N. V. Kozak Yu. N. Nizel'skii L. F. Kosyanchuk S. D. Nesin 《Theoretical and Experimental Chemistry》2005,41(4):265-270
The influence of the nature of the central ion [Cu(2+), Cr(3+), Fe(3+)] of the chelate compound on the possibility of interaction
of the metal-containing modifier with one or both of the components of the incompatible PU/PMMA system was studied by the
ESR method. It was shown by low-angle X-ray diffraction that the change in the degree of microheterogeneity of the semi-IPN
correlated with the characteristics of complex forming metal and the polymer matrix.
__________
Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 4, pp. 252–256, July–August, 2005. 相似文献
977.
D. P. Krutko M. V. Borzov E. N. Veksler A. V. Churakov 《Russian Chemical Bulletin》2005,54(1):117-123
The intracomplex conversion of (2-diphenylphosphanoethyl)cyclopentadienyl zirconium and titanium complexes into the corresponding 2-phosphinothioyl and 2-phosphinoyl derivatives, viz., (η5-C5H5)[η 5-C5H4CH2CH2P(S)Ph2]ZrCl2, [η5-C5H4CH2CH2P(S)Ph2]ZrCl3, [η5:η1C5H4CH2CH2P(O)Ph2]ZrCl3·THF, and [η5:η 1-C5H4CH2CH2P(O)Ph2]TiCl3 (7), was performed. The NMR spectroscopy data revealed the following order of the coordination ability of the functional groups with respect to the Zr center: Ph2P=O > Ph2P > Ph2P=S. An analogous order was found for the monodentate ligands (Ph3P=O > Ph3P > Ph3P=S) with respect to (η5-C5H5)ZrCl3. The molecular structure of complex 7 was established by X-ray diffraction analysis. Coordination of the Ph2P=O group to the titanium atom was found retained both in the crystalline state and solution.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 116–122, January, 2005. 相似文献
978.
979.
Substituted μ3-carbido-capped tricobalt carbonyl clusters have been synthesised by reaction of [Co3(μ3-C(O)OCH2CHCH2)(CO)9] with a range of monodentate and chelating phosphane ligands. The products have been characterised by microanalysis, IR and NMR spectroscopy, mass spectrometry and, in the case of [Co3(μ3-CR)(CO)7(dppe)], [Co3(μ3-CR)(CO)7(dppm)], [Co3(μ3-CR)(CO)7(PPh3)2], [Co3(μ3-CR)(CO)7(PMe3)2] and [Co3(μ3-CR)(CO)6(PEt3)3] (R=C(O)OCH2CHCH2), single crystal X-ray diffraction. 相似文献
980.
The vesicle system consisting of 80 mol% dipalmitoylphosphatidylethanolamine (DPPE) and 20 mol% dipalmitoylphosphatidylglycerol (DPPG) undergoes to structural changes caused by various concentrations of Salmonella minnesota R595 lipopolysaccharide (LPS). The phenomenon was investigated by methods applying small- and wide-angle X-ray scattering (SAXS and WAXS), calorimetry (DSC) and freeze-fracture. In the low LPS concentration regime (investigated at 0.02 LPS/DPPE–DPPG molar ratio) a phase separation was observed. Two kind of domains are formed which are rich and poor in DPPE and in these domains cubic and lamellar structures are present, respectively. Increasing the LPS concentration up to 0.1 LPS/DPPE–DPPG molar ratio the phase separation is more expressed and the temperature domains of the phase transitions are more different. Increasing the temperature chain melting of the lamellar phase occurs first and destruction of the cubic phase is observed later. At high LPS concentration (equimolar ratio of LPS/DPPE–DPPG), where this amphiphilic molecule cannot be considered any more a guest molecule, the cubic structure dominates the phase behaviour of the LPS molecules. 相似文献