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991.
992.
杯芳烃的分子设计(Ⅵ)--一种新的杯[4]磺胺衍生物的合成及晶体结构 总被引:2,自引:0,他引:2
杯芳烃是由酚单体通过亚甲基在羟基邻位桥连而成的环状低聚物, 它具有可调的杯状疏水空腔, 结构柔性较大, 构象可变, 并对中性分子和有机、无机离子具有选择性配位能力. 因此, 在其上下缘进行化学修饰所得到的杯芳烃衍生物可广泛应用于萃取分离、离子选择性电极、色谱分析、功能材料、催化及模拟酶等研究领域[1~4]. 相似文献
993.
S. L. Bogza K. I. Kobrakov M. Yu. Zubritskii S. Yu. Suikov V. I. Dulenko 《Chemistry of Heterocyclic Compounds》1997,33(1):74-77
Treatment of N-phenyl-2-(1-R-indol-3-yl)succinimides with acetyl perchlorate leads to acylation of the benzene ring of the indole substituent.L. M. Litvinenko Institute of Physico-Organic and Carbon Chemistry, Ukrainian Academy of Sciences, Donetsk 340114. A. N. Kosygin State Textile Academy, Moscow 117918, GSP-1. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 85–88, January, 1997. 相似文献
994.
冷态德士古气化炉流场与停留时间分布的研究 总被引:5,自引:1,他引:5
测定了德士古气化炉的冷态速度分布和停留时间分布。结果表明:德士古气化炉内在轴向2.5~3.0倍直径范围内存在回流,最大回流量为射流量的3.5倍左右;在平均停留时间之前,已有50%左右的物料逸出炉外。本文指出,德士古气化炉中存在的问题,如结渣、耐火砖寿命短、有效气体成分偏低均与炉内流场有关。 相似文献
995.
1,2,2-Trimethyldisilane-1,1,2-triol (1) is formed as an unstable intermediate upon hydrolysis of oligo(trimethyldisilanylsesquiazane). In the absence of trapping
agents it undergoes rapid condensation to give ether-soluble poly(trimethyldisilanyloxane) which contains silanol groups.
Treatment of the hydrolysis products with chlorotrimethylsilane in the presence of triethylamine affords trimethylsiloxy derivatives,
(Me3SiO)2MeSiSiMe2(OSiMe3),5,6, and [Si2Me3O
x
(OSiMe3)
y
]
n
. The isolation of these products indicates that disilanetriol1 readily undergoes condensation to form hydroxylcontaining six-membered rings and polysiloxanes. The condensation of compound1 in the presence of Me3SiOH has been studied. The ratio between the isomeric cyclosiloxanes5 and6 has been determined both by1H NMR spectroscopy and by a chemical method (chlorinolysis).
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1788–1792, October, 1993. 相似文献
996.
We have studied the kinetics of the process of epoxidation of 1-octene by tert-butyl hydroperoxide in the presence of molybdenum boride MoB2. We have studied the effect of the concentrations of starting materials and reaction products on the process. We suggest a kinetic scheme and we calculate the kinetic parameters of the process. 相似文献
997.
998.
The metric in vacuum is found for the case of a spherical charged dust source. It is shown that a dead zone occurs in the vacuum, impenetrable to light or test particles. All singularities resulting from theorems about geodesic lines, are located in the dead zone and do not represent a physical problem for the theory. The infinite-density type singularities may be absent inside matter-filled zone.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 94–99, 1987. 相似文献
999.
N. K. Morozova Yu. A. Pashchenko V. D. Chernyi V. G. Galstyan T. P. Dolukhanyan V. I. Muratova 《Russian Physics Journal》1987,30(2):143-149
The nature of the luminescence of zinc sulfide in the spectral range (360), 380–420 nm (SAL) at 80K is analyzed. It is shown that the appearance of SAL radiation is accompanied by additional absorption in the region (350) 365–370 nm at 80K. The low-temperature spectra of sphalerite, exposed to different radiation and subjected to different treatment, are studied. The multiband luminescence of the isoelectronic sulfur impurity in ZnO deposits in the region 383–640 nm is discussed. It is concluded that SAL luminescence is attributable to the localization of excitons in ZnS on clusters, whose formation precedes the precipitation of the ZnO·S phase. The formation of oxygen clusters and deposits on dislocations in ZnS is studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 60–66, February, 1987. 相似文献
1000.
E. Z. Vintaikin V. A. Udovenko S. Yu. Makushev D. F. Litvin 《Russian Physics Journal》1987,30(3):261-265
The method of neutron diffraction is used to construct temperature dependences of the intensity of 110 antiferromagnetic reflection under the influence of compressive stresses = 0–150 MPa along [001]. Application of the stresses leads to an increase in the transition temperature, the transition being delayed in proportion to the increase in the load. On the other hand, the loading leads to a reduction in the magnetization jump for the antiferromagnetic sublattices. Thus, at > 100 MPa, the antiferromagnetic transformation takes on features of a second-order phase transformation. The transition which takes place in the stressed state is characterized by smoother rearrangment of short-order antiferromagnetic order into long-range order, as is evidenced by erosion of the transition boundary. The model proposed here — which does not ascribe the usual effect to uniaxial stresses on the antiferromagnetic transition in -Mn alloys — is based on the anomalous temperature dependence of the elastic constants.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 92–97, March, 1987. 相似文献