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排序方式: 共有86条查询结果,搜索用时 15 毫秒
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SOLIMAN A.Y. BAKEER H.M. ATTIA LA.Science Department Faculty of Teachers P.O.Box Alhasa Saudi Arabia Chemistry Department Faculty of Science Fayoum Cairo University EgyptFaculty of Engineering Ain Shames University Egypt 《中国化学》1996,14(6):532-540
3-(4-Phenyl) benzoyl propionic acid was used as the starting material for the synthesisof furanones (2), pyrrolinones (5), pyridazinones (7), benzoxazinones (8) and quinazolinones (9-11). The behaviour of the derivatives of furanones and benzoxazinones toward different nucleophiles is reported. 相似文献
3.
Waveguide propagation of intense electromagnetic radiation in slightly inhomogeneous nonlinear media
The propagation of self-localizing beams of electromagnetic waves in the form of nonlinear waveguides in a slightly inhomogeneous medium is studied analytically and numerically. The trajectories of the axial ray are studied as a function of its direction and the field strength at the initial point on the basis of a nonlinear scalar Helmholtz equation. Analytic expressions are derived. The longitudinal refractive index, the field intensity, and the waveguide radius are plotted as functions of the instantaneous position of the point on the axial ray. Deep penetration of the beam into the opaque region and the position of the screening surface are studied as functions of the parameters of the beam and the medium. A steady-state 3D problem is analyzed for a power-law nonlinearity with an arbitrary power. A 2D problem is analyzed for the case of a ponderomotive nonlinearity with saturation. 相似文献
4.
MENG Jian REN Yu-Fang LI Xiao-GuangLaboratory of Rare Earth Chemistry Physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun Jilin ChinaPopov V.V. Repin S.M. Smirnov LA. loffe Physicotechnical Institute Russian Academy of Sciences Saint Petersburg Russia 《中国化学》1994,12(5):419-424
YBa2Cu3-xVxO7-y(x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) superconductors have been prepared. X-ray diffraction shows that the system remains orthorhombic for all compositions studied, but for x > 0.4 V2O5 was detected as an impurity phase. Substitution of V5+ for Cu2+ occurs in the Cu(2) sites on the Cu(2)-O planes. The introduction of the high valence element, vanadium, produces the extra free-electrons. These electrons recombine with the positive carrier of the system. It makes depression of the mobility and the Hall number of YBa2Cu3-xVxO7-v and also results in a depression of TC. 相似文献
5.
MARIAN ELBANOWSKI MARIA PAETZ JANUSZ SIAWINSKI LESZEK CIELA 《Photochemistry and photobiology》1988,47(3):463-466
Abstract— Chemiluminescence of the Eu(II)/Eu(III)-adenine nucleotide-H2 O2 system and fluorescence of the Eu(III)-adenosine triphosphate system have been investigated. The spectral distribution of the chemiluminescence emission has shown an occurrence of three main bands (Λ=470–480,590–620 and ca. 700 nm). The energy transfer process from the adenosine triphosphate molecules to the Eu(III) ions has been observed in the fluorescence spectrum. The examined chemiluminescence and fluorescence spectra show that these both kinds of emission originate from the 5 D *** τ7 F*** ( n =1–4) transitions in the Eu(III) ions. 相似文献
6.
A. P. Mikhailovskaya N. E. Serova M. S. Kalugina A. M. Kiselev 《Russian Journal of Applied Chemistry》2014,87(1):108-113
The effect of quaternary ammonium salts on batch dyeing of cellulose materials with active dyes was examined. The use of benzyldimethylhexadecylammonium chloride and benzyldimethyldodecylammonium bromide as intensifi ers in dyeing of cellulose textile materials with active dyes of vinyl sulfone and monochlorotriazine types allows high intensity and durability of the color to be attained owing to increased degree of covalent fi xation of the dyes and their decreased desorption in the course of washing of the dyed material. 相似文献
7.
Z. A. Mikhailovskaya E. S. Buyanova S. A. Petrova V. M. Zhukovskii 《Russian Journal of Electrochemistry》2013,49(7):658-664
The possibility of synthesizing oxygen-ionic conductors from substituted bismuth molybdates containing [Bi12O14] n 8n+ columns, MoO4 tetrahedra, and isolated Bi ions in their structure was studied. The specifics of their structure and electric conductivity were investigated. The general formula of the solid solutions can be recorded as Bi13Mo5 ? x Me x O34 ? δ, where Me is the fouror five-valent d metal (Ti, Zr, V, Nb). The electric conductivity of doped bismuth molybdates considerably increased compared with that of the matrix compound. The electric conductivity reached 5.5 × 10?3 S cm?1 at 700°C and 1.8 × 10?4 S cm?1 at 350°C for the zirconium-doped compound with x = 0.4. The porosity of the ceramics was less than 5%; the thermal expansion coefficient was of the order of 14 × 10?6 K?1. Based on the set of their characteristics, these compounds are recommended as materials for membranes of electrochemical devices. 相似文献
8.
Klimova A. V. Mikhailovskaya Z. A. Buyanova E. S. Petrova S. A. 《Russian Journal of Electrochemistry》2021,57(8):825-832
Russian Journal of Electrochemistry - The possibility of synthesizing oxygen-ion conductors based on bismuth molybdate with antimony and tin substituted to the molybdenum sublattice is studied and... 相似文献
9.
针对纤维材料变温环境力学性能测试的需要,在华中科技大学研制的纤维材料试验机的基础上引入了温控装置,从而实现纤维材料在高低温环境下的力学性能测试。采用该装置对不同直径微米铜丝在不同温度、不同拉伸速率条件下的力学性能开展实验研究,测试结果表明弹性模量和抗拉强度随温度的降低而线性增加,屈服强度的变化不太明显。另外,低温环境下微米铜丝的力学性能表现出与其直径相关的尺度效应,而这一现象在常温下一直没有观测到。最后,还研究了拉伸速率对微米铜丝的力学性能影响,结果表明,在现有装置的许用范围之内,拉伸速率对其力学性能的影响不大。 相似文献
10.
Doklady Mathematics - 相似文献