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排序方式: 共有936条查询结果,搜索用时 15 毫秒
921.
Mohamed Ajax K. Islam Khan S. Hasan Syed Sirajul Shakir Mohammed 《Transition Metal Chemistry》1999,24(2):198-201
A new series of 14–16 membered tetraazatetraimine macrocyclic complexes [ML1X2]-[ML3X2] [M=CoII, NiII and ZnII] and [CuL1]X2-[CuL3]X2 [X=Cl or NO3] have been synthesized by the template condensation of dibenzoylmethane with primary diamines in MeOH. The complexes were characterized by elemental analysis, i.r, 1H-n.m.r., e.p.r. and u.v-vis spectroscopy, as well as by conductivity and magnetic susceptibility measurements. The copper complexes exhibit square planar geometry, whereas an octahedral geometry is suggested for all other complexes. 相似文献
922.
An alternative approach is suggested to determine the spot-size of a multi-mode laser beam. It has been shown by simulations
that the suggested approach can give the beam quality factor and characteristic radius with less than 5% error. Unlike the
power content method, the proposed method is applicable to the beams even with diameter one tenth of the CCD size. The new
approach has been applied to a multi-mode diode laser output and it is shown that the ABCD matrix analysis can be used for beam propagation, with the measured parameters of the laser. 相似文献
923.
A De A Mitra A Ray SR Banerjee M Sengupta A Chatterjee S Kailas HS Patel MG Betigiri SK Dutta 《Pramana》1999,53(3):549-552
In this paper, we report our measurements of back-angle oxygen and carbon particle yields from 16O+89Y, 12C+93Nb reactions forming the same compound nucleus 105Ag at the same excitation energy and spin distribution. We find anomalously large oxygen yield and entrance channel dependence
at high excitation energies from 16O+89Y reaction implying formation of a dinuclear orbiting complex. Possible connection between nuclear orbiting and fast fission
is also discussed. 相似文献
924.
本文基于理论的方法研究了沟道长度和宽度对石墨烯场效应晶体管中大信号和小信号参数的影响. 在快速饱和及高特征频率条件下,石墨烯场效应晶体管均表现出优异的性能. 从传递曲线可以看到,随着沟道长度从440 nm变到20 nm,产生了一个从0.15 V 到0.35 V的狄拉克点正偏移,同时也揭示了石墨烯的双极特性. 而且,由于沟道变宽及漏电流增加,当沟道宽度为2 μm和5 μm时,相应的最大电流为2.4 mA和6 mA. 另外,还在石墨烯场效应晶体管中观察到了几乎对称的电容-电压特性,电容会随着沟道变短而减小,但另一方面电容又可以通过沟道展宽来增加. 最后,在沟道长度为20 nm处获得了一个6.4 mS的高跨导,在沟道宽度为5 μm处获得的跨导值为4.45 mS,特征频率为3.95 THz. 相似文献
925.
Physics of Atomic Nuclei - The core deformation of a one- and two-proton halo $${}^{27}$$ S nucleus was investigated based on experimental data. The Hamiltonian of the three-body systems and the... 相似文献
926.
927.
Islam Md. Rafiqul Kazuaki Shimada Shigenobu Aoyagi Yuji Takikawa Chizuko Kabuto 《Heteroatom Chemistry》2004,15(2):175-186
5H-1,2,4-oxathiazoles were efficiently synthesized from 6H-1,3,5-oxathiazine S-oxides by thermal cycloreversion of the substrates and the products were effectively converted into 1,2,4-thiadiazoles. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:175–186, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20004 相似文献
928.
929.
Dr. Md Motiur Rahaman Mazumder Rezoanul Islam Dr. M. Azizur R. Khan Dr. K. M. Anis-Ul-Haque Prof. Dr. Mohammed M. Rahman 《化学:亚洲杂志》2023,18(1):e202201025
The temperature dependency of the electrochemical analysis of acetyl ferrocene (AcFc) and iron(III) acetylacetonate ([Fe(acac)3]) has been investigated for non-aqueous redox flow batteries (NARFBs). AcFc and [Fe(acac)3] were utilized as catholyte and anolyte species, respectively, in an electrochemical cell with a cell voltage of 1.41 V and Coulombic efficiencies >99% for up to 50 total cycles at room temperature (RT, 25 °C). Experiments with a rotating ring disk electrode (RRDE) indicate that the diffusion coefficient reduces with decreasing temperature from 25 °C to 0 °C, yet the overall storage capacity was higher than that of an aqueous redox flow battery (ARFBs). The electrochemical kinetic rate constant (k0) of AcFc was found to be greater than that of [Fe(acac)3]. However, the value of k0 was not affected by the variable temperature. 1H NMR investigations reveal that temperature change during battery trials did not occur in any structural modification. The obtained result demonstrates the suitability of this battery at low temperatures. 相似文献
930.