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排序方式: 共有7782条查询结果,搜索用时 15 毫秒
941.
We propose an optical H-tree structure to distribute a clock signal onto 16 electronic chips at 1 Gb/s for a clock skew and timing jitter of less than 100 ps. Fabrication steps and performance results are presented. 相似文献
942.
Khan Tahir Ali Hasan Syed Sirajul Varkey Saji P. Rather Manzoor Ahmad Jahan Nafees Shakir Mohammad 《Transition Metal Chemistry》1997,22(1):4-8
A new class of tetraiminetetraamide macrocyclic (Ph4[20]tetraene, N8O4, and Ph6[20]tetraene, N8O4) complexes have been prepared through the metal ion controlled reaction of 1,2-diphenylethane-1,2-dione dihydrazone (DPEDDH) with succinic acid [ML1X2] or phthalic acid [ML2X2] [M=Mn, Co, Ni, Cu or Zn; X=Cl or NO3]. The structures of the complexes have been elucidated on the basis of i.r, 1H-n.m.r, e.p.r. and electronic spectral data and conductance, as well as magnetic, properties. An octahedral geometry is assigned for all the complexes, involving coordination of the all-imine nitrogens. 相似文献
943.
Mohammad A. Mottaleb B. G. Cooksey David Littlejohn 《Fresenius' Journal of Analytical Chemistry》1997,358(4):536-538
A heated gas flow modified thermospray was used to couple gel permeation chromatography (GPC) to Fourier transform infrared
spectrometry (FTIR) for the analysis of the standard polystyrene samples. Effluents from the GPC column were evaporated and
the solutes were deposited as a series of spots on the surface of a moving stainless steel belt (0.025 mm thickness × 13 mm
width). The belt continuously transferred the spots into the diffuse reflectance (DRIFT) accessory of the FTIR spectrometer,
enabling identification of the deposited solutes by measurement of the diffuse reflectance IR spectrum. The IR spectra of
the separated components showed excellent agreement of the spectral features to those of standard FTIR spectra and no thermal
degradation was observed.
Received: 20 May 1996 / Revised: 17 October 1996 / Accepted: 28 November 1996 相似文献
944.
Recent measurements of differential and elastic cross-sections, slope parameters and ratios of the real and imaginary parts
of the forward scattering amplitudes for pion-proton elastic scattering at 200 GeV/c have been fitted by using a simple Regge
pole model with phenomenological residue functions. The computed results for total cross-sections have also been compared
with the experimental data. 相似文献
945.
946.
The Bridgman anvil technique offers a simple and versatile means of generating very high pressures required in solid state
studies. The opposed anvil technique is based on the principle of massive support. The practical case of a gasketted anvil
is considered, and an expression for the maximum pressure generated under massive support is derived in terms of the geometric
parameters, the strength of the anvil material and the gasket properties. In particular, for a given maximum pressure, it
is possible to calculate the taper angle, the taper height and the gasket thickness from this expression. The anvil is assumed
to be in the elastic region under load. Good agreement is obtained between the calculated and the experimental values for
the massive support factor (msf) for various taper angles. By choosing the proper geometry, it is possible to achieve a pressure as high as 130 kbar in an
alloy steel anvil. It has been clearly found that the straight portion, where the taper ends, does not really take any part
in changing the stress pattern. Thus the minimum straight portion can serve the purpose, and will result in material saving.
Anvils exhibit yielding at very high pressure. It is also pointed out that a further strengthening of the anvil can extend
the ultimate pressure. Several methods of further strengthening the anvils are discussed. 相似文献
947.
948.
The leading infra-red divergent corrections to massive quark scattering in quantum chromodynamics are very simple to fourth order. A simple dependence on the effective coupling constant is conjectured to hold to all orders. 相似文献
949.
950.
The crystal structure of the potential antitumor metal compound, viz. chloro, mono(phenanthrenequinone thiosemicarbazonato) palladium(II) dimethyl formamide solvate, is reported. The central palladium(II) atom is in a square planar environment provided by the tridentate, monoanionic thiosemicarbazone ligand and the ancillary chloride ion. The compound exhibited remarkable activity against drug-sensitive and drug-resistant breast cancer cell lines and was relatively nontoxic toward the normal mammary epithelial cells. The drug-induced killing effect against breast cancer cell lines was predominantly mediated via apoptosis, a physiologic form of cell death. 相似文献