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排序方式: 共有298条查询结果,搜索用时 125 毫秒
91.
We consider the Littlest Higgs Model with T-parity (LHT), in the parameter region where a heavy neutrino is the lightest T-odd particle (LTP). Having emphasized that this corresponds to a sizable region in the parameter space of the theory, we show that both the Cryogenic Dark Matter Search (CDMS) and Xenon10 experiments disallow the entire region where the masses of the new particles in LHT can lie within several TeV. Therefore, any observation of the signals of a heavy neutrino LTP is likely to seriously reopen the issue of cold dark matter in the universe. 相似文献
92.
This paper describes an effect of flow rate, carrier gas (H2, N2 and Ar) composition, and amount of benzene on the quality and the yield of carbon nanotubes (CNTs) formed by catalytical
vapour dcomposition (CVD) method. The flow and mass control of gases and precursor vapors respectively were found to be interdependent
and therefore crucial in deciding the quality and yield of CNTs. We have achieved this by modified soap bubble flowmeter,
which controlled the flow rates of two gases, simultaneously. With the help of this set-up, CNTs could be prepared in any
common laboratory. Raman spectroscopy indicated the possibilities of formation of single-walled carbon nanotubes (SWNTs).
From scanning electron microscopy (SEM) measurements, an average diameter of the tube/bundle was estimated to be about 70
nm. The elemental analysis using energy dispersion spectrum (EDS) suggested 96 at.wt.% carbon along with ca. 4 at.wt.% iron
in the as-prepared sample. Maximum yield and best quality CNTs were obtained using H2 as the carrier gas.
相似文献
93.
Nicolas Delerue Sudhir Dixit Fred Gannaway David Howell Myriam Qurshi Grahame Blair Stewart Boogert Gary Boorman Chafik Driouichi Lawrence Deacon Alexander Aryshev Pavel Karataev Nobuhiro Terunuma Junji Urakawa Axel Brachmann Joe Frisch Marc Ross 《Pramana》2007,69(6):1147-1150
A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can
be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC
laser-wires.
相似文献
94.
Hert DG Anderson JL Aki SN Brennecke JF 《Chemical communications (Cambridge, England)》2005,(20):2603-2605
The presence of CO(2) increases the solubility of O(2) and CH(4) in 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide at 25 degrees C and pressures to 13 bar. 相似文献
95.
A generalized VMD mechanism, implemented through the OPC model, is proposed for E1 and M1 decays of mesons wherein the photon couples to two infinite sequences of radial excitations of 3S1 and 3D1 states. The results reveal good accord with data under the conventional assignments, with a parameter signifying a reduced magnetic coupling of ψ-ions with c quarks. 相似文献
96.
Results of a quasi-harmonic calculation of the normal mode frequencies, mode-Grüneisen parameters, the coefficient of thermal expansion α, the heat capacity Cp, and the macroscopic Grüneisen function γ(itT) for CsBr and CsI are presented. Very good agreement with the experimental results for α and Cp is obtained. A self-consistent procedure is used to parametrize the models so that some often neglected vibrational and configuration-dependent effects can be accounted for. Predictions are made for the values that the potential energy derivatives and the elastic constants would have in the absence of vibrational motion. 相似文献
97.
We examine the predictions of gauge theories with colour excitation for the processpp →μ
+
μ
−
X. Relative to the predictions of quark parton model (with three colours) we find enhancements as large as a factor 3 – 4 for
the cross-sectionM
3
d
2
σ/dMdy|y=0 in the region 0·03 ≲M/√s ≲ 0·2 at √s=62 GeV,M being the invariant mass andy the rapidity of the muon pair. We study the sensitivity of this result to the colour gluon mass and the underlying parametrisation
of the quark and gluon distribution functions. 相似文献
98.
Sudhir K Vempati 《Pramana》2000,54(1):133-146
We discuss the various sources of neutrino masses in supersymmetric standard models with explicit lepton number violation.
We show that the bilinear lepton number violating soft terms in models with either bilinear or trilinear lepton number violating
couplings in the superpotential, play an important role in determining the neutrino mass spectrum. A comparative study of
the neutrino mass spectrum and its implications for the present neutrino anomalies in these models is presented. 相似文献
99.
Partha Ghosal Sama Ajay Sanjeev Meena Sudhir Sinha Arun K. Shaw 《Tetrahedron: Asymmetry》2013,24(15-16):903-908
The stereoselective synthesis of Jaspine B has been achieved from easily available (S)-Garner’s aldehyde. The trisubstituted tetrahydrofuran core of Jaspine B was constructed by utilizing a diastereoselective iodocyclization as the key step. Deiodination and debenzylation were performed in a single step by using n-Bu3SnH and ABCN as a conjugate catalyst system. The in vitro cytotoxicity of compounds 1 and 1a against 3 human cancer cell lines-A549 (lung), MCF7 (breast), and KB (oral); and a non-cancer cell line (NIH3T3) was determined by sulphorhodamine B based assay. 相似文献
100.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献