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51.
B. C. Allanach 《Pramana》2003,60(2):239-247
The large hadron collider (LHC) should have the ability to detect supersymmetric particles if low-energy supersymmetry solves
the hierarchy problem. Studies of the LHC detection reach, and the ability to measure properties of supersymmetric particles
are currently underway. We highlight some of these, such as the reach in minimal supergravity space and correlation with a
fine-tuning parameter, precision measurements of edge variables, anomaly or gauge-mediated supersymmetry breaking. Supersymmetry
with baryon-number violation seems at first glance more difficult to detect, but proves to be possible by using leptons from
cascade decays. 相似文献
52.
53.
To investigate the relationship between characteristics of the coherent fine scale eddy and a laminar–turbulent transition, a direct numerical simulation (DNS) of a spatially-developing turbulent mixing layer with Reω,0 = 700 was conducted. On the onset of the transition, strong coherent fine scale eddies appears in the mixing layer. The most expected value of maximum azimuthal velocity of the eddy is 2.0 times Kolmogorov velocity (uk), and decreases to 1.2uk, which is an asymptotic value in the fully-developed state, through the transition. The energy dissipation rate around the eddy is twice as high compared with that in the fully-developed state. However, the most expected diameter and eigenvalues ratio of strain rate acting on the coherent fine scale eddy are maintained to be 8 times Kolmogorov length (η) and :β:γ = −5:1:4 in the transition process. In addition to Kelvin–Helmholtz rollers, rib structures do not disappear in the transition process and are composed of lots of coherent fine scale eddies in the fully-developed state instead of a single eddy observed in early stage of the transition or in laminar flow. 相似文献
54.
Chunbao Xu J.-X. Zhu 《中国颗粒学报》2006,(4)
The influence of gas type (helium and argon) and bed temperature (77-473 K) on the fluidization behaviour of Geldart groups C and A particles was investigated. For both types of particles tested, i.e., Al2O3 (4.8 μm) and glass beads (39 μm), the fluidization quality in different gases shows the following priority sequence: Ar>He. In the same gaseous atmosphere, the particles when fluidized at an elevated temperature usually show larger bed voidages, higher bed pressure drops, and a lower umf for the group A powder, all indicating an enhancement in fluidization quality. Possible mechanisms governing the operations of gas type and temperature in influencing the fluidization behaviours of fine particles have been discussed with respect to the changes in both gas properties and interparticle forces (on the basis of the London-van der Waals theory). Gas viscosity (varying significantly with gas-type and temperature) proves to be the key parameter that influences the bed pressure drops and umf in fluidization of fine particles, while the interparticle forces (also varying with gas-type and temperature) may play an important role in fine-particle fluidization by affecting the expansion behaviour of the particle-bed. 相似文献
55.
为了提高采用转台对惯导系统和惯性仪表进行误差模型标定时的可靠性和精度,对角位置转台的控制系统进行了研究。首先借助NI公司PXI-8101控制器和功能强大的数据采集卡PXIe-6363对转台控制系统进行了硬件设计。随后在对转台常规PID控制方法研究的基础上提出了一种能随系统调节偏差自动改变积分项累加速度的变速PID控制方法。接着又对基于软件实现的双通道旋转变压器轴角解调算法进行了研究并提出了一种粗精组合角纠错方法。最后对本文设计的转台控制系统进行了测试实验,结果表明提出的轴角解调算法具有较好的解码速度和精度,并且变速PID控制方法大大提高了转台控制系统的自学习能力和鲁棒性,显著地改善了转台控制过程的稳定性。 相似文献
56.
57.
S. M. Arabei 《Journal of Applied Spectroscopy》1998,65(4):560-566
Monochromatic photoexcitation and selective registration in bands of purely electronic S1↔S0 transitions resulted in fine fluorescence and absorption (fluorescence excitation) spectra of hypericin in polyvinylbutyral
at a temperature of 4.2 K. Vibration analysis of the spectra is done and conclusions are made about the form of many normal
vibrations. It is found that the formation of intramolecular hydrogen bonds in the hypericin structure has a substantial effect
on the relative position of the electronic vibrational levels of the pigment molecule.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina ave., Minsk 200072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 539–545, July–August, 1998. 相似文献
58.
Michael X. Yang Phillip W. Kash Dong-Hong Sun George W. Flynn Brian E. Bent Michael T. Holbrook Simon R. Bare Daniel A. Fischer John L. Gland 《Surface science》1997,380(2-3):151-164
The bonding and reactions of chloroethylenes (vinyl chloride, trans- and cis-dichloroethylene, trichloroethylene) on a Cu(100) surface have been investigated by temperature-programmed desorption and reaction, near-edge X-ray absorption fine structure (NEXAFS) studies and measurements of changes of the surface work function. The monolayer molecules adsorb molecularly intact at 95 K via π coordination. The molecules orient with their molecular planes parallel to the surface with little increase (<0.02 Å) in the C---C bond distance compared with the gas phase values. The degree of thermal dissociation increases with the extent of halogenation, and no chlorine is present in the hydrocarbon reaction products liberated from the surface. Both cis- and trans-1.2-chloroethylene produce acetylene and a small amount of benzene, while dissociation of trichloroethylene generates acetylene and deposits a carbon residue on the surface. Vinyl chloride desorbs from Cu(100) without reaction. 相似文献
59.
N. A. Boikova S. V. Kleshchevskaya Yu. N. Tyukhtyaev R. N. Faustov 《Theoretical and Mathematical Physics》2006,149(3):1578-1590
Using a modified quasipotential perturbation theory, we study the value of the fine shift of the energy S levels of hydrogen-like
atoms due to the two-photon Coulomb interactions and the dependence of this value on the particle mass ratio parameter.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 149, No. 3, pp. 325–338, December, 2006. 相似文献
60.
J. Zhou 《Surface science》2006,600(7):1540-1546
Formaldehyde adsorption and reaction have been studied on cerium oxide thin films that were vapor deposited on Ru(0 0 0 1). The formaldehyde behavior was examined as a function of temperature, exposure and Ce oxidation state. Formaldehyde chemisorbs on fully oxidized CeO2 as dioxymethylene, CH2O2. The dioxymethylene decomposes and desorbs as formaldehyde between 200 K and 400 K. No other products are formed. On reduced ceria, formaldehyde also adsorbs as dioxymethylene. In addition to the formaldehyde desorption between 200 K and 400 K, a more strongly bound form of dioxymethylene is formed that produces formaldehyde at 440 K. Above 400 K, some of the dioxymethylene reacts to form formate and methoxy on the surface. These species decompose to produce H2, CO and CH2O above 500 K. 相似文献