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排序方式: 共有742条查询结果,搜索用时 15 毫秒
31.
George Cordoyiannis Patricia Losada-Pérez Chandra Shekhar Pati Tripathi Brigita Rožič Uroš Tkalec Vassilios Tzitzios 《Liquid crystals》2013,40(11):1419-1426
The phase transition behaviour of the chiral liquid crystal CE6 doped with spherical surface-functionalised CdSe nanoparticles has been examined by means of high-resolution adiabatic scanning calorimetry and polarising microscopy. The addition of nanoparticles results in an essentially stabilised blue phase III. The phase diagram is displayed upon heating and cooling and the enthalpy changes involved in the conversion between the blue phases are determined. The dispersion of functionalised nanoparticles is prominent for the stabilisation of blue phase III, which is potentially useful for applications, especially if applied on liquid crystals that exhibit blue phases close to room temperature. 相似文献
32.
Efficient cross polarization with simultaneous adiabatic frequency sweep on the source and target channels 总被引:2,自引:2,他引:0
In this work, we propose a new and efficient heteronuclear cross polarization scheme, in which adiabatic frequency sweeps from far off-resonance toward on-resonance are applied simultaneously on both the source and target spins. This technique, which we call as Simultaneous ADIabatic Spin-locking Cross Polarization (SADIS CP), is capable of efficiently locking both the source and target spins with moderate power even in the presence of large spectral distribution and fast relaxation. It is shown that by keeping the time-dependent Hartmann-Hahn mismatch minimal throughout the mixing period, polarization transfer can be accelerated. Experiments are demonstrated in a powder sample of L-alanine. 相似文献
33.
Perturbation to Mei symmetry and Mei adiabatic invariants for mechanical systems in phase space 下载免费PDF全文
For a perturbed mechanical system in phase space, considering d/dt in the structure equation and process of proof including infinitesimal parameter ε obviously, this paper studies the perturbation to Mei symmetry and adiabatic invariants. Firstly, the exact invariant induced directly from the Mei symmetry of the system without perturbation is given. Secondly, based on the concept of high-order adiabatic invariant, the determining equations of the perturbation to Mei symmetry are established, the condition of existence of the Mei adiabatic invariant led by the perturbation to Mei symmetry is obtained, and its form is presented. Lastly, an example is given to illustrate the application of the results. 相似文献
34.
Neji Khelifi 《Journal of Russian Laser Research》2008,29(3):274-287
Adiabatic and diabatic study for all the states dissociating below the ionic limit [i.e., Na (3s, 3p, 4s, 3d, 4p, 5s, 4d,
and 4f) + H (1s)] in 1Σ+ and 3Σ+ symmetries are presented. Adiabatic results are also reported for 1,3Π and 1,3Δ symmetries. Pseudo-potential, operatorial core-valence correlation, and full valence CI approaches combined with an efficient
diabatization procedure are used in these ab initio calculations. Our vibrational-level spacings and spectroscopic constants
are in good agreement with the available experimental data for the low-lying states. Diabatic potentials and dipole moments
are analyzed, revealing the strong imprint of the ionic state in the 1Σ+ adiabatic states. The hydrogen electron affinity correction was taken into account by the use of the efficient diabatization
method. This leads to a better agreement with the available experimental data. Experimental suggestions are also given for
the higher excited states based on their unusual behavior. 相似文献
35.
L. V. Baev V. N. Solodovnikov 《Journal of Applied Mechanics and Technical Physics》2004,45(6):860-870
The problem of spherically symmetric, gravitational compression of an isotropic hyperelastic layered sphere which modeling the region of the Earth below the Mohorovii boundary is solved. The known mechanical characteristics of the Earth in the compressed state are used to find its characteristics in the unstrained state obtained by adiabatic or isothermal stress relief. The stress state differs significantly from the state of purely hydrostatic compression. The minimum bulk compression and maximum radial tension occur not on the boundary of the sphere but in depth at certain distances from the boundary. 相似文献
36.
37.
提出一种利用绝热过程制备多原子GHZ态的方案.本方案可有效地抑制原子的自发辐射噪声.利用相似的方法可制备腔场GHZ态.制备成功的几率约为1.0. 相似文献
38.
M.M. EL-Nicklawy A.F. Hassan A.T. Matar A.A. Hemeda A.I. Ali 《Optics & Laser Technology》2007,39(6):1243-1253
Through the differential equation describing the behavior of the nonlinear polarization of a medium with respect to an incident field, the Maxwell field equations and the boundary conditions of the field inside a resonator, the relationship between the output and the incident fields is obtained, describing a bistability phenomena. The effect of the spectral profile of the incident field and its spectral halfwidth on the bistability phenomena is studied. 相似文献
39.
Alexander M. Kuznetsov Jens Ulstrup 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(1-2):45-54
Expressions are derived for the tunnel electric current between two metals produced by the adiabatic transitions of the electrons through a bridge electron level. A new possible physical phenomenon is discussed, viz. electronically driven oscillations of the electron bridge level between two molecular wires. 相似文献
40.
研究了采用二相非交叠功率时钟的绝热触发器及时序电路的设计,介绍了采用二相无交叠功率时钟的互补传输门绝热逻辑(CPAL)电路,并分析了其工作原理.该电路利用nMOS管自举原理对负载进行全绝热驱动,从而减小了电路整体功耗,且CPAL能耗几乎与工作频率无关.提出了性能良好的低功耗绝热D、T和JK触发器,并与其他几种绝热触发器进行功耗比较.给出了绝热时序电路的一般设计方法,并作为实例采用应用绝热D触发器设计了十进制计数器.SPICE程序模拟表明:设计的电路具有正确的逻辑功能及低功耗的优点. 相似文献