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排序方式: 共有1393条查询结果,搜索用时 15 毫秒
101.
Shape verification aimed for manufacturing process control 总被引:1,自引:0,他引:1
102.
Numerical Algorithms - This paper describes a new MATLAB software package of iterative regularization methods and test problems for large-scale linear inverse problems. The software package, called... 相似文献
103.
Journal of Fourier Analysis and Applications - Localization and convergence almost everywhere of Schrödinger means are studied. 相似文献
104.
The Carleson operator is closely related to the maximal partial sum operator for Fourier series. We study generalizations of this operator in one and several variables. 相似文献
105.
The influence on the short-range packing in dipolar fluids by molecular shape and by additional higher order electrostatic
moments has been investigated by molecular dynamic simulations. The dipole polarization was found to decrease as the particles
were elongated parallel to the dipole and to increase for elongation perpendicular to the dipole, eventually forming a nematic
order. The addition of a quadrupole lead to a reduction of the polarization, and the influence of an axial octupole was weaker
and more complex. Both a decrease and an increase of the polarization is possible depending on the relative dipole–dipole
and octupole–octupole interaction strengths and the relative direction of the symmetry axes of the moments. These observations
were attributed to the different parity of a dipole and a quadrupole and the same parity of a dipole and an axial octupole
under reflection. In addition, further insights into the formation of dipole polarization were obtained. Short polar and long
equatorial radii and strong dipole–dipole interaction are particle properties that promote a fluid with a high dipole polarization. 相似文献
106.
The radiometric methods, alpha (α)-, beta (β)-, gamma (γ)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches, these radionuclides include 3H, 14C, 36Cl, 41Ca, 59,63Ni, 89,90Sr, 99Tc, 129I, 135,137Cs, 210Pb, 226,228Ra, 237Np, 241Am, and isotopes of thorium, uranium and plutonium. The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed. 相似文献
107.
Per Hedegård 《Hyperfine Interactions》1986,31(1-4):135-140
A general formalism for a quantum particle moving in an environment based on the path integral formulation of quantum mechanics
is presented. The environment can be the valence electron gas of a metal or the phonons of the host in which the particle
moves, or both. The advantage of this approach is that it gives a direct space-time picture of the motion. Integrating out
the coordinates of the environment an effective action for the particle is obtained. It consist of two parts. An adiabatic
term, that is local in time (and as such describable as a potential), describing the influence of the fully relaxed environment
on the particle, and a term that accounts for the dynamical part of the response of the environment due to the motion of the
particle. As an example I have considered a particle moving in a tight binding band with an electron gas environment. Three
energy scales play a role here. They are the bare hopping amplitude, the temperature and the inverse tunneling time (i.e.
the time it takes the particle to tunnel from one site to the next). Note that the Fermi energy drops out of the problem.
I find, as did Kondo in his recent theory, a decreasing diffusion constant as a function of temperature. 相似文献
108.
Wallqvist V Claesson PM Swerin A Schoelkopf J Gane PA 《Langmuir : the ACS journal of surfaces and colloids》2007,23(8):4248-4256
Colloidal wood resin components present in pulp are collectively called "pitch". The presence of pitch may cause severe problems due to deposits in and on the paper machine. There is thus a need for controlling pitch aggregation and adsorption. To be able to develop more efficient pitch control systems, one needs to develop the understanding of pitch-pitch interactions and of the interactions between pitch and other materials. With this general goal in mind, we present methods for preparing geometrically well-defined pitch particles attached to atomic force microscopy tips. This has enabled us to investigate the interactions between pitch and talc, an additive commonly used for pitch control. We have used model pitch particles consisting of one component only (abietic acid), a mixture of components (collophonium), and particles prepared from real pitch deposits. We show that the forces acting between pitch and talc are attractive and, once the initial approach is made, exert this attraction out to large distances of separation. We present evidence that the formation of bridging air bubbles or cavities is responsible for this interaction. 相似文献
109.
The ground and low-lying excited states of CoCN have been studied by ab initio multireference single and double excitation configuration interaction (MR-SDCI) calculations with Davidson's correction Q and Cowan-Griffin's relativistic corrections. The electronic ground state of CoCN is (3)Phi(i) and the equilibrium geometry is linear with bond lengths of r(e)(Co-C)=1.8540 A and r(e)(C-N)=1.1677 A, substantially different from the experimentally derived values of r(0)(Co-C)=1.8827(7) A and r(0)(C-N)=1.1313(10) A. The first excited state is (3)Delta(i), separated from the ground state by 727 cm(-1). Larger dynamical electron correlation energy for the low-spin (3)Phi state than for the high-spin (5)Phi state makes the (3)Phi state to be the ground state, which is discussed in terms of the differences in natural orbitals. A new spin-orbit interaction scheme between the X (3)Phi(i) and 1 (3)Delta(i) states is proposed. 相似文献
110.
CAS SCF and CCI calculations have been performed in order to establish the existence or non-existence of the HO3 radical. The potential surface for the dissociation reaction, HO3 → O2(3Σ) + OH, along one chosen coordinate has been calculated. The calculations show that although the wavefunctions describing the short-distance and long-distance states are of different character, the energies are the same and the curve connecting the states is very flat. There is probably no barrier towards dissociation of the radical. However, the existence of HO3 can still not be excluded. 相似文献