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151.
The covariant single-time approach of quantum field theory and perturbation theory are used to construct an explicit form
of the electromagnetic interaction operator for mixedN-particle systems consisting of spinor and scalar particles.
F. Skoriny State University, Gomelsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 13–25, September,
1997. 相似文献
152.
Summary Methods of construction of balancedn-ary designs using difference sets have been studied in this paper. Some properties of balancedn-ary designs are studied. Use of balanced ternary designs has been made to construct some efficient weighing designs.
Institute of Agricultural Research Statistics 相似文献
153.
Mira Dey Tapash Chakraborty Jishnu Dey 《Zeitschrift für Physik A Hadrons and Nuclei》1979,290(3):269-272
A general expression for the binding energy of finite nuclei in the Jastrow-Factor-Cluster method is developed upto the three-body cluster term with centre of mass correction. It is applied in massA=3 and 4 with the standard Chakkalakal function and the average Pauli condition. Compared to the previous work of Afnan (1969) better saturation properties are obtained for two- and three-body truncation. Convergence is also better. 相似文献
154.
The formation of a coloured chelate, having λmax at 540 mμ, between cupric ions and ammonium aurintricarboxylate has been reported. It has been concluded that only one complex having metal : reagent ratio of 1:2 is formed in solution. The method adopted for investigation has been the continuous variation method, using spectrophotometric and electrical conductance measurements. It has been observed that there is an increase in acidity on mixing the reactants, which shows that hydrogen ions are liberated as a result of chelation It has been suggested that chelation occurs between the phenolic oxygen and the adjacent carboxylic oxygen.A method has been presented for the calculation of formation constant from spectrophotometric data and the value of K in the case of the chelate investigated has been calculated to be 6.45.108. The free energy of formation works out to be —14.6 kcal at 25°C. 相似文献
155.
Sign-pattern IPs are a generalization of packing IPs, where for a given column all coefficients are either non-negative or non-positive. We show that the aggregation closure for such sign-pattern IPs can be 2-approximated by the original 1-row closure. This generalizes a result for packing IPs. On the other hand, unlike in the case of packing IPs, we show that the multi-row aggregation closure cannot be well approximated by the original multi-row closure. 相似文献
156.
One-dimensional infinite group problems have been extensively studied and have yielded strong cutting planes for mixed integer
programs. Although numerical and theoretical studies suggest that group cuts can be significantly improved by considering
higher-dimensional groups, there are no known facets for infinite group problems whose dimension is larger than two. In this
paper, we introduce an operation that we call sequential-merge. We prove that the sequential-merge operator creates a very large family of facet-defining inequalities for high-dimensional
infinite group problems using facet-defining inequalities of lower-dimensional group problems. Further, they exhibit two properties
that reflect the benefits of using facets of high-dimensional group problems: they have continuous variables’ coefficients
that are not dominated by those of the constituent low-dimensional cuts and they can produce cutting planes that do not belong
to the first split closure of MIPs. Further, we introduce a general scheme for generating valid inequalities for lower-dimensional
group problems using valid inequalities of higher-dimensional group problems. We present conditions under which this construction
generates facet-defining inequalities when applied to sequential-merge inequalities. We show that this procedure yields some
two-step MIR inequalities of Dash and Günlük. 相似文献
157.
Motion planning and stabilization of the inverted pendulum on a cart is a much-studied problem in the control community. We
focus our attention on asymptotically stabilizing a vertically upright flexible beam fixed on a moving cart. The flexibility
of the beam is restricted only to the direction along the traverse of the cart. The control objective is to attenuate the
effect of disturbances on the vertically upright profile of the beam. The control action available is the motion of the cart.
By regulating this motion, we seek to regulate the shape of the beam. The problem presents a combination of a system described
by a partial differential equation (PDE) and a cart modeled as an ordinary differential equation (ODE) as well as a controller
which we restrict to an ODE. We set our problem in the port-controlled Hamiltonian framework. The interconnection of the flexible
beam to the cart is viewed as a power-conserving interconnection of an infinite-dimensional system to a finite-dimensional
system. The energy-Casimir method is employed to obtain the controller. In this method, we look for some constants of motion
that are invariant of the choice of controller Hamiltonian. These Casimirs relate the controller states to the states of the
system. We finally prove the stability of the equilibrium configuration of the closed-loop system. 相似文献
158.
The transformation mechanism of hexagonal delta phase from the disordered bcc gamma phase has not been reported before in the Zr-rich U–Zr alloy system. With the help of X-ray diffraction, transmission electron microscopy (TEM) and high-resolution TEM analyses it was shown that the gamma to delta conversion takes place by the lattice collapse mechanism of omega transformation. It was also ascertained that a higher aging temperature or time promotes the growth of all four variants of the delta phase within a parent gamma grain. In addition, ab initio electronic structure calculations showed that the bcc to hexagonal transformation, involving partial ordering of the parent bcc phase followed by (111) plane collapse, is energetically favorable. 相似文献
159.
Priyanka Dey William Olds Idriss Blakey Kristofer J. Thurecht Emad L. Izake Peter M. Fredericks 《Journal of Raman spectroscopy : JRS》2013,44(12):1659-1665
We have explored the potential of deep Raman spectroscopy, specifically surface‐enhanced spatially offset Raman spectroscopy (SESORS), for non‐invasive detection from within animal tissue, by employing SERS‐barcoded nanoparticle (NP) assemblies as the diagnostic agent. This concept has been experimentally verified in a clinically‐relevant backscattered Raman system with an excitation line of 785 nm under ex vivo conditions. We have shown that our SORS system, with a fixed offset of 2–3 mm, offered sensitive probing of injected 2‐quinolinethiol‐barcoded NP assemblies through animal tissue containing both protein and lipid. In comparison with that of non‐aggregated SERS‐barcoded gold NPs, we have demonstrated that the tailored SERS‐barcoded aggregated NP assemblies have significantly higher detection sensitivity. We report that these NP assemblies can be readily detected at depths of 7–8 mm from within animal proteinaceous tissue with high signal‐to‐noise ratio. In addition, they could also be detected from beneath 1–2 mm of animal tissue with high lipid content, which generally poses a challenge because of high absorption of lipids in the near‐infrared region. We have also shown that the signal intensity and signal‐to‐noise ratio at a particular depth is a function of the SERS tag concentration used and that our SORS system has a 2‐quinolinethiol detection limit of 10−6 M. Higher detection depths may possibly be obtained with optimization of the NP assemblies, along with improvements in the instrumentation. Such NP assemblies offer prospects for in vivo, non‐invasive detection of tumours along with scope for incorporation of drugs and their targeted and controlled release at tumour sites. These diagnostic agents combined with drug delivery systems could serve as a ‘theranostic agent’, an integration of diagnostics and therapeutics into a single platform. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
160.