红外焦平面探测器制冷组件可靠性研究进展

红外焦平面探测器制冷组件的可靠性研究对推进组件工程化应用具有重要意义。介绍了国外在组件的可靠性模型、失效模式、加速应力以及可靠性试验等方面的研究进展,并对国内的组件可靠性研究状况作了简要分析,总结了对组件可靠性研究的总体思路,为国内红外焦平面探测器制冷组件的可靠性研究提供参考。     

The Effect of Electrochemical and Gas Phase Activation of High Surface Area Carbon Black Ketjen Black EC 600 DJ on Its Surface Composition,Electrochemical Capacitance,and Stability

The effect of electrochemical and gas-phase activation of high-surface-area carbon black Ketjen Black EC 600 DJ on its stability and electrochemical capacitance is studied. The electrochemical activation is carried out according to the “start–stop” protocol (1–1.5 V, 0.5 V/s). The stability of samples is assessed based on variation of their effective resistance (based on the results of cyclic voltammetry (CVA)) and electrochemical capacitance (based on CVA and galvanostatic data) with the cycle number. The changes in the texture and surface properties of activated samples are studied by the methods of nitrogen low-temperature adsorption and X-ray photoelectron spectroscopy. The gas-phase activation of high-surface-area carbon black Ketjen Black EС 600 DJ is shown to impair its stability, while the electrochemical oxidation of carbonblack samples leads to a considerable (two-fold) increase in their electrochemical capacitance.     

Problem of Molecular Vibrations with the Gaussian Potential

The choice of the form of a potential function in calculating the characteristics of stationary states for atomic vibrations in a molecule is discussed. With regard to the features of the purely Coulomb potential and general considerations on the stable states of a bound nucleus set, and also a decrease in distances between the energy levels with increasing excitation energies, it is proposed to use a potential in the form of the “overturned” multidimensional Gaussian. It is demonstrated that this problem is solved by a variational procedure in the basis of products of one-dimensional functions forming a complete set.     

A new formulation of the quantum problem in the theory of spectra of polyatomic molecules

A new approach to calculate energy levels and wave functions of polyatomic molecules with a definite geometric structure of the system assumed from the very beginning has been suggested. The effect of nuclear vibrations has been taken into account explicitly when separating variables in the Hamiltonian of the electronic state problem. The problem of the energy matrix formation has been discussed. It has been shown that some common patterns in higher-order vibrational spectra and in vibronic spectra can be explained without using concepts of anharmonism and changing the potential well parameters for an electron-excited state as compared to those for the ground state.     

Cosmological consequences of the particle-antiparticle gravitational repulsion hypothesis: the Newtonian model of the universe

The model of the gravitationally neutral Universe (GNU), i.e., a giant but finite 3D Ball expanding in the infinite static Euclidean space, is considered. The model is based on the antigravitation between particles and antiparticles. The GNU Ball is filled equally by matter and antimatter clusters and freely expands after epochs of partial annihilation and recombination. The abandonment of the cosmological principle and the problem of our Galaxy position in the GNU Ball are discussed.     

Some unexpected proportionalities between components of the spin—other-orbit interaction in the f shell

The reduced matrix elements of the component z _i of the inter-electronic spin-other-orbit interaction have been calculated for all the states of the atomic f shell. Three of the z _i , each of which belongs to the irreducible representation (30) of Racah's group G₂, are found to exhibit matrix elements that are often related to one another in ways that go beyond what the Wigner-Eckart theorem, generalized to G₂, would predict. Examples are presented for matrix elements whose bras belong to the IR (20) of G₂ and whose kets belong to (31). The challenges to current theory are discussed.     

Calculations of the IR Intensities of Absorption Bands by the Hartree–Fock (ab initio) and Density-Functional Methods

Comparative calculations of the absolute intensities of bands in IR spectra were performed by the Hartree–Fock (ab initio) and density-functional methods for molecules containing different heteroatoms most cases, close coincidence between the curves calculated by these two methods is found, but there are also some unexpected disagreements in the results.     

Theoretical analysis of infrared spectrum of 9,10-anthraquinone molecule

For the molecule of 9,10-anthraquinone, vibration frequencies and intensities have been calculated, and a theoretical spectral curve has been plotted, giving an adequate reflection of experimental manifestations over a broad spectral interval. This study made it possible to obtain a correct system of parameters for a model of the 9,10-anthraquinone molecule. Theoretical analysis has provided a basis for distinguishing vibration frequencies, active in the spectrum, that are characteristic with respect to frequency and intensity.K. A. Timiryazev Agricultural Academy. Scientific-Research Institute of Physical Problems. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 1, pp. 169–178, January–February, 1993.