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991.
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994.
Assuming that the conduction electrons of an amorphous metal contribute to the binding, we investigate whether a magnetic field will influence the transition from the amorphous to the crystalline state. Measurements taken on amorphous Bi, Ga and Yb films show no change in the crystallization temperatures within an accuracy of ±0.1 K due to a magnetic field of 18.5 T parallel to the surface of the films.Dedicated to Prof. Dr. W. Buckel on the occasion of his 60th birthday 相似文献
995.
EFFECTS OF FLUENCE FRACTIONATION ON UV-INDUCED MALIGNANT TRANSFORMATION AND CELL KILLING IN NON-CYCLING PLATEAU PHASE MOUSE CELLS 总被引:1,自引:0,他引:1
Plateau phase C3H 10T 1/2 mouse cells were used to measure the response to split fluence UV light irradiation in the absence of any cell cycle effects. It was found that fluence fractionation with up to 24 h between the fluences resulted in no survival enhancement. The frequency of malignant transformation was potentiated 2.5-fold when the time interval between the fluences was greater than 4h. This potentiation of transformation was attributed to plateau phase holding rather than to fluence fractionation per se. 相似文献
996.
Ohne Zusammenfassung 相似文献
997.
The industrial process of coating flat surfaces with polymeric substances is numerically simulated by solving the full equations of motion for a flow through a contraction with a moving boundary. The four-constant Oldroyd constitutive equation is used to represent the viscoelastic fluid. Some adjustments to existing finite-difference methods are made in such a way as to avoid singular iterative matrices during the solution process. Results are presented for flow situations with Weissenberg numbers up to about three times larger than any previously published results for this problem. 相似文献
998.
J.D. Petke Gerald M. Maggiora Lester L. Shipman Ralph E. Christoffersen 《Journal of Molecular Spectroscopy》1978,73(2):311-331
Ab initio configuration interaction wavefunctions and energies are reported for the ground state and many low-lying singlet and triplet states of magnesium chlorin and chlorin, and are employed in an analysis of the electronic absorption spectra of these systems.In chlorin, the calculated visible spectrum consists of two states, the lower energy, y-polarized state exhibiting moderate absorption intensity in contrast to the very weak absorption of the higher energy x-polarized state. The configurational composition of both states is well described by the four-orbital model. Five states are responsible for the Soret band envelope. A moderately intense y-state lies under the low energy edge of the band envelope, while two x-polarized states of moderate and strong intensity, respectively, are responsible for the band maximum. The final two states lie at the high energy edge of the Soret band and introduce a measure of asymmetry into the band envelope. Two states of very weak oscillator strength are also found in this region of the spectrum. All the Soret states are of complex configurational composition, and several of the higher lying states contain contributions from doubly excited configurations.The calculated visible spectrum of magnesium chlorin also consists of two states, with the weakly absorbing x-polarized state lying approximately 200 cm?1 lower in energy than the moderately intense y-polarized state. The configurational composition of both states is well described by the four-orbital model. Four states constitute the bulk of the intensity in the Soret band envelope. In distinction to chlorin, the moderately intense state at the low energy edge of the band envelope is x-polarized. Two intense states of y- and x-polarization, respectively, constitute the band maximum region, and a single x-polarized state of moderately strong intensity can be assigned to the high energy shoulder of the band envelope. Two other weakly absorbing states are also found in this region, along with another weakly absorbing state of mixed in-plane and out-of-plane polarization. No clearly defined states are observed. As was the case for chlorin, all the Soret states are of complex configurational composition, and some of the higher energy states contain significant contributions from doubly excited configurations.Chlorin and magnesium chlorin both possess three states which lie below S1 and a single which lies slightly above S2. All four of the low-lying states in each molecule are well described by the four-orbital model, with T1 being essentially a single configuration in each case. The remainder of the states are clustered in the same energetic region as the comparable Soret states, with comparably complex configurational compositions.Dipole moments and charge distributions for low-lying singlet and triplet states are also reported, and are used to rationalize chemical reactivity characteristics. 相似文献
999.
Gerald M. Rosen Frederick Q. Gemmill Edgar O. Snoke Frank D. Popp 《Journal of heterocyclic chemistry》1975,12(4):619-622
The hydrazides of benzoic, phenyacetic, and 3-phenylpropionic acids react with an acidic solution of formaldehyde to give 15 . Similar treatment of the corresponding methylhydrazides gave 16 . The ethers 15 can be cleaved to give, after methylation, 16 . Spectral data for 15 and 16 are presented. 相似文献
1000.