摘要:

A new spectrofluorimetric method is developed for the assay of carazolol and its pharmaceutical formulation at room temperature. The method is simple, rapid, accurate and sensitive enough for the quantitative determination of carazolol in nanomolar concentrations. Furthermore the proposed method helps in the identification of the drug. The procedure involves establishment of the calibration curve and comparison of the fluorescence intensity of standard alcoholic solution of carazolol to that of the unknown sample under identical conditions and with reference to the linear part of the curve. The maximum wavelengths employed for excitation and emission were 285 nm and 344 nm respectively.

ISSN:0038-7010    

DOI:10.1080/00387018208062650

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Surface enhanced Raman spectroscopy has been used to study the adsorption of pyridine and cyanide on Cu, Ag, and Au electrodes. The Raman spectra for pyridine on these three substrates closely resembled each other, and the Raman peaks exhibited small shifts from the corresponding peaks in an aqueous pyridine solution. The low frequency vibrational modes in the region 200–250 cm−1are attributed to the metal-pyridine stretches, namely, v[Cu-N(pyridine)] = 241 cm−1, v[Ag-N(pyridine)] = 237 cm−1, and v[Au-N(pyridine)] = 232 cm−1. The energies of the metal-pyridine stretches were quite insensitive to the kind of substrate the molecule was on. We report also the surface enhanced Raman scattering from cyanide adsorbed on Au. The CN stretching frequency was at 2109 cm−1, which was attributed to that of the adsorbed Au(CN)−2complex. In addition, three low frequency modes were observed at 88, 228, and 325 cm−1. Cyanide adsorption on Cu and Ag electrodes was also investigated. For the Cu/cyanide system, Raman shifts at 175, 312, 434, and 2089 cm−1were observed. They are due to the presence of the complex ions, Cu(CN)2-3and Cu(CN)3-4. For the Ag/cyanide system, Raman shifts at 143, 218, 303, and 2104 cm−1were observed. They are due to the presence of Ag(CN)2-3complex.

ISSN:0038-7010    

DOI:10.1080/00387018208062651

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Experimental results are discussed for laser Raman spectra of CO adsorbed on Ni(100) at -131C. Raman shifts are observed at 2050, 2028, 466 and 419 cm−1. Assignments are made for the modes based upon C2vand C4v. point groups. The assignments are compared with earlier experimental and theoretical work.

ISSN:0038-7010    

DOI:10.1080/00387018208062652

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The ways of degradation of electronic excitation energy of singlet states of complex molecules in the gas phase with various character of dependence of the quantun yield and lifetime of fluorescence on the excess vibrational energy of excited molecules, ΔE*vib, are discussed. From the analysis of literature data on phthalimide and anthracene derivatives and perylene, and also from the results of investigations conducted in the present study for 9,10-dimethylanthracene and 9,10-diphenylanthracene it follows that in the majority of cases radiationless degradation of electronic excitation energv is realized both by means of intersystem crossing and internal conversion. For all studied molecules, with the exception of anthracene, an increase in intersystem crossing with increasing ΔE*vibof excited singlet state is observed, while the internal conversion probability may either increase or decrease. In particular, an

ISSN:0038-7010    

DOI:10.1080/00387018208062653

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The simple five-parameter force-field approximations were applied to triphenylene. Symmetry coordinates are specified. The frequencies of both in-plane and out-of-plane vibrations were calculated and correlated with observed data from the literature.

ISSN:0038-7010    

DOI:10.1080/00387018208062654

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Formation of 3-hexene-2,5-dione (diacetylethylene) was observed in the photooxidation of 1,2,4-trimethylbenzene in the mixture of NO-H2O-air. The 3-hexene-2,5-dione is a larger aromatic ring-ruptured compound than has been reported. Although the yield of 3-hexene-2,5-dione collected was very low, the formation of 3-hexene-2,5-dione showed that the formation of other large dicarbonyl compounds due to the cleavage reaction of aromatic ring is possible in the photooxidation of aromatic hydrocarbons. Formation of 3-hexene-2,5-dione was also observed in the photooxidation of the p-xylene system.

ISSN:0038-7010    

DOI:10.1080/00387018208062655

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

At the present time suopicosecond pulses of laser light as short as 0.5·10−12s have been generated and detected and the possssibility of 50·10−15s pulses generation as a limit is predicted [1]. Nothing has been said about the fundamental physical reasons that determine this limit. The aim of our work is to throw some light upon the generate mechanisms that govern the generation of ultrashort photon pulses and other pulses of physical fields of limited short duration. It is also obvious that the pulse duration Δt cann't be shorter than the elementary time length Δtoif if it exists. So let us search for possicis candidates for Δtoand look for methods of their generation. There is only one general method availaole to get automatically snortened pluses of boson fields - the method of boson avalanches [2]. It consists of the following: take an excited particle and put it into a physical resonator for a boson field for getting a boson by means of the sneous boson emission process in the resonator in a time τ. If we put N > 1 equel excited particles into the resonator we shall get a pulse of boson radiation consisting of ∼N bosons in a time (τ/N)·η, where η is an interference factor of the order η (λ2/Ao) for a radiating disk of square section Aoand for bosons of wavelength λ. This law was well established for photons generated by solids for which τ = 10−3s, Ao= 1 cm2, λ2= 10−10cm2and N = 1019and Δt = 10−12s. But these numbers are not the limited ones and we could pose for instance N = 1023and τ = 10−10s. The result Δ t =10−21will be wrong because in 10−11s photons can travel only through a distance Δ1 ∼ 3·10−11cm and a sphere of diameter Δ1 = 3·10−11led with ordinary matter cann't contain 1023particies. It must be said that particles outside of this sphere cann't interact to produce a motor, ava-_anche. So we see thatboson avalancnes can generate pulses as shot as needed if the material is as dense as to fulfill the new condition.

ISSN:0038-7010    

DOI:10.1080/00387018208062656

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018208062649

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor