Table of Content

20 May 1984, Volume 2 Issue 2

Previous Issue    Next Issue

EVOLUTION OF THE IMPURITY CENTRES IN PHOTOGRAPHIC GRAINS AT DIFFERENT STAGES OF THE PHOTOGRAPHIC PROCESS AND ITS MECHANISTIC IMPLICATIONS Ⅲ.BEHAVIOUR OF THE TWO KINDS OF THE LARGESTIMPURITY CENTRES UNDER THE ACTIONOF OXIDIZING SOLUTION

JI SU-XUE, LIU DUN

1984, 2(2):  1-8.  DOI: 10.7517/j.issn.1674-0475.1984.02.1

Asbtract ( 706 )   PDF (410KB) ( 1238 )  

References | Related Articles | Metrics

The behaviour of the two kinds of the largest impurity centres of different sizes in emulsion grains under the action of oxidizing solution is studied by a method of development kinetics. The results indicate that, when acted upon by an oxidizing solution, the emulsion grains bearing larger impurity centres show a lawer development rate and the grains carrying smaller centres show a higher development rate but lose much of their ability to form latent image. Both of these phenomena are attributed to the destruction of the two kinds of the impurity centres by the oxidizing solution. The reason for the enhanced development rate of grains carrying smaller centres is supposed to be the loss of protection of the grains by gelation after the impurity centres being destructed. The results are much the same in the cases of unsensitized, sulphur-sensitized and sulphur-plus-gold-sensitized emulsion.

ON THE DESENSITIZING EFFECT OF SURFACE IODIDE IN EMULSION GRAINS

ZHAN SHI-RONG, WU GUI-LAN, LU GUANG-RONG, LIU DUN, CHENG HU-MIN

1984, 2(2):  9-13.  DOI: 10.7517/j.issn.1674-0475.1984.02.9

Asbtract ( 653 )   PDF (313KB) ( 1210 )  

References | Related Articles | Metrics

A series of double-jet silver halide emulsions are prepared with iodide ions incorporated at different instants of precipitation and thus presumed to locate at different distances from emulsion grain surface. "With iodide ions reaching the grain surface, the emulsion speed falls, the ionic conductivity of the grains rises and, in the case of sulphur-plus-gold sensitization, the drop in ionic conductivity otherwise caused by the sensitization is more than compensated. The desensitizing action of surface iodide, obviously partly due to development retardation, is thought to be connected in some way with the rise in ionic conductivity.

A STUDY OF ESR SPECTRA OF SOME RADICAL PHOTOGRAPHIC SYSTEMS

Zhou Yu-xiang, Kuo Jing-lain, Xu Guang-zhi, Shi Dao-jun

1984, 2(2):  14-23.  DOI: 10.7517/j.issn.1674-0475.1984.02.14

Asbtract ( 684 )   PDF (572KB) ( 1159 )  

References | Related Articles | Metrics

The photochemical processes of CBr₄-φ₂NH, CBr₄-LCV and CBr₄-LMG systems have been studied with the combination of ESR spectra and spin trapping technique. From the hyperfine structures of ESR spectra, and their variation varying with the concentration ratio of CBr₄ to φ₂NH or LCV or LMG, the free radicals such as (C₆H₅NHC₆H₅)₃ C, [(CH₃)₂NC₆H₅]₃C and [(CH₃)₂NC₆H₅]₂ C-C₆H₅ have been identified in these systems respectively in addition to Br.It could be shown that the partial charge-transfer complexes (CBr₄φ₂NH)^*, (CBr₄-LCV)^* and (CBr₄-LMG)^* have been formed with the UV absorption spectra of these systems. Therefore, it is concluded that the photochemical initial step of the above free radical photographic systems includes photolysis of both CBr₄ and (CBr₄-HX)^* (HX =φ₂NH, LCV, LMG).

A STUDY ON THE INFLUENCE OF PHOTON NOISE ON THE PHOTOGRAPHIC GRANULARITY BY A MONTE CARLO COMPUTER SIMULATION TECHNIQUE

XIA PBI-JIE, LIU YU-CHEN

1984, 2(2):  24-33.  DOI: 10.7517/j.issn.1674-0475.1984.02.24

Asbtract ( 638 )   PDF (602KB) ( 1078 )  

References | Related Articles | Metrics

In this paper a probabilistic model for computer simulation is used to simulate an emulsion layer in which the silver halfde grains are random distributed, the latent image formation in grains during exposure and granularity measurement for the emulsion layers as well. By means of a regression analysis approach, the comparisons between the granularities which arise from a random distribution of grains at different grain spatial densities and those of the emulsion layers after exposure to light or one-quantum-threshold radiation are made. It comes to the conclusion that if at each stage of the photographic process each grain in an emulsion layer is independently involved in various reactions concerned, i.e. there is no correlation between grains, there exist no detectable contribution of photon noise to the photographic granularity.

QUENCHING OF ANTHRACENE AND PYRENE FLUORES- CENCE BY DIALKYLANILINES IN SATURATED HYDROCARBONS

LU ZHUNG-HE, YANG NIAN-ZU

1984, 2(2):  34-41.  DOI: 10.7517/j.issn.1674-0475.1984.02.34

Asbtract ( 726 )   PDF (526KB) ( 1089 )  

References | Related Articles | Metrics

The fluorescence quenching of anthracene and pyrene by 1,3-bis-(N-phenyl-N-methylamino)propane (DMA-AMD), N-methyl-N-ethylaniline (MEA) and dimethylani-line (DMA) in n-pentane, methylcyclohexane and n-hexadecane was investigated. The quenching was accompanied by the formation of the corresponding exciplex. The bichromophoric DMA-AMD was found to be a more efficient quencher than either MEA or DMA, yet it yields an exciplex with lower fluorescence efficiency. The result may be accounted for by the intramolecular quenching of the exciplex by the second anilino group in DMA-AMD. The bimolecular quenching constants by these anilines depend on the solvent viscosity and may exceed theoretical diffusion controlled limit in viscous hydrocarbons.

PHOTOCOLOURATION AND PHOTODECOLOURATION PROCESSES OF (E)-2, 5-DIMETHYL -3-FURYLETHYLIDENE (ISOPROPYLIDENE)-SUCCINIC ANHYDRIDE

HUANG FU-XING, JIANG LONG-XIANG, WU GUO-SHENG

1984, 2(2):  42-47.  DOI: 10.7517/j.issn.1674-0475.1984.02.42

Asbtract ( 775 )   PDF (383KB) ( 1266 )  

References | Related Articles | Metrics

The pale yellow title compound 1 underwent photochemical conrotatory ring-closure to give the deep red 7, 7, a-dihydrobenzofuran-5,6-dicarboxylic anhydride 2, which ring-opened back to the title compound in a conrotatory mode on exposure to Ar⁺ laser (515 nm) and did not show a competable thermal 1, 5-H shift against the photodecolouration process due to the lacking of 1-H in the molecule. The extent of photochemical conversion of 1 into its coloured form 2 was determined as 100% by means of Fischer’s method. Thus, the photochemical reaction 1 → 2 was complete. Steady state photochemical analysis revealed the existence of a transition state X somewhere between the excited state of 2 and the ground state of 1 during the photodecolouration process with Ar⁺ laser. X was transformed into compounds 2 and 1 in the specific rates of 22.43 ms.^-1 and 1.11 ms.^-1, respectively. A general reaction scheme has been forwarded hitherto to explain the mechanism of photochromic process of 1. Two different reaction pathways were involved in the photocolouration and photodecolouration processes of the title compound.

1984, 2(2):  48-57.  DOI: 10.7517/j.issn.1674-0475.1984.02.48

Asbtract ( 1515 )   PDF (678KB) ( 1412 )  

References | Related Articles | Metrics

STUDY ON SYNERGISM AND MECHANISM OF NICKEL STEARATE AND 2,2’-THIOBIS (4-TERT-OCTYLPHENOL) IN PROTECTING POLYPROPYLENE AGAINST PHOTO-OXIDATION

PAN JIANG-QING, LI JIAN-XING

1984, 2(2):  58-62.  DOI: 10.7517/j.issn.1674-0475.1984.02.58

Asbtract ( 805 )   PDF (331KB) ( 1013 )  

References | Related Articles | Metrics

The effect of the combination of nickel stearate (NiSt₂) and 2, 2’-thiobis-(-4-tert-octylphenol) (TBP) in protecting polypropylene was studied by the way of using IR-, NMR- and UV-spectra and the measurement of mechanical property. It was shown that the NiSt₂-TBP combination possesses synergism. The mechanism of the synergic action is supposed to form chelate of niekel-thiobisphenol analogous to Am 101 during heat processing of the polymer.

XPS STUDY OF THE OXIDATION PRODUCTS IN THE SURFACE LAYER OF POLYPROPYLENE FILM DURING PHOTO-OXIDATION PROCESS

ZHANG CAN, Hu XIN-ZHOU, WANG DIAN-XUN, CHEN CHUAN-ZHENG, LI SHAO-YU

1984, 2(2):  63-67.  DOI: 10.7517/j.issn.1674-0475.1984.02.63

Asbtract ( 807 )   PDF (296KB) ( 1296 )  

References | Related Articles | Metrics

The various oxidation products and the changes of their relative contents in the surface layer of polypropylene film during photo-oxidation have been studied by XPS. The experimental results show that there are some differences in photo-oxidation pattern between the surface layer and the bulk of polypropylene film.

A STUDY OF IMAGE STABILITY OF ACID SENSITIVE RECORDING MATERIAL BY ACID ADDITIVES

WANG YAN-QIAO, ZHOU XIAO-MIN, DI ZHBN-WEN, CHEN LIU-SHENG, CHEN SU-MING, LI LI-PO

1984, 2(2):  68-72.  DOI: 10.7517/j.issn.1674-0475.1984.02.68

Asbtract ( 706 )   PDF (336KB) ( 978 )  

References | Related Articles | Metrics

The effects of some acid additives, such as phenol, salicylic acid, acetic acid, and benzoic acid etc. on the image stability of the acid sensitive film have been examined. The spectral measurements show that the image stability can be improved by adding certain amount of phenol, but acetic acid and benzoic acid have no such effect. The mechanism of improvement of the image stability by adding phenol has been discussed. It is most probabl ethat proton is released from phenol and inhibits the reversion of quinone, so the image stability is improved.