摘要:

AbstractTrapped electrons,ec−, are produced by photoionization of K4Fc(CN)6in 10MNaOH/H2O and 10MNaOD/D2O glasses at 4.2°K. The linewidth,ΔHms, ofec−changes reversibly between these two temperatures in contrast to the observations for organic matrics. Three proposed mechanisms including dipole relaxation of pendent molecules surrounding the electron cavity, contraction‐expansion model of cavity, and electron retrapping process are each discussed. It appears that no one physical model satisfactorily accounts for the present observations. The electron retrapping process, however, might be a better condidate for interpreting the experimental results in compatible with the optical absorpti

ISSN:0009-4536    

DOI:10.1002/jccs.197500001

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractEPR microwave power saturation technique has been applied to the systems of radiation‐induced radicals in protiated and wholely deuterated 3‐methylpentane to obtain the information concerning the high local spin concentration and radiation energy deposition mechanism. Evidences of spin‐spin interactions have been given from the studies of isothermal decay of these trapped radicals at 77°K. The annealing of the matrix is shown to have almost no effect on the relaxation times of radicals. The influence of nuclear magnetic moment on the spin‐lattice relaxation process of radicals is revealed and discussed on the basis of experimental results from the deuteration of the compound

ISSN:0009-4536    

DOI:10.1002/jccs.197500002

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractTrace amount of mercury in human hair has been determined by destructive neutron activation analysis.It was found that the contents of mercury in the hair of normal people in Taiwan area is the order of 6ppm. It is of interest to point out that very little fluctuation is observed in the contents of mercury in human hair regardless of sex and age of the normal people under investigation.On the other hand for those people who are working in the caustic soda manufacturing plant in which mercury is used as cathode in the electrolysis process of saline water, the mercury contents in their hair are definitely much higher (ca. 30 times) than the average values of normal people.

ISSN:0009-4536    

DOI:10.1002/jccs.197500003

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractX‐ray fluorescence spectra of many coins are studied using a Si(Li) detector and an XRF‐exciter system. Some qualitative and semiquantitative analyses have been carried out. It is demonstrated that this method can be a very powerful means to study the archaeology of metal objects, especially the copper alloys, such as coins and bronze vess

ISSN:0009-4536    

DOI:10.1002/jccs.197500004

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractDirect trimethylsilylation1)of phenanthrene in different molar ratio of phenanthrene/sodium/trimethylchlorosilane is reported and discussed. Instead of the aromatic silyl compounds, such as 9‐trimethylsilylphenanthrene (V), the hydroaromatic silyl compounds, such as 9, 10–bis (trimethylsilyl)‐9, 10‐dihydrophenanthrene (I) were obtained preferentially. Structure of these compounds are characterized and discussed. These silylated products have a general trend to change their properties during long time storage in the atmosphere under exposure to light. A significant difference of chemical shifts between silylated aromatic compound (V) and silylated hydroaromatic compound (I‐IV) was

ISSN:0009-4536    

DOI:10.1002/jccs.197500005

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractFrom the acetone extractive of the bark ofLibocedrus formosana Florin, a new phenolic diterpene, C20H23O3, was isolated. Its structure was elucidated as 6α‐hydroxy‐7‐oxo‐ferrugi

ISSN:0009-4536    

DOI:10.1002/jccs.197500006

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractFrom the fresh leaves ofCirsium arisanenseKitam (Compositae), a flavone glycoside, pectolinarin (II) and an unsaturated dibasic acid, fumaric acid (III), were isolated.

ISSN:0009-4536    

DOI:10.1002/jccs.197500007

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe mechanism which Diammonium Phosphate (DAP) works on cellulose, at thermal state, has been investigated. The thermal behavior was examined by differential scanning calorimetric analysis and thermogravimetric analysis. Infrared spectra of samples before pyrolysis and at several temperatures in pyrolysis were used to obtain further information regarding the pyrolysis reaction.The effect of added DAP, in the temperature range above 200°C, alters the thermal pattern by lowering transition temperature, decreasing far formation and increasing char formation.These observations are interpreted that DAP is acting as an acid, at thermal state, to catalize cellulose dehydration. It is the most significant contribution of fire retardation on cellulose

ISSN:0009-4536    

DOI:10.1002/jccs.197500008

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractA rapid spectrographic method was developed to analyze seven elements collected in glass fiber air filters, they were Cd, Pb, Ni, Zn, Sn, Ti and V. Direct excitation method was used for volatile elements while graphite powder was added for determining involatile elements like titanium and vanadium in a dc arc source. Limits of detection for analyzed elements were between 0.01‐0.1.μg. This simple and sensitive method was employed to analyze samples from fifteen air sampling stations in different areas of Taiw

ISSN:0009-4536    

DOI:10.1002/jccs.197500009

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractGamma radiation induced polymerization of vinyl chloride (VC) and copolymerization of vinyl chloride (VC)‐vinyl acetate (VAc) in Taiwan cedars have been investigated at low temperatures. The polymerization‐rate of VC and the copolymerization‐rate of VC‐VAc system in wood were found to be proportional to the n powers of the dose‐rate, where n became close to the value of 1 as the polymerization temperature being lowered below 0°C. The oxygen in air was recognized to induce the delay of the induction period due to its retardation on the polymerization. The apparent activation energies of VC and VC‐VAc for the polymerization and the copolymerization in wood were determined by use of the Arrhenius plotting as 4.0 Kcal/mole and 3.4 Kcal/mole respectively at the temperature‐range of —15°C∼20°C. The degree of polymerization of VC was greatly affected by the polymerization temperature, although it was observed to be independent on the total gamma dose within 1 Mrad and the kinds of wood. No graft reaction of PVC polymer and PVC‐PVAc copolymer onto the wood cellulose was found, while low graft percentage of about 3% being obtained at 20°Cin the case of using swelling agents. However, this value was found to be decreased to 0.1% at the temperature of —15°C. Based on the above‐mentioned experimental results, the radiation induced low temperature polymerization of VC or copolymerization of VC‐VAc system in Taiwan produced cedars are considered to proceed with ra

ISSN:0009-4536    

DOI:10.1002/jccs.197500010

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY