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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
R.F Fedors 《Polymer》1979,20(10):1255-1258
In a preceding paper it was shown that for high molecular weight polymers, the volume of the repeating unit at Tg is proportional to the total free space defined as Vc?V0 where Vc is the volume of the repeating unit at the critical temperature and V0 is the volume of the repeating unit at absolute zero. Here it will be demonstrated that this proportionality is also true for a host of low molecular weight liquids. In addition, an empirical method of estimating Tc for a high molecular weight polymer is proposed which provides values of Tc which are consistent with those for low molecular weight liquids. 相似文献
993.
Pyrolytic carbon was deposited from acetylene in a fluidized bed at 1100°C on alumina microspheres. In case when only argon was used as the diluent gas, density and BAF of the deposit decreased and deposition yield increased with increasing acetylene concentration. Hydrogen sypply suppressed carbon formation and, consequently, caused an increase in density and Lc. BAF was relatively independent of hydrogen concentration. It was found that high density, isotropic carbon can be deposited from acetylene at 1100°C, if an appropriate proportion of hydrogen is added. 相似文献
994.
Polyurethane prepared from tetramethylene glycol and diisocyanate was exposed in the form of films to small pressures of NO2 and to NO2 plus air. Tensile strength was measured as a function of exposure time and temperature with an apparatus especially constructed for the purpose of measuring mechanical properties in different environmental “atmospheres.” 相似文献
995.
996.
997.
998.
The coupled effects of particle size and 1 wt% NaCl additions on the sequence of melting reactions in a multicomponent system (sand–soda ash–calcite–dolomite–feldspar) were studied using data from DTA, DTGA, and XRD interactively. Glass batches varied in average particle size from 250 μm to finer than 45 μm. Milestone events in the fusion process of the coarse particle base glass were elucidated. The termination temperature of the last significant reaction associated with CO2 release was 35°C lower in the fine particle size batch than with the coarsest batch. Liquid-phase formation at ∼523°C in the batch with 1 wt% NaCl occurred to an increasingly sizable extent with decreasing particle size. This contrasts with a similar effect at ∼630°C for a comparable batch without NaCl via eutectic melting between soda ash and dolomite. Sodium chloride additions significantly enhanced dissolution of CaO relic. 相似文献
999.
K. M. Decossas H. J. Molaison E. F. Pollard 《Journal of the American Oil Chemists' Society》1954,31(8):338-341
Summary and Conclusions A new improved batch solvent extraction plant and its versatility of design have been described. Data have been given on the
cost and initial test operations. The performance of the plant has been tested, and its value as a research tool has been
demonstrated by the production of free gossypol and meals low in gossypol for use in research. Simplicity of operation is
borne out by the fact that only one operator is needed. A limited number of detail drawings of the plant are available on
written request from the Southern Regional Research Laboratory.
Presented at the fall meeting, American Oil Chemists’ Society, Nov. 2–4, 1953, in Chicago, Ill.
One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture. 相似文献
1000.
M. D. Wilding E. E. Rice K. F. Mattil 《Journal of the American Oil Chemists' Society》1963,40(2):55-57
On the basis of the chemical, physical, and biological criteria used, all of which have been shown to be sensitive indicators
of heat damage to oils, it must be concluded that the overall nutritional quality of an oil is not adversely affected by alkali
refining, adsorptive decolorizing, or deodorization; that higher temperatures of deodorization (238C) produce oils nutritionally
equivalent to those deodorized at lower temperatures (160C); and that the normal processes used in manufacturing edible oils
improve the resistance of these oils to heat damage.
Presented at the 6th Congress of the International Society for Fat Research, London, 1962. 相似文献