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121.
Scientometric profile of Indian agricultural research as seen through Science Citation Index Expanded 总被引:1,自引:1,他引:0
Summary An analysis of 16891 publications published by Indian scientists during 1993-2002 and indexed by Science Citation Index Expanded
(Web of Science) indicates that the publication output in the agricultural sciences is on the decline since 1998 onwards.
'Dairy and animal sciences' followed by 'veterinary sciences' constitute the largest component of the Indian agricultural
research output. Agricultural universities and institutes under the aegis of Indian Council of Agricultural Research (ICAR)
are the major producers of research output. Most of the papers have been published in domestic journals and in low normalized
impact factor journals with a low rate of citation per paper. Most of the highly productive institutions are either agricultural
universities or the institutes under the aegis of ICAR. Most of the prolific authors are from the highly productive institutions.
However, only a few highly cited authors are from highly productive institutions. 相似文献
122.
Different parts of ten indigenous medicinal plants were screened for their in vitro anthelmintic activity against Ascaridia galli worms of the birds. Preparations from Carica papaya, Sapindus trifoliatus, Butea frondosa and Momordica charantia were more effective than piperazine hexahydrate. 相似文献
123.
When machining at small depths of cut, metal flow near a rounded tool edge becomes important. It has been established that there is a critical depth of cut which signifies the onset of chip formation. The approximate analysis predicts the neutral point angle corresponding to this critical depth of cut to be 37.6°. The value compares reasonably well with experimental results. 相似文献
124.
An analysis for the formation of nonpropagating fatigue cracks at (the base of V-shaped) notch roots, based on the considerations
of the extent of the critically stressed region ahead of a notch or a crack tip, and the resulting volumetric strength effect,
is developed. Assuming that the minimum local cyclic stress required for crack initiation from a notch root is equal to the
unnotched fatigue limit, σe, and that the minimum local cyclic stress required for the propagation of the crack is equal to the theoretical strength
of the material, σe, a model of notch fatigue limit is proposed that shows that nonpropagating cracks should form at the notch base if ρ≤ ρ0, a critical root radius, provided the notch is sufficiently deep,i.e. d ≥ ρ0. The radius ρ0 is a material constant and can be estimated from known material properties. The estimated values of ρ0 are in fairly good agreement with available experimental values for steels and pure copper. For stresses near the notch fatigue
limit it is suggested that p0 be regarded as a radius above which notch fatigue limit is essentially initiation controlled and below which essentially
propagation controlled. The notch fatigue limit based on complete fracture can then be estimated more accurately with mild
as well as sharp notches.
D. N. LAL, formerly a Graduate Assistant in Materials Science, Syracuse University 相似文献
125.
EMK-Messungen mit einer Diffusionszelle an flüssigen Schlacken der Systeme CaO–Al2O3 und CaO–SiO2 bei 1600°C. EMK und Sulfidkapazität zeigen lineare Abhängigkeit. EMK-Werte können als relatives Basizitätsmaß gewertet werden. 相似文献
126.
The transport of gaseous ethylene oxide (EtO) in several polymer films is studied using the carrier gas method of measurement. Permeability, solubility, and diffusion coefficients describing ethylene oxide (EtO) transport in polypropylene, polyvinylchloride, Teflon-FEP copolymer, and polyethylene films have been obtained over a 30 Celsius degree range at a low concentration of EtO using the carrier gas method of measurement. The results indicate that the diffusion of EtO in polyethylene is independent of penetrant concentration over the range of concentrations used. However, concentration-independent diffusion could not be verified directly for the other films studied. Two different techniques of determining diffusion coefficients were used, and within the precision of the data both yield the same result. An excess enthalpy of solution for the solubility of EtO in Teflon-FEP copolymer was calculated, an observation that suggests that dual-mode sorption may be taking place. 相似文献
127.
128.
B Lal AK Gangopadhyay RM Gidwani M Fernandes R Rajagopalan AV Ghate 《Canadian Metallurgical Quarterly》1998,6(11):2075-2083
Using the novel lead from hydroxy acetyl substituted forskolin analogues, such as 7 beta-hydroxyacetyl-7 beta-deacetyl forskolin or 6 beta-hydroxyacetyl forskolin, a number of water soluble omega-amino acyl derivatives were synthesized. Two such compounds 6 and 18 showed better in vitro activity but failed to show in vivo activity. 相似文献
129.
Inverse gas chromatography technique has been used to study the thermodynamic compatibility of the industrially important elastomers polybutadiene (BR) and polybutadiene copolymerised with acrylonitrile (NBR). The NBR used in this study had nitrile contents of 18 and 34%. The ratio of BR/NBR in blends varied between 1 and 0.25 in both cases and retention volume of twelve probes was measured at 80°C. The Flory-Huggins interaction parameter X′23, computed using a standard procedure, and also the interaction parameter B23 showed that BR and NBR are incompatible in all compositions and that incompatibility increases with nitrile content. © 1995 John Wiley & Sons, Inc. 相似文献
130.
The magnetic and structural properties of the solid solutions Sr2FexRu1?xO4 (O ? x ? 0.5) have been studied using 57Fe and 99Ru Mőssbauer spectroscopy and other techniques. These phases, which are reported for the first time, have the K2NiF4-type structure with iron and ruthenium distributed at random on the B-site. As the ruthenium is replaced by iron the weakly-metallic conductivity and Pauli paramagnetism of Sr2RuO4 give way to localized-electron behaviour and long-range antiferromagnetic order despite the layer-type structure which is unfavourable for 180° Ru-O-M (M = Fe or Ru) magnetic exchange interactions in three dimensions. For x = 0.1-0.4 the iron is present almost entirely in the +3 oxidation state, but for x = 0.5 appreciable amounts of FeIV are also present, in conjunction with FeIII, RuIV, and RuV. 相似文献