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排序方式: 共有290条查询结果,搜索用时 12 毫秒
1.
When a jet of soluble gas is directed on to liquid surface, the kinetic energy of the jet is transferred to the liquid giving rise to circulation, which in turn enhances mass transfer. Consequently, the mass transfer coefficient is related to the characteristics of the jet. 相似文献
2.
Reed M. Izatt Steven R. Izatt Don W. Mcbride Jr. Jerald S. Bradshaw James J. Christensen 《Israel journal of chemistry》1985,25(1):27-32
Macrocycle-mediated fluxes of Cd(NO3)2 and of several binary mixtures of Cd(NO3)2 with the nitrate salt of either Na+, K+, Rb+ Cs+, Ag+, Ca2+, Sr2+, Pb2+, Zn2+, or Cu2+ have been determined in a H2O-CHCl3–H2O liquid membrane system. Of the macrocycles studied, 2.2 and 2.2DD most successfully transported Cd2+ In the Cd2+–Mn+ mixtures, Cd2+ was transported selectively with 2.2 when Mn+ was either an alkali or an alkaline earth cation. However, when Mn+ was either Ag+, Pb2+, or Cu2+ the Cd2+ flux was reduced sharply. Generally, cation flux was greater for 2.2DD than for 2.2 with selectivity for Cd2+ being altered also in several cases. Relative fluxes from binary cation mixtures depend on metal cation radius, macrocycle cavity diameter, ligand ring substituent and log K for metal ion-macrocycle interaction. 相似文献
3.
4.
John E Bradshaw D Wynne Griffiths 《Journal of the science of food and agriculture》1990,50(2):167-172
The sugar content was determined of 19 cultivars of swede (Brassica napus ssp rapifera L) grown in rows 50 and 75 cm apart. Sugar concentration ranged from 54.3 to 78.7 g kg?1 fresh weight and was positively correlated with dry matter content which ranged from 90.4 to 138.7 g kg?1 fresh weight. The average concentration of fructose, glucose and sucrose in the dry matter was 225.0, 328.4 and 34.5 g kg?1 DM, respectively. The high-dry-matter cultivars tended to have less fructose and more sucrose than the low-dry-matter ones, but total sugar concentration in the dry matter was not associated with dry-matter content. Row width had little effect on sugar content compared with the differences between cultivars. The implications for the feeding value of swedes are discussed. 相似文献
5.
Isabella S. Romero Nathan P. Bradshaw Jesse D. Larson Sean Y. Severt Sandra J. Roberts Morgan L. Schiller Janelle M. Leger Amanda R. Murphy 《Advanced functional materials》2014,24(25):3866-3873
Single‐component, metal‐free, biocompatible, electromechanical actuator devices are fabricated using a composite material composed of silk fibroin and poly(pyrrole) (PPy). Chemical modification techniques are developed to produce free‐standing films with a bilayer‐type structure, with unmodified silk on one side and an interpenetrating network (IPN) of silk and PPy on the other. The IPN formed between the silk and PPy prohibits delamination, resulting in a durable and fully biocompatible device. The electrochemical stability of these materials is investigated through cyclic voltammetry, and redox sensitivity to the presence of different anions is noted. Free‐end bending actuation performance and force generation within silk‐PPy composite films during oxidation and reduction in a biologically relevant environment are investigated in detail. These silk–PPy composites are stable to repeated actuation, and are able to generate forces comparable with natural muscle (>0.1 MPa), making them ideal candidates for interfacing with biological tissues. 相似文献
6.
J. H. Marsh S. A. Bradshaw A. C. Bryce R. Gwilliam R. W. Glew 《Journal of Electronic Materials》1991,20(12):973-978
Impurity induced disordering of GaInAs quantum well structures with barriers of AlGaInAs and of GaInAsP has been investigated
using boron and fluorine. The impurities were introduced by ion implantation followed by thermal annealing. Annealing unimplanted
P-based quaternary material at temperatures greater than 500° C caused a blue shift of the exciton peak. At annealing temperatures
greater than 650° C red shifts in the exciton peak of unimplanted Al-based quaternary material were observed. Boron implantation
caused small blue shifts of the exciton peak in both material systems at low annealing temperatures. Much larger blue shifts
were observed in the fluorine implanted samples. 相似文献
7.
John E. Bradshaw Robert K. Heaney G. Roger Fenwick Ian H. McNaughton 《Journal of the science of food and agriculture》1983,34(6):571-575
The glucosinolate content of three fodder kales, one fodder rape, one semi-artificial rape and one radicole were determined. The major glucosinolates (mmol kg?1 dry matter) were: in kale leaf, glucobrassicin (3.21) and sinigrin (3.12); in kale stem, sinigrin (5.82); in rape leaf, gluconapin (3.14) and progoitrin (13.99); in rape stem, gluconapin (3.29) and progoitrin (20.18); in semi-artificial rape leaf, gluconapin (25.64) and progoitrin (9.00); in semi-artificial rape stem, gluconapin (35.33) and progoitrin (12.08); in radicole leaf, progoitrin (4.74) and glucobrassicin (3.28); and in radicole stem, gluconapin (3.26) and progoitrin (5.53). The implications for plant breeding are discussed. 相似文献
8.
Shu-Jen Tsai Li Zhang Phadke A.G. Yilu Liu Ingram M.R. Bell S.C. Grant I.S. Bradshaw D.T. Lubkeman D. Le Tang 《IEEE transactions on circuits and systems. I, Regular papers》2007,54(8):1819-1828
A global view of power system's frequency behavior opens up a new window for analyzing system's dynamics. With the aid of global positioning system, measurements from different locations would have synchronous time; therefore a system-wide observation and analysis would be possible. As part of the US-wide power frequency monitoring network project this paper focus on simulation study results of power frequency dynamics of the Eastern U.S. system. The study assesses the frequency measurement accuracy needed to observe frequency dynamics from events such as remote generation drops. Electromechanical-wave propagation phenomena during system disturbances have been observed. The speeds of electromechanical-wave propagation in different areas of the U.S. systems were estimated and their characteristics were discussed. 相似文献
9.
A comprehensive simulation model of a novel rotating spool compressor is presented. The spool compressor provides a new rotary compression mechanism with easily manufactured components. A detailed analytical geometry model of the spool compressor is presented, which includes the geometry of the vane. This geometry model is included in an overall comprehensive compressor model that includes sub-models for friction, leakage, and heat transfer. The results of the comprehensive model were validated using experimental data from a prototype compressor. The prototype compressor has an overall displacement of 23.9 cm3, and was operated using R410A as the working fluid. The model predicts the volumetric efficiency, discharge temperature, and shaft power of the prototype compressor to within 3.13% MAE, 16.5 K and ?13.2 W average deviation, respectively. The trends and spread in the data indicate that additional effort should be focused on the operation of the active sealing elements within the compressor. 相似文献
10.
M Villar F Lefèvre HD Bradshaw E Teissier du Cros 《Canadian Metallurgical Quarterly》1996,143(1):531-536
With random amplified polymorphic DNA (RAPD) markers, we have tagged a genomic region in Populus sp. involved in qualitative resistance to Melampsora larici-populina. Our approach was based on three steps: use of RAPD markers that can be quickly and efficiently researched: application of "bulked segregant analysis" technique on individuals of one interspecific family P. trichocarpa x P. deltoides to search for RAPD markers linked to resistance; and validation of these markers in two other families linked with the first one in a 2 x 2 factorial mating design. Of five detected markers, only one marker M03/04_480 was polymorphic in the three segregating families, involving 89 individuals and four different parents. We have estimated the recombination value of 1 cM with 1 cM sampling error. 相似文献