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1.
2.
The Co:MgF2 laser, tunable over the range from 1.5 to 2.3 μm, has been investigated under a variety of operating conditions. Included in this paper are reports on basic spectroscopy of Co:MgF2 , a determination of the gain cross section, the efficiency and temporal behavior under pulsed excitation, and performance in theQ -switched mode. In addition, operation with thermoelectric cooling and CW oscillation at the multiwatt power level are discussed. Equations covering laser-pumped lasers are derived and comparisons between experiments and theory are presented. 相似文献
3.
4.
On formalism and stability of switched systems 总被引:1,自引:1,他引:0
In this paper,we formulate a uniform mathematical framework for studying switched systems with piecewise linear partitioned state space and state dependent switching.Based on known results from the the... 相似文献
5.
The humic acids, HA, extracted from a Spanish lignite and the nitrohumic acids, NHA, and nitrofulvic acids, NFA, extracted from the same lignite after its nitration, are hydrolysed with 6N HCI under reflux. The α-amino acids present in the hydrolysates are determined and thirteen α-amino acids are identified. The amounts of nitrogen in the amino-acids released by the hydrolysis increase according to the sequence: NFA > NHA > HA. 相似文献
6.
7.
Isidoro Izquierdo Cubero Maria T. Plaza López-Espinosa Rafael Acuña Castillo 《Journal of chemical ecology》1991,17(8):1529-1541
The synthesis of the title compound13 has been carried out through the preparation of its precursor, (3R,4R,5S,6R)-3,4,5-trihydroxy-1,7-dioxaspiro[5.5]undecane (6), obtained fromd-fructose using Wittig's methodology, reduction, and spiroketalation. Compound6 was transformed into13 by a Barton deoxygenation at C-5 followed by a Corey dideoxygenation at C-3,4 of the appropriately protected derivatives.Enantiospecific synthesis of spiroacetals. Part II. For Part I, see Izquierdo and Plaza (1990). 相似文献
8.
K. J. Moulton R. E. Beal E. L. Griffin 《Journal of the American Oil Chemists' Society》1973,50(11):450-454
Reaction rates, linolenate/linoleate reaction selectivity,trans formation, and conjugated diene formation were determined for mixed commerical catalysts containing 0.5, 1, 2, 10, and 20
parts nickel catalyst (25% nickel) per 1000 parts copper chromite catalyst (ppt) and at catalyst concentrations in the oil
of 1.0, 0.5, and 0.25%. The rate of hydrogenation increased as the amount of nickel increased. Addition of 0.5, 1, and 2 ppt
nickel catalyst to copper chomite catalyst resulted in a small decrease in selectivity compared with straight copper chromite.
When soybean oil was hydrogenated with these mixed catalysts sufficiently to reduce linolenate to 0, iodine values were 102–108
compared to 109–112 for straight copper chromite and to less than 80 for straight nickel.
Presented at the AOCS Meeting, New Orleans April 1973.
ARS, USDA. 相似文献
9.
K. J. Moulton Sr. S. Koritala K. Warner 《Journal of the American Oil Chemists' Society》1985,62(12):1698-1701
Soybean oil was partially hydrogenated in a continuous system with copper and nickel catalysts. The hydrogenated products
were evaluated for flavor and oxidative stability. Processing conditions were varied to produce oils of linolenate contents
between 0.4 and 2.7%, as follows: oil flow, 0.6–2.2 liters/hr; reaction temperature, 180–220 C; hydrogen pressure, 100–525
psig, and catalyst concentration, 0.5–1% copper catalyst or 0.1% nickel catalyst.Trans unsaturation varied from 8 to 20% with copper catalyst and from 15.0 to 27% with nickel catalyst. Linolenate selectivity
was 9 with copper catalyst and 2 with nickel catalyst. Flavor evaluation of finished oils containing 0.01% citric acid (CA),
appraised initially and after accelerated storage at 60 C, showed no significant difference between hydrogenated oils and
nonhydrogenated oil. However, peroxide values and oxidative stability showed that hydrogenated oils were more stable than
the unhydrogenated oil. CA+TBHQ (tertiary butylhydroquinone) significantly improved the oxidative stability of test oils over
oils with CA only, but flavor scores showed no improvement. Dimethylpolysiloxane (MS) had no effect on either flavor or oxidative
stability of the oils. 相似文献
10.
Rafael Diaz 《国际生产研究杂志》2016,54(8):2487-2498
The warehouse order-picking operation is one of the most labour-intense activities that has an important impact on responsiveness and efficiency of the supply chain. An understanding of the impact of the simultaneous effects of customer demand patterns and order clustering, considering physical restrictions in product storage, is critical for improving operational performance. Storage restrictions may include storing non-uniform density stock keeping units (SKUs) whose dimensions and weight constrain the order-picking operation given that a priority must be followed. In this paper, a heuristic optimisation based on a quadratic integer programming is employed to generate a layout solution that considers customer demand patterns and order clustering. A simulation model is used to investigate the effects of creating and implementing these layout solutions in conjunction with density zones to account for restrictions in non-uniform density SKUs. Results from combining layout optimisation heuristics and density zoning indicate statistical significant differences between assignments that ignore the aforementioned factors and those that recognise it. 相似文献