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151.
陈迪 《应用数学与计算数学学报》1994,8(1):70-76
本文讨论了具有r个成败型元件串联系统可靠性的置信下限问题。研究了虚拟系统法置信下限的小样本性质,证明了,在通常情况下虚拟系统法置信下限要大于常见的L-M法置信下限.更一般地,本文证明了在成败型试验中,当成功数与试验数之比保持不变时,试验次数的增加将直接缩小成功率置信区间的长度。 相似文献
152.
Arthur Greenberg Oleg P. Charkin Ralph H. Bartram István Hargittai Gyula Beke 《Structural chemistry》1992,3(3):221-224
Unsigned book reviews are by the Book Review Editor. 相似文献
153.
Erika Vrkonyi-Schlovicsk Klmn Takcs Istvn Hermecz 《Journal of heterocyclic chemistry》1997,34(3):1065-1066
Diastereomeric timolol tartrates 4 are obtained in a one-pot synthesis from the racemic base 2 and optically active O,O-diacetyl- or O,O-dibenzoyltartaric anhydrides 3 , as only one of the diastereomers precipitates from acetone solution. Acidic hydrolysis as the corresponding 4 leads to timolol in high yield and optical purity. 相似文献
154.
Then-th commutator for a,b in a ringR is defined inductively as follows: [a,b]1=[a,b]=ab−ba and[a,b]
n=[[a,b]−1,b]. We characterize the ringsR without non-zero nil right ideals in which[a,b]
nis nilpotent or regular for alla,b∈R. We also examine the case whereR is a semiprime ring with involution in which[t
1, t2]nis nilpotent or regular for all tracest
1,t2∈R. 相似文献
155.
Summary The results of local meteorology, solar radiation and ground-level ozone measurements taken in Antarctica during the second
Italian expedition (December 86–February 87) at Terra Nova Bay are presented. During the summer months the site of the Italian
base camp is characterized by a thin strip of deglaciated ground, along which the temperature measurements close to the ground
and up to 6 m high show a strongly superdiabatic profile. This irregular trend of the temperature in the surface layer is
mainly due to the notable incoming amounts of radiation and to the extreme transparency of the atmosphere. This is also shown
by the low values of the ratio between total radiation and diffuse radiation. The ground is thus subjected to intense heating,
especially in the warmer hours of the day, while the surface layer of the atmosphere will be characterized by strong upward
heat fluxes and by turbulent convective movements. Vertical-temperature-profile measurements show an almost forced persistence
in the superdiabatic trend, which tends towards isothermic values only as a resultof rapid variations in the direction and
intensity of the wind, connected to the downward flux of cold air masses, shown also by the simultaneous increases in ground-level
ozone concentrations which would support the presence of dry-deposition processes in the lower layer. However, the complex
local orography and the horizontal discontinuity (sea, deglaciated coast, snow-covered surfaces) do not permit a correct application
of profile flux relations, normally used in studies on groundlevel dry-deposition.
Paper presented at the IV Congresso del Gruppo Nazionale per la Fisica dell'Atmosfera e dell'Oceano, June 22–24, 1987, Rome. 相似文献
156.
Brandau C. Bartsch T. Böhm S. Böhme C. Hoffknecht A. Kieslich S. Knopp H. Schippers S. Shi W. Müller A. Grün N. Scheid W. Steih T. Bosch F. Franzke B. Kozhuharov C. Krämer A. Mokler P. H. Nolden F. Steck M. Stöhlker T. Stachura Z. 《Hyperfine Interactions》2003,146(1-4):41-45
Hyperfine Interactions - An overview of measurements of dielectronic recombination (DR) with the heaviest lithiumlike ions is presented. The experiments have been carried out at the heavy ion... 相似文献
157.
To Professor Guillermo Torres on the occasion of his 70th birthday. 相似文献
158.
Rafael Caballero Mercedes González Flor M Guerrero Julián Molina Concepción Paralera 《European Journal of Operational Research》2007
In this work we present a multiobjective location routing problem and solve it with a multiobjective metaheuristic procedure. In this type of problem, we have to locate some plants within a set of possible locations to meet the demands of a number of clients with multiple objectives. This type of model is used to solve a problem with real data in the region of Andalusia (Spain). Thus, we study the location of two incineration plants for the disposal of solid animal waste from some preestablished locations in Andalusia, and design the routes to serve the different slaughterhouses in this region. This must be done while taking into account certain economic objectives (start-up, maintenance, and transport costs) and social objectives (social rejection by towns on the truck routes, maximum risk as an equity criterion, and the negative implications for towns close to the plant). 相似文献
159.
160.
In this paper, optical limiting property in a magnetic fluid film is studied. The relationship between the emergent power and the incident power is investigated experimentally and theoretically. It is found that the limiting threshold is linear with the diaphragm aperture which accord with the theoretical prediction. The external magnetic field will affect the limiting property, and increase the limiting threshold. 相似文献