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The dependence of the nuclear temperatures of highly excited systems, extracted by means of the double ratios of the emitted isotopes, on the experimental conditions is investigated. Experimental data obtained in the Xe+Cu 30 MeV/nucleon reaction are used to study the sensitivity of the method and the effects of the energy thresholds on the obtained temperature values. We find that the temperatures extracted using the He/Li ratios can be strongly influenced by the experimental energy thresholds which are different for different elements. These distortions depend on the velocity of the emitting system and on the detection angle and therefore particular care is needed in the choice of the detectors in those experiments in which velocities are low and angles are large. The use of four isotopes of the same element make negligible such effects. Received: 6 October 1999 / Accepted: 28 May 2000  相似文献   
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We continue the study of specialized block-colourings of Steiner triple systems initiated in [2] in which the triples through any element are coloured according to a given partition π of the replication number. Such colourings are equitable if π is an equitable partition (i.e., the difference between any two parts of π is at most one). Our main results deal with colourings according to equitable partitions into two, and three parts, respectively.  相似文献   
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Zusammenfassung Apparate und Methoden, die auf photoelektrischem bzw. auf photographischem Wege arbeiten, werden bezüglich des Endergebnisses der am häufigsten vorkommenden absorptionsspektroskopischen Messungen (Analyse und Strukturuntersuchungen) miteinander verglichen. Nach einem kurzen Hinweis auf die Fehler, die im Endergebnis größenordnungsmäßig zu erwarten sind, werden einige Richtlinien für die Wahl des zweckmäßigsten Apparates diskutiert.
Summary A comparison is given of the apparatus and methods, which function photoelectrically or photographically, with respect to the end results of the most common absorption spectroscopic measurements (analysis and studies of structure). After a short reference to the errors, which may be expected in the final result, with respect to their order of magnitude, a discussion is given concerning several suggestions as to the choice of the most suitable apparatus.

Résumé On compare appareils et méthodes qui fonctionnent suivant un procédé photoélectrique ou photographique, avec les résultats finaux des mesures d'absorption spectroscopiques les plus habituelles (analyses et études de structure). Après un examen des erreurs que l'on peut attendre dans le résultat final et de leur ordre de grandeur, on discute diverses suggestions concernant le choix de l'appareil le plus convenable.
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Energetic proton emission has been investigated as a function of the centrality in the reaction 58Ni + 58Ni at 30 AMeV. Protons with energy extending up to a relevant fraction of the total available energy in the reaction were measured and studied. The dependence on the reaction centrality has been extensively investigated and data have been compared with the results of microscopic transport calculations. The more striking observation concerns the extremely energetic proton (ENN P ≥ 130 MeV) multiplicity which is found to increase almost quadratically with the number of participant nucleons thus indicating the onset of a mechanism beyond one and two-body dynamics.  相似文献   
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Zusammenfassung Es wird eine mikroanalytische Methode zur quantitativen Bestimmung von Iridium als Element oder in Legierung beschrieben. Mengen von 0,2 bis 6 mg der Probe werden, nach Aufschluß mit Cl2 und NaCl und folgender Oxydation, mit Hydrochinon bzw. Kaliumferrocyanidlösung bei Gegenwart von o-Dianisidin als Indikator titriert. Der mittlere Fehler beträgt: –1,3±1% für die Ferrocyanid- und –3,2±0,5% für die Hydrochinontitration.Mit 1 Abbildung.  相似文献   
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The paper presents the numerical simulation results of the surface roughness influence on gas-dynamic processes inside flow parts of a supersonic ejector. These simulations are performed using two commercial CFD solvers (Star- CCM+ and Fluent). The results are compared to each other and verified by a full-scale experiment in terms of global flow parameters (the entrainment ratio: the ratio between secondary to primary mass flow rate - ER hereafter) and local flow parameters distribution (the static pressure distribution along the mixing chamber and diffuser walls). A detailed comparative study of the employed methods and approaches in both CFD packages is carried out in order to estimate the roughness effect on the logarithmic law velocity distribution inside the boundary layer. Influence of the surface roughness is compared with the influence of the backpressure (static pressure at the ejector outlet). It has been found out that increasing either the ejector backpressure or the surface roughness height, the shock position displaces upstream. Moreover, the numerical simulation results of an ejector with rough walls in the both CFD solvers are well quantitatively agreed with each other in terms of the mean ER and well qualitatively agree in terms of the local flow parameters distribution. It is found out that in the case of exceeding the “critical roughness height” for the given boundary conditions and ejector’s geometry, the ejector switches to the “off-design” mode and its performance decreases considerably.  相似文献   
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