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排序方式: 共有1069条查询结果,搜索用时 31 毫秒
71.
Critical-point phase separation in laser ablation of conductors 总被引:1,自引:0,他引:1
Vidal F Johnston TW Laville S Barthélemy O Chaker M Le Drogoff B Margot J Sabsabi M 《Physical review letters》2001,86(12):2573-2576
Laser ablation due to an ultrashort laser pulse on a massive aluminum target was investigated by means of a one-dimensional fluid code. Clear separation between the ablated matter and the unablated target is seen to occur through spinodal decomposition involving thermodynamic instabilities near the critical point of aluminum. The code also shows that the end of the ablation process is preceded by the ejection of droplets, which form about 15% of the total ejected mass. 相似文献
72.
We present the optimal local protocol to distill a Greenberger-Horne-Zeilinger state from a single copy of any pure state of three qubits. 相似文献
73.
Ukegawa F Valls J Vejcik S Velev G Vidal R Vilar R Vologouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Watts T Webb R Wenzel H Wester WC Wicklund AB Wicklund E Williams HH Wilson P Winer BL 《Physical review letters》2000,84(2):232-237
We report a measurement of the fraction of b quarks produced diffractively in &pmacr;p collisions at sqrt[s] = 1.8 TeV. Diffraction is identified by the absence of particles in a forward pseudorapidity region. From events with an electron of transverse momentum 9.5
相似文献
74.
75.
Tkaczyk S Tollefson K Tollestrup A Toyoda H Trischuk W de Troconiz JF Tseng J Turini N Ukegawa F Valls J Vejcik S Velev G Vidal R Vilar R Vologouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Waters D 《Physical review letters》2000,84(6):1110-1115
We search for color singlet technirho and technipion production in p&pmacr; collisions at sqrt[s] = 1.8 TeV recorded with the Collider Detector at Fermilab. These exotic technimesons are present in a model of walking technicolor. The signatures studied are lepton plus two jets plus E(T) and multijet final states. No excess of events is seen in either final state. We set an upper limit on the technirho production cross section and exclude a region in the technipion mass versus technirho mass plane. 相似文献
76.
Toyoda H Trischuk W de Troconiz JF Tseng J Turini N Ukegawa F Vaiciulis T Valls J Vejcik S Velev G Vidal R Vilar R Volobouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Waters D Watts T Webb R 《Physical review letters》2000,84(22):5043-5048
We report results from a study of events with a leading antiproton of beam momentum fraction 0.9057 GeV. Using the dijet events, we evaluate the diffractive structure function of the antiproton and compare it with expectations based on results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA. 相似文献
77.
Jesús del Barrio Eva Blasco Luis Oriol Rafael Alcalá Carlos Sánchez‐Somolinos 《Journal of polymer science. Part A, Polymer chemistry》2013,51(8):1716-1725
We have demonstrated the preparation of a series of photoaddressable supramolecular block copolymers by mixing a carboxy‐terminated azobenzene derivative, 6‐[4‐(4′‐cyanophenylazo)phenyloxy]hexanoic acid (AZO), and two polystyrene‐b‐poly(4‐vinylpiridine) (PS‐b‐P4VP) block copolymers. AZO can be selectively attached to the P4VP block of PS‐b‐P4VP through hydrogen bonding interactions. The assembly of AZO with vinylpyridine group‐containing polymers was initially investigated on a model system composed of P4VP homopolymer and AZO. Homogeneous liquid crystalline materials were obtained for ratios of AZO to vinylpyridine repeating unit, x, lower or equal to 0.50. Mixtures with higher x resulted in heterogeneous materials showing clear macrophase separation. Accordingly, a series of hydrogen‐bonded complexes of PS‐b‐P4VP and AZO, PS‐b‐P4VP(AZO)x, with x = 0.25 and x = 0.50 were prepared. Lamellar and spherical morphologies were observed for the complexes based on PS24‐b‐P4VP9.5 (Mn,PS = 24,000, Mn,P4VP = 9500) and PS24‐b‐P4VP1.9 (Mn,PS = 24,000, Mn,P4VP = 1900), respectively. Photoinduced orientation of the azobenzene units was obtained in films of P4VP(AZO)x and PS‐b‐P4VP(AZO)x with x = 0.25 and 0.50 by using 488 nm linearly polarized light and characterized through birefringence and dichroism measurements. This investigation shows a versatile and less laborious approach to azobenzene‐containing polymer materials with low chromophore content, of interest in optical application. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
78.
79.
Jan Kratochvíl Andrzej Proskurowski Oriol Serra 《Discrete Applied Mathematics》2009,157(12):2575-2576
80.
N. Vidal E. Asua J. Feuchtwanger A. Garcia-Arribas J. Gutierrez J. M. Barandiaran 《The European physical journal. Special topics》2008,158(1):39-44
In recent years, one of the most promising new actuator technologies is based on the use of Shape Memory Alloys (SMA). The
main challenge for the application of devices that use these materials is the hysteresis in the phase transition they suffer
during actuation. Finite element analysis (FEA) is an important aid in the simulation of mechanical properties and thermal
fields in actuators. Dynamic simulations give in many cases enough information without the necessity of building a prototype.
We have used ABAQUS to simulate a Nitinol wire used in a micropositioning actuator. The model parameters, not given by the
supplier but required by the FEA program, have been obtained by thermal and mechanical characterization of the material used.
The output force is computed and compared with the measurements. 相似文献