We present a method for obtaining time-resolved measurements of the amplitude modulation and the phase shift of a chirped probe pulse interacting with a femtosecond-laser-produced plasma. Based on spectral interferometry, the technique allows for single-shot measurements and keeps the temporal resolution associated with the full bandwidth of the probe pulse. We demonstrate the efficiency of this technique by probing femtosecond-laser breakdown of plastic targets. 相似文献
Summary: The lack of accurate knowledge for measuring monomer droplet size and droplet size distribution has hampered the further progress of miniemulsion polymerization. Monomer droplet size is probably the most important characteristics of a miniemulsion, influencing the miniemulsion stability and the nucleation mechanism. To date, several experimental techniques have been tested to measure miniemulsion droplet size, but none are convenient and accurate. This work presents a novel experimental technique, using a powerful new scanning transmission electron microscopy (STEM) imaging system, which allows transmission observations of wet samples in an environmental scanning electron microscopy (ESEM). This new imaging technique is a useful technique to directly measure droplet size and droplet size distribution.
Miniemulsion droplets in dark field wet STEM imaging conditions. 相似文献
We take advantage of the interpretation of stochastic capacity expansion problems as stochastic equilibrium models for assessing the risk exposure of new equipment in a competitive electricity economy. We develop our analysis on a standard multistage generation capacity expansion problem. We focus on the formulation with nonanticipativity constraints and show that their dual variables can be interpreted as the net margin accruing to plants in the different states of the world. We then propose a procedure to estimate the distribution of the Lagrange multipliers of the nonanticipativity constraints associated with first stage decisions; this gives us the distribution of the discounted cash flow of profitable plants in that stage. 相似文献
Abstract The variation of the elastic constant of an oriented C6H6 monocrystal shows the occ urenre of an irreversible process above 20 GPa. This process leads to the format ion of a polymer- as it was shown by IR study. The bulk modulus of the recovered product is one order of magni t ude above that of solid benzene, this gives ev idence for a reconstruct ion of the bonds in the sample. La mesure de constantes élastiques réalisée sur un monocristal orienté de benzene montre qu' un processus irréversible se développe au-delá de 20 GPa. La formation d'un Polymére Peut ětre constatée aprés I'exdpérience. Le module de rigidité du produit formé, un ordre de grandeur au-dessus de Celui du benzene solide, montre clairement qu'une reconstruction des liaisons a eu lieu. 相似文献
Communications in Mathematical Physics - We study the controllability of a closed control-affine quantum system driven by two or more external fields. We provide a sufficient condition for... 相似文献
A two step efficient and practical synthesis of a variety of 4-chromanones is described. Phenols undergo a Michael addition to acrylonitriles in the presence of catalytic amounts of potassium carbonate and tert-butanol to generate the corresponding 3-aryloxypropanenitriles in 50-93% yields. Treatment of the resulting aryloxypropionitriles with 1.5 equiv of TfOH and 5 equiv of TFA, followed by an aqueous work up afforded 4-chromanones in moderate to excellent yields. 相似文献