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211.
The distributed feedback dye laser (DFDL) generates a train of picosecond pulses when pumped well above threshold. This DFDL emission can be quenched by injecting a laser pulse into DFDL. By proper timing of the quencher laser pulse, only the first DFDL pulse is generated while the successive pulses are suppressed. Operational characteristics and practical design considerations of such a quenched DFDL are given. With 2.5 ns long pump pulses from a N2 laser, a shortest DFDL pulse of 17 ps was obtained at 380 nm. 相似文献
212.
Tunable picosecond pulse generation in the 362–420 nm spectral range is reported. The laser is simple in construction and can be easily constructed from relatively inexpensive optical and mechanical parts. 相似文献
213.
G. Battiston G. Sbrignadello G. Bor J.A. Connor 《Journal of organometallic chemistry》1977,131(3):445-452
Under suitable conditions, the reaction of allylzinc bromide with a carbonyl compound can be reversible. 相似文献
214.
O. Borůvka 《Annali di Matematica Pura ed Applicata》1956,41(1):325-342
Résumé Le présent Mémoire contient la partie analytique d'une théorie des transformations des intégrales des équations différentielles
linéaires ordinaires du second ordre. Il s'agit des équations réelles (a), (A) (p. 327) et des questions de caractère global. La théorie développée gravite autour des propriétés des équations différentielles
non-linéaires du troisième ordre (b), (B) (p. 327). Sont donnés, en particulier, les théorèmes sur l'existence et l'unicité ainsi que les expressions explicites pourles intégrales des équations (b), (B). 相似文献
215.
Preferential solvation of polymer molecules and strong EPD-EPA (EPD, electron pair donor; EPA, electron pair acceptor) interaction between solvent and nonsolvent molecules were found to be of great significance in the fabrication of two kinds of aromatic polyimide (AP) nanoparticles. Surfactant free yet stable AP nanoparticles were prepared using a liquid-liquid phase separation method. The stability of the AP nanoparticles can be achieved by the solvation multilayer resulting from a solvation stabilization chain in the form of nonsolvent --> solvent --> AP (a --> b denotes that component b is solvated by component a). The significance of this stabilization chain was identified by many comparative experiments using different types of molecular probes. On the other hand, the formation of AP nanoparticles was found to be governed by a nucleation process and therefore the particle size is controlled by the nucleation rate. A very high level of supersaturation can be attained under the intensive local motions induced by ultrasound, resulting in a very high nucleation rate. This effect was found to be extremely useful in the fabrication of sub-50 nm AP nanoparticles. 相似文献
216.
Electrostatic interaction between two ion-penetrable spheres near a horizontal plate or in a slit pore is investigated theoretically. The orientation of the line connecting the two particle centers can be arbitrary relative to the plate(s). The electrostatic interaction energy and force on each particle are obtained analytically by the method of images. Emphasis is placed on the effect of the presence of the second particle, compared to the case of a single particle or the case without any plate(s). It is found that the horizontal electrical force on each particle is always repulsive. This repulsive force is enhanced by the plate(s) of constant surface charge density, while it is reduced by the plate(s) of constant surface potential. The electrostatic interaction together with the steric effect is used to determine the partition coefficient for the case of a slit pore, correct to O(C(infinity)), where C(infinity) is the volume fraction of particles in the bulk solution. The positive correction coefficient is larger for conducting plates than for insulating plates. Copyright 2001 Academic Press. 相似文献
217.
Giuliana Gervasio Fabrizio Musso Sándor Vastag György Bor Gábor Szalontai László Markó 《Journal of Cluster Science》1994,5(3):401-417
Co2(CO)8 and Me2P(S)P(S)Me2 react to form the two cluster complexes: Co4(CO)9S(PMe2)2) (1) and Co3(CO)7S(SPMe2) (2). The strucure of1 and of the disubstituted triphenyl phosphine derivative of2. Co3(CO)5(PPh3)2S (SPMe3) (2a) were determined. Compound1 contains a quasi-planar rhomboidal Co4 cluster formed by two Co3 isosceles triangles sharing a Co-Co edge. One triangle is capped by a sulfur atom, the other triangle has two edge-bridging PMe2 moieties. Electron counting gives 64 electrons corresponding to a planar system; the distribution of long Co-Co distances, in particular in the triangle bearing PMe2 bridges, suggests that the excess electrons are located on Co-Co antibonding ortibals. Compound2a contains a Co3S cluster with one side bridged by a SPMe2 unit forming a four-membered Co2SP ring. The substitution of two CO groups with two PPh3 causes a large deformation of the cluster Co-Co bondscis to these two phosphorus atoms. Crystal data for1, space group P1,a = 9.728(2) Å,b = 10.288(2) Å,c = 11.860(3) Å, = 86.41(2)°, = 76.20(2)°, = 80.37(5)°,Z = 2, 5300 reflections,R = 0.0398; for2a, space group P1,a = 9.78(3) Å,b = 13.05(4) Å,c = 18.28(6) Å, = 93.23(3)°, = 99.17(2)°, = 97.26(6)°,Z = 2, 2976 reflections,R = 0.0579. 相似文献
218.
Hüseyin Bor 《Proceedings Mathematical Sciences》1994,104(2):367-372
In this paper using δ-quasi-monotone sequences a theorem on
summability factors of infinite series, which generalizes a theorem of Bor [4] on
summability factors of infinite series, is proved. Also, in the special case this theorem includes a result of Mazhar [8]
on |C, 1|k summability factors. 相似文献
219.
Analytical magnetapheresis is a newly developed technique for separating magnetically susceptible particles. The magnetically susceptible particles are deposited on a bottom plate after flowing through a thin (< 0.05 cm) separation channel under a magnetic field applied perpendicular to the flow. Particles with various magnetic susceptibilities can be selectively deposited and separated by adjusting the applying magnetic force and flow rates. Magnetic susceptibility is an important parameter for magnetic separation. Magnetic susceptibility determination of various ion-labeled red blood cells (RBCs) using analytical magnetapheresis with a simple theoretical treatment is reported in this study. Susceptibility determination is based on the balance between maximal channel flow rate and magnetically induced flow rate for deposition. We tried a new approach to determine particle magnetic susceptibilities using a balance of magnetic and drag forces to control magnetically induced particle velocities. The Er3+, Fe3+, Cu2+, Mn2+, Co2+, and Ni2+ ions were used to label RBC at various labeling concentrations for susceptibility determination. The susceptibilities determined for various ion-labeled RBC under two magnetic field intensities fell within a 10% range. The average viabilities of various ion-labeled RBCs were 96.1 +/- 0.8%. The susceptibility determination generally took less than 10 min. Determined susceptibilities from analytical magnetapheresis differed by 10% from reference measurements using a superconducting quantum interference device (SQUID) magnetometer. The cost and time for analysis is much less using analytical magnetapheresis. This technique can provide a simple, fast, and economical way for particle susceptibility determinations. 相似文献
220.
Pier Luigi Stanghellini Giuliana Gervasio Rosanna Rossetti György Bor 《Journal of organometallic chemistry》1980,187(3):C37-C40
sym-(CO)9Co3C(CS2)Co3(CO)7S has been isolated from the mixture formed in the reaction of Co2(CO)8 with CS2. This is the fifth member of the CmSnCop(CO)q family identified by X-ray diffraction studies. The molecular structure of the title compound is discussed and briefly compared with that of the asymmetric isomer and related compounds. 相似文献