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981.
SHI Rongfu XU Mancai SHI Zuoqing WANG Chunhong FAN Yunge FENG Junqian HE Binglin The State Key Laboratory of Functional Polymer Materials for Adsorption Separation Institute of Polymer Chemistry Nankai University Tianjin P. 《Chinese Journal of Reactive Polymers》2001,(1)
1. INTRODUCTIONMacroporous polymers of technical divinylbenzene are often used as polymeric adsorbents for adsorptive separation. These resins may be advantageous compared to other polymeric adsorbents due to the high specific surface area and high porosity. However, the ability of these resins to adsorb polar compounds is very weak because the resins are non-polar and the values of the swelling capacity in aqueous solution are relatively low, and thus these resins are limited for adsorpti… 相似文献
982.
In this paper the limits are presented which were obtained by the search for magnetic monopoles using the MACRO track-etch subdetector as a stand alone detector. We compare the flux upper limit for g = gD monopoles to other limits obtained by different subdetectors of MACRO, till August 1, 1995, when the construction of the apparatus was completed. The global MACRO monopole limit is compared with other limits from different experiments. 相似文献
983.
丁义明 《数学物理学报(B辑英文版)》2004,24(4):698-704
Let f : I → I be a piecewise monotone interval map. The critical point set C(f) of f consists of all the preimages of its turning points. It is proved that the complex dynamical behaviors of f are all concentrated on the derived set of C(f). f is asymptotically periodic if and only if the derived set of C(f) is countable. 相似文献
984.
985.
利用光纤光栅的高功率掺镱光纤激光器 总被引:5,自引:0,他引:5
报道了利用一对光纤光栅作为双包层Yb^3 掺杂光纤激光器的谐振腔,激光二极管光纤模块(LD)进行了抽运,并采用锥形光纤实现了全光纤化结构,获得了高功率双包层光纤激光器。光纤光栅通常是用融接技术实现与双包层光纤的一体化连接的,采用的双包层光纤为内包层为梅花瓣形结构的掺Yb^3 离子的石英光纤,采用的抽运源为中心波长为970nm的半导体激光光纤输出模块,在抽运源电流达到2.4A时,获得了10.8W的光纤激光器单横模输出,输出波长1100.5nm,峰值半峰全宽(FWHM)为0.54nm,激光器斜效率为59%。 相似文献
986.
The standard method used for tagging b-hadrons in the DELPHI experiment at the CERN LEP Collider is discussed in detail. The main ingredient of b-tagging is the impact parameters of tracks, which relies mostly on the vertex detector. Additional information, such as the mass of particles associated to a secondary vertex, significantly improves the selection efficiency and the background suppression. The paper describes various discriminating variables used for the tagging and the procedure of their combination. In addition, applications of b-tagging to some physics analyses, which depend crucially on the performance and reliability of b-tagging, are described briefly.Received: 14 January 2003, Revised: 14 October 2003, Published online: 3 December 2003 相似文献
987.
掺杂PPQ薄膜的电致发光及电场调制 总被引:2,自引:1,他引:1
从掺杂PPQ薄膜单层器件的电致发光光谱在掺杂前后的变化。说明掺杂PPQ薄膜中存在着基质分子和掺杂分子间的能量传递,其电致发光光谱随加电场变化说明电场对PPQ薄膜的电致发光具有调制作用。用一个由单链模型扩展到包括杂质和外场的Hamiltonian进行数值求解。结果表明:在PPQ和TPL分子之间有效的能量传递是源于它们之间的是荷转移,且随着外加电压的变化,其电致发光谱峰位的移动与掺杂前后系统总量的改变及发光强度与掺杂后转移的电荷数之间分别存在对应关系,这一模型很好地解释了电场对PPQ薄膜电致发光的调制作用。 相似文献
988.
G. Kernel D. Korbar P. Križan M. Mikuž U. Seljak F. Sever A. Stanovnik M. Starič D. Zavrtanik C. W. E. van Eijk R. W. Hollander W. Lourens F. G. Michaelis N. W. Tanner S. A. Clark J. V. Jovanovich J. D. Davies J. Lowe S. M. Playfer OMICRON Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,48(2):201-207
The reaction π+ p→π+π+ n was studied in the vicinity of the reaction threshold at ten incident pion beam momenta from 297 MeV/c to 480 MeV/c. From data angular distributions, invariant mass spectra and integrated cross-sections were deduced. The chiral symmetry breaking parameter as determined by this reaction equals to ξ=1.56±0.26±0.39, where the first error is experimental, while the latter reflects the uncertainty in the ansatz used in the extrapolation to the reaction threshold. A comparison with the other reaction channels of the reaction πp→ππN indicates that a single parameter (ξ) is not sufficient to describe low energy ππ interactions. 相似文献
989.
The ZEUS Collaboration S. Chekanov et al. 《The European Physical Journal C - Particles and Fields》2003,26(3):389-409
Diffractive photoproduction of vector mesons, , where Y is a proton-dissociative system, has been measured in e+p interactions with the ZEUS detector at HERA using an integrated luminosity of 25. The differential cross section, , is presented for , where t is the square of the four-momentum transferred to the vector meson. The data span the range in photon-proton centre-of-mass
energy, W, from 80 GeV to 120 GeV. The t distributions are well fit by a power law, . The slope of the effective Pomeron trajectory, measured from the W dependence of the and cross sections in bins of t, is consistent with zero. The ratios to and to increase with increasing -t. Decay-angle analyses for , and mesons have been carried out. For the and mesons, contributions from single and double helicity flip are observed. The results are compared to expectations of theoretical
models.
Received: 22 May 2002 / Published online: 9 December 2002 相似文献
990.
We present a method for generating the set of weakly efficient solutions of a nonconvex multiobjective optimization problem.
The convergence of the method is proven and some numerical examples are encountered.
相似文献