区域开放程度与企业技术创新能力的关系研究——基于有向无环图的实证分析

基于现有研究忽略了区域对外开放程度与企业技术创新能力之间的同期因果关系问题的缺陷,本文使用了有向无环图分析方法来探讨二者之间的同期因果关系,并采用2001~2011年我国战略性新兴产业284家上市企业的面板数据进行了实证分析。结果表明:企业R&D投资越多、R&D波动性越小越有利于直接促进企业的创新产出;外方注册资本情况对企业创新产出具有直接的促进作用,并且还可通过对企业R&D投资来间接地促进企业的创新产出;区域外商投资质量通过企业R&D投资和R&D波动性间接地抑制了企业的创新产出;而区域对外贸易情况则是通过企业R&D波动性和外方注册资本情况来间接地影响企业创新产出。因此,企业应通过维持R&D活动的稳定性来促进企业技术创新的产出,同时当地政府不应盲目过多的吸引FDI,而应重点吸引、鼓励外商投资者在本地建立R&D部门,增强R&D活动的溢出效应。     

Quantum Theory of Electronic Double-Slit Diffraction

Phenomena of electron, neutron, atomic and molecular diffraction have been studied in many experiments, and these experiments have been explained by some theoretical works. We study electronic double-slit diffraction with a quantum mechanical approach and obtain the following results： （1） When the ratio of d ＋ a /a=n （n = 1,2, 3,...）, orders n, 2n, 3n,... are missing in diffraction pattern. （2） When the ratio of d＋a/a≠ n （n =1,2, 3,...）, there is a not missing order in diffraction pattern. （3） The slit thickness c has a large affect on the electronic diffraction pattern, which is a new quantum effect. We believe that all the predictions in our work can be tested by the electronic double slit diffraction experiment.     

基于多孔黑色TiO_2涂层隔膜的锂硫电池性能探究

合成了多孔黑色二氧化钛(PB-TiO_2),并将其作为原料制备得到PB-TiO_2涂层隔膜(PB-TiO_2@PP),研究了隔膜对锂硫电池电化学性能的影响.电化学性能测试表明,PBTiO_2@PP隔膜能够大幅度提高电池的比容量、有效改善电池的倍率性能和循环稳定性.在1C倍率下,放电容量能够保持在882mAh/g.100次循环之后,容量仍能保持在780mAh/g,容量保持率接近90%.     

低温燃料电池非铂催化剂研究进展

简要综述了近年来低温燃料电池阳极和阴极催化剂的研究进展.阳极催化剂主要介绍了金属碳化物、Pd合金以及钙钛矿型氧化物三种,讨论了阳极催化剂对燃料氧化过程的催化活性和抗CO中毒能力;阴极催化剂则重点介绍了过渡金属大环化合物、氮化物以及氧化物,并较详细地阐述了过渡金属大环化合物的反应活性中心、金属-载体相互作用以及化合物制备条件.由于阴极非铂催化剂存在制备过程较复杂、中间产物过氧化物易破坏催化剂结构等问题,仍需探索新型的非铂催化剂.     

Track reconstruction using the TSF method for the BESⅢ main drift chamber

We describe the algorithm to reconstruct the charged tracks for BESⅢ main drift chamber at BEPCⅡ, including the track finding and fitting. With a new method of the Track Segment Finder (TSF), the results of present study indicate that the algorithm can reconstruct the charged tracks over a wide range of momentum with high efficiency, while improving the robustness against the background noise in the drift chamber. The overall performances, including spatial resolution, momentum resolution and secondary vertices reconstruction efficiency, etc. satisfy the requirements of BESⅢ experiment.     

D0-D0 mixing and CP violation at BES-Ⅲ

Recently, both BaBar and Belle experiments found evidences of neutral D mixing. In this paper, we discuss the sensitivities of the measurements of D mixing parameters at BESⅢ. With CP tag technique at ψ(3770) peak, the extraction of the strong phase difference in D⁰ →Kπ decay at BESⅢ are