采用坡度磁场提高同轴腔电子回旋管的效率

 通过选择适当电子初始的横纵向速度比，并引进坡度磁场的方法，来提高同轴腔电子回旋微波激射器效率。非线性模拟表明，用这种办法可以将德国卡尔斯鲁研究中心研制的同轴腔电子回旋微波激射振荡器的实验效率，从26.7%提高到31.5%。这种效率放大的物理机制是：坡度磁场改变了相对论电子的运动条件，有效地改善了波束互作用过程中电子的群聚状态，使电子束有更多的动能转换为电磁能，从而提高了电子束的换能效率。     

Multiple-beams Mutually Pumped Phase Conjugation Generated by a Bridge Phase Conjugator in Photorefractive Ba_(1-x) Sr_x TiO_3 Crystal

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ａｄｏｕｂｌｅ ｂｅａｍｓｍｕｔｕａｌｌｙｐｕｍｐｅｄｐｈａｓｅｃｏｎｊｕｇａｔｏｒｇｅｎｅｒａｔｅｓｔｈｅｐｈａｓｅ ｃｏｎｊｕｇａｔｅｒｅｐｌｉｃａｏｆｅａｃｈｏｆｔｗｏｉｎｃｉｄｅｎｔｏｐｔｉｃａｌｂｅａｍｓ[1～ 7] .Ｔｈｅｔｗｏｉｎｃｉｄｅｎｔｂｅａｍｓｎｅｅｄｎｏｔｂｅｃｏｈｅｒｅｎｔｗｉｔｈｅａｃｈｏｔｈｅｒ,ａｎｄｔｈｅｙｃａｎｅｖｅｎｂｅｆｒｏｍｄｉｆｆｅｒｅｎｔｌａｓｅｒｓｏｐｅｒａｔｉｎｇａｔｔｈｅｓａｍｅｎｏｍｉｎａｌｗａｖｅｌｅｎｇｔｈ .Ｍｕｔ…     

深圳南山托幼机构状况调查

报道了深圳市南山区开展社区卫生保健以来，对三所托幼机构状况的全面调查，调查内容包括：托幼机构性质及各类结构，落实执行卫生保健隔离消毒制度，儿童户内外活动面积和膳食进餐等情况，指出所存在的问题。     

Functionalized Hierarchical ZSM-5 Zeolites for the Viscosity Reduction of Heavy Oil at Low Temperature

Herein, we propose a novel approach to reduce the viscosity of heavy oil by functional hierarchical CTMS-ZSM-5-PTMS zeolites. CTMS-ZSM-5-PTMS zeolites synthesized by asymmetric modification and selective alkali etching can reduce the viscosity of heavy oil through adsorbing asphaltenes. This method can reduce the viscosity of heavy oil from hundreds of thousands mPa·s to about ten thousand mPa·s. The work provides an economical and environmentally friendly candidate for heavy oil viscosity reduction under low-temperature conditions.     

Synchronous fluorescence determination of ciprofloxacin in the pharmaceutical formulation and human serum based on the perturbed luminescence of rare-earth ions

A simple, rapid and sensitive synchronous fluorescence method was developed for the determination of ciprofloxacin (CPFX) in the pharmaceutical formulation and human serum. The results show that when Y³⁺ is added into the CPFX solution, the characteristic fluorescence of Y³⁺ is not emitted whereas the fluorescence intensity of CPFX is significantly enhanced. The synchronous fluorescence technology is employed in this method to directly determine trace amount of CPFX in human serum. A linear relationship between the fluorescence intensity and the CPFX concentration is obtained in the range of 1.0×10⁻⁹ ∼5.0×10⁻⁶ mol L⁻¹. The limit of detection (LOD) of this method attains as low as 2.0×10⁻¹⁰ mol L⁻¹ (S/N=3). The selectivity of this method is also very good. Common metal ions, rare-earth ions and some pharmaceuticals, which are usually used together with CPFX in the clinic, do not interfere with the determination of CPFX under general conditions.     

Non-Markovian Effects on Entanglement Dynamics of Three Qubits

We investigate entanglement dynamics of three independent qubits each locally interacting with a zerotemperature non-Markovian reservoir. The effects of environment＇s amount of non-Markovianity or parameters in initial states on the three-qubit entanglement dynamics are presented in detail. It is found that the entanglement of such a system revives after a finite dark period when a proper degree of non-Markovian is present. A deep comparison to that in two-qubit system is also made.     

NOD随机变量加权和的极限

The strong laws of large numbers and laws of the single logarithm for weighted sums of NOD random variables are established.The results presented generalize the corresponding results of Chen and Gan [5] in independent sequence case.     

取代四苯基卟啉蒽醌化合物的合成、结构和光物理性质

在光合作用模拟研究中,人们常选用与叶绿素具有相同π体系的卟啉类化合物作为电子给体,与另一电子受体组成合成反应中心。由于自然界光台作片用中,多数电子受体都是由醌类承担,因此,对卟啉醌共价相连化合物的研究     

通道电子倍增器内壁涂层的X射线光电子能谱分析

用氩离子溅射-XPS纵深分析方法对通道电子倍增器内二次电子发射材料的元素组成和原子价态进行了分析,结果表明该材料中的主要元素为Pb,Bi,Ba,Si和O,其中Pb和Bi都以混合价态存在,它们分别是Pb^2 和Pb^0;Bi^3 和Bi^0．