Magnesium bistrifluoromethanesulfonimide as an efficient catalyst for the hydroalkylation of aromatic olefins with 1,3-diketones under solvent-free conditions

An efficient magnesium bistrifluoromethanesulfonimide[Mg(NTf_2)_2]catalyzed hydroalkylation of aromatic olefins with 1,3- diketones under solvent-free conditions has been developed.The reactions proceed smoothly to give the desired products in good yields in short reaction times.     

欧拉游历间K1—变换下的算法复杂性

本文主要讨论了欧拉图方面的国际权威ＨｅｒｂｅｒｔＦｌｅｉｃｈｎｅｒ教授所著书［１］中的一个问题；对欧拉图Ｇ的任意两个欧拉游历要经过多少Ｋ－变换或Ｋ＾＊－变换才能从一个游历得到另一个游历？我们得到的结论是：对欧拉图Ｇ中的任两个欧拉游历Ｔ、Ｔ＇最多经过‖Ｅ（Ｇ）‖－‖Ｖ（Ｇ）‖－变换可以使Ｔ变换成Ｔ＇。且此结果不能再改进。进一步我们分别对Ｋ－变换和Ｋ＆－变换的算法复杂性进行了讨论。     

INVESTIGATION OF THE ATRP OF n-BUTYL METHACRYLATE USING THE Cu(I)/N,N,N'''',N",N"-PENTAMETHYLDIETHYLENETRIAMINE CATALYST SYSTEM

INTRODUCTIONThe atom transfer radical polymerization (ATRP) has become an important method for preparing well-definedmacromolecules. This technique offers control over the molecular weights, the chain end functionalities, and thechain architectures[1-12]. It has been used extensively for the preparation of homopolymers, block, and randomcopolymers[13-39], for the preparation of organic/inorganic hybrid materials[40-54], as well as for combining variousother living polymerization methods …     

Extended breakdown of Simpleman approximation

In this letter, we solve three-dimensional time-dependent Newton equations for atoms interacting with a ten-cycle elliptically polarized laser pulse. The ionized electron momentum distributions show a tilt angle between the distribution density peak and the main polarization axis. The tilt angle’s behavior changes with an increasing laser intensity. We show that this behavior change is directly related to the release time of the electron from the atom.     

Intestinal Transport and Biotransformation of Resibufogenin and Cinobufagin in Chan Su via HPLC/APCI-MS~n

In vitro models of human colon carcinoma cell line(Caco-2 cell monolayer) and human intestinal bacteria were used to investigate the intestinal transport and biotransformation of resibufogenin and cinobufagin in Chan Su by HPLC/APCI-MSn. The experimental results of Caco-2 cell monolayer demonstrate that the apparent permeability coefficients(Papp) of resibufogenin and cinobufagin are higher than 10-6 cm/s, which indicates that both resibufogenin and cinobufagin have a good absorption in the small intestine....     

Optical applications of quantum dots in biological system

This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed.     

采用新型La_(0.07)Sr_(0.93)SnO_3电极制备外延透明BiFe_(0.95)Mn_(0.05)O_3铁电薄膜电容器

本文使用脉冲激光沉积的方法在SrTiO3(STO)单晶衬底上采用一种新型的透明导电氧化物材料La0.07Sr0.93SnO3(LSSO)薄膜作为电极材料制备了BiFe0.95Mn0.05O3(BFMO)铁电薄膜电容器.XRD表征结果证实BF-MO/LSSO/STO外延异质结具有很好的单晶质量.光透过率的测试结果表明在500~2500nm的波长范围内,整个异质结的透光率与单纯STO衬底基片相似.在波长500nm附近BFMO出现吸收边,通过对吸收边进行(hνα)2-hν曲线拟合得到BFMO的直接光学带隙约为2.8eV.利用Pt作为上电极,我们测得了饱和的电滞回线,剩余极化Pr~60μC/cm2.     

Relative position determination of a lunar rover using high-accuracy multi-frequency same-beam VLBI

Multi-frequency same-beam VLBI means that two explorers with a small separation angle are simultaneously observed with the main beam of receiving antennas. In the same-beam VLBI, the differential phase delay between two explorers and two receiving telescopes can be obtained with a small error of several picoseconds. The differential phase delay, as the observable of the same-beam VLBI, gives the separation angular information of the two explorers in the celestial sphere. The two-dimensional relative position on the plane-of-sky can thus be precisely determined with an error of less than 1 m for a distance of 3.8×105 km far away from the earth, by using the differential phase delay obtained with the four Chinese VLBI stations. The relative position of a lunar rover on the lunar surface can be determined with an error of 10 m by using the differential phase delay data and the range data for the lander when the lunar topography near the rover and the lander can be determined with an error of 10 m.     

吩噻嗪卤代衍生物的荧光研究

本文主要研究了3-溴-N-乙基吩噻嗪(Br-P)在各种酸度、增敏溶剂、感光效应等条件下的荧光变换现象，并确定了最佳的发光体系。方法简单、准确可靠，其线性范围为1×10     

橡胶硫化促进剂DZ合成工艺探讨

采用两步合成法制备橡胶硫化促进剂ＤＺ（Ｎ，Ｎ－二环己胺－２－苯并噻唑次磺酰胺），控制Ｍ钠盐与氯代二环乙胺的摩尔比为１，选择乙醇作有机溶剂，将缩合反应滴加Ｍ钠盐的温度控制在３０－３５℃，即可制得熔点在９０℃以上，溶程小于１℃，且收率近８０％的高品质ＤＺ产品。