On pinching deformations of rational maps

We introduce the notion of the dynamical length of an invariant arc of a rational map R. A pinching deformation is a sequence of topological deformations of R such that the corresponding dynamical length shrinks to zero. We show that if the sequence converges to a rational map then the spherical diameter of the corresponding arc also shrinks to zero. We use this result to show that if the grand orbits of the closure of finitely many such arcs separate the Julia set, the deformations of R diverge. This is a generalization of a result stated by P. Makienko but with a different approach. We also present a rich collection of examples.     

萃取色层梯度淋洗和柱后反应光度法连续检测装置

用普通材料自制和组装一套能梯度淋洗和柱后反应光度法连续检测萃取色层柱的流出曲线的设备。详细叙述了淋洗液切换阀、六通样样阀、四通混合器、盘管反应器的制作和将国产原子吸分光光度计改装流动光度计。     

ZnSe相变、电子结构的第一性原理计算

基于第一性原理平面波赝势(PWP)和广义梯度近似(GGA)方法,对闪锌矿结构(ZB)和岩盐结构(RS)的ZnSe在0—20GPa高压下的几何结构、态密度、能带结构进行了计算研究,分析了闪锌矿结构ZnSe和岩盐结构ZnSe的几何结构.在此基础上,研究了ZnSe的结构相变、弹性常数、成键情况以及相变压强下电子结构的变化机理.结果发现:通过焓相等原理得到的ZB相到RS相的相变压强为15.3GPa,而由弹性常数判据得到的相变压强为11.52GPa,但在9.5GPa左右并没有发现简单立方相的出现;在结构相变过程中,sp3轨道杂化现象并未消除,Zn原子的4s电子在RS相ZnSe的导电性中起主要贡献.     

Synthesis and Luminescent Properties of Lanthanide Complexes with Structurally Related Novel Multipodal Ligands

To explore the relationship between the structure of the ligands and the luminescent properties of the lanthanide complexes, a series of lanthanide nitrate complexes with two novel structurally related multipodal ligands, 1,3-bis{[(2’-(2-picolylaminoformyl))phenoxyl]methyl}benzene (L ^I ) and 1,2-bis{[(2’-(2-picolylaminoformyl))phenoxyl]methyl}benzene (L ^II ), have been synthesized and characterized by elemental analysis, infrared spectra and molar conductivity measurements. At the same time, the luminescent properties of the Eu(III) and Tb(III) nitrate complexes in solid state and the Tb(III) nitrate complexes in solvents were investigated at room temperature. Under the excitation of UV light, these complexes exhibited characteristic emissions of central metal ions. The lowest triplet state energy levels T₁ of these ligands both match better to the lowest resonance energy level of Tb(III) than to Eu(III) ion. The influence of the structure of the ligands on the luminescent intensity of the complexes was also discussed.     

The high squeezing and entanglement in regular loss modulated optical parametric amplifier

We investigate the quantum fluctuation characteristic for time dependent regular loss modulated optical parametric amplifier for below and above threshold regions.It is found that a high squeezing and entanglement can be achieved.     

Tagged molecule induced nanoparticle aggregation： Raman reporter-labeled immuno-Au aggregate as immuno-sensor

<正>A novel structure with high surface enhanced Raman scattering(SERS) activity and bio-specificity as a SERS-based immuno-sensor(named as Raman reporter-labeled immuno-Au aggregate) is demonstrated and employed for protein detection.In each fabrication process,the features of those aggregates are obtained and characterized by ultraviolet-visible(UV-Vis) extinction spectra,transmission electron microscopy (TEM) images,scanning electron microscopy(SEM) pictures,and SERS spectra.Experimental results indicate that proper amounts of the reporter molecules can result in the moderate aggregation morphologies of gold nanoparticles.Compared with the previously reported method using Raman reporterlabeled immuno-Au nanoparticles,more sensitive SERS-based protein detection is realized with this novel immuno-sensor.     

Circulation times of hepatocellular carcinoma cells by in vivo flow cytometry

Hepatocellular carcinoma （HCC） may metastasize to many organs. The survival rate is almost zero for metastatic HCC patients. Molecular mechanisms of HCC metastasis need to be understood better and new therapies must be developed. We have developed the ＂in vivo microscopy＂ to study the mechanisms that govern liver tumor cells spreading through the microenvironment in vivo. A recently developed ＂in vivo flow cytometer＂ combined with real-time confocal fluorescence imaging is used to assess spreading and the circulation kinetics of liver tumor cells. We measure the depletion kinetics of two related human HCC cell lines, high-metastatic HCCLM3 cells and low-metastatic HepG2 cells, which are from the same origin and obtained by repetitive screenings in mice. More than 60% of the HCCLM3 cells are depleted within the first hour. Interestingly, the low-metastatic HepG2 cells possess noticeably slower depletion kinetics. In comparison, less than 40% of the HepG2 cells are depleted within the first hour. The differences in depletion kinetics might provide insights into early metastasis processes.     

Air-breathing mode a long-pulse laser propulsion with TE CO2 laser

Air-breathing mode laser propulsion experiment with a long-pulse transversely excited （TE） CO2 laser is carried out, and its ignition problem is solved with the ignition needle of lightcraft. Owing to the ignition needle, an order of magnitude reduction in the ignition threshold is demonstrated. The result is compared with previous study. The momentum coupling coefficient is also measured in the experiment and its dependence upon laser pulse energy （6 14 J） and pulse width （20, 32, and 40 μs） is discussed.     

Utilization of 3'-carboxy-containing tyrosine derivatives as a new class of phosphotyrosyl mimetics in the preparation of novel non-phosphorylated cyclic peptide inhibitors of the Grb2-SH2 domain

A new class of phosphotyrosyl (pTyr) mimetics, distinct from the conventional pTyr mimetic design of adding non-hydrolyzable acidic functionalities to the 4'-position of phenylalanine, was created by introducing carboxy-containing groups to the 3'-position of tyrosine. The effect of the chain length of the carboxy substituent was examined. Reported herein is the chiral pool synthesis of the new pTyr mimetics, and their first use in a novel non-phosphorylated Grb2-SH2 domain binding motif with the 5-amino-acid sequence Xx1-Leu-(3'-substituted-Tyr)-Ac6c-Asn. The highest affinity was exhibited by the 3-L-(2-carboxyethyl)tyrosine-containing sulfoxide-cyclized peptide , with an IC50 = 1.1 microM, providing a promising new template for further development of potent Grb2-SH2 domain inhibitors with reduced charge and peptidic nature, but improved selectivity and bioavailability.     

Selective synthesis of epolactaene featuring efficient construction of methyl (Z)-2-iodo-2-butenoate and (2R,3S,4S)-2-trimethylsilyl-2,3-epoxy-4-methyl- gamma-butyrolactone

[reaction: see text] (+)-Epolactaene was synthesized in 14 steps in the longest linear sequence. The synthesis is highlighted by a highly efficient preparation of the lactone intermediate 4, which only requires three steps from the commercially available (S)-3-butyn-2-ol. It also features a fully stereocontrolled synthesis of the intermediate 9, which was constructed through the use of Zr-catalyzed methylalumination of alkynes and a series of Pd-catalyzed organozinc cross-coupling reactions, such as homopropargylation, direct ethynylation, and alkenylation of the methyl ester of (Z)-alpha-iodocrotonic acid (3).