锌离子对聚乳酸结晶和热性能的影响

本文发现了Zn(II)离子掺杂可以加快聚乳酸的结晶过程. 测试了三种Zn(II)盐(ZnCl₂、ZnSt和ZnOAc),并与其它离子Mg(II)和Ca(II)进行对照. FT-IR以及变温拉曼光谱分析发现,经Zn(II)离子掺杂后,聚乳酸的结晶度和结晶速率均增加,差示扫描量热技术以及X射线衍射分析也进一步证实. 差示扫描量热技术测定PLA/ZnSt-0.4 wt%材料的结晶率达到22.46%,PLA/ZnOAc-0.4 wt%材料的结晶率达到24.83%.     

Pharmacophore Modeling and Virtual Screening of Novel Inhibitors for c-Kit Kinase

The stem cell factor receptor (c‐Kit) has been known to play critical roles in regulating numerous aspects of cellular behavior including cell growth, differentiation, migration and metabolism. In this investigation, a three‐dimensional pharmacophore model of c‐Kit inhibitors has been established by using the HypoGen algorithms implemented in the catalyst software package. The best quantitative pharmacophore model, hypothesis 1, which has the highest correlation coefficient (0.989), consists of one hydrogen bond acceptor, two hydrogen bond donors and one hydrophobic feature. To our knowledge, this is the first report on the pharmacophore modeling study of c‐Kit inhibitors. The best hypothesis, hypothesis 1, was used to screen molecular structural databases, including Specs and China Natural Products Database for potential lead compounds. The hit compounds were subsequently subjected to filtering by Lipinski's rules and docking study to refine the retrieved hits and as a result to reduce the rate of false positive. Finally 28 compounds were purchased or synthesized for further in vitro assay against several human tumour cell lines including A549, MCF‐7, HepG2 and PC‐3, in which c‐Kit is overexpressed. Two compounds show very low micromolar inhibition potency against the PC‐3 and HepG2 cell lines respectively. And they were selected for further modification and testing.     

A novel multi-functional magnetic Fe-Ti-V spinel catalyst for elemental mercury capture and callback from flue gas

A novel magnetic Fe-Ti-V spinel catalyst showed an excellent performance for elemental mercury capture at 100 °C, and the formed HgO can be catalytically decomposed by the catalyst at 300 °C to reclaim elemental mercury and regenerate the catalyst.     

STUDY ON THE COMPLICATED DYNAMICAL BEHAVIORS OF NONLINEAR ECOSYSTEM (Ⅰ)

This series of papers is prepared to develop systematically the complicated dynamical behaviors of nonlinear ecosystem and its internal mechanism. In this paper, we state briefly the increasing importance of ecology, describe and comment on the situations and reasons why ecology theory is behind practice. Then, we point out a procedure which modern ecology research should obey, and discuss the four basic characteristics of ecosystem in detail: level, opening, nonlinear and far from equilibrium. At last, we discuss systematically equilibrium and nonequilibrium, stable and unstable, environmental stochasticity and dynamical stochasticity, and conclude that there exists a bridge between deterministic behaviors and stochastic behaviors, which will result in a new model for ecological prediction.Supported by Youth Fund of Chinese Academy of Science and Youth Fund of Lanzhou University.     

基于数据三分法的DEA模型

传统DEA模型在数据两分(偏好与规避)的基础上考察决策单元的有效性,在某些场合不再适用,文章根据决策者的偏好将数据分为三类:规避、偏好、中性类,在此基础上构造评价相对有效性的DEA模型.相较而言,基于数据三分法的DEA模型更具一般性,利用该模型,文章考察了中国近年投入产出绩效问题.     

在多孔γ-Al2O3氧化铝载体上微波合成NaA分子筛膜及气体渗透分离性能

The paper presented novel synthesis of NaA zeolite membrane with good performance using microwave heating. The method involved two steps, prior seeding 120 nm of LTA crystals on substrate and then employing a secondary hydrothermal synthesis. Effects of seeding times, synthesis time and synthesis times were investigated in this work. The quality evaluation of membranes respectively used single component gases (HE and N2) and H2/N2 (equivalent volume) mixture. The ideal H2,/N2 selectivity increased from 1.90 of the substrate to 6.37 of the three-stage synthesized membrane, which was distinctly higher than the corresponding Knudsen diffusion selectivity of 3.74. However, the real H2/N2 selectivity of the three-stage synthesis was much lower than the corresponding ideal selectivity and close to the corresponding Knudsen diffusion selectivity of 3.74.     

THERMODYNAMIC ENTROPY MODELS OF THE FROZEN-WALL SYSTEM (Ⅰ)

In this paper, the author describes, and comments on the traditional thermal theory on artificial ground freezing, and points out its important significance and shortcomings. The frozen-wall is analysed by system analysis methods. According to matter levels, the frozen-wall is divided into three sub-systems: frozen colloid system, frozen soil system and frozen-wall system. They correspond to different characteristics. The frozen-wall system is a large open system with multi-levels and multi-aspects. The problems of stability of the system and its control are the key problems in the techniques of artificial ground freezing. Based on non-equilibrium thermodynamics and dissipative structure theory methods, the author discusses and reveals the problems of the formation and stability of the frozen-wall system and its thermodynamic nature, and proposes the thermodynamic entropy models of the system. The result is a great satisfaction.     

Assembly of Ag（I） Polymers with Thioether-S Binding and Homochiral Helices

A novel coordination polymer [Ag(pyta)]n (pyta^-=4-pyridylthioacetate) containing bound thioether sulfurs and single-stranded helical chains has been synthesized and structurally characterized.     

电子商务与传统商务发展趋势的博弈分析

在消费者对商品价格与供货时间的偏好假设下,建立一个厂商关于电子商务与传统商务交易方式选择的完全信息静态博弈模型,其纳什均衡表明了电子商务与传统商务潜在的发展趋势,特别是两者可能的市场剖分关系.确切而言,若市场满足既定假设,均衡条件下的电子商务交易方式表现为较长的供货时间及低于传统商务约40%的市场交易价格,将获得三分之一的市场份额.     

Sinuhirtins A and B,two uncommon norhumulene-type terpenoids from the South China Sea soft coral Sinularia hirta

Two new uncommon norhumulene-type norsesquiterpenoids, namely sinuhirtins A (1) and B (2), along with two known norcaryophyllene-type norsesquiterpenoids (3 and 4), were isolated from the South China Sea soft coral Sinularia hirta. The structures and absolute configurations of the new compounds were determined by extensive spectroscopic data analyses, and computer-assisted methods including GIAO ¹³C NMR and TDDFT-ECD calculations. A plausible biogenetic relationship of 1–4 was proposed.