ZrV2-xPxO7固溶体的相变与热膨胀性质的研究

本文采用固相烧结法制备了ZrV2-xPxO7@=0,0．2,0．4,0．6,0．8,1）系列材料．粉末X射线衍射（XRD）分析表明,所制备材料的结构为单一立方相．应用变温拉曼光谱研究该材料相变,变温拉曼光谱研究结果表明,材料起始相变温度随着P5＋替代V5＋量的增加逐渐降低,x=0,0．4,0．8,1对应的相变温度分别为383K,363K,273K,213K．热膨胀测试结果表明：随着P替代量的增加正一负膨胀转变温度先降低后增加,x=0,0．2,0．4,0．6,0．8,1对应的正一负膨胀转变温度分别为429K,403K,372K,390K,398K和435K．本文指出了该系列材料存在两个相变过程,为设计和制备ZrV2O7基室温附近的负热膨胀材料奠定了良好的基础．     

Relations between compositional modulation and atomic ordering degree in thin films of ternary III—V semiconductor alloys

This paper derives the expressions for the ordering degree and the modulation factor of A and B atoms in A_xB_1-xC epilayers of ternary III--V semiconductor alloys. Using these expressions, it identifies quantitatively the alternating atom-enhanced planes, compositional modulations, atomic ordering degree on the group-III sublattices and the fine structure of NMR spectra.     

Conception design of helium ion FFAG accelerator with induction accelerating cavity

Technological advancements are strongly required to fulfill the demands of new accelerator devices with the highest accelerating gradients and operation reliability for the future colliders.To this purpose an extensive R&D regarding molybdenum coatings on copper is in progress.In this contribution we describe chemical composition,deposition quality and resistivity properties of diferent molybdenum coatings obtained via sputtering.The deposited films are thick metallic disorder layers with diferent resistivity values above and below the molibdenum dioxide reference value.Chemical and electrical properties of these sputtered coatings have been characterized by Rutherford backscattering,XANES and photoemission spectroscopy.We will also consider multiple cells standing wave section coated by a molybdenum layer designed to improve the performance of X-Band accelerating systems.     

Research advances of endostatin and its short internal fragments

Endostatin, the C-terminal fragment of collagen XVIII, is a potent angiogenesis inhibitor. At present, there are a large number of research papers on endostatin. However, the action mechanism of endostatin is still a matter of ongoing discussion. The objective of this review is to elucidate its origin and elementary structure, and to discuss its structure basis of activity and action mechanisms based on the latest research. Furthermore, some published studies reporting the antiangiogenic effects of endostatin-derived peptides were also reviewed. It is proposed that the amino acid sequence of endostatin contains both angiosuppressive and angiostimulatory domains. Short endostatin fragments may be exploited as a new angiogenesis inhibitor for therapeutic applications, in substitution of the full length endostatin. These studies on endostatin fragments also shed light on our understanding of the molecular action mechanisms of endostatin.     

Tailoring crystal polymorphs of organic semiconductors towards high-performance field-effect transistors

As a quite ubiquitous phenomenon, crystal polymorph is one of the key issues in the field of organic semiconductors. This review gives a brief summary to the advances on polymorph control of thin film and single crystal of representative organic semiconductors towards high-performance field-effect transistors. Particularly, the relationship between crystal polymporh and charge transport behaviour has been discussed to shed light on the rational preparation of outstanding organic semiconducting materials with desired crystal polymorph.     

Design of proton beam optics to realize beam distribution transformation in C-ADS HTBT

The linac to the transmuter beam transport line (LTBT) connecting the end of the linac to the spallation target is a critical sub-system in the accelerator driven system (ADS). It has the function of transporting the accel-erated high power proton beam to the target with a beam footprint satisfying the special requirements of the minor actinide (MA) transmuter. In this paper, a preliminary conceptual design of the hurling magnet to transmuter beam transport section (HTBT), as a part of the LTBT, for the China ADS (C-ADS) system is proposed and developed. In this design, a novel hurling magnet with a two dimensional amplitude modulation (AM) of 1 kHz and scanning of more than 10 kHz at 360 in transverse directions is used to realize a 300 mm diameter uniform distribution of beam on target. The preliminary beam optics design of C-ADS HTBT optimized to minimize the beam loss on the vacuum chamber and the radiation damage caused by back-scattering neutrons will be reported.     

Regioregular Asymmetric Diketopyrrolopyrrole Copolymers with Good Molecular Ordered Assembly Ability for High-performance Polymer Transistors

Introduction of asymmetric units into conjugated polymers is an important strategy to regulate the photophysical and electronic properties of polymers, as asymmetric units can not only regulate solubility and energy levels, but also molecular stacking and orientation, thus giving much higher optoelectronic properties. However, very few studies have been reported in this field. The semiconducting properties of conjugated polymers could be regulated through regioregularity adjustment. Here, we too...     

Self-assembled Conformations of a Core-shell Comb-like Chain with Adjustable Architectural Parameters

Chinese Journal of Polymer Science - Combining Brownian dynamics simulations and self-consistent field theory, we demonstrate that the architectural parameters of core-shell comb-like chains have a...