金属基仿生超滑表面制造及其应用

金属是人类社会赖以生存和发展的重要物质基础,是构成现代文明社会的支撑材料,增加金属材料的特殊性能,拓宽金属材料的应用范围,已经成为 自然科学交叉研究的热点.受自然界启发,研究人员通过探究猪笼草口缘区的超滑行为,在微/纳米结构基底中注入低表面能润滑液,形成固液复合涂层,设计并制备出具有特殊润湿性的仿生超滑表面,显现出优异...     

过氧化氢氧化溴邻苯三酚红催化光度法测定痕量钴

在 NH3 · H2 O- NH4Cl体系中 ,痕量钴与 EDTA协同催化 H2 O2 氧化溴邻苯三酚红 ,据此建立了测定痕量钴的新方法。质量浓度的线性范围为 0— 1.3μg/ m L,检出限为 2 .6× 10 -10 g/ m L。可用于人体尿液、维生素 B12 注射液、百合中痕量钴的测定。     

一维向列相液晶光子晶体的研究

从理论和实验相结合的角度,研究了一维液晶光子晶体透射谱特性.实验给出了不同液晶缺陷层电压下的透射谱,电压范围在0～10 V内,透射峰的相对透过率变化为48%～18%,禁带宽度290 nm调谐范围88 nm,透射峰半峰全宽7 nm.理论计算和实验结果比较接近,这些特性可以使一维液晶光子晶体用于调谐光滤波器和光开关.     

Ⅱ-Ⅵ族半导体激光器的新材料——ZnO量子点

介绍了研制Ⅱ－Ⅵ族半导体激光器方面的一个新途径－－自组织生长ＺｎＯ量子点微晶结构、ＺｎＯ已经实现了室温下光泵激发的受激发射,它将是继Ⅱ－Ⅵ族硒化物、Ⅲ－Ⅴ经物之后的又一种半导体激光器材料。     

Assessment of ultrasound pulsation loops for measurement of local pulse wave velocity of carotid artery

Flow-area (QA) method and ln(diameter)-velocity (ln(D)U) methods based on si-multaneous measurements of velocity (U) and arterial diameter (D) using ultrasound ...     

Synthesis, Crystal Structure and Photoluminescent Property of a 3D Hydrogen-bonded Supramolecular Compound with Large Channels

The title compound, [Pd（2,2′-bipy）2]（Haadip）2·4H2O, was synthesized via the hydrothermal reaction of PdCl2 with 5-aminodiacetic isophthalic acid （H4adip） in an acetic acid water solution. It was characterized by elemental analysis and infrared spectrum. Crystal data for C44H44N6O20Pd： monoclinic, space group P21/n, a = 11.0674（2）, b = 9.9716（2）, c= 20.5770（3）A, β = 92.7300（3）°, V = 2268.29（7）A^3, Z = 2, Mr = 1083.25, Dc = 1.586 g/cm^3, F（000） = 1112,μ = 0.499 mm^-1, 2（MoKa） = 0.71073 A, T = 293（2） K, 2θmax = 51.38°, GOOF = 1.067, R = 0.0268 and wR = 0.0710 for 3770 reflections with 1 〉 2σ（I）. X-ray diffraction studies reveal that the title compound has an interesting 3D microporous architecture via hydrogen bonds with the cations located inside the channel.     

Direct observation of peptide hydrogel self-assembly

The characterization of self-assembling molecules presents significant experimental challenges, especially when associated with phase separation or precipitation. Transparent window infrared (IR) spectroscopy leverages site-specific probes that absorb in the “transparent window” region of the biomolecular IR spectrum. Carbon–deuterium (C–D) bonds are especially compelling transparent window probes since they are non-perturbative, can be readily introduced site selectively into peptides and proteins, and their stretch frequencies are sensitive to changes in the local molecular environment. Importantly, IR spectroscopy can be applied to a wide range of molecular samples regardless of solubility or physical state, making it an ideal technique for addressing the solubility challenges presented by self-assembling molecules. Here, we present the first continuous observation of transparent window probes following stopped-flow initiation. To demonstrate utility in a self-assembling system, we selected the MAX1 peptide hydrogel, a biocompatible material that has significant promise for use in drug delivery and medical applications. C–D labeled valine was synthetically introduced into five distinct positions of the twenty-residue MAX1 β-hairpin peptide. Consistent with current structural models, steady-state IR absorption frequencies and linewidths of C–D bonds at all labeled positions indicate that these side chains occupy a hydrophobic region of the hydrogel and that the motion of side chains located in the middle of the hairpin is more restricted than those located on the hairpin ends. Following a rapid change in ionic strength to initiate self-assembly, the peptide absorption spectra were monitored as function of time, allowing determination of site-specific time constants. We find that within the experimental resolution, MAX1 self-assembly occurs as a cooperative process. These studies suggest that stopped-flow transparent window FTIR can be extended to other time-resolved applications, such as protein folding and enzyme kinetics.

To facilitate the characterization of phase-transitioning molecules, site-specific non-perturbative infrared probes are leveraged for continuous observation of the self-assembly of fibrils in a peptide hydrogel following stopped-flow initiation.     

含钼涂层钨材料在氦等离子体作用下的前期表面形貌演变研究

为了研究纳米绒毛的生成过程及内在的物理机制,采用磁控溅射镀膜的方式在钨片上镀有钼涂层(Mo-W)。借助微观结构观察的手段分析了钨、钼块材以及钨-钼(Mo-W)样品在773K、1073K氦等离子体作用条件下的表面形貌演变过程。结果表明:钨、钼以及钨-钼(Mo-W)样品在氦等离子体作用下表面形貌演变规律基本一致;纳米绒毛及其珊瑚状前驱体是在尺寸相对较大的锥状结构上演化而来的。     

Incompressible multiphase flow and encapsulation simulations using the moment‐of‐fluid method

A moment‐of‐fluid method is presented for computing solutions to incompressible multiphase flows in which the number of materials can be greater than two. In this work, the multimaterial moment‐of‐fluid interface representation technique is applied to simulating surface tension effects at points where three materials meet. The advection terms are solved using a directionally split cell integrated semi‐Lagrangian algorithm, and the projection method is used to evaluate the pressure gradient force term. The underlying computational grid is a dynamic block‐structured adaptive grid. The new method is applied to multiphase problems illustrating contact‐line dynamics, triple junctions, and encapsulation in order to demonstrate its capabilities. Examples are given in two‐dimensional, three‐dimensional axisymmetric (R–Z), and three‐dimensional (X–Y–Z) coordinate systems. Copyright © 2015 John Wiley & Sons, Ltd.