纳米颗粒吸附岩心表面的强疏水特征

通过将疏水的纳米颗粒吸附在岩心微通道壁面,可以形成具有类荷叶表面的双重微结构表面,从而在注水开发的过程中在岩心微通道壁面产生水流滑移,达到降低注水压力、增加注水量的目的.研究纳米颗粒吸附岩心切片表面的强疏水特征对纳米颗粒吸附法减阻技术具有重要的意义.本文简要叙述了荷叶、蚊子腿以及水黾腿的超疏水特征;介绍了制备具有亚微米、纳米双重微结构的强疏水表面的纳米颗粒吸附法;给出了规则排列时纳米颗粒吸附岩心切片表面的强疏水特征的物理机制,根据真实的纳米颗粒吸附岩心切片,给出了接触角的范围,计算结果与实验数据一致.岩心流动实验结果表明,经纳米颗粒分散液处理后,岩心的平均水相渗透率提高94%.     

Real‐time analysis of the microstructural evolution and optical properties of Cu(In,Ga)Se2 thin films as a function of Cu content

Thin films of Cu(In,Ga)Se₂ with various copper contents were deposited by co‐evaporation onto thermally oxidized silicon substrates. Characterization by real‐time spectroscopic ellipsometry reveals clear similarities among the samples, as well as key variations with Cu content. Although all films exhibit a Volmer–Weber nucleation and similar fundamental critical point energies in the analysis of optical properties, Cu‐rich films exhibit enhanced coalescence, smoother surfaces, larger grain sizes, as well as a sub‐bandgap absorption which is absent in Cu‐poor films. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Surface wetting in liquid-liquid-solid triphase systems: solid-phase-independent transition at the liquid-liquid interface by lewis Acid-base interactions

Interfacial phenomena: A solid-phase-independent strategy for tuning the surface wettability is presented. Lewis acid-base interactions at the oil-water interface can greatly decrease the liquid-liquid interfacial tension and induce oleophilic to superoleophobic wetting transition on a nonresponsive microstructured surface.     

Grain size refinement and magnetostriction of ferromagnetic shape memory Fe–Pd–Rh alloys

This paper reports the forging of bulk ferromagnetic shape memory (FSM) Fe–30Pd–2Rh (at%) alloys to a 40% reduction in thickness, followed by thermal annealing at 950–1100 °C for various times and quenching in ice brine to induce recrystallization (i.e. grain size refinement). Investigation with the Vickers microhardness test reveals that the process of recrystallization results in increased ductility of the fine grains. TEM and magnetostriction investigations reveal two kinds of twins contained in the strain-forged sample annealed at 950 °C for 3 h, i.e. deformation and transformation twins, and these twins also improved a higher magnetostriction as well as ductility in the alloys that may be useful in magneto-mechanical applications (such as microactuator or spring).     

灰口铸铁H20-40激光热处理工艺的研究

对灰口铸铁H2 0 40在激光加热条件下不同的功率密度 (W )、扫描速度 (V)对硬化层深度、硬度及组织进行了系统的研究 .发现当W =4.0 76× 10 3 W /cm2 ,V <5mm/s时灰铁的表面呈熔融状态 ,可获得伪共晶莱氏体组织 .硬度Hv90 7- 10 10 ,硬化层深度S =0 .95mm～ 1.5 4mm .当W <4.0 76× 10 3 W /cm2 ,V >5mm/s时 ,只能获得片状马氏体 石墨的混合组织 .硬度Hv6 90 - 840 ,硬化层深度S =0 .6mm～ 0 .9mm之间 .     

DSC analysis of the state of water in surfactant-based microstructures

A review is made about the different kinds of water in surfactant-based microstructures (liquid crystals, microemulsions and micelles) and their study by DSC.     

Facile Microstructure Control of Mesoporous Co1.29Ni1.71O4 and the Effect of the Microstructure on Lithium‐Storage Performance

A simple and efficient pathway has been designed and developed to synthesize mesoporous Co_1.29Ni_1.71O₄ nanostructures without the use of any templates. By adjusting the volume ratio of water to ethanol, the Co_1.29Ni_1.71O₄ microstructure can be facilely controlled, and different nanostructures such as microflowers, nanorods, and nanoparticles were obtained. All three as‐synthesized samples have a mesoporous structure, but with different pore‐size distributions, in which the nanorod sample exhibits the highest capacity, good rate capability, and cycle stability as an anode material in lithium‐ion batteries (LIBs). The possible reason might be that the one‐dimensional structure of the nanorods accounts for their higher conductivity relative to microflowers and nanoparticles, and their high conductivity coupled with their mesoporous structure might contribute to their excellent electrochemical performance.     

Self-Assembly of Hierarchical Microstructures and Their Ring Patterns in Evaporating Droplets

Urchin-like and tree-shaped hierarchical microstructures were prepared within a solution droplet through drying-mediated self-assembly of organic molecules. The hierarchical architectures inside the droplet can orderly arrange into irregular ring patterns. The morphology evolvement of the hierarchical microstructures and the formation of the ring patterns were captured and studies with the assistance of optical microscopy. Their formation mechanisms were discussed on the basis of the results of time-dependent experiments. The amount of organic molecules in the solution had an obvious effect on the size and morphology of hierarchical microstructures and ring pattern formation. The optical properties of the hierarchical microstructures were investigated in detail and the formation of self-assembled structures resulted in significant changes in optical properties. The formation of the complex superstructures and generation of the ring patterns not only enriched synthesis science but also provided new blocks in future architectures of functional devices.     

Modification of polycarbonate surface properties by nano-, micro-, and hierarchical micro–nanostructuring

Polycarbonate surfaces were patterned with nanopillars, microbumps, or nanopillars superimposed on microbumps. Patterning was achieved by applying nanoporous anodized aluminum oxide (AAO) membranes, microstructured aluminum foil, or anodic alumina on microstructured aluminum as mold inserts in injection molding. The effect of the different-sized structures on properties of the polycarbonate surface was investigated in contact angle measurements with water and oleic acid. The water contact angle increased from 82° on the smooth surface to 139° on the hierarchical micro–nanostructure. The transmittance of the polycarbonate increased with nanopatterning, while the reflection properties of the polycarbonate surface decreased. Reflection was lowest for the nanostructure with 53 nm pillar diameter and 77 nm interpillar distance. Values ranged from 0.6 to 1.1% over the whole wavelength range of visible light, which was 4–5% units lower than the corresponding values for the smooth polycarbonate.     

衍射增强成像方法在计算机断层成像中的应用

衍射增强成像是X射线相位衬度成像方法之一，这种方法具有较高的衬度和空间分辨率. 利用它对由轻元素组成的生物、医学样品成像可以观察到常规吸收成像无法观察到的内部微细结构. 这种方法在生物、医学、材料科学等无损检测领域中的应用研究，已成为当前国际上X射线成像领域中的研究热点. 讨论衍射增强成像方法和该方法在计算机断层成像中的应用. 实验结果表明，使用衍射增强成像方法获得的数据源能够重建出微米级的生物组织结构，这些组织结构信息在常规X射线断层成像中是难以得到的. 关键词： 衍射增强成像 CT重建 同步辐射 微细结构