Orthogonal ligation to spherical polymeric microparticles: Modular approaches for surface tailoring

Modular ligation strategies for the functionalization of polymeric microspheres provide new perspectives for their applications in material science. In the current trend article we highlight variable synthetic procedures for generating functional microspheres via orthogonal modular conjugation chemistries. An overview of the different surface chemistries available is provided, followed by surface-sensitive characterization techniques relevant for the microparticles. Finally, we explore future trends in modular orthogonal modification approaches on microparticles and provide an outlook on the perspectives that the field of surface-modification of polymeric microparticles holds.     

Improvement of Stress-rupture Life for Modified-HR6W Austenitic Stainless Steel

Stress-rupture life of HR6W austenitic stainless steel modified with B and Mg additions was measured, and the microstructures were analyzed by optical microscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy equipped with energy dispersive spectroscopy. The results indicated that the enhancement of the stress-rupture life was mainly due to the precipitation with B in the elemental form at the grain boundaries, and the improvement of the form of carbides at grain boundaries and the removal of O and S elements by addition of Mg. The micro-alloying elements have a beneficial effect on stress-rupture life of the modified-HR6W austenitic stainless steel at high temperature.     

Self-Assembly and Ordering of C60 on the WO2/W（110） Surface

The growth and ordering of C₆₀ molecules on the WO₂/W(110) surface have been studied by low-temperature scanning tunnelling microscopy and spectroscopy (STM and STS), low-energy electron diffraction (LEED), and density functional theory (DFT) calculations. The results indicate the growth of a well-ordered C₆₀ layer on the WO₂/W(110) surface in which the molecules form a close-packed hexagonal structure with a unit cell parameter equal to 0.95 nm. The nucleation of the C₆₀ layer starts at the substrate’s inner step edges. Low-temperature STM of C₆₀ molecules performed at 78 K demonstrates well-resolved molecular orbitals within individual molecules. In the C₆₀ monolayer on the WO₂/W(110) surface, the molecules are aligned in one direction due to intermolecular interaction, as shown by the ordered molecular orbitals of individual C₆₀. STS data obtained from the C₆₀ monolayer on the WO₂/W(110) surface are in good agreement with DFT calculations.     

Design and evaluation of an optimized W/Cu interlayer for W monoblock components

Divertor plasma-facing components of future fusion reactors should be able to withstand heat fluxes of 10-20 MW/m² in stationary operation. Tungsten blocks with an inner cooling tube made of CuCr1Zr, so-called monoblocks, are potential candidates for such water-cooled components. To increase the strength and reliability of the interface between the W and the cooling tube of a Cu-based alloy (CuCr1Zr), a novel advanced W-fibre/Cu metal matrix composite (MMC) was developed for operation temperatures up to 550 °C. Based on optimization results to enhance the adhesion between fibre and matrix, W fibres (W_f) were chemically etched, coated by physical vapour deposition with a continuously graded W/Cu_PVD interlayer and then heated to 800 °C. The W_f/Cu MMC was implemented by hot-isostatic pressing and brazing process in monoblock mock-ups reinforcing the interface between the plasma-facing material and the cooling channel. The suitability of the MMC as an efficient heat sink interface for water-cooled divertor components was tested in the high heat flux (HHF) facility GLADIS. Predictions from finite element simulations of the thermal behaviour of the component under loading conditions were confirmed by the HHF tests. The W_f/Cu MMC interlayer of the mock-ups survived cyclic heat loads above 10 MW/m² without any damage. One W block of each tested mock-up showed stable thermal behaviour at heat fluxes of up to 10.5 MW/m².     

Si+自注入Si晶体中缺陷分布的计算模拟

在两体近似碰撞模型基础上,采用SRIM程序对自注入硅离子及其造成的损伤在样品的分布进行了研究,模拟了Si<'+>自注入si晶体的Si<'+>深度分布几率和注入时的能量传递.计算结果表明:在相同注入能量的情况下,注入Si<'+>的分布概率是恒定的,在注入过程中电离能是阻止Si<'+>进一步深入的主导因素.论文还初步讨论了...     

A New Prototype Two‐Phase (TiNi)–(β‐W) SMA System with Tailorable Thermal Hysteresis

The Ti–Ni–W two‐phase shape memory alloy (SMA) thin film system is presented as a prototype for new SMAs with tailorable thermal transformation hysteresis (ΔT). The concept is to combine the SMA TiNi with almost insoluble W to create the two‐phase system (TiNi)–(β‐W). This system behaves like a pseudobinary TiNi system. Phase transformation behavior for compositions above the solubility limit of W in TiNi exhibit a B2–R phase transformation with characteristically small ΔT. Moreover, ΔT is dependent on the amount of W and it can be tailored to zero and even negative. This phenomenon is rationalized as being due to the mechanical interaction between the phases B2‐TiNi and β‐W. The presented results are very promising for the development of high‐speed Ti–Ni‐based SMA actuators.     

石粉替代水泥掺量对砌筑砂浆收缩性能的影响

试验研究了石粉等量替代水泥后砌筑砂浆的干缩性能的影响,结果表明采用适量的石粉等量替代水泥可以有效减小砂浆的收缩值,对砂浆早期干缩性能影响更为显著;影响效果随着水灰比的减小而增大.分析了水灰比和石粉取代水泥量对砂浆收缩性能影响的相关关系,可供工程应用选取最佳水灰比和石粉掺量.     

抗高温水包柴油乳状液研究

针对欠平衡钻井对低密度钻井液的要求,以水包柴油乳状液为研究对象,通过实验优选乳化剂,研究了2种和多种乳化剂协同作用下水包柴油乳状液的稳定性,优选出了抗温性能好、乳化能力强的复合乳化剂,配制出了抗180℃高温的水包油乳状液.     

W/BaCrO_4系延期药延期性能的实验研究

实验研究了金属燃烧剂W粉的粒度及含量对W系延期药延期时间和延期精度的影响。结果表明:在延期体切长相同的情况下,随着W的粒度的减小及W含量的增加,延期药的燃烧速度增加,延期精度明显提高。     

大孔树脂静态吸附番茄内生菌Brevibacillus brevis W4抑细菌成分

[目的]Brevibacillus brevis W4是从番茄茎中分离得到的1株对灰霉病菌有强烈抑制作用的内生菌.为明确其发酵液抑细菌活性,并探索抑细菌物质的大孔树脂吸附条件.[方法]采用管碟法测定了B.brevis W4发酵液对6种病原细菌的抑制活性.并以金黄色葡萄球菌为指示菌,选用大孔树脂对发酵液中的抑细菌活性物质进行静态吸附条件优化.[结果]B.brevis W4发酵液对供试枯草芽孢杆菌、金黄色葡萄球菌、水稻白叶枯病菌、柑橘溃疡病菌、大白菜软腐病菌、姜青枯假单孢杆菌均有抑制活性,对金黄色葡萄球菌和枯草芽孢杆菌的抑菌圈突出,直径分别为21.7、20.1 mm.大孔树脂AB-8对活性物质的吸附效果最好,其较优的静态吸附条件为上样液pH值为8.0,上样量为树脂质量的15倍,最佳的洗脱液体积分数为40％甲醇.[结论]B.brevis W4发酵液具有抑制细菌作用,对金黄色葡萄球菌和枯草芽孢杆菌的抑制作用最强.AB-8可以作为抑细菌活性成分的吸附树脂.