CO2激光诱导液相沉积银的机理研究

激光诱导液相沉积的机理可大致分为光电化学机理、热电化学机理和热分解机理等。通过试验及分析表明 ,CO2 激光诱导液相沉积银属于简单的热分解机理。CO2 激光起到局域热源的作用 ,在激光辐照过程中 ,光照区介质溶液及基体表面均发生了极其复杂的物理化学变化 ,最后诱导产生的银沉积在基体表面并部分扩散到了基体内部 ,成为后续化学镀铜的催化中心及过渡层     

Neurotoxicity of Chronic Co-Exposure of Lead and Ionic Liquid in Common Carp: Synergistic or Antagonistic?

Previous studies have indicated that the harmful heavy metal lead (Pb) contamination in aquatic systems has caused intelligence development disorders and nervous system function abnormalities in juveniles due to the increased permeability of the blood–brain barrier. Ionic liquids (ILs) are considered “green” organic solvents that can replace traditional organic solvents. Studies have found the presence of ILs in soil and water due to chemical applications or unintentional leakage. Therefore, what would happen if Pb interacted with ILs in a body of water? Could ILs enable Pb to more easily cross the blood–brain barrier? Therefore, we examined the combined exposure of Pb and ILs in common carp at low concentration (18.3 mg L⁻¹ of Pb(CH₃COO)₂•3 H₂O and 11 mg L⁻¹ of the IL 1-methyl-3-octylimidazolium chloride, 5% of their LC₅₀) for 28 days in the present study. The result of a neurobehavioral assay showed that chronic exposure of lead at lower concentrations significantly altered fish movement and neurobehaviors, indicating that lead exposure caused neurotoxicity in the carp. Increases in the neurotransmitter dopamine levels and injuries in the fish brain accounted for neurobehavioral abnormalities induced by lead exposure. Moreover, we also found that lead could easily cross the blood–brain barrier and caused significant bioaccumulation in the brain. Particularly, our study indicated that the ionic liquid could not synergistically promote blood–brain barrier permeability and hence failed to increase the absorption of lead in the fish brain, suggesting that the combined exposure of lead and ILs was not a synergistic effect but antagonism to the neurotoxicity. The results of this study suggested that ILs could recede the Pb induced neurotoxicity in fish.     

Energy Deposition around Swift Carbon-Ion Tracks in Liquid Water

Energetic carbon ions are promising projectiles used for cancer radiotherapy. A thorough knowledge of how the energy of these ions is deposited in biological media (mainly composed of liquid water) is required. This can be attained by means of detailed computer simulations, both macroscopically (relevant for appropriately delivering the dose) and at the nanoscale (important for determining the inflicted radiobiological damage). The energy lost per unit path length (i.e., the so-called stopping power) of carbon ions is here theoretically calculated within the dielectric formalism from the excitation spectrum of liquid water obtained from two complementary approaches (one relying on an optical-data model and the other exclusively on ab initio calculations). In addition, the energy carried at the nanometre scale by the generated secondary electrons around the ion’s path is simulated by means of a detailed Monte Carlo code. For this purpose, we use the ion and electron cross sections calculated by means of state-of-the art approaches suited to take into account the condensed-phase nature of the liquid water target. As a result of these simulations, the radial dose around the ion’s path is obtained, as well as the distributions of clustered events in nanometric volumes similar to the dimensions of DNA convolutions, contributing to the biological damage for carbon ions in a wide energy range, covering from the plateau to the maximum of the Bragg peak.     

The Potential Application of Starch and Walnut Shells as Biofillers for Natural Rubber (NR) Composites

The goal of this study was application of corn starch and ground walnut shells in various amounts by weight as biofillers of natural rubber (NR) biocomposites. Additionally, ionic liquid 1-butyl-3-methylimidazolium chloride (BmiCl) and (3-aminopropyl)-triethoxysilane (APTES) were used to increase the activity of biofillers and to improve the curing characteristics of NR composites. The effect of biofillers used and their modification with aminosilane or ionic liquid on the curing characteristics of NR composites and their functional properties, including crosslink density, mechanical properties in static and dynamic conditions, hardness, thermal stability and resistance to thermo-oxidative aging were investigated. Starch and ground walnut shells were classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk. BmiCl and APTES were successfully used to support the vulcanization and to improve the dispersion of biofillers in NR elastomer matrix. Vulcanizates with starch, especially those containing APTES and BmiCl, exhibited improved tensile properties due to the higher crosslink density and homogenous dispersion of starch, which resulted from BmiCl addition. NR filled with ground walnut shells demonstrated improved resistance to thermo-oxidative aging. It resulted from lignin present in walnut shells, the components of which belong to polyphenols, that have an antioxidant activity.     

瞬间液相连接的过冷连接新工艺

提出了瞬间液相(TLP)连接的新工艺--过冷连接工艺,即首先将待连接区域加热至某高温进行短时保温,然后再降至一定温度进行长时保温连接.由于液相经历了一次温度过冷,在液/固界面前沿就形成了成分过冷区,破坏了平衡状态下的界面稳定性,形成胞状界面.随着凝固过程的完成,界面消失,形成跨界面连续晶粒,实现冶金接合.以Fe-Ni基非晶合金为中间层,进行了低碳钢过冷TLP连接实验,并与传统的TLP连接工艺进行了比较.结果表明,过冷TLP连接工艺产生了非平面状界面,并且随着凝固的完成界面消失,形成无界面的组织均匀接头.与传统TLP连接工艺接头相比,过冷TLP连接工艺可大大提高接头冲击韧性,其数值达到母材水平.     

真空电弧镀膜中金属液滴的热过程研究

本文建立了真空电弧镀膜中液滴热过程的理论模型，求解了沉积ＴｉＮ膜过程中液滴的温度与粒径变化。计算表明，液滴在飞行过程中温度和粒径不断减小；粒径较小的液滴温度降低较大，甚至可能发生凝固。计算实例能较好解释早期ＴｉＮ膜的电镜分析结果，揭示液滴在薄膜中引起两种不同微孔的机理。     

Böhler Edelstahl

Böhler Edelstahl produces high performance tool and high speed steels via an optimised powder metallurgy/hot isostatic pressing route, as part of a high value special alloys portfolio.     

Theoretical calculations of the surface tension of Ag(1−x)-Cu(x) liquid alloys

The surface tension of silver-copper binary liquid alloys is calculated, in the frame work of Eyring theory. The calculations were made for different compositions (mole fraction, x_Cu = 0, 0.2, 0.4, 0.6, 0.8 and 1), in the temperature range 1100-1800 K. The surface tension decreases with temperature increase, at a fixed copper fraction x_Cu, and increases with increasing copper content. The calculated results are appropriately compared with existing literature data.     

Brφnsted酸-离子液体体系中酸强度的UV-Vis测定

采用UV-Vis对溶有Brφnsted酸的对水稳定的离子液体的酸强度进行了测定并结合Hammett函数,获得了令人满意的结果。