Free Surface and Interface Thermodynamics of Liquid Nickel in Contact with Alumina

Sessile drop experiments of Ni and Ni(2at.%Al) were conducted under controlled working conditions, at 1500°C, P(O₂) 10^–9 Torr. It is shown that Al and oxygen atoms engaged in the capillary driven mass transport at the interface have a significant impact on the surface/interface thermodynamics. The surface energy of liquid Ni determined from experiments in which Ni comes into contact with Al₂O₃ is significantly lower than that of high purity Ni, due to the segregation of Al. The free energy of segregation of Al to the free surface of Ni ( G _S) was found to range from –164 to –152 kJ/mol, indicating a relatively strong tendency for segregation of Al to the free surface of Ni(Al). It is proposed that an Al(O)-rich liquid layer forms adjacent to the Ni-Al₂O₃ interface, which improves interfacial adhesion. In the Ni(Al)-Al₂O₃ system, an increase in the Al content of the alloy leads to the improvement of both wetting and adhesion of the alloy on the ceramic, correlating with the improvement in the interface strength after solidification.     

光轴方向任意的晶体连续双折射双反射

根据惠更斯定理,研究了单轴晶体光轴任意方向的双折射与全内双反射,给出了光线方向和光波法线方向的普遍公式.讨论了在晶体内沿多个面的连续双折射双反射,分析了前一界面输出量和后一界面输入量之间的联系,得到多次双折射双反射后的光线方向和光波法线方向.在此基础上,适当地选取晶体的界面参数,相当于选取光轴方向,可以使o光和e光的分离角Δoe更大.光轴方向任意的晶体连续双折射双反射对晶体器件的最优化设计非常有帮助.最后给出了改变斜入射2×2电光开关的出射面参数使Δoe优化的实例.     

About the Importance of Nanometer-Thick Intergranular Penetration in the Analysis of Liquid Metal Embrittlement

Liquid metal embrittlement (LME) of copper by liquid bismuth is investigated at 300°C. It is shown that a very rapid damage is due to the synergy between the external stress and the phenomenon of intergranular penetration (IGP). Tests of IGP, i.e. without external stress, were done at 300°C and at 600°C and have resulted in strong intergranular embrittlement due to the formation of nanometer-thick intergranular films, as measured and quantified by Auger electron spectroscopy (AES). The formation of these films is discussed with respect to apparently non-zero dihedral angles at 600°C. A general procedure based on mechanical testing and AES measurements, to check whether IGP has occurred or not, is outlined. This procedure can be seen as an alternative way to determine the wetting transition temperature. The presence of nanometer-thick films due to IGP is discussed with respect to the LME mechanisms.     

晶体的连续双折射双反射及其集成应用:1×N电光开关

根据惠更斯定理 ,给出了单轴晶体内双折射与全内双反射的光线方向和光波法线方向的普遍公式。并讨论了在晶体内沿多个面的连续双折射双反射 ,分析了前一界面输出量和后一界面输入量之间的联系 ,得到多次双折射双反射后的光线方向和光波法线方向。在此基础上 ,提出一种单块晶体集成的 1×N电光开关 ,即把多个电光调制器安置在全反射面之间。由于双折射效应 ,寻常光和非常光有不同的全内反射 ;给不同的电极对上加上半波电压改变输入光的偏振状态 ,再使光通过不同数目的反射面反射 ,最后输出光就有不同的角度。具有结构简单、插入损耗小、抗干扰性强等优点。给出了 1× 4光开关的实例。     

Influence of the Interfaces on Magnetic Properties of Fe/Ag and Fe/Cu Multilayers Prepared by Sputtering

Hyperfine Interactions - Dependence of magnetic behavior of ultrathin Fe layers on the width of the interfaces was investigated by using dc-magnetron sputtering to grow (Fe(110)/Ag(111))...     

Osteoblast and Chrondrocyte Proliferation in the Presence of Alumina And Titania Nanoparticles

Proliferation of osteoblasts (bone-forming cells) and chondrocytes (cartilage-synthesizing cells) exposed to different sizes of alumina as well as titania particles at various concentrations (from 10,000 to 100g/ml of culture media) was investigated in the present in vitro study. Compared to respective conventional (i.e., micron) particle size ceramics, results provided the first evidence of increased osteoblast and chondrocyte proliferation in the presence of nanoparticles. Material characterization studies revealed that the only difference between respective ceramic particles was nano- and conventional-dimensions; specifically, phase, charge, and chemical properties were similar between different size alumina and titania particles, respectively. Thus, the present study provided the first evidence of a less detrimental effect of nano- as compared to conventional-dimension wear debris on cell function; such wear debris may result from friction between articulating components of orthopedic implants composed of novel nanophase ceramic materials. In this manner, results provided additional evidence to the literature that nanophase ceramics may become the next generation of bone prosthetic materials with improved osseointegrative (i.e., ability to bond to juxtaposed bone in situ) properties.     

The Application of Two-dimensional Fluorescence Correlation Spectroscopy on the Interaction Between Bovine Serum Albumin and Paeonolum in the Presence of Fe(III)

The effect of Fe³⁺ on the interaction between bovine serum albumin (BSA) and paeonolum (PAL), which was extracted from the traditional Chinese herb, Paeonia suffruticosa Andr, was investigated by UV and fluorescence spectroscopy. Two-dimensional correlation spectroscopy was applied to the analysis of fluorescence spectra. The results of spectroscopic measurements suggested that PAL had a strong ability to quench the intrinsic fluorescence of BSA through static quenching procedure in the presence of Fe(III). Thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) were calculated. The binding parameters including binding constant (K), and the distance (r) between PAL and BSA were evaluated on the basis of the theory of Föster energy transfer. Owing to the spectral resolution enhancement in 2D correlation spectroscopy, the structure change of PAL–Fe³⁺ can be observed.     

固/液界面原位红外显微镜和步进扫描时间分辨FTIR反射光谱及其在纳米材料科学中的应用

结合红外显微镜和步进扫描FTIR光谱仪 ,发展了固 /液界面电化学原位显微镜红外反射光谱和步进扫描快速时间分辨FTIR反射光谱 ,并应用于纳米材料特殊性能和电化学反应动力学的研究。研制纳米结构Pt微电极 ,获得CO吸附的红外特征随纳米结构和纳米尺度变化的原位显微镜红外谱图。利用纳米结构Pt微电极的异常红外效应 ,显著提高电化学原位红外反射光谱的灵敏度 ,获得分辨率达 5 0 μs的步进扫描时间分辨光谱。不仅发展了固 /液界面显微镜原位红外反射光谱新方法 ,并且拓展了电化学原位红外反射光谱在纳米材料科学研究中的应用。     

ATR-IR分析氢氧化钠对水及离子液体/水体系氢键作用的影响

利用衰减全反射红外光谱(ATR-IR)分析NaOH对水及1-乙基-3-甲基咪唑醋酸酯离子液体水溶液(EmimAc/水)氢键网络的影响,研究结果表明,NaOH的加入会影响水分子的氢键对称性和类型,对称性氢键谱带Ⅰ(3218 cm-1)和Ⅱ(3375 cm-1)随着NaO H浓度的提高而降低.NaO H使水溶液氢键发生极化...     

Comparing the Basic Phenomena Involved in Three Methods of Pore‐size Characterization: Gas Adsorption,Liquid Intrusion and Thermoporometry

Gas adsorption at 77 K is probably the most widely used method to characterize mesoporous adsorbents via capillary condensation. Mercury intrusion is also commonly used for the characterization of such materials with the possibility to extend the pore width distribution measurement to the macropore range. More recently water intrusion was proposed to study hydrophobic porous solids. Thermoporometry is a further characterization method, now based on the study of the solid/liquid transition. We can consider that all these methods rely on the modification of the phase diagram of a pure substance under the effect of confinement. For each of them, the equations and models derived are based either on classical thermodynamics or on statistical approaches. In most cases, the derivation of the pore width distribution is carried out with the assumption that the porous system is made up of non‐connected cylinders, whereas the actual complexity of the structure is derived from the hysteresis shape. Our aim here is to compare the four approaches above (gas adsorption, mercury intrusion, water intrusion, thermoporometry) on samples giving rise, in their gas adsorption isotherms, to the typical hysteresis loops of the IUPAC classification. Our comparison is in great part carried out after the shape of the hysteresis loops obtained with the various methods and after the information it brings on the mechanism of replacement of a phase by the other within the porous system.     

电感耦合等离子体-原子发射光谱法测定TZM合金中Ti和Zr

建立了ICP-AES直接测定TZM合金中钛和锆的分析方法.采用基体匹配法消除基体干扰,对实验条件进行了优化.实验结果表明:回收率为96.33%-110.00%,RSD(n=5)均小于2.0%.本法简便、快速、准确度高.     

Structural and magnetic properties of the Ce/Fe(001) interface: a spin resolved inverse photoemission study

We report a spin-resolved inverse photoemission study on the early stages of the Ce/Fe(001) interface formation in the coverage range 0–10 Å. The interface has been grown in two different fashions (i.e., keeping the substrate temperature either at room temperature or at 600 °C), leading to quite different morphologic and magnetic properties. The room-temperature-grown interface shows the formation of a non-intermixed disordered Ce phase, giving rise to quite featureless spectra and to the absence of detectable spin-dependent effects. The hot-grown interface shows instead the formation of a stable and ordered Ce---Fe compound, with the clear appearance of new structures which show a sizeable spin-dependent behavior. A relevant Ce 4f contribution to them is ruled out on the basis of their angular dependence and of cross-section arguments, indicating their band-like character.     

液态乳三聚氰胺液相色谱和拉曼光谱检测快速前处理方法

三聚氰胺毒牛奶事件对中国乳制品行业造成了巨大冲击。为保证食品安全,贯彻国家相关管理规定,在乳制品收购环节开展液态乳中三聚氰胺快速检测具有重要的现实意义。研究通过絮凝过滤进行液态乳中三聚氰胺快速分离的前处理方法,样品使用碱式氯化铝(PAC)絮凝后经水性滤膜过滤,即可有效去除液态乳中的脂肪等非水溶性干扰物,得到澄清滤液用于后续检测。通过实验确定碱式氯化铝的添加质量比例为2%~3%时有较高的过滤效率;当混合液为弱碱性条件下具有较好的絮凝效果。采用高效液相色谱方法实验测得样品回收率在90%以上,并估算了回收率的置信区间。采用本方法前处理所得样品与离心前处理方法相比更澄清,采用增敏拉曼方法获得的光谱曲线基线更平整,除杂质效果更好。该前处理方法通用性好,分离效果好,比现有三聚氰胺检测标准方法前处理过程更简单、快速,如用于现有快速液相法和拉曼光谱法中前处理步骤将使检测效率大大提高。     

含氢氦锆膜的中子反射及弹性反冲探测表征

采用直流磁控溅射方法制备含氢氦的锆膜,利用中子反射和弹性反冲探测两种方法分别对样品中的氢、氦分布以及浓度进行表征,并探究了不同温度退火处理后H、He的变化.实验结果表明:中子反射与弹性反冲探测两种方法的表征结果具有很好的一致性,H、He在锆层中近似均匀分布,氦浓度与溅射的He/Ar比成正比. 300℃退火处理1 h后,样品中的H从Zr层向外迁移和释放,且这种现象随退火温度升高到500℃时更加明显.     

翡翠贻贝珍珠层的光子彩虹色表征及理论模拟

利用光纤光谱仪、扫描电镜及理论模拟软件对翡翠贻贝珍珠层的彩虹色及微结构进行系统的研究。结果表明,珍珠层具有由文石板片与有机质交替排列形成的典型的一维光子晶体结构;其中文石板片的厚度从生长区的392nm逐渐增大到壳中区的537nm,导致反射光谱中同级别光子带隙出现明显的红移现象;珍珠层彩虹色的主波长从480nm(蓝色)增大到527nm(绿色)。反射光谱测定及理论模拟表明,该珍珠层的2～4级光子带隙位于紫外区、蓝色和红色范围,从而导致珍珠层具有复杂的彩虹色。     

Structure and spectroscopy of the supercapacitor material hydrous ruthenium oxide,RuO2·xH2o,by neutron scattering*

Hydrous ruthenium dioxide, RuO₂·xH₂O, is a material of active investigation as an electrode material for supercapacitors. A combination of elastic and inelastic neutron scattering together with thermal gravimetric studies and DFT calculations have provided new insight into the nature of the surface species present on RuO₂·xH₂O. Our results confirm that hydrous ruthenium oxide is a nanocrystalline material consisting of a core of RuO₂. We show that the surface consists largely of Ru–OH with small amounts of water hydrogen-bonded to the surface. The hydroxyls are stable up to ～200°C, i.e. over the composition range x?=?0.2–2. The optimal supercapacitor material has x?=?0.5–0.7, and in this range, the surface is fully hydroxylated. This provides a route for the proton transport: a proton can attach to a surface hydroxyl to generate coordinated water, proton transport then occurs along the hydrogen-bonded chain by a Grotthuss mechanism.     

Many-body effect in the coincidence L3 and M3 photoelectron spectroscopy spectra of Cu metal

The coincidence L₃ and M₃ photoelectron spectroscopy (PES) main lines of Cu metal are calculated by a many-body theory. There is no peak-energy shift between the singles PES main line and the coincidence one. The asymmetric narrowing of the coincidence PES main line on the low kinetic energy (KE) side is very small. This is in accord with recent experimental findings. In Cu metal, the shakeup satellite intensity is small and the main-line satellite separation energy is much larger than the core–hole lifetime width. The interference via the final-state interaction is negligible. In the PES main line, the imaginary part of the self-energy by shakeup excitations, which is very small compared to the core–hole lifetime width, decreases very slowly in linear with photoelectron KE. The branching ratio of Auger decay of a single hole state then increases very slowly in linear with photoelectron KE so that the deviation of the coincidence PES main line from the singles one is very small. The 939 eV structure seen only in the coincidence L₃ PES spectrum of Cu metal is attributed to the enhancement of the inelastic peak of a smaller energy loss due to electrons of a smaller average emission depth measured in coincidence with the elastic Auger peak. The structure will not be enhanced in the singles PES spectrum. The background subtraction in the coincidence spectrum cannot be the same as that in the singles one. Such consideration is necessary before we can conclude about the asymmetric narrowing on the low KE side. A unique capability of APECS by which one can determine the photoelectron KE dependent part of the imaginary part of the self-energy is pointed out.     

Investigation of the Interaction Between Rutin and Trypsin in Solution by Multi-Spectroscopic Method

ABSTRACT

The interactions between rutin and trypsin were investigated by UV-Vis absorption, CD, fluorescence, resonance light-scattering spectra, synchronous fluorescence, and three-dimensional fluorescence spectra techniques under physiological pH 7.40. Rutin effectively quenched the intrinsic fluorescence of trypsin via static quenching. The enthalpy change and entropy change were estimated to be ?8.23 kJ·mol^?1 and 53.66 J·mol^?1·K^?1 according to the van't Hoff equation. The process of binding rutin to trypsin was a spontaneous molecular interaction procedure. This result indicates that hydrophobic and electrostatic interactions played a major role in stabilizing the complex. The conformation of trypsin was discussed by CD, synchronous, and three-dimensional fluorescence techniques.     

贵金属Au冷却过程中结构及能量变化的分子动力学计算机模拟

通过分子动力学方法,研究了不同冷速下贵金属Ａｕ在温度２０００～３００Ｋ的冷却过程中微观结构的变化特点,结果发现,冷却速度对Ａｕ的微观结构产生重要影响,采用偶关联函数和键对分析技术对原子局域团簇结果者分析,并考察了冷却过程中原子势能随温度的变化,比较了Ａｕ的微观结构转变与能量变化的对应关系,从能量转化的角度对冷却过程中Ａｕ的结构变化进行了说明。