Interface Structures and Hamiltonians: Exact Results

There have been many recent applications of interface models and Hamiltonians to problems in the theory of wetting. These models help to understand more abstract calculations on the type of problem which can be treated on the one hand, and on the other, to extend the type of problem which can be treated. A very recent example of this is corner wetting, also known as filling. This contribution discusses the validity of such concepts from first principles using exactly calculated interface structures and phase diagrams. The planar Ising model, with boundary conditions and surface fields imposed to bring in wetting, is used. The well-known Jordan–Wigner transformation to lattice fermions is composed of a product of spin reversals to one side (on a strip) of the point at which the lattice Fermi operator acts. Such spin reversals introduce a domain wall in a natural way which can be exploited to bring in interface Hamiltonians in a natural and precise way. The perennial problem of intrinsic structure is discussed. The findings do not support the notion of such a structure attached to capillary waves by convolution. In a sense to be made precise, kinks have to be taken into account.     

Exact Results for Wetting and Filling on a Triangular Lattice

New exact analytical results are described for surface tension on the triangular Ising lattice. The triangular Ising lattice forms naturally 60° and 120° corners, and a thermodynamic argument is used, which incorporates the exact results, to obtain conditions for the filling transition for both angles. Monte Carlo simulations with Wang–Landau sampling are performed to independently verify the applicability of this argument. Results are in agreement with previous conjectures for the phase boundary in these systems.     

Citrate Improves Collagen Mineralization via Interface Wetting: A Physicochemical Understanding of Biomineralization Control

Biological hard tissues such as bones always contain extremely high levels of citrate, which is believed to play an important role in bone formation as well as in osteoporosis treatments. However, its mechanism on biomineralization is not elucidated. Here, it is found that the adsorbed citrate molecules on collagen fibrils can significantly reduce the interfacial energy between the biological matrix and the amorphous calcium phosphate precursor to enhance their wetting effect at the early biomineralization stage, sequentially facilitating the intrafibrillar formation of hydroxyapatite to produce an inorganic–organic composite. It is demonstrated experimentally that only collagen fibrils containing ≈8.2 wt% of bound citrate (close to the level in biological bone) can reach the full mineralization as those in natural bones. The effect of citrate on the promotion of the collagen mineralization degree is also confirmed by in vitro dentin repair. This finding demonstrates the importance of interfacial controls in biomineralization and more generally, provides a physicochemical view about the regulation effect of small biomolecules on the biomineralization front.     

Wetting Phenomena in bcc Binary Alloys

We study the influence of the surface orientation on the wetting behavior of bcc binary alloys, using a semiinfinite lattice model equivalent to a nearest-neighbor Ising antiferromagnet in an external magnetic field. This model describes alloys that exhibit a continuous B2–A2 order–disorder transition, such as FeAl or FeCo. For symmetry-breaking surfaces like (100), an effective ordering surface field g ₁0 emerges. Such a field not only crucially affects the surface critical behavior at bulk criticality, but also gives rise to wetting transitions below the critical temperature T _c. Starting from the mean-field theory for the lattice model and making a continuum approximation, a suitable Ginzburg–Landau model is derived. Explicit results for the dependence of its parameters (e.g., of g ₁) on the microscopic interaction constants are obtained. Utilizing these in conjunction with Landau theory, the wetting phase diagram is calculated.     

A Metamaterial Analog of the Ising Model

The interaction between microscopic particles is always a fascinating and intriguing area of science. Direct interrogation of such interactions is often difficult. Structured electromagnetic systems offer a rich toolkit for mimicking and reproducing the key dynamics that govern the microscopic interactions, and thus provides an avenue to explore and interpret the microscopic phenomena. In particular, metamaterials offer the freedom to artificially tailor light–matter coupling and to control the interaction between unit cells in the metamaterial array. Here, a terahertz metamaterial that mimics spin‐related interactions of microscopic particles in a 2D lattice via complex electromagnetic multipoles scattered within the metamaterial array is demonstrated. Fano resonances featured by distinct mode properties due to strong nearest‐neighbor interactions are discussed, which draw parallels with the 2D Ising model. Interestingly, a phase transition from single Fano resonance to hyperfine splitting of the Fano spectrum is observed by manipulating the 2D interactions without applying external magnetic or electric fields, which provides a potential multispectral platform for applications in super‐resolution imaging, biosensing, and selective thermal emission. The dynamic approach to reproduce static interaction between microscopic particles will enable more profound significance in exploring the unknown physical world by the macroscopic analogs.     

随机Kadomtsev-petviashvili方程的精确解

利用厄尔米特变换和F-展开法,得到了随机Kadomtsev-petviashvili方程由Jacobi椭圆函数表示的精确解,此显示了F-展开法也可以用来求解随机微分方程。     

微电子封装领域中合金润湿性测量的研究进展

随着微电子封装领域中合金的使用,润湿性问题已成为封装可靠料学、材料物理、测试科学技术等基础研究领域.综述了目前合金润湿性的常用测量方法,着重介绍了润湿平衡法,最后利用基片曲率法,提出一种新的光学方法来实时测量合金润湿性.     

THERP+HCR分析方法时间接口研究

文章介绍了THERP和HCR方法的基本特点，分析了THERP HCR模型时间接口两种不同处理方法的合理性，并通过实例结果比较，得出了较为合理的时间接口方案。     

Si对SiC－Al系统浸润行为的影响

用液滴技术（Ｔｈｅ　Ｓｅｓｓｉｌｅ　Ｄｒｏｐ　Ｔｅｃｈｎｉｑｕｅ）、ＳＥＭ、ＥＤＳ等研究了Ｓｉ对ＳｉＣ－Ａｌ系统浸润行为的影响，结果表明，在较低温度下，Ｓｉ在熔融Ａｌ合金中的含量不明显影响Ａｌ对ＳｉＣ的浸润行为，然而，在高温下ＳｉＣ和Ａｌ的接触角θ值随时间而减小的速率随Ｓｉ含量的增加而增大；ＳｉＣ－Ａｌ系统从非浸润到浸润的转变温度随Ｓｉ含量的增加而降低；Ｓｉ的添加引起Ａｌ合金在ＳｉＣ表面扩展和向ＳｉＣ基体渗透，而且扩展和渗透的程度随Ｓｉ含量增加而增大。说明在Ａｌ合金中添加Ｓｉ可促进对ＳｉＣ的浸润。本研究还证实了基体参加反应可增强金属Ａｌ对ＳｉＣ陶瓷的浸润能力。     

Mn对熔融Zn-Mn合金与X80钢润湿行为的影响

研究了锌液中0.1%~0.5%(质量分数)Mn对X80钢表面润湿行为的影响。采用改良座滴法获得了450℃时Zn-Mn合金的接触角,通过SEM/EDS观察分析样品表面及界面的组织结构,研究了Zn-χMn(χ=0.1~0.5)合金与X80钢基板的润湿行为和界面反应。结果表明：锰元素对锌合金与钢基体间的润湿性反应起到正吸附作用。在450℃时,当熔体中的锰含量为0.1~0.5时,Zn-χMn合金与钢基间的润湿接触角从85°减小到62°。锌合金熔体/X80钢属于反应性润湿体系,生成的界面产物由FeZn₁₀(δ)、FeZn₁₃(ζ)和Fe₃Zn₁₀(Γ)/Fe₅Zn₂₁(Γ₁)相组成,润湿行为受锌合金界面反应影响。在铺展三相线前沿存在前驱膜,前驱膜的出现能够促进润湿。     

胶接接头界面理论及其表面处理技术研究进展

胶接是用胶粘剂将被粘物表面连接在一起,形成可承受外载的胶接接头的过程,是涉及材料粘附、高分子材料老化机理、表面技术、力学性能测试等多个学科领域的边缘学科.介绍了与胶接接头界面紧密相关的弱界面层理论和润湿理论等领域的研究进展,总结了胶接接头表面处理方面的主要方法.     

Hybrid-lattice系统的精确解

本文在试探函数法的基础上,给出由指数函数所组成的试探函数法,将其应用于非线性离散系统,借助符号计算系统Mathematica构造了Hybrid-Lattice系统的新的精确孤波解。该方法在构造mKdV差分微分方程、Ablowitz-Ladik-Lattice系统等其它的离散差分微分方程的精确解方面具有普遍意义。     

Unidirectional Wetting in the Hydrophobic Wenzel Regime

Unidirectional wetting surfaces can cause liquid droplets to flow/move in one direction while pinning them in the other directions, a feature that is useful for biosensing, adhesives, thermal management, and microfluidics. Such surfaces can be fabricated by employing structurally or chemically asymmetric nanostructures. While unidirectional wetting in the hydrophobic Wenzel regime had previously been observed on surfaces decorated with chemically asymmetric nanostructures, it has yet to be demonstrated on structurally asymmetric nanostructures. Based on the current understanding of the phenomenon, this can only be achieved using highly bent nanowires. Here, evidence to the contrary is provided by showing that mildly bent nanowires can also bring about unidirectional wetting in the hydrophobic Wenzel regime, even for contact angles beyond the superhydrophobic limit. Using NaCl precipitation, the unidirectional wetting mechanism is analyzed on a nanoscale level and it is found that the criteria for unidirectional wetting to take place in the hydrophobic Wenzel regime are different from that in the hydrophilic Wenzel regime. Moreover, it is revealed that slight wetting in the pinned direction can be caused by large scale deformation of high aspect ratio nanostructures during droplet spreading, which may be part of the reason behind previous observations of near‐unidirectional wetting on bent nanowires with high aspect ratios.     

网络界面中的色彩符号

提出了网络界面中的色彩是能指与所指的统一体,具有符号性,并分析了色彩符号以信息传达为目的实用功能和色彩信文构成自我目的化的审美功能,归纳出网络界面中色彩符号的符号特征、艺术特征和设计特征,并结合网络界面设计实例中的色彩符号的分析例证,阐明了色彩符号的研究在网络界面设计中的重要作用.     

非线性扩散方程的精确解

本文研究非线性扩散方程的精确解,文中分别给出非线性扩散方程在推广旋转群和推广伸缩群上不变时满足的条件,并且利用推广旋转群和推广伸缩群构造方程的精确解,最后,给出了非线性扩散方程在推广旋转伸缩群上不变时满足的条件,推广旋转伸缩群也被用来构造非线性扩散方程的精确解.     

确定层状复合材料界面结合强度的新模型

本文提出了一个确定层状复合材料界面结合强度的新模型,即由两种材料交替完全粘结在一起的复合梁。利用材料力学方法对这种梁进行了应力分析,包括正应力分析和剪应力分析。研究了两种情况:一种情况假设两种材料均是线弹性材料;另一种情况假设其中一种材料是纯线弹性材料。而另一种材料是理想弹塑性材料。本文给出的复合梁剪应力的计算公式为复合材料界面剪切强度的测定提供了比较精确的计算公式。     

应用MVC模式的TMN G接口研究与实现

在电信管理网（TMN）中采用接口的方法定义了物理块之间的关系。目前，对应于人机接口G接口的实现还没有一个统一的标准，本文参照ANSI T1-232-1996标准和EURESCOM的设计原则，给出了一个基于MVC模式的G接口模型及其实现方案。该方案采用了基于Web浏览器的Browser/Server结构，适合分布式的网络管理系统开发。     

脉冲紫外激光改性对聚碳酸酯表面润湿性能的影响

355nm脉冲(100kHz)紫外激光刻蚀改性的功率密度对聚碳酸酯(PC)材料表面润湿性能的影响存在规律性:当激光功率密度小于0.27×108W/cm2时,可得到亲水性的PC表面;当激光功率密度在1.15×108～10.19×108W/cm2之间时,可得到疏水性的表面。用扫描电镜技术(SEM)和X射线光电子能谱技术(XPS),详细探讨了紫外激光刻蚀改性对PC表面润湿性能的影响机理。当激光功率密度大于1.15×108W/cm2时,尽管改性后PC表面的含氧极性基团有所增加,但由于"V"字形沟槽结构的存在,使其表面仍然呈现疏水性。探讨了用Cassie模型解释在一定的激光功率密度刻蚀改性条件下,PC材料表面的水接触角和润湿性能变化的可行性。     

基于心智模型因子研究的智能界面优化

目的探索年龄(Age)、科技熟悉度(Technology)因子对用户心智模型及界面操作绩效的影响。方法采用对比实验法,青年、老年被试分别完成系列目标任务(Serial Target Task);结束后利用条列(Listing)与分类(Sorting)法将被试心智模型可视化,记录各因素下产品操作绩效。结果 (1)心智模型对用户操作绩效具有显著相关性(P0.05);(2)科技熟悉度、年龄因素均对用户心智模型具有显著相关性(P0.05);(3)年龄段与科技熟悉度分值因子间具有相关性。结论缩短产品界面结构与心智模型间的差异,提高老年产品使用绩效。     

Coexistence curve equation for several onecomponent fluids in the vicinity of the critical point

Based on the available literature data on (he temperature dependence of coexisting densities near the critical point for Ne, HD, N₂, and C₂,H₄,. the disadvantages of using the extended scaling equation of the coexistence curve with the Ising exponent are shown, Combined statistical methods are proposed to reanalyze these data. For all the above-mentioned substances, in (he range of reduced temperature 1.3 x 10^-4 < r < 6 x 10^-3 to 2 x 10^-2, we obtain for the order parameter a single-term fit, with the common value =0.355. The fit describes the experimental densities with .m uncertainty ol 0,06 to 0.1%.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado. U.S.A.