Potential Applications of Nano-Scale Science and Technology in Geosciences and Experimental Studies of Nanometer-Sized Gold Adsorption on Minerals and Rocks

Potential applications of Nano-scale science and technology are discussed in mineralogy, ore deposits, cosmochemistry and environmental sciences. Adsorption of nanometersized gold was experimentally studied on a variety of minerals and rocks.

Experimental Study on Molecular Arrangement of Nanoscale Lubricant Films——A Review

In order to understand lubrication mechanism at the nanoscale, researchers have used many physical experimental approaches, such as surface force apparatus, atomic force microscopy and ball-on-disk tribometer. The results show that the variation rules of the friction force, film thicknessand viscosity of the lubricant at the nanoscale are different from elastohydrodynamic lubrication （EHL）. It is speculated that these differences are attributed to the special arrangement of the molecules at the nanoscale. However, it is difficult to obtain the molecular orientation and distribution directly from the lubricant molecules in these experiments. In recent years, more and more attention has been paid to use new techniques to overcome the shortcomings of traditional experiments, including various spectral methods. The most representative achievements in the experimental research of molecular arrangement are reviewed in this paper： The change of film structure of a liquid crystal under confinement has been obtained using X-ray method. The molecular orientation change of lubricant films has been observed using absorption spectroscopy. Infrared spectroscopy has been used to measure the anisotropy of molecular orientation in the contact region when the lubricant film thickness is reduced to a few tens of nanometers. In situ Raman spectroscopy has been performed to measure the molecular orientation of the lubricant film semi-quantitatively. These results prove that confinement and shear in the contact region can change the arrangement of lubricant molecules. As a result, the lubrication characteristics are affected. The shortages of these works are also discussed based on practicable results. Further work is needed to separate the information of the solid-liquid interface from the bulk liquid film.

Numerical Analysis of the Adhesive Forces in Nano-Scale Structure

Nanohairs, which can be found on the epidermis of Tokay gecko＇s toes, contribute to the adhesion by means of van der Waals force, capillary force, etc. This structure has inspired many researchers to fabricate the attachable nano-scale structures. However, the efficiency of artificial nano-scale structures is not reliable sufficiently. Moreover, the mechanical parameters related to the nano-hair attachment are not yet revealed qualitatively. The mechanical parameters which have influence on the ability of adhesive nano-hairs were investigated through numerical simulation in which only van der Waals force was considered. For the numerical analysis, finite element method was utilized and van der Waals force, assumed as 12-6 Lennard-Jones potential, was implemented as the body force term in the finite element formulation.

Aspects of Characterisation of Thin Coating Adhesion at the Nano-Scale

In response to current development of materials in nano-science.characterisation of thin coating adhesion ona nano-scale becomes one of the most important research areas,as new coatings get ever thinner and more technologically advanced.With a review of technology and mechanisms of evaluating the adhesion failure of coatings.three techniques,nano-im-pact,nano-scratch and nano-indentation techniques,for charactering the adhesion of thin coatings on a nano scale are described.Results of charactering the adhesion faliure of thin coatings using three different techniques indicate that the nano scratch and nano-indentation techniques are very useful tools particularly in charactering the performance of thin coatings under nano-abra sive wear conditions.However,results from these types of tests cannot be easily applied to predict the performance of coatings whose are subject to nano-erosive wear,cyclic nano-fatigue or multiple nano-impacts during service.Instead,results of the new dynamic testing technique。

Nano-scaled metal powder improving tribological properties of lubricant

Cu nanoparticles were fabricated by ball milling with the anhydrous alcohol as dispersant. The size and figure of Cu nanoparticles were characterized by X-ray diffractometry and transmission electron microscopy. The tribological properties of adding Cu and MoS2 nanoparticles to the pure grease were measured on MM-200 tester, compared with the single additive and pure grease. The results show the size of Cu nanoparticles is about 50 nm. The surface with lubricant added nanopowder as additive possesses a remarkable decrease in wear volume. The friction coefficient and wear volume of lubricant mixed with 5% copper and 30% disulfide molybdenum nanoparticles are 0.09 and 1.80mm3, respectively. This mixed additive can not only increase the ability of supporting heavy load but repair the microscopic channels and cracks on the wear surface. Under higher load and long period of time, this lubricant has the characteristics of self-repairing, occluding resistance and ability of enduring higher temperature.

Effect of Surface Roughness in Micro-nano Scale on Slotted Waveguide Arrays in Ku-band

Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and efficiency of the SWA in Ku-band. Firstly, the roughness is simulated using the electromechanical coupled（EC） model. The relationship between roughness and the antenna＇s radiation properties is obtained. For verification, an antenna proto- type is manufactured and tested, and the simulation method is introduced. According to the prototype, a contrasting experiment dealing with the flatness of the radiating plane is conducted to test the simulation method. The advantage of the EC model is validated by comparisons of the EC model and two classical roughness models （sine wave and fractal function）, which shows that the EC model gives a more accurate description model for roughness, the maxi- mum error is 13%. The existence of roughness strongly broadens the beamwidth and raises the side-lobe level of SWA, which is 1.2 times greater than the ideal antenna. In addition, effect of the EC model＇s evaluation indices is investigated, the most affected scale of the roughness is found, which is 1/10 of the working wavelength. The proposed research provides the instruction for antenna designing and manufacturing.

Nano-scale Interfacial Friction Behavior between Two Kinds of Materials in MEMS Based on Molecular Dynamics Simulations

The aim of this article was to provide a systematic method to perform molecular dynamics simulotion or evaluation for nano-scale interfacial friction behavior between two kinds of materials in MEMS design. Friction is an important factor affecting the performance and reliability of MEMS. The model of the nano-scale interracial friction behavior between two kinds of materials was presented based on the Newton＇ s equations of motion. The Morse potential function was selected for the model. The improved Verlet algorithm was employed to resolve the model, the atom trajectories and the law of the interfacial friction behavior. Comparisons with experimental data in other paper confirm the validity of the model. Using the model it is possible to simulate or evaluate the importance of different factors for designing of the nano-scale interfacial friction behavior between two kinds of materials in MEMS.

Electronic Structure of Single-Crystal CaF₂(111) with Nanoscale Phases of Ca and Si

The impact of Ca and Si nano-scale structures on parameters and density of states of single-crystalline CaF2(111) was studied. It was shown that at low concentration of ions of Ar+ (D ≤ 5 × 1015 cm-2) one witnesses formation of nanoscale phases on CaF2 surface. It was revealed that these phases lead to narrowing of the forbidden band Еg between the phases by 4 - 4.5 eV. At higher concentrations (D ≈ 6 × 1016 cm-2) the surface completely is covered by Ca atoms. It was shown that deposition of θ = 10 thick Si single layer on CaF2 surface manifests island picture. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light. Nano-scale phases and nano-scale films of Ca were obtained by using the technique of bombardment with ions of Ar+ of CaF2 surface. Formation of nano-scale phases were accompanied by change in the composition and structure of CaF2 zones located between the phases. These changes led to narrowing of the forbidden band of CaF2 down to 7.5 - 8 eV. The concentration of Ca and Si nano-scale phases on the surface of CaF2 and the band gap of the phases were investigated as a function of (hν) of passing light.

Schrodinger-Langevin Equation and Ion Transport atNano Scale

Schrodinger-Langevin equation has been constructed for the ion-transport for K-ion channel. The stability of the solutions of this equation has been discussed under various physical situations. This will shed new light on the ion transport at nano-scale as well as the possibility of ion trapping and quantum information processing.

Large scale silver nanowires network fabricated by MeV hydrogen (H＋) ion beam irradiation

A random two-dimensional large scale nano-network of silver nanowires （Ag-NWs） is fabricated by MeV hydrogen （H＋） ion beam irradiation. Ag-NWs are irradiated under H＋ ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by H＋ ion beam-induced welding of Ag-NWs at intersecting positions. H＋ ion beam induced welding is confirmed by transmission electron microscopy （TEM） and scanning electron microscopy （SEM）. Moreover, the structure of Ag NWs remains stable under H＋ ion beam, and networks are optically transparent. Morphology also remains stable under H＋ ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under MeV H＋ ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps： ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from MeV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices.

富钴黄铁矿中钴微-纳米尺度赋存状态:以大横路铜钴矿为例

黄铁矿是重要的载钴矿物,自然界钴矿床中富钴黄铁矿的Co含量可达10%~20%,明显超出实验岩石学和理论计算获得的黄铁矿溶解Co的能力。目前,这些富钴黄铁矿溶解过饱和Co的机制以及Co过饱和黄铁矿是否出溶方硫钴矿尚不清楚。为探讨以上问题,本文选取吉林大横路Cu-Co矿中富钴黄铁矿为研究对象。能谱元素面扫描和电子探针分析结果显示,大横路富钴黄铁矿中Co呈不均匀分布且无规律,单颗粒Co含量变化范围较大(Py108为4.31%~9.74%、Py110为4.54%~8.83%),Co的不均匀很可能与黄铁矿的生长过程和结晶环境有关。透射电镜和原子探针分析结果显示,纳米尺度富钴黄铁矿中Co呈均匀分布,未见富Co的包裹体和方硫钴矿出溶体,Co以类质同象的形式替换Fe存在于富钴黄铁矿中。根据以上结果,我们认为大横路富钴黄铁矿中溶解过饱和的Co很可能与微晶尺寸效应有关,亚稳态Co过饱和FeS_(2)-CoS_(2)固溶体可以长期保持不变。

Hubble Scale Dark Energy Meets Nano Scale Casimir Energy and the Rational of Their T-Duality and Mirror Symmetry Equivalence

We establish that ordinary energy, Casimir energy and dark energy are not only interlinked but are basically the same thing separated merely by scale and topology. Casimir energy is essentially a nano scale spacetime phenomenon produced by the boundary condition of the two Casimir plates constituting the Casimir experimental set up for measuring the Casimir force. By contrast dark energy is the result of the cosmic boundary condition, i.e. the boundary of the universe. This one sided M?bius-like boundary located at vast cosmic distance and was comparable only to the Hubble radius scales of the universe. All the Casimir energy spreads out until the majority of it reaches the vicinity of the edge of the cosmos. According to a famous theorem due to the Ukrainian-Israeli scientist I. Dvoretzky, almost 96% of the total energy will be concentrated at the boundary of the universe, too far away to be measured directly. The rest of the accumulated Casimir energy density is consequently the nearly 4% to 4.5%, the existence of which is confirmed by various sophisticated cosmic measurements and observations. When all is said and done, the work is essentially yet another confirmation of Witten’s T-duality and mirror symmetry bringing nano scale and Hubble scale together in an unexpected magical yet mathematically rigorous way.

固体力学跨尺度计算若干问题研究

本文展示了固体力学领域跨尺度计算的若干问题和研究概况。(1)建立位错动力学与有限元耦合DDD-FEM的计算模型,实现了能够基于纳米尺度离散位错运动机制计算分析连续介质有限变形晶体塑性问题,提出微纳尺度(200 nm~10μm)晶体塑性流动应力解析公式,结合试验数据揭示了在无应变梯度下强度和变形的尺寸效应;(2)建立具有微相分离结构的纳米尺度粗粒化分子动力学模型CG-MD,计算获得聚脲材料在时域和频域下的存储模量和损耗模量,通过动态加载分析的DMA试验和超声波试验的数据验证,解决了连续介质尺度下微相分离高分子共聚物的设计难题;(3)通过数据驱动关联高分辨率的微米尺度CT影像和临床低分辨率的毫米尺度CT影像的特征值,建立了围关节松质骨小梁的等效模量和结构张量,为骨组织增材制造点阵结构设计和实现个性化骨缺损重建奠定了基础。

磁电弹性材料含正六边形纳米缺陷的表面效应研究

在磁电弹性材料断裂力学框架下,利用表面弹性理论和解析函数边值理论,解析研究了反平面机械载荷、面内电载荷和磁载荷耦合作用下磁电弹性体中正六边形孔边均布六条等长裂纹的Ⅲ型断裂力学问题,确定了考虑表面效应时纳米尺寸裂纹问题的精确解.基于以上解析解,通过数值算例揭示了表面效应、缺陷几何参数及所施加的损坏载荷分别在两种理想裂纹面电磁条件假设下对断裂参数的影响规律.研究发现:考虑表面效应时影响裂纹扩展的因素与经典弹性理论解答明显不同.各个物理分量呈现出显著的尺寸依赖效应,但随着缺陷尺寸的增加,表面效应的影响呈下降趋势,并趋于经典弹性理论值.研究可为该材料应用于微纳米结构和微机电系统提供理论指导.

Ultrastructural Findings, at Micrometric and Nanometric Scales, in Rectal and Muscular Mucosa of Patients with HIV/AIDS and Anorectal Pathology

Objective: To determine the ultrastructural findings on Rectal Mucosa (RM) of patients with HIV/AIDS and anorectal pathologies (ARP), at micrometric and nanometric scales. Materials and methods: 5 patients were evaluated, 18 - 55 years old, with ARP (HIV co-infection with HPV, n = 4, and HIV-negative patient with HPV infection) (control n = 1), who were referred to the Coloproctology Unit of the HUC, and subjected to rectoscopy and biopsy. RM samples were identified, placed in a sterile plastic bottle with 1 mL of 2% glutaraldehyde and immediately transported for routine processing of fine cut (60 - 90 nm) to be evaluated via Transmission Electron Microscopy (TEM). They were fixed with Karnovsky solution with Millonig phosphate buffer (pH 7.4 and 320 mOsm) and post-fixed with OsO4 under the same conditions of pH and osmolarity. Results: Ultrastructural findings, at 10−6 scale: 1) Intestinal mucosa: vacuoles of mucus of different sizes that seem to be fused. 2) Smooth muscle cells: loss of definition of contractile myofilaments mass. 3) Unmyelinated axons and terminals of Schwann cells (SC): Edema and loss of their plasma membranes in some areas of association with axon terminals as well as abundant collagen fibers associated with SC. Ultrastructural findings, at 10−9 scale: 1) Smooth muscle cells: folded wrapper cores and edema of mitochondria and rough endoplasmic reticulum cisterns (RER). 2) Myelinated axon terminals: Loss of synaptic vesicles. 3) Fibroblasts: One observes mitochondria and cisterns of RER with alterations. All these alterations can generate intestinal and anorectal dysfunction in these patients. Conclusions: The HIV causes changes in rectal and muscular mucosa despite HAART treatment with undetectable viral load.

芯片研制用微纳米尺度温度测量方法及其展望

微纳米尺度温度测量,提供微小尺度区域的高精度温度信息。然而现有的测温技术无法满足芯片性能日益提升的需求,例如以热电偶等为代表的接触式测温具有较高的测量精度,但其响应速率慢难以实现宽场热成像;以红外辐射等为代表的非接触式测温可实现芯片表面的快速热场测量,但测温精度较低、空间分辨率受到波长的限制。因此传统测温方法难以同时满足高精度、微纳米尺度的快速温度测量,亟需寻求新的测温技术。随着量子精密测温技术的发展,基于固态量子自旋效应的金刚石带负电的氮-空位(negatively charged nitrogen-vacancy,NV-)色心测温技术有望解决上述问题,突破现有微纳米尺度测温在芯片研制方面的应用瓶颈。鉴于此,首先综述对比了现有芯片用测温技术的特点和发展现状,而后调研分析了金刚石NV色心测温计量特性及小型化、集成化技术发展趋势,并展望了金刚石NV色心测温在芯片研制领域的技术优势和应用前景,提出其发展面临的挑战。

微纳尺度气液传质强化油品催化加氢反应

相比于经典的滴流床加氢技术,液相加氢技术由于其一次性投资成本和运行能耗低,受到了企业界和学术界的广泛关注。但如何进一步强化氢油相界面的传质速率来提高液相加氢效率,仍是一个重要的难题。近年来快速发展的微纳尺度气泡或液滴的气液传质强化技术有助于油品催化加氢反应。本文以微纳气泡为例,首先总结了微纳气泡特点及产生方式,简述了微纳尺度气液传质强化液相加氢过程可行性判别,回顾了微纳尺度气液传质强化在油品液相加氢工艺中的相关研究及工业应用。最后分析了微纳尺度气液传质强化在油品液相加氢中面临的挑战以及发展方向,即微纳尺度传质与本征反应的匹配、工况条件微纳气泡在反应器中的流动以及含微纳气泡混合物的气液分离等。

微纳富磷生物炭对土壤-苏柳系统中Cu和Pb稳定性的影响

土壤重金属污染对生态环境和人类健康造成严重威胁,生物炭作为优秀土壤改良剂,与植物联合发挥作用,是修复受重金属污染的土壤的潜力途径。以动物源生物质骨粉为原料,采用高温裂解联合湿法球磨技术,制备了两种不同粒径(<75μm和<1.0μm)的富磷生物炭(BC和MBC)。通过大棚盆栽试验,考察不同施用剂量(0、0.5%、1.0%和2.0%,w%)的BC和MBC对重金属污染土壤中Cu和Pb的赋存形态及其在苏柳172(Salix jiangsuensis ‘172’)的积累和转运影响。主要结果如下:1)通过对两种粒径的富磷生物炭进行SEM-EDS-mapping、TEM、XRD和FT-IR等分析表征,证明了富磷生物炭为含有大量的羟基磷灰石的富炭固相材料,且球磨后的MBC的比表面积和孔体积较BC可分别提升5.93倍和4.65倍;2)施用BC和MBC均能有效降低土壤Cu和Pb的生物可利用态含量,且同等剂量MBC的效果更优。在添加2%BC和MBC条件下,Cu和Pb的生物可利用态含量较对照显著降低了6.41%、17.31%和8.84%、30.31%(P<0.05);3)添加BC和MBC均显著增加了苏柳172生物量(P<0.05),显著降低了苏柳172根部中Cu和Pb的含量(P<0.05),但对苏柳172积累Cu和Pb无显著影响(P>0.05);4)BC(0-2.0%)对苏柳172的Cu和Pb生物富集和转运能力无显著影响(P>0.05),而MBC(1.0%-2%)显著提升苏柳172对Cu和Pb的生物富集和转运能力(P<0.05),2.0%MBC可使Cu和Pb的TF值分别提升101.06%和25.16%。该文对了解微纳富磷生物炭联合树木修复Cu、Pb复合污染土壤具有重要意义,可为重金属污染土壤的生态修复提供科学依据。

微流控技术制备多维纳米氧化锌及其应用进展

重点介绍了在微反应器中不同的反应条件对纳米ZnO形貌和粒径的影响,回顾了集成纳米ZnO的微流控器件在生物传感、催化降解和生物分离领域的具体应用,并简述了微反应器在ZnO量产方面的应用。分析表明,微流控技术为具有特定形态和功能化的ZnO纳米材料的开发提供了新的途径;同时,三维纳米ZnO的合成丰富了纳米材料的多样性。目前的研究工作主要集中在实验室内,对于放大生产所面临的产品变质和成本高等问题还有待研究者们解决。

贵州织金磷-稀土矿床磷块岩的矿物组成及胶磷矿中杂质元素成因

海相沉积磷块岩中常伴生较高含量的稀土元素,其中的重稀土元素含量占稀土总量的30%以上,有望成为未来重稀土元素的重要来源。我国磷块岩资源丰富,主要产于扬子克拉通西南缘的云南、贵州、四川等地。贵州织金磷矿床稀土元素含量高、规模大,其中的稀土资源达大型矿床规模,具有重要的资源意义,但对磷块岩的矿物组成及造成胶磷矿中复杂化学组成的原因仍缺乏系统的研究。本文在对贵州织金磷-稀土矿床磷块岩样品详细的岩矿相观察基础上,通过SEM/EDS、XRD、FIB-TEM、LA-ICP-MS分析,查明了磷块岩的矿物组成和胶磷矿的内部结构及其中多种杂质元素的成因。研究结果表明,颗粒结构是磷块岩最主要的结构类型,由磷质颗粒和碳酸盐胶结物组成。磷质颗粒的矿物组成复杂,主要为氟磷灰石和白云石,另含有少量石英、白云母、黄铁矿(有些氧化后成为褐铁矿)、固体沥青、重晶石,胶结物的矿物组成主要为白云石,并含少量石英、黄铁矿、重晶石和微量的锆石、金红石、铀钙石(可能为其他铀矿物氧化而成)。FIB-TEM结果表明,磷质颗粒外层的隐晶质部分(胶磷矿)由纳米级矿物集合体组成,主要为氟磷灰石,并含少量白云石、黄铁矿和有机质,其矿物组成与磷质颗粒的矿物组成相似。胶磷矿中纳米级氟磷灰石、白云石、黄铁矿和有机质的发现为解释胶磷矿中杂质元素的来源提供了依据。固体沥青和铀钙石的发现及有机质中的高的稀土元素含量也为解释磷块岩中U和稀土元素的赋存状态提供了新的证据。