Metal Nano Layer Coating for Improving the Detection and Recognition of Micro-Poisons Using Reflection Spectroscopic Measurement

Metal nano layer coating for increasing the sensitivity of spectroscopic measurements is proposed and experimentally demonstrated in this paper. The metal nano layer will attract the micro-poisons from any measured aqueous sample increasing the concentration of the micro-poison in the vicinity of the surface and significantly improves the sensitivity of the spectroscopic measurement. The demonstration was carried out using Fourier Transform Infra-Red (FTIR) operating in the MIR 400 cm-1 - 4000 cm-1 and 5 nm Gold layer which was grown on silicon oxide substrate. In the experimental demonstration Malathion organophosphate pesticide was used as micro-poison. The spectroscopic measurement proves that Malathion was attracted to the metal nano layer. Furthermore, the absorption lines of Malathion were detected and recognized. This proof of principle can be applied to any Internal Reflection Elements (IRE) and it can be used to purify any aqueous solutions and atmosphere from micro-poisons which will be attracted to the metal Nano layer.

Thermodynamic properties and phase stability of nanocrystalline metals

The fundamental thermodynamic functions of enthalpy, entropy, and Gibbs free energy, as functions of the excess free volume at interfaces, temperature, and grain size, have been derived for single-phase metal nanocrystals. The model was applied to predict the thermal features of nano-grain boundaries and the characteristics of phase transformation in nanocrystalline metals, such as the transformation temperature and the critical grain size for phase transformation at a given temperature. The model predictions have been verified by experimental studies on the β-Co ←→α-Co phase transformation in nanocrystalline Co prepared by ball milling.

NUMERICAL SIMULATION FOR DEFORMATION OF NANO-GRAINED METALS

Electro-deposition technique is capable of producing nano-grained bulk copper specimens that exhibit superplastic extensibility at room temperature. Metals of such small grain sizes deform by grains sliding,with little distortion occur- ring in the grain cores.Accommodation mechanisms such as grain boundary diffusion, sliding and grain rotation control the kinetics of the process.Actual deformation min- imizes the plastic dissipation and stored strain energy for representative steps of grain neighbor switching.Numerical simulations based on these principles are discussed in this paper.

A nano-metallic-particles-based CMOS image sensor for DNA detection

In this paper we report on a study of the CMOS image sensor detection of DNA based on self-assembled nano- metallic particles, which are selectively deposited on the surface of the passive image sensor. The nano-metallic particles effectively block the optical radiation in the visible spectrum of ordinary light source. When such a technical method is applied to DNA detection, the requirement for a special UV light source in the most popular fluorescence is eliminated. The DNA detection methodology is tested on a CMOS sensor chip fabricated using a standard 0.5 gm CMOS process. It is demonstrated that the approach is highly selective to detecting even a signal-base mismatched DNA target with an extremely-low-concentration DNA sample down to 10 pM under an ordinary light source.

Ultrafast laser dynamics of metal organic frameworks/TiO_2 nano-arrays hybrid composites for energy conversion applications

Herein,we report the victorious synthesis of metal-organic frameworks(MOFs) on TiO_2 nanotubes(NTs)using a layer-by-layer(LbL) approach.Highly crystalline and homogenous thin films of MOFs were grown and characterized using XRD,SEM,FT-IR and UV/Vis spectroscopy.Moreover,the utilization of the MOF films as sensitizers was probed in bespoke Graetzel type liquid junction solar cells.The constructed cell performance revealed an I_(sc) of 1.16 mA cm^(–2),Vocof 0.63 V,FF of 0.33,and E_(ff) of 0.42%.Further,pumpprobe transient laser spectroscopy was performed to investigate the energy and charge transfer dynamics of the MOFs/TiO_2 NTs interface.The results indicated 86% injection efficiency.The ultrafast pump-probe spectroscopy allows the investigation of this process and the differences between MOFs.It also showed that the relaxation of the MOF chromophores is in competition with electron injection in the Ti O2 motif.Thus this study provides a new insight into electron transfer from photoexcited metal-organic frameworks(MOFs) into titanium dioxide.

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.

高选择性部分氧化催化剂Au-Pd/TiO_(2)-SiO_(2)的设计合成与苯甲醇部分氧化反应

贵金属纳米催化剂在苯甲醇部分氧化制备苯甲醛过程中具有较高的反应活性,产物苯甲醛选择性较低。采用一锅法制备TiO_(2)改性的Au-Pd/TiO_(2)-SiO_(2)纳米合金催化剂并用于苯甲醇部分氧化反应。对催化剂结构表征关联反应进行评价。结果表明:少量TiO_(2)的引入会改善贵金属纳米颗粒在载体表面的分散度,调变了金钯合金表面的电子结构,提高反应活性,并显著提高载体表面Lewis酸位的数量,从而大幅提高苯甲醛选择性;大量TiO_(2)的引入会导致金钯合金程度降低,产生大量的Bronsted酸位,使得反应活性和产物选择性都大幅降低。

Atomic simulation on evolution of nano-crystallizaion in amorphous metals

The deformation-induced nano-crystallization behavior of amorphous pure Ni was investigated by using a molecular dynamics simulation. The microevolution mechanism of the nano-crystallization, the crystallization process in the multicomponent amorphous Ni-Pd alloys and the temperature effect on the nano-crystallization behavior in amorphous metals were studied. The results show that the small nano-crystalline grain will nucleate and grow during the compression deformation. The deformation induces the growth of the ordered clusters in the amorphous metals and the nano-crystalline grain grows under the shearing combination and shearing deposition. The nano-crystalline grain will nucleate in a lower strain under a higher temperature. The combining severe plastic deformation with thermal annealing treatments presents a new opportunity for developing bulk nano-crystalline materials with controlled microstructures.

Nanowear of a Zr Based Bulk Metallic Glass/Nanocrystalline Alloy

The hardness, elastic modulus, nano-scratch resistance and wear depth for a bulk metallic glass of and its partial crystallization alloys have been measured by using nanoindentation method. The results showed that partial crystallization did not influence the reduced elastic modulus but increased the hardness, and then increased the scratch coefficient. The scratch coefficient increased linearly with increasing the hardness H but decreases when W>6.2GPa. Partial crystallization decreased evidently the wear depth, and when the load was large the wear depth decreased with increasing the hardness.

Investigation of Physical Properties of Nano Crude Petroleum: Increasing Oil Flow Rate in Reservoirs

The zinc oxide nano-particles have been used in this research. In this work, zinc oxide nanoparticles have been added to light and heavy crude oil. In this research, thermoelectric and physical properties of light and heavy crude petroleum have been measured, experimentally. In addition, dimensionless groups in hydrodynamics and heat transfer calculations are presented. This research illustrates that heat capacity of light and heavy crude petroleum varies from 4256 J/kg·°C to 4457 J/kg·°C and 4476 J/kg·°C to 5002 J/kg·°C, respectively. Moreover, heat capacity of light and heavy nano-crude petroleum is changing from about 4285 J/kg·°C to 4496 J/kg·°C and 4494 J/kg·°C to 5021 J/kg·°C, respectively.

Nanostructured Metal Aggregate-Assisted Lasing in Rhodamine 6G Solutions

We report on the experimental demonstration of considerable lowering of stimulated luminescence (lasing) threshold in R6G laser dye solution doped with metal agglomerates (Ag, Al, Ni) upon second harmonic of Nd:YAG-laser illumination. Due to strong structural coupling between individual nanoparticles, they may form fractal agglomerates providing an extreme optical pump-field enhancement near their complicated surface. For the first time, we have observed more than twofold increase in lasing efficiency of metal aggregated dye solution as compared to non-agglomerated monomeric metal nanocolloids. No random laser manifestation or surface plasmon-polariton resonances excitations were observed.

纳米复合智能防腐涂层在金属表面上的应用研究

智能防腐涂料能可有效地提高金属的使用寿命,因而具有自愈功能的智能防腐涂料越来越受到人们的重视。概述了pH响应、光刺激响应、离子响应等不同触发机制的纳米智能防腐机制研究,总结了不同金属表面纳米复合智能防腐涂层研究进展,最后提出金属表面智能自修复防腐涂层发展所面临的挑战和未来发展前景。

NiCuCoMn电极材料的制备及其储锂性能研究

采用熔炼甩带和化学脱合金相结合的方法制备纳米多孔NiCuCoMn过渡金属氧化物(NiCuCoMn@TMOs),并通过热处理进一步制备R-NiCuCoMn@TMOs。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)等测试对材料进行结构表征并对其进行电化学性能测试。作为锂离子电池负极材料,R-NiCuCoMn@TMOs在0.1 A/g的电流密度下,经过200次循环后具有394.9 mAh/g的高比容量,并且表现出97.53%的优异容量保持率。与热处理前相比,热处理后的材料具有更丰富的氧空位、更低的电荷转移电阻(38Ω)和更优异的倍率性能(在2 A/g的电流密度下,比容量为141.1 mAh/g)。其独特的纳米多孔结构提供了丰富的反应活性位点;不同半径、价态和反应电位的多种金属阳离子的协同效应使得该材料有很好的体积容忍度以适应脱嵌锂过程中的体积变化,表现出优异的电化学性能。此外,该电极材料原料储量丰富,价格低廉,易于实现批量化制备。该工作为设计多组元过渡金属氧化物负极材料提供了新的思路。

改性纳米氮化硼对纤维金属层板的性能影响

纤维金属层板是一种由金属薄板与纤维层依次交替铺叠而成,在一定的温度与压力下粘结固化形成的一种混合复合材料。因为其中有金属与纤维两种材料,因此它既有金属的富延展性、韧性强与导热性好等优点,又具有复合材料纤维的抗疲劳、耐高强度与低密度等特点。文章以提升环氧复合材料基体的拉伸与断裂韧性性能和改善FMLs的性能,尤其是冲击与弯曲性能为主要目的,采用向FMLs环氧树脂基体中添加纳米氮化硼(h-BN)的方法,来提升纤维金属层板的力学性能。先对氮化硼材料进行一系列的球磨改性处理,分成不同含量的组分依次加入环氧树脂基体中,确定用量最好的四组,再将这四组环氧树脂复合材料基体用湿法铺层的方法铺在铝薄板与碳纤维布之间,使用硫化机固化的方式制备FMLs试件,利用水切割技术切割成标准试样,并进行冲击与弯曲测试。实验结果表明,向FMLs的环氧树脂基体中添加一定量的纳米氮化硼对FMLs的性能有着积极的影响。

熔融金属防护面料的开发

熔融金属飞溅是高温工作中常见的危险因素,对工人的生命和健康构成了威胁。为此,开发一种能有效防护熔融金属飞溅的纺织品具有重要意义。文章阐述了以下实验过程:利用纳米SiO_(2)和有机硅整理剂对羊毛混纺面料进行后整理,在织物表面构筑低表面能多级微纳米结构,并通过接触界面热量补偿技术协同提升织物表面熔融金属的滑脱效果,缩短熔融金属与防护服的接触时间,提高防护等级。实验结果表明,当纳米SiO_(2)的添加量为0.6%、有机硅整理剂为60 g/L时,面料的熔融金属飞溅防护性能和热防护性能最佳,同时不会显著降低其机械性能和舒适性。

纳米零价铁复合材料对污染土壤修复的最新进展

土壤污染严重威胁农产品的安全和人类健康。近几年来纳米零价铁(nZVI)复合材料由于环境友好、易于制备、价格低廉、优异化学活性等特点广泛地应用于污染土壤修复,但是对土壤中不同污染类型修复的调研较少。综述主要调研nZVI复合材料修复污染土壤中重金属、有机污染物和石油有机物的最新进展。重点评述nZVI复合材料的不同性质对污染土壤中各种污染物修复效果的影响,最后对n ZVI铁复合材料修复污染土壤得出结论并对未来方向进行展望。该综述为更好地应用nZVI复合材料对污染土壤的修复提供理论依据和指导。

纳米金属氧化物吸附剂除砷研究进展

综述了国内外诸多纳米金属氧化物吸附剂在除砷领域的研究现状和进展,系统地总结了不同类型纳米金属氧化物的材料组成、物相特性、吸附机制、吸附能力、应用情况等。阐述了单一、二元和三元金属氧化物纳米材料在除砷领域的应用。通过不同纳米金属氧化物的比表面积、吸附容量、除砷效率、适用pH范围等指标对比评估材料除砷性能优劣,并探讨了主要的吸附机理。总结归纳了当前纳米金属氧化物吸附剂除砷技术面临的转化应用难度大、再生性能差等问题,并提出了多金属协同、多种机理配合、优化设计专属性等具有一定参考价值的纳米金属氧化物吸附剂未来发展对策和建议。

硼基金属复合物的点火和燃烧特性研究进展

综述了近几年国内外硼基金属复合物点火和燃烧特性的最新研究进展,重点归纳了二元硼基金属复合物、三元硼基金属复合物和纳米硼基金属复合物的点火和燃烧研究现状,并对比了其优缺点,其中对二元硼基金属复合物的研究较为丰富,对三元硼基金属复合物的研究大多集中于制备方向,关于点火和燃烧特性研究较少,对纳米基金属复合物的点火燃烧机理尚不清楚。指出了硼基金属复合物未来的研究方向:(1)对于制备工艺较简单的二元硼基金属复合物,下一步应具体研究其工艺对产物性能的影响;(2)利用分子动力学和有限元分析的方法对其燃烧机理进一步分析;(3)关于纳米硼基金属复合物可考虑建立一种稳定悬浮液进一步探究其点火和燃烧机制。附参考文献71篇。

铂纳米团簇催化剂的制备及产氢性能研究

电催化产氢技术对于推动清洁能源的发展至关重要。基于强金属-载体相互作用,利用铁单原子锚定效应制备负载于多孔碳氮材料的超细铂纳米团簇材料Pt@Fe-N-C,并对材料进行结构表征以及电催化测试。结果表明:Pt@Fe-N-C继承了ZIF-8的正十二面体的多孔结构,且其中的铁单原子通过锚定铂纳米团簇实现铂的良好分散。该材料在0.5 mol/L硫酸溶液中展现出优异的HER(电催化析氢反应)活性和稳定性,过电势η_(10)仅为17 mV,且在3000圈循环退化测试后,η_(10)仅增加4 mV。此外,在20 mV(vs.Ag/AgCl)过电势下,Pt@Fe-N-C的质量活性[12.43 mA/(cm^(2)·μg)]是商业铂碳[2.05 mA/(cm^(2)·μg)]的6.1倍。因此,利用单原子锚定效应分散铂是一种降低贵金属使用量的有效策略,并为今后发展低贵金属电催化材料提供新的思路。

Ti/nano-TiO_2-Pt复合电极催化甲醇氧化的研究

采用溶胶-凝胶法(sol-gel)制备纳米TiO2(Ti/nano-TiO2)膜电极,再用电沉积法在纳米TiO2膜上修饰Pt微粒,制成Ti/nano-TiO2-Pt复合电极。用循环伏安法研究了纯Pt丝电极和Ti/nano-TiO2-Pt电极对甲醇氧化的电催化活性以及稳定性。结果表明:对甲醇氧化,复合电极比Pt丝电极具有更高的催化活性,且对甲醇氧化中间产物CO的吸附量少,因而不易中毒;复合电极载铂量达到一定值时,电极具有最强的催化活性。