Toward a molecular design of porous carbon materials

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Single-walled carbon nanotubes modified carbon ionic liquid electrode for sensitive electrochemical detection of rutin

The single-walled carbon nanotubes (SWCNTs) modified carbon ionic liquid electrode (CILE) was designed and further used for the voltammetric detection of rutin in this paper. CILE was prepared by mixing graphite powder with ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate and liquid paraffin together. Based on the interaction of SWCNTs with IL present on the electrode surface, a stable SWCNTs film was formed on the CILE to get a modified electrode denoted as SWCNTs/CILE. The characteristics of SWCNTs/CILE were recorded by different methods including cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The electrochemical behaviors of rutin on the SWCNTs/CILE were investigated by cyclic voltammetry and differential pulse voltammetry. Due to the specific interface provided by the SWCNTs-IL film, the electrochemical response of rutin was greatly enhanced with a pair of well-defined redox peaks appeared in pH 2.5 phosphate buffer solution. The oxidation peak currents showed good linear relationship with the rutin concentration in the range from 1.0 × 10^− 7 to 8.0 × 10^− 4 mol/L with the detection limit as 7.0 × 10^− 8 mol/L (3σ). The SWCNTs/CILE showed the advantages such as excellent selectivity, improved performance, good stability and it was further applied to the rutin tablets sample detection with satisfactory results.     

Scanning Nanowelding Lithography for Rewritable One‐Step Patterning of Sub‐50 nm High‐Aspect‐Ratio Metal Nanostructures

The development of a new nanolithographic strategy, named scanning nanowelding lithography (SNWL), for the one‐step fabrication of arbitrary high‐aspect‐ratio nanostructures of metal is reported in this study. Different from conventional pattern transfer and additive printing strategies which require subtraction or addition of materials, SNWL makes use of a sharp scanning tip to reshape metal thin films or existing nanostructures into desirable high‐aspect‐ratio patterns, through a cold‐welding effect of metal at the nanoscale. As a consequence, SNWL can easily fabricate, in one step and at ambient conditions, sub‐50 nm metal nanowalls with remarkable aspect ratio >5, which are found to be strong waveguide of light. More importantly, SNWL outweighs the existing strategies in terms of the unique ability to erase the as‐made nanostructures and rewrite them into other shapes and orientations on‐demand. Taking advantages of the serial and rewriting capabilities of SNWL, the smart information storage–erasure of Morse codes is demonstrated. SNWL is a promising method to construct arbitrary high‐aspect‐ratio nanostructure arrays that are highly desirable for biological, medical, optical, electronic, and information applications.     

Parametric study of a new HOS-CFD coupling method

This paper presents a developed new coupled method which combined our in-house CFD solver naoe-FOAM-SJTU and naoe-FOAM-os with a potential theory High Order Spectral method(HOS).A parametric study of nonlinear wave propagation in computational fluid dynamics(CFD)zone is considered.Mesh convergence,time step convergence,time discretization scheme and length of relaxation zone are all carried out.Those parametric studies verify the steady of this new combined method and give better choice for wave propagation.The dissipation in propagation of nonlinear regular wave can be lower than 3%in static mesh,and less than 2%in overset grid mesh.Meanwhile,a LNG FPSO is put into the viscous wave tank to study the suitable size of CFD zone.To achieve a better solution with least calculating resources and best numerical results,the length of CFD zone is discussed.These parametric studies can give reference upon employment of the potential-viscous coupled method and validation of the coupled method.     

Improving the precision of optical metrology by detecting fewer photons with biased weak measurement

In optical metrological protocols to measure physical quantities, it is, in principle, always beneficial to increase photon number n to improve measurement prec...     

Characterization,Expression Profiling,and Biochemical Analyses of the Cinnamoyl-CoA Reductase Gene Family for Lignin Synthesis in Alfalfa Plants

Cinnamoyl-CoA reductase (CCR) is a pivotal enzyme in plant lignin synthesis, which has a role in plant secondary cell wall development and environmental stress defense. Alfalfa is a predominant legume forage with excellent quality, but the lignin content negatively affects fodder digestibility. Currently, there is limited information on CCR characteristics, gene expression, and its role in lignin metabolism in alfalfa. In this study, we identified 30 members in the CCR gene family of Medicago sativa. In addition, gene structure, conserved motif, and evolution analysis suggested MsCCR1–7 presumably functioned as CCR, while the 23 MsCCR-likes fell into three categories. The expression patterns of MsCCRs/MsCCR-likes suggested their role in plant development, response to environmental stresses, and phytohormone treatment. These results were consistent with the cis-elements in their promoters. Histochemical staining showed that lignin accumulation gradually deepened with the development, which was consistent with gene expression results. Furthermore, recombinant MsCCR1 and MsCCR-like1 were purified and the kinetic parameters were tested under four substrates. In addition, three-dimensional structure models of MsCCR1 and MsCCR-like1 proteins showed the difference in the substrate-binding motif H212(X)2K215R263. These results will be useful for further application for legume forage quality modification and biofuels industry engineering in the future.     

ω—正则语言类的一个子类*

ω—语言是由有穷字母表∑上的一些无穷串组成的集合．被ω一有穷自动机接受的ω一语言称为ω一正则语言．作者曾从集合的角度描述了一类ω一正则语言，而不是传统地从生成或识别的角度来描述这一类正则语言．本文从集合的角度来描述更为广泛的一类ω一正则语言．     

一种基于Agent的高可用性网构软件自动构建方法

Internet环境开放、动态的本质,计算实体自身的自主性和独立性以及网络连接的不稳定性等,均对保障软件系统可用性提出了新的要求.提出了一种基于Agent的高可用性软件构造方法.该方法使用Agent建模网络环境中的自主计算实体,在计算实体及其连接方式的可用性未知的情况下,由Agent通过学习,在运行一段时间后自适应地构造出可用性较优的软件系统.实验表明,基于该方法构建的系统能达到较高的可用性,并能在环境发生变化时自适应地调整自身的行为.     

S广义ω－凸语言

本文通过在Σω上定义半序关系“≤ωｓ，引进了Ｓ广义ω－左凸语言、Ｓ广义ω－右凸语言和Ｓ厂义ω－凸语言的概念，并给出了各类Ｓ广义ω－凸语言与其前缀语言之间的关系；还给出了各类Ｓ厂义ω－凸语言族对布尔运算的封闭性以及各类Ｓ广义ω－凸语言的充分必要条件。