Physics and applications of aligned carbon nanotubes

Ever since the discovery of carbon nanotubes (CNTs) by Iijima in 1991, there have been extensive research efforts on their synthesis, physics, electronics, chemistry, and applications due to the fact that CNTs were predicted to have extraordinary physical, mechanical, chemical, optical, and electronic properties. Among the various forms of CNTs, single-walled and multi-walled, random and aligned, semiconducting and metallic, aligned CNTs are especially important since fundamental physics studies and many important applications will not be possible without alignment. Even though there have been significant endeavors on growing CNTs in an aligned configuration since their discovery, little success had been realized before our first report on growing individually aligned CNTs on various substrates by plasma-enhanced chemical vapor deposition (PECVD) [Science 282 (1998) 1105–1108]. Our report spearheaded a new field on growth, characterization, physics, and applications of aligned CNTs. Up to now, there have been thousands of scientific publications on synthesizing, studying, and utilizing aligned CNTs in various aspects. In this communication, we review the current status of aligned CNTs, the physics for their alignment, their applications in field emission, optical antennas, subwavelength light transmission in CNT-based nanocoax structures, nanocoax arrays for novel solar cell structures, etc.

The focus of this review is to examine various aligned CNT systems, either as an individual or as an array, either the orientation is vertical, parallel, or at other angles to the substrate horizon, either the CNT core structures are mostly hollow channels or are composed of complex compartments. Major fabrication methods are illustrated in detail, particularly the most widely used PECVD growth technique on which various device integration schemes are based, followed by applications whereas current limitations and challenges will also be discussed to lay down the foundation for future developments.     

Assigning the ESI mass spectra of organometallic and coordination compounds

Electrospray ionization mass spectrometry (ESI‐MS) is a useful technique for solving organometallic and coordination chemistry characterization problems that are difficult to address using traditional methods. However, assigning the ESI mass spectra of such compounds can be challenging, and the considerations involved in doing so are quite different from assigning the mass spectra of purely organic samples. This is a tutorial article for organometallic/coordination chemists using ESI‐MS to analyze pure compounds or reaction mixtures. The fundamentals of assigning ESI mass spectra are discussed within the context of organometallic and coordination systems. The types of ions commonly observed by ESI‐MS are categorized and described. Finally, a step‐by‐step guide for the assignment of organometallic and coordination chemistry ESI mass spectra is provided along with two case studies.     

构建先进实验平台,适应系列课程实践教学需求

传统的微机系列课程实验教学模式已不适应研究型大学理工科学生"创新型人才培养"的要求。从"模块化微机类课程实验平台"的构建、实验教学方法的探索、多层次实验教学内容的革新和针对"创新型人才培养"的系列实验教程的编著等几方面,探讨了微机系列课程实践教学的改革,并逐步付诸实施,在实际教学过程中成效显著。     

Physics of transparent conductors

Transparent conductors (TCs) are materials, which are characterized by high transmission of light and simultaneously very high electrical DC conductivity. These materials play a crucial role, and made possible numerous applications in the fields of electro-optics, plasmonics, biosensing, medicine, and “green energy”. Modern applications, for example in the field of touchscreen and flexible displays, require that TCs are also mechanically strong and flexible. TC can be broadly classified into two categories: uniform and non-uniform TC. The uniform TC can be viewed as conventional metals (or electron plasmas) with plasma frequency located in the infrared frequency range (e.g. transparent conducting oxides), or ultra-thin metals with large plasma frequency (e.g. graphen). The physics of the nonuniform TC is much more complex, and could involve transmission enhancement due to refraction (including plasmonic), and exotic effects of electron transport, including percolation and fractal effects. This review ties the TC performance to the underlying physical phenomena. We begin with the theoretical basis for studying the various phenomena encountered in TC. Next, we consider the uniform TC, and discuss first the conventional conducting oxides (such as indium tin oxide), reviewing advantages and limitations of these classic uniform electron plasmas. Next, we discuss the potential of single- and multiple-layer graphene as uniform TC. In the part of the paper dealing with non-uniform metallic films, we begin with the review of random metallic networks. The transparency of these networks could be enhanced beyond the classical shading limit by the plasmonic refractive effects. The electrical conduction strongly depends on the network type, and we review first networks made of individual metallic nanowires, where conductivity depends on the inter-wire contact, and the percolation effects. Next, we review the uniform metallic film networks, which are free of the percolation effects and contact problems. In applications that require high-quality electric contact of a TC to an active substrate (such as LED or solar cells), the network performance can be optimized by employing a quasi-fractal structure of the network. We also consider the periodic metallic networks, where active plasmonic refraction leads to the phenomenon of the extraordinary optical transmission. We review the relevant literature on this topic, and demonstrate networks, which take advantage of this strategy (the bio-inspired leaf venation (LV) network, hybrid networks, etc.). Finally, we review “smart” TCs, with an added functionality, such as light interference, metamaterial effects, built-in semiconductors, and their junctions.     

How to write a research article for MRC

This nonscientific tutorial proposes best practice for authors publishing research articles in Magnetic Resonance in Chemistry (MRC). It offers authors essential insights into writing eye-catching article titles, author/co-author names and hierarchy, IMRaD and IRDaM article structures, referencing and the composition of abstracts, introductions, experimental, results and discussion, and conclusions together with the all-important covering letter. This arsenal of insights aims to provide tools for authors to maximize the chance of success for their research articles.     

在物理实验教学中实施导师制,培养学生的创新能力

在物理实验教学中实施导师制教学法是一种新型的教学改革方法。本文介绍了本科生导师制实施办法、导师制的作用以及所取得的成效。     

关于数学建模的创新思维教学模式的探讨

提高大学生数学建模质量,不仅仅为了提高学生的数学建模成绩,更重要的是使学生在建模的过程中提高应用数学知识和方法分析和解决实际问题的能力.结合自己的教学体会,对教学过程中如何构建学生建模意识和提高培养学生的创新思维做了一些探讨.     

Functional analysis and quantum mechanics: an introduction for physicists

We give an introduction to certain topics from functional analysis which are relevant for physics in general and in particular for quantum mechanics. Starting from some examples, we discuss the theory of Hilbert spaces, spectral theory of unbounded operators, distributions and their applications and present some facts from operator algebras. We do not give proofs, but present examples and analogies from physics which should be useful to get a feeling for the topics considered.     

基于应用型人才培养的实验课程体系改革

为适应应用型人才培养,针对本校化学实验课程实际,探讨化学实验课程设置、课程内容及课程实施的改革思路,设置基础实验、综合实验和专业实验,加强实验内容与实践的联系,坚持导师制与实验教学的结合。     

The devil in the details: A tutorial review on some undervalued aspects of density functional theory calculations

Density functional theory (DFT) has become ubiquitous for chemical applications in research and in education. The exact functional at the foundation of DFT is unfortunately unknown, and issues arise when choosing an approximation for a specific application. With this tutorial review, we tackle the selection problem and many related ones, such as the choices of a basis set and of an integration grid, that are often overlooked by occasional practitioners and by more experienced users as well. We offer a practical approach in the form of a commented notebook containing 12 experiences that can be run on a simple computer in just a few hours. We propose this review as a primary source for those who are willing to include DFT in their everyday research or teaching activities in a way that reflects the research advances of the field in the last couple of decades.