somewhere in time

先占个位置，以后再补上。

website:  http://summerschool.ustc.edu.cn

The important question, discussed in connection with the Landauer resistance, is the origin of dissipation in this approach. Indeed, finite dc current at finite dc voltage means that the energy is permanently dissipated. On the other hand, we consider only elastic scattering, so that the energy can not be dissipated in the scattering process. This problem is closely related to the phenomena of the residual resistance at low temperature, caused by impurities. In both cases we should introduce some thermalisation. In the case of the transport between the equilibrium contacts, this puzzle is resolved quite easy, the energy is dissipated in the contacts, the details of the dissipation are not relevant. More precisely, the incoming from the contacts to the System particles are equilibrium distributed, while outgoing particles propagate into the contacts
and are thermalised here.

首先是关于石墨的，一年多以来，石墨引起了人们的极大关注，很多杰出的实验和理论工作冒出来的非常快，这可以从Science, Nature, Phys.Rev.Lett.，arXiv:cond-mat等上面可以初见端倪。石墨这个东西这么常见，最近才发现他一些比较令人兴奋的性质实在是比较奇怪。最近一篇文章（arXiv:0706.2968）将双极电荷密度起伏跟逾渗电流联系起来，并提出了用随机电阻器网络来分析电导对掺杂和无序的标度依赖，以及磁阻和移相率。

 其次是S.Kosov组关于利用哈密顿量中的自相似来研究纳米线中的单通道电荷输运性质（J.Chem.Phys. 124, 104703)。在文章中他们证实了在共振隧道范围内，单通道跃迁表现出依赖于纳米线的长度以及附带电子的能量的一种自相似行为。他们利用DFT理论计算了Na原子线的Transimission，验证了这种自相似行为。Y.Luo组提出的计算大纳米器件的导电能力的CIS方法似乎与此有点相似的地方。CIS方法能够计算10万个电子的体系，这种比较夸张的计算能力让很多人感到惊讶。

Mark Newman proposed an exact solution for the complete distribution of component sizes in random networks with arbitrary degree distributions (arxiv:07070080).  The solution tells us the probability that a randomly chosen node belongs to a component of size s, for any s. They apply results to networks with the three most commonly studied degree distributions — Poisson, exponential, and power-law — as well as to the calculation of cluster sizes for bond percolation on networks, which correspond to the sizes of outbreaks of SIR epidemic processes on the same networks. For the particular case of the power-law degree distribution, also they show that the component size distribution itself follows a power law everywhere below the phase transition at which a giant component forms, but takes an exponential form when a giant component is present.