Comment on 'A new nanoscale metastable iron phase in carbon steels'

We show that the selected area diffraction patterns presented in a recent paper (T. Liu et al. Sci. Rep. 2015 5, 15331) do not prove the existence of a new hexagonal phase in martensitic steels. They can be actually simulated by twin effects.Comment: 5 pagesm 3 figure

Large stars with few colors

A recent question in generalized Ramsey theory is that for fixed positive integers $s\leq t$, at least how many vertices can be covered by the vertices of no more than $s$ monochromatic members of the family $\cal F$ in every edge coloring of $K_n$ with $t$ colors. This is related to an old problem of Chung and Liu: for graph $G$ and integers $1\leq s<t$ what is the smallest positive integer $n=R_{s,t}(G)$ such that every coloring of the edges of $K_n$ with $t$ colors contains a copy of $G$ with at most $s$ colors. We answer this question when $G$ is a star and $s$ is either $t-1$ or $t-2$ generalizing the well-known result of Burr and Roberts

Expansion of a compressible gas in vacuum

Tai-Ping Liu \cite{Liu\_JJ} introduced the notion of "physical solution' of the isentropic Euler system when the gas is surrounded by vacuum. This notion can be interpreted by saying that the front is driven by a force resulting from a H\"older singularity of the sound speed. We address the question of when this acceleration appears or when the front just move at constant velocity. We know from \cite{Gra,SerAIF} that smooth isentropic flows with a non-accelerated front exist globally in time, for suitable initial data. In even space dimension, these solutions may persist for all $t\in\R$ ; we say that they are {\em eternal}. We derive a sufficient condition in terms of the initial data, under which the boundary singularity must appear. As a consequence, we show that, in contrast to the even-dimensional case, eternal flows with a non-accelerated front don't exist in odd space dimension. In one space dimension, we give a refined definition of physical solutions. We show that for a shock-free flow, their asymptotics as both ends $t\rightarrow\pm\infty$ are intimately related to each other

Breach procedure for axillary hyperhidrosis.

Dear Editor, We read with interest the communication on ‘A simple and practical method for axillary osmidrosis resection’ by Liu X, Mao T, Lei Z, Fan D appeared on JPRAS 2009.1 We found the description of the technique very useful with the support of intra-operative pictures. The use of artery clips to evert the skin flaps can be easily reproduced. However it is surprising that the Authors did not consider and mention in the References a paper by Mr N Breach appeared in the Annals of the Royal College of Surgeons of England in the late 70ies,2 when he was Senior Registrar at the Plastic Surgery Department of the Queen Victoria Hospital, East Grinstead, UK. Since then this latter procedure for surgical treatment of axillary hyperhidrosis has been widely adopted, [3], [4] and [5] especially in the Western world and in the UK where is known as the ‘Breach’ procedure. The main difference with the technique described in the paper by Liu X et al. consists in the number of incisions that has now been minimized

Some molecule-based materials low dimension nanostructures

Molecule based materials nanoarchitectures have been employed as important nanoscale building blocks for advanced materials and smart miniature devices to fulfill the increasing needs of high materials usage efficiency. Different dimension molecule based materials based nanoarchitectures, especially low dimension nanostructures, attract significant attention due to its fascinating controlled structure and functionality-easy tailoring with excellent semi-conductive properties and stability. In this report, we discuss the some molecule based materials self-assembled oriented functional nanoarchitectures by coordinated inducing. The molecular material building blocks, aggregate structures and their properties in optical, electrical and photoelectrical properties were shown. REFERENCES [1] Guo, Y.B.; Xu, L.; Liu, H. B.; Li, Y. J.; Che, C.-M.; Li, Y. L. Adv. Mater. 2015, 27, 985. [2] Li, Y. J.; Liu, T. F.; Liu, H. B.; Tian, M.-Z.; Li, Y. L. Acc. Chem. Res., 2014, 47,1186. [3] Li, Y. J.; Liang Xu, Liu, H. B.; Li, Y. L. Chem. Soc. Rev. 2014, 43, 2572. [4] Liu, H. B.; Xu, J. L.; Li, Y. J.; Li, Y. L. Acc. Chem. Res. 2010, 43, 1496. [5] Zheng, H. Y.; Li, Y. J.; Liu, H. B.; Yin, X. D.; Li, Y. L. Chem. Soc. Rev. 2011, 40, 4506