Firm size distribution and mobility of the top 500 firms in China,the United States and the world

This paper considers the macroscopic and microscopic statistical features of the top 500 firms in China, the United States and the world, denoted as China 500 (CH500), Fortune 500 (US500) and Fortune Global 500 (FG500). From a macroscopic perspective, the firm size distribution of each category, when measured by revenue, is steadily distributed over the observed period, even during periods of financial crises. As is evidenced by the Gini coefficient, divergences between firm scales are most significant for the CH500. From a microscopic perspective, the underlying micro-dynamics are volatile and often turbulent due to the exit and entry of firms as well as shifts in their revenues and ranks. Such fluctuations, or mobility, are visualized in rank/revenue/share clocks. We also propose a revenue/rank/share mobility index that is a quantitative measurement of mobility. Among these, we find that the share mobility acts as an effective indicator of economic status; where there is a share mobility spike, there is an ailing economy. The share mobility indexes indicate that the 2008 Financial Crisis had little impact on the Chinese economy, while it triggered violent changes in the top 500 firms in the United States and the world.     

Effective optical path length investigation for cubic diffuse cavity as gas absorption cell

A simple cubic-shaped cavity with a high-diffuse-reflectivity inner coating as a novel gas detection cell was developed. The effective optical path length (EOPL) was evaluated by comparing the oxygen absorption signal in the cavity and in air based on tunable diode laser absorption spectroscopy. The law for a spherical cavity was applied and modified to a cubic cavity as a function of reflectivity ρ, port fraction f, and the side length. Single-pass average path length of the cubic cavity was 0.723(7) times the side length. EOPL can be modified conveniently by adjusting the parameters of the cavity.     

Determination of nifedipine in dog plasma by high‐performance liquid chromatography with tandem mass spectrometric detection

Nifedipine is a dihydropyridine calcium channel blocker used widely in the management of hypertension and other cardiovascular disorders. In this work, a simple, rapid and sensitive liquid chromatography/tandem mass spectrometry method was developed and validated to determine nifedipine in dog plasma using nimodipine as the internal standard. Chromatographic separation was carried out on a C₈ column. The mobile phase consisted of a mixture of acetonitrile, water and formic acid (60:40:0.2, v/v/v) at a flow rate of 0.5 mL/min. Detection was performed on a triple quadrupole tandem mass spectrometer in selected reaction monitoring mode via an atmospheric pressure chemical ionization source. The method has a lower limit of quantification of 0.20 ng/mL with consumption of plasma as low as 0.05 mL. The linear calibration curves were obtained in the concentration range of 0.20–50.0 ng/mL (r = 0.9948). The recoveries of the liquid extraction method were 74.5–84.1%. Intra‐day and inter‐day precisions were 4.1–8.8 and 6.7–7.4%, respectively. The quantification was not interfered with by other plasma components and the method was applied to determine nifedipine in plasma after a single oral administration of two controlled‐release nifedipine tablets to beagle dogs. Copyright © 2013 John Wiley & Sons, Ltd.     

利用MR数据进行WCDMA软切换参数优化的方法

对现网软切换优化的意义、目标、软切换参数影响及传统优化方法的不足进行了分析;首次提出了以MR原始数据统计分析结果为依据进行软切换参数本地化设置的方法,并结合2个城市的实际数据进行了案例分析。     

Vesicle formation between single-chained cationic surfactants and ribo-oligonucleotides

Recently,we reported that deoxyribo-oligonucleotides could induce single chained cationic surfactant aggregation to form vesicles.In this paper,we will present that ribo-oligonucleotides can also induce vesicle formation,and compared with deoxyribo-oligonucleotides,ribo-oligonucleotides exhibit a higher inductive efficiency.     

Synthesis, structure, and luminescent properties of three silver(I) complexes with organic carboxylic acid and 4,4′-bipyridine-like ligands

The reactions of AgNO₃ with combinations of 1,2-bis(4-pyridyl)ethane(bpa)/4,4′-bipyridine (bpy), 4,4′-stilbenedicarboxylic acid (H₂sda)/2,2′-diphenylaminedicarboxylic acid (H₂dpadc)/2,6-naphthalenedicarboxylic acid (H₂ndc) in aqueous alcohol/ammonia at room temperature produce block-like crystals of [Ag₂(bpa)_1.5(sda)_0.5](sda)_0.5·7H₂O, [Ag₂(bpa)₂(H₂O)₃](dpadc), [Ag₂(bpy)₂](ndc)·4H₂O. All three complexes consist of 1D infinite silver–ligand cationic chains, interspersed with organic carboxylate anions that provide charge compensation in the crystal structures. The lattice water molecules are situated among the framework of the crystal structure and show rich hydrogen-bonding interactions, which help to orientate the organic carboxylate anions in the crystal packing, and the presence of Ag···N and Ag···Ag contacts contributes to strengthen the frameworks. The luminescent properties and thermogravimetric analyses of the three complexes are also presented.     

ZTE Communications Call for Papers Special Issue on Using Artificial Intelligence in Internet of Things

Internet of Things has received much attention over the past de-cade.With the rapid increase in the use of smart devices,we arenow able to collect big data on a daily basis.The data we are gather-ing and related problems are becoming more complex and uncer-tain.Researchers have therefore turned to AI as an efficient way ofdealing with the problems created by big data.This special issue of ZTE