Progress in Ionic Liquids as Reaction Media, Monomers and Additives in High-Performance Polymers

In this chapter, we will review the progress in ionic liquids (ILs) widely used as reaction media, monomers and additives in the synthesis, chemical modification and physical processing of high-performance polymers (HPPs). Using ILs as reaction media in the syntheses of HPPs, the high-molecular-weight polymers were obtained in good yields and the shortened dehydration time compared to the conventional methods, the separation efficiency of products was improved. It is particularly noteworthy that the number of novel copolymers of HPPs with polymerisable ILs has steadily increased in recent years. In addition, ILs have been used as various types of additives such as the components of polymer materials, plasticizers and porogenic agents in the physical processing of HPPs, and the materials prepared include membranes, microcapsules, nanocomposites (NCs), electrolytes and grease

Lagrangian data assimilation into layered ocean model

Since much surface ocean data is Lagrangian in nature, its assimilation into ocean models is a key element of an ocean forecasting system. We investigate the propagation of information vertically caused by the existing vertical correlations between a stack of layers in the water column, such as the Eulerian velocity field and other dynamical variables, by observing Lagrangian data in the surface. We test the method by using different layered models with the known Lagrangian observations at discrete time intervals in the surface layer and unknown sub-surface layers. We adopt the method for assimilating Lagrangian data in which the model is augmented with drifter advection equations and track the correlations between the flow and the drifters via the Kalman Filter. The experiments show that Lagrangian data assimilation is feasible and effective for layered models. The technique is first tested on a two layer point vortex flow: a two layer point vortex system of (N(1) v ;N(2) v ) vortices at each layer with a Gaussian white noise term is modeled by its deterministic counterpart. Positions of N(1) d drifter particles in the top layer are observed at regular time intervals and assimilated into the model. Numerical experiments demonstrate successful system tracking for (N(1) v ;N(2) v ;N(1) d ;N(2) d ) = (2; 2; 1; 0). Our numerical model simulations show that our method is capable of successful tracking of the vortices in both of the layers by observing the Lagrangian data from the top layer. It demonstrates that we can capture the Eulerian velocity field of the point vortex flow in the sub-surface layer by assimilating the Lagrangian data in the top layer. The method we have developed gives an understanding of the potential of Lagrangian data assimilation in models with vertical variation. We further test the method on the two and a half layer reduced gravity shallow water double gyre unsteady flow configuration. Our numerical simulations show that the method is capable of correcting both of the active layers even if Lagrangian observations are only available in the top active layer and the assimilation time interval is of the order of the Lagrangian auto-correction time scale of the flow. The results clearly demonstrate that our method is effective when dealing with a more complex dynamics flow with an unknown sub-surface flow structure. The Lagrangian data assimilation method that we have developed, therefore, provides an approach that allows us to fully realize the potential of Lagrangian data for assimilation in more realistic ocean models

Blue Phosphorene Oxide: Strain-tunable Quantum Phase Transitions and Novel 2D Emergent Fermions

Tunable quantum phase transitions and novel emergent fermions in solid state materials are fascinating subjects of research. Here, we propose a new stable two-dimensional (2D) material, the blue phosphorene oxide (BPO), which exhibits both. Based on first-principles calculations, we show that its equilibrium state is a narrow-bandgap semiconductor with three bands at low energy. Remarkably, a moderate strain can drive a semiconductor-to-semimetal quantum phase transition in BPO. At the critical transition point, the three bands cross at a single point at Fermi level, around which the quasiparticles are a novel type of 2D pseudospin-1 fermions. Going beyond the transition, the system becomes a symmetry-protected semimetal, for which the conduction and valence bands touch quadratically at a single Fermi point that is protected by symmetry, and the low-energy quasiparticles become another novel type of 2D double Weyl fermions. We construct effective models characterizing the phase transition and these novel emergent fermions, and we point out several exotic effects, including super Klein tunneling, supercollimation, and universal optical absorbance. Our result reveals BPO as an intriguing platform for the exploration of fundamental properties of quantum phase transitions and novel emergent fermions, and also suggests its great potential in nanoscale device applications.Comment: 23 pages, 5 figure

Modeling redistribution of α-HCH in Chinese soil induced by environment factors

This study explores long-term environmental fate of alpha-HCH in China from 1952 to 2007 using ChnGPERM (Chinese Gridded Pesticide Emission and Residue Model). The model captures well the temporal and spatial variations of alpha-HCH concentration in Chinese soils by comparing with a number of measured data across China in different periods. The results demonstrate alpha-HCH grasshopping effect in Eastern China and reveal several important features of the chemical in Northeast and Southeast China. It is found that Northeast China is a prominent sink region of alpha-HCH emitted from Chinese sources and alpha-HCH contamination in Southwest China is largely attributed to foreign sources. Southeast China is shown to be a major source contributing to alpha-HCH contamination in Northeast China, incurred by several environmental factors including temperature, soil organic carbon content, wind field and precipitation. (C) 2011 Elsevier Ltd. All rights reserved.This study explores long-term environmental fate of alpha-HCH in China from 1952 to 2007 using ChnGPERM (Chinese Gridded Pesticide Emission and Residue Model). The model captures well the temporal and spatial variations of alpha-HCH concentration in Chinese soils by comparing with a number of measured data across China in different periods. The results demonstrate alpha-HCH grasshopping effect in Eastern China and reveal several important features of the chemical in Northeast and Southeast China. It is found that Northeast China is a prominent sink region of alpha-HCH emitted from Chinese sources and alpha-HCH contamination in Southwest China is largely attributed to foreign sources. Southeast China is shown to be a major source contributing to alpha-HCH contamination in Northeast China, incurred by several environmental factors including temperature, soil organic carbon content, wind field and precipitation. (C) 2011 Elsevier Ltd. All rights reserved

Early childhood education in China : Prior foreign influences and alternative directions in the future <International relations>

Since the People’s Republic of China was established, early childhood education has been significantly affected by two negative foreign influences. One influence was the collectivist-based education model of the former Soviet Union. The other was the liberal education model of western countries. Following gradual advances and challenges, reform of early childhood education in China and its development have integrated organically. The current problems for early childhood education in China are to construct a theoretical system and implementation model that reflect the times and national characteristics, and to move forward with a development-based Chinese culture in the age of globalization

Comparison between transgenic maize with exotic betaine aldehyde dehydrogenase (BADH) gene and its untransformed counterpart

We investigated the performance of a transgenic maize (Zea mays L) line with an exotic betaine aldehyde dehydrogenase (BADH) gene and its untransformed counterpart under drought and normal water conditions. Membrane permeability, osmoprotectant contents, and antioxidant enzyme activities of the maize lines as well as plant height and biomass were compared. The results showed that, under drought stress, compared with the untransgenic line, the contents of glycine betaine (GB), soluble sugars, soluble proteins and proline of the trans- genic line were significantly higher, so was the peroxidase (POD) activity; the contents of superoxide anion free radical, malondialdehyde (MDA) and the electrical conductivity of the transgenic line were lower; plant height and the biomass of the transgenic line were significantly higher. Under normal water conditions, the contents of soluble protein and MDA content of the transgenic line were significantly lower; but it was not the case for the content of superoxide anion free radical, electrical conductivity and superoxide dismutase (SOD) activity. No significant difference was observed in GB content and, the plant height and the biomass between the 2 lines. We conclude that the transgenic maize with exotic BADH gene was superior over its untransformed counterpart under drought stress and they performed similarly under normal water conditions

Safety and clinical outcomes of regional anaesthesia in Chinese patients with non-small cell lung cancer undergoing non-intubated lobectomy

Purpose: To determine the safety and clinical outcomes of epidural anaesthesia (EA) relative to internal intercostal nerve block (INB) in Chinese patients with non-small cell lung cancer (NSCLC) who were undergoing non-intubated thoracoscopic lobectomy.Methods: Chinese patients with NSCLC (stage I or II) with no evidence of metastasis were given either EA or INB, with equal number of patients in both groups. The peri-operative outcomes determined were duration of anaesthesia /duration of surgery, SpO2/PaCO2 levels, cases of hypotension, and blood loss. The post-operative outcome indices measured were pain score (determined using visual analogue scale (VAS), post-operative complications, chest drainage, duration of hospital stay, and deaths/mortality.Multiple regression analysis was used to confirm the results obtained in this study by adjusting potential covariates. Peri-operative and post-operative complications were compared between the two groups. The results obtained from 220 patients were subjected to statistical analysis.Results: Peri-operative results showed that patients who underwent INB had shorter duration of anaesthesia (12.3 vs 31.4 min, p &lt; 0.05) and shorter duration of surgery (164.4 vs 197.2 min, p &lt; 0.05) than patients who underwent EA for non-intubated lobectomy. Post-operative results showed that patients who underwent INB had significantly lower number of post-operative complications than those who received EA (29 vs 44 %, p &lt; 0.05). The most common post-operative complications among patients in both treatment groups were nausea, vomiting, emphysema and pulmonary complications. Patients who underwent INB had shorter hospital stay than those who underwent EA (5.1 vs 7.5 days, p &lt; 0.05). These results were confirmed through multiple regression analysis.Conclusion: These findings favour the use of INB for regional anaesthesia in NSCLC patients undergoing non-intubated lobectomy