Detecting the micro-defects in the GaAs materials by time resolved emissions

The GaAs material is a major semiconductor material, and it has high electron transfer rate and direct transition energy band structure. The devices and inte-grated circuits fabricated on the GaAs substrates have a lot of advantages such as high speed information processing. Small perturbations in the manufacturing of GaAs materi-als can lead to defects. The defects in the GaAs materials can degrade the performance of materials. A new method is presented in this paper for detecting the micro-defects in GaAs materials by using time resolved emissions. In this method, the micro-defects in GaAs materials are detected by making use of the photon emission features of micro- defects. The strength of the emitted photons from the micro-defects is increased by applying the electric current or the periodic pulse signals to GaAs materials. The single-photon detector is used to detect the photon emissions of the micro-defects. The time resolved photon emissions and single-photon detection are used to record and compare the amounts of the emitted photons that come from the given regions of the normal GaAs materials and the defective GaAs materials. A lot of experimental results show that the micro-defects in the GaAs materials can be detected by using the method proposed in this paper.     

A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

A new mass transfer model is developped to predict the volatile organic compounds （VOCs） from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds （TVOC） in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the experiment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.     

New secondary batteries and their key materials based on the concept of multi-electron reaction

Facing the significant applications in energy field, this paper introduces how to construct new high specific energy secondary batteries based on the concept multi-electron reaction and by designing multi-electron electrode materials. Recent progress on those new secondary batteries and their key materials based on the theory of multi-electron reaction are overviewed. Representative multi-electronic electrode materials, such as metal borides, metal fluorides, sulfur composite electrode materials and ferrates are briefly introduced, as well as the new secondary battery systems constructed with these materials. Thus gives the significance of the development based on multi- electron reaction mechanism of secondary batteries and their key materials for new chemical battery systems and related energy materials.     

Metal oxide and hydroxide nanoarrays: Hydrothermal synthes is and applications as superc apacitors and nanocatalysts

The development of nanotechnology in recent decades has brought new opportunities in the exploration of new materials for solving the issues of fossil fuel consumption and environment pollution.Materials with nano-array architecture are emerging as the key due to their structure advantages,which offer the possibility to fabricate high-performance electrochemical electrodes and catalysts for both energy storage and effcient use of energy.The main challenges in this feld remain as rational structure design and corresponding controllable synthesis.This article reviews recent progress in our laboratory related to the hydrothermal synthesis of metal oxide and hydroxide nanoarrays,whose structures are designed aiming to the application on supercapacitors and catalysts.The strategies for developing advanced materials of metal oxide and hydroxide nanoarrays,including NiO,Ni(OH)2,Co3O4,Co3O4@Ni–Co–O,cobalt carbonate hydroxide array,and mixed metal oxide arrays like Co3 xFex O4and Znx Co3 xO4,are discussed.The different kinds of structure designs such as 1D nanorod,2D nanowall and hierarchical arrays were involved to meet the needs of the high performance materials.Finally,the future trends and perspectives in the development of advanced nanoarrays materials are highlighted.     

The application of the microstructured metallic grating to light emission extraction

Microstructured metallic gratings can be used to enhance the light emission efficiency of LEDs,and the spectral radiation properties of the LEDs vary with the different metallic materials used,leading to variation of the light emission enhancement at the same wavelength for different metallic grating materials.In this paper,the finite difference time domain(FDTD) method has been used to investigate the light emission extraction enhancement of LEDs in which gratings with different metallic materials have been applied.Through analysis of the permittivity of the metals and the quality factors of the surface plasmons(SPs),we concluded that the larger the plasma frequency obtained for the metallic interband transition,then the more suitable the metals are for light emission extraction of photons with relatively short wavelengths.This is because of the abundance of free electrons in the metals with large plasma frequencies.We also found that the wavelength-dependent trends of the extraction enhancement resulting from the scattering mechanism for different metallic materials are similar to each other.For SP-induced enhancement,either the enhancement peak position or the peak value changes significantly with the different metals.     

Schema Theory and the Teaching of Reading

Schema theory indicates that prior knowledge forms a schema in the mind and this will inevitably influence reading comprehension. Therefore, in the teaching of reading, teachers should find ways to activate the schemata in the mind of the students. Titles, headlines and pictures in a text may serve the function. All texts are related to cultnre to some degree, especially in the case of texts introducing foreign cultures. Therefore, it is also important to integrate cultural factors in teaching, which will form new schemata in the mind of the students. Besides that, teaching materials should be chosen in accordance with the students＇ level of knowledge. New knowledge should be kept in an appropriate proportion to the old knowledge. Only in this way can the schemata stored in the mind of the students be activated easily, and new knowledge will also be acquired at the same time.     

Study on characteristics of double surface VOC emissions from dry fiat-plate building materials

This paper sets up an analytic model of double surface emission of volatile organic compound （VOC） from dry, flat-plate building materials. Based on it, the influence of factors including air change rate, loading factor of materials in the room, mass diffusion coefficient, partition coefficient, convective mass transfer coefficient, thickness of materials, asymmetric convective flow and initial VOC concentration distribution in the building material on emission is discussed. The conditions for simplifying double surface emission into single surface emission are also discussed. The model is helpful to assess the double surface VOC emission from flat-plate building materials used in indoor furniture and space partition.     

Recent Progress on Nanoscale Rare Earth Luminescent Materials

1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescent phenomena such as the shift of CTS,the broadening of emission peaks,the variation of fluorescent lifetimes and quantum efficiency,and the increase of quenching concentration.It is not only of academic interest but also of technological importance for advanced phosphor applications to research and understand these materials.Accordingly, the recent work on nanoscale luminescent rare earth materials has been summarized in this article.Firstly luminescent characteristic of nanoscale rare earth luminescent particles different from those of bulk materials has been introduced;secondly,the chemical preparation methods of nanosized rare earth luminescent materials have been discussed.And special stress has been laid on summarizing the structure,micro-morphology and luminescence properties of nanoscale rare earth materials,which include silicate,vanadate,phosphate,borates and rare earth oxides.     

Reaction of Silane Alkoxide with Acid Anhydride as a Novel Synthetic Method for Organic-Inorganic Hybrid Materials

Sol-gel method is a potent method to produce new inorganic and organic-inorganic hybrid materials. The key step of this methodology is the hydrolysis of a metal alkoxide or other metal substrates such as acetylacetonates to form hydroxyl metal species, followed by their condensation to metal-oxygen-metal （M - O - M） bonds. In this process, the utilization of water, generally in excess, is essential and alcoholic solvents such as ethanol are often required to homogenize the solution when organic compounds coexist. As the common sol-gel method using water allows for limited uses of organic substrates due to their low solubility and stability in aqueous solution, modified variations of sol-gel method are reauired.     

Application prospects of high-voltage cathode materials in all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries are lithiumion batteries with solid-state electrolytes instead of liquid electrolytes.They are hopeful in solving the safety problems of lithium-ion batteries,once their large capacity and long life are achieved,they will have broad application prospects in the field of electric vehicles and large-scale energy storage.The working potential window of solid electrolytes is wider than that of liquid electrolytes,so high-voltage cathode materials could be used in all-solidstate lithium-ion batteries to get higher energy density and larger capacity by elevating the working voltage of the batteries.The spinel LiNi0.5Mn1.5O4material,layered Li–Ni–Co–Mn–O cathode materials and lithium-rich cathode materials can be expected to be applied to all-solid-state lithium-ion batteries as cathode materials due to their highvoltage platforms.In this review,the electrochemical properties and structures of spinel LiNi0.5Mn1.5O4material,layered Li–Ni–Co–Mn–O cathode materials and lithiumrich cathode materials are introduced.More attentions are paid on recent research progress of conductivity and interface stability of these materials,in order to improve their compatibility with solid electrolytes as cathode materials in all-solid-state lithium-ion batteries and fully improve the properties of all-solid-state batteries.Finally,the existing problems of their application in all-solid-state lithium-ion batteries are summarized,the main research directions are put forward and their application prospects in all-solid-state lithium-ion batteries are discussed.     

Review of the fabrication and application of porous materials from silicon-rich industrial solid waste

Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high silicon content waste is a potential raw material for the syn- thesis of silicon-based, multi-porous materials such as zeolites, mesoporous silica, glass-ceramics, and geopolymer foams. Representative sil- icon-rich industrial solid wastes (SRISWs) are the focus of this mini review of the processing and application of porous silicon materials with respect to the physical and chemical properties of the SRISW. The transformation methods of preparing porous materials from SRISWs are summarized, and their research status in micro-, meso-, and macro-scale porous materials are described. Possible problems in the application of SRISWs and in the preparation of functional porous materials are analyzed, and their development prospects are discussed. This review should provide a typical reference for the recycling and use of industrial solid wastes to develop sustainable “green materials.”     

Recent progress in thermoelectric materials

Direct conversion of heat into electricity through advanced thermoelectric(TE)materials has been one of the most attractive solutions to the severe environmental and energy issues facing humanity.In recent years,great progress has been made in improving their dimensionless figure of merit(ZT),which determines the conversion efficiency of TE devices.ZT is related to three‘‘interlocked’’factors—the Seebeck coefficient,electrical conductivity,and thermal conductivity.These three factors are interdependent in bulk TE materials,and altering one changes the other two.The difficulty in simultaneously optimizing them caused TE research to stagnate,until great reductions in thermal conductivity were both theoretically and experimentally proven in nanomaterials in 1993.In this review,we first introduce some TE fundamentals and then review the most recently improvements in ZT in different kinds of inorganic and organic TE materials,which is followed by an investigation of the outlook for new directions in TE technology.     

Nanocomposites based on ferroelectrics and meso- systems modified by high-dielectric and high-field environment

The nanocompoisites of ferroelectric matrix and nanosized particles ( clusters) (" ferroelectric- based nanocomposites" for abbreviation) constitute a group of novel functional materials. A new physical system, meso-system modified by high-dielectric and high-field environment, was formed in the composites. These materials show a promising application prospect in nonlinear optics, low driving voltage electroluminescence devices and quantum dot lasers. In this review, the basic design idea and preparation method are introduced; research progress in this area made by the author and other colleagues are summarized; the dielectric and optical properties, the effect of high-dielectric and high-field environment, and the possibility for realizing low driving voltage high-field electroluminescence are reviewed.     

Heat radiative characteristics of ultra-attenuated materials

From the microstructure of heat radiation, the interaction between the incident heat radiative wave and the electromagnetism syntonic wave is analyzed to reveal the emission, absorption, transmission and reflection mechanisms of the incident heat radiative wave in materials. Based on Lorentz dispersion theory, the effect of optical parameters on heat radiative characteristics is also analyzed. The method of ultra-attenuation and nanocrystallization improving the heat radiative characteristics of the material and the emissivity dispersion of the ultra-attenuated materials are brought to light.     

Mechanical behavior study of microdevice and nanomaterials by Raman spectroscopy: a review

With the rapid development of micro/nano manufacturing technology and nanomaterials, the accurate measurement of the mechanical properties and behaviors at the micronano scale represents a new field of mechanical experiments. Raman spectroscopy, which is based on lat tice dynamics theory, is applicable to the detection of the statistical information of the lattice structure deformation within the measuring points. Due to its peculiarities, such as non-destructiveness, convenience and highresolution, this technology allows the online in situ measurement of residual stress in microstructures caused by processing and can also achieve the realtime deformation of graphene, carbon nanotubes and other nanomaterials under force loading. In recent years, mechanical measurements based on Raman spectroscopy technology have developed rapidly. In this review, Ramanbased stress measurement theories for several commonly used materials are briefly described. Applications related to the residual stress measurements of microstructure and experimental investigations of the mechanical properties of lowdimensional nanomaterials are then reviewed. Finally, the development trend of this method is proposed.     

A new RICEs model with the global emission reduction schemes

Taking into account the fact of global economic integration,this paper improves the RICE model and the MRICES model,and establishes a new integrated assessment model MRICES-2012,which takes Ramsey utility as the standard of fairness.Based on the model,schemes which meet the global emission mitigation targets as well as the interests of developing countries are simulated to assess the international fairness of emission reduction.Therefore,a new feasible scheme is proposed,which can not only reach the Copenhagen Consensus but also ensure interests of every country.Specifically speaking,the US and Japan cut emissions 80% and 70% respectively by 2050 relative to the 1990 level;the EU and other developed countries cut 80% by 2050 relative to 1990 level;high human development countries cut 50% by 2050 relative to 1990 level;all above-mentioned countries start emission reduction from 2020 and keep emission on 2050 level by 2100;China begins emission reduction from 2030 and cuts emission 15% by 2050 and 25% by 2100 relative to 2005 level;medium human development countries keep emission on 2020 level by 2100;low human development countries do not take part in reduction on emission intensity and global emission.     

Multiplex detection of KRAS and BRAF mutations using cationic conjugated polymers

The mutation detections of KRAS and BRAF genes are of significant importance to predict the responses to anti-cancer therapy and develop new drugs. In this paper, we developed a multi-step fluorescence resonance energy transfer (FRET) assay for multiplex detection of KRAS and BRAF mutations using cationic conjugated polymers (CCP). The newly established detection system could detect as low as 2% mutant DNAs in DNA admixtures. By triggering the emission intensity change of CCP and the dyes labeled in the DNA, four possible statuses (three mutations and one wildtype) can be differentiated in one extension reaction. The detection efficiency of this new method in clinical molecular diagnosis was validated by determining KRAS and BRAF mutations of 51 formalin-fixed paraffin-embedded (FFPE) ovary tissue samples. Furthermore, the result of the CCP-based multi-step FRET assay can be directly visualized under UV light so that no expensive instruments and technical expertise are needed. Thus, the assay provides a sensitive, reliable, cost-effective and simple method for the detection of disease-related gene mutations.     

Progress in studies on bulk metallic glasses in China

Bulk metallic glasses (BMGs) are a new class of metallic materials possessing a unique microstructure without long-rangeorder, in contrast to crystalline solids which have periodic arrangements of atoms in space. Since the successful production ofbulk metallic glasses by copper mold casting around the end of the 1980s, great enthusiasm in the study on this new class of