Surface Modification of Ceramic Materials Using Excimer Laser

Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).

First tower line using composite material commissioned in Jiangsu

On December 3, 2009, the upgraded 220-kV Mao-Qiang line of Jiangsu Lianyungang Power Supply Co. was put into operation. It is the first high voltage

A Case Study of an Experienced University EFL Teacher’s Use of POA Teaching Materials

Although research on teaching materials use has important implications for materials development,little literature examines how teachers actually use materials in the classroom.The present study,taking the theoretical framework for using and evaluating Production-Oriented Approach(POA)teaching materials(Wen,2017),explores the procedure and the rationale of an experienced Chinese university EFL teacher’s use of POA teaching materials.Multiple methods were employed in data collection,including classroom observations,teacher interviews,the teacher’s lesson plans,and PowerPoints,as well as students’written and oral products.Data analysis showed that the teacher followed a three-phase process of materials use.Before class,teaching objectives were set,materials were selected,adapted,and then transformed into teaching activities.During class,the teaching activities were implemented with the materials.After class,the effectiveness of using the materials was assessed.The study revealed that the teacher played an active role in practicing the essential POA principles of“productive-objectives-determined”and“input-in-service-to-output”in the entire process of material use.

X-ray diffraction analysis of cold-worked Cu-Ni-Si and Cu-Ni-Si-Cr alloys by Rietveld method

Cold worked and annealed supersaturated Cu-2.65Ni-0.6Si and Cu-2.35Ni-0.6Si-0.6Cr alloys were studied. The microstructural parameters evolution, including crystallite size, root mean square strain and dislocation density was analyzed using Materials Analysis Using Diffraction software （MAUD）. The parameters for both alloys have typical values of cold deformed and subsequently annealed copper based alloy. A net change of the crystallite size, root mean square strain and dislocation density values of the alloys aged at 450 °C for 2.5-3 h seems corresponding to the recovery and recrystallization processes. Addition of Cr as quaternary element did not lead to any drastic changes of post deformation or ageing microstructural parameters and hence of recovery-recrystallization kinetics.

Measurement of the echo reduction for underwater acoustic passive materials by using the time reversal technique

A measuring method of the echo reduction of passive materials by using the time reversal（TR） technique is presented. To measure the echo reduction of a sample with this approach, the received signals are firstly focused according to the TR theory. Then, the sample is removed and the TR processing is again employed to realize the focus of the received signal.Finally, the echo reduction of the sample is evaluated with these focusing signals. Besides, to calibrate the measured echo reduction via the TR technique, a standard sample is employed to measure a constant coefficient that only depends on the measurement environment. An aluminum plate sample and a steel plate sample with the same size of 1.1 mxl.O m x0.005 m axe tested in a wave guide tank. The experimental results show that the calibrated values are well consistent with theoretical results under the free field at the measured frequency range of0.5-20 kHz. The relative errors of all the measured values are less than 10% and the values of the expanded uncertainty are less than 1.5 dB. The TR processing focuses the energy in spatial domain and temporal domain, so it can be used to measure the echo reduction of passive materials in the environments with reflections induced by boundaries and low frequency sources.

Realization of absolute negative refraction index by a photonic crystal using anisotropic dielectric material

A method to realize absolute negative refraction index -1 with a two-dimensional （2D） photonic crystal is presented by introducing dielectric anisotropy in the photonic crystal material. The band structures of E-polarization mode and H-polarization mode can be adjusted by changing the parameters of materials. Thus the two modes with different polarizations have the same negative refraction index -1 for the same frequency. The results are demonstrated by numerical simulation based on the finite-difference time-domain （FDTD） method.

USING AUTHENTIC LISTENING MATERIALS IN FOREIGN LANGUAGE CLASSROOMS

This paper argues for the need for authentic listening materials in the ELT classroom in China,discussing the selection of those materials,and their adaptation for classroom use,whilst outlinig theirconstraints.

USING AUTHENTIC MATERIALS IN AN ESP CLASS

IntroductionThe need for ESP English teaching for Specific Purposes for non-English majors has long beenrecognized in China.However,it has developed slowly,especially in non-key universities.This is duenot only to a lack of teachers who are good at both English and a particular subject and the lack of suitabletextbooks:it is also due to the lack of effective approaches to motivate and orientate students towards thereal goal of ESP training.The goal of ESP training,according to the national syllabus,is to enable students to read authenticmaterials in their fields,at an appropriate speed and with adequate understanding.They should be able touse English as a tool to get information in their specific areas.

Study on the influence of retroreflective materials on the“secondary reflection”on the room above the horizontal sunshade

Existing studies on horizontal sunshade systems mainly focus on the influence of the sunshade on the room under or inside the sunshade systems.Meanwhile,the top surface of horizontal sunshade,especially those with mirror surface or made of metal,reflects solar radiation into the indoor and surroundings,resulting in“secondary reflection”.This paper mainly focuses on the influence of secondary reflection on the room above the sunshade,using DesignBuilder software to conduct numerical simulation analysis and building architectural model for field measurement.Results from simulation and field measurement both prove that mirror materials increase secondary reflection reflected into the indoor.Moreover,results from experiments show that retroreflective materials decrease secondary reflection reflected into the indoor.At low latitude,the application of retroreflective materials on the top surface of horizontal sunshade effectively reduces the adverse influence of secondary reflection on the room above the sunshade.

Development on astable multivibrators using the combination of linear and non-linear materials as switching elements based on all optial method

In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve ps(pico-second). The pulse duration can be made very low and may cross the THz easily by selecting proper material and laser source.

USING RADIO NEWS BROADCASTS AS LISTENING MATERIAL

INTRODUCTION As English teachers, we have devoted a lot of time to the teaching of listening comprehension using radio broadcasts. We began by using VOA news in special English with freshmen and a mixture of news in special English and standard news broadcasts with sophomores. Later BBC news was used. We accumulated a considerable amount of experience and did some research into the design of listening comprehension exercises. This article discusses how listening ability may be improved by using such broadcasts.

A new method of binary addition scheme with massive use of non-linear material based system

The limitations in electronics in arithmetic, algebraic & logic processing are well known. Very high speed performance (above GHz) are not expected at all in conventional electronic mechanism. To achieve high speed performance we may think on the introduction of optics instead of electronics for information, processing and computing. Non-linear optical material is a successful candidate in this regard to play a major role in the optically controlled switching systems and therefore in all-optical parallel computation these materials can show a very good potential aspect. In this paper, we have proposed a new method of an optical half adder as well as full adder circuit for binary addition using non-linear and linear optical materials.

Material flow analysis(MFA)of an eco-economic system:a case study of Wujin District,Changzhou,China

The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in China.It was revealed that:(1)total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2)except for water,the total material input continued to increase.Input of solid materials grew faster than that of gaseous materials,while the total material output declined.The gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel;(3)water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita.The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater discharge;(4)material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed.These results suggest that the efficiency of resource use in the Wujin District has improved.This weakened the direct link between economic development and environmental deterioration.Additionally,we discussed the harmonic development between environment and economy.Potential limitations of MFA’s application were also discussed.It is suggested that effective measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy.

SPACE CARGO TRANSPORT BAGS THROUGH MEMBRANE WATER TREATMENT ELEMENTS TO SPACE ARCHITECTURE BUILDING ELEMENT:A TOTAL PRODUCT SUSTAINABILITY AND LIFE CYCLE DESIGN OPTIMIZATION EXPERIMENT

The CTB Water Wall project is a maximal product life cycle utilization concept study by members of the space architecture design community.Its function is to demonstrate a human space activity Cargo Transport Bag(CTB)that becomes a primary water recycling membrane element after delivery of cargo,and then a permanent architectural building block for sustainable space habitation after its use in water treatment is complete.As such,it is intended as an experiment in radical life cycle product optimization in an extremely mass-constrained application environment(human space operations).It also introduces some fundamentally interesting concepts in architectural use of waste materials in extreme environments.Finally,it is in some ways a simple,tactile and visual demonstration of how far sustainable product design can be taken,if the motivation and technical justification are present.

Automotive Materials Used in China

China’s auto industry in recent years has been enjoying a positive growth in a constant trend. Its present auto production is near 1.6 mill. units.