Kinetics study on biomass pyrolysis for fuel gas production     

陈冠益  方梦祥  ANDRIES J  骆仲泱  SPLIETHOFF H  岑可法 《浙江大学学报(A卷英文版)》2003,4(4):441-447

Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme. Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China  相似文献   

普通话二字组词语的动态声调     

韩军华 《滨州学院学报》2002,18(1):38-40

普通话二字组词语不同的声调组合方式 ,使前后位声调产生不同的动态变化形式。前位声调的动态变化明显表现在上声调变为低降调和中升调上 ;后位声调的动态变化则表现在调值的明显改变上。后位声调的动态变化更为普遍 ,应该引起足够的重视  相似文献   

China’s mass higher education: Problem,analysis, and solutions     

David?Yunchao?ChenEmail author 《Asia Pacific Education Review》2004,5(1):23-33

  相似文献   

Technology as a Tool: Applying an Instructional Model to Teach Middle School Students to Use Technology as a Mediator of Learning     

Angelia?Reid-GriffinEmail author  Glenda?CarterEmail author 《Journal of Science Education and Technology》2004,13(4):495-504

  相似文献   

Sleepless in academia   总被引：3，自引：0，他引：3  

Sandra Acker 《Gender and education》2004,16(1):3-24

The conditions under which women academics work provide the impetus for this article. Current trends in feminist and other writing are moving us away from dwelling on the disadvantages women experience in the academy. Yet the findings from the two Canadian studies reported here suggest that issues around children and career, anxieties about evaluation, and fatigue and stress shape the daily lives of women academics. The women do find ways and means of coping and resisting, ­sometimes collectively, although one of the major responses—working harder and sleeping less—might be considered somewhat short of empowering. We also look at what the prospects are for changes in university policies and practices.  相似文献   

Arithmetic nature of sums of certain convergent series     

S?D?AdhikariEmail author  N?SaradhaEmail author 《Resonance》2002,7(11):35-46

  相似文献   

Teaching Undergraduate Mathematics on the Internet     

Johann?EngelbrechtEmail author  Ansie?Harding 《Educational Studies in Mathematics》2005,60(2):253-266

This is Part 2 of a two-part study of how APOS theory may be used to provide cognitive explanations of how students and mathematicians might think about the concept of infinity. We discuss infinite processes, describe how the mental mechanisms of interiorization and encapsulation can be used to conceive of an infinite process as a completed totality, explain the relationship between infinite processes and the objects that may result from them, and apply our analyses to certain mathematical issues related to infinity.  相似文献   

Improving the precision of the keyword-matching pornographic text filtering method using a hybrid model     

苏贵洋  李建华  马颖华  李生红 《浙江大学学报(A卷英文版)》2004,5(9):1106-1113

With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds:metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.  相似文献   

Differential Reading,Naming, and Transcribing Speeds of Japanese Romaji and Hiragana     

Jun?YamadaEmail author  Che?Kan?Leong 《Reading and writing》2005,18(4):303-323

  相似文献   

Theory Competition and the Process of Change   总被引：1，自引：0，他引：1  

Helen?S.?TimperleyEmail author  Judy?M.?Parr 《Journal of Educational Change》2005,6(3):227-251

The reasons why many educational change initiatives have little impact are often framed in terms of either a poorly designed process on the part of the change initiator, or in terms of problems with the attitudes, skills and/or knowledge of those responsible for implementation. In this paper, we seek to integrate these two perspectives more closely by focusing on their interface and the competing theories frequently held by the change initiators and implementers. This concept of theory competition is illustrated with a case of a national literacy initiative in New Zealand in which the change initiators wished to raise the achievement of low performing students through the development of “learning-centred” leadership in schools and evidence-based practice. The desired outcomes were not achieved because theories about what it means to be a successful leader in such a situation, the data needed to undertake the type of evidence-based analysis envisioned and school personnel beliefs about the target students were understood differently by those responsible for initiating the change and those responsible for implementing it.  相似文献