Run-to-run product quality control of batch processes

Batch processes have been increasingly used in the production of low volume and high value added products. Consequently, optimization control in batch processes is crucial in order to derive the maximum benefit. In this paper, a run-to-run product quality control based on iterative learning optimization control is developed. Moreover, a rigorous theorem is proposed and proven in this paper, which states that the tracking error under the optimal iterative learning control (ILC) law can converge to zero. In this paper, a typical nonlinear batch continuous stirred tank reactor (CSTR) is considered, and the results show that the performance of trajectory tracking is gradually improved by the ILC. Project supported by the Science Foundation of Shanghai Municipal Education Commission (Grant No.09Y208), and the Science Foundation of Science and Technology Commission of Shanghai Municipality (Grant Nos.08DZ2272400, 09DZ2273400) and the “11th Five-Year Plan” 211 Construction Project of Shanghai University     

Bridging professional teacher knowledge for science and literary integration via design-based research

We offer insights for using design-based research (DBR) as a model for constructing professional development that supports curriculum and instructional knowledge regarding science and literacy integration. We spotlight experiences in the DBR process from data collected from a sample of four elementary teachers. Findings from interviews, focus groups and researcher field notes elucidated: the value in establishing a collaborative foundation for professional discourse, the teacher participants developing nascent knowledge of curricular integration in science and literacy, and their apprehensions about using digital technology to support their professional development. Implications are presented for professional development facilitators and researchers using DBR as an innovative approach for teacher development.     

Transmittance tuning by particle chain polarization in electrowetting-driven droplets

A tiny droplet containing nano∕microparticles commonly handled in digital microfluidic lab-on-a-chip is regarded as a micro-optical component with tunable transmittance at programmable positions for the application of micro-opto-fluidic-systems. Cross-scale electric manipulations of droplets on a millimeter scale as well as suspended particles on a micrometer scale are demonstrated by electrowetting-on-dielectric (EWOD) and particle chain polarization, respectively. By applying electric fields at proper frequency ranges, EWOD and polarization can be selectively achieved in designed and fabricated parallel plate devices. At low frequencies, the applied signal generates EWOD to pump suspension droplets. The evenly dispersed particles reflect and∕or absorb the incident light to exhibit a reflective or dark droplet. When sufficiently high frequencies are used on to the nonsegmented parallel electrodes, a uniform electric field is established across the liquid to polarize the dispersed neutral particles. The induced dipole moments attract the particles each other to form particle chains and increase the transmittance of the suspension, demonstrating a transmissive or bright droplet. In addition, the reflectance of the droplet is measured at various frequencies with different amplitudes.     

Structuring academic conflicts between majority and minority students: Hindrance or help to integration

The effects of two types of structured academic conflict, controversy and debate, were compared with individual study in a study on desegregation. Seventy-two sixth grade students were assigned to conditions on a stratified random basis controlling for sex, reading ability, and ethnic membership. In all three conditions students studied a controversial issue with materials representing both pro and con views. In the controversy condition each learning group was divided into two pairs representing the pro and con sides. In the debate condition each member of a learning group was assigned a pro or con position to represent in a debate with the other three members. In the individualistic condition subjects were told to learn the material without interacting with other students and each student was given all the pro and con materials. The results indicate that controversy promotes the most cross-ethnic verbal rehearsal and exchange of the assigned material, the most concern that all students master the assigned material, the most active search for more information about the topic being studied, the most reevaluation of one's position and incorporation of opponents' arguments, the most liking for the subject matter and the instructional experience, the highest self-esteem, and the most accepting and supportive relationships among minority and majority students. The debate condition generated higher levels of these dependent variables than did individualistic study.     

Predictive Relationships between Web and Human Resource Use and Middle School Students’ Interest in Science Careers: An Exploratory Analysis

This study investigated relationships among the use of web and human resource during science class and science career interest. Results suggested that levels of science career interest could be predicted based on classroom use of web and human resources. Regular use of human resources was predictive of science career interests for boys and girls. Use of web resources was only predictive of girls interests, on average, 7 points higher on a 36-point scale than girls who did not use web resources. Girls who used both resources scored 16 points higher than girls who used neither. Two other predictor variables found included (1) teachers who lacked science background and used web resources regularly and (2) level of student-centered instructional strategies used in the classroom. Further research is suggested.     

An experimental study of a museum-based,science PD programme’s impact on teachers and their students

We present results of an experimental study of an urban, museum-based science teacher PD programme. A total of 125 teachers and 1676 of their students in grades 4–8 were tested at the beginning and end of the school year in which the PD programme took place. Teachers and students were assessed on subject content knowledge and attitudes towards science, along with teacher classroom behaviour. Subject content questions were mostly taken from standardised state tests and literature, with an ‘Explain:’ prompt added to some items. Teachers in the treatment group showed a 7% gain in subject content knowledge over the control group. Students of teachers in the treatment group showed a 4% gain in subject content knowledge over the control group on multiple-choice items and an 11% gain on the constructed response items. There was no overall change in science attitudes of teachers or students over the control groups but we did find differences in teachers’ reported self-efficacy and teaching anxiety levels, plus PD teachers reported doing more student-centered science teaching activities than the control group. All teachers came into the PD with high initial excitement, perhaps reflecting its context within an informal learning environment.     

Universals and specifics in learning strategies: Explaining adolescent mathematics, science, and reading achievement across 34 countries

We examined whether strategies of memorization, transfer through elaboration, and metacognition accounted for reading, science, and mathematics achievement across 34 countries. 158,848 fifteen-year-olds completed a reading literacy test and a questionnaire. Of these students, 88,401 completed a science test, and 88,590 completed a mathematics test. We analyzed the data using multi-level regressions of Rasch-estimated test scores and modeled differences across countries and across schools. Students who reported using memorization strategies often scored lower in all subjects. Transfer through elaboration was not significantly linked to any achievement scores. Lastly, students reporting greater use of metacognitive strategies often scored higher. Compared to students in individualistic societies, to achievement scores of students in collective cultures were linked more strongly to schoolmates' use of metacognitive strategies and less strongly to their own use of metacognitive strategies. These results highlight how cultural contexts can moderate the links between adolescents' learning strategies and their academic achievement.     

未来互联网的几点看法

多样性和融合互联网在我们的生活中已根深蒂固,并且它的规模庞大,因此,互联网未来的发展必将是通过不断的进化(迁移),而不是重新建立新的互联网(即使新的互联网某些方面要比传统的互联网更好