In order to reduce the materials cost of COREX ironmaking process,sinter has been introduced into the composite burden in China.This work explored the reducing process of sinter in COREX shaft furnace to clarify its r...In order to reduce the materials cost of COREX ironmaking process,sinter has been introduced into the composite burden in China.This work explored the reducing process of sinter in COREX shaft furnace to clarify its reduction properties change and then the effect of sinter proportion on metallurgical performance of composite burden was investigated.The results show that the reducing process of sinter in COREX shaft furnace was basically same with that in blast furnace but sinter seems like breaking faster.Under reducing condition simulated COREX shaft furnace,sinter possessed the worst reduction degradation index(RDI)and undifferentiated reduction index(RI)compared with pellet and iron ore lumps.Macroscopic and microscopic mineralogy changes indicated that sinter presents integral cracking while pellet and lump ore present surface cracking,and no simple congruent relationship exists between cracks of the burden and its ultimate reduction degradation performance.The existence of partial metallurgical performance superposition between composite and single ferrous burden was confirmed.RDI_(+6.3)≥70%and RDI_(+3.15)≥80%were speculated as essential requirements for the composite burden containing sinter in COREX shaft furnace.展开更多
After the “two sessions” held this year, the state has continuously implemented massive tax and fee cuts. Deepening VAT reform is undoubtedly one of the “main course” in this “big meal” of tax and fee cuts, and ...After the “two sessions” held this year, the state has continuously implemented massive tax and fee cuts. Deepening VAT reform is undoubtedly one of the “main course” in this “big meal” of tax and fee cuts, and the real economy is the main service ob-ject of this “main course”.展开更多
The meaning of the term“reduction”in Double Reduction Policy implores teachers to reflect on their teaching process and improve teaching efficiency.Not only should the quantity be reduced,but so should the behavior....The meaning of the term“reduction”in Double Reduction Policy implores teachers to reflect on their teaching process and improve teaching efficiency.Not only should the quantity be reduced,but so should the behavior.Having a comprehensive understanding of the students’learning process is actually a form of science.Therefore,we need to study and enhance its development[1].In order to reduce the learning burden and increase the efficiency of classroom teaching,we must clearly identify the inefficient and ineffective behaviors in classroom teaching,so as to avoid the following situations:a lack of deep thinking,a lack of ability in lesson preparation,fragmentation of questions and answers,a lack of questions that highlight the key points,anticlimax teaching process,and the habit of running over time in class[2,3].On this basis,this paper elaborates the current education state and clarifies the basic requirements of effective classroom teaching.Meanwhile,to reduce students’workload and increase the efficiency in carrying out assignments,much attention should be paid to optimizing assignment design and refining homework review and feedback.The purpose is to assign homework with an appropriate amount(achievable),precision(targeted),and suitability(personalized).Putting an end to the repetitious and unified training is not enough to improve the effect.展开更多
By comparing the changes from the Organization for Economic Co-operation and Development's results of Programme for International Student Assessment(PISA)2018 and 2022,it is found that 15-year-old students in East...By comparing the changes from the Organization for Economic Co-operation and Development's results of Programme for International Student Assessment(PISA)2018 and 2022,it is found that 15-year-old students in East Asian countries and economies maintain a commanding lead in reading,mathematics,and science.These students from regions such as Singapore,Japan,the Republic of Korea,Hong Kong(China),Macao(China),and Chinese Taipei not only sustain their academic excellence but also experience improvements in learning efficiency and their sense of belonging at school.Drawing on the PISA 2022 data,this study analyzes students'learning time investment,out-of-school-hours(OsH)services,and their relationship with student academic performance.The results show that the above countries and economies have achieved encouraging results in academic burden reduction by decreasing learning time in regular school lessons,controlling homework time,and providing OsH services.These distinctive policy interventions can serve as valuable reference points for the Chinese Mainland's ongoing implementation of the"double reduction"policy while facilitating an informed judgment of potential risks.展开更多
The computation burden in the model-based predictive control algorithm is heavy when solving QR optimization with a limited sampling step, especially for a complicated system with large dimension. A fast algorithm is ...The computation burden in the model-based predictive control algorithm is heavy when solving QR optimization with a limited sampling step, especially for a complicated system with large dimension. A fast algorithm is proposed in this paper to solve this problem, in which real-time values are modulated to bit streams to simplify the multiplication. In addition, manipulated variables in the prediction horizon are deduced to the current control horizon approximately by a recursive relation to decrease the dimension of QR optimization. The simulation results demonstrate the feasibility of this fast algorithm for MIMO systems.展开更多
基金Project(2019JJ51007)supported by the Natural Science Foundation of Hunan Province,China。
文摘In order to reduce the materials cost of COREX ironmaking process,sinter has been introduced into the composite burden in China.This work explored the reducing process of sinter in COREX shaft furnace to clarify its reduction properties change and then the effect of sinter proportion on metallurgical performance of composite burden was investigated.The results show that the reducing process of sinter in COREX shaft furnace was basically same with that in blast furnace but sinter seems like breaking faster.Under reducing condition simulated COREX shaft furnace,sinter possessed the worst reduction degradation index(RDI)and undifferentiated reduction index(RI)compared with pellet and iron ore lumps.Macroscopic and microscopic mineralogy changes indicated that sinter presents integral cracking while pellet and lump ore present surface cracking,and no simple congruent relationship exists between cracks of the burden and its ultimate reduction degradation performance.The existence of partial metallurgical performance superposition between composite and single ferrous burden was confirmed.RDI_(+6.3)≥70%and RDI_(+3.15)≥80%were speculated as essential requirements for the composite burden containing sinter in COREX shaft furnace.
文摘After the “two sessions” held this year, the state has continuously implemented massive tax and fee cuts. Deepening VAT reform is undoubtedly one of the “main course” in this “big meal” of tax and fee cuts, and the real economy is the main service ob-ject of this “main course”.
文摘The meaning of the term“reduction”in Double Reduction Policy implores teachers to reflect on their teaching process and improve teaching efficiency.Not only should the quantity be reduced,but so should the behavior.Having a comprehensive understanding of the students’learning process is actually a form of science.Therefore,we need to study and enhance its development[1].In order to reduce the learning burden and increase the efficiency of classroom teaching,we must clearly identify the inefficient and ineffective behaviors in classroom teaching,so as to avoid the following situations:a lack of deep thinking,a lack of ability in lesson preparation,fragmentation of questions and answers,a lack of questions that highlight the key points,anticlimax teaching process,and the habit of running over time in class[2,3].On this basis,this paper elaborates the current education state and clarifies the basic requirements of effective classroom teaching.Meanwhile,to reduce students’workload and increase the efficiency in carrying out assignments,much attention should be paid to optimizing assignment design and refining homework review and feedback.The purpose is to assign homework with an appropriate amount(achievable),precision(targeted),and suitability(personalized).Putting an end to the repetitious and unified training is not enough to improve the effect.
基金supported by the 2022 Shanghai Pujiang Talent Program"Research on the Production and Dissemination Mechanisms of International Large-Scale Education Assessment and Chinese Approaches under the Background of Global Talent Competition"project(No.22PJC092)。
文摘By comparing the changes from the Organization for Economic Co-operation and Development's results of Programme for International Student Assessment(PISA)2018 and 2022,it is found that 15-year-old students in East Asian countries and economies maintain a commanding lead in reading,mathematics,and science.These students from regions such as Singapore,Japan,the Republic of Korea,Hong Kong(China),Macao(China),and Chinese Taipei not only sustain their academic excellence but also experience improvements in learning efficiency and their sense of belonging at school.Drawing on the PISA 2022 data,this study analyzes students'learning time investment,out-of-school-hours(OsH)services,and their relationship with student academic performance.The results show that the above countries and economies have achieved encouraging results in academic burden reduction by decreasing learning time in regular school lessons,controlling homework time,and providing OsH services.These distinctive policy interventions can serve as valuable reference points for the Chinese Mainland's ongoing implementation of the"double reduction"policy while facilitating an informed judgment of potential risks.
基金Supported by the National Natural Science Foundation of China(61333010,61203157)the Fundamental Research Funds for the Central Universities+2 种基金the National High-Tech Research and Development Program of China(2013AA040701)Shanghai Natural Science Foundation Project(15ZR1408900)Shanghai Key Technologies R&D Program Project(13111103800)
文摘The computation burden in the model-based predictive control algorithm is heavy when solving QR optimization with a limited sampling step, especially for a complicated system with large dimension. A fast algorithm is proposed in this paper to solve this problem, in which real-time values are modulated to bit streams to simplify the multiplication. In addition, manipulated variables in the prediction horizon are deduced to the current control horizon approximately by a recursive relation to decrease the dimension of QR optimization. The simulation results demonstrate the feasibility of this fast algorithm for MIMO systems.
