The classroom is an important place for“three guarantees”education.Classroom culture refers to a group culture with both teachers and students as the main body,the classroom space as the carrier,and spiritual connot...The classroom is an important place for“three guarantees”education.Classroom culture refers to a group culture with both teachers and students as the main body,the classroom space as the carrier,and spiritual connotation as the core.The creation of classroom culture with school characteristics,characteristics of the times,and Chinese characteristics can reflect the aesthetic perspective and value orientation of the school,which has far-reaching significance for the growth of students and their future development.This paper takes the construction of classroom culture in colleges and universities as the research subject,obtains real data,and conducts variable analysis through questionnaire survey and structured interview,with the aim of enriching the educational function of the classroom.It involves how the classroom culture pays attention to the current life,needs,and desires of college and university students,along with the problems and functions that should be improved in the traditional construction.This paper also discusses and reshapes the new paradigm of classroom culture construction in colleges and universities based on the combination of student growth,subject areas,school culture,and advanced technology.展开更多
Robot hands have been developing during the last few decades. There are many mechanical structures and analyti?cal methods for di erent hands. But many tough problems still limit robot hands to apply in homelike envir...Robot hands have been developing during the last few decades. There are many mechanical structures and analyti?cal methods for di erent hands. But many tough problems still limit robot hands to apply in homelike environment. The ability of grasping objects covering a large range of sizes and various shapes is fundamental for a home service robot to serve people better. In this paper, a new grasping mode based on a novel sucked?type underactuated(STU) hand is proposed. By combining the flexibility of soft material and the e ect of suction cups, the STU hand can grasp objects with a wide range of sizes, shapes and materials. Moreover, the new grasping mode is suitable for some situations where the force closure is failure. In this paper, we deduce the e ective range of sizes of objects which our hand using the new grasping mode can grasp. Thanks to the new grasping mode, the ratio of grasping size between the biggest object and the smallest is beyond 40, which makes it possible for our robot hand to grasp diverse objects in our daily life. For example, the STU hand can grasp a soccer(220 mm diameter, 420 g) and a fountain pen(9 mm diameter, 9 g). What's more, we use the rigid body equilibrium conditions to analysis the force condition. Experiment evaluates the high load capacity, stability of the new grasping mode and displays the versatility of the STU hand. The STU hand has a wide range of applications especially in unstructured environment.展开更多
To solve the chattering problem caused by discontinuous switching function in traditional sliding mode observer,a piecewise square root switching function with continuously varying characteristics is designed,and its ...To solve the chattering problem caused by discontinuous switching function in traditional sliding mode observer,a piecewise square root switching function with continuously varying characteristics is designed,and its stability is analyzed by using Lyapunov stability criterion.Secondly,according to the relationship among bus current,switching state and phase current,a single bus resistance sampling current reconstruction scheme without current sensors is adopted,which effectively reduces the cost of motor system.Finally,the feasibility and effectiveness of the proposed scheme are verified by simulation.展开更多
The binding mode of the amino acid ethyl esters(guest) by 5 (2 carboxylphenyl) 10,15,20 triphenylporphyrinatozinc(Ⅱ)(host 1) was studied by means of 1H NMR spectra. The binding mode is the hydrogen bonding between th...The binding mode of the amino acid ethyl esters(guest) by 5 (2 carboxylphenyl) 10,15,20 triphenylporphyrinatozinc(Ⅱ)(host 1) was studied by means of 1H NMR spectra. The binding mode is the hydrogen bonding between the amino group of the guest and the carboxyl group of host 1 plus the coordination between the zinc atom of porphyrinatozinc(Ⅱ) and the carbonyl group of the guest. This is a novel binding mode of the metalloporphyrin to amino acid derivatives.展开更多
The Kinetica-I rocket is designed for small-and medium-sized spacecraft launch missions to sun-synchronous orbit and low Earth orbit.The maiden flight was performed on July 27,2022.The Kinetica-I rocket is characteriz...The Kinetica-I rocket is designed for small-and medium-sized spacecraft launch missions to sun-synchronous orbit and low Earth orbit.The maiden flight was performed on July 27,2022.The Kinetica-I rocket is characterized by competitive payload capability and cost,robust orbital insertion accuracy,high reliability,availability at short notice and logistical versatility.12 new core technologies have been achieved during the development of the rocket.It is of great significance in promoting the innovation of China's solid carrier rocket technology and science exploration.展开更多
We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate element...We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate elemental or isotopic ratios.In order to assess the performance of the new laser analytical mode for the application in the field of earth science,we systematically investigated the elemental quantitative analysis with high spatial resolution(10μm),rapid U-Pb dating in zircons and accurate Sr-Hf isotope analysis in geological samples.The new high-frequency laser analysis technology(20 Hz,100 pulses)reduced the limit of detection(LOD)of 25 elements to 0.005-0.16μg g^(-1) with crater diameters of 10μm,which are significantly lower(decrease to 2-20%)than previous researches.The quantitative analysis of five silicate glass reference materials showed that the precision and accuracy of the 25 trace elements(with the concentration ranging from 0.17 to 683μg g^(-1))were better than 16% and 15%,respectively.The new methods raised the analytical throughput of zircon U-Pb dating,Sr isotope ratios and Hf isotope ratios to 250 analyses per hour,144 analyses per hour and 120 analyses per hour in theory,while the analytical accuracy and precision were not affected.The detailed investigations showed that the proposed new laser analytical mode has good application effects in the field of earth sciences.展开更多
文摘The classroom is an important place for“three guarantees”education.Classroom culture refers to a group culture with both teachers and students as the main body,the classroom space as the carrier,and spiritual connotation as the core.The creation of classroom culture with school characteristics,characteristics of the times,and Chinese characteristics can reflect the aesthetic perspective and value orientation of the school,which has far-reaching significance for the growth of students and their future development.This paper takes the construction of classroom culture in colleges and universities as the research subject,obtains real data,and conducts variable analysis through questionnaire survey and structured interview,with the aim of enriching the educational function of the classroom.It involves how the classroom culture pays attention to the current life,needs,and desires of college and university students,along with the problems and functions that should be improved in the traditional construction.This paper also discusses and reshapes the new paradigm of classroom culture construction in colleges and universities based on the combination of student growth,subject areas,school culture,and advanced technology.
基金National Natural Science Foundation of China(Grant Nos.U1613216,61573333)
文摘Robot hands have been developing during the last few decades. There are many mechanical structures and analyti?cal methods for di erent hands. But many tough problems still limit robot hands to apply in homelike environment. The ability of grasping objects covering a large range of sizes and various shapes is fundamental for a home service robot to serve people better. In this paper, a new grasping mode based on a novel sucked?type underactuated(STU) hand is proposed. By combining the flexibility of soft material and the e ect of suction cups, the STU hand can grasp objects with a wide range of sizes, shapes and materials. Moreover, the new grasping mode is suitable for some situations where the force closure is failure. In this paper, we deduce the e ective range of sizes of objects which our hand using the new grasping mode can grasp. Thanks to the new grasping mode, the ratio of grasping size between the biggest object and the smallest is beyond 40, which makes it possible for our robot hand to grasp diverse objects in our daily life. For example, the STU hand can grasp a soccer(220 mm diameter, 420 g) and a fountain pen(9 mm diameter, 9 g). What's more, we use the rigid body equilibrium conditions to analysis the force condition. Experiment evaluates the high load capacity, stability of the new grasping mode and displays the versatility of the STU hand. The STU hand has a wide range of applications especially in unstructured environment.
文摘To solve the chattering problem caused by discontinuous switching function in traditional sliding mode observer,a piecewise square root switching function with continuously varying characteristics is designed,and its stability is analyzed by using Lyapunov stability criterion.Secondly,according to the relationship among bus current,switching state and phase current,a single bus resistance sampling current reconstruction scheme without current sensors is adopted,which effectively reduces the cost of motor system.Finally,the feasibility and effectiveness of the proposed scheme are verified by simulation.
文摘The binding mode of the amino acid ethyl esters(guest) by 5 (2 carboxylphenyl) 10,15,20 triphenylporphyrinatozinc(Ⅱ)(host 1) was studied by means of 1H NMR spectra. The binding mode is the hydrogen bonding between the amino group of the guest and the carboxyl group of host 1 plus the coordination between the zinc atom of porphyrinatozinc(Ⅱ) and the carbonyl group of the guest. This is a novel binding mode of the metalloporphyrin to amino acid derivatives.
文摘The Kinetica-I rocket is designed for small-and medium-sized spacecraft launch missions to sun-synchronous orbit and low Earth orbit.The maiden flight was performed on July 27,2022.The Kinetica-I rocket is characterized by competitive payload capability and cost,robust orbital insertion accuracy,high reliability,availability at short notice and logistical versatility.12 new core technologies have been achieved during the development of the rocket.It is of great significance in promoting the innovation of China's solid carrier rocket technology and science exploration.
基金supported by the National Natural Science Foundation of China(Grant Nos.41973013,41730211)the Natural Science Foundation of Hubei Province(Grant No.2020CFA045)the Most Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Grant Nos.MSFGPMR04,MSFGPMR08)。
文摘We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate elemental or isotopic ratios.In order to assess the performance of the new laser analytical mode for the application in the field of earth science,we systematically investigated the elemental quantitative analysis with high spatial resolution(10μm),rapid U-Pb dating in zircons and accurate Sr-Hf isotope analysis in geological samples.The new high-frequency laser analysis technology(20 Hz,100 pulses)reduced the limit of detection(LOD)of 25 elements to 0.005-0.16μg g^(-1) with crater diameters of 10μm,which are significantly lower(decrease to 2-20%)than previous researches.The quantitative analysis of five silicate glass reference materials showed that the precision and accuracy of the 25 trace elements(with the concentration ranging from 0.17 to 683μg g^(-1))were better than 16% and 15%,respectively.The new methods raised the analytical throughput of zircon U-Pb dating,Sr isotope ratios and Hf isotope ratios to 250 analyses per hour,144 analyses per hour and 120 analyses per hour in theory,while the analytical accuracy and precision were not affected.The detailed investigations showed that the proposed new laser analytical mode has good application effects in the field of earth sciences.
