Student-centered learning approach is focused on the students' demands and interests.Applying student-centered approach puts forward higher requirement to English teachers.This article first analyzes the theory of...Student-centered learning approach is focused on the students' demands and interests.Applying student-centered approach puts forward higher requirement to English teachers.This article first analyzes the theory of student-centered learning approach and compares teacher-centered approach with it.Based on the research information and teaching experience,the author summarizes four strategies about how to apply student-centered learning approach to English listening and speaking class in vocational schools.展开更多
Nowadays, people have been more critical about the traditional ways of teaching and advocate the student-centered teaching approach. This paper focuses on the student- centered approach in English classroom teaching i...Nowadays, people have been more critical about the traditional ways of teaching and advocate the student-centered teaching approach. This paper focuses on the student- centered approach in English classroom teaching in vocational colleges. It points out that the students' English levels, the current mainstream of teaching in English class as well as the teaching materials in Chinese vocational college are all important factors that influence the outcome of the student-centered teaching approach. Meanwhile, the paper proves that college students can gain more in the student-centered English class. In the end, some suggestions are provided.展开更多
It is very common to have a class of 50 or more students in Chinese schools, and teaching a foreign language effectively to a large class is really hard work. In order to change the teacher-centered teaching model int...It is very common to have a class of 50 or more students in Chinese schools, and teaching a foreign language effectively to a large class is really hard work. In order to change the teacher-centered teaching model into the student-centered one, Teachers should keep students' needs, interests, and learning styles in mind, apply several kinds of teaching techniques, organize different classroom activities and encourage, praise and appreciate both students' success and learning process all the time. If teachers place more responsibility in the hands of students, serve as "presenter or facilitator of knowledge" instead of "source of all knowledge", they can greatly motivate students to learn the language in a very active, cooperative and effective way. After all, people learn by doing, not only by watching and listening.展开更多
Insights obtained from this study may be useful in improving college English teaching in the aim of better preparing teachers to assume teaching responsibilities.This study may also contribute to an understanding of h...Insights obtained from this study may be useful in improving college English teaching in the aim of better preparing teachers to assume teaching responsibilities.This study may also contribute to an understanding of how administrators can improve training programs to better meet the needs,experiences,and beliefs of college students.The information may be useful in improving programs designed to facilitate the development of college teachers' beliefs about teaching and teaching skills and specifically those target the development of inquiry teaching.展开更多
In order to train a student to be a person with ability,who can self-study,use knowledge flexibly and bring firth new ideas constantly,the constant development of society demands a full exertion of student-center appr...In order to train a student to be a person with ability,who can self-study,use knowledge flexibly and bring firth new ideas constantly,the constant development of society demands a full exertion of student-center approach in the process of education.Therefore,how to exert the student-center approach is a question that every teacher is facing.I think that we can exert the student-center approach from the following aspects.One,a teacher must change his teaching conception.He should know that it's the students who are the main body of teaching and the teacher can act as a guider.The other,by all means,we ought to make the students know the purpose of their study and the function of themselves in learning.We also ought to culture their interest in learning,inspire and strengthen their main body consciousness.the teacher should,on the basis of full understanding his students and textbook,exert the leading function of himself.In the course of teaching,the teacher can exert the advantage of advanced teaching method,such as situational language teaching,and advanced teaching instrument,such as multimedia,which will inspire the students' interest and conscious activities.We can train the students' imagining ability through encouragement 、guiding and extracurricular activities.We can improve the students' ability of self-study.Thus,the students' main body function will reach a better exertion and the effect of teaching will be improved.This will train the students to suit the need of society.展开更多
Although it is common for Chinese students to learn English for many years, they are still confronted with problems when it comes to communicating with people in English. Lack of working hard, necessary learning conte...Although it is common for Chinese students to learn English for many years, they are still confronted with problems when it comes to communicating with people in English. Lack of working hard, necessary learning context, and interest does play a part; however, the problem really lies mostly in teaching process, so, to improve the quality of learning, teachers should bear more responsibilities and do more to bring humanism to English class and enhance student-centeredness. To achieve this goal, teachers should know more about students' learning styles so as to apply different approaches to students with different learning styles. What is more, priority should be given to analysis of learners' needs as well as preferences, on the basis of which a curriculum can be developed to meet the needs of a particular group of students. Finally, improvement of learner autonomy will lead to the shift of learning responsibilities from teacher to students, thus achieving student-centered learning ultimately.展开更多
The teaching of Vocal Music Education in normal universities is a core part of vocal skills training in the system of music education, which has a direct impact on the cultivation of teachers of foundation music educa...The teaching of Vocal Music Education in normal universities is a core part of vocal skills training in the system of music education, which has a direct impact on the cultivation of teachers of foundation music education. There has been a lot of discussion about Vocal Music Teaching or specifically aim at improving the students' comprehensive ability, but the number of systematic study which integrates both of the two is little. The training contents of the teaching of Vocal Music Education in normal universities include the features of rich teaching content; instructional mode is composed of classroom teaching, art practice, practice teaching and other diverse forms. The teaching of Vocal Music Education at normal universities can promote the cultivation of the students' comprehensive capabilities, including: the cultivation of moral and intellectual, the enhancement of cultural accomplishment, and the cultivation of language competence, connoisseurship and psychological qualities and such non-professional quality; good singing, correct listening and perception ability, good ability of piano accompaniment, and the cultivation and improvement of ability of teaching practice and such professional quality. The author combines the "student-centered" educational concept to analyze the teaching of Vocal Music at normal universities, hoping to provide some inspiration and help for educators of Vocal Music Teaching.展开更多
BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during or...BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and stabilized.CASE SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and TMDs.The treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep overbite.Therefore,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves.After the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion.After careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion.Eventually,the improved facial appearance and relatively stable occlusion were achieved.The 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was stable.CONCLUSION TMD screening and monitoring is of great clinical importance in the TMD susceptible patients.Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.展开更多
The author tries to point out the right class teaching patterns and the important roles of teachers in class compared with the traditional teaching method---teacher-centered way. Examples are also employed to show the...The author tries to point out the right class teaching patterns and the important roles of teachers in class compared with the traditional teaching method---teacher-centered way. Examples are also employed to show the correct ways for students to learn more and better, to have more confidence and ease in English acquisition.展开更多
The Natural Approach has got through the debates and is proved to be helpful in foreign language teaching.Based on this,the student-centered & topic-based approach is proved to be an appropriate way in college Eng...The Natural Approach has got through the debates and is proved to be helpful in foreign language teaching.Based on this,the student-centered & topic-based approach is proved to be an appropriate way in college English teaching.This paper is devoted to justifying the effectiveness of this approach in the college English classroom,and providing an organization of a typical college English class.展开更多
The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the...The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance.展开更多
The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprin...The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access phases.However,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or types.To address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this paper.The mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint dataset.The complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using BLS.The experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.展开更多
Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and K...Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.展开更多
This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,qua...This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.展开更多
BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lip...BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lips requested orthodontic camouflage.The treatment plan consisted of extracting the right upper third molar,right lower third molar,left lower second molar,and left upper third molar and moving the maxillary dentition distally using a convenient method involving microimplant nail anchors,push springs,long arm traction hooks,and elastic traction chains.After 52 months of treatment,her overbite and overjet were normal,and her facial profile was favorable.CONCLUSION This method can be used for distal movement of the maxillary dentition and to correct severe skeletal class II malocclusion in adults.展开更多
As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers...As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers’consciousness of“identity remodeling”in the process of Integrated Business English flipping classroom teaching.Combining the advantages of MOOC and flipped classroom teaching during before-,during-,and after-class will greatly help promote the overall quality of business English teaching in universities.展开更多
This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while ...This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.展开更多
文摘Student-centered learning approach is focused on the students' demands and interests.Applying student-centered approach puts forward higher requirement to English teachers.This article first analyzes the theory of student-centered learning approach and compares teacher-centered approach with it.Based on the research information and teaching experience,the author summarizes four strategies about how to apply student-centered learning approach to English listening and speaking class in vocational schools.
文摘Nowadays, people have been more critical about the traditional ways of teaching and advocate the student-centered teaching approach. This paper focuses on the student- centered approach in English classroom teaching in vocational colleges. It points out that the students' English levels, the current mainstream of teaching in English class as well as the teaching materials in Chinese vocational college are all important factors that influence the outcome of the student-centered teaching approach. Meanwhile, the paper proves that college students can gain more in the student-centered English class. In the end, some suggestions are provided.
文摘It is very common to have a class of 50 or more students in Chinese schools, and teaching a foreign language effectively to a large class is really hard work. In order to change the teacher-centered teaching model into the student-centered one, Teachers should keep students' needs, interests, and learning styles in mind, apply several kinds of teaching techniques, organize different classroom activities and encourage, praise and appreciate both students' success and learning process all the time. If teachers place more responsibility in the hands of students, serve as "presenter or facilitator of knowledge" instead of "source of all knowledge", they can greatly motivate students to learn the language in a very active, cooperative and effective way. After all, people learn by doing, not only by watching and listening.
文摘Insights obtained from this study may be useful in improving college English teaching in the aim of better preparing teachers to assume teaching responsibilities.This study may also contribute to an understanding of how administrators can improve training programs to better meet the needs,experiences,and beliefs of college students.The information may be useful in improving programs designed to facilitate the development of college teachers' beliefs about teaching and teaching skills and specifically those target the development of inquiry teaching.
文摘In order to train a student to be a person with ability,who can self-study,use knowledge flexibly and bring firth new ideas constantly,the constant development of society demands a full exertion of student-center approach in the process of education.Therefore,how to exert the student-center approach is a question that every teacher is facing.I think that we can exert the student-center approach from the following aspects.One,a teacher must change his teaching conception.He should know that it's the students who are the main body of teaching and the teacher can act as a guider.The other,by all means,we ought to make the students know the purpose of their study and the function of themselves in learning.We also ought to culture their interest in learning,inspire and strengthen their main body consciousness.the teacher should,on the basis of full understanding his students and textbook,exert the leading function of himself.In the course of teaching,the teacher can exert the advantage of advanced teaching method,such as situational language teaching,and advanced teaching instrument,such as multimedia,which will inspire the students' interest and conscious activities.We can train the students' imagining ability through encouragement 、guiding and extracurricular activities.We can improve the students' ability of self-study.Thus,the students' main body function will reach a better exertion and the effect of teaching will be improved.This will train the students to suit the need of society.
文摘Although it is common for Chinese students to learn English for many years, they are still confronted with problems when it comes to communicating with people in English. Lack of working hard, necessary learning context, and interest does play a part; however, the problem really lies mostly in teaching process, so, to improve the quality of learning, teachers should bear more responsibilities and do more to bring humanism to English class and enhance student-centeredness. To achieve this goal, teachers should know more about students' learning styles so as to apply different approaches to students with different learning styles. What is more, priority should be given to analysis of learners' needs as well as preferences, on the basis of which a curriculum can be developed to meet the needs of a particular group of students. Finally, improvement of learner autonomy will lead to the shift of learning responsibilities from teacher to students, thus achieving student-centered learning ultimately.
文摘The teaching of Vocal Music Education in normal universities is a core part of vocal skills training in the system of music education, which has a direct impact on the cultivation of teachers of foundation music education. There has been a lot of discussion about Vocal Music Teaching or specifically aim at improving the students' comprehensive ability, but the number of systematic study which integrates both of the two is little. The training contents of the teaching of Vocal Music Education in normal universities include the features of rich teaching content; instructional mode is composed of classroom teaching, art practice, practice teaching and other diverse forms. The teaching of Vocal Music Education at normal universities can promote the cultivation of the students' comprehensive capabilities, including: the cultivation of moral and intellectual, the enhancement of cultural accomplishment, and the cultivation of language competence, connoisseurship and psychological qualities and such non-professional quality; good singing, correct listening and perception ability, good ability of piano accompaniment, and the cultivation and improvement of ability of teaching practice and such professional quality. The author combines the "student-centered" educational concept to analyze the teaching of Vocal Music at normal universities, hoping to provide some inspiration and help for educators of Vocal Music Teaching.
基金Natural Science Foundation of Jiangsu Province, No. SBK2021021787the Major Project of the Health Commission ofJiangsu Province, No. ZD2022025and the Key Project of the Nanjing Health Commission, No. ZKX20048.
文摘BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and stabilized.CASE SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and TMDs.The treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep overbite.Therefore,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves.After the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion.After careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion.Eventually,the improved facial appearance and relatively stable occlusion were achieved.The 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was stable.CONCLUSION TMD screening and monitoring is of great clinical importance in the TMD susceptible patients.Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.
文摘The author tries to point out the right class teaching patterns and the important roles of teachers in class compared with the traditional teaching method---teacher-centered way. Examples are also employed to show the correct ways for students to learn more and better, to have more confidence and ease in English acquisition.
文摘The Natural Approach has got through the debates and is proved to be helpful in foreign language teaching.Based on this,the student-centered & topic-based approach is proved to be an appropriate way in college English teaching.This paper is devoted to justifying the effectiveness of this approach in the college English classroom,and providing an organization of a typical college English class.
文摘The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance.
基金supported by National Key R&D Program of China(2019YFB2102303)National Natural Science Foundation of China(NSFC61971014,NSFC11675199)Young Backbone Teacher Training Program of Henan Colleges and Universities(2021GGJS170).
文摘The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access phases.However,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or types.To address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this paper.The mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint dataset.The complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using BLS.The experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.
基金supported by Undergraduate Training Program for Innovation and Entrepreneurship of China University of Mining and Technology (CUMT)(Grant No. 202110290059Z)Fundamental Research Funds for the Central Universities of CUMT (Grant No. 2020ZDPYMS33)。
文摘Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.
文摘This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.
基金Supported by Medical Science Research Project Plan by Health Commission of the Hebei Province,No.20220063.
文摘BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lips requested orthodontic camouflage.The treatment plan consisted of extracting the right upper third molar,right lower third molar,left lower second molar,and left upper third molar and moving the maxillary dentition distally using a convenient method involving microimplant nail anchors,push springs,long arm traction hooks,and elastic traction chains.After 52 months of treatment,her overbite and overjet were normal,and her facial profile was favorable.CONCLUSION This method can be used for distal movement of the maxillary dentition and to correct severe skeletal class II malocclusion in adults.
基金“Provincial Online and Offline Hybrid First-Class Course-Integrated Business English 1-of Zhejiang Province in 2020”.
文摘As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers’consciousness of“identity remodeling”in the process of Integrated Business English flipping classroom teaching.Combining the advantages of MOOC and flipped classroom teaching during before-,during-,and after-class will greatly help promote the overall quality of business English teaching in universities.
文摘This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.