Objective To investigate the indication,feasibility and technique of minimally invasive Nuss procedure with thoracoscope by using double braces in the treatment of wide-scope pectus excavatum repairing in adolescence....Objective To investigate the indication,feasibility and technique of minimally invasive Nuss procedure with thoracoscope by using double braces in the treatment of wide-scope pectus excavatum repairing in adolescence. Methods 31 patients including 24 boys and 7 girls,suffered from pectus excavtum were corrected by Nuss procedure under thoracoscope. The average age展开更多
In view of the major defect of the traditionalteacher correction,this paper introduces a new ap-proach to error correction—group error correction,inwhich learners’ role in learning language is greatly in-creased.Gro...In view of the major defect of the traditionalteacher correction,this paper introduces a new ap-proach to error correction—group error correction,inwhich learners’ role in learning language is greatly in-creased.Group error correction can be used to correcterrors in students’ oral work,group work and writtenwork,both in class and after class.Half a year’spractice of group error correction shows that it helpsincrease learner involvement in the teaching and learn-ing process,stimulate learner motivation in learningthe foreign language,raise the learners’ awareness oferrors,facilitate learners’ learning of the foreign lan-guage,relieve the teacher’s burden,and helps theteacher make better teaching plans.Error correction is an enormously complex pro-cess(Ellis,1994,p585).As for which is the most ef-fective method to correct errors,researchers havenot reached an agreement.Therefore more effortsneed to be made in this field.展开更多
A new type of light fiehl display is proposed using a head-mounted display （HMD） and a micro structure array （MSA, lens array or pinhole array）. Each rendering point emits abundant rays from different directions i...A new type of light fiehl display is proposed using a head-mounted display （HMD） and a micro structure array （MSA, lens array or pinhole array）. Each rendering point emits abundant rays from different directions into the viewer＇s pupil, and at one time the dense light field is generated inside the exit pupil of the HMD through the eyepiece. Therefore, the proposed method not only solves the problem of accommodation and convergence conflict in a traditional HMD, but also drastically reduces the huge data in real three-dimensional （3D） display. To demonstrate the proposed method, a prototype is developed, which is capable of giving the observer a real perception of depth.展开更多
Nonlinear materials have been well established as photo refractive switching material. Important applica- tions of isotropic nonlinear materials are seen in self-focusing, defocusing phenomena, switching systems, etc....Nonlinear materials have been well established as photo refractive switching material. Important applica- tions of isotropic nonlinear materials are seen in self-focusing, defocusing phenomena, switching systems, etc. The nonlinear correction term is basically responsible for the optical switches. Mach-Zehnder inter- ferometer （MZI） is a well-known arrangement for determining the above correction term, but there are some major problems for finding out the term by MZI. We propose a new method of finding the nonlinear correction term as well as the second order nonlinear susceptibility of the materials by using a modified MZI system. This method may be used to find out the above parameters for any unknown nonlinear material.展开更多
Peculiarities of propagation of femtosecond pulses through a focusing diffractive optical element (DOE) are considered. It is shown that the time delay between the pulse and phase wavefronts can be decreased by fabric...Peculiarities of propagation of femtosecond pulses through a focusing diffractive optical element (DOE) are considered. It is shown that the time delay between the pulse and phase wavefronts can be decreased by fabricating the DOE on the optimal curvilinear surface.展开更多
文摘Objective To investigate the indication,feasibility and technique of minimally invasive Nuss procedure with thoracoscope by using double braces in the treatment of wide-scope pectus excavatum repairing in adolescence. Methods 31 patients including 24 boys and 7 girls,suffered from pectus excavtum were corrected by Nuss procedure under thoracoscope. The average age
文摘In view of the major defect of the traditionalteacher correction,this paper introduces a new ap-proach to error correction—group error correction,inwhich learners’ role in learning language is greatly in-creased.Group error correction can be used to correcterrors in students’ oral work,group work and writtenwork,both in class and after class.Half a year’spractice of group error correction shows that it helpsincrease learner involvement in the teaching and learn-ing process,stimulate learner motivation in learningthe foreign language,raise the learners’ awareness oferrors,facilitate learners’ learning of the foreign lan-guage,relieve the teacher’s burden,and helps theteacher make better teaching plans.Error correction is an enormously complex pro-cess(Ellis,1994,p585).As for which is the most ef-fective method to correct errors,researchers havenot reached an agreement.Therefore more effortsneed to be made in this field.
基金partially supported by the National Basic Research Program of China(No.2013CB328805)the National Science Foundation of China(NSFC,No.61205024,61178038)the National Key Technology R&D Program(No.2012BAH64F03)
文摘A new type of light fiehl display is proposed using a head-mounted display （HMD） and a micro structure array （MSA, lens array or pinhole array）. Each rendering point emits abundant rays from different directions into the viewer＇s pupil, and at one time the dense light field is generated inside the exit pupil of the HMD through the eyepiece. Therefore, the proposed method not only solves the problem of accommodation and convergence conflict in a traditional HMD, but also drastically reduces the huge data in real three-dimensional （3D） display. To demonstrate the proposed method, a prototype is developed, which is capable of giving the observer a real perception of depth.
文摘Nonlinear materials have been well established as photo refractive switching material. Important applica- tions of isotropic nonlinear materials are seen in self-focusing, defocusing phenomena, switching systems, etc. The nonlinear correction term is basically responsible for the optical switches. Mach-Zehnder inter- ferometer （MZI） is a well-known arrangement for determining the above correction term, but there are some major problems for finding out the term by MZI. We propose a new method of finding the nonlinear correction term as well as the second order nonlinear susceptibility of the materials by using a modified MZI system. This method may be used to find out the above parameters for any unknown nonlinear material.
文摘Peculiarities of propagation of femtosecond pulses through a focusing diffractive optical element (DOE) are considered. It is shown that the time delay between the pulse and phase wavefronts can be decreased by fabricating the DOE on the optimal curvilinear surface.
