Wakefield generation by chirped super-Gaussian laser pulse in inhomogeneous plasma

We study the effect of nonlinearly chirped super-Gaussian （SG） laser pulse on wakefield generation in an inhomogeneous plasma. The different types of nonlinearly chirped pulse are employed, and different kinds of inhomogeneous plasma density are used. The maximum wakefield amplitude as the function of nonlinearly chirped laser pulse and inhomogeneous plasma density in parameter space are obtained. Moreover, the dependence of the maximum wakefield amplitude on the SG laser pulse index is discussed. This shows that a larger wakefield can be obtained when the chirped pulse and inhomogeneous density are in the critical regions. Wakefield generation can be controlled by adjusting the chirped SG pulse and inhomogeneous plasma density parameters. That is, we provide an efficient way for the controlled generation of the wakefield.

Virtual 3D environment for exploring the spatial ability of students

Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.