A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circuit, and a low noise ion detector. The ion filter electronics are capable to generate square waveforms with peak-to-peak voltages up to 1000 V at frequencies up to 1 MHz with adjustable duty cycles. The ion detector current amplifier has a gain up to 10 V/A with an effective equivalent input noise level down to about 1 fA/Hz during operation with the ion filter at the maximum voltage and frequency. The FAIMS system was characterized by detecting different standard chemical compounds. Additionally, we investigated the use of a synchronous modulation/demodulation technique to improve the signal-to-noise ratio in FAIMS measurements. In particular, we implemented the modulation of the compensation voltage with the synchronous demodulation of the ion current. The analysis of the measurements at low concentration levels led to an extrapolated limit of detection for acetone of 10 ppt with an averaging time of 1 s.
The popularity of the Internet has toppled people's thinking models and teaching styles as well as influenced the operation of school education. In teaching processes, computers could attract students' attention through vivid images, bright colors and characters, and sound to further promote their learning concentration and interests. Research on the application of integrating information into instruction is increasing, and lots of studies prove that technology could help students' learning and improve their learning attitudes. In this study, the nonequivalent pretest posttest control group design is utilized for the quasi-experiment research. Total 236 students in two classes each from Xiamen University and Fuzhou University in Fujian Province are selected as the research objects for the 32-week experimental instruction for 3 hours per week (total 96 hours). The research results reveal 1. significant effects of adventure education on comprehension, 2. remarkable effects of adventure education on learning effectiveness, 3.the best promotion of comprehension with Reciprocal Teaching under multimedia teaching, and 4.the best promotion of learning effectiveness with Reciprocal Teaching under multimedia teaching. The results are further discussed to propose specific suggestions in this study. It is expected to enhance teachers' teaching skills and promote students' learning effectiveness.
This paper presents the design and development of a miniature integrated jumping and running robot that can adjust its route trajectory and has passive self-righting. The jumping mechanism of the robot was developed by using a novel design strategy that combines hard-bodied animal (springtail) and soft-bodied animal (gall midge larvae) locomotion. It could reach a height of about 1.5 m under a load of 98.6 g and a height of about 1.2 m under a load of 156.8 g. To enhance the jumping flexibility of the robot, a clutch system with an adjustable height and launch time control was used such that the robot could freely switch to appropriate jumping heights. In addition, the robot has a shell with passive righting to protect the robot while landing and automatically self-righting it after landing, which makes the continuous jumping, running, and steering of the robot possible. The two-wheel mechanism integrated at the bottom of the housing mechanism provides the robot with horizontal running locomotion, which is combined with the vertical jumping locomotion to obtain different locomotion trajectories. This robot has the functions of obstacle surmounting, track adjustability, and load- and self-righting, which has strong practical application value.
Advanced technology enhances the rapid development of civilization. When the living standard is promoted, people start to pursue higher-quality material needs and mind contentment. The prevalence of leisure and entertainment has travel become an essential part of life. Along with the increasing tourist population, rural ecological environments and historical & cultural monuments are utilized for many tourist spots to cope with above needs as well as attract people who live in urban jungles leaving cities for scenery appreciation and local culture experiencing in countryside. Aiming at Yongchun Niumulin Ecological Tourism Zone, the supervisors and employees, with random sampling, are distributed 320 copies of questionnaire. Total 243 valid copies are retrieved, with the retrieval rate 76%. The research results reveal significant correlations between 1.knowledge management and environmental education, 2.environmental education and professional performance, as well as 3.knowledge management and professional performance. According to the research results, suggestions are eventually proposed in this study, expecting to assist domestic eco-tourism in stable and continuous growth.
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