Study Table With Bookshelf Children
The table area is newly upgraded, and the 120cm widened table can free up more space, and parents will be more spacious and study more freely. The height-Adjustable Study Table for children has 9 storage areas, which can make the table tidy and easy to use.
desk bookshelf combo,desk with bookshelf,double desk with storage,children's desk for small spaces Igrow Technology Co.,LTD , https://www.igrowdesks.com
Detachable bookshelves, children can move and combine freely. Different storage methods are used at different school age stages, so that large and small objects can be stored easily, so that storage is not limited. The newly designed children's study table and chair can be stretched back and forth 12cm to fit the child's back, so as to achieve a truly upright sitting posture, and the back of the chair can be stretched in real time. .
Study Table With Bookshelf Children selects imported solid wood mountain, the formaldehyde emission is lower than the international F4 star standard, more environmentally friendly than tap water, strong and durable, and not easy to deform for a long time. The height range of 52-76cm table board is adjusted according to the table leg scale, which matches the height of the child's growth stage of 120cm-180cm. The hidden reading rack is convenient for placing books and tablets to avoid long-term bowing, which can better maintain the scientific sight distance14 and prevent myopia. 4 modes can be adjusted, reading, writing and drawing are all done.
[Zhejiang University] Doppler Effect Comprehensive Experimental Device
**Doppler Effect Comprehensive Experimental Device**
The Doppler Effect is a fundamental concept in physics, and this comprehensive experimental device is designed to help students explore and verify it through hands-on experiments. This system enables the measurement of sound speed, object motion speed, and the verification of the Doppler effect using both qualitative and quantitative methods.
Currently, many educational tools are available for demonstrating the Doppler effect, but few are suitable for detailed experimentation. Most lack precision and flexibility. This device addresses those shortcomings by offering a reliable, user-friendly setup that allows for accurate measurements and diverse experimental conditions.
The device consists of three main components: the host unit, signal generation controller, and signal acquisition and processing system. The host includes a track, stepper motor, belt pulley, trolley, photoelectric gates, sound source, and receiver. It supports adjustable speeds, direction changes, and both uniform and variable motion. The signal generator offers frequency and amplitude control, with digital display and multiple output interfaces. The signal acquisition part uses either a computer or a mini MP3 recorder for audio capture and analysis via spectrum software.
This experiment allows for various configurations, such as changing the frequency of the sound source, adjusting the car's speed and direction, and swapping the positions of the source and receiver. It also supports non-relative motion scenarios, making it ideal for verifying theoretical formulas and calculating physical quantities like sound speed and object velocity.
Key features include:
- Adjustable trolley speed
- Directional movement control
- Uniform or variable speed operation
- Interchangeable sound source and receiver positions
- Non-relative motion capability
- 10–20 kHz frequency range with no noise
- Adjustable photoelectric gate position
- Audio signal input via microphone or recorder
- Spectrum analysis for frequency determination
The device is cost-effective, easy to use, and compatible with standard computers. It enhances learning by combining practical experimentation with data analysis, helping students deepen their understanding of wave physics and signal processing.
Developed by the Physics Experiment Teaching Center at Zhejiang University, this instrument is an essential tool for modern physics education.