Abstract: The present invention discloses a ventilator with dual flow passages. There is a mode switcher on the partition board. The ventilator has a variety of operating modes, such as, the natural or mechanical driving mode according to outdoor wind speed, and single-effect or multi-effect filtration according to the outdoor air pollution conditions. The single-effect filtration uses only the primary-efficiency filter, while the three-effect filtration uses the primary-, medium-, and high-efficiency filters. The mode switcher on the partition board can open or close the by-pass baffle to bypass or go through the medium- and high-efficiency filters for switching between the single-effect and multi-effect filtration. In case some indoor pollution sources need to be removed quickly, the recirculated indoor air filtration can be run. In such situation, the primary-efficiency filter in the mechanically-driven flow passage is bypassed, while the fan drives indoor air passing the medium- and high-efficiency filters.

Abstract: This invention addressed a method for measuring the foreign substance content invaded into a thin plate porous material based on the principle of virtual heat sources. The technical points of the invention are: (1) using the principle of virtual heat sources to improve the traditional heat pulse method to measure the foreign substance content; (2) representing the heat transfer effect on boundaries of the thin plate porous material by establishing an infinite number of virtual heat sources with two different heat intensities; (3) obtaining the volumetric heat capacity of the test material together with the invaded foreign substance content based on the four-parameter search to obtain the best temperature match between the measurement and the solution.

Abstract: A device and method of enhancing terahertz wave signals based on a hollow metal waveguide are disclosed. Simple devices such as a beam splitter, multiple plane mirrors, a beam combiner and an adjustable delay system are used. Two laser beams having a wavelength of 800 nm split by the beam splitter generate a fixed time phase delay, and are converged in the hollow metal waveguide to sequentially overlap with pulse of a laser having a wavelength of 400 nm for nonlinear interaction to ionize gas in the optical fiber to generate terahertz waves. The hollow metal waveguide can converge and transmit the generated terahertz waves due to its total reflection characteristics.

Abstract: Disclosed is a method of enhancing absorption spectral signals of a biological sample in a terahertz waveband in which the biological sample are embedded and supported with black silicon. In the method, the biological sample are filled between the surface micro-nano structures of a black silicon material and then freeze-dried. When the terahertz wave is incident upon the black silicon material, multiple reflections will occur between the micro-nano structures, so that the terahertz wave passes through the biological sample multiple times to increase the distance of interaction between the terahertz waves and the biological sample, allowing for enhanced absorption spectral signals of the biological sample and improved identifiability of the biological sample. The method is simple and easy to implement and low in cost.

Abstract: The present invention provides a method for producing B4C/Al neutron-absorbing material sheet by continuous cast rolling including the steps of: 1) providing B4C particles and aluminum matrix melt, adding the B4C particles into the aluminum matrix melt while stirring the composite of the B4C particles and the aluminum matrix melt; 2) applying an electromagnetic field to the B4C particle-containing aluminum matrix melt passing through a headbox; 3) applying an ultrasonic vibration to the B4C particle-containing aluminum matrix melt passing through a casting nozzle; and 4) conducing twin roll continuous cast rolling on the B4C particle-containing aluminum matrix melt from the casting nozzle to obtain B4C/Al neutron-absorbing material sheet.

Abstract: Various embodiments of systems and methods for transforming a source structured document to a target document are described herein. A request is received for transforming a source structured document. The source structured document is divided into many portions. A transformation rule is applied one by one on the portions of source structured document to obtain portions of the target document. The target document is generated based on the obtained portions of the target document.