Northeastern University (China)

About: Northeastern University (China) is a education organization based out in Shenyang, China. It is known for research contribution in the topics: Control theory & Microstructure. The organization has 36087 authors who have published 36125 publications receiving 426807 citations. The organization is also known as: Dōngběi Dàxué & Northeastern University (东北大学).

Spatial differentiation of urban wind and thermal environment in different grid sizes

Abstract: Due to rapid urbanization, China's urban morphology has undergone tremendous changes, resulting in an increased urban heat island (UHI) effect and negative impact of thermal environment, especially in summer. Studying the scale effect between urban wind and thermal environment can provide the best scale for the wind environment planning on mitigating UHI effect. Taking Dalian as an example, using multi-source data, a nonlinear correlation analysis was used to analyze the correlation between the frontal area index (FAI) and land 77uuyyhsurface temperature (LST) under different grids. The results show that first, FAI is sensitive to grid-size changes. When the grid size increases from 25 × 25 m to 150 × 150 m with a step size of 25 m, in July, the numbers of grids with FAI > 1 are 19,992, 1538, 153, 20, 4, and 0 (0%) accounting for 2.106%, 0.645%, 0.081%, 0.019%, 0.006%, and 0% of the total, respectively. In September, the numbers of grids with FAI > 1 are 17,633, 1643, 164, 22, 8, and 0, accounting for 1.849%, 0.689%, 0.155%, 0.037%, 0.021%, and 0% of the total, respectively. When the grid size is greater than or equal to 150 × 150 m, there is no grid with FAI > 1. Second, the most effective grid size to study the relationship between FAI and LST is 25 m. When the grid size increases from 25 m to 300 m with a step size of 25 m, the correlation between FAI and LST shows a significant decrease. When the grid size is 25 m, the correlation is the strongest.

Sorting of tumour cells in a microfluidic device by multi-stage surface acoustic waves

Abstract: Detection of circulating tumour cells (CTCs) plays a crucial role in the diagnosis of tumour metastasis and evaluation of therapeutic effect on prognosis. The low number of the CTCs, however, makes their isolation from the peripheral blood very difficult. In this paper, a microfluidic device has been developed, which consists of a pair of straight interdigital transducers (IDTs) and focused interdigital transducers (FIDTs), to separate tumour cells from red blood cells (RBCs) in the blood stream by surface acoustic waves (SAWs). The standing SAWs (SSAW) generated by the straight IDTs enabled placing the CTCs and RBCs at the pressure nodes while the FIDTs generated the focused travelling pulsed SAWs (TSAWs) to push the CTCs away from the blood cells to achieve the isolation of CTCs. Using this mechanism, this device was capable of concentrating and separating 2 μm and 5 μm polystyrene particles and about 94.2% of particles with the diameter of 5 μm could be collected at the outlet. Moreover, 90% ± 2.4% of U87 glioma cells could be isolated from the RBCs when the cycle number of the TSAWs was 720 k. In the enrichment process, this microfluidic device totally relied on the SSAW without any additional assistance of the flow focusing. For the separation, unlike the bidirectional acoustic radiation force in SSAW, the unidirectional force generated by TSAWs consistently pushed the particles along the wave propagation, improving the sorting performance. This multi-stage device may provide an alternative method for sorting CTCs in a reliable and flexible manner.

Outputting Olfactory Bionic Electric Impulse by PANI/PTFE/PANI Sandwich Nanostructures and their Application as Flexible, Smelling Electronic Skin

Abstract: A new flexible smelling electronic skin (e-skin) has been realized from PANI(polyaniline)/PTFE(polytetrafluoroethylene)/PANI sandwich nano­structures basing on the triboelectrification/gas-sensing coupling effect. The e-skin can be driven by human motion/breath and efficiently convert mechanical vibration into electric impulse. And the output current/voltage is significantly dependent on the environmental atmosphere (volatile organic compounds in air), which can act as olfactory bionic electric impulse. Taking ethanol gas as an example, the detection limit of the e-skin at room temperature is 30 ppm, and the response is up to 66.8 upon exposure to 210 ppm ethanol. Interestingly, the response of the e-skin keeps stable with different dimensional sizes or under different strains/bending status. The working mechanism can be ascribed to the coupling of triboelectrification effect and surface reaction at the interfaces. Furthermore, an application of the flexible smelling e-skin for visually identifying drunken driver without any external electricity power has been demonstrated. The results can open a possible new direction for the development of specialized-function e-skin and will further expand the scope for self-powered nanosystems.

Fiber-Optic SPR Sensor for Temperature Measurement

Abstract: A fiber-optic surface plasmon resonance (SPR) sensor for temperature detection has been proposed by utilizing a thermosensitive liquid as the intermediate and combining with the fiber SPR structure. The sensing element of the sensor has been fabricated by packaging the fiber probe coated with a silver layer into a capillary filled with thermosensitive anhydrous ethanol. This packaging can protect the metal layer from oxidation and damage. Moreover, this proposed sensor achieves a sensitivity of 1.5745 nm/°C, which is much higher than that of the traditional fiber SPR sensor according to the comparative experiments.