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).

A flexible ultrasensitive optoelectronic sensor array for neuromorphic vision systems

Abstract: The challenges of developing neuromorphic vision systems inspired by the human eye come not only from how to recreate the flexibility, sophistication, and adaptability of animal systems, but also how to do so with computational efficiency and elegance. Similar to biological systems, these neuromorphic circuits integrate functions of image sensing, memory and processing into the device, and process continuous analog brightness signal in real-time. High-integration, flexibility and ultra-sensitivity are essential for practical artificial vision systems that attempt to emulate biological processing. Here, we present a flexible optoelectronic sensor array of 1024 pixels using a combination of carbon nanotubes and perovskite quantum dots as active materials for an efficient neuromorphic vision system. The device has an extraordinary sensitivity to light with a responsivity of 5.1x10(7)A/W and a specific detectivity of 2x10(16) Jones, and demonstrates neuromorphic reinforcement learning by training the sensor array with a weak light pulse of 1 mu W/cm(2). To emulate nature biological processing, highly-integrated ultra-sensitive artificial neuromorphic system is highly desirable. Here, the authors report flexible sensor array of 1024 pixels using combination of carbon nanotubes and perovskite QDs as active matetials, achieving highly responsive device for reinforcement learning.

A Small-Gain Theorem for Switched Interconnected Nonlinear Systems and Its Applications

Abstract: A small-gain theorem for switched interconnected nonlinear systems is set up which provides a tool for analyzing the behavior of switched systems. Also, a method exploiting an average dwell time and the small gain technique is proposed. Based on the small-gain theorem, this technical note investigates the problem of global stabilization of switched nonlinear systems in strict-feedback form whose all zero dynamics are input-to-state stable (ISS) or only some are ISS and others are not. A sufficient condition for the global stabilization problem under a class of switching signals with average dwell time is derived by constructing state-feedback controllers for subsystems. The result is also applied to a class of switched nonlinear network control systems.

Controllable synthesis of NaYF4 : Yb,Er upconversion nanophosphors and their application to in vivo imaging of Caenorhabditis elegans

Abstract: β-NaYF4 : Yb,Er upconversion nanoparticles (UCNPs) can emit bright green fluorescence under near-infrared (NIR) light excitation which is safe to the body and can penetrate deeply into tissues. The application of UCNPs in biolabeling and imaging has received great attention recently. In this work, β-NaYF4 : Yb,Er UCNPs with an average size of 35 nm, uniformly spherical shape, and surface modified with amino groups were synthesized by a one-step green solvothermal approach through the use of room-temperature ionic liquids as the reactant, co-solvent and template. The as-prepared UCNPs were introduced into Caenorhabditis elegans (C. elegans) to achieve successful in vivo imaging. We found that longer incubation time, higher UCNP concentration and smaller UCNP size can make the in vivo fluorescence of C. elegans much brighter and more continuous along their body. The worms have no apparent selectivity on ingestion of the UCNPs capped with different capping ligands while having similar size and shape. The next generation of worms did not show fluorescence under excitation. In addition, low toxicity of the nanoparticles was demonstrated by investigating the survival rates of the worms in the presence of the UCNPs. Our work demonstrates the potential application of the UCNPs in studying the biological behavior of organisms, and lays the foundation for further development of the UCNPs in the detection and diagnosis of diseases.