Nanjing University of Science and Technology

About: Nanjing University of Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 31581 authors who have published 36390 publications receiving 525474 citations. The organization is also known as: Nánjīng Lǐgōng Dàxué & Nánlǐgōng.

Monitoring wind turbine gearboxes

Abstract: Concerns amongst wind turbine (WT) operators about gearbox reliability arise from complex repair procedures, high replacement costs and long downtimes leading to revenue losses. Therefore, reliable monitoring for the detection, diagnosis and prediction of such faults are of great concerns to the wind industry. Monitoring of WT gearboxes has gained importance as WTs become larger and move to more inaccessible locations. This paper summarizes typical WT gearbox failure modes and reviews supervisory control and data acquisition (SCADA) and condition monitoring system (CMS) approaches for monitoring them. It then presents two up-to-date monitoring case studies, from different manufacturers and types of WT, using SCADA and CMS signals. The first case study, applied to SCADA data, starts from basic laws of physics applied to the gearbox to derive robust relationships between temperature, efficiency, rotational speed and power output. The case study then applies an analysis, based on these simple principles, to working WTs using SCADA oil temperature rises to predict gearbox failure. The second case study focuses on CMS data and derives diagnostic information from gearbox vibration amplitudes and oil debris particle counts against energy production from working WTs. The results from the two case studies show how detection, diagnosis and prediction of incipient gearbox failures can be carried out using SCADA and CMS signals for monitoring although each technique has its particular strengths. It is proposed that in the future, the wind industry should consider integrating WT SCADA and CMS data to detect, diagnose and predict gearbox failures.

MnO2 Nanorods Intercalating Graphene Oxide/Polyaniline Ternary Composites for Robust High-Performance Supercapacitors

Abstract: New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long MnO2 nanorods with a diameter ~20 nm are conformably coated with PANI layers and fastened between GO layers. The MnO2 nanorods incorporated ternary composites electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in supercapacitors. The ternary composite with 70% MnO2 exhibits a highest specific capacitance reaching 512 F/g and outstanding cycling performance, with ~97% capacitance retained over 5000 cycles. The ternary composite approach offers an effective solution to enhance the device performance of metal-oxide based supercapacitors for long cycling applications.

Asymptotic Tracking Control of Uncertain Nonlinear Systems With Unknown Actuator Nonlinearity

Abstract: This technical note is concerned with the problem of adaptive tracking control for a class of nonlinear systems with parametric uncertainty, unknown actuator nonlinearity and bounded external disturbance. Two type of actuator nonlinearities, that is, symmetric dead-zone and Bouc-Wen hysteresis, are considered, respectively. First, an adaptive control scheme with positive integrable time-varying function is presented to compensate for the dead-zone nonlinearity. Then, the actuator nonlinearity under consideration is modeled as Bouc-Wen hysteresis, and desired compensation controller is designed based on the backstepping technique and Nussbaum gain approach. In both of the two schemes, the asymptotic tracking is guaranteed with the tracking error converging to zero. Finally, an illustrative example is provided to show the effectiveness of the proposed design methods.

Learning to Super-Resolve Blurry Face and Text Images

Abstract: We present an algorithm to directly restore a clear highresolution image from a blurry low-resolution input. This problem is highly ill-posed and the basic assumptions for existing super-resolution methods (requiring clear input) and deblurring methods (requiring high-resolution input) no longer hold. We focus on face and text images and adopt a generative adversarial network (GAN) to learn a category-specific prior to solve this problem. However, the basic GAN formulation does not generate realistic highresolution images. In this work, we introduce novel training losses that help recover fine details. We also present a multi-class GAN that can process multi-class image restoration tasks, i.e., face and text images, using a single generator network. Extensive experiments demonstrate that our method performs favorably against the state-of-the-art methods on both synthetic and real-world images at a lower computational cost.

0D/2D Co3O4/TiO2 Z-Scheme heterojunction for boosted photocatalytic degradation and mechanism investigation

Abstract: The development of stable, efficient photocatalyst for environmental antibiotics degradation is great significant and remains a major challenge. Herein, zero dimensional Co3O4 nanodots are grown in situ onto two dimensional TiO2 nanosheets, successfully producing a Z-scheme heterojunction Co3O4/TiO2 photocatalyst for the photocatalytic degradation of enrofloxacin. The synthesized nanohybrid exhibits superior photodegradation performance (0.0269 min−1 for enrofloxacin) and excellent stability (four cycles). The matched energy bands allow the formation of the Z-scheme heterojunction, and the built-in electric field provides the reaction driving force. The formed Z-scheme heterojunction can simultaneously inhibit photoinduced electron-hole recombination, boost photoinduced charge carrier transfer, and produce more active electrons and holes, therefore generating more active species for eventual photocatalytic degradation. In addition, a the possible enrofloxacin degradation pathway was proposed based on simulated calculations and GC MS analysis. This work can inspire further design and construction of Z-scheme heterojunction photocatalysts.