Southeast University

About: Southeast University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Computer science & MIMO. The organization has 66363 authors who have published 79434 publications receiving 1170576 citations. The organization is also known as: SEU.

Cooperative distributed antenna systems for mobile communications [Coordinated and Distributed MIMO]

Abstract: Cooperative distributed antenna systems have drawn considerable attention in recent years due to their potential to enhance both the coverage and the spectral efficiency of mobile communication systems In this article the conceptual description of a cooperative DAS for mobile communications is presented together with key techniques for DASs, including distributed multiple- input multiple-output for single and multiple users, handover, and transmit power allocation Furthermore, theoretical and simulation results on the spectral or transmit power efficiency of cooperative DASs are given and compared with those on conventional collocated antenna systems It is shown that a cooperative DAS can provide very promising performance enhancements in capacity and transmit power efficiency

Self-Assembly of Large-Scale and Ultrathin Silver Nanoplate Films with Tunable Plasmon Resonance Properties

Abstract: We describe a rapid, simple, room-temperature technique for the production of large-scale metallic thin films with tunable plasmonic properties assembled from size-selected silver nanoplates (SNPs). We outline the properties of a series of ultrathin monolayer metallic films (8-20 nm) self-assembled on glass substrates in which the localized surface plasmon resonance can be tuned over a range from 500 to 800 nm. It is found that the resonance peaks of the films are strongly dependent on the size of the nanoplates and the refractive index of the surrounding dielectric. It is also shown that the bandwidth and the resonance peak of the plasmon resonance spectrum of the metallic films can be engineered by simply controlling aggregation of the SNP. A three-dimensional finite element method was used to investigate the plasmon resonance properties for individual SNPs in different dielectrics and plasmon coupling in SNP aggregates. A 5-17 times enhancement of scattering from these SNP films has been observed experimentally. Our experimental results, together with numerical simulations, indicate that this self-assembly method shows great promise in the production of nanoscale metallic films with enormous electric-field enhancements at visible and near-infrared wavelengths. These may be utilized in biochemical sensing, solar photovoltaic, and optical processing applications.

Broadband MoS2 Field-Effect Phototransistors: Ultrasensitive Visible-Light Photoresponse and Negative Infrared Photoresponse.

Abstract: Inverse photoresponse is discovered from phototransistors based on molybdenum disulfide (MoS2 ). The devices are capable of detecting photons with energy below the bandgap of MoS2 . Under the illumination of near-infrared (NIR) light at 980 and 1550 nm, negative photoresponses with short response time (50 ms) are observed for the first time. Upon visible-light illumination, the phototransistors exhibit positive photoresponse with ultrahigh responsivity on the order of 104 -105 A W-1 owing to the photogating effect and charge trapping mechanism. Besides, the phototransistors can detect a weak visible-light signal with effective optical power as low as 17 picowatts (pW). A thermally induced photoresponse mechanism, the bolometric effect, is proposed as the cause of the negative photocurrent in the NIR regime. The thermal energy of the NIR radiation is transferred to the MoS2 crystal lattice, inducing lattice heating and resistance increase. This model is experimentally confirmed by low-temperature electrical measurements. The bolometric coefficient calculated from the measured transport current change with temperature is -33 nA K-1 . These findings offer a new approach to develop sub-bandgap photodetectors and other novel optoelectronic devices based on 2D layered materials.

Testing EKC hypothesis with energy and sustainable development challenges: a fresh evidence from belt and road initiative economies.

Abstract: Diverse impact of greenhouse gasses (GHGs) over the landscape of environment is generally believed in literature. As CO2 emission acutely leads to GHGs is a major contributor for global warming, it creates a serious pressure on natural resources and ecological settings. Similarly, low-carbon (CO2) economy, plenty of energy resources, and sustainable growth are a big ask for worldwide economies in this era of mechanization. This paper analyzes the Environmental Kuznets Curve (EKC) hypothesis, for Belt and Road Initiative (BRI) economies, to contend the role of mega projects in BRI as an attribute for ecological detriments. The on-hand study engages fresh data information ranging from 1981 to 2016 holding with heterogeneity and cross-sectional dependence as a special deliberation. The calculated outcomes expose that, mean group estimator provides strong evidence and favor the existence of EKC approximately in every region. The long-run influence is measured by pooled mean group estimators, which shows significant outcomes in every region; additionally, the EKC hypothesis affirmed in the long run especially for developed economies. Mega projects, i.e., BRI requisite immense energy sources to accomplishing the enclosed projects efficiently and effectively. The positive association between carbon emission and energy consumption troubled the governments to make policies for restraining the magnitude of carbon emission and controls energy usage for enduring environment to its original position. Next, the valuations depicted the dense recommendations for state administrations in capacity of rigorous level supremacy, trash managing campaigns, renewable energy reliance, and advance for desirable judgments to sterilize the atmosphere.