Search

The block samples of a Ni-based superalloy named GH4169 were prepared by laser melting deposited method using the corresponding GH4169 alloy powders,and then were heat treated with solution treatment followed by double aging.The microstructure and element segregation analysis of both as-deposited and heat treated samples were studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).The microhardness as well as tensile properties at room and elevated temperatures were tested.The results indicate that the microstructure of as-deposited sample mainly consists of columnar dendritic crystals that grow along with different directions.Grains are refined after solution and aging heat treatment,but remain dendritic crystals substructure inside.Compared with the as-deposited sample,the microhardness and tensile strength of the heat treated sample increase substantially,but the plasticity somewhat decreases.Nonetheless the tensile properties are superior to the standard values of forgings.The fracture surface exhibits ductile transcrystalline fracture mode.

Aberrant composition of glycans in the tumor microenvironment (TME) and abnormal expression of extracellular matrix proteins are hallmarks of hepatocellular carcinoma (HCC); however, the mechanisms responsible for establishing the TME remain unclear. We demonstrate that the chondroitin polymerizing factor (CHPF), an enzyme that mediates the elongation of chondroitin sulfate (CS), is a critical elicitor of the malignant characteristics of HCC as it modifies the potent tumor suppressor, decorin (DCN). CHPF expression is frequently downregulated in HCC tumors, which is associated with the poor overall survival of HCC patients. We observed that restoring CHPF expression suppressed HCC cell growth, migration, and invasion in vitro and in vivo. Mechanistic investigations revealed that TGF-β signaling is associated with CHPF-induced phenotype changes. We found that DCN, as a TGF-β regulator, is modified by CHPF, and that it affects the distribution of DCN on the surface of HCC cells. Importantly, our results confirm that CHPF and DCN expression levels are positively correlated in primary HCC tissues. Taken together, our results suggest that CHPF dysregulation contributes to the malignancy of HCC cells, and our study provides novel insights into the significance of CS, which affects DCN expression in the TME.

In this work, an AlN-ZnO/ZnO/AlN-ZnO double heterojunction (DH) structure prepared using the cosputtering technology was deposited onto the p -type GaN epitaxial layer. The indiffusion of the oxygen atoms to the p -GaN epilayer was obstructed as the cosputtered AlN-ZnO film inset between n -ZnO/ p -GaN interface. The near-ultraviolet (UV) emission from this ZnO/GaN-based light emitting diode (LED) was greatly improved as compared to an n -type ZnO film directly deposited onto the p -GaN epilayer. Meanwhile, the native defects in the n -ZnO layer associated with the green luminescence was less likely to form while it was sandwiched by the cosputtered AlN-ZnO film. As the thickness of the active n- ZnO layer in the DH structure reached 10 nm, the near-band-edge (NBE) emission became the predominated luminescence over the resulting LED spectrum.

In this work, Al-4.5wt.%Cu was selected as the research object, and a phase field-lattice Boltzmann method (PF-LBM) model based on compute unified device architecture (CUDA) was established to solve the problem of low serial computing efficiency of a traditional CPU and achieve significant acceleration. This model was used to explore the evolution of dendrite growth under natural convection. Through the study of the tip velocities, it is found that the growth of the dendrite arms at the bottom is inhibited while the growth of the dendrite arms at the top is promoted by natural convection. In addition, research on the inclined dendrite under natural convection was conducted. It is observed that there is a deviation between the actual growth direction and the preferred angle of the inclined dendrite. With the increase of the preferred angle of the seed, the difference between the actual growth direction and the initial preferred angle of the inclined dendrite shows a trend of increasing at first and then decreasing. In the simulation area, the relative deflection directions of the primary dendrite arms in the top right corner and the bottom left corner of the same dendrite are almost counterclockwise, while the relative deflection directions of the other two primary dendrite arms are clockwise. [ABSTRACT FROM AUTHOR]

The integrated electricity and heat system (IEHS) is an emerging demand‐side flexible resource for power systems. IEHS operators participating in electricity markets considering their capabilities in reserve provision will face the reserve deliverability risk due to the energy‐limited storage nature of heat systems. To address this challenge and increase profitability, a distributionally robust joint chance‐constrained mechanism with enhanced quantifications is adopted for the heating system and reserve deployment uncertainties. Detailed pipeline storage representation for thermal networks and integrated demand response are incorporated into this strategic participation model. A two‐stage distributionally robust joint chance constrained program is then incorporated to effectively manage the reserve deliverability risk by addressing uncertainties from local distributed energy resources and real‐time reserve requests. The L‐shaped algorithm is then customized by incorporating bi‐linear Benders' decomposition and modified scenario filtering method to efficiently tackle solution challenges for the sophisticated model. Numerical results show the advantages of our approach in virtual thermal storage utilization, risk management, computational performance enhancement and scalability. [ABSTRACT FROM AUTHOR]

Fiber-wireless and fiber-invisible laser light communication (IVLLC) convergences that adopt the Mach-Zehnder modulator-optoelectronic oscillator (MZM-OEO)-based broadband light source for microwave (MW)/millimeter-wave (MMW)/baseband (BB) signal transmission are proposed and demonstrated. For downlink transmission, light is optically promoted from 15- and 25-GHz radio-frequency (RF) signals to 10-Gb/s/30-GHz MW, 15-Gb/s/50-GHz MMW, 20-Gb/s/60-GHz MMW, and 25-Gb/s/100-GHz MMW data signals based on fiber-wireless and fiber-IVLLC integrations. Bit error rate (BER) performs efficiently in the 40-km single-mode fiber (SMF) and the 10-m RF/25-m optical wireless transport scenarios. For uplink transmission, downstream light is successfully intensity-modulated with a 25-Gb/s BB data stream based on fiber-IVLLC integration. BER performs efficiently in the 40-km SMF and the 100-m optical wireless transport scenario. Such a hybrid MW/MMW/BB lightwave transmission system is an attractive alternative. It is shown to be a prominent one to present advancements in integrating fiber backbone and radio-frequency (RF)/optical wireless feeder networks.

This paper proposes and presents the experimental demonstration of 320-Gb/s free-space optical (FSO) communication based on dense-wavelength-division-multiplexing (DWDM) technology and afocal scheme. To the best of our knowledge, this is the first one that adopts DWDM technology and afocal scheme to successfully demonstrate 50-m/320-Gb/s FSO communication. Results show that the free-space transmission distance is greatly increased by the afocal scheme and that the free-space transmission rate is significantly enhanced by the DWDM technology. DWDM FSO communication over a 50-m free-space link with a total transmission rate of 320 Gb/s (40 Gb/s/λ × 8λ = 320 Gb/s) is achieved. With the aid of a low-noise amplifier and clock/data recovery at the receiving site, good bit-error-rate (BER) performance and clear eye diagram are obtained at a 50-m/320-Gb/s operation. Such 50-m/320-Gb/s DWDM FSO communication provides the advantages of optical wireless communications for long transmission distance and high transmission rate, which is thoroughly useful for long-haul and high-speed light-based WiFi (LiFi) applications.

An 8 m/9.6 Gbps underwater wireless optical communication (UWOC) system based on a two-stage injection-locked 405 nm blue light laser diode (LD) transmitter with a 16-quadrature amplitude modulation (QAM)-orthogonal frequency-division multiplexing (OFDM) modulating signal is proposed and experimentally demonstrated. To the best of our knowledge, it is the first one that employs a two-stage injection-locked technique to improve the transmission performance of UWOC systems. With the assistance of an equalizer at the receiver site, acceptable bit error rate (BER) performance and a constellation map are obtained over an 8-m underwater link. Such a two-stage injection-locked 405 nm blue light LD transmitter-based UWOC system is shown to be a promising alternative, presenting its feasibility for long-range and high-speed underwater links.