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Wireless energy harvesting is an important application of microwave wireless energy transmission system, but due to the weak energy of RF signals in the 2.45 GHz band, its rectification efficiency is not ideal. As one of the core rectifier components of wireless weak energy harvesting system, the performance of MOSFET determines the rectification efficiency of the system, and its optimized design to improve the rectification efficiency is an important direction of current research in the field. In view of this, this paper proposes and designs Ge quantum well channel PMOS for wireless weak energy harvesting at 2.45 GHz, aiming to improve the rectification efficiency of wireless weak energy harvesting systems. Starting from adjusting the structural physical parameters of the MOS tubes, the absolute value of the threshold voltage is reduced in the weak energy density region, which in turn improves the rectification efficiency of the device. Then, the novel diode connection with the introduction of substrate bias effect is compared with the conventional connection using an ADS simulation circuit, and the simulation results show that the leakage current is smaller and the rectification efficiency is higher under the novel connection. On this basis, a Ge quantum well channel PMOS device is proposed. Compared with the Ge surface channel, the hole mobility of the quantum well channel will be greatly improved, and its rectification efficiency can also be improved. The device is connected to the rectifier circuit with a novel connection and simulated using Silvaco's Mixedmode module. The results show that the rectification efficiencies of the Ge quantum well channel MOS reach 13.53 % and 32 % at low input powers of −20.34 dBm and −6.28 dBm, respectively, which are 3.3 and 1.14 times higher than those of the conventional surface channel MOS. • Wireless energy harvesting system that collects RF signals and converts them into DC currents. • MOSFETs are core rectifier components for wireless weak energy harvesting systems. • Threshold voltage of MOSFET affects rectification efficiency in weak energy region. • MOS transistor rectification efficiency enhancement with novel connections. • Ge quantum well channel enhances device hole mobility. [ABSTRACT FROM AUTHOR]

The low electronic conductivity and Li ion diffusion ability are two major obstacles to realize its wide application for LiFePO 4 materials. The material with hierarchical conductive structure and lower antisite defects concentration can effectively enhance the electronic conductivity and Li ion diffusion ability. We firstly report here a modified solvothemal process for the fabrication of hierarchical conductive C/LiFePO 4 /CNTs composite with less antisite defects. It is found that the modified solvothemal process is facilitated to decrease Fe Li antisite defects and enhance the electronic continuity between LFP and CNTs. In favor of its unique properties, the C/LFP/CNTs composites can deliver superior rate capability and cycling stability. Remarkably, even at a high rate of 20C (3400 mA g −1 ), a high initial discharge capacity of 91.6 mAh g −1 and good cycle retention of 95% with almost 100% coulombic efficiency are still obtained after 100 cycles. [ABSTRACT FROM AUTHOR]

Abstract: A series of olivine LiFe1−xCoxPO4/C (x=0, 0.005, 0.01, 0.015, 0.02 and 0.025) nanoplates were synthesized by a facile solvothermal synthesis combined with esterification reaction. The structure, morphology and electrochemical performance of the samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatic intermittent titration technique (GITT), galvanostatic charge/discharge tests and electrochemical impedance spectroscopy (EIS). Based on the first-principle density functional theory (DFT), the diffusion energy barriers of Li ions for LiFe1−xCoxPO4 (x=0–0.025) were also calculated to further investigate the influence of doping Co on LiFePO4/C cathode material. The results showed that the prepared nanoplates with a very thin thickness along b-axis grow preferentially along the [001] direction of (101) lattice planes, which can minish the distance of Li+ ion diffusion along the [010] direction. The calculated results suggested that the LiFe0.99Co0.01PO4/C had a lowest lithium ion diffusion energy barrier, accordingly possessing a highest lithium ion diffusion coefficient. The electrochemical performance was improved by doping an appropriate amount of Co, and it might be attributed to the fact that the doped Co ion can enhance exchange current density and lithium ion diffusion coefficient. Among all the doped samples, LiFe0.99Co0.01PO4/C exhibited the best rate capability and cycling stability, with the initial discharge capacity of 154.5mAhg−1 at 0.5C. Remarkably, it still showed a high discharge capacity of over 96.9mAhg−1 and good cycle retention even at a high rate of 10C. [Copyright &y& Elsevier]

To develop a photocatalyst with novel structure and high performance, a Z-scheme AgSCN/AgCl/FeOCl heterojunction has been successfully prepared by the in-situ synthesis and anion exchange method for the first time. The photocatalytic activity and photo-Fenton catalytic activity of the AgSCN/AgCl/FeOCl nanosheets for the degradation of ibuprofen are 40.7 times and 4.1 times higher than that of FeOCl, respectively. The interfacial structure of the AgSCN/AgCl/FeOCl heterojunction photocatalyst accelerated the separation of the photogenerated electron-hole pairs. The core-shell structure of AgSCN/AgCl effectively suppressed the photocorrosion. This study provides a new approach to the rational design of photocatalysts for emerging environmental applications. The AgSCN/AgCl/FeOCl nanosheets heterojunction photocatalyst with novel interfacial structure was prepared for ibuprofen degradation. Image 1 • AgSCN/AgCl/FeOCl nanosheet heterojunction photocatalyst has been successfully prepared by in-situ synthesis and anion exchange technology for the first time. • The photocatalytic and photo-Fenton catalytic activities of the AgSCN/AgCl/FeOCl are 40.7 times and 4.1 times of FeOCl, respectively. • The interface structure of -Fe-Cl-Ag- between AgCl and FeOCl accelerated the separation of photogenerated electron-hole pairs. • The core-shell structure of AgSCN/AgCl effectively suppressed the photocorrosion and promoted the production of ·O2− radicals. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • EG-VEGF is significantly upregulated in pancreatic carcinoma (PC) tissues. • EG-VEGF silencing inhibits PC cell proliferation and promotes apoptosis. • EG-VEGF regulates PC progress via PI3K/AKT/mTOR pathway. Abstract Objective Pancreatic carcinoma (PC), one of the most prevalent and malignant tumors, has a poor prognosis and a high mortality rate. EG-VEGF, a vascular endothelial growth factor from endocrine glands, also termed as PROK1, has a high positive expression rate in PC tissues and is involved in the pathogenesis of various tumors. However, the expression and potential role of EG-VEGF in PC has not been thoroughly explored. The aim of this study was to better clarify the expression and potential role of EG-VEGF in pancreatic carcinoma. Methods Immunohistochemical staining, western blotting, and RT-qPCR analysis were performed to detect the EG-VEGF level in PC tissues and cells. Subsequently, two short hairpin RNA (shRNA) lentiviral expression vector, shPROK1-1/shPROK1-2, were transfected into PANC-1 and BxPC-3 PC cell lines. MTT assay was used to determine cell proliferation. Meanwhile, flow cytometry assay was conducted to measure cell cycle and cell apoptosis. The protein levels of PI3K/AKT/mTOR pathway-related genes were also determined by western blotting. Results EG-VEGF was aberrantly expressed in PC samples, as compared with paracancerous samples. Knockdown of PROK1 notably decreased the protein level of EG-VEGF, indicating a successful downregulation model of EG-VEGF. EG-VEGF silencing remarkably attenuated cell proliferation, while also induced G0/G1 arrest and magnified the extent of cell apoptosis. Further, EG-VEGF knockdown significantly inhibited PI3K/AKT/mTOR signaling pathway by downregulating p-PI3K, p-AKT, and p-mTOR levels. Conclusion This study identified the high-expression of EG-VEGF in pancreatic carcinoma tissues and cells, and demonstrated that EG-VEGF silencing inhibits the proliferation of PC cells and promotes apoptosis via regulating PI3K/AKT/mTOR pathway. Thus, EG-VEGF may become an essential target for the therapy of pancreatic cancer in the future. [ABSTRACT FROM AUTHOR]

High-quality low Sn-content GeSn film has been grown on tensile strained Ge/Si (100) substrate using a physical vapor deposition reactor and no subsequent annealing was carried out after the deposition of the film. High Resolution X-ray diffraction (HR-XRD) measurement was performed to estimate the crystallinity and the residual strain in the Ge layer. Secondary-ion mass spectrometry (SIMS) and X-ray photoelectron spectrometer (XPS) show Sn incorporation of the film is approximately 3%. High-resolution transmission electron microscopy (TEM) and atomic force microscopy (AFM) results show that the crystallinity of the film is quite good and it shows a smooth surface (RMS = 0.744 nm) in 5 µm × 5 µm scan. Raman spectroscopy and photoluminescence (PL) measurements were carried out to study the structural and optical properties of the film. Room-temperature PL of the film was observed and it results in a decrease in the difference between Γ and L valleys of tensile strained Ge (0.21%) from 87 meV to 76 meV, which makes this method promising for obtaining Pseudo-direct bandgap group IV films. [ABSTRACT FROM AUTHOR]

Cupric ion substituted LiFePO 4 /C composites were successfully synthesized via a two-step solid state reaction method. The SEM mapping demonstrates that cupric is well substituted in LiFePO 4 . Interestingly, the XRD spectra indicate that the substituted cupric could enlarge the interplanar distance of planes that parallelled to [010] direction of LiFePO 4 crystallines, which could widens the diffusion channels of Li + along [010] direction. For further research, Lithium ion storage behavior of as-synthesized cupric ion substituted LiFePO 4 /C products were investigated via various electrochemical strategies, and the highest capacity of 152.4, 144.4, 126.7 and 110.5 mAh g −1 was achieved by LiFe 0.985 Cu 0.015 PO 4 /C at discharge rate of 1, 2, 5, and 10 C, respectively. Compared the result with that of LiFePO 4 /C, we can see that cupric ion substituted LiFePO 4 /C composites show enhanced electrochemical activity for Li + storage with decreased overpotential and increased high rate capability for electrochemical reaction. [ABSTRACT FROM AUTHOR]

Abstract: Highly regulated peanut-like Fe3O4@N-rich carbon (Fe3O4@CN) core-shell microspheres were prepared using a solvothermal method, combined with a facile surfactant (sodium dodecyl sulfate) directed chemical polymerization and subsequent thermal treatment process. As anode electrode materials for Li-ion batteries, the as-prepared Fe3O4@CN composites exhibit higher specific capacity and better cyclic stability than bare Fe3O4. The reversible specific capacity of Fe3O4@CN composite is 670 mAh g−1 in the voltage range of 0.01-3.0V after 30 cycles with no noticeable fading compared with bare Fe3O4(100 mAh g−1). The enhanced electrochemical performance of the composites can be attributed to peanut-like Fe3O4@CN core-shell structure in which monodisperse Fe3O4 particles are entirely coated in the controllable and uniform carbon shell, and the surface contact among carbon shells further improves electronic conductivity due to slight agglomeration of composites after thermal treatment. Moreover, the residual nitrogen in the carbon crystal lattice resulted from the carbonization of polypyrrole enhances the electronic conductivity and brings active defects for the diffusion of lithium ion. [Copyright &y& Elsevier]

Abstract: A facile solvothermal synthesis and esterification reaction combined with a high temperature calcination technique has been developed to prepare the uniform carbon coating LiFePO4 nanoplates. The carbon coating LiFePO4 nanoplates are investigated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatic intermittent titration technique (GITT) and galvanostatic charge–discharge test. A reasonable growth mechanism of LiFePO4 nanoplates is proposed on the basis of time dependent experimental results. The results show that each nanoplate is a LiFePO4 single crystal with the large (010) plane. According to Raman spectroscopy analysis, carbon is uniformly coated on the surface of LiFePO4 nanoplates. Electrochemical test results also indicate that the carbon coating LiFePO4 nanoplates exhibit a high reversible specific capacity of 144.8 mAh g−1 at 0.5 C and 116.9 mAh g−1 under lower discharging rate at −20 °C. [Copyright &y& Elsevier]

• Perovskite-type oxides (LaCoO 3 and LaMnO 3) with large surface area were firstly derived from MOFs. • LaCoO 3 shows high activity and stability to activate PMS to degrade 2, 4-dichlorophenol. • The excellent activity of LaCoO 3 is due to large specific surface area, rich active sites and the redox reaction of Co2+–Co3+–Co2+. Developing highly efficient and stable catalysts toward advanced oxidation technology is the key to achieve industrial peroxymonosulfate (PMS) activation for pollution degradation. Perovskite-type oxide catalysts show high activity and stability for PMS activation, yet the small specific surface area of perovskite catalysts limits the increase of catalytic performance. Metal-organic frameworks (MOFs) have been widely used as the templates/precursors to prepare high specific surface area nanomaterials. In this study, two kinds of high surface area perovskites LaCoO 3 and LaMnO 3 were firstly fabricated with MOFs as templates. Benefiting from the extraordinary skeleton structure of MOFs, well-defined architecture and porous perovskite catalysts show superior catalytic performance towards PMS activation for the degradation of 2, 4-dichlorophenol (2, 4-DCP), with a 99.8% degradation of 2, 4-DCP in 25 min for LaCoO 3 catalyst. Moreover, the LaCoO 3 catalysts exhibit long-term stability with a slight loss of catalytic activity during 3 times recycled experiments. This study not only developed high activity catalysts for PMS activation, but also expanded the MOFs applications for environment and energy. [ABSTRACT FROM AUTHOR]

• Absorption properties of seven VOC molecules on GeS-based nanosheet were studied. • Enhanced interactions of O-contained VOCs were observed in Al-doped GeS. • Charge transfer and orbital hybridization are main enhanced mechanisms. • Magnetic properties could be utilized to further improve the selectivity. The adsorption characters of seven volatile organic compounds (VOCs) absorbed on intrinsic and Al-doped two-dimensional GeS were investigated by performing density functional theory. VOC molecules are physisorbed on pure GeS nanosheet by Van der Waals forces, however, the weak physical interactions could be significantly enhanced by Al doping. Strong interactions lead to multiplied adsorption energy and charge transfer, as well as improved sensitivity and thermodynamic stability. Orbital hybridization and charge redistribution between VOC molecules and Al-doped GeS substrate are dominant mechanisms of the enhanced interactions. In addition, influence of different functional groups to the magnetic properties of Al-doped GeS nanosheet was clarified, which paves the way to further promote the selectivity of sensors. Our calculating results might provide effective evidences to the design and fabrication of GeS-based VOC sensors with high sensitivity and selectivity at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen-rich materials have fascinating physical and chemical properties such as various structures and superconductivity under high-pressure. They are believed as an alternative approach to realize the hydrogen superconducting. In the previous report ([17] Zhong et al., J. Phys. Chem. C 116 (2012) 5225), we had presented structural phase-transitions and bonding interaction variations induced by pressure, and predicted a stable and superconductive phase above 220GPa, P21/c. In this study, we focus on the change of superconducting transition temperature induced by pressure above 220GPa for GeH4(H2)2. The variations of bond lengths, electronic structures, phonon spectra, and electron–phonon interaction with the increases of pressure are investigated. We find that the superconducting transition temperature monotonously decreases with the increase of pressure from 230 to 350GPa. The origin is mainly the stiff of phonon frequency induced by pressurization. [Copyright &y& Elsevier]

Lithium-sulfur batteries (LSBs) are considered as one of the most promising energy storage devices owing to the high theoretical specific capacity and high theoretical specific energy, as well as natural abundance of sulfur. However, the soluble lithium polysulfide intermediates (LPSs) in electrolyte cause undesirable shuttle effect, resulting in the loss of sulfur and poor cycling stability. Herein, a novel tungsten oxide-decorated N, S co-doped carbon nanofibers (WO 3 @NS-CNFs) functional interlayer is applied to restrain the shuttle effect and enhance the cycling performance of LSBs. On the one hand, the uniformly distributed WO 3 can provide strong chemical anchoring sites for binding the LPSs and enhance the redox reaction kinetics. On the other hand, the NS-CNFs can also serve as the polysulfide trappers and enhance the electronic conductivity of sulfur electrodes. Therefore, benefiting from the synergy effect of WO 3 and NS-CNFs, the LSBs exhibit excellent cycling performance with a high initial capacity of 1444 mA h g−1 and reversible capacity of 1080 mA h g−1 after 100 cycles at 0.2 C, and superior rate capability of 946 mA h g−1 at 2 C. Image 1 • A novel WO 3 @NS-CNFs interlayer is firstly applied as anchor of polysulfides. • Synergistic WO 3 @NS-CNFs can inhibit shuttle effect and enhance redox kinetics. • The LSBs with WO 3 @NS-CNFs interlayers show remarkable electrochemical performance. [ABSTRACT FROM AUTHOR]