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In recent years, the process of urbanization in China has developed rapidly. However, many problems have also appeared, such as a rapid population increase, resource shortage, and deterioration of the ecological environment. The deterioration of the ecological environment has led to increased air pollution and noise pollution, threatening human health, and hindering outdoor sports. This paper takes a certain city outdoor sports venue as the research object and studies the influence of the urban atmospheric ecological environment on the development of outdoor sports through the method of questionnaire survey and mathematical statistics. The results show that the city’s air quality index in 2019 was “excellent” and “good” for a total of 240 days, the greening rate reached 35%, the noise decibels were between 38 dB and 67 dB, and the ecological environment was good. According to statistics, 5.8% of students, 24.23% of middle-aged people, and 37.24% of elderly people in the city who engaged in outdoor sports often experience physical discomfort. After launching outdoor sports in this atmospheric ecological environment, 49.84% of students, 44.59% of office workers, and 39.65% of elderly people feel that their body and mind have improved. A good urban ecological environment can improve the physical and mental health of outdoor sports personnel. Through outdoor sports, the physical and mental health of all sports groups in the ecological environment has been improved. According to the location of this study, the subjects generally said that in the good atmospheric ecological environment of the city, outdoor sports improved physical and mental health.

The performance limit of the sub-5 nm monolayer (ML) indium phosphide (InP) FETs is explored. Ion, τ, and PDP of the ML InP FETs could meet the ITRS demands for the high-performance/low-power devices until gate length is reduced to 2/4 nm.

Presently Si-based field-effect transistors (FETs) are approaching their physical limit, and further scaling their gate length down to the sub-10 nm region is becoming extremely difficult. Benefitting from the atomic-scale thickness and dangling-bond-free flat surface, two-dimensional semiconductors (2DSCs) have good electrostatics and carrier transportability. The FETs based on the 2DSC channel have the potential to scale the FETs’ gate length down to the sub-10 nm region while avoiding apparent degradation of the device performance. In this review, we introduce the recent experimental and ab initio quantum transport simulation progress in the 2D FETs with a gate length less than 10 nm. Remarkably, in the extremely optimistic condition, many 2D FETs (i.e phosphorene, silicane, arsenene, tellurene, WSe2, InSe, Bi2O2Se, GeSe, etc.) show excellent device performance for the high performance and/or low power applications and indeed can extend Moore’s law down to 1 ∼ 2-nm gate length in terms of the ab initio quantum transport simulation. The sub-10 nm 2D tunneling FETs are predicted to generally have smaller energy-delay products compared with the 2D metal–oxide–semiconductor FETs and appear more competitive for the low power application. The carrier effective mass plays a key role in determining the device performance. Via negative capacitance techniques, the device performance can be further improved. Finally, we outline the challenges and outlook on the future development directions in the sub-10 nm 2D FETs.

Nowadays, the development of promising anodes for Na and K ion batteries (NIB and KIB) has got great attention due to their sustainable and renewable energy applications. Graphite is a good candidate but suffers from low Na (

Superionic conductor Li10GeP2S12 has a high lithium-ion conductivity of 12 mS cm−1 at room temperature, but its poor chemical stability against lithium metal anodes restricts its practical use. Introducing suitable two-dimensional (2D) sheets between Li10GeP2S12 and a lithium metal anode as a solid-electrolyte interphase (SEI) is expected to solve the interfacial problem without sacrificing energy density. A set of systematic selection schemes for 2D SEIs involving thermodynamic, electronic, and mechanical properties is proposed. h-BN and α-BNyne are finally selected, and first-principles calculations are carefully performed. Compared with the case where Li10GeP2S12 is directly exposed to a lithium metal anode, the two interfaces added by the ultrathin h-BN or α-BNyne monolayer as a SEI become chemically stabilized, with the electrochemical windows expanded by 2.08–2.41 eV. Significantly higher and wider barriers for electrons form while maintaining acceptable Li-ion diffusion barriers at the interfaces. The simple theoretical 2D SEI screening scheme exhibited here can be extended to other solid-state battery systems.

High-electron-mobility group III-V compounds have been regarded as a promising successor to silicon in next-generation field-effect transistors (FETs). Gallium arsenide (GaAs) is an outstanding member of the III-V family due to its advantage of both good n- and p-type device performance. Monolayer (ML) GaAs is the limit form of ultrathin GaAs. Here, a hydrogenated ML GaAs (GaAsH

Monolayer (ML) MoS2 is one of the most extensively studied two-dimensional (2D) semiconductors. However, it suffers from low carrier mobility and pervasive Schottky contact with metal electrodes. 2D semiconductor Bi2O2S, a sulfur analogue of 2D Bi2O2Se, has been prepared recently. ML fully hydrogen-passivated Bi2O2S2 (Bi2O2S2H2) posseses a comparable band gap (1.92 eV) with ML MoS2 (1.8 eV), but probably has a better device performance than ML MoS2. Based on the density functional theory, the electron and hole mobilities of ML Bi2O2S2H2 at 300 K are calculated to be 16 447–26 699 and 264–968 cm2 V−1 s−1, respectively. Then we firstly characterize the contact properties of ML half hydrogen-passivated Bi2O2S2 (Bi2O2S2H) with four bulk metal electrodes (Ti, Sc, Pd, and Pt) based on ab initio quantum transport simulation. In the lateral direction, a p-type Schottky contact is found in Pd and Pt electrodes, and the corresponding hole Schottky barrier heights (SBHs) are 0.54 and 0.99 eV, respectively. Remarkably, a coveted n-type Ohmic contact appears in Sc and Ti electrodes. Finally, the current on–off ratio of the ML hydrogen-passivated Bi2O2S2 field effect transistor with a Ti electrode reaches 105. Hence, the good intrinsic properties, contact properties, and large switching ability put ML hydrogen-passivated Bi2O2S2 in the rank of potential channel candidates for post-silicon era field effect transistors.

Antiferromagnetism within the two-dimensional (2D) family offers a platform for spintronics. The emergent 2D semiconductor ${\mathrm{Cr}\mathrm{PS}}_{4}$ is proved to be composed of ferromagnetic layers with antiferromagnetic coupling along the stacking direction in the experiment. By using the first-principles quantum-transport simulation, we evaluate the spin-resolved transport in the magnetic tunnel junction built by the 2D ${\mathrm{Cr}\mathrm{PS}}_{4}$ tunnel barrier with large thickness ranges. We find the magnetoresistance generally increases with the number of tunnel layers from 140% (three layers) to a surprising 370 000% (10 layers). An odd-even oscillation magnetoresistance behavior exists in few layers due to the electrode option. Our results will inspire further experimental verification and provide vital insights for 2D spintronics design.

Interlayer engineering of graphite anodes in alkali metal ion (M = Li, Na, and K) batteries is carried out based on the first-principles calculations. By increasing the interlayer spacing of graphite, the specific capacity of Li or Na does not increase while that of K increases continuously (from 279 mA h g-1 at the equilibrium interlayer spacing to 1396 mA h g-1 at the interlayer spacing of 20.0 A). As the interlayer spacing increases, the electrostatic potential of graphite becomes smoother, and the ability to buffer the electrostatic potential fluctuation becomes poorer in M ions. These two effects jointly lead to minima of the diffusion barrier of M ions on graphite (0.01-0.05 eV), instead of strictly monotonous declines with the increasing interlayer spacing. To perform the interlayer engineering of anode candidates more efficiently, a set of high-throughput programs has been developed and can be easily applied to other systems. Our research has guiding significance for achieving the optimal effect in interlayer engineering experimentally.

Fin field-effect transistors (FinFETs) dominate the present Si FETs. However, when the gate length is scaled down to the sub-10 nm region, the experimental Si FinFETs suffer from poor performance due to a large fin width (the minimum value is 3 nm). In this paper, an ultra-thin Si FinFET with a width of 0.8 nm is investigated for the first time by utilizing ab initio quantum transport simulations. Remarkably, even with the gate length down to 5 nm, the on-state current, delay time, power dissipation, and energy-delay product of the optimized perfect ultra-thin Si FinFET still meet the high-performance applications' requirements of the International Technology Roadmap for Semiconductors in the next decade. The overall performance of the simulated ultra-thin Si FinFET is even comparable with that of the typical two-dimensional FETs. Such a good performance can be significantly degraded by the defect. Hence, Si FinFETs have the potential to be scaled down to the sub-10 nm gate length as long as the width is scaled down while keeping a perfect structure.

Due to their outstanding gate electrostatics, two-dimensional (2D) semiconducting materials are regarded as promising channel materials used in the next-generation field-effect transistors (FETs). ...

Layered gallium sulphide (GaS) with hexagonal symmetry is a typical metal mono-chalcogenide and is mechanically stable under tension. In this work, we used first-principles density functional theory to study the performance of monolayer (ML) GaS as an anode material for Li, Na, K, Mg, and Al-ion batteries. The most stable binding sites for the metal atoms on ML GaS are all in the hollow sites, and the Fermi level of ML GaS moves upward into the conduction band after adsorption of Li, Na, K, and Al atoms, showing a semiconductor-to-metal transition of ML GaS, with the exception of Mg atoms. The binding energies of the metal atoms with ML GaS are all negative at all the studied densities, indicating a steady adsorbing process. The Li, Na, K, and Al ions prefer to move along the zigzag direction on ML GaS, with relatively low diffusion barrier heights of 0.110, 0.078, 0.037, and 0.034 eV, respectively. Such low diffusion barriers endow ML GaS with high rate capacity. The maximum theoretical specific capacities for Li, Na, K, and Al-ion batteries are 526.74, 32.92, 32.92, and 98.76 mA h g−1, respectively. Noticeably, the theoretical specific capacity of ML GaS for Li-ion batteries (LIBs) is even higher than the theoretical one (372 mA h g−1) of commercially used graphite. Besides, an appropriate average open circuit voltage of 0.53 V is generated for ML GaS based LIBs. Our study suggests that ML GaS is a suitable anode material for LIBs.

The two-dimensional (2D) transition-metal dichalcogenides (TMDs) field effect transistor (FET) with in-plane heterojunction contacts between the semiconducting 2H phase (as channel) and the metallic 1T or semi-metallic 1T′ phase (as electrode) has received much recent attention because it has significantly reduced contact resistance and enhanced gate tunability and thus improved device performance. However, the underlying mechanism of its good conductivity remains open. We systematically explore for the first time the contact properties of the monolayer (ML) 2H MX2 (MoS2, WS2, MoSe2, WSe2, MoTe2) FET with their 1T′ phase as electrode by using ab initio quantum transport simulations. We find that the metal induced gap states (MIGS) at the interface penetrate the Schottky barrier and bridge the electrodes and the conduction/valence band of the channel, thereby forming a lower and tunable effective Schottky barrier height (ESBH) and causing an equivalent Ohmic contact under the appropriate gate voltage. Our study provides a new insight into the observed reduced contact resistance with the 1T′ phase as electrode and is instructive for further experiment.

Recently, the 2019 Nobel prize in chemistry awards to three pioneers in the lithium-ion batteries (LIBs). However, the most commercially used anode for LIBs is still graphite, which suffers from the limited Li-ion storage of 372 mAh/g. To improve the performance of the intrinsic graphite anode (IGA), we use the ab initio calculations to examine the holey graphite anodes (HGAs) with three hole densities (35%: HGA35, 46%: HGA46 and 61%: HGA61) for LIBs. Remarkably, the maximum Li-ion storages of HGAs are up to 714–1689 mAh/g, which are about 2–4.5 times as high as that of the IGA (372 mAh/g). Besides, the in-plane diffusion barrier for Li-ions is also reduced from 0.57 eV (IGA) to 0.35–0.42 eV (HGAs), suggesting a higher Li-ion diffusion rate. The holey structures could open an extra out-plane Li-ions diffusing channel with only one-fifth of the diffusion barrier of that in the IGA, implying an accelerated charge/discharge process in the applications. We also demonstrate the relatively small surface area change ratio of less than 3%–14% in the HGAs upon adsorption of the maximum Li concentration. Therefore, the holey structure is a promising strategy to improve the graphite anode for LIBs significantly.

A novel chitosan-based multifunctional nanoparticle (PY-CS-PLA) using cationic polylysine (PL) polymer and L-cysteine has been developed and investigated for the oral delivery of paclitaxel (PTX). As amphiphilic polymer, PY-CS-PLA presented good capability in self-assembling into spherical nanoparticle with mean size of 165 nm, and encapsulating PTX into the hydrophobic core. The encapsulated PTX was observed to be sustainedly released from the functionalized chitosan nanoparticle, and with a positive correlation to the pH value of the medium in the range of 1.2 to 7.4. The in vitro studies indicated that PY-CS-PLA/PTX could effectively enhance the cellular uptake of the PTX in Caco-2 cells. Pharmacokinetic result indicated that the oral bioavailability of PY-CS-PLA/PTX in rats was determined to be 5.63-fold to that of Taxol. Moreover, PY-CS-PLA/PTX improved the distribution of PTX in tumor site and presented better antitumor efficacy in Heps tumor-bearing mice and with less toxicity than other formulations. In conclusion, the PY-CS-PLA/PTX nanoparticle might be developed as a promising delivery vehicle for improving the oral bioavailability and therapeutic effect of hydrophobic antitumor drugs.

Two-dimensional (2D) materials are a promising candidate for the anode material of lithium-ion battery (LIB) and sodium-ion battery (NIB) for their unique physical and chemical properties. Recently, a honeycomb borophene (h-borophene) has been fabricated by molecular beam epitaxy (MBE) growth in ultra high vacuum. Here, we adopt the first-principles density functional theory calculations to study the performance of monolayer (ML) h-borophene as an anode material for the LIB and NIB. The binding energies of the ML h-borophene-Li/Na systems are all negative, indicating a steady adsorption process. The diffusion barriers of the Li and Na ions in h-borophene are 0.53 and 0.17 eV, respectively, and the anode overall open-circuit voltages for the LIB and NIB are 0.747 and 0.355 V, respectively. The maximum theoretical storage capacity of h-borophene is 1860 mAh·g−1 for NIB and up to 5268 mAh·g−1 for LIB. The latter is more than 14 times higher than that of commercially used graphite (372 mAh·g−1) and is also the highest theoretical capacity among all the 2D materials for the LIB discovered to date. Our study suggests that h-borophene is a promising anode material for high capacity LIBs and NIBs.

BP neural network; PID control; MATLAB Abstract. Output efficiency decreasing phenomena also occur when environmental factors of flexible amorphous silicon photovoltaic power generation system (PV system) change. On the basis of building the system simulation model via MATLAB tool, researches are conducted on the issues of tracking time (0.04s), overshoot volume (11.7%) and steady-state error (0.5V) when performing maximum power point tracking with classic perturbation and observation method; the paper proposes BP neural network MPPT control algorithm combining PID control. The results of stimulation indicate that this method could complete the maximum power point tracking of flexible amorphous silicon photovoltaic cells in 0.01s, reduce the overshoot volume to 0.003%, decrease the steady-state error to 0.15V, eliminate the voltage oscillation, reduce the lag time, and improve the robustness of the system. Summary

The Ginsenoside Rh2 (Rh2) has been shown to possess anti-cancer properties both in vitro and in vivo. However, the poor bioavailability and fast plasma elimination limit the further clinical applications of Rh2 for cancer treatments. In the present study, three types of Rh2-loaded liposomes including Rh2-loaded normal liposome (Rh2-LP), Rh2-loaded cationic liposome (Rh2-CLP), and Rh2-loaded Methoxy poly(ethylene glycol)-poly(lactide) (mPEG-PLA) liposome (Rh2-PLP) have been optimized and prepared with mean particle size of 80–125 nm. Compared to Rh2-LP, surface modifications with mPEG or octadecylamine significantly improve the physicochemical and biological properties both in vitro and in vivo. Moreover, PLP presented better tumor accumulation of the fluorescent cyanine dye, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine iodide (DiR) in HepG2-xenografted nude mice than CLP (1.3-fold) or LP (1.6-fold) and prolong the resident time of DiR in tumor and organs (more than 24 h). The in vivo anti-cancer efficacy assessments indicate that Rh2-PLP presents the most activity on suppressing tumor growth in HepG2-xenografted mice than Rh2-LP and Rh2-CLP and without any significant toxicity. Our results indicate that mPEG-PLA modified liposome should be a potential and promising strategy to enhance the therapeutic index for anti-cancer agents.

Correction for ‘Gate-tunable interfacial properties of in-plane ML MX2 1T′–2H heterojunctions’ by Shiqi Liu et al., J. Mater. Chem. C, 2018, DOI: 10.1039/c8tc01106k.