Efficient Spin-Orbit Torque Generation in Semiconducting WTe2 with Hopping Transport.

Spin-orbit torques (SOTs) from transition metal dichalcogenide systems (TMDs) in conjunction with ferromagnetic materials are recently found to be attractive in spintronics for their versatile features. However, most of the previously studied crystalline TMDs are prepared by mechanical exfoliation, which limits their potentials for industrial applications. Here, we show that amorphous WTe2 heterostructures deposited by magnetron sputtering possess a sizable damping-like SOT efficiency of ξDLWTe2 ≈ 0.20 and low damping constant of α = 0.009 ± 0.001. Only an extremely low critical switching current density of Jc≈ 7.05 × 109 A/m2 is required to achieve SOT-driven magnetization switching. The SOT efficiency is further proved to depend on the W and Te relative compositions in the co-sputtered W100-xTex samples, from which a sign change of ξDLWTe2 is observed. In addition, the electronic transport in amorphous WTe2 is found to be semiconducting and is governed by a hopping mechanism. With the above advantages and rich tunability, amorphous and semiconducting WTe2 serves as a unique SOT source for future spintronics applications.

Cost Effective Mobile Mapping System for Color Point Cloud Reconstruction.

Survey-grade Lidar brands have commercialized Lidar-based mobile mapping systems (MMSs) for several years now. With this high-end equipment, the high-level accuracy quality of point clouds can be ensured, but unfortunately, their high cost has prevented practical implementation in autonomous driving from being affordable. As an attempt to solve this problem, we present a cost-effective MMS to generate an accurate 3D color point cloud for autonomous vehicles. Among the major processes for color point cloud reconstruction, we first synchronize the timestamps of each sensor. The calibration process between camera and Lidar is developed to obtain the translation and rotation matrices, based on which color attributes can be composed into the corresponding Lidar points. We also employ control points to adjust the point cloud for fine tuning the absolute position. To overcome the limitation of Global Navigation Satellite System/Inertial Measurement Unit (GNSS/IMU) positioning system, we utilize Normal Distribution Transform (NDT) localization to refine the trajectory to solve the multi-scan dispersion issue. Experimental results show that the color point cloud reconstructed by the proposed MMS has a position error in centimeter-level accuracy, meeting the requirement of high definition (HD) maps for autonomous driving usage.

Efficient Spin-Orbit Torque Switching with Nonepitaxial Chalcogenide Heterostructures.

The spin-orbit torques (SOTs) generated from topological insulators (TIs) have gained increasing attention in recent years. These TIs, which are typically formed by epitaxially grown chalcogenides, possess extremely high SOT efficiencies and have great potential to be employed in next-generation spintronics devices. However, epitaxy of these chalcogenides is required to ensure the existence of the topologically protected surface state (TSS), which limits the feasibility of using these materials in industry. In this work, we show that nonepitaxial BixTe1-x/ferromagnet heterostructures prepared by conventional magnetron sputtering possess giant SOT efficiencies even without TSS. Through harmonic voltage measurement and hysteresis loop shift measurement, we find that the damping-like SOT efficiencies originated from the bulk spin-orbit interactions of such nonepitaxial heterostructures can reach values greater than 100% at room temperature. We further demonstrate current-induced SOT switching in these BixTe1-x-based heterostructures with thermally stable ferromagnetic layers, which indicates that such nonepitaxial chalcogenide materials can be potential efficient SOT sources in future SOT magnetic memory devices.

Exploration into the simplex reinforcing-reducing manipulation of acupuncture / 中国针灸

Four controversial types of simplex reinforcing-reducing manipulation of acupuncture and their possible meanings were summarized to explore several key elements of reinforcing-reducing manipulation of acupuncture, in addition, the simplex reinforcing-reducing manipulation of acupuncture was classified by single factor. It is concluded that the definition of simplex reinforcing-reducing manipulation of acupuncture should try not to include other non-manipulative elements. According to single factor, it can be divided into: needle-oriented reinforcing-reducing manipulation, twisting reinforcing-reducing manipulation, lifting and interpolating reinforcing-reducing manipulation, fast and slow reinforcing-reducing manipulation, breathing reinforcing-reducing manipulation, opening and closing reinforcing-reducing manipulation. In addition, after considering the effect and principle of number reinforcing-reducing manipulation, it can be considered.

[Health Risk Evaluation of Organochlorine and Organophosphorous Pesticides in Groundwater in Beijing].

Pollution from organochlorine (OCP) and organophosphorus (OPP) pesticides in groundwater is a key issue for water resource protection. Sixteen kinds of OCP and six kinds of OPP pesticides were detected in 18 groundwater samples determined by GC-MS. Results showed that seven kinds of OPCs and two kinds of OPPs were found in the groundwater in Beijing. Among the OCPs, there were mainly hexachlorobenzene (HCB), hemochromatosis (HCH), and dichlorodiphenyltrichloroethane (DDT), with maximum values of, respectively, 82.4, 193, and 158 ng·L-1. Among the OPPs, there were o, o-dimethyl-o-2,2-dichlorovinylphosphate and o,o-dimethyl methylcarbamoylmethyl phosphorodithioate, with maximum values of 7.1 ng·L-1 and 17.7 ng·L-1, respectively. The OCPs and OPPs were found in the sewage irrigation areas. The results of a probabilistic risk assessment showed that the non-carcinogenic and carcinogenic risks of OCPs and OPPs within the drinking water in Beijing had been controlled, that risks from OCPs were higher, and that women were more sensitive to the toxicity of the pesticides. The monitoring of HCH and DDT in the groundwater should be implemented.

[Distribution Characteristics and Risk Analysis of Antibiotic in the Groundwater in Beijing].

Based on the GC-MS technique, we conducted a survey to investigate the concentration, distributions, and emission sources of sulfonamides (SAs), fluoroquinolones (FQs), tetracycline (TCs), ß-lactam, and macrolides in groundwater in Beijing. Results indicated that SAs, FQs, and TCs were the main types of antibiotic in groundwater, and the detection ratios of trimethoprim, ciprofloxacin, and norfloxacin were above 70%. Concentration of antibiotics in sites from sewage irrigation areas were significantly higher than those from the drinking source area or the south-to-north water recharge areas. The highest concentration of sulfadimidine (236 ng·L-1) and sulfadiazine (96.8 ng·L-1) in groundwater were both found in the sewage irrigation area. An ecological risk analysis showed a low risk for antibiotic in groundwater at drinking source sites, while groundwater at sewage irrigation sites fell into the high risk group. It is important to strengthen the ciprofloxacin monitoring and ensure underground water safety.