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The robotic arm is an automatic control device that imitates the function of a human arm and accurately recognizes specific points in the three-dimensional space according to received instructions. This article aims to study the wireless control system of six-degree-of-freedom manipulator under the Internet of Things. In this paper, the Arduino material platform is used as the main controller, combined with Arduino IDE to complete the six-degree-of-freedom manipulator and main load control program, and use APPinventor to develop Android applications, and realize the wireless control of the manipulator through Bluetooth mode. In addition, the robot arm Jacobi control algorithm is used to describe the differential mapping relationship between the robot arm motion and the camera image space, and the image is updated online through the calculation method to improve the accuracy of the robot arm light control server. Mark the control of each joint, and then collect these control signals and the position information of the six joints. In order to ensure the richness of the entry signs and the safety of the equipment, the control signal given here is a random signal, and the output signal is six connected position signals.A total of 400 input and output sample sets were used. The first 200 units were used for training and the last 200 were used for testing. The experimental results in this paper show that the performance of the six-degree-of-freedom manipulator based on the Internet of Things is 25% higher than that of the traditional machine, and the stability of the wireless control system is also improved by 18% compared with before.

Dissimilar joints between die-cast AZ31 and extruded Al6061-T6 were joined using friction stir welding technology at a constant transverse speed (50 mm/min) and rotation rate of 800 or 1000 rpm. The flow patterns, microstructure evolution and intermetallic compounds in dissimilar joints were studied by optical and scanning electron microscopy. The relationship between microstructure and tensile properties was analyzed. The microhardness distribution along the horizontal centerline in cross section was investigated. Local flow without obvious mixing existed between Mg and Al metals in the tool shoulder-affected zone. For the tool-pin-affected zone, two typical zones, namely, the “extrusion zone” and “flow zone” existed because of the different flow modes of the plastic metals. The phase analysis showed that intermetallic compounds, including Al12Mg17 and Al3Mg2 formed in banded structures. Phase analysis showed that a joint with welding parameters of 800 rpm and 50 mm/min (Joint-500) had good mechanical properties because of the more uniform microstructure distribution and fewer intermetallic compounds. Fracture analysis indicated some microvoids and lamellate intermetallic compounds in the fracture surface of the joint with welding parameters of 1000 rpm and 50 mm/min (Joint-1000), which deteriorated its tensile strength significantly.

BiVO4 powder was synthesized by a simple hydrothermal method. The nanobelts with well dispersed and uniform morphology were synthesized by controlling the temperature. The structure of BiVO4 powder was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The diameter of the nanobelts was about 50 nm. The structure and composition of the nanobelts were studied by X-ray diffraction (XRD), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). The absorption intensity of BiVO4 powder in UV-Vis region was compared by UV–vis diffuse reflectance spectroscopy. As a photocatalyst, BiVO4 nanobelts have good photocatalytic ability under visible light irradiation, which is very useful for the treatment of environmental wastewater. The synthesized nanobelts photocatalyst can be reused without destroying its structure. The reusability and chemical stability of photocatalysts are of great significance for practical application.

In order to improve microstructure distribution and mechanical properties of Mg alloy joint by annealing treatment, die-casting AZ31 Mg alloy was successfully welded at rotation speed of 1 400 rpm and travel speed of 200 mm/min. The welded joints were annealed at 150–300 °C for 15–120 min and then were subjected to transverse tensile. The microstructure of annealed joints was analyzed by optical microscopy and electron backscatter diffraction. The experimental results indicate that (0001) texture intensity in stir zone significantly reduces and sharp transition of grain size is relieved in the interface between stir zone and thermo-mechanically affected zone after annealed at 200 °C for 30 min. Meanwhile, the elongation is increased from 7.5% to 13.0% and strength is increased slightly. It is because that annealing treatment can inhibit twin transformation and retain its ability to coordinate deformation during tensile deformation, which contributes to the improvement of plasticity. In addition, annealing treatment can increase the width of interfacial transition zone and lead to gradual transition of grain size between the SZ and TMAZ, which balances dislocation diffusion rate in different zone.

Die-casting AZ31 Mg alloys were successfully friction stir welded at a constant welding speed and different rotation rates. More uniform and fine grains were obtained at the rotation rate of 1400 rpm due to more suitable temperature for dynamic recrystallization in this welding condition. In addition, the intensity of (0001) texture in stir zone increased with the increasing rotation rate. The results of mechanical property test indicated joint with rotation rate of 1400 rpm had better tensile property, which was associated with fine grains, uniform transition in the interface between thermo-mechanically affected zone and stir zone as well as more favorable Schmidt factor for basal slip and twinning. The corrosion resistance of joints increased with the increasing rotation rate, which is significantly related to the (0001) texture with basal plane parallel to the corroded surfaces.

The selective area growth (SAG) technique has been proved to be an effective method to achieve trench gate normally-off AlGaN/GaN MOSFET. In this paper, the two-dimensional electron gas (2DEG) transport properties of SAG AlGaN/GaN heterostructure are investigated for samples with different insertion layers. As the thickness of the GaN insertion layer increases, the mobility of 2DEG drops at first and then increases dramatically. This is explained by a shift of the location of the 2DEG from the GaN template into the GaN insertion layer. Interface contamination at the template/insertion layer interface is found to be the reason of the degradation of the transport properties. Through optimizing the thickness of the SAG GaN insertion layer, 2DEG mobility is similar to the value of as-grown AlGaN/GaN heterostructure. The proper thickness of SAG GaN insertion layer for device fabrication is 24 nm referring to the variation in 2DEG transport properties.

Al-doped ZnO (AZO) thin films with resistivity of 6.6 × 10−4 Ω cm were prepared by introducing H2 in DC magnetron sputtering atmosphere. The Hall Effect measurement demonstrates that a part of the hydrogen atoms act as shallow donors while others act as neutral scattering impurities. Only proper H2 partial pressure decreases the resistivity to the lowest value. The properties of SiNx free crystalline Si (c-Si) solar cells were improved when AZO thin films were applied. The films served as both anti-reflection (AR) coatings and front electrode assistance. Ensuring an outstanding AR effect and a low sheet resistance, the thickness of the films was optimized in order to reduce the optical absorption, and thus effectively increase the short circuit current density (Jsc). The influence of the films versus different Ag fingers and emitter sheet resistance was investigated. The results showed that the Jsc was improved apparently (at least by 0.7 mA/cm2), while the fill factor was enhanced obviously from 62 to 70 % and from 73 to 75 %, respectively, which depended on the initial series resistance.

The influence of different AlGaN Impurity Blocking Layer (IBL) thickness in the GaN/Si (111) structure with GaN/AlN SLs buffer on the material and electrical properties of GaN/Si (111) system was studied in detail. It is found that the insertion of AlGaN IBL can increase the (102) FWHM and decrease the (002) FWHM. Meanwhile, AlGaN IBL with an optimized thickness can further improve the surface roughness and strain-state of GaN-Si (111) system. By using Secondary Ion Mass Spectroscopy, it is found that AlGaN IBL have a strong effect in blocking the Si donor impurities originating from the Si substrate during the high temperature growth, which can decrease the leakage current while the breakdown voltage can be dramatically increased.

In this paper, the selective area growth (SAG) technique is used to regrow thin AlGaN/GaN heterostructure on access region for realizing trench gate normally-off AlGaN/GaN MOSFET. Heavy background doping is found in SAG AlGaN/GaN heterostructure, which is not expected for its degradation on device performance. The background doping originates from SiO2 residuals at SAG interface. Through reducing the deposition temperature of SiO2 mask, background doping can be efficiently suppressed. As a result, the 2 dimensional electron gas transport property of SAG AlGaN/GaN heterostructure improves greatly, which is as good as the as-grown AlGaN/GaN heterostructure. Moreover, the performance of normally-off SAG AlGaN/GaN MOSFET improves greatly by suppression the Si residual on GaN template.

The arc characteristics of submerged arc welding (SAW) with stainless steel wire were studied by using Analysator Hannover (AH). The tests were carried out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution (PDD) curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.

Cd x Zn1−x S and Ru3+ doped Ru(m)/Cd0.5Zn0.5S photocatalysts were prepared by a simple hydrothermal method, and characterized by X-ray diffraction, UV–Vis absorption spectroscopy and electrochemistry techniques. Their photoactivities were evaluated by hydrogen evolution from aqueous solution containing Na2S and Na2SO3 as a hole scavenger under visible light (λ ≥ 420 nm) irradiation. Ru3+ doping enhances the photocatalytic activity markedly. It was found that 0.10 mol% Ru3+ doped Cd0.5Zn0.5S photocatalyst showed the highest activity. The reason for the positive effects of Ru3+ was discussed.

Several products marketed as natural drugs for enhancement of anti-diabetic function have been analyzed and found to contain synthetic hypoglycemic drugs. In the work discussed in this paper, LC-MS analysis ten such drugs [gliquidone (GLQ), glipizide (GLZ), gliclazide (GLC), glibenclamide (GLB), glimepiride (GLM), rosiglitazone (RGL), repaglinide (RPG), metformin (DMBG), phenformin (DBI), and tolbutamide (TOL)] has been improved. Quantification was by use of multiple reaction monitoring mode. The intra-day and inter-day precision of the method ranged from 2.13 to 5.55% and from 3.78 to 8.14%, respectively. LOQ was 1, 1, 1.2, 2, 3, 3, 5, 5, 2, and 1 μg L−1 for GLQ, GLZ, GLC, GLB, GLM, RGL, RPG, DMBG, DBI, and TOL, respectively. The structures of the compounds were identified by collision-induced dissociation mass spectral analysis. The results showed that a variety of synthetic drugs had been illegally added to anti-diabetic herbal products. A surprising result was that some of the adulterants were added into the capsule shell instead of capsule contents. LC-MS–MS is a powerful tool, and the method has wide applicability.