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The harmful effects of most synthetic corrosion inhibitors on the environment are the motivation for the study of environmentally friendly extracts. The main components of silkworm sand extract (SSE) were studied by infrared spectroscopy (FTIR) and ultraviolet visible spectroscopy (UV-vis). The scale inhibition effect of SSE as scale inhibitor in calcium chloride solution was studied by means of electrical conductivity, static scale inhibition and scanning electron microscopy (SEM). Electrochemical impedance (EIS) and potentiodynamic polarization curve (PDP) were used to study its corrosion inhibition performance in simulated cooling water. The results showed that chlorophyll was the main component of SSE. When the concentration of SSE was more than 30 mg/L, the scale inhibition efficiency of calcium carbonate and calcium sulfate was both more than 90%. SSE could inhibit the supersaturation of calcium carbonate, prolong the nucleation time, and change the crystal shape of calcium scale. SSE had a good corrosion inhibition effect on Q235 steel in salt solution, and its corrosion inhibition mechanism was that SSE formed a protective film on the surface of Q235 steel. SSE could play a dual role of scale inhibition and corrosion inhibition, which was a potential new, environmentally safe corrosion and scale inhibitor for cooling water system.

In order to adapt to the rapid development of green plant extract corrosion inhibitors, spinach extract (SPE) was selected as a corrosion inhibitor for Q235 steel in citric acid (CA) environment. SPE was extracted using a simple ethanol reflux method, and its main components, as well as their stability in CA, were confirmed through Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-Vis). The corrosion inhibition performance of SPE on Q235 steel in 0.5 mol/L CA solution was investigated using various methods including weight loss, dynamic potential polarization (PDP), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and contact angle measurements. Effects of temperature on the activation parameters (Ea, were studied by calculation. Results showed that chlorophyll was the main component of SPE, which exhibited good stability in a 0.5 mol/L CA solution. Furthermore, SPE significantly reduced the corrosion rate of Q235 steel in the 0.5 mol/L CA medium, acting as a mixed corrosion inhibitor for both cathodic and anodic reactions. With the increase of SPE concentration, both cathodic and anodic currents were reduced, active corrosion sites were blocked, the corrosion rate was decreased, and the corrosion inhibition efficiency was enhanced. The corrosion inhibition efficiency of Q235 steel obtained by weight loss method, PDP, LPR and EIS was more than 80% with 2.134 g/L of SPE concentration at 303 K. With the increase of system temperature, the corrosion inhibition efficiency of SPE on Q235 steel decreased, but the change was smaller. Compared to the blank system, the activation energy (Ea) of the system significantly increased after the addition of SPE. The effective components of SPE adsorped to the surface of Q235 steel in accordance with the Langmuir isotherm, predominantly through physical adsorption, and were characterized as monolayer adsorption. SPE exhibited good corrosion inhibition performance for Q235 steel in a 0.5 mol/L CA solution system, which was a green corrosion inhibitor with good application prospects in the pickling field. It could provide certain guidance for the development of plant extract-based corrosion inhibitors.

In this study, based on the effect of compounds on the activation of NF-κB and NO release, compound 51 was discovered as the best one with NO release inhibition IC50 value was 3.1 ± 1.1 μM and NF-κB activity inhibition IC50 value was 172.2 ± 11.4 nM. Compound 51 could inhibit the activation of NF-κB through suppressing phosphorylation and nuclear translocation of NF-κB, and suppress LPS-induced inflammatory response in RAW264.7 cells, such as the over-expression of TNF-α and IL-6, which were target genes of NF-κB. This compound also showed preferable anti-inflammatory activity in vivo, including alleviating significantly gastric distention and splenomegaly caused by LPS stimulation, reducing the level of oxidative stress induced by LPS, and inhibiting the expression of IL-6 and TNF-α in serum. Thus, it’s reasonable to consider that this compound is a promising small molecule with anti-inflammatory effect for inhibiting the NF-κB signalling pathway.

[Introduction] In order to ensure the safety of operation of offshore wind turbine, it is necessary to grasp the change of topography around the offshore wind turbine foundation. [Method] The multi-beam sounding system was used to monitor the terrain around the wind turbine for 6 times, and the high-precision and high-density underwater terrain point cloud data were obtained. Through the data processing and analysis of the point cloud data, the high-precision underwater terrain digital elevation model (DEM) was constructed. Through the superposition analysis of the DEM, the quantity of erosion in different periods was calculated. Finally, the change of terrain in different periods was displayed by 3D model, and the causes of erosion were analyzed. [Result] The most direct reason for the terrain change around the wind turbine is that when a strong typhoon passes through the sea area of the wind farm, the seabed and the local area of the wind turbine usually undergo a large overall change; The combined action of tidal current and waves is another important cause of local erosion and siltation of the seabed topography in this area. [Conclusion] The multi-beam sounding system is effective in monitoring the underwater topography, which can provide important data support for the safe operation and maintenance of offshore wind power. The practice of the project has a good reference significance for carrying out underwater topography monitoring of similar projects.

[Introduction] In order to obtain detailed seafloor topographical information, an application of multi-beam sounding system in offshore wind farm survey is proposed. [Method] Taking an offshore floating wind power equipment development project as an example, the principle and composition of the Reson SeaBat T50-P multi-beam sounding system were introduced in detail, through the implementation of the project, the results were analyzed and the accuracy was evaluated. [Result] Through the practical application of this project, it is verified that the multi-beam sounding system has better convenience, high efficiency and reliability in the offshore wind farm survey. [Conclusion] The practice of this project provides a good reference for other similar offshore wind farm surveys.

The engine suspension device based on magnetorheological fluid is designed,and the magnetic field simulation is performed by using Ansoft Maxwell. The vibration reduction principle of powertrain suspension system is presented and analyze its dynamics. The decoupling calculation model of magnetorheological suspension system is established, and the structural parameters of magnetorheological suspension system are optimized by fruit fly optimization algorithm.

The setting load of hydraulic support plays an important role in the roof-control.There are two methods to control the setting load of hydraulic support, one is open-loop control by manual control valve of three position four port, the other is pilot control by solenoid directional control valve of two position three port.However, these two methods can hardly make the setting load reach the expected value and remain stable.Even when the expected value is reached, pressure drop and fluctuation generally exist.Based on this, a mathematical model of electrohydraulic force control system is established, then the stability of the system is analyzed by using MATLAB.It is obtained that there are no open-loop zeros and poles in the right half S plane of the Pole-Zero diagram of the system, so the system is a minimum phase system;the number of cycles of counter-clockwise winding(-1, j0) from the Nyquist diagram is 0, and the system phase margin is 94.1° and the amplitude margin is 10.7 dB, so the system is stable;the step response is stable for 115 s, the impulse response is stable for 90 s.An adaptive PID control method based on BP Neural Network is proposed, and a three-layer neural network control model is established.Quadratic performance index is used to control error.The weight coefficients of the output and hidden layers are updated by using supervised Hebb learning rules and gradient descent algorithm.Then three control parameters of the PID controller are obtained by training.The simulation results show that:it takes about 8.85 s for the setting load to reach the expected value and maintain stability when the expected input is step signal, and 9.1 s when the expected input is the square wave signal.Compared with no BP neural network PID control, the response time is increased by about 13 times.

Phytic acid (PA) modified polyacrylonitrile (PAN) nanofiber membranes for heavy metal adsorption were fabricated using electrospinning for the first time, and its mechanical properties and heavy metal adsorption under various conditions were tested. The results demonstrated that PA modification improved the mechanical properties of PAN nanofiber membranes at low modification ratio due to increased intermolecular hydrogen bonds and cross-linking. The highest breaking strength and elongation at break were 70.1% and 31.5% over PAN without modification when the PA:PAN ratio was close to 1:5. The [Pb.sup.2+] absorption tests in the water solutions demonstrated that the optimal PA:PAN ratio was 1:1, the optimal temperature was 30[degrees]C, and the optimal pH was 7. With the optimal parameters, the adsorption capacity reached the maximum and equilibrium after 4 h. The adsorption capacities increased with higher initial [Pb.sup.2+] concentrations. The highest adsorption capacity in this study was approximately 240.1 mg [g.sup.-1] at the initial [Pb.sup.2+] concentration of 750.72 mg [L.sup.-1]. In addition, after de-adsorption process, the 1:1 PA modified membranes maintained 91.9% re-adsorption capacities compared to primary adsorption. Consequently, the PA-modified PAN nanofiber membranes showed promising potentials of metal ion adsorption in wastewater treatment. Highlights * Phytic acid modified polyacrylonitrile nanofiber membranes were fabricated. * Low ratio modification improved the mechanical properties. * The optimal modification ratio for [Pb.sup.2+] adsorption is 1:1. * The maximum [Pb.sup.2+] adsorption capacity was 240.1 mg [g.sup.-1] in this study. * The membranes maintained 91.9% capacities at re-adsorption tests. KEYWORDS adsorption, heavy metals, nanofiber membrane, phytic acid, polyacrylonitrile, 1 | INTRODUCTION Lead (Pb) is one of the major types of toxic heavy metals and is commonly found in the anthropogenic activities including battery production, motor production, and old [...]

The working principle of magneto-rheological fluids transmission device（MRFTD） is introduced,and the mechanical structure and heat radiation system are designed based on the magneto-rheological Bingham model.The magnetic circuit design and magnetic field simulation are carried out based on finite element analysis software Ansoft Maxwell,thus,the distributions cloud picture of magnetic field under different excitation currents are obtained.The research results that the references and basis for the optimal design of MRFTD are provided.

A series parallel 7- DOF humanoid mechanical arm is designed and the mathematical model of humanoid mechanical arm is established through integration of kinematics analysis for parallel structure and D-H modeling method. The forward kinematics simulation of humanoid mechanical arm is carried out with Robotics toolbox of MATLAB,and then the continuous and smooth planning curves of joints angel and the Cartesian space trajectory of wrist are obtained. The simulation results show that the design parameters of humanoid mechanical arm are reasonable and can provide the basis for the optimal design of humanoid mechanical arm.

The magnetorheological fluid transmission device power transmission mechanism is analyzed according to the Bingham model,and a disk- type magnetorheological fluid transmission device is designed. By using finite element analysis software Ansoft Maxwell,the magnetic circuit design and magnetic field simulation are carried out and the magnetic field distribution nephogram is obtained. A magnetic field tester is built,on which the magnetic field is tested. This transmission device is able to meet the working requirements,and the foundation for the next experiment is laid.

The hydrofluoric acid-resisting aluminum compounds (AlF3, AlPO4, AlN) supported with Ni catalyst were prepared by the wetness impregnation and tested for dehydrofluorination of hydrofluoroalkane to synthesize fluoroolefins. It is found that Ni/AlF3 catalyst has the best catalytic performance, CF3CFH2 conversion of 29.3% after the reaction at 430 °C for 30 h, CF2HCH3 conversion of 31.8% after the reaction at 250 °C for 30 h, respectively. Comparatively, dehydrofluorination temperature of CF3CFH2 is higher than CF2HCH3 over the aluminum compounds catalyst, and the activity of catalysts is related with Lewis acidity. For the aluminum compounds catalyst, addition of Ni had promoted the activity and stability of Lewis acidic catalysts, it is attributed to synergistic catalysis of Lewis acid sites and Ni.