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In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article.

The microstructure is an essential part of materials, storing the genes of materials and having a decisive influence on materials' physical and chemical properties. The material genetic engineering program aims to establish the relationship between material composition/process, organization, and performance to realize the reverse design of materials, thereby accelerating the research and development of new materials. However, tissue analysis methods of materials science, such as metallographic analysis, XRD analysis, and EBSD analysis, cannot directly establish a complete quantitative relationship between tissue structure and performance. Therefore, this paper proposes a novel data-knowledge-driven organization representation and performance prediction method to obtain a quantitative structure-performance relationship. First, a knowledge graph based on EBSD is constructed to describe the material's mesoscopic microstructure. Then a graph representation learning network based on graph attention is constructed, and the EBSD organizational knowledge graph is input into the network to obtain graph-level feature embedding. Finally, the graph-level feature embedding is input to a graph feature mapping network to obtain the material's mechanical properties. The experimental results show that our method is superior to traditional machine learning and machine vision methods.

TianQin is a planned space-based gravitational wave (GW) observatory consisting of three Earth-orbiting satellites with an orbital radius of about $10^5 \, {\rm km}$. The satellites will form an equilateral triangle constellation the plane of which is nearly perpendicular to the ecliptic plane. TianQin aims to detect GWs between $10^{-4} \, {\rm Hz}$ and $1 \, {\rm Hz}$ that can be generated by a wide variety of important astrophysical and cosmological sources, including the inspiral of Galactic ultra-compact binaries, the inspiral of stellar-mass black hole binaries, extreme mass ratio inspirals, the merger of massive black hole binaries, and possibly the energetic processes in the very early universe and exotic sources such as cosmic strings. In order to start science operations around 2035, a roadmap called the 0123 plan is being used to bring the key technologies of TianQin to maturity, supported by the construction of a series of research facilities on the ground. Two major projects of the 0123 plan are being carried out. In this process, the team has created a new-generation $17 \, {\rm cm}$ single-body hollow corner-cube retro-reflector which was launched with the QueQiao satellite on 21 May 2018; a new laser-ranging station equipped with a $1.2 \, {\rm m}$ telescope has been constructed and the station has successfully ranged to all five retro-reflectors on the Moon; and the TianQin-1 experimental satellite was launched on 20 December 2019 - the first-round result shows that the satellite has exceeded all of its mission requirements.

Using Cu-coated iron filings as the anode and stainless steel plate as the cathode, membrane electrolytic Cu recovery was optimised by single-factor testing. Smooth cathode copper plate grading 99.95% Cu was obtained by 12 h electrowinning at a cathode current density of 350 A/m2 when the catholyte composition was 4.5 mol/l NH3.H2O, 1 mol/l (NH4)2SO4, 30 g/l Cu(II) and 0.4 mol/l ethylenediamine. Current efficiencies were calculated as 106% for the cathode and 126% for the anode, because some anode Cu dissolved in the electrtolyte as Cu(I). The grade of Fe filings after Cu removal was 99.3%., Using Cu-coated iron filings as the anode and stainless steel plate as the cathode, membrane electrolytic Cu recovery was optimised by single-factor testing. Smooth cathode copper plate grading 99.95% Cu was obtained by 12 h electrowinning at a cathode current density of 350 A/m2 when the catholyte composition was 4.5 mol/l NH3.H2O, 1 mol/l (NH4)2SO4, 30 g/l Cu(II) and 0.4 mol/l ethylenediamine. Current efficiencies were calculated as 106% for the cathode and 126% for the anode, because some anode Cu dissolved in the electrtolyte as Cu(I). The grade of Fe filings after Cu removal was 99.3%.

The oxidative leaching behaviour of a low grade copper sulphide concentrate in NH3-NH4Cl-H2O was investigated by using a single-factor experiment method. The results show that 98.89% copper can be leached under the conditions of liquid-solid ratio 4:1, NH3·H2O concentration 1.0 mol/l, ammonium chloride concentration 3.0 mol/l, 1.4 times stoichiometric oxidant dosage, particle size 94-124 micrometres, contact time 2 h and temperature 30 degrees C. In addition, the optimisation experiments of direct pulse copper electro-deposition from this cuprammonia leach solution were carried out. A flat, metallically lustrous cathode copper plate with cathode current efficiency 87.97% is obtained under the optimised conditions NH4Cl concentration 3 mol/l, NH3·H2O concentration 1.5 mol/l, Cu2+ concentration 20 g/l, gelatin concentration 0.05 g/l, thiourea concentration 0.06 g/l, pulse current density 600 A/m2 and duty cycle 90%. XRD analysis results of the resultant cathode copper show that the copper crystal in the ammonia system grows mainly along the (220) crystal plane, and there is no obvious reflection peak on the other crystal planes, which shows that the cathode copper is analogous to the single crystal structure. SEM analysis results show that the surface of the cathode copper is smooth and compact. The growth of copper on the cathode surface is in a one-dimensional direction perpendicular to the cathode surface., The oxidative leaching behaviour of a low grade copper sulphide concentrate in NH3-NH4Cl-H2O was investigated by using a single-factor experiment method. The results show that 98.89% copper can be leached under the conditions of liquid-solid ratio 4:1, NH3·H2O concentration 1.0 mol/l, ammonium chloride concentration 3.0 mol/l, 1.4 times stoichiometric oxidant dosage, particle size 94-124 micrometres, contact time 2 h and temperature 30 degrees C. In addition, the optimisation experiments of direct pulse copper electro-deposition from this cuprammonia leach solution were carried out. A flat, metallically lustrous cathode copper plate with cathode current efficiency 87.97% is obtained under the optimised conditions NH4Cl concentration 3 mol/l, NH3·H2O concentration 1.5 mol/l, Cu2+ concentration 20 g/l, gelatin concentration 0.05 g/l, thiourea concentration 0.06 g/l, pulse current density 600 A/m2 and duty cycle 90%. XRD analysis results of the resultant cathode copper show that the copper crystal in the ammonia system grows mainly along the (220) crystal plane, and there is no obvious reflection peak on the other crystal planes, which shows that the cathode copper is analogous to the single crystal structure. SEM analysis results show that the surface of the cathode copper is smooth and compact. The growth of copper on the cathode surface is in a one-dimensional direction perpendicular to the cathode surface.

Tin was electrodeposited from chloride solutions by using a membrane cell in ultrasonic field. Cyclic voltammetry(CV), linear sweep voltammetry(LSV), chronoamperometry (CHR) and chronopotentiometry were applied to investigate the electrochemical mechanism of tin electrodeposition under ultrasonic field. Cyclic voltammetry and linear sweep voltammetry diagrams analysis shows that the application of ultrasound can change the tin membrane electro-deposition reaction from diffusion control to electrochemical control, and the increasing of temperature, acidity and ultrasonic power is beneficial to tin electrodeposition. Chronoamperometry curves show that the initial process of tin electrodeposition follows the diffusion controlled three-dimensional nucleation and grain growth mechanism. The coupling ultrasonic field plays a role in refining the grain and accelerating the electro-deposition reaction in this process, and the high preferential orientation of tin (tin whisker) tends to be no preferred orientation. The tin deposition tends to form regular network structure, and the tin whisker can be restrained. The ultrasonic coupling is more favorable to obtain the more compact and more smooth cathode tin under the same condition. (Authors.), Tin was electrodeposited from chloride solutions by using a membrane cell in ultrasonic field. Cyclic voltammetry(CV), linear sweep voltammetry(LSV), chronoamperometry (CHR) and chronopotentiometry were applied to investigate the electrochemical mechanism of tin electrodeposition under ultrasonic field. Cyclic voltammetry and linear sweep voltammetry diagrams analysis shows that the application of ultrasound can change the tin membrane electro-deposition reaction from diffusion control to electrochemical control, and the increasing of temperature, acidity and ultrasonic power is beneficial to tin electrodeposition. Chronoamperometry curves show that the initial process of tin electrodeposition follows the diffusion controlled three-dimensional nucleation and grain growth mechanism. The coupling ultrasonic field plays a role in refining the grain and accelerating the electro-deposition reaction in this process, and the high preferential orientation of tin (tin whisker) tends to be no preferred orientation. The tin deposition tends to form regular network structure, and the tin whisker can be restrained. The ultrasonic coupling is more favorable to obtain the more compact and more smooth cathode tin under the same condition. (Authors.)

A process was investigated for the recovery of Sn from Sn-Cu slag by leaching and membrane electrodeposition. Under the optimum leaching conditions of a solid/liquid ratio of 5:1, HCl concentration of 4 mol/l and temperature in the range 50-60 degrees C, 98% of the Sn was leached. Cu2+ and Pb2+ in the leach solution were reduced to less than 50 mg/l using 1.3 times the stoichiometric dosage of Na2S and three times the stoichiometric dosage of BaCO3 at 30 degrees C for 15 minutes. The purified solution was subjected to membrane electrodeposition in a catholyte containing 80 g/l Sn2+ and 3 mol/l HCl at a current density of 200 A/m2 and temperature of 40 degrees C. A compact and smooth Sn product was obtained at the cathode. The current efficiency was more than 98%, the power consumption less than 1 200 kW.h/t and the purity of the Sn obtained was more than 99%. The SnCl4 solution in the anode compartment was re-used as the leaching agent to provide a closed-circuit process., A process was investigated for the recovery of Sn from Sn-Cu slag by leaching and membrane electrodeposition. Under the optimum leaching conditions of a solid/liquid ratio of 5:1, HCl concentration of 4 mol/l and temperature in the range 50-60 degrees C, 98% of the Sn was leached. Cu2+ and Pb2+ in the leach solution were reduced to less than 50 mg/l using 1.3 times the stoichiometric dosage of Na2S and three times the stoichiometric dosage of BaCO3 at 30 degrees C for 15 minutes. The purified solution was subjected to membrane electrodeposition in a catholyte containing 80 g/l Sn2+ and 3 mol/l HCl at a current density of 200 A/m2 and temperature of 40 degrees C. A compact and smooth Sn product was obtained at the cathode. The current efficiency was more than 98%, the power consumption less than 1 200 kW.h/t and the purity of the Sn obtained was more than 99%. The SnCl4 solution in the anode compartment was re-used as the leaching agent to provide a closed-circuit process.