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This study examines the combination of the interplay between managerial majors and creative thinking and entrepreneurial courses using a linked assessment approach. To calculate the weighting of coupled system assessment indicators, the entropy value approach is employed. By dimensionlessly processing indicators and creating indicator data matrices, the degree of coordination of the integrating process between administrative majors and instruction in entrepreneurship and innovation is discovered. By constructing the integration evaluation index system, the integration coordination degree interval and grade were divided. The results show that 70% of the students in their senior year are aware of innovation and entrepreneurship, but they still can’t invest in innovation and entrepreneurship in combination with their own majors. The speed at which students’ abilities advance when given practical instruction in the merger of specialty and innovation is greatest.

The major constituents of sand are silica and silicates. The facile and low-cost purification technology of silica from natural sand is of magnificent importance to the industrial applications of silicon-based materials. Herein, we report a green, low-cost, and universal method to purify silica from natural sand. Sand from deserts, rivers, and seas is selected as the representative of natural sand. The initial purity of silica is 52.1 wt% for desert sand, 39.3 wt% for river sand, and 35.8 wt% for sea sand. High-purity silica has been successfully separated and purified from natural sand via ball milling, reacting with 30 bar CO2 and hydrochloric acid. The purity of silica derived from natural sand reaches >96 wt%. In this work, the mechanism for the purification of silica from natural sand is discussed. This study provides a new method to separate high-purity silica from natural sand without the generation of toxic and harmful substances.

A conjugated polymer, P4TTD-DPP, based on tetra-fused isoindigo-alt-diketopyrrolopyrrole, has been synthesized as a photothermal therapeutic nanotransducer within the near-infrared-II (NIR-II) window. P4TTD-DPP exhibits a notable mass extinction coefficient of 62.8 L g−1 cm−1 at 1064 nm. Additionally, P4TTD-DPP nanoparticles demonstrate remarkable photothermal conversion efficiency of 91.5% at 1064 nm and exhibit excellent anticancer efficacy under photothermal conditions. [ABSTRACT FROM AUTHOR]

ObjectiveTo discuss the characteristics of psychological assistance hotline calls and operators' coping strategies of before and after the COVID-19 outbreak， in order to further improve the assistance ability of the psychological crisis hotline.MethodsA retrospective study was conducted on the demographics characteristics， call problems， coping strategies， and call time trends recorded by Changchun psychological assistance hotline information registration platform before the epidemic in Changchun City （January 20， 2019-April 20， 2019） and during the epidemic period （January 20， 2020-April 20， 2020）.ResultsThe differences between gender， age， marital status， location， and occupation type before and during the epidemic were statistically significant （χ2=11.205， 234.240， 152.083， 265.458， 353.385， P

The double-perovskite LaNixCo1-xO3(LNCO) nanomaterials were synthesized by using sol-gel combustion method, and Ag/LNCO electrical contact materials and their component samples were fabricated by powder metallurgy combined with hot extrusion technique. The effects of different Ni and Co contents on microstructure, phase composition, physical properties, mechanical properties and electrical life service capability of the Ag/LNCO contact materials were investigated, followed by a preliminary investigation on their arc erosion failure behavior in comparison with that of the commercially available SnO2 powder-reinforced Ag-based contact materials. The results show that the LaNixCo1-xO3 nanomaterials with a size of 20-30 nm can be synthesized by the sol-gel method. With a resistivity of 2.10 μΩ·cm and an electrical life service capability of 51287 cycles, Ag/LaNi0.5Co0.5 O3 prepared by powder metallurgy process displayed better electrical contact performance than Ag/SnO2 materials. Therefore, AgZLaNi0.5Co0.5O3 is another potential substitute for traditional Ag/CdO. [ABSTRACT FROM AUTHOR]

Ag/Bi2Sn2O7 materials have high electrical conductivity but mechanical properties similar to those of Ag/SnO2 owing to their poor Ag/Bi2Sn2O7 interfacial wettability. In this study, Ni-doped Ag/Bi2Sn2O7 was prepared by high-energy ball milling, powder metallurgy, and extrusion. The microstructures and physical, mechanical, and electrical properties of Ag/Bi2Sn2O7 (Ni-doped) materials with different Ni molar fractions were investigated by XRD, SEM, XPS, Hall-effect tests, metal resistivity measurements, tensile tests, and electrical life tests. The formation of a crystalline Ni-containing solid solution is also confirmed. With an increase in the Ni-doping molar fraction from 0 to 8.3%, the resistivity of the Ni-doped Bi2Sn2O7 powder increased, the Ag/Bi2Sn2O7 interfacial wetting angle decreased from 104.6°, to 83.1°, the hardness and density of the Ag/Bi2Sn2O7 (Ni-doped) material first increased and then decreased, while the resistivity exhibited an opposite tendency. The Ag/Bi2Sn2O7–5.2Ni (sheets) exhibited the lowest resistivity of 2.00 µΩ·cm, the highest hardness of 687 MPa, and the highest density of 9.99 g/cm3; its electrical life was 1.6 and 1.8 times that of Ag/Bi2Sn2O7 and Ag/SnO2, respectively. Thus, an appropriate amount of Ni-doping can improve the interfacial wettability, physical properties, and electrical properties of Ag/Bi2Sn2O7 electrical contact materials. [ABSTRACT FROM AUTHOR]

Electroless nickel composite coatings have the potential for high-temperature tribological applications, and a combination of high wear resistance and low friction factor is one of the desirable solutions but still a tricky problem. The addition of self-lubricating WS2 and hard Si3N4 nanoparticles to the Ni-P coatings is expected to obtain good high-temperature tribological performance. In this work, Ni-P-Si3N4-WS2 composite coatings with various contents of WS2 nanoparticles were prepared using electroless plating and subsequently annealed at 400 °C in an inert atmosphere. The tribological properties of the coatings were evaluated using a ball-on-disc wear instrument at operating temperatures from 25 to 600 °C. The microstructure, chemical composition, and surface morphology of the coatings were characterized by X-ray diffractometry (XRD), energy disperse spectroscopy (EDS), and scanning electron microscopy (SEM). Upon increasing the WS2 dosage in the bath, the WS2 content in the coating increased and the micro-hardness of the as-plated coating increased from 539 to 717 HV. After heat treatment, the coating underwent a crystallization process, and the hardness increased from 878 to 1094 HV. The main wear mechanism of the coating changed from adhesive wear in the as-plated state to abrasive wear in the annealed state. The annealed Ni-P-Si3N4-WS2 coating with a WS2 dosage of 2.5 g/L in the bath exhibited excellent mechanical properties, with a hardness of 10.9 GPa, a friction coefficient of ~0.51, and a wear rate of 8.4 × 10−15 m3N−1⋅m−1 at room temperature, and maintained optimal performance at high temperatures. At operating temperatures of 200, 400, and 600 °C, the form of wear was adhesive wear for coatings with a WS2 dosage <1.5 g/L and abrasive wear for coatings with a WS2 dosage ≥1.5 g/L. The synergism of WS2 and Si3N4 particles refined the grains of the Ni-P matrix in as-plated coatings and obviously reduced the friction coefficient of friction pairs in annealed coatings at all operating temperatures. [ABSTRACT FROM AUTHOR]

Advanced carbon materials have played an important function in the field of energy conversion and storage. The green and low-carbon synthesis of elemental carbon with controllable morphology and microstructure is the main problem for carbon materials. Herein, we develop a green and low-carbon method to synthesize porous carbon by reacting CO2 with LiAlH4 at low temperatures. The starting reaction temperatures are as low as 142, 121, and 104 °C for LiAlH4 reacting with 1, 30, and 60 bar CO2, respectively. For the elemental carbon, the porosity of elemental carbon gradually decreased, whereas its graphitization degree increased as the CO2 pressure increased from 1 bar to 60 bar. CO2 serves as one of the two reactants and the CO2 pressure can adjust the thermodynamic and kinetic properties of the formation reaction for synthesizing elemental carbon. The mechanism for CO2 pressure-dependent microstructure and morphology of carbon is discussed on the basis of the formation reaction of elemental carbon and gas blowing effect of H2 and CO2. The elemental carbon with different morphology and microstructure exhibits distinct electrochemical lithium storage performance including reversible capacity, rate capability, cycling stability, and Coulombic efficiency, owing to their different lithium storage mechanism. The elemental carbon synthesized at 30 bar CO2 delivers the highest reversible capacity of 506 mAh g−1 after 1000 cycles even at 1.0 A g−1. Advanced energy storage technology based on the green and low-carbon synthesis of carbon materials is a requisite for providing a stable and sustainable energy supply to meet the ever-growing demand for energy. [ABSTRACT FROM AUTHOR]