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[Display omitted] • A coating with pH-dependent Cu2+ release was granted on the Ti. • The coating was composed of polydopamine and silk protein, exhibiting outstanding biocompatibility in vivo and in vitro. • While simulating a large gathering of bacteria (slightly acidic conditions), the coating could set free abundant Cu2+ to strongly kill bacteria and achieve self-defense. The implantation of medical devices is frequently accompanied by the invasion of bacteria, which may lead to implant failure. Therefore, an intelligent and responsive coating seems particularly essential in hindering implant-associated infections. Herein, a self-defensive antimicrobial coating, accompanied by silk fibroin as a valve, was successfully prepared on the titanium (Ti-Cu@SF) for pH-controlled release of Cu2+. The results showed that the layer could set free massive Cu2+ to strive against E. coli and S. aureus for self-defense when exposed to a slightly acidic condition. By contrary, a little Cu2+ was released in the physiological situation, which could avoid damage to the normal cells and showed excellent in vitro pH-dependent antibiosis. Besides, in vivo experiment confirmed that Ti-Cu@SF could work as an antibacterial material to kill S. aureus keenly and display negligible toxicity in vivo. Consequently, the design provided support for endowing the layer with outstanding biocompatibility and addressing the issue of bacterial infection during the implantation of Ti substrates. [ABSTRACT FROM AUTHOR]

To establish and consummate the electric power network, the construction and investment scale of power substation projects is expanding every year. As a capital-technology-intensive project, it has high requirements for power substation project management. Accurate cost forecasting can help to reduce the project cost, improve the investment efficiency, and optimize project management. However, affected by many factors, the construction cost of a power substation project usually presents strong nonlinearity and uncertainty, which make it difficult to accurately forecast the cost. This paper presents a new hybrid substation project cost forecasting method called PCA-PSO-SVM model, which is a support vector machine (SVM) model optimized by a particle swarm optimization (PSO) algorithm with principal component analysis (PCA). In this intelligent prediction model, the PCA method is introduced to reduce the data dimension. Furthermore, the PSO algorithm is used to optimize the model parameters. In the example, 65 sets of substation construction data are input into PCA-PSO-SVM model for construction cost prediction, and the prediction results are compared with other prediction methods to verify the forecasting accuracy. The results show that the MAPE and RMSE of the PCA-PSO-SVM model is 6.21% and 3.62, respectively. And, the prediction accuracy of this model is better than that of other models, which can provide a reliable basis for investment decision-making of substation projects. [ABSTRACT FROM AUTHOR]

To effectively treat the pollutant in sewage, a new-type three-dimensional aerogel based on graphene oxide and waste paper was fabricated via simple mixing and freeze-drying processes. Therein, waste paper was activated in advance, and polyvinyl alcohol served as physical crosslinking agent. The results showed that the obtained aerogel with porous three-dimensional network structure exhibited good thermal stability. When it acted as adsorbent for treating organic dye (methylene blue) and antibiotic (ciprofloxacin), the adsorption process was explored. In single system, the pseudo-first-order and pseudo-second-order kinetic models were used to discuss the detail about the aerogel adsorbing pollutant. Moreover, the Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and calculate the isotherm constants. Thermodynamic results stated that the adsorption of pollutant onto aerogel was feasible and spontaneous. In binary system, the adsorption capacity of methylene blue by aerogel increased, while the adsorption capacity of ciprofloxacin by aerogel declined. The pseudo-second-order kinetics was consistent with the adsorption of pollutant by aerogel in such binary system. This study would provide a new boulevard to develop environmental, low-cost and high-efficiency adsorbent for removing pollutant from wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] Titanium (Ti) was an excellent medical metal material, but the lack of good antibacterial activity confined its further practical application. To solve this dilemma, a coating containing graphene oxide (GO) and copper (Cu) was prepared on the surface of Ti sheet (Ti/APS/GO/Cu). First, physical sterilization could be carried out through the sharp-edged sheet structure of GO. Second, the oxygen-containing functional group on the surface of GO and the released Cu2+ would generate reactive oxygen species for chemical sterilization. The synergistic effect of GO and Cu substantially enhanced the in vitro and in vivo antibacterial property of Ti sheet, thereby reducing bacterial-related inflammation. Quantitatively, the antibacterial rate of Ti/APS/GO/Cu against E. coli or S. aureus reached over 99%. Besides, Ti/APS/GO/Cu showed excellent biocompatibility and no toxicity to cell. Such work developed multiple sterilization avenues to design non-antibiotic, safe and efficient antibacterial implant material for the biomedical domain. [ABSTRACT FROM AUTHOR]

The surge in the number of electric vehicle (EV) users has brought a large amount of EV charging demands in recent years, making China construct tens of thousands of charging piles. However, the blind construction of charging infrastructures in cities brings about problems such as waste of land and funds, as well as irregular fluctuations in power grids. Only knowing the spatial-temporal distribution of EV charging load demands can these problems be solved and charging infrastructures be scientifically arranged. Therefore, this paper mainly discusses the spatial-temporal distribution of EV charging load demands in different urban functional areas and temperatures. First, involving individual differences into the hypothesis of rational people and taking multiple random factors such as time, location, temperature and road conditions into account, this paper establishes a spatial-temporal distribution model of charging load demands and applies the Monte Carlo simulation to solve it. Then, a case study is conducted. The results show that charging load demands of different functional areas have obvious spatial-temporal distribution characteristics and vary from each other. The temperature changes significantly affect the ratio of fast and slow charging load demands. Finally, this paper suggests that the proportion of slow and fast charging piles can be set to 50:1 in residential areas, 85:1 in working areas, while 3:1 in other functional areas, and the proportion in shopping entertainment areas and social rest areas can be set from 4:1 to 5:1. These proportions are related to the rated power of the charging pile. The spatial-temporal distribution of EV charging load demands in different urban functional areas and temperatures. The temperature changes significantly affect the ratio of fast and slow charging load demands. Image 1023 [ABSTRACT FROM AUTHOR]