Building integrated photovoltaic (BIPV) system attracts increasing attention of researchers due to environmentally friendly and saving land resource. Combining storage battery with BIPV can improve ...the flexibility of the entire system, which is promising for distributed renewable energy application. However, how to optimally dispatch the hourly energy flow of PV panel, storage battery and power grid based on a building load is crucial and less investigated. In the paper, a multi-restricted condition nonlinear optimization model is established for a BIPV-battery storage hybrid system under different building loads at a clear day. The optimization model was solved by fmincon function through MATLAB code. In the optimization, overall minimum daily cost including facility cost of the hybrid system, electric price and carbon price were considered as objective function to obtain optimal operation strategy of hourly power distributions of PV, battery and grid for daily building consumption. The key finding indicates that the system has high dependence on power gird when the office building load is heavy, while reduces the depending of power grid as the electrical demand is decreased. Under full-load resident building scenario, when the system with battery cost of 800 Yuan/kW·h or higher, the redundant green power generated by photovoltaic (PV) is sold to power grid in real time to earn extra profit, while the green power is accumulated in the storage batteries as storage battery cost is declined. Moreover, the resident building with BIPV-battery storage hybrid system has less dependence on power gird during day time, realizing self-sufficiency. Under all the scenarios, high storage battery cost limits the capacity of storage battery. And the CO2 emission is reduced as the BIPV-battery storage hybrid system is adopted.
•Operation optimization strategies of a BIPV-battery storage system were studied.•Lower battery cost and building load can enhance competitiveness of the system.•The system improves self-sufficiency of resident building during day time.•High storage battery cost limits the capacity of storage battery.•CO2 emission is reduced as the system is adopted under all the scenarios.
Background Augmented reality (AR) technology is gradually being applied in surgical teaching as an innovative teaching method. Developing innovative teaching methods to replicate clinical theory and ...practical teaching scenarios, simulate preoperative planning and training for bone tumor surgery, and offer enhanced training opportunities for young physicians to acquire and apply clinical knowledge is a crucial concern that impacts the advancement of the discipline and the educational standards for young orthopedic physicians. Objective This study explores the application effect of augmented reality technology in anatomy teaching and surgical clinical teaching for spinal tumor. Methods The method utilizes virtual reality and augmented reality technology to present a spinal tumor model and the surgical process of percutaneous vertebroplasty. We conducted a random selection of 12 students forming into the augmented reality teaching group and 13 students forming into the traditional teaching group among the 8-year medical students from Peking Union Medical College and Tsinghua University, ensuring that the age and learning stage of the students in both groups were similar. Two groups of students were taught using traditional teaching methods and augmented reality technology-assisted teaching methods, respectively. A questionnaire survey was conducted after class to assess the quality of course instruction, student motivation in learning, their proficiency in anatomical structures, their comprehension of spinal tumor growth and metastasis, and their understanding and proficiency in percutaneous vertebroplasty. Results This study was the first to apply augmented reality technology in teaching, using spinal tumors and percutaneous vertebroplasty as examples, a head-mounted augmented reality device was used to create learning scenarios, presenting the complex three-dimensional spatial structure intuitively. The two groups of students differ significantly in their rating of teaching quality, enthusiasm for learning, knowledge of anatomical features, understanding of spinal trabecular structure, and understanding of steps in percutaneous vertebroplasty. The augmented reality technology-assisted teaching system demonstrates outstanding advantages. Conclusion Augmented reality technology has great potential and broad prospects in teaching bone tumors, which can help improve the visualization, interactivity, and three-dimensional spatial sense of medical teaching in spinal tumor. The application and development prospects of using augmented reality technology for anatomy instruction, surgical teaching, and simulation training are extensive.
This paper presents a tri-layer membrane featured with double amido functionalized poly(ether ether ketone) outer layers and a poly(methyl methacrylate) interlayer and its application as a lithium ...ion battery separator. On one hand, the outer layers possess outstanding stability and endurance, which helps the tri-layer membrane to resist harsh conditions. On the other hand, the fusible interlayer can melt to block the pores of membrane once temperature is higher than 100 °C, which helps to prevent the lithium ion transmission between electrodes to terminate reactions in LIB. As a result, the tri-layer membrane exhibits remarkable features, including high maximum service temperature (350 °C), no area shrinkage at 150 °C, and wide shutdown temperature window (100–270 °C). The high stability and the shutdown property can avoid the thermal runaway of lithium ion battery, and greatly improve the safety. In addition, the wettability of the membrane is dramatically increased (contact angle= 0 °, vs. electrolyte) due to the strong interaction between polar polymer matrix and polar electrolyte, and the ionic conductivity of tri-layer membrane is 25.8% higher than the Celgard-2325 membrane at 30 °C (the 25 µm PP/PE/PP tri-layer membrane). The discharge capacity of LIB-NW-CA/P/CA is 3.7%, 7.6%, 9.7%, 12.2%, 13.5% and 54.3% higher than that of LIB-Celgard at 0.1 C, 0.2 C, 0.5 C, 1 C, 2 C and 5 C, respectively.
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•Tri-layer membrane with APEEK outer layers and PMMA interlayer was fabricated.•The tri-layer membrane shuts down the LIB once temperature is higher than 100 °C.•The tri-layer membrane shrinks by 0% and 13.37% at 150 °C and 240 °C, respectively.•The LIB with the tri-layer membrane shows better rate and cycling performances.
The tribological properties of additive manufactured titanium alloy reflect its machinability, and further affect the tool wear during machining. This paper investigated the tribological properties ...of selective laser melting (SLM) processed Ti6Al4V against cemented carbide under dry conditions, with emphasis on the effects of temperature and normal load on the friction process. Adhesive wear is the main wear mechanism between SLM Ti6Al4V and cemented carbide. However, abrasive wear and diffusion wear will also occur under specific conditions. An interesting phenomenon was found that the maximum wear depth reduced obviously at high temperature. The results showed that this was due to the formation of tungsten oxide with lubrication characteristics at high temperature, which reduced the wear.
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Fig. The effects of temperature on the friction process (F=50 N, L=1 mm, f=20 Hz). (a) wear depth of titanium alloy surfaces at different temperatures, (b) statistical distribution of friction stroke under different temperatures.
•Adhesive wear is the main wear form between SLM Ti6Al4V and cemented carbide.•Abrasive wear and diffusion wear will also occur under specific conditions.•Brittleness of Ti6Al4V caused by SLM will lead to the formation of microcracks.•The maximum wear depth decreases unexpectedly with the increase of temperature.
In this study, poly(ether ether ketone) is first chloromethylated to improve the solubility and is later used for nonwoven membrane fabrication by electrospinning. Finally, the chloromethyl group was ...converted to the ethyl ether group and dibenzyl ether group in a hot alkaline solution. The abundant polar groups endow the membrane with excellent wettability, reducing the contact angle to 0°. The polymer matrix is crosslinked by dibenzyl ether group, endowing the membrane with excellent stability (insolubility in many solvents, and ultra-low swelling in the electrolyte at 80 °C) and good anti-shrinkage property (0% at 180 °C). The electrospinning-fabricated membrane remains stable until 4.812 V (vs. Li+/Li), meeting the requirement for use in lithium ion batteries. The interwoven structure of the nonwoven membrane effectively gives rise to the high electrolyte uptake of 215.8%. The ionic conductivity of the electrolyte-swelled electrospinning-fabricated membrane is 51% higher than that of the electrolyte-swelled Celgard membrane. As a result, the lithium ion battery with this nonwoven membrane exhibits an enhanced rate performance (up to 42.5% higher than the lithium ion battery with a PP separator) and satisfactory cycling performance.
•Ether modified PEEK nonwoven membrane was exploited as LIB separator.•The membrane keeps stable in various of solvents, even in concentrated H2SO4.•The membrane is greatly wettable, reflected by the contact angle of 0°.•The membrane shows no shrinkage after being treated at 180 °C for 12 h in air.•The LIB equipped with the membrane shows elevated rate and cycling performance.
Single-ion conducting solid polymer electrolytes (SICSPEs) with high ionic conductivity are vital for next-generation electrochemical devices. Herein, we presented a novel method to manipulate the ...phase separation structure of SICSPEs, leading to the construction of long-range conducting ionic channels for rapid ion transport. Ionic nanowires were first fabricated by anchoring numerous lithium sulfonyl(trifluoromethanesulfonyl)imide groups on poly(ether ether ketone) backbones. Then, the ionic nanowires were dispersed in a well-designed hyperbranched polymer, poly(polyethylene glycol methyl ether methacrylate), to fabricate a blend membrane. Intertwined and continuous ionic channels were observed in the blend membrane by transmission electron microscopy. The blend membrane exhibited high conductivity of 0.17 × 10 −3 to 1.01 × 10 −3 S cm −1 and an outstanding lithium ion transference number of 0.898–0.936. A half-cell using LiFePO 4 and the blend membrane exhibited discharge capacities (0.2C) of 121.7 and 152.7 mA h g −1 at 25 and 60 °C, respectively. This study revealed a facile strategy to design high-performance ion-conducting membranes that are attractive for use in lithium ion batteries.
We prepared peapod-like titanium dioxide@graphene@carbon (TiO2@GO@C) nanofiber membranes through electrospinning. Due to the porous structure, large surface area, abundant surface functional groups ...and excellent thermal conductivity, GO can capsulize TiO2 nanoparticles to form a pea-like TiO2@GO structure. Subsequently, TiO2@GO can be wrapped by the carbon nanofiber during an electrospinning process, forming peapod-like TiO2@GO@C nanofiber membranes. The existence of a peapod-like structure is beneficial for enhancing the crystallinity of TiO2, and preventing the phase transformation of TiO2 from anatase to rutile phase at the same time. Furthermore, on the basis of the excellent carrier transport property of GO, the peapod-like TiO2@GO@C structure could also improve the light absorption, reduce recombination of hole–electron pairs, and improve the carrier transport and finally photocatalytic degradation property of methylene blue. Besides, the pea-like TiO2@GO structure shows a dispersion strengthening effect in the carbon nanofibers, preventing the carbon nanofibers from fracture. In particular, by optimizing the heat treatment temperature and additional amount of GO, the peapod-like TiO2@GO@C nanofiber membranes with 0.3 wt% GO show an excellent photocatalytic degradation efficiency of 98.5% in 3 h, and a high strength of 356.07 cN per dtex.
TG139/146.2+2; The influences of the addition of Ag on the glass forming ability(GFA)and corrosion behavior were investigated in the Mg-Ni-based alloy system by X-ray diffraction(XRD)and ...electrochemical polarization in 0.1mol/L NaOH solution. Results shows that the GFA of the Mg-Ni-based BMGs can be improved dramatically by the addition of an appropriate amount of Ag;and the addition element Ag can improve the corrosion resistance of Mg-Nibased bulk metallic glass. The large difference in atomic size and large negative mixing enthalpy in alloy system can contribute to the high GFA. The addition element Ag improves the forming speed and the stability of the passive film,which is helpful to decrease the passivation current density and to improve the corrosion resistance of Mg-Ni-based bulk metallic glass.
Metal–organic frameworks (MOFs) with aggregation-induced emission (AIE) activity show a high emission intensity, high sensitivity, and high resolution in biological imaging and identification ...technologies. However, their AIE activity is controlled by various Eu precursors’ components and synthesis process parameters, and traditional research methods are hard to deal with these complex multiple parameter systems. In this work, we utilize two machine learning technologies to optimize the synthesis process parameters of Eu-MOFs and analyze their synthesis mechanism. First, we choose gradient boosting decision tree (GBDT) regression as the best fitting model. Second, on the basis of the SHapley Additive exPlanation (SHAP) calculation method with the PL/UV intensity ratio regarded as the evaluation standard, we demonstrate that the Eu-precursor concentration (1.91 × 107) and synthesis time (1.73 × 107) dominate in the synthesis systems. Meanwhile, these two parameters show synergic and antagonistic effects on the PL/UV intensity ratio, respectively. Finally, we employ a greedy random walk method to work out that “142-0.83-4.1” should be the best optimization process parameters, and the corresponding sample shows a high photoluminescence quantum yield (PLQY) with a value of 7.65% in the solid state. More importantly, the screen-printed pattern exhibits bright red fluorescence under UV light.
Single-ion conducting solid polymer electrolytes (SICSPEs) with high ionic conductivity are vital for next-generation electrochemical devices. Herein, we presented a novel method to manipulate the ...phase separation structure of SICSPEs, leading to the construction of long-range conducting ionic channels for rapid ion transport. Ionic nanowires were first fabricated by anchoring numerous lithium sulfonyl(trifluoromethanesulfonyl)imide groups on poly(ether ether ketone) backbones. Then, the ionic nanowires were dispersed in a well-designed hyperbranched polymer, poly(polyethylene glycol methyl ether methacrylate), to fabricate a blend membrane. Intertwined and continuous ionic channels were observed in the blend membrane by transmission electron microscopy. The blend membrane exhibited high conductivity of 0.17 × 10
−3
to 1.01 × 10
−3
S cm
−1
and an outstanding lithium ion transference number of 0.898-0.936. A half-cell using LiFePO
4
and the blend membrane exhibited discharge capacities (0.2C) of 121.7 and 152.7 mA h g
−1
at 25 and 60 °C, respectively. This study revealed a facile strategy to design high-performance ion-conducting membranes that are attractive for use in lithium ion batteries.
An approach to construct ionic channels in SICSPEs by blending pre-assembled ionic nanowires and hyperbranched polymers for high lithium-ion conductivity.
