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ObjectiveThe grid fault of voltage drop will cause severe variations to the load of wind turbines, and seriously affect the safe and stable operation of wind turbines. With the increasing of the wind turbine scale, the blade length and the tower height increase continually, leading to the increase of the sensitivity of load characteristics to the system parameter fluctuations. Therefore, it is necessary to study the load and vibration characteristics of key components in the process of grid voltage drop.MethodsA data interaction method based on dynamic link library and Socket communication was proposed, and a joint simulation method of Simulink and Bladed was established. Firstly, based on a 3.4 MW wind turbine model, the joint simulation platform was verified by a given wind speed variation condition. Then, the relationship between the overall performance of the unit and the load of the blade and tower during low voltage ride through (LVRT) was studied.ResultsThe amplitude of grid voltage drop has a great impact on the generator power, and has little impact on the wind turbine control parameters. In the process of LVRT, the blade pitch angle and rotational speed of the wind turbine fluctuate for a long time, the load change at the outer blade span is greater than that at the inner blade span, the blade tip displacement increases, and the vibration frequency of the tower is close to the natural frequency. These potential risks should be considered in wind turbine design.ConclusionThe joint simulation platform can effectively simulate the aerodynamic performance of the wind turbines and the transient characteristics of the component loads, and provide a reference for the optimal control of the unit.

Phenotypic plasticity manifested after acclimatization is a very important source of biological variability among fish species. We hypothesized that hypoxic acclimation, besides potentially generating a temporary hypoxic respiratory phenotype, would also manifest as a continued benefit after reacclimation to normoxia. Hence, we holistically characterized the respiratory phenotype of European sea bass (Dicentrarchus labrax (Linnaeus, 1758)) acclimated to normoxia with or without prior acclimation to hypoxia. Compared with the original normoxic phenotype, prior acclimation to hypoxia and return to normoxia produced a 27% higher absolute aerobic scope (AAS), a 24% higher citrate synthase activity in red muscle, and a 28% lower excess post exercise [O.sub.2] consumption. Additional testing of hypoxia-acclimated fish under normoxia explored the specific effects of hypoxic acclimation. The hypoxic phenotype, when compared with the original normoxic phenotype, had a lower standard metabolic rate, a better hypoxia performance, and a lower minimum P[O.sub.2] for supporting 50% AAS. Thus, respiratory plasticity allows sea bass to improve its maximum aerobic capacity after returning to normoxia from hypoxic acclimation, a potential benefit from exploiting a hypoxic habitat. Given this respiratory malleability, general predictions for marine fish exploiting a more hypoxic future should better consider respiratory plasticity and prolonged effects of hypoxic exposures. Key words: phenotypic plasticity, hypoxia, acclimation, aerobic capacity, glycolysis, marine fish, Introduction Animals respond to environmental change either by moving to a more favourable location, by changing their phenotype (acclimatization), or potentially by evolving over multiple generations (genetic adaptation). Yet, the [...]

BackgroundPencil beam scanning (PBS) proton systems with a rotating gantry makes proton intensity modulation technology widely used for better protection of organs at risk, but it also brings greater challenges to the quality control of proton system.PurposeThis study aims to verify the accuracy of an XRV-124 cone-shaped scintillation detector and to investigate its feasibility for use in PBS quality assurance (QA) procedures.MethodsFirstly, according to the measurement principle of XRV-124, a single setup was implemented to measure the spot size, beam–X-ray coincidence, gantry angle, star-shot test, and mechanical accuracy simultaneously. Then, the spot size and beam–X-ray coincidence were determined at the isocenter using the XRV-124 for 70~240 MeV at increments of 10 MeV and at 30° increments for all gantry angles. The coincidence of the X-ray system and proton beam was evaluated in the X and Y directions of the International Electrotechnical Commission coordinate system (IEC). Finally, the spot size and coincidence results were compared with those of the widely used Lynx detector, whereas the gantry angle results were compared with those of the proton treatment console (PTC).ResultsThe spot sizes obtained using the XRV-124 and Lynx are in good agreement within 0.10 mm for each energy, and the results show the same trend with a maximum deviation of 0.18 mm and 0.11 mm in the IEC-X and -Y directions, respectively. The gantry angles are less than 0.2° compared to those of the PTC. For the star-shot test, the average 3D and 2D distances from the isocenter are 0.4 mm and 0.2 mm, respectively, meets the quality control requirements. The QA items can be completed in 90 min.ConclusionsThis method of this study has been successfully applied to the QA of Varian ProBeam proton radiotherapy system in Hefei ion medical center, indicating that XRV-124 cone-shaped scintillation detector can be widely used in the same type of proton radiotherapy system to improve the QA efficiency and reduce the human error caused by frequent positioning.

Perovskite is an advanced optoelectronic semiconductor material that has garnered significant attention in recent years. However, its drawback lies in its environmental instability, limiting its practical applications. To tackle this issue, this research delved into the idea of creating a space-confined structure and used electrospinning to produce a film of perovskite nanocomposite fibers. By effectively encapsulating perovskite nanocrystals into a polymer matrix, the perovskite could be shielded from water and oxygen in the environment, thereby reducing the likelihood of perovskite decomposition and enhancing the stability of its structure and properties. This study examined the influence of material composition and the spinning process on the nanofiber structure to create good spatial confinement. This strategy resulted in a high photoluminescence quantum yield of over 80% and a long-term environmental stability of as long as 1000 h over 90% of the original PLQY. By harnessing the flexibility of the composite fibers, this study demonstrated the potential applications and performance of this nanocomposite film in flexible quantum fluorescence conversion for LED applications. [ABSTRACT FROM AUTHOR]

Polyimide (PI) refers to a type of high-performance polymer containing imide rings in the main chain, which has been widely used in fields of aerospace, microelectronic and photonic devices, gas separation technology, and so on. However, traditional aromatic PIs are, in general, the inefficient fluorescence or even no fluorescence, due to the strong inter- and intramolecular charge transfer (CT) interactions causing unavoidable fluorescence quenching, which greatly restricts their applications as light-emitting functional layers in the fabrication of organic light-emitting diode (OLED) devices. As such, the development of fluorescent PIs with high fluorescence quantum efficiency for their application fields in the OLED is an important research direction in the near future. In this review, we provide a comprehensive overview of fluorescent PIs as well as the methods to improve the fluorescence quantum efficiency of PIs. It is anticipated that this review will serve as a valuable reference and offer guidance for the design and development of fluorescent PIs with high fluorescence quantum efficiency, ultimately fostering further progress in OLED research. [ABSTRACT FROM AUTHOR]

Organic perovskites are promising semiconductor materials for advanced photoelectric applications. Their fluorescence typically shows a negative temperature coefficient due to bandgap change and structural instability. In this study, a novel perovskite‐based composite with positive sensitivity to temperature was designed and obtained based on its inverse temperature crystallization, demonstrating good flexibility and solution processability. The supercritical drying method was used to address the limitations of annealing drying in preparing high‐performance perovskite. Optimizing the precursor composition proved to be an effective approach for achieving high fluorescence and structural integrity in the perovskite material. This perovskite‐based composite exhibited a positive temperature sensitivity of 28.563% °C−1 for intensity change and excellent temperature cycling reversibility in the range of 25–40 °C in an ambient environment. This made it suitable for use as a smart window with rapid response. Furthermore, the perovskite composite was found to offer temperature‐sensing photoluminescence and flexible processability due to its components of perovskite‐based compounds and polyethylene oxide. The organic precursor solvent could be a promising candidate for use as ink to print or write on various substrates for optoelectronic devices responding to temperature. A composite based on perovskite was created to demonstrate long‐term positive temperature sensitivity. It could be a great option for use in smart windows that respond quickly to temperature changes. Furthermore, it had the potential to be used as ink for printing or writing on different substrates for optoelectronic devices with good flexibility and solution processability. [ABSTRACT FROM AUTHOR]

At present, the current situation of the phenomenon of sexual assault against minors in China presents the characteristics of large number and obvious characteristics of low age, acquaintances commit serious crimes, strong concealment, many times and long duration, and rising proportion of male victims. However, the current sex education in China belongs to chastity education, which cannot effectively play a preventive role. It is urgent to promote comprehensive sex education in terms of establishing advanced education concept and healthy sexual values, changing sex education mode, implementing age-specific education and strengthening supervision, so as to prevent sexual abuse of minors.

Laser-processing technology has been widely used in the ultra-precision machining of diamond materials. It has the advantages of high precision and high efficiency, especially in the field of super-hard materials and high-precision parts manufacturing. This paper explains the fundamental principles of diamond laser processing, introduces the interaction mechanisms between various types of lasers and diamond materials, focuses on analyzing the current development status of various modes of laser processing of diamond, briefly discusses the relevant applications in diamond cutting, micro-hole forming, and micro-groove machining, etc., and finally discusses the issues, challenges, and potential future advancements of laser technology in the field of diamond processing at this point. [ABSTRACT FROM AUTHOR]