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The grid-forming inverter (GFM) is widely acknowledged for its capabilities of forming both grid frequency and voltage. This letter investigates an extension of GFM, which decouples the capabilities of forming grid frequency and voltage. Based on the GFM inverter with matching control, a virtual resistor in series with the dc-link capacitor is added, so that the inverter can stably and quickly respond to outer grid frequency variations [i.e., frequency-following (FFL)], and meanwhile enhance the voltage stiffness of power grids [i.e., voltage-forming (VFM)]. The dc-link voltage regulation is also integrated into the synchronization control, making this inverter fit for short-term constant power inputs, such as renewable energy resources. A full-order state-space model is established to assess the stability of the inverter. Control parameters are properly tuned. A 3 kW grid-tided inverter experiment platform is tested and a modified IEEE 68-bus power system is simulated to validate the decoupled FFL and VFM features of the inverter.

For indoor communication of next-generation wireless networks, the efficient and realistic analyzing tool is in an urgent demand. Artificial intelligence (AI) methods can be employed with simulated or real-world data to provide effective analysis of wireless channel characteristics in a computational way. However, those methods need to prepare a big valid data for model training. It limits the efficiency improvement of AI methods. Here, a dual-kernel AI framework is proposed to reduce the amount of reference data. In order to verify the validity of the proposed framework, a specific scenario is investigated in the framework. Results obtained show that the proposed framework reduces the demand for data preparation, achieved the purpose of improving the calculation efficiency. The proposed AI framework is useful for the numerical analysis of indoor wireless communication.

• Fe SAs and Fe NPs are subsequently anchored at g-C 3 N 4. • The electronic structure is regulated by the synergistic effect of Fe SAs and Fe NPs. • Fe SAs introduce a midgap state and Fe NPs enhance the oxidation ability of H+. • The gradient charge polarization improves the charge separation and transfer. The introduction of metal single atoms (SAs) and nanoparticles (NPs) are effective approaches to modify electronic configuration of semiconductors, whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification. Herein, a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride. The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization, directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge carriers. With the assistance of the gradient charge polarization, pollutants are readily oxidated by h +, which strengthens the continuous reduction of O 2 on Fe NPs for pollutant oxidation in water. This work reinforces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level, which exhibits great potential for the construction of an efficient and sustainable water purification system. [Display omitted] [ABSTRACT FROM AUTHOR]

An integrated anaerobic digestion system for the simultaneous removal of carbon and nitrogen from fish sludge was developed by coupling iron sludge supplementation with intermittent aeration. In terms of nitrogen removal, Fe(III) in iron sludge could trigger Feammox reactions and intermittent aeration could drive the Fe(II)/Fe(III) cycle to sustain continuous ammonia removal. Mass balance analysis suggested that nitrate was the main product of Feammox, which was subsequently removed through heterotrophic denitrification. In terms of carbon removal, the Fe(III)-induced dissimilatory iron reduction (DIR) process significantly promoted fish sludge hydrolysis and provided more simple organics for methanogens and denitrifiers, but aeration showed a negative impact on methanogenesis. To promote nitrogen removal and avoid serious methanogenesis inhibition, different aeration intensities were studied. Results showed that compared with the control without aeration or iron sludge addition, aeration for 5 min every 3 days (150 mL/min) contributed to a 29.0% lower NH4+-N concentration and a 12.1% lower total chemical oxygen demand level on day 28, and the decline in methane yield was acceptable (only 13.5% lower). Simultaneous methanogenesis, Feammox, and denitrification in a single reactor treating fish sludge were achieved, which provides a simple and low-cost strategy for the treatment of organic wastewater.

The incorporation of magnetic ingredients is critical for ceramic-based microwave absorbers with high efficiency. However, this task is becoming challenging due to the dispersion and oxidation issues. In this study, metal-organic framework (MOF) ZIF-67 was employed as the precursor of magnetic compounds and combined with a polymer solution to fabricate SiC textiles using the electrospinning technique. The microstructure analysis confirmed the successful introduction of MOF particles within the SiC nanofibers. Further examination of chemical compositions and magnetic properties revealed the encapsulation of magnetic compounds in hybrid SiC textiles. Since the applied fabrication approach ensures a superior dispersion and protection of metal compounds in a ceramic matrix, the microwave absorption of SiC fabric with both dielectric loss and magnetic loss exhibits a high reflection loss of −59.4 dB and a wide effective absorption band of 5.70 GHz. The current fabrication strategy for fabricating microwave absorbers with dual loss mechanisms advances the development of ceramic-based microwave absorption materials.

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Pumped storage plants (PSPs) incorporate variable-speed units (VSUs) in parallel with fixed-speed units (FSUs) to balance investment and enhance system response flexibility. However, the parallel operation of FSU and VSU may lead to unfavorable hydraulic disturbance, posing a threat to transient stability of the units. This study aims to reveal the mechanism behind hydraulic disturbance and seeks to mitigate its impact on operational stability. Firstly, a refined simulation model of a PSP employing distinct units sharing a diversion tunnel (DUAT) layout is developed based on real unit data. Taking the load rejection as an example, the superiority of VSU during transient processes is quantified. Subsequently, the underlying causes of hydraulic disturbance generation in transient processes under DUAT layout are investigated. The research reveals that different steady-state operating points result in pressure changes initiated by the FSU being transmitted to VSU through the pipeline, thereby deteriorating the stability of VSU during load rejection process. To alleviate the impact of hydraulic interference, a comprehensive assessment framework is constructed using fuzzy entropy weighting method. This framework effectively balances stability indicators during transient processes and identifies optimization schemes to alleviate hydraulic disturbances caused by parallel operations. Compared with the original scheme, the maximum pressure in volute and the vacuum in draft tube have been reduced by 59.76 m and 11.28 m, respectively. Additionally, there has been an observed 8 % reduction in the maximum oscillation of rotational speed.

The highly random and characteristics of wind power generation challenge the power quality of the wind–hydro complementary generation system (WHCGS). Herein, the transient characteristics of power quality under the complementary generating mode are studied. First, a nonlinear hydropower system (HPS) model is innovatively established considering the dynamic characteristics of hydrounits under part load operation, and then a wind power system model including wind speed model, wind turbine and its controller, generator and converter is established. Finally, the applicability of WHCGS model in power quality evaluation is established and verified by IEEE‐9 node model. Combined with active power, frequency, and voltage power quality indicators, the effects of wind–hydro capacity ratio and voltage sag on the system are quantified. The results show that the increase in wind power penetration will deteriorate the power quality of WHCGS. Moreover, when the wind power capacity reaches 60 MW, it will damage the voltage and frequency stability of HPS. Besides, the larger the voltage sag amplitude, the worse the power quality of WHCGS. The longer the voltage sag lasts, the higher the risk of WHCGS instability. This article provides a technical reference for the safe and stable operation of WHCGS. The increase in wind power penetration will deteriorate the power quality of the wind‐hydro complementary generation system. Besides, the larger the voltage sag amplitude and the longer the voltage sag lasts, the higher the risk of wind‐hydro complementary generation system instability.

Nitrogen (N) deposition, the source of N input into terrestrial ecosystems, is exhibiting an increasingly serious impact on the biogeochemical cycle and functional stability of ecosystems. Grasslands are an important component of terrestrial ecosystems and play a key role in maintaining terrestrial ecosystem balance. Therefore, it is critical to understand the effects of nitrogen addition on grassland ecosystems. We conducted gradient N addition experiments (0, 3, 6, and 9 g N m−2y−1) for three years in grassland communities with similar site conditions. We utilized four typical herbaceous plants, including the dominant species Bothriochloa ischemum(B. ischemum) and companion species Stipa bungeana(S. bungeana), Artemisia gmelinii(A. gmelinii), and Cleistogenes squarrosa(C. squarrosa), to explore how different plant-soil-microbe systems respond to N addition. Stoichiometric homeostasis analysis demonstrated that both plants and microbes were strictly homeostatic. However, the companion species were found to be more susceptible to P dominant species. Furthermore, aggravated overlap in stoichiometric niches between plant species were observed at the N6 and N9 levels. Vector analysis indicated that the vector angle was >45° regardless of plant species and N levels, suggesting that there was a strong P limitation in the rhizosphere microbial community. Variation partitioning analysis revealed that the Composite roots exhibited a greater effect (explaining 34.7% of the variation) on the rhizosphere microbes than on the Gramineae, indicating that there may be more intense nutrient competition in its rhizosphere. In general, the effects of N addition on species were different across functional groups, with asignificant positive effect on the Gramineae (B. ischemum, S. bungeana,and C. squarrosa) and a significant negative effect on the Compositae (A. gmelinii), which should be fully considered in the future ecological management and restoration.

Bismuth telluride (Bi2Te3) has attracted much attention in the field of thermoelectrics since it is one kind of commercial room-temperature thermoelectric material. Herein three kinds of Bi2Te3thermoelectric fibers with internal tensile stress are fabricated utilizing an optical fiber template method. The effects of internal stress on the microstructure and the electrical transportation of Bi2Te3thermoelectric fibers are investigated. The Bi2Te3cores in the fibers are highly crystalline and possess a tensile nanosheet structure with preferential orientation as evidenced by X-ray diffraction and Raman studies. Tensile stress can enhance electrical properties of the fibers. And a paper cup generator covered with 20 pieces of optimized fibers provides a μW-level output power. It is inferred that tensile stress tuning can be an effective tool for the material optimization of thermoelectric performance.

Pumped storage hydropower system (PSHS) has multi-timescale operating characteristics which are divided into hour scale short-term scheduling and second scale power regulation with the objectives of minimizing water consumption and optimizing power regulation characteristics, respectively. However, the operating characteristics of these two scales are often analyzed independently, preventing decision makers from obtaining a strategy with optimal multi-timescale operating characteristics. This paper proposes a novel optimization framework by coupling the second scale model with the hour scale model which balances the stability (power regulation characteristics) with the economy (water consumption). Firstly, the power regulation characteristics of the unit under different operating conditions are summarized in terms of the integrated time and absolute error (ITAE) and maximum deviation of the rotational speed (ntdmax) based on a refined PSHS model. And a novel short-term scheduling model is developed which couples the power regulation characteristics. Secondly, with the novel model, the Pareto solution sets are obtained based on the non-dominated sorting genetic algorithm-III (NSGA-III) with the objective of minimizing the water consumption and ITAE/ntdmax. Finally, by the technique for order preference by similarity to an ideal solution (TOPSIS), the Pareto solution sets are further evaluated to obtain an operating strategy with optimal power regulation characteristics and water consumption. Compared to the traditional solution aiming for the minimum water consumption, this strategy results in a significant improvement in the stability (65.03 % reduction in ITAE and 68.43 % reduction in ntdmax) at the expense of a smaller economic behavior (0.0295 % increase in water consumption). The strategy outstands existing operating rules and innovatively introduces power regulation characteristics to obtain a short-term scheduling strategy that balances stability with economy. It provides a theoretical basis for the multi-timescale operation of PSHS.

The intricate pollutant composition and pronounced water fluctuations of Chinese liquor brewing wastewater (CLBW) pose formidable challenges for effective treatment, thereby raising significant environmental concerns. This study for the first time delves into the exploration of algal–bacterial granular sludge (ABGS) development and its efficacy in the removal of organic matter and nitrogen and phosphorus over a 100–day investigation of real CLBW treatment. Mature ABGS emerged after approximately 40 days of treating wastewater with 20% real CLBW, exhibiting exceptional settling performance and significant removal of COD (86.2%), NH4+–N (98.0%), and TP (51.5%). As the real CLBW proportion increased to 40% or higher, a stable granular structure and excellent settleability persisted, primarily attributed to the consistent content of tightly bound extracellular polymeric substances, the sustained protein–to–polysaccharide ratio, and the proliferation of microalgae within the granules. Microbial community analysis revealed the dominance of microalgal species, including Sphaeropleales, Scenedesmaceae, and Chloromonas. Moreover, the observed decline in nitrification efficiency with increasing CLBW ratio was linked to reductions in Nitrosomonasand Nitrospirapopulations. Conversely, the recovered TN removal was primarily associated with the accumulation of denitrifiers, including Azoarcusand Thauera, especially when the real CLBW ratio reached 100%. The findings from this study are anticipated to offer a practical reference for optimizing and promoting the treatment of real CLBW.

Based on the drive theory of student learning, this study explores the relationship between teachers' autonomy support and the development of and change in students' entrepreneurial enthusiasm in innovation and entrepreneurship classes with consideration of the regulatory effect of student gender. We used a simple sampling method to recruit 2456 college students (46.9% female), who completed a questionnaire on the quality monitoring and evaluation systems of innovation and entrepreneurship education in their schools. The results showed that higher autonomy support from teachers significantly improved students' entrepreneurial enthusiasm. Conversely, their level of class-related boredom had a negative buffering effect on changes, and their evaluation of the innovation and entrepreneurship curriculum played a positive role in the relationship between teachers' autonomy support and students' entrepreneurial enthusiasm, as did sex. We found that the influence of teachers' autonomy support on students’ entrepreneurial enthusiasm was more significant when students were male than female. This study is expected to serve as a useful reference for innovation and entrepreneurship in higher education.

The pumped storage hydropower system (PSHS) is considered a high-quality peaking and frequency regulation energy source due to its operational flexibility and fast response. However, its frequent regulation leads to complex operating conditions with potential harm to the stability of the system. This paper focuses on analyzing and improving the adaptability of guide vane closing law under complex conditions. This is obtained by proposing a refined numerical model of PSHS considering non-linear factors and analyzing the effects of the guide vane closing law and initial operating conditions on the load rejection. The results revealed that a suitable two-stage guide vane closing law effectively reduces the risk of load rejection. In addition, when the initial load of two units is different, it is beneficial to improve the load rejection characteristics when the unit with the smaller load rejects the load first. Finally, three groups of parameters for the optimal guide vane closing law (the Pareto solution sets) are obtained by multi-objective sparrow search algorithm (MOSSA) under the rated, maximum water head, and maximum rotational speed conditions. The obtained Pareto solution and the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) are used for scoring the solutions and obtain an optimal suitable for complex operating conditions. The water head and rotational speed are reduced by an average of 7.76 % and 3.74 % for the different operating conditions compared to the model validation results, respectively. These results provide a theoretical basis for the selection of the optimal guide vane closing laws and improve the safety during load rejection under complex practical operating conditions.

Chlamydia psittacipneumonia is a rare disease with varying clinical presentations. Here, we aimed to investigate the clinical and chest computed tomography (CT) features of severe psittacosis pneumonia. Clinical data of 35 patients diagnosed with psittacosis pneumonia were retrospectively analyzed using metagenomic next-generation sequencing. The patients were classified into severe (n = 20) and non-severe (n = 15) groups. The median age of patients was 54 years, and 27 patients (77.1%) had a definite history of bird contact. Severe patients had more underlying comorbidities and were more prone to dyspnea and consciousness disorders than non-severe patients. The neutrophil count and D-dimer, lactate dehydrogenase, interleukin (IL)-2, IL-6, and IL-10 levels were higher, whereas the lymphocyte, CD3 + T cell, and CD4 + T cell counts, CD4+/CD8 + T cell ratio, and albumin level were substantially lower in severe patients than in non-severe patients. Chest CT findings of severe patients revealed large areas of pulmonary consolidation, and ground-glass opacities were observed in some patients, with a higher risk of involving multiple lobes of the lungs and pleural effusion. One patient died of multiple organ failure, whereas the condition of the other 34 patients improved, and they were discharged from the hospital. Patients with severe psittacosis pneumonia often have underlying comorbidities and are prone to developing dyspnea, consciousness disorder, and lesions in both lungs. Serum D-dimer, IL-2, IL-6, and IL-10 levels and lymphocyte, CD3 + T cell, and CD4 + T cell counts are associated with disease severity.

Silicon core optical fiber expanded silicon photonics to specialty fiber platform. Although great challenges still exist for the fiber fabrication, the presence of semiconductor material has already given optical fiber new features and enormous possibilities for fiber-based devices and sensors. In this Letter, an all fiber silicon cavity Fabry–Perot interferometer was made by splicing silicon core silica cladding fiber with conventional single-mode silica fiber. The cavity shows high temperature sensitivity around 82 pm/°C due to the larger thermo-optical coefficient of silicon material compared with that of silica material.

Ultralong ZnO piezoelectricfinewires PFWs with a perfect hexagonal structure have been prepared by an upstream growing chemical vapor deposition CVD method. Furthermore, isolatable and flexible piezoelectric strain sensors based on individual ZnO PFWs have been fabricated by a simple and reliable technique. The whole device was fully packaged by epoxy polymeric resin EPR. The I–Vcharacteristic of the isolatable sensor is highly sensitive to the strain applied on it, which was well interpreted in terms of variation in Schottky barrier height SBH caused by strain induced band structure change and piezoelectric effect. The sensor exhibited excellent stability and fine reversibility, and a remarkably high gauge factor up to 1010 had been achieved. It is expected that the isolatable and flexible piezoelectric strain sensor demonstrated here will have applications in detection of external mechanical forces, as well as electromechanical switch with a high ONOFF ratio.

•Dynamic stability of pumped storage generation system (PSGS) from condenser mode to generating mode is firstly studied.•Stability performance of PSGS and guide vane laws are deeply explored to diminish risks in system.•The relationship between efficiency and stability is studied under different laws of guide vane.

This study was to investigate the expression correlation between long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1), miR-200a-3p and programmed death-ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC), and their roles in NSCLC. Real-time polymerase chain reaction (PCR) was performed to detect the expressions of MALAT1, miR-200a-3p and PD-L1 in NSCLC tissues and cells for the correlation analysis. The starBase and Targetscan databases were used to predict the binding sites between MALAT1 and miR-200a-3p, and miR-200a-3p and PD-L1, respectively. The targeting relationship between MALAT1 and miR-200a-3p, and miR-200a-3p and PD-L1 were further verified by real-time PCR and dual luciferase reporter gene assay. Cell proliferation was monitored by CCK8 and colony formation assays. The apoptosis was detected using flow cytometry. Wound healing assay and transwell assay were conducted to determine cell migration and invasion. In this study, we demonstrated that in NSCLC tissues, the expression level of MALAT1 was negatively correlated with that of miR-200a-3p, while positively correlated with PD-L1. Besides, MALAT1 promoted proliferation, mobility, migration, and invasion of NSCLC cells via sponging miR-200a-3p. PD-L1 was validated as a target of miR-200a-3p, and indirectly modulated by MALAT1. In conclusion, LncRNA MALAT1 facilitates the progression of NSCLC by modulating miR-200a-3p/PDL1 axis.