To address the issues of reduced available capacity and shortened lifespan in lithium battery packs caused by inconsistent capacities of individual cells, this paper proposes a lithium battery management system based on hybrid passive-active balancing. The system employs passive balancing for “peak clipping” during the charging phase by dissipating excess energy from the highest-voltage battery cell through a load resistor. During the discharging or idle phase, active balancing is used for “valley filling” by charging the battery cell with the lowest voltage using the energy from the entire pack, thereby enhancing the overall performance. Compared with traditional flyback transformer-based solutions, the proposed design features a simpler circuit and can meet the real-time balancing requirements during charging and discharging processes. The experimental results show that the system significantly improves the voltage consistency of the battery cells and facilitates capacity recovery, thus providing reliable support for the efficient and stable operation of the battery pack.
To overcome the issue of requiring additional heat sources during the expansion stage of advanced adiabatic compressed air energy storage (AA-CAES) systems, a combined cooling and power system with compressed air energy storage and auxiliary heating via parabolic trough solar collectors is proposed. The turbine inlet temperature of the CAES system is increased using the solar trough energy, thereby increasing its storage capacity and reducing the consumption of high-temperature heat transfer oil. The heat transfer oil saved via the first coupled parabolic trough solar system is used to drive the [mmim]DMP/CH3OH compression-absorption refrigeration system. A dynamic mathematical model of the Combined Cooling with Solar Auxiliary (CCSA) system was established based on the conservation laws of mass and energy of each subsystem. The operating conditions of the CCSA system during the energy release phase under design conditions were simulated, and energy and exergy analyses were conducted. The impacts of months, latitude, high-pressure generator temperature, and auxiliary compressor pressure ratio of the refrigeration system on the thermodynamic performance of the CCSA system were investigated. The effective solar utilization efficiency of the CCSA system was compared with that of a conventional solar-driven ammonia power system. Moreover, its energy and exergy efficiencies were compared with those of the AA-CAES and Solar Auxiliary Reheating Compressed Air Energy Storage (SAR-CAES) systems. The results revealed that the effective solar utilization efficiency of the CCSA system was 8.44% to 13.87% higher than that of the solar-driven ammonia power system and its energy and exergy efficiencies were higher than those of the AA-CAES and SAR-CAES systems.
The Xiaoqing River serves as a multifunctional waterway in Shandong Province, supporting flood control, irrigation, and navigation activities. Accurate evaluation of its water ecological quality is crucial for informing ecological restoration and guiding the resumption of navigation. This study conducted field monitoring to assess correlations between water quality parameters and biodiversity indices, aiming to identify appropriate biological indicators at the species, population, and community levels for the Jinan section. A hierarchical evaluation framework was developed by integrating indicators across three levels: physicochemical characteristics, habitat quality, and ecological structure. This system was applied for the first time to assess the water ecological quality of the Jinan section. The results aligned with the observed spatial trend of water quality, characterized by a “high-low-high” pattern from upstream to downstream. The study provides a scientific foundation for ecological restoration and navigation planning in the Xiaoqing River basin and offers a methodological reference for evaluating urban river ecosystems in China.
Science and technology (S&T) powerhouse provinces and China as an S&T powerhouse together constitute a coordinated transmission system of “provincial-level practice-national strategy”, serving as an important support for advancing China’s science and technology modernization. This study employs the visualization tool CiteSpace (version 6.1.R6) to conduct a knowledge graph analysis of 795 relevant articles indexed in core journals within the China National Knowledge Infrastructure(CNKI) database from 2006 to 2025. Using keyword co-occurrence analysis, cluster analysis, and burst-term detection, the study systematically examines research hotspots and evolutionary trajectories in this field. The findings indicate that domestic studies mainly focus on four themes: strategic coordination, technological breakthroughs, innovation ecosystems, and digital-intelligent transformation. The research paradigm demonstrates a full-chain, integrated evolution: “national strategy-regional implementation-technology application-ecosystem optimization”. Future research should place greater emphasis on differentiated provincial pathways, interdisciplinary integration, and international comparative studies to further deepen the development of this field.
Soil microbial fuel cells (SMFCs) are low-cost devices capable of converting chemical energy of organic matter into electricity through anodic microorganisms while simultaneously degrading organic pollutants in the soil. Therefore, they have promising applications in soil remediation and sustainable agriculture. However, the existing SMFCs still face limitations in terms of power generation and pollutant degradation efficiency. Moreover, many gaps are observed in their application for soil remediation of organic pollutants. Therefore, this article systematically reviews the research progress of SMFCs for degrading various organic pollutants in the soil, aiming to provide references for enhancing the power generation and degradation efficiency of SMFCs and guiding future research directions. First, the article elucidates the principles of SMFCs in degrading soil organic pollutants, analyzes the application of top-, insertion-, and U-type SMFCs, and deeply discusses the impacts of electrode materials and soil media on the SMFCs performance as well as the criteria for their selection. Second, it analyzes the different microbial species roles in the anode and their distribution changes in SMFCs. Accordingly, this article summarizes various methods to improve the power generation and degradation efficiency of SMFCs, such as optimizing electrode structures, adding electron mediators, and regulating environmental conditions. Future directions for developing SMFCs should focus on enhancing their stability and scalability, exploring highly efficient electrode materials and microbial strains, and expanding their applicability across different soil types and pollutants.
To address the challenges of significant scale variations, numerous environmental interferences, high real-time requirements, and the difficulty in achieving a good balance between detection accuracy and computational cost faced by existing bicycle-type vehicle detection models, this study proposes YOLO-DBG, a lightweight and efficient bicycle-type vehicle detection model based on computer vision. First, a novel dual-branch pooling & depthwise separable convolution bottleneck module is designed, which synchronously extracts global contour and local detail features of bicycle-type vehicles through a differentiated feature aggregation strategy, thereby enhancing multiscale feature extraction capabilities and reducing model computational costs by integrating depthwise separable convolution. Second, a weighted bidirectional feature pyramid network architecture is introduced in the neck network, which enhances the fusion of key vehicle features through bidirectional cross-scale connections and a dynamic weighting mechanism, and effectively reduces model computational costs through node pruning. In addition, ghost convolution is used as a downsampling operator, which considerably compresses the model while maintaining the feature expression ability. These three modules work together to construct an effective lightweight network architecture. Experiments demonstrate that the proposed model achieves a 0.2% increase in mean average precision while reducing parameters, giga floating point operations, and model size by 55.8%, 37.0%, and 53.1%, respectively. The proposed method achieves ideal lightweighting without compromising detection accuracy, offering a novel solution for real-time detection of bicycle-type vehicles.
This study aimed to optimize the rice-fried processing technology of Ganoderma lucidum,determine the optimal processing parameters,and evaluate the impact of fried Ganoderma lucidum rice on its antioxidant activity.The processing temperature,processing time,and ratio of medicinal material to auxiliary material were used as the influencing factors,and the contents of Ganoderma lucidum polysaccharides,triterpenoids,and extracts,as well as the appearance score of the processed product were used as evaluation indexes.The optimal rice-fried processing parameters were determined using the analytic hierarchy process(AHP)-entropy weight method combined with Box-Behnken design and response surface method.The antioxidant activity before and after processing was compared using ABTS+,DPPH,and hydroxyl radical scavenging assays.The optimized process conditions were as follows:processing temperature of 158.91 ℃,frying time of 10.18 minutes,and a material-to-auxiliary ratio of 1∶0.20.The average comprehensive score obtained from process validation was 91.24 with a relative standard deviation of 0.81％.In vitro antioxidant activity assay results showed that the radical scavenging ability of Ganoderma lucidum significantly increased after processing(P＜0.01).The optimized rice-fried process is reliable,stable,and feasible.The rice-fried Ganoderma lucidum prepared using this process exhibited enhanced antioxidant activity,providing a reference for the processing technology and clinical application of Ganoderma lucidum.
With the increasing number of new energy vehicles globally, the density and spatial distribution of urban public charging infrastructure lag behind demand. Moreover, supply-demand imbalance has become an increasingly prominent issue, posing a key bottleneck in the development of green mobility. To address this challenge, this study considers Shunyi District, Beijing, as a case study to propose a comprehensive evaluation and location optimization method for public charging stations using multisource spatiotemporal data. By combining multisource spatiotemporal data such as vehicle trajectories and points of interest, we constructed a spatiotemporal distribution model of urban charging demand to accurately characterize the dynamic charging loads in different functional zones. Furthermore, through traffic accessibility analysis and charging behavior simulation, the effectiveness of the layout of the existing stations is quantitatively assessed and service blind spots are identified. The results reveal that the service capacity in some high-demand areas of Shunyi District is insufficient, with considerable coverage gaps. To overcome this issue, we used the K-means clustering algorithm to identify the cores of unmet demand and proposed a priority-based construction plan for new stations. This study provides a theoretical basis and a practical approach for mitigating regional supply-demand imbalances and enhancing the scientific layout and systemic adaptability of urban public charging facilities.
Land-use change, as a key driving force of the terrestrial ecosystem carbon cycle, plays a critical role in assessing carbon balance and promoting sustainable development. Based on the land-use change patterns in the source region of the Yellow River in the mountainous areas of the Qinghai-Xizang Plateau from 2000 to 2020, this study developed an integrated CA-Markov-InVEST-OPGD model to reveal the spatiotemporal evolution of land cover and carbon storage, analyze the driving mechanism of carbon-storage changes, and predict the characteristics of carbon storage changes in a natural change scenario in the source region of the Yellow River in 2030. The results showed that from 2000 to 2020, grasslands in the source region of the Yellow River declined, while unused land and water areas expanded, leading to an overall reduction in carbon storage, with high-value areas shifting toward the northwest. NDVI, elevation, and temperature were the main factors affecting carbon storage in the region, with NDVI interacting most significantly with temperature, precipitation, and population density. In the natural change scenario in 2030, the grassland area will continue to shrink while the water area will increase significantly. Carbon storage in the east and south will decline significantly, while carbon storage in some areas in the west and north will increase significantly. The overall spatial concentration of carbon storage will tend to decrease, with notable local increases and decreases. Therefore, it is essential to undertake grassland ecological protection and restoration efforts to enhance carbon sink capacity and promote regional carbon balance.
In recent years, extreme precipitation events have become increasingly frequent in Shandong Province. To improve the monitoring, forecasting, and early warning of these short-duration events, this study analyzes minute-level precipitation data from 99 national meteorological stations in Shandong Province, covering the period from 1991 to 2020. Using the climate tendency rate, wavelet analysis, and empirical orthogonal function decomposition, we examine the spatiotemporal distribution and variability of annual maximum precipitation across different short durations. The results indicate that both the average and maximum values of annual maximum precipitation for all short durations increase progressively from central and eastern Shandong outward, peaking in southern Shandong. In most parts of southern Shandong, these annual maxima show a decreasing trend over time, whereas most other areas exhibit an increasing trend. For 5 min durations, the spatial variability trends are generally consistent, with intensity centers located in northwestern Shandong. For the 30 min and 60 min durations, eastern and southern Shandong, as well as the eastern Shandong Peninsula, show trends opposite to those in other regions, with negative intensity centers in central-western, northwestern, and southwestern Shandong. For the 90 min, 120 min, and 180 min durations, the eastern central region and the eastern Shandong Peninsula display opposite trends, with positive intensity centers in southwestern Shandong. Each duration shows significant 2 to 3 year periodicities. An abrupt change was detected in 2004 for the 5 min duration, leading to a marked decrease thereafter, whereas no abrupt changes were observed for other durations. Overall, most annual maximum short-duration precipitation events in Shandong exhibit an increasing trend. These findings underscore the importance of enhancing monitoring efforts and revising storm intensity formulas, particularly in southern and northwestern Shandong.
Ginsenosides are important chemical components of Panax quinquefolius L.and are closely related to its pharmacological activities.In this study,ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS)was used for high-throughput analysis of ginsenosides in the roots,leaves,and seeds of Panax quinquefolius L.,leading to the identification of 72 ginsenosides across these parts.Both univariate and multivariate analyses revealed significant differences in the content and types of ginsenosides among the different plant parts.Based on statistical significance(p＜0.05)and biological significance(fold change＞4),23 differential saponins were identified in the roots vs.leaves comparison,26 in the roots vs.seeds comparison,and 27 in the leaves vs.seeds comparison.Content analysis revealed that the total amounts of Rg1,Re,and Rb1 in the leaves and roots were roughly equivalent and higher than in the seeds,while most other ginsenosides were more abundant in the leaves and roots than in the seeds.The pseudo-ginsenoside F11,which is unique to Panax quinquefolius L.,was most abundant in the leaves,whereas acetylated pseudo-ginsenoside F11 was most abundant in the roots.20(S)-Ginsenoside Rh1,acetylated ginsenoside Rg1,and quinquenoside Ⅳ were all significantly different among the three parts and could serve as markers for differentiation.This study reveals distinct ginsenoside profiles in the roots,leaves,and seeds of Panax quinquefolius L.,providing technical support for its efficient development and utilization.
Mass concrete structures are extensively used in large-scale infrastructure projects; however, temperature cracks after concrete pouring severely affect structural durability and pose safety risks. This study focuses on a 5 MW wind turbine foundation at the Changqing Oilfield, China, to investigate the temperature evolution and spatial distribution of mass concrete after pouring. Based on the dynamic balance between hydration heat release and heat dissipation, the temperature evolution of mass concrete can be divided into three phases: rapid heating, peak maintenance, and slow cooling. The internal temperature of the concrete exhibits a distinct spatial heterogeneity, with higher temperatures at the center and lower temperatures at the edges. The maximum central temperature reaches 74.3 ℃, whereas the edge regions are considerably affected by ambient temperature(5 ℃ to 23 ℃). Theoretical calculations show that the temperature difference between the interior and exterior of the mass concrete after 3 days of pouring is 30.15 ℃. However, when plastic films and burlap are used as insulators, the maximum temperature difference within 10 days after pouring is only 25.2 ℃, thus indicating an effective reduction in the risk of temperature cracks. These findings offer theoretical and practical guidance for temperature control of mass concrete in similar environments, and the proposed insulation measures after pouring are critical for enhancing the durability of large-scale infrastructure projects, such as wind power foundations.
This study investigates the spatiotemporal variation characteristics of negative air ion(NAI)concentration and the primary factors influencing it across different seasons using Jiyuan Nanshan Forest as the research site.Based on continuous observations conducted from June 2021 to May 2022 using RR-9411A monitoring equipment and data obtained from an automatic weather station,this study analyzes the diurnal and seasonal variations in NAI concentration and its correlation with environmental factors.Results show that the order of seasonal average NAI concentrations is autumn(889 ion·cm-3)＞summer(756 ion·cm-3)＞winter(601 ion·cm-3)＞spring(430 ion·cm-3).The diurnal variation patterns reveal that(ⅰ)in autumn,peak NAI concentration in appears at 11:00(1 030 ion·cm-3);(ⅱ)in summer,a"double-peak and double-valley"pattern is observed;(ⅲ)in winter,the peak lags behind noon;and(ⅳ)in spring,fluctuations are minimal.Correlation analysis reveals significant seasonal differences in the relationships between NAI concentration and environmental factors,namely,wind speed,temperature,relative humidity,and particulate matter(PM)—specifically,PM with a diameter of ≤ 10 um and PM with a diameter of ≤2.5 um.In spring,the NAI concentration is primarily influenced by wind speed and humidity.Moreover,in summer,it is positively correlated with temperature and wind speed,and in winter,it is significantly correlated with PM levels and relative humidity.Furthermore,vegetation photosynthesis intensity,meteorological conditions(e.g.,precipitation and inversion layer),and human activities are found to be the key drivers of the seasonal differentiation in NAI.This study provides a scientific basis for optimizing forest ecological management and improving air quality assessments.
Ammonia is an essential chemical feedstock; however, its conventional synthesis via the Haber-Bosch process is associated with high energy consumption and substantial carbon emissions. Developing green and efficient electrocatalytic routes for ammonia synthesis is therefore of significant importance. To overcome sluggish reaction kinetics and limited electron transfer, 26-faceted Cu2O polyhedra were synthesized using a template-free chemical precipitation method, followed by the deposition of Ag particles onto the Cu2O surface via photoreduction. This catalyst design optimizes the electronic structure, facilitates interfacial charge transfer, and enhances the intrinsic activity for converting key reaction intermediates (such as *NO2 and *NH2OH) into NH3. As a result, the hydrogen evolution reaction and by-product formation are suppressed, leading to improved electrocatalytic performance for nitrate reduction to ammonia. Electrochemical evaluations demonstrate that Ag-Cu2O exhibits excellent catalytic activity for the nitrate reduction reaction, achieving a Faradaic efficiency of up to 88%, which outperforms Au-Cu2O and pristine Cu2O, while generating lower amounts of the nitrite by-product and the competing hydrogen product. The catalyst maintains effective performance across a wide range of nitrate concentrations, supporting its potential applicability in nitrate wastewater treatment with varying pollutant levels. This study provides new insights into the rational design of high-performance and durable electrocatalysts for nitrate reduction and offers a valuable reference for advancing electrocatalytic technologies in wastewater treatment and green ammonia synthesis.
Lead-based halide perovskite nanocrystals have attracted extensive attention due to their outstanding optoelectronic properties. However, their small Stokes shifts often lead to severe self-absorption, which greatly limit their luminescence efficiency and practical applications. Moreover, the inherent biological toxicity of lead poses irreversible risks to human health and the environment. To address these issues, this study synthesized lead-free Cs3Cu2X5(X=Cl, Br, I) perovskite nanocrystals using a hot-injection method and systematically characterized their phase purity, compositions, and microstructures. Optical measurements, including fluorescence spectroscopy and temperature-dependent fluorescence lifetimes, revealed that the high photoluminescence quantum yield and large Stokes shifts of Cs3Cu2X5 nanocrystals originate from their self-trapped exciton emission mechanism. To enhance their applicability, we further coated the nanocrystals with a SiO2 shell, which significantly improved their dispersibility in aqueous media and their biocompatibility. Finally, using Escherichia coli as a model bacterium, the photo-induced antibacterial performance of the Cs3Cu2X5@SiO2 core-shell nanocrystals was evaluated through turbidity analysis and colony counting assays. This study revealed the physical origin of the outstanding luminescent properties of Cs3Cu2X5 nanocrystals and demonstrated their potential as efficient and safe optical materials in biomedical applications.
GeTe-based alloys have attracted considerable attention as promising mid-temperature thermoelectric materials owing to their excellent performance.In this study,a series of Ge0.8-xMn0.1Pb0.1BixTe alloys were synthesized by vacuum melting followed by hot-press sintering.The results demonstrate that Bi incorporation significantly enhances the Seebeck coefficient.With increasing Bi content,the crystal structure gradually evolves from a rhombohedral to a cubic phase.Simultaneously,Bi-induced lattice distortion intensifies phonon scattering,leading to a marked reduction in lattice thermal conductivity,while the electronic thermal conductivity also decreases as a result of reduced electrical conductivity.At 773 K,the total thermal conductivity of Ge0.78Mn0.1Pb0.1Bi0.02Te reaches a low value of 1.34 W/(m·K).Consequently,the alloys exhibit enhanced thermoelectric figure of merit(ZT)values in the low-to-mid temperature range while maintaining high ZTat elevated temperatures,yielding a high average thermoelectric figure of merit(ZT,avg)of 0.80.
To achieve efficient utilization of the full solar spectrum and enhance the photocatalytic performance of cobalt tungstate (CoWO4), one-dimensional CoWO4 nanomaterials doped with rare-earth (RE) elements (Ce3+, Eu3+, Yb3+, and La3+) were synthesized using electrospinning technology. The structural, morphological, photocatalytic, and photothermal sterilization properties of the synthesized nanomaterials were systematically investigated. X-ray diffraction analysis revealed that all samples retained the monazite monoclinic structure of wolframite, with RE doping inducing lattice distortion. Scanning electron microscopy and transmission electron microscopy results demonstrated that doping increased the surface roughness of the nanotubes and generated a porous structure, thereby providing more active sites for reactions. Photocatalytic performance tests showed that 7% Ce-CoWO4 achieved a degradation rate of 90.54% for ciprofloxacin under visible light within 140 min and 81.84% under near-infrared (NIR) light within 7 h. Electrochemical tests indicated that RE doping effectively reduced charge-transfer resistance and enhanced the photocurrent response. In terms of photothermal performance, 5% Yb-CoWO4 increased the temperature of the liquid system to 65℃ within 360 s under NIR irradiation, demonstrating excellent photothermal conversion capability. Antimicrobial experiments confirmed that the re-doped samples exhibited significant photothermal sterilization effects against Escherichia coli under NIR irradiation. This study provides new insights into the development of efficient, multifunctional photocatalytic materials with full-spectrum response capabilities.
Ferroelectric optoelectronic artificial synapses, as an emerging class of intelligent devices, are regarded as ideal candidates for constructing neuromorphic visual systems owing to their advantages, such as ultrafast read-write speed and ultra-low energy consumption. This Perspective systematically reviews recent research progress in ferroelectric optoelectronic artificial synaptic devices. First, the operating mechanisms of two types of devices—namely photoconductive and photovoltaic devices—and their simulation of basic synaptic functions are discussed. Subsequently, the applications of these devices in neuromorphic visual systems are reviewed, including the simulation of learning and memory functions in biological visual systems, image information preprocessing and recognition, the detection and processing of dynamic visual information, and applications in multimodal interaction systems. Finally, the main challenges in the development of this class of devices are summarized from the perspectives of material preparation, device fabrication processes, and system architecture, and future development prospects are also presented. This Perspective not only provides a structured knowledge framework for experts in the field but also offers valuable reference information and directional guidance for advancing the development of novel low-power intelligent visual hardware.
Potassium tantalate niobate (KTN)-based ferroelectric single crystals with a perovskite structure have been extensively studied over the past few decades due to their advantages such as high piezoelectric constants, high phase transition temperatures, and nontoxic chemical compositions. With a deeper understanding of crystal growth processes and post-growth treatments, researchers have improved crystal quality and continuously increased crystal sizes using the top-seeded solution growth method. Recent studies have reported a piezoelectric constant exceeding 505 pC/N and an electromechanical coupling factor of 0.75 for tetragonal KTN single crystals. A high unipolar strain of 0.32% was achieved under an electric field of 15 kV/cm. This paper systematically reviews the research progress of piezoelectric properties of KTN-based ferroelectric single crystals, encompassing their growth techniques and approaches for enhancing electromechanical properties, such as ion doping and domain structures. Key technical approaches such as domain engineering and those for reducing growth defects and enhancing electromechanical performance are discussed. In addition, the current research challenges are identified, and future development prospects are outlined.
To address the compatibility issue between microstructure stability and mechanical property matching during the welding of high-nitrogen austenitic stainless steel, autogenous TIG butt welding was employed. With welding speed and shielding gas conditions kept constant, the welding current was used as the primary variable to systematically investigate its effects on the microstructural zoning characteristics, Cr2N nitride precipitation behavior, and the evolution of mechanical properties of the welded joints. The results reveal that the welded joints exhibit typical microstructural zones, including the weld zone, coarse-grained heat-affected zone, and fine-grained heat-affected zone. Welding current significantly affects the grain characteristics and microstructural uniformity in each zone. XRD analysis indicates that Cr2N is detectable in the weld metal at currents from 160 to 200 A, whereas when the welding current is increased to 220 A and above, the diffraction peaks of Cr2N are significantly weakened and eventually disappear. Based on the analysis of welding thermal cycles, this suggests that higher welding currents kinetically suppress the precipitation process of Cr2N by reducing the effective residence time of the weld zone within the critical temperature range sensitive to Cr2N precipitation. Mechanical property tests show that the tensile strength and impact toughness of the welded joints exhibit a nonmonotonic trend with increasing welding current—initially decreasing, then increasing, and finally decreasing again. Optimal strength-toughness matching was achieved at 220 A. Overall, welding current plays a critical role in regulating Cr2N precipitation behavior and microstructural gradient characteristics, thereby substantially affecting the microstructure stability and mechanical properties of high-nitrogen austenitic stainless steel welded joints.
