Landslides
·
2019
·Vol. 16
·期 7
·1313-1324
·
IF 4.252
Yang Wentao,Wang Yunqi,Sun Shao,Wang Yujie,Ma Chao
Detecting slope movement before landslides occur in mountain regions is crucial for disaster reduction. In October 2018, a gigantic landslide occurred on the Jinsha River, causing dammed-lake breach flood 500 km downstream. In this work, we used 25 Sentinel-2 images from November 2015 to August 2018 to explore the capability of this high temporal resolution optical images in detecting slope movement before the Jinsha River landslide. Normalized difference vegetation index (NDVI) was calculated to composite temporal profiles using all Sentinel-2 images. With this NDVI time series, unsupervised K-means classifier was applied to initially classify the study area and find the best thresholds for automatically extracting landslide scars in the image series. These extracted landslide scars were validated using interpreted results from two high spatial resolution images of similar dates in 2015 (user’s accuracy 89.7%, producer’s accuracy 83.6%) and 2018 (user’s accuracy 90.8%, producer’s accuracy 74.9%). After validation, extracted landslide scars of different years were counted and displayed in an RGB composite image to highlight slope movement. In addition, monotonous decrease/increase of NDVI was also observed, indicating continuous expansion of landslide scarps and movement of landslide head along the slope on the landslide surface. This work demonstrated the capability of Sentinel-2 time series images to capture slope movement with short revisit time at low cost. By incorporating other environmental information (such as elevation), this proposed method has the potential to consistently map pre-landslide slope movements over a large region.
研究领域:
遥感地质学
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环境灾害监测
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地理信息系统
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山地灾害防治
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地球观测
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NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 7
·3409-3416
·
IF 3.925
Hao Liu,Yaowei Wang,Fengqi Zhang,Congcong Xu,Xiaoyuan Liao,Yan Jiang,Shuxiang Lu
A series of K-based oxide catalysts supported on aluminium oxide (γ-Al2O3) with different surface areas were synthesized using an impregnation method and investigated by the decomposition of sulfones from oxidized diesel fuels. The synthesized catalysts were characterized by N2 adsorption–desorption isotherms, CO2-TPD and HR-SEM methods to explore the relationship between the structure of the catalysts and sulfone conversion. The results showed that the K element was highly dispersed on the surface of γ-Al2O3. The prepared catalyst was further applied in the decomposition reaction of dibenzothiophene sulfone (DBTS) to evaluate the catalytic performance. The sulfone conversion could achieve 63.9% in 10% K2O/3-Al2O3 within 20-minute reaction time at 260 °C. Moreover, our experimental test showed that the sulfone conversion was linearly correlated with the logarithm of the total basic sites of the K2O/γ-Al2O3 catalyst.
研究领域:
化学工程
·
催化科学
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JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·Vol. 109
·期 1
·e70351
·
IF 3.8
Lulu Jiang,Wenqi Lei,Zhiming Zhao,Kejia Chen,Chuangchang Lei,Donglin Han
Ba 3 MoNbO 8.5 is a recently emerging hexagonal perovskite-derivative oxide with high oxide ion conductivity. Mo and Nb-sites were commonly doped with acceptor dopants to regulate the transport properties. In this work, Ba-site was introduced with cation deficiency and doped with K. The tolerance of Ba-deficiency ( x ) in Ba 3‒ x MoNbO 8.5‒ x is within 0.03–0.06, and the solubility of K ( x ) in Ba 3‒ x K x MoNbO 8.5‒ x /2 is higher than 0.3. Although forming Ba-deficiency of x = 0.03 does not influence the conductivity significantly, doping K to x = 0.15 and 0.3 decreases the bulk conductivity obviously. Furthermore, even though these samples can be hydrated, H 2 O/D 2 O isotope effect was not observed, indicating that there is no or negligibly small proton conduction, and hydration even decreases the bulk conductivity. Interestingly, doping K reduces the difference in conductivity between the measurements in the dry and wet atmospheres. By annealing in a wet atmosphere for 90 h, the Ba 2.7 K 0.3 MoNbO 8.35 composition is unstable at 400°C, but shows good chemical stability at 600°C.
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Educational Research and Evaluation
·
2026
·
IF 1.3
Tzu-Hua Wang,Ence Surahman
Studies on assessment for STEM learning practices have reported several forms of meaningful assessment, however, few systematic reviews have evaluated assessment trends in K–12 context. Hence, in this study, assessment practices in K-12 STEM education were systematically reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A total of 56 empirical research articles published between 2013 and 2025 on the Web of Science were carefully selected. Notable trends were observed in the research context, educational grade levels, course subjects, assessment methods and objectives, research methods, sample size, findings, and future research directions reported in the included studies. Reported assessment methods included surveys, questionnaires, examinations, and peer-based, authentic, and game-based assessments. Overall, the findings offer insights for K-12 STEM educators regarding the development of appropriate assessment methods tailored to the unique requirements of each STEM field.
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ACS Applied Electronic Materials
·
2026
·
IF 4.7
Yi Han,Yichao Wang,Dong Liu,Xiang Hui,Xiaoshuang Ma,Pengju Sun,Jianqiang Li,Zhipeng Xing,Zhenfu Zhang,Li-Feng Zhu
(K,Na)NbO3-based ceramics are promising lead-free piezoelectrics due to their excellent piezoelectric coefficient (d33) and high Curie temperature (Tc), but their poor mechanical properties limit high-reliability applications. To address this issue, 0.97K0.5Na0.5Nb0.95Sb0.05O3-0.03Bi0.5Na0.5ZrO3-0.5%wtBiFeO3-xZrO2(KNNS-xZrO2) textured ceramics were developed. Excessive ZrO2 improved mechanical performance, while <001>-oriented samples exhibited strong piezoelectricity. At x = 0.01, the ceramics achieved high values in the KNN system: d33 ∼ 326 pC·N−1, Hv ∼ 8.46 ± 0.14 GPa, E ∼ 172 ± 4 GPa, and fracture toughness KIC ∼ 1.70 ± 0.09 MPa·m1/2. Based on these outstanding properties, a KNNS-0.01ZrO2 piezoelectric wristband was fabricated to monitor human heart rate, producing stable current signals under different motion states. This work provides insights for reliable piezoelectric sensors and actuators.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2025
·
IF 2.6
Hou Peng-qing,Qu Yingdong,Huang Rui,Tian Xinru,Li Guanglong,Luo Shaohua
Li 2 FeTiO 4 cathode has emerged as a promising option for lithium-ion batteries because of its outstanding capacity and eco-friendly properties. However the abominable conductivity and ion transports hindered its electrochemical performance. In this work, (Li 1-x K x ) 2 FeTiO 4 (LiFT-Kx, x = 0 and 0.01) cathode materials with were successfully synthesized. Remarkably, there was a notable improvement in the properties of interlayer spacing, ionic conductivity and kinetics. As a result, LiFT-K0.01 cathode expressed splendid initial capacitance (108.8 mAh g −1 , 0.05 C), stability (82.9% over 30 cycles), and rate performance (89.8 mAh g −1 , 82.4% of the original values). This work might provide valuable insights for the exploration of lithium storage with excellent long-term stability, and it might open new possibilities for the development of advanced energy storage technologies based on lithium-ion batteries.
研究领域:
材料科学
·
能源存储技术
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Tingting Lv,Jiadong Wu,Linyu Yang,Kunjie Zhu,Kaixing Zhu,Haibing Li,Hongyu Mi
Aqueous zinc-ion batteries (AZIBs) present a highly attractive option with substantial potential for energy storage applications. However, issues such as the structural instability and slow zinc-ion diffusion of the cathode have hindered Zn//vanadium battery development. In this study, K + was chosen as a superior pre-insertion ion to form a novel layered potassium vanadate hydrate (K 1.44 V 8 O 20 ·1.8 H 2 O) cathode. Take advantage of the low electronegativity of K + , the M-O (Metal-Oxygen) bond in vanadium oxide cathode was dramatically enhanced. This leads to a significant enhancement in structural stability and a concurrent suppression of vanadium dissolution in the vanadium oxide cathode. Density functional theory (DFT) calculations were used to elucidate its superior Zn ion diffusion kinetics. The K 1.44 V 8 O 20 ·1.8 H 2 O exhibits outstanding cycling stability (specific capacity of 167.3 mAh g −1 after 9990 cycles at 6 A g −1 ) and excellent rate performance (78.64 % capacity retention after 10,000 cycles at 10 A g −1 ). This study proposes a viable strategy for the design of a stable vanadium oxide cathode.
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JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Jing Zheng,Shenluo Zang,Chi Hu,Luanjie Nie,Hang Chen,Xiaokang Chu,Hao Wang,Mengtao Ma,Qingxue Lai
Modified graphite (MG) with rough edges and reduced crystal particles is developed via ball-milling treatment for commercializable K-storage anode. Importantly, rational electrolyte regulation significantly improves the reaction dynamics as well as reversibility of potassiation/depotassiation behaviors, resulting into a high and stable reversible capacity of 277 mA h g −1 at 200 mA g −1 after 250 cycles in the optimized 3 M KFSI/EC + DEC electrolyte. The enhanced K + -solvents interaction with aggregates (AGGs)-rich solvated structures is revealed to be responsible for the excellent K-storage performance. Furthermore, electrolyte flammability evaluation confirms the remarkably suppressed flammability of the optimized 3 M KFSI/EC + DEC, providing enough security for practical applications of PIBs .
研究领域:
储能
·
材料科学
·
电化学
·
电池技术
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Nature Chemistry
·
2026
·
IF 24.5
Liu Youquan,Jiang Xingxing,Molokeev Maxim S.,Plyaskin Mikhail,Su Zhenhuang,Lin Qianru,Sheng Jie,Wen Wen,Gao Xingyu,Dove M. T.,Lin Zheshuai
Isotropic zero thermal expansion (ZTE) materials are essential for applications requiring extreme dimensional stability, yet their operation is typically limited to narrow temperature windows below 400 K. Here we report the incorporation of flexible interstitial groups via fractionally occupied atoms into a closed-framework sodalite structure (Cd 4 Al 6 O 12 SO 4 , CASO). This material exhibits isotropic ZTE, with a thermal expansion coefficient of 0.21(23) × 10 −6 K −1 from 11 K to 893 K. The high-temperature ZTE behaviour originates from the preserved transverse vibrations that drive negative thermal expansion—arising from the enhanced vibrations of positionally disordered ligand atoms—which effectively counterbalance the intrinsic positive thermal expansion. Moreover, CASO maintains structural integrity up to 1,100 K, features a solar-blind ultraviolet transparency window down to 275 nm and exhibits thermally induced optical fluctuations at least twice as low as those of conventional optical materials. This work provides both a high-performance crystal for extreme thermal environments and a strategy for designing wide-temperature-range ZTE materials. The alternative text for this image may have been generated using AI.
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高影响因子
MATERIALS LETTERS
·
2025
·
IF 2.7
Ying Chen,Chang Liu,Mengxue Hu,Qingfang Li,Jing Su
In this work, KCuCl₃ and K₂CuCl₄·2H₂O crystals were synthesized via a solution evaporation method. Their crystal structures were verified by XRD, while the (110) interplanar spacing of K₂CuCl₄·2H₂O was further identified by HRTEM and the corresponding SAED. Thermal behavior was examined using TG/DSC. Both compounds exhibit reversible discoloration in response to temperature (20–100 °C) and humidity (0–80 % RH). UV–Vis absorption reveals band gaps of 3.05 eV for KCuCl₃ and 3.09 eV for K₂CuCl₄·2H₂O. PL spectra show blue-green emission, with CIE coordinates indicating a warmer hue for K₂CuCl₄·2H₂O, primarily attributed to the Cu 2+ centers. The strong light absorption and efficient PL response of these halides highlight their potential for humidity sensing and luminescent device applications.
研究领域:
材料科学
·
无机化学
·
光学材料
·
晶体学
·
传感器技术
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ACS Applied Electronic Materials
·
2023
·
IF 4.7
Xian Sun,Jiuwu Wang,Chenguang Huang,Yingying Wang,Xiang Cheng,Yue Situ,Hong Huang
Transition metal oxides have attracted extensive research interest for supercapacitors due to efficient ion accessibility of nanostructures. Here, hierarchically hollow α-K0.2MnTi0.07O0.8 nanotubes with high K content are prepared via a self-sacrificial template method. The electrochemical performance of α-K0.2MnTi0.07O0.8 nanotubes is significantly improved when beneficial K+ is intercalated into a considerably ordered α-MnO2 phase with exchangeable Mn–K slabs by a K-pre-reserved reaction. Significantly, the α-K0.2MnTi0.07O0.8 nanotubes activated in a K2SO4 electrolyte exhibit highly capable capacitance behavior with high specific capacitance (334.5 F g–1 at 1 A g–1) and superior cycling stability (88% capacitance retention of the initial after 60,000 cycles). The well-designed α-K0.2MnTi0.07O0.8-based supercapacitor device exhibits an energy density of 25.16 Wh kg–1 at 1600 W kg–1. The morphological electrode-structured designer could be a promising attempt for applications in energy-related fields and even beyond power and storage sources.
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Chinese Medicine
·
2022
·Vol. 17
·期 1
·1-12
·
IF 4.546
Wang Li,Shao Li,Chen Man-Yun,Wang Lin,Zhang Wei,Tan Feng-Bo,Huang Wei-Hua
Background Ginsenoside compound K (GC-K) potentially alleviates ulcerative colitis involved in gut microbiota, which is significantly associated with the occurrence and development of colitis. However, the effect and mechanism of GC-K on anti-colitis in relation to gut microbiota are not clear. This study focused on the prevention and mechanism of GC-K on Dextran sulfate sodium (DSS)-induced colitis of mice pertinent to gut microbiota. Methods DSS was used to establish a chronic colitis mouse model. Body weight analysis, colon length measurement, HE staining, and inflammatory factors levels were processed in animal experiments. Flow cytometry was employed to analyze Th17/Treg cells in the mouse spleen and blood. 16S rRNA sequencing was utilized to analyze gut microbiota. Fecal microbiota transplantation (FMT) experiment was employed to verify the anti-colitis efficacy of GC-K by reshaping gut microbiota. Results GC-K significantly relieved colitis-related symptoms due to decreased disease activity index (DAI) scores, spleen weight, and increased colon length. Additionally, the tight junction proteins were increased, and the pro-inflammatory cytokines, such as TNF-α, IL-6, IL-1β and IL-17, were decreased after GC-K treatment. Furthermore, Bacteroides spp. significantly increased after modeling. Moreover, FMT experiments confirmed that GC-K-driven gut microbiota greatly relieved DSS-induced colitis. Conclusion GC-K alleviated colitis via the modulation of gut microbiota. Graphical Abstract
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