IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2026-06-01 Epub Date: 2026-02-07 DOI: 10.1016/j.clay.2026.108158

Qinqin Zhou, Xiaoshuai Ma, Shaokang Hu, Siyu Hao, Yutong Rao, Chuanjin Wang, Qingyan Bai, Peng Hu, Wei Liu, Jinshu Wang

The insufficient soluble silicon and heavy metal contamination in soil severely threaten the yield and quality of crops, which urgently requires dual-functional materials to address the above issues. Herein, a high-performance hierarchical magnesium silicate/diatomite (Si/Mg/xK) composite is synthesized via a one-step hydrothermal method. Natural diatomite serves as both a porous support and silicon source, while cost-effective magnesium sulfate concentrate derived from flue gas desulfurization (FGD) waste provides the magnesium source and weak alkalinity condition. Potassium hydroxide is introduced as an alkaline activator to accelerate the in-situ formation of magnesium silicate nanostructure on diatomite, creating hierarchical porosity that significantly enhances the specific surface area and increases the interaction interface with target solutions. The resulting composite achieves a remarkable citrate-soluble silicon content of 391.89 mg/L, representing a 39-fold improvement over raw diatomite, while concurrently releasing beneficial soluble magnesium (253.33 mg/L). Furthermore, the composite demonstrates exceptional heavy metal ion adsorption performance with a maximum cadmium ion (Cd²⁺) adsorption capacity of 184.5 mg/L, indicating dual-functional potential for soil remediation. This work establishes a sustainable pathway to valorize natural diatomite and FGD waste into dual-functional materials capable of efficient silicon/magnesium release and Cd²⁺ adsorption.

土壤中可溶性硅不足和重金属污染严重威胁作物的产量和质量，迫切需要双功能材料来解决上述问题。本文采用一步水热法合成了一种高性能的硅酸镁/硅藻土（Si/Mg/xK）复合材料。天然硅藻土既是多孔载体又是硅源，而从烟气脱硫（FGD）废物中提取的高性价比的硫酸镁精矿则提供了镁源和弱碱性条件。引入氢氧化钾作为碱性活化剂，加速硅藻土上硅酸镁纳米结构的原位形成，产生分层孔隙，显著提高比表面积，增加与目标溶液的相互作用界面。所得复合材料的柠檬酸盐可溶性硅含量达到391.89 mg/L，比原硅藻土提高了39倍，同时释放出有益的可溶性镁（253.33 mg/L）。此外，复合材料对重金属离子的吸附性能优异，镉离子（Cd2+）的最大吸附量为184.5 mg/L，具有修复土壤的双重功能潜力。本研究建立了一条可持续的途径，将天然硅藻土和FGD废物转化为能够高效释放硅/镁和吸附Cd2+的双功能材料。

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引用次数: 0

Novel extruded 3D printed potassium geopolymer composites containing chitosan 新型挤压3D打印含壳聚糖钾地聚合物复合材料

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2026-06-01 Epub Date: 2026-02-01 DOI: 10.1016/j.clay.2026.108144

Angelo Oliveira Silva , Marco D'Agostini , Dachamir Hotza , Paolo Colombo

This study investigates the development and characterization of 3D printed potassium-based geopolymers reinforced with chitosan, aiming to enhance material properties for environmental applications. The addition of chitosan improved the microstructure, pore morphology, dimensional accuracy, and rheological properties of the printed samples. X-ray diffraction (XRD) analysis confirmed successful geopolymerization across all chitosan concentrations, with shifts in the amorphous halo indicating structural transformation. Scanning electron microscopy (SEM) revealed fewer cracks and unreacted particles, leading to a dense, homogeneous matrix. Pore morphology analysis, using nitrogen physisorption, showed that the low-water (LW) system had a higher specific surface area (up to 111 m²/g) and more monodisperse mesopores, while the high-water (HW) system exhibited broader pore distributions and macroporosity. Dimensional accuracy analysis revealed deviations, with LW formulations maintaining better geometric precision. Chitosan improved the height-to-width ratios in the manufactured samples, enhancing printability. Rheological tests, including flow curves and amplitude sweeps, confirmed shear-thinning behavior and significant thixotropic recovery for the feedstock, ensuring shape retention and dimensional stability in 3D printing. These findings highlight the potential of chitosan-enhanced potassium-based geopolymers for environmental applications, especially in adsorption processes, by combining tunable porosity, high surface area, and improved printability for sustainable material solutions.

本研究研究了3D打印壳聚糖增强钾基地聚合物的开发和表征，旨在提高材料的环境应用性能。壳聚糖的加入改善了打印样品的微观结构、孔隙形态、尺寸精度和流变性能。x射线衍射（XRD）分析证实了壳聚糖在所有浓度下都能成功地聚合，无定形晕的变化表明结构发生了转变。扫描电子显微镜（SEM）显示较少的裂纹和未反应颗粒，导致致密，均匀的基体。利用氮气物理吸附法对孔隙形态进行分析，发现低水体系具有更高的比表面积（可达111 m2/g）和更多的单分散介孔，而高水体系具有更广泛的孔隙分布和宏观孔隙。尺寸精度分析揭示了偏差，LW配方保持了更好的几何精度。壳聚糖改善了制造样品的高宽比，提高了可印刷性。流变学测试，包括流动曲线和振幅扫描，证实了剪切变薄行为和明显的触变恢复，确保了3D打印的形状保持和尺寸稳定性。这些发现突出了壳聚糖增强钾基地聚合物在环境应用方面的潜力，特别是在吸附过程中，通过结合可调孔隙率、高表面积和改进的可印刷性来实现可持续材料解决方案。

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引用次数: 0

Calcium ferrate-ozone for enhanced removal of methylene blue: An innovative hybrid system 高铁酸钙-臭氧增强去除亚甲基蓝：一种创新的混合系统

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-06-01 Epub Date: 2026-01-30 DOI: 10.1016/j.pce.2026.104314

Gcobisa Ndzungu, Caliphs Zvinowanda, Catherine Jane Ngila

Textile and paper industries produce hazardous dyes, especially methylene blue (MB), which harms the environment. Industrial coloured dyes are difficult to degrade with conventional wastewater treatment processes. Alternative wastewater treatment technologies that breakdown these coloured dyes are needed. This study examined how calcium ferrate (CaFeO₄), ozone (O₃), and their hybrid system degrade methylene blue (MB). Batch tests examined MB degradation under different pH and reaction time conditions at a given temperature and oxidant concentration. The degrading efficiency and performance of CaFeO₄ were measured by measuring MB absorbance at 665 nm using UV–Vis spectroscopy. After 2 and 60 min at pH 2, the average removal efficiencies were 98.52% and 99.91%. Under the same reaction conditions, degradation efficiency was very poor above pH 4. O₃ treatment was highly effective at pH 2 and 12, with 99.03% and 99.99% elimination efficiency, respectively. Calcium ferrate and ozone synergistically degraded 99.7% in 30 s, promising fast and effective wastewater treatment. Thus, the hybrid system outperformed single treatments in removal percentage and reaction time, giving it an alternate remediation method.

纺织和造纸工业生产有害染料，特别是亚甲基蓝（MB），对环境有害。传统的废水处理工艺难以降解工业有色染料。需要替代废水处理技术来分解这些有色染料。本研究考察了高铁酸钙（CaFeO4）、臭氧（O3）及其杂化体系如何降解亚甲基蓝（MB）。批量试验考察了在给定温度和氧化剂浓度下，不同pH值和反应时间条件下MB的降解情况。通过紫外-可见光谱法测定665 nm处的MB吸光度，考察了CaFeO4的降解效率和性能。在pH 2条件下处理2 min和60 min，平均去除率分别为98.52%和99.91%。在相同的反应条件下，pH大于4时，降解效率很差。O3处理在pH为2和12时效果最好，去除率分别为99.03%和99.99%。高铁酸钙与臭氧在30 s内协同降解99.7%，具有快速有效的废水处理前景。因此，混合系统在去除率和反应时间方面优于单一处理，为其提供了一种替代修复方法。

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引用次数: 0

Impact of installation damage on the MIF of multi-layered geogrid-reinforced granular and subgrade layers 安装损伤对多层土工格栅加筋颗粒层和路基层MIF的影响

IF 6.2 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2026-06-01 Epub Date: 2026-01-20 DOI: 10.1016/j.geotexmem.2026.01.004

Sireesh Saride , Shubham Jain , Vipul Arora

This study evaluates the influence of installation damage on the modulus improvement factors (MIF) obtained from a double layer geogrid-reinforced base and subbase layers through a full-scale field study and large-scale laboratory confirmation tests. Four different types of geogrids, viz., two knitted (polyester, PET) and two extruded (polypropylene, PP) geogrids, were considered in this study. Twenty-eight field plate load tests were conducted on control, single, and double-layer geogrid-reinforced pavement sections built along a National Highway on a subgrade with a California bearing ratio of 8 %. The geogrids were exhumed from the test sections before and after the plate load tests to estimate the installation damage. Results indicate that the PET grids provide a higher MIF value when placed at the subgrade-subbase interface, while the PP grids performed better when placed within the granular layers. The MIF values ranged from 1.8 to 2.3 for PET grids at the subgrade-subbase interface and from 1.7 to 1.9 for PP geogrids placed at the subbase and base interface. The average installation damage observed in the PET and PP grids is 25 % and 10 %, respectively. A detailed framework for estimating the field MIF values using laboratory MIF and corresponding installation damage-induced reduction factors was proposed.

本研究通过全尺寸的现场研究和大型实验室验证试验，评估了安装损伤对双层土工格栅基层和次基层模量改善系数（MIF）的影响。四种不同类型的土工格栅，即两种针织（聚酯，PET）和两种挤压（聚丙烯，PP）土工格栅，在本研究中被考虑。28个现场板荷载试验进行了对照，单层和双层土工格栅加固的路面路段沿国道，加州承载比为8%的路基。在板荷载试验前后，分别从试验段中挖掘出土工格栅，估算其安装损伤。结果表明，PET栅格在路基-基层界面处具有较高的MIF值，而PP栅格在颗粒层内具有较好的MIF值。PET栅格的MIF值为1.8 ~ 2.3，PP栅格的MIF值为1.7 ~ 1.9。在PET和PP网格中观察到的平均安装损坏分别为25%和10%。提出了一种利用实验室MIF和相应的装置损伤诱导折减系数估算现场MIF值的详细框架。

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引用次数: 0

Machine learning based evaluation of fluoride contaminated groundwater and health risks in the Pambar River basin, South India 基于机器学习的印度南部潘巴尔河流域氟污染地下水和健康风险评估

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-06-01 Epub Date: 2026-02-04 DOI: 10.1016/j.pce.2026.104334

C.N. Sridhar , T. Subramani , Renato Somma , T. Dineshkumar

Excess fluoride in groundwater has become a significant health issue across several regions globally, yet comprehensive studies integrating seasonal variation, human health implications, and predictive modeling remain limited. This study examines fluoride ranges and adverse health effects in groundwater of Pambar River basin, South India, employing machine-learning techniques to classify groundwater based on its aptness for consumption. Totally, 100 groundwater samples were collected during North-East monsoon 2024, Post-monsoon, Pre-Monsoon and South-West Monsoon of 2025. Hydrochemical investigation indicated predominantly alkaline water, with sodium and bicarbonate as dominant ions. The overall mean fluoride concentration, calculated from four seasonal datasets, was 1.38 mg/L, and 43% of samples exceeded the World Health Organization guideline of 1.5 mg/L. Correlation analysis revealed calcium negatively influenced fluoride levels due to Calcium-Fluoride precipitation. Principal Component Analysis explained 64.9%-68.3% of variance, highlighting geochemical processes as primary controls, with secondary influence from agricultural runoff and waste leaching. Entropy-based water quality evaluation revealed 36.75% of samples were safe for drinking, while 58.75% required treatment. Among machine-learning models, support vector machines achieved the best predictive performance, with random forest and extreme gradient boosting also performing well under limited seasonal datasets. Evaluation of Human health hazard indicated potential fluoride-related risks, particularly for children (50%), teens (45%), women (44%), and men (43%). These findings provide a baseline for future groundwater management and underscores the importance of implementing sustainable measures to mitigate fluoride pollution in Pambar's groundwater resources.

地下水中过量氟化物已成为全球多个地区的重大健康问题，但综合季节性变化、人类健康影响和预测模型的综合研究仍然有限。本研究考察了印度南部潘巴尔河流域地下水中的氟化物范围和对健康的不利影响，采用机器学习技术根据其适合消费的程度对地下水进行分类。在2024年东北季候风、后季候风、前季候风和2025年西南季候风期间共采集了100份地下水样本。水化学研究表明，水以碱性为主，钠和碳酸氢盐为主要离子。根据四个季节数据集计算得出的总体平均氟化物浓度为1.38 mg/L， 43%的样本超过了世界卫生组织1.5 mg/L的指导标准。相关分析显示，由于氟化钙沉淀，钙对氟化物水平有负相关影响。主成分分析解释了64.9%-68.3%的差异，强调地球化学过程是主要控制因素，其次是农业径流和废物浸出的影响。基于熵的水质评价结果显示，36.75%的样本可安全饮用，58.75%的样本需要处理。在机器学习模型中，支持向量机的预测性能最好，随机森林和极端梯度增强在有限的季节性数据集下也表现良好。对人类健康危害的评估表明，与氟化物有关的潜在风险，特别是对儿童（50%）、青少年（45%）、妇女（44%）和男子（43%）。这些发现为未来地下水管理提供了基准，并强调了实施可持续措施以减轻Pambar地下水资源中氟化物污染的重要性。

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引用次数: 0

Investigating hydrological indices for identification of climate change tipping points in groundwater resources for the Upper Zambezi basin 研究水文指标，以确定上赞比西河流域地下水资源的气候变化临界点

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-06-01 Epub Date: 2026-02-02 DOI: 10.1016/j.pce.2026.104318

George Z. Ndhlovu, Kawawa Banda, Christopher Mtonga

Attributes of long-term hydrological regime of a river basin are referred to as Hydrological Indices which can further be used to characterise the river flow behavior with factors including scale, occurrence, period, mastery and rate of change of flow. The focus is to evaluate hydrological indices useful for analysing changes in groundwater quantity and quality arising from impacts of climate change. A larger population in the Upper Zambezi River Basin depend on the groundwater as a source of their rural water supply. Few studies have analysed the hydrological indices from future climate change scenarios for predicting climate change tipping points in Southern Africa. This paper therefore seeks to investigate impacts on groundwater resources by applying climate model projections and hydrological indices. The results show novelty in climate change impact under Representative Concentration Pathways 8.5 scenario that will affect temporal and spatial variability of groundwater. Furthermore, spatial variability of groundwater recharge is predicted to have minimal change in the north of Upper Zambezi River Basin ranging from −12 to – 22% while a huge change is predicted in the southern direction ranging from −31 to −42%. Baseflow across the basin has shown a reduction to a considerable degree while Soil Moisture Index has shown severe dryness in Barotse and Chobe sub catchments. Hydrological indices also show that the future scenario may have reduced groundwater availability. Therefore, the novel results require strategic thinking for adaptation especially in the rural water supplies that largely depend on Groundwater resources.

流域长期水文状况的属性被称为水文指数，它可以进一步用来描述河流的流量行为，包括流量的规模、发生、周期、控制和变化率。重点是评价对分析因气候变化影响而引起的地下水数量和质量变化有用的水文指数。赞比西河上游流域的大量人口依赖地下水作为农村供水的来源。很少有研究分析了来自未来气候变化情景的水文指数，以预测南部非洲的气候变化临界点。因此，本文试图利用气候模式预估和水文指数来研究对地下水资源的影响。结果表明，代表性浓度路径8.5情景下气候变化对地下水时空变异性的影响具有新颖性。在赞比西河上游流域北部，地下水补给的空间变异性变化最小，变化幅度在- 12% ~ - 22%之间，而在南部方向变化较大，变化幅度在- 31% ~ - 42%之间。整个流域的基流显示出相当程度的减少，而土壤湿度指数显示Barotse和Chobe流域严重干旱。水文指数还表明，未来的情景可能会减少地下水的可用性。因此，新的结果需要对适应进行战略思考，特别是在很大程度上依赖地下水资源的农村供水中。

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引用次数: 0

Reassessing early traces of life from the Eoarchean metasedimentary rocks in Labrador, Canada: carbon isotope compositions for individual graphitic grains 加拿大拉布拉多古太古代变质沉积岩中早期生命痕迹的重新评估：单个石墨颗粒的碳同位素组成

IF 3.2 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Precambrian Research

Pub Date : 2026-06-01 Epub Date: 2026-03-03 DOI: 10.1016/j.precamres.2026.108074

Motoko Igisu , Kentaro Tanaka , Naoto Takahata , Ken Takai , Yuji Sano , Tsuyoshi Komiya

Graphite with low carbon isotope ratios (δ¹³C_gr) in the Eoarchean metasedimentary rocks from the Labrador region of northern Canada has attracted attention as possible evidence for the oldest traces of life on the Earth. However, δ¹³C_gr values were primarily determined through whole-rock analysis, and maturation degree was assessed in a limited number of samples. Whether all ¹³C-depleted carbons existed before the peak metamorphism remains unclear. Here, we performed in situ micro-Raman spectroscopy and nanoscale secondary ion mass spectrometry on graphitic grains to determine their crystallinity and carbon isotopic compositions. Based on the occurrence of graphitic grains in thin sections and Raman spectra, we classified the grains into four types: (1) inclusion graphite within matrix minerals, (2) inclusion poorly crystallized graphite (PCG), (3) boundary graphite among mineral grains, and (4) boundary PCG. Inclusion graphite is considered the most primary. The δ¹³C_gr values ranged from −35‰ to 7‰ and were heterogeneous within single hand specimens of pelitic rocks, conglomerates, and chert nodules, regardless of whether grains were inclusions or boundary types, or whether they were graphite or PCG. Carbonate rocks contain grains with relatively homogeneous δ¹³C_gr values. Overall, the δ¹³C_gr values correlate with lithology, increasing from pelitic rocks to conglomerates and carbonate rocks with chert nodules. These data suggest that determining the origin of all graphitic grains from a single source is difficult. Graphitic grains with positive δ¹³C_gr values may have an abiological origin; however, the wide range of δ¹³C_gr values, together with their geological occurrence, does not allow a unique interpretation, but is consistent with multiple origins, including both abiotic and biotic organic carbon.

加拿大北部拉布拉多地区太古代变质沉积岩中的低碳同位素（δ13Cgr）石墨作为地球上最古老生命痕迹的可能证据而备受关注。然而，δ13Cgr值主要通过全岩分析确定，并在有限的样品中评估成熟程度。是否所有的13c耗尽的碳在变质峰之前就已经存在了还不清楚。在这里，我们对石墨颗粒进行了原位微拉曼光谱和纳米级二次离子质谱分析，以确定它们的结晶度和碳同位素组成。根据石墨颗粒的薄片产状和拉曼光谱，我们将石墨颗粒分为4种类型：(1)基质矿物内包裹体石墨，(2)包裹体贫晶石墨（PCG），(3)矿物颗粒间的边界石墨，(4)边界PCG。包裹体石墨被认为是最原始的。在泥质岩、砾岩和燧石结核单手样品中，δ13Cgr值在−35‰~ 7‰之间，无论颗粒是包裹体还是边界型，也无论颗粒是石墨还是PCG， δ13Cgr值都具有非均质性。碳酸盐岩中含有δ13Cgr值相对均匀的颗粒。总体而言，δ13Cgr值与岩性相关，从泥质岩到砾岩和含燧石结核的碳酸盐岩逐渐增大。这些数据表明，从单一来源确定所有石墨颗粒的起源是困难的。δ13Cgr值为正的石墨颗粒可能具有非生物成因；然而，δ13Cgr值的大范围，以及它们的地质产状，不能给出一个唯一的解释，而是与多种来源相一致，包括非生物有机碳和生物有机碳。

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引用次数: 0

TTG plutonism in the Archean Abitibi greenstone belt, Superior craton: geodynamic and metallogenic perspectives 上克拉通太古代阿比提比绿岩带TTG成矿作用：地球动力学与成矿远景

IF 3.2 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Precambrian Research

Pub Date : 2026-06-01 Epub Date: 2026-02-21 DOI: 10.1016/j.precamres.2026.108039

Silvain Rafini , Morgane Gigoux , Michel Jébrak

This study of the Abitibi greenstone belt (Quebec, Canada) relies on TTG (tonalite, trondhjemite, and granodiorite) composition to investigate the spatiotemporal evolution of the Archean crust and evaluate its metallogenic significance. Trace element signatures (e.g., La/Yb, Sr/Y, Eu/Eu*, Nb, Ta) of 32 dated TTG intrusions is analyzed using the FI-FII-FIII fertility typology developed for felsic volcanic rocks, which links mineral systems to melting depth and crustal architecture. Crystallization depths estimated from normative felsic mineralogy correlated with melting depth and showed a crustal thickness increase during incipient tectonics. The spatiotemporal distribution of TTG types indicates an early partitioning of the Abitibi crust into three distinct domains. The Northeastern Abitibi is characterized by FI types, early crustal thickening, and arc-like settings. These geological characteristics are favorable for porphyry-type deposition within syn-volcanic shallow plutons (e.g., the Chibougamau camp) or Windfall-like intrusion-related gold mineralization within syn-tectonic, LILE-enriched intrusions crystallized at deeper levels, possibly below the brittle crust. The southern volcanic zone is dominated by FIII and FIIb types, consistent with thin-crust, high–heat flux environments linked to the major volcanogenic massive sulfide camps. Finally, the western North Volcanic Zone exhibits an intermediate crustal thickness response and a transition from FII to FI types, associated with syn-tectonic crustal thickening; punctual occurrences of FIII-type intrusions occur, which indicate trenches or thermal corridors prospective for volcanogenic massive sulfides. This research emphasizes the utility of TTG geochemistry as a proxy for crustal processes and mineral potential. It demonstrates that TTG compositional variability offers a robust framework for reconstructing Archean crustal evolution and guiding metallogenic models.

以加拿大魁北克省阿比提比绿岩带为研究对象，利用TTG（闪长岩、闪长岩和闪长岩）组成研究太古宙地壳的时空演化，并评价其成矿意义。利用长英质火山岩的fi - FI-FII-FIII丰度类型分析了32年TTG侵入岩的微量元素特征（La/Yb、Sr/Y、Eu/Eu*、Nb、Ta），将矿物系统与熔融深度和地壳结构联系起来。根据规范长英质矿物学估算的结晶深度与熔融深度相关，表明在构造初期地壳厚度增加。TTG类型的时空分布表明阿比蒂比地壳早期划分为三个不同的域。阿比提比东北部以FI型、早期地壳增厚、弧形背景为特征。这些地质特征有利于同火山浅埋岩体（如Chibougamau营地）内斑岩型沉积或同构造中与风沙状侵入体相关的金矿化，富集lile的侵入体在更深层次（可能在脆性地壳以下）结晶。南部火山岩带以FIII型和FIIb型为主，与主要火山岩块状硫化物营地相联系的薄壳高热流环境相一致。北火山区西部地壳厚度响应为中间型，由FII型向FI型过渡，与同构造地壳增厚有关；fiii型侵入岩准时出现，预示着火山块状硫化物可能形成的海沟或热走廊。本研究强调TTG地球化学作为地壳过程和矿物潜力代理的效用。结果表明，TTG组成变率为重建太古宙地壳演化和指导成矿模式提供了强有力的框架。

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引用次数: 0

A new cicadomorphan family (Insecta, Hemiptera) trapped in mid-Cretaceous Burmese amber 中白垩世缅甸琥珀中捕获的蝉蛾新科（昆虫亚目，半翅目）

IF 1.7 3区地球科学 Q2 PALEONTOLOGY

Palaeoworld

Pub Date : 2026-06-01 Epub Date: 2026-01-14 DOI: 10.1016/j.palwor.2026.201070

Jun Chen , Wen-Qian Wang , Yan Zheng , Guang-Jin Wei , Guang-Ying Ren

The Cicadomorpha is a hemipteran phytophagous insect suborder with high palaeo-diversity and abundant extant representatives. As one of the three modern cicadomorphan superfamilies, the Cercopoidea (froghoppers) is inferred to have originated in the Triassic and has three extinct families recorded in the Jurassic and Cretaceous. We herein erect a new cercopoid family, Myanmalidae Chen, n. fam. along with Myanmala zireni Chen, n. gen. n. sp. on the basis of a male adult insect fossil trapped in mid-Cretaceous Kachin amber from northern Myanmar. The new family bears a series of body structures and wing characteristics different from its known con-superfamilials, such as lateral ocelli almost touching coronal posterior margin, thin crown anteriorly extending distinctly beyond postclypeus, and tegminal basal cell greatly shortened. This new family shares some features with the primitive families Procercopidae and Sinoalidae, and also displays some derived traits similar to modern cercopoids. Our new finds suggest froghoppers have a complex evolutionary history in the Mesozoic, with high morphological disparity.

蝉形亚目是一种古多样性高、现存代表性丰富的半足类植食昆虫亚目。作为现代蝉科的三大科之一，蝉科起源于三叠纪，在侏罗纪和白垩纪有三个灭绝科的记录。我们在此建立了一个新的蚁科，Myanmalidae Chen, n. fam。与Myanmala zireni Chen， n. gen. n. sp.一起，基于在缅甸北部的克钦琥珀中捕获的白垩纪中期雄性成虫化石。新科具有一系列不同于其已知的非超级科的身体结构和翅膀特征，如侧眼细胞几乎接触冠状后缘，薄冠向前延伸明显超过后瓣，顶状基底细胞大大缩短。这一新科与原始科原尾猿科和中国尾猿科有一些共同的特征，并表现出与现代尾猿类相似的衍生特征。我们的新发现表明，在中生代，蛙蛙具有复杂的进化史，具有高度的形态差异。

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引用次数: 0

Drought as a risk amplifier: The intensifying regime of compound dry-hot events in China 干旱作为风险放大器：中国复合干热事件的强化机制

IF 4.4 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2026-06-01 Epub Date: 2026-02-06 DOI: 10.1016/j.atmosres.2026.108825

Pengcheng Xu , Dong Wang , Yuankun Wang , Vijay P. Singh , Jianchun Qiu , Xiaolei Fu

Compound dry-hot events (CDH) are escalating climate hazards in China. This study examines spatiotemporal changes in the frequency, duration, dryness severity, and extreme heat characteristics of CDH using high-resolution daily data, including the Standardized Precipitation Evapotranspiration Index (SPEI) and daily maximum temperatures, from 1962 to 2022. Using high-resolution daily data (1962–2022) and a conditional Copula-based framework to calculate a risk amplification ratio (RAR), we analyzed daily CDH events nationwide. Our key results show: (1) a significant increase in the frequency and spatial extent of drought-related heatwaves, especially in recent decades; (2) intensifying CDH events, with annual durations extending by 1.8–3.6 days and severity rising by 2–9 units per event; and (3) drought amplifying concurrent heatwave risks by 3–7 times across most regions, which underscored regionally amplified impacts, particularly in China's arid regions, largely driven by anthropogenic climate change. The analysis, further validated by employing two distinct data products, indicates that background aridity critically modulates both CDH spatiotemporal characteristics and the magnitude of drought-induced heatwave risk amplification. By leveraging daily-scale data and a novel probabilistic framework, this research enhances the mechanistic understanding of compound event dynamics and underscores the necessity of accounting for drought as a key triggering factor in climate risk assessments.

复合干热事件是中国日益严重的气候灾害。本研究利用高分辨率日数据，包括标准化降水蒸散发指数（SPEI）和日最高气温，分析了1962年至2022年CDH的频率、持续时间、干燥严重程度和极端热特征的时空变化。使用高分辨率的每日数据（1962-2022）和基于条件copula的框架来计算风险放大比（RAR），我们分析了全国范围内的每日CDH事件。研究结果表明：(1)近几十年来，干旱相关热浪发生的频率和空间范围显著增加；(2) CDH事件不断加剧，年持续时间延长1.8 ~ 3.6 d，严重程度上升2 ~ 9个单位/次；(3)干旱将大部分地区的热浪风险放大了3 - 7倍，突出了人为气候变化对区域影响的放大，特别是在中国干旱地区。采用两种不同的数据产品进一步验证了该分析，表明背景干旱对CDH时空特征和干旱引起的热浪风险放大程度都有重要调节作用。通过利用日尺度数据和一个新的概率框架，本研究增强了对复合事件动力学的机制理解，并强调了在气候风险评估中将干旱作为关键触发因素考虑在内的必要性。

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