Air-sea CO2 flux (FCO2) in the estuary-coastal continuum plays a vital role in global carbon sequestration; however, the mechanisms governing FCO2 spatial heterogeneity during early spring remain poorly understood, particularly the roles of distinct dissolved inorganic carbon (DIC) sources. In March 2025, we investigated the FCO2 spatial variability and DIC sources across the Yangtze River estuary and adjacent coastal areas using DIC concentration, pH, and delta C-13(DIC) analyses. The study area was a net CO2 source (7.3 +/- 8.7 mmol m(-2) d(-1)), with the intensity declining progressively from the inner estuary to offshore areas. Physical mixing of three principal water masses established the following pattern: high-pCO(2) Changjiang Diluted Water and Yellow Sea Coastal Current drove CO2 outgassing, while low-pCO(2) East China Sea Shelf Water weakened it. Quantitative apportionment revealed atmospheric CO2 invasion as the dominant DIC source, followed by carbonate dissolution and organic matter degradation, with the latter declining from the inner estuary to offshore areas. The spatial variation in DIC source contributions further confirms that, superimposed on the physical mixing, biogeochemical processes-particularly biological activity-modulated reginal source intensities. This early-spring case captures a critical transitional window and highlights the necessity of integrating multi-factor regulation with DIC source partitioning to resolve carbon dynamics in the estuarine-coastal continuum.

The global atmospheric model IGGatm is established from the gridded Chinese reanalysis data CRA-40 with 1° horizontal resolution and optimized with a flexible vertical grid and formulas. It can provide empirical three-dimensional fields of pressure, temperature, and water vapor pressure from the troposphere to the lower stratosphere for satellite positioning and related applications. Accurate slant atmospheric delays and mapping functions are calculated using the revised piecewise linear ray tracing method from the modelled atmospheric field. To reduce model parameter redundancy, the annual mean coefficients are represented on the non-uniform vertical grid determined from the tropopause height feature, and different polynomial fitting formulas are applied to characterize the seasonal amplitude coefficients across all latitude bands. The resulting optimized version, IGGatm Poly, maintains the same level of accuracy while reducing the parameter count to 11

Real-time sensing of precipitable water vapor (PWV) using GNSS is critical for atmospheric monitoring. Conventional real-time precise point positioning (PPP) reliant on the IGS real-time service (RTS) remains limited in oceanic regions due to terrestrial internet dependencies. BeiDou’s satellite-based PPP-B2b service overcomes this limitation, enabling real-time PWV sensing over the ocean. However, its relatively lower accuracy has hindered broader application. Additionally, the potential of combining PPP-B2b with low-cost GNSS devices for oceanic PWV sensing remains insufficiently explored. This study presents a practical and cost-effective approach for real-time oceanic PWV sensing by jointly using PPP-B2b and low-cost GNSS devices. To address the inherent errors in PPP-B2b corrections, we develop a refined PPP strategy based on ambiguity reparameterization and optimized stochastic modeling. Unlike conventional PPP that treats ambiguities as constants, this method models them as time-varying random-walk processes within an optimized range of process-noise values. This allows for adaptive absorption of PPP-B2b correction errors, thereby improving the accuracy of tropospheric estimates. Validation through land-based static and kinematic experiments demonstrates accuracy improvements of 34 and 24

With the rapid advancement of high-precision Global Navigation Satellite System (GNSS) positioning, the demand for high-precision tropospheric delay models has grown substantially, intensifying the trade-off between modeling precision and resource consumption. In network-free environments, such as oceans and deserts, satellite-based broadcasting of atmospheric correction products is essential for achieving global coverage, which further exacerbates challenges associated with large data volumes and high storage and transmission costs. Existing learned-dictionary methods for compressing tropospheric delay parameters often incur substantial training costs and exhibit limited generalization capability. To address these limitations, this study integrates compressed sensing theory to propose a block-wise sparse representation method for tropospheric grid models using a simple analytical dictionary, combined with a binary mask encoding strategy. The proposed approach enables efficient compression of all involved parameters without requiring prior training. Experimental results demonstrate significant resource savings while maintaining model accuracy. Compared with the original models, memory usage is reduced by 63.49

Although using artificial intelligence (AI) to analyze ultrasound images is a promising approach to assessing thyroid nodule risks, traditional AI models lack transparency and interpretability. We developed a multimodal generative pre-trained transformer for thyroid nodules (ThyGPT), aiming to provide a transparent and interpretable AI copilot model for thyroid nodule risk assessment and management. Ultrasound data from 59,406 patients across nine hospitals were retrospectively collected to train and test the model. After training, ThyGPT was found to assist in reducing biopsy rates by more than 40% without increasing missed diagnoses. In addition, it detects errors in ultrasound reports 1,610 times faster than humans. With the assistance of ThyGPT, the area under the curve for radiologists in assessing thyroid nodule risks improved from 0.805 to 0.908 (p < 0.001). As an AI-generated content-enhanced computer-aided diagnosis (AIGC-CAD) model, ThyGPT has the potential to revolutionize how radiologists use such tools.

Precipitable water vapor (PWV) is an important component of atmospheric spatial parameters and plays a vital role in meteorological studies. In this study, PWV retrieval by real-time precise point positioning (PPP) technique is validated by using global navigation satellite system (GNSS) observations and four real-time products from different analysis centers, which are Centre National d’Etudes Spatiales (CNES), Internation GNSS Service (IGS), Japan Aerospace Exploration Agency (JAXA), and Wuhan University (WHU). To comparatively analyze the performance of each scenario, the single-system (GPS/Galileo/BDS3), and multi-system (GPS + Galileo + BDS) PPP techniques are applied for zenith tropospheric delay (ZTD) and PWV retrieval. Then, the ZTD and PWV are evaluated by comparison with the IGS final ZTD product, the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) data, and radiosondes observations provided by the University of Wyoming. Experimental results demonstrate that the root mean squares error (RMS) of ZTD differences from multi-system solutions are below 11 mm with respect to the four-product series and the RMS of PWV differences are below 3.5 mm. As for single-system solution, the IGS real-time products lead to the worst accuracy compared with the other products. Besides the scenario of BDS3 observations with IGS real-time products, the RMS of ZTD differences from the GPS-only and Galileo-only solutions are all less than 15 mm compared to the four-product series, as well as the RMS of PWV differences is under 5 mm, which meets the accuracy requirement for GNSS atmosphere sounding.

In the complex environment of underwater acoustic measurements, the accurate identification and reasonable processing of gross errors are the prerequisites for achieving high-precision underwater acoustic positioning. Conventional data quality control methods often concentrate on examining the residuals derived from Least Square, but they do not always consistently provide the accurate locations and magnitudes of gross errors. In this contribution, Quasi-Accurate Detection with Equivalent Weight (QUADEW) for underwater acoustic measurements is proposed by directly engaging with the true errors of the observations. QUADEW can not only unify the expression of both ship-board positioning and buoy-based positioning models by the Least Squares Filter (LSF), but also integrate the merits of K-Means++ algorithm, Quasi-Accurate Detection method and robust estimation. Results from both simulated and field experiments substantiate the efficacy of the proposed method. Compared to the traditional ship-board model which is limited to static post-processing, the final positioning result of LSF is close to it with a maximum discrepancy of 5 cm, and the internal consistency precision has been significantly enhanced from the centimeter to the millimeter range. Therefore, it is feasible to realize real-time ship-board positioning by QUADEW. The quality control of QUADEW outperforms the traditional Partial Least Squares.

Wind energy is critical in the global shift towards renewable energy sources, necessitating accurate potential assessments for informed decision-making and strategic development in this transition. Despite the widespread use of wind speed data with varying time resolutions for estimating wind energy, the influence of this variability on the accuracy of wind energy assessment remains uncertain. In this study, we investigate the impact of wind speed data’s time resolution on wind power density (WPD) assessment, utilizing high-frequency, in-situ observations collected from eight anemometer towers in China. Through analysis of wind speed data at nine resolutions, ranging from 10-minute to monthly intervals, we uncover significant errors introduced by coarser time resolutions in WPD calculations. Specifically, it reveals a systematic underestimation of WPD with decreasing time resolution, highlighting the importance of time resolution in wind energy evaluation. While hourly wind speed data yield acceptable WPD errors, daily and monthly resolutions lead to substantial underestimation due to the smoothing effect of fluctuations. We also delve into the underlying mechanisms contributing to these errors, including variations in the power law exponent and changes in the Weibull distribution shape factor with time resolution. Furthermore, we propose a novel method to mitigate WPD calculation errors using coarse time resolution data by regressing Weibull distribution factors. The findings offer valuable insights into wind speed data selection and accurate wind energy assessment, with implications for renewable energy planning and policy-making in the context of the global energy transition.

三唑类农药是目前世界上应用最广泛的杀菌剂种类,其中,伊芬三氟康唑(ipfen-trifluconazole)作为新型品种填补了该类杀菌剂十余年无新农药更新的空白.伊芬三氟康唑对锈病、叶斑病、纹枯病等防效高,兼具保护和治疗作用.通过与苯并烯氟菌唑,氟唑菌酰氢胺等杀菌剂复配后体现出更高的杀菌效果,能够有效改善传统三唑类杀菌剂因抗性问题导致田间防效的降低,具有广阔的应用前景.本文旨在对伊芬三氟康唑的化学合成、生物活性和分析方法进行综述,以期对其科学合理应用和健康风险评价提供科学参考.

Diamide pesticides are a class of insecticides attracting great attention after neonicotinoids.The action target of diamide insecticides is ryanodine receptor or γ-aminobutyric acid receptor, which exhibits extraordinary potency on lepidopteran pests. With the widespread application of diamide pesticides, the potential threat to non-target organisms and aquatic ecosystems and the resistance of target pests have been observed. This study summarizes the biological activity, ecological toxicity,analytical methodology, environmental fate and risk assessment of diamide pesticides based on the research progress at home and abroad and prospects the research orientations in future in order to provide scientific references for accurate application, risk aversion and effective management of diamide pesticides.

为阐明新型吡唑酰胺类杀菌剂吡噻菌胺的生态暴露风险与环境行为归趋,本文从合成路径、生物活性、生态毒理、分析方法和环境行为五方面进行分析总结,并对其应用前景进行展望.指出吡噻菌胺对真菌孢子萌发抑制作用显著,防治效果优于治疗效果;吡噻菌胺对水生生物具有较高的生态毒性,且对细胞活力及氧化应激具有显著的对映体选择性差异.建议后续深入开展不同环境下吡噻菌胺的行为特征及其水生生态毒理学研究,特别是对映体选择性的分子机制,探索高效低风险的手性对映体,建立科学精准的风险评估体系,降低其对水生生物安全和人类生殖健康的高潜在暴露风险.

The past few decades have witnessed unprecedented global urbanisation, with direct or indirect impacts on global cultural heritage sites. Research on the spatial relationship between cultural heritage sites and urban areas has provided a new perspective for understanding the impact processes between them, which have previously been discussed at the regional scale. In this article, we analyse the spatial relationship between world cultural heritage sites and neighbouring towns through systematic observations at the global scale and attempt to model change processes and identify impact mechanisms. We adopt spatial analysis and spatial statistics to analyse the changing characteristics of the spatial relationship between world cultural heritage sites and neighbouring towns from 1990 to 2018 and to analyse the impact processes at different spatial and temporal scales by combining indicators, such as income levels and urbanisation rates, at the national scale. The results show that 8.52% of world cultural heritage sites have been incorporated into urban areas over the aforementioned 28 years, with a certain aggregation in the spatial distribution of these sites, and that the growth rate can be divided into three phases, including two periods of rapid growth. The spatial relationship between towns and the 523 world cultural heritage sites that were previously located outside towns has not yet changed substantially, but the distances between most of the towns and these sites have been decreasing, with 81% of the world cultural heritage sites having a variation in distance from the corresponding town of 7.60 km or less. We also analysed the variation in distance between cultural heritage sites and neighbouring towns and found a relationship with indicators, such as the income level and urbanisation rate of the country to which a site belongs. Among the indicators, variation in national urbanisation rates most greatly affected the distance between heritage sites and towns. This study shows that world cultural heritage sites are affected by urbanisation and that particular attention should be given to the relationship between cultural heritage sites and neighbouring towns, especially in countries undergoing rapid urbanisation, so that the authenticity and integrity of cultural heritage are not compromised. This article provides a basis for development plans and policies in urban design, especially those that are sensitive to cultural heritage, and may also provide ideas and references for heritage conservation against the background of urbanisation.

三唑类杀菌剂是当前使用较为广泛的杀菌剂品种,氯氟醚菌唑作为新型三唑类杀菌剂,目前已向全球50个国家和组织递交登记材料,其对于60多种作物病害表现出优异的防效和抗逆性.氯氟醚菌唑在弥补传统三唑类杀菌剂缺陷的同时,还降低了对动植物与生态环境的潜在危害,体现出了广阔的应用前景.旨在对氯氟醚菌唑的化学合成、生物活性、生态毒性、环境行为以及代谢特征进行综述,以期对氯氟醚菌唑的合理使用与有效管理提供科学参考.

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For the timely retrieval of global positioning system based precipitable water vapor (GPS-PWV) over complex topography when there is no in situ pressure-derived zenith hydrostatic delays (ZHDs), this article evaluates three types of ready-made ZHD products, including two newly released products from the Vienna University of Technology (TU Wien, TUW-VMF3) and GeoForschungsZentrum Potsdam (GFZ-VMF1) and a legacy product TUW-VMF1. We implement them for the first time for GPS-PWV retrieval in regions with highly variable topography, such as the Tibetan plateau (TP). First, we present a refined method [model-assisted ZHD height adjustment, model-assisted ZHD height adjustment (MAZHA)] for implementing the above VMF1/VMF3-like ZHD products. The results reveal that the MAZHA method improves the implementation accuracy over the TP by 70% compared to the conventional method. Then, the above multisource VMF1/VMF3-like ZHD products are evaluated using the in situ pressure-derived ZHDs across the TP. The results show that the GFZ-VMF1 outperforms the TUW-VMF1 mainly because a more advanced underlying numerical weather model (ERA5) are adopted. TUW-VMF3 achieves the best performance mainly because it is provided with improved horizontal resolution. Finally, we find that implementing the state-of-the-art TUW-VMF3 ZHD product for GPS-PWV retrieval yields no statistically significant errors, even under extreme weather conditions, and the retrieved GPS-PWVs can well characterize the PWV diurnal variations in all seasons except winter. Additionally, considering the fact that the operational and forecasted TUW-VMF3 ZHDs present almost equivalent performance, this article is also beneficial to real-time GPS-PWV retrieval using forecasted TUW-VMF3 ZHDs, thus allowing for the ease of real-time GPS-PWV retrieval.

This study investigates methods of deriving meteorological parameters needed in space geodetic applications, from the surface data of the numerical weather model (NWM). It is more efficient than pressure level data in terms of storage and transmission. Based on more realistic assumptions for the structure of the troposphere, formulas for accurate vertical reduction of pressure (P) and precipitable water vapor (PWV) are deduced, and they are applied with the gridded lapse rate data provided by the GPT2w model. The new method achieves better accuracy especially when a large height difference between the grid point and station exists. Validation with global radiosonde observations shows that the RMS errors of P, temperature (T), and water vapor pressure (e) derived from 2.5° × 2.5° ERA surface data are 1.16 hPa, 1.95 K, and 1.76 hPa respectively; zenith tropospheric delays (ZTDs) calculated from derived P, T, and e values have a mean RMS error of 3.26 cm, comparable to that obtained from in situ measurements; adding PWV will increase ZTD estimation accuracy to 1.52 cm, comparable to that obtained from NWM pressure level data. Validations with Global Navigation Satellite System estimated ZTDs from global and regional station networks display similar results on the globe, as well as features for localized regions. Using higher spatial resolution NWM seems to have little effect on the accuracy of ZTDs calculated from P, T, and e, while it apparently improves the accuracy of ZTDs calculated from P, T, e, and PWV.

新烟碱类农药自20世纪80年代上市以来便受到广泛应用.呋虫胺作为典型的第三代新烟碱类杀虫剂,因其高效、广谱等优点在全球二十多个国家登记使用.近年来,随着呋虫胺的大量使用,其对非靶标生物的潜在危害,以及在农业生产中大量投入导致的环境风险引起了人们的重点关注.因此,阐明呋虫胺的生物活性和生态毒理,揭示其环境行为归趋,这对于呋虫胺的生态风险评价与科学合理使用具有重要意义.笔者旨在综述呋虫胺对靶标害虫的生物活性、对非靶标生物的生态毒理,及其在生态环境中的耗散动力学规律,并对其应用前景进行展望,以期为呋虫胺的合理使用和科学管理提供有效参考.

建立了乙螨唑在不同样本基质(猕猴桃、木瓜、柠檬、茄子、山楂、柿子、甜椒、香蕉以及枣)中的气相色谱-质谱(GC-MS)分析方法,进而系统研究了-20℃条件下乙螨唑在上述果蔬中储藏112 d的稳定性差异及其影响因素.样品经乙腈提取,氨丙基固相萃取柱净化,GC-MS检测分析.结果表明:在0.01～3mg/kg添加水平下,乙螨唑在9种果蔬中的平均回收率在80％～112％之间,相对标准偏差在1.4％～12％之间,定量限为0.01 mg/kg.于-20℃下储藏14～112 d期间,乙螨唑在甜椒中的降解率为9.0％～28.6％(低于30％),说明其具有较好的储藏稳定性;但在猕猴桃、木瓜、柠檬、茄子、山楂、柿子、香蕉和枣中,其降解率均超过30％,储藏稳定性较差.乙螨唑残留储藏稳定性与样本基质的种类、pH值、含水量等密切相关.因此,乙螨唑的残留试验样本不宜长时间储藏,获取后应当尽快检测,以防农药降解导致检测结果出现偏差.本研究为乙螨唑在多种果蔬作物中的残留检测方法和储藏稳定性提供了基础数据,也为后续乙螨唑的准确定量分析提供了理论参考.

To obtain better zenith hydrostatic delay (ZHD) corrections for global navigation satellite system (GNSS) applications, seven types of Vienna mapping function 1 (VMF1) and VMF3-like ZHD models provided by the Vienna University of Technology (TU Wien, TUW), University of New Brunswick (UNB) and GeoForschungsZentrum Potsdam (GFZ) are evaluated. Firstly, we find that the conventional method for implementing VMF1/VMF3-like ZHD models has issues when applied over regions with highly variable topography. Therefore, we propose an improved implementation method (called Trop_vertical) based on an empirical model as well as a second version, called Trop_vertical-II, which further corrects for small residual biases. The results show that the Trop_vertical-II can effectively reduce the large errors reported in previous studies for complex terrains and yields an improvement in global accuracy of up to 50% over the conventional method. Then, the multisource ZHD models are evaluated and intercompared globally. The results reveal some deficiencies with the TUW-VMF1 over certain regions. The newly developed ZHD models from the TUW (TUW-VMF3) and GFZ (GFZ-VMF3) both achieve reliable performances globally, but there is a systematic difference (~ 2.9 mm) between them. The forecast VMF1/VMF3-like models can well capture the rapid ZHD variation in challenging weather conditions. Finally, the impacts of a priori ZHD errors on both GPS-only and GPS/GLONASS precise point positioning (PPP)-based zenith total delay (ZTD) and height solutions are examined globally. The results suggest that the sensitivities of PPP-ZTD/height solutions to a priori ZHD errors decrease by adding GLONASS data at high latitudes but increase at low latitudes.

利用主成分分析法(PCA)确定了观测噪声中高度角和信噪比(SNR)的贡献,在此基础上建立了精化的全球卫星导航系统(GNSS)随机模型,并验证了基于此随机模型的高纬度测站精密单点定位(PPP)效果.结果表明:在高纬度地区精化随机模型相比于仅顾及高度角或SNR的传统随机模型效果更佳,定位精度较高度角模型提高约30％,较SNR模型提高约20％.在高程方向上精度提高最为明显,对比高度角模型和SNR模型分别提高约37％和24％.该研究对提高高纬度地区GNSS定位精度有一定的参考价值.