Monitoring the hydrological processes of lakes can provide reliable data for regional water resources assessment. This paper analyzed changes in the lake area and water level of Hala Lake from 2011 to 2023, subsequently estimating its lake water storage change (LWSC). We used image data from Landsat series satellites and multi-source satellite altimetry data, and then quantitatively assessed the influence of various driving factors on the LWSC in combination with hydrological and meteorological models. The results show three stages of parallel changes in the area, water level and LWSC of Hala Lake in the past 13 years. The first stage is from 2011 to 2014, when the lake expanded slightly, the second stage is from 2015 to 2019, when the lake expanded rapidly, and the last stage is from 2020 to 2023, with relatively stable conditions. Over the entire study period, the LWSC increased with a trend of 0.192 ± 0.009 km3/a. Lake surface precipitation, precipitation-caused runoff, and glacier meltwater contributed to the total recharge input by 51%, 40.96%, and 8.04%, respectively, while the lake surface evaporation accounted for 59.37% of the total recharge input as water loss. Thus, the left 40.63% of the input caused the LWSC increase. Although lake surface precipitation provided the primary contribution to the Hala Lake LWSC, precipitation-caused runoff was the key factor forming the three stages in the LWSC. The results of this study provide valuable information for the rational development and utilization of water resources by government departments and are also beneficial to the study of global change.

The occurrence, development, and metastasis of tumors often entail abnormal expression of genetic substances. Monitoring and regulating changes in intracellular nucleic acid substances hold promise for achieving accurate tumor diagnosis and effective treatment. However, the effectiveness of integrated tumor diagnosis and treatment based on functional nucleic acids still needs to be improved. In this study, we engineered a multifunctional nucleic acid delivery system grounded in a cationic covalent organic framework carrier. This system not only showcases effective gene silencing but also boasts high sensitivity in detecting miR21 levels within tumor cells, enabling real-time monitoring of tumor gene therapy efficacy. The construction of this integrated functional nucleic acid delivery platform provides new ideas for precise tumor detection and effective tumor treatment

ABSTRACT The surface urban heat island (SUHI) effect presents a significant challenge in urban environments. However, there is spatiotemporal variability in the SUHI effect and its drivers, which is often overlooked. To address this issue, this study employs the geographically and temporally weighted regression (GTWR) model to analyze the spatiotemporal heterogeneity of the SUHI and its driving factors. The findings reveal the following: (1) The SUHIs in the central urban area of Wuhan are located mainly on both sides of the Yangtze and Han Rivers, most notably in the Qingshan Industrial Zone; (2) in the city center, the land surface temperature (LST) is strongly positively correlated with the bare soil index (BSI), normalized difference built‐up index (NDBI), normalized difference vegetation index (NDVI), and nighttime light (NTL); (3) clear temporal disparities exist between the LST and the drivers, with the NDBI, NDWI, and NTL factors displaying the most notable variations; and (4) a comprehensive analysis has yielded quantitative relationships between the LST and associated drivers. In summary, it has been proven that there are spatiotemporal differences in the LST and its driving factors. Therefore, the impact of spatiotemporal heterogeneity should be considered when studying the mitigation of the SUHI effect.

Here, a novel strategy for the preparation of ultra-stable gold nanoparticles was developed based on a core-shell structure of single-molecule micelles, which offered advantages such as convenience, rapid preparation, size control. These ultra-stable gold nanoparticles enable specific miRNA detection, facilitating the precise screening of tumor cells.

Land surface water is a key part in the global ecosystem balance and hydrological cycle. Remote sensing has become an effective tool for its spatio-temporal monitoring. However, remote sensing results exemplified in so-called water indices are subject to several limitations. This paper proposes a new and effective water index called the Sentinel Multi-Band Water Index (SMBWI) to extract water bodies in complex environments from Sentinel-2 satellite imagery. Individual tests explore the effectiveness of the SMBWI in eliminating interference of various special interfering cover features. The Iterative Self-Organizing Data Analysis Technique Algorithm (ISODATA) method and confusion matrix along with the derived accuracy evaluation indicators are used to provide a threshold reference when extracting water bodies and evaluate the accuracy of the water body extraction results, respectively. The SMBWI and eight other commonly used water indices are qualitatively and quantitatively compared through vision and accuracy evaluation indicators, respectively. Here, the SMBWI is proven to be the most effective at suppressing interference of buildings and their shadows, cultivated lands, vegetation, clouds and their shadows, alpine terrain with bare ground and glaciers when extracting water bodies. The overall accuracy in all tests was consistently greater than 96.5%. The SMBWI is proven to have a high ability to identify mixed pixels of water and non-water, with the lowest total error among nine water indices. Most notably, better results are obtained when extracting water bodies under interfering environments of cover features. Therefore, we propose that our novel and robust water index, the SMBWI, is ready to be used for mapping land surface water with high accuracy.

Abstract The Tibetan Plateau (TP) is suffering from a substantial decline in terrestrial water storage (TWS) in exorheic basins, threatening water resources that are critical for ∼2 billion people downstream. TWS changes are commonly estimated using gravity satellites through observations of the total terrestrial mass storage (TMS) change, with an implicit assumption of a negligible contribution from sediment transport. Through long‐term (2002–2017) sediment flux observations in seven headwater basins on the TP, we reveal that the gravity satellite‐derived TMS has decreased at a rate of 3.85 ± 0.23 Gt yr−1 in the seven basins, of which 0.35 ± 0.04 Gt yr−1 is contributed by sediment transport. Neglecting this contribution leads to an overestimation of the TWS loss by 10.1 ± 1.3%, equivalent to the annual water demand of an additional 0.62 million people in the surrounding nations. Regionally, the overestimation is surprisingly high in the Indus River and Yarkant River basins, reaching up to 50.8%–77.6%.

Numerous studies have established the promise of combining phototherapy and gene therapy. However, there are persistent obstacles hindering the full optimization of this combined therapeutic approach, such as the maximum development of photosensitizers and the construction of high-performance gene carriers. The LEGO stacking characteristics of COFs have brought infinite imagination to the construction of delivery systems, allowing for the design of responsive nano castles based on different application scenarios. Here, we have constructed a novel cationic multifunctional nano COF nucleic acid delivery system based on photosensitizer and cationic monomers. The long-range ordered structure of COF effectively regulates the spatial distribution of photosensitizer, thereby preserving their phototherapy efficacy. Simultaneously, the inherent cationic porous nanostructure equips COF with exceptional capabilities for delivering nucleic acids. This integrated multifunctional nano delivery system significantly enhances the combined efficacy of phototherapy and gene therapy. The phototherapy capacity of COF enables precise tumor elimination in a spatiotemporal manner, inducing robust ICD and activating immune cells at the tumor site. Furthermore, loaded siPD-L1 significantly enhances immune cell recognition and killing of tumor cells, effectively shielding mice from re-invasion and tumor metastasis. The development of multifunctional nanomedicine based on COF provides new ideas for efficient tumor combination therapy.

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湖泊作为重要的国土资源,研究湖泊水域的动态变化有利于区域水资源开发利用,以及为生态平衡稳定提供重要保障.本文基于Google Earth Engine平台,以1989—2022年多源遥感数据为数据源,在归一化差分水体指数(NDWI)、改进的归一化差分水体指数(MNDWI)、自动水提取指数(AWEIsh)及基于线性判别分析的水体指数(WI2015)4种目前常用的水体指数中,选取最优水体指数进行洞庭湖流域水体提取;结合流域内降水气温、人口密度及土地利用等多种数据,探究洞庭湖流域水体演变特征并进行驱动力分析.结果表明,1989—2022年,洞庭湖区丰、枯水期水体面积总体呈下降趋势,3大湖区均有不同程度的缩减,平均减少93.27和140.15 km2.流域内湖泊面积是自然气候变化和人类活动共同影响作用的结果.其中,降水和气温是影响湖面积的重要自然因素,人口增加、围湖造田引起的土地利用类型转移是导致湖面积减少的人为因素.

Tibetan Plateau (TP) lakes are crucial water resources for many countries, and the region is sensitive to climate change, so the TP lakes’ dynamics have always been the focus of TP research. Given the vastness of the TP, the diversity of topography, geomorphology, and meteorological features, and the significant disparities in precipitation between river basins, it is vital to examine lake dynamics and influencing variables from the basin’s perspective. Based on Landsat imageries and supported by Google Earth Engine, lakes were mapped from 1990 to 2020. Results show that the TP lake’s number and area have increased significantly in recent 30 years except for a noticeable shrinkage from 1990 to 1995 and a slight decrease from 2013 to 2015. The lake area in the endorheic region basin area has grown obviously, with the most significant dynamics in the Qiangtang Basin, where the lake’s number and total area have increased by about 30

The MS 6.9 Menyuan earthquake occurred in the northeastern Tibetan Plateau on 8 January 2022. High-precision absolute gravity observations provide a unique perspective on seismotectonic feature of strong continental earthquakes. An obvious and coincident gravity increase about 5 years before the Menyuan earthquake with the rate up to 3.94 mu Gal/yr is observed at four absolute gravity stations within 350 km away from the epicenter. These four stations have been carried out repeat gravity observations by the Crustal Movement Observation Network of China (CMONOC) for more than a decade. The observed gravity changes could not be reasonably explained by the land water storage change nor crustal vertical deformation and thus might be related to the processes in the crust. A disc-shaped equivalent source region with a radius of 175 km is then modeled, based on the residual gravity rates. We find that the seismicity increases gradually in the modeled source region from about 2017 to 2021, similar to the pattern of absolute gravity change. Furthermore, the spatiotemporal distri-bution of epicenters is consistent with the fluids diffusion model, indicating that this could be related to the redistribution of deep fluid mass. With consideration of the near-surface processes, regional crustal structure, and seismicity, multiple lines of evidence consistently refer to the presence of deep fluids migration before the Menyuan earthquake. Our results suggest that high-precision absolute gravimetry can be used to monitor crustal fluid environment and determine mass changes in the source regions of potential large earthquakes.

Lakes are important land resources, and the study of the dynamic changes of lake waters is conducive to providing an important guarantee for the development and utilization of regional water resources and the stability of ecological balance. Based on Google Earth Engine, using multi-source remote sensing data from 1989 to 2022 as the data source, in normalized difference water index (NDWI), modified normalized difference water index (MNDWI), automatic water extraction index (AWEIsh) and the water index (WI2015) selects the optimal water body index from the four commonly used water body indexes to extract the water body of Dongting Lake Basin. Combined with various data such as precipitation, temperature, population density and land use in the basin to explore the Dongting Lake analysis of water body evolution characteristics and driving forces in the lake basin. The results show that, from 1989 to 2022, the water body area in the Dongting lake area showed an overall downward trend in the wet and dry seasons, and the three major lake areas all had different degrees of reduction, with an average reduction of 93.27 km2and 140.15 km2. The area of lakes in the basin is the result of the combined effects of natural climate change and human activities. Precipitation and temperature are important natural factors affecting the area of lakes. The increase in population and the transfer of land use types caused by reclamation of lakes are the human factors for the reduction of lake area.

The Tibetan Plateau (TP) has the largest number of high-altitude glaciers on Earth. As a source of major rivers in Asia, this region provides fresh water to more than one billion people. Any terrestrial water storage (TWS) changes there have major societal effects in large parts of the continent. Due to the recent acceleration in global warming, part of the water environment in TP has become drastically unbalanced, with an increased risk of water disasters. We quantified secular and monthly glacier-mass-balance and TWS changes in water basins from April 2002 to December 2021 through the Gravity Recovery and Climate Experiment and its Follow-on satellite mission (GRACE/GRACE-FO). Adequate data postprocessing with destriping filters and gap filling and two regularization methods implemented in the spectral and space domain were applied. The largest glacier-mass losses were found in the Nyainqentanglha Mountains and Eastern Himalayas, with rates of −4.92 ± 1.38 Gt a−1 and −4.34 ± 1.48 Gt a−1, respectively. The Tien Shan region showed strong losses in its eastern and central parts. Furthermore, we found small glacier-mass increases in the Karakoram and West Kunlun. Most of the glacier mass change can be explained by snowfall changes and, in some areas, by summer rainfall created by the Indian monsoon. Major water basins in the north and south of the TP exhibited partly significant negative TWS changes. In turn, the endorheic region and the Qaidam basin in the TP, as well as the near Three Rivers source region, showed distinctly positive TWS signals related to net precipitation increase. However, the Salween River source region and the Yarlung Zangbo River basin showed decreasing trends. We suggest that our new and improved TWS-change results can be used for the maintenance of water resources and the prevention of water disasters not only in the TP, but also in surrounding Asian countries. They may also help in global change studies.

The GRACE twin satellite gravity mission from 2002 to 2017 has considerably improved investigations on global and regional hydrological changes. However, there are different GRACE solutions and products available which may yield different results for certain regions despite applying the same postprocessing and time span. This is especially the case for the Tibetan Plateau (TP) with its special hydrological conditions represented by localized but strong signals that can overlap or merge with signals inside the plateau, which can falsify the determination of terrestrial water storage (TWS) changes in the TP area. To investigate the effect of GRACE solution selection on inverted TWS changes, we analyze quantitatively the secular and monthly changes for 14 glacier areas and 10 water basins in and around the TP area that have been calculated from 16 different available GRACE solutions. Our analysis provides expectable results. While trend results from different spherical harmonic (SH) GRACE solutions match well, there are significant differences to and between mascon GRACE solutions. This is related to the different processing concepts of mascon solutions and their forced handling in our comparisons. SH solution time series match each other when mass changes are strong with a large amplitude and regular periodicity. However, for regions where small TWS changes are associated with small amplitudes, trends, and/or unstable signal periods, SH solutions can also yield different results. Such behavior is known from a time series analysis. Interestingly though, we find that the COST-G and ITSG SH GRACE solutions are closest to the average of all solutions. Therefore, these solutions appear to be preferable for TWS investigations in regions with highly variable hydrological conditions, such as in the Tibetan Plateau and its surroundings. This also indicates that combined solutions such as COST-G provide a promising pathway for an improved TWS analysis, which should be further elaborated.

高校的教学和科研是辩证统一的.青年教师,特别是刚入职的青年教师,由于教学与科研经验不足,难以很好地平衡两者关系.高校青年教师如何平衡教学和科研,是需要深入探讨的话题.从高校青年教师如何面对教学与科研的矛盾困境出发,分析现状,协调矛盾,寻找平衡教学与科研的突破口,总结解决问题的方法举措,以期为广大高校青年教师提供有益参考.

EDITORIAL article Front. Earth Sci., 04 July 2023Sec. Environmental Informatics and Remote Sensing Volume 11 - 2023 | https://doi.org/10.3389/feart.2023.1235259

GRACE-based estimates for groundwater storage (GWS) changes in North America substantially depend upon correction of glacial isostatic adjustment (GIA) effects, which are usually removed with GIA models. In this study, GIA effects are eliminated by employing an independent separation approach with the aid of Global Navigation Satellite System (GNSS) vertical velocity data. Our goal is to provide an independent estimate for monthly GWS changes within North America in 1-degree-grids and their trends over the whole GRACE mission lifetime from April 2002 to June 2017. This estimate is derived from the release-6 version of GRACE monthly level-2 data, GNSS data, land surface models for soil moisture and snow water equivalent, and satellite altimetric lake level data. We find a GWS anomaly in form of an increasing trend in Saskatchewan, which affects the Saskatchewan Province and the states of Montana, North Dakota and Minnesota, and 4 GWS anomalies with declining trends in Nevada, California, Arizona and Texas, respectively. The monthly changes of these GWS anomalies, except for the one in Nevada, are validated by well level data. We provide results for average monthly GWS changes and the trends for the 5 anomalies but also in separate form for the 13 affected states or provinces. The increasing trends of the Saskatchewan GWS anomaly and the affected 3 states are related to increasing precipitation and can be elucidated by the decreasing drought intensity level. On the contrary, the declining trends in GWS can be explained by weakening precipitation and are mostly supported by the increasing drought intensity level in the other 4 anomalies and the affected states, which are Nevada, California, Arizona, New Mexico, Texas, Oklahoma, Kansas, and Colorado. Our estimates of monthly GWS changes and their trends can serve as alternative and beneficial input for the sustainable management of groundwater resources in North America.

Time series of the Gravity Recovery and Climate Experiment (GRACE) satellite mission have been successfully used to reveal changes in terrestrial water storage (TWS) in many parts of the world. This has been hindered in the interior of the Tibetan Plateau since the derived TWS changes there are very sensitive to the selections of different available GRACE solutions, and filters to remove north-south-oriented (N-S) stripe features in the observations. This has resulted in controversial distributions of the TWS changes in previous studies. In this paper, we produce aggregated hydrology signals (AHS) of TWS changes from 2003 to 2009 in the Tibetan Plateau and test a large set of GRACE solution-filter combinations and mascon models to identify the best combination or mascon model whose filtered results match our AHS. We find that the application of a destriping filter is indispensable to remove correlated errors shown as N-S stripes. Three best-performing destriping filters are identified and, combined with two best-performing solutions, they represent the most reliable solution-filter combinations for determination of weak terrestrial water storage changes in the interior of the Tibetan Plateau from GRACE. In turn, more than 100 other tested solution-filter combinations and mascon solutions lead to very different distributions of the TWS changes inside and outside the plateau that partly disagree largely with the AHS. This is mainly attributed to less effective suppression of N-S stripe noises. Our results also show that the most effective destriping is performed within a maximum degree and order of 60 for GRACE spherical harmonic solutions. The results inside the plateau show one single anomaly in the TWS trend when additional smoothing with a 340-km-radius Gaussian filter is applied. We suggest using our identified best solution-filter combinations for the determination of TWS changes in the Tibetan Plateau and adjacent areas during the whole GRACE operation time span from 2002 to 2017 as well as the succeeding GRACE-FO mission.

高等院校普遍存在教学和科研严重失衡的问题,该问题一直困扰着大多数高校教师.教学与科研的失衡不利于高校的生存与发展,以及高校教师自身的职业发展.文章纠正了"教学与科研不可兼容"的错误认识,阐述了教学和科研融合发展带来的相互促进效应,为广大高校教师提供有益参考,对实现高校人才培养和科学研究两大职能具有重要意义.

We provide estimates of glacier mass changes in the High Mountain Asia (HMA) area from April 2002 to August 2016 by employing a new version of gravity solutions of the Gravity Recovery and Climate Experiment (GRACE) twin-satellite mission. We find a total mass loss trend of the HMA glaciers at a rate of −22.17 (±1.96) Gt/a. The largest mass loss rates of −7.02 (±0.94) and −6.73 (±0.78) Gt/a are found for the glaciers in Nyainqentanglha Mountains and Eastern Himalayas, respectively. Although most glaciers in the HMA area show a mass loss, we find a small glacier mass gain of 1.19 (±0.55) and 0.77 (±0.37) Gt/a in Karakoram Mountains and Western Kunlun Mountains, respectively. There is also a nearly zero mass balance in Pamirs. Our estimates of glacier mass change trends confirm previous results from the analysis of altimetry data of the ICESat (ICE, Cloud and Land Elevation Satellite) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) DEM (Digital Elevation Model) satellites in most of the selected glacier areas. However, they largely differ to previous GRACE-based studies which we attribute to our different post-processing techniques of the newer GRACE data. In addition, we explicitly show regional mass change features for both the interannual glacier mass changes and the 14-a averaged seasonal glacier mass changes. These changes can be explained in parts by total net precipitation (net snowfall and net rainfall) and net snowfall, but mostly by total net radiation energy when compared to data from the ERA5-Land meteorological reanalysis. Moreover, nearly all the non-trend interannual mass changes and most seasonal mass changes can be explained by the total net radiation energy data. The mass loss trends could be partly related to a heat effect due to increased net rainfall in Tianshan Mountains, Qilian Mountains, Nyainqentanglha Mountains and Eastern Himalayas. Our new results for the glacier mass change in this study could help improve the understanding of glacier variation in the HMA area and contribute to the study of global change. They could also serve the utilization of water resources there and in neighboring areas.