Land surface temperature (LST) is a crucial parameter that reflects land–atmosphere interaction and has thus attracted wide interest from geoscientists. Owing to the rapid development of Earth ...observation technologies, remotely sensed LST is playing an increasingly essential role in various fields. This review aims to summarize the progress in LST estimation algorithms and accelerate its further applications. Thus, we briefly review the most‐used thermal infrared (TIR) LST estimation algorithms. More importantly, this review provides a comprehensive collection of the widely used TIR‐based LST products and offers important insights into the uncertainties in these products with respect to different land cover conditions via a systematic intercomparison analysis of several representative products. In addition to the discussion on product accuracy, we address problems related to the spatial discontinuity, spatiotemporal incomparability, and short time span of current LST products by introducing the most effective methods. With the aim of overcoming these challenges in available LST products, much progress has been made in developing spatiotemporal seamless LST data, which significantly promotes the successful applications of these products in the field of surface evapotranspiration and soil moisture estimation, agriculture drought monitoring, thermal environment monitoring, thermal anomaly monitoring, and climate change. Overall, this review encompasses the most recent advances in TIR‐based LST and the state‐of‐the‐art of applications of LST products at various spatial and temporal scales, identifies critical further research needs and directions to advance and optimize retrieval methods, and promotes the application of LST to improve the understanding of surface thermal dynamics and exchanges.
Plain Language Summary
Land surface temperature (LST) is a crucial geophysical parameter related to surface energy and water balance of the land‐atmosphere system. Satellite remote sensing provides the best way to measure LST and generate various LST products at regional and global scales. In this review, to facilitate the application of LST products in different fields, we first present the physical meaning of satellite‐derived LST. Subsequently, we summarize recent advances in LST retrieval and validation methods, with a special focus on the state‐of‐the‐art product collections, product accuracies and intercomparisons, and main problems in current LST products as well as their possible solutions. Additionally, we also review the major applications of LST products in agricultural drought monitoring, thermal environment monitoring, thermal anomaly monitoring, and climate change. Finally, we offer recommendations or perspectives to promote LST retrieval methods and their applications. This review will aid the user in gaining a thorough comprehensive understanding of satellite‐derived LST products and promoting their appropriate applications.
Key Points
State‐of‐the‐art satellite‐derived land surface temperature (LST) product levels, sources, uncertainties, and differences are provided
Typical applications of LST products in various fields are summarized
Future directions for the generation and applications of LST products are recommended
High‐strength petroleum‐based materials like plastics have been widely used in various fields, but their nonbiodegradability has caused serious pollution problems. Cellulose, as the most abundant ...sustainable polymer, has a great chance to act as the ideal substitute for plastics due to its low cost, wide availability, biodegradability, etc. Herein, the recent achievements for developing cellulose “green” solvents and regenerated cellulose materials with high strength via the “bottom‐up” route are presented. Cellulose can be regenerated to produce films/membranes, hydrogels/aerogels, filaments/fibers, microspheres/beads, bioplastics, etc., which show potential applications in textiles, biomedicine, energy storage, packaging, etc. Importantly, these cellulose‐based materials can be biodegraded in soil and oceans, reducing environmental pollution. The cellulose solvents, dissolving mechanism, and strategies for constructing the regenerated cellulose functional materials with high strength and performances, together with the current achievements and urgent challenges are summarized, and some perspectives are also proposed. The near future will be an exciting era for high‐strength biodegradable and renewable materials. The hope is that many environmentally friendly materials with good properties and low cost will be produced for commercial use, which will be beneficial for sustainable development in the world.
Rengenerated cellulose materials with the forms of films/membranes, fibers, hydrogels, aerogels, beads/microspheres can be designed via chemical crosslinking, chemically dual‐crosslinking, physical crosslinking, and chemically and physically double crosslinking for achieving the high strength and bidegradability. These cellulose‐based materials are a promising substitute for nonbiodegradable petroleum‐derived synthetic polymers, contribut ing to a sustainable development in the world.
Land surface temperature (LST) is an important physical quantity at the land-atmosphere interface. Since 2016 the Collection 6 (C6) MODIS LST product is publicly available, which includes three ...refinements over bare soil surfaces compared to the Collection 5 (C5) MODIS LST product. To encourage the use of the C6 MODIS LST product in a wide range of applications, it is necessary to evaluate the accuracy of the C6 MODIS LST product. In this study, we validated the C6 MODIS LST product using temperature-based method over various land cover types, including grasslands, croplands, cropland/natural vegetation mosaic, open shrublands, woody savannas, and barren/sparsely vegetated. In situ measurements were collected from various sites under different atmospheric and surface conditions, including seven SURFRAD sites (BND, TBL, DRA, FPK, GCM, PSU, and SXF) in the United States, three KIT sites (EVO, KAL, and GBB) in Portugal and Namibia, and three HiWATER sites (GBZ, HZZ, and HMZ) in China. The spatial representativeness of the in situ measurements at each site was separately evaluated during daytime and nighttime using all available clear-sky ASTER LST products at 90 m spatial resolution. Only six sites during daytime are selected as sufficiently homogeneous sites despite the usually high spatial thermal heterogeneity, whereas during nighttime most sites can be considered to be thermally homogeneous and have similar LST and air temperature. The C6 MODIS LST product was validated using in situ measurements from the selected homogeneous sites during daytime and nighttime: except for the GBB site, large RMSE values (>2 K) were obtained during daytime. However, if only satellite LST with a high spatial thermal homogeneity on the MODIS pixel scale are used for LST validation, the best daytime accuracy (RMSE <1.3 K) for the C6 MODIS LST product is achieved over the BND and DRA sites. Except for the DRA site, the RMSE values during nighttime are <2 K at the selected homogeneous sites. Furthermore, the accuracy of the C6 MODIS LST product was compared with that of the C5 MODIS LST product during nighttime at the selected homogeneous sites. Except for the GBB site, there are only small differences (<0.4 K) between the RMSE values for the C5 and C6 MODIS LST products.
•C6 MODIS LST product was validated using the temperature-based method.•We compared with C5 and C6 MODIS LST products over various land cover types.•Except for bare soil sites, the RMSE difference between C5 and C6 is <0.4 K.•The existing issues of C6 MODIS LST product were analyzed and discussed.
A highly hydrophobic and oleophilic chitin sponge was synthesized, for the first time, via a freeze-dried method and then by using a thermal chemical vapor deposition of methyltrichlorosilane (MTCS) ...at different relative humidity. Fourier-transform infrared, energy-dispersive X-ray spectra, and scanning electron microscopy confirmed that the silanization occurred on the pore wall surface of the chitin sponge. The MTCS-coated chitin sponge had interconnected open-cell structures with the average pore size from 20 to 50 μm, and the MTCS nanofilaments immobilized on the chitin matrix, leading to the high hydrophobicity, as a result of the existence of a solid/air composite rough surface. Cyclic compression test indicated that the hydrophobic chitin sponges exhibited excellent elasticity and high mechanical durability. The sponges could efficiently collect organics both on the surface and bottom from the water with the highest 58 times of their own weight absorption capacities through the combination of the particular wettability and great porosity. Furthermore, the biodegradation kinetics of the chitin sponge forecasted that the chitin could be completely biodegraded within 32 days by the microorganisms in the soil. This work provided a new pathway to prepare the chitin-based materials for highly effective removal of oil from water, showing potential application in the pollutant remediation field.
We have developed surface-initiated organocatalytic ring-opening polymerization on functional nanocrystals and synthesized amphiphilic gold nanorods carrying well-defined mixed polymer brushes of ...poly(ethylene glycol) and polylactide. Self-assembly of the amphiphilic gold nanorods affords biodegradable plasmonic vesicles that can be destructed by both enzymatic degradation and near-infrared photothermal heating. When tagged with Raman probes, strongly coupled gold nanorods in the self-assembled vesicles give rise to highly active SERS signals. The biodegradable plasmonic vesicles exhibit a unique combination of optical and structural properties that are of particular interest for theranostic applications. We have demonstrated that bioconjugated SERS-active plasmonic vesicles can specifically target EpCAM-positive cancer cells, leading to ultrasensitive spectroscopic detection of cancer cells. Furthermore, integration of photothermal effect of gold nanorods and large loading capacity of the vesicles provides opportunities for localized synergistic photothermal ablation and photoactivated chemotherapy, which have shown higher efficiency in killing targeted cancer cells than either single therapeutic modality. The versatile chemistry of organocatalytic ring-opening polymerization, in conjugation with recent development in synthesizing functional nanocrystals with tailored optical, electronic, and magnetic properties opens the possibilities for constructing multifunctional biodegradable platforms for clinical translation.
Land surface temperatures (LSTs) at high spatial resolution are crucial for hydrological, meteorological, and ecological studies. Downscaling LSTs from coarse resolution to finer resolution is an ...alternative way to obtain LSTs at high spatial resolution. In this paper, we proposed a new algorithm based on geographically weighted regression (GWR) to downscale Moderate Resolution Imaging Spectroradiometer LST data from 990 to 90 m. Unlike previous LST downscaling algorithms, this algorithm built the nonstationary relationship between LST and other environmental factors (including the normalized difference vegetation index and a digital elevation model) using geographically varying regression coefficients. The uncertainty in this algorithm was evaluated with a sensitivity analysis. The results show that the total uncertainty in this algorithm is less than 2 K. The performance of the GWR-based algorithm was assessed using concurrent ASTER LST data as a reference LST data set. Moreover, this algorithm was compared against the TsHARP algorithm, which was widely used for LST downscaling. The results indicate that the GWR-based algorithm outperforms the TsHARP algorithm in terms of statistical results. The root mean square error (mean absolute error) value decreases from 3.6 K (2.7 K) for the TsHARP algorithm to 3.1 K (2.3 K) for the GWR-based algorithm.
Land surface temperature (LST) reflects the cold and hot conditions of the land surface and is one of the most important geophysical parameters in the study and research of the land-atmosphere ...system. Passive microwave (PMW) is one of the primary techniques for obtaining spatially continuous LST at regional, continental, and global scales. However, there is an orbital gap in the LST retrieved from PMW (PMW LST) due to the scanning scheme of the PMW sensor, which limits the application of PMW LST, so it is necessary for the proposed some methods to fill the orbital gap of PMW LST. In this study, a new orbital gap-filling method based on a deep neural network (DNN) was developed to address the issue of PMW LST orbital gaps. This method first established the DNN model based on the nonlinear relationship between AMSR2 LST and 11 environmental variables and then used the DNN model to generate a new spatially continuous LST product, namely, DNN-LST, and, finally, used DNN-LST to fill the orbital gaps of AMSR2 LST to generate the daytime/nighttime spatially seamless gap-filled LST (GF-LST) product for China from 2012 to 2020. GF-LST can more correctly represent the spatiotemporal variation of surface temperature in China than AMSR2 LST because it has continuous spatial texture information and no obvious boundary reconstruction effect. After verifying the accuracy of GF-LST products through simulated gap region validation and in situ validation, it can be found that: 1) DNN-LST in simulated gap regions showed high accuracy during the daytime and nighttime on July 15, 2012-2020, and the mean values of bias and root mean square error (RMSE) compared with AMSR2 LST at day (night) were, respectively, −0.08 K (−0.22 K) and 1.89 K (2.23 K); 2) the accuracy of DNN-LST was the best in autumn (mean RMSE values of 1.43 K at day and 1.89 K at night) and the worst in winter (mean RMSE values of 2.35 K at day and 2.36 K at night), no matter during daytime or nighttime, in different seasons in 2015-2017; 3) the RMSE value of DNN-LST during nighttime was slightly higher than the RMSE value of DNN-LST during daytime; and 4) the accuracy of DNN-LST was equivalent to AMSR2 LST, that is, the unbiased RMSE (ubRMSE) of DNN-LST and AMSR2 LST was all about 4 K compared with in situ LST, but the ubRMSE of DNN-LST was slightly lower than AMSR2 LST. The above accuracy validation analysis shows that DNN-LST has good robustness and good spatial consistency with AMSR2 LST and can be well used to fill the orbital gap of AMSR2 LST to generate spatial seamless GF-LST product.
3D printing is becoming increasingly popular for construction owing to its reduced environmental impact and lower energy demand than conventional manufacturing. Rapid application of this technology ...relies largely on the development of high-performance cement-based composites compatible with 3D printers. This study aims to develop high-quality and sustainable cement-based composites containing microcrystalline cellulose (MCC) that can satisfy the requirements for 3D printing. The workability, rheological behavior, buildability, and mechanical properties of the cement-based composites for 3D printing were examined systematically. The rheological analysis revealed that the plastic viscosity and yield stress of mortars with 1 wt% MCC were increased by 20.9% and 190.0%, respectively, compared with those of mortars without MCC. The buildability of mortars with 1 wt% MCC was also improved, and the printed structure exhibited neither large cracks among the printed filaments nor distorted components in the printing process. Compared with the mortars without MCC, the 28-d compressive and flexural strengths of the mortars with 1 wt% MCC were increased by 18.6% and 12.5%, respectively. In addition, the carbon emissions from the overall life cycle of a printed residence were quantified by considering the material attributes of additive manufacturing and using software tools to conduct building information modeling (BIM)-enabled life cycle assessment (LCA) modeling. The results indicated that compared with the mortars without MCC at equivalent mechanical strengths, the mortars containing 1 wt% MCC could reduce the CO2 emissions by 6.82%. The comprehensive improvement in rheological properties and buildability as well as the environmental benefits can promote the sustainable industrial utilization of MCC-reinforced cement-based materials in the 3D-printing industry.
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1.Micro-crystalline cellulose (MCC) was evaluated in composites for 3D-printing2.Printable MCC-reinforced composites exhibited good rheology and buildability3.BIM and LCA tools were coupled to evaluate the environmental impact4.Addition of MCC contributed to a reduction in CO2 emissions from the composites5.High-quality sustainable composites meeting 3D printing requirements were proposed
Land surface temperature (LST) plays a crucial role in the physical and chemical processes of the land-atmosphere system. Remote sensing technology has greatly advanced the measurement of thermal ...infrared LST (TIR LST), which is the most widely utilized surface temperature product. However, cloud cover and mist often cause significant data loss in TIR LST. To address this issue and reconstruct the MYD11A1 LST under cloudy conditions, this study proposes an all-weather LST generation method based on the extreme gradient boosting (XGBoost) model. This method incorporates spatial-seamless passive microwave LST (PMW LST) to capture the nonlinear relationship between TIR LST and other variables. Compared to the MYD11A1 LST, the generated all-weather LST provides continuous spatial texture information without a significant boundary reconstruction effect, improving the accuracy of spatiotemporal variations in LST in China. In situ validation demonstrated the high accuracy of the generated all-weather LST, with mean <inline-formula> <tex-math notation="LaTeX">R^{2} </tex-math></inline-formula>, bias, and unbiased root-mean-square error (ubRMSE) of 0.96 (0.91), 1.08 K (3.61 K), and 2.92 K (4.54 K) under clear (cloudy) daytime conditions, and 0.92 (0.95), −0.93 K (−2.96 K), and 3.09 K (3.04 K) under clear (cloudy) nighttime conditions. These results indicate the feasibility and reasonableness of the all-weather LST generation method developed in this study and affirm its ability to generate highly accurate all-weather LST.
Accumulating evidence demonstrated that long noncoding RNAs (lncRNAs) played important regulatory roles in many cancer types. However, the role of lncRNAs in gastric cancer (GC) progression remains ...unclear.
RT-qPCR assay was performed to detect the expression of HNF1A-AS1 in gastric cancer tissues and the non-tumourous gastric mucosa. Overexpression and RNA interference approaches were used to investigate the effects of HNF1A-AS1 on GC cells. Insight into competitive endogenous RNA (ceRNA) mechanisms was gained via bioinformatics analysis, luciferase assays and an RNA-binding protein immunoprecipitation (RIP) assay, RNA-FISH co-localisation analysis combined with microRNA (miRNA)-pulldown assay.
This study displayed that revealed expression of HNF1A-AS1 was associated with positive lymph node metastasis in GC. Moreover, HNF1A-AS1 significantly promoted gastric cancer invasion, metastasis, angiogenesis and lymphangiogenesis in vitro and in vivo. In addition, HNF1A-AS1 was demonstrated to function as a ceRNA for miR-30b-3p. HNF1A-AS1 abolished the function of the miRNA-30b-3p and resulted in the derepression of its target, PIK3CD, which is a core oncogene involved in the progression of GC.
This study demonstrated that HNF1A-AS1 worked as a ceRNA and promoted PI3K/AKT signalling pathway-mediated GC metastasis by sponging miR-30b-3p, offering novel insights of the metastasis mechanism in GC.
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