Classification of ice and water in the Arctic using radar altimeter and microwave radiometer data from HY-2B satellite

Several Chinese marine satellites have been launched in recent years.Monitoring sea ice and the ocean in the Arctic is of great importance for climate research.Sea ice in the Arctic has changed rapidly during the past few decades with respect to the extent and thickness.In this study,we applied combined passive and active microwave data from the Chinese HaiYang-2B(HY-2B)satellite to classify ice and sea water in the Arctic.We use data from a radar altimeter(RA)and a calibration microwave radiometer(CMR)to discriminate between ice and water by applying several approaches(1)the single parameter threshold criteria,(2)the multi-parameters linear segmentations and(3)the K-means clustering.The results yielded by these methods were in good agreement(classification accuracy>95%)with the Satellite Application Facility on Ocean and Sea Ice products between November and April.For other months(May–October),however,the agreement was less good(lowest classification accuracy approximate 85%in summer).A hybrid approach combined with graphical ice edges detection and microwave radar waveform analysis is therefore developed.A visual comparison with SAR images suggested the hybrid approach results greatly improved the ice and water discrimination in summer.This study demonstrated that multi-sensors(RA and CMR)configurations from HY satellites can offer comparable polar earth observation to the European Space Agency and NOAA satellite products.

Advances in Research on Soil Moisture by Microwave Remote Sensing in China

Soil moisture is an important factor in global hydrologic circulation and plays a significant role in the research of hydrology, climatology, and agriculture. Microwave remote sensing is less limited by climate and time, and can measure in large scale. With these characteristics, this technique becomes an effective tool to measure soil moisture. Since the 1980s, Chinese researchers have investigated the soil moisture using microwave instruments. The active re- mote sensors are characteristic of high spatial resolution, thus with launch of a series of satellites, active microwave remote sensing of soil moisture will be emphasized. The passive microwave remote sensing of soil moisture has a long research history, and its retrieval algorithms were developed well, so it is an important tool to retrieve large scale moisture information from satellite data in the future.

Hierarchical pore structure of activated carbon fabricated by CO_2/microwave for volatile organic compounds adsorption

An activated carbon pore-expanding technique was achieved through innovative reactivation by CO_2/microwave.The original and modified activated carbons were characterized by nitrogen adsorption–desorption,scanning electron microscopy,transmission electron microcopy,and Fourier transform infrared spectroscopy.The mesopore volume increased from 0.122 cm^3·g^(-1) to 0.270 cm^3·g^(-1),and a hierarchical pore structure was formed.A gradual decrease in the phenolic hydroxyl and carboxyl groups on the surface of activated carbon enhanced the surface inertia of granular activated carbon(GAC).The toluene desorption rate of the modified sample increased by 8.81% compared with that of the original GAC.Adsorption isotherm fittings revealed that the Langmuir model was applicable for the original and modified activated carbons.The isosteric adsorption heat of toluene on the activated carbon decreased by approximately 50%,which endowed the modified sample with excellent stability in application.The modified samples showed an enhanced desorption performance of toluene,thereby opening a way to extend the cycle life and improve the economic performance of carbon adsorbent in practical engineering applications.

New Activated Carbon with High Thermal Conductivity and Its Microwave Regeneration Performance

Using a walnut shellas a carbon source and ZnCl_2 as an activating agent,we resolved the temperature gradient problems of activated carbon in the microwave desorption process.An appropriate amount of silicon carbide was added to prepare the composite activated carbon with high thermalconductivity while developing VOC adsorption-microwave regeneration technology.The experimentalresults show that the coefficient of thermalconductivity of SiC-AC is three times as much as those of AC and SY-6.When microwave power was 480 W in its microwave desorption,the temperature of the bed thermaldesorption was 10 ℃ to 30 ℃ below that of normalactivated carbon prepared in our laboratory.The toluene desorption activation energy was 16.05 k J·mol^（-1）,which was 15% less than the desorption activation energy of commercialactivated carbon.This study testified that the process could maintain its high adsorption and regeneration desorption performances.

Enhancing Surface Soil Moisture Estimation through Integration of Artificial Neural Networks Machine Learning and Fusion of Meteorological, Sentinel-1A and Sentinel-2A Satellite Data

For many environmental and agricultural applications, an accurate estimation of surface soil moisture is essential. This study sought to determine whether combining Sentinel-1A, Sentinel-2A, and meteorological data with artificial neural networks (ANN) could improve soil moisture estimation in various land cover types. To train and evaluate the model’s performance, we used field data (provided by La Tuscia University) on the study area collected during time periods between October 2022, and December 2022. Surface soil moisture was measured at 29 locations. The performance of the model was trained, validated, and tested using input features in a 60:10:30 ratio, using the feed-forward ANN model. It was found that the ANN model exhibited high precision in predicting soil moisture. The model achieved a coefficient of determination (R2) of 0.71 and correlation coefficient (R) of 0.84. Furthermore, the incorporation of Random Forest (RF) algorithms for soil moisture prediction resulted in an improved R2 of 0.89. The unique combination of active microwave, meteorological data and multispectral data provides an opportunity to exploit the complementary nature of the datasets. Through preprocessing, fusion, and ANN modeling, this research contributes to advancing soil moisture estimation techniques and providing valuable insights for water resource management and agricultural planning in the study area.

Insight to defects regulation on sugarcane waste-derived hard carbon anode for sodium-ion batteries

A great deal of attention has been paid on developing plant-derived hard carbon(HC)materials as anodes for sodium-ion batteries(SIBs).So far,the regulation of HC has been handicapped by the well-known ambiguity of Na^(+)storage mechanism,which fails to differentiate the Na^(+)adsorption and Na^(+)insertion,and their relationship with the size of d-interlayer spacing and structural porosity.Herein,bagassederived HC materials have been synthesized through a combination of pyrolysis treatment and microwave activation.The combined protocol has enabled to synergistically control the d-interlayer spacing and porosity.Specifically,the microwave activation has created slit pores into HC and these pores allow for an enhanced Na^(+)adsorption with an increased sloping capacity,establishing a strong correlation between the porosity and sloping capacity.Meanwhile,the pyrolysis treatment promotes the graphitization and it contributes to an intensified Na^(+)insertion with an increased plateau capacity,proving that the plateau capacity is largely contributed by the Na^(+)insertion between interlayers.Therefore,the structural regulation of bagasse-derived HC has provided a proof on positively explaining the Na^(+)storage with HC materials.The structural changes in the pore size distribution,specific surface area,d-interlayer spacing,and the electrochemical properties have been comprehensively characterized,all supporting our understanding of Na^(+)storage mechanism.As a result,the HC sample with an optimized d-interlayer spacing and porosity has delivered an improved reversible capacity of 323.6 m Ah g^(-1) at 50 m A g^(-1).This work provides an understanding of Na^(+)storage mechanism and insights on enhancing the sloping/plateau capacity by rationally regulating the graphitization and porosity of HC materials for advanced SIBs.

Rapid and simple spectrophotometric determination of persulfate in water by microwave assisted decolorization of Methylene Blue

A rapid and simple method for determination of persulfate in aqueous solution was developed. The method is based on the rapid reaction of persulfate with Methylene Blue（MB） via domestic microwave activation, which can promote the activation of persulfate and decolorize MB quickly. The depletion of MB at 644 nm（the maximum absorption wavelength of MB） is in proportion to the increasing concentration of persulfate in aqueous solution. Linear calibration curve was obtained in the range 0-1.5 mmol/L, with a limit of detection of 0.0028 mmol/L. The reaction time is rapid（within 60 sec）, which is much shorter than that used for conventional methods. Compared with existing analytical methods, it need not any additives, especially colorful Fe2＋, and need not any pretreatment for samples, such as p H adjustment.

High electromechanical reponses of ultra-high-density aligned nano-porous microwave exfoliated graphite oxide/polymer nanocomposites ionic actuators

High elastic energy density and high-efficiency ionic electromechanical actuators were prepared from aligned activated microwave exfoliated graphite oxide(A-aMEGO)/polymer nano-composites,and the electromechanical performance was characterized.The elastic modulus and elastic energy density of the ionic actuators can be tuned over a wide range by varying the polymer(poly(vinylidene fluoride/chlorotrifluoroethylene)[P(VDF-CTFE)])concentration in the nano-composite actuators.The A-aMEGO/P(VDF-CTFE)nano-composite actuators with 35 wt.%of polymer content exhibit an elastic energy density higher than 5 J/cm^(3) and an electromechanical conversion efficiency higher than 3.5%,induced under 4 V.The results show the promise of high-density highly aligned graphene electrodes for high-performance ionic electromechanical transduction devices.

Conventional and microwave irradiated synthesis,biological activity evaluation and molecular docking studies of highly substituted piperazine-azole hybrids

Azole derivatives（3,6） obtained starting from 1-（2-methoxyphenyl） piperazine were converted to the corresponding Mannich bases containing β-lactame or flouroquinolone core via a one pot three component reaction.The synthesis of conazole analogues was carried out starting from triazoles by three steps.Reactions were carried out under conventional and microwave mediated conditions.All the newly synthesized compounds were screened for their antimicrobial,enzyme inhibition and antioxidant activity,and most of them displayed good-moderate activity.Binding affinities and non-covalent interactions between enzyme-ligand complexes were predicted with molecular docking method at molecular level.Docking results complemented well the experimental results on α-glucosidase and urease inhibitory effects of the compounds.Higher binding affinities and much more interaction networks were observed for active compounds in contrary to inactive ones.It was predicted with the docking studies that triazole and anisole moieties in the structure of the synthesized compounds contributed to the stabilization of corresponding enzymes through noncovalent interactions.