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In this research, AlN nano-powders were prepared by combining carbon-containing droplet combustion (CCDC) and carbothermal reduction (CR) methods. Firstly, Al 2 O 3 +C mixed precursor was synthesized by the CCDC method, and then AlN nano-powder was obtained by the carbothermal reduction of this CCDC precursor. The effects of urea and glucose contents, ignition temperature, and combustion atmosphere on precursors and AlN powders were studied in detail. The results showed that with the molar ratio of urea to aluminum nitrate (U/A) of 3, the atomic ratio of carbon to aluminum (C/Al) of 6, and the ignition temperature at 800 °C under air atmosphere, the prepared precursor was composed of hollow and spherical structure particles exhibiting rough and porous surface morphology with high specific surface area (SSA) (41.4 m2/g). AlN nano-powders obtained by the carbothermal reduction of this precursor were found to be consisted of fine particles with the size of 20–30 nm with high SSA of 39.9 m2/g. [ABSTRACT FROM AUTHOR]

Natural animal-based flavors have great appeal to consumers and have broad applications in the food industry. In this review, we summarized findings related to bacon and Cheddar cheese flavors' components and their precursors, reaction mechanisms, influential factors, and characterization methods. The results show that free sugars, free amino acids, peptides, vitamins, lipids, and nitrites are precursors to bacon flavor. The conditions governing the formation of bacon flavor are thermally dependent, which facilitates the use of thermal food processing to generate such a flavor. For Cheddar cheese flavor, milk ingredients such as lactose, citrate, fat, and casein are reported as precursors. The optimum conditions to generate Cheddar cheese flavor from precursors are quite strict, which limits its application in food processing. As an alternative, it is more practical to generate Cheddar cheese flavor by combining key aroma compounds using thermal food processing. This review provides the food industry the comprehensive information about the generation of bacon and Cheddar cheese flavors using precursor molecules. [ABSTRACT FROM AUTHOR]

Using citric acid, ethylene glycol, ZrOCl 2 ·8H 2 O, HfOCl 2 ·8H 2 O, NbCl 5 , and TaCl 5 as raw materials, based on the principle of Pechini coordination polymerization, the (Zr 0.25 Hf 0.25 Ta 0.25 Nb 0.25)C high-entropy ceramic precursor solution was successfully prepared, and the corresponding high-entropy ceramic powder was formed by pyrolysis at a low temperature of 1500 °C. The molecular structure of the precursor and its pyrolysis products were analyzed and characterized by different analytical and testing methods. The results show that in the precursor solution, the organic compound and the metal ions form a stable three-dimensional macromolecular structure, so that the metal ions show a uniform distribution at the molecular level, shortening the diffusion path during the carbothermal reduction reaction, thereby enabling the formation of the single-phase high-entropy carbide ceramic powders at a relatively low temperature. The obtained ceramic powders have high purity, uniform element distribution, with an average particle diameter of approximately 42 nm and an oxygen content of about 1.61 wt%. The precursor solution prepared in this study has a moderate viscosity of 20–50 mPa s and a high ceramic yield of 45 %, which is ideal for the preparation of high-entropy ceramic matrix composites. [ABSTRACT FROM AUTHOR]

Among the REBa2Cu3O7‐δ (REBCO or RE123, RE = rare earth element) family, SmBCO is preferably used in top‐seeded melt‐growth (TSMG) because of its outstanding property and more controllable stoichiometry 123. Nevertheless, the refinement of Sm2BaCuO5 (Sm211) particles has been challenging for high‐performance SmBCO bulks. Conventional precursor powders (SmBa2Cu3O7‐δ plus Sm2BaCuO5) intrinsically result in enlarging Sm2BaCuO5 particles due to their coarsening and epitaxial growth during the heating process. Here, we used modified precursor powders (MPPs, Sm2O3 plus Ba2Cu3O5) in air‐processed TSMG, in which there is neither Sm211 in the beginning nor related enlargement during heating. Consequently, the nucleation catastrophe of Sm211 occurred above the peritectic temperature, which in situ formed, possessing naturally small size. Further, aiming to suppress the Sm/Ba substitution, Ba‐rich MPP, substituting Ba2Cu3O5 with Ba3Cu4O7) was employed, producing an excellent SmBCO bulk with a diameter of 24 mm: levitation force of 51.5 N and trapped field of 0.537 T. Optical micrographs and quantitative analyses confirmed the superior refinement and distribution of Sm211 particles in SmBCO bulks. Most importantly, new strategies in this work are widely applicable for developing cost‐effective and high‐performance other REBCO bulk superconductors. [ABSTRACT FROM AUTHOR]

The article analyzes Edith Wharton's ghost story "All Souls'," focusing on the character of Doctor Selgrove as a harbinger of aging and unwelcome changes. The story follows Sara Clayburn, a wealthy widow who breaks her ankle on Halloween and is left alone in her mansion during a snowstorm. Both Sara and Doctor Selgrove represent relics of the past, struggling to adapt to modern technology and societal changes. As Sara's physical and mental decline accelerates, she ultimately ends up in assisted living, reflecting the inevitability of aging for both her and Doctor Selgrove. [Extracted from the article]

New hematopoietic cell models have recently emerged through immortalization of CD34 cells to study and understand various molecular mechanisms of erythropoiesis. Here, we characterize the JK-1 CML-derived cell line, previously shown to spontaneously differentiate without cytokines. Using an epigenetic differentiation inhibitor that keeps JK-1 in an early differentiation phase, we characterized 2 progenitor stages: BFU-E JK-1 and CFU-E JK-1 with CD34+/CD36− and CD34−/CD36 + phenotypes respectively. Then, using the PFI-1 inducer known to synchronously control the terminal differentiation of JK-1 cells, 5 precursor stages were obtained (ProE, Baso1-2, PolyC, OrthoC) and characterized via cell morphology, CD49a and Band3 markers. Enlarged phenotyping was carried out for the earlier phase, and expression kinetics of membrane proteins such as RhAG, RhD/CE, CD47, DARC and CD44 were performed on each stage of the terminal phase. Furthermore, since JK-1 offers the unique property of covering a broad spectrum of differentiation stages, we explored deeper the GATA2/GATA1 and the non-erythroid/erythroid spectrin 'switching'. The possibility of obtaining large quantities of JK-1 cells at each stage of differentiation, as shown in this study, as well as the potential to genetically modify these cells, via CrisprCas9, makes their use of considerable interest for studying pathologies occurring during erythropoiesis. [ABSTRACT FROM AUTHOR]

This study focuses on the primary synoptic‐scale patterns and precursors of extreme and non‐extreme precipitation over the Tibetan Plateau (TP). Atmospheric circulation anomalies and their precursors associated with regional extreme precipitation events (REPE) demonstrate distinct precursor wave train and heightened intensity than regional non‐extreme precipitation events (non‐REPE). Specifically, REPE over the northwestern TP (NWTP) exhibits a geopotential height anomaly induced by a latitudinal propagating Rossby wave train along 40°N. In contrast, over the southeastern TP (SETP), REPE is characterized by a geopotential height anomaly caused by a northwest‐southeastward propagating Rossby wave train. The ascending motion anomalies of REPE over both NWTP and SETP are primarily attributed to the geostrophic zonal temperature advection, which is significantly stronger during REPE compared to non‐REPE. This finding provides valuable insights for forecasting summer extreme precipitation over TP. Plain Language Summary: Tibetan Plateau (TP) is experiencing warming and increased humidity in the context of climate change, leading to a rise in extreme precipitation events. This study focuses on analyzing the circulation patterns and precursors associated with summer extreme precipitation over TP, aiming to identify differences between extreme and non‐extreme precipitation events, as well as explaining the unique characteristics of summer extreme precipitation over TP to answer the question of what distinguishes summer extreme precipitation from non‐extreme precipitation over TP. The findings suggest that summer regional extreme precipitation events (REPE) over the northwest and southeast TP (NWTP and SETP, respectively) display distinct characteristics in terms of atmospheric circulation anomalies and their precursors, which are significantly stronger compared to regional non‐extreme precipitation events (non‐REPE) of varying intensities observed in these two regions. The ascending motion (ω) anomalies responsible for TP's REPE are primarily influenced by the Laplacian of geostrophic zonal temperature advection (term B‐x). Key Points: The extreme precipitation characteristics of the NWTP and SETP, as well as the atmospheric circulation patterns influencing them, exhibit significant disparitiesCirculation anomalies associated with extreme precipitation exhibit a stronger and more distinct precursor wave train, compared to non‐extreme precipitationThe dominant factor driving ascending motion for extreme precipitation over TP is the geostrophic zonal temperature advection [ABSTRACT FROM AUTHOR]

The geopolymerization reaction is a chemical process involving the dissolution of amorphous, semi-crystalline and crystalline phases following alkaline or acid attack at ambient or at low temperature (T˂100 °C). Together with precondensed entities of the used activator solution the dissolved parts form a geopolymer network which glues together all remaining unreacted parts as ingredients of the artificial stone. The fate of the mineralogical phases present in the precursors used in the synthesis of alkaline and acid geopolymers is reviewed in this article. The different starting materials used in the synthesis of geopolymers and the different techniques used to modify the reactivity of these materials are reported. The mineralogical evolution of the amorphous, semi-crystalline and crystalline phases after activation at ambient and at low temperatures (T < 100 °C) is also reported. This study shows that for the mineralogical investigation of raw material, precursors and geopolymers, XRD is the most widely used analytical method. The most commonly used method to confirm the participation of crystalline phases in geopolymerization is the comparison of the diffractograms of the raw material to those of the products. It also indicates that, in addition to the amorphous aluminosilicate phases, certain semi-crystalline, and crystalline phases participate in this geopolymerization dynamic either by undergoing total or partial dissolution to form an inorganic macromolecule with an amorphous structure of the zeolitic type and other new minerals. The composition of the phases formed depends on the base material. Increasing the synthesis temperature promotes the dissolution of phases, the formation of geopolymer networks, and in some cases, the formation of new phases such as sodalities, zeolite A and zeolite P. Little work has been done to quantify the mineralogical phases before and after precursor activation, making it impossible to assess dissolution, the degree of geopolymerization, and mineral formation. The exact structure of the phases formed is often questionable, as most of the papers do not mention their reference structure number. There is also a lack of quantification of the amorphous phase resulting from the hardening of the activating solution and the evaluation of the fraction of the amorphous phase contained in the precursor remains unreacted. The mineralogical investigation must also extend to the quantification of phases using Rietveld refinement with internal standards to correlate these with the physical and mechanical properties of geopolymer products. Additional mineralogical study techniques, such as thin sections, should be used in future work for in-depth mineralogical investigation of geopolymers. [ABSTRACT FROM AUTHOR]

Rock-burst prediction is an important issue faced by deep coal mining operations and holds significant significance for ensuring the safety of workers and the sustainable development of mines. This study investigates the crack-propagation behavior of coal and magnetite under uniaxial compression, introduces the characteristic parameter γ within the framework of the flicker noise spectrum (FNS), analyzes the trends in the variation of acoustic emission (AE) b-value and γ-value, and explores the relationship between these two parameters. Experimental results reveal that the proportion of tensile cracks is significantly higher than shear cracks during the loading process, shear failure becomes the main factor as the specimen approaches failure. Both the b-value and γ-value are proven to effectively reflect the damage evolution process of coal and magnetite and exhibit noticeable changes prior to collapse. Specifically, the peak γ-value serves as a precursor indicator for coal and magnetite collapse. Furthermore, this study uncovers a negative linear relationship between the b-value and γ-value. By delving into the feature parameter γ of AE signals, this research offers a new perspective and approach for predicting the instability of coal and magnetite formations and monitoring dynamic hazards. It contributes to a better understanding of the damage evolution process of coal and magnetite formations and provides valuable guidance and reference for preventing and mitigating dynamic hazards associated with coal and magnetite. Highlights: A novel monitoring indicator for coal and magnetite dynamic hazards, known as the γ-value, was introduced within the framework of the Flicker Noise Spectroscopy method. The study revealed a notable negative linear correlation between the b-value and the γ-value derived from acoustic emission signals. Experimental and on-site data have demonstrated that b-value and γ-value can effectively prevent rock burst. [ABSTRACT FROM AUTHOR]

Using free microorganisms for industrial processes has some limitations, such as the extensive consumption of substrates for growth, significant sensitivity to the microenvironment, and the necessity of separation from the product and, therefore, the cyclic process. It is widely acknowledged that confining or immobilizing cells in a matrix or support structure enhances enzyme stability, facilitates recycling, enhances rheological resilience, lowers bioprocess costs, and serves as a fundamental prerequisite for large-scale applications. This report summarizes the various cell immobilization methods, including several synthetic (polyvinylalcohol, polyethylenimine, polyacrylates, and Eudragit) and natural (gelatin, chitosan, alginate, cellulose, agar–agar, carboxymethylcellulose, and other polysaccharides) polymeric materials in the form of thin films, hydrogels, and cryogels. Advancements in the production of well-known antibiotics like penicillin and cephalosporin by various strains were discussed. Additionally, we highlighted cutting-edge research related to strain producers of peptide-based antibiotics (polymyxin B, Subtilin, Tyrothricin, varigomycin, gramicidin S, friulimicin, and bacteriocin), glusoseamines, and polyene derivatives. Crosslinking agents, especially covalent linkers, significantly affect the activity and stability of biocatalysts (penicillin G acylase, penicillinase, deacetoxycephalosporinase, L-asparaginase, β-glucosidase, Xylanase, and urease). The molecular weight of polymers is an important parameter influencing oxygen and nutrient diffusion, the kinetics of hydrogel formation, rigidity, rheology, elastic moduli, and other mechanical properties crucial for long-term utilization. A comparison of stability and enzymatic activity between immobilized enzymes and their free native counterparts was explored. The discussion was not limited to recent advancements in the biopharmaceutical field, such as microorganism or enzyme immobilization, but also extended to methods used in sensor and biosensor applications. In this study, we present data on the advantages of cell and enzyme immobilization over microorganism (bacteria and fungi) suspension states to produce various bioproducts and metabolites—such as antibiotics, enzymes, and precursors—and determine the efficiency of immobilization processes and the optimal conditions and process parameters to maximize the yield of the target products. [ABSTRACT FROM AUTHOR]

Spent lithium NCA (LiNCA) battery was recycled using organic and inorganic acids and the performances were compared against the cathode synthesized from precursor. The metals in the spent cathode were leached using sulfuric or citric acid and coprecipitated into ternary metal oxalate (TMO) after reduction and lithium separation. Subsequently, the coprecipitated solution was used for cathode synthesis. Leaching efficiencies for nickel, cobalt and aluminum using citric acid were 85.6, 94.1, and 99%, respectively, while the efficiencies using sulfuric acid were 96, 98, and 100%, respectively. TMO produced from coprecipitation had the same physical characteristics. It was important to acknowledge that all cathodes also had similar physical characteristics. The electrochemical tests showed that commercial cathodes had the highest capacity of 150 mAh/g. This was followed by those from precursors, sulfuric acid leaching, and citric acid leaching, which recorded 142, 135, and 130 mAh/g, respectively. Based on the cycle test at 1C, the sample from citric acid leaching was 86% after 20 cycles compared to others at 82–83%. The results suggested that spent LiNCA could be regenerated into new cathodes using acid with performance comparable to those synthesized from precursor. This presented a viable alternative for LiNCA cathode synthesis.

Ion beam-induced deposition (IBID) using Pt(CO)2Cl2 and Pt(CO)2Br2 as precursors has been studied with ultrahigh-vacuum (UHV) surface science techniques to provide insights into the elementary reaction steps involved in deposition, complemented by analysis of deposits formed under steady-state conditions. X-ray photoelectron spectroscopy (XPS) and mass spectrometry data from monolayer thick films of Pt(CO)2Cl2 and Pt(CO)2Br2 exposed to 3 keV Ar+, He+, and H2+ ions indicate that deposition is initiated by the desorption of both CO ligands, a process ascribed to momentum transfer from the incident ion to adsorbed precursor molecules. This precursor decomposition step is accompanied by a decrease in the oxidation state of the Pt(II) atoms and, in IBID, represents the elementary reaction step that converts the molecular precursor into an involatile PtX2 species. Upon further ion irradiation these PtCl2 or PtBr2 species experience ion-induced sputtering. The difference between halogen and Pt sputter rates leads to a critical ion dose at which only Pt remains in the film. A comparison of the different ion/precursor combinations studied revealed that this sequence of elementary reaction steps is invariant, although the rates of CO desorption and subsequent physical sputtering were greatest for the heaviest (Ar+) ions. The ability of IBID to produce pure Pt films was confirmed by AES and XPS analysis of thin film deposits created by Ar+/Pt(CO)2Cl2, demonstrating the ability of data acquired from fundamental UHV surface science studies to provide insights that can be used to better understand the interactions between ions and precursors during IBID from inorganic precursors.

Abstract New hematopoietic cell models have recently emerged through immortalization of CD34 cells to study and understand various molecular mechanisms of erythropoiesis. Here, we characterize the JK-1 CML-derived cell line, previously shown to spontaneously differentiate without cytokines. Using an epigenetic differentiation inhibitor that keeps JK-1 in an early differentiation phase, we characterized 2 progenitor stages: BFU-E JK-1 and CFU-E JK-1 with CD34+/CD36− and CD34−/CD36 + phenotypes respectively. Then, using the PFI-1 inducer known to synchronously control the terminal differentiation of JK-1 cells, 5 precursor stages were obtained (ProE, Baso1-2, PolyC, OrthoC) and characterized via cell morphology, CD49a and Band3 markers. Enlarged phenotyping was carried out for the earlier phase, and expression kinetics of membrane proteins such as RhAG, RhD/CE, CD47, DARC and CD44 were performed on each stage of the terminal phase. Furthermore, since JK-1 offers the unique property of covering a broad spectrum of differentiation stages, we explored deeper the GATA2/GATA1 and the non-erythroid/erythroid spectrin ‘switching’. The possibility of obtaining large quantities of JK-1 cells at each stage of differentiation, as shown in this study, as well as the potential to genetically modify these cells, via CrisprCas9, makes their use of considerable interest for studying pathologies occurring during erythropoiesis.

Sodium-ion batteries are expected to gradually replace lithium-ion batteries in large-scale energy storage and two-wheeled electric vehicles because of their excellent low-temperature performance, cost advantages, and high safety. The development of sodium-ion battery anode materials with low cost, high reversible capacity, and excellent cycling stability is challenging for the industry. Because sodium ions are larger than lithium ions, graphite materials with long-range ordered structures suitable for lithium-ion battery anodes cannot be applied to sodium-ion batteries. Instead, the graphite domains of hard carbon materials are short and chaotically aligned, exhibiting a short-range ordered structure with local graphite zones inside the carbon layer. Moreover, the layer spacing of hard carbon is larger than that of graphite, which is conducive to the storage of sodium ions. Hard carbon is easily accessible and environmentally friendly, with a high carbon yield. Biomass-based hard carbon has attracted considerable attention because of its abundant raw material sources, low cost, easy accessibility, high carbon yield, environmental friendliness, and the presence of various elements. Its unique microstructure exhibits notable advantages and great commercial potential among several anode materials for sodium-ion batteries. The storage mechanism of sodium ions in hard carbon is controversial. Herein, we first analyze the adsorption behavior of sodium ions at the active sites on the hard carbon surface and the sequential process of their entry into the graphite scale layer. Moreover, we review four controversial sodium-ion storage mechanisms. Furthermore, we explore the storage mechanism of sodium ions in hard carbon and the differences between various biomass-based precursors. The content of each component and microstructure of different precursors vary, and several differences exist between nutshells, woody plants, and herbs. Their internal structural characteristics and different component contents play a key role in the performance of hard carbon. We enumerate the structural and component differences among various biomass-based precursors and summarize the distinctions in sodium-ion storage properties among different precursor hard carbons. To enhance the sodium storage performance of biomass-based hard carbon, an optimization strategy is proposed for sodium-ion battery anodes. This strategy involves manipulating the microstructure of the hard carbon anode, including adjusting the carbon layer spacing, pore structure, and specific surface area. In addition, the doping of elements, introduction of functional groups, and optimization of the electrolyte can improve the sodium storage performance of hard carbon. These insights can provide significant guidance for developing sodium-ion batteries.

Direct electron beam writing is a powerful tool for fabricating complex nanostructures in a single step. The electron beam locally cleaves the molecules of an adsorbed gaseous precursor to form a deposit, similar to 3D printing but without the need for a resist or development step. Here, we employ for the first time a silver β-diketonate precursor for focused electron beam-induced deposition (FEBID). The used compound (hfac)AgPMe3 operates at an evaporation temperature of 70–80 °C and is compatible with commercially available gas injection systems used in any standard scanning electron microscope. Growth of smooth 3D geometries could be demonstrated for tightly focused electron beams, albeit with low silver content in the deposit volume. The electron beam-induced deposition proved sensitive to the irradiation conditions, leading to varying compositions of the deposit and internal inhomogeneities such as the formation of a layered structure consisting of a pure silver layer at the interface to the substrate covered by a deposit layer with low silver content. Imaging after the deposition process revealed morphological changes such as the growth of silver particles on the surface. While these effects complicate the application for 3D printing, the unique deposit structure with a thin, compact silver film beneath the deposit body is interesting from a fundamental point of view and may offer additional opportunities for applications.

Using acetate as the precursor, different proportions of Cu/Zn catalysts were prepared by hydrothermal method, and the performance of CO2 hydrogenation to methanol was evaluated without H2 pretreatment. The effects of different Cu/Zn ratios on the crystalline phase structure, surface properties and valence state of the catalyst were investigated by XRD, TG-DSC, H2-TPR, CO2 temperature-programmed desorption and XPS, and its active sites were studied. The results show that the activity of the Cu/Zn catalyst prepared with acetate as the precursor is evaluated without pretreatment, and the H2 in the reaction gas (H2 : CO2 =3 : 1) will reduce the Cu2+ of the Cu/Zn catalyst to Cu° to form a new Cu0-ZnO interface, which makes the Cu/Zn45 achieve a spatiotemporal yield of 7.97 mmol/(g· h) at 3 MPa and 240 °C. [ABSTRACT FROM AUTHOR]

BACKGROUND: Aerobic fermentation always suffers from nitrogen loss and low humification degree. The objective of this study was to investigate the promotion of phosphate buffer on organic matter degradation and precursor polymerization into humus (HS) in aerobic fermentation, and to analyze the key roles played by different precursors. In order to achieve this, sludge aerobic fermentation tests were conducted on control (CK), phosphate buffer addition treatment (KP) and potassium chloride addition treatment (K). RESULTS: The HS content of KP treatment exhibited a notable increase compared to the CK and K treatments, with a maximum increase of 38.29%. In addition, phosphate addition improved the nitrogen retention capacity and the complexity of the HS structure. Phosphate buffer enhanced both the polyphenol and Maillard humification pathways by promoting the condensation of precursors (polysaccharides, reducing sugars, polyphenols, amino acids and proteins). Among these precursors, reducing sugars, amino acids and proteins were identified as the key driving precursors of phosphate. CONCLUSIONS: Phosphate, as an exogenous additive to the fermentation system, reduces nitrogen loss while promoting precursor polymerization to form HS, which benefits the improvement of soil fertility and crop growth upon organic fertilizer application. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Layered oxides with ultrahigh nickel content are considered promising high energy cathode materials. However, their cycle stability is constrained by a series of heterogeneous structural transformations during the complex solid‐state lithiation process. By in‐depth investigation into the solid‐state lithiation process of LiNi0.92Co0.04Mn0.04O2, it is found that the protruded parts on the surface of precursor particles tend to be surrounded by locally excessive LiOH, which promotes the formation of a rigid and dense R3-m ${{\rm { R}}\mathrel{\mathop{{\rm { 3}}}\limits^{{\rm -}}}{\rm { m}}}$ shell during the early stage of lithiation process. The shell will hinder the diffusion of lithium and topotactic lithiation within the particles, culminating in spatially heterogeneous intermediates that can impair the electrochemical properties of the cathode material. The spheroidization of the precursor can enhance uniformity in structural evolution during solid‐phase lithiation. Ultrahigh nickel cathodes derived from spherical precursors demonstrate high initial discharge specific capacity (234.2 mAh g−1, in the range of 2.7–4.3 V) and capacity retention (89.3 % after 200 cycles), significantly superior to the non‐spherical samples. This study not only sheds light on the intricate relationship between precursor shape and structural transformation but also introduces a novel strategy for enhancing cathode performance through precursor spheroidization. [ABSTRACT FROM AUTHOR]

Chemical vapor deposition (CVD) has become a favorable method for preparation of iron-containing films. However, as a key role in the CVD process, the available liquid iron precursor is scarce. To this aim, this study synthesized two liquid iron complexes using sec-butyl-containing amidines as ligands, and the synthesized complexes' structures were characterized through 1H NMR spectroscopy and elemental analysis. Thermogravimetric analysis (TGA) was employed to study the thermal properties (including volatility, thermal stability, and vapor pressure) of the designed complexes, and the results demonstrated that both complexes have excellent volatility, sufficient thermal stability and vapor pressure. The reactivity of the complexes was observed through solution reactions between them and conventional co-reagents, and both complexes exhibited high reactivity. Moreover, the applicability of the synthesized complexes as CVD precursors were evaluated through film deposition experiment, and a continuous, uniform, high purity, and smooth α-Fe2O3 film was obtained. These results demonstrated that the synthesized complexes are promising precursors for the CVD of iron-containing films. [ABSTRACT FROM AUTHOR]

Earthquake prediction is the holy grail of seismology and one of humanity's greatest dreams. The Earth's magnetic field appears to be one of the best possible precursors of earthquakes, although the topic is controversial. Recent advancements have made it possible to observe magnetic fields from satellites with great accuracy. We utilize magnetic measurements from Swarm satellites to explore the potential identification of anomalous magnetic signals preceding earthquakes. Focusing on 1077 major earthquakes that occurred in 2014–2023 in the Alpine–Himalayan belt, we apply an automatic algorithm to data recorded 10 days before each earthquake. This analysis reveals clear pre-earthquake anomalies in the magnetic field components. Notably, a robust correlation is established between the duration of these anomalies and the earthquake magnitude, indicating that as the earthquake magnitude increases, so does the duration of the anomaly. Here we show that this method has a great ability to make predictions (high accuracy 79%, precision 88%, F1-score and hit rate 84%), thus becoming the basis for an Operational Earthquake Prediction System (OEPS). [ABSTRACT FROM AUTHOR]

Spectral analysis is an effective tool for processing seismic signals, particularly when time-domain characteristics are challenging to capture. In this study, we developed a method using P-wave signals to calculate the power spectrum, enabling the estimation of two spectral parameters—peak frequency and shape factor—for earthquakes recorded by regional seismic networks in the Xiangjiaba (XJB) reservoir area from 2010 to 2015. The temporal evolution of the two spectral parameters was analyzed, revealing that the mean values of individual spectral parameters remain relatively stable despite variations in reservoir water levels. However, a notable increase in the ratio of the shape factor to the peak frequency is observed when the XJB reservoir reaches its maximum water level, suggesting its potential as a precursor indicator for reservoir-induced seismicity (RIS). Furthermore, we performed spatial interpolation on the spectral parameters, and the results show that reservoir impoundment significantly influences the spatial distribution of these parameters. In addition, several regions between the two faults in the tail section of the XJB reservoir exhibit an elevation in the proposed precursor indicator. This study presents a new approach for monitoring and early warning of RIS. [ABSTRACT FROM AUTHOR]

Landslides are a widely recognized phenomenon, causing huge economic and human losses worldwide. The detection of spatial and temporal landslide deformation, together with the acquisition of precursor information, is crucial for hazard prediction and landslide risk management. Advanced landslide monitoring systems based on remote sensing techniques (RSTs) play a crucial role in risk management and provide important support for early warning systems (EWSs) at local and regional scales. The purpose of this article is to present a review of the current state of knowledge in the development of RSTs used for identifying landslide precursors, as well as detecting, monitoring, and predicting landslides. Almost 200 articles from 2010 to 2024 were analyzed, in which the authors utilized RSTs to detect potential precursors for early warning of hazards. The applications, challenges, and trends of RSTs, largely dependent on the type of landslide, deformation pattern, hazards posed by the landslide, and the size of the area of interest, were also discussed. Although the article indicates some limitations of the RSTs used so far, integrating different techniques and technological developments offers the opportunity to create reliable EWSs and improve existing ones. [ABSTRACT FROM AUTHOR]

Amorphous IGZO (a‐IGZO) thin‐film transistors (TFTs) are standard backplane electronics to power active‐matrix organic light‐emitting diode (AMOLED) televisions due to their high carrier mobility and negligible low leakage characteristics. Despite their advantages, limitations in color depth arise from a steep subthreshold swing (SS) (≤ 0.1 V/decade), necessitating costly external compensation for IGZO transistors. For mid‐size mobile applications such as OLED tablets and notebooks, it is important to ensure controllable SS value (≥ 0.3 V/decade). In this study, a conversion mechanism during plasma‐enhanced atomic layer deposition (PEALD) is proposed as a feasible route to control the SS. When a pulse of a diethylzinc (DEZn) precursor is exposed to the M2O3 (M = In or Ga) surface layer, partial conversion of the underlying M2O3 to ZnO is predicted on the basis of density function theory calculations. Notably, significant distinctions between In‐Ga‐Zn (Case I) and In‐Zn‐Ga (Case II) films are observed: Case II exhibits a lower growth rate and larger Ga/In ratio. Case II TFTs with a‐IGZO (subcycle ratio of In:Ga:Zn = 3:1:1) show reasonable SS values (313 mV decade−1) and high mobility (µFE) of 29.3 cm2 Vs−1 (Case I: 84 mV decade−1 and 33.4 cm2 Vs−1). The rationale for Case II's reasonable SS values is discussed, attributing it to the plausible formation of In‐Zn defects, supported by technology computer‐aided design (TCAD) simulations. [ABSTRACT FROM AUTHOR]

Infiltrating ductal adenocarcinoma of the pancreas, referred to here as "pancreatic cancer," is one of the deadliest of all of the solid malignancies. The five-year survival rate in the United States for individuals diagnosed today with pancreatic cancer is a dismal 12%. Many invasive cancers, including pancreatic cancer, however, arise from histologically and genetically well-characterized precursor lesions, and these precancers are curable. Precursor lesions therefore are an attractive target for early detection and treatment. This is particularly true for individuals with an increased risk of developing invasive cancer, such as individuals with a strong family history of pancreatic cancer, and individuals with a germline variant known to increase the risk of developing pancreatic cancer. There is therefore a need to understand the precursor lesions that can give rise to invasive pancreatic cancer in these individuals. [ABSTRACT FROM AUTHOR]

The synthesis of hafnium carbide nanowires (HfC NWs) on carbon fibers was successfully achieved by employing HfCl 4 and furfuryl alcohol as precursor materials, facilitated by Ni-assisted catalytic pyrolysis. In the polymerization and cross-linking processes of furfuryl alcohol, hafnium cations play a crucial role, leading to the atomic-level amalgamation and effectively enhancing the reactivity of the Hf-O-C system. The nucleation of HfC NWs takes place at 1300 °C, followed by growth through a solid-liquid-solid (SLS) mechanism. Carbon fibers were uniformly coated with tens micrometer-long HfC NWs having an approximate diameter of 500 nm. Notably, the tips of these HfC NWs exhibited clean surfaces free of Ni catalyst particles, indicating their root growth model. This novel catalyst-assisted pyrolysis method holds great potential for enabling cost-effective large-scale production of transition metal carbide nanowires. [ABSTRACT FROM AUTHOR]

In this work, the precursors and intermediates of catalytic dehydrogenation of toluene, ethylbenzene, and styrene (TES) stream were detected, quantified, and classified at 750–800 °C. The classification approach for tracing the structural changes of the produced precursors was designed based on different residence times of intermediates, leading to the presentation of a morphology prediction model for precipitated coke according to the restriction of stream pass. The results revealed that the coke structure of encapsulating is formed by heavier precursors produced at a restricted direction of flow. On the other hand, the filamentous coke made from lighter precursors is formed at smooth streams with no restricted areas. [ABSTRACT FROM AUTHOR]

Erythropoiesis occurs through specification from multipotent progenitors to erythroid restricted potential, expansion of erythroid progenitors, and terminal maturation of precursors to red blood cells. Acute anemia can induce changes at multiple stages of erythropoiesis, thus delineation and comparison of intermediates is critical to understanding this regulation. Historically, erythropoietic intermediates have been defined by functional colony forming assays (progenitors) or microscopy (precursors). While these sensitive single cell techniques have allowed detailed studies of the erythron, they do not allow for prospectively identifying and isolating live cells for experimental analyses. This has fueled development of flow cytometric criteria for analyzing the erythron from many different research groups for both the human and mouse systems. With these data, models of the immunophenotypic continuum of the erythron can be generated progressing from the earliest erythroid specific progenitors through late erythroblasts revealing remarkable conservation between human and murine cells. Recent data have also uncovered issues with previous classification schemes of erythromyeloid progenitors that are particularly problematic for erythroid progenitors. Applying these flow cytometric tools requires consideration of gating on a continuum in a reproducible fashion, fragments of macrophages caused by tissue dissociation on a proportion of erythropoietic cells, and ultimately application in anemia where signaling may impact the range of expression of specific immunophenotyping markers.

Detection of neurotransmitters requires high sensitivity and temporal resolution, favoring electrochemical techniques for the sensing mechanism. However, electrochemical detection of amine neurotransmitters is highly dependent on electrode surface condition and thus, results obtained in clean buffer solutions are not directly applicable to the real measurement environment in vivo or in vitro. In these more complex electrolyte solutions, the presence of antioxidants and surface-adsorbing molecules drastically alters the redox characteristics of amine neurotransmitters, their precursors and metabolites. Accordingly, we surveyed their redox characteristics in the phosphate buffered saline (PBS), cerebrospinal fluid (CSF) and cell culture medium, with high-sensitivity electrodes made of single-walled carbon nanotube network.The concentration of surface-fouling molecules was lowest in the PBS and highest in the culture medium. Accordingly, electrochemical reaction kinetics were facile in the PBS and sluggish in the culture medium. Surprisingly, analyte molecular structure had much more importance in the CSF compared to other electrolytes, however the reaction kinetics remained to be generally slower in the CSF compared to when measured in the PBS.Whereas the CSF also contains L-Ascorbic acid and uric acid that are electrochemically active interfering molecules, they are either completely absent or can be omitted in the in vitro setting. On the contrast, the culture medium contains substantially higher concentration of surface-adsorbing molecules that causes more significant fouling of electrode and thus loss of sensitivity. As the in vitro brain-on-a-chip applications are rapidly being adopted, direct comparison of these different experimental settings was essential to understand their implications for electrochemical sensors.

Abstract This study focuses on the primary synoptic‐scale patterns and precursors of extreme and non‐extreme precipitation over the Tibetan Plateau (TP). Atmospheric circulation anomalies and their precursors associated with regional extreme precipitation events (REPE) demonstrate distinct precursor wave train and heightened intensity than regional non‐extreme precipitation events (non‐REPE). Specifically, REPE over the northwestern TP (NWTP) exhibits a geopotential height anomaly induced by a latitudinal propagating Rossby wave train along 40°N. In contrast, over the southeastern TP (SETP), REPE is characterized by a geopotential height anomaly caused by a northwest‐southeastward propagating Rossby wave train. The ascending motion anomalies of REPE over both NWTP and SETP are primarily attributed to the geostrophic zonal temperature advection, which is significantly stronger during REPE compared to non‐REPE. This finding provides valuable insights for forecasting summer extreme precipitation over TP.

In order to fulfill the demand for high energy and capacity, an electrode with high-voltage capability, namely LiNi0.5Mn1.5O4 (LNMO) that has an operating potential of up to 4.7 V vs Li/Li+, is currently becoming popular in Li-ion battery chemistries. This research produced LNMO by using a solid-state method with only one-step synthesis route to compare its electrochemical performance with different lithium sources, including hydroxide (LNMO-LiOH), acetate (LNMO-LiAce), and carbonate (LNMO-LiCar) precursors. TGA/DSC was first performed for all three sample precursors to ensure the optimal calcination temperature, while XRD and SEM characterized the physical properties. The electrochemical measurements, including cyclic voltammetry and charge-discharge, were conducted in the half-cell configurations of LNMO//Li-metal using a standard 1 M LiPF6 electrolyte. LNMO-LiOH samples exhibited the highest purity and the smallest particle size, with values of 93.3% and 418 nm, respectively. In contrast, samples with higher impurities, such as LNMO-LiCar, mainly in the form of LixNi1-xO (LiNiO), displayed the largest particle size. The highest working voltage possessed by LNMO-LiOH samples was 4.735 V vs Li/Li+. The results showed that LNMO samples with LiNiO impurities would affect the reaction behavior that occurs at the cathode-electrolyte interface during the release of lithium-ions, resulting in high resistance at the battery operations and decreasing the specific capacity of the LNMO during discharging. The highest value, shown by LNMO-LiOH, was up to 92.75 mAh/g. On the other side, LNMO-LiCar only possessed a specific capacity of 44.57 mAh/g, indicating a significant impact of different lithium sources in the overall performances of LNMO cathode.

Polymer-derived-ceramic (PDC) route is an excellent strategy to tailor components at the molecular level, while existing synthetic methods face various problems such as complex preparation, multi-step reaction, and high conversion temperature, etc. Here, we propose an approach to prepare Zr-, Hf-, or Zr/Hf-containing metallocene-based ceramic precursors, which are constructed by the alkylation reaction between cyclopentadienyl ligand and methylene. Through the homogeneous and one-pot reaction occurs, we collect the target products. The reaction condition is mild, and the conversion temperature (1400 °C) is relatively low, and with a high ceramic yield (57.50–66.34%). The obtained metal-containing polymers are further converted to the orthorhombic phase (M7O8.79F9.71, M = Zr, Hf) after pyrolysis at 800 °C. Annealing at an intermediate temperature of 1400 °C in an argon atmosphere results in cubic crystalline ZrC or HfC nanoparticles embedded in a ceramic matrix. The free carbons are in-situ formed after high-temperature treatment, and higher disorder of carbons is observed with increasing temperature. This work provides a good strategy for the potential precursor of ultrahigh-temperature ceramics.

Nickel nanopowders coated by magnesium oxide used for inner electrode of multilayer ceramic capacitor (MLCC) were prepared by coating thermal decomposition sintering method. The effects of reactant concentration and dispersant content on the particle size and homogeneity of the nano-coated nickel salt precursors were investigated, and the influences of reduction sintering temperature on the sphericity and dispersion of the coated nano-nickel powders were discussed. The nickel nanopowders coated by MgO were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermomechanical analyzer (TMA). The results show that the nano-nickel salt particles can be obtained when the reactant concentration reaches enough to cause the reaction explosion nucleation. The well-dispersed nano-nickel salt precursor particles can be obtained by adding the proper dosage of dispersant. The nickel nanopowders coated by MgO with good sphericity and dispersion can be obtained at the reduced sintering temperature of 700 ℃. The core-shell structure of the nickel nanopowders coated by MgO is formed, which show the good shrinkage delay effect.

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plasma discharges under atmospheric pressure are applicable for modifying the electrical properties of dielectric surfaces. The aim of the plasma discharge treatment of such surfaces is to design a procedure so that its characteristic parameters improve the resulting levels of the breakdown electrical strength Eb when tested under pulsed or alternating electrical voltages. In this research, a set of functional experiments performed by using plasma in samples of two types of materials (thermoset, thermoplastic) were processed and evaluated, and the resulting effect of the magnitude of the breakdown electrical voltage, electrical intensity, and electrical conductivity of the surface were compared. A slit plasma chamber, previously described and parameterized, was employed to treat the surface of the dielectric samples. The surface structure was modified via plasma discharge without precursors, and methodologies were developed to evaluate these modifications with respect to the change in the electrical strength parameters of the insulator surface. Subsequently, the surface strength of the affected and unaffected samples was measured and evaluated as a function of exposure time, and the stability of the modification was assessed. The first methodical test showed that plasma discharge without precursors improved the long-term surface electrical strength of the dielectric surface. The test and its parameters were carried out with respect to feasibility in an industrial environment. [ABSTRACT FROM AUTHOR]

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Additive manufacturing for open-cell aluminum foam is attracting attention because the cell morphology determined by the characteristics of the aluminum foam can be accurately controlled according to the application. However, there are few reports on the additive manufacturing of closed-cell aluminum foams. Wire arc additive manufacturing (WAAM) is a low-cost additive manufacturing method and has potential for manufacturing closed-cell aluminum foams from a wire precursor. In this study, WAAM was used to produce closed-cell aluminum foam. The precursor round bar was obtained by hot-pressing a mixture of pure aluminum powder, 3 mass% TiH2 powder, and 1 mass% Al2O3 powder. After the precursor round bar with a diameter of 15mm was inserted into an A5052 aluminum alloy tube with an outer diameter of 19mm and inner diameter of 15.5 mm, the assemblage was swaged to a precursor wire measuring ϕ1.6 © 100 mm. The WAAM equipment was based on the torch of a TIG arc welding machine that moved under numerical control. Foam formation tests were carried out with the precursor wire at a torch travel speed range from 120mm/min to 620mm/min. An additive foaming test was also carried out using a precursor wire measuring ϕ1.6 © 100mm to investigate welding of the second layer to the first layer while the second layer was foaming. The density of the aluminum foam was measured by Archimedes' method to calculate the porosity. The aluminum foam samples were cut perpendicular to the long axis, and cross-sections were observed with an optical microscope. For the single-layer aluminum foam formed with a TIG arc, the maximum porosity of 60% was obtained at a travel speed of 320mm/min. A two-layer aluminum foam with a porosity of 18% and mean pore diameter of approximately 86µm was obtained in the additive experiment. The second and first layers were bonded without forming a boundary. These results indicate that closed-cell aluminum foam was successfully produced using WAAM. However, the viscosity of the base aluminum of the precursor wire must be high to obtain a high-porosity aluminum foam with WAAM. [ABSTRACT FROM AUTHOR]

One of the key factors of space weather is solar flare activity, the monitoring and prediction of which is an important task of specialized dedicated groups of space experts and solar astronomers. Solar flare forecasts are based on identifying and detecting the so-called precursors, specific processes in solar activity events that occur before flares. Collecting data for space weather analysis and prediction comes down to several types of measurements performed by more than a dozen spacecraft. Ground-based observations and monitoring nowadays are becoming more or less complimentary. One of the reasons for this is the limitation of observation time with ground-based telescopes due to adverse Earth weather conditions. However, solar radio astronomy is immune to almost any weather activity, and the main question here is what new quality it can bring. Observational data accumulated in the 20th century show that solar radio bursts can be associated with flare activity. In addition, the existing network of solar radio telescopes is already well established. As an example, in this paper, we describe the possibilities of a fully steerable 32-meter radio telescope of Ventspils International Radio Astronomy Centre (VIRAC), Latvia, which can be useful for searching for new precursors of solar flares. [ABSTRACT FROM AUTHOR]

α‐Al2O3 powder with excellent sintering properties plays an irreplaceable role in advanced ceramics. However, the preparation of α‐Al2O3 at low temperature still remains a grand challenge. Herein, aluminum sulfate, aluminum nitrate, and aluminum chloride are used as raw materials for α‐Al2O3 synthesis. In general, the Al3+ will be hydrolyzed to form AlOOH during the hydrothermal process. But SO42− reacted with Al3+ and OH− to form Al4(OH)10SO4 during the hydrothermal process. During the calcining process, the transition temperatures from AlOOH to α‐Al2O3 were 1100°C, which can be summarized as follows: AlOOH → γ‐Al2O3 → θ‐Al2O3 → α‐Al2O3. Meanwhile, Al4(OH)10SO4 converted into pure α‐Al2O3 at only 1050°C, due to the direct conversion from γ‐Al2O3 to α‐Al2O3. This spherical α‐Al2O3 was made up by completely uniformed small particles of about 10–20 nm. Finally, an Al2O3 ceramic with 98.07% of theoretical density and.01% water absorption rate was obtained at a temperature of 1600°C. This work offers an intriguing solution toward the development of Al2O3‐based advanced ceramics. [ABSTRACT FROM AUTHOR]

In the context of global warming, the extreme summer precipitation over the Tibetan Plateau (TP) has changed significantly. In this study, the summer (June–August) extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution (1/30°) precipitation dataset (TPHiPr, 1979–2020). The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were investigated. The results showed that the summer extreme precipitation of the TP can be categorized into northwestern (NW), southeastern (SE), and southern Himalayan (HS) types based on extreme precipitation thresholds. The NW and SE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them, whereas the HS type is controlled by the localized subtropical anomalous circulation. On the 8th day before the onset of the NW type, an anomalous cyclone was observed in the western Atlantic Ocean (60°W, 50°N), which triggered the west-to-east quasi-latitudinal propagation of Rossby waves. On the onset day of the NW type, the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian Sea, the western part of Xinjiang, to the northeastern TP. Moisture entered from the Arabian Sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern TP. Compared to the NW type, the precursors of the SE type appeared at higher latitudes and were more intense. On the 8th day before the onset of the SE type, an anomalous cyclone occurred near Greenland (60°W, 70°N) and excited Rossby waves propagating southeastward. On the onset day of the SE type, the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast direction and entered the southeastern TP from the Bay of Bengal along the southeastern edge of the anomalous cyclone in the southern TP. On the 6th day before the onset of the HS type, the anomalously high pressure in the middle and lower layers of the low-latitude region extended westward, and a significant anticyclonic anomalous circulation occurred on the southern TP on the onset day of the HS type, enabling the delivery of moisture from the Bay of Bengal to the southern foothills of the Himalayas. Additionally, an anomalous cyclone perched in the northeastern TP at a geopotential height of 200 hPa strengthened westerly winds in the southern TP and contributed to the maintenance of the anticyclonic system on the southern TP. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new 3-D bi-metal organic framework was synthesized by hydrothermal method. • After pyrolysis, binary metal oxides were prepared and applied to the anode materials of LIBs. • CeCo-700 has the highest specific capacity of 952 mAh g−1 at 100 mA g−1 after 150 cycles. Precursor method is a well-known technology for preparing certain functional materials. In this work, a novel 3d-4f bimetallic organic framework, denoted as 45MCeCo (45 M representing 4,5-imidazole dicarboxylic acid), was successfully synthesized via a hydrothermal technique. The compound thus obtained has the molecular formula of C 10 H 11 CeCoN 4 O 12. By meticulously controlling the amounts of the experimental materials, it was feasible to prepare flower-like crystals possessing identical single crystal structures and significantly larger specific surface areas. As a precursor for electrode materials, this structure underwent calcination at different temperatures to prepare Co 3 O 4 /CeO 2 composites with in situ composite heterostructures. Post-electrochemical tests revealed that CeO 2 remains unreactive across all potentials, thereby contributing to the stabilization of the electrode material structure. In contrast, Co 3 O 4 participated in redox reactions to provide a specific capacity to the sample. In addition, when comparing the performance of the electrode material under different calcination conditions, it became evident that the material exhibited optimal electrochemical performance when subjected to a temperature of 700 °C for 2 h. [ABSTRACT FROM AUTHOR]

Earthquake cloud is an ancient and visual precursor of an earthquake that sometimes forms over the earthquake fault and is often close to its epicenter several days before the earthquake. The most important characteristic of an earthquake cloud is that it emanates from the ground and stays in the sky for hours. The present study aims to find the terrible 2017 Azgeleh earthquake cloud by the visual interpretation of Meteosat-8 satellite images. The characters of the cloud in question are then investigated by using the same satellite products. In this study, the Azgeleh earthquake cloud and also the 2021 Sisakht earthquake cloud were found. The cloud was shown to have had a geological origin, and the formation of such a cloud was not a common occurrence there. The Azgeleh earthquake occurred near the High Zagros fault (HZF), whereas its cloud had been formed about 700km further away from its epicenter, on other parts of the same fault over a 160km-long line. Visual searching for earthquake clouds from the ground and the sky is a public scientific hobby, especially for amateur meteorologists using satellite imagery. The formation of an earthquake cloud over a fault can be a warning of a possible impending earthquake on that fault, which, of course, needs further investigation.1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 [ABSTRACT FROM AUTHOR]

This review discusses some research on two earthquake precursors—soil radon concentration, a geochemical precursor; and Total Electron Content (TEC), an atmospheric one, studied in some earthquake-prone regions in the world. These two precursors were chosen because their generation mechanisms are interlinked. The selected soil radon studies focused on establishing anomalous radon fluctuations as a robust precursory signal for medium to high-magnitude earthquakes, including determination and removal of meteorological effects from soil radon time series, and identification of genuine pre-seismic anomalies. For the seismic precursory property of TEC, studies on detecting seismogenic TEC fluctuations and their formation mechanisms were discussed. [ABSTRACT FROM AUTHOR]

East Java is one of the seismically active regions in part of the Sunda Arc whose seismicity pattern must be studied. Therefore, a spatio-temporal analysis of seismicity between 2002 - 2022 in East Java has been conducted. This analysis aims to investigate the seismotectonic conditions in the East Java region over the last twenty years, especially the seismicity patterns associated with significant earthquakes in East Java. The analysis was carried out by quantifying the spatial and temporal variations of seismicity parameters using b-value and z-value. The used data used are earthquake data from the USGS earthquake catalog during 2002 - 2022 in the East Java region. The analysis was performed using the ZMAP 6.0 program code using the maximum likelihood method. The results of the temporal analysis of b-values show that almost all significant earthquakes in East Java were characterized by a decrease in b-values of up to 0.2. Spatially, the significant earthquake on 10 April 2021 was associated with a low b-value (0.9). Temporal z-value analysis shows that the significant East Java earthquake was preceded by a quiet period (positive z-value) between 4 - 5 years (2003 - 2008 and 2012 - 2016). Spatial analysis of the z-value in the last 7 shows an increase in the z-value before the significant earthquakes occurred on 16 July 2019, 18 March 2020, and 10 April 2021. Therefore, the results of this study indicate that the b-value and z-value potentially can be used as precursors of the significant East Java earthquake. [ABSTRACT FROM AUTHOR]

The key to achieving rockburst warning lies in the understanding of rockburst precursors. Considering the correlation characteristics of rockburst acoustic emission (AE) parameters, a self-organizing map neural network (SOMNN) based method for rockburst precursor inversion was proposed. The feature of this method lies in a cyclic data segmentation iteration process based on the thinking of "interference signal screening", "key signal extraction", and "precursor signal inversion". The rationality of this method has been verified in three groups of rockburst experiments. The results revealed that rockburst AE precursor signals consist of a series of signals characterized by long duration, high energy, low average frequency, high energy amplitude, and low peak frequency. Subsequently, potential value in long term rockburst warning of the precursor obtained in this study was shown via the comparison of conventional precursors. Finally, a preliminary interpretation for rockburst precursor was proposed under the framework of AE parameters physical significance, and it is revealed that AE precursor signals are likely linked to the creation of large-scale tensile cracks before rockburst. [ABSTRACT FROM AUTHOR]