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As a kind of clean energy, the exploration and development of coalbed methane (CBM) are of great importance and significance. In this paper, the CBM reservoir parameters of a working area in Western Guizhou Province, China, were predicted by using 3D seismic exploration technology, and the sweet-spot area was evaluated based on the prediction results. In terms of data interpretation, while the traditional technology is extended to the study of CBM, new technologies and methods suitable for CBM were also actively explored, especially in the quantitative prediction methods of parameters such as coal seam thickness, CBM content, coal body structure, in situ stress, etc., and a three-highs quantitative prediction technology of CBM sweet spots characterized by high precision, high resolution, and high coincidence was explored, which is based on logging evaluation and petrophysics. In addition, in the comprehensive evaluation of multiparameter sweet spots, the multiparameter weighted step-by-step evaluation method based on inversion was innovatively proposed, which made the prediction of CBM sweet spots more focused, effective, and practical, and the distribution law of sweet spots was more consistent with the geological law, providing enough basis for subsequent well location deployment. Based on this method, the C409 coal seam was selected as the sweet spot. [ABSTRACT FROM AUTHOR]

Red arils, derived from the yew tree (Taxus spp.), are renowned for their edible and nutritional properties. In this study, a novel red aril (RA) wine was produced and evaluated for its quality characteristics and sensory attributes. The flavor compounds in RA wine changed dynamically during fermentation, with a total of 26 differential volatiles identified. PLSR analysis indicated that ketones positively contributed to the citrus odor. Furthermore, RA wine exhibited high levels of organic acids, polyphenols, and amino acids after fermentation, influencing its bitterness and sourness profile. Molecular docking revealed that the activation of receptor OR1G1 by 6-methyl-5-hepten-2-one, a key ketone volatile, generated the citrus odor in RA wine. Furthermore, the taste profile of RA wine was inclined towards bitterness and sourness. Molecular docking analysis also demonstrated interactions between the key differential taste compounds with bitter-taste receptor TAS2R14 and sour-taste receptor OTOP1. Moreover, an intricate metabolic profile of RA wine was revealed through an overall metabolic map, providing insights into the underlying formation mechanisms contributing to RA wine quality. • A novel red aril (RA) wine was produced and its quality was characterized. • Ketones, particularly 6-methyl-5-hepten-2-one, elevated citrus aroma in RA wine. • Flavor compound-receptor docking revealed RA wine flavor formation mechanisms. • The characteristic metabolic profile during fermentation of RA wine was elucidated. [ABSTRACT FROM AUTHOR]

The anisotropy of tight sandstone (a type of unconventional gas reservoirs) is a significant factor influencing the characteristics of cracks network under hydrofracturing; thus, it also has a large influence on the final production capacity of the gas reservoirs. To improve the understanding of anisotropy degree and mechanical properties of the tight sandstone of Xujiahe Formation and thus to provide reliable reference for the establishment of hydrofracture model and parameter designing in fracture field, a series of experiments including ultrasonic wave velocity and uniaxial and triaxial compression tests of the tight sandstone samples obtained from Xujiahe Formation with different inclination angles (the angle between sample drilling direction and bedding plane) have been conducted. With the increase of inclination angle, the velocity of the longitudinal wave and elastic modulus both show the tendency of decreasing, whereas the compressive strength shows a "U" shape varying pattern, which is high on sides and low in the middle region. The values of uniaxial compression strength (UCS) are the lowest of sandstone with the inclination angles of 30° and 45°. The fracture patterns are dominant by splitting fracture under uniaxial compression tests. However, shear fracture and dilatancy morphology is the main pattern under triaxial compression test. But the local morphology of the failure surfaces behaves different if the inclination angle is changed. Combining the mechanic theory of transversely isotropic material, the anisotropy parameters of the tight sandstone are analyzed, as well as the influence on the hydrofracturing technology for tight sandstone in the field. [ABSTRACT FROM AUTHOR]

Abstract: A comprehensive orthogonal two-dimensional liquid chromatography (2D-LC) based on the modification of mobile phases was developed with a sample loop–valve interface. To improve the compatibility of mobile phases and analysis speed, some special solvents were chosen as the mobile phases, and the column temperature was elevated to decrease the viscosity of mobile phases of reversed-phase liquid chromatography (RPLC). Based on this principle, the first dimension was normal-phase liquid chromatography (NPLC) with a SiO2 column, and the second dimension was reversed-phase liquid chromatography containing two tandem C18 columns. 1,4-Dioxane was used in the NPLC mobile phase, and isopropyl alcohol was employed in the RPLC mobile phase. Moreover, the elevated column temperature enabled the reduction of the backpressure and using tandem C18 columns to improve the resolving power in RPLC. The new comprehensive 2D-LC system and applied strategy offered a novel idea for construction of 2D-LC system. A traditional Chinese medicine, Zhengtian pill, was used as the test sample to evaluate the constructed 2D-LC system. 876 peaks were detected, and the peak capacity reached 1740. [Copyright &y& Elsevier]

Abstract: In this study, a 38mL monolith with homogeneous porous structure was produced by a single polymerization from glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA) in the presence of porogens and an initiator. The uniform temperature distribution within the reaction system was achieved by adding reactant mixture continuously and enhancing the heat transfer ability of the polymerization system. Homogeneous porous structure in the monolith was proved by SEM and the pore size distribution profiles measured by mercury intrusion porosimetry. Experimental results from proteins separation indicated that the dynamic capacity and resolution of radial flow monolithic column were independent of flow rates. Furthermore, the pressure drop on the column was linearly dependent on the flow rate and did not exceed 1.7MPa even at a flow rate of 50mL/min, which proved that the prepared monolith could be used in the quick separation and preparation of biopolymers. [Copyright &y& Elsevier]

In the peak-shaving process of underground salt cavern hydrogen storage, the surrounding rock experiences periodic stress and temperature variations over decades, leading to the induction of thermal stress that may compromise the safe operation of the storage during hydrogen injection and extraction. This study utilizes existing research on thermal stress associated with gas injection and extraction in salt caverns to establish boundary conditions for numerical simulations based on analytical solutions of gas temperature and pressure over time. It investigates the impact of injection-extraction cycles and rates on cavern stability, employing the tensile failure criterion as an evaluation metric. The findings reveal: 1. Tensile failure in the surrounding rock predominantly occurs during hydrogen extraction, with higher extraction rates and more frequent cycles exacerbating this failure. 2. During hydrogen extraction, tensile stress in the surrounding rock increases, causing failure near the interlayers of the cavern wall. Although tensile failure does not occur during hydrogen injection, stress concentration appears at the interface between rock salt and interlayers. 3. To mitigate tensile failure, it is recommended to increase the minimum internal pressure of hydrogen storage from 0.3 to 0.4 times the vertical stress at the cavern roof when designing for the maximum hydrogen extraction rate based on the minimum operating internal pressure of the cavern. By identifying critical factors influencing tensile failure, this study offers valuable insights for optimizing operational parameters of underground hydrogen storage, ensuring long-term stability and reliability in response to evolving energy storage demands. • Investigates thermal stress in hydrogen storage caverns in bedded salt rock. • Higher extraction rates and cycles increase tensile failure risk. • Hydrogen extraction causes more tensile failure than injection. • Increasing minimum pressure mitigates cavern wall tensile failure. [ABSTRACT FROM AUTHOR]

A matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS)–based assay was developed for kinetic measurements and inhibitor screening of acetylcholinesterase. Here, FTMS coupled to MALDI was applied to quantitative analysis of choline using the ratio of choline/acetylcholine without the use of additional internal standard, which simplified the experiment. The Michaelis constant (K m) of acetylcholinesterase (AChE) was determined to be 73.9 μmol L−1 by this approach. For Huperzine A, the linear mixed inhibition of AChE reflected the presence of competitive and noncompetitive components. The half maximal inhibitory concentration (IC50) value of galantamine obtained for AChE was 2.39 μmol L−1. Inhibitory potentials of Rhizoma Coptidis extracts were identified with the present method. In light of the results the referred extracts as a whole showed inhibitory action against AChE. The use of high-resolution FTMS largely eliminated the interference with the determination of ACh and Ch, produced by the low-mass compounds of chemical libraries for inhibitor screening. The excellent correlation with the reported kinetic parameters confirms that the MS-based assay is both accurate and precise for determining kinetic constants and for identifying enzyme inhibitors. The obvious advantages were demonstrated for quantitative analysis and also high-throughput characterization. This study offers a perspective into the utility of MALDI-FTMS as an alternate quantitative tool for inhibitor screening of AChE. [Copyright &y& Elsevier]

The AC/DC hybrid transmission line is affected by electromagnetic coupling. After the line is failed, the secondary arc is difficult to extinguish, which posed a serious threat to the stable and reliable operation of the line. Taking a 500 kV AC double-circuit and ± 800 kV Yun-Guang UHV DC transmission line on the same tower as an example, this paper is built an AC/DC hybrid transmission line model through PSCAD, studied the influence of coupling section length and fault point location on the transient characteristics of the secondary arc, and analyzed the suppression effect of the DC line coupling operation mode on the secondary arc. According to the findings, the secondary arc current of AC and DC lines is greatly influenced by the length and location of the coupling section. The AC line fault is located at the midpoint of the coupling section. When the length of the coupling section is 400 m, the amplitude of the secondary arc current has reached the minimum value. When the DC line fault is located at the midpoint of the coupling section, the amplitude of the secondary arc current has reached the maximum value. In addition, the bipolar coupling operation mode of DC lines can effectively limit the amplitude of secondary arc current and recovery voltage of AC and DC lines, and the suppressive effect of secondary arc is obvioused. [ABSTRACT FROM AUTHOR]

• The series compensation of transmission lines can alleviate the problem of voltage instability. • When a short roadblock occurs in the ultra-high voltage series compensation line, TRV increases with the increase of compensation degree. • Compared with the hybrid multiplexing of TCSC and FSC, the peak TRV and RRRV are reduced when TCSC is mixed with composite FCL. • A reasonable series compensation configuration scheme can not only limit the short-circuit current, but also ensure the normal breaking of the circuit breaker. The influence of thyristor controlled series compensation (TCSC) on the transient characteristics of transmission lines needs to be studied urgently. Firstly, the structure and function of compound FCL and TCSC are analyzed. Secondly, based on the background of 500 kV extra-high voltage demonstration line, a single-phase ground fault equivalent model of ultra-high voltage line with FCL and TCSC is established. The influence of FCL hybrid multiplexing TCSC on the breaking characteristics of circuit breakers is studied. Based on the Laplace transform and the equivalent parameter concentration circuit, the influence of the fast switching time and the current limiting ratio of the FCL on the transient recovery voltage is analyzed. The influence mechanism of different modes of FCL on transient recovery voltage is obtained. The research scheme of FCL instead of FSC is proposed, and the change rules of transient recovery voltage and rise rate RRRV under different compensation degrees are compared. The results show that under the same compensation degree, the FCL replaces the FSC to reduce the peak value of the transient recovery voltage and reduce the RRRV over-standard condition, which verifies the feasibility of replacing the FSC with FCL. A new design scheme for extra-high voltage series compensated transmission lines is provided. [ABSTRACT FROM AUTHOR]

Hollow magnetic graphitic carbon microspheres (HMGSs) with/without a TiO2nanoparticle layer on their surfaces are designed and synthesized by combining the bubble-template method, assembly of β-cyclodextrin and Fe3O4stabilized by oleic acid and ammonia, and consequent graphitization reaction. HMGSs have potential in adsorption, enrichment, magnetic-assisted separation and drug delivery. [ABSTRACT FROM AUTHOR]

Hollow magnetic graphitic carbon microspheres (HMGSs) with/without a TiO2nanoparticle layer on their surfaces are designed and synthesized by combining the bubble-template method, assembly of β-cyclodextrin and Fe3O4stabilized by oleic acid and ammonia, and consequent graphitization reaction. HMGSs have potential in adsorption, enrichment, magnetic-assisted separation and drug delivery. [ABSTRACT FROM AUTHOR]

Hollow magnetic graphitic carbon microspheres (HMGSs) with/without a TiO2nanoparticle layer on their surfaces are designed and synthesized by combining the bubble-template method, assembly of β-cyclodextrin and Fe3O4stabilized by oleic acid and ammonia, and consequent graphitization reaction. HMGSs have potential in adsorption, enrichment, magnetic-assisted separation and drug delivery. [ABSTRACT FROM AUTHOR]

Hollow magnetic graphitic carbon microspheres (HMGSs) with/without a TiO2nanoparticle layer on their surfaces are designed and synthesized by combining the bubble-template method, assembly of β-cyclodextrin and Fe3O4stabilized by oleic acid and ammonia, and consequent graphitization reaction. HMGSs have potential in adsorption, enrichment, magnetic-assisted separation and drug delivery. [ABSTRACT FROM AUTHOR]

In this paper, an improved single-phase grounding fault (SPGF) nature identification strategy based on machine learning is proposed. To solve the problem of conventional single-phase automatic reclosure cannot distinguishing the nature of SPGF in AC-DC hybrid lines, the fault phase voltage characteristics of AC lines with DC feed are analyzed, and the voltage harmonic energy feature vector is extracted. The whale optimization algorithm (WOA) designed by orthogonal experiment design (OED) is used to select the model parameters of the least square support vector machine (LSSVM), and a discriminative model for the fault properties of the hybrid transmission line is obtained. The simulation experiments based on PSCAD/EMTDC 4.5.0 platform are conducted for model training and fault identification performance testing, and the results verifies the effectiveness and feasibility of the proposed method. Compared with LSSVM, the fault identification strategy based on OED-WOA-LSSVM has a higher accuracy in fault identification. In addition, the accuracy of the model identification strategy under different fault locations, parallel compensation degree, transition resistance, and power system noise effects is also verified. [ABSTRACT FROM AUTHOR]

Near infrared spectroscopy (NIRS), coupled with principal component analysis and wavelength selection techniques, has been used to develop a robust and reliable reduced-spectrum classification model for determining the geographical origins of Nanfeng mandarins. The application of the changeable size moving window principal component analysis (CSMWPCA) provided a notably improved classification model, with correct classification rates of 92.00%, 100.00%, 90.00%, 100.00%, 100.00%, 100.00% and 100.00% for Fujian, Guangxi, Hunan, Baishe, Baofeng, Qiawan, Sanxi samples, respectively, as well as, a total classification rate of 97.52% in the wavelength range from 1007 to 1296 nm. To test and apply the proposed method, the procedure was applied to the analysis of 59 samples in an independent test set. Good identification results (correct rate of 96.61%) were also received. The improvement achieved by the application of CSMWPCA method was particularly remarkable when taking the low complexities of the final model (290 variables) into account. The results of the study showed the great potential of NIRS as a fast, nondestructive and environmentally acceptable method for the rapid and reliable determination for geographical classification of Nanfeng mandarins. [ABSTRACT FROM AUTHOR]

Abstract: A simple, rapid and reliable method was proposed for the simultaneous determination of 27 pesticides (organophosphorus, organochlorine, pyrethroid and carbamate pesticides) in Radix astragali. The pesticides were extracted by acetonitrile and the experimental variables, such as temperature, extraction time and volume of acetonitrile, were optimized through orthogonal array experimental design. Cleanup of extracts was performed with dispersive-solid phase extraction using primary secondary amine (PSA) as the sorbent. The determination of pesticides in the final extracts was carried out by gas chromatography–mass spectrometry in selected ion monitoring mode (GC–MS, SIM). The linearity of the calibration curves is good in matrix-matched standard, and yields the coefficients of determination (R 2)≥0.99 for approximately 96% of the target analytes. Under optimized conditions, the average recoveries (six replicates) for most pesticides (spiked at 0.02, 0.1 and 0.2mgkg−1) range from 70% to 120%, and RSDs are less than 17.2%. [Copyright &y& Elsevier]