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The explosive and biorefractory nature of nitrocellulose (NC) poses major risks to both humans and the environment. Expanding the range of microorganisms capable of degrading NC is essential, though the most effective known microorganisms, Desulfovibrio genera and Fusarium solani, achieve degradation rates of 5%-25%. Here, a novel strain, Rhodococcus pyridinivorans LZ1 was isolated, demonstrating the ability to degrade NC, with its growth potentially enhanced by the presence of NC. The degradation process was monitored by assessing changes in nitrate, nitrite, and ammonium. Notably, the -OH strength of NC increased over time, whereas the energetic functional groups (-NO2 and O-NO2) diminished. Furthermore, the presence of NC enhanced nitrate esterase activity 1-2-fold, indicating that ammonification was the primary pathway for NC biodegradation. By converting the nitrate ester of NC into hydroxyl, R. pyridinivorans LZ1 mitigates the harmful effects of NC, offering a promising approach for the treatment of NC waste and wastewater.

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Both controllable regulation of the conformational structure of a polypeptide and specific recognition of an amino acid are still arduous challenges. Here, a novel dual-mode (electrochemical and colorimetric) biosensor was built for arginine (Arg) recognition based on a conformation switch, utilizing controllable and synergistic self-assembly of a ferrocene-grafted hexadecapeptide (P16Fc) with gold nanoparticles (AuNPs). Benefiting from the flexibility and unique topological structure of P16Fc formed nanospheres, the assembly and disassembly can undergo a conformation transition induced by Arg through controlling the distance and number of Fc detached from the gold surface, producing on-off electrical signals. Also, they can induce aggregation and dispersion of AuNPs in solution, causing a color change. The mechanism of Arg recognition with polypeptide conformation regulation was well explored by combining microstructure characterizations with molecular mechanics calculations. The electrochemical and colorimetric assays for Arg were successfully established in sensitive and selective manner, not only obtaining a very low detection limit, but also effectively eliminating the interference from other amino acids and overcoming the limitation of AuNP aggregation. Notably, the conformational change-based assay with the peptide regulated by the target will make a powerful tool for the amino acid biosensing and health diagnosis.

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In the context of 'energy shortage', developing a novel energy-based power system is essential for advancing the current power system towards low-carbon solutions. As the usage duration of lithium-ion batteries for energy storage increases, the nonlinear changes in their aging process pose challenges to accurately assess their performance. This paper focuses on the study LiFeO4(LFP), used for energy storage, and explores their performance degradation mechanisms. Furthermore, it introduces common battery models and data structures and algorithms, which used for predicting the correlation between electrode materials and physical parameters, applying to state of health assessment and thermal warning. This paper also discusses the establishment of digital management system. Compared to conventional battery networks, dynamically reconfigurable battery networks can realize real-time monitoring of lithium-ion batteries, and reduce the probability of fault occurrence to an acceptably low level.

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As a new type of progressive energy release propellant, nitro gradiently distributed propellant (NGDP) was prepared by a denitration reaction between a denitration reagent and the propellant to remove the energy-containing functional group (-O-NO2) from the surface of the propellant. The kinetics of the denitration reaction determines distribution of the nitrate group in the surface layer of NGDP, which further affects the combustion progressivity. In this paper, the kinetic model for the denitration reaction process of the cylindrical single-base gun propellant was studied by the shrinking unreacted core model (SUC model). The energy change of the propellant particles before and after the denitration reaction was used to evaluate the denitration rates, which were used to fit the proposed SUC cylindrical model. The results show that the rate-controlling step of the denitration reaction process is largely dependent on the concentration of the denitration reagent. At low concentrations (the concentration of the denitration reagent was 6%), the denitration reaction process was controlled by the chemical reaction, and the activation energy was found to be 48.40 kJ·mol-1. When the concentration increased (the concentration of the denitration reagent was 15%), the rate-controlling step changed to a solid product layer diffusion control with an activation energy of 84.77 kJ·mol-1. The kinetic models obtained in this study can provide theoretical guidance for the controlled preparation of NGDP with good combustion progressivity.

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Through electrochemical polymerization using L-glutamic acid (L-Glu) as a template and 4,6-diaminoresorcinol as a functional monomer, an enzyme-free molecularly imprinted polymer (MIP) based L-Glu sensor with multi-walled carbon nanotubes (MWCNTs) decorated on a glassy carbon electrode (GCE), namely G-MIP/MWCNTs/GCE, was developed in this work. The reaction conditions were optimized as follows: electrochemical polymerization of 23 cycles, pH of 3.0, molar ratio of template/monomer of 1 : 4, volume ratio of elution reagents of acetonitrile/formic acid of 1 : 1, and elution time of 2 min. The prepared materials and molecularly imprinted polymer were characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as well as electrochemical methods. The electrochemical properties of different electrodes were investigated via differential pulse voltammetry (DPV), showing that the electrode of G-MIP/MWCNTs/GCE exhibited excellent catalytic oxidation activity towards L-Glu. A good linear relationship between peak-currents and L-Glu concentrations in a range from 1.00 × 10-8 to 1.00 × 10-5 mol L-1 was observed, with a detection limit of 5.13 × 10-9 mol L-1 (S/N = 3). The imprinted sensor possesses excellent selectivity, high sensitivity, and good stability, which have been successfully applied for the detection of L-Glu in pig serum samples with a recovery rate of 97.4-105.5%, being comparable to commercial high-performance liquid chromatography, demonstrating a simple, rapid, and accurate way for the determination of L-Glu in the fields of animal nutrition and biomedical engineering.

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Metal-organic frameworks (MOFs) offer promising opportunities for modifying energetic materials due to their micro-porous structure and high performance. In this study, we present a novel green MOF named cyclodextrin-MOF (CD-MOF), which incorporates potassium ions, synthesized using a simple methanol vapor diffusion approach. The CD-MOF incorporates potassium ions and enhances propellant performance through intermolecular force optimization with nitrocellulose (NC). Molecular dynamics simulations reveal stronger interactions between the CD-MOF and NC. The loading of the CD-MOF within NC forms a stable structure with resistance to migration and defense against crystalline precipitation and water absorption. Notably, in static combustion and pyrolysis tests, the CD-MOF exhibits efficient flame and flash inhibition. The thermal degradation and cauterization of the CD-MOF resulted in the formation of a complex microporous material capable of absorbing flammable and harmful gases such as CO, NO, NO2, and N2O. These findings shed light on the superior performance of the CD-MOF compared to conventional inorganic salts, and the comprehensive characterization and molecular simulations provide insights into the unique properties and applications of the CD-MOF, emphasizing its significant contribution to the field of green propellants.

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LiNi0.8Co0.1Mn0.1O2(NCM811) is one of the most promising cathode materials for high-energy lithium-ion batteries, but there are still problems such as rapid capacity decay during charge and discharge and poor cycle performance. Elemental doping can significantly improve the electrochemical performance of high nickel ternary cathode materials. In this work, Nb5+-doped NCM811 cathode material was successfully synthesized. The results show that Nb5+doping helps to increase the interlayer spacing of the lithium layer, electron transport, and structural stability, thereby significantly improving the conductivity of Li+. At a high voltage of 4.6 V, the initial discharge specific capacity of 1% Nb5+-doped NCM811 cathode material at 0.1 C is 222.3 mAh·g-1, and the capacity retention rate after 100 cycles at 1 C is 92.03%, which is far more than the capacity retention rate of NCM811 under the same conditions (74.30%). First-principles calculations prove that 1% Nb5+-doped NCM811 cathode material shows the highest electronic conductivity and Nb5+doping will not change the lattice structure, demonstrating the effectiveness of the proposed strategy.

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In recent years, ternary nickel-rich layered oxides have gradually replaced traditional binary cathode materials in the lithium-ion battery market due to their advantages of high energy density and environmental protection. However, their structural instability of cathode materials has seriously affected the cycle performance of the battery. In order to optimize the internal structure of LiNi0.5Co0.2Mn0.3O2(NCM523), the modified LiNi0.5Co0.2Mn0.3O2was prepared byin situdoping Na and Cl wet grinding solid phase method. After 80 cycles at 1 C, the capacity retention rate was 80.91%, which was higher than that of LiNi0.5Co0.2Mn0.3O2by 70.00%. Scanning electron microscopy showed that the surface corrosion of LiNi0.5Co0.2Mn0.3O2was effectively alleviated by Na and Cl co-doping. In addition, the band structure, state density and volume changes were obtained by simulation. The results show that the impedance, capacity and capacity retention data are very compatible with the simulation results. Therefore, Na and Cl doping can effectively optimize the internal structure of LiNi0.5Co0.2Mn0.3O2and improve its electrochemical performance. The combination of simulation and experiment provides a new approach for the modification of ternary cathode materials.

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In this work, a new type of H2S sensor was fabricated by means of drop-coating of an Au/SnO-SnO2 nanosheet material, which was prepared by a one-pot hydrothermal reaction, onto a gold electrode in an alumina ceramic tube with the formation of a thin nanocomposite film. The microstructure and morphology of the nanosheet composites were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A gas-sensitivity study presented good H2S-sensing performance of such Au/SnO-SnO2 nanosheet composites. At an optimal operating temperature of 240 °C and ambient temperature of 25 °C, the resulting sensor showed a good linear response to H2S in a range of 1.0 to 100 ppm with a low detection limit of 0.7 ppm, and a very fast response-recovery time of 22 s for response and 63 s for recovery, respectively. The sensor was also unaffected by ambient humidity and had good reproducibility and selectivity. When being applied to the monitoring of H2S in an atmospheric environment in a pig farm, the response signal to H2S was only attenuated by 4.69% within 90 days, proving that the sensor had a long and stable service lifetime for continuous running and showing its important practical application prospects.

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In this study, zinc oxide@cupric oxide hollow nanospheres (ZnO@CuO HNS, 330 nm in diameter) were successfully prepared by a hard-template method using amino-phenolformaldehyde resin spheres (APF) as the templates. A new type of thin-film gas sensor toward hydrogen sulfide (H2S) was fabricated by means of drop-coating on the gold electrode of an alumina ceramic tube. The microstructure and morphology of the nanosphere composites were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the gas-sensing performance of the composites toward the detection of H2S were investigated. The ZnO@CuO nanocomposite with a hollow structure exhibited good gas-sensing properties. Under the optimum operating temperature of 260 °C, ambient temperature of 30 °C, and ambient humidity of 70%, the linear response of the sensor to H2S was in the concentration range of 0.1-100 ppm, and its detection limit reached 0.0611 ppm, with a quick response time of 78 s. Also, the sensor possessed good repeatability, selectivity, and stability. The long-term stability and run duration of such sensors were pronounced, with only a 1.9% reduction in the signal after the continuous monitoring of H2S gas in a pig farm for 18 months using Alibaba's cloud remote transmission system, which presents an important practical application prospect in atmosphere environment monitoring on livestock-raising fields.

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An interesting phenomenon is described that the fluorescence signal of poly(adenine) (A) DNA-templated gold nanoclusters (AuNCs) is greatly improved in the presence of L-histidine by means of L-histidine-DNA interaction. The modified nanoclusters display strong fluorescence emission with excitation/emission maxima at 290/475 nm. The fluorescence quantum yield (QY) is improved from 1.9 to 6.5%. Fluorescence enhancement is mainly ascribed to the L-histidine-DNA interaction leading to conformational changes of the poly(A) DNA template, which offer a better microenvironment to protect AuNCs. The assay enables L-histidine to be determined with good sensitivity and a linear response that covers the 1 to 50 nM L-histidine concentration range with a 0.3 nM limit of detection. The proposed method has been applied to the determination of imidazole-containing drugs in pharmaceutical samples. A turn-on fluorescent method has been designed for the sensitive detection of L-histidine as well as imidazole-containing drugs on the basis of the L-histidine-DNA interaction.

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In order to achieve ideal burning progressivity and reduce harmful phenomena such as muzzle flame and smoke, energetic composite deterring agents (ECDAs) deterring spherical propellants were designed and prepared. The combustion performance of ECDA-deterred propellants was characterized by a closed vessel, and the interior ballistic performance was studied by a ballistic gun. High-speed photography and a smoke box were employed to capture muzzle flames and smoke. The results showed that triethylene glycol dinitrate (TEGDN) had a slight deterring effect weaker than that of poly(neopentyl glycol adipate) (PNA) on the propellants. The maximum pressure in the closed vessel bore of the ECDA-deterred propellants was 2.29 MPa higher than that of the dibutyl phthalate (DBP)-deterred propellants, though the L-B curve of the ECDA-deterred propellants was slightly lower and its combustion time was 0.44 ms longer. For ECDA containing 5 wt % PNA and 3.2 wt % TEGDN, 80 °C and 150 min are the best deterring conditions. The average velocity of the bullet propelled by ECDA-deterred propellants was increased by 93.4 m·s-1, while the average maximum pressure in the gun bore was decreased by 19 MPa, compared with the original propellants. The muzzle flame and smoke of the ECDA-deterred propellants were significantly reduced compared with the DBP-deterred propellants, where the smoke concentration was reduced by up to 44.5%.

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To address increasingly prominent energy problems, lithium-ion batteries have been widely developed. The high-nickel type nickel-cobalt-manganese (NCM) ternary cathode material has attracted attention because of its high energy density, but it has problems such as cation mixing. To address these issues, it is necessary to start from the surface and interface of the cathode material, explore the mechanism underlying the material's structural change and the occurrence of side reactions, and propose corresponding optimization schemes. This article reviews the defects caused by cation mixing and energy bands in high-nickel NCM ternary cathode materials. This review discusses the reasons why the core-shell structure has become an optimized high-nickel ternary cathode material in recent years and the research progress of core-shell materials. The synthesis method of high-nickel NCM ternary cathode material is summarized. A good theoretical basis for future experimental exploration is provided.

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A novel family of fully nitroamino-functionalized [1,2,4]triazolo[4,3-b][1,2,4]triazole-based energetic salts were synthesized. All salts were characterized by IR and multinuclear NMR spectroscopy, thermal analysis and elemental analysis. The crystal structures of salts 5, 6, and 7 were confirmed by single-crystal X-ray diffraction. The densities of these salts are between 1.65 (4) and 1.89 g cm-3 (3), whilst their oxygen balances are between -42.8% (7) and -11.3% (3). Theoretical performance calculations (Gaussian 09 and EXPLO 6.01) provided detonation pressures and velocities for salts 2-7 in the ranges of 27.6-41.1 GPa and 8519-9518 m s-1, respectively, which make them competitive energetic materials.

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The electrochemical performances and thermostability of LiNi0.8Co0.1Mn0.1O2 is affected by temperature. High ambient temperature or irregular heat distribution accelerates the decline of LiNi0.8Co0.1Mn0.1O2 performance, shortens cathode material life. In this work, the energy storage and thermostability of the Li3VO4-coated LiNi0.8Co0.1Mn0.1O2 cathode material were studied for the first time by electrochemical calorimetry methode at different temperatures and rates. Results show that Li3VO4-coated LiNi0.8Co0.1Mn0.1O2 cathode material has excellent rate and cycle performance. The thermal electrochemical experiments further show that the thermal stability of Li3VO4-coated LiNi0.8Co0.1Mn0.1O2 cathode material in charge-discharge energy storage and conversion system is better than LiNi0.8Co0.1Mn0.1O2 at 30, 40, and 50°C. The enhanced performance can be attributed to the fact that Li3VO4 coating promotes the transmission of lithium ions and protects the active material from electrolyte corrosion at different temperature, as well as reduces side reaction, electrode polarization and heat generation of cathode materials. The Li3VO4-coated LiNi0.8Co0.1Mn0.1O2 cathode material has excellent energy storage properties and thermostability, which are beneficial to the development of electronic equipment.

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To assess the health conditions of tree trunks, it is necessary to estimate the layers and anomalies of their internal structure. The main objective of this paper is to investigate the internal part of tree trunks considering their irregular contour. In this respect, we used ground penetrating radar (GPR) for non-invasive detection of defects and deteriorations in living trees trunks. The Hilbert transform algorithm and the reflection amplitudes were used to estimate the relative dielectric constant. The point cloud data technique was applied as well to extract the irregular contours of trunks. The feasibility and accuracy of the methods were examined through numerical simulations, laboratory and field measurements. The results demonstrated that the applied methodology allowed for accurate characterizations of the internal inhomogeneity. Furthermore, the point cloud technique resolved the trunk well by providing high-precision coordinate information. This study also demonstrated that cross-section tomography provided images with high resolution and accuracy. These integrated techniques thus proved to be promising for observing tree trunks and other cylindrical objects. The applied approaches offer a great promise for future 3D reconstruction of tomographic images with radar wave.

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A simple and rapid mercury ion selective electrode based on 1-undecanethiol (1-UDT) assembled Au substrate (Au/1-UDT) has been well constructed. 1-UDT was for the purpose of generating self-assembled monolayer on gold surface to recognize Hg2+ in aqueous solution, which had a working concentration range of 1.0×10-8-1.0×10-4molL-1, with a Nernst response slope of 28.83±0.4mV/-pC, a detection limit of 4.5×10-9molL-1, and a good selectivity over the other tested cations. Also, the Au/1-UDT possessed good reproducibility, stability, and short response time. The recovery obtained for the determination of mercury ion in practical tremella samples was in the range of 99.8-103.4%. Combined electrochemical analysis and X-ray photoelectron spectroscopy (XPS) with quantum chemical computation, the probable recognition mechanism of the electrode for selective recognition of Hg2+ has been investigated. The covalent bond formed between mercury and sulfur is stronger than the one between gold and sulfur and thus prevents the adsorption of 1-UDT molecules on the gold surface. The quantum chemical computation with density functional theory further demonstrates that the strong interaction between the mercury atom and the sulfur atom on the gold surface leads to the gold sulfur bond ruptured and the gold mercury metallophilic interaction.

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Several molecule counting methods based on electrochemical characterization of alkanethiol and thiolated single-stranded oligonucleotide (HS-ssDNA) immobilized on gold microplates, which were used as extended gates of field effect transistors (FETs), have been investigated in this paper. The surface density of alkanethiol and DNA monolayers on gold microplates were quantitatively evaluated from the reductive desorption charge by using cyclic voltammetry (CV) and fast CV (FCV) methods in strong alkali solution. Typically, the surface density of 6-hydroxy-1-hexanethiol (6-HHT) was evaluated to be 4.639 molecules/nm(2), and the 28 base-pair dsDNA about 1.226-4.849 molecules/100 nm(2) on Au microplates after post-treatment with 6-HHT. The behaviors on surface potential and capacitance of different aminoalkanethiols on Au microplates were measured in 0.1 mol/L Na2SO4 and 10 mmol/L Tris-HCl (pH=7.4) solutions, indicating that the surface potential increases and the double-layer capacitance decreases with the length of carbon chain increased for the thiol monolayers, which obey a physics relationship for a capacitor. Comparably, a simple sensing method based on the electronic signals of biochemical reaction events on DNA immobilization and hybridization at the Au surface of the extended gate FET (EGFET) was developed, with which the surface density of the hybridized dsDNA on the gold surface of the EGFET was evaluated to be 1.36 molecules per 100 nm(2), showing that the EGFET is a promising sensing biochip for DNA molecule counting.

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The quantitative structure-activity relationship (QSAR) for neutral carriers used to prepare hydrogen ion sensors has been studied. A series of synthesized carrier compounds were taken as the training set. Five molecular structure parameters of the compounds were calculated by using CNDO/2 algorithm and used as feature variables in constructing QSAR model. The lower and upper limits of the linear pH response range were taken as the activity measure. The corresponding model equations were derived from the stepwise regression procedure. With the established QSAR model, a new pH carrier, (4-hydroxybenzyl) didodecylamine (XIII) was proposed and synthesized. The PVC membrane pH electrode based on carrier XIII with a wide pH linear response range of 2.0-12.5 was prepared. Having a theoretical Nernstian response slope of 57.2+/-0.3 mV/pH (n=5 at 25 degrees C) without a super-Nernstian phenomenon, the sensor had low resistance, short response time, high selectivity and good reproducibility. Moreover, the sensor was successfully applied to detecting the pH value of serum samples.

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