[en] An iterative CT image reconstruction method based on half-fan scan is proposed to solve the problems of limited field of view and over-usage of radiation dose. Firstly, detector array is placed horizontally. Secondly, projection data of object are sampled sparsely in a circular scan. Thirdly, the collected projection data and reconstruct CT image by ART-TV reconstruction method are used. At last, output reconstructed image after the set number of iterations reaches. Experiments show that half-fan scan can double the field of view approximately, and reduce the cost of detector. Additionally, radiation dose can be reduced by using sparse sampling and good-quality image is reconstructed by iterative image reconstruction. (authors)

[en] Highlights: • HA would significantly affect the migration and transformation of SMZ. • Kinetics and thermodynamics of HA–SMZ interactions were studied using SPR and ITC. • The interaction is enhanced by increasing ionic strength and decreasing temperature. • Hydrogen bond and electrostatic interaction play important roles in the process. - Abstract: The presence of sulfonamide antibiotics in the environments has been recognized as a crucial issue. Their migration and transformation in the environment is determined by natural organic matters that widely exist in natural water and soil. In this study, the kinetics and thermodynamics of interactions between humic acids (HA) and sulfamethazine (SMZ) were investigated by employing surface plasmon resonance (SPR) combined with isothermal titration microcalorimetry (ITC) technologies. Results show that SMZ could be effectively bound with HA. The binding strength could be enhanced by increasing ionic strength and decreasing temperature. High pH was not favorable for the interaction. Hydrogen bond and electrostatic interaction may play important roles in driving the binding process, with auxiliary contribution from hydrophobic interaction. The results implied that HA existed in the environment may have a significant influence on the migration and transformation of organic pollutants through the binding process.

[en] Thorium dioxide powder has seen important as a new nuclear fuel, which has better thermal conductance than uranium dioxide powder. Nitrogen adsorption is an effective method in the study of specific surface area of ThO₂. Basing on the BET theory and studying the behavior of ThO₂ powder absorbing N₂ at liquid nitrogen temperature. It has been taking many studies on the sample volume, the time of desorption and the temperature of desorption to study the factors that influence the specific surface area of ThO₂. Through orthogonal experiments, the best determination parameters were found and the determination method of specific surface area of thorium dioxide powder was established. The precision of this test method can be better than 2%. (authors)

[en] A simple, sensitive fluorescent method for detecting biological aminothiols has been developed based on the inner filter effect principle that utilizes CePO₄:Tb³⁺ luminescent nanoparticles as the donor and gold nanoparticles (AuNPs) as the energy receptor. Stable, water-soluble and well-dispersible CePO₄:Tb³⁺ nanoparticles with low photobleaching features were synthesized conveniently by a facile solvothermal method. At the same time, AuNPs with a high extinction coefficient are expected to be capable of functioning as powerful receptor. Based on the complementary overlap between the emission spectrum of CePO₄:Tb³⁺ nanoparticles and the absorption spectrum of Au NPs, an inner filter effect system was constructed. In the presence of aminothiols (such as cysteine), AuNPs interacted with the aminothiols, thereby inducing the aggregation of AuNPs, which induced the fluorescence recovery. In the present work, we developed a turn-on fluorescent assay for the determination of biological aminothiols. Under the optimum conditions, the linear concentration ranges were 1.0×10⁻⁷–2.0×10⁻⁶ M for cysteine, 5.0×10⁻⁸–5.0×10⁻⁷ M for glutathione and 8.0×10⁻⁸–1.0×10⁻⁶ M for homocysteine, respectively. The method is successfully applied to the quantification of biological aminothiols in synthetic samples. -- Highlights: • An inner filter effect method for detecting biological aminothiols has been developed. • CePO₄:Tb³⁺ nanoparticles were synthesized and used as the donor. • Gold nanoparticles (AuNPs) were synthesized and used as the energy receptor

[en] Highlights: • WO_3 mesoscopic microspheres self-assembled by nanofibers. • Inorganic solvent H_2O_2 play an integral role in the process of self-assembly. • WO_3 mesoscopic microspheres exhibit specific capacitance value of 797.05 F g"−"1 at a constant density of 0.5 A g"−"1 in 2 M H_2SO_4 aqueous solution. • The WO_3 //AC asymmetric supercapacitor displays a maximum energy density of 97.61 Wh kg"−"1 and power density of 28.01 kW kg"−"1. - Abstract: Mesoscopic WO_3 microspheres composed of self-assembly nanofibers were prepared by hydrothermal reaction of tungsten acid potassium and H_2O_2. The mesoscopic WO_3 microspheres offer desired porous properties and large effective active areas provided by intertwining nanofibers, thereby resulting in excellent supercapacitive properties due to facile electrolyte flow and fast reaction kinetics. In three electrode configuration, mesoscopic WO_3 microspheres exhibit specific capacitance value of 797.05 F g"−"1 at the current density of 0.5 A g"−"1 and excellent cycling stability without decay after 2000 cycles in 2 M H_2SO_4 aqueous solution. These values are superior to other reported WO_3 composites. An asymmetric supercapacitor is constructed using the as-prepared WO_3 mesoscopic microspheres as the positive electrode and the activated carbon as the negative electrode, which displays excellent electrochemical performance with a maximum energy density of 97.61 Wh kg"−"1 and power density of 28.01 kW kg"−"1. These impressive performances suggest that the mesoscopic WO_3 microspheres are promising electrode materials for supercapacitor

[en] We have studied the dynamics and transfer of the entanglement of the two identical atoms simultaneously interacting with vacuum field by employing the dressed-state representation. The two atoms are driven by classical fields. The influence of the initial entanglement degree of two atoms, the coupling strength between the atom and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is discussed. The initial entanglement of the two atoms can be transferred into the entanglement between the atom and cavity field when the dissipation is neglected. The maximally entangled state between the atoms and cavity field can be obtained under some certain conditions. The time of disentanglement of two atoms can be controlled and manipulated by adjusting the detuning and classical driving fields. Moreover, the larger the cavity decay rate is, the more quickly the entanglement of the two atoms decays. (paper)

[en] Highlights: • The accuracy of power generation prediction in CCPP is improved by an ensemble model. • A stacking prediction model based on a multi-model ensemble is proposed. • The power prediction model based on stacking under environmental variables is realized. • The hyperparameters of the sub-model are optimized by the grid-search algorithm. • The proposed method provides more accurate predictions than other methods. Electric power makes a significant contribution to society. Predicting power generation is becoming increasingly important for electric power planning and energy utilization. A reliable forecasting model is necessary for accurate planning of electricity generation. The main goal of this study is to develop effective and realistic solutions for the full-load power generation prediction of combined cycle power plants. According to 9568 items of data pertaining to a combined cycle power plant in six years of its full-load operation, a prediction method based on stacking ensemble hyperparameter optimization is established. The results demonstrate that this method provides high prediction accuracy for the power plant under multiple complex environmental variables. Besides, the predictions generated using this method are compared with those of traditional machine learning methods, random forest, and other ensemble methods, as well as those cited in the literature using the same dataset. The predictions show that the proposed method offers more accurate predictions of the power generation from a combined cycle plant, which opens up a new idea for power planning and energy utilization.

[en] With the introduction of manganese (Mn) ion, lignin composite carbon aerogels with improved pore structure were quickly prepared by a microwave assisted sol-gel method. The influence of the amount of manganese ion added on the pore structure of lignin composite carbon aerogel was investigated. The results show that the introduction of Mn ion can significantly improve the pore structure of lignin composite carbon aerogels. The lignin composite carbon aerogels with the Mn ion amount of 5%, exhibit a high specific surface area (SSA) of 582 m² g⁻¹ and large total pore volume of 0.35 cm³ g⁻¹, which are respectively up to 259.3% and 218.2% larger than the lignin composite carbon aerogels without Mn ion addition. Benefiting from the more-developed pore structure and synergetic effect, the as-obtained lignin composite carbon aerogels exhibit a high specific capacitance up to 186 F g⁻¹. In addition, the lignin composite carbon aerogels exhibit outstanding cycling stability. The specific capacitance retains 96% after 2000 cycles. The lignin composite carbon aerogels with improved pore structure show great potential for application in supercapacitors. (paper)

[en] Hierarchical porous carbon aerogels with a high specific surface area and excellent electrochemical performance were synthesized by pyrolysis and CO₂ activation of Cu-doped lignin-based aerogels. The Cu-doped lignin-based aerogels were prepared by a microwave assisted sol-gel process of alkali lignin, resorcinol, and formaldehyde under the catalysis of CuCl₂ · 6H₂O. The microwave assisted sol-gel process reduces the gelation time from weeks to 10 min. The Cu-doped lignin-based carbon aerogels exhibit an interconnected porous network structure, a high specific surface area of 431 m² g⁻¹, a large total pore volume of 0.24 cm³ g⁻¹, and a high specific capacitance of 222.96 F g⁻¹, which increase to 899 m² g⁻¹, 0.63 cm³ g⁻¹ and 257.65 F g⁻¹ after CO₂ activation process, respectively. The microporosity of Cu-doped lignin-based carbon aerogels reached 66.7%, which decreased to 47.6% after CO₂ activation process. The activation process contributes to the fusion of adjacent micropores into larger ones. In addition, the CO₂ activated Cu-doped lignin-based carbon aerogels exhibit outstanding cycling stability. The specific capacitance retains 95% after 2000 cycles at the current density of 20 A g⁻¹. These findings open up the rapid fabrication of low-cost and high-performance carbon aerogels and show potential application in energy storage. (paper)

[en] This paper studies the influence of the reagent vibration on the reaction O(¹D)+HF→HO+F by using a quasi-classical trajectory method on the new ab initio ¹A' ground singlet potential energy surface (Gómez-Carrasco et al 2007 Chem. Phys. Lett. 435 188–193). The product angular distributions which reflect the vector correlation are calculated. Four polarization-dependent differential cross sections (PDDCSs) which are sensitive to many photoinitiated bimolecular reaction experiments are presented in the center of the mass frame, respectively. The differential cross section indicates that the OH product mainly tends to the forward scattering, and other PDDCSs are also influenced by the vibration levels of HF. (atomic and molecular physics)