Abstract Using the semiclassical ensemble model, the dependence of relative amplitude for the recollision dynamics in nonsequential double ionization (NSDI) of neon atom driven by the orthogonally ...polarized two-color field (OTC) laser field was theoretically studied. And the dynamics in two typical collision pathways, recollision-impact-ionization (RII) and recollision-excitation with subsequent ionization (RESI) is systematically explored. Our results reveal that the V-shaped structure in the correlated momentum distribution is mainly caused by the RII mechanism when relative amplitude of OTC laser field is zero, and the first ionized electrons will quickly skim through the nucleus and share few energy with the second electron. As the relative amplitude increases, the V-shaped structure gradually disappears and electrons are concentrated on the diagonal in the electron correlation spectrum indicating that the energy sharing after electrons collision is symmetric for OTC laser fields with large relative amplitudes. Our studies show that changing the relative amplitude of the OTC laser field can efficiently control the electron-electron collisions and energy exchange efficiency of the NSDI process.
The present study was carried out to produce a high quality puffed infant rice cereal from rice and mung bean through extrusion technology. Experiments were designed using 3 independent variables ...(i. e. 14–18% feed moisture, 400–550 r/min screw speed and 125–175 °C barrel temperature) and 3 response variables (i. e. bulk density, water solubility index and degree of gelatinisation) at five different levels of central composite rotatable design (CCRD). The results of optimization demonstrated that 14% feed moisture, 400 r/min screw speed and 175 °C barrel temperature could generate rice-mungbean extrudates with desirable functional properties. The selected extrudate samples were further examined using scanning electron microscope (SEM), rapid viscosity analyzer (RVA), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD) analysis,
digestibility and fundamental nutrient analysis. Notably, the initial oval-shaped particle structure of starch in the raw materials disappeared, the surface debris and roughness increased, and the density decreased. The time required for the gelatinization of puffed infant rice cereal was the shortest, which was in agreement with the positioning of ready-to-eat weaning food for infants. Moreover, the puffed infant rice cereal displayed higher peak viscosity and breakdown value, smaller retrogradation value and greater top taste value compared to the commercial infant rice cereal. Besides maintaining the initial characteristic peak of starch, the puffed infant rice cereal demonstrated characteristic absorption peaks of COO- in the vicinity of 1546 cm
and 1437 cm
, indicating the formation of carboxylate during extrusion. In addition, the puffed infant rice cereal exhibited firm diffraction peaks at the diffraction angles of 7.4°, 12.5° and 20.5°, indicating that a certain amount of starch changed from type A to type V. Furthermore, the digestive rate of puffed infant rice cereal was higher than that of commercial infant cereal (90.21 versus 86.96%, respectively;
< 0.05). Altogether, our findings reveal that the developed puffed infant rice cereal meets the standards set by the Codex Alimentarius Commission (CAC; 74-1981).
The effects of different durations of hydrolysis with Protemex on the foaming properties, surface tension, physicochemical properties and static rheological properties of corn glutelin were ...determined. The results showed that the solubility and foaming properties of corn glutelin were significantly improved by Protamex hydrolysis. The foaming capacity of the 120 min hydrolysate was highest, which was 2.8 times higher than that of corn glutelin, and its foam stability was also good. The hydrolysate had the lowest surface tension and the highest apparent viscosity. The microscopic morphology of the foam formed was fine and uniform, with a thick protein film. With the prolongation of hydrolysis time, the average particle size of corn glutelin hydrolysates decreased continuously, the endogenous fluorescence intensity and surface hydrophobicity increased gradually, while the surface net charge decreased first and then increased. The results of Raman spectroscopy showed that after appropriate hydrolysis, the α-helix content decreased, and the random coil and β-angle contents increased; the peak intensity ratio of tyrosine residues (I850/I830) increased, and the peak intensity of tryptophan residues (I760) decreased. Nevertheless, the β-folding content changed little. Long-time hydrolysis significantly increased the content of random coil and decreased the peak intensity ratio of tyrosine residues (I850/I830). Therefore, restricted hydrolysis can change the structure and interface properties of corn glutelin, improve its foam properties, and consequently increase the potential utilization rate of corn gluten meal in the food field.
A single-atom TM-N
(TM = Fe, Co, Mn, etc.) embedded graphene matrix is known for its excellent activity and durability in oxygen reduction reaction (ORR) catalysis. Among them, Mn-N
sites have been ...theoretically proved to undergo a complete 4-electron pathway with low ORR overpotentials and low activation barriers in O
dissociation. However, in reality there still remain significant activity gaps between such Mn-N
based catalysts (such as MnPc and MnP) and Fe-N
or Pt-group metal catalysts. The inferior ORR performance of MnPc and MnP could be attributed to the strong binding ability of Mn that causes great difficulties in removing the ORR products from the surface sites. On this basis, 17 types of Mn-N
models containing various three-, four- and five-coordination groups were established. Systematic density functional theory (DFT) calculations were performed to investigate the N,C coordination effects on their corresponding ORR activities. Scaling relations were found among the binding strengths of key ORR intermediates, which could be modulated by the N doping level among different coordination groups. A volcano plot for ORR overpotentials (η
) as a function of *OH adsorption free energy (ΔG
) was further established. The 3D five-coordination sites exhibit much higher ORR activity due to the great decrease in strong binding abilities compared with 2D three- or four-coordination sites. Particularly, (Cyan)Mn-N
/D is positioned near the apex of the volcano plot with an η
of 0.33 V even lower than that of Pt(111) (0.34 V). Furthermore, the electron withdrawing/donating mechanisms among Mn, N, C, and O were investigated and related to the binding abilities of different coordination groups. Electronic structure calculations indicate that the binding abilities of Mn-N
well correlate with the σ-type anti-bonding components between Mn-3d and O-2p states near the Fermi energy level.
Water inrush disaster occurs easily when the tunnel is close to the water rich fault fracture zone. To clarify the disaster evolution process and the critical thickness of the water-resistant rock ...mass is the key problem of the prevention and control of water inrush disaster in jointed rock tunnel. However, the water inrush disaster in jointed rock tunnels involves solid-fluid interaction, and the conventional single-phase numerical method is difficult to realize the real simulation of the disaster. To solve this problem, we gave full play to the advantages of the discontinuous deformation analysis method (DDA) in simulating solid motion and the smoothed particle hydrodynamics method (SPH) in simulating fluid motion, and the two-dimensional DDA-SPH (2D DDA-SPH) method was used to simulation the solid-fluid interaction in the water inrush disasters. Firstly, the 2D DDA-SPH method was used to replicate the solitary wave experiment, named Scott Russell's wave generator, and the result of the simulation was almost the same with experiment, which verified the accuracy of 2D DDA-SPH method in simulating solid-fluid interaction dynamic problems. Secondly, taking the Yonglian Tunnel as the research object, we simulated the water inrush disaster in the F2 fault of Yonglian Tunnel under the condition of different thickness of water-resistant rock mass. Based on the results of the simulation, the critical thickness of water-resistant rock mass was determined, which was about 5m. Lastly, we analyzed the process of the water inrush disasters based on the movement state of the fluid near the water-resistant rock mass. And we divided the process of the water inrush disasters in the jointed rock mass into three stage, which were mutation stage, cataclysmic stage and stable stage, which provided a theoretical basis for the prevention and control of water inrush in jointed rock tunnel.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZRSKP
AbstractA rock burst can cause a serious disaster. For the mitigation of rock burst-induced disaster, the possibility assessment of a rock burst for an underground excavation is a key undertaking and ...also a great challenge because rock burst failure involves a dynamic and large deformation process. In this paper, a numerical simulation method of rock burst using discontinuous deformation analysis (DDA) is proposed by showing the advantage of DDA in handling the large deformation of this dynamic process. First, the problem of using the number of the adjacent boundary in the original algorithm of the DDA program was determined and solved, which is critical and important in analyzing artificial mesh models. The DDA model was used for simulating a rock burst process and was verified by a true triaxial test in which the critical stress for rock burst had been clarified. Then, the effects of rock hardness and brittleness on critical stresses were clarified quantitatively. The critical stresses of a rock burst were estimated for rocks with various values of the elastic modulus, Poisson’s ratio, cohesion, friction angle, and tension strength. Finally, a strategy is proposed for examining the critical depth of a rock burst for various types of rocks under different tectonic levels. Rocks are classified by the mechanical properties of them, such as elastic modulus, Poisson’s ratio, cohesion, friction angle, and tensile strength. The depth condition was converted to initial stress. The tectonic condition was represented by the ratio of horizontal-to-vertical components of the initial stress. Through a large set of simulations, the critical depths of rock bursts in seven types of rocks were estimated for different tectonic levels. The results show that the proposed rock burst analysis using DDA simulation is effective and useful.
Ever since the deployment of the first-generation of mobile telecommunications, wireless communication technology has evolved at a dramatically fast pace over the past four decades. The upcoming ...fifth-generation (5G) holds a great promise in providing an ultra-fast data rate, a very low latency, and a significantly improved spectral efficiency by exploiting the millimeter-wave spectrum for the first time in mobile communication infrastructures. In the years beyond 2030, newly emerged data-hungry applications and the greatly expanded wireless network will call for the sixth-generation (6G) communication that represents a significant upgrade from the 5G network - covering almost the entire surface of the earth and the near outer space. In both the 5G and future 6G networks, millimeter-wave technologies will play an important role in accomplishing the envisioned network performance and communication tasks. In this paper, the relevant millimeter-wave enabling technologies are reviewed: they include the recent developments on the system architectures of active beamforming arrays, beamforming integrated circuits, antennas for base stations and user terminals, system measurement and calibration, and channel characterization. The requirements of each part for future 6G communications are also briefly discussed.
Effective drug delivery systems that can systematically and selectively transport payloads to disease cells remain a challenge. Here, a targeting ligand‐modified DNA origami nanostructure (DON) as an ...antibody–drug conjugate (ADC)‐like carrier for targeted prostate cancer therapy is reported. Specifically, DON of six helical bundles is modified with a ligand 2‐3‐(1,3‐dicarboxy propyl)‐ureido pentanedioic acid (DUPA) against prostate‐specific membrane antigen (PSMA), to serve as the antibody for drug conjugation in ADC. Doxorubicin (Dox) is then loaded to DON through intercalation to dsDNA. This platform features in spatially controllable organization of targeting ligands and high drug loading capacity. With this nanocomposite, selective delivery of Dox to the PSMA+ cancer cell line LNCaP is readily achieved. The consequent therapeutic efficacy is critically dependent on the numbers of targeting ligand assembled on DON. This target‐specific and biocompatible drug delivery platform with high maximum tolerated doses shows immense potential for developing novel nanomedicine.
This DNA‐based, DNA origami nanostructure (DON)‐enabled, cell‐selective, and biocompatible drug delivery platform with high “drug/ligand ratio” shows immense potential as an efficient drug carrier for developing novel nanomedicine with high pharmacokinetics and therapeutic index.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
Peptide-MHC (pMHC) multimers have excelled in the detection of antigen-specific T cells and have allowed phenotypic analysis using other reagents, but their use for detection of low-affinity ...T cells remains a challenge. Here we develop a multimeric T cell identifying reagent platform using two-dimensional DNA origami scaffolds to spatially organize pMHCs (termed as dorimers) with nanoscale control. We show that these dorimers enhance the binding avidity for low-affinity antigen-specific T cell receptors (TCRs). The dorimers are able to detect more antigen-specific T cells in mouse CD8
+
T cells and early-stage CD4
+
CD8
+
double-positive thymocytes that express less dense TCRs, compared with the equivalent tetramers and dextramers. Moreover, we demonstrate dorimer function in the analysis of autoimmune CD8
+
T cells that express low-affinity TCRs, which are difficult to detect using tetramers. We anticipate that dorimers could contribute to the investigation of antigen-specific T cells in immune T cell function or immunotherapy applications.
Tunnel excavation unloading is the primary factor in disasters such as collapse and large deformations of surrounding rock. Therefore, it is a key issue to study the deformation mechanism of the ...surrounding rock in the process of tunnel excavation unloading. However, the original three-dimensional discontinuous deformation analysis method (3D DDA) can only simulate the displacement of the surrounding rock after the completion of tunnel excavation, which is not suitable for studying the mechanism of the surrounding rock’s deformation caused by tunnel excavation. Therefore, this paper proposes a virtual block removal algorithm that moves the blocks out of the calculation area while ensuring the consistency of the array and develops an improved 3D DDA method (3D DDA_exc) by embedding the algorithm into the original 3D DDA program, which is suitable for the simulation of tunnel excavation. In addition, based on the free fall models of static and sliding blocks, we compare the results of the 3D DDA_exc simulation with theoretical calculation results, which are basically the same. Then, both the 3D DDA_exc method and the discrete element method (DEM) are used to simulate the excavation of the tunnel in a blocky rock mass, and the rock displacements around the tunnel hole are basically the same, which further illustrates the accuracy of the 3D DDA_exc method in simulating tunnel excavation. Finally, taking the Huangjiazhuang Tunnel of the Rizhao-Lankao high-speed railway as a case study, we simulated block collapse during the excavation process of the tunnel using the centre diaphragm method (CD method). Compared with the result of the 3D DDA method without the process of tunnel excavation, block collapse can be avoided if the dangerous blocks are supported and reinforced during the excavation of part ① and part ② of the tunnel, which was of guiding significance to the safe construction of the tunnel.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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