High-energy Reactions Research Articles

Alkylation of Complex Glycine Precursor (CGP) as a Prebiotic Route to 20 Proteinogenic Amino Acids Synthesis.

It is not known why the number of proteinogenic amino acids is limited to 20. Since Miller's experiment, many studies have shown that amino acids could have been generated under prebiotic conditions. However, the amino acid compositions obtained from simulated experiments and exogenous origins are different from those of life. We hypothesized that some simple precursor compounds generated by high-energy reactions were selectively combined by organic reactions to afford a limited number of amino acids. To this direction, we propose two scenarios. One is the reaction of HCN with each side-chain precursor (the aminomalononitrile scenario), and the other is alkylation of the "complex glycine precursor", which is the main product of proton irradiation of the primordial atmosphere (the new polyglycine scenario). Here, selective formation of the 20 amino acids is described focusing on the latter scenario. The structural features of proteinogenic amino acids can be described systematically. The scenario consists of three stages: a high-energy reaction stage (Gly, Ala, Asn, and Asp were established); an alkylation stage (Gln, Glu, Ser, Thr, Val, Ile, Leu, and Pro were generated in considerable amounts); and a peptide formation stage (Phe, Tyr, Trp, His, Lys, Arg, Cys, and Met were selected due to their structural advantages). This scenario is a part of the evolution of Garakuta World, in which many prebiotic materials are contained.

High-Energy Reaction Dynamics of N3.

The atom-exchange and atomization dissociation dynamics for the N(4S) + N2(1Σg+) reaction are studied using a reproducing kernel Hilbert space (RKHS)-based, global potential energy surface (PES) at the MRCI-F12/aug-cc-pVTZ-F12 level of theory (MRCI, multireference configuration interaction). For the atom exchange reaction (NANB + NC → NANC + NB), computed thermal rates and their temperature dependence from quasi-classical trajectory (QCT) simulations agree to within error bars with the available experiments. Companion QCT simulations using a recently published CASPT2-based PES confirm these findings. For the atomization reaction, leading to three N(4S) atoms, the computed rates from the RKHS-PES overestimate the experimentally reported rates by 1 order of magnitude, whereas those from the permutationally invariant polynomial (PIP)-PES agree favorably, and the T dependence of both computations is consistent with the experiment. These differences can be traced back to the different methods and basis sets used. The lifetime of the metastable N3 molecule is estimated to be ∼200 fs depending on the initial state of the reactants. Finally, neural-network-based exhaustive state-to-distribution models are presented using both PESs for the atom exchange reaction. These models will be instrumental for a broader exploration of the reaction dynamics of air.

Photo-to-Thermal Conversion Harnessing Low-Energy Photons Renders Efficient Solar CO2 Reduction.

Efficient photocatalytic solar CO2 reduction presents a challenge because visible-to-near-infrared (NIR) low-energy photons account for over 50% of solar energy. Consequently, they are unable to instigate the high-energy reaction necessary for dissociating C═O bonds in CO2. In this study, we present a novel methodology leveraging the often-underutilized photo-to-thermal (PTT) conversion. Our unique two-dimensional (2D) carbon layer-embedded Mo2C (Mo2C-Cx) MXene catalyst in black color showcases superior near-infrared (NIR) light absorption. This enables the efficient utilization of low-energy photons via the PTT conversion mechanism, thereby dramatically enhancing the rate of CO2 photoreduction. Under concentrated sunlight, the optimal Mo2C-C0.5 catalyst achieves CO2 reduction reaction rates of 12000-15000 μmol·g-1·h-1 to CO and 1000-3200 μmol·g-1·h-1 to CH4. Notably, the catalyst delivers solar-to-carbon fuel (STF) conversion efficiencies between 0.0108% to 0.0143% and the STFavg = 0.0123%, the highest recorded values under natural sunlight conditions. This innovative approach accentuates the exploitation of low-frequency, low-energy photons for the enhancement of photocatalytic CO2 reduction.

Analysis of Altitude and Ambient Temperature Effects on the Reactivity of Oxidation Catalysts in the Presence of H2

Worldwide emission standards are now required to cover engine operation under extreme ambient conditions, which affect the raw emissions and the efficiency of the exhaust aftertreatment systems. These regulations also target new combustion technologies for decarbonization, such as neat hydrogen (H2) combustion or dual-fuel strategies, which involve a challenge to the analysis of exhaust aftertreatment system requirements and performance. This work addresses the impact of high altitude and low ambient temperature conditions on the reactivity of an oxidation catalyst in the presence of H2. A reaction mechanism is proposed to cover the main conversion paths of CO, HC, and H2, including the formation and consumption of high-energy surface reaction intermediates. The mechanism has been implemented into a faster-than-real-time reduced-order model for multi-layer washcoat honeycomb catalytic converters. The model was utilized to investigate the effect of H2 concentration on the reactivity of CO and HC within the catalyst under various operating and ambient conditions. By applying the model and examining the selectivity towards different reaction pathways in the presence of H2, insights into surface intermediates and reactivity across different cross-sections of the monolith were obtained. This analysis discusses the underlying causes of reactivity changes promoted by H2 and its relative importance as a function of driving boundary conditions.

Defect Engineering Simultaneously Regulating Exciton Dissociation in Carbon Nitride and Local Electron Density in Pt Single Atoms Toward Highly Efficient Photocatalytic Hydrogen Production.

The high exciton binding energy (Eb) and sluggish surface reaction kinetics have severely limited the photocatalytic hydrogen production activity of carbon nitride (CN). Herein, a hybrid system consisting of nitrogen defects and Pt single atoms is constructed through a facile self-assembly and photodeposition strategy. Due to the acceleration of exciton dissociation and regulation of local electron density of Pt single atoms along with the introduction of nitrogen defects, the optimized Pt-MCT-3 exhibits a hydrogen production rate of 172.0µmolh-1 (λ ≥ 420nm), ≈41 times higher than pristine CN. The apparent quantum yield for the hydrogen production is determined to be 27.1% at 420nm. The experimental characterizations and theoretical calculations demonstrate that the nitrogen defects act as the electron traps for the exciton dissociation, resulting in a decrease of Eb from 86.92 to 43.20meV. Simultaneously, the stronger interaction between neighboring nitrogen defects and Pt single atoms directionally drives free electrons to aggregate around Pt single atoms, and tailors the d-band electrons of Pt, forming a moderate binding strength between Pt atoms and H* intermediates.

The Theory of Observation —The Propagation of Wave and the Apparent Velocity of Object Motion

This paper deepens and develops the Galileo's principle of relativity of motion, and summarizes the Laws of relativity and superposition of motion or wave (light). The essence of light is analyzed. The characteristics of various waves (sound waves, water waves, electromagnetic waves or light waves, etc.) and their relationship with the motion velocity of objects (wave sources) are analyzed. Wave acts as a messenger for people to know things, and are used as a signal to receive, perceive and know things far away. The observation of an object is a perspective effect, not represent the real motion of the object. The real motion of the wave source can exceed the velocity of wave, and the observed velocity of the object moving at the super wave (light) velocity can be much lower than the wave (light) velocity in some visual angles, while the observed speed of the object moving below the wave (light) speed will be much higher than the wave velocity in some visual angles. Objects moving at super wave (light) speed will produce special phenomena when observed from some angles. Super wave velocity (including superlight velocity) of real motion of objects and inversion of observation time sequence are common phenomena. Finally, the superluminal phenomenon of quasars and the technical application prospect of observation angle effect are discussed. This theory is widely used in remote sensing, astronomical observation, microscopic detection, satellite navigation, weather forecast, microscopic observation, medical detection, dynamic identification and so on. All of them are calibrated by the formula of observation angle effect derived in this paper, which can improve the accuracy of observation results. Especially in the observation technology of objects moving in high-speed such as high-energy collider, cosmic ray, cosmic radiation and nuclear reaction, the application effects are more remarkable, more real and accurate.

Magnetic properties of Sm-doped M-type barium ferrite by high-energy ball mill-assisted solid-phase reaction method

The primary objective of this study is to enhance the overall magnetic properties of pure barium ferrite through the addition of trace amounts of the light rare earth element Sm. This approach is more cost-effective compared to using heavy rare earth elements. The M-shaped barium ferrite, denoted as Ba1−xSmxFe12O19, was synthesized using a combination of solid-phase sintering method and high-energy ball milling. The high purity of samples was confirmed by determining their crystal structure using XRD. The internal structure of samples was examined using FTIR, and it was observed that the samples contained tetrahedral and octahedral clusters with corresponding bands at 599 cm−1 and 445 cm−1, respectively. The appearance of samples was examined using FESEM, and it was found that grains had hexagonal structures. EDS was used to characterize the elemental content of samples, and it was found that the content of Ba decreased with an increase in the content of Sm. The magnetic properties of samples were examined using VSM, and the coercivity reached a maximum value of 3096.22 Oe at a dopant fraction of 0.06, and the saturation magnetization reached a maximum value of 73.115 emu/g. The synthesized material has the potential for utilization in magnetic recording applications.

Highly Reproducible Synthesis of Hollow Zirconia Particles via Atmospheric-Pressure Plasma Processing with Inkjet Droplets

Hollow particles have attracted considerable attention owing to their unique properties. In this study, hollow monoclinic zirconia particles were directly synthesized from inkjet droplets of a zirconyl hydroxychloride aqueous solution via atmospheric-pressure plasma processing. Hollow structures with craggy surfaces were obtained in the plasma at gas temperatures above 1000 K. The steep solvent evaporation rate induced by the localized high-energy reaction field of the atmospheric-pressure plasma may have induced solute condensation near the droplet surface and contributed to the formation of hollow particles. The average diameter of the synthesized particles was ~ 3 μm, while their size distribution was narrow (coefficient of variation: 0.06–0.10). The high reproducibility of the synthesized particles was attributed to the small variations in inkjet droplet size. The proposed method enables the rapid synthesis of hollow particles of various inorganic materials, while controlling their number and composition.

Carbon Nanorings and Nanobelts: Material Syntheses, Molecular Architectures, and Applications

AbstractCarbon nanorings (CNRs) and carbon nanobelts (CNBs) of various sizes and innovative molecular architectures have ushered improvement in research in recent years. This serves as a prerequisite for further advances and applications, such as organic semiconductors and bottom‐up synthesis of single‐walled carbon nanotubes. Nevertheless, challenges such as high strain energy, excessive reactivity, end‐product stability, low‐scale yields, and side reactions inhibit material synthesis and applications. In this review, CNRs, CNBs, and other heteroatom‐doped molecular belts are discussed based on their molecular structural characteristics, with a special focus on their developments in the past two years. Furthermore, current applications, research obstacles, and future developments related to CNRs and CNBs are discussed. For the first time, studies and advancements in organic field‐effect transistors (OFETs) have been summarized in detail.

Multipole expansion for the electron-nucleus scattering at high energies in the unified electroweak theory

The paper presents the multipole expansion for the electron-nucleus scattering cross section at high energies within the framework of the unified electroweak theory. The electroweak currents of the nucleus are expanded into the simple components with definite angular momenta, called the multipole form factors. The multipole expansion of the cross section is a consequence of the above expansion. Besides the familiar electromagnetic form factors, there are also the vector and axial form factors, respectively, related to weak interactions. To determine multipole form factors, general formulas for the calculation of reduced matrix elements are established using the fractional parentage coefficient method and the multiparticle shell model. Calculation of them enables us to obtain more detailed information about the nuclear structure and elucidate the role played by the weak interaction in the high-energy reaction mechanisms.

Mechanistic Origin of Selective Methane to Methanol Oxidation on Vanadium-Doped Mesoporous Amorphous Silica Photocatalyst

Selective direct oxidation of methane to methanol is an important reaction for efficient utilization of natural gas. Photocatalytic routes for methane oxidation processes have advantages over traditional thermal catalysis as they can be more easily deployed at small-scale and remote off-grid sites, potentially reducing the rate of methane release and flaring. Hu and co-workers identified single-site vanadium-doped mesoporous amorphous silica photocatalysis which demonstrated methane conversion with high methanol selectivity ( J. Photochem. Photobiol., A 2013, 264, 48−55, DOI: 10.1016/j.jphotochem.2013.05.005). Photocatalysts using amorphous SiO2 frameworks are significantly less studied than other heterogeneous photocatalysts. As a result, computational studies are important for elucidating mechanisms in order to gain fundamental understanding as to how amorphous SiO2-based photocatalysts can be used for partial oxidation of methane. This work uses density functional theory to establish the reaction barriers associated with the photocatalytic methane to methanol reaction combined with microkinetic modeling. The work is able to elucidate the role of terminal versus bridging oxygens at the photocatalytic center in enhancing photocatalytic efficiency. In addition, avoiding non-Mars–van Krevelen reaction pathways, in which the oxygen vacancy is filled before methanol is formed, is found to be important, owing to overstabilization of reaction intermediates leading to subsequent high energy reaction barriers. Finally, the amorphous SiO2 surface is found to modify reaction barriers by stabilizing intermediates through dispersion and preventing the photocatalytic center from forming the optimum coordination geometry.

Several Topics on Transverse Momentum-Dependent Fragmentation Functions

The hadronization of a high-energy parton is described by fragmentation functions which are introduced through QCD factorizations. While the hadronization mechanism per se remains uknown, fragmentation functions can still be investigated qualitatively and quantitatively. The qualitative study mainly concentrates on extracting genuine features based on the operator definition in quantum field theory. The quantitative research focuses on describing a variety of experimental data employing the fragmentation function given by the parameterizations or model calculations. With the foundation of the transverse-momentum-dependent factorization, the QCD evolution of leading twist transverse-momentum-dependent fragmentation functions has also been established. In addition, the universality of fragmentation functions has been proven, albeit model-dependently, so that it is possible to perform a global analysis of experimental data in different high-energy reactions. The collective efforts may eventually reveal important information hidden in the shadow of nonperturbative physics. This review covers the following topics: transverse-momentum-dependent factorization and the corresponding QCD evolution, spin-dependent fragmentation functions at leading and higher twists, several experimental measurements and corresponding phenomenological studies, and some model calculations.

Probing system size dependence at high baryon density by systematic comparison of Ag+Ag and Au+Au reactions at 1.23A GeV

We present UrQMD predictions for the comparison of the recently measured Ag+Ag and Au+Au runs at a beam energy of E lab = 1.23A GeV explored by the HADES experiment. To this aim, different centrality definitions are investigated: We suggest that in the case of particle production, both systems should be compared at the same number of participating nucleons, while for a comparison of the (elliptic) flow, a selection on the initial state eccentricity—as in high energy reactions—is better suited. Generally, we find good agreement between both systems, if these centrality criteria are used. Specifically, the deuteron yields per participant and the pion to proton ratios are shown to scale with A part except for very central Ag+Ag reactions due to stronger stopping in such reactions. The elliptic flow in both systems follows initial state eccentricity scaling, albeit with the opposite sign as compared to high energies, suggesting a strong relation between final flows and the initial state also at the low energies explored here. The observation of this scaling might then allow to obtain further information on the expansion properties (and the EoS) of matter at high baryon densities.

Coherent photons induced high energy reactions in ultraperipheral heavy ion collisions

We review the recent progress in the studies of coherent photons induced high energy reactions in ultraperipheral heavy ion collisions. The strong electromagnetic field created by a fast moving charged heavy ion can be effectively viewed as a flux of quasi-real coherent photons. In this paper, we mainly discuss two different type processes that coherent photons take part in: lepton pair production via photon fusion and diffractive vector meson production in UPCs. We focus on investigating the impact parameter dependent effect and the final state soft radiation effect. On the other hand, a series of recent work have revealed that coherent photons are highly linearly polarized with its polarization vector being parallel to its transverse momentum. It has been shown that the linearly polarized photons can lead to <inline-formula><tex-math id="M2">\begin{document}$\cos 4\phi$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="7-20230074_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="7-20230074_M2.png"/></alternatives></inline-formula> azimuthal asymmetries in di-lepton production. This theoretical predication soon has been confirmed by the STAR measurement. With this new development from both theory and experiment sides, the linearly polarized photons provide a new experimental avenue to explore novel QCD phenomenology. For example, the linearly polarized photons can give rise to various different azimuthal asymmetries in diffractive vector meson production. These observables provide us unique chance to study two source interference effect in high energy scatterings, Coulomb-Nuclear interference effect as well as extracting gluon Wigner distribution. We will discuss these novel phenomenology studies and the possible future developments.

Search for D-D Fusion initiated by Nuclear Hotspots in Boranes

In the group of boron hydrogen compounds, decaborane and aminoborane belong to those with a particularly high hydrogen density in the molecular volume. Almost 100% of the protons in the molecule can be replaced by deuterons. In the element boron, the isotope 10B is 19.9% naturally present. By capturing thermal neutrons in this isotope, the high-energy reaction products 4He and 7Li are formed. It thus forms a hotspot in a spatially stable cloud of deuterium nuclei, which can be triggered by external action and whose energy could be transferred to deuterium in a similar way to neutral beam injection, a successful method to heat a fusion plasma.

Nanoengineering of NiO/MnO2/GO Ternary Composite for Use in High-Energy Storage Asymmetric Supercapacitor and Oxygen Evolution Reaction (OER)

Designing multifunctional nanomaterials for high performing electrochemical energy conversion and storage devices has been very challenging. A number of strategies have been reported to introduce multifunctionality in electrode/catalyst materials including alloying, doping, nanostructuring, compositing, etc. Here, we report the fabrication of a reduced graphene oxide (rGO)-based ternary composite NiO/MnO2/rGO (NMGO) having a range of active sites for enhanced electrochemical activity. The resultant sandwich structure consisted of a mesoporous backbone with NiO and MnO2 nanoparticles encapsulated between successive rGO layers, having different active sites in the form of Ni-, Mn-, and C-based species. The modified structure exhibited high conductivity owing to the presence of rGO, excellent charge storage capacity of 402 F·g-1 at a current density of 1 A·g-1, and stability with a capacitance retention of ~93% after 14,000 cycles. Moreover, the NMGO//MWCNT asymmetric device, assembled with NMGO and multi-wall carbon nanotubes (MWCNTs) as positive and negative electrodes, respectively, exhibited good energy density (28 Wh·kg-1), excellent power density (750 W·kg-1), and capacitance retention (88%) after 6000 cycles. To evaluate the multifunctionality of the modified nanostructure, the NMGO was also tested for its oxygen evolution reaction (OER) activity. The NMGO delivered a current density of 10 mA·cm-2 at the potential of 1.59 V versus RHE. These results clearly demonstrate high activity of the modified electrode with strong future potential.

Aerobic Oxidative N-Heterocyclic Carbene-Catalyzed Formal [3+3] Cyclization for the Synthesis of Tetrasubstituted Benzene Derivatives.

Herein, we present an accessible aerobic N-heterocyclic carbene (NHC)-catalyzed method that efficiently produces tetrasubstituted benzene rings in a single reaction. The method employs atmospheric oxygen (O2) as the terminal oxidant in a reaction that requires two oxidative steps. The aerobic oxidation is achieved by a selection of electron transfer mediators orchestrating a redox cascade, turning a high-energy aerobic oxidation reaction pathway into a favorable process.

Structure and production mechanism of the enigmatic X(3872) in high-energy hadronic reactions

We calculate the total cross section and transverse momentum distributions for the production of the enigmatic chi _{c1}(3872) (or X(3872)) assuming different scenarios: c bar{c} state and D^{0*} {bar{D}}^0 + D^0 {bar{D}}^{0*} molecule. The derivative of the c bar{c} wave function needed in the first scenario is taken from a potential model calculations. Compared to earlier calculations of molecular state we include not only single parton scattering (SPS) but also double parton scattering (DPS) contributions. The latter one seems to give smaller contribution than the SPS one. The upper limit for the DPS production of chi _{c1}(3872) is much below the CMS data. We compare results of our calculations with existing experimental data of CMS, ATLAS and LHCb collaborations. Reasonable cross sections can be obtained in either c bar{c} or molecular D {bar{D}}^* scenarios for X(3872), provided one takes into account both directly produced D^0, bar{D}^0, as well as D^0, bar{D}^0 from the decay of D^*. However arguments related to the lifetime of D^* suggest that the latter component is not active.

Electrochemiluminescence Systems for the Detection of Biomarkers: Strategical and Technological Advances.

Electrochemiluminescence (ECL)-based sensing systems rely on light emissions from luminophores, which are generated by high-energy electron transfer reactions between electrogenerated species on an electrode. ECL systems have been widely used in the detection and monitoring of diverse, disease-related biomarkers due to their high selectivity and fast response times, as well as their spatial and temporal control of luminance, high controllability, and a wide detection range. This review focuses on the recent strategic and technological advances in ECL-based biomarker detection systems. We introduce several sensing systems for medical applications that are classified according to the reactions that drive ECL signal emissions. We also provide recent examples of sensing strategies and technologies based on factors that enhance sensitivity and multiplexing abilities as well as simplify sensing procedures. This review also discusses the potential strategies and technologies for the development of ECL systems with an enhanced detection ability.

Hadron pair production in semi-inclusive electron positron annihilation process at twist-4

Fragmentation functions are important quantities in describing the hadronization process in high energy reactions. They can induce various azimuthal modulations which can be measured to reveal correlations between transverse momenta and polarizations. Without introducing initial state uncertainties, electron positron annihilation process is known as an ideal process to investigate the fragmentation functions. In this paper, therefore, we calculate the hadron pair production in the semi-inclusive electron positron annihilation process e^+ + e^- rightarrow h_1+h_2 + {bar{q}} +X at twist-4 to study dihadron fragmentation functions. Here {bar{q}} denotes an antiquark that corresponds to a jet of hadrons in experiments. Together with single hadron fragmentation functions, dihadron fragmentation functions can provide additional ways to extract nucleon parton distribution functions from the semi-inclusive deeply inelastic scattering experiments with two detected final state hadrons. We calculate the differential cross section of the hadron pair production semi-inclusive electron positron annihilation process at twist-4 level. The calculation is carried out by using the collinear expansion method. We also calculate azimuthal asymmetries in terms of dihadron fragmentation functions. Contributions from four-quark correlator are also taken into account. Both the electromagnetic and weak interactions are considered in this paper.