Effects of surface chlorine atoms on charge distribution and reaction barriers for photocatalytic CO_(2)reduction

Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.

Pseudo-rapidity distributions of charged particles in asymmetric collisions using Tsallis thermodynamics

The pseudo-rapidity distributions of the charged particles produced in the asymmetric collision systems p+Al,p+Au and ^(3)He+Au at√S_(NN)=200 GeV GeV are evaluated in the framework of a fireball model with Tsallis thermodynamics.The fireball model assumes that the experimentally measured particles are produced by fireballs following the Tsallis distribution and it can effectively describe the experimental data.Our results as well as previous results for d+Au collisions at√S_(NN)=200 GeV GeV and p+Pb collisions at√S_(NN)=5.02 TeV TeV validate that the fireball model based on Tsallis thermodynamics can provide a universal framework for pseudo-rapidity distribution of the charged particles produced in asymmetric collision systems.We predict the centrality dependence of the total charged particle multiplicity in the p+Al,p+Au and 3He+Au collisions.Additionally,the dependences of the fireball model parameters(y_(0a),y_(0A),σ_(a) and σ_(A))on the centrality and system size are studied.

Analytical model of non-uniform charge distribution within the gated region of GaN HEMTs

A physics-based analytical expression that predicts the charge,electrical field and potential distributions along the gated region of the GaN HEMT channel has been developed.Unlike the gradual channel approximation(GCA),the proposed model considers the non-uniform variation of the concentration under the gated region as a function of terminal applied volt-ages.In addition,the model can capture the influence of mobility and channel temperature on the charge distribution trend.The comparison with the hydrodynamic(HD)numerical simulation showed a high agreement of the proposed model with numerical data for different bias conditions considering the self-heating and quantization of the electron concentration.The ana-lytical nature of the model allows us to reduce the computational and time cost of the simulation.Also,it can be used as a core expression to develop a complete physics-based transistorⅣmodel without GCA limitation.

Memristor Hypothesis in Malignant Charge Distribution

Tissues in biological objects from the point of view of electromagnetic effects must be modeled not only for their conductivity. The ionic double layer induced by the electric field, built by electrolytic diffusion, must be counted. The micro (frequency dispersion phenomena) and macro (interfacial polarization), as well as more generalized by Nernst-Planck cells describe the biophysical aspects of this phenomena. The charge distribution depends on the processes and produces charge gradients in space. The dynamic feasibility of the-charge transition layer has memory and adaptability, working like a memristor in cancerous development. The memristor processes may complete the adaptation mechanisms of cancer cells to extremely stressful conditions. Our objective is to show the distribution and redistribution of space charges that generate memristors and internal currents like injury current (IC) in the development of cancer. We show some connected aspects of the modulated electrohyperthermia (mEHT) limiting the proliferation process in the micro-range like the macro-range electrochemotherapy (ECT) processes do. The internal polarization effects form space-charge, which characteristically differ in malignant and healthy environments. The electrical resistivity of the electrolytes depends on the distribution of the charges and concentrations of ions in the electrolytes, consequently the space-charge differences appear in the conductivity parameters too. The polarization heterogeneities caused by the irregularities of the healthy tissue induce a current (called injury current), which appears in the cancerous tumor as well. Due to the nonlinearity of the space-charge production and the differences of the relaxation time of the processes in various subunits. The tumor develops the space-charge which appears as an inductive component in the otherwise capacitive setting and forms a memristive behavior of the tumorous tissue. This continuously developing space-charge accommodates the tumor to the permanently changing conditions and helps the adopting the malignant cells in the new environment. Applying external radiofrequency electric field, the disturbance of the space-charge may change the conditions, and seek to reestablish the healthy homeostatic equilibrium, blocking the pathologic injury current components. The hypothetical memristive behavior of the tumor microenvironment and the tumor mass may be a biophysical addition to the adaption mechanisms of tumor cell and could provide a way to block the pathogen biophysical processes. An electric field in the direction of the place of disturbance from the healthy neighborhood appears, starting a current, which promotes cell migrations and wound healing, re-establishing homeostatic equilibrium. In pathological disturbance, the same process starts, which supports further proliferation, so its blocking is desired.

A New Electron Charge Distribution Function of Electron

Here we derive a new charge distribution function for an electron by using as an equation of motion a segment of charge whose self energy interaction is due to electric field potential. Our method is based on the consideration that a charged distribution function should be represented as an eigenfunction of electron mass energy. We compare our electron charge distribution function to that of Weinberg’s η(r) and our charged electron radius to that obtained by Kim.

Geometric properties of the first singlet S-wave excited state of two-electron atoms near the critical nuclear charge

The geometric structure parameters and radial density distribution of 1s2s1S excited state of the two-electron atomic system near the critical nuclear charge Z_(c)were calculated in detail under tripled Hylleraas basis set.Contrary to the localized behavior observed in the ground and the doubly excited 2p^(23)Pe states,for this state our results identify that while the behavior of the inner electron increasingly resembles that of a hydrogen-like atomic system,the outer electron in the excited state exhibits diffused hydrogen-like character and becomes perpendicular to the inner electron as nuclear charge Z approaches Z_(c).This study provides insights into the electronic structure and stability of the two-electron system in the vicinity of the critical nuclear charge.

Rules Governing Pressure Distribution for a Traveling Charge Under the Condition of Lagrange Hypothesis

Aim To study the rules governing pressure distribution of traveling charge under the condition of Lagrange hypothesis. Methods\ The study is based on the laws of conservation of momentum and energy. Results\ The gas flow velocity distribution formula at the back of a projectile and the momentum equation of a traveling charge are deduced, and rules governing their pressure distribution under the Lagrange hypothesis conditions are established. The pressure distribution of a traveling charge is compared with that of a conventional charge. Conclusion\ The pressure distribution in the bore of a traveling charge can be accurately predicted. A parabolic pressure distribution type is revealed.

Electric Vehicle Charging Capacity of Distribution Network Considering Conventional Load Composition

At present,the large-scale access to electric vehicles(EVs)is exerting considerable pressure on the distribution network.Hence,it is particularly important to analyze the capacity of the distribution network to accommodate EVs.To this end,we propose a method for analyzing the EV capacity of the distribution network by considering the composition of the conventional load.First,the analysis and pretreatment methods for the distribution network architecture and conventional load are proposed.Second,the charging behavior of an EVis simulated by combining the Monte Carlo method and the trip chain theory.After obtaining the temporal and spatial distribution of the EV charging load,themethod of distribution according to the proportion of the same type of conventional load among the nodes is adopted to integrate the EV charging load with the conventional load of the distribution network.By adjusting the EV ownership,the EV capacity in the distribution network is analyzed and solved on the basis of the following indices:node voltage,branch current,and transformer capacity.Finally,by considering the 10-kV distribution network in some areas of an actual city as an example,we show that the proposed analysis method can obtain a more reasonable number of EVs to be accommodated in the distribution network.

Theoretical and numerical simulation investigation of deep hole dispersed charge cut blasting

Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways.With the advent of digital electronic detonators and the need for increased production efciency,the traditional blasting design is no longer suitable for deep hole blasting.In this paper,a disperse charge cut blasting method was proposed to address the issues of low excavation depth and high block rate in deep hole undercut blasting.First,a blasting model was used to illustrate the mechanism of the deep hole dispersive charge cut blasting process.Then,continuous charge and dispersed charge blasting models were developed using the smooth particle hydrodynamics-fnite element method(SPHFEM).The cutting parameters were determined theoretically,and the cutting efciency was introduced to evaluate the cutting efect.The blasting efects of the two charging models were analyzed utilizing the evolution law of rock damage,the number of rock particles thrown,and the cutting efciency.The results show that using a dispersed charge improves the cutting efciency by about 20%and the rock breakage for the deep hole cut blasting compared to the traditional continuous charge.In addition,important parameters such as cutting hole spacing,cutting hole depth and upper charge proportion also have a signifcant impact on the cutting efect.Finally,the deep hole dispersed charge cut blasting technology is combined with the digital electronic detonator through the feld engineering practice.It provides a reference for the subsequent deep hole cutting blasting and the use of electronic detonators in rock roadways.

Construction and Weight Distributions of Binary Linear Codes Based on Deep Holes

Deep holes are very important in the decoding of generalized RS codes, and deep holes of RS codes have been widely studied, but there are few works on constructing general linear codes based on deep holes. Therefore, we consider constructing binary linear codes by combining deep holes with binary BCH codes. In this article, we consider the 2-error-correcting binary primitive BCH codes and the extended codes to construct new binary linear codes by combining them with deep holes, respectively. Furthermore, three classes of binary linear codes are constructed, and then we determine the parameters and the weight distributions of these new binary linear codes.

An Improved Charge Pumping Method to Study Distribution of Trapped Charges in SONOS Memory

In silicon-oxide-nitride-oxide-silicon （SONOS） memory and other charge trapping memories, the charge distribution after programming operation has great impact on the devic＇s characteristics,such as reading,programming/erasing, and reliability. The lateral distribution of injected charges can be measured precisely using the charge pumping method. To improve the precision of the actual measurement, a combination of a constant low voltage method and a constant high voltage method is introduced during the charge pumping testing of the drain side and the source side, respectively. Finally, the electron distribution after channel hot electron programming in SONOS memory is obtained,which is close to the drain side with a width of about 50nm.

Homogenous charge distribution by free-standing porous structure for dendrite-free Li metal anode

Lithium metal has a high theoretical capacity of 3860 mAh g^-1 and a low electrochemical potential(-3.04 V vs.H2/H^+).Hence,using a lithium anode significantly improves the energy density of a secondary battery.However,the lithium dendrites generated on the lithium anode during the platingdissolution process significantly reduce its cycling life and safety.Here,we provide a simple method for lithium anode protection,by applying a free-standing porous carbon film with a high specific surface area to reduce the local current density and obtain a homogenous ion distribution.The protected lithium anode has a long cycle life over 1000 h when cycled at 3 mA cm^-2 with a lithium capacity of 2.5 mAh cm^-2.Moreover,the deposited lithium has a smoother surface than Li anode without carbon protection.This study will promote the wide application of Li-metal-based batteries with high safety levels.

Prediction of nuclear charge density distribution with feedback neural network

Nuclear charge density distribution plays an important role in both nuclear and atomic physics,for which the two-parameter Fermi(2pF)model has been widely applied as one of the most frequently used models.Currently,the feedforward neural network has been employed to study the available 2pF model parameters for 86 nuclei,and the accuracy and precision of the parameter-learning effect are improved by introducing A^(1∕3)into the input parameter of the neural network.Furthermore,the average result of multiple predictions is more reliable than the best result of a single prediction and there is no significant difference between the average result of the density and parameter values for the average charge density distribution.In addition,the 2pF parameters of 284(near)stable nuclei are predicted in this study,which provides a reference for the experiment.

Method of Images to Study the Charge Distribution in Cases of Potentials Deviating from Coulomb’s Law

The method of images is used to study the charge distribution for cases where Coulomb’s law deviates from the inverse square law. This method shows that in these cases some of the charge goes to the surface, while the remainder charge distributed over the volume of the conductor. In accord with the experimental work, we show that the charge distribution will depend on the photon rest mass and is very sensitive to it;a very small value of the rest of mass of the photon will create deviation from Coulomb’s law.

Electron beam modeling and analyses of the electric field distribution and space charge effect

In electron beam technology, one of the critical focuses of research and development efforts is on improving the measurement of electron beam parameters. The parameters are closely related to the generation, emission, operation environment, and role of the electron beam and the corresponding medium. In this study, a field calculation method is proposed, and the electric field intensity distribution on the electron beam’s cross-section is analyzed. The characteristics of beam diffusion caused by the space charge effect are investigated in simulation, and the obtained data are compared with the experiment. The simulation demonstrated that the cross-sectional electric field distribution is primarily affected by the electron beam current, current density distribution, and electron beam propagation speed.

The Evolution of the Charge Density Distribution Function for Spherically Symmetric System with Zero Initial Conditions

The evolution of the charge density distribution function is simulated for both the case of a uniformly charged sphere with zero initial conditions and for the case of a non-uniform charged sphere. For the case of a uniformly charged sphere the comparison of a numerical result and an exact analytical demonstrated the agreement between the results. The process of “scattering” of a charged system under the influence of its own electric field has been illustrated on the basis of both the particle-in-cell method and the solution of the Cauchy problem for vector functions of the electric field and vector velocity field of a charged medium.

A Computational Evaluation of Bond Order and Charge Distributions in Isomeric Aminotroponiminiums and Their Benzo-Fused Derivatives

This paper reports the results on the nature of bond-order and net charge distributions predicted by Ab initio Hartree- Fock procedures for 1-amino-2-iminio-, 1-amino-3-iminio- and 1-amino-4-iminiotropylium cations that incorporate, in order, the 1,7-, 1,3- and 1,5-diazapentadienium (vinamidinium) elements. There appears to be very little contribution from tropylium-type charge distribution, the positive charges residing largely in the nitrogen atoms. The partial bond fixations and charge distributions show interesting variation in the three isomers. The 1,3-isomer in which the 1,3-diazapentadienium element is preserved in the favoured zigzag conformation appears to be relatively the best stabilized. The six isomeric benzo-fused derivatives arising from the three amino-iminiotropylium cations show similar differences in patterns of behaviour. Interestingly, the isomer in which a zigzag 1,3-diazapentadienium element is conjugated with a styrene moiety receives the deepest stabilization. While showing that the element largely contributes to the relative stabilization among the systems studied, contribution from certain stereochemical destabilizing factors may not be insignificant.

The charge state distribution of B, C, Si, Ni, Cu and Au ions on 5 MV pelletron accelerator

Stripper gas and terminal potential play a key role for the charge state distribution in a tandem pelletron accelerator. The knowledge of this distribution is important for experiments performed on tandem accelerators. The charge state distribution of B, C, Si, Ni, Cu and Au beams is measured by using Ar as stripper gas, and terminal potential is varied from 0.3 to 3.0 MV on 5UDH-2 tandem pelletron accelerator installed at the National Centre for Physics, Islamabad. The individual charge state is measured after the switching magnet at 15° in high-energy portion. It is observed that the higher charge states are stable in the range of lower and middle atomic masses of periodic table, whereas higher atomic mass(Au) shows beam current instability in higher charge states. For carbon,the charge distribution at 1.7 MV terminal potential by varying stripper gas pressure is also studied, which resulted in decreased overall transmission with good current value for higher charge states.

Charge distribution in graphene from quantum calculation

The local charge distributions of different shape graphene sheets are investigated by using the quantum calculations. It is found that the charge distribution on carbon atom is not uniform, strongly depending on its position in the graphene and its local atomic environment condition. The symmetrical characteristic and geometrical structures of graphene also have an important influence on the charge distribution. The charges of atom at the graphene edge are strongly related to their surrounding bonds. It is found that the charges of double-bonded atom at the zigzag edge are closely related to the bond angle, but the charges of double-bonded atom at the armchair edge are mainly influenced by the area of triangle. The charges of triple-bonded atom at the edge are mainly affected by the standard deviation of the length of the associated triple bonds.

Off-axis electron holography of manganite-based heterojunctions:Interface potential and charge distribution

The interfacial electrical potentials and charge distributions of two manganite-based heterojunctions, i.e.,La_(0.67)Ca_(0.33)MnO_3/SrTiO_3:0.05 wt% Nb(LCMO/STON) and La_(0.67)Ca_(0.33)MnO_3/LaMnO_3/SrTiO_3:0.05 wt% Nb(simplified as LCMO/LMO/STON), are studied by means of off-axis electron holography in a transmission electron microscope.The influences of buffer layer on the microstructure and magnetic properties of the LCMO films are explored. The results show that when a buffer layer of LaMnO_3 is introduced, the tensile strain between the STON substrate and LCMO film reduces, misfit dislocation density decreases near the interfaces of the heterojunctions, and a positive magnetoresistance is observed. For the LCMO/STON junction, positive and negative charges accumulate near the interface between the substrate and the film. For the LCMO/LMO/STON junction, a complex charge distribution takes place across the interface, where notable negative charges accumulate. The difference between the charge distributions near the interface may shed light on the observed generation of positive magnetoresistance in the junction with a buffer layer.