An Improved Solov2 Based on Attention Mechanism and Weighted Loss Function for Electrical Equipment Instance Segmentation

The current existing problem of deep learning framework for the detection and segmentation of electrical equipment is dominantly related to low precision.Because of the reliable,safe and easy-to-operate technology provided by deep learning-based video surveillance for unmanned inspection of electrical equipment,this paper uses the bottleneck attention module(BAM)attention mechanism to improve the Solov2 model and proposes a new electrical equipment segmentation mode.Firstly,the BAM attention mechanism is integrated into the feature extraction network to adaptively learn the correlation between feature channels,thereby improving the expression ability of the feature map;secondly,the weighted sum of CrossEntropy Loss and Dice loss is designed as the mask loss to improve the segmentation accuracy and robustness of the model;finally,the non-maximal suppression(NMS)algorithm to better handle the overlap problem in instance segmentation.Experimental results show that the proposed method achieves an average segmentation accuracy of mAP of 80.4% on three types of electrical equipment datasets,including transformers,insulators and voltage transformers,which improve the detection accuracy by more than 5.7% compared with the original Solov2 model.The segmentation model proposed can provide a focusing technical means for the intelligent management of power systems.

The Most Probable Mechanism Function and Kinetic Parameters of Gibbsite Dissolution in NaOH

Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction.

Pyrolysis Mechanisms of Quinoline and Isoquinoline with Density Functional Theory

The pyrolysis mechanisms of quinoline and isoquinoline were investigated using the density functional theory of quantum chemistry,including eight reaction paths and a common tautomeric intermediate 1-indene imine.It is concluded that the conformational tautomerism of the intermediate decides the pyrolysis products(C6H6,HC≡C—C≡N,C6H5C≡N and HC≡CH)to be the same,and also decides the total disappearance rates of the reactants to be the same,for both original reactants quinoline and isoquinoline during the pyrolysis reaction.The results indicate that the intramolecular hydrogen migration is an important reaction step,which often appears in the paths of the pyrolysis mechanism.The activation energies of the rate determining steps are obtained.The calculated results are in good agreement with the experimental results.

Formation mechanism of methane during coal evolution:A density functional theory study

The formation mechanism of methane （CH4） during coal evolution has been investigated by density functional theory （DFT） of quantum chemistry. Thermogenic gas, which is generated during the thermal evolution of medium rank coal, is the main source of coalbed methane （CBM）. Ethylbenzene （A） and 6,7-dimethyl-5,6,7,8-tetrahydro-1-hydroxynaphthalene （B） have been used as model compounds to study the pyrolysis mechanism of highly volatile bituminous coal （R）, according to the similarity of bond orders and bond lengths. All possible paths are designed for each model. It can be concluded that the activation energies for H-assisted paths are lower than others in the process of methane formation; an H radical attacking on β-C to yield CH4 is the dominant path for the formation of CH4 from highly volatile bituminous coal. In addition, the calculated results also reveal that the positions on which H radical attacks and to which intramolecular H migrates have effects on methyl cleavage.

Effect and function mechanism of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite

The effect of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite(Cr-V-Ti magnetite) was investigated and the function mechanism was simultaneously analyzed.The results show that with increasing sinter basicity from 1.71 to 2.36,the softening interval tends to increase from 149.3 ℃ to 181.7 ℃while the melting interval tends to decrease from 178.0 ℃ to 136.7 ℃.The location of cohesive zone moves downwards firstly and then ascends slightly,but the cohesive zone becomes thinner.The softening-melting characteristic value becomes small,which indicates that the permeability of burden column is improved.The dripping ratio of mixed burden tends to increase firstly and then decrease,which comes to the highest value of 74.50%when the sinter basicity is 2.13.The content and the recovery of V and Cr in dripping iron are all increased.The generation amount of components with high melting point in slag becomes little with the increase of sinter basicity,which could improve the permeability of mixed burden.Taking softening-melting behaviors of mixed burden and recovery of valuable elements into account,the proper sinter basicity is no less than 2.13 for smelting mixed burden made from Cr-V-Ti magnetite in blast furnace.

Design and additive manufacturing of bionic hybrid structure inspired by cuttlebone to achieve superior mechanical properties and shape memory function

Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.aerospace,automobiles,electronics,etc.Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient,enabling stress homogenization,significant load bearing,and damage tolerance to protect the organism from high external pressures in the deep sea.This work illustrated that the complex hybrid wave shape in cuttlebone walls,becoming more tortuous from bottom to top,creates a lightweight,load-bearing structure with progressive failure.By mimicking the cuttlebone,a novel bionic hybrid structure(BHS)was proposed,and as a comparison,a regular corrugated structure and a straight wall structure were designed.Three types of designed structures have been successfully manufactured by laser powder bed fusion(LPBF)with NiTi powder.The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4μm.Microstructural analysis indicated that the LPBF-processed BHS had a strong(001)crystallographic orientation and an average size of 9.85μm.Mechanical analysis revealed the LPBF-processed BHS could withstand over 25000 times its weight without significant deformation and had the highest specific EA value(5.32 J·g^(−1))due to the absence of stress concentration and progressive wall failure during compression.Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity.Importantly,the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated(over 99% recovery rate).These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities.

“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. Herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: Si-Fe@NG (U_(L) = –0.14 V), Si-Co@NG (U_(L)= –0.15 V), Si-Mo@BP1 (U_(L) = 0 V), and Si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and Si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and Si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

Computational and bioinformatics tools for understanding disease mechanisms

Computational methods have significantly transformed biomedical research,offering a comprehensive exploration of disease mechanisms and molecular protein functions.This article reviews a spectrum of computational tools and network analysis databases that play a crucial role in identifying potential interactions and signaling networks contributing to the onset of disease states.The utilization of protein/gene interaction and genetic variation databases,coupled with pathway analysis can facilitate the identification of potential drug targets.By bridging the gap between molecular-level information and disease understanding,this review contributes insights into the impactful utilization of computational methods,paving the way for targeted interventions and therapeutic advancements in biomedical research.

The action mechanisms and structures designs of F-containing functional materials for high performance oxygen electrocatalysis

Non-renewable fossil fuels have led to serious problems such as global warming,environmental pollution,etc.Oxygen electrocatalysis including oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)plays a central role in clean energy conversion,enabling a number of sustainable processes for future air battery technologies.Fluorine,as the most electronegative element(4.0)not only can induce more efficient regulation for the electronic structure,but also can bring more abundant defects and other novel effects in materials selection and preparation for favorable catalysis with respect to the other nonmetal elements.However,an individual and comprehensive overview of fluorine-containing functional materials for oxygen electrocatalysis field is still blank.Therefore,it is very meaningful to review the recent progresses of fluorine-containing oxygen electrocatalysts.In this review,we first systematically summarize the controllable preparation methods and their possible development directions based on fluorine-containing materials from four preparation methods.Due to the strong electron-withdrawing properties of fluorine,its control of the electronic structure can effectively enhance the oxygen electrocatalytic activity of the materials.In addition,the catalytic enhancement effect of fluorine on carbonbased materials also includes the prevent oxidation and the layer peeling,and realizes the precise atomic control.And the catalytic improvement mechanism of fluorine containing metal-based compounds also includes the hydration of metal site,the crystal transformation,and the oxygen vacancy induction.Then,based on their various dimensions(0D–3D),we also have summarized the advantages of different morphologies on oxygen electrocatalytic performances.Finally,the prospects and possible future researching direction of F-containing oxygen electrocatalysts are presented(e.g.,novel pathways,advanced methods for measurement and simulation,field assistance and multi-functions).The review is considered valuable and helpful in exploring the novel designs and mechanism analyses of advanced fluorine-containing electrocatalysts.

Functional mechanism on stem cells by tea(Camellia sinensis)bioactive compounds

Camellia sinensis(tea),one of the most popular commercial crops,is commonly applied in all parts of the world.The main active ingredients of tea include polyphenols,alkaloids,polysaccharides,amino acids,aroma and volatile constitutes,all of which are potentially responsible for the activities of tea.Stem cells(SCs)are the immature and undifferentiated cells by a varying capacity for proliferation,self-renewal and the capability to differentiate into one or more different derivatives with specialized function or maintain their stem cell phenotype.Herein,a thorough review is conducted of the functional mechanism on SCs by tea bioactive compounds.

Unveiling the decomposition mechanism of formic acid on Pd/WC(0001) surface by using density function theory

In pursuit of low-cost direct formic acid fuel cells,tungsten carbide(WC)supported Pd catalyst is considered as an ideal candidate for efficient decomposition of formic acid due to low Pd utilization and excellent performance.Herein,different adsorption configurations and active sites of the intermediates,involved in the HCOOH decomposition,on WC(0001)-supported Pd monolayer(Pd/WC(0001))surface investigated by using density functional theory.The results reveal that trans-HCOOH,HCOO,cis-COOH,trans-COOH,HCO,CO,H2 O,OH and H exhibit chemisorption on Pd/WC(0001)surface,whereas cis-HCOOH and CO2 exhibit weak interactions with Pd/WC(0001)surface.In addition,the minimum energy pathways of HCOOH decomposition are analyzed to generate CO and CO2 due to the fracture of C–H,H–O and C–O bonds.The adsorbed HCOOH,HCOO,mH COO,cis-COOH and trans-COOH configurations exhibit dissociation rather than desorption.CO formation occurs through the decomposition of cis-COOH,trans-COOH and HCO,whereas the CO2 formation happens due to the decomposition of HCOO.It is found that the most favorable pathway for HCOOH decomposition on Pd/WC(0001)surface is HCOOH→HCOO→CO2,where the formation of CO2 from HCOO dehydrogenation determines the reaction rate.Overall,CO2 is the most dominant product of HCOOH decomposition on Pd/WC(0001)surface.The presence of WC,as monolayer Pd carrier,does not alter the catalytic behavior of Pd and significantly reduces the Pd utilization.

Effect of Exchange-Correlation Functional on the Structural, Mechanical, and Optoelectronic Properties of Orthorhombic RbSrBr3 Perovskite

In the present study, the effect of the exchange-correlation functional on the structural, mechanical, and optoelectronic properties of orthorhombic RbSrBr3 perovskite has been investigated using various functionals in Density Functional Theory (DFT) with the CASTEP code. The optimized lattice parameters are quite similar for all the functionals. The electronic properties have shown that RbSrBr3 perovskite is a wide direct band gap compound with a band gap energy ranging from 4.296 eV to 4.494 eV for all the functionals. The mechanical parameters like elastic constants, Young’s modulus, Shear modulus, Poisson’s ratio, Pugh’s ratio, and an anisotropic factor reveal that the RbSrBr3 perovskite has ductile behavior and an anisotropic nature which signifies the mechanical stability of the compound. The Debye temperature might withstand lattice vibration heat. High absorption coefficient (>104 cm−1), high optical conductivity, and very low reflectivity have been found in the RbSrBr3 perovskite for all functions. The computed findings on the RbSrBr3 perovskite suggested that the presented studied material is potentially applicable for photodetector and optoelectronic devices.

Density Functional Theory Study on the Histidine-assisted Mechanism of Arylamine N-Acetyltransferase Acetylation

Arylamine N-acetyltransferases （NATs, EC 2.3.1.5） catalyze the N-acetylation of primary arylamines, and play a key role in the biotransformation and metabolism of drugs, carcinogens, etc. In this paper, three possible reaction mechanisms are investigated and the results indicate that if the acetyl group directly transfers from the donor to the acceptor, the high activation energies will make it hard to obtain the target products. When using histidine to mediate the acetylation process, these energies will drop in the 15-45 kJ/mol range. If the histidine residue is protonated, the corresponding energies will be decreased by about 35-87 kJ/mol. The calculations predict an enzymatic acetylation mechanism that undergoes a thiolate-imidazolium pair, which agrees with the experimental results very well.

Mechanisms of autophagy function and regulation in plant growth,development,and response to abiotic stress

Autophagy is an evolutionarily conserved degradation pathway of lysosomes(in mammals)and vacuoles(in yeasts and plants)from lower yeasts to higher mammals.It wraps unwanted organelles and damaged proteins in a double-membrane structure to transport them to vacuoles for degradation and recycling.In plants,autophagy functions in adaptation to the environment and maintenance of growth and development.This review systematically describes the autophagy process,biological functions,and regulatory mechanisms occurring during plant growth and development and in response to abiotic stresses.It provides a basis for further theoretical research and guidance of agricultural production.

Laser irradiation effects and its possible mechanisms of action on spermatozoa functions in domestic animals

This article presents a review pertains the laser irradiation effects and its possible mechanisms of action on spermatozoa functions in domestic animals. To improve artificial insemination, laser is sensitive and cost effective technique, when compared to other conventional methods. Laser may have both positive and negative effects on spermatozoa functions. Since the effects of light are mediated by reactive oxygen species, and the levels of these reactive oxygen species following irradiating spermatozoa with laser may be responsible for determining the effects of laser on sperm. Dose of laser may be regarded as of great significance and this dosage of laser may be responsible for determining its effects on spermatozoa. Optimum dosage of laser for improving seminal attributes may vary among various species and this need to be standardized in each of them. The beneficial effects include improving sperm livability, acrosomal integrity, hypo-osmotic swelling response, mitochondrial function and computer-aided sperm analysis parameters. The increase in cytochrome c oxidase activity, ATP levels and mitochondrial membrane potential, in laser irradiated cells may be responsible for enhanced sperm quality parameters. Improving fertility with laser irradiated spermatozoa has been reported in few species like boar and need to be elaborated in other species. In conclusion laser may be regarded as an easy, cheap and time saving technology for improving artificial insemination;in addition, laser may have various potential applications in the field of reproductive biotechnology as well as in livestock farms and veterinary polyclinics.

Synthesis of Stephenson in Six-Link Mechanism for Function Generation Using an Improved Homotopy Method

This paper presents solutions to the function generation problems of Stephenson Ⅲ six-link mechanism with the maximum precision positions for the first time using homotopy method with an improved path-tracking scheme. The new path-tracking scheme is based on the characteristics of the zero sets of homotopy function for polynomial mapping and thus the tracking speed is dramatically increased.

Thermal dehydration kinetic mechanism of Mn_(1.8)Co_(0.1)Mg_(0.1)P_2O_7·2H_2O using Málek's equations and thermodynamic functions determination

Mn1.8Co0.1Mg0.1P2O7·2H2O was synthesized via hydrothermal method and the thermal dehydration product was confirmed to be Mn1.8Co0.1Mg0.1P2O7.The thermogravimetry/differential thermogravimetry/differential thermal analysis,Fourier transform infrared,atomic absorption spectrophotometry,X-ray diffraction and scanning electron microscopy techniques were employed for sample characterization.Non-isothermal kinetics was studied under air atmosphere at four heating rates and the single thermal dehydration process was observed.Iterative Kissinger-Akahira-Sunose equation was used to calculate the apparent activation energy Eαvalues.Dehydration process was confirmed to be a single-step kinetic process with the unique kinetic triplets.Málek’s equations were used to determine the kinetic model f（α）and pre-exponential factor A.？esták-Berggren model was suggested to be the mechanism function for the dehydration process.The best fit led to the kinetic triplets of Eα=（79.97±6.51）k J/mol,ln A=16.83 and f（α）=α^0.520（1-α）^1.255（αis the extent of conversion）.The thermodynamic functions of activation were calculated using activated complex theory together with A value.

Density Function Theory Study on the Reaction Mechanism of Cerium with Oxygen for Ce-bearing Aerosol Particle Formation

We obtained the reaction mechanism of cerium with oxygen by means of density functional theory (DFT) under the explosive or detonation situation. The energy level order of cerium was calculated and the potential energy profile was plotted. The properties of the bonds of all special structures in the reaction path were analyzed using the method of the electron localization function (ELF). The results indicate that the final reaction pathway can be expressed as Ce+O2→ FC→TS→IM→O-Ce-O, and the formation of Ce2O3 has not been found. In addition, the ELF diagram of the final product CeO2 shows that Ce bonds with both O atoms and the bond angles increase significantly.

Fluoridation routes,function mechanism and application of fluorinated/fluorine-doped nanocarbon-based materials for various batteries:A review

With the popularity and widespread applications of electronics,higher demands are being placed on the performance of battery materials.Due to the large difference in electronegativity between fluorine and carbon atoms,doping fluorine atoms in nanocarbon-based materials is considered an effective way to improve the performance of used battery.However,there is still a blank in the systematic review of the mechanism and research progress of fluorine-doped nanostructured carbon materials in various batteries.In this review,the synthetic routes of fluorinated/fluorine-doped nanocarbon-based(CF_x)materials under different fluorine sources and the function mechanism of CF_x in various batteries are reviewed in detail.Subsequently,judging from the dependence between the structure and electrochemical performance of nanocarbon sources,the progress of CF_x based on different dimensions(0D–3D)for primary battery applications is reviewed and the balance between energy density and power density is critically discussed.In addition,the roles of CF_x materials in secondary batteries and their current applications in recent years are summarized in detail to illustrate the effect of introducing F atoms.Finally,we envisage the prospect of CF_x materials and offer some insights and recommendations to facilitate the further exploration of CF_x materials for various high-performance battery applications.

Healthy Functions and Mechanisms of Bamboo-Charcoal Modified Polyesters

In this paper, healthy functions and mechanisms of bamboo-charcoal modified polyesters are studied. The results show that there are five healthy functions incorporated effectively in bamboo-charcoal modified polyesters, such as good far-infrared radiation, good UV protection, certain negative ion emission, certain antibacteria and good absorption functions. The metal elements and carburets are mainly responsible for far-infrared, negative ion emission functions. UV prevent/on function results mainly from the carbon elements. The absorbability and bacteriostasis functions lie in the porous structures.