The transition energies, E1 transitional oscillator strengths of the spin-allowed as well as the spin-forbidden and the corresponding transition rates, and complete M1, E2, M2 forbidden transition rates for 1s^(2), 1s...The transition energies, E1 transitional oscillator strengths of the spin-allowed as well as the spin-forbidden and the corresponding transition rates, and complete M1, E2, M2 forbidden transition rates for 1s^(2), 1s2s, and 1s2p states of He I, are investigated using the multi-configuration Dirac–Hartree–Fock method. In the subsequent relativistic configuration interaction computations, the Breit interaction and the QED effect are considered as perturbation, separately. Our transition energies, oscillator strengths, and transition rates are in good agreement with the experimental and other theoretical results. As a result, the QED effect is not important for helium atoms, however, the effect of the Breit interaction plays a significant role in the transition energies, the oscillator strengths and transition rates.展开更多
This paper investigates a wireless powered and backscattering enabled sensor network based on the non-linear energy harvesting model, where the power beacon(PB) delivers energy signals to wireless sensors to enable th...This paper investigates a wireless powered and backscattering enabled sensor network based on the non-linear energy harvesting model, where the power beacon(PB) delivers energy signals to wireless sensors to enable their passive backscattering and active transmission to the access point(AP). We propose an efficient time scheduling scheme for network performance enhancement, based on which each sensor can always harvest energy from the PB over the entire block except its time slots allocated for passive and active information delivery. Considering the PB and wireless sensors are from two selfish service providers, we use the Stackelberg game to model the energy interaction among them. To address the non-convexity of the leader-level problem, we propose to decompose the original problem into two subproblems and solve them iteratively in an alternating manner. Specifically, the successive convex approximation, semi-definite relaxation(SDR) and variable substitution techniques are applied to find a nearoptimal solution. To evaluate the performance loss caused by the interaction between two providers, we further investigate the social welfare maximization problem. Numerical results demonstrate that compared to the benchmark schemes, the proposed scheme can achieve up to 35.4% and 38.7% utility gain for the leader and the follower, respectively.展开更多
We present here a two-step method of classification and calculation for decay rates in the Standard Model. The first step is a phenomenological classification method, which is an extended and improved schematic experi...We present here a two-step method of classification and calculation for decay rates in the Standard Model. The first step is a phenomenological classification method, which is an extended and improved schematic experimental formula for decay width originally introduced by Chang. This schematic formula separates decays into seven classes. Furthermore, from it is derived a process-specific interaction energy m<sub>X</sub>. The second step is a numerical calculation method, which calculates this interaction energy m<sub>X</sub> numerically by minimization of action from the Lagrangian of the process, from which follows the decay width via the phenomenological formula. The Lagrangian is based on an extension of the Standard Model, the extended SU(4)-preon-model. A comparison of numerically calculated and observed decay widths for a large selection of decays shows a good agreement.展开更多
Low energy ions exist widely in natural world, but people pay a little attention on. the interaction between low energy ions and matter, it is even more out of the question of studying on the relation of low energy io...Low energy ions exist widely in natural world, but people pay a little attention on. the interaction between low energy ions and matter, it is even more out of the question of studying on the relation of low energy ions and the complicated organism. The discovery of bioeffect induced by ion implantation has, however, opened a new branch in the field of ion beam application in life sciences. This paper reports recent advances in research on the role of low energy ions in Chemical synthesis of the biomolecules and application in genetic modification.展开更多
In addition to the hexagonal crystals of class 6 mm, many piezoelectric materials(e.g., BaTiO3), piezomagnetic materials(e.g., CoFe2O4), and multiferroic composite materials(e.g., BaTiO3-CoFe2O4 composites) also exhib...In addition to the hexagonal crystals of class 6 mm, many piezoelectric materials(e.g., BaTiO3), piezomagnetic materials(e.g., CoFe2O4), and multiferroic composite materials(e.g., BaTiO3-CoFe2O4 composites) also exhibit symmetry of transverse isotropy after poling, with the isotropic plane perpendicular to the poling direction. In this paper, simple and elegant line-integral expressions are derived for extended displacements, extended stresses, self-energy, and interaction energy of arbitrarily shaped, threedimensional(3D) dislocation loops with a constant extended Burgers vector in transversely isotropic magneto-electro-elastic(MEE) bimaterials(i.e., joined half-spaces). The derived solutions can also be simply reduced to those expressions for piezoelectric, piezomagnetic, or purely elastic materials. Several numerical examples are given to show both the multi-field coupling effect and the interface/surface effect in transversely isotropic MEE materials.展开更多
Gas adsorption has an important influence on gas flow in a coal body.Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal.In this paper,the interaction betw...Gas adsorption has an important influence on gas flow in a coal body.Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal.In this paper,the interaction between methane,carbon dioxide and surface molecules of anthracite was simulated using the quantum chemistry method.Adsorption energy and adsorption configurations of different quantities of gas molecules absorbed on the coal surface were calculated.The results show that adsorption between coal and the two kinds of gas molecules is a physical adsorption process and there is an optimal configuration.Gas molecules are more easily adsorbed in the hydroxyl-containing side chain,while it is difficult for them to be adsorbed at the position of the benzene ring.Besides,carbon dioxide molecules are more readily adsorbed on the coal surface than methane molecules.The findings have an important significance in revealing the nature of gas adsorption in coal.展开更多
Five optimized geometries of F-?(H2O)n (n = 1, 2) were obtained with ab initio calculation at the B3LYP/6-311++G** level. The accurate intermonomer interaction energy was calculated using the MP2 electron correlation ...Five optimized geometries of F-?(H2O)n (n = 1, 2) were obtained with ab initio calculation at the B3LYP/6-311++G** level. The accurate intermonomer interaction energy was calculated using the MP2 electron correlation correction as well as the basis set superposition error correction by the Boys-Bernardi “counterpoise” protocol. Natural bond orbital (NBO) theory was applied to quantify the relative strength of these interactions and account for their effects on the stability, structural and vibrational parameters of Fˉ?(H2O)n (n = 1, 2). It is shown that the charge transferring from the lone pair of F-1 to the σ?OH(…F) antibonding orbital is important. The results indicate the occupancy of σ?OH(…F) is increased (denoted ?σ?OH(…F)) and the σOH(…F) bond is leng- thened (denoted ?ROH(…F)), leading to the red-shift and the red-shift values have linear correlation with both ?σ?OH(…F) and ?ROH(…F).展开更多
The threshold values of CO_(2) gas stripped off membranous residual oil from the pore walls are not clear under different temperatures, pressures and wettability conditions. The extent to which temperature, pressure a...The threshold values of CO_(2) gas stripped off membranous residual oil from the pore walls are not clear under different temperatures, pressures and wettability conditions. The extent to which temperature, pressure and wettability influence CO_(2) flooding for enhancing the recovery of residual oil in membranous formations also remains uncertain. Therefore, further quantitative characterization is entailed. In this study, the molecular dynamics method was employed to explore CO_(2) flooding under different temperatures, pressures and wettability conditions, aiming to enhance the production of membranous residual oil. The results reveal that the interaction energy between CO_(2), decane molecules and pore walls exhibits a decrease with increasing temperature and an increase with increasing pressure, respectively, in distinct wettability scenarios. When the temperature was at or below 363 K and the pressure was not lower than 40 MPa, CO_(2) gas could detach the membranous residual oil from the pore walls in the water-wet systems. When the temperature was equal to 363 K and the pressure remained under 40 MPa, or the temperature surpassed 363 K, CO_(2) gas failed to detach the membranous residual oil from the pore walls in the water-wet systems. For the mixed-wet and oil-wet systems, CO_(2) molecules could not detach the membranous residual oil from the pore walls. The hierarchy of influence regarding temperature, pressure and wettability on the competitive adsorption capacity of CO_(2) and decane molecules on the pore walls emerged as follows: wettability > temperature > pressure. The findings of this study offer valuable insights into the application of CO_(2) gas flooding for the exploitation of membranous residual oil on pore walls.展开更多
The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibriu...The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibrium state,equilibrium concentration distribution,MSD of layer and different groups,and interaction energy of two interface models,the influencing mechanism on the interface properties of adding organosiloxane into coating system was studied at the atomic scale.It shows that the temperature and energy of interface oscillated in a small range and it was exited in a state of dynamic equilibrium within the initial simulation stage(t<20 ps).It can be seen from the multiple peak states of concentration distribution that the iron substrate,organo-siloxane and zinc silicate are distributed in the form of a concentration gradient in the real environment.The rapid diffusion of free zinc powder in zinc silicate coating was the essential reason that affected the comprehensive properties of coating.The interface thickness decreased from 7.45 to 6.82Å,the MSD of free zinc powder was effectively reduced,and the interfacial energy was increased from 104.667 to 347.158 kcal/mol after being modified by organo-siloxane.展开更多
The separation of methanol(MeOH)and dimethyl carbonate(DMC)is important but difficult due to the formation of an azeotropic mixture.In this work,isobaric vapor–liquid equilibrium(VLE)data for the ternary systems cont...The separation of methanol(MeOH)and dimethyl carbonate(DMC)is important but difficult due to the formation of an azeotropic mixture.In this work,isobaric vapor–liquid equilibrium(VLE)data for the ternary systems containing different imidazolium–based ionic liquids(ILs),i.e.MeOH+DMC+1-butyl-3-methy-limidazolium bis[(trifluoromethyl)sulfonyl]imide([Bmim][Tf2N]),MeOH+DMC+1-ethyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide([Emim][Tf2N]),and MeOH+DMC+1-ethyl-3-methylimidazolium hexafluorophosphate([Emim][PF6])were measured at 101.3 kPa.The mole fraction of IL was varied from0.05 to 0.20.The experimental data were correlated with the NRTL and Wilson equations,respectively.The results show that imidazolium-based ILs were beneficial to improve the relative volatility of MeOH to DMC,and[Bmim][Tf2 N]showed a much more excellent performance on the activity coefficient of MeOH.The interaction energies of system components were calculated using Gaussian program,and the effects of cation and anion on the separation coefficient of the azeotropic system were discussed.展开更多
Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discus...Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discussed before. It has been mentioned in previous studies that the proton of the H-C group could be involved in hydrogen bonding, but with conventional acceptors. In this study, we explored the ability of hydrogen bond formation of Se, S and Te acceptors with the H-C donor using Cambridge Structural Database in conjunction with Ab Initio calculations. In the CSD, there are respectively 256, 6249 and 11 R1,R2,-C=Se, R1,R2,-C=S and R1,R2,-C=Te structures that form hydrogen bonds, in which the N,N groups are majority. Except for C=S acceptor which can form a hydrogen bond with its C, C group, both C=Se and C=Te acceptors could form a hydrogen bond only with N,C and N,N groups. CSD analysis shows very similar d (norm) around -0.04 Å, while DFT-calculated interaction for N,C and N,N groups are also similar. Both interaction distances derived from CSD analysis and DFT-calculated interaction energies demonstrate that the acceptors form stable complexes with H-CF3. Besides hydrogen bonds, dispersion interactions are forces stabilizing the complexes since their contribution can reach 50%. Analysis of intra-molecular geometries and Ab Initio partial charges show that this bonding stems from resonance induced C<sup>δ+</sup>=X<sup>δ-</sup> dipoles. In many respects, both C=Se, C=S and C=Te are similar to C=S, with similar d (norm) and calculated interaction strengths.展开更多
The adsorption of free acid of low concentration by crosslinked chitosan resin was followed by electrochemical experimental technique. The effect of acid concentration and the media on adsorption was discussed. The ex...The adsorption of free acid of low concentration by crosslinked chitosan resin was followed by electrochemical experimental technique. The effect of acid concentration and the media on adsorption was discussed. The experimental results show that both the apparent rate constant and the interaction energy between the adsorbent and adsorbate are decreased while the concentration of hydrochloric acid is increased. In the adsorption system, the adsorption was effected by addition of organic solvent.展开更多
Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing wit...Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R1-X-R2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R1 or X-R2 antibonding orbital.展开更多
Glass sample of Zinc Lithium Bismuth Borate (25-x) Bi<sub>2</sub>O<sub>3</sub>:20Li<sub>2</sub>O:20ZnO:35B<sub>2</sub>O<sub>3</sub>:xPr<sub>6</sub&g...Glass sample of Zinc Lithium Bismuth Borate (25-x) Bi<sub>2</sub>O<sub>3</sub>:20Li<sub>2</sub>O:20ZnO:35B<sub>2</sub>O<sub>3</sub>:xPr<sub>6</sub>O<sub>11</sub>, (where x = 1, 1.5 and 2 mol%) has been prepared by melt-quenching technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The absorption spectra of three Pr<sup>3+</sup> doped zinc lithium bismuth borate glasses have been recorded at room temperature. The observed optical spectra are discussed in terms of energy states and the intensity of the transitions. The various interaction parameters like Slater-Condon, Lande, bonding and Racah parameters have been computed. Judd-Ofelt intensity parameters and laser parameters have also been calculated. The stimulated emission cross section (σ<sub>p</sub>) for the transition (<sup>3</sup>P<sub>0</sub> → <sup>3</sup>F<sub>2</sub>) is found to be in the range 3.12 - 10.43 * 10<sup>-20</sup> cm<sup>2</sup>. The σ<sub>p</sub> values are comparatively large suggesting the possible utilization of these materials in laser applications.展开更多
We consider a new cosmological model(calledΛ~CDM),in which the vacuum energy interacts with matter and radiation,and test this model using the current cosmological observations.Using the CMB+BAO+SN(CBS)dataset to con...We consider a new cosmological model(calledΛ~CDM),in which the vacuum energy interacts with matter and radiation,and test this model using the current cosmological observations.Using the CMB+BAO+SN(CBS)dataset to constrain the model,we find that H0 and S8 tensions are relieved to 2.87σand 2.77σ,respectively.However,in this case,theΛ~CDM model is not favored by the data,compared withΛCDM.We find that when the H0 and S8 data are added to the data combination,the situation is significantly improved.In the CBS+H0 case,the model relieves the H0 tension to 0.47σ,and the model is favored overΛCDM.In the CBS+H0+S8 case,we obtain a synthetically best situation,in which the H0 and S8 tensions are relieved to 0.72σand 2.11σ,respectively.In this case,the model is most favored by the data.Therefore,this cosmological model can greatly relieve the H0 tension and simultaneously effectively alleviate the S8 tension.展开更多
To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals.Herein,the relationship between structural halogenation...To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals.Herein,the relationship between structural halogenation and molecular-level stacking,micro/nanoscale surface morphology,and macroscopic mechanical properties are investigated.Elastic crystals of halo-pyrimidinyl carbazoles(CzM-Cl,CzM-Br and CzM-I)with lamellar structure and brittle crystal(CzM-F)were quantitatively analyzed by crystal energy framework(CEF)providing the inter/intralayer interaction energy(Inter/Intra-IE).It is revealed that the elastic crystals bend under external force as a result from stronger Intra-IE to prevent cleavage and weaker Inter-IE for the short-range movement of molecules on the slip plane.This research will provide an insight for the molecular design of flexible crystals and facilitate the development of next-generation smart crystal materials.展开更多
Hydrogels are promising candidates for mimicking native extracellular matrix(ECM)and are therefore widely adopted as scaffolds in tissue engineering.However,conventional hydrogels composed of static networks are prone...Hydrogels are promising candidates for mimicking native extracellular matrix(ECM)and are therefore widely adopted as scaffolds in tissue engineering.However,conventional hydrogels composed of static networks are prone to permanent structural damages and lack the ability to provide the time-dependent mechanical cues,which are essential for cell development,ECM remodeling,and tissue regeneration.The recent substantial development in the structurally dynamic hydrogels with energy-dissipative ability has demonstrated the unique capability of such viscoelastic hydrogels to withstand extreme biomechanical loads and regulate cellular behaviors not present in classical hydrogels.This review starts with the general design principles for energy-dissipative hydrogels,followed by recent advancements in fabrication approaches for energy-dissipative hydrogels.We then highlight some applications of energy-dissipative hydrogels in tissue engineering,including bone and cartilage regeneration,vessel regeneration,nerve regeneration,and wound healing.Finally,we discuss about the key current challenges and future development of energy-dissipative hydrogels for biomedical applications.展开更多
We investigate the impacts of dark energy on constraining massive(active/sterile)neutrinos in interacting dark energy(IDE)models by using the current observations.We employ two typical IDE models,the interacting w col...We investigate the impacts of dark energy on constraining massive(active/sterile)neutrinos in interacting dark energy(IDE)models by using the current observations.We employ two typical IDE models,the interacting w cold dark matter(IwCDM)model and the interacting holographic dark energy(IHDE)model,to make an analysis.To avoid large-scale instability,we use the parameterized post-Friedmann approach to calculate the cosmological perturbations in the IDE models.The cosmological observational data used in this work include the Planck cosmic microwave background(CMB)anisotropies data,the baryon acoustic oscillation data,the type Ia supernovae data,the direct measurement of the Hubble constant,the weak lensing data,the redshift-space distortion data,and the CMB lensing data.We find that the dark energy properties could influence the constraint limits of active neutrino mass and sterile neutrino parameters in the IDE models.We also find that the dark energy properties could influence the constraints on the coupling strength parameterβ,and a positive coupling constant,β>0,can be detected at the 2.5σstatistical significance for the IHDE+νs model by using the all-data combination.In addition,we also discuss the"Hubble tension"issue in these scenarios.We find that the H0 tension can be effectively relieved by considering massive sterile neutrinos,and in particular in the IHDE+νsmodel the H0 tension can be reduced to be at the 1.28σlevel.展开更多
We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy(IDE)models. In this study, we focus on two typical interacting dynamical dark energy models, i...We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy(IDE)models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting w cold dark matter(IwCDM) model and the interacting holographic dark energy(IHDE) model. To avoid the large-scale instability problem in IDE models, we apply the parameterized post-Friedmann approach to calculate the perturbation of dark energy. We employ the Planck 2015 cosmic microwave background temperature and polarization data, combined with low-redshift measurements on baryon acoustic oscillation distance scales, type Ia supernovae, and the Hubble constant, to constrain the cosmological parameters. We find that the dark energy properties could influence the constraint limits on the total neutrino mass. Once dynamical dark energy is considered in the IDE models, the upper bounds of ∑mν will be changed. By considering the values of χ^2min , we find that in these IDE models the normal hierarchy case is slightly preferred over the inverted hierarchy case;for example, △χ^2= 2.720 is given in the IHDE+∑mν model. In addition, we also find that in the Iw CDM+∑mν model β = 0 is consistent with current observational data inside the 1σ range, and in the IHDE+∑mν model β > 0 is favored at more than 2σ level.展开更多
Self-accommodation microstructure,a typical crystallographic texture developed from phase transformation,is often observed in various alloys.In this work,a molecular dynamics simulation was conducted to reveal the fin...Self-accommodation microstructure,a typical crystallographic texture developed from phase transformation,is often observed in various alloys.In this work,a molecular dynamics simulation was conducted to reveal the fine details of self-accommodation microstructure evolution during the phase transformation from austenite to ferrite in pure iron.The growth and shrinkage of ferrite grains with different orientation relationships(ORs)are interpreted based on the analysis combining the elastic interaction energy and the interfacial energy.It was found that the strain energy determines the priority of potential ORs,while the interfacial energy selects the specific preferred ORs to form.The present atomistic process and energetic interpretation of the self-accommodation microstructure provide helpful insight into phase transformation textures observed in various alloys.展开更多
基金Supported by the National Key Research and Development Program of China (Grant No. 2017YFA0402300)the National Natural Science Foundation of China (Grant Nos. 11774344 and 11474033)。
文摘The transition energies, E1 transitional oscillator strengths of the spin-allowed as well as the spin-forbidden and the corresponding transition rates, and complete M1, E2, M2 forbidden transition rates for 1s^(2), 1s2s, and 1s2p states of He I, are investigated using the multi-configuration Dirac–Hartree–Fock method. In the subsequent relativistic configuration interaction computations, the Breit interaction and the QED effect are considered as perturbation, separately. Our transition energies, oscillator strengths, and transition rates are in good agreement with the experimental and other theoretical results. As a result, the QED effect is not important for helium atoms, however, the effect of the Breit interaction plays a significant role in the transition energies, the oscillator strengths and transition rates.
基金supported by National Natural Science Foundation of China(No.61901229 and No.62071242)the Project of Jiangsu Engineering Research Center of Novel Optical Fiber Technology and Communication Network(No.SDGC2234)+1 种基金the Open Research Project of Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology(No.NJUZDS2022-008)the Post-Doctoral Research Supporting Program of Jiangsu Province(No.SBH20).
文摘This paper investigates a wireless powered and backscattering enabled sensor network based on the non-linear energy harvesting model, where the power beacon(PB) delivers energy signals to wireless sensors to enable their passive backscattering and active transmission to the access point(AP). We propose an efficient time scheduling scheme for network performance enhancement, based on which each sensor can always harvest energy from the PB over the entire block except its time slots allocated for passive and active information delivery. Considering the PB and wireless sensors are from two selfish service providers, we use the Stackelberg game to model the energy interaction among them. To address the non-convexity of the leader-level problem, we propose to decompose the original problem into two subproblems and solve them iteratively in an alternating manner. Specifically, the successive convex approximation, semi-definite relaxation(SDR) and variable substitution techniques are applied to find a nearoptimal solution. To evaluate the performance loss caused by the interaction between two providers, we further investigate the social welfare maximization problem. Numerical results demonstrate that compared to the benchmark schemes, the proposed scheme can achieve up to 35.4% and 38.7% utility gain for the leader and the follower, respectively.
文摘We present here a two-step method of classification and calculation for decay rates in the Standard Model. The first step is a phenomenological classification method, which is an extended and improved schematic experimental formula for decay width originally introduced by Chang. This schematic formula separates decays into seven classes. Furthermore, from it is derived a process-specific interaction energy m<sub>X</sub>. The second step is a numerical calculation method, which calculates this interaction energy m<sub>X</sub> numerically by minimization of action from the Lagrangian of the process, from which follows the decay width via the phenomenological formula. The Lagrangian is based on an extension of the Standard Model, the extended SU(4)-preon-model. A comparison of numerically calculated and observed decay widths for a large selection of decays shows a good agreement.
基金National Science & Technology Key ProgramNational Nature Science FOundation+1 种基金Chinese Academy of Sciences FoundationAnh
文摘Low energy ions exist widely in natural world, but people pay a little attention on. the interaction between low energy ions and matter, it is even more out of the question of studying on the relation of low energy ions and the complicated organism. The discovery of bioeffect induced by ion implantation has, however, opened a new branch in the field of ion beam application in life sciences. This paper reports recent advances in research on the role of low energy ions in Chemical synthesis of the biomolecules and application in genetic modification.
基金Project supported by the National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology of China(No.2009BAG12A01-A03-2)the National Natural Science Foundation of China(Nos.10972196,11090333,11172273,and 11321202)
文摘In addition to the hexagonal crystals of class 6 mm, many piezoelectric materials(e.g., BaTiO3), piezomagnetic materials(e.g., CoFe2O4), and multiferroic composite materials(e.g., BaTiO3-CoFe2O4 composites) also exhibit symmetry of transverse isotropy after poling, with the isotropic plane perpendicular to the poling direction. In this paper, simple and elegant line-integral expressions are derived for extended displacements, extended stresses, self-energy, and interaction energy of arbitrarily shaped, threedimensional(3D) dislocation loops with a constant extended Burgers vector in transversely isotropic magneto-electro-elastic(MEE) bimaterials(i.e., joined half-spaces). The derived solutions can also be simply reduced to those expressions for piezoelectric, piezomagnetic, or purely elastic materials. Several numerical examples are given to show both the multi-field coupling effect and the interface/surface effect in transversely isotropic MEE materials.
基金foundation by the National Key Basic Research and Development Project Program of China(No.2011CB201202-2)the Research Fund for the Doctoral Program of Higher Education(No.20120023120005)+1 种基金the Foundation of State Key Laboratory of Coal Resources and Safety Mining(No.SKLCRSM11KFB04)the Fundamental Research Funds for the Central Universities(No.2009kz03)
文摘Gas adsorption has an important influence on gas flow in a coal body.Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal.In this paper,the interaction between methane,carbon dioxide and surface molecules of anthracite was simulated using the quantum chemistry method.Adsorption energy and adsorption configurations of different quantities of gas molecules absorbed on the coal surface were calculated.The results show that adsorption between coal and the two kinds of gas molecules is a physical adsorption process and there is an optimal configuration.Gas molecules are more easily adsorbed in the hydroxyl-containing side chain,while it is difficult for them to be adsorbed at the position of the benzene ring.Besides,carbon dioxide molecules are more readily adsorbed on the coal surface than methane molecules.The findings have an important significance in revealing the nature of gas adsorption in coal.
基金This work was supported by the Foundation of Education Committee of Gansu Province (021-227).
文摘Five optimized geometries of F-?(H2O)n (n = 1, 2) were obtained with ab initio calculation at the B3LYP/6-311++G** level. The accurate intermonomer interaction energy was calculated using the MP2 electron correlation correction as well as the basis set superposition error correction by the Boys-Bernardi “counterpoise” protocol. Natural bond orbital (NBO) theory was applied to quantify the relative strength of these interactions and account for their effects on the stability, structural and vibrational parameters of Fˉ?(H2O)n (n = 1, 2). It is shown that the charge transferring from the lone pair of F-1 to the σ?OH(…F) antibonding orbital is important. The results indicate the occupancy of σ?OH(…F) is increased (denoted ?σ?OH(…F)) and the σOH(…F) bond is leng- thened (denoted ?ROH(…F)), leading to the red-shift and the red-shift values have linear correlation with both ?σ?OH(…F) and ?ROH(…F).
基金supported by the Creative Groups of Natural Science Foundation of Hubei Province,China(Grant No.2021CFA030)the National Natural Science Foundation of China(Grant Nos.41872210 and 41274111).
文摘The threshold values of CO_(2) gas stripped off membranous residual oil from the pore walls are not clear under different temperatures, pressures and wettability conditions. The extent to which temperature, pressure and wettability influence CO_(2) flooding for enhancing the recovery of residual oil in membranous formations also remains uncertain. Therefore, further quantitative characterization is entailed. In this study, the molecular dynamics method was employed to explore CO_(2) flooding under different temperatures, pressures and wettability conditions, aiming to enhance the production of membranous residual oil. The results reveal that the interaction energy between CO_(2), decane molecules and pore walls exhibits a decrease with increasing temperature and an increase with increasing pressure, respectively, in distinct wettability scenarios. When the temperature was at or below 363 K and the pressure was not lower than 40 MPa, CO_(2) gas could detach the membranous residual oil from the pore walls in the water-wet systems. When the temperature was equal to 363 K and the pressure remained under 40 MPa, or the temperature surpassed 363 K, CO_(2) gas failed to detach the membranous residual oil from the pore walls in the water-wet systems. For the mixed-wet and oil-wet systems, CO_(2) molecules could not detach the membranous residual oil from the pore walls. The hierarchy of influence regarding temperature, pressure and wettability on the competitive adsorption capacity of CO_(2) and decane molecules on the pore walls emerged as follows: wettability > temperature > pressure. The findings of this study offer valuable insights into the application of CO_(2) gas flooding for the exploitation of membranous residual oil on pore walls.
基金supported by the National Science Fundation of China(No.U1937601),and the National Natural Science Foundation of China(Grant No.NSFC51905471).
文摘The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibrium state,equilibrium concentration distribution,MSD of layer and different groups,and interaction energy of two interface models,the influencing mechanism on the interface properties of adding organosiloxane into coating system was studied at the atomic scale.It shows that the temperature and energy of interface oscillated in a small range and it was exited in a state of dynamic equilibrium within the initial simulation stage(t<20 ps).It can be seen from the multiple peak states of concentration distribution that the iron substrate,organo-siloxane and zinc silicate are distributed in the form of a concentration gradient in the real environment.The rapid diffusion of free zinc powder in zinc silicate coating was the essential reason that affected the comprehensive properties of coating.The interface thickness decreased from 7.45 to 6.82Å,the MSD of free zinc powder was effectively reduced,and the interfacial energy was increased from 104.667 to 347.158 kcal/mol after being modified by organo-siloxane.
基金supported by the National Key R&D Program of China(2018YFB0605804)the National Natural Science Foundation of China(21606237)+2 种基金the Transformational Technologies for Clean Energy and Demonstration,Strategic Priority Research Program of the Chinese Academy of Sciences(XDA 21030500)the Fund of State Key Laboratory of Multiphase Complex Systems,IPE,CAS(MPCS-2019-A-02)the DNL Cooperation Fund,CAS(DNL180202)。
文摘The separation of methanol(MeOH)and dimethyl carbonate(DMC)is important but difficult due to the formation of an azeotropic mixture.In this work,isobaric vapor–liquid equilibrium(VLE)data for the ternary systems containing different imidazolium–based ionic liquids(ILs),i.e.MeOH+DMC+1-butyl-3-methy-limidazolium bis[(trifluoromethyl)sulfonyl]imide([Bmim][Tf2N]),MeOH+DMC+1-ethyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide([Emim][Tf2N]),and MeOH+DMC+1-ethyl-3-methylimidazolium hexafluorophosphate([Emim][PF6])were measured at 101.3 kPa.The mole fraction of IL was varied from0.05 to 0.20.The experimental data were correlated with the NRTL and Wilson equations,respectively.The results show that imidazolium-based ILs were beneficial to improve the relative volatility of MeOH to DMC,and[Bmim][Tf2 N]showed a much more excellent performance on the activity coefficient of MeOH.The interaction energies of system components were calculated using Gaussian program,and the effects of cation and anion on the separation coefficient of the azeotropic system were discussed.
文摘Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discussed before. It has been mentioned in previous studies that the proton of the H-C group could be involved in hydrogen bonding, but with conventional acceptors. In this study, we explored the ability of hydrogen bond formation of Se, S and Te acceptors with the H-C donor using Cambridge Structural Database in conjunction with Ab Initio calculations. In the CSD, there are respectively 256, 6249 and 11 R1,R2,-C=Se, R1,R2,-C=S and R1,R2,-C=Te structures that form hydrogen bonds, in which the N,N groups are majority. Except for C=S acceptor which can form a hydrogen bond with its C, C group, both C=Se and C=Te acceptors could form a hydrogen bond only with N,C and N,N groups. CSD analysis shows very similar d (norm) around -0.04 Å, while DFT-calculated interaction for N,C and N,N groups are also similar. Both interaction distances derived from CSD analysis and DFT-calculated interaction energies demonstrate that the acceptors form stable complexes with H-CF3. Besides hydrogen bonds, dispersion interactions are forces stabilizing the complexes since their contribution can reach 50%. Analysis of intra-molecular geometries and Ab Initio partial charges show that this bonding stems from resonance induced C<sup>δ+</sup>=X<sup>δ-</sup> dipoles. In many respects, both C=Se, C=S and C=Te are similar to C=S, with similar d (norm) and calculated interaction strengths.
文摘The adsorption of free acid of low concentration by crosslinked chitosan resin was followed by electrochemical experimental technique. The effect of acid concentration and the media on adsorption was discussed. The experimental results show that both the apparent rate constant and the interaction energy between the adsorbent and adsorbate are decreased while the concentration of hydrochloric acid is increased. In the adsorption system, the adsorption was effected by addition of organic solvent.
文摘Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R1-X-R2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R1 or X-R2 antibonding orbital.
文摘Glass sample of Zinc Lithium Bismuth Borate (25-x) Bi<sub>2</sub>O<sub>3</sub>:20Li<sub>2</sub>O:20ZnO:35B<sub>2</sub>O<sub>3</sub>:xPr<sub>6</sub>O<sub>11</sub>, (where x = 1, 1.5 and 2 mol%) has been prepared by melt-quenching technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The absorption spectra of three Pr<sup>3+</sup> doped zinc lithium bismuth borate glasses have been recorded at room temperature. The observed optical spectra are discussed in terms of energy states and the intensity of the transitions. The various interaction parameters like Slater-Condon, Lande, bonding and Racah parameters have been computed. Judd-Ofelt intensity parameters and laser parameters have also been calculated. The stimulated emission cross section (σ<sub>p</sub>) for the transition (<sup>3</sup>P<sub>0</sub> → <sup>3</sup>F<sub>2</sub>) is found to be in the range 3.12 - 10.43 * 10<sup>-20</sup> cm<sup>2</sup>. The σ<sub>p</sub> values are comparatively large suggesting the possible utilization of these materials in laser applications.
基金Supported by the National SKA Program of China(2022SKA0110200,2022SKA0110203)the National Natural Science Foundation of China(11975072,11875102,11835009)。
文摘We consider a new cosmological model(calledΛ~CDM),in which the vacuum energy interacts with matter and radiation,and test this model using the current cosmological observations.Using the CMB+BAO+SN(CBS)dataset to constrain the model,we find that H0 and S8 tensions are relieved to 2.87σand 2.77σ,respectively.However,in this case,theΛ~CDM model is not favored by the data,compared withΛCDM.We find that when the H0 and S8 data are added to the data combination,the situation is significantly improved.In the CBS+H0 case,the model relieves the H0 tension to 0.47σ,and the model is favored overΛCDM.In the CBS+H0+S8 case,we obtain a synthetically best situation,in which the H0 and S8 tensions are relieved to 0.72σand 2.11σ,respectively.In this case,the model is most favored by the data.Therefore,this cosmological model can greatly relieve the H0 tension and simultaneously effectively alleviate the S8 tension.
基金the primary financial support by the National Natural Science Foundation of China (No. 21975126)the open research fund from Anhui Province Key Laboratory of Optoelectronic Materials Science and Technology+1 种基金the Technology and Research Innovation in University of Jiangsu Province (No.KYCX21_0772)the Ministry of Education and Synergetic Innovation Center for Organic Electronics and Information Displays
文摘To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals.Herein,the relationship between structural halogenation and molecular-level stacking,micro/nanoscale surface morphology,and macroscopic mechanical properties are investigated.Elastic crystals of halo-pyrimidinyl carbazoles(CzM-Cl,CzM-Br and CzM-I)with lamellar structure and brittle crystal(CzM-F)were quantitatively analyzed by crystal energy framework(CEF)providing the inter/intralayer interaction energy(Inter/Intra-IE).It is revealed that the elastic crystals bend under external force as a result from stronger Intra-IE to prevent cleavage and weaker Inter-IE for the short-range movement of molecules on the slip plane.This research will provide an insight for the molecular design of flexible crystals and facilitate the development of next-generation smart crystal materials.
基金This work was supported by the National Key R&D Program of China(2022YFB380440003)the National Natural Science Foundation of China(32271385).
文摘Hydrogels are promising candidates for mimicking native extracellular matrix(ECM)and are therefore widely adopted as scaffolds in tissue engineering.However,conventional hydrogels composed of static networks are prone to permanent structural damages and lack the ability to provide the time-dependent mechanical cues,which are essential for cell development,ECM remodeling,and tissue regeneration.The recent substantial development in the structurally dynamic hydrogels with energy-dissipative ability has demonstrated the unique capability of such viscoelastic hydrogels to withstand extreme biomechanical loads and regulate cellular behaviors not present in classical hydrogels.This review starts with the general design principles for energy-dissipative hydrogels,followed by recent advancements in fabrication approaches for energy-dissipative hydrogels.We then highlight some applications of energy-dissipative hydrogels in tissue engineering,including bone and cartilage regeneration,vessel regeneration,nerve regeneration,and wound healing.Finally,we discuss about the key current challenges and future development of energy-dissipative hydrogels for biomedical applications.
基金the National Natural Science Foundation of China(Grant Nos.11947022,11975072,11835009,11875102,11522540,11690021)the Liaoning Revitalization Talents Program(Grant No.XLYC1905011)+3 种基金the Fundamental Research Funds for the Central Universities(Grant No.N2005030)the National Program for Support of Top-Notch Young Professionalsthe 2019 Annual Scientific Research Funding Project of the Education Department of Liaoning Province(Grant No.LJC201915)the Doctoral Research Project of Shenyang Normal University(Grant No.BS201844)。
文摘We investigate the impacts of dark energy on constraining massive(active/sterile)neutrinos in interacting dark energy(IDE)models by using the current observations.We employ two typical IDE models,the interacting w cold dark matter(IwCDM)model and the interacting holographic dark energy(IHDE)model,to make an analysis.To avoid large-scale instability,we use the parameterized post-Friedmann approach to calculate the cosmological perturbations in the IDE models.The cosmological observational data used in this work include the Planck cosmic microwave background(CMB)anisotropies data,the baryon acoustic oscillation data,the type Ia supernovae data,the direct measurement of the Hubble constant,the weak lensing data,the redshift-space distortion data,and the CMB lensing data.We find that the dark energy properties could influence the constraint limits of active neutrino mass and sterile neutrino parameters in the IDE models.We also find that the dark energy properties could influence the constraints on the coupling strength parameterβ,and a positive coupling constant,β>0,can be detected at the 2.5σstatistical significance for the IHDE+νs model by using the all-data combination.In addition,we also discuss the"Hubble tension"issue in these scenarios.We find that the H0 tension can be effectively relieved by considering massive sterile neutrinos,and in particular in the IHDE+νsmodel the H0 tension can be reduced to be at the 1.28σlevel.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875102,11835009,11522540,11690021,and61603265)the National Program for Support of Top-Notch Young ProfessionalsDoctoral Research Project of Shenyang Normal University(Grant Nos.BS201844,and BS201702)
文摘We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy(IDE)models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting w cold dark matter(IwCDM) model and the interacting holographic dark energy(IHDE) model. To avoid the large-scale instability problem in IDE models, we apply the parameterized post-Friedmann approach to calculate the perturbation of dark energy. We employ the Planck 2015 cosmic microwave background temperature and polarization data, combined with low-redshift measurements on baryon acoustic oscillation distance scales, type Ia supernovae, and the Hubble constant, to constrain the cosmological parameters. We find that the dark energy properties could influence the constraint limits on the total neutrino mass. Once dynamical dark energy is considered in the IDE models, the upper bounds of ∑mν will be changed. By considering the values of χ^2min , we find that in these IDE models the normal hierarchy case is slightly preferred over the inverted hierarchy case;for example, △χ^2= 2.720 is given in the IHDE+∑mν model. In addition, we also find that in the Iw CDM+∑mν model β = 0 is consistent with current observational data inside the 1σ range, and in the IHDE+∑mν model β > 0 is favored at more than 2σ level.
基金financially supported by the National Natural Science Foundation of China (Nos.51471097 and 51671111)the National Key Research and Development Program of China (No. 2016YFB0701304)
文摘Self-accommodation microstructure,a typical crystallographic texture developed from phase transformation,is often observed in various alloys.In this work,a molecular dynamics simulation was conducted to reveal the fine details of self-accommodation microstructure evolution during the phase transformation from austenite to ferrite in pure iron.The growth and shrinkage of ferrite grains with different orientation relationships(ORs)are interpreted based on the analysis combining the elastic interaction energy and the interfacial energy.It was found that the strain energy determines the priority of potential ORs,while the interfacial energy selects the specific preferred ORs to form.The present atomistic process and energetic interpretation of the self-accommodation microstructure provide helpful insight into phase transformation textures observed in various alloys.
