期刊文献+
共找到24篇文章
< 1 2 >
每页显示 20 50 100
Nuclear Stopping and Pauli Blocking in Heavy-Ion Reactions near Fermi Energy
1
作者 邢永忠 刘晓斌 +2 位作者 师应龙 张鸿飞 郑玉明 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第12期28-31,共4页
The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe+^129Sn with the isospin-dependent quantum molecular dynamics model. The calcu... The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe+^129Sn with the isospin-dependent quantum molecular dynamics model. The calculations involving a proper prescription of implementing the Pauli exclusion principle show that the isotropy ratio measured by free protons emitted in the reaction at energy slightly higher than the Fermi energy is in agreement with the experimental data recently released by the INDRA collaboration. A feasible value of the Pauli-blocking factor is estimated by comparing the theoretical results with the experimental data for the energy range considered here. 展开更多
关键词 in on of Nuclear Stopping and Pauli Blocking in Heavy-Ion reactions near Fermi energy been IS
下载PDF
THEORETICAL INVESTIGATION OF COLLISION ENERGY EFFECT ON REACTION O(?) BARIUM WITH METHYL BROMIDE
2
作者 Ke Li HAN Ben Fan SUN Guo Zhong HE State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Science,Dalian 116023 Xi Guang ZHFNG Qin Xing LI Zhen Xin YU Institute for Lasers and Spectroscopy,Zhongshan University,Guangzhou 510275 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第6期513-516,共4页
The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in... The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in molecular beam experiments,the results of the present study show significant effect of the reagent collision energy on the dynamics of the reaction,and are in good agreement with the experimental ones. 展开更多
关键词 BARIUM WITH METHYL BROMIDE THEORETICAL INVESTIGATION OF COLLISION energy EFFECT ON reaction O
下载PDF
Nonequilibrium Solvent Free Energy Curve from Molecular Theory in Electron Transfer Reaction
3
作者 Jian XIJ Zheng YM ZHOU(Department of Chendstry, Qufu Normal University, Qufu, 273165)Ke Zhong ZHANG(Linyi Anucahon College, Linyi, 276000) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第5期439-442,共4页
The microscopic moleeular theory for electron transfer in a model solvent ishahr developed. The nonlinear response of the solvent molecules is be computedquanitatively in a new way. Adopting computer simulation daa an... The microscopic moleeular theory for electron transfer in a model solvent ishahr developed. The nonlinear response of the solvent molecules is be computedquanitatively in a new way. Adopting computer simulation daa and choosingappropriate reaction coordinae, a reasonable free energy dinram is constructed and thercorganhaion energy for the product state is calculated. 展开更多
关键词 Free Nonequilibrium Solvent Free energy Curve from Molecular Theory in Electron Transfer reaction CM
下载PDF
Improving the energy release characteristics of PTFE/Al by doping magnesium hydride 被引量:5
4
作者 Jia-xiang Wu Qiang Liu +6 位作者 Bin Feng Qin Yin Yu-chun Li Shuang-zhang Wu Zhong-shen Yu Jun-yi Huang Xin-xin Ren 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第2期219-228,共10页
Magnesium hydride(MgH2)was doped into PTFE/Al to improve the energy release characteristics of the material system and strive for better application in military engineering.Five types of PTFE/Al/MgH2 reactive material... Magnesium hydride(MgH2)was doped into PTFE/Al to improve the energy release characteristics of the material system and strive for better application in military engineering.Five types of PTFE/Al/MgH2 reactive materials with different MgH2 content were prepared by molding sintering method.The dynamic mechanical properties of the materials were studied by performing split-Hopkinson pressure bar(SHPB)tests and scanning electron microscope characterizations.The thermal behavior,reaction energy,reaction process and reaction mechanism were systematically investigated by conducting thermogravimetry-differential scanning calorimetry tests,oxygen bomb calorimeter measurements,Xray diffraction and SHPB tests.The results show that MgH2 particles less than 10%content contribute to heightening the dynamic mechanical properties of PTFE/Al system.The product Mg generated by decomposition of MgH2 can not only react with gas phase C2F4þbut also undergo a Grignard-type reaction with condensed PTFE.The reaction energy and ignition threshold of PTFE/Al/MgH2 reactive materials enhance monotonously as MgH2 content rose.With the increase of MgH2 content from 0%to 20%,the reaction time is prolonged as well as the reaction intensity is enhanced dramatically arising from the massive water vapour produced by the reaction between O2 and H2.The gaseous products generated can form a high pressure shortly after the reaction,which helps to elevate the damage effect of the PTFE/Al system. 展开更多
关键词 PTFE/Al/MgH_(2) Mechanical properties Thermal behavior reaction energy Ignition threshold
下载PDF
Density Functional Theory Study of Mechanism of Cycloaddition Reaction Between Dimethyl-Silylene Carbene and Acetone
5
作者 卢秀慧 向萍萍 +2 位作者 时乐义 韩军锋 廉贞霞 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第2期169-174,I0001,共7页
The mechanism of the cycloaddition reaction between singlet dimethyl-silylene carbene and acetone has been investigated with density functional theory, From the potential energy profile, it can be predicted that the r... The mechanism of the cycloaddition reaction between singlet dimethyl-silylene carbene and acetone has been investigated with density functional theory, From the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction pathways. The presented rule of this reaction: the [2+2] cycloaddition effect between the πorbital of dimethyl-silylene carbene and the π orbital of π-bonded compounds leads to the formation of a twisty four-membered ring intermediate and a planar four-membered ring product; The unsaturated property of C atom from carbene in the planar four-membered ring product,resulting in the generation of CH3-transfer product and silicic bis-heterocyclic compound. 展开更多
关键词 Dimethyl-silylene carbene reaction mechanism Potential energy surface
下载PDF
Nuclear Fusion Research and Development Need New Relativistic Mass and Energy Corrections Given by the Information Relativity Theory 被引量:3
6
作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2022年第5期1813-1836,共24页
Hundred years after the conjecture of the British astronomer Eddington that the sun is powered by nuclear fusion of hydrogen, new physics theory may help make energy harvesting by nuclear fusion soon a reality. Resear... Hundred years after the conjecture of the British astronomer Eddington that the sun is powered by nuclear fusion of hydrogen, new physics theory may help make energy harvesting by nuclear fusion soon a reality. Researchers as well as investors funding fusion megaprojects are asked to deal with new relativistic corrections for mass and energy proposed by Suleiman in his Information Relativity Theory (IRT). These corrections were calculated in this contribution. It will help to decide whether a venture will be successful and to save big investments when in doubt. The assumed optimal kinetic energy for controlled nuclear fusion must be corrected to a somewhat higher level. At very high kinetic energy in the upper GeV range, it remains not enough baryonic mass to be transformed in energy. The fusion probability faded out to zero already at the golden limit of the recession speed of  between target nucleon and projectile nucleon. Cold nuclear fusion, if ever possible, is recommended for protons rather than deuterons at highest experimental possible temperatures around 1000 (K) and needs fine-tuned kinetic nucleon energy. It would be also of interest whether a golden ratio based nuclear fuel confinement chamber could be beneficial. In this connection, also cold nuclear fusion setups should be discussed. Nature is governed by the golden ratio and criticality of physical systems influenced by it, and nuclear physics is not an exception. Computer simulations of the underlying controlled nuclear fusion processes should gain profit from IRT corrected starting information and may tackle anew possible low energy nuclear transmutations considering the wave-like dark components of matter and energy. 展开更多
关键词 Controlled Thermonuclear Fusion IRT Theory Relativistic Mass Correction Low energy Nuclear reaction Golden Ratio Golden Limit of Nuclear Fusion
下载PDF
KELEA (Kinetic Energy Limiting Electrostatic Attraction) Offers an Alternative Explanation to Existing Concepts Regarding Wave-Particle Duality, Cold Fusion and Superconductivity 被引量:4
7
作者 W. John Martin 《Journal of Modern Physics》 2016年第15期1995-2007,共13页
Existing explanations for several major phenomena in physics may need to be reconsidered in light of the description of a natural force termed KELEA (kinetic energy limiting electrostatic attraction). Three examples a... Existing explanations for several major phenomena in physics may need to be reconsidered in light of the description of a natural force termed KELEA (kinetic energy limiting electrostatic attraction). Three examples are selected for discussion in this paper: i) The proposed wave-particle duality of electrons;ii) cold fusion;and iii) superconductivity. The current interpretations of these enigmatic concepts are incomplete and not fully validated by scientific methods. The observations underlying these processes are seemingly consistent with KELEA acting as a repelling force between opposite electrical charges. Relatively simple experiments can be designed to either confirm or exclude KELEA in these and in various other currently perplexing physical phenomena. 展开更多
关键词 KELEA Kinetic energy Limiting Electrostatic Attraction LENR Low energy Nuclear reaction Wave-Particle Duality Double Slit Experiment Cold Fusion DEUTERIUM Palladium SUPERCONDUCTIVITY Condensed Matter Nuclear Science Brown’s Gas ELECTROLYSIS Activated Water
下载PDF
Theoretical Study on the Mechanism of a New Synthesis Reaction of 1,3,5-Substituted-1,2,4-triazoles by Carboxylic Acids,Amidines,and Hydrazines
8
作者 王志玲 汪智娜 卢秀慧 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第3期367-374,共8页
The synthesis of 1,3,5-substituted-1,2,4-triazoles from α-imino-3-pyridine formic acid,acetamidine and anisole hydrazine as a model reaction in this paper and the synthesis mechanism of 1,3,5-substituted-1,2,4-triazo... The synthesis of 1,3,5-substituted-1,2,4-triazoles from α-imino-3-pyridine formic acid,acetamidine and anisole hydrazine as a model reaction in this paper and the synthesis mechanism of 1,3,5-substituted-1,2,4-triazole compounds from carboxylic acids,amidines and hydrazines have been first investigated with the B3 LYP/6-311++G** method.According to the potential energy profile,it can be predicted that the course of the reaction consists of five reactions containing six elementary reactions.The α-imino-3-pyridine formic acid and acetamidine form first an intermediate product through a dehydration reaction; the intermediate product further combines with hydrogen ion to form a positive ion; the positive ion reacts with anisole hydrazine by a dehydration reaction to form another positive ion; then,followed by two isomerization reactions,the final reaction with the acetate ion(Ac-) produces the final product.The research results reveal the laws of synthesis reaction of 1,3,5-substituted-1,2,4-triazoles by the carboxylic acids,amidines,hydrazines and their derivatives on theoretical level.It provides the systemic theoretical basis for the synthesis,development and application of 1,3,5-substituted-1,2,4-triazole compounds. 展开更多
关键词 1 3 5-substituted-1 2 4-triazole synthetic reaction potential energy profile molar gibbs free energy of reaction(△rGm)-
下载PDF
Three-Body Calculation of 4He(αα,γ)12C Reaction at Stellar Energies
9
作者 Firoozabadi M. M. Sadeghi H. 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第7期25-28,共4页
The triple-alpha reaction is the key to our understanding about the nucleosynthesis and the observed abundance of 12C in stars. On the basis of our model, the triple-alpha radiative capture process is studied by using... The triple-alpha reaction is the key to our understanding about the nucleosynthesis and the observed abundance of 12C in stars. On the basis of our model, the triple-alpha radiative capture process is studied by using the three-body Faddeev approach as well as two- and three-body electromagnetic currents. The bound and resonance states of 12 C are calculated via an inverse process: three-a photodisintegration of a 12 C nucleus. 展开更多
关键词 Three-Body Calculation of C reaction at Stellar Energies
下载PDF
Scaling for Experimental Inner-Sphere Reorganization Energy of Hydrated Ions via Accurate Potential Function
10
作者 BU Yu-xiang (Department oj Chemistry,Qufu Normal University,Qufu,273165)DENG Cong-hao (Department of Chemistry,Shandong University,Jinan,250100) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1995年第2期137-144,共8页
Reported here are several new calculation methods for the inner-sphere reorganization energy of hydrated metal ions involved in electron transfer processes.It is based on the self-exchange model of reorganization and ... Reported here are several new calculation methods for the inner-sphere reorganization energy of hydrated metal ions involved in electron transfer processes.It is based on the self-exchange model of reorganization and utilizes the more exact potential functions between central metal ion and the inner-sphere ligands.The parameters involved are determined via the spectroscopic and thermodynamic data.The predictions of the inner-sphere reorganization energies from those models agree well with the photoemission experimental results. 展开更多
关键词 Hydrated metal ion Inner-sphere reorganization energy self-exchange reaction Accurate potential function
下载PDF
Effects of temperature, particle size, and air humidity on sensibility of typical high-energetic explosives
11
作者 WU Sanzhen FANG Mingkun +3 位作者 WU Xingliang GUO Guangfei WANG Junhong XU Sen 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期408-416,共9页
The production and utilization of high-energetic explosives often pose a range of safety hazards,with sensitivity being a key factor in evaluating these risks.To investigate how temperature,particle size,and air humid... The production and utilization of high-energetic explosives often pose a range of safety hazards,with sensitivity being a key factor in evaluating these risks.To investigate how temperature,particle size,and air humidity affect the responsiveness of commonly used high-energetic explosives,a series of BAM(Bundesanstalt für Materialforschung und-prüfung)impact and friction sensitivity tests were carried out to determine the critical impact energy and critical load pressure of four representative high-energetic explosives(RDX,HMX,PETN and CL-20)under different temperatures,particle sizes,and air humidity conditions.The experimental findings facilitated an examination of temperature and particle size affecting the sensitivity of high-energetic explosives,along with an assessment of the influence of air humidity on sensitivity testing.The results clearly indicate that high-energetic explosives display a substantial decline in critical reaction energy when subjected to micrometre-sized particles and an air humidity level of 45%at a temperature of 90℃.Furthermore,it was noted that the critical reaction energy of high-energetic explosives diminishes with an increase in temperature within 25℃−90℃.In the same vein,as the particle sizes of high-energetic explosives increase,so does the critical reaction energy for micrometre-sized particles.High air humidity significantly affects the sensitivity testing of high-energetic explosives,emphasizing the importance of refraining from conducting sensitivity tests in such conditions. 展开更多
关键词 high-energetic explosives TEMPERATURE particle size air humidity critical reaction energy
下载PDF
Understanding the Effect of the Exchange-Correlation Functionals on Methane and Ethane Formation over Ruthenium Catalysts
12
作者 Chen Chen Minzhen Jian +1 位作者 Jin-Xun Liu Wei-Xue Li 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第4期619-628,I0017-I0037,I0149,共32页
Density functional theory(DFT)has been established as a powerful research tool for heterogeneous catalysis research in obtaining key thermodynamic and/or kinetic parameters like adsorption energies,enthalpies of react... Density functional theory(DFT)has been established as a powerful research tool for heterogeneous catalysis research in obtaining key thermodynamic and/or kinetic parameters like adsorption energies,enthalpies of reaction,activation barriers,and rate constants.Understanding of density functional exchangecorrelation approximations is essential to reveal the mechanism and performance of a catalyst.In the present work,we reported the influence of six exchange-correlation density functionals,including PBE,RPBE,BEEF+vdW,optB86b+vdW,SCAN,and SCAN+rVV10,on the adsorption energies,reaction energies and activation barriers of carbon hydrogenation and carbon-carbon couplings during the formation of methane and ethane over Ru(0001)and Ru(1011)surfaces.We found the calculated reaction energies are strongly dependent on exchange-correlation density functionals due to the difference in coordination number between reactants and products on surfaces.The deviation of the calculated elementary reaction energies can be accumulated to a large value for chemical reaction involving multiple steps and vary considerably with different exchange-correlation density functionals calculations.The different exchange-correlation density functionals are found to influence considerably the selectivity of Ru(0001)surface for methane,ethylene,and ethane formation determined by the adsorption energies of intermediates involved.However,the influence on the barriers of the elementary surface reactions and the structural sensitivity of Ru(0001)and Ru(1011)are modest.Our work highlights the limitation of exchange-correlation density functionals on computational catalysis and the importance of choosing a proper exchange-correlation density functional in correctly evaluating the activity and selectivity of a catalyst. 展开更多
关键词 Density functional exchange-correlation approximation Adsorption energy reaction energy Activation barriers Structural sensitivity
下载PDF
Syntheses and Crystal Structures of Two AlxRE3(Si1-yAly)S7(RE=Sm and Gd)Compounds 被引量:2
13
作者 迟洋 郭胜平 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第3期341-347,共7页
Two new quaternary rare-earth chalcogenides,Al_(0.42)Sm_3(Si_(0.74)Al_(0.26))S_7(1) and Al_(0.38)Gd_3(Si_(0.86)Al_(0.14))S_7(2),have been synthesized by a facile solid-state route with boron as the... Two new quaternary rare-earth chalcogenides,Al_(0.42)Sm_3(Si_(0.74)Al_(0.26))S_7(1) and Al_(0.38)Gd_3(Si_(0.86)Al_(0.14))S_7(2),have been synthesized by a facile solid-state route with boron as the reducing reagent.They crystallize in the noncentrosymmetric hexagonal space group P6_3,belonging to the Ce_6Al_(3.33)S_(14) structure-type.Their 3-D structures feature 3-D frameworks constructed by RES_8 bicapped trigonal prisms,and Al and Si occupy the octahedral and tetrahedral voids,respectively.Al(2) and Si(1) co-occupying the 2b site and Al(1) partially occupying the 2a site have to be considered for the stability of the structures and charge balances.The Ce_6Al_(3.33)S_(14) structure-type compounds with their rich compositions and traits are discussed.The diffuse reflectance spectrum measurement of 2 indicates that it has an energy gap of 2.13 eV. 展开更多
关键词 rare-earth chalcogenides solid-state reaction crystal structure energy gap
下载PDF
Theoretical Studies on the Structure and Detonation Properties of a Furazanbased Energetic Macrocycle Compound 被引量:1
14
作者 梅争 李小红 +2 位作者 崔红玲 王会娴 张瑞州 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第1期16-24,共9页
Based on the full optimized molecular geometric structure at 6-311++G** level,the density(ρ),detonation velocity(D),and detonation pressure(P) for a new furazan-based energetic macrocycle compound,hexakis[1... Based on the full optimized molecular geometric structure at 6-311++G** level,the density(ρ),detonation velocity(D),and detonation pressure(P) for a new furazan-based energetic macrocycle compound,hexakis[1,2,5]oxadi-azole[3,4-c:3',4'-e;3'',4''-g:3''',4'''-k:3'''',4''''-m:3''''',4'''''-o][1,2,9,10]-tetraazacyclohexadecine,were investigated to verify its capacity as high energy density material(HEDM). The infrared spectrum was also predicted. The heat of formation(HOF) was calculated using designed isodesmic reaction. The calculation on the bond dissociation energies(BDEs) was done and the pyrolysis mechanism of the compound was studied. The result shows that the N3–O1 bond in the ring may be the weakest one and the ring cleavage is possible to happen in thermal decomposition. The condensed phase HOF and the crystal density were also calculated for the title compound. The detonation data show that it can be considered as a potential HEDM. These results would provide basic information for the molecular design of novel high energy materials. 展开更多
关键词 detonation properties heat of formation high energy density material isodesmic reaction
下载PDF
Determining the nuclear temperature dependence on source neutron-proton asymmetry in heavy-ion reactions at intermediate energy
15
作者 曲国峰 黄宇 +9 位作者 郑华 刘星泉 R.Wada 林炜平 黄美容 韩纪锋 任培培 杨振雷 张鑫 冷强钟 《Chinese Physics C》 SCIE CAS CSCD 2023年第5期152-159,共8页
In this article,we investigate the dependence of nuclear temperature on emitting source neutron-proton(N/Z)asymmetry with light charged particles(LCPs)and intermediate mass fragments(IMFs)generated from intermediate-v... In this article,we investigate the dependence of nuclear temperature on emitting source neutron-proton(N/Z)asymmetry with light charged particles(LCPs)and intermediate mass fragments(IMFs)generated from intermediate-velocity sources in thirteen reaction systems with different N/Z asymmetries,^(64)Zn on^(112)Sn,and^(70)Zn,^(64)Ni on^(112,124)Sn,^(58,64)Ni,^(197)Au,and^(232)Th at 40 MeV/nucleon.The apparent temperature values of LCPs and IMFs from different systems are deduced from the measured yields using two helium-related and eight carbon-related double isotope ratio thermometers,respectively.Then,the sequential decay effect on the experimental apparent temperature deduction with the double isotope ratio thermometers is quantitatively corrected explicitly with the aid of the quantum statistical model.The present treatment is an improvement compared to our previous studies in which an indirect method was adopted to qualitatively consider the sequential decay effect.A negligible N/Z asymmetry dependence of the real temperature after the correction is quantitatively addressed in heavy-ion reactions at the present intermediate energy,where a change of o.1 units in source N/Z asymmetry corresponds to an absolute change in temperature of an order of 0.03 to 0.29 MeV on average for LCPs and IMFs.This conclusion is in close agreement with that inferred qualitatively via the indirect method in our previous studies. 展开更多
关键词 nuclear temperature N/Z asymmetry dependence Albergo thermometer sequential decay correction heavy-ion reactions at intermediate energy
原文传递
Theoretical Study of the Phenomenon of Cold Fusion within Condensed Matter and Analysis of Phases (α,β,γ)
16
作者 Fulvio Frisone 《Journal of Energy and Power Engineering》 2017年第4期215-224,共10页
The aim of this work is to explain the deuteron-deuteron reactions within palladium lattice by means of the coherence theory of nuclear and condensed matter. The coherence model of condensed matter affirms that within... The aim of this work is to explain the deuteron-deuteron reactions within palladium lattice by means of the coherence theory of nuclear and condensed matter. The coherence model of condensed matter affirms that within a deuteron-loaded palladium lattice there are three different plasmas: electrons, ions and deuterons plasma. Then, according to the loading percentage x = D/Pd, the deuterium ions can take place on the octahedral sites or in the tetrahedral on the (1, 0, 0)-plane. Further, the present work is concentrated on Palladium because, when subjected to thermodynamic stress, this metal has been seen to give results which are interesting from both the theoretical and experimental points of view. Moreover in Pd lattice we can correlate the deuterium loading with D-Pd system phases (i.e. α,β and γ) by means of theory of condensed matter. 展开更多
关键词 Condensed matter dislocations of the ions within the metal coherence theory LENR (low energy nuclear reactions).
下载PDF
Linear free energy relationships between reaction rate constants and equilibrium constants of complex compounds——III. Kinetics and mechanisms of ternary complex formation between (5-X-1, 10-phenanthroline)copper(II) and threonine 被引量:1
17
作者 CHEN Rong-Ti (Y.T.Chen) +1 位作者 ZHANG Qi-Yan LI Yue-Jin 《Acta Chimica Sinica English Edition》 SCIE CAS CSCD 1989年第4期342-348,共1页
The kinetics of ternary complex formation involving Cu(5-X-1, 10-phen) and threonine (CuAL, A=5-X-1, 10-phen; L=threonine or represented by O-N; X=NO_2, Cl, H, CH_3) has been studied by temperature-jump and stopped-fl... The kinetics of ternary complex formation involving Cu(5-X-1, 10-phen) and threonine (CuAL, A=5-X-1, 10-phen; L=threonine or represented by O-N; X=NO_2, Cl, H, CH_3) has been studied by temperature-jump and stopped-flow methods. The formation rate constants, k_f(M^(-1).s^(-1)), for the complexation reaction, CuA + LCuAL, are as follows; X=NO_2, 8.68×10~8; X=Cl, 7.13×10~8; X=H, 6.12×10~8; X=CH_3, 5.42×10~8. The rate constants for zwitterion attack are nil within experimental error. It has been found that a linear free energy relationship exists between the stability(logK_(CuAL)^(CuA) of the complexes CuAL and log kf as follows: IogK_(CuAL)^(CuA)=0.13 + 0.83 logk_f, r=0.99. It suggested that the formation rate governed the stability of the ternary complexes. The rates of formation of the ternary complexes increased with decreasing electron-donating property of the substituents. A linear relationship was found to exist as expressed by the following equation: log(k_f^R/k_F^O) = 0.097σ, r=0.96. A mechanism involves a rapid equilibrium between CuA and L followed by a slow ring closure of L. 展开更多
关键词 rate Kinetics and mechanisms of ternary complex formation between and threonine phenanthroline)copper II Linear free energy relationships between reaction rate constants and equilibrium constants of complex compounds X-1 III free
全文增补中
High entropy alloy electrocatalysts
18
作者 Guoliang Gao Yangyang Yu +4 位作者 Guang Zhu Bowen Sun Ren He Andreu Cabot Zixu Sun 《Journal of Energy Chemistry》 SCIE EI CAS 2024年第12期335-364,共30页
Compared to traditional pure metals or alloys based on just one principal element,high entropy alloys(HEAs)exhibit notable structural and physical characteristics,drawing significant attention.While significant advanc... Compared to traditional pure metals or alloys based on just one principal element,high entropy alloys(HEAs)exhibit notable structural and physical characteristics,drawing significant attention.While significant advancements have been made in the synthesis and utilization of HEAs,there is a lack of comprehensive understanding and systematic approach towards the rational design of electrocatalysts.This review begins by introducing the fundamental principles and impacts of HEAs,followed by an overview of traditional and emerging synthesis techniques;in particular,we categorize and critically analyze approaches.Subsequently,a detailed examination of the advancements and comparative performance of HEAs in specific electrocatalytic reactions is presented.The paper concludes by outlining the current challenges and opportunities associated with HEAs catalysts,along with offering personal insights on potential future developments. 展开更多
关键词 High entropy alloys Electrocatalysis Synthesis strategies energy conversion reactions
下载PDF
Production of super-heavy nuclei in cold fusion reactions
19
作者 V.Yu.Denisov I.Yu.Sedykh 《Chinese Physics C》 SCIE CAS CSCD 2021年第4期301-324,共24页
A model for cold-fusion reactions related to the synthesis of super-heavy nuclei in collisions of heavy projectile-nuclei with a ^(208)Pb target nucleus is discussed.In the framework of this model,the production of th... A model for cold-fusion reactions related to the synthesis of super-heavy nuclei in collisions of heavy projectile-nuclei with a ^(208)Pb target nucleus is discussed.In the framework of this model,the production of the com-pound nucleus by two paths,the di-nuclear system path and the fusion path,are taken into account simultaneously.The formation of the compound nucleus in the framework of the di-nuclear system is related to the transfer of nucle-ons from the light nucleus to the heavy one.The fusion path is linked to the sequential evolution of the nuclear shape from the system of contacting nuclei to the compound nucleus.It is shown that the compound nucleus is mainly formed by the fusion path in cold-fusion reactions.The landscape of the potential energy related to the fusion path is discussed in detail.This landscape for very heavy nucleus-nucleus systems has an intermediate state,which is linked to the formation of both the compound nucleus and the quasi-fission fragments.The decay of the intermediate state is taken into account in the calculation of the compound nucleus production cross sections and the quasi-fission cross sections.The values of the cold-fusion cross sections obtained in the model agree well with the experimental data. 展开更多
关键词 super-heavy nuclei production statistical compound-nucleus reactions low energy heavy-ion reactions fusion and fusion-fission reactions
原文传递
Features of Mechanism of Cycloaddition Reaction between Me2Ge=Sn:and Ethylene
20
作者 TAN Xiao-Jun LU Xiu-Hui GU Jin-Song 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2020年第9期1627-1632,1555,共7页
X2Ge=Sn:(X=H,Me,F,Cl,Br,Ph,Ar…)are new species of chemistry.The cycloaddition reaction of X2Ge=Sn:is a new study field of stannylene chemistry.To explore the rules of cycloaddition reaction between X2Ge=Sn:and the sy... X2Ge=Sn:(X=H,Me,F,Cl,Br,Ph,Ar…)are new species of chemistry.The cycloaddition reaction of X2Ge=Sn:is a new study field of stannylene chemistry.To explore the rules of cycloaddition reaction between X2Ge=Sn:and the symmetric p-bonded compounds,the cycloaddition reactions of Me2Ge=Sn:and ethylene were selected as model reactions in this paper,and the mechanism was investigated for the first time here using the MP2 theory together with the 6-311++G**basis set for C,H and Ge atoms and the LanL2dzbasis set for Sn atoms.From the potential energy profile,it could be predicted that the reaction has one dominant reaction channel.The reaction rule present is that the 5p unoccupied orbital of Sn in Me2Ge=Sn:and theπorbital of ethylene form a p→p donor–acceptor bond,resulting in an intermediate which,due to its instability,makes itself isomerize into a four-membered Ge-heterocyclic ring stannylene.Because the 5p unoccupied orbital of Sn atom in the four-membered Ge-heterocyclic ring stannylene and theπorbital of ethylene form a p→p donor-acceptor bond,the four-membered Ge-heterocyclic ring stannylene further combines with ethylene to get another intermediate.Because the Sn atom in this intermediate exhibits sp3 hybridization after transition state,the intermediate isomerizes to a Ge-heterocyclic spiro-Sn-heterocyclic ring compound.The research result indicates the laws of cycloaddition reaction between X2Ge=Sn:and the symmetricπ-bonded compounds.This study opens up a new research field for stannylene chemistry. 展开更多
关键词 Me2Ge=Sn: cycloaddition reaction molar Gibbs free energy of reaction(△_rG_m) potential energy profile
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部