U-Pu混合氧化物(Mixed oxide,MOX)燃料应用前景广阔。以国内M310型堆芯为对象,对使用30%MOX燃料的部分低泄漏堆芯燃料管理方案进行分析,比较了含MOX燃料堆芯和传统的全UO2燃料堆芯在平衡循环下压力容器快中子注量、原子位移次数(Displac...U-Pu混合氧化物(Mixed oxide,MOX)燃料应用前景广阔。以国内M310型堆芯为对象,对使用30%MOX燃料的部分低泄漏堆芯燃料管理方案进行分析,比较了含MOX燃料堆芯和传统的全UO2燃料堆芯在平衡循环下压力容器快中子注量、原子位移次数(Displacement per atom,DPA)和辐照监督管超前因子的特性差异。结果表明,与国内主流的高泄漏全UO2燃料堆芯平衡循环相比,平衡循环压力容器内表面快中子注量率和DPA率小20%左右,343°处的辐照监督管快中子注量率小8%,超前因子大15%;与国内占少数比例的低泄漏全UO2燃料堆芯平衡循环相比,平衡循环压力容器内表面快中子注量率和DPA率大40%左右。进一步分析发现,虽然同等功率下MOX燃料比UO2燃料释放的中子多7%,但与国内主流的高泄漏全UO2燃料堆芯相比,部分低泄漏MOX燃料堆芯的燃料管理方式使堆芯外围组件功率降低,使得压力容器受到的快中子辐照损伤降低。展开更多
Ferromagnetism is induced in pure TiO2 single crystals by oxygen ion irradiation. The ferro- magnetism is observed up to room temperature and is with weak temperature dependence. By combining X-ray diffraction, Ruther...Ferromagnetism is induced in pure TiO2 single crystals by oxygen ion irradiation. The ferro- magnetism is observed up to room temperature and is with weak temperature dependence. By combining X-ray diffraction, Rutherford backseattering/channelling, Raman scattering, and electron-spin resonance spectroscopy, supperconducting quantum interference device, displacement per atom, we measured tile lattice damage accumulation with increasing flu- ences. A defect complex, i.e., Ti3＋ on the substitutional accoiflpanied by oxygen vacancies, has been identified in the irradiated Ti02. This kind of defect complex results in a local （TiO6-x） stretching Raman mode. We elucidate that Ti3＋ with one unpaired 3d electron provide the local magnetic moments.展开更多
An all-atom dimethyl sulfoxide （DMSO） and water model have been used for molecular dynamics simulation. The NMR and IR spectra are also performed to study the structures and interactions in the DMSO-water system. An...An all-atom dimethyl sulfoxide （DMSO） and water model have been used for molecular dynamics simulation. The NMR and IR spectra are also performed to study the structures and interactions in the DMSO-water system. And there are traditional strong hydrogen bonds and weak C-H- ~ ~ O contacts existing in the mixtures according to the analysis of the radial distribution functions. The insight structures in the DMSO-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Interestingly, the molar fraction of DMSO 0.35 is found to be a special concentration by the network. It is the transitional region which is from the water rich region to the DMSO rich region. The stable aggregates of （DMSO）m＇S=O…… HW-OW-（H20）n might play a key role in this region. Moreover, the simulation is compared with the chemical shifts in NMR and wavenumbers in IR with concentration dependence. And the statistical results of the average number hydrogen bonds in the MD simulations are in agreement with the experiment data in NMR and IR spectra.展开更多
The interactions and structures of the urea-water system are studied by an all-atom molecular dynamics （MD） simulation. The hydrogen-bonding network and the radial distribution functions are adopted in MD simulation...The interactions and structures of the urea-water system are studied by an all-atom molecular dynamics （MD） simulation. The hydrogen-bonding network and the radial distribution functions are adopted in MD simulations. The structures of urea-water mixtures can be classified into different regions from the analysis of the hydrogen-bonding network. The urea molecule shows the certain tendency to the self-aggregate with the mole fraction of urea increasing. Moreover, the results of the MD simulations are also compare with the chemical shifts and viscosities of the urea aqueous solutions, and the statistical results of the average number hydrogen bonds in the MD simulations are in agreement with the experiment data such as chemical shifts of the hydrogen atom and viscosity.展开更多
The acidic oxygen evolution reaction(OER)is central to water electrolysis using proton‐exchange membranes.However,even as benchmark catalysts in the acidic OER,Ru‐based catalysts still suffer from sluggish kinetics ...The acidic oxygen evolution reaction(OER)is central to water electrolysis using proton‐exchange membranes.However,even as benchmark catalysts in the acidic OER,Ru‐based catalysts still suffer from sluggish kinetics owing to the scaling relationship that arises from the traditional concerted proton‐electron transfer(CPET)process.Motivated by the knowledge that a charged surface may be favorable for accelerating the OER kinetics,we posited the incorporation of elements with pseudocapacitive properties into Ru‐based catalysts.Herein,we report a RuPbOx electrocatalyst for efficient and stable water oxidation in acid with a low overpotential of 191 mV to reach 10 mA cm^(−2) and a low Tafel slope of 39 mV dec^(−1).The combination of electrochemical analysis,X‐ray photoelectron spectroscopy,and in situ Raman spectroscopy demonstrated that the improved OER kinetics was associated with the formation of superoxide precursors on the strongly charged surface after Pb incorporation,indicating a non‐concerted proton‐electron transfer mechanism for the OER on RuPbOx.展开更多
文摘U-Pu混合氧化物(Mixed oxide,MOX)燃料应用前景广阔。以国内M310型堆芯为对象,对使用30%MOX燃料的部分低泄漏堆芯燃料管理方案进行分析,比较了含MOX燃料堆芯和传统的全UO2燃料堆芯在平衡循环下压力容器快中子注量、原子位移次数(Displacement per atom,DPA)和辐照监督管超前因子的特性差异。结果表明,与国内主流的高泄漏全UO2燃料堆芯平衡循环相比,平衡循环压力容器内表面快中子注量率和DPA率小20%左右,343°处的辐照监督管快中子注量率小8%,超前因子大15%;与国内占少数比例的低泄漏全UO2燃料堆芯平衡循环相比,平衡循环压力容器内表面快中子注量率和DPA率大40%左右。进一步分析发现,虽然同等功率下MOX燃料比UO2燃料释放的中子多7%,但与国内主流的高泄漏全UO2燃料堆芯相比,部分低泄漏MOX燃料堆芯的燃料管理方式使堆芯外围组件功率降低,使得压力容器受到的快中子辐照损伤降低。
文摘Ferromagnetism is induced in pure TiO2 single crystals by oxygen ion irradiation. The ferro- magnetism is observed up to room temperature and is with weak temperature dependence. By combining X-ray diffraction, Rutherford backseattering/channelling, Raman scattering, and electron-spin resonance spectroscopy, supperconducting quantum interference device, displacement per atom, we measured tile lattice damage accumulation with increasing flu- ences. A defect complex, i.e., Ti3＋ on the substitutional accoiflpanied by oxygen vacancies, has been identified in the irradiated Ti02. This kind of defect complex results in a local （TiO6-x） stretching Raman mode. We elucidate that Ti3＋ with one unpaired 3d electron provide the local magnetic moments.
文摘An all-atom dimethyl sulfoxide （DMSO） and water model have been used for molecular dynamics simulation. The NMR and IR spectra are also performed to study the structures and interactions in the DMSO-water system. And there are traditional strong hydrogen bonds and weak C-H- ~ ~ O contacts existing in the mixtures according to the analysis of the radial distribution functions. The insight structures in the DMSO-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Interestingly, the molar fraction of DMSO 0.35 is found to be a special concentration by the network. It is the transitional region which is from the water rich region to the DMSO rich region. The stable aggregates of （DMSO）m＇S=O…… HW-OW-（H20）n might play a key role in this region. Moreover, the simulation is compared with the chemical shifts in NMR and wavenumbers in IR with concentration dependence. And the statistical results of the average number hydrogen bonds in the MD simulations are in agreement with the experiment data in NMR and IR spectra.
基金This work was supported by the National Natural Science Foundation of China （No.20903026）, the Doctoral Scientific Research Foundation of the Natural Science Foundation of Guangdong Province （No.7301567）, and the Research Foundation of Guangdong Pharmaceutical University （No.2006YKX05）.
文摘The interactions and structures of the urea-water system are studied by an all-atom molecular dynamics （MD） simulation. The hydrogen-bonding network and the radial distribution functions are adopted in MD simulations. The structures of urea-water mixtures can be classified into different regions from the analysis of the hydrogen-bonding network. The urea molecule shows the certain tendency to the self-aggregate with the mole fraction of urea increasing. Moreover, the results of the MD simulations are also compare with the chemical shifts and viscosities of the urea aqueous solutions, and the statistical results of the average number hydrogen bonds in the MD simulations are in agreement with the experiment data such as chemical shifts of the hydrogen atom and viscosity.
文摘The acidic oxygen evolution reaction(OER)is central to water electrolysis using proton‐exchange membranes.However,even as benchmark catalysts in the acidic OER,Ru‐based catalysts still suffer from sluggish kinetics owing to the scaling relationship that arises from the traditional concerted proton‐electron transfer(CPET)process.Motivated by the knowledge that a charged surface may be favorable for accelerating the OER kinetics,we posited the incorporation of elements with pseudocapacitive properties into Ru‐based catalysts.Herein,we report a RuPbOx electrocatalyst for efficient and stable water oxidation in acid with a low overpotential of 191 mV to reach 10 mA cm^(−2) and a low Tafel slope of 39 mV dec^(−1).The combination of electrochemical analysis,X‐ray photoelectron spectroscopy,and in situ Raman spectroscopy demonstrated that the improved OER kinetics was associated with the formation of superoxide precursors on the strongly charged surface after Pb incorporation,indicating a non‐concerted proton‐electron transfer mechanism for the OER on RuPbOx.
