湖南省四地区室内氡调查

采用ＣＲ－３９固体径迹探测器，在湖南省４地区进行了居室内氡浓度调查，统计学分析表明，４地区室内氡浓度呈对数正态分布。在地形分布上，有西北高、东南低的特点，反映了地质构造和建筑材料等对室内氡浓度的影响。     

光诱导4-硝基喹啉氧化物与甲硫氨酸衍生物的电子转移

利用纳秒级激光光解瞬态吸收光谱装置,研究了４－硝基喹啉氧化物（４ＮＱＯ）与含硫氨基酸及其肽的光化学反应。水溶液中的４ＮＱＯ被２４８ｎｍ激光激发,生成４ＮＱＯ三重态,并在４１０ｎｍ和５９０ｎｍ观察到它的特征吸收,４ＮＱＯ激发三重态能被甲硫氨酸及其肽猝灭,其过程是电子转移反应,生成４ＮＱＯ的加氢自由基和甲硫氨酸及其肽抽氧自由基。     

Dosimetric characterization of a new preparation of BaSO4 activated by Eu ions

The results of a thermoluminescent investigation carried out on a new preparation of BaSO₄ activated by Eu ions at different concentrations (0.1, 0.5 and 1.0 mol%) are reported in this paper. Several batches were prepared by varying Dy, Tm and Sm ions concentrations. The TL sensitivity property of each of the doped barium sulphate samples were compared to the BaSO₄:Eu. The highest sensitivity was found for BaSO₄:Eu (0.5 mol%). The main dosimetric characteristics, i.e. thermoluminescent (TL) response as a function of the dose, reproducibility, lower detection limit, and fading, have been investigated for the BaSO₄:Eu. Furthermore, the kinetic parameters, i.e. activation energy, E, the frequency factor, s, the pre-exponential factor s^* and the kinetic order, b, have been calculated using initial-rise and deconvolution methods. The peak shape methods related to the geometric properties of a TL peak were also used. In order to analyse the TL response at different energies, the effective atomic number (Z_eff = 45–47) for this material was determined.     

CunAum(n+m=4)类晶结构团簇电子结构性质的第一性原理计算

用基于第一性原理的密度泛函理论计算分析了CunAum(n m=4)类晶结构团簇的电子结构性质。计算得到的晶格参数与实验值吻合较好。体系能带结构和态密度分析表明,对能级的贡献主要来自d轨道的电子,且在费米能级附近出现较强的峰,此处的光吸收作用显著增强。电荷密度分布说明,体系的键结构致密度较大,其中存在共价键和金属键,金属键主要由d轨道电子的共有化运动而形成。     

ALD-coated ultrathin Al2O3 film on BiVO4 nanoparticles for efficient PEC water splitting

Bismuth vanadate(BiVO_4) is a promising semiconductor material for solar energy conversion via photoelectrochemical(PEC) water splitting,whereas its performance is limited by surface recombination due to trapping states.Herein,we developed a new method to passivate the trapping states on BiVO_4 surface using ultrathin aluminum oxide(Al_2O_3) overlayer by atomic layer deposition.The coated ultrathin Al_2O_3 film on BiVO_4 significantly enhanced photocurrent densities of the BiVO_4 anodes under standard illumination of AM1.5 G(100 mW/cm2).The electrochemical impedances and photoluminescence spectra were studied to confirm that the improved PEC water splitting performance of BiVO_4 was due to the decreased surface recombination state on BiVO_4,which effectively enhanced the charge separation.     

Primary study on solvent effect of COCA4 by laser photolysis

Reaction of p-tert-oxocalix[4]arene in acetonitrile (CH3CN) by 308nm laser pulses was investigated to understand its mechanism as polymer stabilizer. Four main absorption bands were observed at 300nm, 400nm, 460nm and 540nm. The 300nm absorption was assigned to the absorption of phenoxy radical, and the 460nm and 540nm were triple state absorption. It was concluded that the relative stable phenoxy radical mediate was formed through intramolecular energy transition of carbonyl triplet after laser excitation in CH3CN. The formation mechanism of phenoxyl radical was quite different from that in cyclohexane (C6H12), which was cooperation of two-photon process and one-photon process.     

酪氨酸敏化胸腺嘧啶二聚作用机理

本文研究了γ引发酪氨酸敏化胸腺嘧啶二聚作用反应机理,并发现,胸腺嘧啶二聚体的产额G_d(分子/100 eV)随酪氨酸浓度而变。揭示在胸腺嘧啶浓度较高时,酪氨酸敏化胸腺嘧啶二聚作用,并不是经由酪氨酸三重激发态的能量向胸腺嘧啶转移的途径,而是经由酪氨酸单重激发态的能量向胸腺嘧啶聚集态转移的机理。同时研究了这种敏化作用的反应动力学历程。     

SOP堆芯次临界状态监测问题研究

对事故后一些物理现象下的堆外中间量程测量通道IRC(Intermediate Range Channel)的响应进行了分析,包括停堆后(N-1)组控制棒组件下落、反应堆水池淹没、堆芯空泡份额或堆芯裸露等。分析发现,事故工况下IRC的响应并不一定反映堆芯次临界度的变化。从状态导向事故运行程序SOP(State Oriented Procedure)堆芯次临界度监测的目的出发,对SOP中堆芯次临界度监测阈值的选取和一回路状态功能监测优先级的确定给出了建议。     

Y-Ba-Cu-O超导体的声子异常

利用中国原子能科学研究院重水反应堆旁的Be过滤探测器中子非弹性散射谱仪,测量了Y-Ba-Cu-O超导体在298K和87K两种温度下的广义声子谱,结果如图1所示。当温度在低于超导转变温度T_e(90.5K)的87 K时,声子谱在能量小于6 meV处出现了较强的声学模,而在289 K 时10 neV和19 meV处呈现的两个低频模消失了,也可能     

锝化学研究——Ⅳ.锝的氧化态

统计有关键长,发现Tc氧化态对Tc-L键长的影响不如其他因素显著。例举了一些还原剂大大过量,但Tc却能稳定于某一价态的事实,以及十几种已测定结构的平均氧化态为非整数的Tc化合物,认为配位环境是决定Tc氧化态的首要因素。     

丙烯酰胺的固态辐射聚合

本文研究了固态丙烯酰胺辐射场内聚合和场外聚合,但得到的都是不溶的聚合物。当添加了链转移剂异丙醇,则65％的丙烯酰胺浓水溶液在冰浴中聚合,可以得到分子量超过500万,转化率达95％可溶的聚合物。     

Theoretical energy level spectra and transition data for 4p4d, 4p4d4f,and 4p4d configurations of W

The ab initio   quasirelativistic Hartree–Fock method developed specifically for the calculation of spectral parameters of heavy atoms and highly charged ions is used to derive transition data for a multicharged tungsten ion. The configuration interaction method is applied to include electron correlation effects. The relativistic effects are taken into account in the Breit–Pauli approximation for quasirelativistic Hartree–Fock radial orbitals. The energy level spectra, radiative lifetimes and Lande g$g$-factors are calculated for the 4p⁶4d², 4p⁶4d4f, and 4p⁵4d³ configurations of the ion W³⁶⁺. The transition wavelengths, spontaneous transition probabilities, oscillator strengths, and line strengths for the electric dipole, electric quadrupole, electric octupole, and magnetic dipole transitions among the levels of these configurations are tabulated.     

射频反馈电子直线加速器的稳态特性

本文讨论了含聚束器的射频反馈电子直线加速器基于耗散方程的稳态束负载理论,导出了加速器稳态特性的解析关系,最后计算了桥比n=1和n=n_(opt)加速器的负载特性。     

HI－13串列加速器的第二剥离器系统研制

建立ＨＩ－１３串列加速器的第二剥离器系统，是提高加速离子能量的显现实、投资少和见效快的技术方案。文章介绍了第二剥离器系统的工作原理、技术关键，并给出了系统性能和工作成果。     

Experimental study on the sub-atmospheric loop heat pipe passive cooling system for spent fuel pool

As one kind of the natural circulation cooling system, loop heat pipe is promising in improving the safety of the nuclear power station since it is passive and has no electricity driven components. A novel heat pipe cooling system is designed for passively removing the residual heat released by the spent fuel stored in the spent fuel pool (SFP) under the accidental conditions such as the station blackout. This system is characterized by its large-diameter and long-length evaporator. Its working fluid is water and it's sub-atmospheric. To test such system's heat transfer performance and get to know its thermo-fluid dynamics, a test facility for a simplified heat pipe made of one evaporator tube and one condenser has been developed. The heat transfer rate of the simplified heat pipe is obtained in a wide range of conditions covering the potential working conditions in spent fuel pool. Moreover, it's found that heat pipe with such a large-diameter and long-length evaporator is vulnerable to be unstable. The periodic state mode is more likely to happen when the heat source temperature, the air velocity or the volumetric filling ratio is low. Furthermore, the effects of hot water temperature, the air velocity and the filling ratio of the water in the circulation system have been analyzed.     

Theoretical energy level spectra and transition data for 4p4d, 4p4f and 4p4d configurations of W ion

The ab initio quasirelativistic Hartree-Fock method developed specifically for the calculation of spectral parameters of heavy atoms and highly charged ions was applied to determine atomic data for tungsten ions. The correlation effects were included by adopting the configuration interaction method. The Breit-Pauli approximation for quasirelativistic Hartree-Fock radial orbitals was employed to take into account relativistic effects. The energy level spectra, radiative lifetimes, Lande factors g were calculated for the 4p⁶4d, 4p⁶4f and 4p⁵4d² configurations of W³⁷⁺ ion. The atomic data, namely, the transition wavelengths, spontaneous emission rates and oscillator strengths for the electric dipole, electric quadrupole and magnetic dipole transitions among and within the levels of these configurations are tabulated.     

安全棒系统试验样机冷、热态性能试验研究

安全棒系统是空间核反应堆的关键设备之一，它具有结构紧凑、传动精度高、与反应堆容器连接接口多、工作温度高等特点。通过采用全尺寸的安全棒系统试验样机，确定了冷、热态性能试验方案，设计了专用的试验装置开展冷、热态性能试验。试验结果表明，安全棒系统试验样机运行正常，性能达到设计要求，为试验样机的抗震试验提供了条件，也为安全棒系统后续设计及试验装置的改进提供了参考依据。