钢塔的米式腹杆

介绍了钢管塔架米式腹杆体系的产生,对钢塔米式腹杆用钢量少、结构架简洁、稳固、高空作业方便、安全等特点进行了阐述,并分析了不宜采用该腹杆体系的一些建筑情况,为相关设计人员提供了参考。     

Formation and evolution of oxygen vacancies in ZnO white paint during proton exposure

The formation and evolution of oxygen vacancies in ZnO white paint during <200 keV protons exposure was investigated using photoluminescence spectroscopy. After irradiation, the shape of photoluminescence spectra changes little, but the peak height decreases. With increasing fluence, the amount of doubly ionized oxygen vacancies decreases, while that for the singly ionized oxygen vacancies increases. The former can trap electrons in the conduction bands to become the singly ionized oxygen vacancies, leading to that the latter gradually becoming the major defects induced by irradiation. The increase in content of singly ionized oxygen vacancies due to the irradiation can also promote an increase in the amount of absorbed oxygen in the paint, enhancing the quenching effect of photoluminescence and thus decreasing the photoluminescence peak.     

Radiation induced defects in BaBPO5:Ce and their role in thermally stimulated luminescence reactions: EPR and TSL investigations

Defect centers induced by gamma irradiation in Ce doped BaBPO₅ were investigated using EPR spectroscopy. From EPR studies, three phosphorous centered radicals were characterized on the basis of observed ³¹P hyperfine splitting and g values as , and radicals. In addition to this, two types of boron oxygen hole centers (BOHC) and O⁻ were also formed at room temperature. An intense broad signal in sample annealed in argon (g_⊥ = 1.9258 and g_‖ = 1.8839) was assigned to Ce³⁺ ions associated with the electron trapped at anion vacancy or nearby lattice defect. TSL studies showed two glow peaks, a relatively weaker one at 425 K and an intense one at 575 K. Spectral studies of the TSL glow peaks have shown that Ce³⁺ ion acts as emission center. From the temperature dependence of the EPR spectra of gamma irradiated samples, the glow peaks at 425 K and 575 K were attributed to thermal destruction of /O⁻ and BOHC, respectively, by trapping of electrons from elsewhere. The energy released in electron hole recombination process is used for the excitation of Ce³⁺ ions resulting in these glow peaks at 425 K and 575 K. The spectral studies of the TSL glow peaks have shown emission at 330 nm indicating Ce³⁺ acts as the luminescent centre. The trap depth and the frequency factor for the 425 K and 575 K peaks were determined using different heating rates method.     

Synthesis of KNaSO4:Tb and MgSO4:Dy phosphors for lyoluminescence dosimetry

KNaSO₄:Tb³⁺ phosphors were synthesized by melt technique with different concentration of Tb³⁺ ions and MgSO₄:Dy³⁺ phosphor is prepared by solid state diffusion method. Lyoluminescence and photoluminescence characterization of KNaSO₄:Tb and MgSO₄:Dy³⁺ phosphors are reported in this paper. Only one sharp peak is observed in the lyoluminescence (LL) glow curve and KNaSO₄:Tb(0.05 mol%) phosphor shows maximum efficiency. The LL intensity increases linearly with gamma ray dose. LL emission occurs in the blue and yellow region of the spectrum. Photoluminescence (PL) characterization of KNaSO₄:Tb(0.05 mol%) phosphor shows PL emission at 486 and 546 nm. These PL emissions from KNaSO₄:Tb³⁺ are due to ⁵D₄ → ⁷F₆ and ⁵D₄ → ⁷F₅ transitions of Tb³⁺ ion respectively. Lyoluminescence of MgSO₄:Dy³⁺ phosphor shows the high sensitivity to γ-ray exposure and LL emission observed at 486 and 572 nm in the blue and yellow emission of the spectrum is due to Dy³⁺ ion. Experimental results obtained in the present investigation show that KNaSO₄:Tb³⁺ and MgSO₄:Dy³⁺ phosphors are suitable as a lyoluminescence dosimetry phosphor for ionizing radiations.     

世界文化遗产大足石刻的价值再认识

目前．国际上关于世界文化遗产的理论研究有了很大的进展,特别是对其价值的认识达到了一个全新的高度。该文结合国际前沿的文化遗产研究理论对大足石刻世界文化遗产的价值认识的现状进行了分析,并尝试对大足石刻世界文化遗产地的价值进全面、综合地再认识。     

敦密断裂带构造特征与控煤规律

论述了敦密断裂带的发生，发展及演化特征。在演化过程中，断裂带严格控制了工岩系的沉积及时空展布，从而明确了找煤方向。     

《大公报·文学副刊》与中国早期比较文学

20世纪初期,中国比较文学作为一门独立学科登上了历史舞台,而创办于此时的《大公报·文学副刊》也促进了这门新生学科在中国的传播。从20世纪初期我国学界的状况来看,《大公报·文学副刊》构筑了完整的欧美文学知识谱系,强调全面地介绍欧洲文学;从我国当下的比较文学发展来看,对《大公报·文学副刊》的研究将有助于整合我国比较文学初期的学术资源,进一步规范我国比较文学的研究范式,促进我国文学中人文精神的发展。     

基于玄秘塔碑的柳体二级字库重组

提出一种基于玄秘塔碑的柳体二级字库重组方法。以柳公权的《玄秘塔》碑文为基础,将其原有的汉字拆分为所需部件,对部件进行编码,定义汉字的结构及区位信息编码。采用Visual C++语言设计汉字查询、合成、入库的界面程序,建立碑文二级字库。软件运行结果验证了该方法的可行性。     

米芾的书学实践在当代书法创作中的反思

米芾是中国艺术史上最杰出的人物之一,他广交友,善收藏,精书法,篆、隶、行、草、楷各体皆能,行草造诣尤深。立足临摹古典传统,勤学善思,奠定了米芾坚实的书法创作基础。植根于书法本体,继承传统,又重新构造传统,构建了米芾超然的书学理念。崇尚古人的创新精神,勇于否定和批判,形成了米芾鲜明的书法艺术风格。在东西文化的交融汇合下,米芾的创作实践对当下的传统书法艺术创作有着重要的借鉴意义。     

智能手机可用性清单的构建

目的创建一套更加适用于当今智能手机的可用性清单。方法选取10名可用性专家和11名手机熟练使用者运用启发式评估法来创建智能手机的可用性清单。我们选取14名在校大学生分别使用两款不同的手机来完成21个手机操作任务的实验,以验证该可用性清单的有效性。结果智能手机可用性清单包括基于任务的清单和基于界面的清单两个子清单。结论我们所创建的智能手机可用性清单可以有效地评估手机的可用性。