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1.
Xiaojun Xie Yonghong Cheng Hong Wang Qian Wang Xiaolin Chen Caixin Sun 《Ceramics International》2008,34(4):689-693
In the ideal A2B2O6O′ pyrochlore structure, the x-value of O atom position is a variable parameter. In Bi1.5ZnNb1.5−xTaxO7 (BZNT) cubic pyrochlores, the x-values alter with the different compositions of Nb/Ta. In this work, a series of initial models for BZNT were established by analyzing X-ray diffraction data. Then three structure modifying methods, including Rietveld refinement, Rietveld refinement with energy and geometry optimization based on quantum mechanics, were employed to obtain the precise models using Materials Studio. Moreover, the reflectivities of BZNT were computed by quantum mechanical simulation based on the refined models. Comparing the simulation results from different modifying models with the experimental results, it is found that Rietveld refinement with energy optimization is the most accurate method for BZNT pyrochlores. According to the simulation results, the different reflectivities correspond well with various x-values of O atom positions in BZNT pyrochlores. 相似文献
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基于凸凹信号的网格分割 总被引:2,自引:0,他引:2
网格分割在网格参数化、纹理atlas图等几何处理问题中有着重要的应用,提出一种基于顶点或面凸凹信号的简单高效的网格分割算法,基于均匀支撑半径的顶点凸凹信号分析将顶点分为平坦点、凸点、凹点和特征点,先从平坦点进行平坦区域扩展,再从剩下的凸凹点出发进行凸凹区域扩展,最后根据顶点和边界边的光滑度进行区域竞争扩展;对于未能完全分割的简化程度高的模型,基于面的凸凹信号采用类似的过程进一步完成最后的分割,该算法可以快速地进行网格分割并能较好地保持网格特征,特别适用于CAD模型的分割。 相似文献
4.
Qin Yang Bingqing Ge Pei Yuan Shuting Luo Hongwei Zhang Zhengyu Zhao Jiujun Zhang Shidong Wang Xiaojun Bao Xiangdong Yao 《Advanced functional materials》2023,33(25):2214588
Electrocatalytic hydrogenation (ECH) is a burgeoning strategy for the sustainable utilization of hydrogen. However, how to effectively suppress the competitive hydrogen evolution reaction (HER) is a big challenge to ECH catalysis. In this study, amine (NH2 R)-coordinated Pd nanoparticles loaded on carbon felt (Pd@CF) as a catalyst is successfully synthesized by a one-step solvothermal reduction method using oleylamine as the reducing agent. An exceptional ECH reactivity on benzaldehyde is achieved on the optimal Pd@CF catalyst in terms of a high conversion (89.7%) and selectivity toward benzyl alcohol (89.8%) at −0.4 V in 60 min. Notably, the Faradaic efficiency for producing benzyl alcohol is up to 90.2%, much higher than that catalyzed by Pd@CF-without N-group (41.1%) and thecommercial Pd/C (20.9%). The excellent ECH performance of Pd@CF can be attributed to the enriched electrons on Pd surface resulted from the introduction of NH2 R groups, which strengthens both the adsorption of benzaldehyde and the adsorbed hydrogen (Hads) on Pd, preventing the combination of Hads to form H2, that is, inhibiting the HER. This study gives a new insight into design principles of highly efficient electrocatalysts for the hydrogenation of unsaturated aldehydes molecules. 相似文献
5.
针对我校信息对抗技术专业的发展方向和培养定位,结合我校办学特色,提出该专业的知识体系和实践教学体系。通过对当前现状和存在问题的分析,研究探讨符合实际的专业教学和人才培养模式。 相似文献
6.
分析了计算机应用基础课程传统教材的局限性,提出了基于工作过程来开发新的计算机应用基础教材的基本思想.从实践出发,对计算机应用基础教材项目分析确定、任务过程设计、教材设计等环节进行了论述,以体现该教材的鲜明特色.新开发的教材应用后,学生的学习水平与技能得到了极大的提升,从而为基于工作过程的教材开发提供了一种基本思路. 相似文献
7.
Three-dimensional quantitative structure-activity relationship (3D-QSAR) models were developed using comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) on a series of agonists of thyroid hormone receptor beta (TRbeta), which may lead to safe therapies for non-thyroid disorders while avoiding the cardiac side effects. The reasonable q(2) (cross-validated) values 0.600 and 0.616 and non-cross-validated r(2) values of 0.974 and 0.974 were obtained for CoMFA and CoMSIA models for the training set compounds, respectively. The predictive ability of two models was validated using a test set of 12 molecules which gave predictive correlation coefficients (r(pred)(2)) of 0.688 and 0.674, respectively. The Lamarckian Genetic Algorithm (LGA) of AutoDock 4.0 was employed to explore the binding mode of the compound at the active site of TRbeta. The results not only lead to a better understanding of interactions between these agonists and the thyroid hormone receptor beta but also can provide us some useful information about the influence of structures on the activity which will be very useful for designing some new agonist with desired activity. 相似文献
8.
VB因其简单易学,功能强大而倍受测控软件开发人员的青睐。本文针对作者在开发点火线圈测试台软件的过程中遇到的重点、难点问题—串口通讯、端口读写、数据库操作等,介绍了用Visual BasiC 6.0实现的方法。 相似文献
9.
Lai Huasheng Chen Baojiu Wang Linsheng Xu Wu Wang Xiaojun Xie Yihua Ren Xinguang Di Weihua 《中国稀土学报(英文版)》2005,23(6)
White body-color (Y, Gd)BxV1- xO4-x :Eu3 phosphors were prepared by coprecipitation reaction. Under VUV excitation at 147 nm, the red emission colorimetric purity of (Y, Gd)BxV1- xO4-x :Eu3 phosphor is much better than that of commercial PDP (plasma display panels) phosphor (Y, Gd)BO3:Eu3 . But its relative emission intensity is only about 90% of the commercial phosphor. 相似文献
10.
RTK技术在水下地形测量中的应用--以杭州湾跨海大桥的水下地形为例 总被引:1,自引:0,他引:1
以杭州湾跨海大桥的水下地形测量为例,简要介绍了水下地形测量主流技术的基本原理和工作流程以及影响测量精度的两大关键技术:测深和定位同步以及坐标转换,并结合实际的测量数据,重点阐述了如何通过保证测深和定位同步以及坐标转换精度来保证水下地形测量的精度. 相似文献