数据科学与大数据技术专业建设思考与洞见     

刘颖  王爱莲  张可心  白鸽 《科教文汇》2020,(6):95-96

数据科学与大数据技术专业作为一门在新工科背景下崛起的新兴学科,受到了学术界与教育界的广泛关注。本文围绕新工科背景下数据科学与大数据技术专业建设问题和近四年新专业获批数据,剖析新专业建设面临的问题,提出基于角色差异化的数据科学与大数据技术专业人才培养体系。  相似文献   

On theory and methods for advanced detonation-driven hypervelocity shock tunnels     

Zonglin Jiang  Jinping Li  Zongmin Hu  Yunfeng Liu  Hongru Yu 《国家科学评论(英文版)》2020,7(7):1198

This study describes theory and methods for developing detonation-driven shock tunnels in hypervelocity test facilities. The primary concept and equations for high-enthalpy shock tunnels are presented first to demonstrate the unique advantage of shock tubes for aerodynamic ground-based testing. Then, the difficulties in simulating flight conditions in hypervelocity shock tunnels are identified, and discussed in detail to address critical issues underlying these difficulties. Theory and methods for developing detonation drivers are proposed, and relevant progress that has advanced the state of the art in large-scale hypersonic test facilities is presented with experimental verifications. Finally, tailored conditions for detonation-driven shock tunnels are described, laying a solid foundation to achieve long test duration. This interface-matching key issue encountered in developing shock tunnels has been investigated for decades, but not solved for detonation drivers in engineering applications.  相似文献   

Experiments on Cu-isotope fractionation between chlorine-bearing fluid and silicate magma: implications for fluid exsolution and porphyry Cu deposits     

Haihao Guo  Ying Xia  Ruixia Bai  Xingchao Zhang  Fang Huang 《国家科学评论(英文版)》2020,7(8):1319

Hydrothermal fluid is essential for transporting metals in the crust and mantle. To explore the potential of Cu isotopes as a tracer of hydrothermal-fluid activity, Cu-isotope fractionation factors between Cl-bearing aqueous fluids and silicate magmas (andesite, dacite, rhyolite dacite, rhyolite and haplogranite) were experimentally calibrated. Fluids containing 1.75–14 wt.% Cl were mixed together with rock powders in Au₉₅Cu₅ alloy capsules, which were equilibrated in cold-seal pressure vessels for 5–13 days at 800–850°C and 2 kbar. The elemental and Cu-isotopic compositions of the recovered aqueous fluid and solid phases were analyzed by (LA-) ICP–MS and multi-collector inductively coupled plasma mass spectrometry, respectively. Our experimental results show that the fluid phases are consistently enriched in heavy Cu isotope (⁶⁵Cu) relative to the coexisting silicates. The Cu-isotope fractionation factor (Δ⁶⁵Cu_FLUID-MELT) ranges from 0.08 ± 0.01‰ to 0.69 ± 0.02‰. The experimental results show that the Cu-isotopic fractionation factors between aqueous fluids and silicates strongly depend on the Cu speciation in the fluids (e.g. CuCl(H₂O), CuCl₂^– and CuCl₃²⁻) and silicate melts (CuO_1/2), suggesting that the exsolved fluids may have higher δ⁶⁵Cu than the residual magmas. Our results suggest the elevated δ⁶⁵Cu values in Cu-enriched rocks could be produced by addition of aqueous fluids exsolved from magmas. Together with previous studies on Cu isotopes in the brine and vapor phases of porphyry deposits, our results are helpful for better understanding Cu-mineralization processes.  相似文献   

职业教育人才培养的控制机制初探     

白继恩 《中国职业技术教育》2010,(6)

从前馈控制机制、过程控制机制、反馈控制机制三个方面探索职业教育如何适应市场机制的要求,并在过程控制中,针对职业指导提出了筛分养成理论。  相似文献   

我国高校图书馆电子文献数据库资源建设计量分析     

朱文岩  白崇远 《图书馆学研究》2007,(1):22-25

通过对我国30省市区912所高校图书馆所拥有的电子文献数据库资源状况的计量分析,发现我国目前高校图书馆电子文献数据库资源分布呈现金字塔型分布,具有十分鲜明的集中-分散特点,并对我国高校特色数据库建设的特点进行了分析和总结。  相似文献   

基于特征权重优化的改进KNN Web文本分类算法     

王煜  白石  王正欧 《情报学报》2007,26(5):643-647

本文提出了一种基于权重优化的样本相似度测量的距离公式,改进了KNN文本分类算法.KNN算法通常采用传统的VSM模型,各个特征具有相同的权重,使其不适应于文本处理的环境.本文首先根据神经网络理论,采用灵敏度方法对文本特征向量的每个特征的权重进行修正,并且采用降低运算量的神经网络特征选择方法进行第二次降维处理.然后根据同一特征对不同类别的文本类的分类作用不同,对距离公式中的特征权重进行进一步改进,从而进一步提高了KNN文本分类算法的精度.  相似文献   

我与刘国钧先生——我与老一辈文献分类学家(回忆录)之四     

白国应 《江西图书馆学刊》2007,37(4):1-3

介绍了刘国钧先生的生平及其图书馆学学术成就.  相似文献   

CSI模型适用性分析     

甘利人  白晨 《数字图书馆论坛》2007,(12):8-13

文章在阐述Oliver顾客满意模型形成机理的基础上,分析、比较了有形商品消费与科技用户信息产品消费过程中的差异性,由此为CSI模型的引用借鉴提供支持.  相似文献   

男子武术套路运动员皮纹特征的研究     

姜娟  白威 《上海体育学院学报》2002,26(1):68-70

采用双手皮纹测试观察法，对40名优秀男子武术套路运动员的指端纹型、各类指端纹型频率、指端纹型对应格局、指端嵴纹总数等7个皮纹单项指标进行调查和统计分析。结果发现，优秀男子武术套路运动员在许多单项指标上，有别于普通人群和其它项目的运动员。  相似文献   

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白广琴 《图书情报工作》1995,39(6):49-51

在分析了《四库全书总目》分类法及其局限性的基础上,阐述了用《中图法》类分《四库全书》的必要性,提出按汉语拼音音序编排书名及著者姓名索引的可行性。  相似文献