技术商品综合计价模型探讨

本文综合考虑影响技术商品计价的各种因素,分别建立了技术商品买,卖双方的理论、上限、下限、实际计价模型,并形象地给出技术商品买卖双方成交图示。     

C语言在数据库中的应用

根据ＤＢＦ数据文件的存储特点,本文利用Ｃ语言读取数据库文件,并对数据库信息进行加密。     

稀土氧化物负载CuO催化剂的CO氧化活性和还原性能

考察了稀土氧化物负载CuO催化剂的CO氧化活性和还原性能,发现CuO／CeO2催化剂具有很高的CO氧化活性,65℃时,CO转化率可达95％．     

电磁矢势A的认识

电磁矢势反映了场的能量、动量,而且在量子水平上可通过实验对进行直接观测,因此应该是具有物理意义的物理量。     

Fuzzy幂集格(非汉字符号)(X)中的Brouwer伪补

讨论Fuzzy幂集格■（X）中的Brouwer伪补的21种型式,并建立了这种伪补的若干性质．     

从电子阅览室的设立谈参考服务工作的改革

以武汉大学图书馆为个案,分析了其电子信息服务的实效,并从宏观上就电子信息服务的未来预测、存在问题与发展对策作了进一步探讨.     

抗战时期上海的"代价券"

第二次世界大战爆发以后,在东南亚,尽管日本侵略者以其军事优势占领了许多国家和地区,但各国人民顽强抵抗,在前方战场和沦陷区内仍与之作不懈的殊死斗争.     

数字图书馆的知识产权保护初探

介绍了国外对于数字版权问题的观点、做法, 阐述了对数字化图书馆版权问题的观点, 即在法律上首先应对数字的复制概念作出具体的界定第二必须明确图书馆合理使用的范围第三如果要向读者提供数字化作品的拷贝, 必须经过版权人的授权。在技术上也应该在现有条件下, 采取有效的措施防止侵权。     

Co13O8—metalloxocubes: a new class of perovskite-like neutral clusters with cubic aromaticity

Exploring stable clusters to understand structural evolution from atoms to macroscopic matter and to construct new materials is interesting yet challenging in chemistry. Utilizing our newly developed deep-ultraviolet laser ionization mass spectrometry technique, here we observe the reactions of neutral cobalt clusters with oxygen and find a very stable cluster species of Co₁₃O₈ that dominates the mass distribution in the presence of a large flow rate of oxygen gas. The results of global-minimum structural search reveal a unique cubic structure and distinctive stability of the neutral Co₁₃O₈ cluster that forms a new class of metal oxides that we named as ‘metalloxocubes’. Thermodynamics and kinetics calculations illustrate the structural evolution from icosahedral Co₁₃ to the metalloxocube Co₁₃O₈ with decreased energy, enhanced stability and aromaticity. This class of neutral oxygen-passivated metal clusters may be an ideal candidate for genetic materials because of the cubic nature of the building blocks and the stability due to cubic aromaticity.     

Effect of Twinning on Chinese and English Vocabulary Knowledge

Vocabulary knowledge was tested in a native (Cantonese-Chinese) and foreign (English) language in 150 twins and 150 singletons aged 6–11 years, matched on age, gender, grade level, nonverbal intelligence, parents’ education, family income, and number of siblings and household members. The singletons clearly outperformed the twins on the native vocabulary, but this “twinning effect” was much less noticeable for the foreign vocabulary. The effect on English vocabulary was further reduced after exposure to English at home was controlled. Given that these participants learned most of their English in school rather than home, the present findings support the notion that the twinning effect is associated with increased competition for family interaction in twins compared with singletons.