高校图书馆现实馆藏与虚拟馆藏的整合

分析了高校图书馆现实馆藏及网络信息资源的特点,提出了高校图书馆应开发网络信息资源,形成虚拟馆藏,并在此基础上整合图书馆的现实馆藏和虚拟馆藏。     

丰富精神力量构筑隐性文化

通过对隐性文化作用的阐述,讨论了如何把高校图书馆建成隐性文化的中心,发挥高校图书馆在校园文化建设中的作用。     

锂离子二次电池铜锡合金负极研究进展

与碳负极材料相比,锡基合金材料具有高容量、高密度的优势,有望成为新一代高容量锂离子电池的首选负极材料。Cu-Sn合金是研究最为广泛的锡基合金材料之一。综述了近年来该领域的研究进展,并对其发展方向进行了展望。     

燃烧室新型迷宫复合冷却结构冷却比较

以燃烧室新型迷宫复合冷却结构为研究对象,取燃烧室新型迷宫复合冷却结构的一块瓦块,并在某型航空发动机原型气膜冷却火焰筒相同位置切出尺寸相等的1块,在流量、吹风比与实际流场相同的条件下分别对它们的三维流场和壁温进行了数值模拟,获得了其壁温及冷却效率的分布规律,并与原型火焰筒进行了对比。研究表明:相对某型航空发动机燃烧室原型火焰筒,该冷却结构的冷却效率高,流场分布均匀,温度梯度小。     

静止、流动空-燃混合气的高能点火研究

在脉冲爆震发动机的实际应用中,高能点火相对于传统的点火方式有利于减少延迟时间、上升时间,缩短爆燃向爆震的转变距离。实验结果显示对于静止混合气延迟时间通常可以减少3倍,对于流动混合气(0.35 kg/s)延迟时间减少超过4倍,并且可以得到其他一些性能上的提高。进一步实验证明,如果反应物的化学当量比合适,则存在一个与其最适应的点火能量可以使爆燃向爆震的转变距离最小。     

江西龙宫洞不同季节土壤微生物群落结构比较

采用非培养法和传统培养法相结合,利用Illumina高通量测序技术对江西省九江市彭泽县龙宫洞微生物的16S rDNA和ITS相关区域进行测序及生物信息学分析,通过实时荧光定量PCR(qPCR)对洞穴土壤中细菌和真菌含量进行绝对定量,探究不同季节对洞穴土壤微生物群落结构的影响,同时观察相应可培养微生物分布情况.结果表明:...     

中外建设现代化图书馆的比较和启示

通过对中外图书馆的网络资源环境、管理和服务意识、人员和组织结构等方面的比较,提出了我国建设现代化图书馆的一些建议。     

Extraction of Signal Frequency in Laser Ranging of Space Target Based on FPGA

Aiming at the problems in a linear frequency modulation continuous wave(LFMCW) ranging lidar system, such as low signal-to-noise in echo beat frequency and difficult extraction of the signal frequency, a method with high-speed and high accuracy based on field programmable gate array(FPGA) is proposed. Firstly, the laser echo beat signal is sampled by high-speed analog to digital converter(ADC) and then processed in FPGA for data preprocessing. After the signal is processed by the 8 192-point FPGA will obtain the frequency spectrum and then apply the frequency spectrum to data processing and adaptive noise signal peak detection. These two steps realize the real-time and accurate extraction process of the target echo beat signal frequency. Finally, the spectrum data is transmitted to the host computer and processed through the external data acquisition board for real-time spectrum display. Experimental results show that data preprocessing and spectrum data processing can effectively suppress DC bias and system modulation noise. Adaptive noise peak detection can accurately divide the threshold contour according to the dynamic noise of the system and realize the detection of target signal peak. When the sampling clock of the system is 100 MHz, the time needed for each calculation of the spectrum is 81.92 μs, and the refresh rate of the spectrum reaches 12.2 kHz, which meets the real-time requirements of the system.     

Will Tax Burden Be a Stumbling Block to Carbon-Emission Reduction?Evidence from OECD Countries

The influence of taxation on the economy and society is everywhere. Given the fact that CO2 emission is closely connected with human activities, the question naturally arises whether the tax burden affects the carbon emissions. To address this issue, based on the data of 21 OECD countries over the period from 1991–2014, we use the ratio of tax revenue to GDP as a proxy of the tax burden and employ a panel quantile model with the non-additive fixed effects for analysis. The results suggest that the impact of the tax burden on carbon emissions is heterogeneous across countries based on the level of carbon emissions. Moreover, we find a stable U-shaped relationship between the tax burden and carbon emissions whether for countries with a high or low level of carbon emissions. Our findings suggest that moderate taxes could help reduce carbon emissions, but the effect of excessive taxation is the opposite.     

高校图书馆馆藏文献数字化和著作权保护

对高校图书馆馆藏文献数字化的目的、著作权保护问题和著作权保护采取的措施进行了探析,为图书馆法建设提出了一些建议。