为信息之舟保驾护航——6款小功率非后备式UPS电源评测

一、评测背景 UPS不间断电源是计算机重要的外围设备之一。在今天的社会里,各个角落无不渗透着信息技术的血脉,计算机对人们工作和生活的影响愈来愈大。作为为信息的传输、处理和存取保驾护航的UPS电源在滚滚而来的信息大潮中显得并不那么招摇扎眼,然而它却维系着信息时代的每一个关键,默默地保护着信息之源长流不息。     

Experimental study of density gradient-driven micro-instabilities and the confinement degradation during H-mode in EAST

A broadband(BB) mode is observed by collective Thomson scattering diagnostics in repeatable shots of EAST and analyzed for the first time. This BB mode usually grows during L–H transitions,featuring a BB quasi-coherent mode with increasing frequency. During H-mode operations, it is characterized by steady-state BB in the high-frequency range( f ～ 200–2000 k Hz), at the electron scale(k_θρ_s= 1–2), mainly driven by the density gradient, and is sensitive to the value of ηein th...     

编辑推荐

在参加此次评测的8000元以下别的数码相机中,柯达DC290的售价是10款产品中最高的,但硬件性能与图像的表现力也是最出色的之一,在色卡图,线条图,实物图的对比中我们可以看出插值运算出的230万像素的明显优势。 DC290随机附带的存储卡为20MCF卡,也是所有参测相机中容量最大的,最多可存储220张普通画质的照片。DC290还采用了柯达专利色彩管理技术“True Color”,能使图像表现出绝佳的亮丽色彩与清晰画     

二次再热超临界机组热力系统热经济性计算模型的研究

以常规热平衡方法和等效热降的基本理论为基础，经过严格的数学推导，建立了既能用于其单位新蒸汽俘功又能用于循环吸热量计算的二次再热超临界机组热力系统通用计算模型，实例计算结果与常规法完全一致，为此类机组热经济性与局部因素的快速准确定量计算奠定了基础，并可应用于其它任何凝汽式火电机组热力系统。     

滑压运行机组最佳定期排污负荷的研究

以滑压运行状态下锅炉汽包质量平衡方程和杂质平衡方程为基础,根据汽轮机功率方程和变工况特性,首次推导出了炉水杂质含量下降率与机组负荷及其定期排污投用时间的理论关系式,为定期排污达到最佳效果奠定了理论基础.滑压运行状态下300 MW机组定期排污的实际试验结果证明了相应理论分析结论的正确性.     

外置式蒸汽冷却器机组热力系统循环吸热量计算的研究

以常规热平衡方法为基础,经过严格的数学推导,首次将等效热降理论应用于外置式蒸汽冷却器机组热力系统循环吸热量计算的研究,并提出了相应的数学计算模型。经实例验证,该数学模型简捷、准确,为外置式蒸汽冷却器机组热力系统热经济性的定量计算和在线诊断奠定了基础。     

Effect of Cold Plasma Treatment on Seed Germination and Growth of Wheat简

This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential （6.0%） and germination rate （6.7%） compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Com- pared with the control, plant height （20.3%）, root length （9.0%） and fresh weight （21.8%） were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content （9.8%）, nitrogen （10.0%） and moisture content （10.0%） were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t-ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield.     

长距离输水管线压力波动预止阀开阀时间对突然停泵水锤低压的影响

针对长距离输水系统事故停泵后易导致水柱分离及产生具有破坏性的断流再弥合水锤的现象,建立了突然停泵管道系统气液两相水锤计算模型及其边界条件,并结合某工程实例,应用特征线法对采用注气微排阀和压力波动预制阀防护措施的防护效果进行数值模拟,对压力波动预止阀在不同开阀时间下管线的负压变化进行比较,得到通过采用延迟开阀时间可有效避免因压力波动预止阀的动作而引起的系统管路负压恶化发生汽化的结论,对装设有压力波动预止阀的输水系统的泵站水锤防护具有重要参考价值。     

CO2 laser collective Thomson scattering diagnostics on the HT-7 tokamak

A CW CO2 laser collective Thomson scattering diagnostics was developed to measure plasma density fluctuations on the HT-7 tokamak. The design and construction of CO2 laser scattering apparatus is described. The laser source is a continuous-wave CO2 laser with a cavity length of 1.9 m and a power output of about 10 W at 10.6 μm. The k-resolution of the system is △k ≈ 3.2 cm^-1. The preliminary data from the diagnostic is presented.