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991.
棒束通道中环状流气液界面行为的研究,能为压水堆的事故处理和沸水堆电厂的正常运行提供数据和理论支撑。本研究针对3×3棒束通道中环状流气液波状界面形式进行记录与分析,绘制详细的环状流流型图,并针对其形成机理进行分析。结果表明:棒束通道中的环状流主要有搅混型、未全润湿、平滑边界型、单一波状流、包状扰动波、带状扰动波和带状扰动波叠加液相丧失7种形式;单一波状流是当气相速度较高、液相速度较低时,气液界面上发生的有固定波峰和波谷、以固定速度向上运动的流动形式,其现象可通过Kelvin-Helmholtz型不稳定性理论来解释;当液相流量升高或气相流量减少时,发生单一波状流界面失稳,界面能量增加,进入到包状扰动波或带状扰动波阶段;当能量超过1.6 kPa2/Hz时,界面能量超过底层液膜束缚能力,产生液相丧失型环状流。 相似文献
992.
Understanding player behavior has an interest to computer games researchers and developers since it allows them to improve the design and implementation of computer games and also to ensure that players have the expected experiences. Currently this knowledge is not usually reported to players as feedback, although sometimes it is already used as an analysis tool. This paper presents a novel technology for automatically generating linguistic reports and immediate feedback from actions performed by players during play sessions. These reports allow developers to provide players with a more complete and personalized feedback about their behaviors, abilities, attitudes, skills or movements. In order to show and explore the possibilities of this new technology, we have incorporated it in the core of a computer game. We have evaluated positively that the incorporation of this kind of feedback into the core of YADY computer game allows us to improve the overall player experience. 相似文献
993.
车站建筑群作为轨道类交通体系中的一部分,具有城市代表性,它是城市基础性建筑。要把车站建筑工程与其他基础性工程视为同等重要的工作来考虑。在逐步完善和优化资源配置的过程中,最终建设与这个城市发展配套的现代化交通轨道衔接体系。 相似文献
994.
The paper investigates the medium-term self-healing performance of fiber reinforced cementitious composites with intrinsic crack-width control capability under natural weathering. The pre-cracked specimens with different damage levels are exposed to various humidity conditions, namely, water submersion, natural weathering, and a laboratory environment with constant humidity. The medium-term self-healing performance is evaluated using a resonant frequency test, tensile test, SEM, and EDX. It is concluded that the medium-term cracked specimens can moderately recover their mechanical properties within 90 days after being submerged in water or exposed to natural weathering. In particular, they are able to resume the multiple cracking behavior and exhibit a reloading strength larger than the preloading strength. Furthermore, the identified compositions of the medium-term healing products for specimens exposed to water and natural weathering conditions are similarly characterized. The reported results imply that effective medium-term self-healing can be realized in fiber reinforced cementitious composites with intrinsic crack-width control capability under natural weathering. 相似文献
995.
Abdollah Omrani Abbas Ali RostamiSepide Khostavan Yousef Vazifeshenas 《Composites Part A》2012,43(3):381-387
A novel nanocomposite consisting bisphenol A diglycidyl ether/1,4-Bis(3-aminopropoxy) butane (1,4-APB)/multiwall carbon nanotube (MWCNT) was synthesized and characterized. Kinetics of the reaction was described by applying differential scanning calorimetry (DSC) data to isoconversional methods of Flynn-Wall-Ozawa (FWO), advanced isoconversional method of Vyazovkin, and non-linear integral isoconversional algorithm (NLN). It was found that at the presence of MWCNT the thermal decomposition temperature increased by rising the curing temperature and time. Data from dynamic mechanical thermal analysis (DMTA) showed that the glass transition temperature of the cured nanocomposite is 7 °C higher than that value found for the system without carbon nanotube. Scanning electron microscopy (SEM) was used to observe the fracture surface morphology and results indicated evidence of the interfacial interaction improvement and adhesion strength due to good dispersion of MWCNT. 相似文献
996.
3G业务目前的流量经营是粗放式、流量包形式的营销。因此客户上网行为数据分析就成了拉动流量、提高精确性、针对性的必要数据,基于此,开发上网行为分析系统成为电信公司迫在眉睫的工作。因此电信运营商尽快建立自己的精细化营销体系,开展精细化运营工作,尽快从传统被动营销时代进入到新的主动运营时代,是本文重点探讨的内容。 相似文献
997.
The majority of research on cyberbullying has been conducted with middle school and high school students and has not focused on specific technology platforms. The current study investigated college student experiences with cyberbullying on Social Networking Sites (SNS). College students (N = 196) from a northwestern university shared their conceptualizations of what cyberbullying looked like on SNS. Some college students (19%) reported that they had been bullied on SNS and 46% indicating that they had witnessed cyberbullying on SNS. The majority (61%) of college students who witnessed cyberbullying on SNS did nothing to intervene. College students were also asked about their perceived responsibility when they witnessed cyberbullying on SNS. Two diverging themes emerged that indicated some college students believed their responsibility to intervene was circumstantial, while others believed there is a constant clear level of responsibility for college student cyberbullying bystanders on SNS. 相似文献
998.
针对大采高大倾角伪斜综采面初采期间老顶分段初次来压的矿压显现规律,结合工作面具体的地质生产条件及初采期间老顶破断特征,分析了大采高伪斜综采面老顶呈现分段初次来压的原因,并提出了相应的支架—围岩稳定性控制措施。 相似文献
999.
The tribological behavior of micro- and nano-crystalline diamond films is evaluated in dry sliding and water lubricating condition. The main wear mechanism is found to be abrasive wear mode induced by self-polishing. Non-diamond components and higher compressive residual stresses are detected in flat MCD films after dry sliding, in comparison to NCD. Origin of decreased friction coefficient in CVD diamond tribosystems under water lubrication is attributed to the effect of water on the formed graphic material and the chemisorbing of diamond surface with H2O, hydrogen or hydroxyl ions. For the MCD/NCD or NCD/MCD contact, the surface roughness of ball largely determines the stable friction coefficient in dry sliding, where NCD film usually presents higher wear rate. 相似文献
1000.
Co‐TiO2 nanocomposite coatings with various contents of TiO2 nanoparticles were prepared by electrodeposition in Co sulfate plating bath containing TiO2 nanoparticles. The influence of the TiO2 nanoparticles concentration in the bath, of the current density and of sodium dodecyle sulfate (SDS) as anionic surfactant on the morphology, composition, texture, roughness, and microhardness of the coatings was investigated. The morphology and composition of coatings were studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The phase structure of coatings was analyzed by X‐ray diffraction (XRD). The results showed that the maximum codeposition of TiO2 nanoparticles in Co matrix was around 4.5 vol% obtained in 60 g/L TiO2 in the bath, 30 mA/cm2 and 0.15 g/L SDS. The microhardness of coatings was increased up to 504 Hv by increasing TiO2 concentration in the bath to 60 g/L TiO2. The electrochemistry tests including potentiodynamic polarization and impedance spectroscopy revealed that by addition of TiO2 into Co matrix, the corrosion current density, polarization resistance, and charge transfer resistance of Co‐TiO2 coating were increased compared with Co coating. 相似文献