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排序方式: 共有826条查询结果,搜索用时 26 毫秒
1.
Karimi Bayan Chang Yu-Cheng Pekola Jukka P. 《Journal of Low Temperature Physics》2022,207(3-4):220-225
We discuss the temperature dependence of a common low temperature local thermometer, a tunnel junction between a superconductor and a normal metal (NIS junction). Towards the lowest temperatures its characteristics tend to saturate, which is usually attributed to selfheating effects. In this technical note, we reanalyze this saturation and show that the temperature independent subgap current of the junction alone explains in some cases the low temperature behavior quantitatively.
相似文献2.
Staub Adrian; Rayner Keith; Pollatsek Alexander; Hy?n? Jukka; Majewski Helen 《Canadian Metallurgical Quarterly》2007,33(6):1162
Readers' eye movements were monitored as they read sentences containing noun-noun compounds that varied in frequency (e.g., elevator mechanic, mountain lion). The left constituent of the compound was either plausible or implausible as a head noun at the point at which it appeared, whereas the compound as a whole was always plausible. When the head noun analysis of the left constituent was implausible, reading times on this word were inflated, beginning with the first fixation. This finding is consistent with previous demonstrations of very rapid effects of plausibility on eye movements. Compound frequency did not modulate the plausibility effect, and all disruption was resolved by the time readers' eyes moved to the next word. These findings suggest (contra Kennison, 2005) that the parser initially analyzes a singular noun as a head instead of a modifier. In addition, the findings confirm that the very rapid effect of plausibility on eye movements is not due to strategic factors, because in the present experiment, unlike in previous demonstrations, this effect appeared in sentences that were globally plausible. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
A heat balance reaction calorimeter was used to obtain information about the most informative process parameters in polymerizations carried out with Et[Ind]2ZrCl2-methylaluminoxane catalyst. The viscosity of the reaction mixture was found to increase dramatically during the homopolymerization of ethylene, but it could be controlled through appropriate selection of the reaction mixture medium. The mass transfer between the gas and liquid phases was the rate-determining step for the polymerization when the reaction mixture-based Reynolds number was below 2.500. The limited mass transfer between the gas and liquid phases was caused by the intensive activity of the metallocene catalyst and the increased viscosity of the reaction mixture. 相似文献
4.
泛在电力物联网(UPIoT)是2019年国家电网公司提出的在电力系统各个环节中应用移动互联、人工智能等先进技术,实现万物互联、人机交互的全景信息高效处理网络系统.文章通过分析并设计具有中国特色的基于泛在电力物联网的二次设备全景信息感知系统,从而为下一代二次系统的升级改造提供必要的大数据和信息载体,探索了其应用于变电二次专业大数据应用与分析的可行性,为实现"碳达峰、碳中和"提供更为精准的能源调配信息系统. 相似文献
5.
Kshama Motha Ulla Hippi Kimmo Hakala Maija Peltonen Vuokko Ojanper Barbro Lfgren Jukka Seppl 《应用聚合物科学杂志》2004,94(3):1094-1100
This article reports a study of some functionalized polyolefins evaluated as compatibilizers in polyethylene nanocomposites. The functionalized polymers were prepared by direct metallocene‐mediated copolymerizations of ethylene and a functional comonomer. The prepared nanocomposites were evaluated for mechanical and barrier property enhancement. A good combination of mechanical and barrier properties was obtained with the metallocene‐based functionalized polyethylene. The toughness–stiffness balance was better than or comparable to that achieved with conventional functionalized polymers such as maleic anhydride grafted polyethylene. The results also indicated that these metallocene‐based functionalized polyolefins, when used as compatibilizers, could have relatively higher molar masses and lower functionality than those of conventional post‐reactor‐modified compatibilizers, and so the drawbacks associated with the latter could be avoided. Their inherent properties could also further improve the final nanocomposite properties. This was attributed to the more homogeneous nature of metallocene‐catalyzed polymers in comparison with post‐reactor‐modified products. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1094–1100, 2004 相似文献
6.
In this study, we explored how stereoscopic depth affects performance and user experience in a mobile device with an autostereoscopic touch display. Participants conducted a visual search task with an image gallery application on three layouts with different depth ranges. The task completion times were recorded, and the participants were asked to rate their experiences. The results revealed that the image search times were facilitated by a mild depth effect and that too great a depth slowed search times and decreased user-experience ratings. 相似文献
7.
Ville Alopaeus Jukka Koskinen Kari I. Keskinen 《Chemical Engineering Communications》2003,190(11):1468-1484
A simulation model has been developed to model drop populations in a mixed tank. A multiblock mixed tank model has been used with the drop population balance equations developed in the literature. The drop breakage and coalescence functions used in the population balance model take into account the local turbulent energy dissipation values. The drop breakage and coalescence function parameters are fitted against drop size measurements from dense liquid-liquid dispersions, which were assumed fully turbulent. Since the local turbulence and flow values of a mixed tank are used in the present model, the fundamental breakage and coalescence phenomena can be taken into closer examination. Furthermore, the present model is capable of predicting inhomogeneities occurring in a mixed tank. It is also considered as an improved tool for process scale-up, compared to the simple vessel-averaged population balance approach, or use of correlations of dimensionless numbers only. The present model can use two sources of data for fitting parameters in the drop rate functions. One is the transient data of the measured drop size distribution as the impeller speed is changed. The other is the time-averaged data measured at different locations of the mixed tank. Different flow regions can be chosen from direct measurements or from the CFD simulations in a straightforward manner. CFD flow simulation results can be used when no experimentally obtained flow conditions are available. This is especially useful for nonstandard vessels, such as reactors containing cooling coils. 相似文献
8.
推动区域均衡协调与可持续发展是我国的重大战略之一,植被净初级生产力(NPP)对生态环境是否可持续发展起着重要作用。以“胡焕庸线”为界把我国分为东、西部,从像元尺度和县级行政单元研究分析我国NPP、人口以及人均NPP时空变化,尤其是东、西部的区域差异。结果表明:我国人口增长较快,从1982年的10.05亿增长到2017年的13.95亿,以“胡焕庸线”为界的西部占比由5.91%增长到6.42%;我国NPP整体呈现增长的趋势,总量由1982年的2.69 Pg C增长到2015年的3.24 Pg C,增长率为16.60 Tg C/a,其中东部增长率12.30 Tg C/a是西部(4.30 Tg C/a)的近3倍;西部人均NPP远大于东部与全国,1982、2000、2010、2017年西部与全国人均NPP持续处于下降的状态,但下降速率略有放缓,东部人均NPP则在2017年首次出现增长。据此可知我国整体生态环境处于恢复的状态,但不同区域之间差异较大,因此在相关政策制定方面应该充分考虑区域差异性,以实现我国生态环境的区域协调发展。 相似文献
9.
基于压电本构方程,建立了压电弹性复合驱动膜的机电耦合模型,利用ANSYS软件对压电复合膜进行了静态及一阶模态分析,对比分析了空心与实心PZT复合膜片的驱动能力,分别讨论了复合膜厚度、压电膜与弹性膜直径比等结构参数对膜片振动挠度的影响,获得了压电层与弹性层最佳粘贴比. 相似文献
10.
N80钢CO2腐蚀产物膜研究 总被引:7,自引:7,他引:7
在模拟油田CO2腐蚀环境下,用XRD、EDS和SEM研究了N80钢腐蚀产物膜的形成与发展情况。结果表明,在本试验条件下N80钢CO2腐蚀产物膜对基体具有一定的保护作用,可以降低腐蚀速率。腐蚀产物膜分3层,讨论了3层膜的结构特征与形成机理。初步研究了腐蚀产物膜的破坏特征。腐蚀产物膜的晶体类型是(Fe,Ca)CO3复盐。 相似文献