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11.
在介绍了FIFO芯片基本结构和功能的基础上 ,介绍了一个有极大深度的高速先入先出(FIFO)存储器芯片IDT72V3680的功能特点和应用要点 ,给出了其在基于PCI总线的高速数据传输系统的运用实例以及与PCI总线的接口电路 相似文献
12.
J.J. Wei 《International Journal of Heat and Mass Transfer》2003,46(21):4059-4070
Experiments were performed to study the effects of the height and thickness of square micro-pin-fin on boiling heat transfer from silicon chips immersed in a pool of degassed or gas-dissolved FC-72. Six kinds of micro-pin-fins with the dimensions of 30 × 60, 30 × 120, 30 × 200, 50 × 60, 50 × 200 and 50 × 270 μm2 (thickness, t × height, h) were fabricated on the surface of a square silicon chip with the dimensions of 10 × 10 × 0.5 mm3 by using the dry etching technique. The fin pitch was twice the fin thickness. The experiments were conducted at the liquid subcooling, ΔTsub, of 0, 3, 25 and 45 K under the atmospheric condition. The results were compared with previous results for a smooth chip and three chips with enhanced heat transfer surfaces. The micro-pin-finned chips showed a considerable heat transfer enhancement in the nucleate boiling region and increase in the critical heat flux, qCHF, as compared to the smooth chip. The wall temperature at the CHF point was always less than the maximum allowable temperature for LSI chips (=85 °C). For a fixed value of t, qCHF increased monotonically with increasing h. The increase was more significant for larger t. The qCHF increased almost linearly with increasing ΔTsub. The maximum value of allowable heat flux (=84.5 W/cm2), 4.2 times as large as that for the smooth chip, was obtained by the chip with h=270 μm and t=50 μm at ΔTsub=45 K. 相似文献
13.
Effects of club size in the provision of public goods. Network and congestion effects in the case of the French municipalities 总被引:2,自引:0,他引:2
The article formalizes and measures the impact of club size on the quality of the public good provided to its members. Under
a general framework we describe various functional forms that allow either network or crowding effects. Mechanisms of provision
are that of a political process in which both the demand and the supply sides are considered. Estimations use the whole set
of French municipalities. The supply model performs better than the demand model in the case of small municipalities, while
for large cities the demand model has higher explanatory power. In so far as impact of city size on the quality of club goods
is concerned, crowding does appear, but it does so in different patterns. For small towns marginal congestion first decreases
then increases with population. Marginal congestion is decreasing for cities of intermediate size. For larger cities no significant
effects are observed.
Received: 27 June 2000 / Accepted: 20 August 2001
RID="*"
ID="*" We have received particularly helpful comments from the editor-in-chief and two anonymous referees. We also thank Danièle
Moret-Bailly for her friendly computational assistance. 相似文献
14.
In this paper we study a more general class of linear maps on fuzzy subsets of vector spaces than those on fuzzy subspaces. We obtain a version of the fundamental theorem of homomorphisms which applies to these pseudo-fuzzy linear maps. In the case of fuzzy subspaces, the results become those for fuzzy linear maps. We introduce the notion of magnification of pseudo-fuzzy linear mappings. It is shown that this notion behaves well with respect to the fundamental theorem and with respect to the composition of mapping. We note that the class of distribution functions of random variables naturally produces pseudo-fuzzy linear mappings, which are not fuzzy linear mappings. We observe that pseudo-fuzzy linear mappings are examples of gain relations. We consider general properties of these relations as well as many other examples. From these results additional properties of pseudo-fuzzy linear mappings are obtained. 相似文献
15.
16.
Karin Bucher Jens Mende Michael Mehring Martin Jansen 《Fullerenes, Nanotubes and Carbon Nanostructures》2007,15(1):29-42
A new Eu-endohedral fullerene cage, namely, Eu@C72, was synthesized, separated, and a single isomer, Eu@C72-I, has been isolated by multi-step HPLC for the first time and characterized by LDI-TOF mass spectrometry, UV-Vis and EPR spectroscopy. Additionally, a second isomer, Eu@C72-II, has been separated by HPLC and identified by LDI-TOF mass spectrometry. 相似文献
17.
18.
利用光学显微镜、X射线衍射仪、扫描电镜和力学万能试验机研究ZA72镁合金在不同固溶时间下T6处理后的显微组织和力学性能。结果表明:ZA72镁合金主要由α-Mg和分布在晶界的连续粗大的Mg32(Al,Zn)49和Mg7Zn3相组成,经过固溶处理后第二相呈细小的颗粒状分布在晶界和晶粒上,随着固溶时间的增加,第二相的尺寸和数量逐渐减小;经T6处理后,细小、弥散的白色点状强化相在晶界和晶粒内部弥散析出,并且随着固溶时间的增加,析出相的数量增加;通过T6处理后合金的力学性能有了明显的改善,合金的抗拉强度和显微硬度随固溶时间的增加呈先上升后下降的趋势,其中在固溶28 h后抗拉强度出现峰值308 MPa,相对于铸态提高了52.4%。 相似文献
19.
在温度343.15~383.15 K、压力14~22 MPa条件下,采用动态法测定分散紫27、分散蓝72在超临界CO2中的溶解度。并采用Chrastil半经验模型和AdMST半经验方程对实验结果进行关联,探讨影响分散染料在超临界CO2中溶解度的因素。结果表明:分散紫27在超临界CO2中的溶解度为2.69×10-6~7.35×10-6 mol/mol,压力越高,CO2密度越大,分散紫27在超临界CO2中的溶解度越高;随着温度的升高,分散紫27的溶解度先升高后降低;分散蓝72在超临界CO2中的溶解度为7.17×10-6~13.38×10-6 mol/mol,且随着温度的升高而升高,随着压力的升高而升高。 相似文献
20.