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961.
An inductively coupled (ic) radio-frequency (rf) stabilized argon plasma was generated in a quartz tube using a 7 MHzrf generator. The electrical and thermal powers were measured and the efficiency of energy conversion was computed. The results
indicate that for a constant power input, there is an optimum argon flow rate for which maximum energy conversion efficiency
occurs. 相似文献
962.
Intergranular stress corrosion cracking(ISCC) of α-brass in neutral Mattsson's solutionwas found to be controlled by an unusual"W"-shaped galvanic cell whose cathode is thegrain boundary oxide film (G.B.0. film) andsurface film and the anode is fresh metal atthe cracked tip on both sides of the G.B.0.film. Redox reactions involved in the cellhave been proposed here. According to thismdel, initidtion of ISCC is caused by therupturing of surface film along grain boundaries,thus forming a galvanic cell. Propagation ofISCC resulted from alternate advances of G.B.0.film and dissolution on both sides of G.B.0.film caused by the effect of electrochemicalreaction. This work developed an effective approachto investigate the embrittlement process atthe tip of the crack, by increasing the lengthof the embrittlement region through constantstrain test and distinguishing the morphologyand the nature of the corrosion products byoptical microscopy and scanning electronmicroscopy (SEH). 相似文献
963.
The behavioral and electrophysiological activity of a mimic [(Z,E)7,9,11-dodecatrienyl formate] of the major sex pheromone component [(Z,E) 9,11,13-tetradecatrienal] of carob moth was assessed. Wind-tunnel bioassays demonstrated that the formate was as effective as natural gland extracts, and significantly more effective than the trienal alone or than the trienal blended with two minor pheromone components, in evoking source contact. Dispensers containing the formate were as effective as trienal-containing blend lures in attracting males when placed at the same dosage in traps in date gardens. Single-cell recordings showed that at least two olfactory neurons, differentiated by spike amplitude, are located in the long trichoid hairs on male carob moth antennae. Dose-response relationships indicated that puffs from cartridges loaded with at least 0.1 g of the formate or of the trienal were necessary to elicit spiking by either the small or the large-spiking cell within a sensillum. Cross-adaptation studies demonstrated that both compounds stimulated the same large-spiking cell. The frequencies of spikes evoked from the large cell when stimulated by emissions from 0.1-g, 1-g, or 10-g cartridges of either the formate or the trienal were not significantly different, suggesting that the formate is an effective mimic of the trienal at the antennal receptor cell level. 相似文献
964.
The surface structure of the oxidized and ammonia dissolved MoO3/-Al2O3 samples and the adsorption characteristics of the sulfided samples were investigated by Laser Raman Spectroscopy (LRS) and Low Temperature Infrared Spectroscopy (LTIR) techniques.It was verified that there were two kinds of coordinated unsaturated Mo sites (denoted as MoA(CUS) and MoB(CUS)) on the surface and the precursors of MoA(CUS) and MoB(CUS) were Mo(O) and Mo(T), respectively. It was also concluded that MoA(CUS) sites could adsorb NO and CO, while MoB(CUS) could adsorb CO only. The surface concentration of MoA(CUS) might be far smaller than that of MoB(CUS). 相似文献
965.
Thermophysical properties of molten semiconductors are reviewed. Published data for viscosity, thermal conductivity, surface tension, and other properties are presented. Several measurement methods often used for molten semiconductors are described. Recommended values of thermophysical properties are tabulated for Si, Ge, GaAs, InP, InSb, GaSb, and other compounds. This review shows that further measurements of thermophysical properties of GaAs and InP in the molten state are required. It is also indicated that a very limited amount of data on emissivity is available. Space experiments relating to thermophysical property measurements are described briefly.Nomenclature
Density
-
C
p
Specific heat
-
Kinematic viscosity
-
Dynamic viscosity=
-
Thermal diffusivity
-
Thermal conductivity=Cp
-
Volumetric thermal expansion coefficient
-
Surface tension
-
d/dT
Temperature coefficient of surface tension
-
g
Gravitational acceleration
-
T
Temperature
-
T
Temperature difference
-
L
Characteristic dimension 相似文献
966.
K. Balcerek Cz. Marucha J. Rafałowicz R. Wawryk 《International Journal of Thermophysics》1992,13(6):1085-1096
A universal curve relating the maximum of thermal conductivity and its respective temperature with the residual electrical resistivity has been proposed for metals and dilute alloys. Based on the equation of that curve, a comparative analysis of selected literature data of thermal conductivity of metals, which have residual electrical resistivity in the range 10–11<0<10–5. cm, have been performed. Using the data for 33 metals, confirmation of the Wiedemann-Franz law for the impurity component/T of thermal conductivity was obtained, which means that th/el1, where
th and
el are the parameters of the electron-lattice defect interaction obtained from measurements of thermal and electrical conductivity, respectively. Examples of the failure of the Wiedemann-Franz law are also presented, exhibiting the values of
th/el in the range 0.16 to 25. Measurements of thermal conductivity in the range 2 to 20 K and determination of the residual electrical resistivity for the samples of Cd doped with Zn and quenched were performed, resulting in values
th/el1. 相似文献
967.
The mathematical model that describes a dynamic thermal conductivity experiment is reconsidered by taking into account the role of thermal expansion. Two differential equations are presented that take into account the various physical phenomena occurring in a long thin rod directly heated by a current pulse. One of the two equations keeps variables space and time completely separate and is particularly useful for computer simulations.Paper presented at the Second Workshop on Subsecond Thermophysics, September 20–21, 1990, Torino, Italy. 相似文献
968.
969.
提出利用均衡化特征匹配来进行非刚性细胞形体跟踪的方法。采用重启动的随机游走方法建立并求解特征匹配概率模型,利用双向均衡方法对匹配邻接矩阵进行均衡化处理,得到指定目标与待跟踪目标之间的精确匹配,以获得目标的定位跟踪结果。同时利用特征匹配结果进行目标的自动标定,并应用图像分割方法进行目标的精确轮廓跟踪。实验结果表明,将该方法应用于视频中动态背景下的运动细胞形态跟踪时,在背景相似度较高及目标迅速移动的条件下,表现出了良好的性能,与同类方法相比可获得较高的定位精度以及更为准确的目标轮廓。 相似文献
970.
大学生物品交换系统的宗旨在于不求回报无偿付出,在充分利用各种资源的同时,培养学生的勤俭节约意识和"低碳"意识,加强学生之间的联系与互动,促进节约型校园的发展,并且符合近年来一直倡导的"和谐校园"与"低碳校园"的要求。系统基于B/S结构,采用ASP作为系统开发语言,使用SQL SERVER 2000数据库作为整个交易系统的数据库服务器,提供数据存储和调用,实现基于B/S结构的大学生物品交换系统。 相似文献