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151.
本文给出轴对称问题线元上高次分布源和偶极在无界域中的诱导速度势和诱导速度的计算公式,可供用分布奇点法求解轴对称势流问题时参考. 相似文献
152.
蒙特卡洛法速度谱的自动拾取 总被引:3,自引:3,他引:0
蒙特卡洛速度谱的自动拾取采用一种非线性优化的快速方法,所得叠加速度的精度可以满足常规地震资料处理中叠加的要求,转换为层速度后可用于叠前深度偏移成象,在给定初始速度模型前提下建立优化目标函数。采用蒙特卡洛非线性优化算法,以最大相似度量准则在考虑实际地质条件前提下给出速度约束条件,对初始速度模型加以扰动,自动寻找速度谱中叠加能量的全局最优解,从而获得合理的速度模型。实际地震资料处理的应用结果表明,自动拾取速度谱比常规的人工速度谱解释工作的效率大幅度提高。在SUN Ultra60机上,仅需1h即可完成2000km的地震资料的速度谱拾取任务,而且所获得的速度模型不受人为因素影响,转换所得的层速度模型用于叠前深度偏移后,获得了满意的成象效果。 相似文献
153.
一种蒸发式冷凝器的新型设计方法 总被引:3,自引:0,他引:3
蒸发式冷凝器设计方法的粗糙和繁琐限制其广泛应用,特别是限制其应用于民用和小型商用建筑中。针对上述问题,作者通过实验研究了蒸发式冷凝器的影响因素(进风湿球温度、最小截面风速和喷淋水量)对蒸发式冷凝器热质交换的影响。同时提出了一种新型设计方法,此方法简单,精度较高。适合工程设计、选型和生产应用。 相似文献
154.
155.
We have grown thin carbon films by pulsed laser deposition and have investigated the extent to which the properties of such
films, as well as the processes responsible for these properties, are laser wavelength dependent. Films were grown by ablating
material from a graphite target onto room temperature Si(100) substrates with 1064 and 248 nm laser radiation. The films were
analyzed byin situ electron energy loss spectroscopy and byex situ Raman spectroscopy. The results indicated that films grown with 1064 nm ablation were graphitic, while those grown with 248
nm radiation were diamond-like. We have also examined the mass and kinetic energy distributions of the particles ejected from
graphite by the two laser wavelengths. The results indicated that irradiation of graphite with 1064 nm laser radiation results
in the ejection of a series of carbon cluster ions C
n
+
(1 ≤ n ≤ 30) with mean kinetic energies less than 5 eV. Ablation of graphite with 248 nm radiation results in the ejection
of primarily C
2
+
and C
3
+
with mean kinetic energies of 60 and 18 eV, respectively. These results suggest that large, low energy clusters produce graphitic
films, while small, high energy clusters produce films of diamond-like carbon. 相似文献
156.
A bright electroless Ni-P deposition on AM50 magnesium alloy in a sulfate plating bath was proposed by using direct plating process with non-chromate pretreatment. The electroless Ni-P plating on AM50 magnesium alloy has an admirable appearance and good adhesion. The results indicate that the electroless Ni-P deposition with non-chromate pretreatment has better adhesion than that of zinc immersion coating. Anodic polarization curves indicate that the electroless Ni-P deposition obtained from the sulfate bath has similar corrosion-resistance to that obtained from basic nickel carbonate bath. The deposition process generates less pollutant by a non-chromate plating bath and is suitable for the magnesium alloys manufacture because of its low cost. The hardness of the electroless Ni-P plated AM50 is about HV 720.6 and HV 969.7 after heat treatments at 180℃ for 2 h. The wear resistance of Ni-P plated magnesium alloy specimens is about 5 to 9 times as high as that of bare magnesium alloys. 相似文献
157.
简要介绍了国内少有的干气催化部分氧化转化制氢工艺,重点讨论了转化水碳比的控制条件,对降低水碳比操作进行了有益地探讨。 相似文献
158.
Rui Morimoto Chisato Yokomori Akiko Kikkawa Akira Izumi Hideki Matsumura 《Thin solid films》2003,430(1-2):230-235
In this paper, bulk-Si metal–oxide–semiconductor field effect transistors (MOSFETs) are fabricated using the catalytic chemical vapor deposition (Cat-CVD) method as an alternative technology to the conventional high-temperature thermal chemical vapor deposition. Particularly, formation of low-resistivity phosphorus (P)-doped poly-Si films is attempted by using Cat-CVD-deposited amorphous silicon (a-Si) films and successive rapid thermal annealing (RTA) of them. Even after RTA processes, neither peeling nor bubbling are observed, since hydrogen contents in Cat-CVD a-Si films can be as low as 1.1%. Both the crystallization and low resistivity of 0.004 Ω·cm are realized by RTA at 1000 °C for only 5 s. It is also revealed that Cat-CVD SiNx films prepared at 250 °C show excellent oxidation resistance, when the thickness of films is larger than approximately 10 nm for wet O2 oxidation at 1100 °C. It is found that the thickness required to stop oxygen penetration is equivalent to that for thermal CVD SiNx prepared at 750 °C. Finally, complementary MOSFETs (CMOSs) of single-crystalline Si were fabricated by using Cat-CVD poly-Si for gate electrodes and SiNx films for masks of local oxidation of silicon (LOCOS). At 3.3 V operation, less than 1.0 pA μm−1 of OFF leakage current and ON/OFF ratio of 107–108 are realized, i.e. the devices can operate similarly to conventional thermal CVD process. 相似文献
159.
160.
E. V. Chernyshev E. N. Veprov V. A. Petrov S. L. Bogdanov T. Yu. Levina T. I. Petrova V. I. Kashinskii A. A. Zonov A. E. Verkhovskii 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2006,40(1):34-37
Results of a study of tube specimens cut from hot-water boilers show that film-forming octadecyl amine (ODA) used in the process
of preservation removes deposition from the surface of the metal. An ODA film is preserved on the surface after repeated washing
of the latter with hot water. The concentration of chlorides at the surface of the metal after treatment with ODA is lower
than before the treatment.
__________
Translated from élektricheskie Stantsii, No. 11, November 2005, pp. 15–18. 相似文献