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91.
本文首先介绍一种用于卵砾石地层钻进的新型针状硬质合金钻头的设计原理,而后简要说明其胎体配方组成机理。在分析胎体性能要求的基础上,选择了六组配方,对其进行抗弯强度、抗剪强度,硬度性能、冲击韧性、SEM照片等试验,优选了四号配方,试制了钻头。生产试验结果表明,这种新型复合型钻头钻进萝日砾石地层的平均时效1.89m/h、平均每回次进尺为2.3m,平均钻头寿命19.81m,具有实用和推广价值。 相似文献
92.
根据已知镍基合金成分和γ′相成分,运用分层宽容多目标优化法,分别计算了γ相成分及γ′相含量.优化测算过程的实现是通过建立使杠杆定律等式两端数值差最小和两相共格错配度最小的目标函数,并通过设置γ′相含量和基体相成分取值范围的约束条件而实现的.验证了该方法的可行性和准确性. 相似文献
93.
Many isotopic techniques can be applied to determine the relative immediate and residual effectiveness of P fertilizers. Using isotopes as tracers, the percentage of utilization by plants of the P derived from a fertilizer can be determined. However this is only possible during the three or four months after the application. Therefore, the P fertilizers may be classified only according to their relative immediate effectiveness. To also evaluate residual effect, which can be observed when more P is applied than is removed with harvest, isotopes of phosphorus can be used. This residual effect is determined by comparing pool sizes of bioavailable soil P in soils with and without P fertilizer aged in soil. The bioavailable soil P pool may be analyzed according to three isotopic experimental procedures which give access to either the A value, or the E value or the L value. The aims, the similarities and the differences between these three procedures, are examined. Some of the theoretical and practical constraints of each method are described in this paper; they must be followed in order to obtain reliable information for agronomic purposes. A method involves measuring the rate of isotopic exchange of phosphate ions in soil-solution systems maintained in steady-state. It is now possible to predict the effectiveness of P fertilizers, whatever their chemical form when this method is applied on soil samples where P fertilizers were applied.This paper was originally submitted as part of the special issue on Evaluation of the Agronomic Effectiveness of Phosphate Fertilizers through the use of Nuclear Related Techniques edited by F. Zapata 相似文献
94.
锂电极表面膜的组成和阻抗行为 总被引:1,自引:0,他引:1
介绍了锂电池中锂电极的表面膜的组成和阻抗行为,并根据其表面膜的阻抗行为提出了电化学模型。 相似文献
95.
影响磷石膏中残磷含量的主要因素分析 总被引:5,自引:1,他引:5
实现磷石膏的资源化,已经成为贵州省肥、磷化工企业可持续发展的重要影响因素;磷石膏中残磷的高含量不仅降低了磷酸的萃取率,同时影响磷石膏的资源化利用;分析了影响磷石膏化学成分的各种主要因素,并从磷石膏资源化的角度,讨论了磷石膏中的残磷及其影响因素;磷石膏成分随这些影响因素的不同而变化。 相似文献
96.
We have applied near-edge X-ray absorption fine structure (NEXAFS) to characterize the surface and bulk properties of LixNi1–xO catalysts. In our experimental set-up, NEXAFS spectra of powder materials could be obtained by measuring the intensity of either electron-yield or fluorescence-yield. While the electron-yield method is sensitive only to the top few atomic layers, the fluorescence-yield method can detect species up to a few thousands angstroms deep into the bulk structure. The ability to distinguish surface and bulk compositions is demonstrated in studies of a number of Li0.5Ni0.5O samples, of which the surface compositions vary as a function of preparation procedures. In addition, NEXAFS investigations following the reaction of LixNi1–xO with CH4 have also been carried out and the results indicate that the initial surface reaction intermediates are Li2CO3. 相似文献
97.
98.
KeShun Liu Frank Orthoefer Edward A. Brown 《Journal of the American Oil Chemists' Society》1995,72(2):189-192
Ten soybean genotypes grown in 1992 with seed size ranging from 7.6 to 30.3 g/100 seeds and maturity group V or VI were selected
and tested for oil and protein content and for fatty acid composition. In these germplasm, protein varied from 39.5 to 50.2%,
oil, 16.3 to 21.6%, and protein plus oil, 59.7 to 67.5%. Percentages of individual fatty acids relative to total fatty acids
varied as follows: palmitic, 11.0 to 12.8; stearic, 3.2 to 4.7; oleic, 17.6 to 24.2; linoleic, 51.1 to 56.3 and linolenic,
6.9 to 10.0. Seed size showed no significant correlations with individual saturated fatty acids, protein or oil content. However,
significant correlations were found between seed size and individual unsaturated fatty acids: positive with oleic, and negative
with linoleic and linolenic. Oil and protein content were negatively correlated with each other. Among the major fatty acids,
only the unsaturated were significantly correlated with each other: negative between oleic and linoleic or linolenic, and
positive between linoleic and linolenic. A subsequent study with soybeans grown in 1993 generally confirmed these findings.
Variation in relative percentages of unsaturated fatty acids andr values for most pairs of relationships were even higher than those obtained from the 1992 crop.
Presented at the 85th AOCS Annual Meeting and Expo, Atlanta, Georgia, May 8–12, 1994. 相似文献
99.
100.
能源多元化对保障国家能源安全,紧跟世界能源发展趋势,及时转变能源发展战略的意义重大。分类讨论替代燃料,分析其发展态势和需要的支撑条件。 相似文献