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51.
Johan P. Hansen Henning Stichtenoth 《Applicable Algebra in Engineering, Communication and Computing》1990,1(1):67-77
We construct a series of algebraic geometric codes using a class of curves which have many rational points. We obtain codes of lengthq
2 over
q
, whereq = 2q
0
2
andq
0 = 2
n
, such that dimension + minimal distance q
2
+ 1 – q
0
(q – 1). The codes are ideals in the group algebra
q
[S], whereS is a Sylow-2-subgroup of orderq
2 of the Suzuki-group of orderq
2
(q
2
+ 1)(q – 1). The curves used for construction have in relation to their genera the maximal number of
GF
q
-rational points. This maximal number is determined by the explicit formulas of Weil and is effectively smaller than the Hasse—Weil bound.Supported by Deutsche Forschungsgemeinschaft while visiting Essen University 相似文献
52.
以银耳为原料, 采用超声波辅助热水浸提法提取银耳多糖, 以多糖提取率为指标, 以超声波功率、提取料液比、提取温度和提取时间为影响因素, 设计单因素试验, 并通过正交试验得到较佳提取工艺。通过用TRPV1(Transient Receptor Potential Vanilloid1)试剂盒检测了小胶质细胞TRPV1的释放水平, 与脂多糖(Lipopolysaccharide, LPS)对照组相比, 不同质量浓度的银耳多糖组(62.5, 250, 1000 μg/mL)均能不同程度地抑制TRPV1的释放量。说明了银耳多糖对于BV2小胶质细胞炎症具有良好的抑制作用。 相似文献
53.
S. Kapi
ski 《Journal of Materials Processing Technology》1996,60(1-4):197-200
The paper presents the concepts of solving of deep drawing process for bimetal elements of sheet materials. The inertia forces, plastic hardening behaviour of the deformed material and dynamic stress are utilized in the problems of plasticity. The experimental results and general conclusion are presented at the end of the paper. 相似文献
54.
利用外加物理场凝固细晶技术是目前材料加工领域的研究热点。综述了各种电、磁场对金属凝固组织的影响,并对其主要的机理进行了探讨;并对电、磁场在金属凝固成形中的应用和进一步研究进行了展望。 相似文献
55.
56.
锌铝基合金陶瓷层激光重熔区的表面温度场 总被引:1,自引:0,他引:1
使用HSC 31快速扫描红外热像仪 ,测量了含Al2 O3 表层的锌铝合金激光熔覆时的表面温度场 ,测得熔池中最高温度为 16 72℃ ,边缘温度为 6 0 0~ 70 0℃ ,冷却速率为 2× 10 3 ~ 3× 10 4 ℃ /s以及熔池形状和等温曲线。 相似文献
57.
An efficient method to monitor changes in soil inorganic N content during crop growth would be a useful means to guide N fertilization
to ensure high yields and low N losses to the environment. In this study, soil apparent electrical conductivity (ECa) measured by the widely used conductivity meter EM38 was tested as an indirect measurement of available N in spring barley
during two cropping seasons at two sites with morainic loam in SE Norway. The experiment was constructed to maximize soil
variation. In spite of the ȁ8noiseȁ9 caused by the soil heterogeneity, concentrations of inorganic N (cNinorg) or NO3-N were most strongly correlated with ECa in both years and at both locations (with one exception). The measurements of ECa reflected well the temporal variation in inorganic N content (Ninorg), and a ranking of the treatments based on ECa fitted very well with a ranking based on Ninorg at the first three sampling times after fertilizing. The best subset of sensor variables (i.e. variables which can be measured
ȁ8on-the-goȁ9 by sensor techniques in the field) described 27–69% (average 47%) of the variation in topsoil cNinorg. When expanding the regression models to include pH as well, the degree of explanation increased significantly. In conclusion,
the method of using ECa appears to be quite robust in terms of detecting relative differences in cNinorg, whereas a determination of absolute levels of cNinorg with the method is unreliable. 相似文献
58.
高温高压设备瞬态密封分析的三维力学与传热学模型 总被引:2,自引:0,他引:2
以大型加氢反应器的高压法兰密封结构为研究对象,建立了瞬态及稳态密封分析的三维力学与传热学模型,主要解决了螺栓载荷的动态模拟和螺栓孔内空气环层的传热计算问题。利用该模型对加氢反应器的瞬态及稳态密封状况进行了计算。 相似文献
59.
This paper presents a multivehicle sampling algorithm to generate trajectories for nonuniform coverage of a nonstationary spatiotemporal field characterized by spatial and temporal decorrelation scales that vary in space and time, respectively. The sampling algorithm described in this paper uses a nonlinear coordinate transformation that renders the field locally stationary so that existing multivehicle control algorithms can be used to provide uniform coverage. When transformed back to the original coordinates, the sampling trajectories are concentrated in regions of short spatial and temporal decorrelation scales. For fields with coupled spatial statistics, i.e., the spatial decorrelation scales are functions of both spatial dimensions, the coordinate transformation is implemented numerically, whereas for decoupled spatial statistics, the transformation is expressed analytically. We show that the analytical transformation results in vehicle motion that preserves the vehicle sampling speed (which is a measure of vehicle speed scaled by the ratio of the spatial and temporal decorrelation scales), in the original domain; the sampling speed determines the minimum number of vehicles needed to cover a spatiotemporal domain. Theoretical results are illustrated by numerical simulations. 相似文献
60.
A simple transient performance of floating cum tilted-wick type solar still has been presented by incorporating the effects of water flowing over a glass cover, heat capacity of tilted-wick water surface and floating-wick water surface. Explicit expressions for flowing water, glass, tilted-wick water surface and floating-wick water surface temperature and efficiency of the system have been derived. Numerical calculations have been carried out for a typical day in the month of March 2004. The relative standard deviations between the numerical and experimental results of different temperature components of the proposed still have been found. The results indicate that the relative standard deviations between theoretical and experimental results are less than 8% (glass cover), 2% (tiltedwick water surface), 1% (floating-wick water surface) and 2% (flowing water at the lower end of the glass cover) an average for the working hours of the day. Moreover, based on the numerical results, the following conclusions have been drawn: (i) glass cover temperature decreases significantly; (ii) the effect of water flowing over the glass cover has a fascinating effect on the production of distillate output during peak sunny hours; (iii) water flow rate of 1.5 m/s is optimum, and beyond it the efficiency decreases. Experimental investigations have been performed at Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore, India. 相似文献