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991.
This paper provides a continuation of ideas presented by Davvaz and Mahdavipour [B. Davvaz, M. Mahdavipour, Roughness in modules, Inform. Sci. 176 (2006) 3658-3674]. The notion of hypermodule is a generalization of the notion of module. In this paper, we consider the quotient hypermodule M/A and interpret the lower and upper approximations as subsets of the quotient hypermodule M/A. Then, we introduce the concept of quotient rough sub-hypermodule. Also, using the concept of fuzzy sets, we introduce and discuss the concept of fuzzy rough hypermodules and then we obtain the relation between fuzzy rough sub-hypermodules and level rough sets. This relation is characterized as a necessary and sufficient condition. 相似文献
992.
准噶尔盆地西北缘沉积特征及油气成藏规律——以五、八区佳木河组为例 总被引:6,自引:2,他引:4
准噶尔盆地西北缘前陆冲断带是剖析西准噶尔地区盆山耦合关系、盆地成因与造山带演化、沉积体系发育的关键地段。准噶尔盆地西北缘五、八区二叠系佳木河组为火山岩、火山碎屑岩、碎屑岩组成的混积地层,佳木河组下亚组分为2个三级层序PSQ1、PSQ2,中亚组和上亚组分别为三级层序PSQ3和PSQ4,下亚组主要充填火山岩和火山碎屑岩,中亚组及上亚组主要充填扇三角洲为主的粗碎屑沉积物。五、八区佳木河组主要发育扇三角洲相、火山口及近火山口相、远火山口相,扇三角洲砂体和火山岩体是最重要的油气储集体。研究区已知油气藏多分布于扇三角洲平原亚相、前缘亚相和火山口及近火山口相中,但是否能成藏关键在于构造(裂缝)、成岩作用、油源、圈闭等与储集层的空间匹配关系。图4参18 相似文献
993.
论川东苟家场构造带天然气勘探 总被引:2,自引:1,他引:1
川东苟家场构造带石炭系天敢勘探累遭失利。分析钻探及探井测试资料,认为苟家场构造天然气充满程度不同,原因在于;构造两翼倾轴逆断层封闭性差,石炭系及上覆盖层破碎严重南端已缺失石炭系;氢此,认为家场构造的圈各地层-地垒背斜复合圈闭、志留系气源岩生成的天然气只能在狭2长的圈闭范围内由下向上,自北向南端多,聚集,因而控气范围有限,可能只在构造顶部有气。 相似文献
994.
995.
996.
Assessing biological control of Acarus siro by Cheyletus malaccensis under laboratory conditions: Effect of temperatures and prey density 总被引:2,自引:0,他引:2
In stored grain, the predatory mite Cheyletus spp. may be used to control the pest mite Acarus siro. The efficiency of control depends on many factors, particularly ambient temperature. In this study we investigated the effects of temperature and initial prey density on the prey–predator system under laboratory conditions. Ratio–response models were fitted to estimate the efficiency of control for three temperatures. At 15 °C a 90% reduction of A. siro was achieved by releasing nine Cheyletus malaccensis individuals into a population of 100 A. siro individuals in 1 kg of grain. At 20 °C, 90% reduction required seven C. malaccensis individuals and at 25 °C, it required three C. malaccensis individuals. Without the predator the intrinsic rates of increase of A. siro populations increased with temperature and were highest for an initial density of 100 individuals, revealing some form of positive interaction among A. siro individuals during food processing. The intrinsic rates of increase of C. malaccensis populations also increased with temperature and decreased with increasing density of the predator, presumably as a result of interference competition among predators.At 15 °C the rate of increase for A. siro was higher than that for C. malaccensis, while at higher temperatures it was the other way around. Lower developmental thresholds were 10 °C for A. siro and 13.6 °C for C. malaccensis. In order to find when an artificial release of C. malaccensis is most efficient we simulated a population increase of A. siro using temperature records from one grain store. In Central Europe this type of biological control can be efficient only when the predator is released at the beginning of storage, i.e. in September and October. 相似文献
997.
Ying Han 《Electrochimica acta》2008,53(21):6196-6201
The formation process of self-assembled monolayer (SAM) of decanethiol (C10SH) on Au(1 1 1) single crystal electrode has been investigated for wide range of C10SH concentration (0.1-500 μM) and temperature (253-298 K). The amount and quality of C10SH SAM were determined from area and position, respectively, of reductive desorption peak of the SAM modified Au(1 1 1) electrode measured in 0.5 M KOH aqueous solution. The kinetic analysis indicates that SAM formation proceeded by two steps, diffusion-limited physisorption followed by chemisorption. 相似文献
998.
针对天然水体体积计算难题,从水侵量的定义公式出发,以S理想边水驱油藏为例,以廖运涛方法获得的精确解为约束条件,主要是对采用的综合压缩系数进行校正,获得了理想边水驱油藏天然水体体积的简便估算方法,在类似油藏上应用取得了好效果,为选择合适的开发方式提供了重要依据。对于井网完善、已全面投入开发、完全依靠边水补充能量、以自喷为主的高渗透、稀油油藏,在经历几年的开发后有明显的油层压降情况下,只要能够落实清楚总压降值和与之对应的水侵量,就可以估算出天然水体的体积。至于该方法能否拓宽应用范围,尚需进一步探讨。 相似文献
999.
1000.
The lower Colorado River from Laughlin, Nevada, to the border with Mexico is one of the most regulated rivers in North America. An analysis of particulate organic matter (POM) transport through the system was made to determine POM concentrations, composition and point of origin, as well as to determine the effect dams had on this transport. Particulate organic matter concentrations generally increased from upstream to downstream, and were dominated by very fine organic detritus (< 25μm size fraction). Reservoirs released more POM than they received during spring and summer, but less during autumn and winter. Reservoirs recycled POM, taking in organic detritus and discharging small limnoplankton. Backwater complexes functioned as filters during storm events, trapping coarse material and releasing fine material. Agricultural drains made only minor contributions of POM, but provided important nutrients for in-channel production of POM. Water diversions forced POM off-channel, whereas sluicing operations reduced inorganic loads in the canals. Despite the presence of six mainstem dams, the lower reaches support a diverse assemblage of detritivorous fishes, similar to that found in the lowermost reaches of natural, unregulated rivers. The food base for this fishery stems from autochthonous production of POM. 相似文献