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任基 《成都信息工程学院学报》1990,(1)
本文介绍了一种新的标定流气式正比计数管的方法。此方法的特点是把正比管作为吸收体,利用He气对光子较为透明的原理,标定正比管的探测效率。方法简便实用,并对P-10(90%Ar+10%CH_4)为工作气体的正比管进行了标定。 相似文献
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Brian D. Ramsey 《Experimental Astronomy》1995,6(4):119-127
Gas-filled detectors, such as proportional counters, have long been used in x-ray astronomy. They are robust, relatively easy to fabricate, and can provide large collecting areas with reasonable spatial and energy resolution. Despite coming of age in the 50's and 60's, their versatility is such that they are still planned for future missions. A vigorous development program, led mostly by the high energy physics community, has ensured continued improvements in proportional counter technology. These include multistep counters, microstrip technologies and optical avalanche chambers. High fill-gas pressures and the use of suitable converters permit operation up to 100s of GeV. The current status of imaging gas-filled detectors will be reviewed, concentrating on the lower energy region (<100 keV) but also briefly covering higher energy applications up to the GeV region. This review is not intended to be exhaustive and draws heavily on work currently in progress at MSFC. 相似文献
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刘善昭 《紫金山天文台台刊》1997,16(2):111-115
本文叙述了一种性能良好的电荷灵敏前置放大器,把它用于低能X射线的探测,从其计算结果看是可行的。并在实验中取得了较好的结果。 相似文献
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M. M. Saç E. Yumurtaci G. Yener B. Camgöz A. Uğur B. Özden 《Environmental Geology》2008,55(3):477-483
Gediz Basin is one of the regions where intense agricultural activities take place in Western Turkey. Erosion and soil degradation
have long been causing serious problems to cultivated fields in the basin. This work describes the application of two different
137Cs models for estimating soil erosion rates in cultivated sites of the region. Soil samples were collected from five distinct
cultivated regions subject to soil erosion. The variations of 137Cs concentrations with depth in soil profiles were investigated. Soil loss rates were calculated from 137Cs inventories of the samples using both proportional model (PM) and simplified mass balance model (SMBM). When PM was used,
erosion and deposition rates varied from −15 to −28 t ha−1 year−1 and from +5 to +41 t ha−1 year−1, respectively; they varied from −16 to −33 t ha−1 year−1 and from +5 to +55 t ha−1 year−1 with SMBM. A good agreement was observed between the results of two models up to 30 t ha−1 year−1 soil loss and gain in the study area. Ulukent, a small representative agricultural field, was selected to compare the present
data of 137Cs techniques with the results obtained by universal soil loss equation (USLE) applied in the area before. 相似文献
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高能天体物理观测中,宇宙线带电粒子通过探测器丢失的能量常是产生探测器本底信号的重要来源。宇宙线产生的信号与它通过探测器的径迹长度和探测器大小、形状有关。因气球X射线天文观测和γ射线暴观测的需要,空间天文实验室研制了若干种正比计数器,为此我们进行了宇宙线通过正比管径迹长度的模拟计算,它是整个设计工作中的一部分。 相似文献
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