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1.
The longitudinal polarization of strangeness Arizona muon, namely, the 236 MeV/c + from the K+ + v decay, has been measured to search for right-handed weak current in the strangeness changing process. The polarization has been determined to be –0.967±0.047.We are grateful to Professors T. Nishikawa, S. Ozaki, A. Kusumegi, and H. Sugawara of KEK for their encouragement and support during the course of this experiment. We are grateful to the operating crew of the KEK proton synchrotron and its experimental facilities for their cooperation during the experiment. This work is partially supported by the Grant-in-Aid of the Ministry of Education, Science and Culture.  相似文献   

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We investigated the environmental water sources used in mid-summer by three Sonoran Desert phreatophytic riparian tree species, Salix gooddingii, Populus fremontii, and the exotic Tamarix spp., at sites that differed in water table depth. Salix gooddingii was most sensitive to water table decline, as evidenced by lower predawn water potentials. Although P. fremontii was less sensitive to water table decline than S. gooddingii, its leaf gas exchange was the most responsive to atmospheric water stress imposed by high leaf-to-air vapor pressure deficit. Tamarix spp. was least sensitive to water table decline and showed no reduction of predawn water potential over the measured range of depth to groundwater. Comparison between D/H of xylem and sampled environmental water sources suggest that S. gooddingii and P. fremontii used groundwater at most sites with no change in water source as depth to groundwater varied. In contrast, xylem D/H of Tamarix spp. was depleted in deuterium compared to groundwater at most sites, suggesting use of water from an unsampled source, or discrimination against deuterium during water uptake. This study highlights the difficulty in sampling all water sources in large-scale studies of riparian ecosystems with complex subsurface hydrogeology.  相似文献   

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In the Basin and Range Province of the Southwestern U.S.A., deep carbonate groundwater has been suggested as a significant source to many overlying basin-fill alluvial aquifer systems. Notwithstanding, testing this hypothesis is limited by obtaining data from such considerable depths and complex geology.

This study uses δ2H and δ18O data from springs, rivers, and wells tapping shallow basin-fill groundwater to test the hydrochemical interpretation of deep regional carbonate groundwater flow into the basin-fill aquifers. Stable isotopic and major ion attributes of hydrochemical facies suggest basin-fill alluvial groundwater of the Lower Virgin River Basin is a mixture of precipitation recharge within the Lower Virgin River Basin or the Clover and Escalante Desert Basin northwards, and the deep carbonate flow. The data support the conclusions that in the Lower Virgin River Basin, deep carbonate groundwater is an important source to the alluvial aquifer system and likely accounts for approximately 50% of the alluvial aquifer groundwater. Na+, K+, and SO42– increase in the basin-fill alluvial groundwaters outside the Virgin River floodplain appears to be related with upwelling of deep regional groundwater, and indicating that the chemical character of the basin-fill alluvial groundwaters are related to the deeper flow systems.  相似文献   


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采用原子吸收光谱法,测定了稚鸡蛋中的钙、铜、铁、锌、锰、硒、铬和铅的含量,并对其结果进行了分析。各元素在实验范围内,线性关系良好,回收率在97.9%—102.2%之间。稚鸡蛋中Ca、Cu、Fe、Zn、Mn、Se含量分别为973.2、5.86、419.40、99.78、7.66、1.25μg·g~(-1),显著高于罗曼鸡蛋。测定结果显示稚鸡蛋中含有丰富的矿物元素,具有较高的营养和保健价值。  相似文献   

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本文提供了一种测定金属硅中B,Fe,Al,Ca,Mn等14个杂质元素的ICP-AES方法,在样品处理过程中,加入适量体积的甘露醇能够抑制B的挥发。用本方法测定了一个国家地球化学标准样(GSR-4),结果令人满意。  相似文献   

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The lowest absorption band of the tetraphenyl compounds resembles that of the lowest absorption band of benzene with the following difference. In benzene the electronic origin is strictly forbidden, and all intensity is associated with a symmetric progression built on one mode of asymmetric vibration. In the tetraphenyl compounds the intensity associated with the asymmetric vibration is relatively unaffected; however, there is increasing intensity associated with the electronic origin and a symmetric progression built on it along the series
φ4Pb < φ4Sn < φ4Ge < φ4Si < φ4C ? φ4B? < φ4Sb+ < φ4As+ < φ4P+
. For the cations it is the electronic origin and the progression built on it that are the primary source of intensity. This effect is attributed to an inductive perturbation. A similar effect is observed in the fluorescence spectrum. In phosphorescence, the relative enhancement of the electronic origin and the progression built on it is far less marked. The phosphorescence emission of φ4Pb and φ4Sb+ are red shifted from the others by ~0.5 eV, an effect attributed to formation of a triplet excimer. Increasing spin-orbit coupling in the triplet due to a heavy atom effect can be seen in the decreasing phosphorescence lifetime (range 4 sec to 4 msec) and decreasing ratio of φfφp (fluorescence to phosphorescence quantum yields) in the order
φ4C > φ4B > φ4Si > φ4P+ > φ4Ge > φ4As+ > φ4Sn
In all cases nonexponential decay of phosphorescence is observed.  相似文献   

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K shell X-ray production cross-sections in the Ti, V, Cr, Mn, Fe, Co, Ni, and Cu in the molecules were studied at 59.5 keV excitation energy by using a Si(Li) detector ( FWHM = 155 eV at 5.96 keV). The present results are compared with other theoretical values.  相似文献   

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以电荷耦合器件为检测器的全谱直读等离子体光谱仪直接测定锡锭中As、Al、Bi、Cd、Cu、Fe、Pb、Se、Sb、Zn十种杂质元素的含量.该方法简便、快速且具有比化学法更低的检出限,加标回收试验结果表明,回收率为92%-105%,RSD均小于1.5%.  相似文献   

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