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991.
用原子吸收仪进行钛的紫外分光光度测定 总被引:1,自引:0,他引:1
在原子吸收仪上添置了一个自制的简易比色皿托架,成功地利用原子吸收仪进行TiO2与二安替比林甲烷显色的分光光度测定。 相似文献
992.
ZHI Xiachen CHEN PengDepartment of Earth Space Sciences University of Science Technology of Chin Laboratory of Chemical Geodynamics USTC Advanced Research Center for Earth Science Astronomy in USTC Third World Academy of Science Hefei LIN Chengzhong CHEN Shuqing ZHANG GuilanInstitute of Mineral Resources Chinese Academy of Geology Sciences Beijing LI Yuzhi LIN Lei Open Laboratory of Structure Analysis USTC Hefei 《《地质学报》英文版》2001,75(1)
The Mossbauer spectra of natural megacrystal clinopyroxene are usually fitted by 4 sets of symmetric doublets, A-A', B-B', C-C' and D-D', respectively, in terms of increasing Qs value in literature. But the assignments of those doublets are quite different, except the D-D' doublet assigned to Fe3+ at the lattice site Ml in previous papers. Particularly, the assignment and interpretation of the C-C' doublet are diverse.The oxidation experiments of natural megacrystal clinopyroxene collected from the Hannuoba basalt, North China, were performed under controlled conditions of temperature at 1000℃ and oxygen fugacity of FMQ buffer in 1, 2, 3 and 5 days respectively. The oxidized samples were then measured by X-ray diffraction spectrometry and Mossbauer spectrometry. The oxidation of clinopyroxene is characterized by Fe2+→ Fe3+ at Ml under the subsolidus conditions, which is consistent with the increase of the area of the D-D' doublet when the heating time increases. Accordingly, the area of the A-A' and B 相似文献
993.
994.
简单介绍了核磁测井数据弛豫谱反演方法原理 ,用混合编程方法和动态连接库技术 ,将用FORTRAN语言编写的核心处理模块转换为动态连接库 ,并在C++语言中动态调用。应用快速应用程序开发工具完成了图形用户界面的核磁测井数据处理软件设计。 相似文献
995.
Ultra low frequency electromagnetic wave anomaly and its spectrum characteristics before earthquakes 总被引:1,自引:0,他引:1
Jian-Guo Hao Yun-Fu Zhang Huai-Wen Pan De-Rui Li Tian-Ming Tang Xiao-Qin Liu 《地震学报(英文版)》1995,8(1):101-109
Many observations and researches show that abundant and intense ultra low frequency (ULF) electromagnetic anomalies appeare
before local earthquakes. In order to understand this phenomenon systematically, the transmission property and the formation
of the seismic-electric dipole are discussed in this paper. The results show that the vertical component of the ULF electric
anomaly before earthquake has the properties of better penetration, less disturbance and high signal-to-noise ratio. The signal
can be easily extracted and received. The anomaly should be an important way to seek for reliable short-term and imminent
earthquake precursors. After the spectrum analysis of the (ULF) electric field anomalies, we found that the periods of the
anomaly related to local earthquakes are from a few minutes to a dozens minutes. There is a relation between the spectrum
of the anomaly and the epicentral distance. The ULF electric field anomalies strongly rely on the orientation of the seismogenic
zone. The percolation electric field anomaly and its spectrum amplitude do not have obvious relation with the size of local
earthquakes.
Contribution No. 94A0097, Institute of Geophysics, SSB, China.
The English version is improved by Prof. Guo-Hua FAN, Institute of Geophysics, State Seismological Bureau. 相似文献
996.
本文针对现行的抗震规范中设计反应谱应用范围只能到结构自振周期T≤3秒一现实问题,提出应用长周期地脉动的傅立叶振幅谱比值直接推算概率一地表长周期反应谱的方法。 相似文献
997.
Ultra low frequeney electromagnetic wave anomaly and its spectrum characteristics before earthquakes
UltralowfrequeneyelectromagneticwaveanomalyanditsspectrumcharacteristicsbeforeearthquakesJian-GuoHAO;Yun-FuZHANG;Huai-WenPAN;... 相似文献
998.
New laboratory measurements of NO2 absorption cross-sections have been performed between 300 and 500 nm at ambient temperature with improved experimental conditions: low gas pressures, long absorption paths, suitable absorbance values, narrow spectral bandwidths. The data, stored at 0.01 nm intervals, have been compared to those of the more recent studies and some reasons of disagreement are discussed.In the photolysis region below 400 nm, our absorption cross-sections are larger than those previously published, suggesting that the photodissociation coefficient calculated from the current data sets is underestimated. In the structured region of the spectrum above 400 nm, improvement of the resolution gives more precise values useful for optical measurements in atmosphere.Unité de Recherche Associée au CNRS. 相似文献
999.
A chemistry module has been incorporated into a Lagrangian type model that computes the dynamics and microphysics of an orographical cloud formed in moist air flowing over the summit of Great Dun Fell (GDF) in England. The cloud droplets grow on a maritime aerosol which is assumed to be an external mixture of sea-salt particles and ammonium-sulfate particles. The dry particle radii are in the range 10 nm<r<1 µm. The gas-phase chemical reaction scheme considers reactions of nitrogen compounds that are important at night. The treatment of scavenging of gases into the aqueous phase in the model takes into account the different solubilities and accommodation coefficients. The chemistry in the aqueous phase focusses on the oxidation of S(IV) via different pathways.Sensitivity analyses have been performed to investigate deviations from gas-liquid equilibria according to Henry's law and also to study the influence of iron and of nitrogen compounds on the aqueous-phase oxidation of dissolved SO2. When addressing these questions, special attention has been given to the dependence on the droplet size distribution and on the chemical composition of the cloud condensation nuclei on which the droplets have formed. It was found that the oxidation of S(IV) via a chain reaction of sulfur radicals can be important under conditions where H2O2 is low. However, major uncertainties remain with respect to the interaction of iron with the radical chain. It was shown that mixing of individual cloud droplets, which are not in equilibrium according to Henry's law, can result in a bulk sample in equilibrium with the ambient air. The dependence of the aqueous-phase concentrations on the size of the cloud droplets is discussed for iron, chloride and NO3. 相似文献
1000.