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71.
本文开发的弹出式窗口系统和下拉式菜单系统,具有显示速度快、通用性好、移植性强的特点。全部程序在VGA/EGA的PC机上调试通过,取得了较为满意的效果。笔者愿提供大家广为利用。  相似文献   
72.
采用西藏测震台网记录的2008年1月—2018年12月谢通门区域定位地震,系统分析该区M_L1.5以上地震频度变化及与附近强震的对应关系,发现地震台站建设密度对谢通门地震窗监控能力影响较大,故从2008—2011年和2012年7月—2018年12月2个时段予以分析。分析发现,2012年7月开始,谢通门地震窗小震活动水平在每月20次范围内随机波动,当超过20次以上(含20次)即异常高值出现或结束后1.5年内,在半径100 km以内具有发生M_S 5.0以上地震的可能,在半径1 000 km以内具有发生M_S 6.5以上强震的可能。  相似文献   
73.
Tremolite–tschermakite solid solutions have been synthesized between 700 and 850 °C and 200 and 2000 MPa. The starting materials were oxide–hydroxide mixtures and an additional 0.1–1.8 molal CaBr2 solution. The run products were characterized using SEM, HRTEM, EMP, XRD and FTIR. The synthesized Al tremolites formed needles and lath-shaped crystals of up to 300 × 20 μm. HRTEM investigations showed that the majority of the amphiboles were well ordered. The EMP analysis revealed that the Al tremolites were solid solutions in the ternary tremolite–tschermakite–cummingtonite. The highest observed Al content was close to the composition of magnesiohornblende (Xts=0.54). Different cummingtonite concentrations (Xcum=0.00–0.18) were observed, which generally increased with Al content. Rietveld refinements of the lattice constants showed a linear decrease of the cell parameters a and b with increasing Al content, whereas c and β increased. Small deviations from the linear behaviour were caused by variable amounts of the cummingtonite component. For pure tschermakite lattice parameters of a=9.7438(11) Å, b=17.936(14) Å, c=5.2995(3) Å, β=105.68(9)° and V=891.7 ± 1.4 Å3 were extrapolated by least-squares regression. Using the a and β lattice parameters for tremolite, tschermakite and cummingtonite, it was possible to derive amphibole compositions using powder XRD. IR spectra of the Al tremolites showed a total of 12 individual bands. The FWHMs of all bands increased with increasing Al content. According to their FWHMs, these bands were grouped into three band systems at 3664–3676 cm?1 (I), 3633–3664 cm?1 (II) and 3526–3633 cm?1 (III). Assuming [6]Al substitution at M2 and/or M3 and [4]Al at T1, three principal different configurational groups could be assigned as local environments for the proton. I: only Si4+ at T1 and one or two Al3+ at M2 and/or M3far, II: one Al3+ at T1 and one to three Al3+ at M2 and/or at M3far, III: either Al3+ on M3near and/or two Al3+ on T1 and additional one to four Al3+ at M2. It is assumed that these three configurational groups correspond to the three groups of observed bands. This was quantitativly supported by Monte-Carlo simulations. A model with random distribution at M2 and M3 including Al avoidance at tetrahedral and octahedral sites yielded the best agreement with the spectroscopical results.  相似文献   
74.
磷氯铅矿(Pyromorphite)在我国比较罕见,2001年在广西岛坪发现的磷氯铅矿结晶较好,运用XRD、XRFI、R和UV/Vis等分析方法对黄色和绿色样品进行了研究。结果表明,二者XRD谱只是峰强有所不同。在它们的红外吸收谱带中,除了标准的PO43-吸收峰外,在670~800 cm-1之间和430 cm-1左右出现的两组肩峰为SiO44-振动峰。黄色样品的振动频率偏高、半峰宽偏窄、透射率与绿色样品相比较高。通过XRF分析发现黄色晶体比绿色晶体含有更多的Fe3 ,而Fe3 常使矿物呈现黄色,同时证实了黄色磷氯铅矿的红外吸收峰频率偏高是因为它的铅含量低于绿色矿。UV/Vis进一步说明在可见光区的吸收不同是使二者颜色差异的主要原因,Fe离子含量较大使磷氯铅矿呈现黄色。  相似文献   
75.
用神舟三号中分辨率成像光谱仪数据反演大气水汽   总被引:1,自引:0,他引:1  
2002年3月中国神舟三号飞船发射成功,所携带的中分辨率成像光谱仪获取了一批940nm波段的遥感数据。本文用其中的部分资料做了反演水汽的试验,给出一些结果和分析。  相似文献   
76.
We report here, for the first time, on the new finding of extrusive calciocarbonatite (alvikite) rocks from the Pleistocene Mt. Vulture volcano (southern Italy). These volcanic rocks, which represent an outstanding occurrence in the wider scenario of the Italian potassic magmatism, form lavas, pyroclastic deposits, and feeder dikes exposed on the northern slope of the volcano. The petrography, mineralogy and whole-rock chemistry attest the genuine carbonatitic nature of these rocks, that are characterized by high to very high contents of Sr, Ba, U, LREE, Nb, P, F, Th, high Nb/Ta and LREE/HREE ratios, and low contents of Ti, Zr, K, Rb, Na and Cs. The O–C isotope compositions are close to the “primary igneous carbonatite” field and, thus, are compatible with an ultimate mantle origin for these rocks. The Sr–Nd–Pb–B isotope compositions, measured both in the alvikites and in the silicate volcanic rocks, indicate a close genetic relationship between the alvikites and the associated melilitite/nephelinite rocks. Furthermore, these latter products are geochemically distinct from the main foiditic-phonolitic association of Mt. Vulture. We propose a petrogenetic/geodynamic interpretation which has important implications for understanding the relationships between carbonatites and orogenic activity. In particular, we propose that the studied alvikites are generated through liquid unmixing at crustal levels, starting from nephelinitic or melilititic parent liquids. These latter were produced in a hybrid mantle resulting from the interaction through a vertical slab window, between a metasomatized mantle wedge, moving eastward from the Tyrrhenian/Campanian region, and the local Adriatic mantle. The occurrence of carbonatite rocks at Mt. Vulture, that lies on the leading edge of the Southern Apennines accretionary prism, is taken as an evidence for the carbonatation of the mantle sources of this volcano. We speculate that mantle carbonatation is related to the introduction of sedimentary carbon from the Adriatic lithosphere during Tertiary subduction.  相似文献   
77.
Infrared stimulated luminescence (IRSL) properties of the Old Crow tephra and bracketing loess from the Halfway House site in Central Alaska are investigated in order to test newly developed techniques, including SAR and recently proposed fading corrections. Loess samples investigated show a standard growth of luminescence with regenerative dose while the tephra sample is less sensitive by an order of magnitude and saturates at lower dose. The growth curves obtained using multiple-aliquots regeneration (MAR) saturate at a higher value than those with the single-aliquot regeneration (SAR) protocol. Fading rate determinations for these samples are shown to be imprecise and no noticeable difference was observed between loess and tephra materials. Anomalous fading corrections using an average g value of 5% are applied to the natural test dose signal intensity using the dose rate correction (DRC) method. IRSL ages obtained for loess are in agreement with the expected age while the tephra age is lower than expected, suggesting the measured fading rate is underestimated for this material.  相似文献   
78.
舒孝敬 《铀矿地质》2007,23(3):150-155
加拿大萨斯喀彻温省西北部阿萨巴斯卡盆地McArthur River铀矿床是世界上最大、最富的不整合面型铀矿床。笔者通过对该矿床的剖析,从宏观上对这类铀矿床的一些形成规律进行了初步探讨,并对在我国寻找不整合面型或相似类型的铀矿床提出了一些认识。  相似文献   
79.
GIS中多幅地图的缩放漫游及其数据组织   总被引:1,自引:0,他引:1  
赵仁亮 《四川测绘》1998,21(4):151-155
本文在分析现存GIS软件中处理多幅不同比例尺或相同比例尺地图的放缩漫游时的不足及其原因的基础上,提出了一种使用地理逻辑窗口动态裁剪快速而安全的多幅地图无级缩放和全区域自由漫游的方法,并对其数据组织和管理作了探讨。  相似文献   
80.
塔里木盆地沉积剥蚀过程与油气关系   总被引:3,自引:0,他引:3  
塔里木盆地典型井的周期分析表明,塔里木盆地在其地质历史时期100Ma左右的周期是很明显的,自寒武纪以来共经历了4个完整的周期,每一完整周期都由正相位和负相位两个半周期所组成。而第三纪为第5个周期的正相位阶段。该周期控制了盆地内的沉积与剥蚀的过程及成藏旋回。对沉积与剥蚀过程的控制作用表现在周期波正相位和负相位分别对应于沉积期和剥蚀期,这在地质年代序列中表现为沉积与间断的互为消长的演化进程。对食油气系统的控制作用表现在:第1个周期波构成以早古生代地层为主体的含油气系统,第2个周期波至第4个周期波构成以晚古生代至中生代地层为主体的含油气系统,第5个周期的正相位阶段构成以第三纪地层为主体的含油气系统。  相似文献   
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