胶北地块与金矿有关的花岗岩类的研究---第一章 胶北地块的地质发展史          下载免费PDF全文

徐金芳  沈步云  牛良柱  郑文深 《山东国土资源》1989,(2)

Jiaobei block is well known as rich in gold mineral resources. The gold mineralization is closely related to granitoids, but there are different views about the age of granits and the type of granitoids with which gold mineralization is associated. Based on the study of petrology, mineralogy, geochemistry and isotopic geology of the granitoids, enclaves and viens in this region, some conclusions are obtained.  相似文献   

基于GNSS资料分析漾濞MS6.4地震前应变时空演变特征     

王伶俐  洪敏  高涵  徐良叶  王岩  牛甜 《中国地震》2023,39(1):116-127

基于云南省内及邻区2009—2020年GNSS观测数据解算结果,在各个测点时间序列和速度场的基础上,采用克里金插值方法估计区域应变率场;以连续基准站时间序列为约束,获取漾濞M_S6.4地震近场区域的块体应变时间序列。分析发现:漾濞地震发生在前期最大剪应变高值区以及面应变高梯度带的张压转换区,发震的时间处于区域应变积累速率逐渐降低的过程之后。震中近场区域均以NW向断层的右旋走滑应变积累为主,且大多呈现持续增强趋势,与漾濞地震的发震断层走向及其破裂特征一致。震前震区东部块体出现了短期应变趋势转折及反向加速的异常现象,反映了应力-应变积累在接近临界破裂状态时的非线性调整。  相似文献   

模糊模式在金矿成矿预测中的应用     

江涛  牛如宝 《山东国土资源》1998,(3)

通过对焦家金矿田地球化学异常的分析,并以此为基础设计隶属函数,进而建立了模糊模式。根据隶属函数计算的各个元素信息变量的模糊数,把它作为模糊判别指标,然后用贴近度的度量方法与预测区内待识别的模糊判别指标进行识别。应用此方法对水系沉积物中Ａｕ、Ａｇ、Ｃｕ、Ｐｂ四种元素进行模糊模式识别与处理,并在胶东７８００ｋｍ２范围内进行了金矿预测,其中有些贴近度（Ｔ）异常已经得到验证,获得了较好的效果。  相似文献   

A re-assessment of nickel-doping method in iron isotope analysis on rock samples using multi-collector inductively coupled plasma mass spectrometry     

Gong  Hongmei  Guo  Pengyuan  Chen  Shuo  Duan  Meng  Sun  Pu  Wang  Xiaohong  Niu  Yaoling 《中国地球化学学报》2020,39(3):355-364

Element doping has been proved to be a useful method to correct for the mass bias fractionation when analyzing iron isotope compositions. We present a systematic re-assessment on how the doped nickel may affect the iron isotope analysis in this study by carrying out several experiments. We find three important factors that can affect the analytical results, including the Ni:Fe ratio in the analyte solutions, the match of the Ni:Fe ratio between the unknown sample and standard solutions, and the match of the Fe concentration between the sample and standard solutions. Thus, caution is required when adding Ni to the analyte Fe solutions before analysis. Using our method, the δ⁵⁶Fe and δ⁵⁷Fe values of the USGS standards W-2a, BHVO-2, BCR-2, AGV-2 and GSP-2 are consistent with the recommended literature values, and the long-term (one year) external reproducibility is better than 0.03 and 0.05‰ (2SD) for δ⁵⁶Fe and δ⁵⁷Fe, respectively. Therefore, the analytical method established in our laboratory is a method of choice for high quantity Fe isotope data in geological materials.

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Design of the cryogenic system of the wideband phased array feed for QTT     

Jun Ma  Yang Wu  Song Xiao  Sheng-Pu Niu  Kai Wang 《天文和天体物理学研究(英文版)》2021,(4):90-94

Phased array feeds(PAFs),which illuminate the dish with digitally synthesized beams instead of separated horns,provide the capability for wider and continuous field-of-view surveys.As a promising technology for next generation radio telescopes,PAFs will provide the Qi Tai Telescope(QTT),which will be next world-class fully steerable radio telescope,an opportunity of reaching several cutting-edge science goals.This paper presents a brief introduction of the wideband PAF for QTT,and the detailed design and simulation of the cryogenic system.Based on this design,a scaled prototype of the spherical vacuum window,which is the key part of the cryogenic system,has been built and the performance is verified.  相似文献   

二维GaAs 基光子晶体微腔的制作与光谱特性分析     

彭银生  叶小玲  徐波  牛洁斌  贾锐  王占国  梁松  杨晓红 《海洋学报》2010,32(10):7073-7077

研究了以InAs量子点为有源区的二维GaAs基光子晶体微腔的设计与制作,测试并分析了室温下微腔的光谱特性.观察到了波长约为1137 nm,谱线半高宽度约为1 nm的尖锐低阶谐振模式发光峰.我们比较了不同刻蚀条件下光子晶体微腔的发光谱线,结果表明空气孔洞截面的垂直度是影响光子晶体微腔发光特性的重要因素之一.通过调节干法刻蚀工艺,改变空气孔半径与晶格常数的比率,可以在较大范围内调节谐振模式发光峰位置,达到谐振模式与量子点发光峰调谐的目的.  相似文献   

硬X射线相位光栅的设计与研制     

刘鑫  雷耀虎  赵志刚  郭金川  牛憨笨 《海洋学报》2010,32(10):6927-6932

针对在普通实验室和医院实现40—100 keV X射线相衬成像的需求,考虑到成像系统参数、X射线源空间相干特性及光栅衍射效率,设计出硅基相位光栅结构参数.利用我们已发展的光助电化学刻蚀技术研制出直径为5英寸的相位光栅,其空间周期为5.6 μm,线宽为2.8 μm,深度为40—70 μm.在理论分析的基础上,通过提高硅片两端有效工作电压和修正Lehmann电流密度公式,解决了实际刻蚀过程中出现的钻蚀问题.由实验结果可知,本方案对制作大面积高精度相位光栅十分有效.  相似文献   

Electromagnetically induced transparency based six-wave mixing in a Doppler-broadened folded four-level system     

牛金艳  裴丽娅  吴令安  傅盘铭 《海洋学报(英文版)》2010,29(11)

We study phase-conjugate six-wave mixing spectroscopy based on electromagnetically-induced-transparency in a Doppler-broadened folded four-level system. It is found that the six-wave mixing spectrum can be either Doppler-free or very broad, depending on whether the interference between the polarisations of atoms with different velocities is constructive or destructive. To obtain the Doppler-free six-wave mixing spectrum in the folded four-level system, the conditions are more stringent in comparison with those in the cascade and N-type four-level systems. This polarisation interference can be controlled in the presence of a strong coupling field.  相似文献   

Transcriptome profiling analysis of Mactra veneriformis by deep sequencing after exposure to 2,2′,4,4′-tetrabromodiphenyl ether     

Shi  Pengju  Dong  Shihang  Zhang  Huanjun  Wang  Peiliang  Niu  Zhuang  Fang  Yan 《中国海洋湖沼学报》2018,36(2):490-507

Journal of Oceanology and Limnology - Polybrominated diphenyl ethers (PBDEs) are ubiquitous global pollutants, which are known to have immune, development, reproduction, and endocrine toxicity in...  相似文献   

Variations in the northern permafrost boundary over the last four decades in the Xidatan region,Qinghai–Tibet Plateau     

Jing Luo  Fu-jun Niu  Zhan-ju Lin  Ming-hao Liu  Guo-an Yin 《山地科学学报》2018,15(4):765-778

The distribution and variations of permafrost in the Xidatan region, the northern permafrost boundary of the Qinghai-Tibet Plateau, were examined and analyzed using ground penetrating radar(GPR), borehole drilling, and thermal monitoring data. Results from GPR profiles together with borehole verification indicate that the lowest elevation limit of permafrost occurrence is 4369 m above sea level in 2012. Compared to previous studies, the maximal rise of permafrost limit is 28 m from 1975 to 2012. The total area of permafrost in the study region has been decreased by 13.8%. One of the two previously existed permafrost islands has disappeared and second one has reduced by 76% in area during the past ~40 years. In addition, the ground temperature in the Xidatan region has increased from 2012 to 2016, with a mean warming rate of ~0.004℃ a~(-1) and ~0.003℃ a~(-1) at the depths of 6 and 15 m, respectively. The rising of permafrost limit in the Xidatan region is mainly due to globalwarming. However, some non-climatic factors such as hydrologic processes and anthropic disturbances have also induced permafrost degradation. If the air temperature continues to increase, the northern permafrost boundary in the Qinghai-Tibet Plateau may continue rising in the future.  相似文献