哈密南部暴雨成因分析   总被引：6，自引：1，他引：6  

张云惠  王勇 《气象》2004,30(7):41-43

通过对 2 0 0 2年 6月 1 8～ 1 9日哈密南部暴雨的环流背景、物理机制、T2 1 3产品的物理量及卫星云图分析 ,揭示形成暴雨的成因  相似文献   

高温超导磁强计在瞬变电磁法中的应用研究     

陈晓东  赵毅  吕国印  张杰  王赤军 《地质与勘探》2004,40(Z1):176-179

高温超导磁强计具有直接测量磁场、高灵敏度、频带宽且低频响应好的特点,它可以做瞬变电磁仪的探头.在瞬变电磁仪中使用高温超导磁强计做探头与使用感应线圈相比,在晚期道高温超导磁强计测得的数据的信噪比要大大优于感应线圈的数据.野外试验表明:高温超导磁强计性能稳定,满足瞬变电磁法的要求,在瞬变电磁法中应用,将为寻找深部隐伏矿提供一种更好的新方法.  相似文献   

内蒙古孟恩陶勒盖银铅锌铟矿床成因研究   总被引：10，自引：1，他引：10  

朱笑青  张乾  何玉良  邵树勋 《矿床地质》2004,23(1):52-60

文章从地质特征及地球化学特征方面论证了孟恩陶勒盖矿床的成因。地质特征显示该矿床的形成与花岗岩之间不存在成因联系，矿床相对于岩浆岩围岩是后成的，花岗岩及断裂构造只是为矿床提供了储存空间。矿床地球化学特征显示该矿床的成因与可能位于深部的燕山期岩浆活动有关，成矿元素及硫主要来自岩浆，成矿流体以岩浆水为主。因此该矿床属于岩浆热液型多金属矿床。  相似文献   

铜陵地区老鸦岭层状钼矿床铅同位素组成研究   总被引：1，自引：0，他引：1  

喻钢  陈江峰  钱卉  陈树榆  杨刚  闫峻  张成火 《矿床地质》2004,23(4):422-430

安徽铜陵老鸦岭矿床中二叠系大隆组(P2d)顶部的含矿(钼矿化)黑色页岩以及附近(立新煤矿)同一层位不含矿黑色页岩的实测铅同位素组成分别为：^206Pb/^204Pb20.20～22.37,^207Pb/^204Pb15.67～15.82,^208Pb/^204Pb38.47～38.60和^206Pb/204Pb18.83～20.80,^207Pb/^204Pb15.65～15.76,^208Pb/^204Pb38．84～39．22。对137Ma的放射成因Pb进行校正后的铅同位素组成表明，含矿黑色页岩和不含矿黑色页岩均与燕山晚期火成岩无关，老鸦岭含矿黑色页岩可能具沉积成因。对沉积(约250Ma)以来的放射成因Pb进行校正后的铅同位素组成表明：不含矿黑色页岩的Pb源自上地壳，而含矿黑色页岩的Pb(因而推测其他成矿金属)可能源于上地壳物质(与不含矿黑色页岩的Pb源相似)与下地壳物质的混合。  相似文献   

地质雷达快速检测运营公路隧道隐患   总被引：4，自引：0，他引：4  

赵天库  葛为中  张忠良 《上海国土资源》2004,18(3):62-66

为了评价运行多年隧道的衬砌质量，查找隐患，开展了拱顶的地质雷达无损快速检测。在雷达波形剖面图上分析空洞、不密实异常，推断出大量隐患。物探成果经过开凿验证，证明其隐患定位成功率在85％以上。地质雷达快速检测方法为隧道病害治理提供了可靠的基础资料。  相似文献   

中国2010年上海世博会场址区地质环境条件分析与评价     

张鹏飞  史玉金  曾正强  严学新 《上海国土资源》2004,(4):1-6

文章在简要介绍世博会场址地质条件的基础上，分别分析了场址区流砂、软土和地下水等不良地质现象对工程建设的影响，然后评价了场址区天然地基工程、桩基工程以及地下工程建设的适宜性，为世博会场址区工程建设提供必要的地质依据。  相似文献   

Estimate of Loading Rate for a TBM Machine Based on Measured Cutter Forces   总被引：1，自引：1，他引：1  

Z. X. Zhang 《Rock Mechanics and Rock Engineering》2004,37(3):239-248

  相似文献   

Removal of Cu(Ⅱ) from Wastewater Using Acidified Sewage Sludge Ash     

Gan Yiqun  Wang Yanxin  Zhang Congjun 《中国地质大学学报(英文版)》2004,15(3)

Sewage sludge ash (SSA), the waste generated in sewage sludge incineration, was obtained from Wuhan Sewage Treatment Plant and used as a low-cost sorbent for removing Cu(Ⅱ) from wastewaters. The sorbent was first modified with 5 % sulfuric acid to increase its sorption capacity. The specific surface area, porosity, cation-exchange capacity (CEC) and pHZPC of the sorbent were measured. Batch experiments were made to study the effect of contact time, solution pH value and temperature on sorption. Both Langmuir and Freundlich models well described the Cu(Ⅱ) sorption process, with correlation coefficient (R2) values of 0.993 4 and 0.989 9 respectively. And the sorption process follows the Lagergren first order kinetic model. The equilibrium sorption capacity of acidified SSA to Cu(Ⅱ) is estimated to be 7.78 mg/g under optimal conditions.  相似文献   

Geochronology and petrogenesis of the post-orogenic Cu–Ni sulfide-bearing mafic–ultramafic complexes in Jilin Province, NE China     

Fu-yuan Wu  Simon A. Wilde  Guang-liang Zhang  De-you Sun 《Journal of Asian Earth Sciences》2004,23(5):781

Northeastern (NE) China is a well-documented example of a collisional zone characterized by widespread post-orogenic granites and mafic–ultramafic complexes. Based on a study of the Hongqiling and Piaohechuan Cu–Ni sulfide-bearing mafic–ultramafic complexes in central Jilin province, we present geological, petrological, geochemical and geochronological data which indicates their post-orogenic origin.The Hongqiling complex comprises pyroxenite, olivine websterite, lherzolite, gabbro and leucogabbro. Zircon U–Pb SHRIMP analyses on a leucogabbro of the Hongqiling complex yield a weighted mean ²⁰⁶Pb–²³⁸U age of 216±5 Ma. The Piaohechuan complex is composed of gabbro, pyroxenite and dolerite, exposed as dikes. A plagioclase-bearing pyroxenite has a U–Pb zircon weighted mean ²⁰⁶Pb–²³⁸U age of 217±3 Ma, identical to that of the Hongqiling complex. These ages are coeval with the emplacement of A-type granites in the area, but slightly younger than the regional metamorphism (240 Ma) and syn-orogenic granitic magmatism (246±4 Ma). This suggests that these mafic–ultramafic complexes are post-orogenic in origin. The age data also indicated a short period of lithospheric stabilization of about 30 Ma after cessation of orogenic activity.Geochemical investigation indicates that the primary mafic magma was a lithospheric mantle-derived basalt resulting from the upwelling of asthenosphere due to lithospheric delamination during post-orogenic processes. The magmatic source was contaminated by a small amount of crustal material, and subsequent crystal fractionation resulted in the Cu–Ni mineralization.The widespread occurrence of mafic–ultramafic complexes in the Xing'an–Mongolian Orogenic Belt of NE China and in the Altay–Tianshan–Junggar Orogenic Belt of Northern Xinjiang indicates that mafic intrusions are an important magmatic suite that evolved during post-orogenic processes. Portions of this mafic magma could have underplated the lower crust, and served as the heat source for associated late-stage granitic magmas.  相似文献   

Continental crustal growth and the supercontinental cycle: evidence from the Central Asian Orogenic Belt   总被引：15，自引：0，他引：15  

Dawei Hong  Jisheng Zhang  Tao Wang  Shiguang Wang  Xilin Xie 《Journal of Asian Earth Sciences》2004,23(5):799

Studies of supercontinental cycle are mainly concentrated on the assembly, breakup and dispersal of supercontinents, and studies of continental crustal growth largely on the growth and loss (recycling) of the crust. These two problems have long been studied separately from each other. The Paleozoic–Mesozoic granites in the Central Asian Orogenic Belt have commonly positive Nd values, implying large-scale continental crustal growth in the Phanerozoic. They coincided temporally and spatially with the Phanerozoic Pangea supercontinental cycle, and overlapped in space with the P-wave high-V anomalies and calculated positions of subducted slabs for the last 180 Ma, all this suggests that the Phanerozoic Laurasia supercontinental assembly was accompanied by large-scale continental crustal growth in central Asia. Based on these observations, this paper proposes that there may be close and original correlations between a supercontinental cycle, continental crustal growth and catastrophic slab avalanches in the mantle. In this model we suggest that rapid continental crustal growth occurred during supercontinent assembly, whereas during supercontinental breakup and dispersal new additions of the crust were balanced by losses, resulting in a steady state system. Supercontinental cycle and continental crustal growth are both governed by changing patterns of mantle convection.  相似文献