排序方式： 共有55条查询结果，搜索用时 31 毫秒
41.
在灾害环境下，对UWB基站/标签相对位置关系、不同天线指向方向、不同基站布设高度、不同基站数量和不同布设网型5个方面分别进行试验研究。试验结果表明，基站高度对UWB定位精度没有明显影响、标签越靠近基站网型中心定位精度越高、天线方向竖直向上时定位精度更高、基站数量越多定位精度越高、常用网型中矩形网型精度较高。应急环境下，按“以定位区域为中心、天线竖直向上、基站数量尽可能多、矩形网型”的方案布设UWB基站，以最短的时间获得次优定位精度，为UWB应急定位实际应用提供可行基站布设指导和依据。 相似文献
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南祁连化隆地区镁铁-超镁铁质侵入岩地质、地球化学特征与铜镍成矿 总被引：1，自引：0，他引：1
南祁连化隆地区的镁铁-超镁铁质侵入岩带是青海省重要的含镍矿岩带,铁质系列良好的岩相分异及较高的Ni、Cu、Co元素含量表现出了很好的成矿条件与找矿潜力。通过对区内裕龙沟、亚曲、阿什贡及下什堂等岩体地质特征、岩石地球化学特征及区域对比分析研究,表明稀土元素的球粒陨石和微量元素的原始地幔蛛网图表现出轻稀土元素相对富集的右倾模式,并且富集大离子亲石元素(Sr、Rb、Ba)、相对亏损高场强元素(Nb、Ta、Hf、Zr)。γOs值表现为大的正值且变化范围较大(+80~+1183),连同普遍存在的Nb、Ta亏损,进一步说明可能也与地壳同化混染密切相关。这些表明带内岩体的母岩浆来自一个曾被交代富集的地幔源区,其εNd(t)=-7.74~+8.36,这些共同表明其岩浆源区应该位于软流圈地幔,并混有一部分被俯冲板片交代的地幔楔物质。而这种交代富集事件可能与祁连、柴北缘在早古生代期间大规模的板片俯冲有关。化隆群富硅地层为硫化物的不混溶创造了同化混染的条件,并最终导致富硅物质的加入,致使岩浆中硫化物的不混溶作用发生,从而可形成不同品位不同类型的岩浆铜镍硫化物矿床。 相似文献
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沙井子构造带位于塔里木盆地西北缘,是分隔阿瓦提凹陷和温宿凸起的边界断裂。它是塔里木盆地研究最薄弱的大型断裂构造带之一。根据系统、精细的地震资料解释,沙井子构造带存在3套断裂体系:深部楔状冲断构造、狭义沙井子断裂和浅部的伸张构造。深部楔状冲断构造形成于志留纪—泥盆纪,由北西倾向的主冲断层和南东倾向的反冲断层形成构造楔; 构造楔主要由前寒武纪变质岩组成,冲断前锋楔入于寒武系中部,造成上覆地层向温宿凸起方向的急剧抬升。狭义的沙井子断裂,即通常所说的沙井子断裂,为一条高角度基底卷入型挤压走滑断裂,形成于二叠纪末—三叠纪初,错断了早期的深部冲断楔。浅部的伸展构造形成于第四纪早-中期,为一系列较小规模的正断层,沿狭义沙井子断裂呈右步雁列状排列,构成左行剪切张扭性断裂带。深部的楔状冲断构造和浅部的伸展构造是本次研究的新发现。 相似文献
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Phenol is one of the main pollutants in phenol wastewater and has been proved non‐biodegradable. In this study, based on strongly ring‐opening capability of boron doped diamond film electrode, a highly efficient and energy‐saving method with ultra‐low carbon emission is established through a combination of electrochemical oxidation and biological degradation. On one hand, electrochemical oxidation as pretreatment can solve the critical problem that phenol wastewater is a biological recalcitrant. On the other hand, the relatively low current efficiency during the late stage of electrochemical oxidation can be solved by follow‐up biological treatment, thus reduce the energy consumption and the cost significantly. More importantly, the carboxylic acids (oxidized from phenol) can be fully used as carbon source (no additional carbon source is added) for microbial growth instead of being oxidized to carbon dioxide and water through selecting optimizing sequencing batch reactor access time, so the carbon emission is greatly reduced. The results showed that it can save about 76.5% energy consumption and about 51.2% chemical oxygen demand can be used to maintain microorganism self‐reproduction. This is significant that this combined technology not only runs highly effectively at low cost, but also reduces the emission of greenhouse gas, carbon dioxide, thus environment friendly with wide application prospects. 相似文献
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卡拉库姆盆地位于中亚地区图兰地台南部,北西走向,是中亚地区最重要的含油气盆地之一。对于盆地晚二叠世-三叠纪的构造属性一直都存在着很多争论,我们根据钻井、地球物理及露头资料,认为卡拉库姆盆地是以增生杂岩为基底形成的一个沉积盆地,晚二叠世-三叠纪具有弧后裂谷的性质。卡拉库姆盆地前侏罗纪的构造演化分为4个阶段:1)石炭纪之前古特提斯洋壳开始俯冲增生; 2)石炭纪-早二叠世形成丝路弧; 3)晚二叠世-三叠纪马什哈德-北帕米尔弧形成,卡拉库姆盆地处于弧后拉张的位置; 4)晚三叠世末伊朗等地块与欧亚大陆碰撞,卡拉库姆盆地进入短暂的周缘前陆盆地阶段。其晚二叠世-三叠纪的沉积中心在北阿姆河坳陷,木尔加布坳陷和科佩特山前坳陷,沉积环境主要为陆相,三叠纪发生海侵,部分地区接受海相沉积。岩石类型主要为陆源碎屑岩、火山岩及少量灰岩。 相似文献
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Elevated fluoride (F) concentration in groundwater is posing a public health risk in the Manas River Basin (MRB), Northwest China. Based on the characterization of regional groundwater flow, 90 groundwater samples from aquifers were analyzed, along with top-soil leachate and pore-water samples from aquitards. Stable oxygen (δ18O) and hydrogen isotopes, radiocarbon and hydrochemical analyses of the groundwater and pore-water samples were conducted to trace groundwater hydrological and hydrochemical processes and thereby understand the distribution and migration mechanism of F. The groundwater is recharged by meteoric precipitation through vapor condensation processes in the Tianshan Mountains. The F concentration in groundwater samples from this basin ranged from 0.11 to 48.15 mg/L (mean 2.56 mg/L). In 37 of the 90 groundwater samples, the F concentrations were above the safe level for drinking water. The F concentrations progressively increased with the residence time and well depths in the northwest of the alluvial-fluvial plain, where groundwater is overexploited for agricultural and domestic use. Positive correlations between F and sodium (Na)/calcium (Ca) indicate that the enrichment and migration of F are influenced by cation exchange processes under high-Na and alkaline pH conditions. The relationships between δ18O and F and chloride (Cl) concentrations were nonlinear due to leaching and mixing processes. This shows that vertical leaching by irrigation return flow and mixing with pore water are the dominant processes driving the migration of F in the groundwater flow system of MRB, in addition to geochemical processes. 相似文献
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吐木休克断裂位于塔里木盆地西部,巴楚隆起和阿瓦提凹陷之间,是一条大型基底卷入型冲断构造。走向NW‐SE,呈弧形向NEE凸出;倾向巴楚隆起。根据构造变形特征,断裂自NW向SE可以划分为4段。Ⅰ和Ⅲ段为简单基底卷入型冲断构造段;Ⅱ段发育背冲断层,与主干断层呈“y”字型剖面组合关系;Ⅳ段为基底卷入型楔状构造,主冲断层顶部出现一条向巴楚隆起逆冲的反冲断层。断裂上盘发育背斜,下盘有明显的“牵引构造”,显示吐木休克断裂可能是由吐木休克背斜北翼突破形成的,是一条褶皱相关断层。吐木休克断裂形成于中新世晚期至上新世初,持续演化至第四纪。断裂带上发育的上新世末—第四纪初正断层代表印度—亚洲碰撞脉动式远程效应的一个构造间歇期。吐木休克断裂东侧的巴东断裂是巴楚隆起与塔中隆起的过渡构造带,雏形形成于奥陶纪晚期—志留纪,晚新生代复活。 相似文献
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东昆仑冰沟南铜镍矿锆石SHRIMP U Pb年龄及构造意义 总被引：5，自引：0，他引：5
冰沟南镁铁—超镁铁质岩体位于东昆仑造山带西段祁漫塔格岩浆岩带内,邻近昆北断裂,主要由橄榄辉石岩、辉长岩、闪长岩及辉长辉绿岩脉构成,铜镍矿体仅赋存于橄榄辉石岩中。岩体地质特征、岩石地球化学特征及矿体地质特征表明,成矿岩体为铁质系列的基性-超基性岩,岩性为含长橄榄辉石岩。锆石SHRIMP U-Pb同位素测年获得含长橄榄辉石岩年龄为377.8±3.4Ma,为晚古生代岩浆作用的产物,这也是东昆仑造山带目前发现时代较新的岩浆铜镍矿床。岩石Sr-Nd同位素特征表明,(~(87)Sr/~(86)Sr)_i值在0.7057~0.7105之间,变化范围相对较宽,ε_(Nd)(t)值变化在2.35~3.81之间,均为正值。推测矿床形成过程为幔源岩浆上涌过程中,由于地壳物质的加入,伴随着同化混染作用的发生,岩浆中S达到饱和,进而硫化物发生不混溶作用,富含硫化物的岩浆运移至东昆仑造山带邻近昆北断裂构造薄弱的部位成岩成矿。冰沟南铜镍矿床可能是形成于造山后伸展背景,与夏日哈木超大型铜镍硫化物矿床形成时的构造背景不同,本次研究对东昆仑造山带同类矿床的勘查评价工作具有一定指导意义。 相似文献