隧道衬砌质量地质雷达检测研究   总被引：2，自引：0，他引：2  

吴彬  李远强  黄来源  李军辉 《城市地质》2008,3(2):39-42

采用地质雷达检测的方法可以对隧道衬砌混凝土的厚度,密实性,脱空,钢格栅数量等进行快速检测,这种检测方法不仅克服了目测不准确及打孔抽查检测不全面的缺点,而且以其高分辨率,高准确性,探测快速及无损检测的优,点,在隧道衬砌质量检测中取得了非常明显的效果,并得到了广泛的应用。地质雷达在隧道检测中所暴露的技术问题也亟待解决。本文介绍了地质雷达在隧道衬砌质量检测中的实际应用,研究了在不同的隧道衬砌设计条件下的雷达探测方式,雷达天线频率的选择、参数选择和检测成果。  相似文献   

2012年4月2日华东灾害性飑线大风成因分析   总被引：4，自引：0，他引：4  

李艳芳  程胜  吴彬 《河南气象》2014,(4):59-65

2012年4月2-3日华东地区出现8～11级灾害性大风,此次大风影响时间长,持续强度大,造成了严重的人员伤亡和经济损失。为探讨大风天气成因,运用传统的天气学方法和多普勒雷达等资料,对此次飑线大风过程产生的天气背景及中尺度发展演变特征进行了分析。结果表明,此次大风是由中尺度系统飑线和冷空气共同影响造成的。前期是在江淮气旋天气背景下,近地面激发出中尺度飑线系统,飑线经历了形成、发展、减弱三个阶段,在每个阶段,雷达强度图上的回波形状、强度、回波顶高,以及速度图上的逆风区、速度模糊等特征都与实况有很好的对应关系;在发展成熟阶段出现了冷湿雷暴高压和冷池,加剧了大风的发展和维持。后期大风主要是受冷空气影响产生。在实际业务工作中,传统的天气学分析方法和以多普勒雷达为代表的先进探测手段相结合,是监测和预警此类强对流天气的主要手段,能够在一定程度上弥补数值预报模式的不足。  相似文献   

Chemical dispersant effectiveness testing: influence of droplet coalescence     

Sterling MC  Bonner JS  Ernest AN  Page CA  Autenrieth RL 《Marine pollution bulletin》2004,48(9-10):969-977

Thermodynamic and kinetic investigations were performed to determine the influence of coalescence of chemically dispersed crude oil droplets in saline waters. For the range of pH (4-10) and salinity (10 per thousand, 30 per thousand, 50 per thousand ) values studied, zeta-potential values ranged from -3 to -10 mV. As the interaction potential values calculated using Derjaguin-Landau-Verway-Overbeek (DLVO) theory were negative, the electrostatic barrier did not produce significant resistance to droplet coalescence. Coalescence kinetics of premixed crude oil and chemical dispersant were determined within a range of mean shear rates (Gm = 5, 10, 15, 20 s(-1)) and salinity (10 per thousand, 30 per thousand ) values. Coalescence reaction rates were modeled using Smoluchowski reaction kinetics. Measured collision efficiency values (alpha = 0.25) suggest insignificant resistance to coalescence in shear systems. Experimentally determined dispersant efficiencies (alpha = 0.35) were 10-50% lower than that predicted using a non-interacting droplet model (alpha = 0.0). Unlike other protocols in which the crude oil and dispersant are not premixed, salinity effects were not significant in this protocol. This approach allowed the effects of dispersant-oil contact efficiency eta(contact) to be separated from those of water column transport efficiency (eta(transport)) and coalescence efficiency (eta(coalescence)).  相似文献   

共有建筑面积分摊的城市综合体功能区划分方法     

赵海云  张馨元  吴彬  余哲 《测绘通报》2017,(10):79-83

功能区划分直接影响分摊结果,进而影响房产面积的真实性和可靠性。建筑空间或综合体的结构、服务功能、使用对象交织错落,增加了功能区划分的复杂性。本文对一个城市综合体进行了案例分析,提出了共有面积中功能区服务范围为主、用途为辅的划分方法。  相似文献   

查明不同岩溶危险区的三维工程地震勘探的基本方法     

波格.  MC  刘吉成 《国土资源信息化》1994,(1):31-33

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基于无人机摄影测量技术的高陡边坡危岩体特征构建与分析     

付德荃  王珊珊  吴彬  夏鑫 《地球学报》2024,45(1):53-62

在高陡边坡的危岩体调查中, 受限于调查人员可到达的范围, 难以获取危岩体的特征参数, 从而影响危岩体的稳定性判别。无人机摄影测量技术能够安全、快速、全面、精准的获取危岩体的特征信息。本文以鸡冠岭崩塌隐患为例, 利用无人机摄影测量技术获取坡面高精度影像, 通过提取点云数据构建三维模型, 基于最小二乘法完成平面拟合获取危岩体的体积及结构面产状信息, 并结合实际测量数据, 采用赤平极射投影法和极限平衡法定性和定量评价危岩体的稳定性。经过分析计算, 鸡冠岭崩塌四处主要危岩体的体积分别为102.86 m3、355.27 m3、236.60 m3和454.91 m3, 根据定性分析和定量计算, 危岩体均为欠稳定状态。通过本文的实践, 体现了无人机摄影测量技术在识别高位隐蔽危岩体方面的优势, 对于发展基于无人机摄影测量技术定量判定危岩体的稳定性方面具有借鉴意义。  相似文献   

Characterizing aquatic sediment-oil aggregates using in situ instruments     

Sterling MC  Bonner JS  Ernest AN  Page CA  Autenrieth RL 《Marine pollution bulletin》2004,48(5-6):533-542

The effects of emulsified crude oil and salinity (15, 30 per thousand ) on the steady state aggregate volume distributions and fractal dimensions were determined for a range of mean velocity gradients, (G(m) =5-50 s(-1)). Aggregation was performed in a 40-L cylindrical tank with a 4-blade paddle mixer. Three-dimensional fractal dimensions (D3) and volume distributions were determined using a procedure integrating data from an electrozone and an in situ light scattering instrument. Two-dimensional fractal dimensions (D2) and derived volume distributions were determined using a recently developed submersible flow cytometer equipped with a digital camera and image analysis software. For latex beads or emulsified crude oil systems, the above listed instruments yielded consistent size distributions and fractal dimensions (D2=1.92 +/- 0.16, D3=2.94 +/- 0.12). Mean volume aggregate diameters determined using the FlowCAM were consistently larger that those determined using the LISST-100 or Coulter Multisizer due to aggregate orientations during measurements. With increasing G(m) values, all colloidal aggregates showed increasing D3 values due to reduced aggregate length. Because of the compactness of all the aggregates (D3 >2), D2 values remained constant at 2. Neither salinity nor sediment type significantly affected D2 values calculated for sediment-crude oil aggregates. However, clay-oil aggregates showed higher D3 values than clay aggregates. This suggests that colloidal oil and mixing shear are the more dominant factors influencing aggregate morphology in nearshore waters. Overall, the data suggests that the analysis methods provide consistent size distribution results. However, because of the shear and salinity of coastal waters, resulting aggregates are too compact to estimate their D3 values using image analysis alone.  相似文献   

Biomarkers for endocrine disruptors in three species of Mediterranean large pelagic fish   总被引：2，自引：0，他引：2  

Fossi MC  Casini S  Marsili L  Neri G  Mori G  Ancora S  Moscatelli A  Ausili A  Notarbartolo-di-Sciara G 《Marine environmental research》2002,54(3-5):667-671

The hypothesis that Mediterranean top predator species, such as large pelagic fish, are potentially at risk due to endocrine disrupting chemicals (EDCs), is investigated. The potential estrogenic effects of PHAHs in three fish species of commercial interest, the top predators bluefin tuna (Thunnus thynnus thynnus), swordfish (Xiphias gladius), and Mediterranean spearfish (Tetrapturus belone), were investigated using vitellogenin (Vtg), zona radiata proteins (Zrp) and mixed function oxidases (EROD, BPMO) as diagnostic tools. High induction of Vtg and Zrp was detected by western blot and ELISA techniques in adult males of X. gladius and T. thynnus thynnus, suggesting that these species are at high toxicological risk in the Mediterranean sea. Comparison of BPMO and EROD activities in the three species indicated, both in male and female, much higher MFO activity in bluefin tuna. This data suggests high exposure of this species to lipophilic xenobiotic contaminants in the Mediterranean environment.  相似文献   

房产测量中"谁使用谁分摊"原则的适用性研究     

赵海云  吴彬  张馨元  黄荣萍 《测绘通报》2016,(9):77-80

"谁使用谁分摊"原则在房产测绘中存在误用滥用的情形。本文利用经济外部性等理论对"谁使用谁分摊"原则的局限性进行了系统分析,提出了适用条件,包括分摊主体产权明晰、分摊对象同一层级且功能单一、分摊评价标准统一、局部空间与整体空间不发生冲突等,为正确运用"谁使用谁分摊"作了初步探索。  相似文献   

西南三江兰坪盆地金满铜矿床成因研究:来自铜和硫同位素的联合约束   总被引：7，自引：4，他引：3  

杨立飞  石康兴  王长明  吴彬  杜斌  陈晶源  夏锦胜  陈晶 《岩石学报》2016,32(8):2392-2406

三江地区兰坪盆地中-新生代砂岩和板岩中赋存有脉状铜矿床,其成因一直存在争议。本文选取金满矿床作为实例进行了详细的铜和硫同位素研究。解析了该矿床成矿物质来源及其富集机理。研究表明金满矿床具有多期性、成矿物质多来源性。硫同位素数据显示,大部分分布在-5.0‰~+3.4‰之间,个别富集硫的轻同位素,δ~(34)S值达-10.1‰、-11.4‰、-11.6‰,认为硫主要来源于盆地蒸发岩硫酸盐,通过有机质热分解作用还原成H_2S,同时有少量生物成因硫及深部来源硫。铜同位素研究表明,成矿早阶段铜同位素δ~(65)Cu值在零附近,铜主要来源于深部地壳或上地幔,晚阶段硫化物富集铜的轻同位素,δ~(65)Cu值达-1.10‰、-1.02‰,铜主要来自盆地内成矿流体流经的地层。结合研究区成矿物质来源、流体性质及地质背景,认为不同性质流体混合发生氧化还原作用促使金属硫化物沉淀是金满矿床主要形成机制。另外,成矿流体沿断裂上涌,外界条件突变,压力下降,气体逸出等过程对硫化物沉淀也起到一定作用。  相似文献