Transparent characterization and quantitative analysis of broken gangue's 3D fabric under the bearing compression

Broken gangue has been extensively used in rockfill dams,subgrade,embankment,foundation cushion and other engineering construction.The deformation characteristics of broken gangue under the bearing compression play a decisive role in the firmness,stability and safety of these structures(buildings),and the meso-fabric change of broken gangue under the bearing compression significantly affects its macro deformation.In this study,the transparent characterization and quantitative analysis of 3D fabric of broken gangue under the bearing compression were performed through CT scanning test,image processing and 3D reconstruction technology,and the influence mechanism of internal fabric of broken gangue on its macro deformation was revealed.The results show that:In the loading stage of 0–2 MPa,the sharp corners,thin edges on the blocks and the bar-shaped and blade-shaped blocks with poor regularity are broken first under the bearing compression;in the loading stage of 2–8 MPa,a large number of larger particles in the sample are crushed in the mode of fragmentation;in the loading stage of 8–10 MPa,the breakage degree of samples is relieved.The axial displacement of the block inside the sample occurs,as well as the lateral displacement of the block converging to the central axis of the sample.In the rapid deformation stage,the macro deformation of the broken gangue is mainly caused by the rearrangement and adjustment of the block structure and the breakage of the block;in the slow deformation stage,it is mainly caused by the breakage of the block;in the stable deformation stage,it is mainly caused by the optimization and adjustment of the bearing skeleton in the sample.

Surface characteristics analysis of fractures induced by supercritical CO_(2)and water through three-dimensional scanning and scanning electron micrography

Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyzed the fracture surface characteristics induced by supercritical carbon dioxide(SC-CO_(2))and water in open-hole and perforation completion conditions under triaxial stresses.A simple calculation method was proposed to quantitatively analyze the fracture surface area and roughness in macro-level based on three-dimensional(3D)scanning data.In micro-level,scanning electron micrograph(SEM)was used to analyze the features of fracture surface.The results showed that the surface area of the induced fracture increases with perforation angle for both SC-CO_(2)and water fracturing,and the surface area of SC-CO_(2)-induced fracture is 6.49%e58.57%larger than that of water-induced fracture.The fractal dimension and surface roughness of water-induced fractures increase with the increase in perforation angle,while those of SC-CO_(2)-induced fractures decrease with the increasing perforation angle.A considerable number of microcracks and particle peeling pits can be observed on SC-CO_(2)-induced fracture surface while there are more flat particle surfaces in water-induced fracture surface through SEM images,indicating that fractures tend to propagate along the boundary of the particle for SC-CO_(2)fracturing while water-induced fractures prefer to cut through particles.These findings are of great significance for analyzing fracture mechanism and evaluating fracturing stimulation performance.

Three-dimensional mixed convection stagnation-point fow past a vertical surface with second-order slip velocity

This study is concerned with the three-dimensional(3D)stagnation-point for the mixed convection flow past a vertical surface considering the first-order and secondorder velocity slips.To the authors’knowledge,this is the first study presenting this very interesting analysis.Nonlinear partial differential equations for the flow problem are transformed into nonlinear ordinary differential equations(ODEs)by using appropriate similarity transformation.These ODEs with the corresponding boundary conditions are numerically solved by utilizing the bvp4c solver in MATLAB programming language.The effects of the governing parameters on the non-dimensional velocity profiles,temperature profiles,skin friction coefficients,and the local Nusselt number are presented in detail through a series of graphs and tables.Interestingly,it is reported that the reduced skin friction coefficient decreases for the assisting flow situation and increases for the opposing flow situation.The numerical computations of the present work are compared with those from other research available in specific situations,and an excellent consensus is observed.Another exciting feature for this work is the existence of dual solutions.An important remark is that the dual solutions exist for both assisting and opposing flows.A linear stability analysis is performed showing that one solution is stable and the other solution is not stable.We notice that the mixed convection and velocity slip parameters have strong effects on the flow characteristics.These effects are depicted in graphs and discussed in this paper.The obtained results show that the first-order and second-order slip parameters have a considerable effect on the flow,as well as on the heat transfer characteristics.

Stochastic analysis of excavation-induced wall deflection and box culvert settlement considering spatial variability of soil stiffness

In this study, a three-dimensional (3D) finite element modelling (FEM) analysis is carried out to investigate the effects of soil spatial variability on the response of retaining walls and an adjacent box culvert due to a braced excavation. The spatial variability of soil stiffness is modelled using a variogram and calibrated by high-quality experimental data. Multiple random field samples (RFSs) of soil stiffness are generated using geostatistical analysis and mapped onto a finite element mesh for stochastic analysis of excavation-induced structural responses by Monte Carlo simulation. It is found that the spatial variability of soil stiffness can be described by an exponential variogram, and the associated vertical correlation length is varied from 1.3 m to 1.6 m. It also reveals that the spatial variability of soil stiffness has a significant effect on the variations of retaining wall deflections and box culvert settlements. The ignorance of spatial variability in 3D FEM can result in an underestimation of lateral wall deflections and culvert settlements. Thus, the stochastic structural responses obtained from the 3D analysis could serve as an effective aid for probabilistic design and analysis of excavations.

Incremental Linear Discriminant Analysis Dimensionality Reduction and 3D Dynamic Hierarchical Clustering WSNs

Optimizing the sensor energy is one of the most important concern in Three-Dimensional(3D)Wireless Sensor Networks(WSNs).An improved dynamic hierarchical clustering has been used in previous works that computes optimum clusters count and thus,the total consumption of energy is optimal.However,the computational complexity will be increased due to data dimension,and this leads to increase in delay in network data transmission and reception.For solving the above-mentioned issues,an efficient dimensionality reduction model based on Incremental Linear Discriminant Analysis(ILDA)is proposed for 3D hierarchical clustering WSNs.The major objective of the proposed work is to design an efficient dimensionality reduction and energy efficient clustering algorithm in 3D hierarchical clustering WSNs.This ILDA approach consists of four major steps such as data dimension reduction,distance similarity index introduction,double cluster head technique and node dormancy approach.This protocol differs from normal hierarchical routing protocols in formulating the Cluster Head(CH)selection technique.According to node’s position and residual energy,optimal cluster-head function is generated,and every CH is elected by this formulation.For a 3D spherical structure,under the same network condition,the performance of the proposed ILDA with Improved Dynamic Hierarchical Clustering(IDHC)is compared with Distributed Energy-Efficient Clustering(DEEC),Hybrid Energy Efficient Distributed(HEED)and Stable Election Protocol(SEP)techniques.It is observed that the proposed ILDA based IDHC approach provides better results with respect to Throughput,network residual energy,network lifetime and first node death round.

Methods of configuration test and deformation analysis for large airship

In recent years, high-altitude aerostats have been increasingly developed in the direction of multi-functionality and large size. Due to the large size and the high flexibility, new challenges for large aerostats have appeared in the configuration test and the deformation analysis. The methods of the configuration test and the deformation analysis for large airship have been researched and discussed. A tested method of the configuration,named internal scanning, is established to quickly obtain the spatial information of all surfaces for the large airship by the three-dimensional(3D) laser scanning technology. By using the surface wrap method, the configuration parameters of the large airship are calculated. According to the test data of the configuration, the structural dimensions such as the distances between the characteristic sections are measured. The method of the deformation analysis for the airship contains the algorithm of nonuniform rational B-splines(NURBS) and the finite element(FE)method. The algorithm of NURBS is used to obtain the reconfiguration model of the large airship. The seams are considered and the seam areas are divided. The FE model of the middle part of the large airship is established. The distributions of the stress and the strain for the large airship are obtained by the FE method. The position of the larger deformation for the airship is found.

天青A比色法测定海藻中3-(6-脱氧-6-磺酸基-α-D-吡喃型葡萄糖苷基)-sn-酰基甘油脂的含量

提出快速、准确地测定海藻中 3 ( 6 脱氧 6 磺酸基 α D 吡喃型葡萄糖苷基 ) sn 酰基甘油脂 (sulfoquinovosylacylglyc erol,SQAG)含量的方法。该方法是根据天青A能与SQAG形成 1种可溶于氯仿的天蓝色复合物 ,在一定范围内 ,SQAG的量和反应液的颜色强度呈比例关系 ,线性范围为 0 .0 0 44 2～ 0 .114 88μmol,检测限为 0 .0 0 44 2 μmol,该测定方法操作简单、重现性好。经过实验和统计学分析表明 ,海藻中的色素等成分对本方法测定SQAG结果影响较小 ,因此从海藻中提取样品后 ,可以直接采用天青A比色法测定SQAG含量。

海藻中3-(6-脱氧-6-磺酸基-α-D-吡喃型葡萄糖苷基)-sn-酰基甘油脂含量测定方法

介绍了一种快速、准确地测定3-(6-脱氧-6-磺酸基-α-D-吡喃型葡萄糖苷基)-sn-酰基甘油脂的方法。测定方法是基于苯酚和糖类能在浓硫酸快速加热下形成一种有色复合物。经过实验和统计学分析,结果表明酰基链对测定结果没有影响。该测定方法有较高的灵敏度和准确度,而且可以直接测定从薄层层析板获得的样品。

Multi-Schlieren CT Measurements of Supersonic Microjets from Circular and Square Micro Nozzles

Instantaneous three-dimensional (3D) density distributions of a shock-cell structure of perfectly and imperfectly expanded supersonic microjets escaping into an ambient space are measured. For the 3D observation of supersonic microjets, non-scanning 3D computerized tomography (CT) technique using a 20-directional quantitative schlieren optical system with flashlight source is employed for simultaneous schlieren photography. The 3D density distributions data of the microjets are obtained by 3D-CT reconstruction of the projection’s images using maximum likelihood-expectation maximization. Axisymmetric convergent-divergent (Laval) circular and square micro nozzles with operating nozzle pressure ratio 5.0, 4.5, 4.0, 3.67, and 3.5 have been studied. This study examines perfectly expanded, overexpanded, and underexpanded supersonic microjets issued from micro nozzles with fully expanded jet Mach numbers Mj ranging from 1.47 - 1.71, where the design Mach number is Md = 1.5. A complex phenomenon for free square microjets called axis switching is clearly observed with two types “upright” and “diagonal” of “cross-shaped”. The initial axis-switching is 45° within the first shock-cell range. In addition, from the symmetry and diagonal views of square microjets for the first shock-cells, two different patterns of shock waves are viewed. The shock-cell spacing and supersonic core length for all nozzle pressure ratios are investigated and reported.

Quantitative data graphics in 3D desktop-based virtual environments-an evaluation

3D desktop-based virtual environments provide a means for displaying quantitative data in context.Data that are inherently spatial in three dimensions may benefit from visual exploration and analysis in relation to the environment in which they were collected and to which they relate.We empirically evaluate how effectively and efficiently such data can be visually analyzed in relation to location and landform in 3D versus 2D visualizations.In two experiments,participants performed visual analysis tasks in 2D and 3D visualizations and reported insights and their confidence in them.The results showed only small differences between the 2D and 3D visualizations in the performance measures that we evaluated:task completion time,confidence,complexity,and insight plausibility.However,we found differences for different datasets and settings suggesting that 3D visualizations or 2D representations,respectively,may be more or less useful for particular datasets and contexts.

3D-QSAR studies on glycogen phosphorylase inhibitors by flexible comparative molecular field analysis

Canceling grids accommodating probes in comparative molecular field analysis (CoMFA), the idea of flexibleness is introduced into the CoMFA, and in combination with swarm intelligent algorithm which attempts to optimize distributions of diverse probes around drug molecules, a new 3D-QSAR method is proposed in this context as flexible comparative molecular field analysis (FCoMFA). In preliminary at-tempts to performing QSAR studies on 47 glycogen phosphorylase inhibitors, FCoMFA is employed and confirmed to be potent to exploring ligand-receptor interaction manners at active positions and thus to generating stable and predictable models. Simultaneously by an intuitive graphics regarding probe distribution patterns, impacts of different substituted groups on activities is also given an insight into.

基于UHPLC法的巨豆三烯酮前体物同分异构体的定量分析及其在不同产地烟叶中的分布情况

以烟叶中重要致香成分巨豆三烯酮前体物(3-氧代-α-紫罗兰醇-β-D-吡喃葡萄糖苷)两种同分异构体,即(6R, 9R)-3-氧代-α-紫罗兰醇-β-D-吡喃葡萄糖苷(rrOIPG)和(6R, 9S)-3-氧代-α-紫罗兰醇-β-D-吡喃葡萄糖苷(rsOIPG)为研究对象,建立超声辅助萃取-超高效液相色谱法对rrOIPG和rsOIPG进行定量分析,并利用该方法考查国内外7个产地烟叶中两种同分异构体的分布情况。结果表明:rrOIPG和rsOIPG分别在25.85~258.50μg/mL(R2=0.999 1)和6.28~62.75μg/mL(R2=0.999 0)内具有良好的线性关系,检出限分别为2.5μg/mL和2.9μg/mL,仪器精密度较高,样品的稳定性和重复性较好,加标回收率分别为83.94%和105.90%,RSD分别为1.22%和1.93%;根据rrOIPG和rsOIPG含量分布可较好地区分国内外产地烟叶,国外产地烟叶中rsOIPG含量明显高于国内产地烟叶,且国内外产地烟叶中rrOIPG的含量均高于rsOIPG。该方法可行性较好,前处理步骤简单,适用于烟叶中rrOIPG和rsOIPG的定量分析。

Key Parameters Analysis and Regulation of Singlet Oxygen Quenching Rate of Carotenoids

28 kinds of carotenoids are studied to reveal the key parameters and regulation on the singlet oxygen quenching rate.First,the quantum chemistry parameters of carotenoids calculated by Gaussian software combined with substitution parameters were used to construct the quantitative structure-activity relationship model(QSAR)of the singlet oxygen quenching rate of carotenoids.The key parameters affecting the antioxidant activity of carotenoids are revealed,and the data predicted via the QSAR model were provided for subsequent research.Then,a three-dimensional(3D)pharmacophore model was used to regulate and modify the antioxidant activity of carotenoids.The correlation coefficients of the modeling group(R2)and verification group(Rpre2)of the established QSAR model were 0.945 and 0.916,respectively,which can be used for the analysis of antioxidant activity of carotenoids;the antioxidant activity of carotenoids can be significantly regulated by the number of conjugated C=C bonds,the energy difference between frontier molecular orbitals and the partial Mulliken charge in C1 and theπ···π*excitation energy E(s);the antioxidant activity of carotenoids can be effectively regulated by the hydrogen bond acceptor pharmacophores on both sides of the conjugated C=C bonds and the hydrophobic groups on the conjugated C=C bond;the hydrophobic substituents attached to conjugated C=C bonds can effectively improve the singlet oxygen quenching rate of carotenoids.

三维观测系统采集脚印定量分析技术

"采集脚印"是三维地震勘探中的一种地震噪声,是三维地震观测系统的固有属性,严重影响采集资料的振幅保真度及处理和解释效果。本文论述的三维观测系统采集脚印定量分析技术可定量描述三维观测系统接收、激发参数及施工方式与采集脚印的关系,综合考虑道距、接收线距、炮点距、炮线距、排列滚动线数、地层深度及变观方式等因素对形成采集脚印的影响,提供了从设计源头压制采集脚印、优化三维观测系统的方法。该方法在地震勘探实践中取得了良好的应用效果。

新型苯环5-(取代)苯甲酰胺基苯磺酰脲类化合物的比较定量构效关系研究

采用比较分子力场分析(CoMFA)方法,对26个新型苯环5-(取代)苯甲酰胺基苯磺酰脲类化合物的除草活性进行了三维定量构效关系(3D-QSAR)研究,建立了三维定量构效关系CoMFA模型(R2=0.948,F=91.364,SE=0.141).结果表明,此类磺酰脲类化合物的除草活性与苯环5位取代基的立体结构和电场性质密切相关.根据CoMFA模型的立体场和静电场三维等值线图不仅直观地解释了结构与活性的关系,而且为进一步设计高活性的目标化合物提供理论依据.

骨计量学方法在骨质疏松模型中的定量观察

目的观察骨结构与骨质疏松关系即骨构筑学的定量测量"骨质量"的价值,探讨骨组织形态计量学与μCT三维重建计量方法的价值意义。方法采用30只SD雌性大鼠,分成假手术组、切除卵巢去势组和去势后服用阿伦膦酸钠组,每组10只。在服药100 d后处死,进行全股骨骨密度测量及股骨下端不脱钙切片的骨计量学观察。三维重建采用美国GE公司eXplore Locus SP型μCT,用Micview V2.1.2重建软件选取股骨下端骨骺板下2 mm3兴趣窗进行结构计量测量。结果去势后骨体积密度显著性下降,由假手术组的(53.00±3.20)%降至(19.16±2.97)%(P<0.001);经二膦酸盐治疗后得到显著性改善(升至(40.40±3.07)%,与去势组比较P<0.001)。同时假手术组与去势组和去势组与二膦酸盐组之间,骨计量学指标中四环素标记率,类骨质的表面密度、平均类骨质表面厚度及动态指标,骨矿化沉积率与骨矿化延迟时间等均有显著性差异(P<0.05)。μCT结果显示骨小梁体积比与骨表面积体积比显示结果同骨计量学结果相似,数值均同比例减少。另外在三维结构计量上,除骨小梁厚度外,骨小梁数目、骨小梁间隙等均出现显著性变化。结论骨组织形态计量学与显微CT三维重建定量分析对骨结构与骨质量指标均能进行定性、定量的客观评价;骨计量学方法能从静态和动态两个方面反映骨新陈代谢过程,可以精确地反映出骨重建过程的变化规律和特点。

证据理论组合模型用于三维荧光光谱水质分析

为了充分利用三维荧光光谱信息,提高分析模型对水质综合指标的预测精度及稳健性,提出了一种基于D-S(Dempster-Shafe)证据理论的模型组合方法。传统的模型组合方法主要依赖于对某个单一的预测性能评价指标进行优化来确定组合权值,没有对多个性能指标进行综合性考虑。将三维荧光光谱看作多个不同波长的激发光照射下的发射光谱,基于每个发射光谱建立子模型,将多个性能指标作为证据,确定子模型的概率分配函数,然后基于DS证据合成理论对子模型的可信度进行评价并确定组合权值。实验以40个不同来源的地表水样本为研究对象,建立组合分析模型,对总有机碳值(TOC)进行定量分析。实验证明,组合模型相对于子模型而言各个评价指标均有较大提高,充分说明了该方法的有效性。

延庆地电阻率西洋参种植干扰有限元定量分析

依据测区地下构造条件、电性结构以及地电阻率特征,结合电测深曲线,建立三维有限元模型。通过数值模拟,计算测区内种植西洋参对地电阻率观测的影响形态和幅度。计算结果表明,在扣除地电阻率基准值后,西洋参种植干扰形态和幅度与实际观测值的异常变化较为吻合。

黄酮类化合物的3D-QSAR研究

从NCI数据库中,筛选出67个与矢车菊黄素类似的天然黄酮化合物。采用CoMFA方法研究其构效关系,构建CoMFA模型,其模型相关系数为q^2=0.599,r^2=0.919,验证模型的预测能力和拟合能力较好。通过分子场等势图,可直观分子周围立体和静电特征对化合物活性的影响,为设计高活性黄酮衍生物提供理论依据。

三维彩色多普勒超声定量血流分析在早期宫颈癌筛查诊断中的应用

目的探讨三维彩色多普勒超声定量血流分析在早期宫颈癌筛查诊断中的临床价值。方法选择早期宫颈癌患者60例为观察组,同时选择宫颈细胞学检查正常者60例为对照组。均行三维彩色多普勒超声定量血流分析,比较两组血流参数血管形成指数(VI)、血流指数(FI)、血管化血流指数(VFI)。结果观察组49例肿块内血管丰富,走形杂乱,其丰富的彩色血流呈"火球"状或网状,11例宫颈局部血流较丰富,三维成像后可见数支条状或"短棒"状血管,但无"火球"状表现;对照组宫颈仅显示宫颈内无或少许血流信号。两组VI、FI、VFI值随病变严重程度呈上升趋势,其宫颈血流信号随着宫颈病变升为恶性而明显增强,观察组定量血流分析参数值VI、FI、VFI均显著高于正常对照组,差异有统计学意义(P<0.05)。结论三维彩色多普勒超声定量血流分析参数VI、FI、VFI可提供宫颈肿块内血流情况,评估早期宫颈癌肿瘤血管生成,了解局部血供特点及血管生成状况,为早期宫颈癌的筛查诊断提供了重要诊断信息。