Quantitatively characterizing sandy soil structure altered by MICP using multi-level thresholding segmentation algorithm

The influences of biological,chemical,and flow processes on soil structure through microbially induced carbonate precipitation(MICP)are not yet fully understood.In this study,we use a multi-level thresholding segmentation algorithm,genetic algorithm(GA)enhanced Kapur entropy(KE)(GAE-KE),to accomplish quantitative characterization of sandy soil structure altered by MICP cementation.A sandy soil sample was treated using MICP method and scanned by the synchrotron radiation(SR)micro-CT with a resolution of 6.5 mm.After validation,tri-level thresholding segmentation using GAE-KE successfully separated the precipitated calcium carbonate crystals from sand particles and pores.The spatial distributions of porosity,pore structure parameters,and flow characteristics were calculated for quantitative characterization.The results offer pore-scale insights into the MICP treatment effect,and the quantitative understanding confirms the feasibility of the GAE-KE multi-level thresholding segmentation algorithm.

A Multi-level Approach for Complex Fault Isolation Based on Structured Residuals

In industrial processes,there exist faults that have complex effect on process variables.Complex and simple faults are defined according to their effect dimensions.The conventional approaches based on structured residuals cannot isolate complex faults.This paper presents a multi-level strategy for complex fault isolation.An extraction procedure is employed to reduce the complex faults to simple ones and assign them to several levels.On each level,faults are isolated by their different responses in the structured residuals.Each residual is obtained insensitive to one fault but more sensitive to others.The faults on different levels are verified to have different residual responses and will not be confused.An entire incidence matrix containing residual response characteristics of all faults is obtained,based on which faults can be isolated.The proposed method is applied in the Tennessee Eastman process example,and the effectiveness and advantage are demonstrated.

Improved Fibroblast Adhesion and Proliferation by Controlling Multi-level Structure of Polycaprolactone Microfiber

Improving wound healing efficiency is a key issue for high performance dressings.The surface topology of fibers in wound dressings plays an important role in regulating cell behaviors during the regeneration.Herein,a polycaprolactone(PCL)scaffold with a shish-kebab structure was prepared by electrospinning and solution-induced crystallization.L929 cells were used to investigate the behavior of fibroblasts on the multi-level microfiber.The results showed that the shish-kebab fiber-based scaffold enhanced the cell proliferation when compared with the normal fiber and the fiber with a porous structure.Protein absorption,cell adhesive force,and cell modulus also increased by the shish-kebab fiber.The shish-kebab fiber-based scaffold with improved fibroblast-regulation ability can be applied in rapid wound healing.

Multi-level Flocculation Structures of Fresh Cement Paste by Confocal Laser Scanning Microscope

Under saturation dosage of all kinds of SP, the free water amount was examined by centrifuge. The distribution of solution and flocculation microstructures in fresh cement paste was observed in three- dimensional space by confocal laser scanning microscope（CLSM）. Results indicate that SP can increase the free water amount by destroying the flocculated cement particle structure and different free water amount is released by different kinds of SP. The changes of the size of flocculation structures and the dispersion of solution were obviously detected with confocal laser scanning microscope： the size of flocculation structures was smaller and more dispersed in fresh cement paste with polycarboxylate superplasticizer, but the size of flocculation structures was bigger and cannot be dispersed uniformly in fresh cement paste with others SP. The multi- level flocculation structures theoretical model of fresh cement paste was then set up. The theory indicates that different kinds of SP with different dispersion strength will open the flocculation structures at different levels, which in turn present different water reducing rate.

Structural analysis of multi-level detachments and identification of deep-seated anticline

Based on forward modeling of detachment fold, this study presents a method to analyze multi-level detachment structures and identify the authenticity of deep-seated anticlines using time-domain seismic section. The steps include the conversion of the time-migrated seismic image into depth domain image using a constant velocity field, structural interpretation of the depth seismic image, measurement of each structural relief area and each height above reference level, plotting of area-height relationship chart with piecewise fitting etc. The area-depth correlation can help the division of structural sequences, the definition of detachment levels, the calculation of the tectonic shortening, and the identification of deep-seated structure. The segment area-height relationship is a feature of multi-level detachment structures, while little or no linear correlation between area and height is an indicator of non-deformation or pseudo-anticline. Regardless of the uncertainty of area-height relationship, the segment slopes will correspond to the differential shortenings of multi-level detachments, the intersection between adjacent segments will give the height of detachment surface above reference level and then help define the detachment level in original time-domain seismic section. This method can make use of time-domain seismic data to determine the geologic structure of complicated structure areas and assess risks of deep exploration targets. It has achieved good results in southern Junggar and eastern Sichuan areas.

四塔高位连体钢桁架结构施工关键技术

以江门市档案中心高层建筑工程为例,该工程为四塔高位连体结构,在高层塔楼结构顶部采用带悬挑的大跨度钢桁架作为连接体,将4栋塔楼连为一体,其结构形式较复杂、施工难度大。为此,根据结构特点、工期、场地及垂直运输等因素,提出高位连体桁架采用“胎架拼装、低位滑移后整体提升”的一体化施工工艺,局部悬挑桁架采用“高空散装+临时支撑”的常规施工方法。在此基础上,制定了钢结构施工总体流程和具体实施要点。

三联钢桁架拱屋盖高滑移支架设计技术研究

南昌东站钢屋盖工程分为三个分区,屋盖为三联钢桁架拱,结构形式复杂,滑移支架高度最高为56 m,高度高,所受荷载大,传统屋盖对称形式设计对称支撑用钢量大,施工时间长,不满足现代建筑的节能要求。文中结合钢屋盖结构形式及现场施工条件,设计非对称滑移支撑,既满足滑移支架施工受力要求,又节约成本及工期,确保了施工安全。

辽西地区幔支构造与多金属矿的关系

辽西地区多金属找矿工作一直以传统的理论指导找矿,虽已取得较大的成果,但近年来成果甚微,基本处于停滞状态,本文作者意以新的找矿理论研究该区域的各个典型多金属矿山,探究成矿物质来源、分析成矿、控矿因素、总结成矿规律、提出找矿新思路,结合新理论找到突破口,以期能有新的找矿成果。

简阳文体中心游泳馆屋盖网架带柱滑移施工技术

简阳文体中心5号楼游泳馆屋盖钢结构为大跨度网架结构,通过选用将三道滑移轨道的各自标高保持一致带柱滑移的方案,系统阐述了网架带柱滑移施工的具体步骤,实现了带悬挑网架同步滑移。在滑移施工过程中减少拼装胎架及高空作业量。通过对南北两侧滑移柱及网架杆件采取刚性的临时加强措施,保证了滑移过程中,支撑柱与网架连接节点的变形受控。并利用有限元模拟软件对滑移轨道位移进行分析,保证了滑移法施工的安全性。可为今后类似场馆类钢结构工程提供参考。

桥梁支座滑移现象的控制策略研究

桥梁支座滑移作为一种关键的结构现象,涉及多方面的因素。温度变化、自然灾害和材料特性的多因素成因分析揭示了支座滑移的多层次挑战。在此基础上,通过支座设计与材料选择的优化、温度与环境控制策略的制定、润滑技术与摩擦特性的深入研究,以及结构监测与维护策略的完善,文章提出了全面的桥梁支座滑移控制策略,以增强桥梁结构的安全性和可靠性。

Structural geology and favorable exploration prospect belts in northwestern Sichuan Basin, SW China

The northwestern Sichuan region has experienced multi-stage tectonic evolution including marine cratonic basin from the Sinian to the Middle Triassic and intra-continental basin from the Late Triassic to the Cenozoic. Several regional tectonic activities caused complicated stratigraphic distribution and structural deformations in the deep-buried layers. During the key tectonic periods, some characteristic sedimentary and deformation structures were formed, including the step-shaped marginal carbonate platform of Dengying Formation, the western paleo-high at the end of Silurian, and the passive continental margin of the Late Paleozoic–Middle Triassic. The Meso-Cenozoic intra-continental compressional tectonic processes since the Late Triassic controlled the formation of complex thrusting structures surrounding and inside the northwestern basin. The northern Longmenshan fold-thrust belt has a footwall in-situ thrust structure,which is controlled by two sets of detachments in the Lower Triassic and Lower Cambrian and presents as a multi-level deformation structure with the shallow folds, the middle thin-skin thrusts and the deeper basement-involved folds. The thrust belt in front of the Micangshan Mountain shows a double-layer deformation controlled by the Lower Triassic salt detachment, which is composed by the upper monocline and deep-buried imbricate thrust structures. The interior of the basin is characterized by several rows of large-scale basement-involved folds with NEE strike direction. From the perspective of structural geology, the favorable exploration reservoirs and belts in northwestern Sichuan have obvious zoning characteristics. The favorable exploration layers of Dengying Formation of Upper Sinian are mainly distributed in the eastern and northern areas of the northwestern Sichuan Basin, in which the Jiulongshan structural belt, Zitong syncline and Yanting slope are the most favorable. The Lower Paleozoic was transformed by Caledonian paleo-uplift and late Cenozoic folding, and the midwest area such as the Zitong syncline is a potential area for hydrocarbon exploration. The favorable part of the Upper Paleozoic is mainly distributed in the northern Longmenshan belt and its frontal area, where the deep-buried thin-skin thrust structures in the footwall are the key exploration targets.

Application of biochar-based materials in environmental remediation:from multi-level structures to specific devices

The development of biochar has triggered a hot-spot in various research fields including agriculture,energy,environment,and materials.Biochar-based materials provide a novel approach against environmental challenging issues.Considering the rapid development of biochar materials,this review serves as a valuable platform to summarize the recent progress on the theoretical investigation and engineering applications of biochar materials in environmental remediation.For a better understanding of the structure-application relationships,the structural properties of biochar from macroscopic and microscopic aspects are summarized.The multilevel structures including elements,phases,surface chemistry,and molecular are highlighted to elucidate the multi-functional properties of biochars.Sorption,catalysis,redox reaction,and biological activity of biochar are briefly illustrated,which influence the transport,transformation,and removal of organic and inorganic pollutants in the environments.According to the multi-level structures and structure-application relationships of biochar,specific biochar-based materials and devices have been designed for practical environmental application.The important progress on the functionalization and device of biochar-based materials,including magnetic biochars,2D and 3D biochar-based macrostructures,immobilized microorganism on biochar,and biochar-amended biofilters are highlighted.The environmental friendliness and sustainability of biochar-based materials,considering the whole cycle from synthesis to application,are evaluated.

火烧铺煤矿地质构造特征及其对矿井生产的影响

为了查明火烧铺井田构造发育特征及其对矿井生产的影响,从而为矿井深部开拓设计、安全生产管理提供资料,首先收集整理以往勘探、矿井生产揭露断层发育资料,分析开采范围内地质构造特征;其次,统计分析地质构造对资源量、井巷掘进、顶板支护管理、煤质灰分等的影响;然后,采用地面填图、地面槽探、地质钻探、三维地震、地球物理测井等多种技术手段对下一开采水平进行地质构造预测探查;最后,针对地质构造特征提出采区设计、开采、支护管理的措施。结果表明,矿井断层发育以正断层为主、局部发育层间滑动和逆断层;断层走向以NEE-SWW为主、倾角40°~60°,断层的发育密度以14、10煤层最发育,7煤层最小;深部开采水平设计应合理利用断层发育和展布特征进行采区布置,将火6断层作为采区划分边界,滥2断层作为采面划分边界,同时注意采空区边界附近断层在采动条件下的导水性。

Traffic Scene Captioning with Multi-Stage Feature Enhancement

Traffic scene captioning technology automatically generates one or more sentences to describe the content of traffic scenes by analyzing the content of the input traffic scene images,ensuring road safety while providing an important decision-making function for sustainable transportation.In order to provide a comprehensive and reasonable description of complex traffic scenes,a traffic scene semantic captioningmodel withmulti-stage feature enhancement is proposed in this paper.In general,the model follows an encoder-decoder structure.First,multilevel granularity visual features are used for feature enhancement during the encoding process,which enables the model to learn more detailed content in the traffic scene image.Second,the scene knowledge graph is applied to the decoding process,and the semantic features provided by the scene knowledge graph are used to enhance the features learned by the decoder again,so that themodel can learn the attributes of objects in the traffic scene and the relationships between objects to generate more reasonable captions.This paper reports extensive experiments on the challenging MS-COCO dataset,evaluated by five standard automatic evaluation metrics,and the results show that the proposed model has improved significantly in all metrics compared with the state-of-the-art methods,especially achieving a score of 129.0 on the CIDEr-D evaluation metric,which also indicates that the proposed model can effectively provide a more reasonable and comprehensive description of the traffic scene.

基于径向滑移传播理论的新型防松结构设计

螺栓接头在振动环境下容易发生自松动,并可能引起螺栓疲劳断裂,造成严重后果。明确螺纹的自松机理,在此基础上开发新型防松螺纹结构是十分必要的。径向滑移传播理论为自松动过程提供了新的见解,该理论指出沿螺纹表面径向方向的滑移引起了更多的滑移区域(滑移传播),并且随着振动循环次数的增加,螺纹和轴承表面接触状态的动态演变和传播导致了自松动的发生。因此,基于径向滑移传播理论提出了一种新型的防松结构——阶梯螺纹啮合螺栓接头,该接头可以防止外螺纹和内螺纹在径向上发生相对运动,从而阻止滑移的传播。实验验证了改新型防松结构优异的防松、抗疲劳性能,且安装拆卸方便。

钢结构桥梁顶推滑移技术在景洪路春申塘桥工程的应用

随着我国基础设施建设的快速发展,钢结构桥梁得到了广泛应用。钢结构桥梁安装通常使用大型吊装机械、架桥机等安装工艺,但受施工场地限制、环境因素干扰等原因制约,某些项目无法采用常规方式来进行钢结构桥梁的安装。近年来,顶推滑移技术逐步在钢结构桥梁安装中得到广泛应用。现以景洪路(金都路—华泾港)道路新建工程春申塘桥为例,进行介绍,以期为类似工程提供参考。

女胸衣肩带滑落的原因及改进

针对胸衣肩带滑落现象 ,以标准人体为研究对象 ,查找肩带滑落原因 ,从结构、款式、面料及肩带与肩形搭配方面提出应对方法。以结构改进为研究重点 ,综合运用物理的力学分析和数学的解析几何分析方法 ,导出背部肩带的设计角θ :平行式肩带为 78 4 8° ,交叉式肩带为 76 .38°。

龙门山北段推覆构造带变形特征研究

文章以大量的野外调查为基础,结合最新的地震资料和钻井资料,较系统地研究了龙门山北段推覆构造变形特征,首次提出龙门山北段浅部滑脱层系为飞仙关组上部泥岩层段,而不是如川东或川东北地区一样的嘉陵江组膏盐岩层;总结了龙门山北段推覆构造样式;通过大剖面研究,提出了一种新的、更能体现油气地质特征的龙门山推覆构造带的划分方法;采用地震剖面作了构造变形恢复的探索性研究,以此计算复位推覆岩片的推覆距离,进而确定推覆地层的原始沉积位置。这一系列研究,对指导地震资料解释、对储层的横向分布研究等都具有重要的指导作用,对该地区油气勘探工作具有重要的参考价值。

羊毛拉伸细化中的结构理论

目前羊毛细化加工工艺和理论仍采用早期的纤维湿态拉伸中的结构模型和理论 ,主张细化拉伸是因肽链大分子由α螺旋到 β折叠的转变所引起。为此提出羊毛纤维“滑移细化”的机理 ,并做了实验验证。

塔里木盆地内构造样式类型

引用哈丁 (T .P .Harding)和劳威尔 (J .D .Lowell)构造样式理论的一些观点 ,结合塔里木盆地多期构造运动、多期沉积旋回、多期构造变形的特点 ,对塔里木盆地内构造样式类型进行了划分。首先分出基底卷入和盖层滑脱两大类 ,在此基础上又细分为 6种构造样式类型 ,最后 ,讨论了构造样式类型与油气藏的关系。