3D segmentation and visualization of lung and its structures using CT images of the thorax

Computing systems have been playing an important role in various medical fields, notably in image diagnosis. Studies in the field of Computational Vision aim at developing techniques and systems capable of detecting various illnesses automatically. What has been highlighted among the existing exams that allow diagnosis aid and the application of computing systems in parallel is Computed Tomography (CT). CT enables the visualization of internal organs, such as the lung and its structures. Computational Vision systems extract information from the CT images by segmenting the regions of interest, and then recognize and identify details in those images. This work focuses on the segmentation phase of CT lung images with singularity-based techniques. Among these methods are the region growing (RG) technique and its 3D RG variations and the thresholding technique with multi-thresholding. The 3D RG method is applied to lung segmentation and from the 3D RG segments of the lung hilum, the multi-thresholding can segment the blood vessels, lung emphysema and the bones. The results of lung segmentation in this work were evaluated by two pulmonologists. The results obtained showed that these methods can integrate aid systems for medical diagnosis in the pulmonology field.

A NEW APPROACH TO MANUFACTURING 3D WOVEN PREFORMS USED FOR STRUCTURAL COMPOSITES

The manufacturing of three-dimensional textile preforms used for composites started to re-ceive much attention in the last decade.The major barriers to accelerating the transition from thelamination of two-dimensional fabrics to manufacturing integral three-dimensional near-netshaped textile preforms are high cost and database deficiency.To reduce the cost of weaving three-dimensional preforms,and make full use of the potential of conventional looms,a rig was designedwhich can convert two-dimensional woven fabric to particular three-dimensional preforms wherethe yarn is orientated in the directions of maximum stress.

Crustal velocity, density structure, and seismogenic environment in the southern segment of the North- South Seismic Belt, China

The southern segment of the North-South Seismic Belt in China is a critical region for earthquake preparedness and risk reduction efforts.However,limited by the low density of seismic stations and the use of single-parameter physical structural models,the deep tectonic features and seismogenic environment in this area remain controversial.Thus,a comprehensive analysis based on high-resolution crustal structures and multiple physical parameters is required.In this study,we applied the ambient noise tomography method to obtain the three-dimensional(3D)crustal S-wave velocity structure using continuous waveform data from 112 permanent stations and 350 densely distributed temporary stations in the southern segment of the North-South Seismic Belt.Then,we obtained the high-resolution 3D density structure through wavenumber-domain 3D gravity imaging constrained by the velocity structure.The low-velocity and low-density anomalies in the upper crust of the study area were mainly distributed in the Sichuan Basin and around Dali and Simao,while the high-velocity and high-density anomalies were primarily distributed in the Panxi region,corresponding to the surface geological features.Two prominent low-velocity and low-density anomalies were observed in the middle and lower crust:one to the west of the Songpan-Garzêblock and Sichuan-Yunnan diamond-shaped block,and the other near the Anninghe-Xiaojiang fault.Combined with the spatial distribution of seismic events in the study area,we found that previous earthquakes predominantly occurred in the transition zones between high and low anomaly regions and in the low-velocity and low-density zones in the upper crust.In contrast,moderate-to-strong earthquakes mainly occurred within the transition zones between high and low anomaly regions and close to the high-velocity and high-density regions,often with low-velocity and low-density layers below their hypocenters.Fluids play a critical role in the seismogenic process by reducing fault strength and destabilizing the stress state,which may be a triggering factor for earthquakes in the study area.Additionally,the upwelling of molten materials from the mantle may lead to energy accumulation and stress conce-ntration,providing an important seismogenic background for moderate-to-strong earthquakes in this area.

Three-dimensional macroscopic absorbents: From synergistic effects to advanced multifunctionalities

The accelerated arriving of 5G era has brought a new round of intelligent transformation which will completely emancipate smart terminal devices.While the subsequent deleterious effect of electromagnetic wave on electronic devices is increasingly serious,driving the growth of next-generation electromagnetic wave absorbents.As a tactful combination of components and structures,three-dimensional(3D)macroscopic absorbents with fascinating synergy afford exceptional electromagnetic wave absorption,and tremendous efforts have been devoted to this investigation.However,in terms of macroscopic absorbents and their synergistic effect,few reviews are proposed to comb the latest achievements and detailed synergy.This review article focuses on the synergistic effect of macro-architectured absorbents mainly including structure-induced synergy,structure-components synergy,and multiple-components induced synergy.And then the potential construction principles and strategies of macroscopic absorbents are combed.Significantly,the key information for structures and components manipulation including nano-micro design and components regulation is further dissected by critically selected cutting-edge 3D macroscopic absorbents.Moreover,a brief summary of multifunctional electromagnetic wave absorbents(EWAs)-based macroscopic structures is presented.Finally,the development prospects and challenges of these materials are discussed.

Control of electromechanical performance in 3D printing latticestructured BaTiO_(3) piezoelectric ceramics

Barium titanate(BaTiO_(3))piezoelectric ceramics with triply periodic minimal surface(TPMS)structures have been frequently used in filters,engines,artificial bones,and other fields due to their high specific surface area,high thermal stability,and good heat dissipation.However,only a limited number of studies have analyzed the effect of various parameters,such as different wall thicknesses and porosities of TPMS structures,on ceramic electromechanical performance.In this study,we first employed vat photopolymerization(VPP)three-dimensional(3D)printing technology to fabricate high-performance BaTiO_(3) ceramics.We investigated the slurry composition design and forming process and designed a stepwise sintering postprocessing technique to achieve a density of 96.3%and a compressive strength of 250±25 MPa,with the piezoelectric coefficient(d_(33))reaching 263 pC/N.Subsequently,we explored the influence of three TPMS structures,namely,diamond,gyroid,and Schwarz P,on the piezoelectric and mechanical properties of BaTiO_(3) ceramics,with the gyroid structure identified as exhibiting optimal performance.Finally,we examined the piezoelectric and mechanical properties of BaTiO_(3) ceramics with the gyroid structure of varying wall thicknesses and porosities,thus enabling the modulation of ceramic electromechanical performance.

Numerical analysis of the failure process of soil-rock mixtures through computed tomography and PFC3D models

Soil-rock mixture （SRM） is a unique type of geomaterial characterized by a heterogeneous composition and a complicated structure. It is intractable for the continuum-based soil and rock mechanics theories to accurately characterize and predict the SRM＇s mechanical properties. This study reports a novel numerical method incorporating microfocus computed tomography and PFC3D codes to probe the deformation and failure processes of SRM. The three-dimensional （3D） PFC models that represent the SRM＇s complex structures were built. By simulating the entire failure process in PFC3D, the SRM＇s strength, elastic modulus and crack growth were obtained. The influence of rock ratios on the SRM＇s strength, deformation and failure processes, as well as its internal mesoscale mechanism, were analyzed. By comparing simulation results with experimental data, it was verified that the 3D PFC models were in good agreement with SRM＇s real structure and the SRM＇s compression process, deformation and failure patterns; its intrinsic mesomechanism can be effectively analyzed based on such 3D PFC models.

3D Modeling and Simulation of Fancy Fabrics in Weft Knitting

Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.

RNA structure prediction:Progress and perspective

Many recent exciting discoveries have revealed the versatility of RNAs and their importance in a variety of cellular functions which are strongly coupled to RNA structures. To understand the functions of RNAs, some structure prediction models have been developed in recent years. In this review, the progress in computational models for RNA structure prediction is introduced and the distinguishing features of many outstanding algorithms are discussed, emphasizing three- dimensional （3D） structure prediction. A promising coarse-grained model for predicting RNA 3D structure, stability and salt effect is also introduced briefly. Finally, we discuss the major challenges in the RNA 3D structure modeling.

Ultrahigh-power electrochemical double-layer capacitors based on structurally integrated 3D carbon tube arrays

The rational design of electrodes is the key to achieving ultrahigh-power performance in electrochemical energy storage devices.Recently,we have constructed well-organized and integrated three-dimensional(3D)carbon tube(CT)grids(3D-CTGs)using a 3D porous anodic aluminum oxide template-assisted method as electrodes of electrical double-layer capacitors(EDLCs),showing excellent frequency response performance.The unique design warrants fast ion migration channels,excellent electronic conductivity,and good structural stability.This study achieved one of the highest carbon-based ultrahigh-power EDLCs with the 3D-CTG electrodes,resulting in ultrahigh power of 437 and 1708 W·cm−3 with aqueous and organic electrolytes,respectively.Capacitors constructed with these electrodes would have important application prospects in the ultrahigh-power output.The rational design and fabrication of the 3D-CTGs electrodes have demonstrated their capability to build capacitors with ultrahighpower performance and open up new possibilities for applications requiring high-power output.

Development of 3D Scanning System for Robotic Plasma Processing of Medical Products with Complex Geometries

This paper describes the development of an intelligent automated control system of a robot manipulator for plasma treatment of medical implants with complex shapes.The two-layer coatings from the Ti wire and hydroxyapatite powders are applied on the surface of Ti medical implants by microplasma spraying to increase the biocompatibility of implants.The coating process requires precise control of a number of parameters,particularly the plasma spray distance and plasma jet traverse velocity.Thus,the development of the robotic plasma surface treatment involves automated path planning.The key idea of the proposed intelligent automatic control system is the use of data of preliminary three-dimensional (3D) scanning of the processed implant by the robot manipulator.The segmentation algorithm of the point cloud from laser scanning of the surface is developed.This methodology is suitable for robotic 3D scanning systems with both non-contact laser distance sensors and video cameras,used in additive manufacturing and medicine.

34 GHz Bandpass Filter for Low-temperature Co-fired Ceramic System-in-Package Application

Modern electronic circuit requires compact,multifunctional technology in communication systems.However,it is very difficult due to the limitations in passive component miniaturization and the complication of fabrication process.The bandpass filter is one of the most important passive components in millimeter（mm）-wave communication system,attracting significant interest in three-dimension（3D） miniaturized design,which is few reported.In this paper,a bandpass filter structure using low-temperature co-fired ceramic（LTCC） technology,which is fully integrated in a system-in package（SIP） communication module,is presented for miniaturized and high reliable mm-wave application.The bandpass filter with 3D end-coupled microstrip resonators is implemented in order to achieve a high performance bandwidth characteristic.Specifically,all of the resonators are embedded into different ceramic layers to decrease the insertion loss and enhance the out-of-band rejection performance by optimizing the coupling coefficient and the coupling strength.A fence structure,which is formed by metal-filled via array with the gap less than quarter wavelength,is placed around the embedded bandpass filter to avoid electromagnetic（EM） interference problem in multilayer structure.This structural model is validated through actual LTCC process.The bandpass filter is successfully manufactured by modifying the co-fireablity characteristics,adjusting the sintering profile,releasing the interfacial stress,and reducing the shrinkage mismatch with different materials.Measured results show good performance and agree well with the high frequency EM full wave simulation.The influence of layer thickness and dielectric constant on the frequency response in fabricated process is analyzed,where thicker ceramic sheets let the filter response shift to higher frequency.Moreover,measured S-parameters denote the center frequency is also strongly influenced by the variation of ceramic material＇s dielectric constants.By analyzing the relationship between the characteristics of the ceramic tape and the center frequency of the filter,both theoretical and experimental data are accumulated for broadening application filed.With the coupling resonators embedded into the ceramic layers,the bandpass filter exhibits advantages of small size and high reliability compared to conventional planar filter structure,which makes the bandpass filter suitable for SIP communicational application.

3D fully-enclosed triboelectric nanogenerator with bionic fish-like structure for harvesting hydrokinetic energy

The hydrokinetic energy of river current,as one of the essential and widespread renewable energies,is difficult to be harvested in low flow velocity and shallow water areas.In this work,a three-dimensional(3D)fully-enclosed triboelectric nanogenerator(FETENG)with bionic fish-like structure for harvesting hydrokinetic energy is reported,which is comprised of the triboelectric powergeneration unit,bionic fish-like structure and connection unit.Through the bionic structure,the FE-TENG realizes zero head power generation in shallow water with low flow velocity.What’s more,the effect of external excitations and bionic structures on the electrical performance are systematically studied in this work.The FE-TENG can generate peak power density of 7 and 0.36 W/m^(3)respectively under the simulated swing state with frequency of 1.25 Hz and simulated river current with flow velocity of 0.81 m/s.In practical applications,due to the 3D fully-enclosed design,the FE-TENG immersed in water for 35 days demonstrates excellent immersion durability with undiminished electrical performance.Therefore,the work proposes an efficient method realizing zero head power generation,and provides a good candidate for long-term service in the river current.

Co-developing an international TLS network for the 3D ecological understanding of global trees:System architecture,remote sensing models,and functional prospects

Trees are spread worldwide,as the watchmen that experience the intricate ecological effects caused by various environmental factors.In order to better understand such effects,it is preferential to achieve finely and fully mapped global trees and their environments.For this task,aerial and satellite-based remote sensing(RS)methods have been developed.However,a critical branch regarding the apparent forms of trees has significantly fallen behind due to the technical deficiency found within their globalscale surveying methods.Now,terrestrial laser scanning(TLS),a state-of-the-art RS technology,is useful for the in situ three-dimensional(3D)mapping of trees and their environments.Thus,we proposed co-developing an international TLS network as a macroscale ecotechnology to increase the 3D ecological understanding of global trees.First,we generated the system architecture and tested the available RS models to deepen its ground stakes.Then,we verified the ecotechnology regarding the identification of its theoretical feasibility,a review of its technical preparations,and a case testification based on a prototype we designed.Next,we conducted its functional prospects by previewing its scientific and technical potentials and its functional extensibility.Finally,we summarized its technical and scientific challenges,which can be used as the cutting points to promote the improvement of this technology in future studies.Overall,with the implication of establishing a novel cornerstone-sense ecotechnology,the co-development of an international TLS network can revolutionize the 3D ecological understanding of global trees and create new fields of research from 3D global tree structural ecology to 3D macroecology.

Synergistically assembled RGO/Si_(3)N_(4) whiskers hybrid aerogels to endow epoxy composites with excellent thermal and tribological performance

Epoxy resin(EP)composites with satisfactory thermal and tribological performance are highly required for engineering moving components.However,the simple addition of fillers leaded to the serious filler agglomeration and limited promotion in tribological properties.In this work,we constructed a new kind of three-dimensional(3D)reduced graphene oxide(RGO)/Si_(3)N_(4) hybrid aerogel for EP composites,which was prepared by a facile hydrothermal self-assembly method followed by freeze-drying technique.As a result,the dispersibility of Si_(3)N_(4) whiskers was greatly improved through wrapping of polydopamine–polyethyleneimine copolymer(PDA–PEI)copolymer and physical spacing of 3D skeleton.Furthermore,benefiting from the synergistic effect of RGO and Si_(3)N_(4)@PDA–PEI in the thermal network,the thermal conductivity of RGO/Si_(3)N_(4) hybrid aerogel(GSiA)–EP increased by 45.4%compared to that of the neat EP.In addition,the friction coefficient and wear rate of GSiA–EP decreased by 83.7%and 35.8%,respectively.This work is significant for opening a tribological performance enhancement strategy though constructing 3D hybrid architecture.

Designing electrodes and electrolytes for batteries by leveraging deep learning

High-performance batteries are poised for electrification of vehicles and therefore mitigate greenhouse gas emissions,which,in turn,promote a sustainable future.However,the design of optimized batteries is challenging due to the nonlinear governing physics and electrochemistry.Recent advancements have demonstrated the potential of deep learning techniques in efficiently designing batteries,particularly in optimizing electrodes and electrolytes.This review provides comprehensive concepts and principles of deep learning and its application in solving battery-related electrochemical problems,which bridges the gap between artificial intelligence and electrochemistry.We also examine the potential challenges and opportunities associated with different deep learning approaches,tailoring them to specific battery requirements.Ultimately,we aim to inspire future advancements in both fundamental scientific understanding and practical engineering in the field of battery technology.Furthermore,we highlight the potential challenges and opportunities for different deep learning methods according to the specific battery demand to inspire future advancement in fundamental science and practical engineering.

郯庐断裂带鲁苏皖段及邻区地壳速度结构

郯庐断裂带是我国东部规模最大的深断裂带.为了揭示该断裂带的深部结构,本文利用江苏、安徽、山东、上海和浙江地震台网记录的近震到时资料,对8700个地震事件重新精确定位,进而开展了多震相地震走时成像法反演地壳速度结构.通过分析郯庐断裂带鲁苏皖段及邻区三维地壳速度结构图像,发现(1)研究区内不同构造块体具有差异明显的地壳速度结构,即下扬子断块总体速度偏低,华北断块速度高于下扬子断块,大别断褶带和苏鲁断块整体速度最高;(2)在上地壳5～15 km内苏鲁超高压变质岩带的P波速度明显高于其他地区,中地壳速度与周围区别不大,但下地壳该区域速度电较高;(3)在20～25 km深度范围内,30°N～36°N,115°E～124°E间显示为低速异常区,研究区内发生的中强地震与该低速异常区分布有较强的空间对应关系;(4)莫霍面总体呈现西深东浅,南深北浅的形态;(5)研究区内沿郯庐断裂带速度结构呈现分段性,反映了不同构造块体间的速度差异,郯庐断裂带具有明显的构造块体边界特征.

126kV真空灭弧室1/2线圈纵磁触头三维磁场仿真

建立了126kV、1/2线圈纵磁触头三维电极结构模型,并利用有限元法对考虑了电弧影响的有限元模型进行了三维静磁场和涡流场仿真。结果表明静磁场下纵向磁场在触头片开槽处发生畸变,在触头间隙中心平面分布呈“平顶帐篷”形状。在涡流场下,当电流处于峰值时,纵向磁场在触头片上的分布和触头间隙中心平面上的分布与静磁场作用下相似:在电流过零时,纵向磁场在触头片中心形成一个最高峰,在最高峰周围形成6个次高峰;而在触头间隙中心平面分布呈“尖顶帐篷”形;沿路径(0,-60,110)～(0,60,110)纵向磁场的分布为开口向上的抛物线型,最大滞后时间0.36ms。

应用于医学三维影像的血管结构自动提取

针对从计算机断层扫描血管造影术(CTA)的三维体数据中提取血管结构信息通常需要大量的人为介入操作的问题,提出了一种全自动血管分割方法。首先,采用多尺度增强滤波器对数据中的管状结构进行增强,剔除非管状结构,并过滤噪声。然后,利用Sigmoid函数作用于梯度图像产生水平集的速度图像,并通过测地活动轮廓模型迭代逼近真实的三维血管轮廓。最后,通过拉普拉斯算法对提取的血管表面网格进行平滑处理,获得光滑的血管曲面。实验采用胸部和颈部的CTA体数据对算法进行测试,结果表明:该方法无需人工干预即可从CTA体数据中准确地提取出血管的三维信息;血管中心线提取的平均误差为0.26mm,直径测量平均误差为0.16mm,分割精度满足临床血管疾病辅助诊疗的要求。

由地壳速度结构判断郯庐断裂带江苏段未来大震位置

用多震相地震走时成像法反演郯庐断裂带鲁苏皖段及邻区三维地壳速度结构。一些地区如郯庐断裂带临沭到定远及以东地区在中地壳的2025km出现低速层,一些地区莫霍面埋深有变化。浅层速度结构的分段与断裂活动的分段相一致,表明新沂到泗洪是活动断裂的闭锁段。对比1668年山东郯城8级地震区和研究区的深部速度结构,结合与郯庐带相交的断裂、地震活动、活动断裂的闭锁段、中地壳低速层及莫霍面深度变化,综合判断郯庐断裂带江苏段未来可能发生大震的地区为33.4°34.1°N,118.2°118.8°E,重点是宿迁、沭阳、泗阳和泗洪。震级估计可达8级。

塔北古隆起的三维地质结构及相关问题探讨

盆地深层构造地质学的研究可以揭示沉积盆地早期的物质记录,揭示盆地深层地质结构、构造样式及其变化特点,还原构造-古地理环境等。塔北古隆起是塔里木盆地油气最富集的构造单元之一,是研究板块内部变形的理想场所。对塔北古隆起地质结构的精细解析有利于加深对古隆起控油气理论的理解,对深层海相油气勘探具有指导意义。文中基于整个塔北地区的地震资料以及大量钻井资料,建立其三维地质结构,通过Petrel软件实现三维可视化。塔北古隆起存在12个不整合面,可划分为五大构造层:基底(AnZ)、震旦系—下古生界(Z-S)、上古生界(D3d-P)、中生界(T-K1)、新生界(E-Q)构造层。塔北古隆起的地质结构受其深层主干断裂系统控制,依据深层主干断裂发育模式的差异,可将古隆起分为4段:(Ⅰ)温宿凸起段;(Ⅱ)英买力低凸起段;(Ⅲ)哈拉哈塘凹陷与轮南低凸起段;(Ⅳ)草湖凹陷与库尔勒鼻状凸起段。哈拉哈塘凹陷-库尔勒鼻状凸起(甚至包括孔雀河斜坡)的古生界构造层保留了NE-SW向的古生代构造形迹,与近E-W向深层主干断裂系统斜交,可能指示塔北古隆起在晚古生代处于右旋压扭性或NW-SE向主应力环境,直到侏罗纪—早白垩世才发生改变。