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Dynamical analysis and circuit simulation of a new three-dimensional chaotic system 被引量:1
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作者 王爱元 凌志浩 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第7期96-101,共6页
This paper reports a new three-dimensional autonomous chaotic system. It contains six control parameters and three nonlinear terms. Two cross-product terms are respectively in two equations. And one square term is in ... This paper reports a new three-dimensional autonomous chaotic system. It contains six control parameters and three nonlinear terms. Two cross-product terms are respectively in two equations. And one square term is in the third equation. Basic dynamic properties of the new system are investigated by means of theoretical analysis, numerical simulation, sensitivity to initial, power spectrum, Lyapunov exponent, and Poincar~ diagrams. The dynamic properties affected by variable parameters are also analysed. Finally, the chaotic system is simulated by circuit. The results verify the existence and implementation of the system. 展开更多
关键词 chaotic system dynamical properties circuit simulation nonlinear analysis
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A new three-dimensional chaotic system and its modified generalized projective synchronization
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作者 戴浩 贾立新 +1 位作者 惠萌 司刚全 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第4期139-148,共10页
Based on the Chen chaotic system, this paper constructs a new three-dimensional chaotic system with higher order nonlinear term and studies the basic dynamic behaviours of the system. The modified generalized projecti... Based on the Chen chaotic system, this paper constructs a new three-dimensional chaotic system with higher order nonlinear term and studies the basic dynamic behaviours of the system. The modified generalized projective synchronization has been observed in the coupled new three-dimensional chaotic system with unknown parameters. Furthermore, based on Lyapunov stability theory, it obtains the control laws and adaptive laws of parameters to make modified generalized projective synchronization of the coupled new three-dimensional chaotic systems. Numerical simulation results are presented to illustrate the effectiveness of this method. 展开更多
关键词 chaotic system generalized projective synchronization Lyapunov stability theory
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A novel four-wing chaotic attractor generated from a three-dimensional quadratic autonomous system 被引量:12
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作者 董恩增 陈在平 +1 位作者 陈增强 袁著祉 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第7期2680-2689,共10页
This paper presents a new 3D quadratic autonomous chaotic system which contains five system parameters and three quadratic cross-product terms,and the system can generate a single four-wing chaotic attractor with wide... This paper presents a new 3D quadratic autonomous chaotic system which contains five system parameters and three quadratic cross-product terms,and the system can generate a single four-wing chaotic attractor with wide parameter ranges. Through theoretical analysis,the Hopf bifurcation processes are proved to arise at certain equilibrium points.Numerical bifurcation analysis shows that the system has many interesting complex dynamical behaviours;the system trajectory can evolve to a chaotic attractor from a periodic orbit or a fixed point as the proper parameter varies. Finally,an analog electronic circuit is designed to physically realize the chaotic system;the existence of four-wing chaotic attractor is verified by the analog circuit realization. 展开更多
关键词 CHAOS four-wing chaotic attractor bifurcation analysis chaotic circuit
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An image encryption scheme based on three-dimensional Brownian motion and chaotic system 被引量:6
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作者 Xiu-Li Chai Zhi-Hua Gan +2 位作者 Ke Yuan l Yang Lu Yi-Ran Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第2期99-113,共15页
At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional(3D) bit matrices, and thus bits cannot move to any position, th... At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional(3D) bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion(BCB3DBM)is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system(LTS). Furthermore, block confusion based on position sequence group(BCBPSG) is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed. 展开更多
关键词 image encryption logistic-tent system(LTS) memristive chaotic system three-dimensional(3D) Brownian motion
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Asymmetric image encryption algorithm based on a new three-dimensional improved logistic chaotic map 被引量:1
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作者 叶国栋 吴惠山 +1 位作者 黄小玲 Syh-Yuan Tan 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期153-163,共11页
Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shami... Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shamir–Adleman(RSA)is presented in this paper.In the first stage,a new 3D-ILM is proposed to enhance the chaotic behavior considering analysis of time sequence,Lyapunov exponent,and Shannon entropy.In the second stage,combined with the public key RSA algorithm,a new key acquisition mathematical model(MKA)is constructed to obtain the initial keys for the 3D-ILM.Consequently,the key stream can be produced depending on the plain image for a higher security.Moreover,a novel process model(NPM)for the input of the 3D-ILM is built,which is built to improve the distribution uniformity of the chaotic sequence.In the third stage,to encrypt the plain image,a pre-process by exclusive OR(XOR)operation with a random matrix is applied.Then,the pre-processed image is performed by a permutation for rows,a downward modulo function for adjacent pixels,a permutation for columns,a forward direction XOR addition-modulo diffusion,and a backward direction XOR addition-modulo diffusion to achieve the final cipher image.Moreover,experiments show that the the proposed algorithm has a better performance.Especially,the number of pixels change rate(NPCR)is close to ideal case 99.6094%,with the unified average changing intensity(UACI)close to 33.4634%,and the information entropy(IE)close to 8. 展开更多
关键词 three-dimensional improved logistic chaotic map(3D-ILM) Rivest–Shamir–Adleman(RSA)algorithm image encryption CONFUSION ENTROPY
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Generation of countless embedded trumpet-shaped chaotic attractors in two opposite directions from a new three-dimensional system with no equilibrium point 被引量:1
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作者 孙常春 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第9期133-137,共5页
A new three-dimensional (3D) continuous autonomous system with one parameter and three quadratic terms is presented firstly in this paper. Countless embedded trumpet-shaped chaotic attractors in two opposite directi... A new three-dimensional (3D) continuous autonomous system with one parameter and three quadratic terms is presented firstly in this paper. Countless embedded trumpet-shaped chaotic attractors in two opposite directions are generated from the system as time goes on. The basic dynamical behaviors of the strange chaotic system are investigated. Another more complex 3D system with the same capability of generating countless embedded trumpet-shaped chaotic attractors is also put forward. 展开更多
关键词 three-dimensional system trumpet-shaped chaotic attractor equilibrium point
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Chaos Control in a New Three-Dimensional Chaotic T System 被引量:5
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作者 CHEN Yong YAN Zhen-Ya 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第4期951-954,共4页
In this paper, we study chaos control of the new 3D chaotic system. We use three feedback methods (the linear, speed, doubly-periodic function controller) to suppress the chaos to unstable equilibrium. As a result, ... In this paper, we study chaos control of the new 3D chaotic system. We use three feedback methods (the linear, speed, doubly-periodic function controller) to suppress the chaos to unstable equilibrium. As a result, some controllers are obtained. Moreover, numerical simulations are used to verify the effectiveness of the obtained controllers. 展开更多
关键词 chaos control chaotic T system feedback control Routh-Hurwitz theorem numerical simulation
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Global Mapping of Three-Dimensional Urban Structures Reveals Escalating Utilization in the Vertical Dimension and Pronounced Building Space Inequality 被引量:1
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作者 Xiaoping Liu Xinxin Wu +6 位作者 Xuecao Li Xiaocong Xu Weilin Liao Limin Jiao Zhenzhong Zeng Guangzhao Chen Xia Li 《Engineering》 2025年第4期86-99,共14页
Three-dimensional(3D)urban structures play a critical role in informing climate mitigation strategies aimed at the built environment and facilitating sustainable urban development.Regrettably,there exists a significan... Three-dimensional(3D)urban structures play a critical role in informing climate mitigation strategies aimed at the built environment and facilitating sustainable urban development.Regrettably,there exists a significant gap in detailed and consistent data on 3D building space structures with global coverage due to the challenges inherent in the data collection and model calibration processes.In this study,we constructed a global urban structure(GUS-3D)dataset,including building volume,height,and footprint information,at a 500 m spatial resolution using extensive satellite observation products and numerous reference building samples.Our analysis indicated that the total volume of buildings worldwide in2015 exceeded 1×10^(12)m^(3).Over the 1985 to 2015 period,we observed a slight increase in the magnitude of 3D building volume growth(i.e.,it increased from 166.02 km3 during the 1985–2000 period to 175.08km3 during the 2000–2015 period),while the expansion magnitudes of the two-dimensional(2D)building footprint(22.51×10^(3) vs 13.29×10^(3)km^(2))and urban extent(157×10^(3) vs 133.8×10^(3)km^(2))notably decreased.This trend highlights the significant increase in intensive vertical utilization of urban land.Furthermore,we identified significant heterogeneity in building space provision and inequality across cities worldwide.This inequality is particularly pronounced in many populous Asian cities,which has been overlooked in previous studies on economic inequality.The GUS-3D dataset shows great potential to deepen our understanding of the urban environment and creates new horizons for numerous 3D urban studies. 展开更多
关键词 three-dimensional Global mapping Building volume Building height Building space inequality
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Three-dimensional line-of-sight-angle-constrained leader-following cooperative interception guidance law with prespecified impact time 被引量:2
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作者 Hao YOU Xinlong CHANG Jiufen ZHAO 《Chinese Journal of Aeronautics》 2025年第1期491-506,共16页
To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D lea... To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance law.First,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact time.Next,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go.Then,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption.Moreover,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering applications.Finally,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law. 展开更多
关键词 three-dimensional cooperative interception Leader-following missiles Prespecified impact time LOS-angle-constrained Fixed-time stability Global integral sliding mode
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Three-dimensional models:from cell culture to Patient-Derived Organoid and its application to future liposarcoma research
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作者 SAYUMI TAHARA SYDNEY RENTSCH +4 位作者 FERNANDA COSTAS CASAL DE FARIA PATRICIA SARCHET ROMA KARNA FEDERICA CALORE RAPHAEL E.POLLOCK 《Oncology Research》 SCIE 2025年第1期1-13,共13页
Liposarcoma is one of the most common soft tissue sarcomas,however,its occurrence rate is still rare compared to other cancers.Due to its rarity,in vitro experiments are an essential approach to elucidate liposarcoma ... Liposarcoma is one of the most common soft tissue sarcomas,however,its occurrence rate is still rare compared to other cancers.Due to its rarity,in vitro experiments are an essential approach to elucidate liposarcoma pathobiology.Conventional cell culture-based research(2D cell culture)is still playing a pivotal role,while several shortcomings have been recently under discussion.In vivo,mouse models are usually adopted for pre-clinical analyses with expectations to overcome the issues of 2D cell culture.However,they do not fully recapitulate human dedifferentiated liposarcoma(DDLPS)characteristics.Therefore,three-dimensional(3D)culture systems have been the recent research focus in the cell biology field with the expectation to overcome at the same time the disadvantages of 2D cell culture and in vivo animal models and fill in the gap between them.Given the liposarcoma rarity,we believe that 3D cell culture techniques,including 3D cell cultures/co-cultures,and Patient-Derived tumor Organoids(PDOs),represent a promising approach to facilitate liposarcoma investigation and elucidate its molecular mechanisms and effective therapy development.In this review,we first provide a general overview of 3D cell cultures compared to 2D cell cultures.We then focus on one of the recent 3D cell culture applications,Patient-Derived Organoids(PDOs),summarizing and discussing several PDO methodologies.Finally,we discuss the current and future applications of PDOs to sarcoma,particularly in the field of liposarcoma. 展开更多
关键词 Cell culture LIPOSARCOMA Patient-Derived Organoid(PDO) SPHEROID three-dimensional(3D)cell culture
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Generation of a novel spherical chaotic attractor from a new three-dimensional system
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作者 孙常春 赵恩良 徐启程 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第5期145-153,共9页
A new three-dimensional (3D) system is constructed and a novel spherical chaotic attractor is generated from the system. Basic dynamical behaviors of the chaotic system are investigated respectively. Novel spherical... A new three-dimensional (3D) system is constructed and a novel spherical chaotic attractor is generated from the system. Basic dynamical behaviors of the chaotic system are investigated respectively. Novel spherical chaotic attractors can be generated from the system within a wide range of parameter values. The shapes of spherical chaotic attractors can be impacted by the variation of parameters. Finally, a simpler 3D system and a more complex 3D system with the same capability of generating spherical chaotic attractors are put forward respectively. 展开更多
关键词 three-dimensional system spherical chaotic attractor chaos generation
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Glasses-free three-dimensional laparoscopic systems in oncologic surgery:Innovation or equivalence?
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作者 Gustavo Eder González Alvarez Christian Ramírez Sánchez +3 位作者 Melissa Martínez Nieto Mario A Alarcón-Sánchez Juan JoséVarela-Hernández Sarah M LomelíMartínez 《World Journal of Gastrointestinal Surgery》 2025年第11期6-11,共6页
The development of minimally invasive surgery has transformed the management of gastrointestinal cancer.Notably,three-dimensional visualization systems have increased surgical precision.This editorial discusses a rece... The development of minimally invasive surgery has transformed the management of gastrointestinal cancer.Notably,three-dimensional visualization systems have increased surgical precision.This editorial discusses a recent study by Shen and Zhang,which compared the clinical applications of naked-eye threedimensional laparoscopic systems vs traditional optical systems in radical surgery for gastric and colorectal cancer.Both systems appeared to yield comparable surgical and oncological outcomes in terms of safety parameters,operating times,and quality of lymph node dissection.However,the spectacle-free system’s technical and logistical limitations hindered its effects on the surgical team’s overall competency.This editorial examines the authors’findings within the broader context of the evolution of oncologic laparoscopy,discusses the relevance of the results in light of the current literature,and proposes future research directions focused on multicenter validation,comprehensive ergonomic analysis,and technological advancements aimed at enhancing intraoperative collaboration.As technology continues to evolve,clinical implementation of new methods must be supported by robust scientific evidence and standardized criteria,to ensure tangible improvements in efficiency,safety,and oncologic outcomes. 展开更多
关键词 Autostereoscopic three-dimensional technology Laparoscopic surgery three-dimensional laparoscopy Twodimensional laparoscopy Oncologic surgery
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Investigation into the degradation of 2,4,6-trichlorophenol utilizing a three-dimensional electrocatalytic reactor filled with fluorine-doped copper-carbon particle electrodes
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作者 Hongrui Zhang Wenyu Huang +4 位作者 Hainong Song Hanhui Yan Jia Zhang Fang Zhong Huilan Li 《Journal of Environmental Sciences》 2025年第9期701-719,共19页
The three-dimensional particle electrode system exhibits significant potential for application in the treatment of wastewater.Nonetheless,the advancement of effective granular electrodes characterized by elevated cata... The three-dimensional particle electrode system exhibits significant potential for application in the treatment of wastewater.Nonetheless,the advancement of effective granular electrodes characterized by elevated catalytic activity and minimal energy consumption continues to pose a significant challenge.In this research,Fluorine-doped copper-carbon(F/Cu-GAC)particle electrodes were effectively synthesized through an impregnationcalcination technique,utilizing granular activated carbon as the carrier and fluorinedoped modified copper oxides as the catalytic agents.The particle electrodes were subsequently utilized to promote the degradation of 2,4,6-trichlorophenol(2,4,6-TCP)in a threedimensional electrocatalytic reactor(3DER).The F/Cu-GAC particle electrodes were polarized under the action of electric field,which promoted the heterogeneous Fenton-like reaction in which H2O2 generated by two-electron oxygen reduction reaction(2e-ORR)of O_(2) was catalytically decomposed to·OH.The 3DER equipped with F/Cu-GAC particle electrodes showed 100%removal of 2,4,6-TCP and 79.24%removal of TOC with a specific energy consumption(EC)of approximately 0.019 kWh/g·COD after 2 h of operation.The F/Cu-GAC particle electrodes exhibited an overpotential of 0.38 V and an electrochemically active surface area(ECSA)of 715 cm^(2),as determined through linear sweep voltammetry(LSV)and cyclic voltammetry(CV)assessments.These findings suggest a high level of electrocatalytic performance.Furthermore,the catalytic mechanism of the 3DER equipped with F/Cu-GAC particle electrodes was elucidated through the application of X-ray photoelectron spectroscopy(XPS),electron spin resonance(ESR),and active species capture experiments.This investigation offers a novel approach for the effective degradation of 2,4,6-TCP. 展开更多
关键词 2 4 6-TRICHLOROPHENOL Heterogeneous Fenton-like process three-dimensional electrocatalytic reactor three-dimensional particle electrode system Fluorine-doped copper-carbon particle electrodes
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A Review of Three-Dimensional Research on Urban Recreation Space Based on CiteSpace
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作者 LIU Yongli 《Journal of Landscape Research》 2025年第1期30-34,共5页
In this study,CiteSpace software is used to carry out visual analysis on the three-dimensional research literature on urban recreation space from the perspective of compact city theory in the past 20 years,exploring t... In this study,CiteSpace software is used to carry out visual analysis on the three-dimensional research literature on urban recreation space from the perspective of compact city theory in the past 20 years,exploring the scientific development trend and research hotspots in this field.The results show that the number of published documents shows a fluctuating upward trend,and the significant growth rate reflects the role of policy orientation in promoting the concept of compact city.The co-occurrence analysis of keywords reveals the research hotspots of“compact city”,“recreation space”and“urban park”,while the emergence of new keywords such as“vertical city”and“spatial justice”indicates the new trend of recent research.The cluster analysis and timeline map further show the evolution of research themes,with“compact city”being the largest cluster and having rich connections with other themes such as“urban design”and“urban park”. 展开更多
关键词 Compact city Urban recreation space three-dimensional CITESPACE
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Resection of a ganglioneuroma encasing major blood vessels using three-dimensional laparoscopy combined with organ suspension:A case report
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作者 Guo-Zhen Wu Shen-Zhe Fang +1 位作者 Shi-An Yu Min Yu 《World Journal of Gastrointestinal Surgery》 2025年第8期467-475,共9页
BACKGROUND Ganglioneuroma is a rare,well-differentiated,slow-growing benign tumor of the peripheral nerves,with surgical resection being the only curative treatment.Surgical resection of ganglioneuromas encasing major... BACKGROUND Ganglioneuroma is a rare,well-differentiated,slow-growing benign tumor of the peripheral nerves,with surgical resection being the only curative treatment.Surgical resection of ganglioneuromas encasing major blood vessels remains a substantial clinical challenge.Traditionally,these cases often require open abdominal surgery or combined organ resections,and in some instances,the tumors are considered unresectable.Currently,no reports have described the resection of such tumors via laparoscopy.CASE SUMMARY A 35-year-old woman was admitted to our hospital after the incidental discovery of a retroperitoneal space-occupying lesion.Imaging revealed a mass with the celiac axis and superior mesenteric artery passing through it.A neurogenic tumor was suspected,with ganglioneuroma being the most likely diagnosis.Following comprehensive preoperative preparation,the retroperitoneal tumor was resected using a three-dimensional laparoscopy combined with an organ suspension technique.The surgical approach involved incising the tumor along the vascular axis and conducting meticulous,vascular-preserving tumor excision.The operation lasted approximately 458 minutes,with an estimated blood loss of 50 mL.The patient was discharged on the 8th postoperative day.A transient liver injury occurred after surgery but improved rapidly.After 11 months of postoperative follow-up,no complications or tumor recurrence were observed.CONCLUSION This case illustrates the feasibility of minimally invasive laparoscopic resection for retroperitoneal ganglioneuromas encasing major blood vessels. 展开更多
关键词 Ganglioneuromas Retroperitoneal three-dimensional laparoscopy Organ suspension Case report
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Reconfigurable Three-Dimensional Thermal Dome
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作者 Yuhong Zhou Fubao Yang +5 位作者 Liujun Xu Pengfei Zhuang Dong Wang Xiaoping Ouyang Ying Li Jiping Huang 《Engineering》 2025年第3期236-244,共9页
Thermal metamaterial represents a groundbreaking approach to control heat conduction,and,as a crucial component,thermal invisibility is of utmost importance for heat management.Despite the flourishing development of t... Thermal metamaterial represents a groundbreaking approach to control heat conduction,and,as a crucial component,thermal invisibility is of utmost importance for heat management.Despite the flourishing development of thermal invisibility schemes,they still face two limitations in practical applications.First,objects are typically completely enclosed in traditional cloaks,making them difficult to use and unsuitable for objects with heat sources.Second,although some theoretical proposals have been put forth to change the thermal conductivity of materials to achieve dynamic invisibility,their designs are complex and rigid,making them unsuitable for large-scale use in real threedimensional(3D)spaces.Here,we propose a concept of a thermal dome to achieve 3D invisibility.Our scheme includes an open functional area,greatly enhancing its usability and applicability.It features a reconfigurable structure,constructed with simple isotropic natural materials,making it suitable for dynamic requirements.The performance of our reconfigurable thermal dome has been confirmed through simulations and experiments,consistent with the theory.The introduction of this concept can greatly advance the development of thermal invisibility technology from theory to engineering and provide inspiration for other physical domains,such as direct current electric fields and magnetic fields. 展开更多
关键词 Thermal domes Reconfigurable metamaterials three-dimensional invisibility
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Three-dimensional spectral analysis of gravity waves from airglow observations over Northwest China
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作者 QinZeng Li JiYao Xu +3 位作者 Wei Yuan Xiao Liu YaJun Zhu WeiJun Liu 《Earth and Planetary Physics》 2025年第4期988-994,共7页
The three-dimensional spectral analysis method was applied to airglow data from September 2023 to August 2024 derivedfrom an OH airglow imager located at the Hejing station (42.79°N, 83.73°E) to study the pr... The three-dimensional spectral analysis method was applied to airglow data from September 2023 to August 2024 derivedfrom an OH airglow imager located at the Hejing station (42.79°N, 83.73°E) to study the propagation characteristics of gravity waves(GWs) over Northwest China. We found that obvious seasonal variations occur in the propagation of GWs. In spring, GWs mainlypropagate in the northeast direction. In summer and autumn, GWs mainly propagate in the north direction. However, GWs mainlypropagate in the south direction in winter. The direction of GW propagation in the zonal direction is controlled by the wind-filteringeffect, whereas the north–south meridional direction is mainly determined by the location of the wave source. We found that the averageenergy spectrum exhibits a 10%–20% higher intensity in summer and winter compared with spring and autumn. For the first time, wereport the seasonal variation characteristics of GWs over the inland areas of Northwest China, which is of great significance forunderstanding the regional distribution characteristics of GWs. 展开更多
关键词 AIRGLOW gravity wave three-dimensional spectral analysis seasonal variation
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Three-dimensional internal multiple elimination in complex structures using Marchenko autofocusing theory
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作者 Pei-Nan Bao Ying Shi +2 位作者 Xin-Min Shang Hong-Xian Liang Wei-Hong Wang 《Petroleum Science》 2025年第1期222-233,共12页
Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With ... Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With the development of seismic exploration into deep and ultradeep events,especially those from complex targets in the western region of China,the internal multiple eliminations become increasingly challenging.Currently,three-dimensional(3D)seismic data are primarily used for oil and gas target recognition and drilling.Effectively eliminating internal multiples in 3D seismic data of complex structures and mitigating their adverse effects is crucial for enhancing the success rate of drilling.In this study,we propose an internal multiple prediction algorithm for 3D seismic data in complex structures using the Marchenko autofocusing theory.This method can predict the accurate internal multiples of time difference without an accurate velocity model and the implementation process mainly consists of several steps.Firstly,simulating direct waves with a 3D macroscopic velocity model.Secondly,using direct waves and 3D full seismic acquisition records to obtain the upgoing and down-going Green's functions between the virtual source point and surface.Thirdly,constructing internal multiples of the relevant layers by upgoing and downgoing Green's functions.Finally,utilizing the adaptive matching subtraction method to remove predicted internal multiples from the original data to obtain seismic records without multiples.Compared with the two-dimensional(2D)Marchenko algo-rithm,the performance of the 3D Marchenko algorithm for internal multiple prediction has been significantly enhanced,resulting in higher computational accuracy.Numerical simulation test results indicate that our proposed method can effectively eliminate internal multiples in 3D seismic data,thereby exhibiting important theoretical and industrial application value. 展开更多
关键词 Marchenko Internal multiple elimination Autofocusing three-dimensional seismic data
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Three-dimensional reconstruction under computed tomography and myopectineal orifice measurement under laparoscopy for quality control of inguinal hernia treatment
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作者 Lei Zhang Jing Chen +7 位作者 Yu-Ying Zhang Lei Liu Han-Dan Wang Ya-Fei Zhang Jun Sheng Qiu-Shi Hu Ming-Liang Liu Yi-Lin Yuan 《World Journal of Gastrointestinal Endoscopy》 2025年第3期50-59,共10页
BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are ne... BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size. 展开更多
关键词 HERNIA INGUINAL Myopectineal orifice three-dimensional reconstruction Computed tomography Inguinal hernia
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Application of Transvaginal Three-Dimensional Ultrasound in Assessing Endometrial Receptivity in Patients with Ovulation Disorder Infertility and the Impact on Subendometrial Vascular Index(VI)and Vascular Flow Index(VFI)Level
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作者 Yongping Sun 《Journal of Clinical and Nursing Research》 2025年第12期351-357,共7页
Objective:To analyze the diagnostic value of transvaginal three-dimensional ultrasound(3D-TVS)in evaluating endometrial receptivity(ER)for ovulation disorder infertility(ODI),and to investigate the impact of subendome... Objective:To analyze the diagnostic value of transvaginal three-dimensional ultrasound(3D-TVS)in evaluating endometrial receptivity(ER)for ovulation disorder infertility(ODI),and to investigate the impact of subendometrial endometrial vascular index(VI)and endometrial vascular flow index(VFI)levels on ODI.Methods:A total of 110 patients diagnosed with ODI admitted between January 2023 and June 2024 were selected.All patients underwent ovulation induction therapy,3D-TVS examination,and sex hormone testing.Based on pregnancy outcomes,patients were divided into a successful pregnancy group(73 cases)and an unsuccessful pregnancy group(37 cases).ER parameters,sex hormone levels,and endometrial blood flow patterns were compared between the two groups.Receiver operating characteristic(ROC)curves were plotted to evaluate the predictive value of ER for ODI.Results:The spiral artery peak systolic velocity(PSV),endometrial volume(EMV),endometrial flow index(FI),and VFI in the successful pregnancy group were significantly higher than those in the unsuccessful pregnancy group(p<0.05).No significant differences were observed in other ER parameters between the two groups(p>0.05).There was no significant difference in sex hormone levels between the two groups on the day of human chorionic gonadotropin(hCG)treatment(p>0.05).Among the endometrial blood flow classifications in the pregnant group,the proportion of Type II was lower than that in the nonpregnant group(p<0.05).The Receiver Operating Characteristic(ROC)curve demonstrated that the area under the curve(AUC)for Endometrial Volume(EMV)in predicting pregnancy after Ovarian Dysfunction Infertility(ODI)treatment was 0.854,with a sensitivity of 92.61%and a specificity of 71.75%.The AUC for Vascularization Index(VI)was 0.771,with a sensitivity of 52.18%and a specificity of 88.70%.The AUC for Vascularization Flow Index(VFI)of the endometrium was 0.887,with a sensitivity of 80.01%and a specificity of 69.20%.Conclusion:Three-dimensional transvaginal sonography(3D-TVS)assessment of endometrial receptivity(ER)can effectively detect ODI,and the levels of subendometrial VI and VFI demonstrate superior predictive performance for pregnancy outcomes in this condition,serving as commonly used predictive indicators for the disease. 展开更多
关键词 Transvaginal three-dimensional ultrasound Endometrial receptivity Ovarian dysfunction infertility VI VFI
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