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Variable leading-edge cone method for waverider design 被引量:1
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作者 Zhihao LI Chongwen JIANG +1 位作者 Shuyao HU Chun-Hian LEE 《Chinese Journal of Aeronautics》 2025年第3期262-279,共18页
The optimization of the waverider is constrained by the reversely designed leading edge and the constant shock angle distribution. This paper proposes a design method called the variable Leading-Edge Cone (vLEC) metho... The optimization of the waverider is constrained by the reversely designed leading edge and the constant shock angle distribution. This paper proposes a design method called the variable Leading-Edge Cone (vLEC) method to address these limitations. In the vLEC method, the waverider is directly designed from the preassigned leading edge and the variable shock angle distribution based on the Leading-Edge Cone (LEC) concept. Since the vLEC method is an approximate method, two test waveriders are designed and evaluated using numerical simulations to validate the shock design accuracy and the effectiveness of the vLEC method. The results show that the shocks of the test waveriders coincide well with the preassigned positions. Furthermore, four specifically designed application cases are conducted to analyze the performance benefits of the vLEC waveriders. The results of these cases indicate that, due to their variable shock angle distributions, the vLEC waveriders exhibit higher lift-to-drag ratios and better longitudinal static stability than conventional waveriders. Additionally, the vLEC waveriders demonstrate superior volumetric capacities near the symmetry plane, albeit with a minor decrease in volumetric efficiency. 展开更多
关键词 Hypersonic vehicles Waverider design methods Leading-edge cone method Variable shock angles Direct design method
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Volcanic Geomorphology and Morphometry Classification of Cinder Cone in Harrat Lunayyir Saudi Arabia by Using GIS and Remote Sensing
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作者 Azizah Aziz al Shehri 《Journal of Environmental & Earth Sciences》 2025年第5期304-318,共15页
Harrat Lunayyir,a volcanic field in western Saudi Arabia,exhibits diverse geomorphological and topographical features shaped by volcanic,tectonic,and climatic processes.This study integrates field observations,remote ... Harrat Lunayyir,a volcanic field in western Saudi Arabia,exhibits diverse geomorphological and topographical features shaped by volcanic,tectonic,and climatic processes.This study integrates field observations,remote sensing,and GIS analysis to investigate the spatial distribution and relationships between volcanic landforms,lava flows,and topographical variation result obtained is a morphological classification of the cinder cones of Harrat Lunayyir,which can be sub-divided into four types:tephra rings,horseshoe-shaped volcanoes,multiple volcanoes and volcanoes without craters.All of these are monogenetic volcanoes,unlike central volcanoes(stratovolcanoes)which live for tens or hundreds of thousands of years and erupt numerous times.In Harrat Lunayyir,there is a clear dominance of arched horseshoe-shaped volcanoes(58)over ring-shaped cinder cones(10),A1_symmetric cones(circular,uniform cinder cones with a single crater)(32),A2_asymmetric cones(elongated,irregular cones and may feature one or more craters)(8),volcanoes without craters(55)and multiple volcanoes(20).The classification presented in this paper makes it possible to include all morphological types of volcanoes found in the region.This fact also renders the present classification a useful tool to apply in other,both insular and continental volcanic areas to eventually analyze and systematize the study of eruptive edifices with similar traits.Hence,this research will explore the standard physical volcanology literature so as to follow accepted definitions. 展开更多
关键词 GIS Morphology DEM Topography LITHOLOGY Cinder cones
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Stability Analysis of a Floating Multirobot Coordinated Towing System Based on the Stability Cone Method
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作者 Xiangtang Zhao Zhigang Zhao +1 位作者 Cheng Su Jiadong Meng 《哈尔滨工程大学学报(英文版)》 2025年第2期449-457,共9页
Currently,the cranes used at sea do not have enough flexibility,efficiency,and safety.Thus,this study proposed a floating multirobot coordinated towing system to meet the demands for offshore towing.Because of the fle... Currently,the cranes used at sea do not have enough flexibility,efficiency,and safety.Thus,this study proposed a floating multirobot coordinated towing system to meet the demands for offshore towing.Because of the flexibility of rope-driven robots,the one-way pulling characteristics of the rope,and the floating characteristics of the base,towing robots are easily overturned.First,the spatial configuration of the towing system was established according to the towing task,and the kinematic model of the towing system was established using the coordinate transformation.Then,the dynamic model of the towing system was established according to the rigid-body dynamics and hydrodynamic theory.Finally,the stability of the towing system was analyzed using the stability cone method.The simulation experiments provide a reference for the practical application of the floating multirobot coordinated towing system,which can improve the stability of towing systems by changing the configuration of the towing robot. 展开更多
关键词 Offshore towing Kinematic model Dynamic model Stability cone method STABILITY
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BOUNDEDNESS OF FORELLI-RUDIN TYPE OPERATORS ON TUBE DOMAINS OVER THE FORWARD LIGHT CONES
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作者 Jiaxin LIU Guantie DENG Zhiqiang GAO 《Acta Mathematica Scientia》 2025年第4期1235-1246,共12页
We explore some necessary and sufficient conditions for the boundedness of the Forelli-Rudin type operator T on the weighted Lebesgue space associated with tubular domains over the forward light cone.Our approach invo... We explore some necessary and sufficient conditions for the boundedness of the Forelli-Rudin type operator T on the weighted Lebesgue space associated with tubular domains over the forward light cone.Our approach involves conducting precise computations for a series of complex integrals to identify appropriate test functions,and through a detailed analysis of these test functions,we derive the boundedness properties of the operator T.This work is significant in the study of the Bergman projection operators. 展开更多
关键词 Forelli-Rudin type operators test function light cone Bergman projection
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Influence of diversion cone structure on inner characteristic in hydrogen-enriched shaft furnace:a DEM study
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作者 Xu Tian Heng Zhou +5 位作者 Tian Xia Zhi-tao Qin Hui-dong Guo Da-wei Sun Ming-yin Kou Sheng-li Wu 《Journal of Iron and Steel Research International》 2025年第7期1844-1855,共12页
The hydrogen-enriched direct reduction shaft furnace addresses the high CO_(2) emissions associated with the blast furnace process.A discrete element method(DEM)model was introduced to explore how the structure of the... The hydrogen-enriched direct reduction shaft furnace addresses the high CO_(2) emissions associated with the blast furnace process.A discrete element method(DEM)model was introduced to explore how the structure of the diversion cone affects particle descent behavior in a hydrogen-enriched shaft furnace.The results indicated that in the absence of a diversion cone,the descending velocity near the furnace wall zone is significantly lower than that at its center,resulting in a‘V’-shaped burden flow pattern.The discharge velocity has a minor impact on the flow pattern in the shaft furnace.Upon installation of a diversion cone,burden descending velocity becomes more uniform,leading to a‘-’-shaped burden flow pattern.As the bottom of the diversion cone ascends(i.e.,the lower end of the diversion cone is progressively closer to the top),there is an increase in the volume fraction of the dead zone within the shaft furnace.This is particularly evident in the formation of a triangular dead zone at the base of the diversion cone.It is suggested that the lower cone of the bi-conical diversion cone should maintain a sufficient height. 展开更多
关键词 Discrete element method Diversion cone Shaft furnace Flow pattern Residence time distribution
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Numerical Validation of A Simple Dynamic Beam Filtration Strategy in Cone Beam CT
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作者 WANG Heran XIE Jixiong +4 位作者 ZHU Jiongtao ZHANG Xin TAN Yuhang SU Ting GE Yongshuai 《集成技术》 2025年第2期71-85,共15页
For cone beam computed tomography(CBCT),there has long been a desire to modulate the intensity and distribution of the X-rays to accommodate the patient’s anatomy as the gantry rotates from one projection to another.... For cone beam computed tomography(CBCT),there has long been a desire to modulate the intensity and distribution of the X-rays to accommodate the patient’s anatomy as the gantry rotates from one projection to another.This would reduce both image artifacts and radiation dose.However,the current beam modulation setups,such as dynamic bowtie filters,may be too complex for practical use in clinical applications.This study aimed to investigate a simplified dynamic beam filtration strategy for CBCT imaging to reduce image artifacts and radiation dose.In this study,the beam filtration was designed to vary dynamically as the CBCT gantry rotates around the object.Specifically,two distinct components were integrated:the sheet filter part and the bowtie filter part.The dynamic beam filtration setup has two working schemes,one is a combination of dynamic sheet filter and dynamic bowtie filter,denoted as dynamic filterdynamic bowtie(DFDB);the other is a combination of dynamic sheet filter and static bowtie filter,denoted as dynamic filter-static bowtie(DFSB).Numerical imaging experiments were performed for three human body parts:the shoulder,chest,and knee.In addition,the Monte Carlo simulation platform MC-GPU was used to generate the dose distribution maps.Results showed that the proposed DFDB and DFSB beam filtration schemes can significantly reduce the image artifacts and thus improve the CBCT image quality.Depending on the scanned object,the total radiation dose could be reduced by 30%.The proposed simple dynamic beam filtration strategy,especially the DFSB approach,could be beneficial in the future to improve the CBCT image quality with reduced image artifacts and radiation dose. 展开更多
关键词 dynamic filtration radiation dose reduction artifacts reduction cone beam computed tomography
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Deep learning technique based efficient optimization method for cone dielectric energy generator
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作者 Demin Zhao Aoyu Xiao +4 位作者 Zewen Gu Menghang Chen Guoqiang Xu Bin Zhao Jianlin Liu 《Acta Mechanica Sinica》 2025年第12期189-206,共18页
Dielectric elastomer(DE)is an electroactive polymer with the characteristics of high energy output,great flexibility,light-weight,mechanical compliance,and low cost,which are particularly suitable for DE energy genera... Dielectric elastomer(DE)is an electroactive polymer with the characteristics of high energy output,great flexibility,light-weight,mechanical compliance,and low cost,which are particularly suitable for DE energy generators.Energy harvesting efficiency is a key index to evaluate the performance of the energy generator,which depends on the structural configuration and the mechanical and dielectric properties of the DE material.This paper proposes a fractional viscoelastic polarization(FVP)model by combining the fractional viscoelasticity model and the polarization-based lumped parameter model.A dynamical model of a cone dielectric energy generator(CDEG)considering stretch-dependent electrostriction and nonlinear viscoelasticity is established.Additionally,a deep neural network(DNN)model is developed to explore the relationships between various parameters and the output energy of CDEGs to efficiently and accurately predict the energy output of CDEGs.Based on the DNN model,optimal parameter designs for CDEGs are obtained by using non-dominated sorting genetic algorithm II(NSGA-II).The experiments verified that the FVP model predicts accurately the output energy of CDEG and the established optimal design framework can accurately provide the optimal design parameters of CDEG,which offers deep insights for the design and fabrication of a high-efficiency dielectric energy generator. 展开更多
关键词 cone dielectric energy generator Energy harvesting Fractional viscoelasticity Stretch-dependent electrostriction Deep neural network
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Understanding the scattering data from cone penetration tests based on sedimentary facies
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作者 Youkou Dong Kuanjun Wang +1 位作者 Kanmin Shen Lan Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期5282-5306,共25页
Cone penetration testing(CPT)and its variant with pore pressure measurements(CPTu)are versatile tools that have been traditionally used for in situ geotechnical site investigations.These investigations are among the m... Cone penetration testing(CPT)and its variant with pore pressure measurements(CPTu)are versatile tools that have been traditionally used for in situ geotechnical site investigations.These investigations are among the most challenging yet indispensable tasks,providing a crucial reference for infrastructure planning,design and construction.However,data obtained through the CPT/CPTu testing often exhibit significant variability,even at closely spaced test points.This variability is primarily attributed to the complex mineral compositions and sedimentary process of the Quaternary sediments.Problems induced by the scattering data include the difficulties in estimating the shear strength of the sediments and determining the appropriate bearing stratum for pile foundations.In this paper,the conventional interpretation methods of the CPT/CPTu data are enhanced with sedimentary facies knowledge.The geotechnical investigation mainly involves 42 CPTu tests(39 essential data sets available)and 4 boring samples.Sediment types are interpreted from the CPTu data and calibrated by the nearby boring samples.Sedimentary facies are derived from the interpreted sequence stratigraphy,for which the interpretation skills are summarized in the form of characteristic curves of the CPTu data.Scattering distribution of the sediment types and their mechanical parameters are well explained by the sedimentary facies.The sediments are then categorized into a few groups by their sedimentary facies,resulting in reduced uncertainties and scattering in terms of shear strength.Bearing stratum of pile foundations is also suggested based on the sedimentary regulations. 展开更多
关键词 Site investigation cone penetration test(CPT) Spatial uncertainty Quaternary sediment Sedimentary facies
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Accelerating and guiding of electron beams in a cone target filled with near-critical-density plasmas
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作者 Jie-Jie Lan Zhang-Hu Hu You-Nian Wang 《Chinese Physics B》 2025年第12期334-341,共8页
Direct laser acceleration is one of the mechanisms for producing electron bunches carrying up to μC charge,which has attracted much attention in recent decades.Currently,one major challenge for its applications to hi... Direct laser acceleration is one of the mechanisms for producing electron bunches carrying up to μC charge,which has attracted much attention in recent decades.Currently,one major challenge for its applications to high-flux x-ray beams and Comptonγ-ray sources is the relatively large divergence angle(hundreds of mrad).In this work,a scheme to guide and focus the incident laser and the accelerated electrons is proposed and tested through two-dimensional(2D)particle-in-cell(PIC)simulations.The scheme is based on a hollow cone target(made of aluminum or gold)filled with near-critical-density(NCD)plasmas(pre-ionized polymer foams).Instead of separating the acceleration and focusing processes,it is convenient to simultaneously realize both requirements in such an NCD plasma-filled cone target.PIC simulations reveal that the laser,electrons,and emitted photons can be well-guided along the cone axis in the NCD plasma-filled cone target,preserving the characteristic of high beam charge.Detailed PIC simulations are also performed to show the dependence of the electron energy and charge on the plasma density for a given laser. 展开更多
关键词 laser–plasma interactions direct laser acceleration plasma-filled cone target electron beams
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Predictors of Early Right Ventricular Dysfunction after Cone Reconstruction for Ebstein’s Anomaly:A Retrospective Cohort Study
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作者 Jing Ling Naijimuding Abudurexiti +5 位作者 Jiaxiong Wu Runzhang Liang Zirui Peng Yuting Huang Haiyun Yuan Shusheng Wen 《Congenital Heart Disease》 2025年第1期13-25,共13页
Background:Although Cone reconstruction has been shown to improve biventricular functionover time,postoperative right ventricular dysfunction(RVD)is frequently observed,signiffcantly affectingreoperation and long-term... Background:Although Cone reconstruction has been shown to improve biventricular functionover time,postoperative right ventricular dysfunction(RVD)is frequently observed,signiffcantly affectingreoperation and long-term prognosis.This study aims to identify the predictors for postoperative RVD.Methods:This retrospective cohort study included 51 patients with Ebstein’s anomaly who underwentthe Cone reconstruction.RVD was deffned as right ventricular fractional area change(RV-FAC)lessthan 35%and tricuspid annular plane systolic excursion(TAPSE)less than 17 mm through pre-dischargeechocardiography.Univariate and multivariate analyses were used to analyze the pre-operative predictors.Results:The median age at surgery was 37.7(±15.3)years,RVD was documented in 25 patients(49%)of the51 patients.Patients with RVD had signiffcantly higher right ventricular end-systolic volume index(RVESVi)(p=0.001),right ventricular end-diastolic volume index(RVEDVi)(p=0.03),and septal leaffet displacement(p=0.003).Multivariate analysis conffrmed that septal leaffet displacement was independently associatedwith postoperative RVD(p=0.02).Additionally,RVD was not related to the cardiopulmonary bypass time,ICU stay and total hospital time.Conclusions:This study suggests that preoperative right ventricularejection fraction(RVEF)reduction,severe septal leaffet displacement and signiffcant right ventriculardilatation are key predictors of early postoperative RVD.RVD may exacerbate tricuspid regurgitation,andthis ffnding indicates that predicting RVD may aid in identifying high-risk patients prone to recurrence oftricuspid regurgitation after Cone reconstruction. 展开更多
关键词 cone reconstruction right ventricular dysfunction cardiac magnetic resonance
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下颌骨前部Stafne骨腔1例报告及文献复习
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作者 吴平凡 陈林林 《口腔颌面外科杂志》 2026年第1期70-73,共4页
Stafne骨腔(Stafne bone cavity,SBC)又称静止性骨腔,是一种出现在下颌骨舌面少见的骨质缺损。SBC通常发生在下颌角附近,极少出现在下颌骨前部。本文报道1例位于下颌骨前磨牙区的SBC病例,通过复习相关文献,加深口腔医生对不典型位置SBC... Stafne骨腔(Stafne bone cavity,SBC)又称静止性骨腔,是一种出现在下颌骨舌面少见的骨质缺损。SBC通常发生在下颌角附近,极少出现在下颌骨前部。本文报道1例位于下颌骨前磨牙区的SBC病例,通过复习相关文献,加深口腔医生对不典型位置SBC的认识,避免误诊。 展开更多
关键词 Stafne骨腔 下颌骨前部 锥形束CT
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PAOO术后下前牙唇侧骨量变化:2D线性与3D体积分析的效能与临床意义
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作者 魏雅芹 陈烈金 +2 位作者 黄辉 吴敏婷 陈玉婷 《中国美容医学》 2026年第3期76-83,共8页
目的:比较二维线性测量法与三维体积分析法在评估牙周加速成骨正畸术(Periodontal Accelerated Osteogenic Orthodontic,PAOO)术后下前牙唇侧骨量变化中的差异及其临床应用价值,为精准评估骨改建效果提供科学依据。方法:选取2018年1月-2... 目的:比较二维线性测量法与三维体积分析法在评估牙周加速成骨正畸术(Periodontal Accelerated Osteogenic Orthodontic,PAOO)术后下前牙唇侧骨量变化中的差异及其临床应用价值,为精准评估骨改建效果提供科学依据。方法:选取2018年1月-2024年12月于佛山市第二人民医院和华南理工大学附属第六医院口腔科接受PAOO治疗的15例患者,采用锥形束计算机断层扫描(CBCT)分别获取术前(T0)、术后6个月(T1)及术后18个月(T2)的影像数据。通过二维线性测量法评估唇侧骨高度和厚度,通过三维体积分析法测量唇侧骨体积,分析两种方法的评估效能。结果:术后18个月,中央截面骨厚度(二维测量)的中位数减少1.05 mm(IQR:0.96~1.13 mm,范围:0.00~1.19 mm,P<0.01),三维骨体积的中位数减少25.78 mm^(3)(IQR:24.89~26.67 mm^(3),P<0.01)。二维测量与三维测量在骨厚度上的相关性较高(r=0.98,P<0.01),但在垂直高度上的相关性较低(r=0.36,P=0.20)。三维体积分析在检测微小骨量变化方面表现出更高的敏感性。结论:PAOO术后下前牙唇侧骨增量随时间逐渐减少。三维体积分析法在评估骨改建动态变化方面优于二维线性测量法,具有更高的敏感性和精确性,推荐作为临床精准评估的首选方法。 展开更多
关键词 牙周加速成骨正畸术(PAOO) 下前牙 唇侧骨量 二维三维分析 锥形束计算机断层扫描(CBCT) 骨改建
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儿童骨性Ⅱ类错颌畸形修复中锥形束CT三维头影测量与传统X射线片测量方法的对比研究
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作者 任红艳 张博 +2 位作者 杨欣 彭辉 张忠宝 《中国医学装备》 2026年第1期40-44,共5页
目的:探讨锥形束计算机体层扫描(CBCT)三维头影测量技术相较于传统X射线头影测量在儿童骨性Ⅱ类错颌畸形诊断中的临床价值。方法:回顾性选取2023年1月至2024年6月南京医科大学第四附属医院就诊的100例骨性Ⅱ类错颌畸形患儿,按测量方法... 目的:探讨锥形束计算机体层扫描(CBCT)三维头影测量技术相较于传统X射线头影测量在儿童骨性Ⅱ类错颌畸形诊断中的临床价值。方法:回顾性选取2023年1月至2024年6月南京医科大学第四附属医院就诊的100例骨性Ⅱ类错颌畸形患儿,按测量方法的不同将其分为CBCT组(20例)和X射线组(80例)。建立三维坐标系测量蝶鞍点-鼻根点-上齿槽座点(SNA)、蝶鞍点-鼻根点-下齿槽座点角(SNB)、上齿槽座点-鼻根点-下齿槽座点角(ANB)及下颌平面-前颅底平面角(MPSN)等常规参数,并新增髁突三维位移及气道容积测量指标。观察比较两组SNA、SNB、ANB、MP-SN、髁突位移、气道容积、临床疗效指标、测量信度及辐射剂量。结果:CBCT组ANB测量值高于X射线组(t=3.217,P=0.002),MP-SN低于X射线组(t=2.985,P=0.003)。CBCT组髁突x轴平均前移距离(1.23±0.45)mm,z轴平均上移距离(0.87±0.32)mm,而X射线组无三维位移信息。CBCT组气道容积低于X射线组(t=5.217,P<0.001)。CBCT组磨牙关系协调度和面型改善度高于X射线组(x^(2)=4.326、3.981,P<0.05)。CBCT组在SNA、SNB、ANB及MP-SN测量上的组内相关系数(ICC)值均高于X射线组(F=16.327、14.895、9.874、8.932,P<0.001)。CBCT组有效剂量和甲状腺吸收剂量高于X射线组(Z=8.927、9.123,P<0.001)。结论:CBCT三维头影测量在儿童骨性Ⅱ类错颌畸形诊断中具有更高的精度和临床价值,但辐射剂量较高,需个体化评估风险效益。 展开更多
关键词 锥形束计算机体层扫描(CBCT) 三维头影测量 传统X射线摄影 骨性Ⅱ类错颌畸形 髁突位移 气道容积 辐射剂量
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CBCT检测联合显微根管技术在评估老年上颌第二磨牙根管治疗疗效中的应用
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作者 刘思佳 张旭 熊芳 《川北医学院学报》 2026年第2期217-220,共4页
目的:探讨锥形束计算机断层扫描(CBCT)检测结合显微根管技术在老年上颌第二磨牙根管检测和治疗疗效评估中的应用。方法:将108例老年上颌第二磨牙根管治疗患者按照干预方法不同分为对照组与观察组,每组各54例。对照组行曲面断层片(PAN)+... 目的:探讨锥形束计算机断层扫描(CBCT)检测结合显微根管技术在老年上颌第二磨牙根管检测和治疗疗效评估中的应用。方法:将108例老年上颌第二磨牙根管治疗患者按照干预方法不同分为对照组与观察组,每组各54例。对照组行曲面断层片(PAN)+常规根管治疗;观察组行CBCT+显微根管治疗。比较PAN、CBCT术前诊断、术后评估结果及两组治疗效果。结果:观察组CBCT对颊侧近中第二根管(MB2)的检出率高于PAN(P<0.05),两者对根充质量的判断结果差异具有统计学意义(P<0.05),两者对根尖周愈合情况判断的差异有统计学意义(P<0.05);观察组术中并发症总发生率及术后疼痛视觉模拟评分法(VAS)评分均低于对照组(P<0.05),临床成功率高于对照组(P<0.05)。结论:CBCT联合显微根管技术可提高老年上颌第二磨牙根管检测、治疗成功率,并对疗效进行客观评估。 展开更多
关键词 锥形束计算机断层扫描 牙科手术显微镜 根管治疗 老年人 上颌第二磨牙 疗效评估
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三维牵引钩导板辅助对下颌阻生异位尖牙的矫治效果观察
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作者 卢春燕 徐泽 任海峰 《中国美容医学》 2026年第2期138-141,共4页
目的:探讨三维牵引钩导板辅助对下颌阻生异位尖牙的矫治效果。方法:选择2018年4月-2023年4月在笔者医院接受治疗的96例下颌阻生异位尖牙患者为研究对象,共96颗阻生牙。采用随机数字表法将患者分为观察组和对照组,每组48例,对照组采用常... 目的:探讨三维牵引钩导板辅助对下颌阻生异位尖牙的矫治效果。方法:选择2018年4月-2023年4月在笔者医院接受治疗的96例下颌阻生异位尖牙患者为研究对象,共96颗阻生牙。采用随机数字表法将患者分为观察组和对照组,每组48例,对照组采用常规矫治方案,观察组基于数字化模型结合CBCT 3D模型矫治。记录两组患者的矫正成功率及矫治前至尖牙牙冠移动至侧切牙牙根远中位时(矫治后)的牵引时长,比较两组患者矫治前后邻牙的吸收状态,包括矫治前后冠状面下颌侧切牙、中切牙的牙根面积及长度,轴向切面下颌中切牙、侧切牙的牙根中和牙根尖1/3处的截面面积。结果:两组患者经5~12个月的矫治,下颌阻生异位尖牙均排齐至牙列。观察组牵引时长(6.43±0.71)个月,短于对照组的(8.31±0.58)个月(P<0.05)。矫治后,观察组下颌侧切牙和中切牙的牙根面积及长度与矫治前比较,差异无统计学意义(P>0.05);对照组下颌侧切牙和中切牙的牙根面积及长度低于矫正前(P<0.05)。矫治后,观察组下颌侧切牙和中切牙的牙根中1/3截面面积及牙根尖1/3截面面积与矫正前比较,差异无统计学意义(P>0.05);对照组下颌侧切牙和中切牙的牙根中1/3截面面积及牙根尖1/3截面面积低于矫治前(P<0.05)。结论:数字化模型结合CBCT 3D模型的三维牙颌模型治疗下颌阻生异位尖牙,更有助于缩短患者的矫治时间,减少邻近切牙牙根吸收,矫治效果良好。 展开更多
关键词 下颌阻生尖牙 锥形束CT 数字化3D模型 三维牵引钩导板
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基于CBCT分析上颌埋伏阻生切牙的牙根形态和长度特征
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作者 孙香 史雅绒 《中国美容医学》 2026年第3期152-156,共5页
目的:基于锥形束计算机断层扫描(CBCT)分析上颌切牙埋伏阻生患者的牙根形态和牙根长度特征。方法:纳入2021年1月-2023年12月榆林市第一人民医院收治的164例上颌切牙埋伏阻生患者为研究对象,根据患者上颌切牙与腭平面的角度分为唇侧埋伏... 目的:基于锥形束计算机断层扫描(CBCT)分析上颌切牙埋伏阻生患者的牙根形态和牙根长度特征。方法:纳入2021年1月-2023年12月榆林市第一人民医院收治的164例上颌切牙埋伏阻生患者为研究对象,根据患者上颌切牙与腭平面的角度分为唇侧埋伏阻生组(n=90)和腭侧埋伏阻生组(n=74),再根据Nolla牙龄推断法对牙龄进行分期,并分为早期牙龄组(n=96)和晚期牙龄组(n=68)。分析患者牙根形态和牙根长度特征。结果:唇侧埋伏阻生组和腭侧埋伏阻生组患者牙根总长度比较,差异无统计学意义(P>0.05),但唇侧埋伏阻生组牙根未脱位部分长度及冠根角高于腭侧埋伏阻生组(P<0.05),牙根脱位部分长度、牙根总脱位率低于腭侧埋伏阻生组(P<0.05)。早期牙龄组牙根总长度、牙根未脱位部分长度、牙根脱位部分长度、冠根角均低于晚期牙龄组(P<0.05)。唇侧埋伏阻生组中早期牙龄患者牙根总长度、牙根脱位部分长度、牙根脱位率低于晚期牙龄患者(P<0.05),冠根角高于晚期牙龄组(P<0.05),牙根未脱位部分长度比较,差异无统计学意义(P>0.05);腭侧埋伏阻生组中早期牙龄患者牙根总长度、牙根未脱位部分长度低于晚期牙龄患者(P<0.05),冠根角高于晚期牙龄患者(P<0.05),牙根脱位部分长度、脱位率比较,差异无统计学意义(P>0.05);唇侧埋伏阻生组中所有患者牙根弯曲方向均向唇侧,腭侧埋伏阻生组中,晚期牙龄患者中4例唇侧弯曲,其余均向腭侧弯曲。结论:唇侧埋伏阻生患者牙根未脱位部分长度及冠根角高于腭侧埋伏阻生患者,但牙根脱位部分长度唇侧埋伏阻生低于腭侧埋伏阻生,且晚期牙龄患者冠根角较早期牙龄患者小,而牙根总长度均高于早期牙龄患者。 展开更多
关键词 上颌切牙 唇侧埋伏阻生 腭侧埋伏阻生 锥形束计算机断层扫描(CBCT) 牙根
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正畸和正颌手术对青年骨性Ⅱ类错[牙合]畸形患者颞下颌关节三维骨结构与骨重塑的影响分析
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作者 钟秋 冷建琼 +1 位作者 刘露畅 周吉 《口腔颌面修复学杂志》 2026年第1期37-46,共10页
目的:探讨骨性Ⅱ类错[牙合]畸形正畸正颌联合治疗后颞下颌关节骨性结构的三维改变及骨质重塑指标的相关性。方法:选择2020年3月至2024年5月我院口腔科收治的123例骨性Ⅱ类错[牙合]畸形患者,其中男性62例,女性61例;实际入组年龄处于19~2... 目的:探讨骨性Ⅱ类错[牙合]畸形正畸正颌联合治疗后颞下颌关节骨性结构的三维改变及骨质重塑指标的相关性。方法:选择2020年3月至2024年5月我院口腔科收治的123例骨性Ⅱ类错[牙合]畸形患者,其中男性62例,女性61例;实际入组年龄处于19~29岁区间,平均年龄为(23.78±2.82)岁。依据前颅底平面和下颌平面所成交角(SN-MP),将患者划分成三组:高角组(SN-MP>38°)、均角组(29°≤SN-MP≤38°)以及低角组(SN-MP<29°)。在正畸治疗的T0阶段(术前初诊阶段)、T1阶段(术前正畸去代偿完成阶段)和T2阶段(正颌手术后6个月阶段),分别进行锥形束CT扫描;同时检测同一时间点的Dickkopf-1蛋白、骨保护素、核因子κB受体活化因子配体(RANKL)以及硬化素等骨质重塑相关指标,运用Pearson法分析二者的相关性。结果:低角组的左侧关节内间隙、髁状突前后径、关节结节后斜面角度以及髁状突长轴径均显著高于高角组和均角组。特别是低角组的右侧关节上间隙、髁状突长轴径、髁状突前后径、关节内间隙和关节结节后斜面角度均显著高于高角组和均角组。此外,右侧关节内间隙在高角组显著高于均角组(P<0.008)。在骨质重塑生物标志物分析方面,三组患者在T1和T2时间点的血清Dickkopf-1蛋白和RANKL水平明显低于T0时间点;同时,血清骨保护素和硬化素在T1和T2时间点明显高于T0时间点(P<0.008)。相关性分析显示,T1时间点硬化素与左侧和右侧的关节内间隙、髁状突长轴径、髁状突前后径以及关节结节后斜面角度呈负相关,且与右侧关节上间隙也呈负相关(P<0.05)。此外,T2时间点的骨保护素和硬化素分别与左侧和右侧的关节内间隙、髁状突长轴径、髁状突前后径、关节结节后斜面角度呈负相关,并与右侧关节上间隙也呈负相关(P<0.05)。结论:骨性Ⅱ类错[牙合]畸形经过正畸正颌联合治疗后颞下颌关节骨性结构在关节窝位置和髁突形态上出现显著三维变化,并与骨质重塑指标相关,在临床诊断和治疗过程中有一定参考价值。 展开更多
关键词 骨性Ⅱ类错[牙合]畸形 颞下颌关节 骨性结构 骨质重塑 三维分析 锥形束CT
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考虑台区运行控制及经济性提升的调容变压器配置评估方法
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作者 陆旦宏 李艳 +2 位作者 杨婷 柏生奎 鱼泓漪 《电力需求侧管理》 2026年第1期48-56,共9页
当前已有调容变压器配置评估方法中存在着考虑因素单一、综合成本考虑不充分以及缺乏台区运行控制结果分析等问题。对此提出了一种综合考虑台区运行控制与经济性提升的调容变压器配置评估方法。首先基于二阶锥规划构建了潮流模型,通过... 当前已有调容变压器配置评估方法中存在着考虑因素单一、综合成本考虑不充分以及缺乏台区运行控制结果分析等问题。对此提出了一种综合考虑台区运行控制与经济性提升的调容变压器配置评估方法。首先基于二阶锥规划构建了潮流模型,通过台区优化运行控制结果得到典型日净负荷数据,作为调容变压器容量选取的基础数据。其次分析了影响调容变压器配置评估的多维关键因素,然后建立了面向经济性提升的综合成本评估指标。最后依据典型台区历史负荷数据,开展调容变压器配置算例分析。在考虑光伏接入和不考虑光伏接入的两种场景下,基于不同运行规划周期和容量裕量,通过与传统变压器配置方案进行对比,验证了文中所提调容变压器配置方案的有效性和优越性。 展开更多
关键词 调容变压器配置 台区运行控制 经济性提升 综合成本评估 二阶锥规划
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用CONE法研究木材阻燃剂FRW的阻燃性能 被引量:71
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作者 李坚 王清文 +1 位作者 李淑君 吴绍利 《林业科学》 EI CAS CSCD 北大核心 2002年第5期108-114,共7页
利用锥形量热仪 (CONE)系统地测定了新型木材阻燃剂FRW的阻燃性能 ,讨论了FRW对阻燃木材在燃烧时的热释放、质量变化及耐点燃性的影响 ,并与Dricon阻燃剂进行了对比。结果表明 ,在 5 0kW·m2 的热辐射功率下 ,FRW阻燃处理木材的热... 利用锥形量热仪 (CONE)系统地测定了新型木材阻燃剂FRW的阻燃性能 ,讨论了FRW对阻燃木材在燃烧时的热释放、质量变化及耐点燃性的影响 ,并与Dricon阻燃剂进行了对比。结果表明 ,在 5 0kW·m2 的热辐射功率下 ,FRW阻燃处理木材的热释放速率 (RHR)和总热释放量 (THR)随FRW载药率的升高而降低 ,至载药率达到 10 %左右时 ,RHR及THR降低为未处理木材的 5 0 %左右 ,并且降低的趋势明显变缓 ;FRW与Dri con阻燃木材的有效燃烧热 (EHC)曲线基本重合 ,说明二者的阻燃机理类似 ;FRW阻燃木材的质量损失速率(MLR)曲线与RHR曲线相似 ,失重和热释放主要发生在有焰燃烧阶段 ;FRW阻燃处理能显著提高木材燃烧时的成炭率 ,但对木材的点燃时间影响不大 ;FRW与Dricon的阻燃效力相当 ,属高效木材阻燃剂。 展开更多
关键词 cone 木材阻燃剂FRW 阻燃性能 锥形量热仪
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用CONE法研究木材阻燃剂FRW的抑烟性能 被引量:39
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作者 王清文 李坚 +1 位作者 李淑君 吴绍利 《林业科学》 EI CAS CSCD 北大核心 2002年第6期103-109,共7页
采用锥形量热仪 (CONE)法系统地测定了新型木材阻燃剂FRW的抑烟性能 ,讨论了FRW对木材燃烧时发烟及烟气毒性的影响 ,并与Dricon阻燃剂进行了对比。结果表明 ,当热辐射功率为 5 0kW·m- 2 时 ,FRW阻燃处理木材的烟化率SR、比消光面积... 采用锥形量热仪 (CONE)法系统地测定了新型木材阻燃剂FRW的抑烟性能 ,讨论了FRW对木材燃烧时发烟及烟气毒性的影响 ,并与Dricon阻燃剂进行了对比。结果表明 ,当热辐射功率为 5 0kW·m- 2 时 ,FRW阻燃处理木材的烟化率SR、比消光面积SEA、二氧化碳浓度CO2 及二氧化碳产率YCO2 比未处理木材显著降低 ;FRW阻燃处理对木材燃烧时一氧化碳的生成元显著影响 ;FRW与Dricon均具有很强的抑烟作用 。 展开更多
关键词 cone 木材阻燃剂 抑烟性能 锥形量热仪 FRW 发烟性 烟气毒性
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