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Hyponormal Block Toeplitz Operators on the Weighted Bergman Space with Circulant Symbols
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作者 FU Guangyang ZHOU Jiang 《数学进展》 北大核心 2026年第1期183-191,共9页
In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and... In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and G(z)=∑^(N)_(i)=1 A_(−i)z^(i),A_(i)ae culants. 展开更多
关键词 block Toeplitz operator hyponormal weighted Bergman space CIRCULANT COMMUTATOR
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Engineering stimuli-responsive block copolymers for multimodal bioimaging
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作者 Lizhuang Zhong Ming Liu +3 位作者 Shilong Su Dongxin Zeng Jing Hu Zhiqian Guo 《Chinese Chemical Letters》 2026年第1期116-124,共9页
The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytot... The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytotoxicity.These limitations have catalyzed the development of intelligent stimuli-responsive block copolymers-based bioimaging agents,which was engineered to dynamically respond to endogenous biochemical cues(e.g.,p H gradients,redox potential,enzyme activity,hypoxia environment) or exogenous physical triggers(e.g.,photoirradiation,thermal gradients,ultrasound(US)/magnetic stimuli).Through spatiotemporally controlled structural transformations,stimuli-responsive block copolymers enable precise contrast targeting,activatable signal amplification,and theranostic integration,thereby substantially enhancing signal-to-noise ratios of bioimaging and diagnostic specificity.Hence,this mini-review systematically examines molecular engineering principles for designing p H-,redox-,enzyme-,light-,thermo-,and US/magnetic-responsive polymers,with emphasis on structure-property relationships governing imaging performance modulation.Furthermore,we critically analyze emerging strategies for optical imaging,US synergies,and magnetic resonance imaging(MRI).Multimodal bioimaging has also been elaborated,which could overcome the inherent trade-offs between resolution,penetration depth,and functional specificity in single-modal approaches.By elucidating mechanistic insights and translational challenges,this mini-review aims to establish a design framework of stimuli-responsive block copolymersbased for high fidelity bioimaging agents and accelerate their clinical translation in precise diagnosis and therapy. 展开更多
关键词 STIMULI-RESPONSIVE block copolymers Molecular engineering Multimodal bioimaging Diagnosis and therapy
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The Magic of Organocatalytic Synergism in Switchable Polymerization:One-pot Synthesis of Block Copolymers with Programmable Sequences and Compositions
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作者 Shuai-Shuai Zhu Mao-Ji Zhao +1 位作者 Ying-Jie Yuan Yong Wang 《Chinese Journal of Polymer Science》 2026年第1期68-78,I0010,共12页
Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford prod... Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford products with fixed sequences and compositions.Herein,we report the triethylborane/1,8-diazabicyclo[5.4.0]undec-7-ene(Et_3B/DBU)pair-mediated four-component switchable polymerization of propylene oxide(PO),CO_(2),phthalic anhydride(PA),and racemic lactide(rac-LA),which enables the on-demand synthesis of four different block copolymers,i.e.,poly(propylene phthalate)-b-polylactide(PPE-b-PLA),PPE-b-PLA-b-poly(propylene carbonate)(PPC),PPE-b-PPC-b-PLA,and PPE-b-PPCb-poly(propylene oxide)(PPO),through rationally modulating the Lewis pair(LP)ratio.Core to this protocol is that increasing the loading of Et_(3)B accelerates the ring-opening of PO while impeding the reactivity of rac-LA,thus allowing for fine-tuning of the thermodynamic and kinetic of the switchable polymerization.Therefore,the four polymerization cycles involving PO/PA ring-opening copolymerization(ROCOP),PO/CO_(2) ROCOP,rac-LA ring-opening polymerization(ROP),and PO ROP can be connected and discriminated in precisely programmed manners. 展开更多
关键词 Switchable polymerization Organic Lewis pair block copolymers Ring-opening copolymerization Multicomponent reaction
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Slope rockbolting using key block theory:Force transfer and artificial intelligence-assisted multi-objective optimisation
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作者 Jessica Ka Yi Chiu Charlie Chunlin Li +1 位作者 Ole Jakob Mengshoel Vidar Kveldsvik 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期73-91,共19页
This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material u... This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material usage,and costs.In the first stage,an extended key block analysis identifies key blocks and key block groups,accounting for progressive failure and force interactions.The second stage uses AI algorithms to optimise rockbolting design,balancing stability,cost,and material use.The most efficient algorithms include the multi-objective tree-structured Parzen estimator(MOTPE)and non-dominated sorting genetic algorithms(NSGA-II and NSGA-III).Applied to the Larvik rock slope,the optimised solution uses 18 pre-tensioned cablebolts,providing 13.2 MN of active force and achieving a factor of safety of 1.31 while reducing the average anchorage length by approximately 16%compared to traditional design.The AI-assisted approach also reduces computation time by over 90%compared to Quasi-Monte Carlo(QMC)methods,demonstrating its efficiency for small-scale civil engineering projects and large-scale mining operations.The developed tool is practical,compatible with Building Information Modelling(BIM),and ready for engineering implementation,supporting sustainable and cost-effective rock slope stabilisation.While the method is largely automated,professional judgement remains crucial for verifying ground conditions and selecting the final solution.Future work will focus on integrating data uncertainties,addressing complex block deformation mechanisms,refining optimisation objectives,and improving the performance of multi-objective optimisation for slope rockboling applications to further enhance the method's versatility. 展开更多
关键词 Rock anchoring Slope stability 3D modelling Key block Parametric design Bio-inspired artificial intelligence(AI)
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Preparation of low-expansion high-performance Si-C composites based on porous advantage of detoxified and purified waste cathode graphite blocks
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作者 Guoqing Yu Mingzhuang Xie +4 位作者 Zhihao Zheng Zegang Wu Yi Wang Hongliang Zhao Fengqin Liu 《International Journal of Minerals,Metallurgy and Materials》 2026年第2期716-726,共11页
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi... Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials. 展开更多
关键词 waste graphitization cathode carbon blocks defect advantage silicon/carbon anode materials hazardous waste resource util-ization
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Twin-block矫治器对不同舌位下颌后缩患者上气道的改善作用
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作者 周志翀 《医师在线》 2026年第1期87-90,共4页
目的探讨静息舌位是否会影响Twin-block矫治器对下颌后缩患者上气道的扩张作用。方法选取2021年1月至2022年10月于上海市静安区牙病防治所正畸科就诊并使用Twin-block矫治器行功能矫治(以下颌前导为主)的40例患者作为研究对象。所有患... 目的探讨静息舌位是否会影响Twin-block矫治器对下颌后缩患者上气道的扩张作用。方法选取2021年1月至2022年10月于上海市静安区牙病防治所正畸科就诊并使用Twin-block矫治器行功能矫治(以下颌前导为主)的40例患者作为研究对象。所有患者均行锥形束CT(CBCT)检查,经三维重建后获取正中矢状面图像。根据舌体与上腭的位置关系分为两组:舌体与上腭紧密贴合者为舌高位组,舌体与上腭分离者为舌低位组,每组20例。观察两组患者的气道二维测量(最小横截面积)及气道三维测量(气道体积)值及变化量。结果舌低位组治疗后鼻咽段、腭咽段最小横截面积、体积及总体积均较治疗前显著增加(P<0.05);舌咽段最小横截面积、体积治疗前后比较,差异无统计学意义(P>0.05)。舌高位组治疗后鼻咽段、腭咽段最小横截面积、体积及总体积均较治疗前显著增加(P<0.05);舌咽段最小横截面积、体积治疗前后比较,差异无统计学意义(P>0.05)。组间比较显示,舌高位组腭咽段最小横截面积、体积的变化量显著大于舌低位组(P<0.05);两组鼻咽段及舌咽段最小横截面积、体积及总体积变化量比较,差异均无统计学意义(P>0.05)。结论Twin-block矫治器对下颌后缩患者上气道有扩张作用,且舌高位组患者较舌低位组患者的腭咽段气道扩张效果更为明显。 展开更多
关键词 TWIN-block矫治器 下颌后缩 气道体积 儿童
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Automatic identification of concealed dangerous rock blocks on highsteep slopes considering finite-sized discontinuity intersections
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作者 Xiaohan Zhao Wen Zhang +6 位作者 Junqi Chen Zhengxuan Xu Yingxu Zhang Han Yin Jia Wang Tengyue Li Bo Han 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第11期7093-7106,共14页
The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to ca... The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to capture high-resolution discontinuity data and develops a fully automated rock block extraction method consisting of three steps:(1)determination of free face and non-free fracture intersections,(2)surface search for rock blocks on free face.and(3)extraction and analysis of rock blocks.This approach simplifies the determination of discontinuity intersections while maintaining high accuracy.By incorporating all types of discontinuities contributing to rock block formation,the method enables precise in-situ rock block identification and extraction.Application to a rock slope in China,produced results consistent with the rock blocks observed in the 3D model,highlighting its accuracy and practical value. 展开更多
关键词 Concealed dangerous rock block High-steep rock slope Rock block identification In-situ block characterization
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改良Twin-block矫治器联合微种植体支抗治疗安氏Ⅱ类1分类错[牙合]畸形效果评价 被引量:2
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作者 卢春燕 崔雪蕾 曹培培 《上海口腔医学》 2025年第2期152-156,共5页
目的:探讨改良Twin-block矫治器联合微种植体支抗治疗安氏Ⅱ类1分类错[牙合]畸形的效果。方法:回顾性分析2018年1月—2022年1月如皋市中医院收治的96例安氏Ⅱ类1分类错[牙合]畸形患者资料,根据治疗方法分为试验组(52例)和对照组(44例),... 目的:探讨改良Twin-block矫治器联合微种植体支抗治疗安氏Ⅱ类1分类错[牙合]畸形的效果。方法:回顾性分析2018年1月—2022年1月如皋市中医院收治的96例安氏Ⅱ类1分类错[牙合]畸形患者资料,根据治疗方法分为试验组(52例)和对照组(44例),对照组采用改良Twin-block矫治器,试验组采用改良Twin-block矫治器联合微种植体支抗。比较2组矫治时间、咬合打开时间、排列整齐时间、上下牙槽座角(ANB)、下牙槽座角(SNB)、上牙槽座角(SNA)、上中切牙长轴与NA连线的夹角(U1-NA)、下中切牙长轴与NA连线的夹角(U1-NB)、上颌中切牙长轴与前颅底平面夹角(U1-SN)、下颌中切牙长轴与下颌平面的后上交角(L1-MP)、上颌唇突度(ULP)、下颌唇突度(LLP)、上下唇突点与颏前点切线和眼耳平面夹角(Z角)、菌斑指数(PLI)、牙龈指数(GI)和龈沟出血指数(SBI)。记录并发症及患者满意度。采用SPSS 24.0软件包对数据进行统计学分析。结果:试验组患者矫治时间、咬合打开时间及排列整齐时间显著少于对照组(P<0.05)。治疗后,2组ANB、U1-NA和U1-SN小于治疗前,试验组显著小于对照组(P<0.05);U1-NB、L1-MP大于治疗前,试验组显著大于对照组(P<0.05);SNB、SNA相比无显著差异(P>0.05)。治疗后,2组ULP、LLP低于治疗前,试验组显著低于对照组(P<0.05);Z角升高,试验组显著高于对照组(P<0.05);PLI低于治疗前,试验组显著低于对照组(P<0.05);GI、SBI相比无显著差异(P>0.05)。2组患者满意度相比无显著差异(P>0.05)。结论:改良Twin-block矫治器联合微种植体支抗治疗安氏Ⅱ类1分类错[牙合]畸形,有助于缩短矫治时间,改善颌骨及面部软组织轮廓,促进牙美学效果的恢复。 展开更多
关键词 错[牙合]畸形 安氏Ⅱ类1分类错[牙合] 改良Twin-block矫治器 微种植体支抗
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Pass矫治器与Twin-block功能矫治器联合自锁托槽在安氏Ⅱ类1分类错[牙合]畸形中的矫正效果比较 被引量:1
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作者 黄飞 陈倩 张胜男 《中国现代医学杂志》 2025年第6期6-11,共6页
目的对比Pass矫治器与Twin-block功能矫治器联合自锁托槽在安氏Ⅱ类1分类错[牙合]畸形中的矫正效果。方法选取2020年2月—2022年5月在彭州市中医医院就诊的安氏Ⅱ类1分类错[牙合]畸形患者72例,采用随机数字表法将其分成研究组和对照组,... 目的对比Pass矫治器与Twin-block功能矫治器联合自锁托槽在安氏Ⅱ类1分类错[牙合]畸形中的矫正效果。方法选取2020年2月—2022年5月在彭州市中医医院就诊的安氏Ⅱ类1分类错[牙合]畸形患者72例,采用随机数字表法将其分成研究组和对照组,每组36例。对照组接受Twin-block功能矫治器联合自锁托槽治疗,研究组接受Pass矫治器治疗。对比两组临床疗效、颌牙排齐时间、硬组织头影测量指标[上中切牙轴与蝶鞍中心-鼻根点平面夹角(U1-SN)、下中切牙轴与鼻根点-上齿槽座点连接角(U1-NA)、上齿槽座点、鼻根点及下次槽座点连接角(ANB)、蝶鞍中心、鼻根点及上齿槽座点连接角(SNA)]、软组织头影测量目标[上唇到审美平面距离(TUL-FP)、下唇H线距、下唇到审美平面距离(TLL-FP)、鼻唇角]、矫治效果及患者满意度。结果研究组总有效率高于对照组(P<0.05)。研究组上颌牙排齐时间和下颌牙排齐时间均短于对照组(P<0.05)。两组治疗前后U1-SN、ANB、SNA、SNB的差值比较,差异无统计学意义(P>0.05)。研究组治疗前后U1-NA的差值高于对照组(P<0.05)。研究组治疗前后下唇H线距、TUL-FP、鼻唇角、TLL-FP的差值高于对照组(P<0.05)。研究组治疗前后同行评估等级指数(PAR)评分的差值高于对照组(P<0.05)。研究组满意度高于对照组(P<0.05)。结论相比于Twin-block功能矫治器联合自锁托槽,Pass矫治器治疗安氏Ⅱ类1分类错[牙合]畸形患者效果确切,可提高矫治效果,改善面部侧貌美学,缩短颌牙排齐时间,且患者满意度较高。 展开更多
关键词 安氏Ⅱ类1分类错[牙合]畸形 Pass矫治器 TWIN-block功能矫治器 自锁托槽 矫正效果
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基于Chisel语言的LBlock密码算法实现
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作者 王建新 周闰泽 +1 位作者 张磊 肖超恩 《北京电子科技学院学报》 2025年第4期14-23,共10页
针对传统硬件描述语言(Verilog/VHDL)实现密码算法时代码复杂性高、开发周期长且调试困难等问题,本文提出了一种基于Chisel语言的轻量级分组密码算法LBlock的硬件实现方案。利用Chisel的高级硬件构建能力,通过模块化设计和有限状态机控... 针对传统硬件描述语言(Verilog/VHDL)实现密码算法时代码复杂性高、开发周期长且调试困难等问题,本文提出了一种基于Chisel语言的轻量级分组密码算法LBlock的硬件实现方案。利用Chisel的高级硬件构建能力,通过模块化设计和有限状态机控制,高效地实现了密钥扩展、加密和解密核心模块。通过在Xilinx ISE Design Suite 14.7上综合后,结果表明,基于Chisel的LBlock算法实现方案在逻辑资源消耗和工作频率上均表现出优势。最高工作频率达到250.197MHz,加密吞吐率为485.815 Mbps,与传统的Verilog实现相比,本设计在显著降低代码量的同时,吞吐率提升了55.7%,为资源受限环境下的密码硬件实现提供了一种更敏捷、高效的设计思路。 展开更多
关键词 Verilog HDL Lblock密码算法 分组密码 Chisel语言 有限状态机
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Diagnosis and treatment of pupillary block glaucoma following implantable collamer lens surgery:a case report
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作者 Bei-Bei Wang Ying-Ying Zou +2 位作者 Dong-Mei Liu Fang Sha Hong-Sheng Bi 《International Journal of Ophthalmology(English edition)》 2025年第6期1173-1177,共5页
Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow ... Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow of the aqueous humor between the sides of the intraocular lens.The design of Aquaport can also eliminate the complications associated with iridotomy and iridectomy.Therefore,the V4c ICL has the potential to significantly reduce the risk of pupillary block compared to its predecessors. 展开更多
关键词 implantable collamer lens surgery laser iridotomy Visian ICL visian implantable collamer lens icl diagnosis pupillary block glaucoma pupillary block aqueous humor
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Enhanced Cutaneous Melanoma Segmentation in Dermoscopic Images Using a Dual U-Net Framework with Multi-Path Convolution Block Attention Module and SE-Res-Conv
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作者 Kun Lan Feiyang Gao +2 位作者 Xiaoliang Jiang Jianzhen Cheng Simon Fong 《Computers, Materials & Continua》 2025年第9期4805-4824,共20页
With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object si... With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis. 展开更多
关键词 Dual U-Net skin lesion segmentation squeeze-and-excitation modified receptive field block multi-path convolution block attention module
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A knowledge-data dually driven paradigm for accurate identification of key blocks in complex rock slopes
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作者 Xiaoyu Qi Han Meng +2 位作者 Nengxiong Xu Gang Mei Jianbing Peng 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3726-3746,共21页
Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impair... Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impairs the ability to characterize complex rock slopes accurately and inhibits the identification of key blocks.In this paper,a knowledge-data dually driven paradigm for accurate identification of key blocks in complex rock slopes is proposed.Our basic idea is to integrate key block theory into data-driven models based on finely characterizing structural features to identify key blocks in complex rock slopes accurately.The proposed novel paradigm consists of(1)representing rock slopes as graph-structured data based on complex systems theory,(2)identifying key nodes in the graph-structured data using graph deep learning,and(3)mapping the key nodes of graph-structured data to corresponding key blocks in the rock slope.Verification experiments and real-case applications are conducted by the proposed method.The verification results demonstrate excellent model performance,strong generalization capability,and effective classification results.Moreover,the real case application is conducted on the northern slope of the Yanqianshan Iron Mine.The results show that the proposed method can accurately identify key blocks in complex rock slopes,which can provide a decision-making basis and rational recommendations for effective support and instability prevention of rock slopes,thereby ensuring the stability of rock engineering and the safety of life and property. 展开更多
关键词 Key blocks identification Rock slope stability Key block theory Knowledge-data dually driven Graph deep learning
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Twin-block矫治器治疗青少年骨性Ⅱ类错[牙合]畸形的效果及对上气道体积的影响
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作者 詹育香 《临床医学研究与实践》 2025年第36期50-53,共4页
目的研究Twin-block矫治器治疗青少年骨性Ⅱ类错[牙合]畸形的效果及对上气道体积的影响。方法选择2023年7月至2024年9月在本院接受治疗的40例青少年骨性Ⅱ类错[牙合]畸形患者,随机将其分为研究组(n=20,Twin-block矫治器)与对照组(n=20,... 目的研究Twin-block矫治器治疗青少年骨性Ⅱ类错[牙合]畸形的效果及对上气道体积的影响。方法选择2023年7月至2024年9月在本院接受治疗的40例青少年骨性Ⅱ类错[牙合]畸形患者,随机将其分为研究组(n=20,Twin-block矫治器)与对照组(n=20,无托槽隐形矫治器)。比较两组治疗前、后的头颅侧位片X线测量结果、上气道矢状径指标及治疗满意度。结果研究组治疗后的头颅侧位片X线测量结果[蝶鞍点-鼻根点-下牙槽座点角(SNB)、蝶鞍点-鼻根点-上牙槽座点角(SNA)、上牙槽座点-鼻根点-下牙槽座点角(ANB)]优于对照组(P<0.05)。研究组治疗后的上气道矢状径指标(鼻咽后壁至基底的矢状径、软腭后缘至咽后壁的矢状径、第一磨牙间矢状径、上颌骨后壁至中线矢状径、下颌骨后壁至中线矢状径)大于对照组(P<0.05)。研究组的治疗满意度高于对照组(P<0.05)。结论Twin-block矫治器、无托槽隐形矫治器均对青少年骨性Ⅱ类错[牙合]畸形患者有一定治疗效果,但前者能够显著改善患者的面部侧貌及上气道体积,且满意度较高。 展开更多
关键词 骨性Ⅱ类错[牙合]畸形 TWIN-block矫治器 青少年 隐形矫治器 上气道体积
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Nd:YAG laser peripheral iridotomy for reverse pupillary block:a case report
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作者 Ze-Yu Zhang Zhi-Qiao Liang Yong-Zhen Bao 《International Journal of Ophthalmology(English edition)》 2025年第8期1606-1609,共4页
Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium alum... Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium aluminum garnet(Nd:YAG)laser peripheral iridotomy(LPI). 展开更多
关键词 eye pain reverse pupillary blockwhich intraocular pressure Nd YAG laser peripheral iridotomy peripheral iridotomy lpi reverse pupillary block
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一种基于页面Block的Web信息提取方法 被引量:3
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作者 蒙韧 邵延振 袁鼎荣 《计算机技术与发展》 2010年第1期197-200,共4页
基于页面结构的信息提取是Web数据挖掘中三大研究领域之一。该研究的关键技术是如何识别Web页面的组织形式,从中挖掘所需要的页面信息。文中基于页面的语义分块(Block)给出一个新的块主题提取算法,与传统的以页面为单位的Web信息提取相... 基于页面结构的信息提取是Web数据挖掘中三大研究领域之一。该研究的关键技术是如何识别Web页面的组织形式,从中挖掘所需要的页面信息。文中基于页面的语义分块(Block)给出一个新的块主题提取算法,与传统的以页面为单位的Web信息提取相比,更符合实际情况,粒度优势明显。该算法针对页面中不同分块的重要性给予不同的权值,依据权值大小取舍页面信息提供给用户。针对该算法进行了模拟实验,从实验结果可以看出该算法具有一定的实用性和有效性。 展开更多
关键词 语义block block权值 block主题提取 WEB信息挖掘
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Identification,characteristics and classification of cryogenic block streams
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作者 Stuart A.Harris 《Research in Cold and Arid Regions》 CSCD 2016年第3期177-186,共10页
Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle... Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle of repose of coarse sediments. They are usually formed on perennially frozen ground, but can also occur as relict landforms. There are three main active kinds forming today, viz., Siberian and Tibetan dynamic rock streams and lag block streams. During their formation, the blocks in the active Siberian and Tibetan dynamic block streams move downslope at up to 1 rn/a. They are forming today on the Tibetan Plateau and in the more arid parts of south-central Siberia, although the processes involved in the movement are different. In the case of the Tibetan type, individual blocks slide downslope over the substrate in winter on an icy coating in areas of minimal winter precipitation. The Siberian type develops in areas of 15-80 cm of winter snow cover and an MAAT (mean annual air temperature) of-4 ~C to -17 ~C. The movement is due to creep of snow and ice and collapse of the blocks downslope during thawing. Lag block streams are formed by meltwater flowing over the surface of sediment consisting primarily of larger blocks with a limited amount of interstitial sediment. The erosion of the matrix is primarily in the spring in areas of higher winter precipitation on 10^-30~ slopes. The blocks remain stationary, but the interstitial sediment is washed out by strong seasonal flows of meltwater or rain to form an alluvial fan. The boulders undergo weathering and become more rounded in the process. Lag block streams can also develop without the presence of permafrost in areas with cold climates or glaciers. Block streams also occur as relict deposits in older deposits under various climatic regimes that are unsuitable for their formation today. An example of relict lag block streams with subangular to subrounded blocks occurs in gullies on the forested mountainsides at Felsen in Germany, and is the original "felsenmeer". Similar examples occur near Vitosha Mountain in Bulgaria. The "stone runs" in the Falkland Islands are examples of the more angular relict lag block streams. In both Tasmania and the Falkland Islands, they mask a more complex history, the underlying soils indicating periods of tropical and temperate soil formation resulting from weathering during and since the Tertiary Period. Block streams have also been reported from beneath cold-based glaciers in Sweden, and below till in Canada, and when ex- humed, can continue to develop. 展开更多
关键词 active dynamic block streams felsemeer relict block steams Tibetan type block streams Siberian typeblock streams lag block streams
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安氏Ⅱ类错[牙合]畸形佩戴Twin-block矫治器时上颌骨的应力分布 被引量:1
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作者 李帅 刘桦 +3 位作者 商永慧 刘义琮 赵启航 刘文 《中国组织工程研究》 CAS 北大核心 2025年第5期881-887,共7页
背景:Twin-block矫治器常用于安氏Ⅱ类错[牙合]畸形的矫治,其刺激下颌骨生长的作用机制已得到许多研究证实,但对上颌骨生长的影响尚不清楚。目的:通过有限元法分析安氏Ⅱ类错[牙合]畸形患者佩戴Twin-block矫治器时上颌骨复合体、周围骨... 背景:Twin-block矫治器常用于安氏Ⅱ类错[牙合]畸形的矫治,其刺激下颌骨生长的作用机制已得到许多研究证实,但对上颌骨生长的影响尚不清楚。目的:通过有限元法分析安氏Ⅱ类错[牙合]畸形患者佩戴Twin-block矫治器时上颌骨复合体、周围骨缝及上颌牙列的应力分布。方法:选择在山东省康复大学青岛医院/青岛市市立医院口腔正畸科进行正畸治疗的安氏Ⅱ类错[牙合]畸形患者1例,测量患者佩戴Twin-block矫治器时的咬合力数据,采集其锥形束CT数据,建立包含上颌骨复合体、周边各骨缝、Twin-block矫治器及上颌牙列在内的有限元模型,通过ABAQUS软件模拟患者戴入Twin-block时上颌骨、骨缝及上颌牙列的应力分布与位移。结果与结论:①上颌前牙受到的等效应力明显小于后牙,两侧牙齿的最大等效应力分别为4.7975 MPa和8.7161 MPa,均位于第一前磨牙处;最大位移呈现在两侧上颌切牙处,分别为0.0805 mm和0.0810 mm;②骨缝的最大等效应力为1.284 MPa,主要集中在两侧翼腭缝及额颌缝,其余骨缝受力情况几乎无差异;骨缝的最大位移为0.07 mm,其中翼腭缝的位移量最大,其次是额颌缝;③上颌骨复合体受到的最大等效应力为27.18 MPa,主要集中在上颌骨前面梨状孔两侧、鼻额缝周边及颚骨后部翼腭缝附近;上颌骨的最大位移值为0.07 mm,主要集中于上颌牙槽骨;④结果显示,咬合力通过Twin-block矫治器作用于上颌骨复合体,导致上颌骨顺时针旋转、牙合平面变陡,应采取相应措施补偿这种趋势,例如建牙合过程中考虑上颌磨牙伸长、下颌磨牙压低,不仅能够将牙合平面整平,同时有利于下颌前伸,这将进一步提高Ⅱ类错[牙合]正畸治疗效果。 展开更多
关键词 错牙合畸形 组织构建 骨组织工程 TWIN-block矫治器 功能矫治 有限元分析
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新型固定式Twin-block矫治器治疗青春期骨性Ⅱ类错[牙合]畸形的疗效分析 被引量:1
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作者 丁盟 张薇 +5 位作者 沈群 陈玉成 张慧 葛非凡 杭梦月 吴建华 《上海口腔医学》 2025年第3期291-297,共7页
目的:评价一种新型固定式Twin-block矫治器治疗青春期骨性Ⅱ类错[牙合]畸形的临床疗效。方法:选择年龄10~13岁的骨性Ⅱ类下颌骨后缩患者21例,使用一种新型固定式Twin-block矫治器进行功能矫形治疗,治疗前后拍摄全景片及头颅侧位片并进... 目的:评价一种新型固定式Twin-block矫治器治疗青春期骨性Ⅱ类错[牙合]畸形的临床疗效。方法:选择年龄10~13岁的骨性Ⅱ类下颌骨后缩患者21例,使用一种新型固定式Twin-block矫治器进行功能矫形治疗,治疗前后拍摄全景片及头颅侧位片并进行头影测量。结果:治疗过程中未出现矫治器松动、脱落,平均疗程为(11.42±1.78)个月。治疗前后矢状向测量指标中,下颌骨位置(SNB)、下颌骨综合长度(Co-Gn)、鼻唇角(Cm-Sn-UL)、髁突矢状向位置(Pcd-S)、下唇突度(LL-SnPg)显著增大(P<0.05);上下颌骨相对位置(ANB)、Y轴角(SGn/FH)、上前牙倾斜度(U1/SN)、颏唇沟深度(Si-LLPg')显著减小(P<0.05);上颌骨位置(SNA)、下颌后部位置(S Vert-Co)、下颌体长度(Go'-Me)、下前牙倾斜度(IMPA),上下中切牙角度(U1/L1)、上唇突度(UL-SnPg')的差异无统计学意义(P>0.05)。垂直向测量指标除后面高(S-Go')、上前牙垂直向距离(U1-PP)、平面角(SN/OP)、下颌高度(Ar-Go')、下颌支高度(Co-Go)显著增加外(P<0.05),下牙列垂直向位置(Ll-MP、L6-MP)、上后牙垂直向距离(U6-PP)、前面高(N-Me)、面高指数(S-Go'/N-Me)、下颌平面角(MP/SN)均无显著改变(P>0.05)。结论:新型固定式Twin-block矫治器可显著促进下颌骨生长改建,有效进行垂直向控制,内收前牙同时改善患者侧貌,临床疗效可靠。 展开更多
关键词 固定式Twin-block矫治器 骨性Ⅱ类错[牙合]畸形 功能矫治 垂直向控制
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改良Twin-block矫治器治疗骨性Ⅱ类下颌后缩患者颞下颌关节变化的三维分析研究 被引量:1
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作者 葛非凡 吴建华 +3 位作者 沈群 陈玉成 杭梦月 吴云芳 《皖南医学院学报》 2025年第5期458-462,共5页
目的:研究新型固定式改良Twin-block矫治器对青少年骨性Ⅱ类下颌后缩患者治疗前后颞下颌关节的三维变化。方法:从生长发育高峰期骨性Ⅱ类下颌后缩患者中随机选取20例为研究对象,均使用新型固定式改良Twin-block矫治器进行矫形治疗,矫治... 目的:研究新型固定式改良Twin-block矫治器对青少年骨性Ⅱ类下颌后缩患者治疗前后颞下颌关节的三维变化。方法:从生长发育高峰期骨性Ⅱ类下颌后缩患者中随机选取20例为研究对象,均使用新型固定式改良Twin-block矫治器进行矫形治疗,矫治前、后拍摄口腔颌面锥形束CT(CBCT),运用Mimics 21.0软件重建颞下颌关节的三维模型,在模型上测量并进行定量分析,再将治疗前后三维模型进行重叠配准,在颜色编码图上利用相同比例尺进行测量,可视化显示髁突的生长方向。结果:治疗后髁突高度、内外径和前后径均比治疗前增加(P<0.01);且髁突体积和表面积也均有增大(P<0.001);在颜色编码图中可见,髁突后上部颜色变化显著。结论:骨性Ⅱ类下颌后缩患者经新型固定式改良Twin-block矫治器治疗后,颞下颌关节内部分结构发生了适应性改建,髁突有明显向后上生长的趋势,在关节窝的相对位置也发生了前移。运用三维重建技术对该型矫治器治疗前后颞下颌关节进行定性定量分析,为临床应用提供了理论依据。 展开更多
关键词 改良Twin-block矫治器 骨性Ⅱ类错牙合 颞下颌关节 髁突
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