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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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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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An Incremental Algorithm for Non-Slicing Floorplan Based on Corner Block List Representation 被引量:1
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作者 杨柳 马昱春 +2 位作者 洪先龙 董社勤 周强 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第12期2335-2343,共9页
We present a novel incremental algorithm for non-slicing floorplans based on the corner block list representation. The horizontal and vertical adjacency graphs are derived from the packing of the initial floorplanning... We present a novel incremental algorithm for non-slicing floorplans based on the corner block list representation. The horizontal and vertical adjacency graphs are derived from the packing of the initial floorplanning results. Based on the critical path and the accumulated slack distances we define,we choose the best position for insertion and do a series of operations incrementally, such as deleting modules, adding modules, and resizing modules quickly. This incremental floorplanning algorithm has a very high speed less than 1μm,which is one of the most important measures in this research. The algorithm preserves the original good performances on area and wire length. It can also supply other tools with good physical estimates for area, wire length, and other performance guidelines. 展开更多
关键词 incremental floorplanning corner block list adjacency graph balance node
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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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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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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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A NOTE ON THE REPRESENTATIONS FOR THE GENERALIZED DRAZIN INVERSE OF BLOCK MATRICES
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作者 Dijana MOSIC 《Acta Mathematica Scientia》 SCIE CSCD 2015年第6期1483-1491,共9页
We present some representations for the generalized Drazin inverse of a block matrix x =[cd ab]in a Banach algebra ~4 in terms of ad and (be)d under certain conditions,extending some recent result related to the gen... We present some representations for the generalized Drazin inverse of a block matrix x =[cd ab]in a Banach algebra ~4 in terms of ad and (be)d under certain conditions,extending some recent result related to the generalized Drazin inverse of an anti-triangular operator matrix. Also, several particular cases of this result are considered. 展开更多
关键词 generalized Drazin inverse block matrix Banach algebra
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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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A weighted block cooperative sparse representation algorithm based on visual saliency dictionary
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作者 Rui Chen Fei Li +2 位作者 Ying Tong Minghu Wu Yang Jiao 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第1期235-246,共12页
Unconstrained face images are interfered by many factors such as illumination,posture,expression,occlusion,age,accessories and so on,resulting in the randomness of the noise pollution implied in the original samples.I... Unconstrained face images are interfered by many factors such as illumination,posture,expression,occlusion,age,accessories and so on,resulting in the randomness of the noise pollution implied in the original samples.In order to improve the sample quality,a weighted block cooperative sparse representation algorithm is proposed based on visual saliency dictionary.First,the algorithm uses the biological visual attention mechanism to quickly and accurately obtain the face salient target and constructs the visual salient dictionary.Then,a block cooperation framework is presented to perform sparse coding for different local structures of human face,and the weighted regular term is introduced in the sparse representation process to enhance the identification of information hidden in the coding coefficients.Finally,by synthesising the sparse representation results of all visual salient block dictionaries,the global coding residual is obtained and the class label is given.The experimental results on four databases,that is,AR,extended Yale B,LFW and PubFig,indicate that the combination of visual saliency dictionary,block cooperative sparse representation and weighted constraint coding can effectively enhance the accuracy of sparse representation of the samples to be tested and improve the performance of unconstrained face recognition. 展开更多
关键词 cooperative sparse representation dictionary learning face recognition feature extraction noise dictionary visual saliency
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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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MMHCA:Multi-feature representations based on multi-scale hierarchical contextual aggregation for UAV-view geo-localization 被引量:1
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作者 Nanhua CHEN Tai-shan LOU Liangyu ZHAO 《Chinese Journal of Aeronautics》 2025年第6期517-532,共16页
In global navigation satellite system denial environment,cross-view geo-localization based on image retrieval presents an exceedingly critical visual localization solution for Unmanned Aerial Vehicle(UAV)systems.The e... In global navigation satellite system denial environment,cross-view geo-localization based on image retrieval presents an exceedingly critical visual localization solution for Unmanned Aerial Vehicle(UAV)systems.The essence of cross-view geo-localization resides in matching images containing the same geographical targets from disparate platforms,such as UAV-view and satellite-view images.However,images of the same geographical targets may suffer from occlusions and geometric distortions due to variations in the capturing platform,view,and timing.The existing methods predominantly extract features by segmenting feature maps,which overlook the holistic semantic distribution and structural information of objects,resulting in loss of image information.To address these challenges,dilated neighborhood attention Transformer is employed as the feature extraction backbone,and Multi-feature representations based on Multi-scale Hierarchical Contextual Aggregation(MMHCA)is proposed.In the proposed MMHCA method,the multiscale hierarchical contextual aggregation method is utilized to extract contextual information from local to global across various granularity levels,establishing feature associations of contextual information with global and local information in the image.Subsequently,the multi-feature representations method is utilized to obtain rich discriminative feature information,bolstering the robustness of model in scenarios characterized by positional shifts,varying distances,and scale ambiguities.Comprehensive experiments conducted on the extensively utilized University-1652 and SUES-200 benchmarks indicate that the MMHCA method surpasses the existing techniques.showing outstanding results in UAV localization and navigation. 展开更多
关键词 Geo-localization Image retrieval UAV Hierarchical contextual aggregation Multi-feature representations
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Genesis and Metallogenic Potential of the 80 Ma High Sr/Y Anglonggangri Granodiorite in the Northwestern Lhasa Block,China 被引量:1
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作者 LI Baoliang WANG Liqiang +4 位作者 DENG Shilin ZHAXI Pingcuo GAO Teng LUOSANG Taqing WANG Haiyong 《Acta Geologica Sinica(English Edition)》 2025年第4期1013-1024,共12页
Multiple instances of the Late Cretaceous granodiorites within the Anglonggangri region of the northwestern Lhasa Block were identified,their petrogenesis were explored and mineralization potential were assessed.The z... Multiple instances of the Late Cretaceous granodiorites within the Anglonggangri region of the northwestern Lhasa Block were identified,their petrogenesis were explored and mineralization potential were assessed.The zircon U-Pb dating of the Anglonggangri granodiorites revealed ages of 82.8 and 80.8 Ma.Granodiorite samples have SiO2 contents of 64.36-68.33 wt%,with high Sr/Y(55-95)and A/CNK ratios(0.99-1.06).Zirconε_(Hf)(t)values range from−0.3 to+16.2.Two granodiorite samples have(^(87)Sr/^(86)Sr)i values of 0.7034 and 0.7043 and positiveɛNd(t)values of 3.51 and 3.83.These geochemical properties indicate that they are adakitic rocks formed by partial melting of the juvenile thickened lower crust,slightly contaminated with material from the mantle due to the small-scale delamination of the lower crust.The zircons in the granodiorites have moderate Ce/Nd(2.5-43),logfO2(−20.0 to−9.6),andΔFMQ(−1.28 to+4.00)values;low(Ce/Nd)/Y(0.001-0.049)ratios;and high Dy/Yb(0.17-1.16)ratios,which indicate that these granodiorites exhibit moderate oxygen fugacity and lower magma water content than the Miocene Gangdese porphyry copper deposits associated with high-Sr/Y granites.Their ability to create porphyry-type copper deposits could have been hampered by their low magma water content and moderate oxygen fugacity. 展开更多
关键词 adakitic rocks PETROGENESIS mineralization potential Anglonggangri northern Lhasa block
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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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On the representations of string pairs over virtual field
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作者 TAO Kun FU Chang-Jian 《四川大学学报(自然科学版)》 北大核心 2025年第5期1103-1108,共6页
Let F_(1)be the virtual field consisting of one element and(Q,I)a string pair.In this paper,we study the representations of string pairs over the virtual field F_(1).It is proved that an indecomposable F_(1)-represent... Let F_(1)be the virtual field consisting of one element and(Q,I)a string pair.In this paper,we study the representations of string pairs over the virtual field F_(1).It is proved that an indecomposable F_(1)-representation is either a string representation or a band representation by using the coefficient quivers.It is worth noting that for a given band and a positive integer,there exists a unique band representation up to isomorphism. 展开更多
关键词 string pair string representation band representation
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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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3种不同类型Twin-block矫治器对前牙应力分布和位移的影响
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作者 李星雨 张春艳 +8 位作者 李希贝 黄文莉 于少洋 杨文科 张映玥 郭骏 阎潇 张强 袁晓 《医用生物力学》 北大核心 2025年第4期844-850,共7页
目的 研究3种不同类型Twin-block矫治器对前牙、牙周膜及牙槽骨应力及位移的影响。方法 构建上下颌骨、关节盘、牙列及牙周膜的三维有限元模型。3组不同类型Twin-block矫治器的有限元模型分别为传统Twin-block矫治器、带切牙帽Twin-bloc... 目的 研究3种不同类型Twin-block矫治器对前牙、牙周膜及牙槽骨应力及位移的影响。方法 构建上下颌骨、关节盘、牙列及牙周膜的三维有限元模型。3组不同类型Twin-block矫治器的有限元模型分别为传统Twin-block矫治器、带切牙帽Twin-block矫治器、改良隐形Twin-block矫治器(clear twin-block aligner, CTBA)。所有类型矫治器的斜面角度均为70°,双侧分别加载200 N垂直于斜面的力。利用有限元方法分析前牙的应力分布与位移差异。结果 3种不同类型Twin-block矫治器均会导致上前牙舌倾及下前牙唇倾。CTBA组上前牙舌向位移及应力最大,最大应力为30.6 MPa,而下前牙唇向位移及应力最小,位移约为0.02 mm。同时CTBA组下前牙、牙周膜及牙槽骨所受等效应力在3组中最低,而传统Twin-block矫治器组最高。结论 在使用传统Twin-block矫治器治疗安氏Ⅱ类错[牙合]时,无论有无切牙帽,均会导致下前牙的唇倾;而与传统Twin-block矫治器相比,CTBA可减少对下前牙、牙槽骨、牙周膜应力和位移的影响,进而减小下前牙的牙周风险,但需注意上前牙舌向位移带来的舌倾效应。 展开更多
关键词 TWIN-block矫治器 功能矫治 隐形矫治器 安氏Ⅱ类错[牙合] 前牙
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Advances in small molecule representations and AI-driven drug research:bridging the gap between theory and application 被引量:1
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作者 Junxi Liu Shan Chang +2 位作者 Qingtian Deng Yulian Ding Yi Pan 《Chinese Journal of Natural Medicines》 2025年第11期1391-1408,共18页
Artificial intelligence(AI)researchers and cheminformatics specialists strive to identify effective drug precursors while optimizing costs and accelerating development processes.Digital molecular representation plays ... Artificial intelligence(AI)researchers and cheminformatics specialists strive to identify effective drug precursors while optimizing costs and accelerating development processes.Digital molecular representation plays a crucial role in achieving this objective by making molecules machine-readable,thereby enhancing the accuracy of molecular prediction tasks and facilitating evidence-based decision making.This study presents a comprehensive review of small molecular representations and AI-driven drug discovery downstream tasks utilizing these representations.The research methodology begins with the compilation of small molecule databases,followed by an analysis of fundamental molecular representations and the models that learn these representations from initial forms,capturing patterns and salient features across extensive chemical spaces.The study then examines various drug discovery downstream tasks,including drug-target interaction(DTI)prediction,drug-target affinity(DTA)prediction,drug property(DP)prediction,and drug generation,all based on learned representations.The analysis concludes by highlighting challenges and opportunities associated with machine learning(ML)methods for molecular representation and improving downstream task performance.Additionally,the representation of small molecules and AI-based downstream tasks demonstrates significant potential in identifying traditional Chinese medicine(TCM)medicinal substances and facilitating TCM target discovery. 展开更多
关键词 Small molecular representation Drug-target interaction prediction Drug-target affinity prediction Drug property prediction De novo drug generation Traditional Chinese medicine
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