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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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A case report with the progression from atrial fibrillation to complete AV block, heart failure and electrical storm
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作者 Shi-Xing LI Xiang-Min SHI +1 位作者 Jian LI Chuang ZHANG 《Journal of Geriatric Cardiology》 2026年第1期65-68,共4页
When patients initially present with atrial fibrillation along with an enlarged heart and heart failure, followed by atrioventricular block, it's essential to consider genetic factors.^([1])Genetic testing can off... When patients initially present with atrial fibrillation along with an enlarged heart and heart failure, followed by atrioventricular block, it's essential to consider genetic factors.^([1])Genetic testing can offer crucial diagnostic evidence, aiding in prognosis assessment and the adoption of appropriate treatment strategies. 展开更多
关键词 heart failure atrial fibrillation enlarged heart atrioventricular block genetic factors genetic testing adoption appropriate treatment strategies complete av block prognosis assessment
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Engineering repairable nanoporous functional coatings on arbitrary substrates by manipulating phase behaviors of block copolymers
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作者 Jiemei Zhou Xiang Ying +3 位作者 Daiwen Li Mingjie Wei Xiangyue Ye Yong Wang 《Chinese Journal of Chemical Engineering》 2026年第1期36-46,共11页
Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with co... Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with complex surfaces.Herein,by manipulating the interactions between block copolymers and selective solvents,we prepare repairable nanoporous polymers on arbitrary substrates.This is realized by an extremely simple sequential coating process:sequential coating of block copolymers and their swelling agents on substrate surfaces.The swelling agents are comprised of two solvents that swell the constituent blocks of the copolymers to different degrees,rapidly producing polymer coatings with uniform,interconnected,sub-50 nm pores.This sequential coating process is able to conformally build nanoporous polymers on nonplanar substrates with large lateral sizes and complex surface features,and also to in situ repair defects arising during usages.We further demonstrate that the nanoporous coatings show excellent antireflective and membrane separation performances.This sequential coating process is dictated by polymer–solvent interactions,and is expected to find applications in diverse fields for its simplicity,adaptability,and the capability to produce well-defined nanoporosities. 展开更多
关键词 Nanoporous coating block copolymers Selective swelling Polymer-solvent interactions ANTIREFLECTION
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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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ResghostNet:Boosting GhostNet with Residual Connections and Adaptive-SE Blocks
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作者 Yuang Chen Yong Li +2 位作者 Fang Lin Shuhan Lv Jiaze Jiang 《Computers, Materials & Continua》 2026年第2期1524-1541,共18页
Aiming at the problem of potential information noise introduced during the generation of ghost feature maps in GhostNet,this paper proposes a novel lightweight neural network model called ResghostNet.This model constr... Aiming at the problem of potential information noise introduced during the generation of ghost feature maps in GhostNet,this paper proposes a novel lightweight neural network model called ResghostNet.This model constructs the Resghost Module by combining residual connections and Adaptive-SE Blocks,which enhances the quality of generated feature maps through direct propagation of original input information and selection of important channels before cheap operations.Specifically,ResghostNet introduces residual connections on the basis of the Ghost Module to optimize the information flow,and designs a weight self-attention mechanism combined with SE blocks to enhance feature expression capabilities in cheap operations.Experimental results on the ImageNet dataset show that,compared to GhostNet,ResghostNet achieves higher accuracy while reducing the number of parameters by 52%.Although the computational complexity increases,by optimizing the usage strategy of GPU cachememory,themodel’s inference speed becomes faster.The ResghostNet is optimized in terms of classification accuracy and the number of model parameters,and shows great potential in edge computing devices. 展开更多
关键词 Residual connections adaptive-SE blocks lightweight neural network GPU memory usage
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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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Star-shaped Block Copolymers of Poly-2-alkyl-5,6-dihydrooxazines:Synthesis,Conformational Characteristics,Thermoresponsiveness and Complexation with Curcumin
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作者 Tatyana U.Kirila Serafim V.Rodchenko +2 位作者 Nina D.Kozina Andrey V.Tenkovtsev Alexander P.Filippov 《Chinese Journal of Polymer Science》 2026年第2期423-436,I0012,共15页
Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cat... Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cationic ring-opening polymerization.The ratio of blocks,the order of their attachment to the core,and arm length were varied.Conformation of synthesized stars was determined by methods of molecular hydrodynamics and optics.It has been shown that star-shaped molecules were characterized by high intramolecular density,and the arm folding increased with their lengthening.The influence of the structure of block copolymers and their molar mass on the critical micelle concentration has been established.Complexes of synthesized star-shaped block copolymers with curcumin were obtained and the efficient binding of curcumin to polymer molecules was demonstrated.The behavior of the aqueous solutions of the prepared polymer stars and their complexes with curcumin was investigated by light scattering and turbidimetry methods.The influence of the structure and molar mass of star polymers on their thermoresponsiveness and the phase separation temperatures in aqueous solutions was analyzed.A slight increase in the phase separation temperature was found on passage from polymer solutions to solutions of polymer complexes with hydrophobic curcumin. 展开更多
关键词 Thermoresponsive star-shaped polymers block copolymer of poly-2-alkyl-5 6-dihydrooxazine Aqueous solutions Complex of polymer with curcumin Phase separation
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Geochronology and Geochemistry of Late Devonian I- and A-Type Granites from the Xing’an Block,NE China:Implications for Slab Break-off during Subduction of the Hegenshan-Heihe Ocean 被引量:3
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作者 Zheng Ji Wenchun Ge +4 位作者 Hao Yang Yanlong Zhang Yu Dong Junhui Bi Xiwen Liu 《Journal of Earth Science》 SCIE CAS CSCD 2022年第1期150-160,共11页
We present detailed geochronological,geochemical,and zircon Hf isotopic data for Late Paleozoic granitic rocks from Handagai and Zhonghe plutons in the Xing’an Block,NE China,aiming to provide constraints on their or... We present detailed geochronological,geochemical,and zircon Hf isotopic data for Late Paleozoic granitic rocks from Handagai and Zhonghe plutons in the Xing’an Block,NE China,aiming to provide constraints on their origin and tectonic implications.New zircon U-Pb ages indicate they were formed in the Late Devonian(ca.379 Ma) immediately after a striking 50 Ma magmatic lull(ca.430-380 Ma) in the Xing ’ an Block.Petrological and geochemical features suggest that the Handagai monzogranites and Zhonghe alkali-feldspar granites are I- and A-type granites,respectively,although both of them have high-K calc-alkaline features and positive zircon ε_(Hf)(t) values(+3.47 to +10.77).We infer that the Handagai monzogranites were produced by partial melting of juvenile basaltic crustal materials under a pressure of <8-10 kbar,whereas the Zhonghe alkali-feldspar granites were generated by partial melting of juvenile felsic crustal materials at shallower depths(P ≤ 4 kbar).Our results,together with published regional data,indicate their generation involves a subduction-related extensional setting.Slab break-off of the Hegenshan-Heihe oceanic plate may account for the subduction-related extensional setting,as well as the transformation of arc magmatism from the Early-Middle Devonian lull to the Late Devonian-Early Carboniferous flare-up in the Xing’an Block. 展开更多
关键词 Late Devonian granitoids GEOCHEMISTRY slab break-off Hegenshan-Heihe Ocean Xing’an block
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Edge Computing-Based Tasks Offloading and Block Caching for Mobile Blockchain 被引量:3
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作者 Yong Yan Yao Dai +2 位作者 Zhiqiang Zhou Wei Jiang Shaoyong Guo 《Computers, Materials & Continua》 SCIE EI 2020年第2期905-915,共11页
Internet of Things(IoT)technology is rapidly evolving,but there is no trusted platform to protect user privacy,protect information between different IoT domains,and promote edge processing.Therefore,we integrate the b... Internet of Things(IoT)technology is rapidly evolving,but there is no trusted platform to protect user privacy,protect information between different IoT domains,and promote edge processing.Therefore,we integrate the blockchain technology into constructing trusted IoT platforms.However,the application of blockchain in IoT is hampered by the challenges posed by heavy computing processes.To solve the problem,we put forward a blockchain framework based on mobile edge computing,in which the blockchain mining tasks can be offloaded to nearby nodes or the edge computing service providers and the encrypted hashes of blocks can be cached in the edge computing service providers.Moreover,we model the process of offloading and caching to ensure that both edge nodes and edge computing service providers obtain the maximum profit based on game theory and auction theory.Finally,the proposed mechanism is compared with the centralized mode,mode A(all the miners offload their tasks to the edge computing service providers),and mode B(all the miners offload their tasks to a group of neighbor devices).Simulation results show that under our mechanism,mining networks obtain more profits and consume less time on average. 展开更多
关键词 Edge computing blockchain mining offloading block caching
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Analysis of Horizontal Block Stripe in TFT-LCD Panel in Switching-off Process 被引量:1
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作者 LU Lin-lin XU Shuai 《液晶与显示》 CAS CSCD 北大核心 2011年第4期464-468,共5页
The horizontal block stripe,as an image quality defect,was analyzed by means of output signals and bias voltage stress(BVS)test.The results showed that the defect was correlated with discharging efficiency.Further,two... The horizontal block stripe,as an image quality defect,was analyzed by means of output signals and bias voltage stress(BVS)test.The results showed that the defect was correlated with discharging efficiency.Further,two approaches were proposed,one was to improve TFT characteristic,the other was to add reset function.The combined experiments indicated that discharging promotion can improve the defect.Especially the latter is most optimal to eliminate the phenomenon. 展开更多
关键词 horizontal block stripe DISCHARGE switch off bias voltage stress drain current
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Tectono-Sedimentary Evolution of the Offshore Hydrocarbon Exploration Block 5, East Africa: Implication for Hydrocarbon Generation and Migration 被引量:1
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作者 Ezekiel J. Seni Gabriel D. Mulibo Giovanni Bertotti 《Open Journal of Geology》 2018年第8期819-840,共22页
Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in re... Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in relation to structural styles, sedimentation and hydrocarbon potential evolved in Block 5. Results show that during Early to Late Jurassic, Block 5 was affected by the break-up of Gondwana and the drifting of Madagascar as evidenced by patterns of sediments and structural features. The chaotic and discontinuous reflectors are characteristics features on the sediments pattern indicating a possible transitional setting following the breakup of Gondwana. From the Late Cretaceous, Block 5 sits in more stable subsiding sag as the consequence of the high thermal subsidence. The period displayed continuous parallel reflectors with few markable faults. This was followed by the late post rift sedimentation that occurred after Middle Eocene Unconformity characterized by high wavy and sub parallel reflectors. The evolution of Block 5 through major tectonic events reveals a more complete petroleum system towards the south. Thus, Block 5 responded in both space and time to a complex interplay between tectonics and sedimentation. This indicates that structural styles and associated features are potential control for hydrocarbon generation and migration. 展开更多
关键词 offSHORE Tanzania basin block 5 TECTONICS SEDIMENTATION HYDROCARBON East Africa
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Off Label Use of Exparel in an Axillary Block for Prolonged Postoperative Analgesia 被引量:1
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作者 Reet Lawhon Robert LaCivita +1 位作者 John Fanouse Dennis Feierman 《Open Journal of Anesthesiology》 2015年第7期170-172,共3页
Post-operative analgesia is both necessary for patient comfort and satisfaction. Peripheral nerve block offer both good post-operative analgesia and patient satisfaction, but rarely cover the entire period of post-ope... Post-operative analgesia is both necessary for patient comfort and satisfaction. Peripheral nerve block offer both good post-operative analgesia and patient satisfaction, but rarely cover the entire period of post-operative pain. Nonnarcotic drugs are extremely helpful, but with severe pain, narcotics are usually used to help with post-operative pain when the nerve block wears off. However, nausea and vomiting, as well as other side effects associated with narcotic use can be severe and limit their use for post-operative analgesia. The addition of supplements to the local anesthetic used for the nerve blocks can extend the analgesia, but few blocks last greater than 24 hours. We describe the use of a relatively new extended release bupivacaine, Exparel that provide significantly longer analgesia than presently used single shot techniques protocols for extended nerve block analgesia. 展开更多
关键词 AMBULATORY NERVE block Exparel
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Self-embedding Image Watermarking based on Combined Decision Using Pre-offset and Post-offset Blocks
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作者 Daofu Gong Yan Chen +2 位作者 Haoyu Lu Zhenyu Li Yibing Han 《Computers, Materials & Continua》 SCIE EI 2018年第11期243-260,共18页
To detect and recover random tampering areas,a combined-decision-based self-embedding watermarking scheme is proposed herein.In this scheme,the image is first partitioned into 2×2 size blocks.Next,the high 5 bits... To detect and recover random tampering areas,a combined-decision-based self-embedding watermarking scheme is proposed herein.In this scheme,the image is first partitioned into 2×2 size blocks.Next,the high 5 bits of a block’s average value is embedded into its offset block.The tampering type of block is detected by comparing the watermarks of its pre-offset and post-offset blocks.The theoretical analysis and experiments demonstrate that the proposed scheme not only has a lower ratio of false detection but also better performance with regard to avoiding random tampering. 展开更多
关键词 Fragile watermarking SELF-EMBEDDING offset block tamper recovery random tampering
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Research on Welding Quality Traceability Model of Offshore Platform Block Construction Process
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作者 Jinghua Li Wenhao Yin +1 位作者 Boxin Yang Qinghua Zhou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第1期699-730,共32页
Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platf... Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platform and the process level of the offshore industry.Currently,qualitymanagement remains in the era of primary information,and there is a lack of effective tracking and recording of welding quality data.When welding defects are encountered,it is difficult to rapidly and accurately determine the root cause of the problem from various complexities and scattered quality data.In this paper,a composite welding quality traceability model for offshore platform block construction process is proposed,it contains the quality early-warning method based on long short-term memory and quality data backtracking query optimization algorithm.By fulfilling the training of the early-warning model and the implementation of the query optimization algorithm,the quality traceability model has the ability to assist enterprises in realizing the rapid identification and positioning of quality problems.Furthermore,the model and the quality traceability algorithm are checked by cases in actual working conditions.Verification analyses suggest that the proposed early-warningmodel for welding quality and the algorithmfor optimizing backtracking requests are effective and can be applied to the actual construction process. 展开更多
关键词 Quality traceability model block construction process welding quality management long short-term memory quality data backtracking query optimization algorithm
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The Action of the Middle Blocker According to the Opposing Offensive Organization in Volleyball
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作者 Rui Pinto Susana Vale Joao P.Vicente 《Journal of Sports Science》 2018年第3期178-185,共8页
In modern Volleyball,the block action differentiates the world-class teams.The purpose of this study is to understand what determines the action of the middle blocker in the moment that precedes the technical procedur... In modern Volleyball,the block action differentiates the world-class teams.The purpose of this study is to understand what determines the action of the middle blocker in the moment that precedes the technical procedure of the block.The sample consisted of n4895 actions from 24 middle blockers,representing 30 footages of games from the 1st male volleyball division in the Portuguese league on season 2013/2014.We have also recorded the type of setting(ball tempo)of the opposing setter and the area where the opposing attack occurred.The chi-squared test analysis allowed us to establish that there is a relationship between the actions and the attack zones(x2=109.956;p≤0.001),as well as between the actions and the type of setting,in each attack zone(x2=3,523.678;p≤0.001 in all of them).Thus,we have verified that the action performs block but does not make contact with the ball that is the most frequent.We have also established that there is a strong tendency for the middle blocker to attempt to carry out the block in zones 3 and 4,to the detriment of the attack performed in defensive zone. 展开更多
关键词 VOLLEYBALL action MIDDLE blockER block
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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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Impact coal internal block size effect on physical and mechanical parameters’similarity criteria validity:Numerical simulation and adjustment 被引量:1
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作者 Zihao Kan Linming Dou +2 位作者 Wu Cai Jinrong Cao Xiaotao Ma 《International Journal of Mining Science and Technology》 2025年第4期659-675,共17页
Physical analog modeling is an effective approach for studying the hazards of coal bursts in coal similarity criteria for physical and mechanical parameters of the actual and similar materials are crucial to yield rea... Physical analog modeling is an effective approach for studying the hazards of coal bursts in coal similarity criteria for physical and mechanical parameters of the actual and similar materials are crucial to yield realistic results.The derivation of similarity criteria is predominantly based on dimensional analysis,while a systematic methodology has yet to be developed.This paper attempts to fill this gap by combining the equation transformation method with similarity theory to conduct an in-depth study on the similarity criteria of physical parameters of impact coal with various internal block sizes.On this basis,the influence of internal block size of impact coal on similarity criteria was studied.Block size can provide a selection basis for similar materials,and the influence of block size on model physical parameters and similarity criteria under different geometric similarity ratios was explored.The variation laws between geometric similarity ratio,block size,and physical properties were clarified,and the similarity criteria of impact coal under the influence of block size were adjusted.New insights into material selection for physical analog modeling were proposed.The established similarity criteria for impact coal under the influence of different block sizes can provide a theoretical basis for determining various parameters in the physical analog modeling of coal bursts,when building a physical model of impact coal,material selection and size selection can be based on similarity criteria to more accurately reproduce coal explosion disasters in the laboratory. 展开更多
关键词 Physical analog modeling Coal burst Impact coal Similarity criteria block size Similar materials
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Differential accumulation characteristics and production of coalbed methane/coal-rock gas:A case study of the No.8 coal seam of the Carboniferous Benxi Formation in the Daji block,Ordos Basin,NW China 被引量:1
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作者 ZHOU Lihong LI Yong +9 位作者 DING Rong XIONG Xianyue HOU Wei LI Yongzhou MA Hui FU Haijiao DU Yi ZHANG Weiqi ZHU Zhitong WANG Zhuangsen 《Petroleum Exploration and Development》 2025年第4期872-882,共11页
Based on the coalbed methane(CBM)/coal-rock gas(CRG)geological,geophysical,and experimental testing data from the Daji block in the Ordos Basin,the coal-forming and hydrocarbon generation&accumulation characterist... Based on the coalbed methane(CBM)/coal-rock gas(CRG)geological,geophysical,and experimental testing data from the Daji block in the Ordos Basin,the coal-forming and hydrocarbon generation&accumulation characteristics across different zones were dissected,and the key factors controlling the differential CBM/CRG enrichment were identified.The No.8 coal seam of the Carboniferous Benxi Formation in the Daji block is 8-10 m thick,typically overlain by limestone.The primary hydrocarbon generation phase occurred during the Early Cretaceous.Based on the differences in tectonic evolution and CRG occurrence,and with the maximum vitrinite reflectance of 2.0%and burial depth of 1800 m as boundaries,the study area is divided into deeply buried and deeply preserved,deeply buried and shallowly preserved,and shallowly buried and shallowly preserved zones.The deeply buried and deeply preserved zone contains gas content of 22-35 m^(3)/t,adsorbed gas saturation of 95%-100%,and formation water with total dissolved solid(TDS)higher than 50000 mg/L.This zone features structural stability and strong sealing capacity,with high gas production rates.The deeply buried and shallowly preserved zone contains gas content of 16-20 m^(3)/t,adsorbed gas saturation of 80%-95%,and formation water with TDS of 5000-50000 mg/L.This zone exhibits localized structural modification and hydrodynamic sealing,with moderate gas production rate.The shallowly buried and shallowly preserved zone contains gas content of 8-16 m^(3)/t,adsorbed gas saturation of 50%-70%,and formation water with TDS lower than 5000 mg/L.This zone experienced intense uplift,resulting in poor sealing and secondary alteration of the primary gas reservoir,with partial adsorbed gas loss,and low gas production rate.A depositional unification and structural divergence model is proposed,that is,although coal seams across the basin experienced broadly similar depositional and tectonic histories,differences in tectonic intensity have led to spatial heterogeneity in the maximum burial depth(i.e.,thermal maturity of coal)and current burial depth and occurrence of CRG(i.e.,gas content and occurrence state).The research results provide valuable guidance for advancing the theoretical understanding of CBM/CRG enrichment and for improving exploration and development practices. 展开更多
关键词 deep coalbed methane deep coal-rock gas depositional unification and structural divergence differential enrichment Carboniferou Benxi Formation No.8 coal seam Daji block Ordos Basin
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