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ProRE:A Protocol Message Structure Reconstruction Method Based on Execution Slice Embedding
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作者 Yuyao Huang Hui Shu Fei Kang 《Computers, Materials & Continua》 2026年第3期936-960,共25页
Message structure reconstruction is a critical task in protocol reverse engineering,aiming to recover protocol field structures without access to source code.It enables important applications in network security,inclu... Message structure reconstruction is a critical task in protocol reverse engineering,aiming to recover protocol field structures without access to source code.It enables important applications in network security,including malware analysis and protocol fuzzing.However,existing methods suffer from inaccurate field boundary delineation and lack hierarchical relationship recovery,resulting in imprecise and incomplete reconstructions.In this paper,we propose ProRE,a novel method for reconstructing protocol field structures based on program execution slice embedding.ProRE extracts code slices from protocol parsing at runtime,converts them into embedding vectors using a data flow-sensitive assembly language model,and performs hierarchical clustering to recover complete protocol field structures.Evaluation on two datasets containing 12 protocols shows that ProRE achieves an average F1 score of 0.85 and a cophenetic correlation coefficient of 0.189,improving by 19%and 0.126%respectively over state-of-the-art methods(including BinPRE,Tupni,Netlifter,and QwQ-32B-preview),demonstrating significant superiority in both accuracy and completeness of field structure recovery.Case studies further validate the effectiveness of ProRE in practical malware analysis scenarios. 展开更多
关键词 Protocol reverse engineering program slicing code embedding hierarchical clustering
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Darboux Transformations for Space-Like Isothermic Surfaces in R^m,1 被引量:4
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作者 ZUODa-Feng CHENQing CHENGYi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第6期816-820,共5页
In this paper,by using the G_(m,1)~(1,1)-system,we study Darboux transformations for space-like isothermic surfaces in Minkowski space R~(m,1),where G_(m,1)~(1,1)=O(m+1,2)/O(m,1)×O(1,1).
关键词 G_(m 1)~(1 1)-system Darboux transformation space-like isothermic surfaces
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Compact Space-like Submanifolds in Pseudo-Riemann Manifold 被引量:1
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作者 SUNHe-jun WUBao-qiang 《Chinese Quarterly Journal of Mathematics》 CSCD 2004年第1期6-15,共10页
We first establish a integral inequality for compact maximal space-like subman ifolds in pseudo-Riemannian manifolds Np(n+p). Then, we investigate compact space-like sub manifolds and hupersurfaces with parallel secon... We first establish a integral inequality for compact maximal space-like subman ifolds in pseudo-Riemannian manifolds Np(n+p). Then, we investigate compact space-like sub manifolds and hupersurfaces with parallel second fundamental form in Np(n+p) and some other ambient spaces. We obtain some distribution theorems for the square norm of the second fundamental form. 展开更多
关键词 pseudo-Riemannian manifold SUBMANIFOLD HYPERSURFACE parallel second fundamental form space-like
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Complete Space-like Submanifolds with Constant Scalar Curvature in de Sitter Spaces 被引量:1
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作者 刘建成 张德燕 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第3期357-364,共8页
In this paper,we study the complete space-like submanifold Mn with constant scalar curvature R≤c in the de Sitter space Spn+p(c) and obtain a pinching condition for Mn to be totally umbilical ones.The result generali... In this paper,we study the complete space-like submanifold Mn with constant scalar curvature R≤c in the de Sitter space Spn+p(c) and obtain a pinching condition for Mn to be totally umbilical ones.The result generalizes that in [5,Main Theorem] to higher codimension and give a complement for n=2 there. 展开更多
关键词 space-like submanifold second fundamental form scalar curvature
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Compact Maximal Space-like Submanifolds in a Pseudo-Riemannian Spacetime S_p^(m+p) 被引量:1
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作者 徐森林 胡自胜 《Northeastern Mathematical Journal》 CSCD 2006年第3期253-259,共7页
Abstract: This paper concerns space-like submanifolds in a pseudo-Riemannianspace-time Sp^m+p∪→Ep^m+p+1 (P ≥ 1), and proves that connected compact maximalsuace-like submanifolds in a pseudo-Riemannian spaceti... Abstract: This paper concerns space-like submanifolds in a pseudo-Riemannianspace-time Sp^m+p∪→Ep^m+p+1 (P ≥ 1), and proves that connected compact maximalsuace-like submanifolds in a pseudo-Riemannian spacetime Sp^m+p∪→Ep^m+p+1 (P ≥ 1) must be totally umbilical, and also totally geodesic. Particularly, when p = 1, our result is just Montiel's in case of H = 0. 展开更多
关键词 pseudo-Riemannian spacetime maximal space-like submanifold totallyumbilical
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COMPLETE SPACE-LIKE SUBMANIFOLDS IN LOCALLY SYMMETRIC SEMI-DEFINITE SPACES
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作者 XuSenlin ChenDongmei 《Analysis in Theory and Applications》 2004年第4期383-390,共8页
The purpose of this paper is to study complete space-like submanifolds with parallel mean curvature vector and flat normal bundle in a locally symmetric semi-defnite space satisfying some curvature conditions. We firs... The purpose of this paper is to study complete space-like submanifolds with parallel mean curvature vector and flat normal bundle in a locally symmetric semi-defnite space satisfying some curvature conditions. We first give an optimal estimate of the Laplacian of the squared norm of the second fundamental form for such submanifold. Furthermore, the totally umbilical submanifolds are characterized. 展开更多
关键词 space-like submanifolds constant mean curvature flat normal bundle second fundamental form locally symmetric semi-definite space
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Look at Neutrino Oscillations in Space-Like Continuum
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作者 Xiaobai Ai 《Journal of Modern Physics》 2018年第7期1432-1440,共9页
Based on the special theory of relativity in space-like continuum, the pre-sent author points that if there exist tachyons in nature, they should be neutral point-like particles with lepton appearance, which are very ... Based on the special theory of relativity in space-like continuum, the pre-sent author points that if there exist tachyons in nature, they should be neutral point-like particles with lepton appearance, which are very much like our early understanding about neutrinos before. The author also points that an alternative explanation for neutrino oscillations may be the conversion between mass-less neutrinos with different flavors expressed in different “lowest limited momentum” during their flight journey, which originates from that the argument in the squared sine function of the probability of neutrino oscillation may be less than zero, which is mathematical foresight and may not be ignored. 展开更多
关键词 Neutrino Oscillations space-like CONTINUUM TACHYON Lorentz Invariance ENERGY-MOMENTUM Relation Lowest Limited Momentum Time-Like Representation Face-Changing Effect
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A splicing algorithm for best subset selection in sliced inverse regression
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作者 Borui Tang Jin Zhu +1 位作者 Tingyin Wang Junxian Zhu 《中国科学技术大学学报》 北大核心 2025年第5期22-34,21,I0001,共15页
In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by re... In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors. 展开更多
关键词 splicing technique best subset selection sliced inverse regression nonconvex optimization sparsity constraint optimal conditions
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Slice-GCN:基于程序切片与图神经网络的智能合约漏洞检测方法
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作者 张人娄 吴胜 +1 位作者 张浩 刘方宇 《信息安全学报》 2025年第1期105-118,共14页
智能合约是一段由计算机代码构成的程序。随着智能合约数量的暴涨,如何利用漏洞检测方法来提升智能合约的安全性显得更加重要。已有的符号执行、模糊测试与形式化验证等漏洞检测方法自动化程度低,而基于序列模型的深度学习方法由于对智... 智能合约是一段由计算机代码构成的程序。随着智能合约数量的暴涨,如何利用漏洞检测方法来提升智能合约的安全性显得更加重要。已有的符号执行、模糊测试与形式化验证等漏洞检测方法自动化程度低,而基于序列模型的深度学习方法由于对智能合约源代码的特征挖掘不足导致检测结果的精度偏低。因此,本文提出一个基于程序切片与图神经网络的以太坊智能合约(简称智能合约)漏洞检测方法Slice-GCN。该方法先对程序进行代码预处理简化程序,再使用基于图可达性和数据流方程的程序切片方法对预处理后的程序进行切片,并将切片结果输入长短期记忆网络(LSTM)中提取智能合约的程序语义特征。接着,简化程序依赖图后将其输入图卷积神经网络中,并提取智能合约的程序结构特征。然后,将智能合约的程序语义特征和结构特征拼接后输入多层感知机(MLP)中,并对智能合约进行漏洞检测。在提出Slice-GCN方法的基础上,针对重入攻击、时间戳依赖及整数溢出三类漏洞,本文对Slice-GCN方法与Oyente、Osiris和Soliditycheck三款智能漏洞检测工具进行了对比实验,并且通过消融实验分析了程序切片、图神经网络及图收缩比例对实验结果的影响。实验结果表明本文提出的方法在各类指标上均有较大提升,能有效提升检测准确度和精度,降低误报率,同时在检测速度上也明显优于传统的智能合约漏洞检测工具。 展开更多
关键词 智能合约 漏洞检测 图神经网络 程序切片
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Slice-Based 6G Network with Enhanced Manta Ray Deep Reinforcement Learning-Driven Proactive and Robust Resource Management
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作者 Venkata Satya Suresh kumar Kondeti Raghavendra Kulkarni +1 位作者 Binu Sudhakaran Pillai Surendran Rajendran 《Computers, Materials & Continua》 2025年第9期4973-4995,共23页
Next-generation 6G networks seek to provide ultra-reliable and low-latency communications,necessitating network designs that are intelligent and adaptable.Network slicing has developed as an effective option for resou... Next-generation 6G networks seek to provide ultra-reliable and low-latency communications,necessitating network designs that are intelligent and adaptable.Network slicing has developed as an effective option for resource separation and service-level differentiation inside virtualized infrastructures.Nonetheless,sustaining elevated Quality of Service(QoS)in dynamic,resource-limited systems poses significant hurdles.This study introduces an innovative packet-based proactive end-to-end(ETE)resource management system that facilitates network slicing with improved resilience and proactivity.To get around the drawbacks of conventional reactive systems,we develop a cost-efficient slice provisioning architecture that takes into account limits on radio,processing,and transmission resources.The optimization issue is non-convex,NP-hard,and requires online resolution in a dynamic setting.We offer a hybrid solution that integrates an advanced Deep Reinforcement Learning(DRL)methodology with an Improved Manta-Ray Foraging Optimization(ImpMRFO)algorithm.The ImpMRFO utilizes Chebyshev chaotic mapping for the formation of a varied starting population and incorporates Lévy flight-based stochastic movement to avert premature convergence,hence facilitating improved exploration-exploitation trade-offs.The DRL model perpetually acquires optimum provisioning strategies via agent-environment interactions,whereas the ImpMRFO enhances policy performance for effective slice provisioning.The solution,developed in Python,is evaluated across several 6G slicing scenarios that include varied QoS profiles and traffic requirements.The DRL model perpetually acquires optimum provisioning methods via agent-environment interactions,while the ImpMRFO enhances policy performance for effective slice provisioning.The solution,developed in Python,is evaluated across several 6G slicing scenarios that include varied QoS profiles and traffic requirements.Experimental findings reveal that the proactive ETE system outperforms DRL models and non-resilient provisioning techniques.Our technique increases PSSRr,decreases average latency,and optimizes resource use.These results demonstrate that the hybrid architecture for robust,real-time,and scalable slice management in future 6G networks is feasible. 展开更多
关键词 sliced network manta ray foraging optimization Chebyshev chaotic map levy flight
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Unknown DDoS Attack Detection with Sliced Iterative Normalizing Flows Technique
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作者 Chin-Shiuh Shieh Thanh-Lam Nguyen +1 位作者 Thanh-Tuan Nguyen Mong-Fong Horng 《Computers, Materials & Continua》 2025年第3期4881-4912,共32页
DDoS attacks represent one of the most pervasive and evolving threats in cybersecurity,capable of crippling critical infrastructures and disrupting services globally.As networks continue to expand and threats become m... DDoS attacks represent one of the most pervasive and evolving threats in cybersecurity,capable of crippling critical infrastructures and disrupting services globally.As networks continue to expand and threats become more sophisticated,there is an urgent need for Intrusion Detection Systems(IDS)capable of handling these challenges effectively.Traditional IDS models frequently have difficulties in detecting new or changing attack patterns since they heavily depend on existing characteristics.This paper presents a novel approach for detecting unknown Distributed Denial of Service(DDoS)attacks by integrating Sliced Iterative Normalizing Flows(SINF)into IDS.SINF utilizes the Sliced Wasserstein distance to repeatedly modify probability distributions,enabling better management of high-dimensional data when there are only a few samples available.The unique architecture of SINF ensures efficient density estimation and robust sample generation,enabling IDS to adapt dynamically to emerging threats without relying heavily on predefined signatures or extensive retraining.By incorporating Open-Set Recognition(OSR)techniques,this method improves the system’s ability to detect both known and unknown attacks while maintaining high detection performance.The experimental evaluation on CICIDS2017 and CICDDoS2019 datasets demonstrates that the proposed system achieves an accuracy of 99.85%for known attacks and an F1 score of 99.99%after incremental learning for unknown attacks.The results clearly demonstrate the system’s strong generalization capability across unseen attacks while maintaining the computational efficiency required for real-world deployment. 展开更多
关键词 Distributed denial of service sliced iterative normalizing flows open-set recognition CYBERSECURITY deep learning
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Drying Characteristics and Process Optimization of Banana Slices Using Hot Air-Infrared Combined Drying
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作者 Guofeng Han Chenxi Luo +4 位作者 Xin Liu Yuanyuan Li Yuling Cheng Shuai Huang Dan Huang 《Frontiers in Heat and Mass Transfer》 2025年第6期1981-1999,共19页
Bananas are highly perishable after harvest,and processing them into dried products is a crucial approach to reducing losses and adding their economic values.To address the inefficiency and prolonged duration of tradi... Bananas are highly perishable after harvest,and processing them into dried products is a crucial approach to reducing losses and adding their economic values.To address the inefficiency and prolonged duration of traditional hot air drying(HAD)and the quality inconsistency associated with single infrared drying(IRD),this study proposed a novel hot air-infrared combined drying(HAD-IRD)strategy.The effects of HAD,IRD,and HAD-IRD on the drying kinetics,color,rehydration capacity,moisture diffusion mechanism,and sensory quality of banana slices were systematically investigated.The parameters of the combined drying process were optimized using an L_(9)(3^(3))orthogonal experimental design.Results indicated that both IRD and HAD-IRD significantly reduced drying time compared to single HAD.While single IRD achieved a rapid drying rate,the lack of effective convective airflow led to potential case-hardening and unstable product quality.In contrast,the HAD-IRD strategy demonstrated a synergistic effect.The optimal parameters were determined as follows:hot air temperature of 70℃,infrared temperature of 60℃,and radiation distance of 16 cm.Under these optimized conditions,HAD-IRD reduced the total drying time by over 70%while simultaneously yielding products with superior color,higher sensory scores,and improved rehydration ratio.This study confirms that HAD-IRD is an efficient and high-quality drying method for banana slices,providing a reliable theoretical foundation and technical solution for the drying of thermosensitive fruits. 展开更多
关键词 Banana slices hot air drying(HAD) infrared drying(IRD) combined drying process optimization product quality
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P-Slicer:面向路径表示学习的程序切片方法
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作者 刘天阳 石剑君 +1 位作者 叶嘉威 计卫星 《电子学报》 北大核心 2025年第11期3894-3909,共16页
程序切片技术作为软件分析中的基础性手段,在程序理解、缺陷定位、代码重构等任务中具有重要作用.其核心挑战在于如何在复杂控制流和数据流结构中准确识别与切片准则相关的代码片段.近年来,基于预训练大语言模型的切片方法因其对程序语... 程序切片技术作为软件分析中的基础性手段,在程序理解、缺陷定位、代码重构等任务中具有重要作用.其核心挑战在于如何在复杂控制流和数据流结构中准确识别与切片准则相关的代码片段.近年来,基于预训练大语言模型的切片方法因其对程序语义建模能力较强而展现出良好性能,然而受限于模型输入长度限制,难以有效处理长方法体及跨过程依赖等实际场景.针对以上问题,本文提出一种面向路径表示学习的程序切片方法P-Slicer.该方法首先通过构建基于语法结构的控制流图,从中提取多条可能的执行路径,以实现高代码覆盖率并保留上下文信息;随后,采用基于学习的分类模型对方法内部语句进行切片相关性判断;最后,结合变量的定义-使用传播机制,实现跨过程切片的递归分析.该方法在保持可扩展性的同时,融合了语义理解能力,提升了切片结果的准确性与实用性.实验结果表明,P-Slicer在切片任务中取得了95.95%的准确率、86.89%精确度和88.95%的召回率,且在处理长方法和跨过程切片时仍能保持良好性能,表明其在软件工程领域中的良好应用前景. 展开更多
关键词 程序切片 路径提取 跨过程分析
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基于电子鼻技术的不同白芷饮片气味特征分析
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作者 孙健 李海申 +1 位作者 蔡龙 王志安 《核农学报》 北大核心 2026年第4期754-761,共8页
为实现对不同白芷饮片品质的快速分析,本研究采用Super Nose电子鼻分析技术,结合主成分分析(PCA)、聚类分析(CA)、正交偏最小二乘法判别分析(OPLS-DA)等化学模式识别方法,快速判别白芷的种源、产地以及是否硫熏加工。结果表明,同圃不同... 为实现对不同白芷饮片品质的快速分析,本研究采用Super Nose电子鼻分析技术,结合主成分分析(PCA)、聚类分析(CA)、正交偏最小二乘法判别分析(OPLS-DA)等化学模式识别方法,快速判别白芷的种源、产地以及是否硫熏加工。结果表明,同圃不同种源白芷间的传感器响应值近似,电子鼻区分度不高;不同产地以及是否硫熏加工可以应用电子鼻进行有效区分,PCA、CA分析将样品分为川、浙无硫熏组,四川硫熏组,安徽无硫熏组,安徽硫熏组,河南、河北硫熏组以及河南、河北无硫熏组6组;OPLS-DA模型能对是否硫熏进行准确判别(Q^(2)=0.808),其中S8、S1和S2的变量重要性投影(VIP)值大于1。本研究可为白芷品质快速区分提供技术参考。 展开更多
关键词 电子鼻 白芷 饮片 产地 硫熏加工
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基于5G承载网硬切片部署方案研究及测试验证
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作者 张旭 屠礼彪 +1 位作者 郭胜楠 任枫华 《邮电设计技术》 2026年第1期24-28,共5页
为满足5G业务的差异化服务需求,推进5G承载网网络差异化能力构建,提出基于5G承载网的网络切片部署方案,并通过模拟测试论证了方案可行性,实现了异厂家技术解耦。该方案在实现业务差异化承载的同时,满足用户的定制化需求,推动网络高质量... 为满足5G业务的差异化服务需求,推进5G承载网网络差异化能力构建,提出基于5G承载网的网络切片部署方案,并通过模拟测试论证了方案可行性,实现了异厂家技术解耦。该方案在实现业务差异化承载的同时,满足用户的定制化需求,推动网络高质量发展和业务综合承载。 展开更多
关键词 5G 硬切片 FlexE 差异化服务
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基于图和代码切片的可解释性漏洞检测方法
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作者 高文超 索建华 张傲 《电子与信息学报》 北大核心 2026年第1期311-320,共10页
深度学习已被广泛应用于漏洞检测,其主流方法可分为基于代码序列和基于代码图两类:前者易因忽视结构而误报,后者则难以捕获执行顺序。此外,两者普遍缺乏可解释性,难以定位漏洞根源。为此,该文提出一种基于图和代码切片的可解释性漏洞检... 深度学习已被广泛应用于漏洞检测,其主流方法可分为基于代码序列和基于代码图两类:前者易因忽视结构而误报,后者则难以捕获执行顺序。此外,两者普遍缺乏可解释性,难以定位漏洞根源。为此,该文提出一种基于图和代码切片的可解释性漏洞检测方法GSVD。该模型通过门控图卷积网络提取代码多维度图(AST,DDG,CDG)的结构语义,并结合“污点”分析驱动的代码切片与双向长短时记忆网络,精准捕获代码序列特征,实现二者优势互补。同时,引入HITS算法思想,设计VDExplainer解释器,直观揭示了模型的决策过程。实验表明,GSVD在Devign数据集上准确率达64.57%,优于多种基线模型,证明了其在有效检测漏洞的同时,能实现代码行级的可解释定位。 展开更多
关键词 漏洞检测 深度学习 图神经网络 代码切片 可解释性
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硬模板构建纳米β-磷酸三钙和纳米羟基磷灰石根管封闭材料
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作者 李倩 曲曼姑丽·阿布都克力木 +1 位作者 邵子瑜 胡杨 《中国组织工程研究》 北大核心 2026年第14期3597-3608,共12页
背景:现阶段根管封闭剂多存在生物相容性、机械力学性能和降解性不佳的缺点,纳米β-磷酸三钙和纳米羟基磷灰石具有较好的生物相容性能、降解性和封闭性,在根管封闭剂领域有重要研究价值。目的:以牙本质片硬模板调控纳米β-磷酸三钙和纳... 背景:现阶段根管封闭剂多存在生物相容性、机械力学性能和降解性不佳的缺点,纳米β-磷酸三钙和纳米羟基磷灰石具有较好的生物相容性能、降解性和封闭性,在根管封闭剂领域有重要研究价值。目的:以牙本质片硬模板调控纳米β-磷酸三钙和纳米羟基磷灰石材料晶体的成核、生长及重构,构建微观形态和三维结构与牙体硬组织结构类似的新型根管封闭材料。方法:收集因智齿阻生而拔除的废弃第三磨牙30颗,制备牙本质片。将不同质量的纳米β-磷酸三钙(或纳米羟基磷灰石)分别溶于蒸馏水中,将溶液倒入含有牙本质片的培养皿中,置于37℃恒温培养箱中12 h,得到10%,20%,30%纳米β-磷酸三钙/牙本质片和10%,20%,30%纳米羟基磷灰石/牙本质片,以单纯的纳米β-磷酸三钙、纳米羟基磷灰石为对照。通过扫描电子显微镜、拉曼光谱、X射线衍射仪和X射线光电子能谱技术对8组样本进行表征和分析。结果与结论:①扫描电子显微镜:在牙本质片的调控下,纳米β-磷酸三钙和纳米羟基磷灰石的微观结构和形貌特征均发生了改变,纳米β-磷酸三钙颗粒形态由不规则多边形变为短棒状、球状,排列成三维团簇状,纳米羟基磷灰石颗粒形态由棒状、针状变为短棒状等多种形态;纳米β-磷酸三钙和纳米羟基磷灰石颗粒有序地排列在牙本质胶原纤维网络之间,并且随着纳米β-磷酸三钙或纳米羟基磷灰石浓度的增加,附着及团聚现象越来越明显,排列越来越紧密。②拉曼光谱:在牙本质片的调控作用下,纳米β-磷酸三钙和纳米羟基磷灰石的官能团未发生改变,但是随着纳米β-磷酸三钙或纳米羟基磷灰石浓度的增加,官能团特征峰的强度增强。③X射线衍射:在牙本质片的调控作用下,纳米β-磷酸三钙和纳米羟基磷灰石的结晶度提升,晶体结构更完整,晶粒变小,其中30%纳米β-磷酸三钙/牙本质片和30%纳米羟基磷灰石/牙本质片的结晶性最好。④X射线光电子能谱:在牙本质片的调控作用下,纳米β-磷酸三钙和纳米羟基磷灰石的元素组成未变,但出现部分化学态变化以及特征峰强度增强特征。⑤结果表明,以牙本质片为硬模板构建的纳米β-磷酸三钙或纳米羟基磷灰石复合材料表征性能稳定,牙本质片对纳米β-磷酸三钙和纳米羟基磷灰石具有一定的调控功能,其中30%纳米β-磷酸三钙/牙本质片、30%纳米羟基磷灰石/牙本质片表征性能更为优异。 展开更多
关键词 纳米β-磷酸三钙 纳米羟基磷灰石 硬模板 牙本质片 表征性能 晶体 微观形貌 分子结构
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开发地震沉积学方法在松辽盆地M2区块扶余油层砂岩预测中的应用
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作者 李操 杨春生 +2 位作者 刘宗堡 陈国松 史洪波 《物探与化探》 2026年第1期43-52,共10页
松辽盆地北部长垣南地区扶余油层砂岩储层发育,是大庆油田增储建产的重点区域,孔隙度为9.0%~13.6%,渗透率为0.1%~3.21%,属于致密砂岩储层,需要采用水平井+大规模体积压裂的方式开发动用,因而对砂体预测提出了较高的精度要求。本区扶余... 松辽盆地北部长垣南地区扶余油层砂岩储层发育,是大庆油田增储建产的重点区域,孔隙度为9.0%~13.6%,渗透率为0.1%~3.21%,属于致密砂岩储层,需要采用水平井+大规模体积压裂的方式开发动用,因而对砂体预测提出了较高的精度要求。本区扶余油层的主要储层以扶Ⅰ油层组、扶Ⅱ油层组为主,其沉积环境以三角洲平原亚相为主,砂体分布具有平面变化快、单层厚度薄、纵向错叠分布的特征,砂体的地震响应特征复杂,储层预测难度大。针对扶余油层致密砂岩储层的沉积特点,本文采用开发地震沉积学方法开展砂体预测,通过基于本区井参数的地震正演分析明确了薄层致密砂岩的地震响应特征,进而开展了地层切片自动优选、砂岩厚度平面定量预测等技术的综合应用。研究表明:长垣南扶余油层地震振幅与小层砂岩厚度之间存在正相关关系;开发地震沉积学技术的研究与应用能够定量描述小层砂体平面分布规律,有力支撑了本区水平井开发先导试验区的井位成功部署与实施。长垣南M2区块扶余致密油水平井开发试验的成功,为松辽盆地北部致密油开发提供了示范,在后续的水平井设计与实施中应强化开发地震沉积学砂岩预测技术的应用,保障砂岩和油层钻遇率,为扶余油层致密油的成功开发提供技术保障。 展开更多
关键词 地震正演 地层切片优选 开发地震沉积学 水平井 致密砂岩储层
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基于Slice的H.264并行视频编码算法 被引量:11
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作者 宁华 梅铮 李锦涛 《计算机工程》 EI CAS CSCD 北大核心 2005年第4期181-182,211,共3页
从H.264视频编码标准的特点出发,提出了基于Slice级别的H.264视频编码并行算法,该算法不仅能够保证节点间的负载平衡,减少各节点间数据的依赖关系,还充分利用了已有的计算能力。最后给出了在曙光3000上的实验结果。
关键词 H.264 视频编码 并行 slice
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弱胶结覆岩下顶分层综放面强矿压机理及拱形工作面控制技术
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作者 王家臣 陈建强 +2 位作者 潘卫东 彭宝山 邓藏 《煤炭学报》 北大核心 2026年第1期193-208,共16页
弱胶结覆岩可导致工作面强矿压,甚至压架事故,严重威胁安全和影响生产。以准东二矿55 m巨厚煤层顶分层综放开采为研究背景,采用现场实测、理论分析、室内试验以及数值模拟等方法对弱胶结覆岩下特厚综放面矿压规律及控制技术进行研究。... 弱胶结覆岩可导致工作面强矿压,甚至压架事故,严重威胁安全和影响生产。以准东二矿55 m巨厚煤层顶分层综放开采为研究背景,采用现场实测、理论分析、室内试验以及数值模拟等方法对弱胶结覆岩下特厚综放面矿压规律及控制技术进行研究。结果表明:准东二矿首采区覆岩赋存表现为基岩厚度大,整体胶结程度弱,软或极软岩层占比87%;顶分层首采1101综放面推进期间,基本顶砌体梁在高位岩块回转的动荷载下二次破断失稳,原砌体梁承载结构被破坏,支架由给定载荷转为与直接顶共同承担体系变形,导致强矿压;据此,建立了支架上方拱结构岩块段的稳定方程并揭示了不同位置的受力规律,进而提出工作面“拱形”布置及回采工艺,以便顶板形成倾向承载结构从而控制强矿压,并揭示其将部分覆岩载荷转化为拱块段之间的相互作用力的矿压控制机理;数值模拟结果进一步得出新工艺下工作面顶板塑性区发育程度降低,顶板下沉量减小33.1%,支架上方拱结构将部分上覆载荷转化为内力,结构的应力水平上升,垂直应力高于原来的18%,最终降低了支架整体承受的载荷。现场实践表明,该技术对强矿压控制发挥着重要作用,支架受力最高峰值下降12%,较强来压范围由20~120号支架缩小至40~100号支架,同时,拱脚处最大挤压力有利于工作面两端三角煤及顶板及时折断垮落。 展开更多
关键词 弱胶结覆岩 巨厚煤层 分层综放 强矿压 拱形工作面
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