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On Tensor Spaces for Rook Monoid Algebras
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作者 Zhan Kui XIAO 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2016年第5期607-620,共14页
Let m, n ∈ N, and V be an m-dimensional vector space over a field F of characteristic 0. Let U = F + V and Rn be the rook monoid. In this paper, we construct a certain quasi-idempotent in the annihilator of U^×... Let m, n ∈ N, and V be an m-dimensional vector space over a field F of characteristic 0. Let U = F + V and Rn be the rook monoid. In this paper, we construct a certain quasi-idempotent in the annihilator of U^×n in FRn, which comes from some one-dimensional two-sided ideal of rook monoid algebra. We show that the two-sided ideal generated by this element is indeed the whole annihilator of U^×n in FR^n. 展开更多
关键词 Rook monoid tensor space general linear group symmetric group
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CANONICAL REPRESENTATIONS AND DEGREE OF FREEDOM FORMULAE OF ORTHOGONAL TENSORS IN N-DIMENSIONAL EUCLIDEAN SPACE
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作者 熊祝华 郑泉水 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第1期93-101,共9页
In this paper, with the help of the eigenvalue properties of orthogonal tensors in n-dimensional Euclidean space and the representations of the orthogonal tensors in 2-dimensional space, the canonical representations ... In this paper, with the help of the eigenvalue properties of orthogonal tensors in n-dimensional Euclidean space and the representations of the orthogonal tensors in 2-dimensional space, the canonical representations of orthogonal tensors in n-dimensional Euclidean space are easily gotten. The paper also gives all the constraint relationships among the principal invariants of arbitrarily given orthogonal tensor by use of Cayley-Hamilton theorem; these results make it possible to solve all the eigenvalues of any orthogonal tensor based on a quite reduced equation of m-th order, where m is the integer part ofn \2. Finally, the formulae of the degree of freedom of orthogonal tensors are given. 展开更多
关键词 CANONICAL REPRESENTATIONS AND DEGREE OF FREEDOM FORMULAE OF ORTHOGONAL tensorS IN N-DIMENSIONAL EUCLIDEAN space exp
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Tensor Product of 2-Frames in 2-Hilbert Spaces
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作者 G. Upender Reddy 《Advances in Pure Mathematics》 2016年第8期517-522,共6页
2-frames in 2-Hilbert spaces are studied and some results on it are presented. The tensor product of 2-frames in 2-Hilbert spaces is introduced. It is shown that the tensor product of two 2-frames is a 2-frame for the... 2-frames in 2-Hilbert spaces are studied and some results on it are presented. The tensor product of 2-frames in 2-Hilbert spaces is introduced. It is shown that the tensor product of two 2-frames is a 2-frame for the tensor product of Hilbert spaces. Some results on tensor product of 2-frames are established. 展开更多
关键词 tensor Product 2-Inner Product spaces FRAMES 2-Frames
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HiTrain:面向大模型训练的异构内存卸载与I/O优化
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作者 汤志航 兰颢 +3 位作者 刘政国 汪庆 赵来平 李克秋 《计算机研究与发展》 北大核心 2026年第3期627-639,共13页
随着大语言模型(large language models,LLMs)(以下简称“大模型”)参数规模的持续增长,微调百亿级参数大模型对计算和存储资源提出了极高要求。传统分布式训练方案通常依赖大量高端GPU和高速互联网络,训练成本极为昂贵。现有单GPU训练... 随着大语言模型(large language models,LLMs)(以下简称“大模型”)参数规模的持续增长,微调百亿级参数大模型对计算和存储资源提出了极高要求。传统分布式训练方案通常依赖大量高端GPU和高速互联网络,训练成本极为昂贵。现有单GPU训练方案虽通过张量卸载缓解显存压力,但仍然面临I/O传输效率低和设备利用率不足等问题。传统内核态I/O操作在大规模张量迁移中引入频繁的系统调用和上下文切换,成为制约性能的关键瓶颈;同时,优化器计算无法充分发挥多核CPU的并行能力,难以实现与GPU计算的有效重叠,进一步限制了系统性能。针对上述问题,提出了一种面向大模型训练的异构内存卸载与I/O优化方案HiTrain。首先构建了基于存储性能开发工具包(storage performance development kit,SPDK)的高性能张量存储模块,通过在用户态管理张量数据,避免了内核I/O栈开销,从而提高张量卸载的并发性与吞吐率;其次,设计并实现了基于异步优化器的存储-计算流水线调度模块,通过对优化器的执行进行优化重排来减少GPU等待时间,提高整体训练效率。实验结果表明,在配备单张GPU和非易失性存储器快速固态硬盘(non-volatile memory express solid state drive,NVMe SSD)的服务器上,所提出的方案能够充分利用系统中的存算资源,使得模型训练过程中张量卸载与加载效率提升32.7%,整体训练吞吐提升至现有方案的1.49倍,为低成本大模型训练提供了切实可行的技术路径。 展开更多
关键词 大模型训练 异构内存 张量卸载 用户态高性能I/O 存储-计算流水线
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Targeting the brain’s glymphatic pathway:A novel therapeutic approach for cerebral small vessel disease 被引量:2
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作者 Yuhui Ma Yan Han 《Neural Regeneration Research》 2026年第2期433-442,共10页
Cerebral small vessel disease encompasses a group of neurological disorders characterized by injury to small blood vessels,often leading to stroke and dementia.Due to its diverse etiologies and complex pathological me... Cerebral small vessel disease encompasses a group of neurological disorders characterized by injury to small blood vessels,often leading to stroke and dementia.Due to its diverse etiologies and complex pathological mechanisms,preventing and treating cerebral small vessel vasculopathy is challenging.Recent studies have shown that the glymphatic system plays a crucial role in interstitial solute clearance and the maintenance of brain homeostasis.Increasing evidence also suggests that dysfunction in glymphatic clearance is a key factor in the progression of cerebral small vessel disease.This review begins with a comprehensive introduction to the structure,function,and driving factors of the glymphatic system,highlighting its essential role in brain waste clearance.Afterwards,cerebral small vessel disease was reviewed from the perspective of the glymphatic system,after which the mechanisms underlying their correlation were summarized.Glymphatic dysfunction may lead to the accumulation of metabolic waste in the brain,thereby exacerbating the pathological processes associated with cerebral small vessel disease.The review also discussed the direct evidence of glymphatic dysfunction in patients and animal models exhibiting two subtypes of cerebral small vessel disease:arteriolosclerosis-related cerebral small vessel disease and amyloid-related cerebral small vessel disease.Diffusion tensor image analysis along the perivascular space is an important non-invasive tool for assessing the clearance function of the glymphatic system.However,the effectiveness of its parameters needs to be enhanced.Among various nervous system diseases,including cerebral small vessel disease,glymphatic failure may be a common final pathway toward dementia.Overall,this review summarizes prevention and treatment strategies that target glymphatic drainage and will offer valuable insight for developing novel treatments for cerebral small vessel disease. 展开更多
关键词 AQUAPORIN-4 ASTROCYTES cerebral amyloid angiopathy cerebral small vessel disease cerebrospinal fluid diffusion tensor image analysis along the perivascular space glymphatic system interstitial fluid perivascular space therapeutic strategies
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DTI-ALPS在阿尔茨海默病中的研究进展
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作者 李若冰 方圆 班允清 《影像研究与医学应用》 2026年第2期13-16,共4页
阿尔茨海默病(AD)是一种进行性神经退行性疾病,其病理特征为β-淀粉样蛋白(Aβ)沉积与神经原纤维缠结。淋巴功能障碍可促进Aβ和tau蛋白的积累、神经炎症和血管损伤,推动神经退行性疾病进展。沿血管周围间隙弥散张量成像(DTI-ALPS)通过... 阿尔茨海默病(AD)是一种进行性神经退行性疾病,其病理特征为β-淀粉样蛋白(Aβ)沉积与神经原纤维缠结。淋巴功能障碍可促进Aβ和tau蛋白的积累、神经炎症和血管损伤,推动神经退行性疾病进展。沿血管周围间隙弥散张量成像(DTI-ALPS)通过人脑间隙流体动力学评估淋巴系统功能,为早期识别AD提供可能。本文对DTI-ALPS技术在AD中的影像学研究进展进行综述。 展开更多
关键词 沿血管周围间隙弥散张量成像 阿尔茨海默病 类淋巴系统 弥散张量成像 Β-淀粉样蛋白
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基于Q空间轨迹成像具有半正定约束的扩散偏度成像
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作者 陈赞 滕召翼 冯远静 《高技术通讯》 北大核心 2026年第1期15-28,共14页
Q空间轨迹成像(Q-space trajectory imaging,QTI)旨在通过扩散张量分布(diffusion tensor distribution,DTD)模型对微观组织结构进行探索,从而提高微环境中组织结构的区分度。在这项工作中,考虑到被测信号的不规则性,单靠低阶项拟合会... Q空间轨迹成像(Q-space trajectory imaging,QTI)旨在通过扩散张量分布(diffusion tensor distribution,DTD)模型对微观组织结构进行探索,从而提高微环境中组织结构的区分度。在这项工作中,考虑到被测信号的不规则性,单靠低阶项拟合会丢弃较多的有用信息,为丰富结构信息并提高指标精确性,引入了具有更高阶数的偏度张量。针对拓展后的模型,为保证结果的合理性,提出了扩散张量、协方差张量和偏度张量应满足的3个约束条件,并证明其必要性。为便于约束条件加入到计算中,使用半正定规划(semidefinite programming,SDP)对问题进行求解。此外,本文还引入一个滤波函数,对微观组织结构进行表征。最后,在预处理后的数据集中加入高斯噪声,研究噪声对所提方法的影响。通过对约束条件必要性的讨论可以发现,若不对模型执行严格非负性,最终得到的结果会出现较大的误差,从而影响组织结构的分析。相应地,本文对高斯噪声可能带来的影响进行了测试,从实验结果可以看出,噪声的出现会给结果带来一定的误差,且误差不可以忽略。 展开更多
关键词 扩散磁共振成像 Q空间轨迹成像 偏度张量 半正定规划 微观分数各向异性
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闭收缩梯度里奇孤立子的一些刚性定理
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作者 岳文艳 张世金 《首都师范大学学报(自然科学版)》 2026年第1期14-20,共7页
本文研究闭流形上收缩梯度里奇孤立子的一些性质,在无迹曲率张量的L^(n/2)范数足够小和直径有上界且体积有下界的假设条件下,利用经典的Moser迭代,给出了一些刚性结果,如当维数为4时,不需要体积有下界的条件。
关键词 收缩梯度里奇孤立子 无迹曲率张量 球空间形式
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基于半张量积方法的绿地灌溉模糊系统设计
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作者 周琳超 吕红丽 冯俊娥 《聊城大学学报(自然科学版)》 2026年第1期1-10,共10页
针对城市绿地面积增长与淡水资源不足的现状,提出一种基于半张量积方法的城市绿地灌溉模糊系统。通过半张量积构造模糊关系矩阵,将传统抽象的模糊规则语言信息进行量化并转化成矩阵运算。利用降雨量、土壤湿度等输入,通过矩阵运算得到... 针对城市绿地面积增长与淡水资源不足的现状,提出一种基于半张量积方法的城市绿地灌溉模糊系统。通过半张量积构造模糊关系矩阵,将传统抽象的模糊规则语言信息进行量化并转化成矩阵运算。利用降雨量、土壤湿度等输入,通过矩阵运算得到相应的灌溉水时间,从而实现智能灌溉。最后,分别通过模糊规则与实际数据两种方法进行了仿真。 展开更多
关键词 半张量积 模糊关系矩阵 绿地灌溉模糊系统 模糊控制
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中枢淋巴系统在脑小血管病相关认知障碍中的作用研究进展
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作者 王天任 杜冰滢 毕晓莹 《海军军医大学学报》 北大核心 2026年第1期105-111,共7页
中枢淋巴系统是中枢神经系统特有的代谢网络,该系统可清除大脑积累的代谢废物,维持中枢神经系统的内环境稳态。脑小血管病(CSVD)是血管性认知障碍的主要病因。越来越多的证据表明,中枢淋巴系统在CSVD相关认知障碍中起着复杂且重要的作... 中枢淋巴系统是中枢神经系统特有的代谢网络,该系统可清除大脑积累的代谢废物,维持中枢神经系统的内环境稳态。脑小血管病(CSVD)是血管性认知障碍的主要病因。越来越多的证据表明,中枢淋巴系统在CSVD相关认知障碍中起着复杂且重要的作用。本文综述了中枢淋巴系统的功能、驱动因素及影像学评估方法,并探讨了中枢淋巴系统与CSVD相关认知障碍之间的关系,期望为未来的研究和临床干预提供参考。 展开更多
关键词 中枢淋巴系统 脑小血管病 血管性认知障碍 沿血管周围间隙弥散张量成像分析 类淋巴系统 脑膜淋巴管
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ON THE CENTRAL LIMIT THEOREM IN PRODUCT SPACES
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作者 SU ZHONGGEN 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第4期367-378,共12页
Suppose that E and F are separable Banach spaces, X and Y are independent symmetric E and F-valued random vectors respectively. This paper is devoted to the study of the central limit theorem for X Y in the injective... Suppose that E and F are separable Banach spaces, X and Y are independent symmetric E and F-valued random vectors respectively. This paper is devoted to the study of the central limit theorem for X Y in the injective and projective tensor product spaces E F and E F. Special attention is paid to l2 l2. In addition, two counter-examples are given. 展开更多
关键词 Central limit theorem injective and projective tensor product spaces Gaussian process.
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Projective Tensor Products of <i>C*</i>-Algebras
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作者 Ajay Kumar Vandana Rajpal 《Advances in Pure Mathematics》 2014年第5期176-188,共13页
For C*-algebras A and B, the constant involved in the canonical embedding of into is shown to be . We also consider the corresponding operator space version of this embedding. Ideal structure of is obtained in case A ... For C*-algebras A and B, the constant involved in the canonical embedding of into is shown to be . We also consider the corresponding operator space version of this embedding. Ideal structure of is obtained in case A or B has only finitely many closed ideals. 展开更多
关键词 Banach space PROJECTIVE tensor NORM Operator space PROJECTIVE tensor NORM
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YANG-BAXTER OPERATORS AND TENSOR TRANSFORMATIONS
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作者 汪振华 《Acta Mathematica Scientia》 SCIE CSCD 2002年第3期427-432,共6页
The author considers relations between Yang-Baxter operators and tensor transformations, and proves that all tensor transform at ions over the category of modules of a Yang-space form a group.
关键词 Yang-Baxter operators Yang-space tensor transformations
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Flat Space-Time and Motion in Gravitational Field
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作者 Zhang Junhao Chen Xiang (Department of Physics, Shantou University Shantou, Guangdong 515063, P. R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1995年第4期273-284,共12页
Two fundamental hypotheses of special relativistic gravitational theory are: (1) the equivalence of gravitational mass and inertial mass, (2) the equation of the gravitational tensor potential in linear approximat... Two fundamental hypotheses of special relativistic gravitational theory are: (1) the equivalence of gravitational mass and inertial mass, (2) the equation of the gravitational tensor potential in linear approximation. Main results: (1) the values of the planetary perihelion shill, and the angle of deflection of light are the same as those of general relativity. The value of the red shill is consistent with the experiment. One cannot use these experimental values to judge whether space-time is curved. (2) In GP-B experiment, the gyroscope will be acted on by the additional gravitational fields due to the Earth's spin (S) and the orbital motion of satellite (L). The average precession rates are , where β and δ are the gyroscope's polar angles, (S) and (G) designate values deduced from special and general relativity, respectively. The GP-B experiment is the first one to judge whether space-time is flat. 展开更多
关键词 GRAVITY Coupling coefficient tensor potential Flat space-time.
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Einstein’s Pseudo-Tensor in <i>n</i>Spatial Dimensions for Static Systems with Spherical Symmetry
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作者 Frank R. Tangherlini 《Journal of Modern Physics》 2013年第9期1200-1204,共5页
It was noted earlier that the general relativity field equations for static systems with spherical symmetry can be put into a linear form when the source energy density equals radial stress. These linear equations lea... It was noted earlier that the general relativity field equations for static systems with spherical symmetry can be put into a linear form when the source energy density equals radial stress. These linear equations lead to a delta function energymomentum tensor for a point mass source for the Schwarzschild field that has vanishing self-stress, and whose integral therefore transforms properly under a Lorentz transformation, as though the particle is in the flat space-time of special relativity (SR). These findings were later extended to n spatial dimensions. Consistent with this SR-like result for the source tensor, Nordstrom and independently, Schrodinger, found for three spatial dimensions that the Einstein gravitational energy-momentum pseudo-tensor vanished in proper quasi-rectangular coordinates. The present work shows that this vanishing holds for the pseudo-tensor when extended to n spatial dimensions. Two additional consequences of this work are: 1) the dependency of the Einstein gravitational coupling constant κ on spatial dimensionality employed earlier is further justified;2) the Tolman expression for the mass of a static, isolated system is generalized to take into account the dimensionality of space for n ≥ 3. 展开更多
关键词 Field EQUATIONS Point Particle Dimensionality of space Einstein’s Pseudo-tensor
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Space-Time Curvature Mode Quanta
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作者 Philipp Kornreich 《Journal of Modern Physics》 2020年第12期1977-1992,共16页
Einstein theorized that Gravity is not a force derived from a potential that acts across a distance. It is a distortion of space and time in which we live by masses and energy. Consistent with Einstein’s theory, a mo... Einstein theorized that Gravity is not a force derived from a potential that acts across a distance. It is a distortion of space and time in which we live by masses and energy. Consistent with Einstein’s theory, a model of space-time curvature modes and associated curvature quanta in slightly warped space-time generated by a light Photon is derived. Both a Schr<span style="white-space:nowrap;">?</span>dinger and a Second Quantized representation of the space-time curvature mode quanta are calculated and are fourth rank tensors. The eigenvalues of these equations are radii of curvature, not energy. The Eigenfunctions are linear functions of the components of the tensor that describes the curvature of space-time. 展开更多
关键词 PHOTONS PHONONS GRAVITY General Relativity space-TIME Radius of Curvature tensor
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基于多尺度3D-CNN-CBAM的空气质量指数时空预测
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作者 刘金培 罗瑞 +1 位作者 陈华友 周礼刚 《控制与决策》 北大核心 2025年第2期404-412,共9页
精确地把握空气质量指数(AQI)的实时动态演变规律对大气污染防治和城市公共卫生治理至关重要.因此,通过构建三维空间张量,将AQI特征信息由时间维度扩展至时空维度,并提出一种基于多尺度三维卷积注意力机制的时空预测网络模型,以提高AQI... 精确地把握空气质量指数(AQI)的实时动态演变规律对大气污染防治和城市公共卫生治理至关重要.因此,通过构建三维空间张量,将AQI特征信息由时间维度扩展至时空维度,并提出一种基于多尺度三维卷积注意力机制的时空预测网络模型,以提高AQI预测精度.预测方法首先对相关影响因素数据进行有效筛选.其次,将AQI数据及其影响因素分解为不同模态下的子序列.进而,基于时间、空间地理位置和影响因素3个维度,构建三维空间张量,以反映AQI数据的时空特征演变.然后,设计三维卷积注意力机制网络模型对子序列进行预测,以有效提取AQI与其影响因素之间的关键时空关联性特征.通过学习局部AQI序列特征的重要程度,该模型能够对空间时域信息赋予不同权重,以增强关键信息的影响力.将所提出的方法应用于3大城市群2019年~2024年的日度AQI预测,结果表明,该方法适用于具有时空属性的AQI预测,与现有方法相比具有更高的预测精度和适用性. 展开更多
关键词 时空预测 空气质量指数 卷积神经网络 注意力机制 三维空间张量 多元经验模态分解
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Spin and Quantization of Gravitational Space
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作者 Bin Liang 《Journal of Modern Physics》 2012年第11期1757-1762,共6页
According to the formula of translational motion of vector along an infinitesimal closed curve in gravitational space, this article shows that the space and time both are quantized;the called center singularity of Sch... According to the formula of translational motion of vector along an infinitesimal closed curve in gravitational space, this article shows that the space and time both are quantized;the called center singularity of Schwarzschild metric does not exist physically, and Einstein’s theory of gravity is compatible with the traditional quantum theory in essence;the quantized gravitational space is just the spin network which consists of infinite quantized loops linking and intersecting each other, and that whether the particle is in spin eigenstate depends on the translational track of its spin vector in gravitational space. 展开更多
关键词 QUANTIZATION of GRAVITATIONAL space TRANSLATIONAL Motion of Vector Curvature Area tensor SPIN Network SPIN EIGENSTATE
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经缝匠肌与髂腰肌间隙置钉在骨盆骨折治疗中的应用效果
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作者 梁健 陈绍巨 +1 位作者 陈瑜 梁增章 《中国社区医师》 2025年第35期40-42,共3页
目的:探讨经缝匠肌与髂腰肌间隙置钉在骨盆骨折治疗中的应用效果。方法:选取2023年1月—2024年12月廉江市人民医院收治的骨盆骨折患者60例作为研究对象,按照随机数字表法分为参照组与研究组,各30例。参照组实施经阔筋膜张肌与缝匠肌间... 目的:探讨经缝匠肌与髂腰肌间隙置钉在骨盆骨折治疗中的应用效果。方法:选取2023年1月—2024年12月廉江市人民医院收治的骨盆骨折患者60例作为研究对象,按照随机数字表法分为参照组与研究组,各30例。参照组实施经阔筋膜张肌与缝匠肌间隙置钉,研究组实施经缝匠肌与髂腰肌间隙置钉。比较两组治疗效果。结果:研究组手术时间、住院时间短于参照组,术中出血量少于参照组,术后首次下床负重时间、骨折愈合时间早于参照组(P<0.001)。研究组骨折恢复总优良率高于参照组(P=0.038)。术后6个月,两组日常生活活动能力量表评分提高,且研究组高于参照组(P<0.001)。结论:经缝匠肌与髂腰肌间隙置钉在骨盆骨折治疗中的应用效果显著,可缩短手术时间,减少术中出血量,促进骨折愈合,提高骨折复位质量和日常生活自理能力。 展开更多
关键词 骨盆骨折 经缝匠肌与髂腰肌间隙置钉 经阔筋膜张肌与缝匠肌间隙置钉 日常生活活动能力
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General Relativity without Curved Space-Time (&#8370;R)
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作者 Abed El Karim S. Abou Layla 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第1期156-166,共11页
The theory of general relativity is related to the concept of curvature of space- time induced by the presence of the massive objects. We will see through this paper that the general relativity can be linked with line... The theory of general relativity is related to the concept of curvature of space- time induced by the presence of the massive objects. We will see through this paper that the general relativity can be linked with linear Algebra and Vector Analysis without the need for concept of space-time. This is important for the unification of general relativity with quantum mechanics, gravity with electromagnetic, and a better understanding of the universe, gravity, black holes. The most important is the separation between the space-time and the big bang theory, which prove the existence of space-time before that, which leads to the existence of the creator of the universe. 展开更多
关键词 Gravity Electromagnetism BIG Bang space-TIME General RELATIVITY LORENTZ Force Density The Einstein’s tensor
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