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Gauge Gravitational Field in a Fractal Space-Time
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作者 M. Agop Camelia Popa Anca Harabagiu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第11期1197-1204,共8页
Considering the fractal structure of space-time, the scale relativity theory in the topological dimension DT = 2 is built. In such a conjecture, the geodesics of this space-time imply the hydrodynamic model of the qua... Considering the fractal structure of space-time, the scale relativity theory in the topological dimension DT = 2 is built. In such a conjecture, the geodesics of this space-time imply the hydrodynamic model of the quantum mechanics. Subsequently, the gauge gravitational field on a fractal space-time is given. Then, the gauge group, the gauge-covariant derivative, the strength tensor of the gauge field, the gauge-invariant Lagrangean, the field equations of the gauge potentials and the gauge energy-momentum tensor are determined. Finally, using this model, a Reissner- Nordstrom type metric is obtained. 展开更多
关键词 fractal space-time scale relativity theory gauge gravitational field Reissner-Nordstrom metric
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FLAT SUPERSYMMETRIC SPACE-TIME AND THE THEORY OF SUPER FIELDS
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作者 张厉宁 《Acta Mathematica Scientia》 SCIE 1985年第4期371-378,共8页
Flat supersymmetric space-time (x, θ) has been discussed under assumption that the Fermi variables are symplectic vectors only. We have abandoned the traditional assumption, that it must be the spinor representation ... Flat supersymmetric space-time (x, θ) has been discussed under assumption that the Fermi variables are symplectic vectors only. We have abandoned the traditional assumption, that it must be the spinor representation of Lorentz group, which makes in the usual theory of supersymmetry.The even and odd generators of the ortho-symplectic group OS_p(414) have been calculated concretely in its dyads representation.New superfields, Lagrangian and the action integral, different from the usual theory, have been introduced in this flat case. 展开更多
关键词 FLAT SUPERSYMMETRIC space-time AND THE THEORY OF SUPER fieldS
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Analysis of Space-time Characteristics of Energy Field of Seismicity in Jiangsu and Its Neighboring Areas
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作者 Wang Jun Sun Yejun Zhan Xiaoyan Zheng Jiangrong Jiang Haolin Huo Zhuqing 《Earthquake Research in China》 2010年第4期445-455,共11页
The paper analyzes the variation characteristics of energy fields of seismicity 2.1≤M L ≤4.5 in Jiangsu and its neighboring areas during the period between January 1970 and December 2007.It also analyzes the variati... The paper analyzes the variation characteristics of energy fields of seismicity 2.1≤M L ≤4.5 in Jiangsu and its neighboring areas during the period between January 1970 and December 2007.It also analyzes the variations of time "weight" coefficients of the major typical energy fields,using random function theory with seismic energy fields as a space-time random function field based on Empirical Orthogonal Function (EOF) expansion methods.The results show that the expansion accuracy of the first seven typical fields is 0.9244.The strength of seismic energy varies remarkably in different tectonic blocks in the study area.High value areas are in middle and southern Jiangsu,and the south Yellow Sea.The distribution of the typical fields also shows that it is an area that affects most significantly the seismic energy fields of the study region.The time "weight" coefficients of the first six typical fields vary with time,and the amplitude of the variations has strong temporal correlations with moderate-strong earthquakes in the region. 展开更多
关键词 Jiangsu and earthquakes its neighboring areas Energy Empirical Orthogonal Function field of moderate and small space-time characteristics
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The Normative Enlightenment of China's Human Rights Studies from the Space-Time Dimensions of the Chinese Dream
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作者 HUO GUIHUAN 《The Journal of Human Rights》 2014年第6期16-18,共3页
In order to gradually build a theoretical system of human rights with Chinese characteristics that conforms to the development of the times through rigorous academic research, researchers need to break through the bas... In order to gradually build a theoretical system of human rights with Chinese characteristics that conforms to the development of the times through rigorous academic research, researchers need to break through the basic think- ing tendency of "from idea to idea" step by step and finally establish the fundamental research orientation of "specifying human rights stud- ies." Through comprehensive and systematic analysis and sorting out various basic concepts relating to human rights, researchers also need to finally establish a solid foundation and prerequisite for fruitful academic study. 展开更多
关键词 time The Normative Enlightenment of China’s human Rights Studies from the space-time Dimensions of the Chinese Dream
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Effects of 13 T Static Magnetic Fields (SMF) in the Cell Cycle Distribution and Cell Viability in Immortalized Hamster Cells and Human Primary Fibroblasts Cells 被引量:2
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作者 赵国平 陈少鹏 +8 位作者 赵烨 朱玲燕 黄佩 鲍凌志 王军 王磊 吴李君 吴跃进 许安 《Plasma Science and Technology》 SCIE EI CAS CSCD 2010年第1期123-128,共6页
Magnetic resonance image (MRI) systems with a much higher magnetic flux density were developed and applied for potential use in medical diagnostic. Recently, much attention has been paid to the biological effects of... Magnetic resonance image (MRI) systems with a much higher magnetic flux density were developed and applied for potential use in medical diagnostic. Recently, much attention has been paid to the biological effects of static, strong magnetic fields (SMF). With the 13 T SMF facility in the Institute of Plasma Physics, Chinese Academy of Sciences, the present study focused on the cellular effects of the SMF with 13 T on the cell viability and the cell cycle distribution in immortalized hamster cells, such as human-hamster hybrid (AL) cells, Chinese hamster ovary (CHO) cells, DNA double-strand break repair deficient mutant (XRS-5) cells, and human primary skin fibroblasts (AG1522) cells. It was found that the exposure of 13 T SMF had less effect on the colony formation in either nonsynchronized or synchronized AL cells. Moreover, as compared to non-exposed groups, there were slight differences in the cell cycle distribution no matter in either synchronized or nonsynchronized immortalized hamster ceils after exposure to 13 T SMF. However, it should be noted that the percentage of exposed AG1522 cells at G0/G1 phase was decreased by 10% as compared to the controls. Our data indicated that although 13 T SMF had minimal effects in immortalized hamster cells, the cell cycle distribution was slightly modified by SMF in human primary fibroblasts. 展开更多
关键词 static magnetic fields immortalized hamster cells human primary fibroblasts cells
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High Field MRI in Human African Trypanosomiasis (HAT) 被引量:1
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作者 Cherif Mohamadou Aidara Caroline Magne +4 位作者 Philomene Kouna Gaelle Ebinda Mipinda Abdoulaye Dione Diop Abdoulaye Ndoye Diop Sokhna Ba 《Open Journal of Radiology》 2017年第3期190-198,共9页
Human African Trypanosomiasis (HAT) or sleeping thickness is a forest and rural disease;where agriculture is the main activity. It is a chronic and lethal disease without treatment. HAT is caused by two parasites;Tryp... Human African Trypanosomiasis (HAT) or sleeping thickness is a forest and rural disease;where agriculture is the main activity. It is a chronic and lethal disease without treatment. HAT is caused by two parasites;Trypanosoma Brucei Gambiense (gTB) and Trypanosoma Brucei Rhodesiense (rTB) transmitted to humans by the tsetse fly. It is endemic condition in Africa between the 15&deg north latitude and the 20° south latitude. It is reported outside this area in travelers who stayed in endemic zone. Infection by gTB is wider and more frequent (98%) than that by rTB (2%). The Democratic Republic of Congo is the most affected country with more than 75% of reported cases. The geographical distribution is not homogeneous. There are more affected regions in a zone called “foci” which represents areas favorable to the development of the vector. Its diagnosis and treatment are very important because of its social and economic impact at both the individual and community levels. Promising molecules including fexinidazole are currently undergoing testing. Nowadays populations move more and more easily but the discovery of this disease in daily neuroradiological practice is exceptional. We propose in this paper through two observations, reminders on epidemiological, clinical and MRI features of HAT. It typically performs the edematous, bilateral and diffuse encephalitis. It is important to distinguish these aspects from the arsenic-induced encephalitis that may occur during treatment. Only vector control allows eradicating this disease. WHO has set targets elimination of HAT as a public health problem for 2020 deadline. 展开更多
关键词 human AFRICAN TRYPANOSOMIASIS High field MRI DIFFUSE ENCEPHALITIS Optic TRACT Arsenic-Induced ENCEPHALITIS
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Beat-to-Beat Variability in Field Potential Duration in Human Embryonic Stem Cell-Derived Cardiomyocyte Clusters for Assessment of Arrhythmogenic Risk, and a Case Study of Its Application 被引量:1
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作者 Kazuto Yamazaki Taro Hihara +7 位作者 Hiroshi Kato Tatsuto Fukushima Kazuyuki Fukushima Tomohiko Taniguchi Takashi Yoshinaga Norimasa Miyamoto Masashi Ito Kohei Sawada 《Pharmacology & Pharmacy》 2014年第1期117-128,共12页
We established a QT interval assessment system that uses human embryonic stem cell-derived cardiomyocyte clusters (hES-CMCs) in which the field potential duration (FPD) or corrected FPD (FPDc) was measured as an indic... We established a QT interval assessment system that uses human embryonic stem cell-derived cardiomyocyte clusters (hES-CMCs) in which the field potential duration (FPD) or corrected FPD (FPDc) was measured as an indicator of drug-induced QT interval prolongation. To investigate the applicability of the hES-CMC system to drug safety assessment, we investigated short-term variability in FPDc (STVFPDc) (beat rate rhythmicity) as a marker of torsadogenic risk. We investigated the FPDc and STVFPDc of hES-CMCs treated with hERG channel blockers (E-4031 or cisapride) or with our proprietary compounds X, Y, and Z. We also evaluated the electrocardiograms and hemodynamics of dogs treated with compound X, Y, or Z. The torsadogenic hERG channel blockers increased STVFPDc and prolonged FPDc. Compounds X, Y, and Z had hERG inhibitory activity. Compound X prolonged FPDc with increased STVFPDc, whereas compounds Y and Z tended to shorten FPDc in the hES-CMC system. In the in vivo canine study, compound X prolonged corrected QT (QTc), and compounds Y and Z tended to shorten QTc, showing a good correlation with the results in hES-CMCs. These findings suggest that combined assessment of FPDc and STVFPDc in the hES-CMC system increases the predictability of torsadogenic risk. 展开更多
关键词 human Embryonic Stem Cell-Derived Cardiomyocytes field Potential DURATION Short-Term VARIABILITY QT Interval Torsades de POINTES RISK ASSESSMENT
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Space-Time Properties as Quantum Effects. Restrictions Imposed by Grothendieck’s Scheme Theory
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作者 Leonid Lutsev 《Journal of Modern Physics》 2019年第7期795-823,共29页
In this paper we consider properties of the four-dimensional space-time manifold M caused by the proposition that, according to the scheme theory, the manifold M is locally isomorphic to the spectrum of the algebra A,... In this paper we consider properties of the four-dimensional space-time manifold M caused by the proposition that, according to the scheme theory, the manifold M is locally isomorphic to the spectrum of the algebra A, M &cong;Spec (A), where A is the commutative algebra of distributions of quantum-field densities. Points of the manifold M are defined as maximal ideals of density distributions. In order to determine the algebra A, it is necessary to define multiplication on densities and to eliminate those densities, which cannot be multiplied. This leads to essential restrictions imposed on densities and on space-time properties. It is found that the only possible case, when the commutative algebra A exists, is the case, when the quantum fields are in the space-time manifold M with the structure group SO (3, 1) (Lorentz group). The algebra A consists of distributions of densities with singularities in the closed future light cone subset. On account of the local isomorphism M &cong;Spec (A) , the quantum fields exist only in the space-time manifold with the one-dimensional arrow of time. In the fermion sector the restrictions caused by the possibility to define the multiplication on the densities of spinor fields can explain the chirality violation. It is found that for bosons in the Higgs sector the charge conjugation symmetry violation on the densities of states can be observed. This symmetry violation can explain the matter-antimatter imbalance. It is found that in theoretical models with non-abelian gauge fields instanton distributions are impossible and tunneling effects between different topological vacua | n> do not occur. Diagram expansion with respect to the -algebra variables is considered. 展开更多
关键词 space-time PROPERTIES Quantum field ARROW of Time CHIRALITY ALGEBRA of Distributions Symmetry VIOLATION
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Change of Space-Time Structure under Lorentz Transformation
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作者 Ning Wu 《Journal of Modern Physics》 2014年第10期940-947,共8页
When we study Lorentz transformation in the framework of quantum gauge theory of gravity, we will find that the vacuum gravitational gauge field will be changed under gravitational gauge transformation, which will cha... When we study Lorentz transformation in the framework of quantum gauge theory of gravity, we will find that the vacuum gravitational gauge field will be changed under gravitational gauge transformation, which will change the structure of the physical space-time and cause clock dilation effect. The study in this paper provides us with new insights to understand the essential and intrinsic relation between special relativity and general relativity. It provides us with a new way to unify special relativity and general relativity. 展开更多
关键词 LORENTZ TRANSFORMATION GRAVITATIONAL GAUGE TRANSFORMATION space-time STRUCTURE GAUGE Theory of Gravity GRAVITATIONAL GAUGE field
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Currents and Electric Fields Induced in Anatomically Realistic Human Models by Extremely Low Frequency Electric Fields
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作者 Hiroo Tarao Noriyuki Hayashi +1 位作者 Takashi Matsumoto Katsuo Isaka 《Journal of Energy and Power Engineering》 2013年第10期1985-1991,共7页
There is increasing public concern about biological interactions with and the potential health effects of low frequency electric and magnetic fields. Recently, the ICNIRP (International Commission on Non-Ionizing Rad... There is increasing public concern about biological interactions with and the potential health effects of low frequency electric and magnetic fields. Recently, the ICNIRP (International Commission on Non-Ionizing Radiation Protection) has published new exposure guidelines with regard to these fields. The aim of this paper is to demonstrate the calculation of the currents and electric fields induced in the human body by external electric fields at 60 Hz, using numerical human models of anatomically-realistic human bodies, and to compare those results with the basic restrictions proposed by the new guidelines. As a result, in the case that a human is exposed to an electric field of 1 kV/m at 60 Hz the short-circuit current of 18 μA flows though the ankles. Furthermore, the electric field of 40 mV/m in the nervous tissue of the adult model is induced by exposure to external electric fields at the reference level, which is enough smaller than the basic restrictions established in the ICNIRP guidelines for occupational exposure. 展开更多
关键词 Electric field exposure induced currents induced electric fields numerical human models.
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Gravitational Space-Time Curve Generation via Accelerated Charged Particles
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作者 Edward A. Walker 《Journal of Modern Physics》 2016年第9期863-874,共12页
A force with an acceleration that is equal to multiples greater than the speed of light per unit time is exerted on a cloud of charged particles. The particles are resultantly accelerated to within an infinitesimal fr... A force with an acceleration that is equal to multiples greater than the speed of light per unit time is exerted on a cloud of charged particles. The particles are resultantly accelerated to within an infinitesimal fraction of the speed of light. As the force or acceleration increases, the particles’ velocity asymptotically approaches but never achieves the speed of light obeying relativity. The asymptotic increase in the particles’ velocity toward the speed of light as acceleration increasingly surpasses the speed of light per unit time does not compensate for the momentum value produced on the particles at sub-light velocities. Hence, the particles’ inertial mass value must increase as acceleration increases. This increase in the particles’ inertial mass as the particles are accelerated produce a gravitational field which is believed to occur in the oscillation of quarks achieving velocities close to the speed of light. The increased inertial mass of the density of accelerated charged particles becomes the source mass (or Big “M”) in Newton’s equation for gravitational force. This implies that a space-time curve is generated by the accelerated particles. Thus, it is shown that the acceleration number (or multiple of the speed of light greater than 1 per unit of time) and the number of charged particles in the cloud density are surjectively mapped to points on a differential manifold or space-time curved surface. Two aspects of Einstein’s field equations are used to describe the correspondence between the gravitational field produced by the accelerated particles and the resultant space-time curve. The two aspects are the Schwarzchild metric and the stress energy tensor. Lastly, the possibility of producing a sufficient acceleration or electromagnetic force on the charged particles to produce a gravitational field is shown through the Lorentz force equation. Moreover, it is shown that a sufficient voltage can be generated to produce an acceleration/force on the particles that is multiples greater than the speed of light per unit time thereby generating gravity. 展开更多
关键词 Charged Particles Accelerated Particles Inertial Mass Gravitational Force Einstein’s field Equations space-time Manifold Schwardchild Metric Stress Energy Tensor Surjective Mapping Lorentz Force
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时空矢量场下人群活动聚散模式提取与分析
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作者 李静 刘海砚 +3 位作者 李佳 陶泽坤 刘俊楠 叶林 《测绘工程》 2024年第3期1-13,25,共14页
由于传统方法缺乏顾及人群在区域间的动态流动而无法反映人群在未来(下一时刻)的活动聚散趋势,因此,文中借助时空矢量场来建模人群活动的趋向性,通过矢量场理论中的散度算子来定量计算人群活动聚散强度,将人群活动聚散模式提取问题转化... 由于传统方法缺乏顾及人群在区域间的动态流动而无法反映人群在未来(下一时刻)的活动聚散趋势,因此,文中借助时空矢量场来建模人群活动的趋向性,通过矢量场理论中的散度算子来定量计算人群活动聚散强度,将人群活动聚散模式提取问题转化为时间序列聚类问题识别出主要聚散模式。在海口市滴滴出行数据集上进行实验,选取角度偏态系数证明了主体方向计算方法的有效性,提取出了4种主要人群活动聚散模式,并结合POI类型的分布情况对4种模式进行了语义解释,为探索人类移动性提供研究思路和方法支持。 展开更多
关键词 人群活动 主体方向 矢量场 聚散模式 散度
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空间科学实验数据可视化分析系统技术研究
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作者 于海军 杨梦博 李盛阳 《载人航天》 CSCD 北大核心 2024年第3期328-336,共9页
为提升空间科学实验数据的分析效率与利用水平,设计以数据可视化为切入点,支持多领域、长周期空间科学实验数据交互分析的系统架构,对系统关键技术进行研究。设计分析算法动态扩展和服务映射流程,支持数据分析算法的扩展与更新,建立算... 为提升空间科学实验数据的分析效率与利用水平,设计以数据可视化为切入点,支持多领域、长周期空间科学实验数据交互分析的系统架构,对系统关键技术进行研究。设计分析算法动态扩展和服务映射流程,支持数据分析算法的扩展与更新,建立算法的快速处理模式和复杂分析模式,兼容与支持不同类型分析算法的处理流程。通过多可视化组件之间的数据联动,直观且同步呈现相关联数据之间的相关性。采用可视化视图交互调整和布局,支持不同数据、不同显示屏幕的个性可视化需求。系统应用表明:系统已集成了十余种空间科学实验数据分析算法,实现了多领域空间科学实验数据的可视化分析。 展开更多
关键词 可视化分析 空间科学 多领域 人机交互 系统架构
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地面高精度磁法测量在青海某区地质矿产调查中的应用
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作者 刘仕刚 陈向平 +3 位作者 袁霆 刘钧沅 王铎道 刘高杰 《矿产勘查》 2024年第5期827-836,共10页
为综合研究青海某区成矿远景和找矿潜力,本文通过对该区1∶5万地面高精度磁法测量数据资料进行一系列位场转换处理,分析全区磁场分布规律和异常信息特征,结合地质背景、岩石磁性特征和化探水系沉积物测量等资料着重对M1异常进行解释推断... 为综合研究青海某区成矿远景和找矿潜力,本文通过对该区1∶5万地面高精度磁法测量数据资料进行一系列位场转换处理,分析全区磁场分布规律和异常信息特征,结合地质背景、岩石磁性特征和化探水系沉积物测量等资料着重对M1异常进行解释推断,圈定1处与基性—超基性岩关系密切的铜钴镍多金属A类找矿靶区,采用2.5D人机交互反演,拟合出异常体埋深、形态等赋存情况。本研究建立的与基性—超基性岩带有关的铜钴多金属矿的找矿模型,为邻区甚至布青山—阿尼玛卿构造带区域内的找矿工作提供借鉴经验。 展开更多
关键词 地面高精度磁法 位场转换 2.5D人机交互反演 阿尼玛卿构造带
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微电场对人脐带间充质干细胞增殖和成骨分化的影响 被引量:1
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作者 刘中 李克威 +5 位作者 王敏 刘文惠 张蕾蕾 郭松 钱晖 付强 《中国组织工程研究》 CAS 北大核心 2024年第13期1983-1988,共6页
背景:电刺激是一种可用于诱导细胞增殖、分化、凋亡等各种细胞活动的物理方法,诱导干细胞成骨分化将有利于骨的再生。目的:观察微电场是否可以促进人脐带间充质干细胞的增殖与成骨分化。方法:从人新鲜脐带组织获取脐带间充质干细胞,待... 背景:电刺激是一种可用于诱导细胞增殖、分化、凋亡等各种细胞活动的物理方法,诱导干细胞成骨分化将有利于骨的再生。目的:观察微电场是否可以促进人脐带间充质干细胞的增殖与成骨分化。方法:从人新鲜脐带组织获取脐带间充质干细胞,待细胞培养传代至第3代接种于6孔板内,24 h后分别给予0,50,100 mV/mm微电场刺激,刺激频率为每天1 h,连续刺激3 d,然后用显微镜观察细胞生长情况与形态变化,CCK-8和EdU染色法检测细胞的增殖情况,茜素红染色检测细胞的成骨分化能力,Western blot检测ERK通路蛋白的表达水平。结果与结论:①50,100 mV/mm组人脐带间充质干细胞的吸光度值和增殖细胞数目显著高于未刺激组(P<0.05);②微电场刺激前后人脐带间充质干细胞均能诱导分化为骨细胞,但50,100 mV/mm组的成骨分化速度比未刺激组快;③50,100 mV/mm组的p-ERK1/2蛋白表达高于未刺激组,且100 mV/mm组与未刺激组比较差异有显著性意义(P<0.05);④微电场促进人脐带间充质干细胞增殖的机制可能是通过促进ERK的磷酸化实现的。 展开更多
关键词 微电场 细胞增殖 人脐带间充质干细胞 细胞分化
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基于条件随机场挖掘文本史料中事件信息的方法与实证研究——以《拉贝日记》数字人文研究为例 被引量:1
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作者 赵小萱 陈刚 黄紫荆 《图书馆杂志》 北大核心 2024年第3期101-108,115,共9页
文本史料被广泛数字化,如何从文本中提取地理命名实体及相关信息,有效开展地理信息挖掘成为重要研究课题。本文针对历史档案文档的特点,提出一种以地理命名实体为核心,使语义信息与地理位置关联,将文本描述的事件信息转化为各个地理命... 文本史料被广泛数字化,如何从文本中提取地理命名实体及相关信息,有效开展地理信息挖掘成为重要研究课题。本文针对历史档案文档的特点,提出一种以地理命名实体为核心,使语义信息与地理位置关联,将文本描述的事件信息转化为各个地理命名实体的属性数据的事件抽取理念,提取出有关时间、地点、人物、事物、事件、现象等与地理命名实体相关的事件要素。研究以《拉贝日记》中收录的《日本士兵在南京安全区的暴行》档案为实证案例,采用条件随机场方法,抽取事件信息,结合历史地图等相关资料,将地理信息最终映射到地图上。本文方法有助于拓展文本资料在数字信息时代的开发利用方式,开辟文本挖掘分析与知识发现的新思路。 展开更多
关键词 条件随机场 特征模板 数字人文 信息提取 地理命名实体
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中国医学人文学科社会应用领域现状研究
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作者 吴亚楠 何仲 +1 位作者 刘欢 王锦帆 《中国医学伦理学》 北大核心 2024年第5期592-602,共11页
目的明晰中国医学人文学科社会应用领域现状及其态势,挖掘学科间领域贡献与特征,为完善学科研究体系以及形成学科合力提供参考。方法利用可视化软件CiteSpace对中国知网、万方和维普三大数据库收录的2010—2022年医学人文学科社会应用... 目的明晰中国医学人文学科社会应用领域现状及其态势,挖掘学科间领域贡献与特征,为完善学科研究体系以及形成学科合力提供参考。方法利用可视化软件CiteSpace对中国知网、万方和维普三大数据库收录的2010—2022年医学人文学科社会应用类期刊论文进行关键词聚类,参照当代大学功能划归聚类。归纳当前中国医学人文学科社会应用领域,展开整体性分析。结果当前中国医学人文学科社会应用领域分别为医学人文教育教学、学科专业建设、学科思想学术研究、医学科研工作应用、医疗健康服务与安全管理、医患关系与纠纷处理、中医文化与人文精神、适应国家战略发展理念等八个领域。结论中国医学人文学科在社会应用领域中存在发展不均倾向;其社会应用领域分布总体呈“人文教育强-学术科研强-医疗安全强-文化理念弱”的态势;医学人文教育教学是中国医学人文学科社会应用的共同着力点。 展开更多
关键词 医学人文学科 社会应用 领域分布 发展态势 文献计量学
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STABC-IR:An air target intention recognition method based on bidirectional gated recurrent unit and conditional random field with space-time attention mechanism 被引量:8
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作者 Siyuan WANG Gang WANG +3 位作者 Qiang FU Yafei SONG Jiayi LIU Sheng HE 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第3期316-334,共19页
The battlefield environment is changing rapidly,and fast and accurate identification of the tactical intention of enemy targets is an important condition for gaining a decision-making advantage.The current Intention R... The battlefield environment is changing rapidly,and fast and accurate identification of the tactical intention of enemy targets is an important condition for gaining a decision-making advantage.The current Intention Recognition(IR)method for air targets has shortcomings in temporality,interpretability and back-and-forth dependency of intentions.To address these problems,this paper designs a novel air target intention recognition method named STABC-IR,which is based on Bidirectional Gated Recurrent Unit(Bi GRU)and Conditional Random Field(CRF)with Space-Time Attention mechanism(STA).First,the problem of intention recognition of air targets is described and analyzed in detail.Then,a temporal network based on Bi GRU is constructed to achieve the temporal requirement.Subsequently,STA is proposed to focus on the key parts of the features and timing information to meet certain interpretability requirements while strengthening the timing requirements.Finally,an intention transformation network based on CRF is proposed to solve the back-and-forth dependency and transformation problem by jointly modeling the tactical intention of the target at each moment.The experimental results show that the recognition accuracy of the jointly trained STABC-IR model can reach 95.7%,which is higher than other latest intention recognition methods.STABC-IR solves the problem of intention transformation for the first time and considers both temporality and interpretability,which is important for improving the tactical intention recognition capability and has reference value for the construction of command and control auxiliary decision-making system. 展开更多
关键词 Bidirectional gated recurrent network Conditional random field Intention recognition Intention transformation Situation cognition space-time attention mechanism
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磁场对血红蛋白氧合速率的影响
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作者 刘颜 方彦雯 +1 位作者 张欣 谢灿 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2024年第9期2210-2221,共12页
目的血红蛋白是高等动物体内运输氧气的载体蛋白,本工作拟探究磁场对血红蛋白氧合的影响,并比较人和牦牛血红蛋白在磁场下氧合的差异。方法构建人和牦牛血红蛋白的重组表达纯化系统;分别将人和牦牛脱氧血红蛋白置于地磁场或外加磁场下,... 目的血红蛋白是高等动物体内运输氧气的载体蛋白,本工作拟探究磁场对血红蛋白氧合的影响,并比较人和牦牛血红蛋白在磁场下氧合的差异。方法构建人和牦牛血红蛋白的重组表达纯化系统;分别将人和牦牛脱氧血红蛋白置于地磁场或外加磁场下,通过收集紫外可见光谱数据,计算氧合血红蛋白、脱氧血红蛋白和高铁血红蛋白3种组分的浓度和比例,分析磁场对血红蛋白氧合速率的影响;使用超导量子干涉磁测量系统SQUID对人氧合血红蛋白和人脱氧血红蛋白进行磁性测量,探讨磁场影响血红蛋白氧合速率的可能机制。结果利用大肠杆菌原核表达系统成功表达并纯化得到了人和牦牛的血红蛋白样品。发现牦牛血红蛋白比人血红蛋白的氧合速率更快,外加0.3 T静磁场显著提高了血红蛋白的氧合速率,且牦牛血红蛋白比人血红蛋白对磁场更为敏感。结论本研究成功表达和纯化了人和牦牛血红蛋白,发现磁场促进了血红蛋白的氧合过程。磁场对血红蛋白氧合速率的影响可能与血红蛋白本身的磁学性质有关。这些发现为未来使用外加磁场作为辅助手段改善低氧症状提供了理论支撑,有望在临床中发挥作用。 展开更多
关键词 血红蛋白 磁场 人血红蛋白 牦牛血红蛋白 氧合速率
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Local field potentials,spiking activity,and receptive fields in human visual cortex
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作者 Lu Luo Xiongfei Wang +5 位作者 Junshi Lu Guanpeng Chen Guoming Luan Wu Li Qian Wang Fang Fang 《Science China(Life Sciences)》 SCIE CAS CSCD 2024年第3期543-554,共12页
The concept of receptive field(RF) is central to sensory neuroscience. Neuronal RF properties have been substantially studied in animals,while those in humans remain nearly unexplored. Here, we measured neuronal RFs w... The concept of receptive field(RF) is central to sensory neuroscience. Neuronal RF properties have been substantially studied in animals,while those in humans remain nearly unexplored. Here, we measured neuronal RFs with intracranial local field potentials(LFPs) and spiking activity in human visual cortex(V1/V2/V3). We recorded LFPs via macro-contacts and discovered that RF sizes estimated from lowfrequency activity(LFA, 0.5–30 Hz) were larger than those estimated from low-gamma activity(LGA, 30–60 Hz) and high-gamma activity(HGA, 60–150 Hz). We then took a rare opportunity to record LFPs and spiking activity via microwires in V1 simultaneously. We found that RF sizes and temporal profiles measured from LGA and HGA closely matched those from spiking activity. In sum, this study reveals that spiking activity of neurons in human visual cortex could be well approximated by LGA and HGA in RF estimation and temporal profile measurement, implying the pivotal functions of LGA and HGA in early visual information processing. 展开更多
关键词 human visual cortex receptive field intracranial EEG local field potential spiking activity
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