Frontiers of Physics in China最新文献

Dynamics of the Fluctuating Flying Chain 波动飞链动力学

Frontiers of Physics in China Pub Date : 2019-11-19 DOI: 10.3389/fphy.2019.00187

E. Flekkøy, M. Moura, K. Måløy

引用次数: 3

Keller-Box Scheme for Casson Nanofluid Flow over Nonlinear Inclined Surface with Soret and Dufour Effects 考虑Soret和Dufour效应的卡森纳米流体在非线性倾斜表面上流动的Keller-Box格式

Frontiers of Physics in China Pub Date : 2019-10-11 DOI: 10.3389/FPHY.2019.00139

K. Rafique, M. Anwar, M. Misiran, I. Khan, S. Alharbi, P. Thounthong, K. Nisar

引用次数: 20

Editorial: Proceedings of the International School on Magnetic Resonance and Brain Function – XII Workshop 社论：国际磁共振与脑功能学院论文集-第十二期工作坊

Frontiers of Physics in China Pub Date : 2018-03-06 DOI: 10.3389/fphy.2018.00018

F. Giove, I. Ronen

引用次数: 0

Editorial: Applications of Quantum Mechanical Techniques to Areas Outside of Quantum Mechanics 社论:量子力学技术在量子力学以外领域的应用

Frontiers of Physics in China Pub Date : 2017-11-24 DOI: 10.3389/FPHY.2017.00060

E. Haven, A. Khrennikov

引用次数: 4

Corrigendum: Ultra-High Field NMR and MRI–The Role of Magnet Technology to Increase Sensitivity and Specificity 勘误:超高场核磁共振和核磁共振-磁铁技术的作用，以提高灵敏度和特异性

Frontiers of Physics in China Pub Date : 2017-09-12 DOI: 10.3389/fphy.2017.00041

E. Moser, E. Laistler, F. Schmitt, G. Kontaxis

引用次数: 6

Analysis of an Integrated 8-Channel Tx/Rx Body Array for Use as a Body Coil in 7-Tesla MRI 集成8通道Tx/Rx体阵列在7特斯拉MRI中用作体线圈的分析

Frontiers of Physics in China Pub Date : 2017-06-07 DOI: 10.3389/fphy.2017.00017

S. Orzada, A. Bitz, S. Johst, M. Gratz, Maximilian N. Völker, O. Kraff, A. Abuelhaija, Thomas M. Fiedler, K. Solbach, H. Quick, M. Ladd

{"title":"Analysis of an Integrated 8-Channel Tx/Rx Body Array for Use as a Body Coil in 7-Tesla MRI","authors":"S. Orzada, A. Bitz, S. Johst, M. Gratz, Maximilian N. Völker, O. Kraff, A. Abuelhaija, Thomas M. Fiedler, K. Solbach, H. Quick, M. Ladd","doi":"10.3389/fphy.2017.00017","DOIUrl":"https://doi.org/10.3389/fphy.2017.00017","url":null,"abstract":"Object In this work an 8-channel array integrated into the gap between the gradient coil and bore liner of a 7-Tesla whole-body magnet is presented that would allow a workflow closer to that of systems at lower magnetic fields that have a built-in body coil; this integrated coil is compared to a local 8-channel array built from identical elements placed directly on the patient. Materials and Methods SAR efficiency and the homogeneity of the right-rotating B1 field component (B_1^+) are investigated numerically and compared to the local array. Power efficiency measurements are performed in the MRI System. First in vivo gradient echo images are acquired with the integrated array. Results While the remote array shows a slightly better performance in terms of B_1^+ homogeneity, the power efficiency and the SAR efficiency are inferior to those of the local array: the transmit voltage has to be increased by a factor of 3.15 to achieve equal flip angles in a central axial slice. The g-factor calculations show a better parallel imaging g-factor for the local array. The field of view of the integrated array is larger than that of the local array. First in vivo images with the integrated array look subjectively promising. Conclusion Although some RF performance parameters of the integrated array are inferior to a tight-fitting local array, these disadvantages might be compensated by the use of amplifiers with higher power and the use of local receive arrays. In addition, the distant placement provides the potential to include more elements in the array design.","PeriodicalId":49264,"journal":{"name":"Frontiers of Physics in China","volume":"5 1","pages":"17"},"PeriodicalIF":0.0,"publicationDate":"2017-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3389/fphy.2017.00017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45840165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Time As a Geometric Property of Space 时间作为空间的几何性质

Frontiers of Physics in China Pub Date : 2016-11-17 DOI: 10.3389/fphy.2016.00044

J. M. Chappell, J. Hartnett, Nicolangelo Iannella, A. Iqbal, D. Abbott

{"title":"Time As a Geometric Property of Space","authors":"J. M. Chappell, J. Hartnett, Nicolangelo Iannella, A. Iqbal, D. Abbott","doi":"10.3389/fphy.2016.00044","DOIUrl":"https://doi.org/10.3389/fphy.2016.00044","url":null,"abstract":"The proper description of time remains a key unsolved problem in science. Newton conceived of time as absolute and universal which {it `flows equably without relation to anything external'}. In the nineteenth century, the four-dimensional algebraic structure of the quaternions developed by Hamilton, inspired him to suggest that they could provide a unified representation of space and time. With the publishing of Einstein's theory of special relativity these ideas then lead to the generally accepted Minkowski spacetime formulation in 1908. Minkowski, though, rejected the formalism of quaternions suggested by Hamilton and adopted rather an approach using four-vectors. The Minkowski framework is indeed found to provide a versatile formalism for describing the relationship between space and time in accordance with Einstein's relativistic principles, but nevertheless fails to provide more fundamental insights into the nature of time itself. In order to answer this question we begin by exploring the geometric properties of three-dimensional space that we model using Clifford geometric algebra, which is found to contain sufficient complexity to provide a natural description of spacetime. This description using Clifford algebra is found to provide a natural alternative to the Minkowski formulation as well as providing new insights into the nature of time. Our main result is that time is the scalar component of a Clifford space and can be viewed as an intrinsic geometric property of three-dimensional space without the need for the specific addition of a fourth dimension.","PeriodicalId":49264,"journal":{"name":"Frontiers of Physics in China","volume":"4 1","pages":"44"},"PeriodicalIF":0.0,"publicationDate":"2016-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3389/fphy.2016.00044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69647688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Fundamental Fermion Interactions via Vector Bosons of Unified SU(2)⊗SU(4) Gauge Fields 统一SU(2)⊗SU(4)规范场中矢量玻色子的基本费米子相互作用

Frontiers of Physics in China Pub Date : 2016-02-26 DOI: 10.3389/fphy.2016.00005

E. Marsch, Y. Narita

{"title":"Fundamental Fermion Interactions via Vector Bosons of Unified SU(2)⊗SU(4) Gauge Fields","authors":"E. Marsch, Y. Narita","doi":"10.3389/fphy.2016.00005","DOIUrl":"https://doi.org/10.3389/fphy.2016.00005","url":null,"abstract":"Employing the fermion unification model based on the intrinsic SU(8) symmetry of a generalized Dirac equation, we discuss the fundamental interactions under the SU(8)=SU(2)$otimes$SU(4) symmetry group. The physics involved can describe all fermions, the leptons (electron and neutrino), and the coloured up and down quarks of the first generation in the standard model (SM) by a complex SU(8) octet of Dirac spinor fields. The fermion interactions are found to be mediated by the unified SU(4) and SU(2) vector gauge boson fields, which include the photon, the gluons, and the bosons $Z$ and $W$ as well known from the SM, but also comprise new ones, namely three coloured $X$ bosons carrying a fractional hypercharge of $pm4/3$ and transmuting leptons into quarks and vice versa. The full covariant derivative of the model is derived and discussed. The Higgs mechanism gives mass to the $Z$ and $W$ bosons, but also permits one to derive the mass of the coloured $X$ boson, for which depending on the choice of the values of the coupling constant, the estimates are 35~GeV or 156~GeV, values that are well within reach of the LHC. The scalar Higgs field can also lend masses to the fermions and fix their physical values for given appropriate coupling constants to that field.","PeriodicalId":49264,"journal":{"name":"Frontiers of Physics in China","volume":"4 1","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2016-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3389/fphy.2016.00005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69647595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Apparent Exchange Rate and Isotropic and Anisotropic Kurtosis in Meningioma and Glioma Tumors 脑膜瘤和胶质瘤的表观交换率、各向同性和各向异性峰度

Frontiers of Physics in China Pub Date : 2016-01-01 DOI: 10.3389/CONF.FPHY.2016.01.00004

S. Filip, Lampinen Bjrn, Nilsson Markus

引用次数: 0

Towards Optimal dMRI Sequence Sets 优化dMRI序列集

Frontiers of Physics in China Pub Date : 2016-01-01 DOI: 10.3389/CONF.FPHY.2016.01.00019

Knutsson Hans

引用次数: 0