Frontiers of Physics最新文献_第10页

Design and realization of a 3-K cryostat for a 10-cm ultrastable silicon cavity 10cm超稳定硅腔3-K低温恒温器的设计与实现

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-22 DOI: 10.3389/fphy.2023.1176783

Wen-Wei Wang, Zhi-Ang Chen, Han Zhang, Shize Du, Ruixuan Wu, Chang Qiao, Shiyin Kuang, Xibo Zhang

{"title":"Design and realization of a 3-K cryostat for a 10-cm ultrastable silicon cavity","authors":"Wen-Wei Wang, Zhi-Ang Chen, Han Zhang, Shize Du, Ruixuan Wu, Chang Qiao, Shiyin Kuang, Xibo Zhang","doi":"10.3389/fphy.2023.1176783","DOIUrl":"https://doi.org/10.3389/fphy.2023.1176783","url":null,"abstract":"Crystalline optical cavities operating at cryogenic temperatures provide a promising route for realizing the next generation of ultrastable lasers with extremely low thermal noise floor. However, it remains challenging to realize a closed-cycle cryostat for cooling a relatively long cavity to very low temperatures. Here we report on the design and experimental realization of a cryostat operating continuously at 3.1 K for an ultrastable 10-cm silicon cavity. Based on a combination of active temperature control and passive thermal damping, we realize at 3.1 K a two-second temperature instability of 6 × 10−8 K for the cavity. By implementing separate supporting structures for the cryocooler and the sample chamber, we realize vibration control on the 1 × 10−7 g level at one second in each spatial direction, where g is the gravitational acceleration. With all these features, our cryostat can support an ultrastable silicon cavity with instability near its fundamental thermal noise floor at averaging time of 1–50 s. With proper upgrading, our platform holds promise for realizing ultrastable lasers with 3 × 10−17 or better frequency stability, which will in turn enable numerous studies on precision metrology and quantum many-body physics.","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":" ","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42338963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Machine learning transforms the inference of the nuclear equation of state 机器学习对核状态方程的推理进行了转换

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-22 DOI: 10.1007/s11467-023-1313-3

Yongjia Wang, Qingfeng Li

引用次数: 3

Correlation, superconductivity and topology in graphene moiré superlattice 石墨烯超晶格的相关、超导性和拓扑结构

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-22 DOI: 10.1007/s11467-023-1302-6

Lingxiao Li, Min Wu, Xiaobo Lu

引用次数: 0

Superconducting undulator activities at the European X-ray Free-Electron Laser Facility 欧洲x射线自由电子激光设备的超导波动活动

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-22 DOI: 10.3389/fphy.2023.1204073

S. Casalbuoni, S. Abeghyan, Levon Alanakyan, J. Baader, S. Barbanotti, W. Decking, M. D. Felice, H. Eckoldt, U. Englisch, G. Geloni, V. Grattoni, A. Grau, A. Hauberg, Christian Helwich, A. Hobl, K. Jensch, S. Karabekyan, D. Civita, S. Lederer, C. Lechner, L. Lilje, Shan Liu, B. Marchetti, A. Potter, T. Schnautz, E. Schneidmiller, H. Sinn, W. Walter, R. Wichmann, T. Wohlenberg, G. Yakopov, M. Yakopov, I. Zagorodnov, René Zimmermann, P. Ziółkowski

{"title":"Superconducting undulator activities at the European X-ray Free-Electron Laser Facility","authors":"S. Casalbuoni, S. Abeghyan, Levon Alanakyan, J. Baader, S. Barbanotti, W. Decking, M. D. Felice, H. Eckoldt, U. Englisch, G. Geloni, V. Grattoni, A. Grau, A. Hauberg, Christian Helwich, A. Hobl, K. Jensch, S. Karabekyan, D. Civita, S. Lederer, C. Lechner, L. Lilje, Shan Liu, B. Marchetti, A. Potter, T. Schnautz, E. Schneidmiller, H. Sinn, W. Walter, R. Wichmann, T. Wohlenberg, G. Yakopov, M. Yakopov, I. Zagorodnov, René Zimmermann, P. Ziółkowski","doi":"10.3389/fphy.2023.1204073","DOIUrl":"https://doi.org/10.3389/fphy.2023.1204073","url":null,"abstract":"For more than 5 years, superconducting undulators (SCUs) have been successfully delivering X-rays in storage rings. The European X-Ray Free-Electron Laser Facility (XFEL) plans to demonstrate the operation of SCUs in X-ray free-electron lasers (FELs). For the same geometry, SCUs can reach a higher peak field on the axis with respect to all other available technologies, offering a larger photon energy tunability range. The application of short-period SCUs in a high electron beam energy FEL > 11 GeV will enable lasing at very hard X-rays > 40 keV. The large tunability range of SCUs will allow covering the complete photon energy range of the soft X-ray experiments at the European XFEL without changing electron beam energy, as currently needed with the installed permanent magnet undulators. For a possible continuous-wave (CW) upgrade under discussion at the European XFEL with a lower electron beam energy of approximately 7–8 GeV, SCUs can provide the same photon energy range as available at present with the permanent magnet undulators and electron energies. This paper will describe the potential of SCUs for X-ray FELs. In particular, it will focus on the different activities ongoing at the European XFEL and in collaboration with DESY to allow the implementation of SCUs in the European XFEL in the upcoming years.","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":" ","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43688322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Flat band localization due to self-localized orbital 自定域轨道平带定位

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-21 DOI: 10.1007/s11467-023-1306-2

Zhen Ma, Wei-Jin Chen, Yuntian Chen, Jin-Hua Gao, X. C. Xie

{"title":"Flat band localization due to self-localized orbital","authors":"Zhen Ma, Wei-Jin Chen, Yuntian Chen, Jin-Hua Gao, X. C. Xie","doi":"10.1007/s11467-023-1306-2","DOIUrl":"10.1007/s11467-023-1306-2","url":null,"abstract":"<div><p>We discover a new wave localization mechanism in a periodic wave system, which can produce a novel type of flat band and is distinct from the known localization mechanisms, i.e., Anderson localization and flat band lattices. The first example we give is a designed electron waveguide (EWG) on 2DEG with special periodic confinement potential. Numerical calculations show that, with proper confinement geometry, electrons can be completely localized in an open waveguide. We interpret this flat band localization (FBL) phenomenon by introducing the concept of self-localized orbitals. Essentially, each unit cell of the waveguide is equivalent to an artificial atom, where the self-localized orbital is a special eigenstate with unique spatial distribution. These self-localized orbitals form the flat bands in the waveguide. Such self-localized orbital induced FBL is a general phenomenon of wave motion, which can arise in any wave systems with carefully engineered boundary conditions. We then design a metallic waveguide (MWG) array to illustrate that similar FBL can be readily realized and observed with electromagnetic waves.\u0000</p><figure><div><div><div><picture><source><img></source></picture></div></div></div></figure></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"18 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4827518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Feedforward resonance control for the European X-ray free electron laser high duty cycle upgrade 欧洲x射线自由电子激光器高占空比升级的前馈共振控制

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-21 DOI: 10.3389/fphy.2023.1170175

A. Bellandi, J. Branlard, H. Schlarb, C. Schmidt

引用次数: 0

Multi-band polarization imaging and image processing in sea fog environment 海雾环境下的多波段偏振成像与图像处理

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-21 DOI: 10.3389/fphy.2023.1221472

N. Liu, Qiankun Fu, Hongrui Guo, Longxiao Wang, Yang Tai, Yi Liu, Zhuang Liu, Haodong Shi, Juntong Zhan, Su Zhang, Jiazhuo Liu

{"title":"Multi-band polarization imaging and image processing in sea fog environment","authors":"N. Liu, Qiankun Fu, Hongrui Guo, Longxiao Wang, Yang Tai, Yi Liu, Zhuang Liu, Haodong Shi, Juntong Zhan, Su Zhang, Jiazhuo Liu","doi":"10.3389/fphy.2023.1221472","DOIUrl":"https://doi.org/10.3389/fphy.2023.1221472","url":null,"abstract":"Considering the advancement in marine research in recent years, studies on the identification of offshore scenery are becoming popular globally. In this study, multiband polarimetric imaging is presented to address the deficiencies of the previous single-band study. Polarization imaging experiments of sea fog and non-sea fog in an indoor simulated environment are carried out and compared and analyzed by establishing an artificial simulation system to characterize the sea fog concentration by optical thickness with different concentrations of sea fog environment as the medium. The polarization information of each waveband converted by Stokes parametric is then brought into the two-dimensional discrete wavelet algorithm for image fusion processing. The findings indicate that when the optical thickness of sea fog increases, the polarized light in the chaotic medium recedes and the effect of the image blurs. Finally, after the image fusion process, the contrast of the image is improved and the detail of the target contour is obvious, which proves that the method has good robustness under the low signal-to-noise ratio of the sea fog environment. This provides a solid platform for targeted surveys and civic operations under dense marine fog conditions.","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":" ","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47889833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Combination of deep learning with representation learning in X-ray prohibited item detection X射线违禁品检测中深度学习与表征学习的结合

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-21 DOI: 10.3389/fphy.2023.1174220

Jianghao Rao, Penglin Qin, Gaofan Zhou, Meihui Li, Jianlin Zhang, Q. Bao, Zhenming Peng

{"title":"Combination of deep learning with representation learning in X-ray prohibited item detection","authors":"Jianghao Rao, Penglin Qin, Gaofan Zhou, Meihui Li, Jianlin Zhang, Q. Bao, Zhenming Peng","doi":"10.3389/fphy.2023.1174220","DOIUrl":"https://doi.org/10.3389/fphy.2023.1174220","url":null,"abstract":"During X-ray inspection detection, a detector converts the collected X-rays from objects into electrical signals, which are then transmitted to a computer for image processing and analysis. From the aspect of digital image processing, detection tasks mainly focus on data processing and transformation to identify valuable features, which make the algorithms more effective. The consistent requirement for speed and accuracy in X-ray prohibited item detection is still not fully satisfied, especially in pictures obtained under special imaging conditions. For noisy X-ray images with heavy occlusion, a direct and suitable approach of representation learning is the optimal solution. According to our study, we realized that heterogeneous information fusion from different extraction approaches can be applied effectively to overcome this issue. We proposed two innovative algorithms to extract effective features of X-ray objects to significantly improve the efficiency of X-ray prohibited item detection. The brief model we proposed fuses the representations learned from the noisy X-ray images and outperforms the best model (DOAM-O) so far on OPIXray. Furthermore, the attention module we designed to select information on deep learning and representation strengthens the model; considering this, the model utilizes lesser time for both training and inference, which makes it easier to be trained on a lightweight computing device.","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":" ","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46230817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Configuration of the active region for the Ge-on-Si photodetector based on carrier mobility 基于载流子迁移率的锗硅光电探测器有源区的结构

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-20 DOI: 10.3389/fphy.2023.1150684

Chan-Hsiang Chang, Xiaohui Xie, Tiantian Li, Jishi Cui

引用次数: 1

Hybrid weighted communication network node importance evaluation method 混合加权通信网络节点重要性评价方法

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-06-19 DOI: 10.3389/fphy.2023.1133250

Gan Tian, Xinzhi Yang, Yaxiong Li, Zhengwei Yang, Gong Chen

{"title":"Hybrid weighted communication network node importance evaluation method","authors":"Gan Tian, Xinzhi Yang, Yaxiong Li, Zhengwei Yang, Gong Chen","doi":"10.3389/fphy.2023.1133250","DOIUrl":"https://doi.org/10.3389/fphy.2023.1133250","url":null,"abstract":"Communication networks are used as an important guarantee for information interaction and efficient collaboration within many fields and systems; however, under information technology conditions, the destruction of a number of nodes in a network may have a great impact on the overall operation of the network. Therefore, it is important to accurately determine the critical nodes in the network to enhance the network’s resistance to destruction. Combining the characteristic attributes of the communication network, a node contribution evaluation matrix is proposed based on the efficiency matrix, from the perspective of node receiving information; a node value evaluation matrix is proposed from the perspective of a node providing information to neighboring nodes, and node importance is calculated by integrating the evaluation results of the two matrices and the node’s own attributes. The algorithm is suitable for directed-weighted network node value evaluation, and the effectiveness and accuracy of the algorithm are verified by comparing other algorithms for a small-scale network. In further experimental validation, a hybrid weighted communication network evolution model based on organizational structured networks is proposed, and networks of different sizes are generated for experimental simulation. The results show that when nodes with high importance are removed from the network, they can cause a rapid decrease in the network efficiency and maximum connectivity, confirming the accuracy of the algorithm in evaluating the importance of nodes and identifying critical nodes in the network.","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":" ","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44773779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0