Filters








106,460 Hits in 3.4 sec

Synthetic 𝒫𝒯 Symmetry and Nonreciprocal Amplification in Optomechanics [article]

Jian-Qi Zhang, Jing-Xin Liu, Hui-Lai Zhang, Zhi-Rui Gong, Shuo Zhang, Lei-Lei Yan, Shi-Lei Su, Hui Jing, Mang Feng
2021 arXiv   pre-print
We propose how to achieve synthetic 𝒫𝒯 symmetry in optomechanics without using any active medium. We find that harnessing the Stokes process in such a system can lead to the emergence of exceptional point (EP), i.e., the coalescing of both the eigenvalues and the eigenvectors of the system. By encircling the EP,non-reciprocal optical amplification and chiral mode switching can be achieved. This provides a surprisingly simplified route to realize 𝒫𝒯-symmetric optomechanics, indicating that a
more » ... range of EP devices can be created and utilized for various applications such as topological optical engineering and nanomechanical processing or sensing.
arXiv:2107.10421v1 fatcat:l33f7b75irdmdnynveay3tvcki

Pure temporal dispersion for aberration free ultrafast time-stretch applications [article]

Liao Chen, Xin Dong, Ningning Yang, Lei Zhang, Xi Zhou, Zihui Lei, Chi Zhang, Xinliang Zhang
2019 arXiv   pre-print
Lei, and the time-stretch OCT was co-developed by L. Zhang. C. Zhang and X. Zhang developed the concept and supervised measurements and analysis.  ...  Zhang, Xi Zhou, Zihui Lei, Chi Zhang, * and Xinliang Zhang ** Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China *chizheung@hust.edu.cn;  ...  the slow scanning (5 Hz) OSA with 0.05-nm resolution. 27 Supplementary information Pure temporal dispersion for aberration free ultrafast time-stretch applications Liao Chen, Xin Dong, Ningning Yang, Lei  ... 
arXiv:1903.06030v1 fatcat:wdoshzti3rdxbh34nlhqnjvaea

Water Temperature at Different Depths Affects the Distribution of Neon Flying Squid (Ommastrephes bartramii) in the Northwest Pacific Ocean

Jintao Wang, Jintao Wang, Jintao Wang, Jintao Wang, Jintao Wang, Yiqi Cheng, Huajie Lu, Huajie Lu, Huajie Lu, Huajie Lu, Huajie Lu, Xinjun Chen (+14 others)
2022 Frontiers in Marine Science  
Ommastrephes bartramii can vertically swim during its life, and previous studies have suggested the need to account for preferred habitat distribution influenced by water temperatures at different depths. To explore the impacts of deep-water temperature on O. bartramii spatial distribution, we constructed generalized additive models (GAMs) based on the Chinese squid-jigging fishery data and the Argo deep water temperature data during 2005–2018 in the Northwest Pacific Ocean to analyze the
more » ... onships between the local abundance of O. bartramii and deep-water temperatures. The results showed that the variables including surface water temperature (T0), water temperature at 30- and 100-m depths (T30 and T100), and water differences between T0 and T30 (D0–30) significantly affected the spatial distribution of O. bartramii. The suitable ranges of each variable are different, > 15.5°C for T0, 11–18°C for T30, < 6°C for T100, and 4–4.5°C for D0–30. The areas occupied by the suitable T30 seemed to reflect the outline of fishing ground, whereas the areas with suitable T100 were to indicate the high density of O. bartramii. The predicted suitable habitat area and high-density area for O. bartramii are also regulated by El Niño–Southern Oscillation (ENSO) events. We demonstrated how the estimates of O. bartramii spatial distribution would vary influenced by deep-water temperatures in the Northwest Pacific Ocean. This information may help develop an appropriate method for investigating the effects of deep-water temperature on species with vertical migration.
doi:10.3389/fmars.2021.741620 doaj:08f3e13dd9724dbfabe3befe462e27aa fatcat:vyjxioxhwndyxmxulhh7py5wza

Symmetric illumination in Fourier ptychography

Zhang Lei-Lei, Tang Li-Jin, Zhang Mu-Yang, Liang Yan-Mei
2017 Wuli xuebao  
Zhang 等 [16] 基于 内容的自适应照明原理, 提出了自学习 FP 技术, 使 用低分辨率图像预测频谱信息最丰富的区域, 且仅 点亮这些区域所对应的 LED, 可以减少约 70% 的 低分辨率图像.  ... 
doi:10.7498/aps.66.224201 fatcat:77wzuyr65vdl3eai53nddqx5ry

Ferroptosis in cancer and cancer immunotherapy

Lei Zhao, Xiaoxue Zhou, Feng Xie, Lei Zhang, Haiyan Yan, Jun Huang, Chong Zhang, Fangfang Zhou, Jun Chen, Long Zhang
2022 Cancer Communications  
The hallmark of tumorigenesis is the successful circumvention of cell death regulation for achieving unlimited replication and immortality. Ferroptosis is a newly identified type of cell death dependent on lipid peroxidation which differs from classical programmed cell death in terms of morphology, physiology and biochemistry. The broad spectrum of injury and tumor tolerance are the main reasons for radiotherapy and chemotherapy failure. The effective rate of tumor immunotherapy as a new
more » ... nt method is less than 30%. Ferroptosis can be seen in radiotherapy, chemotherapy, and tumor immunotherapy; therefore, ferroptosis activation may be a potential strategy to overcome the drug resistance mechanism of traditional cancer treatments. In this review, the characteristics and causes of cell death by lipid peroxidation in ferroptosis are briefly described. In addition, the three metabolic regulations of ferroptosis and its crosstalk with classical signaling pathways are summarized. Collectively, these findings suggest the vital role of ferroptosis in immunotherapy based on the interaction of ferroptosis with tumor immunotherapy, chemotherapy and radiotherapy, thus, indicating the remarkable potential of ferroptosis in cancer treatment.
doi:10.1002/cac2.12250 pmid:35133083 pmcid:PMC8822596 fatcat:aibbputp7ffknbx5d4afsah7jq

Modeling And Validation Of Microspheres Generation In The Modified T-Junction Device

Lei Lei, Hongbo Zhang, Donald J. Bergstrom, Bing Zhang, K. Y. Song, W. J. Zhang
2015 Zenodo  
CONCLUSION Lei, Hongbo Zhang is with East China University of Science and Technology, Shanghai, 200237 China (e-mail: leileiearth@gmail.com, hbzhang@ecust.edu.cn). Donald J.  ...  Bing Zhang is with the Biomedical Engineering Division, University of Saskatchewan, Saskatoon, SK S7N5A9 Canada (e-mail: 080506zb@gmail.com).  ... 
doi:10.5281/zenodo.1100727 fatcat:oxbqaaquzng2bo4xwy5fx4wicq

Generalization Bounds for Domain Adaptation [article]

Chao Zhang, Lei Zhang, Jieping Ye
2013 arXiv   pre-print
In this paper, we provide a new framework to obtain the generalization bounds of the learning process for domain adaptation, and then apply the derived bounds to analyze the asymptotical convergence of the learning process. Without loss of generality, we consider two kinds of representative domain adaptation: one is with multiple sources and the other is combining source and target data. In particular, we use the integral probability metric to measure the difference between two domains. For
more » ... er kind of domain adaptation, we develop a related Hoeffding-type deviation inequality and a symmetrization inequality to achieve the corresponding generalization bound based on the uniform entropy number. We also generalized the classical McDiarmid's inequality to a more general setting where independent random variables can take values from different domains. By using this inequality, we then obtain generalization bounds based on the Rademacher complexity. Afterwards, we analyze the asymptotic convergence and the rate of convergence of the learning process for such kind of domain adaptation. Meanwhile, we discuss the factors that affect the asymptotic behavior of the learning process and the numerical experiments support our theoretical findings as well.
arXiv:1304.1574v1 fatcat:2o2tiftdynhmbm4k6lxbv6ye74

Molecular Investigation of Klebsiella pneumoniae from Clinical Companion Animals in Beijing, China, 2017–2019

Zhenbiao Zhang, Lei Lei, Haixia Zhang, Hegen Dai, Yu Song, Lei Li, Yang Wang, Zhaofei Xia
2021 Pathogens  
Acknowledgments: Thanks to Weiwei Zhang and Yue Wang for their help in collecting samples.  ... 
doi:10.3390/pathogens10030271 pmid:33673656 pmcid:PMC7997213 fatcat:cnq7xxo5vnelpnmhdrzo2bm2ga

2-(4-Aminophenyl)-1,3-benzoxazole

Yuan Qu, Shi-lei Zhang, Lei Teng, Xian-you Xia, Yong Zhang
2008 Acta Crystallographica Section E  
E64, o1210 [doi:10.1107/S160053680801653X] 2-(4-Aminophenyl)-1,3-benzoxazole Yuan Qu, Shi-lei Zhang, Lei Teng, Xian-you Xia and Yong Zhang S1.  ... 
doi:10.1107/s160053680801653x pmid:21202849 pmcid:PMC2961872 fatcat:nm5pm5om4fbnfi7q3637iyhxtm

Body Composition-Specific Asthma Phenotypes: Clinical Implications

Xin Zhang, Ke Deng, Yulai Yuan, Lei Liu, Shuwen Zhang, Changyong Wang, Gang Wang, Hongping Zhang, Lei Wang, Gaiping Cheng, Lisa G. Wood, Gang Wang
2022 Nutrients  
Previous studies have indicated the limitations of body mass index for defining disease phenotypes. The description of asthma phenotypes based on body composition (BC) has not been largely reported. Objective: To identify and characterize phenotypes based on BC parameters in patients with asthma. Methods: A study with two prospective observational cohorts analyzing adult patients with stable asthma (n = 541 for training and n = 179 for validation) was conducted. A body composition analysis was
more » ... erformed for the included patients. A cluster analysis was conducted by applying a 2-step process with stepwise discriminant analysis. Logistic regression models were used to evaluate the association between identified phenotypes and asthma exacerbations (AEs). The same algorithm for cluster analysis in the independent validation set was used to perform an external validation. Results: Three clusters had significantly different characteristics associated with asthma outcomes. An external validation identified the similarity of the participants in training and the validation set. In the training set, cluster Training (T) 1 (29.4%) was "patients with undernutrition", cluster T2 (18.9%) was "intermediate level of nutrition with psychological dysfunction", and cluster T3 (51.8%) was "patients with good nutrition". Cluster T3 had a decreased risk of moderate-to-severe and severe AEs in the following year compared with the other two clusters. The most important BC-specific factors contributing to being accurately assigned to one of these three clusters were skeletal muscle mass and visceral fat area. Conclusion: We defined three distinct clusters of asthma patients, which had distinct clinical features and asthma outcomes. Our data reinforced the importance of evaluating BC to determining nutritional status in clinical practice.
doi:10.3390/nu14122525 pmid:35745259 pmcid:PMC9229860 fatcat:p36fsvuaojcqpa7ifrdwypi6ja

Robust Time-Frequency Reconstruction by Learning Structured Sparsity [article]

Lei Jiang, Haijian Zhang, Lei Yu
2020 arXiv   pre-print
Time-frequency distributions (TFDs) play a vital role in providing descriptive analysis of non-stationary signals involved in realistic scenarios. It is well known that low time-frequency (TF) resolution and the emergency of cross-terms (CTs) are two main issues, which make it difficult to analyze and interpret practical signals using TFDs. In order to address these issues, we propose the U-Net aided iterative shrinkage-thresholding algorithm (U-ISTA) for reconstructing a near-ideal TFD by
more » ... iting structured sparsity in signal TF domain. Specifically, the signal ambiguity function is firstly compressed, followed by unfolding the ISTA as a recurrent neural network. To consider continuously distributed characteristics of signals, a structured sparsity constraint is incorporated into the unfolded ISTA by regarding the U-Net as an adaptive threshold block, in which structure-aware thresholds are learned from enormous training data to exploit the underlying dependencies among neighboring TF coefficients. The proposed U-ISTA model is trained by both non-overlapped and overlapped synthetic signals including closely and far located non-stationary components. Experimental results demonstrate that the robust U-ISTA achieves superior performance compared with state-of-the-art algorithms, and gains a high TF resolution with CTs greatly eliminated even in low signal-to-noise ratio (SNR) environments.
arXiv:2004.14820v1 fatcat:brzwry5r5zcrpdxaszxa7dgn4y

Decoherence-Suppressed Non-adiabatic Holonomic Quantum Computation [article]

Bao-Jie Liu, Lei-Lei Yan, Yuan Zhang, Man-Hong Yung, Erjun Liang, Shi-Lei Su, Chong-Xin Shan
2022 arXiv   pre-print
Nonadiabatic holonomic quantum computation~(NHQC) provides an essential way to construct robust and high-fidelity quantum gates due to its geometric features. However, NHQC is more sensitive to the decay and dephasing errors than conventional dynamical gate since it requires an ancillary intermediate state. Here, we utilize the Hamiltonian reverse engineering technique to study the influence of the intermediate state-decoherence on the NHQC gate fidelity, and propose the novel schemes to
more » ... ct the arbitrary single-qubit holonomic gate and nontrivial two-qubit holonomic gate with high fidelity and robustness to the decoherence. Although the proposed method is generic and can be applied to many experimental platforms, such as superconducting qubits, trapped ions, quantum dots, here we take nitrogen-vacancy (NV) center as an example to show that the gate fidelity can be significantly enhanced from 89\% to 99.6\% in contrast to the recent experimental NHQC schemes [Phys. Rev. Lett. 119, 140503 (2017); Nat. Photonics 11, 309 (2017); Opt. Lett. 43, 2380 (2018)], and the robustness against the decoherence can also be significantly improved. All in all, our scheme provides a promising way for fault-tolerant geometric quantum computation.
arXiv:2204.06249v1 fatcat:kxkbwj5lgvhwtf6q4gsyipe2wu

Moving Target Defense Techniques: A Survey

Cheng Lei, Hong-Qi Zhang, Jing-Lei Tan, Yu-Chen Zhang, Xiao-Hu Liu
2018 Security and Communication Networks  
Since Markov chain does not take the impact of offensive and defensive behaviors on system state into consideration, Lei et al.  ...  Lei et al. [71] proposed Self-Adaptive Endpoint Hopping Technique (SEHT) by dividing scanning strategy into three categories.  ... 
doi:10.1155/2018/3759626 fatcat:4ywagqoxhbeyhpxjhtuienvvea

Interpretations of the DAMPE electron data [article]

Qiang Yuan, Lei Feng, Peng-Fei Yin, Yi-Zhong Fan, Xiao-Jun Bi, Ming-Yang Cui, Tie-Kuang Dong, Yi-Qing Guo, Kun Fang, Hong-Bo Hu, Xiaoyuan Huang, Shi-Jun Lei, Xiang Li (+14 others)
2017 arXiv   pre-print
The DArk Matter Particle Explorer (DAMPE), a high energy cosmic ray and γ-ray detector in space, has recently reported the new measurement of the total electron plus positron flux between 25 GeV and 4.6 TeV. A spectral softening at ∼0.9 TeV and a tentative peak at ∼1.4 TeV have been reported. We study the physical implications of the DAMPE data in this work. The presence of the spectral break significantly tightens the constraints on the model parameters to explain the electron/positron
more » ... . The spectral softening can either be explained by the maximum acceleration limits of electrons by astrophysical sources, or a breakdown of the common assumption of continuous distribution of electron sources at TeV energies in space and time. The tentive peak at ∼1.4 TeV implies local sources of electrons/positrons with quasi-monochromatic injection spectrum. We find that the cold, ultra-relativistic e^+e^- winds from pulsars may give rise to such a structure. The pulsar is requird to be middle-aged, relatively slowly-rotated, mildly magnetized, and isolated in a density cavity. The annihilation of DM particles (m_χ∼1.5 TeV) into e^+e^- pairs in a nearby clump or an over-density region may also explain the data. In the DM scenario, the inferred clump mass (or density enhancement) is about 10^7-10^8 M_ (or 17-35 times of the canonical local density) assuming a thermal production cross section, which is relatively extreme compared with the expectation from numerical simulations. A moderate enhancement of the annihilation cross section via, e.g., the Sommerfeld mechanism or non-thermal production, is thus needed.
arXiv:1711.10989v1 fatcat:drsalq5efzdslnc2am546tull4

Reference Product Search [article]

Chu Wang, Lei Tang, Shujun Bian, Da Zhang, Zuohua Zhang, Yongning Wu
2019 arXiv   pre-print
For a product of interest, we propose a search method to surface a set of reference products. The reference products can be used as candidates to support downstream modeling tasks and business applications. The search method consists of product representation learning and fingerprint-type vector searching. The product catalog information is transformed into a high-quality embedding of low dimensions via a novel attention auto-encoder neural network, and the embedding is further coupled with a
more » ... nary encoding vector for fast retrieval. We conduct extensive experiments to evaluate the proposed method, and compare it with peer services to demonstrate its advantage in terms of search return rate and precision.
arXiv:1904.05985v1 fatcat:x4ckluhy2ff5fdvj4ggwon7sfq
« Previous Showing results 1 — 15 out of 106,460 results