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P-symmetric Subharmonic Solutions for Nonlinear Hamiltonian Systems

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1388-1408页

作者： duan zhi ZHANG zhi Hao ZHAO School of Mathematical Sciences Nankai UniversityTianjin 300071P.R.China

In this paper,we prove that for each positive k≡1 mod m there exists a P-symmetric kmτ-periodic solution xk for asymptotically linear mτ-periodic Hamiltonian systems,which are nonautonomous and endowed with a *** the P-symmetric Hamiltonian function is semi-positive,one can prove,under a new iteration inequality of the Maslov-type P-index,that xk_(1) and xk_(2) are geometrically distinct for k_(1)/k_(2)≥(2n+1)m+1;and xk_(1),xk_(2) are geometrically distinct for k_(1)/k_(2)≥m+1 provided xk_(1) is non-degenerate.

关键词： P-symmetric subharmonic Hamiltonian systems Maslov-type index theory iteration inequality asymptotically linear

Advances in bio-inspired electrocatalysts for clean energy future

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Nano Research 2024年第2期17卷 515-533页

作者： Jing-wen duan Mu Min-Rui Gao Division of Nanomaterials&Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Electrocatalysis can enable efficient energy storage and conversion and thus is an effective way to achieve carbon *** unique structure and function of organisms can offer many ideas for the design of electrocatalysts,which has become one of the most promising research ***,the understanding of the mechanism of bio-inspired electrocatalysis has become clearer,which has promoted the design of bio-inspired catalysts and catalytic *** bio-inspired catalysts(enzyme-like catalysts,layered porous catalysts,superhydrophobic/superhydrophilic surfaces,and so on)have been developed to enable efficient electrocatalytic ***,we discuss the key advances in the field of bio-inspired electrocatalysts progressed in recent ***,the role of bio-inspiration in increasing the intrinsic activity and number of active sites of catalysts is ***,the structure and mechanism of layered porous catalytic systems that mimic biological transport systems are comprehensively ***,the design of three-phase interfaces from micro-nanoscale to atomic scale is highlighted,including the wettability of the electrode surface and the transport system near the *** conclude the review by identifying challenges in bio-inspired electrocatalysts and providing insights into future prospects for the exciting research field.

关键词： bio-inspired electrocatalysts active sites layered porous structure three-phase interface

Equivalence between the internal observability and equation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： LIU wen-jun TU zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

The Multi-parameter Test of Gravitational Wave Dispersion with Principal Component Analysis

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Research in Astronomy and Astrophysics 2024年第5期24卷 140-150页

作者： zhi-Chu Ma Rui Niu wen Zhao CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

In this work, we consider a conventional test of gravitational wave(GW) propagation which is based on the phenomenological parameterized dispersion relation to describe potential departures from General Relativity(GR)along the propagation of GWs. But different from tests conventionally performed previously, we vary multiple deformation coefficients simultaneously and employ the principal component analysis(PCA) method to remedy the strong degeneracy among deformation coefficients and obtain informative posteriors. The dominant PCA components can be better measured and constrained, and thus are expected to be more sensitive to potential departures from the waveform model. Using this method we analyze ten selected events and get the result that the combined posteriors of the dominant PCA parameters are consistent with GR within 99.7% credible intervals. The standard deviation of the first dominant PCA parameter is three times smaller than that of the original dispersion parameter of the leading order. However, the multi-parameter test with PCA is more sensitive to not only potential deviations from GR but also systematic errors of waveform models. The difference in results obtained by using different waveform templates hints that the demands of waveform accuracy are higher to perform the multiparameter test with PCA. Whereas, it cannot be strictly proven that the deviation is indeed and only induced by systematic errors. It requires more thorough research in the future to exclude other possible reasons in parameter estimation and data processing.

关键词： gravitational waves-gravitation-black hole physics

Biopsy forceps are useful for measuring esophageal varices in vitro

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 539-545页

作者： zhi-Hui duan Sheng-Yun Zhou Endoscopy Center Xingtai People’s HospitalXingtai 054000Hebei ProvinceChina

BACKGROUND To avoid acute variceal bleeding in cirrhosis,current guidelines recommend screening for high-risk esophageal varices(EVs)by determining variceal size and identifying red wale ***,visual measurements of EV during routine endoscopy are often *** To determine whether biopsy forceps(BF)could be used as a reference to improve the accuracy of binary classification of variceal *** An in vitro self-made EV model with sizes ranging from 2 to 12 mm in diameter was *** online image-based survey comprising 11 endoscopic images of simulated EV without BF and 11 endoscopic images of EV with BF was assembled and sent to 84 *** endoscopists were blinded to the actual EV size and evaluated the 22 images in random *** The respondents included 48 academic and four private *** accuracy of EV size estimation was low in both the visual(13.81%)and BF-based(20.28%)*** use of open forceps improved the ability of the endoscopists to correctly classify the varices by size(small≤5 mm,large>5 mm)from 71.85%to 82.17%(P<0.001).CONCLUSION BF may improve the accuracy of EV size assessment,and its use in clinical practice should be investigated.

关键词： Accuracy Liver cirrhosis Esophageal varices Endoscopy Measurement

Clinical efficacy of femtosecond laser-assisted phacoemulsification in diabetic cataract patients

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World Journal of Clinical Cases 2024年第10期12卷 1733-1741页

作者： Yi-Fei Tang zhi-Hui duan Department of Glaucoma and Cataracts Han Yang Eyegood Ophthalmic HospitalWuhan 430056Hubei ProvinceChina

BACKGROUND Diabetic patients with cataracts encounter specific difficulties during cataract surgery due to alterations in microcirculation,blood supply,metabolism,and the *** phacoemulsification may not fully tackle these issues,especially in instances with substantial preoperative *** utilization of femtosecond laser-assisted phacoemulsification,in conjunction with Toric intraocular lens(IOL)implantation,offers a potentially more efficient *** research seeks to evaluate the efficacy and possible complications of this approach in diabetic cataract *** To investigate the clinical efficacy and complications of femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation in diabetic cataract patients,comparing it with traditional phacoemulsification *** This retrospective study enrolled 120 patients with diabetes cataract from May 2019 to May *** patients were divided into two groups:the control group underwent traditional phacoemulsification and Toric IOL implantation,while the treatment group received Len Sx femtosecond laser-assisted *** measures included naked eye vision,astigmatism,high-level ocular phase difference detection,clinical efficacy,and *** There were no significant preoperative differences in astigmatism or naked eyesight between the two ***,postoperative improvements were observed in both groups,with the treatment group showing greater enhancements in naked eye vision and astigmatism six months after the ***-level corneal phase difference tests also indicated significant differences in favor of the treatment *** This study suggests that femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation appears to be more effective in enhancing postoperative vision in diabetic cataract patients compared to traditional methods offering valuable insights for clinical practice.

关键词： Diabetic cataract Femtosecond laser-assisted phacoemulsification Toric intraocular lens implantation Naked vision

Effect of BaO and MgO on structure and properties of aluminate slag with various CaO/Al_(2)0_(3)ratios

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Journal of Iron and Steel Research International 2024年第1期31卷 204-214页

作者： Yu-qi Kong Ting Wu wen-zhi Xia wen Yang Hai-chuan Wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resource Recycling(Ministry of Education) Anhui University of TechnologyMa’anshan243002AnhuiChina

To provide theoretical guidance for performance stability control of low-reactive mold fluxes,the effects of BaO and MgO on the structure and properties of aluminate slag with various CaO/Al_(2)0_(3)(C/A)ratios were investigated using the Fourier transform infrared spectrometer,Raman spectroscope,hemispherical melting point instrument,rotational viscometer and X-ray *** results indicated that with BaO and MgO addition,the structure polymerization was first weakened and then enhanced at C/A of 1.1,and the transition contents corresponded to 8 wt.%BaO and 2 wt.%MgO,respectively,while the structure polymerization decreased continuously at C/A of *** the viscosity change was well consistent with the structure evolution,the polymerization degree played a more prominent role in the slag viscosity than superheat degree when the melting temperature difference was within 40℃.The break temperature decreased initially and then increased with augment of BaO and MgO at C/A of 1.1,while it manifested a decrease trend with BaO addition,and it decreased obviously but then turned to increase with MgO increment at C/A of *** crystallization phase and crystallization ratio kept stable with BaO increment,while the crystallization ratio rose greatly with MgO promoting LiAlO_(2)precipitation at C/A of *** crystal types of all experimental slags were mainly Ca_(12)Al_(14)O_(33)and CaF_(2)at C/A of 1.3,and the precipitation of crystalline phase BaAl2O4 demonstrated a rising trend,while that of Ca_(12)Al_(14)O_(33)gradually declined with BaO augment.

关键词： Aluminate slag Structure MgO BaO Viscosity Property

Adaptive joint configuration optimization for collaborative inference in edge-cloud systems

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Science China(Information Sciences) 2024年第4期67卷 335-336页

作者： Zheming YANG wen JI zhi WANG Institute of Computing Technology Chinese Academy of Sciences University of Chinese Academy of Sciences Peng Cheng Laboratory Tsinghua Shenzhen International Graduate School Tsinghua University

With the rapid development of technologies such as deep learning and the Internet of Things(IoT), the deployment and application of various IoT devices are becoming increasingly widespread, resulting in the inference tasks generated increasing dramatically [1]. Many deep neural network(DNN) models are deployed on servers for performing inference tasks.

关键词： Inference engines

Achieving strength–ductility synergy in novel paramagnetic Fe-based medium-entropy alloys through deep cryogenic deformation

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Rare Metals 2024年第9期43卷 4493-4507页

作者： Hu-wen Ma Yan-Chun Zhao Li Feng Tian-Zeng Liu zhi-Qi Yu Bo Jin Wang-Chun duan Peter K.Liaw Dong Ma State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of Technology wenzhou Pump and Valve Engineering Research Institute Lanzhou University of Technology Iron and Steel Research Institute Jiuquan Iron and Steel Corporation Lanzhou Resources and Environment Voc-Tech University Department of Materials Science and Engineering The University of Tennessee Neutron Science Center Songshan Lake Materials Laboratory

Cryogenic pre-deformation treatment has been widely used to effectively improve the comprehensive mechanical properties of steels and novel metals. However,the dislocation evolution and phase transformation induced by different degrees of deep cryogenic deformation are not yet fully elucidated. In this study, the effects of multiple cryogenic pre-treatments on the mechanical properties and deformation mechanisms of a paramagnetic Fe63.3Mn14-Si9.1Cr9.8C3.8medium-entropy alloy（MEA） were investigated, leading to the discovery of a pretreated MEA that exhibits exceptional mechanical properties, including a fracture strength of 3.0 GPa, plastic strain of 26.1% and work-hardening index of 0.57. In addition, X-ray diffraction（XRD） and transmission electron microscopy（TEM）analyses revealed that multiple cryogenic pre-deformation treatments significantly increased the dislocation density of the MEA(from 9 × 1015to 4 × 1016m-2after three pretreatments), along with a transition in the dislocation type from predominantly edge dislocations to mixed dislocations（including screw-and edge-type dislocations）. Notably, this pretreated MEA retained its paramagnetic properties（μr< 1.0200） even after fracture. Thermodynamic calculations showed that cryogenic pretreatment can significantly reduce the stacking fault energy of the MEA by a factor of approximately four(i.e., from 9.7 to2.6 m J·m-2), thereby activating the synergistic effects of transformation-induced plasticity, twinning-induced plasticity and dislocation strengthening mechanisms. These synergistic effects lead to simultaneous strength and ductility enhancement of the MEA.

关键词： Deep cryogenic transformation Dislocation evolution Iron-based medium-entropy alloys Phase transformation Stacking fault energy