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Elastic three-dimensional phononic topological insulators with Dirac hierarchy

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： Shao-Yong Huo Qiu-Shuang yang Jiu-Jiu Chen Hong-Kang Li Long-Chao Yao Fu-chun He chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3D)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3D phononic TI with gapless surface states and hinge states,the realization of elastic 3D phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3D *** this study,we demonstrate an elastic 3D phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3D double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3D elastic wave systems and provides new possibilities for designing 3D ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Artificial neural network-based method for discriminating Compton scattering events in high-purity germaniumγ-ray spectrometer

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Nuclear Science and Techniques 2024年第2期35卷 64-84页

作者： chun-Di Fan Guo-Qiang Zeng Hao-Wen Deng Lei Yan Jian yang Chuan-Hao Hu Song Qing yang Hou College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China

To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resulting in an extremely low detection limit and improving the measurement ***,the complex and expensive hardware required does not facilitate the application or promotion of this ***,a method is proposed in this study to discriminate the digital waveform of pulse signals output using an HPGe detector,whereby Compton scattering background is suppressed and a low minimum detectable activity(MDA)is achieved without using an expensive and complex anticoincidence detector and *** electric-field-strength and energy-deposition distributions of the detector are simulated to determine the relationship between pulse shape and energy-deposition location,as well as the characteristics of energy-deposition distributions for fulland partial-energy deposition *** relationship is used to develop a pulse-shape-discrimination algorithm based on an artificial neural network for pulse-feature *** accurately determine the relationship between the deposited energy of gamma(γ)rays in the detector and the deposition location,we extract four shape parameters from the pulse signals output by the *** learning is used to input the four shape parameters into the ***,the pulse signals are identified and classified to discriminate between partial-and full-energy deposition *** partial-energy deposition events are removed to suppress Compton *** proposed method effectively decreases the MDA of an HPGeγ-energy dispersive *** results show that the Compton suppression factors for energy spectra obtained from measurements on ^(152)Eu,^(137)Cs,and ^(60)Co radioactive sources are 1.13(344 keV),1.11(662 keV),and 1.08(1332 keV),respectively,and that the corresponding MDAs are 1.4%,5.

关键词： High-purity germaniumγ-ray spectrometer Pulse-shape discrimination Compton scattering Artificial neural network Minimum detectable activity

Microstructure Evolution and Nanomechanical Behavior of Micro-Area in Molten Pool of Selective Laser Melting(CoCrNi)_(82)Al_(9)Ti_(9)High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1019-1033页

作者： Hong-Wei Zhang Li-Wei Lan Zhe-Yu yang Chang-chun Li Wen-Xian Wang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyTaiyuan030024China Shanxi-Zhejiang University New Materials and Chemical Research Institute Taiyuan030032China

In this work,the phase evolution mechanism and nanomechanical properties of(CoCrNi))(82)Al_(9)Ti_(9)high-entropy alloy(HEA)prepared by selective laser melting(SLM)in the molten pool were *** HEA contains multiple primary elements and undergoes high-temperature gradient and rapid cooling during *** leads to significant inhomogeneity of nano-scale microstructure characteristics and instability of *** optimizing process parameters,the microstructure evolution at the optimal parameter volume energy density of 440 J/mm^(3)was studied.A phase transition from BCC to FCC occurred in the melt *** the micro-area of the melt pool results in a temperature rise and the combustion-induced loss of Al ***,the Ni element content increases significantly outside the melt *** process enhances the phase stability of FCC and facilitates phase ***,rapid cooling leads to the formation of distinctive ultrafine equiaxial crystals inside the melt pool,accompanied by the generation of intracrystalline needle-like nano-scale *** the melt pool,the accumulation of energy results in the formation of coarse ***,the nano-hardness inside the molten pool is remarkably high at 11.79 GPa,while the outside the molten pool is reduced to 9.58 *** the fracture toughness outside the melt pool also *** with inside the melt pool,the residual stress outside the melt pool changed from compressive to tensile stress and decreased from 603.28 to 322.84 MPa.

关键词： High-entropy alloys Selective laser melting Microstructure evolution Nanoindentation

Vortex identification based on the Liutex method and its effect on fish passage upstream

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Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： chun-ying Shen Rui-guo yang Xiao-tao Shi Ming-ming Wang Shi-hua He Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

The influence of yttrium and manganese additions on the degradation and biocompatibility of magnesium-zinc-based alloys:In vitro and in vivo studies

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Journal of Magnesium and Alloys 2024年第2期12卷 608-624页

作者： Lei Shi yang Yan chun-sheng Shao Kun Yu Bo Zhang Liang-jian Chen Third Xiangya Hospital Central South UniversityChangsha 410013China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China Department of Mechanical Engineering City University of Hong KongHong KongChina

The repair and regeneration of bone defects are highly challenging orthopedic ***,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human *** aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion *** this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a *** then investigated the effect of additions of Y and Mn on alloys'*** results show that Mn and Y can improve not only compression strength but also corrosion *** alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in *** degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or ***,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.

关键词： Magnesium alloy Biodegradation Biocompatibility Bone regeneration Bone defect repair

Effects of different moxibustion durations on lumbar disk herniation:a clinical study

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Frontiers of Nursing 2024年第1期11卷 47-56页

作者： Bin Chen Ting yang chun-Qin Zhu Department of Nursing Affiliated Hospital of Nanjing University of Chinese MedicineNanjingJiangsu 210004China

Objective:To explore the best duration of moxibustion on lumbar disk herniation(LDH).Methods:A total of 88 patients were randomly divided into control group and 15-min,30-min,and 45-min moxibustion *** control group was treated with conventional therapy,while the other 3 groups were intervened with different moxibustion *** back pain,dysfunction,lumbar function,and effective rates were evaluated before,in the first week and second week of ***:In low back pain,compared with the control group,the score of the 15-min group had no significant difference,but it was significantly lower in the 30-min and 45-min *** dysfunction and lumbar function,compared with the control group,the scores of the 15-min,30-min,and 45-min groups were significantly higher,and the scores of the 30-min and 45-min groups were significantly higher,but there was no significant difference between the 30-min and 45-min *** effective rates,there was no significant difference between the control group and 15-min group;the effective rates of the 30-min and 45-min groups were significantly higher than those of the control ***:Moxibustion has good therapeutic effect on LDH with specific moxibustion time.

关键词： duration of moxibustion lumbar disc herniation moxibustion

Emodin suppresses alkali burn-induced corneal inflammation and neovascularization by the vascular endothelial growth factor receptor 2 signaling pathway

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Journal of Traditional Chinese Medicine 2024年第2期44卷 268-276页

作者： zheng Xueying GUO Liang LAI Siyi LI Fengyue LIANG Mingli LIU Wanting MENG chun LIU Guanghui Department of Bioengineering College of Biological Science and BiotechnologyFuzhou UniversityFuzhou 350104China Eye Institute of Integrated Chinese and Western Medicine Fujian University of Traditional Chinese MedicineFuzhou 350004China Department of Ophthalmology Affiliated People's Hospital(Fujian Provincial People's Hospital)Fujian University of Traditional Chinese MedicineFuzhou 350004China

OBJECTIVE:To investigate the effects of emodin on alkali burn-induced corneal inflammation and ***:The ability of emodin to target vascular endothelial growth factor receptor 2(VEGFR2)was predicted by molecular *** effects of emodin on the invasion,migration,and proliferation of human umbilical vein endothelial cells(HUVEC)were determined by cell counting kit-8,Transwell,and tube formation *** of apoptosis was performed by flow ***31 levels were examined by *** abundance and phosphorylation state of VEGFR2,protein kinase B(Akt),signal transducer and activator of transcription 3(STAT3),and P38 were examined by immunoblot *** alkali burn was performed on 40 *** were divided randomly into two groups,and the alkali-burned eyes were then treated with drops of either 10μM emodin or phosphate buffered saline(PBS)four times a *** microscopy was used to evaluate inflammation and corneal neovascularization(CNV)in all eyes on Days 0,7,10,and *** mice were killed humanely 14 d after the alkali burn,and their corneas were removed and preserved at-80℃ until histological study or protein ***:Molecular docking confirmed that emodin was able to target *** findings revealed that emodin decreased the invasion,migration,angiogenesis,and proliferation of HUVEC in a dose-dependent *** mice,emodin suppressed corneal inflammatory cell infiltration and inhibited the development of corneal neovascularization induced by alkali *** to those of the PBS-treated group,lower VEGFR2 expression and CD31 levels were found in the emodintreated *** dramatically decreased the expression of VEGFR2,p-VEGFR2,p-Akt,p-STAT3,and p-P38 in VEGF-treated ***:This study provides a new avenue for evaluating the molecular mechanisms underlying corneal inflammation and *** might be a promising new therapeutic option for corneal alkal

关键词： alkali burn emodin corneal inflammation corneal neovascularisation vascular endothelial growth factor receptor-2 signal transduction

Impact of different anastomosis methods on post-recurrence after intestinal resection for Crohn's disease:A meta-analysis

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World Journal of Gastrointestinal Surgery 2024年第4期16卷 1165-1175页

作者： zheng-Zuo Wang chun-Hua Zhao Hui Shen Gui-Ping Dai Department of Anorectal Jiashan Hospital of Traditional Chinese MedicineJiaxing 314100Zhejiang ProvinceChina Department of Oncology Jiashan Hospital of Traditional Chinese MedicineJiaxing 314100Zhejiang ProvinceChina Department of Gastroenterology Jiashan Hospital of Traditional Chinese MedicineJiaxing 314100Zhejiang ProvinceChina Department of Oncology The Second Hospital of JiaxingJiaxing 314000Zhejiang ProvinceChina

BACKGROUND Crohn's disease(CD)is a chronic inflammatory disease of the gastrointestinal tract,often requiring intestinal resection as a common ***,recurrence after surgery is *** anastomotic configuration after bowel resection appears to be associated with the recurrence of *** studies have suggested that the Kono-S anastomosis may help to reduce the recurrence ***,the results remain ***,evidence-based evidence is needed to prove the advantages of Kono-S *** To measure the influence of anastomosis techniques on the long-term relapse rate of CD by conducting a *** PubMed,Scopus,and Cochrane Library were searched until October 8,*** who underwent intestinal resection due to CD were *** intervention measures included Kono-S anastomosis,whereas the control group received traditional anastomosis such as end-to-end,end-to-side,and side-to-side *** randomized clinical trials and observational studies were *** primary outcome measures were hospital stay post-surgery,overall postoperative complication incidence,the proportion of Clavien-Dindo grade IIIa or higher,overall postoperative recurrence rate,and Rutgeerts *** From 2011 to 2023,six articles met the inclusion and exclusion *** results indicated that Kono-S anastomosis can reduce the hospital stay post-surgery of patients with CD[MD=-0.26,95%CI:-0.42 to-0.10,P=0.002]than other traditional anastomosis *** to other traditional anastomosis methods,Kono-S anastomosis can significantly reduce the total recurrence rate[MD=0.40,95%CI:0.17 to 0.98,P=0.05]and postoperative Rutgeerts score[MD=-0.81,95%CI:-0.96 to-0.66,P<0.001]in patients with ***,there is no significant disparity in the overall occurrence of postoperative complications and the proportion of Clavien-Dindo≥*** Kono-S anastomosis has the potential to expedite the recuperation of CD and di

关键词： Kono-S Crohn’s disease Traditional anastomosis Postoperative recurrence Meta-analysis

Unique polysulfide reaction on VO_(2) for restraining shuttle effect in soft-packaged Li-S pouch cells

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Rare Metals 2024年第6期43卷 2842-2850页

作者： Ruo-Xuan yang Qing-chun Zhang Jing-Sheng Cai Xuan Cao Qin yang Ying-Ze Song Wei Zhang State Key Laboratory of Environment-Friendly Energy Materials Tianfu Institute of Research and InnovationSchool of Materials and ChemistrySouthwest University of Science and TechnologyMianyang 621010China School of Materials Engineering Changshu Institute of TechnologyChangshu 215500China Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China

The shuttle phenomenon and retarded conversion kinetics of lithium poly sulfides(LiPSs)are relatively severe in lithium-sulfur(Li-S)pouch *** to their redox potential in the sulfur working window,VO_(2)nanobelts show ... 详细信息

关键词： mechanism sulfide lithium