检索结果-南通市图书馆

Parity-dependent skin effects and topological properties in the multilayer nonreciprocal Su−Schrieffer−Heeger structures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第3期19卷 115-133页

作者： Jia-Rui Li Cui Jiang han Su Di Qi lian-lian Zhang Wei-Jiang Gong College of Sciences Northeastern UniversityShenyang 110819China Basic Department Shenyang Institute of EngineeringShenyang 110136China

We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.

关键词： multilayer SSH lattice nonreciprocal couplings band structure skin effect

Influence of Micro/Nano-Ti Particles on the Corrosion Behavior of AZ31-Ti Composites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 484-498页

作者： Jinchao Jiao Jin Zhang Yong lian Shengli han Kaihong Zheng Fusheng Pan Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 10083China Beijing Key Laboratory for Corrosion Erosion and Surface Technology Beijing 100083China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 404100China

Adding Ti particles to magnesium alloy simultaneously enhances its strength and ***,how these particles influence on Mg alloy’s corrosion performance is seldom *** corrosion behavior of AZ31-Ti composites containing titanium nanoparticles(1.5 and 5 wt%)and micron particles(10 wt%)prepared by powder metallurgical in 3.5 wt%NaCl solution was *** results indicate that Ti particles serve as the primary location for the cathodic hydrogen reduction reaction,resulting in intense galvanic corrosion between the Ti and Mg *** nanoparticles distributed at the interface of the original AZ31 powder were in a discontinuous mesh structure,thus failing to act as a barrier against *** corrosion products with the existence of numerous cracks gradually peel off during the corrosion process and cannot protect the *** average corrosion rate P_(w) of AZ31,AZ31-1.5%Ti,AZ31-5%Ti,and AZ31-10%Ti after 7 days of immersion is 27.55,105.65,283.67,and 99.35 mm/y,***,AZ31-Ti composites can be considered as potential candidates for degradable fracturing ***,it is recommended to improve their corrosion resistance through surface treatment.

关键词： AZ31-Ti composite Nano-Ti Micro-Ti Corrosion behavior Scanning Kelvin probe force microscopy(SKPFM)

Residual subsidence time series model in mountain area caused by underground mining based on GNSS online monitoring

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2024年第2期11卷 173-186页

作者： Xugang lian Lifan Shi Weiyu Kong Yu han Haodi Fan School of Mining Engineering Taiyuan University of TechnologyTaiyuanChina

The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining ***,it is necessary to use appropriate monitoring methods and mathematical models to effectively monitor and predict the residual subsidence caused by underground *** with traditional level survey and InSAR(Interferometric Synthetic Aperture Radar)technology,GNSS(Global Navigation Satellite System)online monitoring technology has the advantages of long-term monitoring,high precision and more flexible monitoring *** empirical equation method of residual subsidence in mining subsidence is effectively combined with the rock creep equation,which can not only describe the residual subsidence process from the mechanism,but also predict the residual ***,based on GNSS online monitoring technology,combined with the mining subsidence model of mountain area and adding the correlation coefficient of the compaction degree of caving broken rock and the Kelvin model of rock mechanics,this paper constructs the residual subsidence time series model of arbitrary point on the ground in mountain *** the example,the predicted results of the model in the inversion parameter phase and the dynamic prediction phase are compared with the measured data *** results show that the model can carry out effective numerical calculation according to the GNSS monitoring data of any point on the ground,and the model prediction effect is good,which provides a new method for the prediction of residual subsidence in mountain mining.

关键词： Underground mining in mountain area Residual subsidence GNSS online monitoring Mathematical model Subsidence prediction

Simulation Study on Constraining Gravitational Wave Propagation Speed by Gravitational Wave and Gamma-ray Burst Joint Observation on Binary Neutron Star Mergers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第8期24卷 44-53页

作者： Jin-Hui Rao shu-Xu Yi lian Tao Qing-Wen Tang Department of Physics School of Physics and Materials ScienceNanchang University Institute of High Energy Physics Chinese Academy of Sciences

Theories of modified gravity suggest that the propagation speed of gravitational waves （GW） vgmay deviate from the speed of light c.A constraint can be placed on the difference between c and vgwith a simple method that uses the arrival time delay between GW and electromagnetic wave simultaneously emitted from a burst *** simulated the joint observation of GW and short gamma-ray burst signals from binary neutron star merger events in different observation campaigns,involving advanced LIGO （aLIGO） in design sensitivity and Einstein Telescope（ET） joint-detected with Fermi/*** a result,the relative precision of constraint on vgcan reach～10-17（aLIGO） and～10-18（ET）,which are one and two orders of magnitude better than that from GW170817,*** continue to obtain the bound of graviton mass mg≤7.1（3.2）×10-20eV with aLIGO （ET）.Applying the Standard-Model Extension test framework,the constraint on vgallows us to study the Lorentz violation in the nondispersive,nonbirefringent limit of the gravitational *** obtain the constraints of the dimensionless isotropic coefficients ■at mass dimension d=4,which are■for aLIGO and■for ET.

关键词： (stars:) gamma-ray burst: general gravitational waves stars: neutron

Poly(heptazine imide)nanocrystal for hydrogen peroxide evolution in the dark by accumulating photo-generated electrons

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8036-8044页

作者： Song Kou shu lian Xiaodong Xie Wei Ren Yu Jin Jiahui Bao Honghui Ou Guidong Yang XJTU-Oxford International Joint Laboratory for Catalysis School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China Fujian-Taiwan-Hongkong-Macao Science and Technology Cooperation Base of Intelligent Pharmaceutics Institute of OceanographyCollege of Materials and Chemical EngineeringMinjiang UniversityFuzhou 350108China School of Food and Bioengineering Fujian Polytechnic Normal UniversityFuqing 350300China

Organic conjugated polymers have received extensive attention due to their unique electronic ***,there have been relatively few reports on the dark photocatalytic reactions utilizing organic conjugated ***,we report the successful synthesis of an organic conjugated polymer based on poly(heptazine imide)nanocrystals(CNNCs)for H_(2)O_(2)evolution and biomedical applications using a simple salt molten method and sonication-centrifugation *** results show that these colloid CNNCs have the characteristics of photogenerated electrons accumulation and realize dark photocatalysis with high reducibility under visible light ***,these accumulating photogenerated electrons can reduce O_(2)in darkness to produce H_(2)O_(2).In addition,cytotoxicity tests were conducted and it was found that H_(2)O_(2)produced under dark conditions could oxidize L-arginine(L-Arg)to NO,which effectively killed tumors in the *** work provides an important strategy to construct organic conjugated semiconductor nanocrystals and applying them to future energy and biomedical fields.

关键词： poly(heptazine imide) photocatalysis photogenerated electrons hydrogen peroxide evolution cancer treatment

Phenylalanine Hydroxylase Deficiency and Citrin Deficiency in a Chinese Infant

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2015年第21期128卷 2979-2980页

作者： Jun Ye Wen-Juan Qiu lian-shu han Hui-Wen Zhang Xue-Fan Gu Department of Pediatric Endocrinology/Genetics Shanghai Institute for Pediatric Research Xin Hua Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200092 China

To the Editor： Tandem mass spectrometry （MS/MS）-based expanded newborn screening was first introduced in Pediatric Endocrinology/ Genetics of Xin Hua Hospital in 2003. The screening is expected to detect genetic disorders leading to a secondary increase in blood phenylalanine （Phe） in newborns. We reported a rare case in a Chinese infant with hyperphenylalaninemia （HPA） caused by phenylalanine hydroxylase （PAH） deficiency and neonatal intrahepatic cholestasis caused by citrin deficiency （NICCD）. This constellation of two different metabolic pathway defects in one patient has not been reported previously.

关键词： Phenylalanine Hydroxylase Deficiency Citrin Deficiency Chinese Infant

维普期刊数据库

Fractional anisotropy for assessment of white matter tracts injury in methylmalonic acidemia

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2009年第8期122卷 945-949页

作者： GAO Yu GUAN Wen-ye WANG Jiang ZhanG Yu-zhen LI Yu-hua han lian-shu Department of Radiology Xinhua Hospital Medical School of Shanghai Jiao Tong University Shanghai 200092 China Neuroscience Research Group School of Electrical and Automation Engineering Tianjin University Tianjin 300072 China Department of Pediatric Internal Medicine Xinhua Hospital Medical School of Shanghai Jiao Tong University Shanghai 200092 China

Background Methylmalonic acidemia （MMA） is a multifactorial autosomal recessive inborn error of organic acid metabolism, often presenting with neurological symptoms. As neurological disorders are often related to white matter injury, diffusion tensor imaging （DTI） is an excellent tool for assessment of white matter injury and possibly for diagnosing this disorder. Methods We retrospectively analyzed DTI images of 12 patients with MMA （7 males, 5 females, age range： 7-12 months, mean age： 9.25±1.70 months） with negative MRI findings. And another 12 age-matched and gender-matched infants were enrolled as control subjects. Fractional anisotropy （FA） of different white matter tracts of the brain was measured in both groups. Results For patients with negative MRI findings, compared with healthy infants, a statistically significant reduction in DTI FA value of the frontal white matter, temporal white matter, and occipital white matter was observed （P〈0.01）. Conclusions In addition to conventional TlW and T2W MR Image, Brain DTI presents a useful, sensitive and complementary tool for the assessment of brain damage in patients with MMA.

关键词： diffusion tensor imaging magnetic resonance imaging fractional anisotropy methylmalonic acidemia children

维普期刊数据库

Novel intelligent reasoning system for tool wear prediction and parameter optimization in intelligent milling

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 76-93页

作者： Long-Hua Xu Chuan-Zhen Huang Zhen Wang han-lian Liu shui-Quan Huang Jun Wang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiPeople’s Republic of China Center for Advanced Jet Engineering Technologies(CaJET) Key Laboratory of High-efficiency and Clean Mechanical Manufacture(Ministry of Education)National Experimental Teaching Demonstration Center for Mechanical Engineering(Shandong University)School of Mechanical EngineeringShandong UniversityJinan250061People’s Republic of China Institute of Manufacturing Technology Guangdong University of TechnologyGuangzhou510006People’s Republic of China

Accurate intelligent reasoning systems are vital for intelligent *** this study,a new intelligent reasoning system was developed for milling processes to accurately predict tool wear and dynamically optimize machining *** developed system consists of a self-learning algorithm with an improved particle swarm optimization(IPSO)learning algorithm,prediction model determined by an improved case-based reasoning(ICBR)method,and optimization model containing an improved adaptive neural fuzzy inference system(IANFIS)and *** results showed that the IPSO algorithm exhibited the best global convergence *** ICBR method was observed to have a better performance in predicting tool wear than standard CBR *** IANFIS model,in combination with IPSO,enabled the optimization of multiple objectives,thus generating optimal milling *** paper offers a practical approach to developing accurate intelligent reasoning systems for sustainable and intelligent manufacturing.

关键词： Improved particle swarm optimization(IPSO)algorithm Improved case-based reasoning(ICBR)method Adaptive neural fuzzy inference system(ANFIS)model Tool wear prediction Intelligent manufacturing

Synthesis and characterization of iron clusters with an icosahedral [Fe@Fe12]16+ Core

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 123-129页

作者： Gan Xu Yun-shu Cui Xue-lian Jiang Cong-Qiao Xu Jun Li Xu-Dong Chen Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials Science Nanjing Normal University Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry Southern University of Science and Technology Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education Tsinghua University State Key Laboratory of Coordination Chemistry Nanjing University

Iron-metal clusters are crucial in a variety of critical biological and material systems,including metalloenzymes,catalysts,and magnetic storage ***,a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron *** this work,we have synthesized,crystallized,and characterized a（Tp*）4W4S12(Fe@Fe12) cluster(Tp*=tris（3,5-dimethyl-1-pyrazolyl）borate（1-）),which features a rare trideca-nuclear,icosahedral[Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron（Fei） and peripheral irons（Fep）,as well as Fep…Fepferromagnetic *** chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+core,assisted by its bonding interactions with the peripheral tridentate [（Tp*）WS3]4-ligands which possess both S→Fe donation and spin-polarized Fe-Wσ *** ground-state electron spin is theoretically predicted to be S=32/2 for the *** existence of low oxidation-state（OS～+1.23） iron in this compound may find interesting applications in magnetic storage,spintronics,redox chemistry,and cluster catalysis.

关键词： Fe13 cluster iron-sulfur cluster low-valence iron iron−iron bond high spin complex