Lithuanian Journal of Physics最新文献_第3页

Chirped LG modes interference formed chiral beams 啁啾 LG 模式干扰形成的手性光束

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-11-26 DOI: 10.3952/physics.2023.63.3.4

G. Kontenis, D. Gailevičius, V. Jukna, K. Staliūnas

引用次数: 0

On evaluation of image quality in nonparaxial single-pixel imaging 非轴向单像素成像的图像质量评估

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-11-24 DOI: 10.3952/physics.2023.63.3.1

S. Mundrys, S. Orlov, P. Kizevičius, L. Minkevičius, G. Valušis

{"title":"On evaluation of image quality in nonparaxial single-pixel imaging","authors":"S. Mundrys, S. Orlov, P. Kizevičius, L. Minkevičius, G. Valušis","doi":"10.3952/physics.2023.63.3.1","DOIUrl":"https://doi.org/10.3952/physics.2023.63.3.1","url":null,"abstract":"High numerical apertures lead to an appearance of distortions in a single-shot image, which make obtaining images troublesome if not impossible. These obstacles can be overcome in single-pixel imaging, where different strategies lead to inspection of objects with a good resolution, contrast and brightness. Recent advances in flat photonic elements have enabled the creation of compact nonparaxial imaging systems, which are especially promising in the THz range of wavelengths, bringing advances to such fields as communication, material inspection and spectroscopy. In this work, we dive into the problematics of single-pixel imaging: we introduce an object sample, which we use to investigate the resolution, contrast and brightness of the classical two-lens imaging setup. We evaluate the nonparaxial imaging of the sample and report that the conditions for the best contrast and the best brightness are decoupled in nonparaxial single pixel imaging. To overcome this hurdle, we use two integral image quality assessment techniques from computational imaging theory and estimate the quality of the image in a virtual numerical THz imaging scenario. The localized mean square error metric did not cause additional constraints to the quality of the image, whereas the global mean square error has restricted the range of possible imaging setups. Thus, the computational integral image quality assessment techniques back up the main claim of this study that in the single-pixel imaging the resolution is decoupled from the image brightness.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139238831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Stochastic theory of charge dynamics and recombination in defect clusters in bulk silicon. 体硅缺陷团簇中电荷动力学和重组的随机理论。

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-05-31 DOI: 10.3952/physics.2023.63.2.2

D. Abramavičius

引用次数: 0

Increase of the surface recombination velocity at high bias voltage in silicon irradiated by neutrons to extremely high fluences 中子辐照到极高通量时硅在高偏压下表面复合速度的增加

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-05-31 DOI: 10.3952/physics.2023.63.2.3

J. Vaitkus, A. Mekys

{"title":"Increase of the surface recombination velocity at high bias voltage in silicon irradiated by neutrons to extremely high fluences","authors":"J. Vaitkus, A. Mekys","doi":"10.3952/physics.2023.63.2.3","DOIUrl":"https://doi.org/10.3952/physics.2023.63.2.3","url":null,"abstract":"The upgrading of ionizing radiation detectors is an actual problem especially related to the high energy physics and space research experiments. The simplest way to restore the signal of the irradiation degraded detector is the increase of the detector bias voltage. This method is widely used worldwide, including high energy physics experiments in ATLAS and CMS. This work presents an effect, which was caused by increased bias voltage in detectors irradiated to extreme high neutron fluence at low temperature. The effect could be related to the increase of surface recombination velocity.The intrinsic photoconductivity spectra were exploited in order to investigate the properties of highly irradiated silicon as this effect depends on parameters that are important in radiation detectors. Two characteristic effects were observed in such highly irradiated samples: the increase of photoconductivity quantum yield and the enhancement of surface recombination at higher bias voltages. The increase of the quantum yield was analyzed in Ref. [1]. The increase of the surface recombination with bias electric field was analyzed in this work as an extension of the performed investigation in the same samples as in Ref. [1]. The investigated silicon samples were irradiated by neutrons to wide range fluence up to 1017 n/cm2.The origin of this effect was analyzed and related to the radiation clusters, which decrease the free carrier lifetime.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44183248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Assessment of the input of particulate 239,240Pu and 137Cs from the Neman River into the Curonian Lagoon Neman河颗粒物239,240Pu和137Cs输入库尔潟湖的评价

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-05-31 DOI: 10.3952/physics.2023.63.2.6

V. Romanenko, G. Lujaniene, S. Šemčuk, J. Mažeika, O. Jefanova

引用次数: 0

The impact of groupvelocity dispersion on femtosecond laser filamentation with higher-order Kerr effect at different atmospheric pressures 不同大气压下群速度色散对高阶克尔效应飞秒激光成丝的影响

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-05-31 DOI: 10.3952/physics.2023.63.2.1

Y. Qian, L. Wang, G. Shi, Y. Zhang, Z. Sun, Y. Lin

引用次数: 0

A computational study of the electronic and thermoelectric properties of metal halide cubic perovskites CsBX3 (B = Ge, Sn, Pb and X = Cl, Br, I) 金属卤化物立方钙钛矿CsBX3 (B = Ge, Sn, Pb, X = Cl, Br, I)电子和热电性质的计算研究

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-05-31 DOI: 10.3952/physics.2023.63.2.4

M. Zemzemi

{"title":"A computational study of the electronic and thermoelectric properties of metal halide cubic perovskites CsBX3 (B = Ge, Sn, Pb and X = Cl, Br, I)","authors":"M. Zemzemi","doi":"10.3952/physics.2023.63.2.4","DOIUrl":"https://doi.org/10.3952/physics.2023.63.2.4","url":null,"abstract":"Metal halide perovskites have received a tremendous interest recently in new applications. Photovoltaic, diverse photonic and optoelectronic applications of these materials are in full expansion, but thermoelectricity also instigates a great interest. In this work, we will focus on the thermoelectric properties of a particular material family of metal halide cubic perovskites CsBX3 (B = Ge, Sn, Pb and X = Cl, Br, I). The structural and electronic properties of CsBX3 are computed using first-principles calculations based on the density functional theory which allows calculating equilibrium lattice parameters, band structures, the nature (direct/indirect) and value of the band gap. These studied compounds are semiconductors with direct band gap energy. We have also detected the effect of replacement of halogen and metal cation atoms with other halogen and metal cation atoms on electronic and thermoelectric properties. Boltzmann transport calculations are carried out to explore their thermoelectric properties like the Seebeck coefficient, electrical conductivity and power factor. Large values of the Seebeck coefficient and the power factor obtained for these compounds indicate that these compounds can be used for thermoelectric devices. Our theoretical analysis of the electronic and thermoelectric properties of these compounds suggests that CsSnBr3 and CsGeBr3 are the best Pb-free inorganic metal halide semiconductor for a high thermoelectric performance.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48235632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Novel approaches to generic non-Fermi liquids: higher- dimensional bosonization vs generalized holography 一般非费米液体的新方法：高维玻色子化与广义全息术

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-05-31 DOI: 10.3952/physics.2023.63.2.5

D. V. Khveshchenko

引用次数: 0

Li+ intercalation current generation in amorphous and crystalline MoS2: Experiment and theory 非晶和结晶二硫化钼中Li+嵌入电流的产生:实验与理论

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-04-06 DOI: 10.3952/physics.2023.63.1.4

O. Balaban, O. Izhyk, A. Zaichenk, N. Mitina, I. Grygorchak, K. Harhay

{"title":"Li+ intercalation current generation in amorphous and crystalline MoS2: Experiment and theory","authors":"O. Balaban, O. Izhyk, A. Zaichenk, N. Mitina, I. Grygorchak, K. Harhay","doi":"10.3952/physics.2023.63.1.4","DOIUrl":"https://doi.org/10.3952/physics.2023.63.1.4","url":null,"abstract":"In this work, crystalline and amorphous nano-MoS2 materials for effective Li+-intercalation current generation have been synthesized. The effect of disordering on the structural and electrochemical properties of nano-MoS2 has been systematically investigated by multiple characterizations: transmission electron microscopy (TEM), X-ray diffraction method and electrochemical measurements. Thermodynamic and kinetic peculiarities of intercalation processes have been studied. Dependences of the change in Gibbs’ free energy of the intercalation reaction on the extent of ‘guest’ lithium loading are analyzed. The distinctive feature of disordered structures is their ability to show colossal lithium ‘guest’ load, which ensures the specific capacity of the material in cathode processes up to ~2500 mAh·g–1 under the discharge not less than 2.6 V relative to lithium. The diffusion coefficient of lithium cations in the structure of disordered nano-MoS2 is two orders of magnitude higher than that in the crystalline MoS2.A quantum-mechanical model of the observed phenomena is suggested.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42075565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Physical-and-chemical processes at the interfaces of (Cu–Ni–Mn–Fe)/ (W–C) composites （Cu–Ni–Mn–Fe）/（W–C）复合材料界面的物理化学过程

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2023-04-06 DOI: 10.3952/physics.2023.63.1.3

O. Sukhova

{"title":"Physical-and-chemical processes at the interfaces of (Cu–Ni–Mn–Fe)/ (W–C) composites","authors":"O. Sukhova","doi":"10.3952/physics.2023.63.1.3","DOIUrl":"https://doi.org/10.3952/physics.2023.63.1.3","url":null,"abstract":"The spontaneous infiltration method for fabricating composites was used, in which molten Cu–Ni–Mn–Fe binders penetrated W–C filler particles due to capillary forces. The metal matrix composites thus obtained were characterized for phase composition, microstructure, porosity and microhardness. All composites were studied in their as-prepared condition with further annealing at 900°С for 60 and 750 h. It was shown that the mechanism based on the dissolution/diffusion bonding of the particulate/matrix interface was in agreement with the results of this study. The interfacial reactions provided a driving force for wetting but did not give rise to unwanted phases that could degrade the properties of the composite materials. From the EDX measurements it was concluded that mainly Fe atoms diffused from the Cu–Ni–Mn–Fe binders into the WC phase of the eutectic (WC+W2C) filler. Dissolution of this phase resulted in the appearance of W2C layer at the interface. Annealing at 900°С significantly promoted the interfacial reaction especially during the first 60 h of heat treatment. The degree of the reaction between the molten Cu–Ni–Mn–Fe alloys and W–C particulate could be limited by controlling the iron content of the binders to obtain an optimal interface.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46844884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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