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{"title":"Models of (boldsymbol{f(Q)}) Gravity with Electromagnetic Field","authors":"S. H. Shekh,&nbsp;Hira Sohail,&nbsp;Irfan Mahmood,&nbsp;Allah Ditta,&nbsp;Anil Kumar Yadav,&nbsp;Suresh Parekh","doi":"10.1134/S0202289324700543","DOIUrl":"10.1134/S0202289324700543","url":null,"abstract":"<p>There are so many ideas that potentially explain the dark energy phenomenon, current research is focusing on a more in-depth analysis of the potential effects of modified gravity on both local and cosmic scales. In this paper we investigate some cosmic reconstructions in <span>(f(Q))</span> cosmology, where <span>(Q)</span> is the nonmetricity corresponding to the evolution background in the Friedmann–Lemaître–Robertson–Walker (FLRW) universe. This allows us to determine how any FLRW cosmology can emerge from a particular <span>(f(Q))</span> theory. We employ the reconstruction technique to generate explicit formulations of the <span>(f(Q))</span> Lagrangian for several types of matter sources like a perfect fluid, a dustlike fluid, stiff fluid and a binary mixture of two fluids. Furthermore, we compute the field equations and the equation of state (EoS) parameter <span>(omega)</span> for two different reconstructed <span>(f(Q))</span> models with variation of the involved constants, which gives a scenario of an accelerating universe, a quintessence region and the cosmological constant. We also observe that the time dependence of <span>(omega)</span> admits cosmic acceleration. These new <span>(f(Q))</span> gravity inspired models may have an impact on gravitational phenomena at other cosmological scales.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"31 1","pages":"113 - 124"},"PeriodicalIF":1.2,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529930","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}

{"title":"The full period interactive response mechanism between surface subsidence and large energy events in deep mining of super-thick weakly cemented overburden","authors":"Tiening Wang,&nbsp;Guangli Guo,&nbsp;Huaizhan Li,&nbsp;Hejian Yin,&nbsp;Hui Zheng,&nbsp;Fanzhen Meng,&nbsp;Liangui Zhang","doi":"10.1007/s12665-025-12139-x","DOIUrl":"10.1007/s12665-025-12139-x","url":null,"abstract":"<div><p>The western mining area is an essential coal mining base in China. Because of the presence of the super-thick weakly cemented overburden, deep mining in this area faces problems such as high energy events and serious dynamic disasters, and the surface subsidence is slight in the initial stage of mining. To solve the above problems, this paper takes Ordos mine as research object, systematically studies the linkage mechanism between surface subsidence and large energy events in the full period mining. In the initial stage of mining, the two large energy mining seismic in the mining process of 1208 working face both occurred near the maximum subsidence point and were accompanied by sudden increase of surface subsidence. With the increase of mining area, there is an obvious interactive response between the subsidence incremental of surface and the energy release in high position super-thick rock strata. Moreover, based on the simulation of overburden breaking and the energy evolution of key horizon, the mechanism of action of super-thick overburden failure on surface subsidence and energy release is clarified. Based on this, the mining seismic activity for the full period of mining is predicted by the mechanical analysis. The results can provide theoretical support for large-scale continuous mining in weakly cemented mining areas in western China.</p></div>","PeriodicalId":542,"journal":{"name":"Environmental Earth Sciences","volume":"84 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compact Star Modeling of Durgapal Solution in (boldsymbol{f(Q)}) Gravity","authors":"Akanksha Singh,&nbsp;S. K. Maurya,&nbsp;Sacheendra Shukla","doi":"10.1134/S0202289324700531","DOIUrl":"10.1134/S0202289324700531","url":null,"abstract":"<p>This study uses a specific ansatz within <span>(f(Q))</span> gravity theory to examine the characteristics of spherically symmetric anisotropic compact stars. The research aims at enhance comprehension of these atypical entities by examining the physical properties of the compact star model using the Durgapal geometry within the context of <span>(f(Q))</span> gravity. The <span>(f(Q))</span> gravity field equations are resolved using the Karmarkar condition, and the physical characteristics such as density and pressure are computed for the resulting solution. The energy criteria are fulfilled, and the TOV equations perform the equilibrium analysis. The physical study indicates that our models meet the requirements for a well-behaved stellar system. This indicates that our solution is suitable for modeling astrophysical objects.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"31 1","pages":"99 - 112"},"PeriodicalIF":1.2,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529929","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}

{"title":"Bending performance of adhesive-free cross-laminated timber panels fabricated with fast-growing Chinese fir","authors":"Yi Zhang,&nbsp;Weiguo Long,&nbsp;Jiajia Ou,&nbsp;Di Chen,&nbsp;Zhao Chen","doi":"10.1007/s00107-025-02230-2","DOIUrl":"10.1007/s00107-025-02230-2","url":null,"abstract":"<div><p>To effectively utilize China’s abundant fast-growing forest resources for the manufacturing of engineered wood products (EWPs) and reduce the environmental impact induced by adhesives in EWPs, this study developed nailed cross-laminated timber (NCLT) using machine-graded fast-growing Chinese fir laminations, with wooden nails as the fasteners. Four-point bending tests were conducted on 28 NCLT panels. The failure modes, bending strength, and stiffness of the specimens were investigated. The parametric analysis was carried out based on the validated finite element analysis of NCLT panels. The results show that the failure mode of NCLT panels differs from the brittle failure of cross-laminated timber (CLT) panels, demonstrating a better plastic deformation capacity. The bending strength and stiffness of NCLT panels ranged from 8.67 to 12.33 MPa and 5.90 to 13.95 kN·m², respectively. Moreover, both the bending strength and stiffness of the NCLT panels showed a positive correlation with the diameter and quantity of wooden nails. The mechanically jointed beam model can accurately predict the bending stiffness of NCLT. Through the rational arrangement of the laminations and wooden nails, NCLT has the potential to serve as a substitute for CLT.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studies of the Inhomogeneous Cosmology in Higher Dimensional Space-Time with a Cosmological Constant","authors":"D. Panigrahi,&nbsp;S. Chatterjee","doi":"10.1134/S020228932470049X","DOIUrl":"10.1134/S020228932470049X","url":null,"abstract":"<p>We study an inhomogeneous cosmology in Kaluza–Klein space-time with a positive cosmological constant in a dust dominated era (<span>(p=0)</span>). Depending on an integration constant, we have derived two types of solutions. The dimensional reduction of the extra-dimensional scale factor is possible due to an inhomogeneity depending on the curvature of the metric for the positive cosmological constant in all solutions. The high value of entropy in the present observable universe and the possible matter leakage in 4D world due to reduction of the extra dimension are also discussed. Our solutions show an early decelerating and late accelerating nature of the universe. The findings are verified by the well-known Raychaudhuri equation.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"31 1","pages":"53 - 63"},"PeriodicalIF":1.2,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530031","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}

{"title":"Syn-MolOpt: a synthesis planning-driven molecular optimization method using data-derived functional reaction templates","authors":"Xiaodan Yin,&nbsp;Xiaorui Wang,&nbsp;Zhenxing Wu,&nbsp;Qin Li,&nbsp;Yu Kang,&nbsp;Yafeng Deng,&nbsp;Pei Luo,&nbsp;Huanxiang Liu,&nbsp;Guqin Shi,&nbsp;Zheng Wang,&nbsp;Xiaojun Yao,&nbsp;Chang-Yu Hsieh,&nbsp;Tingjun Hou","doi":"10.1186/s13321-025-00975-9","DOIUrl":"10.1186/s13321-025-00975-9","url":null,"abstract":"<div><p>Molecular optimization is a crucial step in drug development, involving structural modifications to improve the desired properties of drug candidates. Although many deep-learning-based molecular optimization algorithms have been proposed and may perform well on benchmarks, they usually do not pay sufficient attention to the synthesizability of molecules, resulting in optimized compounds difficult to be synthesized. To address this issue, we first developed a general pipeline capable of constructing functional reaction template library specific to any property where a predictive model can be built. Based on these functional templates, we introduced Syn-MolOpt, a synthesis planning-oriented molecular optimization method. During optimization, functional reaction templates steer the process towards specific properties by effectively transforming relevant structural fragments. In four diverse tasks, including two toxicity-related (GSK3β-Mutagenicity and GSK3β-hERG) and two metabolism-related (GSK3β-CYP3A4 and GSK3β-CYP2C19) multi-property molecular optimizations, Syn-MolOpt outperformed three benchmark models (Modof, HierG2G, and SynNet), highlighting its efficacy and adaptability. Additionally, visualization of the synthetic routes for molecules optimized by Syn-MolOpt confirms the effectiveness of functional reaction templates in molecular optimization. Notably, Syn-MolOpt’s robust performance in scenarios with limited scoring accuracy demonstrates its potential for real-world molecular optimization applications. By considering both optimization and synthesizability, Syn-MolOpt promises to be a valuable tool in molecular optimization.</p><p><b>Scientific contribution</b> Syn-MolOpt takes into account both molecular optimization and synthesis, allowing for the design of property-specific functional reaction template libraries for the properties to be optimized, and providing reference synthesis routes for the optimized compounds while optimizing the targeted properties. Syn-MolOpt’s universal workflow makes it suitable for various types of molecular optimization tasks.</p></div>","PeriodicalId":617,"journal":{"name":"Journal of Cheminformatics","volume":"17 1","pages":""},"PeriodicalIF":7.1,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://jcheminf.biomedcentral.com/counter/pdf/10.1186/s13321-025-00975-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the electronic, elastic anisotropy, and thermodynamic properties of Li2SiO3 and Li2GeO3 compounds using first-principles calculations","authors":"Jian-Li Ma,&nbsp;Zhi-Gang Fan,&nbsp;Qun Wei","doi":"10.1140/epjb/s10051-025-00886-6","DOIUrl":"10.1140/epjb/s10051-025-00886-6","url":null,"abstract":"<div><p>The first-principles calculation was employed to investigate the electronic structure, mechanical properties, and thermodynamic properties of Li₂SiO₃ and Li₂GeO₃ compounds. The optimized lattice parameters and atomic positions are in good agreement with the available experiment datas. The calculated formation enthalpy and elastic constant indicated that Li₂SiO₃ and Li₂GeO₃ compounds were thermodynamic and mechanical stability, respectively. The elastic properties, including bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio, were computed based on the obtained elastic constants. Furthermore, the elastic anisotropy was characterized by the graphs of three-dimensional (3D) surface constructions of elastic modulus. Finally, the longitudinal sound velocity, transverse sound velocity, Debye temperature, and minimum thermal conductivity were estimated by the elastic moduli. The obtained results can provide the relevant support of physical parameters for the development and application of Li₂SiO₃ and Li₂GeO₃ compounds.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529947","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}

{"title":"Existence and Physical Properties of Gradient Ricci–Yamabe Solitons","authors":"Sinem Güler,&nbsp;Fatma Karaca","doi":"10.1134/S0202289324700464","DOIUrl":"10.1134/S0202289324700464","url":null,"abstract":"<p>We first prove the existence of the gradient Ricci–Yamabe soliton (briefly GRYS) by constructing an explicit example endowed with the Robertson–Walker metric. Then we focus on the physical properties of the gradient Ricci–Yamabe solitons satisying Einstein’s field equations, under the assumptions of different subspaces of Gray’s decompositions. For instance, we prove that if a GRYS space-time satisfying Einstein’s field equations, in which the gradient of the potential function <span>(psi)</span> is a unit-timelike torse-forming vector field, belongs to the subspaces <span>(mathcal{B})</span> and <span>(mathcal{B}^{prime})</span>, then it is a Robertson–Walker space-time with vanishing shear and vorticity. Moreover, its possible local cosmological structures are of Petrov types I, D, or O. Finally, we obtain the equations of state of a perfect-fluid space-time admitting the GRYS whose velocity field is a unit-timelike Killing vector field.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"31 1","pages":"28 - 36"},"PeriodicalIF":1.2,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530021","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}

{"title":"Can Ring-Shaped Structures form Due to the Instability of Vertical Perturbations in a Self-Gravitating Disk?","authors":"K. T. Mirtadjieva,&nbsp;C. N. Nuritdinov,&nbsp;F. U. Botirov,&nbsp;J. M. Ganiev","doi":"10.1134/S0202289324700488","DOIUrl":"10.1134/S0202289324700488","url":null,"abstract":"<p>We study the question of whether the instability of the vertical perturbation mode of a self-gravitating disk can lead to the formation of a certain ring-shaped structure. Thus, we have discovered two modes of vertical perturbations. The gravitational instability of these perturbation modes is investigated below against the background of a radially pulsating disk model, which is a nonstationary generalization of the well-known Bisnovaty-Kogan–Zeldovich equilibrium model. The corresponding nonstationary analogues of the dispersion equation of these two modes of vertical perturbations are found. The results of the study are presented in the form of critical dependencies of the initial virial ratio on the disk rotation parameter. It is shown that with an increase in the disk’s degree of rotation, there decreases the range of the initial virial ratio at which ring structures can form. The initial physical conditions, criteria and the corresponding mechanisms for the formation of ring-shaped structures due to the instability of the bending mode of the vertical perturbation are determined. A comparative analysis of the gravitational instability increments of the annular horizontal and vertical perturbation modes is also carried out.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"31 1","pages":"46 - 52"},"PeriodicalIF":1.2,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530030","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}

{"title":"Bondi Accretion onto a Damour–Solodukhin Wormhole","authors":"R. M. Yusupova,&nbsp;R. Kh. Karimov,&nbsp;A. Bhattacharya","doi":"10.1134/S0202289324700476","DOIUrl":"10.1134/S0202289324700476","url":null,"abstract":"<p>The Damour–Solodukhin wormhole (hereinafter DSWH) is known to mimic a Schwarzschild black hole (hereinafter SBH) horizon in some properties. To act as a mimicker, the DSWH parameter <span>(lambda)</span> by definition is required to be extremely tiny, i.e., <span>(lambdasim 0)</span>. Our comparative analysis shows that such a requirement may be too restrictive at least as far as the Bondi accretion profiles of the two objects, the DSWH and SBH, are concerned. Intriguingly, it turns out that some profiles of a DSWH mimic those for the SBH near the horizon even at values of <span>(lambda)</span> considerably higher, i.e., <span>(lambdasim 1)</span>.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"31 1","pages":"37 - 45"},"PeriodicalIF":1.2,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530032","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}