Conventional Theory Research Articles

Fiscal support during the COVID-19 pandemic and its determinants: evidence for OECD countries

ABSTRACT This study examines the factors influencing governments’ fiscal support strategies during the pandemic, aiming to contribute to sustainable development. Through an analysis of data from 34 prominent economies, representative of OECD countries, up to the conclusion of 2022, and utilizing GMM regression analysis, we challenge conventional economic theories. Contrary to expectations, governments opted to reduce tax rates amid the pandemic, resulting in decreased revenue due to lockdown-induced economic disruptions. These findings underscore the imperative of expanding fiscal support during pandemics for progress toward Sustainable Development Goals (SDGs), particularly SDG 3 (Good Health and Wellbeing) and SDG 10 (Reducing Inequality).

Building an agreement in a farming cooperative governance: A Sociology of conventions approach

This study examines how a board of directors and management team establish an agreement under an agricultural cooperative governance structure. We carried out a case study of an agricultural cooperative based in France, the board members and management team of which were interviewed and observed for over four years regarding their ability to create and maintain an agreement in the governance of the cooperative. Building on the theory of conventions, our findings indicate that board members' and managers' hybridity constitutes the basis for establishing a compromise and developing a trusting relationship between board members and managers. Furthermore, we highlighted the chairperson's crucial role in building, negotiating, and permanently repairing cohesion between these two bodies. Our study contributes to a more holistic understanding of the relationship between the board and management by explaining how previous experiences in different “worlds” (e.g., farming, cooperative, commercial) create hybrid individuals and how this facilitates agreement between actors with different dominant logics.

Theoretical and kinetic study of the H-atom abstraction reactions by Ḣ atom from alkyl cyclohexanes.

Reaction kinetics of hydrogen atom abstraction from six alkyl cyclohexanes, methyl cyclohexane (MCH), ethyl cyclohexane (ECH), n-propyl cyclohexane (nPCH), iso-propyl cyclohexane (iPCH), sec-butyl cyclohexane (sBCH) and iso-butyl cyclohexane (iBCH), by the Ḣ atom are systematically studied in this work. The M06-2X method combined with the 6-311++G(d,p) basis set is used to perform geometry optimization, frequency analysis and zero-point energy calculations for all species. The intrinsic reaction coordinate (IRC) calculations are performed to confirm the transition states connecting the reactants and products correctly. One-dimensional hindered rotors are used to treat the low frequency torsional models with potentials scanned at the M06-2X/6-31G level of theory. Electronic single-point energy calculations for all reactants, transition states, and products are performed at the QCISD(T)/CBS level of theory. High-pressure limiting rate constants of 39 reaction channels are obtained using conventional transition state theory with asymmetric Eckart tunneling corrections in the temperature range 298.15-2000 K. Reaction rate rules for H-atom abstraction by the Ḣ atom from alkyl cyclohexanes on primary, secondary and tertiary carbon sites on both the side chain and ring are provided. The obtained rate constants are given by the Arrhenius expression in the temperature range 500-2000 K, which can be used for the combustion kinetics model development for alkyl cyclohexanes.

Theoretical study on the H-atom abstraction reactions of pentanol + HȮ2, part I: five branched pentanol isomers.

The chemical kinetic studies of hydrogen atom (H-atom) abstraction reactions by hydroperoxyl (HȮ2) radicals from five branched pentanol isomers, including 3-methyl-1-butanol, 2-methyl-1-butanol, 1,1-dimethyl-1-propanol, 1,2-dimethyl-1-propanol, and 2,2-dimethyl-1-propanol were investigated systematically through high-level ab initio calculations. Geometry optimization, frequency analysis, and zero-point energy (ZPE) corrections were performed for six reactants, twenty-three transition states (TSs), and twenty-four products at the M06-2X/6-311++G(d,p) level of theory. The intrinsic reaction coordinate calculation was performed at the same level of theory to confirm the transition state connection. The one-dimensional hindered rotor treatment for low-frequency torsional modes was also treated at the M06-2X/6-311++G(d,p) level of theory. The QCISD(T)/CBS level of theory was used to calculate the single-point energies for the species whose T1 diagnostic value was lower than 0.035. At the same time, the CASPT2/CBS level of theory was used to calculate the single-point energies for the channel in which the T1 diagnostic value of transition states was greater than 0.035. Rate constants for the H-atom abstraction reactions from the five branched pentanol isomers by HȮ2 radicals were calculated by using conventional transition state theory with asymmetric Eckart tunneling corrections in the temperature range of 500-2000 K. Rate constants and branching ratios for the title reactions and the rate rules for ten different H-atom abstraction types were investigated. Temperature-dependent thermochemistry properties for all reactants and products were calculated by the composite methods of G3/G4/CBS-QB3/CBS-APNO, which were in good agreement with the data available in the literature. Rate constants for the H-atom abstraction reactions by HȮ2 radical from branched pentanol isomers were investigated in this work as part I, and those for linear pentanol isomers will be analyzed in part II. All the calculated kinetics and thermochemistry data can be utilized in the model development for branched pentanol isomers oxidation.

Record high electron mobilities in high-purity GaN by eliminating C-induced mobility collapse

Impact of carbon impurities on the electrical properties of lightly doped n-type GaN [electron concentration ∼(1–2)×1015 cm−3 at room temperature] was investigated using temperature-dependent Hall effect measurements. GaN crystals with a threading dislocation density of (1–3)×106 cm−2 were grown by our originally developed quartz-free hydride vapor phase epitaxy method, which enabled the background Si, O, and C concentrations to be suppressed to below the mid-1014 cm−3 range. We prepared three samples with different C concentrations ([C]) by intentional C doping. The C incorporation induced severe mobility collapse at temperatures greater than 60 K, where the measured mobility decreased and deviated from the theoretical value as [C] increased. The mobility collapse was eliminated for the purest GaN crystal with [C] ∼1.4×1014 cm−3, exhibiting a record high room-temperature mobility of 1480 cm2/(V·s), as well as a record high maximum mobility of 14 300 cm2/(V·s) at 62 K. The latter was almost double the previous record. We found that the overall mobility behavior can be well reproduced by adding an empirical [C]-dependent mobility component expressed as μUNK=K/TnUNK with 1≤nUNK≤2 and K∝C−1 to the conventional mobility theory (phonon and impurity scattering). Although the mechanism of the component remains uncertain, our findings provide insight into the unsolved issue of mobility collapse.

Steering non-Hermitian skin states by engineering interface in 1D nonreciprocal acoustic crystal

Topological insulators, which possess robust topologically protected properties for manipulating the wave propagation against the disorder and defects, have grown into a large research field in photonic and phononic crystals. However, the conventional topological band theory is used to describe a closed photonic/phononic crystal that is assumed to be Hermitian system. In fact, practical physical systems often couple with outside environment, and induce non-Hermitian Hamiltonian with complex eigenvalues. Recently, many novel topological properties have been induced by the interacting between non-Hermitian and topological phases, a prominent example is non-Hermitian skin effect that all eigenstates are localized to the boundary in open system, which different from the conventional topological edge states. The unique physical phenomenon has stimulated various applications, such as wave funneling, enhanced sensing, and topological lasing. In this work, we describe the non-Hermitian skin effect using winding numbers. The sign of the winding number determines the rotation direction of the loops in the complex frequency plane, which the sign can be controlled by the nonreciprocal coupling direction. In this context, we designed different topological skin interface between different domains with opposite winding numbers to manipulate the energy focusing to middle or two-end of non-Hermitian 1D acoustic cavity chain. In experiment, we used an electroacoustic coupling method, employing a unidirectional coupler composed of microphones, speakers, phase shifters, and amplifiers, to introduce positive and negative non-reciprocal couplings between the two acoustic cavities and studied the characteristics of these non-reciprocal couplings. Then, the non-reciprocal coupling cavities were extended into a chain structure, and the magnitude and sign of the non-reciprocal couplings were flexibly controlled using phase shifters and amplifiers. Through this method, we successfully constructed interfaces between different winding numbers, achieving a one-dimensional non-Hermitian skin effect at various interfaces. The experimental results indicate that the sound can be focused at middle interface or two-end interfaces for different nonreciprocal coupling distributions, and the skin interface can also be switched from middle to two-end by exchanging the nonreciprocal coupling direction of the domains. Our research results offer greater flexibility in the design of acoustic devices and may provide a new platform for exploring advanced topological acoustic systems for controlling sound propagation.

SOLVING THE UKRAINIAN DEMOGRAPHIC DISASTER: A POSTMODERN PERSPECTIVE

This paper explores the demographic crisis in Ukraine through the innovative lens of postmodern theory. Departing from traditional approaches, the authors argue that solving the country's pressing issues of low birth rates and high mortality, especially among the elderly, requires a comprehensive, interdisciplinary strategy grounded in postmodern principles. The analysis first situates Ukraine's demographic woes within the broader global context of climate change, socioeconomic inequality, mass migration, and technological disruption - factors that heighten the complexity of the challenge. It then delves into the specific demographic data, examining not only the statistical trends, but also the sociocultural shifts impacting family formation and reproductive behaviors. Drawing on postmodern concepts of complexity, diversity, anti-universalism, and emphasis on inclusion, the paper proposes a multi-faceted set of solutions. These range from promoting individual expression and creativity, to developing targeted policies supporting young families, revamping migration frameworks, combating discrimination, and even exploring the potential of reproductive technologies. Importantly, the authors frame these interventions within the context of a new national idea centered on preserving and strengthening Ukrainian identity. Ultimately, this study represents a bold, unconventional approach to the demographic crisis, challenging conventional demographic theories and offering a fresh, contextual perspective rooted in postmodern thought. Its findings hold significant implications for policymakers, academics, and civil society stakeholders seeking innovative pathways to address Ukraine's pressing demographic challenges.

Flexible hydrogels connecting adhesion and wetting.

Raindrops falling on window-panes spread upon contact, whereas hail can cause dents or scratches on the same glass window upon contact. While the former phenomenon resembles classical wetting, the latter is dictated by contact and adhesion theories. The classical Young-Dupre law applies to the wetting of pure liquids on rigid solids, whereas conventional contact mechanics theories account for rigid-on-soft or soft-on-rigid contacts with small deformations in the elastic limit. However, the crossover between adhesion and wetting is yet to be fully resolved. The key lies in the study of soft-on-soft interactions with material properties intermediate between liquids and solids. In this work, we translate adhesion to wetting by experimentally probing the static signature of hydrogels in contact with soft PDMS of varying elasticity of both the components. Consequently, we probe this transition across six orders of magnitude in terms of the characteristic elasto-adhesive parameter of the system. In doing so, we reveal previously unknown phenomenology and a theoretical model which smoothly bridges adhesion of glass spheres with total wetting of pure liquids on any given substrate.

Non-uniform magnetic fields for single-electron control.

Controlling single-electron states becomes increasingly important due to the wide-ranging advances in electron quantum optics. Single-electron control enables coherent manipulation of individual electrons and the ability to exploit the wave nature of electrons, which offers various opportunities for quantum information processing, sensing, and metrology. Here we explore non-uniform magnetic fields, which offer unique mechanisms for single-electron control. Considering the modeling perspective, conventional electron quantum transport theories are commonly based on gauge-dependent electromagnetic potentials. A direct formulation in terms of intuitive electromagnetic fields is thus not possible. In an effort to rectify this, a gauge-invariant formulation of the Wigner equation for general electromagnetic fields has been proposed [M. Nedjalkov et al., Phys. Rev. B, 2019, 99, 014423]. However, the complexity of this equation requires the derivation of a more convenient formulation for linear electromagnetic fields [M. Nedjalkov et al., Phys. Rev. A, 2022, 106, 052213]. This formulation directly includes the classical formulation of the Lorentz force and higher-order terms, depending on the magnetic field gradient, that are negligible for small variations of the magnetic field. In this work, we generalize this equation in order to include a general, non-uniform electric field and a linear, non-uniform magnetic field. The thus obtained formulation has been applied to investigate the capabilities of a linear, non-uniform magnetic field to control single-electron states in terms of trajectory, interference patterns, and dispersion. This has led to the exploration of a new type of transport inside electronic waveguides based on snake trajectories and the possibility of splitting wavepackets to realize edge states.

Physical properties of ferromagnetic Mn-doped double perovskites (DPs) Cs2AgInCl/Br6 for spintronics and solar cell devices: DFT calculations.

A computational framework based on density functional theory (DFT) has been effectively employed to investigate the wide-ranging physical characteristics of ferromagnetic manganese (Mn)-substituted double perovskites (DPs) with composition Cs2AgIn1-xMnxCl/Br6 (x = 0.0, 0.25). This research covers a systematic exploration of the mentioned DPs for potential applications in the domains of spintronics and energy conversion devices. The physics concerning ferromagnetic (FM) Cs2AgIn0.75Mn0.25Cl/Br6 DPs was studied computationally using the modified Becke-Johnson (mBJ-LDA) potential and the generalized gradient approximation (PBEsol GGA) method introduced by Perdew, Burke, and Ernzerhof. The structural, electronic, magnetic, and transport behavior of materials were investigated using these computations. Structural parameters for both perovskite materials were computed subsequent to their optimization in FM phase. According to evaluations of the electronic band structure and density of states (DOS), the incorporation of Mn ions into the host lattice causes exchange splitting induced by p-d hybridization, consequently stabilizing the FM state. Probing the sharing of magnetic moment, charge, and spin between the substituent cations and the host anions led to the comprehensive elaboration of this exchange splitting of bands. Important parameters such as exchange constants (N0α, N0β), and direct spin-exchange splitting Δx(d), support the stability of the FM state. Finally, we briefly explored the spin effect on other aspects of electronic transport, the Seebeck coefficient, and the power factor, using the conventional Boltzmann transport theory.

Analytical solutions for the thermo-mechanical bending of FG beams using a higher order shear deformation theory (HSDT)

The aim of this paper is to analyze a thermo-mechanical behavior of functionally graded beam in thermal environment. Therefore, this research work investigates a thermal, mechanical and thermo-mechanical bending of functionally graded beam resting on simple supports and using a higher order shear deformation theory. the proposed kinematic uses only three variables, which is even less than the first order shear deformation theory (FSDT) and the conventional higher order shear deformation theories (HSDTs). The present model adopts a new displacement field, The material properties of the FG beam are varied along the thickness direction according to the power law distribution (P-FGM). The governing equations for the thermo-mechanical bending investigation are obtained through the principal of virtual work and solved via Navier-type solution method was used to obtain results. All the results are presented in non-dimensional form and validated it by developing the classical beam theory (CBT), and other higher order theories. Parametric studies are thus elaborated to see the influence of the characteristic’s geometries and mechanical in particular: thickness of the FG beam, material index and ratio (width, length).

Oxidation pathways and kinetics of the 1,1,2,3-tetrafluoropropene (CF2CF-CH2F) reaction with Cl-atoms and subsequent aerial degradation of its product radicals in the presence of NO.

To give a comprehensive account of the environmental acceptability of 1,1,2,3-tetrafluoropropene (CF2CF-CH2F) in the troposphere, we have examined the oxidation reaction pathways and kinetics of CF2CF-CH2F initiated by Cl-atoms using the second-order Møller-Plesset perturbation (MP2) theory along with the 6-31+G(d,p) basis set. We also performed single-point energy calculations to further refine the energies at the CCSD(T) level along with the basis sets 6-31+G(d,p) and 6-311++G(d,p). The estimation of the relative energies and thermodynamic parameters of the CF2CF-CH2F + Cl reaction clearly shows that Cl-atom addition reaction pathways are more dominant compared to H-abstraction reaction pathways. The value of the rate coefficient for each reaction channel is calculated using the conventional transition state theory (TST) over the temperature range of 200-1000 K at 1 atm. The estimated overall rate coefficients for the title reaction are found to be 1.10 × 10-12, 1.21 × 10-10, and 1.13 × 10-8 cm3 per molecule per s via the respective calculation methods viz. MP2/6-31+G(d,p), CCSD(T)//MP2/6-31+G(d,p), and CCSD(T)/6-311++G(d,p)//MP2/6-31+G(d,p), at 298.15 K. Moreover, the calculated rate coefficients and percentage branching ratio values suggest that the Cl-atom addition reaction at the β-carbon atom is more preferable to that of the α-carbon addition to CF2CF-CH2F. Based on the rate coefficient values calculated by the three different methods, the atmospheric lifetime for the title reaction at 298.15 K is estimated. The radiative efficiency (RE) and Global Warming Potential (GWP) results of the title molecule show that its GWP would be negligible. Further, we have explored the degradation of its product radicals in the presence of O2 and NO. From the degradation results, we have found that CF2(Cl)COF, FCOCH2F, FCFO and FCOCl are formed as stable end products along with various radicals such as ˙CF2Cl and ˙CH2F. Therefore, these findings of kinetic and mechanistic data can be applied to the development and implementation of a novel CFC replacement.

Oral health in lower middle-income African societies - surprising outcomes and strategic consequences

Objective: To assess the oral health status of the population in selected African countries and compare the outcomes with emerging and highly developed countries worldwide using quantifiable results. Method: By means of a composite indicator - the Dental Health Index (DHI) - the dental status of a country´s entire population is measured to arrive at a ranking of oral health performance. This performance is then compared with countries belonging to other development stages. The present study is descriptive and, whenever possible, uses existing epidemiological data from national representative surveys. Results: With the exception of Rwanda, the Sub-Saharan African countries performed better than the three North African countries of Egypt, Morocco and Tunisia, although the Arabic-speaking countries have higher Human Development Indices by comparison. Within Sub-Saharan Africa, the best rankings were achieved by Uganda, Kenya and Nigeria. However, the other Sub-Saharan countries studied also exhibited similarly low DHIs. Rwanda, Egypt, Tunisia and Morocco ranked last. One striking finding is that the Sub-Saharan countries studied show more favourable DHI outcomes than emerging or high-income countries. As large parts of the African population have been widely untouched for decades by dental services, the relatively favourable outcomes in African societies are difficult to explain and contradict conventional dental theory. The reasons behind this finding are not fully understood. It is only in the area of untreated oral diseases that the African countries perform much worse than the more developed countries. Conclusion: If African countries were to concentrate their scarce resources on a few vital segments of oral health, they would have the opportunity, in light of favourable morbidity structures, to gradually improve the oral health status of large parts of the population. Should they choose this route, priority should be given to the young generation. Three key action fields are decisive: mobilising oral self-care, enlarging the dental workforce by training sufficient mid-level personnel and creating a true primary oral health care system which is community-centred and complemented by strictly preventive, minimally invasive and tooth-retaining treatments under the guidance of a strong public sector.

Theory of Space Quantization (Tsq) Driven Version of the Conventional Theories of Physics, Relativity and Gravitation-A Concise Report

The global scientific community at the moment is awaiting passionately for a ‘Theory of Everything’ (TOE) and the level of expectation of the said community is, i) the Theory has to be very robust and versatile ii) the theory should be in a position to fully explain and connect all the happenings and aspects of the universe and iii) the said TOE has to be a multi block compatibilizing one (is in harmony with the existing theories of physics) and as well has to establish the fact that the theories of physics proposed so far, though have been presented in many different forms but they are inherently being identical by their origins or routes. In this small article it is being reported that the recently discovered ‘ Topological Theory of Quantum gravity (TTQG) or the ‘ Theory of Space Quantization’ (TSQ) has already unified the theories of ‘Newtonian physics or classical physics’, ‘thermodynamics’, ‘quantum mechanics’, ‘cosmological theories’ and the ‘theories of relativities’ under a single umbrella and revealed the dimensionalities of ‘time’ , ‘mass’, ‘space expansion-space inversion’ of the universe , geometries of ‘gravitation’ the ‘singularity’ and the dimensionality of the universe itself and as well presented an ‘Universal Graviton Cycle’ to explain most of the cosmic/astronomical phenomena of the universe in a single frame. It is a first foot step of TSQ or TTQG to ultimately converge to the ‘Theory of Everything’.

A Study on Familiarity Bias in Investor Decision-Making

Abstract: For a considerable amount of time, conventional finance theories have maintained that investors make judgments based on logical analyses and economic models. But the development of behavioral finance casts doubt on this notion, showing that emotions, cognitive biases, and natural tendencies frequently influence human decision-making. This study looks into familiarity bias, a psychological component that affects investor decisions, and how common it is. Using a thorough methodology, the study examines investor choices in the banking, FMCG, and auto mobile industries. Results repeatedly point to a considerable preference for well-known businesses, even in situations when risks and returns on investment are similar. Investors exhibit behavioral biases and brand loyalty; familiarity bias is particularly persistent across various investor profiles. The findings show that investors, irrespective of expertise level, devote a sizeable chunk of their capital to reputable businesses. The results of hypothesis testing show relationships between gender and familiarity bias as well as between different investor types according to holding length and risk. However, monthly income did not show a significant correlation with familiarity bias, indicating that it is prevalent at different income levels. The study comes to the conclusion that a thorough understanding of investor decision-making requires an awareness of behavioral biases.

Unintentional Evolution: The Rise of Reciprocal Altruism

In this study, we propose a groundbreaking hypothesis for the evolution of reciprocal altruism, suggesting its emergence from random encounters characterized by theft rather than the traditionally accepted cooperative reciprocation and intertemporal choice. We challenge the conventional theory, critiquing its circular reasoning that presupposes cooperation to explain its own origin. Our approach posits that theft, when passively tolerated during times of abundance, does not negatively impact survival and reproduction. This leads to a novel understanding of cooperation as a form of “tolerated theft”. To support our theory, we developed a Python-based simulation model that succinctly demonstrates how this mechanism could operate. Our key finding is that in environments where theft is tolerated, offspring may evolve to overlook such acts, eventually emerging as reliable reciprocators in times of scarcity. This hypothesis, while potentially controversial due to its originality, opens up new perspectives on the accidental evolution of reciprocal altruism and encourages a reevaluation of the fundamental mechanisms driving cooperative behaviors.

Development of a rapid solidification model for additive manufacturing process and application to Al-Si alloy

Accurate prediction of the solidification microstructure produced by additive manufacturing (AM) process is indispensable for the precise manufacturing process control. In the present study, a simple solidification model that can be applied to the powder bed fusion – laser beam (PBF-LB) process has been developed by integrating conventional and rapid solidification theories in literature. Based on the solidification parameters calculated by Rosenthal equation, the present solidification model can predict the primary dendrite arm spacing (PDAS), primary cell fraction, and solute profile using solute trapping, dendrite tip undercooling, and eutectic undercooling. Single track experiments for Al-12Si binary alloy were also performed to validate the accuracy of the model.

Addressing the Challenges of English Language Acquisition among Social Science Students in Resource Constrained Environments

A portrayal of pedagogical, motivational and resource dilemmas that hinder students in the acquisition of English language is discussed in this study. The study shows that students hardly bothered to learn English because they do not see any relevance of the language to their future professions. This is made worse by conventional theories which have insisted on mechanical language acquisition, memorization, drilling for grammar rules and structures without the development of communicative efficiency, and lack of instruction based on the individual learning abilities of the learners. Also, extreme scarcity of resources such as the English texts and technological facilities sufficiently affect opportunities of student language practice beyond the classroom. The study suggests that it is necessary to use more comprehensive approaches for overcoming these challenges such as changes is curricular in order to align it to English and students and their career needs, using more communicative and interactive methods, and supporting teachers for the implementation of differentiation. The study brings out important information that aligns well with other research done on language education especially in the developing countries so a policy maker or a practitioner you will find useful information to act on.

Vacuum-field-induced state mixing

By engineering the electromagnetic vacuum field, the induced Casimir-Polder shift (also known as Lamb shift) and spontaneous emission rates of individual atomic levels can be controlled. When the strength of these effects becomes comparable to the energy difference between two previously uncoupled atomic states, an environment-induced interaction between these states appears after tracing over the environment. This interaction has been previously studied for degenerate levels and simple geometries involving infinite, perfectly conducting half-spaces or free space. Here, we generalize these studies by developing a convenient description that permits the analysis of these non-diagonal perturbations to the atomic Hamiltonian in terms of an accurate non-Hermitian Hamiltonian. Applying this theory to a hydrogen atom close to a dielectric nanoparticle, we show strong vacuum-field-induced state mixing that leads to drastic modifications in both the energies and decay rates compared to conventional diagonal perturbation theory. In particular, contrary to the expected Purcell enhancement, we find a surprising decrease of decay rates within a considerable range of atom-nanoparticle separations. Furthermore, we quantify the large degree of mixing of the unperturbed eigenstates due to the non-diagonal perturbation. Our work opens new quantum state manipulation possibilities in emitters with closely spaced energy levels.

Time Dependence of the Graphene Surface Adhesion Force of the Sphere-Plane Contact at Different Relative Humidities.

Graphene has a promising application prospect in integrated circuits and microelectromechanical systems, and sphere-plane contacts are their common contact types. At present, it is difficult to explain the time dependence of the adhesion force of the sphere-plane contact by conventional theory. Therefore, a single rough peak of sphere-plane contact adhesion force model based on variable water contact angle theory and Bradley contact theory was established; the aim is to reveal the changing law of graphene adhesion force. Then, the time dependence of the graphene surface adhesion force at different humidity levels was investigated by using an atomic force microscopy spherical probe. Finally, a quantitative comparative analysis of the theory and experiment was performed. The results show that the theoretical adhesion force was in good agreement with the experimental measurement results. The time dependence of graphene surface adhesion was not obvious within a relative humidity of 45-55%. When the relative humidity was greater than 65%, the graphene surface adhesion first increased and then decreased with dwell time and finally tended to be stable. Because of the increase in relative humidity, the capillary condensation effect increases, and then the adhesion force increases with the development of the meniscus. When the water film was generated on the sample surface, the adhesion force decreased until the meniscus achieved equilibrium.