Dissipation Energy in Tapping-Mode Atomic Force Microscopes Caused by Liquid Bridge

The dissipation of energy during the process of contact and separation between a tip and a sample is very important for understanding the phase images in the tapping mode of atomic force microscopes（AFMs）. In this study, a method is presented to measure the dissipated energy between a tip and a sample. The experimental results are found to be in good agreement with the theoretical model, which indicates that the method is reliable.Also, this study confirms that liquid bridges are mainly produced by extrusion modes in the tapping mode of AFMs.

Energy of the Gravitational Field as an Equivalent of the Dark Energy of the Universe

Determination of the structural foundations and parameters of the Universe is an important urgent task since it enables us to understand and explain the structure and basic parameters of the material world. Herewith, it is necessary to be aware of modern problems of physics and possible ways to solve them. Among such problems, hypotheses concerning dark matter and the energy of the Universe occupy an important place. However, the determination of their on the basis of modern theories still leads to abstract equations that do not give concrete results;therefore, they have a level of hypotheses. A number of initial scientific propositions based on this abstract of mathematical dependencies have controversial meanings. Elimination of this disadvantage is the main goal of the work performed. Its main difference and scientific novelty are the justification of the energy parameters of the gravitational field of the Universe, the magnitude of which can replace its dark energy and dark mass. The solution to this problem is justified by strict physical dependencies, which are obtained on the basis of fundamental physical constants. It is an urgent and important scientific and applied problem, since it develops knowledge about the gravitational field and the material world in general. The performed work is based on the methods of deduction and induction in the research of the material world based on the application of the well-known reliable laws of physics and the general principles of the development of the theory of knowledge. Other research methods are still unknown, since the work performed is associated with new scientific discoveries, the search for which is difficult to formalize by technique methods. The results of the study consist of the analysis of wave, force and energy parameters of the relict gravitational field of the Universe. The calculated value of this energy is 1.58 × 1070 J. This energy is enough to cover the amount of dark energy and mass in the Universe, which casts doubt on their existence. Conclusions: This paper can supplement previously performed research on the dark mass and energy of the Universe, which requires further for their reconciliation.

Mechanical Properties of Simple s-p Metals, and Defect Energies from Electron Theory and from Interatomic Force Laws

The cleavage force F(z) needed to separate parallel atomic planes by a distance z is first discussed for simple s-p metals using density functional theory.For the s-p nearly free-electron metals the linearized Thomas-Fermi equation is solved self-consistently in the cases of (a) semi-infinite planes of jellium (i.e. smeared uniform positive ions) and (b) a semi-infinite cylinder of finite radius, cleaved by a plane perpendicular to its axis. In (a), the elastic region has the form F(z)=Az ∝ Zrs-11/2, where rs is the mean interelectronic distance in the jellium model. Size effects are then considered, with possible relevance to atomic force microscopy.Defect energies are treated, using both electron theory and pair force laws.

The Formation of the Electronic Tornado is the Basis of Superconductivity

The space-time ladder theory reveals that the formation of electronic tornadoes,or the formation of electronic dissipative structures,to be precise,the enhancement of electronic Energy Qi field is the basis of superconductivity.The surrounding area of the electronic tornado is expanding,which is the basis of the Meissner effect,and the center is contracting,which is the basis of the pinning force.When the attractive force of the Energy Qi field is greater than the Coulomb repulsive force,the electrons form a Cooper pair and release dark energy into virtual space-time.When the dark energy increases to a certain extent,the virtual space-time frees the Cooper pair and forms an electron-virtual space-time wave,which fluctuates freely in the superconducting material,which is the basis for the superconducting resistance to be zero.This is similar to the principle of a hot air balloon.The virtual space-time is hot air and the electron pair is a hot air balloon device.Conductor electrons are free and easy to emit dark energy,resulting in insufficient dark energy,and it is not easy to form electron-pair virtual space-time waves,so the superconducting critical temperature is very low.This is because the emission coefficient of the conductor is too high.Insulator electrons are not easy to emit dark energy and easily form electron-pair virtual space-time waves.Therefore,the superconducting critical temperature is slightly higher because of the low emission coefficient of the insulator.The solution of the Qi-space-time wave equation,that is,the coherence coefficient,is an important factor in superconductivity.In addition,the conditions under which tornadoes form are also an important basis for superconductivity.Finally,it is emphasized that the coherence coefficient and prevention of dark energy emission are the two most important elements for preparing superconducting materials.

Forced vibration control of an axially moving beam with an attached nonlinear energy sink

This paper investigates a highly efficient and promising control method for forced vibration control of an axially moving beam with an attached nonlinear energy sink（NES）.Because of the axial velocity,external force and external excitation frequency,the beam undergoes a high-amplitude vibration.The Galerkin method is applied to discretize the dynamic equations of the beam–NES system.The steady-state responses of the beams with an attached NES and with nothing attached are acquired by numerical simulation.Furthermore,the fast Fourier transform（FFT）is applied to get the amplitude–frequency responses.From the perspective of frequency domain analysis,it is explained that the NES has little effect on the natural frequency of the beam.Results confirm that NES has a great potential to control the excessive vibration.

A capillary force model for interactions between two spheres

Based on the method of energy principle, an analytical approach for computing the capillary force for sphere/sphere geometry is presented in this paper. In modeling the capillary force, we consider spheres with both equal and non-equal radii, for both symmetric and asymmetric configurations at liquid/solid interfaces. We use numerical analysis to investigate the validity and efficiency of the derived model. The effect of various parameters including humidity, distance between two spheres, radii of spheres and contact angles on the meniscus force are investigated. Finally the results obtained from the model are compared with experimental measurements, and the accuracy and precision of the presented approach is verified.

Effect of protein on PVDF ultrafiltration membrane fouling behavior under different pH conditions： interface adhesion force and XDLVO theory analysis

To further detem3ine the fouling behavior of bovine serum albumin （BSA） on different hydrophilic PVDF ultrafiltration （UF） membranes over a range of pH values, self-made atomic force microscopy （AFM） colloidal probes were used to detect the adhesion forces of membrane-BSA and BSA BSA, respectively. Results showed that the membrane-BSA adhesion interaction was stronger than the BSA-BSA adhesion interaction, and the adhesion force between BSA-BSA-fouled PVDF/PVA membranes was similar to that between BSA-BSA-fouled PVDF/PVP membranes, which indicated that the fouling was mainly caused by the adhesion interaction between membrane and BSA. At the same pH condition, the PVDF/PVA membrane-BSA adhesion force was smaller than that of PVDF/ PVP membrane-BSA, which illustrated that the more hydrophilic the membrane was, the better antifouling ability it had. The extended Derjaguin-Landau-Verwey Overbeek （XDLVO） theory predicts that the polar or Lewis acid-base （AB） interaction played a dominant role in the interracial free energy ofmcmbrane-BSA and BSA BSA that can be affected by pH. For the same membrane, the pH values of a BSA solution can have a significant impact on the process of membrane fouling by changing the AB component of free energy.