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In this paper, we study the electroosmotic transport in a nanofluidic channel by using a mean-field theory accounting for non-uniform size effect and solvent polarization effect. We witness that in the presence of the given zeta potential, an enhancement of ion size invariably lowers the electroosmotic velocity, thereby increasing the magnitude of electrostatic potential, irrespective of considering solvent polarization. It is also proved that solvent polarization allows both the magnitude of electrostatic potential and the electroosmotic velocities to decrease. In addition, we find that increasing zeta potential augments not only ion size effect but also solvent polarization effect. Furthermore, we demonstrate that decreasing bulk ion number density causes an increase in electroosmotic velocity at the centerline. We compare the properties of aqueous electrolytes with those of the electrolytes where solvent is ethylalcohol. Finally, we study how solvent polarization and ionic size affect streaming potential and electroviscous effect. It is emphasized that the present study can provide a good way to control the nanofluidic transport for a plethora of biological and industrial applications.

We theoretically study the size effect of water molecule clusters not only on electrostatic interaction between two charged surfaces in an aqueous electrolyte but also on electroosmotic transport in a nanofluidic channel. Applying a free energy based mean-field approach accounting for different sizes of ions and water molecule clusters, we derive a set of coupled equations to compute electrostatic and electroosmotic properties between charged surfaces. We verify that the smaller the size of a water cluster, the stronger the electroosmotic transport in nanofluidic channels. In addition, we find that an increase in size of a water cluster yields a decrease in electrostatic interaction strength between similar or oppositely charged planar surfaces.

In this paper is considered nonlinear electrodynamics (NE) which does not satisfy the linear superposition principle (LSP). Since the presentation of the special theory of relativity, it has been commonly accepted that a famous formula E = mc^2 = m_0c^2 /(1-v^2/c^2)^(1/2) expresses the energy of a free particle only. However, while studying the experiment for the annihilation of particle and antiparticle and the production of the photon in terms of the law of energy conservation of particle and field, we obtain a conclusion that E includes not only the energy of a free particle but also the energy of its self -fields (electromagnetic field and gravitational field). Hence, a formula for the energy in the special theory of relativity comes to have a more inclusive meaning than Einstein had thought of it. Based upon such an idea and the correspondence principle, through introducing a new non-Euclidean four-dimensional space, so-called KR space in which the metric is the function of coordinates and 4-velocity, we reformulate the action function to be a function defined in the nonlinear version and from it find equation system for a charge and the field with a modified version, which is reduced to that in the Maxwell theory under the weak field condition: here, weak field condition is given by |U/m_0c^2|<<1, U; interactional energy. With the equation system, we show that the divergence problem arising from the Maxwell theory, without invoking renormalization, is very naturally solved by sensible mathematics and then demonstrate that the total energy of a free charge and its field equals mc^2 and so the energy of an electrostatic field leads to the finite. In this course are derived the modified version of Coulomb potential and of radiation reaction without renormalization which contains an interference effect (a nonlinear effect that does not obey LSP)., Comment: 56 pages, 1 figure

The power-law distribution is ubiquitous and its mechanism seems to be various. We find a general mechanism for the distribution. The distribution of a geometrically growing system can be approximated by a log - completely squared chi distribution with 1 degree of freedom (log-CS$\chi_1$), which reaches asymptotically a power-law distribution, or by a log-normal distribution, which has an infinite asymptotic slope, at the upper limit. For the log-CS$\chi_1$, the asymptotic exponent of the power-law or the slope in a log-log diagram seems to be related only to the variances of the system parameters and their mutual correlation but independent of an initial distribution of the system or any mean value of parameters. We can take the log-CS$\chi_1$ as a unique approximation when the system should have a singular initial distribution. The mechanism shows a comprehensiveness to be applicable to wide practice. We derive a simple formula for the Zipf's exponent, which will probably demand that the exponent should be near -1 rather than exactly -1. We show that this approach can explain statistics of the COVID-19 pandemic.

In most studies on all-optical diodes spatial asymmetry has been by necessity applied to break Lorentz reciprocity. Here we suggest a paradigm for optically induced nonreciprocity in semiconductor wires which are spatially asymmetry-free and provide a very simple and efficient platform for plasmonic devices. An azimuthal magnetic field induced by a plasmonic pump in the semiconductor wire alters the material parameters and thus results in a cross-nonlinear modulation of the plasmonic signal. Peculiarly the nonlinear wavenumber shift has opposite signs for forward and backward signals whereas Kerr or Kerr-like nonlinearity does not break Lorentz reciprocity in spatially symmetric structures. This principle may open an avenue towards highly integrated all-optical nonreciprocal devices.

The effects of purification methods and its hypolipidemic function on the total flavonoids of Aurea Helianthus flower were investigated. Liquid-liquid extraction of ethanol extract from Aurea Helianthus flower was carried out by using different polar solvents. The extract with the highest total flavonoid content was selected, and the optimal conditions for purification of total flavonoids were determined by purification with macroporous resin. The human digestive environment was simulated in vitro, and the binding ability of different flavonoid samples to three kinds of cholate was compared. The results showed that the purity of total flavonoids in ethanol extract was 27.8%, the purity of total flavonoids in ethyl acetate extract was 46.4%, and the purity was increased by 18.6%. Subsequent purification with AB-8 macroporous resin; loading of total flavonoids at a concentration of 5.5 mg/mL, flow rate of 1.5 mL/min, 110 mL; use of 75% ethanol, 80 mL as eluent at a flow rate of 1.5 mL The elution at /min resulted in a total flavonoid purity of 83.5 % and an increase of 37.1%, and a good purification effect was obtained. The binding rate of total flavonoids purified by AB-8 macroporous resin to sodium taurocholate, sodium glycocholate and sodium cholate was 88.2%, 73.2% and 75.8 %, respectively. The binding ability was the strongest, and the others were ethyl acetate. Extract, ethanol extract. The purity of total flavonoids showed a good correlation with the binding capacity of cholate, and the correlation coefficient was between 0.963 and 0.988. The total flavonoids of Aurea Helianthus flower have good bile acid binding ability and can be used as the focus of natural hypolipidemic substances., Comment: 10 pages, 8 figures

The total phenols and flavonoids content of different polar solvent extracts from Aurea Helianthus flowers, and their antioxidant activity were determined. The ethanol extract of Aurea Helianthus flowers were suspended in water and fractionated using different polar solvents; hexane, chloroform, ethyl acetate, butanol and water. The parameters of each extract mentioned above were determined using Floin-ciocalteu reagent(FCR) method, AlCl3 colorimetry method, ferric reducing ability of plasma(FRAP) assay, total antioxidant activity(TAA) assay and DPPH radical scavenging assay. The highest total phenols content(516.21 mg GAE/g) and flavonoids content(326.06 mg QCE/g) were obtained in ethyl acetate extract, the correlation between TPC and TFC assay was founded to be 0.967. All polar solvent extracts of Aurea Helianthus flowers showed significant antioxidant effects, the hightest inhibition was obtained in ethyl acetate and choroform extracts and the lowest inhibition in the water extract. There is a good correlation of total phenols and flavonoids content with antioxidant activity. This work indicated that the polar solvent extracts of Aurea Helianthus flowers contain high phenols and flavonoids content and exhibited antioxidant activities in vitro, therefore, could be candidates for use as natural antioxidant., Comment: 7 pages, 2 figures

Inorganic halide perovskite \ce{Cs(Rb)PbI3} has attracted significant research interest in the application of light-absorbing material of perovskite solar cells (PSCs). Although there have been extensive studies on structural and electronic properties of inorganic halide perovskites, the investigation on their thermodynamic stability is lack. Thus, we investigate the effect of substituting Rb for Cs in \ce{CsPbI3} on the chemical decomposition and thermodynamic stability using first-principles thermodynamics. By calculating the formation energies of solid solutions \ce{Cs$_{1-x}$Rb$_x$PbI3} from their ingredients \ce{Cs$_{1-x}$Rb$_x$I} and \ce{PbI2}, we find that the best match between efficiency and stability can be achieved at the Rb content $x\approx$ 0.7. The calculated Helmholtz free energy of solid solutions indicates that \ce{Cs$_{1-x}$Rb$_x$PbI3} has a good thermodynamic stability at room temperature due to a good miscibility of \ce{CsPbI3} and \ce{RbPbI3}. Through lattice-dynamics calculations, we further highlight that \ce{RbPbI3} never stabilize in cubic phase at any temperature and pressure due to the chemical decomposition into its ingredients \ce{RbI} and \ce{PbI2}, while \ce{CsPbI3} can be stabilized in the cubic phase at the temperature range of 0$-$600 K and the pressure range of 0$-$4 GPa. Our work reasonably explains the experimental observations, and paves the way for understanding material stability of the inorganic halide perovskites and designing efficient inorganic halide PSCs.

Recently, replacing or mixing organic molecules in the hybrid halide perovskites with the inorganic Cs or Rb cations has been reported to increase the material stability with the comparable solar cell performance. In this work, we systematically investigate the electronic and optical properties of all-inorganic alkali iodide perovskites Rb1-xCsxPbI3 using the first-principles virtual crystal approximation calculations. Our calculations show that as increasing the Cs content x, lattice constants, band gaps, exciton binding energies, and effective masses of charge carriers decrease following the quadratic (linear for effective masses) functions, while static dielectric constants increase following the quadratic function, indicating an enhancement of solar cell performance upon the Rb addition to CsPbI3. When including the many-body interaction within the GW approximation and incorporating the spin-orbit coupling (SOC), we obtain more reliable band gap compared with experiment for CsPbI3, highlighting the importance of using GW+SOC approach for the all-inorganic as well as organic-inorganic hybrid halide perovskite materials.

In this paper, we have established the couple system of a spectroscope, CCD and computer and proposed a method of the rapid measurement on spectral characteristics such as central wavelengths, relative intensities, sensitivity lines and the wavelength range and image pixel of the spectral images of a material by using the correlation matching method for the image discernment of digital spectra.

In the 1960s, it has been substantiated that an equation of Schrodinger type could describe the diffusion phenomena, and the main consequence from this finding has been that there would be wave property in the diffusion processes as well. This theory has been immediately proved through laboratorial experiments. Afterwards the theory was applied to the primordial nebula which was thought to surround the protosun, and has found the consistency of the prediction of the theory with current distance distribution of the planets to be excellent. At the end of 20th century new satellites of planets were discovered. On the basis of the new data, the theory is tested thoroughly and the result allows us to come to the conclusion that the basic process for the distances of the planets from the protosun to be determined has been the diffusion of the primordial nebula consisting of mainly molecular gas., Comment: 24 pages, 5 tables

An experimental method for suppression of DC term in the reconstructed images from Fresnel digital holograms is presented. In this method, two holograms for the same object are captured sequentially and subtracted. Since these two holograms are captured at different moments, they are slightly different from each other for fluctuations of noises. The DC term is suppressed in the image reconstructed from the subtraction hologram, while the two virtual and real images are successfully reconstructed. This method can be potentially used for the improvement of image quality reconstructed from Fresnel digital holograms.

For white LEDs used for lighting museums, it is possible to reduce their effects on the discoloration of exhibits to a great extent by regulating their spectral distribution so that less lights with 420~470 nm of wavelength which acts on increasing the span of preservation of exhibits, such as pictures, color paper and color cloth. For same illumination of radiation of 5000 lx of white LEDs with different color temperature of about 3000, 3200, 4200 and 6500 K, the density of radiation energy of 420 nm was 34.2, 71.8, 83.1 and 268.3 {\mu}W/cm2, respectively. The discoloration experiment shows that the effects of discoloration of cold white LEDs was much greater than those of warm white LEDs.

The apparent positions of planets are determined by means of the fundamental ephemerides, the precession-nutation models of the Earth, the gravitational effects and aberrations et al. Around 2000, many astrometrical conceptions, models and theories had been newly defined and updated:for the fiducial celestial reference system, the ICRS is introduced, the fundamental ephemerides - DE405/LE405 et al.,precession-nutation model - IAU 2000A/IAU 2006 model. Using the traditional algorithm and the updated models, we develop the system of calculating the apparent positions of planets. The results are compared with the Astronomical Almanac and proved in their correctness., Comment: 9 pages, 3 figures

SNIA and CMB datasets have shown both of evolving Newton's "constant" and a signature of the coupling of scalar field to matter. These observations motivate the consideration of the scalar-matter coupling in Jordan frame in the framework of scalar-tensor gravity. So far, majority of the works on the coupling of scalar matter has performed in Einstein frame in the framework of minimally coupled scalar fields. In this work, we generalize the original scalar-tensor theories of gravity introducing a direct coupling of scalar to matter in the Jordan frame. The combined consideration of both evolving Newton's constant and scalar-matter coupling using the recent observation datasets, shows features different from the previous works. The analysis shows a vivid signature of the scalar-matter coupling. The variation rate of the Newton's constant is obtained rather greater than that determined in the previous works., Comment: 13 pages, 2 figures, 2 tables