The Influence of the Sun and Moon on the Observation of Very High Energy Gamma-ray Sources Using EAS Arrays

With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the night.Hence,the Sun and Moon would have some impacts on the observation of gamma-ray sources,which have not been taken into account in previous analysis.In this paper,the influence of the Sun and Moon on the observation of very high energy gamma-ray sources when they are near the line of sight of the Sun or Moon is estimated.The tracks of all the known VHE sources are scanned and several VHE sources are found to be very close to the line of sight of the Sun or Moon during some period.The absorption of very high energy gamma rays by sunlight is estimated with detailed method and some useful conclusions are achieved.The main influence is the block of the Sun and Moon on gamma rays and the shadow on the cosmic ray background.The influence is investigated considering the detector angular resolution and some strategies on data analysis are proposed to avoid the underestimation of the gamma-ray emission.

Solving the Olbers’s Paradox, Explaining the “Red-Shift”, and Challenging the Relativities by “Sun Matters Theory” and “Sun Model of Universe”, an Evolution of the Einstein’s Static Universe Model

Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used to partially explain this paradox, while introducing new problems. Hereby, we propose a better theory, named Sun Matters Theory, to explain this paradox. Moreover, this unique theory supports and extended the Einstein’s static universe model proposed by Albert Einstein in 1917. Further, we proposed our new universe model, “Sun Model of Universe”. Based on the new model and novel theory, we generated innovative field equation by upgrading Einstein’s Field Equation through adding back the cosmological constant, introducing a new variable and modifying the gravitationally-related concepts. According to the Sun Model of Universe, the dark matter and dark energy comprise the so-called “Sun Matters”. The observed phenomenon like the red shift is explained as due to the interaction of ordinary light with Sun Matters leading to its energy and frequency decrease. In Sun Model, our big universe consists of many universes with ordinary matter at the core mixed and surrounded with the Sun Matters. In those universes, the laws of physics may be completely or partially different from that of our ordinary universe with parallel civilizations. The darkness of night can be easily explained as resulting from the interaction of light with the Sun Matters leading to the sharp decrease in the light intensity. Sun Matters also scatter the light from a star, which makes it shining as observed by Hubble. Further, there is a kind of Sun Matters named “Sun Waters”, surrounding every starts. When lights pass by the sun, the Sun Waters deflect the lights to bend the light path. According to the Sun Model, it is the light bent not the space bent that was proposed in the theory of relativities.

Variation in the Flaring Potential of Different Sunspot Groups During Different Phases of Solar Cycles 23 and 24

In this present study,we have analyzed different types of X-ray solar flares(C,M,and X classes)coming out from different classes of sunspot groups(SSGs).The data which we have taken under this study cover the duration of 24 yr from 1996 to 2019.During this,we observed a total of 15015 flares(8417 in SC-23 and 6598 in SC-24)emitted from a total of 33780 active regions(21746 in SC-23 and 12034 in SC-24)with sunspot only.We defined the flaring potential or flare-production potential as the ratio of the total number of flares produced from a particular type of SSG to the total number of the same-class SSGs observed on the solar surface.Here we studied yearly changes in the flaring potential of different McIntosh class groups of sunspots in different phases of SC-23 and 24.In addition,we investigated yearly variations in the potential of producing flares by different SSGs(A,B,C,D,E,F,and H)during different phases(ascending,maximum,descending,and minimum)of SC-23 and 24.These are our findings:(1)D,E,and F SSGs have the potential of producing flares≥8 times greater than A,B,C and H SSGs;(2)The larger and more complex D,E,and F SSGs produced nearly 80%of flares in SC-23 and 24;(3)The A,B,C and H SSGs,which are smaller and simpler,produced only 20%of flares in SC-23 and 24;(4)The biggest and most complex SSGs of F-class have flaring potential 1.996 and 3.443 per SSG in SC-23 and 24,respectively.(5)The potential for producing flares in each SSG is higher in SC-24 than in SC-23,although SC-24 is a weaker cycle than SC-23.(6)The alterations in the number of flares(C+M+X)show different time profiles than the alterations in sunspot numbers during SC-23 and 24,with several peaks.(7)The SSGs of C,D,E,and H-class have the highest flaring potential in the descending phase of both SC-23 and 24.(8)F-class SSGs have the highest flaring potential in the descending phase of SC-23 but also in the maximum phase of SC-24.

Study on the preparation and properties of sunscreen O/W/Si multiple emulsion

To solve the greasiness and irritation risks brought about by organic sun-screening agents in sunscreen emulsions,in this work,a sunscreen O/W/Si multiple emulsion was prepared by two-step emulsification method,in which the outer oil phase was silicone oil and the inner oil phase was solid lipid nanoparticles coated with organic sun-screening agent.Several influencing factors on the formation and stability of the emulsion were analyzed,including inorganic salts,the volume fraction of outer oil phase(silicone oil),and the dosage of W/O emulsifier.The in vitro sunscreen performance,water resistance and skin permeability of different types of sunscreen emulsions were further studied.The results showed that the sunscreen O/W/Si multiple emulsion containing 22.5%silicone oil,2.5%emulsifier and 0.2%NaCl had the best stability under the experimental conditions.The SPF value and water resistance of sunscreen O/W/Si multiple emulsion were slightly higher than those of sunscreen W/O emulsion,but significantly higher than those of sunscreen O/W emulsion.Compared with sunscreen W/O emulsion,the in vitro transdermal permeability of organic sun-screening agent in sunscreen O/W/Si multiple emulsion was reduced by approximately 60%,indicative of higher safety and good application prospect in sunscreen cosmetics.

The Nature of the Elongated Granulations and Stretched Dark Lanes in a Newly Emerging Flux Region

In this study,we explore the elongated granulations and stretched dark lanes within the emerging anti-Hale active region NOAA AR 12720.Utilizing high-resolution observations from the New Vacuum Solar Telescope,we discern a prevalence of elongated granules and stretched dark lanes associated with the emergence of new magnetic flux positioned between two primary opposing magnetic polarities.These elongated granulations and stretched dark lanes exhibit an alignment of strong transverse fields and a significant inclination angle.The endpoints of these features separate from each other,with their midpoints predominantly characterized by blueshifted signals in the photosphere.This suggests a close association between elongated granules and stretched dark lanes with the newly emerging flux.Additionally,we find that the stretched dark lanes display a more pronounced correlation with strong blueshifts and photospheric transverse magnetic fields compared to the elongated granulations.The transverse magnetic field within these stretched dark lanes reaches magnitudes of approximately 300-400 G,and the inclination angle demonstrates an“arch-like”pattern along the trajectory of the stretched dark lane.Based on these observed characteristics,we infer the presence of an emerging flux tube with an“arch-like”shape situated along the stretched dark lane.Consequently,we conclude that the stretched dark lanes likely represent manifestations of the emerging flux tube,while the elongated granulations may correspond to the gaps between the emerging flux tubes.

Long-term Evolution of Solar Activity and Prediction of the Following Solar Cycles

Solar activities have a great impact on modern high-tech systems,such as human aerospace activities,satellite communication and navigation,deep space exploration,and related scientific research.Therefore,studying the long-term evolution trend of solar activity and accurately predicting the future solar cycles are highly anticipated.Based on the wavelet transform and empirical function fitting of the longest recorded data of the annual average relative sunspot number(ASN)series of 323 yr to date,this work decisively verifies the existence of the solar century cycles and confirms that its length is about 104.0 yr,and the magnitude has a slightly increasing trend on the timescale of several hundred years.Based on this long-term evolutionary trend,we predict solar cycles 25 and26 by using phase similar prediction methods.As for solar cycle 25,its maximum ASN will be about146.7±33.40,obviously stronger than solar cycle 24.The peak year will occur approximately in 2024,and the period will be about 11±1 yr.As for solar cycle 26,it will start around 2030,and reach its maximum between2035 and 2036,with maximum ASN of about 133.0±3.200,and period of about 10 yr.

Nonlinear Coupling of Kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere

We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-Sun streamer belt solar wind using dynamical equations in the form of modified Zakharov systems.Numerical simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher wavenumbers.The magnetic power spectra exhibit an inertial range Kolmogorov-like spectral index value of-5/3 for k_(⊥)ρ_(i)<1 followed by a steeper dissipation range spectra with indices~-3 for the radiation belt case and~-4 for the nearSun streamer belt solar wind case,here k_(⊥)andρ_(i)represent the wavevector component perpendicular to the background magnetic field and the ion thermal gyroradius,respectively.Applying quasilinear theory in terms of the Fokker-Planck equation in the region of wavenumber turbulent spectra,we find the particle distribution function flattening in the superthermal tail population which is the signature of particle energization and plasma heating.

Observation and Analysis of VLF Nocturnal Multimode Interference Phenomenon based on Waveguide Mode Theory

Very low frequency(VLF)signals are propagated between the ground-ionosphere.Multimode interference will cause the phase to show oscillatory changes with distance while propagating at night,leading to abnormalities in the received VLF signal.This study uses the VLF signal received in Qingdao City,Shandong Province,from the Russian Alpha navigation system to explore the multimode interference problem of VLF signal propagation.The characteristics of the effect of multimode interference phenomena on the phase are analyzed according to the variation of the phase of the VLF signal.However,the phase of VLF signals will also be affected by the X-ray and energetic particles that are released during the eruption of solar flares,therefore the two phenomena are studied in this work.It is concluded that the X-ray will not affect the phase of VLF signals at night,but the energetic particles will affect the phase change,and the influence of energetic particles should be excluded in the study of multimode interference phenomena.Using VLF signals for navigation positioning in degraded or unavailable GPS conditions is of great practical significance for VLF navigation systems as it can avoid the influence of multimode interference and improve positioning accuracy.

Inverse Calculation and Regularization Process for the Solar Aspect System(SAS) of HXI Payload on ASO-S Spacecraft

For the ASO-S/HXI payload, the accuracy of the flare reconstruction is reliant on important factors such as the alignment of the dual grating and the precise measurement of observation orientation. To guarantee optimal functionality of the instrument throughout its life cycle, the Solar Aspect System (SAS) is imperative to ensure that measurements are accurate and reliable. This is achieved by capturing the target motion and utilizing a physical model-based inversion algorithm. However, the SAS optical system’s inversion model is a typical ill-posed inverse problem due to its optical parameters, which results in small target sampling errors triggering unacceptable shifts in the solution. To enhance inversion accuracy and make it more robust against observation errors, we suggest dividing the inversion operation into two stages based on the SAS spot motion model. First, the as-rigid-aspossible (ARAP) transformation algorithm calculates the relative rotations and an intermediate variable between the substrates. Second, we solve an inversion linear equation for the relative translation of the substrates, the offset of the optical axes, and the observation orientation. To address the ill-posed challenge, the Tikhonov method grounded on the discrepancy criterion and the maximum a posteriori (MAP) method founded on the Bayesian framework are utilized. The simulation results exhibit that the ARAP method achieves a solution with a rotational error of roughly±3 5 (1/2-quantile);both regularization techniques are successful in enhancing the stability of the solution, the variance of error in the MAP method is even smaller—it achieves a translational error of approximately±18μm (1/2-quantile) in comparison to the Tikhonov method’s error of around±24μm (1/2-quantile). Furthermore, the SAS practical application data indicates the method’s usability in this study. Lastly, this paper discusses the intrinsic interconnections between the regularization methods.

Jovian Planet Influence on the Forcing of Sunspot Cycles

The history of our solar system has been greatly influenced by the fact that there is a large gas giant planet, Jupiter that has a nearly circular orbit. This has allowed relics of the early solar system formation to still be observable today. Since Jupiter orbits the Sun with a period of approximately 12 years, it has always been thought that this could be connected to the nearly 11-year periodic peak in the number of sunspots observed. In this paper, the Sun and planets are considered to be moving about a center of mass point as the different planets orbit the Sun. This is the action of gravity that holds the solar system together. The center of mass for the Jupiter-Sun system actually lies outside the Sun. The four gas giant planets dominate such effects and the four gas giant Jovian planets can be projected together to determine an effective distance from the Sun’s center. Taken together these effects do seem to function as a sunspot forcing factor with a periodicity very close to 11 years. These predictions are made without consideration of any details of what is happening in the interior of the Sun. From these estimates, sunspot cycle 25 will be expected to peak in about September-October of 2025. Sunspot cycle 26 should peak in the year March of 2037.

New Insight to the Surface Temperature of the Sun

Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, the solar spectrum data measured by Kondratyev lead to a value of at least 7134 K. Such a higher value can be obtained by interpreting the Planck formula for the black radiation spectrum for the Kondratyev data. In addition, using the Stefan-Boltzmann law, the energetic emissivity of the Sun’s surface was determined to be 0.431. Furthermore, based on Petela’s formulae for exergy of thermal radiation, the exergetic emissivity of the Sun’s surface was also calculated at the level of 0.426.

The causality between the rapid rotation of a sunspot and an X3.4 flare

Using multi-wavelength data of Hinode, the rapid rotation of a sunspot in active region NOAA 10930 is studied in detail. We found extraordinary counterclockwise rotation of the sunspot with positive polarity before an X3.4 flare. From a series of vector magnetograms, it is found that magnetic force lines are highly sheared along the neutral line accompanying the sunspot rotation. Furthermore, it is also found that sheared loops and an inverse S-shaped magnetic loop in the corona formed gradually after the sunspot rotation. The X3.4 flare can be reasonably regarded as a result of this movement. A detailed analysis provides evidence that sunspot rotation leads to magnetic field lines twisting in the photosphere. The twist is then transported into the corona and triggers flares.

Priori knowledge based a bathymetry assessment method using the sun glitter imagery:a case study of sand waves on the Taiwan Banks

High resolution optical satellite imageries containing the sun glitter,similar to synthetic aperture radar（SAR） imageries,are useful in identifying and mapping of bottom topography in shallow waters.The errors in the previous studies are corrected,and a method for mapping submarine bottom topography is developed using the sun glitter satellite imagery.The method is established on the basis of empirical description of a sand wave using an equation with two unknowns named r and k.In order to determine r and k,a ＂trial and error＂ approach is introduced and testified by a case study on the Taiwan Banks using an ASTER imagery.The results show that the inversed water depths match well with the sounding water depths.The agreement between the inversed results and the in situ measurements is about 78% by comparing 371 points.Moreover,this method has the advantage in keeping the original appearance of a sand wave,especially in positions around the sand wave crest.The fine agreement indicates that the imaging model is flexible and the approach developed is feasible.

A study of the relation between intensity oscillations and magnetic field parameters in a sunspot: Hinode observations

We present properties of intensity oscillations of a sunspot in the photo- sphere and chromosphere using G band and Ca u H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of power in the G band with an increase in photospheric magnetic field strength at all frequencies. In Ca II H, however, stronger fields exhibit more power at high frequen- cies, particularly in the 4.5-8.0 mHz band. Power distributions in different locations of the active region show that the oscillations in Ca II H exhibit more power compared to that of the G band. We also relate the power in intensity oscillations with differ- ent components of the photospheric vector magnetic field using near simultaneous spectro-polarimetric observations of the sunspot from the Hinode spectropolarime- ter. The photospheric umbral power is strongly anti-correlated with the magnetic field strength and its line-of-sight component but there is a good correlation with the trans- verse component. A reversal of this trend is observed in the chromosphere except at low frequencies （V≤ 1.5 mHz）. The power in sunspot penumbrae is anti-correlated with the magnetic field parameters at all frequencies （1.0 ≤ v ≤ 8.0 mHz） in both the photosphere and chromosphere, except that the chromospheric power shows a strong correlation in the frequency range 3-3.5 mHz.

The Emission Heights of Transition Region Lines in an Equatorial Coronal Hole and the Surrounding Quiet Sun

Using the correlation between the radiance or Doppler velocity and the extrapolated magnetic field, we determined the emission heights of a set of solar transition region lines in an equatorial coronal hole and in the surrounding quiet Sun region. We found that for all of the six lower-transition-region lines, the emission height is about 4-5 Mm in the equatorial coronal hole, and around 2 Mm in the quiet Sun region. This result confirms the previous findings that plasma with different temperature can coexist at the same layer of transition region. In the quiet Sun region, the emission height of the upper-transition-region line Ne VIII is almost the same that of the lower-transition-region line, but in the coronal hole, it is twice as high. This difference reveals that the outflow of Ne VIII is a signature of solar wind in the coronal hole and is just a mass supply to the large loops in the quiet Sun.

The brightness reversal of submarine sand waves in “HJ-1A/B” CCD sun glitter images

The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observation and depth inversion of sand wave topography. The simulations of the normalized sun glitter radiance on the submarine sand waves confirm that the reversal would happen at a specific sensor viewing angle, defined as the critical angle. The difference between the calculated critical angle position and the reversal position in the image is about 1＇, which is excellent in agreement. Both the simulation and actual image show that sand wave crests would be indistinct at the reversal position, which may cause problems when using these sun glitter images to analyze spatial characteristics and migration of sand waves. When using the sun glitter image to obtain the depth inversion, one should take the advantage of image properties of sand waves and choose the location in between the reversal position and the brightest position. It is also necessary to pay attention to the brightness reversal when using ＂HI-1A/B＂ CCD images to analyze other oceanic features, such as internal waves, oil slicks, eddies, and ship wakes.

What did Sun Yat-sen really die of?A re-assessment of his illness and the cause of his death

This year is the 150 th anniversary of the birth of Sun Yat-sen(November 12, 1866) and the 91 st year following his death(March 12, 1925). It generally has been believed that the cause of his death was "liver cancer." However, as indicated in the oicial autopsy report, dated March 13, 1925, of the Peking Union Medical College Hospital(PUMCH) in Beijing, the cause of his death in reality was an adenocarcinoma of the gallbladder with direct extension to the liver and diaphragm as well as widespread metastases to the peritoneal cavity. This important piece of information seems to have never been reported in the English language literature, and it was only in 2013 that the true cause of his death was stated in a one-line sentence in a non-medical Chinese online source. It had been mistakenly believed that the cause of Dr. Sun's death was liver cancer, based on the observations made following an exploratory laparotomy, which had been performed at PUMCH on January 26, 1925. The purpose of this short report is to provide more details relating to his terminal illness and to correct the historical record for a medical audience as to the cause of the death of Sun Yat-sen, a very important igure in the history of 20 th century China.

The relationships of solar flares with both sunspot and geomagnetic activity

The relationships between solar flare parameters （total importance, time duration, flare index, and flux） and sunspot activity （R z ） as well as those between geomagnetic activity （aa index） and the flare parameters can be well described by an integral response model with the response time scales of about 8 and 13 months, respectively. Compared with linear relationships, the correlation coefficients of the flare parameters with R z , of aa with the flare parameters, and of aa with R z based on this model have increased about 6%, 17%, and 47% on average, respectively. The time delays between the flare parameters with respect to R z , aa to the flare parameters, and aa to R z at their peaks in a solar cycle can be predicted in part by this model （82%, 47%, and 78%, respectively）. These results may be further improved when using a cosine filter with a wider window. It implies that solar flares are related to the accumulation of solar magnetic energy in the past through a time decay factor. The above results may help us to understand the mechanism of solar flares and to improve the prediction of the solar flares.

Characterizing motion types of G-band bright points in the quiet Sun

We study the motion of G-band bright points （GBPs） in the quiet Sun to obtain the characteristics of different motion types. A high resolution image sequence taken with the Hinode/Solar Optical Telescope （SOT） is used, and GBPs are automat- ically tracked by segmenting 3D evolutional structures in a space-time cube. After putting the GBPs that do not move during their lifetimes aside, the non-stationary GBPs are categorized into three types based on an index of their motion type. Most GBPs that move in straight or nearly straight lines are categorized as a straight mo- tion type, a few moving in rotary paths into rotary motion, and the others fall into a motion type we called erratic. The mean horizontal velocities are 2.18±0.08 km s-1, 1.63±0.09km s^-1 and 1.33±0.07 km s^-1 for straight, erratic and rotary motion types, respectively. We find that a GBP drifts at a higher and constant velocity during its whole life if it moves in a straight line. However, it has a lower and variational velocity if it moves on a rotary path. The diffusive process is ballistic-, super- and sub-diffusion for straight, erratic and rotary motion types, respectively. The corresponding diffusion index （γ） and coefficients （K） are 2.13±0.09 and 850±37km^2 s^-1, 1.82±0.07 and 331 ±24 km^2 s^-1, and 0.73±0.19 and 13±9 km^2 s^-1. In terms of direction of motion, it is homogeneous and isotropic, and usually persists between neighboring frames, no matter what motion type a GBP is classified as.

Analysis of Stresses and Deflection of Sun Gear by Theoretical and ANSYS Method

Gearing is one of the most critical components in mechanical power transmission systems. This article examines the various stresses and deflection developed in sun gear tooth of planetary gearbox which is used in Grabbing Crane. Article includes checking sun gear wear stresses and bending stresses using IS 4460 equations. Also calculate various forces acting on gear tooth. In this study, perform the calculation for sun gear tooth to calculate bending, shear, wear & deflection using theoretical method. 3D model is created of circular root fillet & trochoidal root fillet of gear tooth for simulation using ProE Wildfire 3. In Pro-E, the geometry is saved as a file and then it is transferred from Pro-E to ANSYS 10 in IGES format. The results of the 3 D analyses from ANSYS are compared with the theoretical values. Comparison of ANSYS results in circular root fillet & trochoidal root fillet also carry out.