Research on the Learning and Information System Based on Blockchain[]

With the development of The Times, the number of various diploma forms at home and abroad has increased sharply. At the same time, there are many problems such as falsification of academic certificates, and it is urgent to strengthen the real control of various diploma certificates. As a new generation of data management technology, blockchain technology can provide a new path and a new method for the authenticity of academic certificates. With the help of the decentralization, immutability, openness and independence of blockchain, a blockchain technology based academic certificate guarantee system is built from the aspect of talent security to protect the authenticity control of academic certificates

Self-cancellation of ephemeral regions in the quiet Sun

With the observations from the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, we statistically investigate the ephemeral regions (ERs) in the quiet Sun. We find that there are two types of ERs: normal ERs (NERs) and self-cancelled ERs (SERs). Each NER emerges and grows with separation of its opposite polarity patches which will cancel or coalesce with other surrounding magnetic flux. Each SER also emerges and grows and its dipolar patches separate at first, but a part of magnetic flux of the SER will move together and cancel gradually, which is described with the term "self-cancellation" by us. We identify 2988 ERs among which there are 190 SERs, about 6.4% of the ERs. The mean value of self-cancellation fraction of SERs is 62.5%, and the total self-cancelled flux of SERs is 9.8% of the total ER flux. Our results also reveal that the higher the ER magnetic flux is, (i) the easier the performance of ER self-cancellation is, (ii) the smaller the self-cancellation fraction is, and (iii) the more the self-cancelled flux is. We think that the self-cancellation of SERs is caused by the submergence of magnetic loops connecting the dipolar patches, without magnetic energy release.Comment: 6 pages, 4 figures, accepted for publication in ApJ

Nova metoda mjerenja ekonomske konvergencije i njena primjena na centralne kineske provincije

In order to solve the shortcomings of classical convergence analysis and spatial econometric analysis, this paper proposes a delta statistics method to assess economic growth convergence of central China cities. The result shows to be more close to the reality by analyzing the drawbacks of the classical relative beta convergence, combining the advantages of gams convergence, reference panel data, co-integration theory with the time factor into model. Then, Monte Carlo simulation method is used to analyze its distribution, which shows that it obeys to the normal distribution assumption in large samples. At last, our method is applied to the analysis of economic convergence of central China.Kako bi se otklonili nedostaci klasične analize konvergencije i prostorne ekonometrijske analize, ovaj rad predlaže delta statističku metodu za potrebe procjene konvergencije ekonomskog rasta u gradovima centralne Kine. Rezultati pokazuju da se dolazi bliže stvarnosti analizirajući loše strane klasične relativne beta konvergencije kombinirajući prednosti gama konvergencije, referentnih panelnih podataka, kointegracijske teorije s vremenskim faktorom u modelu. Zatim, Monte Carlo model simulacije se koristi za analizu distribucije što pokazuje da odgovara pretpostavci normalne distribucije u velikim uzorcima. Naposljetku, naša se metoda primjenjuje na analizu ekonomske konvergencije u centralnoj Kini

Characterizations of silicon-germanium nanocomposites fabricated by the marine diatom Nitzschia frustulum

Marine diatoms are a class of microalgae that possess cell walls composed of silica nanoparticles. These organisms actively assimilate silicic acid Si(OH)4 from seawater, polymerize silicic acid to silica nanoparticles by a protein-mediated precipitation process, and then assemble the silica nanoparticles into intricate patterns that constitute the cell wall microarchitecture (consists of around 30nm of SiO2 nanoparticles) of the diatom frustule. The biomineralization capacity of marine diatoms, Nitzschia,was harnessed to biologically manufacture silicon oxide / germanium oxide nanocomposite materials. Germanium was incorporated into living diatom cell mass by a two-stage cultivation process. The micro- and nanostructures of biogenic oxide nanocomposite before and after post processing were characterized by FT-IR, HR-TEM with EDX, and XRD. Photoluminescence (PL) measurements were performed on these biogenic nanocomposites after different post processing to remove the organics. Strong blue photoluminescence was observed from samples treated with H202 and oxygen plasma. However, no photoluminescence could be observed after NOT thermal annealing. A clear blueshift was observed from samples with the addition of germanium. Based on the comparison of the PL from diatom samples with that from synthesized silica, the self-trapped exciton (STE) affected by quantum confinement effect (QCE) is proposed as the mechanism of the PL from diatom

A Novel Idea of Coherent Acoustic Wave-Induced Atmospheric Refractivity Fluctuation and Its Applications

The physical mechanism of generating the lasting tropospheric refractivity fluctuation with a stable array-distributed structure by coherent acoustic waves is investigated. An example of the quantitative calculation of atmospheric refractive index is given and analyzed. Based on the theory of electromagnetic wave propagation and scattering in the troposphere, the feasibility to purposefully affect radio wave propagation is qualitatively demonstrated by the experiment of the coherent acoustic source-induced laser interference fringe change. The potential application aspects of synthetically controlling the radio wave propagation by the artificial refractivity fluctuation structure are preliminarily proposed. This chapter will promote the development of the coherent acoustic wave-induced tropospheric refractivity fluctuation, and it has the important theoretical significance and potential application value to purposely apply the positive or negative effects on radio wave propagation