Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3122
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Ca(1-x)Al2Si2O8 : Eu(x)(x = 0, 0.01, 0.05, 0.15) were synthesized by solid-state reaction respectively at 1 150, 1 250 1350 and 1 450 degrees C. With X-ray diffraction(XRD), Raman spectroscopy(Raman), photoluminescence spectroscopy(PL) and X-ray fluorescence spectrometer(XRF), the relationship between surface structure and fluorescence intensity of Ca(1-x) Al2Si2O8: Eu(x) were studied. XRD and Raman results show that, CaAl2Si2O8 anorthite single-phase has formed gradually along with the temperature rising in the process of synthesis. Raman spectroscopy is clear that when the Eu doping amount is the same, Si-O amorphous phase disappear gradually and the CaAl2Si2O8 phase form gradually with the temperature increases. As the temperature increases, vibration peaks position silicon oxygen tetrahedron shift to lower wave number. When 1 450 degrees C, the temperature is too high to destroy the structure of silicon oxygen tetrahedron. At the same time, there is a broadening amorphous peak appears in Raman spectroscopy. The procedure of Al to replace Si is hindered with Eu doped in. It is the result that the peak at 1 620 cm(-1) decreases after the first increases. The change of surface structure associated with the scattering amount of Eu. PL and XRF results show that: as the temperature increases, the amount of Eu atom scattering on the material surface increases gradually, this change lead to the fluorescence intensity raise. Therefore, there is proportional relationship between the fluorescence intensity of the samples and the number of samples per unit surface area of Eu atoms.
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