A Facile Method towards Carbon Quantum Dots with Strong Photoluminescence

2016 ◽  
Vol 859 ◽  
pp. 85-89
Author(s):  
Rui Lin ◽  
Gu Qiao Ding ◽  
Peng He ◽  
Jing Chen
Keyword(s):  
Quantum Dots ◽  
Photoluminescence Property ◽  
Carbon Quantum Dots ◽  
Lateral Size ◽  
High Quality ◽  
Average Value ◽  
Whole Process ◽  
Sharp Band ◽  
Concentrated Sulfuric Acid

A facile method is proposed to synthesize carbon quantum dots (C-dots) from citric acid using concentrated sulfuric acid as carbonization reagents with temperature below 100 °C during the whole process. The prepared C-dots has a Gaussian distribution in its lateral size with the average value around 6.37 nm. High quality of the C-dots is revealed through the optical performances such as sharp band-edge absorption, typical absorption peak and nearly excitation-independent blue emissions. Further, the pH condition is found to have correlation on the strong and stable photoluminescence property.

scholarly journals Evaluation of Quality and Readability of Online Health Information on High Blood Pressure Using DISCERN and Flesch-Kincaid Tools

2020 ◽  
Vol 10 (9) ◽  
pp. 3214
Author(s):  
Muhammad Tahir ◽  
Muhammad Usman ◽  
Fazal Muhammad ◽  
Shams ur Rehman ◽  
Imran Khan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Health Information ◽  
High Blood Pressure ◽  
Statistical Significance ◽  
Treatment Options ◽  
Online Health Information ◽  
High Quality ◽  
Average Value ◽  
Pertinent Data

High Blood Pressure (BP) is a vital factor in the development of cardiovascular diseases worldwide. For more than a decade now, patients search for quality and easy-to-read Online Health Information (OHI) for symptoms, preventions, therapy and other medical conditions. In this paper, we evaluate the quality and readability of OHI about high BP. In order that the first 20 clicks of three top-rated search engines have been used to collect the pertinent data. Using the exclusion criteria, 25 unique websites are selected for evaluation. The quality of all included links is evaluated through DISCERN checklist, a questionnaire for assessing the quality of written information for a health problem. To enhance the reliability of evaluation, all links are separately assessed by two different groups—a group of Health Professional (HPs) and a group of Lay Subjects (LS). A readability test is performed using Flesch-Kincaid tool. Fleiss’ kappa has been calculated before considering average value of each group. After evaluation, the average DISCERN value of HPs is 49.43 ± 14.0 (fair quality) while for LS, it is 48.7 ± 12.2; the mean Flesch-Reading Ease Score (FRES) is 58.5 ± 11.1, which is fairly difficult to read and the Average Grade Level (AGL) is 8.8 ± 1.9. None of the websites scored more than 73 (90%). In both groups, only 4 (16%) websites achieved DISCERN score over 80%. Mann-Whitney and Cronbach’s alpha have been computed to check the statistical significance of the difference between two groups and internal consistency of DISCERN checklist, respectively. Normality and homoscedasticity tests have been performed to check the distribution of scores of both evaluating groups. In both groups, information category websites achieved high DISCERN score but their readability level is worse. Highest scoring websites have clear aim, succinct source and high quality of information on treatment options. High BP is a pervasive disease, yet most of the websites did not produce precise or high-quality information on treatment options.

scholarly journals How Universities Use Alumni Resources to Help Students’ Growth: China Perspective

2020 ◽  
Vol 7 (2) ◽  
pp. p33
Author(s):  
Xiaohua Ning
Keyword(s):  
High School ◽  
Cooperative Education ◽  
Colleges And Universities ◽  
Educational Resource ◽  
Education Programs ◽  
High Quality ◽  
Education Resources ◽  
Long Period ◽  
Whole Process

As an important force of social cooperative education in colleges and universities, alumni are not only the embodiment of high school achievements, but also an important educational resource in colleges and universities. By grasping the advantages of alumni as educational resources, alumni education should be carried out throughout the whole process of alumni work, and the concept of “all staff, all process, all aspects, all society and all heart” service for students and prospective alumni should be established. A high-quality alumni education team should be established, rich alumni education programs should be developed, key alumni education fields should be focused, intensive alumni education resources should be expanded, and a win-win cooperation mode between universities and alumni should be established. Taking the initiative to transform the advantages of alumni resources accumulated over a long period of time into the advantages of continuously improving the quality of personnel training, providing a solid social foundation for the school’s education work.

SOFTNESS OF LIGHT PASSING THROUGH WINDOWS AND ITS RELATIONSHIP WITH LUMINANCE GRADIENT

2021 ◽  
Author(s):  
Y. Sasajima ◽  
Y. Miyake ◽  
K. Ogasawara ◽  
Y. Oe ◽  
N. Yoshizawa
Keyword(s):  
High Quality ◽  
Luminance Change ◽  
Change Rate ◽  
Average Value ◽  
Light Passing ◽  
Subjective Experiment

Architects and users frequently use window coverings, such as frosted glasses, shoji screens, and lace curtains to create high quality of light. This kind of light is sometimes called “soft light”, and most people feel that it is required in residential spaces. However, the term “soft light” is somewhat vague, and we do not accurately understand what is the “soft light” and how we can create it. The aim of this research is to derive a physical indicator of "ambiguity of brightness-darkness boundary”, which is one of factors for judging the softness of light. We conducted a subjective experiment with 53 evaluation items including the “ambiguity of brightness-darkness boundary” in various actual daylighting spaces. It was found that "ambiguity of brightness-darkness boundary", was not highly evaluated when the average value of the luminance change rate on the wall is high.

Photoluminescence property of laser-ablated zinc oxide-carbon quantum dots nanocomposites for detection of Hg and Pb ions

2020 ◽  
Vol 14 (04) ◽  
Author(s):  
Amir Reza Sadrolhosseini ◽  
Mohr. Ikmal Hafizi Bin Azaman ◽  
Amir Masoud Arabi ◽  
Suhaidi Shafie ◽  
Nur Hazahsha Shamsudin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Zinc Oxide ◽  
Photoluminescence Property ◽  
Carbon Quantum Dots ◽  
Pb Ions

scholarly journals Frei-Chen bases based lossy digital image compression technique

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahmood Al-khassaweneh ◽  
Omar AlShorman
Keyword(s):  
Image Compression ◽  
Compression Rate ◽  
High Quality ◽  
Compression Technique ◽  
Average Value ◽  
Second Stage ◽  
Compression Factor ◽  
Digital Image Compression ◽  
And Performance

In the big data era, image compression is of significant importance in today’s world. Importantly, compression of large sized images is required for everyday tasks; including electronic data communications and internet transactions. However, two important measures should be considered for any compression algorithm: the compression factor and the quality of the decompressed image. In this paper, we use Frei-Chen bases technique and the Modified Run Length Encoding (RLE) to compress images. The Frei-Chen bases technique is applied at the first stage in which the average subspace is applied to each 3 × 3 block. Those blocks with the highest energy are replaced by a single value that represents the average value of the pixels in the corresponding block. Even though Frei-Chen bases technique provides lossy compression, it maintains the main characteristics of the image. Additionally, the Frei-Chen bases technique enhances the compression factor, making it advantageous to use. In the second stage, RLE is applied to further increase the compression factor. The goal of using RLE is to enhance the compression factor without adding any distortion to the resultant decompressed image. Integrating RLE with Frei-Chen bases technique, as described in the proposed algorithm, ensures high quality decompressed images and high compression rate. The results of the proposed algorithms are shown to be comparable in quality and performance with other existing methods.

Size dependent photoluminescence property of hydrothermally synthesized crystalline carbon quantum dots

2016 ◽  
Vol 178 ◽  
pp. 314-323 ◽  
Author(s):  
S. Sarkar ◽  
D. Banerjee ◽  
U.K. Ghorai ◽  
N.S. Das ◽  
K.K. Chattopadhyay
Keyword(s):  
Quantum Dots ◽  
Photoluminescence Property ◽  
Carbon Quantum Dots ◽  
Size Dependent

Influence of technology parameters of free-cutting steel continuous casting on the billet internal structure

2020 ◽  
Vol 76 (2) ◽  
pp. 139-142
Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova
Keyword(s):  
Regression Analysis ◽  
Continuous Casting ◽  
Internal Structure ◽  
Sulfur Content ◽  
Manganese Content ◽  
High Quality ◽  
Correlation And Regression Analysis ◽  
Cutting Steel ◽  
Continuously Cast

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.

Development and Application of Quality Control System for Highway Subgrade Construction

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Detection Method ◽  
System Development ◽  
Effective Control ◽  
Construction Process ◽  
Development Mode ◽  
The Road ◽  
Whole Process

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.

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