Search Results

You are looking at 1 - 10 of 18 items for

  • Author or Editor: Yi Wu x
  • All content x
Clear All Modify Search

Abstract  

228Ra levels in the Yellow Sea and East China Sea were determined using the emanation method. The seawater radium was concentrated using an Mn-fiber and the 224Ra ingrowth was measured after about half a year when the initial 224Ra in the sample would have decayed. The 224Ra activity in the sample was evaluated using the decay dynamics relationship between parent 228Ra and daughter 228Th. The concentration and distribution feature of 228Ra in the Yellow Sea and East China Sea were studied and the 228Ra concentrations in the surface seawater of the Yellow Sea and the East China Sea were in the range 0.09–15.0 Bq/m3 with an average of 6.84 Bq/m3 during the summer cruise, and in the range 0.09–16.9 Bq/m3 with an average of 6.37 Bq/m3 during the winter cruise. The 228Ra distribution in the northern Yellow Sea was different from the southern Yellow Sea and East China Sea. The highest 228Ra activity of surface water was located in the middle of the northern Yellow Sea, but for the southern Yellow Sea and East China Sea, it decreased with increasing distance from China continent.

Restricted access

Abstract

In tonal music, pitch orthography reflects different structural and functional meanings of notes in various contextual and textural settings such as harmony, melody, and voice leading. At the turn of the twentieth century, many composers attempt to progress beyond the confines of traditional tonality, whose works, as generally perceived by most analysts nowadays, treat the twelve chromatic notes as the twelve enharmonically equivalent pitch-classes and thus present “the dissolution of … [the] notational conventions of earlier times” (Gillies 1993, 43). Contrary to this general sentiment regarding orthography, the present paper brings the significance of pitch notation into sharper focus by investigating its crucial role in the course of the text setting and form in Webern's op. 12, no. 2. I will demonstrate how Webern utilizes orthography to reinforce the structure of the text and the narrative of form, assisting the analyst in considering notation as a core element while examining the pitch structure of the early twentieth-century music.

Restricted access

Abstract  

This paper presents the synergetic effect of Te2MoO7 and MoO3 (WO3) in the partial oxidation of propylene to acrolein. The study found that the addition of MoO3 (or WO3) to Te2MoO7 greatly promoted the propylene conversion and acrolein yield. As the results of the investigation revealed, the higher catalytic performance could be attributed to the increased acidity, which is beneficial for the adsorption of propylene.

Restricted access

Abstract  

The action of three kinds of the selenomorpholine compounds on a strain ofEscherichia coli was studied by microcalorimetry. Differences in their capacities to affect the metabolism of this bacterium were observed. The extent and duration of the effect on the metabolism as judged from the rate constant (k) of Escherichia coli (in log phase) varied with the different drugs. The kinetics show that selenomorpholine compounds had an effect on the metabolism process of Escherichia coli. The k of Escherichia coli in the presence of the drugs increased with the increasing concentrations of the drugs (C) at low concentration; but at high concentration, the rate constant decreased with the increasing concentrations of the drugs. The experimental results reveal that the sequence of antibiotic activity of selenomorpholines is: N-selenomorpholinemethyl succinimide and its hydrochloride>N-(α-selenomorpholinebenzyl) succinimide.

Restricted access

Abstract  

A statistical analysis is made of two data sets and it is found that the distribution of major scientific and technological achievements in terms of the age of those achievement makers is Weibull distribution. Pearson'sx 2 test results are satisfactory. This finding holds for different centuries, different nations and different disciplines.

Restricted access

Abstract

A recent review by Montag et al. raised a taxonomical argument about internet addiction. We propose a two-dimensional taxonomy of internet addiction by both the device and the content as the solution. For the assessment of smartphone addiction, measurements should be based on functional impairment and validated by diagnostic criteria rather than solely on self-reported questionnaires. We detail the potential of mobile applications (apps) to improve the assessment of smartphone addiction. App-generated indicators could fulfill the unmet need of assessment of smartphone addiction and facilitate future assessment and treatment planning of smartphone addiction.

Open access

Background and aims

The nine-item Internet Gaming Disorder Scale – Short Form (IGDS-SF9) is brief and effective to evaluate Internet Gaming Disorder (IGD) severity. Although its scores show promising psychometric properties, less is known about whether different groups of gamers interpret the items similarly. This study aimed to verify the construct validity of the Persian IGDS-SF9 and examine the scores in relation to gender and hours spent online gaming among 2,363 Iranian adolescents.

Methods

Confirmatory factor analysis (CFA) and Rasch analysis were used to examine the construct validity of the IGDS-SF9. The effects of gender and time spent online gaming per week were investigated by multigroup CFA and Rasch differential item functioning (DIF).

Results

The unidimensionality of the IGDS-SF9 was supported in both CFA and Rasch. However, Item 4 (fail to control or cease gaming activities) displayed DIF (DIF contrast = 0.55) slightly over the recommended cutoff in Rasch but was invariant in multigroup CFA across gender. Items 4 (DIF contrast = −0.67) and 9 (jeopardize or lose an important thing because of gaming activity; DIF contrast = 0.61) displayed DIF in Rasch and were non-invariant in multigroup CFA across time spent online gaming.

Conclusions

Given the Persian IGDS-SF9 was unidimensional, it is concluded that the instrument can be used to assess IGD severity. However, users of the instrument are cautioned concerning the comparisons of the sum scores of the IGDS-SF9 across gender and across adolescents spending different amounts of time online gaming.

Open access

Atractylodis exerted a variety of pharmacological effects such as anti-tumor, anti-inflammatory, anti-bacterial, and anti-aging effects etc. The major ingredients of Atractylodis are atractylenolide I and II that exhibited activities in anti-inflammatory and anticancer. In this work, a sensitive and selective ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for determination of atractylenolide I and II in rat plasma was developed. The UPLC–MS/MS method was validated for selectivity, linearity, accuracy, precision, recovery, and stability with a total run time of 4.0 min. After addition of atractylenolide III as an internal standard (IS), protein precipitation by acetonitrile was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 231.1 → 185.1 for atractylenolide I, m/z 233.1 → 91.0 for II, and m/z 249.0 → 231.1 for IS. Calibration plots were linear throughout the range 1–1000 ng/mL for atractylenolide I and II in rat plasma. Mean recoveries of atractylenolide I and II in rat plasma ranged from 86.2% to 96.3%. Relative standard deviation (RSD) of intra-day and inter-day precision was both less than 12%. The accuracy of the method was between 91.0% and 109.0%. The method was successfully applied to pharmacokinetic study of atractylenolide I and II after intravenous administration in rats.

Open access