| 1. |
- Dong, Yi-Min, et al.
(författare)
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Reply to Collins et al
- 2021
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press. - 1058-4838 .- 1537-6591. ; 73:3, s. 558-559
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
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| 3. |
- Meng, Qijun, 1990-, et al.
(författare)
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Integrating Cobalt-sites-rich Aza-fused Conjugated Microporous Polymers on BiVO4 for Efficient Photoelectrochemical Water Splitting
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Advanced surface and interface engineering has been demonstrated to be of critical importance for the development of photoanodes for highly efficient photoelectrochemical (PEC) water oxidation. In this study, cobalt-sites-rich aza-fused conjugated microporous polymer was integrated on the nanoporous bismuth vanadate electrode. The hybrid BiVO4/eCMP-Co photoanode exhibited a high photocurrent density of 4.3 mA cm-2 at 1.23 VRHE and a very low onset potential of ~ 0.2 VRHE with an applied bias photon to current efficiency of 1.62% at around 0.6 VRHE. Moreover, studies on charge carrier kinetics showed that eCMP-Co can not only accelerate water oxidation kinetics but also significantly suppress surface recombination, thereby dramatically increasing charge transfer efficiency. These results demonstrate the great potential of conjugated polymers combined with metal coordination as heterogenous catalysts on photoelectrodes in PEC devices.
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| 4. |
- Meng, Qijun, 1990-, et al.
(författare)
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Ultra-thin Nanolayers of Photodeposited Cobalt Phytate on BiVO4 for Efficient Photoelectrochemical Water Oxidation
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Strategical engineering of semiconducting films by loading co-catalysts is pivotal for optimizing the properties of photoelectrodes used for solar fuel production. In this study, an ultrathin layer of cobalt phytate (CoPhy) was integrated onto the nanoporous bismuth vanadate (BiVO4) photoanode by a simple photo-assisted electrodeposition method. The introduction of CoPhy significantly improved the PEC performance of BiVO4 photoanode, displaying a photocurrent density up to 4.3 mA cm-2 at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5G) and an impressive early onset of potential of ~0.2 VRHE as well as superior stability. Moreover, charge kinetics studies showed that the enhancement in PEC performance by CoPhy is primarily due to the suppression of surface recombination and acceleration of interfacial charge transfer.
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| 5. |
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| 6. |
- Yang, Yi, et al.
(författare)
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Facile Hydrothermal Synthesis of Highly Efficient and Durable Ternary Ptpdcu Electrocatalysts For Methanol Oxidation Reaction : Iodide Matters
- 2022
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Ingår i: Social Science Research Network SSRN. - : Elsevier BV. - 1556-5068.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Precious metal Pt-based electrocatalysts have been widely used in methanol catalytic oxidation of anodes in direct methanol fuel cells (DMFCs). However, it has been still the challenge to decrease their cost and improve their efficiency and stability. In this study, ternary PtPdCu nanocatalysts were synthesized through a facile one-step hydrothermal synthesis method. When KI was present with a suitable amount in the synthesis, PtPdCu nanospheres with surface embedded CuI clusters (CuI/PtPdCu) were obtained. While without using KI, the prepared PtPdCu catalysts show a distinct hollow structure (h-PtPtCu). CuI/PtPdCu displays the highest specific activity with a 4 times enhancement than commercial Pt/C for methanol oxidation reaction (MOR) in an alkaline medium. The superior activity can attribute to the two aspects: i) Electronic effect originated from the highly alloyed PtPdCu. ii) synergetic effect due to the surface inlayed CuI clusters which can promote the CO intermediate removal. Furthermore, owing to the stable Pt-Pd-rich surface and its special linked hollow structure, h-PtPtCu catalyst exhibits the best durability with only a 3.6 % decay in specific activity.
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| 7. |
- Barausse, Enrico, et al.
(författare)
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Prospects for fundamental physics with LISA
- 2020
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Ingår i: General Relativity and Gravitation. - : SPRINGER/PLENUM PUBLISHERS. - 0001-7701 .- 1572-9532. ; 52:8
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, which is of programmatic rather than quantitative nature, we aim to further delineate and sharpen the future potential of the LISA mission in the area of fundamental physics. Given the very broad range of topics that might be relevant to LISA,we present here a sample of what we view as particularly promising fundamental physics directions. We organize these directions through a "science-first" approach that allows us to classify how LISA data can inform theoretical physics in a variety of areas. For each of these theoretical physics classes, we identify the sources that are currently expected to provide the principal contribution to our knowledge, and the areas that need further development. The classification presented here should not be thought of as cast in stone, but rather as a fluid framework that is amenable to change with the flow of new insights in theoretical physics.
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| 8. |
- Ding, Yi, 1992, et al.
(författare)
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Construct Validity and Measurement Invariance of Mathematics Self-Efficacy and Self-Concept in Swedish PISA 2003 and 2012
- 2021
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Ingår i: World Education Research Association (WERA) Virtual Focal Meeting. - Santiago de Compostela, Spain.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A large amount of research has shown that individuals’ beliefs in their ability have a major impact on their actions in different situations (Bandura, 1986; Marsh et al., 2018; Usher & Pajares, 2006). According to Bandura (1986), students’ self-related beliefs plays a vital role in their academic achievements. Self-belief of competence is a broad conception which involves several facets and constructs, among which, self-efficacy and self-concept have been given considerable attention (Bong & Skaalvik, 2003; Lee, 2009; Marsh, 1987; Shavelson et al., 1976). According to Bong and Skaalvik (2003), both self-efficacy and self-concept can contribute to the prediction of academic performance. Students with different self-beliefs demonstrate different level of cognitive engagement as well as well-being in school (Bong & Skaalvik, 2003). Self-efficacy refers to one’s thoughts and belief in the self’s capability, which is built through previous experiences. According to Bandura’s (1986) social cognitive theory, self-efficacy captures the one’s belief in his or her competence on a specific task or process. Mathematics self-efficacy (MSE) in Programme for International Student Assessment (PISA) is a measure of student’s expectation and conviction of what can be accomplished when they need to solve pure and applied mathematics tasks. The students are asked to report on their perceived ability by responses whether they feel confident, confident, not very confident or not at all confident towards "using a train timetable", "calculating TV discount", "calculating square metres of tiles" etc (OECD, 2012). Self-concept is generally defined as one’s perception of his- or herself, which is established through experiences as well as interpretations of social atmosphere and with reference with their peers (Rosenberg, 1979; Marsh, 1987; Parker et al., 2014). It refers to general perception of the competence to a subject matter but not linked to specific tasks in that subject. Mathematics self-concept (MSC) in PISA is constructed index based on students’ responses about their perceived competence in mathematics, whether they strongly agree, agree, disagree or strongly disagree with the statements towards "get good grades", "learn quickly", "not good at math", etc (OECD, 2012). The aim of the study is two-fold. First, to evaluate construct validity of mathematics self-efficacy and self-concept as measured in PISA through exploring the measurement property of these constructs. Second, to examine measurement invariance of mathematics self-efficacy and self-concept scales over time. Data on Swedish students participating in PISA 2003 and PISA 2012 was used, which consists of 4624 and 4736 students respectively.
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| 9. |
- Ding, Yi, 1992, et al.
(författare)
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Examining the Role of Students’ Mathematics Self-concept and Self-efficacy in Mathematics Achievement in Sweden over Time: A Multigroup Multilevel Analysis
- 2022
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Ingår i: The European Conference on Educational Research (ECER), 2022, Yerevan (online).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Mathematics, as one of the mandatory and key school subjects worldwide, plays a vital role in equipping young people with mathematical knowledge and skills and preparing them not only for higher education but also for later private and professional life in modern society. Previous research has established that student self-concept and self-efficacy could predict and impact academic achievement (Bong & Skaalvik, 2003; Multon et al., 1991). It has also been observed for many decades that student gender, socioeconomic status and immigration background influence academic achievement, directly and indirectly (Bondy et al., 2017; Leder, 1992; Tate, 1997; White, 1982). By using data from the Programme for International Student Assessment (PISA), it is possible not only to analyse the relationships among students’ characteristics, self-related constructs and academic achievement but also review to what extent differences in these relationships are conditioned across the Swedish educational system and over time. The main aim of the study was to investigate the relative importance of student mathematics self-concept and self-efficacy for mathematics achievement in Sweden.
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| 10. |
- Ding, Yi, 1992, et al.
(författare)
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Measurement Invariance in Comparing Mathematics Self-Efficacy and Self-Concept across 40 Countries and Economies in PISA 2003 and 2012
- 2021
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Ingår i: The European Conference on Educational Research (ECER), Geneva (online).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In PISA studies, self-reported questionnaire data is used to assess student mathematics self-efficacy and self-concept across different education systems and measurement cycles. The comparability of these constructs is thus essential for the validity of the inferences drawn from any cross-nation and cross-cycle analyses involving these constructs. Invariance is a statistical property of measurement, indicating the measured construct being equivalence across groups and/or over time (Vandenberg and Lance, 2000). Therefore, studies aiming to make cross-national/cultural comparisons or comparisons over time, measurement invariance has to be reached to make such comparisons appropriate and proper. The aim of the present study was to assess the measurement invariance of mathematics self-efficacy and self-concept employed in the PISA 2003 and 2012 cycles, and across 40 countries and economies (by cohort by country). The study was intended to identify patterns of non-invariance in the measurement of student mathematics self-efficacy and self-concept related to participant’s country and cohort, and assess whether these two constructs can be comparably measured across groups. The study considered 40 countries and economies participated in both the PISA 2003 and 2012 cycles, giving a total sample size 605,564 respondents. The alignment method was used.
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