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Cu3SbSe4-Based materials were fabricated through Sn-doping and AgSb0.98Ge0.02Se2 incorporation and their thermoelectric properties were investigated in the temperature range from 300 K to 675 K. A remarkable enhancement in thermoelectric performance was obtained, which can be ascribed to the synergistic adjustment of electrical and thermal transport. The introduction of AgSb0.98Ge0.02Se2 nanoparticles strengthened phonon scattering in the composites, resulting in a low thermal conductivity. Simultaneously, a high power factor was maintained. As a result, a maximum figure of merit of 1.23 was obtained at 675 K for the sample Cu3Sb0.96Sn0.04Se4–3 wt% AgSb0.98Ge0.02Se2, which is one of the highest values ever reported in the Cu3SbSe4-based system.

Cu3SbSe4-based materials have attracted much attention for thermoelectric power generation in the mid-temperature range due to their low cost, ecofriendliness, and abundant elements on the earth. However, the peak figure of merit (ZT) for the Cu3SbSe4-based system prepared by the fusion method is usually smaller than unity because of its high thermal conductivity. Here, we show that through a coprecipitation method combined with spark plasma sintering ultrafine-grained Cu3Sb0.94Sn0.06Se4–ySy (y = 0, 0.5) embedded with Cu3SbSe3 nanoprecipitates can be prepared. Due to the ultralow thermal conductivity and enhanced Seebeck coefficient, a record-high ZT value of 1.32 is achieved for the sample Cu3Sb0.94Sn0.06Se3.5Se0.5. The ultralow thermal conductivity is attributed to the enhanced phonon scattering caused by the nanoprecipitates and fine grains of the samples, and the improved Seebeck coefficient originates from the enhancement of electronic density-of-state effective mass. Present results demonstrate that...

Potassium-ion batteries are promising candidates for large-scale energy storage applications owing to their merits of abundant resources, low cost, and high working voltage. However, the unsatisfying rate performance and cycling stability caused by sluggish K+ diffusion kinetics and dramatic volume expansion hinder the development of potassium-ion batteries. In this study, we design a flexible potassium-ion hybrid capacitor (PIHC) by combining the K-Sn alloying mechanism on the Sn anode and the fast capacitive behavior on the AC cathode with high surface area and mesoporous structure. After optimization, the fabricated Sn||AC PIHC achieves both a high energy density of 120 W h kg-1 and high power density of 2850 W kg-1, much better than other similar hybrid devices. Moreover, a gel polymer electrolyte with a 3D porous structure and high ionic conductivity was employed to improve the structural stability of the Sn anode, which not only realizes good flexibility but also achieves long cycling stability with a capacity retention of nearly 100% for 2000 cycles at a high current density of 3.0 A g-1.

Dental restoration is a complex process to recover patients' teeth using artificial materials. It is important to improve the utilization of the expensive material for cost saving. The tooth side surface is projected as a two-dimensional (2D) contour in the actual processing, which forms a packing problem of irregular contours. The 2D irregular packing has received a lot of attention in research to solve this NP-hard problem. Contours of the dental restoration are more complicated than those in traditional 2D irregular packing problems. The existing packing methods cannot obtain good results for these complex contours. In order to solve the contour packing problem of restoration models using the NC machining technology, a dental restoration contour packing algorithm is proposed based on the contour similar feature matching and collision. The algorithm uses dynamic programming for the longest common subsequence to search the solution of 2D free contour packing. Comparing with the existing packing methods, our proposed method can significantly reduce the processing time and improve the filling rate.

Traumatic brain injury (TBI) is one of the most devastating nervous injuries. Neural tissue engineering based on stem cells and bioactive scaffold is a promising but challenging approach for neural repair. A cutting-edge system with capability to control the fate of encapsulated stem cells is attractive to enhance neural regeneration after TBI. Herein, an injectable gelatin hydrogel dual-enzymatically cross-linked by horse radish peroxidase (HRP) and choline oxidase (ChOx) was performed as the neural scaffold to load murine bone marrow-derived mesenchymal stem cells (BMSC) for TBI treatment. The results of in vitro cellular experiments showed that low cross-linked gelatin hydrogel could obviously promote cellular viability, neural differentiation, and neurotrophins secretion of the loaded BMSC. In vivo tests on a TBI model of C57BL/6 mouse demonstrated that BMSC-laden gelatin hydrogel implants could significantly reduce the damaged area, ameliorate inflammation, attenuate neuronal apoptosis, facilitate survival and proliferation of endogenous neural cells, and promote the neurological function recovery of TBI mice. All data suggest that establishment of this three-dimensional (3D) gelatin hydrogel stem cell-loaded system is a promising therapeutic strategy for TBI or other neurological rehabilitation.

Many methods have been focused on improving the thermoelectric performance of Cu3SbSe4 based materials. However, no effective way can simultaneously achieve the significant improvement of power factor and the remarkable reduction of thermal conductivity. In this work, we introduce AgSb0.98Sn0.02Se2 particles into Cu3Sb0.96Sn0.04Se4 matrix forming Cu3Sb0.96Sn0.04Se4/x wt%AgSb0.98Sn0.02Se2 (x = 0, 1, 3, 5, 7) nanocomposites by milling and spark plasma sintering technique. Due to the reduced thermal conductivity and enhanced carrier mobility, a record-high ZT value of 1.17 is obtained for the sample Cu3Sb0.96Sn0.04Se4/5wt%AgSb0.98Sn0.02Se2. The reduced thermal conductivity is attributed to the enhanced phonon scattering caused by the second phase AgSb0.98Sn0.02Se2 with multiscale size and the enhanced power factor originated from increased carrier mobility due to the reduced carrier concentration, which is caused by the new acceptor energy level related to the interfacial defects. Present results demonstrate that excellent thermoelectric performance can be realized in Cu3Sb0.96Sn0.04Se4 matrix with AgSb0.98Sn0.02Se2 particles embedded.

Purpose– This paper aims to explore academics’ perspectives on the quality of appraisal evidence at a Chinese university.Design/methodology/approach– An online survey with both closed items and open-ended questions was distributed among all academics at the university (n= 1,538). A total of 512 responded to the questionnaire. The closed items were initially analysed using EXCEL and SPSS; the open-ended questions were thematically analysed.Findings– The academics believed that the quality of student survey and peer observation of teaching were affected by subjectivity and the lack of understanding of appraisal. Academics also suggested that appraisals should be contextualised and the approach standardised. The study suggests the need for training that informs and engages relevant stakeholders to ensure the rigour of appraisal.Originality/value– The study raises the issue of quality assurance regarding appraisal data from the perspective of academics. It is based on the collaborative effort of academics in Australia, China and New Zealand, with the support of the management staff at the case study university. The study informs both appraisers and academics of quality assurance issues in appraisal. It also contributes to the literature, in that it initiates dialogues between communities of practices through collective questioning on the quality and mechanisms of appraisal in tertiary education.

This paper aims to conduct a quantitative evaluation on the achievement, research productivity, and research hotspots of “Library, Information and Archives management” Science schools or departments in China. In this paper, the “LIS” in China is firstly defined. Before evaluation, data are collected from CSSCI (Chinese Social Science Citation Index)-indexed papers and SSCI (Social Science Citation Index)-indexed papers, as well as projects granted by the two authoritative national foundations in China, SSFC (National Social Science Foundation of China) and NSFC (National Natural Science Foundation of China). Then, a bibliometric-based method and a keyword-based method are employed to analyze the collected data from different perspectives, including annual distribution, author productivity, institute productivity and influence. Through the analysis, several conclusions are made: a) collaborative groups exist, though no particular collaboration preference is exhibited. b) Interdisciplinary research promotes the emergence of new disciplines. c) There are four top institutes with outstanding productivity and six hot research topics in the “LIS” study in China. Also, in a five-year period, “LIS” scholars have paid much attention on network technology and its application in this field. Research addressing the view of “information” is much more popular than the ubiquitous conception of “library”. d) There still exist some issues in China's LIS research, for example, the unbalanced development of educational institutes, the excessive preference of theoretical research over technical research, etc.

This article reviews 37 empirical studies, selected from 363 articles and 20 journals, on assessment feedback published between 2000 and 2011. The reviewed articles, many of which came out of studies in the UK and Australia, reflect the most current issues and developments in the area of assessing disciplinary writing. The article aims to outline current studies on assessment feedback. These studies have explored undergraduate students' wide-ranging perspectives on the effectiveness and utility of assessment feedback, the divergent styles of assessment feedback of lecturers and tutors in various disciplines, teachers' divergent interpretations of assessment criteria and confusion about the dual roles of assessment feedback, and the divergences between teachers' beliefs and practices. The review includes analysis and comparison of the research methods and findings of the studies. It identifies a research space for assessment feedback and outlines implications for further studies.

Teachers’ feedback on students’ written work is an important aspect of pedagogy. However, theoretical views differ on what constitutes ‘good’ feedback, both among applied linguists and academics in other disciplines. In-depth research needs to be carried out into the contextual difficulties of evaluating and assessing academic assignments, and the awarding of grades, especially by those who are relatively inexperienced in this work. This article reports aspects of a case study which explored the beliefs and practices of a group of untrained and inexperienced part-time tutors in a New Zealand university. Data were collected from a preliminary survey, individual interviews, ‘think aloud’ and stimulated recall sessions, and focus group meetings. Extracts from the collected data are presented and discussed. The findings indicate that these tutors initially stated their belief that the purpose of providing feedback was to assist the students to improve their academic writing skills; however, it emerged that their primary concern was to justify the grades that they awarded. It is suggested that using a multi-method approach to data collection can bridge the gap between theoretical perspectives on what constitutes ‘good’ feedback and what tutors actually believe and do in their everyday work.

For absorption lines, the distortion of spectral lines by experimental spectrometers must be considered in measuring linewidth which has been investigated by many authors. While in the derivative spectrum, we managed to give the corrections of instrumental broadening and distortion to obtain accurate linewidths. We developed a universal fitting program which was explored together with the method of correction in the fundamental band spectra of LMR of NO. The uncorrected halfwidths were compared with the corrected values, which were obtained from the program. The results of comparison are very satisfactory and demonstrate their useful application to analyze experimental spectra.

Warpage is a major reliability concern for IC packages. Package structure, material property and assembly process will all impact warpage behavior, which can be characterized by 3D Finite Element Analysis (FEA). Traditionally, the FEA simulation will only analyze warpage of a free standing package with thermo-mechanical stress induced by Coefficient of Thermal Expansion (CTE) mismatch during cooling process of Epoxy Molding Compound (EMC) from cure temperature to room temperature. In this paper, a dedicated FEA model has been developed to simulate a strip type Fine-Pitch Ball Grid Array (FBGA) package. Different from conventional simulation, effect of both EMC chemical shrinkage due to polymerization conversion during post molding cure and actual measurement operation on warpage have been taken into consideration in the FEA model. Parametric study with different package layout, die area and die thickness has been performed. Result showed package layout of the strip can significantly impact warpage; and die area had more influence on warpage than die thickness. Warpage performance can be improved by optimizing these parameters. Compare to measurement, the simulation result is in good agreement with actual package warpage.