共查询到20条相似文献，搜索用时 0 毫秒
1.
Recent research indicates that traditional academic structures may not effectively promote self‐directed learning. We investigated whether an experiential interdisciplinary projects program, called the Global Studies Program, increased readiness for self‐directed learning (SDL) and life‐long learning (LLL) using three methods: a nationally recognized course evaluation system called the Individual Development and Educational Assessment system (IDEA); an internal student project quality assessment protocol; and the Self‐Directed Learning Readiness Scale (SDLRS). Student self‐assessments through the IDEA system showed Global Studies Program students reported much greater progress in LLL‐related skills than did national and local comparison groups. Similarly, review of student projects by independent faculty teams found Global Studies Program students consistently outscored on‐campus project students in LLL‐related measures by wide margins. The SDLRS also showed a positive, but less emphatic increase in SDL readiness among a Global Studies Program cohort. The research demonstrates the success of one experiential learning environment in promoting SDL/LLL, while raising interesting issues regarding alternative methods of measuring potential benefits. 相似文献
2.
《Advanced Materials Technologies》2017,2(9)
A manufacturing process to 3D print engineered materials comprised of a user‐specified pattern of nano‐ or microparticles embedded in a polymer matrix material is described. The materials are printed layer‐by‐layer using stereolithography, and in each layer, ultrasound directed self‐assembly is employed to organize a user‐specified pattern of particles. This process allows manufacturing macroscale 3D materials with a user‐specified microstructure consisting of particles of any material, and contrasts with existing processes, which are often limited to laboratory scale, specific materials, and/or 2D implementations. Using this manufacturing process, 3D printing of macroscale multilayer engineered materials containing a Bouligand microstructure commonly found in composite laminate and biological materials is demonstrated. Additionally, engineered materials containing a pattern of electrically conductive nickel‐coated carbon fibers are fabricated, which illustrate the feasibility of 3D printing structures with embedded insulated electrical wiring. This process finds application in manufacturing of multifunctional composite materials. 相似文献
3.
Under control: Controlled assemblies of gold nanorods in a poly(vinyl alcohol) (PVA) nanofiber matrix with tunable optical properties can be achieved by using electrospinning. The resultant assemblies can be used as substrates for surface-enhanced Raman spectroscopy (SERS). This work provides a facile way to control alignment of anisotropic nanostructures in a polymer nanofiber matrix and generates new assemblies with interesting properties. 相似文献
4.
5.
6.
Hyeong Min Jin Dae Yong Park Seong‐Jun Jeong Gil Yong Lee Ju Young Kim Jeong Ho Mun Seung Keun Cha Joonwon Lim Jun Soo Kim Kwang Ho Kim Keon Jae Lee Sang Ouk Kim 《Advanced materials (Deerfield Beach, Fla.)》2017,29(32)
One of the fundamental challenges encountered in successful incorporation of directed self‐assembly in sub‐10 nm scale practical nanolithography is the process compatibility of block copolymers with a high Flory–Huggins interaction parameter (χ). Herein, reliable, fab‐compatible, and ultrafast directed self‐assembly of high‐χ block copolymers is achieved with intense flash light. The instantaneous heating/quenching process over an extremely high temperature (over 600 °C) by flash light irradiation enables large grain growth of sub‐10 nm scale self‐assembled nanopatterns without thermal degradation or dewetting in a millisecond time scale. A rapid self‐assembly mechanism for a highly ordered morphology is identified based on the kinetics and thermodynamics of the block copolymers with strong segregation. Furthermore, this novel self‐assembly mechanism is combined with graphoepitaxy to demonstrate the feasibility of ultrafast directed self‐assembly of sub‐10 nm nanopatterns over a large area. A chemically modified graphene film is used as a flexible and conformal light‐absorbing layer. Subsequently, transparent and mechanically flexible nanolithography with a millisecond photothermal process is achieved leading the way for roll‐to‐roll processability. 相似文献
7.
In this Review, recent achievements in the multilevel interior‐structured hollow 0D and 1D micro/nanomaterials are presented and categorized. The 0D multilevel interior‐structured micro/nanomaterials are classified into four main interior structural categories that include a macroporous structure, a core‐in‐hollow‐shell structure, a multishell structure, and a multichamber structure. Correspondingly, 1D tubular micro/nanomaterials are of four analogous structures, which are a segmented structure, a wire‐in‐tube structure, a multiwalled structure, and a multichannel structure. Because of the small sizes and complex interior structures, some special synthetic strategies that are different from routine hollowing methods, are proposed to produce these interior structures. Compared with the same‐sized solid or common hollow counterparts, these fantastic multilevel hollow‐structured micro/nanomaterials show a good wealth of outstanding properties that enable them broad applications in catalysis, sensors, Li‐ion batteries, microreactors, biomedicines, and many others. 相似文献
8.
9.
Yiming Wang Sander Oldenhof Frank Versluis Maulik Shah Kai Zhang Volkert van Steijn Xuhong Guo Rienk Eelkema Jan H. van Esch 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(8)
Herein, the micropatterning of supramolecular gels with oriented growth direction and controllable spatial dimensions by directing the self‐assembly of small molecular gelators is reported. This process is associated with an acid‐catalyzed formation of gelators from two soluble precursor molecules. To control the localized formation and self‐assembly of gelators, micropatterned poly(acrylic acid) (PAA) brushes are employed to create a local and controllable acidic environment. The results show that the gel formation can be well confined in the catalytic surface plane with dimensions ranging from micro‐ to centimeter. Furthermore, the gels show a preferential growth along the normal direction of the catalytic surface, and the thickness of the resultant gel patterns can be easily controlled by tuning the grafting density of PAA brushes. This work shows an effective “bottom‐up” strategy toward control over the spatial organization of materials and is expected to find promising applications in, e.g., microelectronics, tissue engineering, and biomedicine. 相似文献
10.
Mishchenko L Hatton B Kolle M Aizenberg J 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(12):1904-1911
Biological strategies for bottom-up synthesis of inorganic crystalline and amorphous materials within topographic templates have recently become an attractive approach for fabricating complex synthetic structures. Inspired by these strategies, herein the synthesis of multi-layered, hierarchical inverse colloidal crystal films formed directly on topographically patterned substrates via evaporative deposition, or \"co-assembly\", of polymeric spheres with a silicate sol-gel precursor solution and subsequent removal of the colloidal template, is described. The response of this growing composite colloid-silica system to artificially imposed 3D spatial constraints of various geometries is systematically studied, and compared with that of direct colloidal crystal assembly on the same template. Substrates designed with arrays of rectangular, triangular, and hexagonal prisms and cylinders are shown to control crystallographic domain nucleation and orientation of the direct and inverse opals. With this bottom-up topographical approach, it is demonstrated that the system can be manipulated to either form large patterned single crystals, or crystals with a fine-tuned extent of disorder, and to nucleate distinct colloidal domains of a defined size, location, and orientation in a wide range of length-scales. The resulting ordered, quasi-ordered, and disordered colloidal crystal films show distinct optical properties. Therefore, this method provides a means of controlling bottom-up synthesis of complex, hierarchical direct and inverse opal structures designed for altering optical properties and increased functionality. 相似文献
11.
Block copolymers self‐assemble into nanoscale morphologies, spontaneously ordering under thermal annealing conditions owing to the chemical incompatibility between the blocks. While the morphologies that form can be rationalized based on equilibrium arguments, the structures seen experimentally are strongly influenced by kinetic effects including process history. Recently, a variety of photothermal processing techniques have been used to control block copolymer ordering. Photothermal methods provide access to extreme conditions, including high temperatures, large heating rates, and sharp thermal gradients. This can correspondingly be used to greatly accelerate block copolymer ordering kinetics, to pattern material order, or to probe fundamental aspects of self‐assembly by exploring process histories. 相似文献
12.
13.
14.
May Lin Wee 《工程教育杂志》2010,99(3):237-251
Background Simulation‐based Learning (SBL) was used in Machining Technology, a sixty‐hour module for second year engineering students, at the School of Engineering at Temasek Polytechnic. The aim of this study was to investigate the effect of SBL on learners' motivation and performance. In assessing students' motivation, we adopted a framework based on the Self‐determination Theory (SDT), chosen on account of its comprehensive treatment of the relationship between students' perceived needs satisfaction and their motivation. Purpose (Hypothesis ) It is hypothesized that SBL, which provides learners with interactive learning experiences, will enhance students' motivation and performance. We explored the effect of SBL on students' perceived psychological needs satisfaction, motivation, and learning, and how SBL affected students' understanding and application of content knowledge. Design /Method The intervention procedure involved the incorporation of SBL in Machining Technology, a 60 hour module in the mechanical engineering program. Survey findings and post‐intervention assessment outcomes were used to assess the students' perceptions of their basic psychological needs satisfaction, motivation, and performance. Results Our findings suggest that the students perceived their psychological needs to be satisfied and had high levels of self‐determined motivation. Students who undertook SBL had higher mean performance test scores, although SBL may have differential effects on learners depending on factors such as gender, educational backgrounds, and IT knowledge. Conclusions Our findings suggest that the students perceived their basic psychological needs to be met and that SBL can potentially enhance self‐determined motivation as well as improve learning in general. 相似文献
15.
16.
17.
18.
Bingbing Yue Xin Jin Pei Zhao Mingjie Zhu Liangliang Zhu 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(7)
Magnetic control has been a prosperous and powerful contactless approach in arraying materials into high‐order nanostructures. However, it is tremendously difficult to control organic polymers in this way on account of the weak magnetic response. The preparation of block copolymers (BCPs) with high magnetostatic energy is reported here, relying on an effective electrostatic coupling between paramagnetic ions and polymer side chains. As a result, the BCPs undergo a magnetically directed self‐assembly to form microphase‐segregated nanostructures with long‐range order. It is emphasized that such a precisely controlled alignment of the BCPs is performed upon a single commercial magnet with low‐intensity field (0.35 Tesla). This strategy is profoundly easy‐to‐handle in contrast to routine electromagnetic methods with high‐intensity field (5–10 Tesla). More significantly, the paramagnetic metal component in the BCP samples can be smartly removed, providing a template effect with a preservation of the directed self‐assembled nanofeatures for patterning follow‐up functionalized species through the original binding site. 相似文献
19.
Xu J Hong SW Gu W Lee KY Kuo DS Xiao S Russell TP 《Advanced materials (Deerfield Beach, Fla.)》2011,23(48):5755-5761
The combination of solvent annealing, surface reconstruction, and a tone-reversal etching procedure provides an attractive approach to utilize block copolymer (BCP) lithography to fabricate highly ordered and densely packed silicon oxide nano-dots on a surface. The obtained silicon oxide nano-dots feature an areal density of 1.3 teradots inch(-2) . 相似文献