An Analysis of Chinese Community Education Policy

Based on the systematic review of the government- issued regulatory documents related to community education using the leading Chinese data base of WanFang, the article maps the terrain of community education in china from 1992 to present. It is found that community education in China has experienced a fundamental change from being responsible merely for out-of-school ethic education for primary and secondary school students before 21st century to training and education activities for adults in need of them under social transformation. In addition, it grows from mere community education committee responsible for its work to a comparatively complete system capable of rallying necessary human and material resources to ensure its function. The changes of community education policy were directly motivated by the domestic socioeconomic development in the past 30 years and the global educational notion of lifelong learning and building a learning society. Finally, the problems such as the absence of national laws and some others in current community education in China are discussed

Oxidation and phase transitions of epitaxial tin oxide thin films on (012)(1̄012) sapphire

We studied the structural behavior and electrical transport properties of epitaxial α-SnO thin films grown on the (012) α-Al2O3(1̄012) α-Al2O3 (sapphire) substrate. Hall effect measurements revealed that the epitaxial as-deposited SnO film is a p-type semiconductor. In situ x-ray diffraction studies show that the α-SnO phase is metastable and will transform into SnO2SnO2 with the rutile type structure when annealed at high temperatures in air. The onset of this phase transformation was observed to begin approximately at 300 °C during heating. Shortly thereafter, rutile SnO2SnO2 was observed to coexist with α-SnO and intermediate products such as Sn and Sn3O4.Sn3O4. After being annealed at temperatures above 600 °C, the film then fully transformed into the rutile SnO2SnO2 phase. Our results show that the α-SnO to SnO2SnO2 structural transformation proceeds initially by the localized disproportionate redistribution of internal oxygen at low temperature, followed by the transformation of the remaining SnO phase and intermediate phases into SnO2SnO2 via the inward diffusion of external oxygen at higher temperatures. Most of the SnO2SnO2 crystallites nucleate epitaxially on α-SnO with the orientation relationship of (101)SnO2//(001)SnO(101)SnO2//(001)SnO and their growth processes are controlled by the (101)SnO2//(001)SnO(101)SnO2//(001)SnO interfaces, leading to a (101) texture and a laminar grain shape for SnO2.SnO2. The relationship between the electrical transport properties and the structural evolution of the film has also been investigated. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70650/2/JAPIAU-89-11-6048-1.pd

Methodology for standard cell compliance and detailed placement for triple patterning lithography

As the feature size of semiconductor process further scales to sub-16nm technology node, triple patterning lithography (TPL) has been regarded one of the most promising lithography candidates. M1 and contact layers, which are usually deployed within standard cells, are most critical and complex parts for modern digital designs. Traditional design flow that ignores TPL in early stages may limit the potential to resolve all the TPL conflicts. In this paper, we propose a coherent framework, including standard cell compliance and detailed placement to enable TPL friendly design. Considering TPL constraints during early design stages, such as standard cell compliance, improves the layout decomposability. With the pre-coloring solutions of standard cells, we present a TPL aware detailed placement, where the layout decomposition and placement can be resolved simultaneously. Our experimental results show that, with negligible impact on critical path delay, our framework can resolve the conflicts much more easily, compared with the traditional physical design flow and followed layout decomposition

Spin-flip phenomena at the Co|graphene|Co interfaces

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98663/1/ApplPhysLett_98_133111.pd

Epitaxial nanocrystalline tin dioxide thin films grown on (0001) sapphire by femtosecond pulsed laser deposition

Nanocrystalline tin dioxide (SnO2)(SnO2) thin films of different thicknesses were fabricated on the (0001) surface of α-Al2O3α-Al2O3 (sapphire) using femtosecond pulsed laser deposition. X-ray diffraction and transmission electron microscopy (TEM) analysis revealed that the microstructure of the films strongly depends on the film thickness. The films with a small thickness (<30 nm) are composed of nanosized columnar (100) oriented grains (3–5 nm in diameter) which grow epitaxially on the substrate with three different in-plane grain orientations. The (101) oriented grains (25 nm in diameter) appear when the film thickness becomes larger than a critical value (about 60 nm). The volume fraction of the (101) grains increases with film thickness. Cross-section TEM studies indicated that the (101) oriented grains nucleate on the top of the (100) oriented nanosized grains and show abnormal grain growth driven by surface energy minimization. As a result, the electrical transport properties are strongly dependent on the film thickness. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70608/2/APPLAB-79-5-614-1.pd

Effect of crystal defects on the electrical properties in epitaxial tin dioxide thin films

Epitaxial (101) tin dioxide thin films with thickness ranging from 6 and 100 nm were deposited on the (102) α-Al2O3(101̄2)α-Al2O3 substrate by femtosecond pulsed laser ablation. Due to the lattice and thermal expansion mismatch with the substrate, the SnO2SnO2 film shows interfacial misfit dislocations, antiphase boundaries (APBs), and partial dislocations. The APBs lie along the (01)(1̄01) planes with a displacement of 1/2[101]. The densities of APBs and partial dislocations vary with film thickness, whereas the average spacing of misfit dislocations remains constant. Hall effect measurements showed that both electron concentration and mobility decrease with a reduction in the film thickness, which is ascribed to the scattering of electrons by crystal defects and interfaces and the effect of a native space charge region at the near-surface region of the films. The response of the films to reducing gases was found to depend on the electron concentration of the film and the relative fraction, with respect to film thickness, of material that is depleted of electrons. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70824/2/APPLAB-81-27-5168-1.pd

Combinatorial search of superconductivity in Fe-B composition spreads

We have fabricated Fe-B thin film composition spreads in search of possible superconducting phases following a theoretical prediction by Kolmogorov et al.^1 Co-sputtering was used to deposit spreads covering a large compositional region of the Fe-B binary phase diagram. A trace of superconducting phase was found in the nanocrystalline part of the spread, where the film undergoes a metal to insulator transition as a function of composition in a region with the average composition of FeB_2. The resistance drop occurs at 4K, and a diamagnetic signal has also been detected at the same temperature. The superconductivity is suppressible in the magnetic field up to 2 Tesla.Comment: 11 pages, 4 figure

Experimental Evidence of Ferroelectric Negative Capacitance in Nanoscale Heterostructures

We report a proof-of-concept demonstration of negative capacitance effect in a nanoscale ferroelectric-dielectric heterostructure. In a bilayer of ferroelectric, Pb(Zr0.2Ti0.8)O3 and dielectric, SrTiO3, the composite capacitance was observed to be larger than the constituent SrTiO3 capacitance, indicating an effective negative capacitance of the constituent Pb(Zr0.2Ti0.8)O3 layer. Temperature is shown to be an effective tuning parameter for the ferroelectric negative capacitance and the degree of capacitance enhancement in the heterostructure. Landau's mean field theory based calculations show qualitative agreement with observed effects. This work underpins the possibility that by replacing gate oxides by ferroelectrics in MOSFETs, the sub threshold slope can be lowered below the classical limit (60 mV/decade)

Rh single atoms on TiO2 dynamically respond to reaction conditions by adapting their site.

Single-atom catalysts are widely investigated heterogeneous catalysts; however, the identification of the local environment of single atoms under experimental conditions, as well as operando characterization of their structural changes during catalytic reactions are still challenging. Here, the preferred local coordination of Rh single atoms is investigated on TiO2 during calcination in O2, reduction in H2, CO adsorption, and reverse water gas shift (RWGS) reaction conditions. Theoretical and experimental studies clearly demonstrate that Rh single atoms adapt their local coordination and reactivity in response to various redox conditions. Single-atom catalysts hence do not have static local coordinations, but can switch from inactive to active structure under reaction conditions, hence explaining some conflicting literature accounts. The combination of approaches also elucidates the structure of the catalytic active site during reverse water gas shift. This insight on the real nature of the active site is key for the design of high-performance catalysts