Perceptual sensitivity to a visual target presented in a random continuous sequence of targets and nontargets decreased rapidly over time when stimuli were highly degraded visually but not when moderately degraded or undegraded. Large declines in sensitivity, independent of changes in response criterion, were found after only 5 minutes of observation. These rapid decrements of sensitivity to degraded targets seem to result from demands on the limited capacity of visual attention.

Triangular voltage waveform was employed to distinguish the contributions of dielectric permittivity, electric conductivity and domain switching in current-electric field curves. At the same time, it is shown how those contributions can affect the shape of the electric displacement — electric field loops (D–E loops). The effects of frequency, temperature and microstructure (point defects, grain size and texture) on the ferroelectric properties of several ferroelectric compositions is reported, including: BaTiO 3; lead zirconate titanate (PZT); lead-free Na 0.5 K 0.5 NbO 3; perovskite-like layer structured A 2 B 2 O 7 with super high Curie point (T c ); Aurivillius phase ferroelectric Bi 3.15 Nd 0.5 Ti 3 O 12; and multiferroic Bi 0.89 La 0.05 Tb 0.06 FeO 3. This systematic study provides an instructive outline in the measurement of ferroelectric properties and the analysis and interpretation of experimental data.

In addition, it is of importance to note that a high power factor ( S 2 / ρ ) is also indispensable for a given TE material to maximize its output power. [ 3 ] Therefore, by taking account of the practical application, a simultaneously optimization in the electrical and thermal transport properties of TE materials is imperative to maximize the output power and conversion efficiency concurrently. Recently, some strategies have been proved to be effective and even high ZT values greater than 2.0 have been achieved in the Pb-based TE materials, [ 4,5 ] such as the band convergence, [ 6 ] electronic density of states (DOS) distortion, [ 7 ] carrier energy barrier fi ltering, [ 8 ] and the conduction (valence) band modifi cation [ 9 ] to enhance Seebeck coefficient for high power factor; while defect engineering, [ 10 ] nanostructuring, [ 11 ] and multiscale hierarchical architecturing [ 12 ] to enhance the scattering of phonons for low thermal conductivity. However, the environmentally hazardous Pb element prevents them from widespread application. Therefore, it is of signifi cance to develop eco-friendly TE materials for middle temperature application, such as Mg 2 Si, [ 13 ] Half-Heusler, [ 14 ] and BiCuSeO [ 15 ] based TE materials.More recently, chalcopyrite CuInTe 2 is being considered as a promising p-type TE material because of the merits of environmentally friendly chemical component, intrinsically high electrical conductivity, and high Seebeck coeffi cient owing to the degenerate energy bands near the valence band maximum (VBM). [ 16 ] Thus many efforts have been made theoretically and experimentally [17][18][19][20][21][22] to enhance its TE performance already, such as Cu defi ciency and cation substitution. However, since there are two cation sites (Cu and In) in CuInTe 2 , cation substitution often lacks specifi city and may generate both electron and hole simultaneously, making it diffi cult to enhance the electrical transport properties substantially. Besides, the less phonon scattering, mainly by point defects originated from chemical component regulation, rendering its thermal conductivity is still relatively high. It is well known that refi ning the microstructure into nanoscale is often effective in optimizing thermal transport properties, yet the electrical transport properties are usually deteriorated due to the inevitably scattering of carriers, as typical shown in the CuInTe 2 /graphene [ 23 ] and our

The authors present the structure transformation and magnetic properties of Bi1−xLaxFeO3 (x=0.0–0.15) ceramics prepared by a conventional solid-state reaction processing. Magnetic measurements reveal that remnant magnetization of 15% La-doped BiFeO3 has enhanced about 20 times as compared to pure BiFeO3. It is the structural phase transition (R3c–C222) near x=0.15 that destructs the spin cycloid, and thus enhances the ferromagnetic properties significantly. In these Bi1−xLaxFeO3 ceramic samples, besides the known antiferromagnetic Néel temperature TN1∼615K, another Néel temperature TN2∼260K can be observed due to the trace impurity phase of Bi2Fe4O9 in these ceramic samples.

We studied the effect of doping with Bi on the thermoelectric properties of SnTe-based materials.

Single-phase multiferroic BiFeO3 thin films were grown on (111) Pt∕Ti∕SiO2∕Si substrates via a simple sol-gel spin-coating technique, as evidenced by x-ray diffraction. The thickness of the films can be controlled by the number of layers spin coated. Scanning electron microscope confirmed good surface and cross-section morphology of the films. Obvious multiferroic behavior with small saturation polarization but high saturation magnetization was observed in the films. X-ray photoelectron spectroscopy was used to examine the combination state of Fe 2p electron in the BiFeO3 films.

For a typical perovskite solar cell (PKSC), both the electron transport layers (ETLs) and hole transport materials (HTMs) play a very important role in improving the device performance and long-term stability. In this paper, we firstly improve the electron transport properties by modification of TiO ETLs with Na species, and an enhanced power conversion efficiency (PCE) of 16.91% has been obtained with less hysteresis. Subsequently, an inorganic CuI film prepared by a facile spray deposition method has been employed to replace the conventional spiro-OMeTAD as the HTM in PKSCs. Because of the improved transport properties at the ETL/perovskite and perovskite/HTM interfaces, a maximum photovoltaic efficiency of 17.6% with reduced hysteresis has been achieved in the PKSC with both the Na-modified TiO ETL and 60 nm-thick CuI layer HTM. To our knowledge, the PCE achieved in this paper is one of the highest values ever reported for the PKSC devices with inorganic HTMs. More significantly, the PKSCs exhibit an outstanding device stability, their PCE remains constant after storage in the dark for 50 days, and they can retain approximately 92% of their initial efficiency after storage even for 90 days.

For a typical perovskite solar cell (PKSC), the electron transport layer (ETL) has a great effect on device performance and stability. Herein, we manifest that low-temperature solution-processed ZnSe can be used as a potential ETL for PKSCs. Our optimized device with ZnSe ETL has achieved a high power conversion efficiency (PCE) of 17.78% with negligible hysteresis, compared with the TiO based cell (13.76%). This enhanced photovoltaic performance is attributed to the suitable band alignment, high electron mobility, and reduced charge accumulation at the interface of ETL/perovskite. Encouraging results were obtained when the thin layer of ZnSe cooperated with TiO. It shows that the device based on the TiO/ZnSe ETL with cascade conduction band level can effectively reduce the interfacial charge recombination and promote carrier transfer with the champion PCE of 18.57%. In addition, the ZnSe-based device exhibits a better photostability than the control device due to the greater ultraviolet (UV) light harvesting of the ZnSe layer, which can efficiently prevent the perovskite film from intense UV-light exposure to avoid associated degradation. Consequently, our results present that a promising ETL can be a potential candidate of the n-type ETL for commercialization of efficient and photostable PKSCs.