"It Felt Good to Be Included": A Mixed-Methods Study of Pre-Kindergarten Teachers' Experiences with Professional Learning.

This article reports findings from a study to investigate the efficacy beliefs, experiences, and instructional practices of pre-kindergarten (pre-k) teachers from a high-need district who engaged in collaborative professional learning experiences provided by a partner university. The study also examined language and literacy instruction for children in their pre-k classrooms. The professional learning occurred as part of a project to support pre-k teachers within the district and to boost teaching effectiveness. Researchers employed a mixed methods approach to investigate how pre-k teacher participants (a) perceived their efficacy as teachers; (b) experienced early literacy-focused professional learning; and (c) approached literacy teaching within their classrooms. Analysis of three years of data reveal alignment between participants' sense of efficacy and instructional strengths and areas for growth both self-reported and observed. Additionally, participants echoed feelings of exclusion from most professional learning experiences and offered insight into considerations for designing and delivering professional learning opportunities to effectively support pre-k teachers' literacy instructional practices. Supplementary Information: The online version contains supplementary material available at 10.1007/s10643-021-01175-4.

Water Splitting Exceeding 17% Solar-to-Hydrogen Conversion Efficiency Using Solution-Processed Ni-Based Electrocatalysts and Perovskite/Si Tandem Solar Cell.

Various noble metal-free electrocatalysts have been explored to enhance the overall water splitting efficiency. Ni-based compounds have attracted substantial attention for achieving efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysts. Here, we show superior electrocatalysts based on NiFe alloy electroformed by a roll-to-roll process. NiFe (oxy)hydroxide synthesized by an anodization method for the OER catalyst shows an overpotential of 250 mV at 10 mA cm-2, which is dramatically smaller than that of bare NiFe alloy with an overpotential of 380 mV at 10 mA cm-2. Electrodeposited NiMo films for the HER catalyst also exhibit a small overpotential of 100 mV at 10 mA cm-2 compared with that of bare NiFe alloy (550 mV at 10 mA cm-2). A combined spectroscopic and electrochemical analysis reveals a clear relationship between the surface chemistry of NiFe (oxy)hydroxide and the water splitting properties. These outstanding fully solution-processed catalysts facilitate superb overall water splitting properties due to enlarged active surfaces and highly active catalytic properties. We combined a solution-processed monolithic perovskite/Si tandem solar cell with MAPb(I0.85Br0.15)3 for the direct conversion of solar energy into hydrogen energy, leading to the high solar-to-hydrogen efficiency of 17.52%. Based on the cost-effective solution processes, our photovoltaic-electrocatalysis (PV-EC) system has advantages over latest high-performance solar water splitting systems.

Psychometric Properties of an Instrument to Measure Word Problem Solving Skills in Mathematics.

The purpose of this study is to examine the psychometric properties of an instrument to measure word problem solving skills in mathematics related to speed with 706 sixth grade Chinese and Singaporean students. Rasch measurement models were applied to examine the reliability, unidimensionality, rating scale functioning, item difficulty, and person difficulty. The differential item functioning (DIF) analysis was also performed to examine the differences in item difficulty estimates between Chinese and Singaporean students. Results suggest that the data satisfied the unidimensionality requirements of the Rasch model and that most of the item difficulty measures aligned the person ability distribution. The instrument demonstrated adequate reliability. The fit statistics were within acceptable limits for the vast majority of items, with a few exceptions. The rating scale structure functioned properly although the middle categories had very few observations. Deleting misfitting cases and collapsing middle categories slightly improved the psychometric properties. DIF analysis revealed that four items were more difficult for Chinese students whereas two other items were more difficult for the Singaporean students. Results also indicated that the Chinese participants scored higher than the Singaporean participants for 11 of the 14 items and the Singaporean students scored higher than their Chinese cohorts in the other 3 items. The validation of this instrument has implications for the teaching and learning of mathematical word problems in practice.

Flexible Room-Temperature NH3 Sensor for Ultrasensitive, Selective, and Humidity-Independent Gas Detection.

Ammonia (NH3) is an irritant gas with a unique pungent odor; sub-parts per million-level breath ammonia is a medical biomarker for kidney disorders and Helicobacter pylori bacteria-induced stomach infections. The humidity varies in both ambient environment and exhaled breath, and thus humidity dependence of gas-sensing characteristics is a great obstacle for real-time applications. Herein, flexible, humidity-independent, and room-temperature ammonia sensors are fabricated by the thermal evaporation of CuBr on a polyimide substrate and subsequent coating of a nanoscale moisture-blocking CeO2 overlayer by electron-beam evaporation. CuBr sensors coated with a 100 nm-thick CeO2 overlayer exhibits an ultrahigh response (resistance ratio) of 68 toward 5 ppm ammonia with excellent gas selectivity, rapid response, reversibility, and humidity-independent sensing characteristics at room temperature. In addition, the sensing performance remains stable after repetitive bending and long-term operation. Moreover, the sensors exhibit significant response to the simulated exhaled breath of patients with H. pylori infection; the simulated breath contains 50 ppb NH3. The sensors thus show promising potential in detecting sub-parts per million-level NH3, regardless of humidity fluctuations, which can open up new applications in wearable devices for in situ medical diagnosis and indoor/outdoor environment monitoring.

Highly Conductive Transparent and Flexible Electrodes Including Double-Stacked Thin Metal Films for Transparent Flexible Electronics.

To keep pace with the era of transparent and deformable electronics, electrode functions should be improved. In this paper, an innovative structure is suggested to overcome the trade-off between optical and electrical properties that commonly arises with transparent electrodes. The structure of double-stacked metal films showed high conductivity (<3 Ω/sq) and high transparency (∼90%) simultaneously. A proper space between two metal films led to high transmittance by an optical phenomenon. The principle of parallel connection allowed the electrode to have high conductivity. In situ fabrication was possible because the only materials composing the electrode were silver and WO3, which can be deposited by thermal evaporation. The electrode was flexible enough to withstand 10 000 bending cycles with a 1 mm bending radius. Furthermore, a few µm scale patterning of the electrode was easily implemented by using photolithography, which is widely employed industrially for patterning. Flexible organic light-emitting diodes and a transparent flexible thin-film transistor were successfully fabricated with the proposed electrode. Various practical applications of this electrode to new transparent flexible electronics are expected.

Toward High-Performance Hematite Nanotube Photoanodes: Charge-Transfer Engineering at Heterointerfaces.

Vertically ordered hematite nanotubes are considered to be promising photoactive materials for high-performance water-splitting photoanodes. However, the synthesis of hematite nanotubes directly on conducting substrates such as fluorine-doped tin oxide (FTO)/glass is difficult to be achieved because of the poor adhesion between hematite nanotubes and FTO/glass. Here, we report the synthesis of hematite nanotubes directly on FTO/glass substrate and high-performance photoelectrochemical properties of the nanotubes with NiFe cocatalysts. The hematite nanotubes are synthesized by a simple electrochemical anodization method. The adhesion of the hematite nanotubes to the FTO/glass substrate is drastically improved by dipping them in nonpolar cyclohexane prior to postannealing. Bare hematite nanotubes show a photocurrent density of 1.3 mA/cm(2) at 1.23 V vs a reversible hydrogen electrode, while hematite nanotubes with electrodeposited NiFe cocatalysts exhibit 2.1 mA/cm(2) at 1.23 V which is the highest photocurrent density reported for hematite nanotubes-based photoanodes for solar water splitting. Our work provides an efficient platform to obtain high-performance water-splitting photoanodes utilizing earth-abundant hematite and noble-metal-free cocatalysts.

Organolead Halide Perovskites for Low Operating Voltage Multilevel Resistive Switching.

Organolead halide perovskites are used for low-operating-voltage multilevel resistive switching. Ag/CH3 NH3 PbI3 /Pt cells exhibit electroforming-free resistive switching at an electric field of 3.25 × 10(3) V cm(-1) for four distinguishable ON-state resistance levels. The migration of iodine interstitials and vacancies with low activation energies is responsible for the low-electric-field resistive switching via filament formation and annihilation.

Monolayer Co3 O4 Inverse Opals as Multifunctional Sensors for Volatile Organic Compounds.

Monolayers of periodic porous Co3 O4 inverse opal (IO) thin films for gas-sensor applications were prepared by transferring cobalt-solution-dipped polystyrene (PS) monolayers onto sensor substrates and subsequent removal of the PS template by heat treatment. Monolayer Co3 O4 IO thin films having periodic pores (d≈500 nm) showed a high response of 112.9 to 5 ppm C2 H5 OH at 200 °C with low cross-responses to other interfering gases. Moreover, the selective detection of xylene and methyl benzenes (xylene+toluene) could be achieved simply by tuning the sensor temperature to 250 and 275 °C, respectively, so that multiple gases can be detected with a single chemiresistor. Unprecedentedly high ethanol response and temperature-modulated control of selectivity with respect to ethanol, xylene, and methyl benzenes were attributed to the highly chemiresistive IO nanoarchitecture and to the tuned catalytic promotion of different gas-sensing reactions, respectively. These well-ordered porous nanostructures could have potential in the field of high-performance gas sensors based on p-type oxide semiconductors.

Microcavity effect using nanoparticles to enhance the efficiency of organic light-emitting diodes.

In this paper, in contrast with previously reported approaches, we suggest exploiting a microcavity effect using nanoparticles to improve the optical efficiency of organic light-emitting diodes (OLED). The method to input the nanoparticles inside the OLED device is simple and cost effective by virtue of employing a solution process using a spin coating fabrication method. Titanium dioxide (TiO2) nanoparticles were used to improve the reflection by its high refractive index. In tandem with optimized heights of the organic layers, the increased light reflectance at the anode side, which includes the TiO2 nanoparticle layer, improved the optical efficiency of the OLED device via the microcavity effect. In order to prove that the enhancement of the optical efficiency was due to an enhanced microcavity effect caused by TiO2 nanoparticles, a microcavity simulation was conducted. The electrical characteristics were not affected by the nanoparticles and a clear pixel image was maintained. The results in this paper show that a nanoparticle based microcavity effect can be exploited to enhance the optical efficiency of OLEDs.

Validating a developmental scale for young children using the Rasch model: applicability of the teaching strategies GOLD assessment system.

This article reports the results of an application of the Rasch rating scale model to the Teaching Strategies GOLD assessment system in a norm sample of children aged birth to 71 months. The analyses focused on the examination of dimensionality, rating scale effectiveness, the hierarchy of item difficulties, and the relationship of developmental scale scores to child age. Results show that each subscale satisfies the Rasch model for unidimensionality. Ratings were found to be less reliable at the lowest and highest ends of the scale and less distinct at 'In-between' levels. Items appear to form theoretically expected hierarchies, supporting evidence for construct validity for the measures. Moderately high correlations of developmental scale scores with child age suggest that teachers are able to make valid ratings of the developmental progress of children across the intended age range.

Vertically ordered hematite nanotube array as an ultrasensitive and rapid response acetone sensor.

Vertically ordered nanotube array is a desirable configuration to improve gas sensing properties of the hematite which is the most abundant and cheapest metal oxide semiconductor on earth but has low and sluggish chemiresistive responses. We have synthesized a vertically aligned, highly ordered hematite nanotube array directly on a patterned SiO2/Si substrate and then it used as a gas sensor without additional processing. The nanotube array sensor shows unprecedentedly ultrahigh and selective responses to acetone with detection limits down to a few parts per billion and response time shorter than 3 s.

Extracting optical modes of organic light-emitting diodes using quasi-periodic WO3 nanoislands.

Quasi-periodic WO(3) nanoislands are introduced to extract two optical modes in organic light-emitting diodes. The nano-scaled and size-tunable WO(3) islands were fabricated by use of wet-etching with self-aggregated Ag mask. The improvement of light extraction efficiency originates to the recovery of light losses which are surface plasmon mode and waveguide mode. As a result, external quantum efficiency and power efficiency were increased. No changes in emission spectrum and CIE color coordinates with WO(3) nanoislands at various observation angles are desirable if this device is to be utilized in optical system. Furthermore, cost-effective fabrication makes it possible to adopt this system in large area fabrication.

Highly ordered large-area colloid templates for nanostructured TiO2 thin film gas sensors.

We report a novel process that uses highly ordered colloidal templating to fabricate nanostructured TiO2 thin film gas sensors. An O2 plasma treatment is used to decrease the contact angle of a water droplet on a SiO2/Si substrate from 46 degrees to 3 degrees. The formation of this hydrophilic surface enhances the adhesion of polystyrene microspheres to the substrate during the spin coating of the colloidal solution, leading to a large-area colloid template of closely packed monolayer microspheres on the substrates. Embossed TiO2 thin film gas sensors fabricated through highly ordered colloidal templating using O2 plasma exhibit substantially enhanced gas sensing performance as compared to those without surface treatments prior to colloidal templating.

Self-activated ultrahigh chemosensitivity of oxide thin film nanostructures for transparent sensors.

One of the top design priorities for semiconductor chemical sensors is developing simple, low-cost, sensitive and reliable sensors to be built in handheld devices. However, the need to implement heating elements in sensor devices, and the resulting high power consumption, remains a major obstacle for the realization of miniaturized and integrated chemoresistive thin film sensors based on metal oxides. Here we demonstrate structurally simple but extremely efficient all oxide chemoresistive sensors with ~90% transmittance at visible wavelengths. Highly effective self-activation in anisotropically self-assembled nanocolumnar tungsten oxide thin films on glass substrate with indium-tin oxide electrodes enables ultrahigh response to nitrogen dioxide and volatile organic compounds with detection limits down to parts per trillion levels and power consumption less than 0.2 microwatts. Beyond the sensing performance, high transparency at visible wavelengths creates opportunities for their use in transparent electronic circuitry and optoelectronic devices with avenues for further functional convergence.

A Rasch rating scale modeling of the Schutte Self-Report Emotional Intelligence scale in a sample of international students.

This study examined the psychometric properties of the Schutte Self-Report Emotional Intelligence (SSREI) scale in a sample of international students studying in the U.S. universities using Rasch analysis. The results indicated that the original five-category rating structure may not function effectively for the international student sample. The results also revealed that although most of the items in the SSREI scale contributed to a single underlying construct, reverse-keyed items appeared to be problematic. Examination of the person-item map suggested that the items may be inappropriately targeted for this sample. In sum, the original version of the SSREI scale needs further improvement to adequately measure emotional intelligence.