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Artificial skin that simultaneously mimics sensory feedback and mechanical properties of natural skin holds substantial promise for next-generation robotic and medical devices. However, achieving such a biomimetic system that can seamlessly integrate with the human body remains a challenge. Through rational design and engineering of material properties, device structures, and system architectures, we realized a monolithic soft prosthetic electronic skin (e-skin). It is capable of multimodal perception, neuromorphic pulse-train signal generation, and closed-loop actuation. With a trilayer, high-permittivity elastomeric dielectric, we achieved a low subthreshold swing comparable to that of polycrystalline silicon transistors, a low operation voltage, low power consumption, and medium-scale circuit integration complexity for stretchable organic devices. Our e-skin mimics the biological sensorimotor loop, whereby a solid-state synaptic transistor elicits stronger actuation when a stimulus of increasing pressure is applied.

Traditional definitions of school readiness hinge on children’s academic skills in literacy and numeracy that underpin later scholastic achievement (Snow, 2006). However, both theoretical and political concerns highlight the need to include behavioural and social skills, and family support (Hughes et al., 2015). Taking a holistic approach to school readiness, Hughes et al. (2015; 2018) developed the Brief Early Skills and Support Index (BESSI), which has shown promising reliability and validity as well as longitudinal measurement invariance. However, so far, the use of the BESSI has been confined to English-speaking Western contexts. Our study aims to investigate how the BESSI performs in Hong Kong (HK) and Mainland China (MC). First, we will examine the factor structure of the BESSI and identify the best-fitting model for children aged four to six across HK and MC. Second, we will compare mean BESSI subscale scores across sites, for a cohort of children severely influenced by the COVID-19 pandemic, which led to long-time school closure and short periods of peer play. Our third objective of the study is, therefore, to examine whether COVID-19 related family stress, classroom chaos, and teachers’ burnout significantly correlate to children’s school readiness. Implications for research and practices on nurturing school readiness will be discussed.

Traditional definitions of school readiness hinge on children’s academic skills in literacy and numeracy that underpin later scholastic achievement (Snow, 2006). However, both theoretical and political concerns highlight the need to include behavioural and social skills, and family support (Hughes et al., 2015). Taking a holistic approach to school readiness, Hughes et al. (2015; 2018) developed the Brief Early Skills and Support Index (BESSI), which has shown promising reliability and validity as well as longitudinal measurement invariance. However, so far, the use of the BESSI has been confined to English-speaking Western contexts. Our study aims to investigate how the BESSI performs in Hong Kong (HK) and Mainland China (MC). First, we will examine the factor structure of the BESSI and identify the best-fitting model for children aged four to six across HK and MC. Second, we will compare mean BESSI subscale scores across sites, for a cohort of children severely influenced by the COVID-19 pandemic, which led to long-time school closure and short periods of peer play. Our third objective of the study is, therefore, to examine whether COVID-19 related family stress, classroom chaos, and teachers’ burnout significantly correlate to children’s school readiness. Implications for research and practices on nurturing school readiness will be discussed.

Wrinkled surfaces and materials are found throughout the natural world in various plants and animals and are known to improve the performance of emerging optical and electrical technologies. Despite much progress, the reversible post-fabrication tuning of wrinkle sizes and geometries across multiple length scales has remained relatively challenging for some materials, and the development of comprehensive structure-function relationships for optically active wrinkled surfaces has often proven difficult. Herein, by drawing inspiration from natural cephalopod skin and leveraging methodologies established for artificial adaptive infrared platforms, we engineer systems with hierarchically reconfigurable wrinkled surface morphologies and dynamically tunable visible-to-infrared spectroscopic properties. Specifically, we demonstrate architectures for which mechanical actuation changes the surface morphological characteristics; modulates the reflectance, transmittance, and absorptance across a broad spectral window; controls the specular-to-diffuse reflectance ratios; and alters the visible and thermal appearances. Moreover, we demonstrate the incorporation of these architectures into analogous electrically actuated appearance-changing devices that feature competitive figures of merit, such as reasonable maximum areal strains, rapid response times, and good stabilities upon repeated actuation. Overall, our findings constitute another step forward in the continued development of cephalopod-inspired light- and heat-manipulating systems and may facilitate advanced applications in the areas of sensing, electronics, optics, soft robotics, and thermal management.

Next-generation light-emitting displays on skin should be soft, stretchable and bright

A series of Dy3+/Eu3+ ions doped Ca2(Mg0.75Al0.25)(Si1.75Al0.25)O7 (denote as CMAS) phosphors were synthesized by conventional high temperature solid-state reaction method. The crystal phase was characterized by X-ray diffraction and crystal structure refinement employed the Rietveled method. The luminescence properties of CMAS host, CMAS:Dy3+/Eu3+ and CMAS:Dy3+,Eu3+ phosphors were researched. The energy transfer phenomenon from CMAS host to Dy3+/Eu3+ ions in CMAS phosphors and from Dy3+ to Eu3+ ions in co-doped CMAS phosphors was studied and confirmed. The energy transfer efficiency was calculated and the energy transfer mechanism was identified. The color tunability and thermal stability were researched. All the studies of CMAS:Dy3+,Eu3+ phosphors showed a great potential application for solid state lighting and display application.

A novel luminescence material of emitting color-tunable Ca20Al26Mg3Si3O68 (denoted as CAMSO):Ce3+,Tb3+ phosphors have been synthesized via the high temperature solid-phase reaction process. The crystal cell structure, photoluminescence properties and application performance such as thermal stability and LED device performance of the phosphors were researched in detail. CAMSO:Ce3+,Tb3+ phosphors showed multicolor with the different concentration of Ce3+ and Tb3+ ions. Although the concentration of Ce3+ ions was settled and there was the existence of energy transfer from Ce3+ to Tb3+ ions, it was found that Ce3+ ions’ blue light emission intensity showed abnormal increasing with the increase of Tb3+ ions doping concentration. The irregular phenomenon was discussed in detail. The phosphor CAMSO:0.2Ce3+,0.1Tb3+ photoluminescence emission intensity motivated by 374 nm at 150 °C retained about 81% of that measured at room temperature, which demonstrating the good thermal and color stability of the sample. In ad...

Defect detection on solid wood surface has two main problems: (1) the real-time performance of the available methods are poor despite good detection accuracy, and (2) the defect extraction process is complicated. Here, we propose a mixed, fully convolutional neural network (Mix-FCN) to detect the location of wood defects and classify the types of defects from the wood surface images automatically. The images were collected first by a data acquisition device developed in our laboratory. We then employed TensorFlow and Python language to construct a VGG16 model. We used two kinds of datasets (dataset1 and dataset2) to maximize the limited, collected data and enable the Mix-FCN to converge rapidly during training. The weights of the filters in front of the Mix-FCN during training were initialized from the trained VGG16 model. The weights of the VGG16 net were learned by dataset1. Our model was trained, validated, and tested by dataset 2. Overall classification accuracy (OCA), pixel accuracy (PA), mean intersection over union, detection rate, missing alarm, false alarm rate, and precision were used to evaluate the network, and the performance was good based on the seven evaluation indicators. We achieved 99.14% OCA and 91.31% PA, and a batch of 50 images required only 0.368 s of detection time. Our proposed method has better accuracy and less detection time compared to the previous methods of wood detection.

Protein- and peptide-based proton conductors have been extensively studied because of their important roles in biological processes and established potential for bioelectronic device applications. However, despite much progress, the demonstration of long-range proton transport for such materials has remained relatively rare. Herein, we fabricate, electrically interrogate, and physically characterize films from a reflectin-derived polypeptide. The electrical measurements indicate that device-integrated films exhibit proton conductivities with values of ∼0.4 mS/cm and sustain proton transport over distances of ∼1 mm. The accompanying physical characterization indicates that the polypeptide possesses characteristics analogous to those of the parent protein class and furnishes insight into the relationship between the polypeptide's electrical functionality and structure in the solid state. When considered together, our findings hold significance for the continued development and engineering of not only reflectin-based materials but also other bioinspired proton conductors.

In this research, a focus is on the development of simplified models to represent the behavior of electric machinery within the time-domain models of power systems. Toward this goal, a generator model is considered in which the states include the machine’s active and reactive power. In the case of the induction machine, rotor slip is utilized as a state and the steady-state equivalent circuit of the machine is used to calculate active and reactive power. The power network model is then configured to accept the generator and induction machine active and reactive power as inputs and provide machine terminal voltage amplitude and angle as outputs. The potential offered by these models is that the number of dynamic states is greatly reduced compared to traditional machine models. This can lead to increased simulation speed, which has potential benefits in model-based control. A potential disadvantage is that the relationship between the reactive power and terminal voltage requires the solution of nonlinear equations, which can lead to challenges when attempting to predict system dynamics in real-time optimal control. In addition, the accuracy of the generator model is greatly reduced with variations in rotor speed. Evaluation of the models is performed by comparing their predictions to those of traditional machine models in which stator dynamics are included and neglected.

A series of emission-tunable Ce3+/Tb3+/Eu2+ doped Ca2(Mg0.75Al0.25)(Si1.75Al0.25)O7 (denoted as CMAS) phosphors have been synthesized via a high temperature solid-state reaction method. The luminescence properties, color tuning, quantum yields (QYs), energy transfer of Ce3+ to Tb3+/Eu2+, thermal stability, performance of LED devices and ratiometric temperature sensing application have been systematically investigated, respectively. Importantly, through the study of thermal stability, we found that Ce3+ and Tb3+ co-doped samples were suitable for WLED applications, while Ce3+ and Eu2+ co-doped samples were suitable for temperature sensing applications. Due to the energy transfer, Ce3+/Tb3+ co-doped samples had high luminous efficiency and the quantum efficiency of more than 80% could be achieved. Their emission colors can modulate from blue to green. In addition, on the basis of the evaluation of the as-fabricated white LED lamps via selecting the corresponding phosphors, the CCT can reach 4275 K and the CRI can increase to 86.8, indicating that this series of phosphors can act as potential color-tunable phosphors for possible applications in ultraviolet light based white LEDs. Importantly, it is found that the fluorescence intensity ratio of CMAS : 5%Ce3+,0.5%Eu2+ displays linear correlation with temperature in a wide range of 253–373 K with a high sensitivity of 2.49% K−1, indicating that it could be a good candidate for ratiometric optical thermometry.

In this paper, the synthesis of rare earth fluoride GdF 3 multiform morphologies via l -arginine hydrothermal method has been fulfilled for the first time. The size and shape of the products could be tuned just by adjusting the pH values of the initial reaction solutions. The morphologies for the products include submicron round disc, submicron flower disc, submicron rods and submicron bulks. Additionally, the possible formation mechanism of multiform morphologies was proposed. Furthermore, we systematically investigate the luminescence properties of different lanthanide ions (Tm 3+ , Dy 3+ , Eu 3+ ) in GdF 3 host. By adjusting their relative doping concentrations in the GdF 3 host, the different color hue of blue and yellow light are obtained by co-doped Tm 3+ ,Dy 3+ and Dy 3+ , Eu 3+ in GdF 3 host, respectively. Besides, there exist two energy transfer pairs in the GdF 3 host: (1) Tm 3+ →Dy 3+ ; (2) Dy 3+ →Eu 3+ . More significantly, in the Tm 3+ , Dy 3+ , Eu 3+ tri-doped GdF 3 phosphors, white light can also be achieved upon excitation of UV light by adjusting the doping concentration of rare earth ion (Tm 3+ , Dy 3+ , Eu 3+ ). Importantly, when the temperature was raised to 225 °C, the emission intensities of Dy 3+ (475 nm) and Eu 3+ (592 nm) was 65% and 71% of the initial value at 25 °C for GdF 3 : Dy 3+ , Eu 3+ , which indicating that the thermal stability of the phosphors of the GdF 3 :2%Dy 3+ , 3%Eu 3+ is excellent. In addition, the obtained samples also exhibit paramagnetic properties at room temperature (300 K). The result shows that the obtained nanophosphors have a promising application in display and lighting fields.

A series of emission-tunable YF3:RE3+ (RE = Dy, Tb, Eu) phosphors were first synthesized by a glutamic acid-assisted one-step hydrothermal process. The structure and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the samples were YF3 and Na(Y1.5Na0.5)F6 and the size and shape of the products could be tuned just by adjusting the pH values of the initial reaction solutions or by adjusting the RE3+/NaF ratio or RE3+/NaBF4 ratio. The morphologies for the products include bundlelike microstructures, fantail-like shape, microspindles, irregular bulk, walnutlike shape, irregular ellipsoidal microrods, the asymmetric hexagonal-prismatic tubular structures and irregular microrods and irregular nanoparticles and microsphere. Furthermore, the photoluminescence properties of YF3:Dy3+,Tb3+ and YF3:Tb3+,Eu3+ were investigated in detail. Blue and yellow emissions corresponding to the 4F9/2 → 6H15/2 (475 nm), 4F9/2 → 6H13/2 (570 nm) transition of...

Ce 3+ /Tb 3+ ions singly and co-doped SrAl 2 Si 2 O 8 phosphors were synthesized by solid-state reaction method. The crystal structure, photoluminescence excitation and emission spectra, decay lifetime, energy transfer, quantum yield and thermal stability have been investigated in detail. The SrAl 2 Si 2 O 8 :0.04Ce 3+ and SrAl 2 Si 2 O 8 :0.04 Tb 3+ phosphors can emit blue and green light, respectively. Under 365 nm excitation, the emission color of SrAl 2 Si 2 O 8 :Ce 3+ , Tb 3+ can be adjusted from blue to green by changing the proportion of Ce 3+ and Tb 3+ ions based on the energy transfer. With constantly increasing of Tb 3+ ions concentration, the energy transfer efficiency from Ce 3+ to Tb 3+ in SrAl 2 Si 2 O 8 host increased gradually and reached as high as 82.91%, the quantum yield was about 67.37%. The energy transfer mechanism is proved to be dipole-quadrupole interaction. Over 100 °C, 90% initial emission intensity can be still remained. The above results indicate that SrAl 2 Si 2 O 8 :Ce 3+ , Tb 3+ is a potential multicolor emission phosphor for the application in w-LEDs.

In this paper, long afterglow luminescent materials CaAl 2 O 4 :Eu 2+ , Nd 3+ and SrAl 2 O 4 :Eu 2+ , Dy 3+ were successfully synthesized by high temperature solid state reaction using the alumina extracted from oil shale ash. The properties of samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF) photoluminescence (PL) spectra, thermoluminescent (TL) curve, long afterglow material optical test system. CaAl 2 O 4 :Eu 2+ , Nd 3+ and SrAl 2 O 4 :Eu 2+ , Dy 3+ prepared with alumina extracted from oil shale ash showed persistent phosphorescence in blue (440 nm) and green (515 nm) with persistence time over 10 h for the blue and 8 h for the green. This result indicates that the alumina extracted from oil shale ash can be used to prepare fluorescent materials. This reuse can not only utilize the oil shale ash rationally but also substantially increased the added-value of oil shale ash.

In this paper, the synthesis of rare earth fluoride GdF3 multiform morphologies via a glutamic acid hydrothermal method has been fulfilled. The size and shape of the products could be tuned just by adjusting the pH values of the initial reaction solutions. The morphologies for the products include spindle-like, peanut-like, submicrometer flowers, and nanoflowers. Additionally, the possible formation mechanism of multiform morphologies was proposed. Furthermore, we systematically investigate the luminescence properties of different lanthanide ions (Dy3+, Tb3+, and Sm3+) in GdF3 host. In the GdF3:Tb3+,Sm3+system, the energy transfer process fromTb3+ to Sm3+ was demonstrated to be resonant type via a dipole–dipole mechanism. Most interestingly, white light and multicolor light have been obtained in Tb3+ and Sm3+ coactivated or Dy3+,Tb3+,Sm3+ tridoped GdF3 phosphors. The results show that the obtained nanophosphors have a promising application in display and lighting fields.

A series of emission-tunable Na1−xAl1+2xSi1−2xO4:xCe3+/Tb3+/Dy3+ phosphors were synthesized via a high temperature solid-state reaction method. Luminescence properties, energy transfer from Ce3+ to Tb3+ or Dy3+ ions, color tuning and thermal stability were systematically investigated. Particularly, the charge compensating defect generated by doping of rare earth ions was remedied through Al3+ substituted Si4+. Meanwhile, the emission intensity was significantly improved. The presence and content of various elements were demonstrated through data combined with the crystallographic data from Rietveld refinements and the analysis of SEM and mapping for each element. The results indicated that this charge balance strategy was an effective method. The energy transfer from Ce3+ to Tb3+ and Dy3+ in the co-doped NaAlSiO4 (NAS) samples was deduced from the spectral overlap between the Ce3+ emission and Tb3+/Dy3+ excitation spectra, the photoluminescence spectra and the fluorescence decay curves. The energy transfer mechanisms of Ce3+ to Tb3+ and Dy3+ in the host were studied. And the emission hue can be tuned from blue to green and yellow by properly varying the ratio of Ce3+ and Tb3+/Dy3+. Additionally, the temperature-dependent photoluminescence of the as-prepared phosphors was investigated in detail. All these properties indicate that the developed phosphor may potentially be used as a single-component multicolor-emitting phosphor for UV light-emitting diodes.

A series of Tb 3+ or/and Bi 3+ doped BaAl 2 Si 2 O 8 phosphors were synthesized via solid-state method. The structure, luminescence properties and thermal stability were investigated. The optimum concentrations of Bi 3+ and Tb 3+ were 1.5 mol% and 7 mol%, respectively. Furthermore, BaAl 2 Si 2 O 8 :0.015Bi 3+ and BaAl 2 Si 2 O 8 :0.07Tb 3+ phosphors emitted blue and green light and the emission color of BaAl 2 Si 2 O 8 :Bi 3+ , Tb 3+ could be tuned from blue to green through the energy transfer. This energy transfer from Bi 3+ to Tb 3+ was confirmed and investigated by photoluminescence spectrum and decay lifetime. With constantly increasing Tb 3+ concentrations, the energy transfer efficiency from Bi 3+ to Tb 3+ in BaAl 2 Si 2 O 8 host increased gradually and reached as high as 86.54%, the quantum yield was about 44.26%. The energy transfer mechanism (Bi 3+ -Tb 3+ ) was proved to be dipole–dipole mechanism. The Tb 3+ emission intensity can be considerably enhanced when monitored at NUV (377 nm) by co-doping Bi 3+ ion. Moreover, the phosphor of BaAl 2 Si 2 O 8 :0.015Bi 3+ , 0.07Tb 3+ could exhibited strong green emission with good CIE chromaticity coordinate. The results indicate that BaAl 2 Si 2 O 8 :Tb 3+ , Bi 3+ is a potential green emitting phosphor for the application in w-LEDs.

Background and Objective: Spontaneous coronary artery dissection (SCD) remains a rare and important cause of coronary artery disease (CAD). The purpose of this study was to describe the clinical and angiographic features in SCD and to evaluate the treatment and long-term prognosis of this condition in China. Methods: This retrospective cohort study included 118 Chinese patients with SCD confirmed by coronary angiography. Clinical and angiographic features, treatment modalities and outcomes of SCD were estimated. Results: The overall prevalence of SCD was 0.15%. Age was 57 ± 10 years; 86% patients were men; 75% presented with acute coronary syndrome (ACS); 72% had concomitant atherosclerotic CAD. SCD often affected right coronary artery (RCA) and caused a short dissection (< 20mm). A conservative therapy was used in 28% of patients and revascularization in 72% (percutaneous coronary intervention [PCI] 57%; coronary artery bypass grafting [CABG] 15%). Only one patient died during hospitalization due to multiple organ failure after CABG. During a median follow-up of 43 months (range, 1 - 158 months), 32 patients had a new-onset ACS, 9 received revascularization (7 PCI and 2 CABG), and 8 died. The Kaplan-Meier estimated 12-year rates of freedom from cardiac death and ACS were both higher in revascularization versus conservative therapy (78% versus 57%; P = 0.023; 48% versus 25%, P = 0.014). No significant difference was found in freedom from revascularization between the two therapies. Conclusions: In China, SCD was usually associated with atherosclerosis and predominantly affected male population. SCD often affected RCA and caused a short dissection. In-hospital mortality rate was low regardless of therapeutic strategy. However, a significantly better long-term prognosis was observed in the revascularization compared with conservative therapy. How to cite this:Liu X, Xu C, Liu C, Su X. Clinical characteristics and long-term prognosis of spontaneous coronary artery dissection: A single-center Chinese experience. Pak J Med Sci. 2019;35(1):106-112. doi: https://doi.org/10.12669/pjms.35.1.321 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A series of Dy3+ - Eu3+ co-doped BaAl2Si2O8 phosphors were prepared via the conventional solid-state reaction method. Their crystal structure, luminescent characteristic and lifetime were investigated. The optimum doping concentrations of Dy3+and Eu3+ are both 0.05 for Dy3+ or Eu3+ singly doped BaAl2Si2O8. Furthermore, BaAl2Si2O8: 0.05Dy3+ and BaAl2Si2O8: 0.05Eu3+ emits yellow and red light. The emission color of BaAl2Si2O8: Dy3+, Eu3+ could be tuned from yellow to white due to the energy transfer. This energy transfer from Dy3+ to Eu3+ was confirmed and investigated by photoluminescence spectra and the decay time of energy donor Dy3+ ions. With constantly increasing Eu3+ concentration, the energy transfer efficiency from Dy3+ to Eu3+ in BaAl2Si2O8 host increased gradually and reached as high as 81%, the quantum yield was about 47.43%. BaAl2Si2O8: Dy3+, Eu3+ phosphors can be effectively excited by UV (about 348 nm) light and emit visible light from yellow to white by altering the concentration ratio of Dy3+ and Eu3+, indicating that the phosphors have potential applications as a white light-emitting phosphor for display and lighting.

A series of blue-to-red emitting Ca20Al26Mg3Si3O68:Bi3+/Sm3+/Eu3+ phosphors were synthesized via a high temperature solid-state reaction method. The crystal structure, luminescence properties, energy transfer and multisite luminescence were investigated in detail. Under ultraviolet (UV) light excitation of 343 nm, Bi3+-doped Ca20Al26Mg3Si3O68 phosphors exhibit a broad blue emission band from 370 to 600 nm which is derived from the allowed transition 3P1 → 1S0 of Bi3+ ions. The Ca20Al26Mg3Si3O68:Sm3+ samples show orange-reddish emission bands at 561, 598, 649 and 708 nm under the excitation of 401 nm. The red emission of Ca20Al26Mg3Si3O68:Eu3+ samples at 587, 616, 654 and 700 nm were detected under the excitation of 392 nm, due to 5D0 → 7FK (K = 1, 2, 3, and 4) transitions. In addition, two kinds of sites for cations (Ca2+) in the host were considered from the high resolution site-selective spectroscopy of Ca20Al26Mg3Si3O68:Eu3+ at low temperature, which matches with the crystal structure of Ca20Al26Mg3Si3O68. Meanwhile, in the Bi3+, Sm3+ co-doped Ca20Al26Mg3Si3O68 samples, the energy transfer from Bi3+ to Sm3+ can be found from the photoluminescence spectra and the fluorescence decay curves. The emission hue can be tuned from cool white (0.270, 0.267) to white (0.334, 0.293), and finally to warm white light (0.405, 0.317) by suitably varying the ratio of Bi3+/Sm3+, indicating that the developed phosphor may be potentially used as a single-component white-emitting phosphor for UV light-emitting diodes. The phosphors CAMSO:Bi3+,Eu3+ develop excellent red-emission properties, so that the Eu3+ doped samples have potential application in WLED.

A series of Dy(3+), Tb(3+), Eu(3+) singly or doubly or triply doped GdF3 phosphors were synthesized by a glutamic acid assisted one-step hydrothermal method. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and photoluminescence (PL) spectroscopy. The results show that the synthesized samples are all pure GdF3. The obtained samples have a peanut-like morphology with a diameter of about 270 nm and a length of about 600 nm. Under UV excitation, GdF3:Dy(3+), GdF3:Tb(3+) and GdF3:Eu(3+) samples exhibit strong blue, green and red emissions, respectively. By adjusting their relative doping concentrations in the GdF3 host, the different color hues of green and red light are obtained by co-doped Dy(3+), Tb(3+) and Tb(3+), Eu(3+) ions in the GdF3 host, respectively. Besides, there exist two energy transfer pairs in the GdF3 host: (1) Dy(3+) → Tb(3+) and (2) Tb(3+) → Eu(3+). More significantly, in the Dy(3+), Tb(3+), and Eu(3+) tri-doped GdF3 phosphors, white light can also be achieved upon excitation of UV light by adjusting the doping concentration of Eu(3+). In addition, the obtained samples also exhibit paramagnetic properties at room temperature (300 K) and low temperature (2 K). It is obvious that multifunctional Dy(3+), Tb(3+), Eu(3+) tri-doped GdF3 materials including tunable multicolors and intrinsic paramagnetic properties may have potential applications in the field of full-color displays.

A series of BaGdF5:x% Tb3+,y% Sm3+ phosphors are synthesized by a hydrothermal method, taking the form of irregular nanospheres with average sizes of about 20 nm. An energy transfer from Tb3+ to Sm3+ is observed in the BaGdF5:Tb3+,Sm3+ system, which is justified by the luminescence spectra. Simultaneously, a resonance-type energy transfer from Tb3+ to Sm3+ is demonstrated to occur via the dipole–dipole interaction, for which the critical distance (RTb–Sm) is calculated to be 13.49 A. Furthermore, based on the rare earth concentrations and excitation wavelengths, multiple (white, orange red, green and green yellow) emissions are obtained by Sm3+ ion co-activated BaGdF5:Tb3+ phosphors, which could make them good candidates to be used as full-color phosphors for nUV-LED. More importantly, the obtained samples also exhibit paramagnetic properties at room temperature and low temperature.

Existing cross-cultural findings related to school-aged children’s executive function (EF) from studies using computerized tasks highlight both an East–West contrast (East > West) and potential methodological confounds (e.g., contrasting levels of computer fluency). Capitalizing on two recent data sets, this multisite study of 1,311 children living in mainland China (n = 453; Mage = 11.89 years, SD = 0.87), Hong Kong (n = 371; Mage = 12.21 years, SD = 0.99), and the United Kingdom (n = 487; Mage = 11.91 years, SD = 0.93) tested measurement invariance of a computerized EF-task battery prior to investigating cultural contrasts in mean levels of EF efficiency scores. Our models established partial scalar invariance across sites. Latent factor means were substantially lower for British children than for their counterparts from either mainland China or Hong Kong, with a significant but smaller contrast between the latter two groups. Within the Chinese sample, self-reported computer use was unrelated to variation in children’s performance on online tests of EF, indicating that peripheral effects of task modality are unlikely to explain the between-culture differences in EF task performance.

Considering the difficult problem of robot recognition and grasping in the scenario of disorderly stacked wooden planks, a recognition and positioning method based on local image features and point pair geometric features is proposed here and we define a local patch point pair feature. First, we used self-developed scanning equipment to collect images of wood boards and a robot to drive a RGB-D camera to collect images of disorderly stacked wooden planks. The image patches cut from these images were input to a convolutional autoencoder to train and obtain a local texture feature descriptor that is robust to changes in perspective. Then, the small image patches around the point pairs of the plank model are extracted, and input into the trained encoder to obtain the feature vector of the image patch, combining the point pair geometric feature information to form a feature description code expressing the characteristics of the plank. After that, the robot drives the RGB-D camera to collect the local image patches of the point pairs in the area to be grasped in the scene of the stacked wooden planks, also obtaining the feature description code of the wooden planks to be grasped. Finally, through the process of point pair feature matching, pose voting and clustering, the pose of the plank to be grasped is determined. The robot grasping experiment here shows that both the recognition rate and grasping success rate of planks are high, reaching 95.3% and 93.8%, respectively. Compared with the traditional point pair feature method (PPF) and other methods, the method present here has obvious advantages and can be applied to stacked wood plank grasping environments.