Electrical Polarity Modulation in V-Doped Monolayer WS2 for Homogeneous CMOS Inverters.

As demand for higher integration density and smaller devices grows, silicon-based complementary metal-oxide-semiconductor (CMOS) devices will soon reach their ultimate limits. 2D transition metal dichalcogenides (TMDs) semiconductors, known for excellent electrical performance and stable atomic structure, are seen as promising materials for future integrated circuits. However, controlled and reliable doping of 2D TMDs, a key step for creating homogeneous CMOS logic components, remains a challenge. In this study, a continuous electrical polarity modulation of monolayer WS2 from intrinsic n-type to ambipolar, then to p-type, and ultimately to a quasi-metallic state is achieved simply by introducing controllable amounts of vanadium (V) atoms into the WS2 lattice as p-type dopants during chemical vapor deposition (CVD). The achievement of purely p-type field-effect transistors (FETs) is particularly noteworthy based on the 4.7 at% V-doped monolayer WS2, demonstrating a remarkable on/off current ratio of 105. Expanding on this triumph, the first initial prototype of ultrathin homogeneous CMOS inverters based on monolayer WS2 is being constructed. These outcomes validate the feasibility of constructing homogeneous CMOS devices through the atomic doping process of 2D materials, marking a significant milestone for the future development of integrated circuits.

Modeling of a multireflector terahertz imaging system using a geometrical optics model based on angular spectrum theory.

We propose a simulation method for a multireflector terahertz imaging system. The description and verification of the method are based on an existing active bifocal terahertz imaging system at 0.22 THz. Using the phase conversion factor and angular spectrum propagation, the computation of the incident and received fields requires only a simple matrix operation. The phase angle is used to calculate the ray tracking direction, and the total optical path is used to calculate the scattering field of defective foams. Compared with the measurements and simulations of aluminum disks and defective foams, the validity of the simulation method is confirmed in the field of view of 50 cm × 90 cm at 8 m. This work aims to develop better imaging systems by predicting their imaging behavior for different targets before manufacturing.

Pseudo-transistors for emerging neuromorphic electronics.

Artificial synaptic devices are the cornerstone of neuromorphic electronics. The development of new artificial synaptic devices and the simulation of biological synaptic computational functions are important tasks in the field of neuromorphic electronics. Although two-terminal memristors and three-terminal synaptic transistors have exhibited significant capabilities in the artificial synapse, more stable devices and simpler integration are needed in practical applications. Combining the configuration advantages of memristors and transistors, a novel pseudo-transistor is proposed. Here, recent advances in the development of pseudo-transistor-based neuromorphic electronics in recent years are reviewed. The working mechanisms, device structures and materials of three typical pseudo-transistors, including tunneling random access memory (TRAM), memflash and memtransistor, are comprehensively discussed. Finally, the future development and challenges in this field are emphasized.

Synergistic Regulation Effect of Nitrate and Calcium Ions for Highly Luminescent and Robust α-CsPbI3 Perovskite.

The α-CsPbI3 nanocrystals (NCs) easily transform into yellow non-perovskite, accompanying with declining photoelectric properties that restricting their practical applications in diverse fields. Herein, the highly luminescent and robust α-CsPbI3 NCs is achieved through engineering the lattice symmetry of perovskite, enabled by the synergistic effect of NO3- ion passivation and Ca2+ ion doping. The introduced NO3- ions enhance the phase-change energy barrier and the surface steric hindrance, thus promoting the formation of α-CsPbI3 NCs with hyper-symmetric crystal structure, while the Ca2+ ion doping contributes to improving their lattice symmetry by significant regulation of the tolerance factor. As a result, the obtained α-CsPbI3 NCs display an outstanding photoluminescence quantum yield of 96.6%, together with the reduced defect state density and eminent conductivity. Most importantly, the as-engineered α-CsPbI3 NCs exhibit excellent stability under ambient conditions for 9 months and UV illumination for 32 h. It displays brilliant thermal stability, maintaining luminous intensity for 15 min under 140 °C, and performing desired durability and reversibility, evidenced by 160 °C cyclic test and 120 °C reversibility test. Given enhanced robustness, the as-engineered α-CsPbI3 NCs based light-emitting-diode devices are constructed, exhibiting a power efficiency of 105.3 lm W-1 and the excellent working stability for 18 h.

Highly efficient and stable blue-emitting CsPbBr3@SiO2 nanospheres through low temperature synthesis for nanoprinting and WLED.

Inorganic perovskite quantum dots (QDs) have attracted wide attention in display and solid-state lighting because of their easily tunable band-gaps and high photoluminescence quantum yields (PLQY) of green light emission. However, some drawbacks limit their practical applications, including the low PLQY of blue light emission and the instability in the moisture environment. In this work, efficient blue-light emitting CsPbBr3 perovskite QDs with PLQY of 72% were developed through a bandgap engineering approach. The achieved blue-light emitting PLQY is much higher than the values acquired in the inorganic perovskite QDs in the literature. And the emission color of the as-prepared QDs can be facially tuned by only adjusting the reaction temperature. Further, the mono-dispersed perovskite QDs@SiO2 composites were constructed benefiting from the low temperature synthesis. The optical performance of the QDs could be well persisted even in the moisture environment. Finally, the as-prepared QDs@SiO2 composite was fabricated as the QD ink on the anti-counterfeit printing technology, from which the obtained pattern would emit varied color under UV lamp. And the as-prepared composites was also applied for fabricating WLED, with Commission Internationale de l'Eclairage (CIE) color coordinates of (0.33, 0.38) and power efficiency of 32.5 lm W-1, demonstrating their promising potentials in solid-state lighting.

Emitting color tunable carbon dots by adjusting solvent towards light-emitting devices.

Carbon dots (CDs), one of the most significant classes of carbon-based nanophosphors, have attracted extensive attention in recent years. However, few attempts have been reported for realizing CDs with tunable emissions, especially for obtaining the red-light emissions with high photoluminescence quantum yields. Herein, we synthesized CDs with different chromatic blue, green and red emissions by facilely changing the reaction solvent during hydrothermal conditions. The photoluminescence quantum yields of 34%, 19% and 47% for the blue, green and red emissions, respectively, were achieved. Furthermore, the solid-state CD/PVA composite films were constructed through mixing the CDs with PVA polymer, in which the self-quenching of photoluminescence of CDs had been successfully avoided benefiting from the formation of hydrogen bonds between the CDs and PVA molecules. Finally, the warm white light emitting diode (WLED) was fabricated by integrating CD/PVA film on a UV-LED chip. The WLED exhibited the Commission International de l'Eclairage coordinates (CIE) of (0.38, 0.34), correlated color temperature of 3913 K and color rendering index of 91, respectively, which were comparable with the commercial WLEDs.

Modulation of the photoluminescence in carbon dots through surface modification: from mechanism to white light-emitting diodes.

Carbon dots (CDs) have emerged as a new type of fluorescent material because of their unique optical advantages, such as high photoluminescence quantum yields (QYs), excellent photo-stability, excitation-dependent emissions, and low toxicity. However, the photoluminescence mechanism for CDs remains unclear, which limits their further practical application. Here, CDs were synthesized via a solvothermal route from citric acid and urea. Through the oxidation and reduction treatment of pristine CDs, the origin of the photoluminescence and the involved mechanism were revealed. We found that the blue/green/red emissions originated from three diverse emitting states, i.e. the intrinsic state, and C=O- and C=N-related surface states, respectively. Based on the as-prepared CDs, a pH sensor depending on the radiometric luminescence detection was developed. Furthermore, we constructed CD/PVP (PVP, polyvinylpyrrolidone) composite films, which exhibited white light emission with photoluminescence QYs of 15.3%. The white light emission with different correlated color temperatures (CCTs), from 4807 K to 3319 K, was obtained by simply changing the amount of PVP solution. Benefiting from the white light-emitting solid-state films, single-component white light-emitting diodes were fabricated with an average color rendering index value (Ra) of 80.0, luminous efficiency of 10.2 lm W-1, and good working stability, thus indicating a promising potential for practical lighting applications.

[Research progress of 5-hydroxymethylfurfural, a safety-related substance in traditional Chinese medicine injections].

Screening out the safety-related substances and establishing the corresponding standard has been a key research issue to improve the safety of traditional Chinese medicine injections(TCMIs). 5-HMF which widely exists in sugar-containing TCMIs has long been considered as an important safety-related substance. In this review, we summarizes the research progress on the toxicology of 5-HMF as well as the content and standards of 5-HMF in TCMIs.Therein, both literature summary and analysis results indicate that there are lack of toxicology researches of 5-HMF and its metabolites in TCMIs, although the potential toxicity of 5-HMF and its metabolites has been reported. Moreover, the content of 5-HMF largely varies from TCMIs to TCMIs, and even in the same TCMIs from different factories. To ensure the clinical efficacy of TCMIs, it urgent to carry out the study of the toxicology of 5-HMF in TCMIs comprehensively and systematically, so as to set up a relatively uniform standard as well as to develop process quality control method.

An inorganic-blended p-type semiconductor with robust electrical and mechanical properties.

Inorganic semiconductors typically have limited p-type behavior due to the scarcity of holes and the localized valence band maximum, hindering the progress of complementary devices and circuits. In this work, we propose an inorganic blending strategy to activate the hole-transporting character in an inorganic semiconductor compound, namely tellurium-selenium-oxygen (TeSeO). By rationally combining intrinsic p-type semimetal, semiconductor, and wide-bandgap semiconductor into a single compound, the TeSeO system displays tunable bandgaps ranging from 0.7 to 2.2 eV. Wafer-scale ultrathin TeSeO films, which can be deposited at room temperature, display high hole field-effect mobility of 48.5 cm2/(Vs) and robust hole transport properties, facilitated by Te-Te (Se) portions and O-Te-O portions, respectively. The nanosphere lithography process is employed to create nanopatterned honeycomb TeSeO broadband photodetectors, demonstrating a high responsibility of 603 A/W, an ultrafast response of 5 µs, and superior mechanical flexibility. The p-type TeSeO system is highly adaptable, scalable, and reliable, which can address emerging technological needs that current semiconductor solutions may not fulfill.

A Reconfigurable Optoelectronic Synaptic Transistor with Stable Zr-CsPbI3 Nanocrystals for Visuomorphic Computing.

Reconfigurable phototransistor memory attracts considerable attention for adaptive visuomorphic computing, with highly efficient sensing, memory, and processing functions integrated onto a single device. However, developing reconfigurable phototransistor memory remains a challenge due to the lack of an all-optically controlled transition between short-term plasticity (STP) and long-term plasticity (LTP). Herein, an air-stable Zr-CsPbI3 perovskite nanocrystal (PNC)-based phototransistor memory is designed, which is capable of broadband photoresponses. Benefitting from the different electron capture ability of Zr-CsPbI3 PNCs to 650 and 405 nm light, an artificial synapse and non-volatile memory can be created on-demand and quickly reconfigured within a single device for specific purposes. Owing to the optically reconfigurable and wavelength-aware operation between STP and LTP modes, the integrated blue feature extraction and target recognition can be demonstrated in a homogeneous neuromorphic vision sensor array. This work suggests a new way in developing perovskite optoelectronic transistors for highly efficient in-sensor computing.

Linear Strain Sensors via a Spatial Heteromodulus Tricontinuous Structure Design for High-Resolution Recording of Snoring Breath.

Porous conductive elastomer composites are very attractive for designing flexible and air-permeable mechanical sensors for healthcare, while it is challenging to achieve a linear and sensitive electromechanical response over a wide strain range for high-resolution recording of physiological activities and body motions. Here, a scalable strategy is developed to construct porous elastomer composites with a bamboo-shaped heteromodulus microstructure in the pores for the fabrication of linear stretchable strain sensors. Such a spatial heteromodulus microstructure is fabricated via phase separation and selective location of high-modulus phase during melt compounding of elastomers and thermoplastics, together with green etching of the water-soluble plastic in the tricontinuous elastomer composites. The bamboo-shaped heteromodulus microstructure is constructed on the pore struts via the fracture of a high-modulus polymer self-assembled on the pore surface and relaxation recovery of the elastomer matrix after prestretching, which blocks the propagation of cut-through microcracks upon stretching. The composites with super low resistance after in situ growth of silver nanoparticles sustain up to 110% tensile strain with a linear and sensitive electromechanical response, demonstrating potential applications in discriminating respiration status and monitoring snoring breath. This work unveils a new approach to fabricate high-performance air-permeable strain sensors in a simple and scalable way.

Transgenic nude mouse with green fluorescent protein expression-based human glioblastoma multiforme animal model with EGFR expression and invasiveness.

Previously, we developed an orthotopic xenograft model of human glioblastoma multiforme (GBM) with high EGFR expression and invasiveness in Balb/c nu/nu nude mice. Now we also developed the same orthotopic xenograft model in transgenic nude mice with green fluorescent protein (GFP) expression. The present orthotopic xenografts labeled by phycoerythrin fluorescing red showed high EGFR expression profile, and invasive behavior under a bright green-red dual-color fluorescence background. A striking advantage in the present human GBM model is that the change of tumor growth can be observed visually instead of sacrificing animals in our further antitumor therapy studies.

Cloning and characterization of a phosphate transporter gene in Dunaliella salina.

The full-length cDNA of a Na(+) -dependent Pi transport gene (DsSPT1) in Dunaliella salina was cloned by 3' and 5' Rapid Amplification of cDNA Ends (RACE), with an open reading frame (ORF) encoding 716 predicted amino acids, which exhibited 60.5% identity to that of Na(+) -dependent Pi transport 1 (DvSPT1) from Dunaliella viridis. Hydrophobicity and secondary structure prediction revealed 11 conserved transmembrane domains similar to those found in DvSPT1 from D. viridis and PHO89 from Saccharomyces cerevisiae. The result of real-time quantitative PCR showed that expression level of DsSPT1 was enhanced at first and reached its peak at 90 min after salt stress; however, D. salina cells rapidly absorbed extracellular inorganic phosphorus which was determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) during the first 5 min under salt stress. It suggested that D. salina on the absorption of inorganic phosphorus was regulated at DsSPTI posttranslational level.

Efficient Radiative Enhancement in Perovskite Light-Emitting Devices through Involving a Novel Sandwich Localized Surface Plasmon Structure.

In recent years, CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) have been considered as the most promising materials for light-emitting diodes (LEDs). However, the advances of CsPbX3 quantum dot-based light emitting diodes (QLEDs) still lagged behind inorganic III-V LEDs and other organic LEDs. Herein, a strategy to improve the performances of perovskite QLEDs is reported by utilizing the localized surface plasmon resonance (LSPR) effects of Au nanospheres (NSs). It is accomplished by introducing a Au NS layer into the electron transport layer of Ca2+ -CsPbBr3 QLEDs, where the diameter and spacing of Au NSs and the interaction distance between the Ca2+ -CsPbBr3 QD and Au NS layers are modulated, according to the theoretical simulation of Finite-difference time-domain. As a result, the photoluminescence quantum yield of Ca2+ -CsPbBr3 QD layer is improved from 31.5% to 73.3%. Finally, the luminance of Ca2+ -CsPbBr3 QLEDs is improved from 16824 to 63931 cd m-2 and external quantum efficiency (EQE) is improved from 4.2% to 10.5%. The radiative transition rate can be remarkably modulated from 0.7 × 107 to 6.6 × 107 s-1 . The enhancement in luminance and EQE are the best values in the LSPR modified perovskite QLEDs and the strategy offered in this work fits with other LEDs and optoelectrical devices.

Highly Stable and Efficient Mn2+ Doping Zero-Dimension Cs2ZnxPb1-xCl4 Alloyed Nanorods toward White Electroluminescent Light-Emitting Diodes.

Zero-dimensional (0D) crystal structure perovskite NCs have reemerged as promising materials owing to their superior long-term stability; however, their poor conductivity leads to the inferior electrical performances and critically restricts the optoelectronic application of 0D perovskite materials. Herien, the alloyed 0D crystal structure Cs2ZnxPb1-xCl4 nanorods (NRs) have been synthesized by the modified hot-injection method, which emits bright blue-violet light at 408 nm, and the optimized photoluminescence quantum yield (PLQY) reaches 26%. The Cs2Zn0.88Pb0.12Cl4 NRs display more excellent air stability and an order of magnitude higher conductivity than CsPbCl3 nanocube films. In addition, we dope Mn2+ ions into the Cs2Zn0.88Pb0.12Cl4 NRs, which accomplished the optimized PLQY of 40.3% and polarized emission with r = 0.19. The light-emitting diodes (LEDs) based on Mn2+ ion doped Cs2Zn0.88Pb0.12Cl4 NRs exhibit a chromaticity coordinate (CIE) of (0.36, 0.33), an EQE of 0.3%, and a maximum luminance of 98 cd m-2. This work has enriched ideas for the production of white light perovskite LEDs.

Characteristics and Safety of CO2 for the Fire Prevention Technology with Gob-Side Entry Retaining in Goaf.

The mining technology of gob-side entry retaining without a coal pillar is gradually becoming a mature and increasingly important mining technology. As it maintains the roadway near goaf, the air leakage should be greater than a U-type ventilation system in goaf, so it is prone to cause coal spontaneous combustion problems. CO2 is an inert gas, and it is usually used to prevent spontaneous combustion and extinguish coal fire. However, there is a lack of research on characteristics and safety of CO2 for the mining technology of gob-side entry retaining without the coal pillar. In this paper, the indexes of influencing factors were proposed on gas, pipelines, and mining technical parameters. Using a three-dimensional physical model of coal stope, the gas migration law of CO2, the relationship between gas injection rate and the oxidation zone area, and the safety of the CO2 inerting technology were analyzed. The results indicate that the O2 concentration is diluted between the working face and the injection port, especially in the air intake side. Furthermore, the CO2 injection rate is an important parameter to the fire prevention and extinguishing technology. When the gas injection rate ranges from 240 to 720 m3/h, the oxidation zone area varies from 7380 to 14 760 m2, and the gas injection rate grows exponentially with the area of the oxidation zone. Moreover, the redundant CO2 gas flows to the retaining roadway, and it reduces the O2 concentration, resulting in asphyxia accidents of miners. The research results are helpful to balance the relationship between inert gas injection and production safety and provide guidance for the practical application of the inert gas fire prevention technology.

Voxel-based analysis of amyloid positron emission tomography probe [C]BF-227 uptake in mild cognitive impairment and alzheimer's disease.

AIM: To determine early brain changes in the distribution of an amyloid positron emission tomography (PET) probe, (11)C-labeled BF-227 or [(11)C]BF-227, in order to accurately predict the progression of mild cognitive impairment (MCI) to Alzheimer's disease (AD). PATIENTS AND METHODS: Amyloid plaque burden was evaluated using [(11)C]BF-227 PET in AD, MCI and aged normal controls. A voxel-based analysis of [(11)C]BF-227 PET images was performed to characterize the culprit brain lesion in patients with MCI who were destined to progress to AD, referred to as MCI converters (MCI-C). In addition, binding characteristics of BF-227 to amyloid deposits were examined using postmortem AD brain samples. RESULTS: Voxel-based statistical analyses of the BF-227 PET images clearly demonstrated an abnormal distribution of BF-227 mainly in the posterior association area in MCI-C and patients with AD. BF-227 uptake in the lateral temporal cortex was consistently observed in almost all MCI-C and patients with AD, and it distinguished MCI-C from MCI nonconverters. BF-227 binding strongly correlated with dense amyloid-ß protein plaque density, but not with diffuse plaque density in the frontal cortex. CONCLUSION: BF-227 uptake in the lateral temporal cortex is a reliable indicator that can be used for predicting prognosis in patients with MCI.

High brightness blue light-emitting diodes based on CsPb(Cl/Br)3 perovskite QDs with phenethylammonium chloride passivation.

All inorganic perovskite quantum dots (QDs) (CsPbX3, X = Cl, Br, I) have been applied on light-emitting devices (LEDs) in recent years due to their excellent optical and optoelectronic properties. However, blue-light emitting perovskite QD LEDs (PQD-LEDs) exhibit poor performances compared with their green- and red-light emitting counterparts. Herein, we fabricated high performing blue-light emitting PQD-LEDs based on phenethylammonium chloride (PEACl) modified CsPb(Cl/Br)3 QDs. Firstly, the PEA-CsPbCl3 QDs were synthesized by introducing certain amounts of PEACl in the conventional hot-injection synthesis process. The merit of our synthesis lies in the fact that not only the Cl vacancies of CsPbCl3 QDs are efficiently modified by introducing the PEACl precursor, but also the partial long-chain organic ligands (OLA) capping on the surface of CsPbCl3 QDs are simultaneously replaced by shorter PEACl chains. Consequently, the PEA-CsPbCl3 QDs emitting at 410 nm with a PLQY of 62.3% were achieved. Furthermore, to meet the requirement of display applications, we exchanged Cl- with Br- ions at room temperature to precisely control the blue emission in the 460-470 nm spectral region and with a maximum PLQY of 80.2% at 470 nm. Finally, the PQD-LEDs based on PEA-CsPb(Cl/Br)3 perovskite QDs emitting at 462, 465, 468 and 470 nm were fabricated. The PQD-LEDs exhibit a maximal EQE of 2.15% and luminance of 620 cd m-2, which provides the highest value of luminance for the PQD-LEDs in the blue spectral range that satisfies the requirement of practical display applications.

Bright Blue Light Emission of Ni2+ Ion-Doped CsPbClxBr3-x Perovskite Quantum Dots Enabling Efficient Light-Emitting Devices.

In recent years, significant advances have been achieved in the red and green perovskite quantum dot (PQD)-based light-emitting diodes (LEDs). However, the performances of the blue perovskite LEDs are still seriously lagging behind that of the green and red counterparts. Herein, we successfully developed Ni2+ ion-doped CsPbClxBr3-x PQDs through the room-temperature supersaturated recrystallization synthetic approach. We simultaneously realized the doping of various concentrations of Ni2+ cations and modulated the Cl/Br element ratios by introducing different amounts of NiCl2 solution in the reaction medium. Using the synthetic method, not only the emission wavelength from 508 to 432 nm of Ni2+ ion-doped CsPbClxBr3-x QDs was facially adjusted, but also the photoluminescence quantum yield (PLQY) of PQDs was greatly improved due to efficient removal of the defects of the PQDs. Thus, the blue emission at 470 nm with PLQY of 89% was achieved in 2.5% Ni2+ ion-doped CsPbCl0.99Br2.01 QDs, which increased nearly three times over that of undoped CsPbClBr2 QDs and was the highest for the CsPbX3 PQDs with blue emission, fulfilling the National Television System Committee standards. Benefiting from the highly luminous Ni2+ ion-doped PQDs, the blue-emitting LED at 470 nm was obtained, exhibiting an external quantum efficiency of 2.4% and a maximum luminance of 612 cd/m2, which surpassed the best performance reported previously for the corresponding blue-emitting PQD-based LED.

Methamphetamine- and 3,4-methylenedioxymethamphetamine-induced behavioral changes in histamine H3-receptor knockout mice.

Histamine H(3) receptors inhibit the release of not only histamine itself, but also other neurotransmitters including dopamine. Previous papers have reported that histaminergic neurons inhibit psychostimulant-induced behavioral changes. To examine whether deficiency in histamine H(3) receptors influences psychostimulant-induced behavioral sensitization and reward, we examined locomotor activity, conditioned place preference (CPP), and c-Fos expression in histamine H(3) receptor-gene knockout mice (H3KO) and their wild-type (WT) counterparts before and after treatment with methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA). The increase in locomotion induced by treatment with METH or MDMA was lower in histamine H3KO mice than in WT mice, while the locomotor sensitization was developed by METH or MDMA in both strains. However, no significant difference in METH- and MDMA-induced preference scores of CPP between histamine H3KO mice and WT mice was observed. Following treatment with METH, the number of c-Fos-positive neurons in the the caudate-putamen of histamine H3KO mice was lower than that in the caudate-putamen of WT mice. In contrast, there was no significant difference in the number of the psychostimulant-induced c-Fos-positive cells in the nucleus accumbens between the two strains of mice. These findings suggest that deficiency in histamine H(3) receptors may have inhibitory effects on psychostimulant-induced increase in locomotion, but insignificant effects on the reward.