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Carbon dots (CDs), as a kind of zero‐dimensional nanomaterials, have been widely synthesized by bottom‐up methods from various precursors. However, the formation mechanism is still unclear and controversial, which also brings difficulty to the regulation of structures and properties. Only some tentative formation processes were postulated by analyzing the products obtained at different reaction times and temperatures. Here, the effect of crosslinking on the formation of carbonized polymer dots (CPDs) is explored. Crosslinking‐induced nucleation and carbonization (CINC) is proposed as the driving force for the formation of CPDs. Under hydrothermal synthesis, the precursors are initiated to polymerize and crosslink. The crosslinking brings higher hydrophobicity to generate the hydrophilic/hydrophobic microphase separation, which promotes dehydration and carbonization resulting in the formation of CPDs. Based on the principle of CINC, the influence factors of size are also revealed. Moreover, the dissipative particle dynamics (DPD) simulation is employed to support this formation mechanism. This concept of CINC will bring light to the formation process of CPDs, as well as facilitate the regulation of CPDs' size and photoluminescence. [ABSTRACT FROM AUTHOR]

Self‐protective carbonized polymer dots (CPDs) with advantageous crosslinked nano‐structures have attracted considerable attention in metal‐free room temperature phosphorescence (RTP) materials, whereas their RTP emissions are still limited to short wavelength. Expanding their RTP emissions to Near‐Infrared (NIR) range is attractive but suffers from the difficulties in constructing narrow energy levels and inhibiting intense non‐radiative decay. Herein, a crosslink‐enhanced emission (CEE)‐dominated construction strategy was proposed, achieving desired NIR RTP (710 nm) in self‐protective CPDs for the first time. Structural factors, i.e. crosslinking (covalent‐bond CEE), conjugation (conjugated amine with bridging N−H and C=C group), and steric hindrance (confined‐domain CEE), were confirmed indispensable for triggering NIR RTP emission in CPDs. Contrast experiments and theoretical calculations further revealed the rationality of the design strategy originating from CEE in terms of promoting the narrow energy level emission of triplet excitons and inhibiting the non‐radiative quenching. This work not only firstly achieves NIR RTP in self‐protective CPDs but also helps understand the origin of NIR RTP to further guide the synthesis of diverse CPDs with efficient long‐wavelength RTP emission. [ABSTRACT FROM AUTHOR]

To get maximum efficiency, potential in perovskite solar cells (PSCs) has made it hot research area now a days. Power conversion efficiency of PSCs is increasing by every passing day. Moreover, performance of perovskite absorber layer is important for high efficiency andlong term stability of PSCs. In this work, 2‐4 (Methyl sulphonyl) Phenyl) Ethylamine small molecules with functional groups are added inperovskite and enlarged grains are observed in the result. These effects show improvement in the performance of perovskite. Consequently, density of imperfections with additive in PSCs is alleviated and champion efficiency 24.16% has been achieved. Within corporation of additive with polar functional group crystallinity of absorber film is increased, that is confirmed by X‐ray diffraction and Uv‐Vis results. PL result show absorption is increased with addition ofadditive due to mitigation of nonradiative charge recombination. It is confirmed by GIWAX that charge transportation is increased since output peakintensity for (100) plane is larger than that of input. Overall, efficiencyis increased from 22% for control and exceeding 24% and stability enhanced with incorporation of small molecules. [ABSTRACT FROM AUTHOR]

A general approach is reported to fabricate a series of single‐phase 2:17‐type rare‐earth cobalt (RE2Co17, RE = Y, Ce, Pr, Nd, and Gd) nanoalloys by precisely controlled calcium thermic reduction of amorphous RE‐Co precursors. High‐purity hexagonal RE2Co17 phases are formed without the precipitation of Co and the other RE‐Co phases through the accurately manipulated co‐reduction of the two ions, which avoids the disadvantages of the impurity or second phases for RE metal alloys. RE2Co17/graphite nanostructures constructed with flower‐like RE2Co17 nanoalloys superficially decorated with nanosized graphite are further fabricated by introducing graphene oxides into the co‐reduction process. Compared with traditional magnetic planar‐anisotropy RE2Co17 alloys, the preserved high saturation magnetization (51.2–102.9 A m2 kg−1) and unusually increased coercivity (152–310.5 Oe) are achieved in these graphite‐decorated RE2Co17 nanoalloys. Moreover, these RE2Co17/graphite nanostructures exhibit good microwave absorption with an applied frequency range of 11.76–18 GHz, which shows their potential applications as new‐type Ku‐band electromagnetic materials. This work provides a facial way for the large‐scale production for varieties of single‐phase 2:17‐type RE‐Co nanoalloys and expands their application fields by constructing novel composite structures. [ABSTRACT FROM AUTHOR]

The full‐screen mobile phone can be fabricated by integrating the camera beneath the screen, which needs the nanocomposite light guide plate (nano‐LGP) with exceptional transparency and light‐guiding properties simultaneously. Choosing an appropriate nanoparticle with a high refractive index and exceptional compatibility within the polymer matrix is crucial for producing the nano‐LGP. In this study, the high refractive index carbonized polymer dots (HRI‐CPDs) are synthesized through the solvothermal treatment, achieving a refractive index value of 1.7220 at 450 nm. Subsequently, the modified HRI‐CPDs (mHRI‐CPDs)/polymethyl methacrylate (PMMA) nanocomposites are fabricated by copolymerizing the mHRI‐CPDs with methyl methacrylate. Due to the high visible light transmittance and Rayleigh scattering characteristics when light passes through the nanocomposites, this kind of nanocomposites is suitable for serving as nano‐LGPs. The potential of carbonized polymer dots as light‐scattering unit is originally explored to improve surface illuminance and uniformity of nano‐LGPs. The best‐performing 4.3‐inch LGP with 1.0 wt.% doping content shows 15.8 times higher surface illuminance and 2.1 times higher uniformity than pure PMMA. This new type of LGP based on mHRI‐CPDs/PMMA nanocomposite holds tremendous promise in conjunction with advanced liquid crystal display technology. [ABSTRACT FROM AUTHOR]

Developing a facile strategy to realize fine‐tuning of phosphorescence color in time‐dependent room temperature phosphorescence (RTP) materials is essential but both theoretically and practically rarely exploited. Through simultaneously confining carboxyl dimer association and isolated carboxyl into the particle via a simple hydrothermal treatment of polyacrylic acid, a dual‐peak emission of red phosphorescence (645 nm) and green phosphorescence (550 nm) was observed from carbonized polymer dots (CPDs). The ratio of the two luminescent species can be well regulated by hydrochloric acid inhibiting the dissociation of carboxyl to promote hydrogen bond. Due to comparable but different lifetimes, color‐tunable time‐dependent RTP with color changing from yellow to green or orange to green were obtained. Based on the crosslinking enhanced emission effect, the phosphorescence visible time was even extended to 7 s through introducing polyethylenimide. This study not only proposes a novel and facile method for developing CPDs with color‐tunable time‐dependent RTP, but also provides a bran‐new non‐conjugated red phosphorescence unit and its definite structure. [ABSTRACT FROM AUTHOR]

High refractive index polymers (HRIPs) are widely used in lenses, waveguide, antireflective layer and encapsulators, especially the advanced fields of augmented/virtual reality (AR / VR) holographic technology and photoresist for chip manufacturing. In order to meet the needs of different applications, the development of HRIPs focuses not only on the increase in refractive index but also on the balance of other properties. Sulfur‐containing high refractive index polymers have received extensive attention from researchers due to their excellent properties. In recent years, not only ultrahigh refractive index sulfur‐containing polymers have been continuously developed, but also low dispersion, low birefringence, high transparency, good mechanical properties, and machinability have been studied. The design of HRIPs is generally based on formulas and existing experience. In fact, molecular structure and properties are closely related. Mastering the structure–property relationship helps researchers to develop high refractive index polymer materials with balanced properties. This review briefly introduces the preparation methods of sulfur‐containing high refractive index polymers, and summarizes the structure–property relationship between the sulfur‐containing molecular structure and optical properties, mechanical properties, thermal properties, etc. Finally, the important role of synergistic effect in the synthesis of HRIPs and the prospect of future research on HRIPs are proposed. [ABSTRACT FROM AUTHOR]

The development of persistent room‐temperature phosphorescence (pRTP) materials has been rapid in recent years; however, producing pRTP materials with high luminescent characteristics, mechanical strength, and processability is a difficult issue. Herein, a new class of pRTP materials named carbonized oligomer‐like dots (CODs) is reported, which have injection molding capacity and high mechanical strength in castings. The luminescence and mechanical properties of the CODs (PN1‐PN4) may be altered by altering the quantity of phosphoric acid and diethylenetriamine using a microwave‐assisted heating technique. Among them, the longest lifetime of PN3 attains 1.21 s with an afterglow time of over 20 s, while the maximum Young's modulus of PN1 is up to 2.36 GPa. The existence of n–π* transition is beneficial to promote the intersystem crossing, and multiple hydrogen bonds in the aggregates play a crucial role in the formation of pRTP with mechanical and hot melt adhesive properties. This study may pave the way for the development of pRTP materials with superior mechanical strength in the fields of information encryption and flexible displays. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The carbon dots (CDs), as emerging carbon based nanomaterials, are a kind of fluorescent materials with wide application prospects. Highly luminous CDs can simply be synthesized by a wide variety of easily accessible precursors. CDs have excellent optical properties, high biocompatibility and low toxicity, which makes them be used in the fields of optics, biology, energy, and so on. In this review, the classification, nomenclature, photoluminescence mechanism and property regulation of CDs are reviewed. Finally, the future research interests and potential challenges of CDs are prospected. [ABSTRACT FROM AUTHOR]

In this study we examined a data set of nearly two‐year collection and investigated the effects of low‐level jets (LLJ) on near‐surface turbulence, especially wind direction changes, in the nocturnal boundary layer. Typically, nocturnal boundary layer is thermally stratified and stable. When wind profiles exhibit low gradient (in the absence of LLJ), it is characterized by very weak turbulence and very large, abrupt, but intermittent wind direction changes (∆WD) in the layers near the surface. In contrast, presence of LLJs can cause dramatic changes through inducing wind velocity shears, enhancing vertical mixing, and weakening the thermal stratification underneath. Ultimately, bulk Richardson number (Rb) is reduced and weakly stable conditions prevail, leading to active turbulence, close coupling across the layers between the LLJ height and ground surface, relatively large vertical momentum and sensible heat fluxes, and suppressed ∆WD values. Rb can be a useful parameter in assessing turbulence strength and ∆WD as well. The dependence of ∆WD on Rb appears to be well defined under weakly stable conditions (0.0 < Rb ≤ 0.25) and ∆WD is generally confined to small values. However, the relationship between ΔWD and Rb breaks when Rb increases, especially Rb > 1.0 (very stable conditions), under which ΔWD varies across a very wide range and the potential for large ΔWD increases greatly. Our findings have provided important implications to the plume dispersion in the nocturnal boundary layers. Plain Language Summary: This paper investigated how low‐level jets affect the near‐surface turbulence, especially wind direction changes, in the nocturnal atmospheric boundary layers. Atmospheric stability parameter (e.g., Rb‐bulk Richardson number) can be the key in determining the wind direction changes in the nocturnal atmospheric boundary layer. Under weakly stable conditions (0.0 < Rb ≤ 0.25), in general, wind direction only changes within a small range (less than 10°) between two consecutive 10‐min intervals. In contrast, when Rb > 1.0 (very stable conditions), wind direction can vary across a very wide range and the probability for large wind direction changes also increases. Low‐level jets often enhance the turbulence near the surface, reduce the atmospheric stability and lead to small wind direction shifts. In absence of low‐level jets, nocturnal boundary layers are characterized by very weak turbulence and very large, abrupt, but intermittent wind direction changes (from a couple of 10° to 100°) in the layers near the surface. Our findings have provided important implications to the plume dispersion in the nocturnal boundary layers. Key Points: Bulk Richardson number (Rb) can be a useful parameter in assessing wind direction change (∆WD) near the surface in the nocturnal boundary layer∆WD is generally confined to small values under weakly stable conditions (0.0 < Rb ≤ 0.25) but varies across a very wide range with increasing potential for large ΔWD under very stable conditions (Rb > 1.0), which implies a complicated relationship between Rb and ΔWDPresence of the Low‐Level Jets (LLJ) enhances the turbulence activities, decreases the Rb values, leads to relatively large vertical momentum and sensible heat fluxes, and suppresses ∆WD values [ABSTRACT FROM AUTHOR]

The low‐dimensional halide perovskites have attracted increasing attention due to their improved moisture stability, reduced defects, and suppressed ions migration in many optoelectronic devices such as solar cells, light‐emitting diodes, X‐ray detectors, and so on. However, they are still limited by their large band gap and short charge carriers' diffusion length. Here, we demonstrate that the introduction of metal ions into organic interlayers of two‐dimensional (2D) perovskite by cross‐linking the copper paddle‐wheel cluster‐based lead bromide ([Cu(O2C−(CH2)3−NH3)2]PbBr4) perovskite single crystals with coordination bonds can not only significantly reduce the perovskite band gap to 0.96 eV to boost the X‐ray induced charge carriers, but can also selectively improve the charge carriers' transport along the out‐of‐plane direction and blocking the ions motion paths. The [Cu(O2C−(CH2)3−NH3)2]PbBr4 single‐crystal device can reach a record charges/ions collection ratio of 1.69×1018±4.7 % μGyair−1 s, and exhibit a large sensitivity of 1.14×105±7% μC Gyair−1 cm−2 with the lowest detectable dose rate of 56 nGyair s−1 under 120 keV X‐rays irradiation. In addition, [Cu(O2C−(CH2)3−NH3)2]PbBr4 single‐crystal detector exposed to the air without any encapsulation shows excellent X‐ray imaging capability with long‐term operational stability without any attenuation of 120 days. [ABSTRACT FROM AUTHOR]

Seeking clean energy as an alternative to traditional fossil fuels is the inevitable choice to realize the sustainable development of the society. Photocatalytic technique is considered a promising energy conversion approach to store the abundant solar energy into other wieldy energy carriers like chemical energy. Carbon dots, as a class of fascinating carbon nanomaterials, have already become the hotspots in numerous photoelectric researching fields and particularly drawn keen interests as metal‐free photocatalysts owing to strong UV–vis optical absorption, tunable energy‐level configuration, superior charge transfer ability, excellent physicochemical stability, facile fabrication, low toxicity, and high solubility. In this review, the classification, microstructures, general synthetic methods, optical and photoelectrical properties of carbon dots are systematically summarized. In addition, recent advances of carbon dots based photoinduced reactions including photodegradation, photocatalytic hydrogen generation, CO2 conversion, N2 fixation, and photochemical synthesis are highlighted in detail, deep insights into the roles of carbon dots in various systems combining with the photocatalytic mechanisms are provided. Finally, several critical issues remaining in photocatalysis field are also proposed. [ABSTRACT FROM AUTHOR]

All-inorganic perovskite cesium lead triiodide [CsPbI3] has attracted much attention among the perovskite family due to its excellent optoelectronic properties and chemical stability. However, the high-temperature crystallization process makes CsPbI3 less compatible with commercially flexible substrates, limiting its application into flexible optoelectronics. Here, a cation of 1-[3-aminopropyl]-2pyrrolidinone [APP] is reported that can form 1D [APP]PbI3 perovskite as templates, and significantly reduce the CsPbI3 black-phase transition energy with a low annealing temperature of 75 °C, which further enables a flexible [APP]PbI3/j-CsPbI3 [1D/3D] heterostructure photodetector on ITO/ PET substrate. A high external quantum efficiency [EQE] greater than 2377% is observed along the orientated 1D/3D heterostructure. The high gain and low noise result in a high specific detectivity [D*] over 1012 Jones under -0.6 V low bias. The optimized device structure brings a high EQE χ bandwidth product of 119 kHz under a low driving bias. Due to the high toughness of orientated APP+ ions and the face-connected [PbI3]- chains structure as a strong energy absorber, the flexible photodetector also shows excellent phase stability and impressive flexibility, remaining >90% initial responsivity after over 20 000 times bending with potential flexible imaging application in harsh environments. [ABSTRACT FROM AUTHOR]

Double-crystal monochromators (DCMs) are one of the most critical optical devices in beamlines at synchrotron sources, directly affecting the quality of the beam energy and position. As the performance of synchrotron light sources continues to improve, higher demands are placed on the stability of DCMs. This paper proposes a novel adaptive vibration control method combining variational modal decomposition (VMD) and filter-x normalized least mean squares (FxNLMS), ensuring DCM stability under random engineering disturbance. Firstly, the sample entropy of the vibration signal is selected as the fitness function, and the number of modal components k and the penalty factor x are optimized by a genetic algorithm. Subsequently, the vibration signal is decomposed into band frequencies that do not overlap with each other. Eventually, each band signal is individually governed by the FxNLMS controller. Numerical results have demonstrated that the proposed adaptive vibration control method has high convergence accuracy and excellent vibration suppression performance. Furthermore, the effectiveness of the vibration control method has been verified with actual measured vibration signals of the DCM. [ABSTRACT FROM AUTHOR]

Photosensors, photodetectors, or color sensors are key components for various optical and optoelectronic applications. Semiconductor-based photodetection has been a dominator which is excellent at measuring the photon intensity of incident light. However, the wavelength of the incident light to bemeasured must be known beforehand and it mostly depends on auxiliary methods to filter unknown wavelengths. Herein, an alternative but simple mechanism that is using a monolithic, bandgap-engineered photoferroelectric ceramic to blindly determine the wavelength and intensity of incident light at the same time is demonstrated. The photoferroelectric compound is Ba- and Ni-codoped (K,Na) NbO3 exhibiting a direct bandgap of -2 eV and a spontaneous polarization of -0.25 Cm-2. The band-band charge carrier transition is confirmed by multiple characterization methods of photoluminescence, photodielectric spectroscopy, and photoconductivity. The existent optoelectrical cumulative effect enabled by the simultaneous narrow bandgap and strong ferroelectricity allows to reliably distinguish the wavelengths of 405, 552, and 660 nm as well as the power density ranging from -0.1 to 10Wcm-2, with the photoresponsivity of up to 60 µAW-1. Consequently, this work proposes an alternative to semiconductor-based counterparts for filterless, wavelength-selective photodetection and color sensing. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) or carbonized polymer dots (CPDs) are an emerging class of optical materials that have exceptional applications in optoelectronic devices, catalysis, detection, and bioimaging. Although cell studies of CPDs have produced impressive results, in vivo imaging requires available CPDs to fluoresce in the near‐infrared‐II (NIR‐II) window (1000−1700 nm). Here, a two‐step bottom‐up strategy is developed to synthesize NIR‐CPDs that provide bright emissions in both NIR‐I and NIR‐II transparent imaging windows. The designed strategy includes a hydrothermal reaction to form a stable carbon core with aldehyde groups, followed by the Knoevenagel reaction to tether the molecular emission centers. This procedure is labor‐saving, cost‐efficient, and produces a high yield. The NIR‐CPDs enable high‐performance NIR‐II angiography and real‐time imaging of the disease degree of colitis noninvasively. This technology may therefore provide a next‐generation synthesis strategy for CPDs with rational molecular engineering that can accurately tune the absorption/emission properties of NIR‐emissive CPDs. [ABSTRACT FROM AUTHOR]

In domestic goats, wattles often appear in even numbers, mostly on the neck and a few under the ear. Goat wattle is composed of ectopic cartilage tissue covered by skin and was reported as a dominant inheritance. Thirty‐eight goats from two Southwest Chinese breeds were studied to elucidate the genetic basis of wattle phenotype in goat. Their genomes were sequenced for wide‐genome selective sweep analysis (WGSA) and a genome‐wide association study (GWAS). The WGSA results revealed 500 candidate genes identified by fixation index and π ratio and 261 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched with 195 genes and 38 significantly enriched KEGG items. In particular, three chondrogenesis‐related pathways (Wnt, Hippo and MAPK signaling pathways) were found. Among the 500 genes, 474 were enriched to 2855 Gene Ontology items, and four (BMP2, BMP4, RARA and MSX1) were annotated in the regulation and development of chondrogenesis. Four chondrogenesis‐related genes (GREM1, NEDD4, ATG7 and ITGA1) were identified from 519 single‐nucleotide polymorphisms (SNPs) with a GWAS above the threshold. Six and 11 SNPs on chromosome 10 are located on GREM1 and NEDD4 respectively, and the highest numbers of SNPs on chromosomes 20 and 22 are located on ITGA1 and ATG7 respectively. All of these genes are related to cartilage development. This study identified a series of genes related to chondroplasia by GWAS and WGSA and presented the possibility that wattle inheritance may be influenced by multiple genes. This work provides a new theoretical understanding of the hereditary basis of wattle phenotype. [ABSTRACT FROM AUTHOR]

This work reports the successful preparation of a new type of crystalline luminescent organic nanodot (<3.5 nm) by kinetically trapped self‐assembly, which is then used as a simplified π‐packing model to simulate the structure of CDs. The precise structure and J‐aggregation‐induced photoluminescence (PL) of the nanodots are revealed by investigating the structural relationship between the nanodots and the corresponding single crystals and their properties. Compared with the single crystals, crystalline organic nanodots show longer PL lifetime, higher PL quantum yield, and narrower PL peak, indicating that they are potential organic quantum nanodots. In addition, the efficient π‐stacking environment in the corresponding single crystals can promote π‐aggregation‐induced PL anisotropy. This work indicates crystalline organic nanodots with precise structures to be potentially useful for understanding the structures of CDs and to be attractive potential luminescent materials. [ABSTRACT FROM AUTHOR]

The conductivity of 2D perovskite is mainly dominated by halide metal octahedron skeletons. However, in contrast to 3D perovskite structures, the layered inorganic skeletons are easily compressed or stretched by large organic cations, causing serious microstrain with impaired optoelectronic responses. Here, fluorination modulated supramolecular interactions in 2D fluorophenethylammonium lead iodide (FPEA2PbI4) perovskites are reported. In the double layered organic spacer, interlayer supramolecular interactions between electronegative F atoms and electron‐rich benzene rings dominate the lattice microstrain of 2D (p‐FPEA)2PbI4 perovskite, which can be released by interlayer interactions pulling during compressively bending the flexible devices. This strong electrostatic interaction can maximally release the compression to the inorganic octahedron skeleton during compressive bending, leading to a maximum degree of released microstrain with improved stability. The 60% microstrain can be released by compressive bending, and the corresponding photocurrent response is recovered by about three times in (p‐FPEA)2PbI4 perovskite film. In contrast, intralayer supramolecular interactions dominate microstrain of 2D (o‐FPEA)2PbI4 perovskites, which prevents the microstrain release during compressive bending. The strong electrostatic interaction design in the organic spacer of 2D perovskite takes an important role in releasing the microstrain and re‐bursting the device performance of flexible perovskite devices. [ABSTRACT FROM AUTHOR]

Foliar nitrogen (N) or phosphorus (P) status and their stoichiometric homeostasis are integral parts of the plant nutrient economy that determines the success of plant species in environments where N or P limits plant growth. Despite growing evidence for higher predictability of stoichiometric homeostasis of N (HN) than that of P (HP) on plant species abundance in temperate grasslands, no previous studies explicitly examined how foliar N and P status modulate the relationships between stoichiometric homeostasis and species distribution (regional species abundance) of woody plants, especially in P‐limited (sub)tropical ecosystems. We hypothesized that species with a conservative foliar nutrient status but a higher HP (but not HN) would be regional abundant in P‐limited forest.We measured foliar N (LNC) and P (LPC) contents of 54 woody species, community composition and soil N and P contents across 94 forest plots in Chinese subtropical forests. Then we evaluated the species' levels of N and P stoichiometric homeostasis and their regional abundance to test our hypotheses.HN and HP significantly increased with decreasing LNC and LPC. Foliar nutrient status positively correlated with the minimum values of both soil N and P contents, but only negatively associated with the maximum value of soil P content, indicating that conservative species can occupy a wider range of soil P‐ than N‐based nutrient niche. Meanwhile, species abundance negatively correlated with LNC and LPC, and positively correlated with HN and HP. However, the structure equation model analysis showed that species abundance increased with decline of LNC but not yet with increased HN. In contrast, species abundance enhanced with increased HP and decreased LPC via HP, rather than directly with a decline of LPC.Synthesis. This study provides empirical evidence that species with conservative foliar nutrient status are more stable in terms of N and P stoichiometric homeostasis, and foliar N and P economy modulate species abundance distribution in different ways. Our results suggest that maintaining strong stoichiometric homeostasis of leaf P, while maintaining conservative economy of N, is a key physiochemical mechanism for shaping species abundance distribution in P‐limited forests. [ABSTRACT FROM AUTHOR]

Currently, there is a strong drive to discover alternative materials that exhibit room‐temperature phosphorescence (RTP) for displays, bioimaging, and data security. Ideally, these materials should be nontoxic, cheap, and possess controllable photoluminescent properties. Carbon dots (CDs) possess each of these characteristics, but to date, less attention has been paid to their RTP mechanism. Herein, we synthesized a series of CDs by self‐crosslinking and carbonization of precursor. The resultant CDs were luminescent and exhibited a bright, micro‐second afterglow lifetime. To increase the RTP, a second microwave processing step was used to coat the CDs with polyvinyl alcohol (PVA), polyacrylamide (PAM), or tetraethyl orthosilicate (TEOS), producing CDs@PVA, CDs@PAM, and CDs@TEOS composites. The core–shell structure acted to enhance crosslinking at the surface of the CDs to boost the RTP, creating abundant energy levels for intersystem crossover. In situ X‐ray photoelectron spectroscopy verified electron transfer during luminescence. Finally, we present a design rule that can be used to tune the quantum yields and RTP lifetime of CDs, based on the effective stabilization of triplet excited states through the extent and strength of cross‐linking. This simple strategy provides a flexible route for guiding the further development of CDs with tailored RTP properties for various applications. [ABSTRACT FROM AUTHOR]

Currently, the most efficient electrocatalyst for the hydrogen evolution reaction (HER) in water dissociation is Pt‐based catalyst. Unfortunately, the high cost and less than perfect efficiency hinder wide‐range industrial/technological applications. Here, by controlling the treatment temperature of tris (2,2‐bipyridine) ruthenium dichloride hexahydrate, synthesis of compounds with novel ruthenium single/dual atoms (Ru S/DAs) mixed with Ru nanoclusters (Ru S/DAs + Ru NCs) and supported by carbon dots is demonstrated. These compounds are shown to be highly efficient and competitive catalysts for hydrogen evolution. Ru S/DAs + Ru NCs exhibit very high activity, with overpotentials of 15 and 40 mV at a current density of 10 mA/cm2 in 1.0 mol/L KOH and 0.5 mol/L H2SO4, respectively. Furthermore, the composites are found to possess outstanding stability and rapid HER kinetics. X ray absorption fine structure analysis, supported by density functional theory calculations, shows charge rearrangement in single‐atomic Ru, and the Ru dual sites promote active hydrogen adsorption and recombination. Ru S/DAs and Ru NCs demonstrate high electroactivity due to the electroactive Ru 4d orbitals. The introduction of Ru NCs activates the carbon support, providing a high electronic conductivity to transfer electrons from Ru NCs to Ru S/DAs, and facilitates water dissociation for the HER process. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), comprising crystalline graphitized carbon cores and polymer surface groups, are currently attracting a lot of interest in biological fields owing to their fluorescent properties, high photostability, biocompatibility and low toxicity. In addition, the easy preparation and functionalization of CDs stimulate the development of CDs‐based composite materials with specific functions. Presently, the biological applications of CDs are growing at a remarkable speed, justifying the need for up‐to‐date review articles that capture recent progress in this blossoming field. In this review, breakthroughs in the synthesis, modification, optical properties, toxicology and biocatalytic platforms of CDs are described. Further, recent research related to bioimaging, biosensing, drug delivery, antibacterial, anticancer (photothermal therapy, photodynamic therapy and synergistic therapy) and antiviral therapies involving CDs are discussed in detail. Finally, a perspective on the prospects and challenges of CDs in the fields of biomedicine and biotechnology is provided. [ABSTRACT FROM AUTHOR]

Metal halide perovskite scintillators encounter unprecedented opportunities in indirect ionizing radiation detection due to their high quantum yields. However, the long scintillation lifetime of microseconds upon irradiation, known as the afterglow phenomenon, obviously limits their fast development. Here, a new type of hybrid X‐ray detector wafer combining direct methylamine lead iodide (MAPbI3) semiconductor and indirect zero‐dimensional cesium copper iodide (Cs3Cu2I5) scintillator through low‐cost fast tableting processes is reported. Due to the fast energy transfer from Cs3Cu2I5 to MAPbI3, the device response time to X‐rays is dramatically reduced by nearly 30 times to 36.6 ns, which enables fast X‐ray detection capability by a large area detector arrays within 1 s. Moreover, Cs3Cu2I5 exists at the grain boundaries of MAPbI3 crystals, and blocks the paths of mobile ions of perovskite, leading to the lowest detectable dose rate of hybrid X‐ray detector is thus reduced by 1.5 times compared with control MAPbI3 direct‐type semiconductor, and 10 times compared with the Cs3Cu2I5 indirect‐type scintillator. The direct/indirect hybrid wafer also exhibits improved operation stability at ambient conditions without any encapsulation. This new kind of hybrid X‐ray detectors provides strong competitiveness by combining the advantages of both direct perovskite semiconductors and indirect perovskite scintillators for next‐generation products. [ABSTRACT FROM AUTHOR]

Conductive hydrogels have recently gained impressive attention in biological medicine and intelligent electronics. Despite the multifunctions demonstrated by existing conductive hydrogels, it is still a challenge to introduce a hydrogel to adjust the distance between the peritumoral organs and the tumor, reducing the radiation damage to the peritumoral organs. Here, a hydrophobic associating hydrogel with multiple desirable features is fabricated based on diverse supramolecular assembly. The introduction of MXene and hydrolyzed keratin (HK) imparts the hydrogel with excellent conductivity, ultra‐stretchability (>2000%), and good self‐adhesion. Moreover, the hydrogel is utilized as an intelligent sensor intended for monitoring various human movements and physiological signals, demonstrating a wide strain window, the rapid response time (130 ms), and outstanding strain sensitivity (GF = 10.22). Inspired by balloon inflation, the hydrogel is designed to separate the tumor from the peritumoral organs in brachytherapy. It plays a role in reducing the radiation dose and damage to the peritumoral organs. The authors also simulate the attenuation process of the radiation signal according to the change of the hydrogel size and develop a smartphone application (app) to monitor the safety range of the different radiation risks, manifesting its great potential in soft intelligent sensors. [ABSTRACT FROM AUTHOR]

Cancer remains a formidable global problem with a high mortality rate. There are many effective anti‐cancer drugs in clinical use, among which paclitaxel (PTX) has good effects on non‐small cell lung cancer, ovarian cancer, and breast cancer. However, when applied to the clinic, PTX still has many limitations, such as poor water solubility, drug resistance, and side effects on healthy tissues. A gold nanodots‐paclitaxel‐polylysine (AuNDs‐PTX‐PLL) core‐shell nano‐system of integrated diagnosis and treatment is constructed to achieve intelligent responsive drug delivery. On the one hand, the problem of poor water‐solubility and drug resistance of PTX are solved. On the other hand, the nano‐system has an excellent intelligent response effect. Drugs can only be released in the weakly acidic environment of the tumor, which reduces the damage and side effects to normal tissues. Moreover, the nano‐system can be used for real‐time tracking and auxiliary diagnosis for the tumor through the multi‐mode imaging mode, such as fluorescence, photoacoustic, and computed tomography to achieve accurate visualization. The photothermal effect of AuNDs is beneficial to promote the release of drugs. The nano‐system integrates multi‐mode imaging, chemotherapy, intelligent drug release in tumor weakly acidic environment, and has excellent practical application prospects in tumor diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Designing a stable and efficient dual‐functional catalyst for the hydrogen evolution and oxygen evolution reactions (HER/OER) is of great significance to the development of hydrogen production by water splitting. This work reports on novel halogen (X = F, Cl, and Br)‐doped carbon dots modifying amorphous cobalt phosphide (X‐CDs/CoP), which can be tuned by the choice of X‐CDs to have urchin, Pinus bungeana, and Albizia julibrissin type structures. The different characteristics of the various X‐CDs led to different formation mechanisms and final structures. As a bifunctional catalyst, urchin‐shaped F‐CDs/CoP crystals achieve superior electrocatalytic performance, exhibiting excellent HER/OER activity and sustained stability in an alkaline solution. For overall water splitting, they provide current density of 10 mA cm−2 and require a low cell voltage of 1.48 V in 1 M KOH. In addition, the catalytic performance shows negligible degradation after 100 h, thus demonstrating excellent long‐term cycling stability. Density functional theory calculations show that the improved electrocatalytic performance of F‐CDs/CoP catalysts is due to the coupling interface between CoP and F‐CDs, which optimizes the hydrogen/oxygen adsorption energy and accelerates the water splitting kinetics. This work provides guidance for the rational design of transition metal phosphide electrocatalysts with outstanding performance. [ABSTRACT FROM AUTHOR]

Synthetic systems of nonequilibrium self‐assembly have made considerable progress; however, the achievement of innovative materials with self‐regulated functions analogous to living systems remains a grand challenge. Herein, a versatile nonequilibrium system of polymer brushes with spatiotemporally programmable properties and functions driven by chemical fuels is reported. By combining a responsive polymer with an autonomous pH regulator, the polymer brushes self‐regulate their swelling and deswelling process with tunable lifetimes. By using patterned copolymer brushes with pH‐responsive fluorescence moiety, an autonomous fluorescence modulator is created that self‐regulates its fluorescence in spatiotemporally programmable fashion driven by a chemical or an enzymatic reaction. Furthermore, a self‐regulated wettability switcher of polymer brushes both in air and in an aqueous solution is implemented. The methodology and results in the work provide a useful avenue into the exploration of nonequilibrium synthetic materials with programmable functions and would accelerate the transformative developments of nonequilibrium materials and systems in practical applications. [ABSTRACT FROM AUTHOR]

There is extensive experimental evidence for the importance of biodiversity in sustaining ecosystem functioning. However, such experiments typically prevent immigration by continuously removing non‐target species, thereby questioning the generality of these findings to real‐world ecosystems. This is particularly true in forest ecosystems where understorey herbaceous species are key biodiversity components but are usually weeded in tree diversity experiments. Consequently, little is known about how tree diversity influences the natural dynamics of understorey herbaceous layers.We conducted a 3‐year non‐weeded tree diversity experiment composed of eight woody species differing widely in plant economic strategies. We examined how the functional diversity and identity of tree species mixtures drive the temporal dynamics of understorey productivity, functional diversity and composition through canopy packing (CP).Tree mixtures with high functional diversity experienced increased CP over time, thereby decreasing understorey productivity and diversity. Furthermore, herbaceous communities were dominated by species with functional traits typical of low‐light conditions [lower community‐weighted mean (CWM) of maximum plant height, but larger CWM of specific leaf area] in response to increased CP.Our results provide mechanistic insights into the role of tree functional diversity in shaping the dynamics of biomass, functional diversity and composition of the understorey herbaceous layer during the early successional period. It is expected that the effects of tree functional diversity would also be relevant over time due to the increasing usage of canopy space. This study highlights the significance of natural community processes in determining the effects of tree diversity on the temporal dynamics of previously neglected ecosystem structures and functioning. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Both semiconductors and scintillators have their own advantages in direct and indirect X‐ray detection, respectively. However, they are also limited by their intrinsic properties and detection mechanisms. Here, a low‐cost and large‐area flat X‐ray detector is reported by combining a cesium silver bismuth bromide (Cs2AgBiBr6) perovskite semiconductor with a ethylenebis‐triphenylphosphonium manganese (II) bromide ((C38H34P2)MnBr4) scintillator through fast tableting processes. Cs2AgBiBr6 and (C38H34P2)MnBr4 can attenuate the X‐ray photons to induce charge carriers that are collected through the continuous Cs2AgBiBr6 grains. (C38H34P2)MnBr4 blocks the Cs2AgBiBr6 ions migration paths at the grain boundaries to reduce the device dark current/noise and improves the working stability. Most charges generated by (C38H34P2)MnBr4 are transferred to the adjacent Cs2AgBiBr6, and recombined charges radiate light through scintillation, which will be further absorbed by the surrounding Cs2AgBiBr6 perovskite, and further induce collectable charges for indirect X‐ray detection, avoiding the unwanted light scattering, self‐absorption, or afterglow effects of scintillators. The hybrid X‐ray detector displays a high sensitivity of 114 µC Gyair−1 cm−2 to 120 keVp hard X‐rays with a lowest detectable dose rate of 0.2 μGyair s−1, showing 75 times lower detection limit compared to (C38H34P2)MnBr4 scintillator, which provides a new path for X‐ray flat‐panel design. [ABSTRACT FROM AUTHOR]

Electrocatalytic reactions possess wide application prospects in solving the energy crisis. Recently, the emerging 0D carbon dots (CDs) have become potential candidate materials due to their low cost, high conductivity, easy modification, and simple synthesis. CDs‐based composite materials showcase attractive electrocatalytic performances because of the abundant active sites and charge distribution on the material surface. Considering the complicated structure of CDs, it's important to identify the specific catalytic activity source and understand catalytic mechanisms with the aid of theoretical method. In this review, the latest advancements are presented on improving the electrocatalytic activity and stability of CDs‐based composite materials from theoretical perspective. Meanwhile, the opportunity and challenges about developing high‐performance CDs catalysts are also highlighted. [ABSTRACT FROM AUTHOR]

Halide perovskites exhibit diverse properties depending on their compositions. However, integrating desired properties into one material is still challenging. Here, a facile solution‐processed epitaxial growth method to grow 2D perovskite single crystal on top of 3D perovskite single crystal, which can passivate the surface defects for improved device performance is reported. Short formamidine (FA+) ions are replaced by long organic cations, which can fully align and cover the single crystal surface to prevent the ions migration or short FA+ ions volatilization. The thickness of epitaxial layer can be finely adjusted by controlling the growth time. The defect density of single crystals heterojunction is only 3.18 × 109 cm−3, and the carrier mobility is 80.43 cm2 V−1 s−1, which is greater than that of the control 3D perovskite single crystal. This study for the first time realized large area 3D/2D perovskite single crystals heterojunction, which suppressed ions migration and exhibited advanced performance in hard X‐rays detection applications. This strategy also provides a way to grow large area 2D perovskite single crystal from solution processes. [ABSTRACT FROM AUTHOR]

Miniaturized solid‐state lasers with a single longitudinal mode are vital for various photonic applications. Here we prepare red‐emissive carbon dots (CDs) with a photoluminescence quantum yield (PLQY) of 65.5 % by combining graphitic nitrogen doping and surface modification. High‐concentration doping alters the CDs' emission from blue to red, while the electron‐donating groups and polymer coating on their surfaces improve the PLQY and photostability. The CDs exhibit excellent stimulated emission characteristics, with a low threshold of amplified spontaneous emission (ASE) and long gain lifetime. A planar microcavity with only one resonant mode, which fitted with the CDs' ASE peak, was constructed. Combining the CDs and microcavity produced a solid‐state laser with a single longitudinal mode, a linewidth of 0.14 nm and a signal‐to‐noise ratio of 14.8 dB (Q∼4600). Our results will aid the development of colorful solid‐state micro/nano lasers with potential use in practical photonics. [ABSTRACT FROM AUTHOR]

Conductive hydrogels as flexible electronic devices, not only have unique attractions but also meet the basic need of mechanical flexibility and intelligent sensing. How to endow anisotropy and a wide application temperature range for traditional homogeneous conductive hydrogels and flexible sensors is still a challenge. Herein, a directional freezing method is used to prepare anisotropic MXene conductive hydrogels that are inspired by ordered structures of muscles. Due to the anisotropy of MXene conductive hydrogels, the mechanical properties and electrical conductivity are enhanced in specific directions. The hydrogels have a wide temperature resistance range of −36 to 25 °C through solvent substitution. Thus, the muscle‐inspired MXene conductive hydrogels with anisotropy and low‐temperature resistance can be used as wearable flexible sensors. The sensing signals are further displayed on the mobile phone as images through wireless technology, and images will change with the collected signals to achieve motion detection. Multiple flexible sensors are also assembled into a 3D sensor array for detecting the magnitude and spatial distribution of forces or strains. The MXene conductive hydrogels with ordered orientation and anisotropy are promising for flexible sensors, which have broad application prospects in human–machine interface compatibility and medical monitoring. [ABSTRACT FROM AUTHOR]

The ecotype population of goats (Capra hircus) was created by long‐term artificial selection and natural adaptation. Mile red‐bone goat is an indigenous breed with visible red bones, and its special bone structure has received extensive attention. This study aimed to identify genetic variants and candidate genes associated with specific bone phenotypes using next‐generation sequencing technology (NGS). The results revealed that 31,828,206 single nucleotide polymorphisms (SNPs) were obtained from 72 goats (20 Mile red‐bone goats and 52 common goats) by NGS. A total of 100 candidate genes were identified on the basis top 1% window interaction from nucleotide diversity (π), π ratio (πA/πB), and pairwise fixation index (FST). Exactly 77 known signaling pathways were enriched. Specifically, three coding genes (NMNAT2, LOC102172983, and PNLIP) were annotated in the vitamin metabolism signaling pathways, and NCF2 was annotated to the osteoclast (OC) differentiation pathway. Furthermore, 5862 reliable copy number variations (CNVs) were obtained, and 14 and 24 genes were annotated with the top 1‰ CNV based on FST (>0.490) and VST (>0.527), respectively. Several pathways related to bone development and metabolism of exogenous substances in vivo, including calcium signaling pathway, OC differentiation, and glycerophospholipid metabolism, were annotated. Specifically, six genes from 19 candidate CNVs, which were obtained by interaction of the top 1‰ CNVs with FST and VST, were annotated to mucin‐type O‐glycan biosynthesis and metabolic pathways. Briefly, the results implied that pseudopurpurin and specific genetic variants work together to contribute to the red‐bone color and specific bone structure of Mile red‐bone goat. This study is helpful to understanding the genetic basis of the unique bone phenotype of Mile red‐bone goats. [ABSTRACT FROM AUTHOR]

Full‐thickness skin injuries have always been an intricate problem in clinical treatment. The application of biomaterials provides an artificial matrix for the recruitment of cells and deposition of extracellular matrix to accelerate wound healing. For the recovery of full‐thickness skin defects, the double cross‐linking of MgO‐catechol and Schiff's base bonds are used as part of the gel‐forming mechanism, and a bio‐multifunctional hydrogel (CCOD‐MgO) is prepared by adding MgO to catechol‐modified chitosan (CHI‐C) and oxidized dextran (ODex). The CCOD‐MgO demonstrates high tissue adhesion, excellent self‐repairing, hemostasis function, and low swelling rate. With the addition of MgO and catechol chelation, the adhesion strength of CCOD‐MgO is about 35 kpa, which is much greater than fibrin glue. Moreover, the CCOD‐MgO has better antibacterial properties than CHI‐C/ODex hydrogel (CCOD) due to the synergy of chitosan and MgO in vitro. Accordingly, the CCOD‐MgO can protect the wounds from infection and accelerate the healing speed of the epidermis in full‐thickness cutaneous defect and burn model in vivo. These results demonstrate that the CCOD‐MgO would be a promising therapeutic strategy in full‐thickness skin injuries for clinical therapies. [ABSTRACT FROM AUTHOR]