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Red-emitting cesium lead iodide (CsPbI3) perovskite quantum dots (CQDs) are extremely unstable due to their structural composition and the weak binding force of ligands on the surface of nanocrystals. Herein, we report an effective method to enhance the photoluminescence and stability of CQDs by simple post-processing with cysteine (Cys). Compared to the pristine CQDs with a photoluminescence quantum yield (PLQY) of 38.61%, the Cys-processed one has fewer surface defects, obtaining a PLQY of 70.77%, nearly twice as much as the pristine samples, and, simultaneously, the Cys-processed CQDs retained more than 86% of the initial PL intensity after 20 days of storage in the atmosphere. This research provides a new idea for the preparation of high-performance and red-emitting quantum dots.

HighlightsSynergistic effect triggers the Ostwald ripening for the downward recrystallization of perovskite to form buried submicrocavities as light output coupler.The simulation suggests the buried submicrocavities can improve the light out-coupling efficiency from 26.8% to 36.2% for near-infrared light.Light-emitting diodes yields peak external quantum efficiency increasing from 17.3% at current density of 114 mA cm−2 to 25.5% at current density of 109 mA cm−2 and a radiance increasing from 109 to 487 W sr−1 m−2 with low rolling-off.Embedding submicrocavities is an effective approach to improve the light out-coupling efficiency (LOCE) for planar perovskite light-emitting diodes (PeLEDs). In this work, we employ phenethylammonium iodide (PEAI) to trigger the Ostwald ripening for the downward recrystallization of perovskite, resulting in spontaneous formation of buried submicrocavities as light output coupler. The simulation suggests the buried submicrocavities can improve the LOCE from 26.8 to 36.2% for near-infrared light. Therefore, PeLED yields peak external quantum efficiency (EQE) increasing from 17.3% at current density of 114 mA cm−2 to 25.5% at current density of 109 mA cm−2 and a radiance increasing from 109 to 487 W sr−1 m−2 with low rolling-off. The turn-on voltage decreased from 1.25 to 1.15 V at 0.1 W sr−1 m−2. Besides, downward recrystallization process slightly reduces the trap density from 8.90 × 1015 to 7.27 × 1015 cm−3. This work provides a self-assembly method to integrate buried output coupler for boosting the performance of PeLEDs.

Novel reduced graphene oxide and carbon nanotube (rGO/CNT) hybrid fibers were prepared using a facial low-temperature chemical reduction self-assembly with vitamin C as the reducing agent. Mechanical measurements showed that hybrid fibers with an ultimate elongation of 150% had better mechanical properties than the single rGO fiber with an ultimate elongation of 105%. Cyclic voltammetry (CV) results showed that rGO/CNTs hybrid fibers exhibited better electrochemical performance than the rGO fiber because of the larger CV curve area of the former. The volumetric specific capacitance of the rGO/CNTs electrode was 559.9 F cm −3 , and its qualitative specific capacitance was 59.76 F g −1 at a high current density of 1 A g −1 . Both the volumetric specific capacitance and qualitative specific capacitance of the rGO/CNTs hybrid fibers were higher than those of single rGO fibers, particularly at low sweep speed. The scanning electron microscopy and transmission electron microscopy images of the rGO/CNTs composite fiber clearly showed the rGO and CNTs co-assembly and the interconnected porous structure formation. In the hybrid nanostructure, CNTs served as a reinforced bar, and the synergic effect between rGO and CNTs led to hybrid fibers with enhanced mechanical and electrochemical performances. The flexible rGO/CNT hybrid fibers showed large volumetric capacity, good rate capability, high stability and excellent flexibility. The micro-SCs made of the rGO/CNT hybrid fibers electrode are ideal energy-storage devices for next-generation flexible wearable electronics.

Nerve conduit is one of strategies for spine cord injury（SCI）treatment.Recently,studies showed that biomaterials could guide the neurite growth and promote axon regeneration at the injury site.However,the scaffold by itself was difficult to meet the need of SCI functional recovery.The basic fibroblast growth factor（bFGF）administration significantly promotes functional recovery after organ injuries.Here,using a rat model of T9 hemisected SCI,we aimed at assessing the repair capacity of implantation of collagen scaffold（CS）modified by collagen binding bFGF（CBD-bFGF）.The results showed that CS combined with CBD-bFGF treatment improved survival rates after the lateral hemisection SCI.The CS/CBD-bFGF group showed more significant improvements in motor than the simply CS-implanted and untreated control group,when evaluated by the 21-point Basso-Beattie-Bresnahan（BBB）score and footprint analysis.Both hematoxylin and eosin（H＆E）and immunohistochemical staining of neurofilament（NF）and glial fibrillary acidic protein（GFAP）demonstrated that fibers were guided to grow through the implants.These findings indicated that administration of CS modified with CBD-bFGF could promote spinal cord regeneration and functional recovery.

Understanding the temporal and spatial distribution characteristics of the cultural heritage of the Yellow River Basin can effectively improve the scientific understanding of the historical changes, environmental evolution, and cultural and economic development of the Yellow River Basin and thus provide a scientific and reasonable decision-making basis for the protection and development of its cultural heritage. The research object of this paper are the national cultural relic protection units. These are examined using the GIS spatial analysis method to explore the spatial and temporal distribution characteristics and spatial structure of 2,102 national material cultural heritage sites in the Yellow River basin. The results show that the spatial distribution of cultural heritage has a significant spatial agglomeration effect. The whole basin is concentrated in stable high- and low-value areas, and the difference between the high- and low-value areas is clear. Some aspects of the spatial structure heterogeneity are strong, showing a low value dispersion distribution trend. In different periods, the distribution direction and scope of cultural heritage have low ranges of rotation, a clear direction, and a high degree of centripetal distribution. The spatial and temporal distribution of cultural heritage is the result of the combined action of natural geographical environment such as climate change, topography, river hydrology, and human environment such as administrative institutional changes, ideological evolution, and social and economic development.

Photodynamic therapy (PDT) is a promising cancer treatment but has limitations due to its dependence on oxygen and high-power-density photoexcitation. Here, we report polymer-based organic photosensitizers (PSs) through rational PS skeleton design and precise side-chain engineering to generate •O 2 − and •OH under oxygen-free conditions using ultralow-power 808 nm photoexcitation for tumor-specific photodynamic ablation. The designed organic PS skeletons can generate electron-hole pairs to sensitize H 2 O into •O 2 − and •OH under oxygen-free conditions with 808 nm photoexcitation, achieving NIR-photoexcited and oxygen-independent •O 2 − and •OH production. Further, compared with commonly used alkyl side chains, glycol oligomer as the PS side chain mitigates electron-hole recombination and offers more H 2 O molecules around the electron-hole pairs generated from the hydrophobic PS skeletons, which can yield 4-fold stronger •O 2 − and •OH production, thus allowing an ultralow-power photoexcitation to yield high PDT effect. Finally, the feasibility of developing activatable PSs for tumor-specific photodynamic therapy in female mice is further demonstrated under 808 nm irradiation with an ultralow-power of 15 mW cm −2 . The study not only provides further insights into the PDT mechanism but also offers a general design guideline to develop an oxygen-independent organic PS using ultralow-power NIR photoexcitation for tumor-specific PDT. Conventional photodynamic therapy (PDT) is hindered by oxygen-dependent photosensitization pathways and high-power-density photoexcitation. Here, the authors develop polymer-based organic photosensitizers (PSs) through PS skeleton design and side-chain engineering to allow tumor-specific PDT under oxygen-free conditions using ultralow-power 808 nm photoexcitation.

Evapotranspiration (ET) is a key ecological process connecting the soil-vegetation-atmosphere system, and its changes seriously affects the regional distribution of available water resources, especially in the arid and semiarid regions. With the Grain-for-Green project implemented in the Loess Plateau (LP) since 1999, water and heat distribution across the region have experienced great changes. Here, we investigate the changes and associated driving forces of ET in the LP from 2000 to 2012 using a remote sensing-based evapotranspiration model. Results show that annual ET significantly increased by 3.4 mm per year ( p  = 0.05) with large interannual fluctuations during the study period. This trend is higher than coincident increases in precipitation (2.0 mm yr −2 ), implying a possible pressure of water availability. The correlation analysis showed that vegetation change is the major controlling factor on interannual variability of annual ET with ~52.8% of pixels scattered in the strip region from the northeastern to southwestern parts of the LP. Further factorial analysis suggested that vegetation greening is the primary driver of the rises of ET over the study period relative to climate change. Our study can provide an improved understanding of the effects of vegetation and climate change on terrestrial ecosystem ET in the LP.

Coupling myoelectric and mechanical signals during voluntary muscle contraction is paramount in human–machine interactions. Spatiotemporal differences in the two signals intrinsically arise from the muscular excitation–contraction process; however, current methods fail to deliver local electromechanical coupling of the process. Here we present the locally coupled electromechanical interface based on a quadra-layered ionotronic hybrid (named as CoupOn) that mimics the transmembrane cytoadhesion architecture. CoupOn simultaneously monitors mechanical strains with a gauge factor of ~34 and surface electromyogram with a signal-to-noise ratio of 32.2 dB. The resolved excitation–contraction signatures of forearm flexor muscles can recognize flexions of different fingers, hand grips of varying strength, and nervous and metabolic muscle fatigue. The orthogonal correlation of hand grip strength with speed is further exploited to manipulate robotic hands for recapitulating corresponding gesture dynamics. It can be envisioned that such locally coupled electromechanical interfaces would endow cyber–human interactions with unprecedented robustness and dexterity. Designing efficient systems capable emulating the muscular excitation-contraction signatures, remains a challenge. Here, the authors propose cytoadhesion-inspired hybrids as locally-coupled electromechanical interfaces capable retrieving the myoelectric and mechanical signals.

The level of sustainable livelihoods, as a yardstick for measuring the social development of migrants, is of great importance to the sustainable development of the region. Based on the analysis of the policy logic of ecological protection and high-quality development in the Yellow River basin, this paper constructs a “ternary” system model and evaluation index system for sustainable livelihoods of farm households in the ecological resettlement areas of the upper Yellow River, and proposes that the harmonious relationship between the three basic dimensions of economy, society and environment is the key to evaluate the sustainable livelihood level of farm households in ecological resettlement areas. Based on the comprehensive evaluation index to assess the comprehensive development level of ecological resettlement areas, we introduced the coupling coordination degree and constructed the coordinated development degree model of “economic-social-environmental” system to characterize the sustainable livelihood level. Through the data of 1116 questionnaires and in-depth interviews in the ecological migrant resettlement area of Liujiaxia reservoir in the upper reaches of the Yellow River basin, the sustainable livelihood status and spatial distribution differences of farm households in 14 townships in the region were evaluated, and the validity of the indicator system was empirically tested. Finally, sustainable livelihood strategies for farm households in the ecological resettlement areas of the upper Yellow River are proposed for the economic, social and environmental dimensions, and the indicator system is further revised. The evaluation system can not only advance the research paradigm of sustainable livelihood assessment for farmers in ecological migrant resettlement areas but can also be widely guided and applied to the sustainable development of ecological migrant practices in China.

Albizia odoratissima is a valuable drought-tolerant native tree species in the dry and hot river valleys of China, which has important ecological and economic values. Exploring its genetic background and phylogenetic direction will be conducive to its further exploitation and use, and promote the process of vegetation restoration in the dry hot river valley region. A genome assembly of approximately 719.88 Mb was achieved at the contig level, featuring a contig N50 of 53.74 Mb. Of this, 98.58% of gene sequences were organized into 13 pseudochromosomes. The A. odoratissima genome contained 96.96% of conserved genes, including 1,538 intact single-copy genes and 42 intact duplicated genes. It had an angiosperm palaeotripling event and the last whole genome duplication event occurred approximately 62.9 million years ago. A. odoratissima shares 8,936 gene families with five other legume species, while 1,420 gene families are unique to A. odoratissima . Under drought stress, photosynthesis was significantly inhibited to reduce water consumption, osmoregulatory substances were significantly increased to alleviate osmotic stress, and flavonoid accumulation was induced to enhance antioxidant capacity through the up-regulation of AoANS ( Aod07G019900 ) gene expression, thereby improving drought tolerance. High-quality reference genomes generated through molecular studies are advancing research into the molecular mechanisms of A. odoratissima .