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Abstract Carbon quantum dots (CQDs) have emerged as prominent contenders in the realm of luminescent nanomaterials over the past decade owing to their tunable optical properties, robust photostability, versatile surface functionalization and doping potential, low toxicity, and straightforward synthesis utilizing environmentally friendly precursors. In this review, we commence with a concise introduction, presenting both top‐down and bottom‐up strategies for the eco‐friendly synthesis of CQDs. Subsequently, we delve into a comprehensive examination of CQDs' structure and optical characteristics, encompassing their ultraviolet–visible absorption properties, surface confinement effects, and surface state emissions contributing to room‐temperature photoluminescence (PL). This review proceeds to elucidate recent advancements in modification strategies for CQDs, specifically focusing on surface oxidation, passivation, and the incorporation of heteroatoms. These strategies serve to afford control over the physicochemical properties, facilitating the enhancement of PL through the decoration of highly visible‐responsive CQDs. This enhancement is achieved by suppressing the nonradiative recombination of electron‐hole pairs, enabling red/blue shifts in CQDs for the generation of a full‐color emission spectrum, and regulating the band‐gap and surface states to broaden the photoabsorption range. Finally, we offer an overview of the most recent developments in the applications of fluorescent CQDs, emphasizing their utility in biomedicine, fluorescent sensors, lighting, and displays, as well as photocatalysis.

Abstract Side‐chain symmetry‐breaking strategy plays an important role in developing photovoltaic materials for high‐efficiency all‐small‐molecule organic solar cells (ASM OSCs). However, the power conversion efficiencies (PCEs) of ASM OSCs still lag behind their polymer‐based counterparts, which can be attributed to the difficulties in achieving favorable morphology. Herein, two asymmetric porphyrin‐based donors named DAPor‐DPP and DDPor‐DPP were synthesized, presenting stronger intermolecular interaction and closer molecular stacking compared to the symmetric ZnP‐TEH. The DAPor‐DPP:6TIC blend afforded a favorable morphology with nanoscale phase separation and more ordered molecular packing, thus achieving more efficient charge transportation and suppressed charge recombination. Consequently, the DAPor‐DPP:6TIC‐based device exhibited superior photovoltaic parameters, yielding a champion PCE of 16.62% higher than that of the DDPor‐DPP‐based device (14.96%). To our knowledge, 16.62% can be ranked as one of the highest PCE values among the binary ASM OSC filed. This work provides a prospective approach to address the challenge of ASM OSCs in improving film morphology and further achieving high efficiency via side‐chain symmetry‐breaking strategy, exhibiting great potential in constructing efficient ASM OSCs.

A high-precision equipment is very sensitive to vibration, even micro vibration. How to isolate the low-frequency broadband multidirectional vibration remains a challenge. As the main component of piezoelectric smart vibration isolation model, the piezoelectric stack consists of a piezoelectric actuator, a piezoelectric sensor, and a rubber layer. The numerical results obtained by the finite element method agree well with theoretical solutions. The vibration attenuates rapidly under displacement and velocity feedback control with negative gains. As the control gain decreases, the vibration isolation band is extended to lower frequency. A piezoelectric smart multidirectional vibration isolation platform model is further proposed by inclined installation of two piezoelectric stacks. A spring-like structure is designed to exert a preload pressure on these piezoelectric stacks. After optimization on the control gain, the platform can isolate vibration from 0 to 3000 Hz in multiple directions.

Reliable transfer techniques are critical for the integration of 2D materials with arbitrary substrates. Here, the authors describe a method to transfer 4-inch and A4-sized defect-free graphene films onto rigid and flexible substrates with controllable conformal contact, leading to improved electrical properties and uniformity.

To ensure the stability of the electricity spot market and the safety of the provincial and regional power systems, a safety check method is proposed to maximize the effective reserve resources in the power system by optimizing the power of each tie-line. This safety check method accurately models the tie-line equipment and the effective reserve resources and is coupled with each constraint of the electricity spot market clearing model to form a safety check algorithm to optimize the power of tie-line power. The model involved in this paper is a linear model, which has a clear implementation method in practical dispatching applications. Through this method, the power configuration scheme of each tie-line to meet the electricity spot market constraints can be obtained, and the safety check results have the executability of the power market. The rationality and feasibility of the safety check algorithm results are verified by simulating the provincial-scale electricity spot market. According to the simulation results, this method can release effective reserve resources and provide more guarantees for the safe operation of the power grid. In addition, this method can save up to 4.9% of the total operation cost of the power system and improve the dispatching economy of the power system. This method is of great significance to ensure the safe operation of the power system and the day-ahead market and real-time market scheduling in the actual power spot system. In addition, this method also has great guiding significance for the analysis of the actual reserve situation of the power market after the event.

Inflammatory pseudotumor (IP) is a rare benign group of lesions which mimics invasive malignancies clinically and radiologically. We described five cases of nasopharyngeal and skull base IP treated by endoscopic surgery. These patients suffered from headache, tinnitus and some symptoms of posterior cranial nerve injury such as hoarseness. Three of them had history of type 2 diabetes mellitus and four patients underwent mastoidectomy or puncture of tympanic membrane. The diagnosis of IP was confirmed histologically. Endoscopic surgical excision was proved to be effective and safe for anterior skull base IP.

Abstract Background Phoebe (Lauraceae) comprises of evergreen trees or shrubs with approximately 100 species, distributed in tropical and subtropical Asia and Neotropical America. A total of 34 species and three varieties occur in China. Despite of economic and ecological value, only limited genomic resources are available for this genus. Results We sequenced the two complete chloroplast (cp) genomes of Phoebe chekiangensis and P. bournei using Illumina sequencing technology via a combined strategy of de novo and reference-guided assembly. We also performed comparative analyses with the cp genomes of P. sheareri and P. sheareri var. oineiensis previously reported. The chloroplast genomes of P. chekiangensis and P. bournei identically contain 112 genes consisting of 78 protein coding genes, 30 tRNA genes, and 4 rRNA genes, with the size of 152,849 and 152,853 bp, respectively. From the two chloroplast genomes, 131 SSRs were identified and 12 different SSRs located in five protein coding genes. The analysis showed the extremely conserved structure of chloroplast genomes with surprisingly little variations at the LSC/IR and SSC/IR boundaries. Moreover, the mean nucleotide diversity was found to be 0.162% for 77 regions, suggesting an extraordinarily low level of sequence divergence. Four highest divergent regions (trnH-psbA, rps14-trnT, petA-psbJ, ccsA-ndhD) with the percentage of nucleotide diversity higher than 0.50% were identified, which had potential use for species identification and phylogenetic studies. Conclusion This study will facilitate our understanding of population genetics, phylogenetic relationship and plant evolution of Phoebe species.

A greenhouse pot experiment was conducted to study the effects of nitrogen fertilization on Calophy- llum inophyllum seedlings grown with 0, 50, 100, 150, 200, 300, 400 and 600 mg N per seedling according to exponential functions. Seedling height, root collar diameter, leaf area and total biomass increased with increasing fertilization from 0 to 200 mg N per seedling and decreased with further increase in fertilization from 300 to 600 mg N per seedling. The net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate of C. inophyllum seedlings showed a unimodal parabolic trend, with peak values of 7.29 mmol·m−2·s−1, 0.071 mol·m−2·s−1, 220 mmol·mol−1 and 1.34 mmol·m−2·s−1, respectively, when the rate of fertilization was 200 mg N per seedling. Photosynthetic gas exchange parameters were significantly different among nitrogen treatments. Based on the critical values of leaf N and P concentration and N/P ratio, the optimum amount of nitrogen of C. inophyllum seedlings was 200–400 mg per seedling for leaf N and P concentration, and 100–400 mg per seedling for N/P ratio. It was concluded that 200–400 mg N per seedling was the most suitable nitrogen range for C. inophyllum seedlings.

Taking advantage of multiple new remote sensing data sources, especially from Chinese satellites, the CropWatch system has expanded the scope of its international analyses through the development of new indicators and an upgraded operational methodology. The approach adopts a hierarchical system covering four spatial levels of detail: global, regional, national (thirty-one key countries including China) and “sub-countries” (for the nine largest countries). The thirty-one countries encompass more that 80% of both production and exports of maize, rice, soybean and wheat. The methodology resorts to climatic and remote sensing indicators at different scales. The global patterns of crop environmental growing conditions are first analyzed with indicators for rainfall, temperature, photosynthetically active radiation (PAR) as well as potential biomass. At the regional scale, the indicators pay more attention to crops and include Vegetation Health Index (VHI), Vegetation Condition Index (VCI), Cropped Arable Land Fraction (CALF) as well as Cropping Intensity (CI). Together, they characterize crop situation, farming intensity and stress. CropWatch carries out detailed crop condition analyses at the national scale with a comprehensive array of variables and indicators. The Normalized Difference Vegetation Index (NDVI), cropped areas and crop conditions are integrated to derive food production estimates. For the nine largest countries, CropWatch zooms into the sub-national units to acquire detailed information on crop condition and production by including new indicators (e.g., Crop type proportion). Based on trend analysis, CropWatch also issues crop production supply outlooks, covering both long-term variations and short-term dynamic changes in key food exporters and importers. The hierarchical approach adopted by CropWatch is the basis of the analyses of climatic and crop conditions assessments published in the quarterly “CropWatch bulletin” which provides accurate and timely information essential to food producers, traders and consumers.

Crop condition assessment in the early growing stage is essential for crop monitoring and crop yield prediction. A normalized difference vegetation index (NDVI)-based method is employed to evaluate crop condition by inter-annual comparisons of both spatial variability (using NDVI images) and seasonal dynamics (based on crop condition profiles). Since this type of method will generate false information if there are changes in crop rotation, cropping area or crop phenology, information on cropped/uncropped arable land is integrated to improve the accuracy of crop condition monitoring. The study proposes a new method to retrieve adjusted NDVI for cropped arable land during the growing season of winter crops by integrating 16-day composite Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance data at 250-m resolution with a cropped and uncropped arable land map derived from the multi-temporal China Environmental Satellite (Huan Jing Satellite) charge-coupled device (HJ-1 CCD) images at 30-m resolution. Using the land map’s data on cropped and uncropped arable land, a pixel-based uncropped arable land ratio (UALR) at 250-m resolution was generated. Next, the UALR-adjusted NDVI was produced by assuming that the MODIS reflectance value for each pixel is a linear mixed signal composed of the proportional reflectance of cropped and uncropped arable land. When UALR-adjusted NDVI data are used for crop condition assessment, results are expected to be more accurate, because: (i) pixels with only uncropped arable land are not included in the assessment; and (ii) the adjusted NDVI corrects for interannual variation in cropping area. On the provincial level, crop growing profiles based on the two kinds of NDVI data illustrate the difference between the regular and the adjusted NDVI, with the difference depending on the total area of uncropped arable land in the region. The results suggested that the proposed method can be used to improve the assessment of early crop condition, but additional evaluation in other major crop producing regions is needed to better assess the method’s application in other regions and agricultural systems.