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Purpose: The purpose of this paper is to help patients with calcium oxalate stones to access prevention and treatment options with dietary management. Methods: Typical cases in our hospital and other hospitals were selected for case review; combined with literature review through PubMed search, comprehensive analysis and suggestions were put forward. Results: By retrieving the literature with sufficient evidence, selecting, and summarizing, analysis of dietary liquid, oxalate and oxalate precursors, calcium, protein, fruits and vegetables, salt, high dietary fiber, and other content with high evidence index was carried out, respectively. Conclusion: Through the retrospective analysis of typical cases and literature review, the importance of diet management in the prevention and treatment of calcium oxalate stones was emphasized again, and suggestions were put forward to promote the prevention and treatment of calcium oxalate stones. [ABSTRACT FROM AUTHOR]

Topology optimization of hexahedral (hex) meshes has been a widely studied topic, with the primary goal of optimizing the singularity structure. Previous works have focused on simplifying complex singularity structures by collapsing sheets/chords. However, these works require a large number of checks during the process to prevent illegal operations. Moreover, the employed simplification strategies are not based on the topological characteristics of the structure, but rather on the rank of the components that can be simplified. To overcome these problems, we analyze how topology operations affect the degree of edges in hex meshes, and introduce a fast and automatic algorithm to simplify the singularity structure of hex meshes. The algorithm relies on sheet operations, using mesh volume as a metric to assess the degree of simplification. Moreover, it designs constraints to prevent illegal operations and employs integer linear program to plan the overall optimization strategy for a mesh. After that, we relax the singularity constraints to further simplify the structure, and handle unreasonable singularities via sheet inflation operation. Our algorithm can also improve singularity structure without merging singularities by adjusting the singularity constraint conditions. Numerous experiments demonstrate the effectiveness and efficiency of our algorithm. [Display omitted] [ABSTRACT FROM AUTHOR]

This work proposes a novel metric based algorithm for quadrilateral mesh generating. Each quad-mesh induces a Riemannian metric satisfying special conditions: the metric is a flat metric with cone singularities conformal to the original metric, the total curvature satisfies the Gauss–Bonnet condition, the holonomy group is a subgroup of the rotation group { e i k π ∕ 2 } , there is cross field obtained by parallel translation which is aligned with the boundaries, and its streamlines are finite geodesics. Inversely, such kind of metric induces a quad-mesh. Based on discrete Ricci flow and conformal structure deformation, one can obtain a metric satisfying all the conditions and obtain the desired quad-mesh. This method is rigorous, simple and automatic. Our experimental results demonstrate the efficiency and efficacy of the algorithm. • For any given locations and indices of singularities automatically produce quad mesh. • Give sufficient and necessary conditions for a Riemannian Metric to be induced by a quad mesh. • Based on Ricci Flow method, the existence and uniqueness are guaranteed. [ABSTRACT FROM AUTHOR]

An intriguing reversible band gap narrowing behavior of the lead‐free hybrid perovskite single crystal DMASnI3 (DMA=CH3NH2CH3+) from yellow to black is observed without phase transformation. We discuss the transformation mechanism in detail. More interestingly, the transformed samples in black can rapidly self‐heal into yellow ones when exposed to deionized water (DI water). Contrary to other hybrid perovskites, DMASnI3 crystals exhibit excellent water phase stability. For example, DMASnI3 was immersed in DI water for 16 h and no decomposition was observed. Inspired by its excellent water phase stability, we demonstrate a potential eco‐friendly application of DMASnI3 in photo‐catalysis for H2 evolution in DI water. We present the first H2 evolution rate of 0.64 μmol h−1 with good recycling properties for pure DMASnI3 crystals. After the narrowing process, the optical band gap of DMASnI3 can be lowered from 2.48 eV to 1.32 eV. Systematical characterizations are applied to investigate their structures and optoelectronic properties. The reversible band gap narrowing behavior and outstanding electrical properties, such as higher carrier mobility and long carrier lifetime show that DMASnI3 has a great potential for optoelectronic applications. Reversible band gap narrowing behavior of Sn‐based hybrid perovskite single crystal was first revealed with excellent phase stability, narrow band gap, higher carrier mobility and longer carrier lifetime. This is encouraging for the optoelectronic application. [ABSTRACT FROM AUTHOR]

An intriguing reversible band gap narrowing behavior of the lead‐free hybrid perovskite single crystal DMASnI3 (DMA=CH3NH2CH3+) from yellow to black is observed without phase transformation. We discuss the transformation mechanism in detail. More interestingly, the transformed samples in black can rapidly self‐heal into yellow ones when exposed to deionized water (DI water). Contrary to other hybrid perovskites, DMASnI3 crystals exhibit excellent water phase stability. For example, DMASnI3 was immersed in DI water for 16 h and no decomposition was observed. Inspired by its excellent water phase stability, we demonstrate a potential eco‐friendly application of DMASnI3 in photo‐catalysis for H2 evolution in DI water. We present the first H2 evolution rate of 0.64 μmol h−1 with good recycling properties for pure DMASnI3 crystals. After the narrowing process, the optical band gap of DMASnI3 can be lowered from 2.48 eV to 1.32 eV. Systematical characterizations are applied to investigate their structures and optoelectronic properties. The reversible band gap narrowing behavior and outstanding electrical properties, such as higher carrier mobility and long carrier lifetime show that DMASnI3 has a great potential for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Owing to their high efficiency, low-cost solution-processability, and tunable bandgap, perovskite solar cells (PSCs) made of hybrid organic-inorganic perovskite (HOIP) thin films are promising top-cell candidates for integration with bottom-cells based on Si or other low-bandgap solar-cell materials to boost the power conversion efficiency (PCE) beyond the Shockley-Quiesser (S-Q) limit. In this review, recent progress in such tandem solar cells based on the emerging PSCs is summarized and reviewed critically. Notable achievements for different tandem solar cell configurations including mechanically-stacked, optical coupling, and monolithically-integrated with PSCs as top-cells are described in detail. Highly-efficient semitransparent PSC top-cells with high transmittance in near-infrared (NIR) region are critical for tandem solar cells. Different types of transparent electrodes with high transmittance and low sheet-resistance for PSCs are reviewed, which presents a grand challenge for PSCs. The strategies to obtain wide-bandgap PSCs with good photo-stability are discussed. The PCE reduction due to reflection loss, parasitic absorption, electrical loss, and current mismatch are analyzed to provide better understanding of the performance of PSC-based tandem solar cells. [ABSTRACT FROM AUTHOR]

Automatic hexahedral mesh generation plays a fundamental role in CAD/CAE fields, especially for IGA (isogeometric analysis). Recently, an automatic hex-mesh generation method has been proposed, which is based on the equivalence among three key concepts: colorable quadrilateral meshes, finite measured foliations and Strebel differentials. This work focuses on the computational aspect of Strebel differentials on high genus surfaces, which is based on graph-valued harmonic mapping. The algorithmic pipeline is as follows: first, the user inputs an admissible curve system, which induces a cylindric-decomposition graph; then the user specifies the lengths of the edges of the graph; third, the algorithm finds the unique harmonic map from the surface to the metric graph by a non-linear heat flow; finally, the harmonic map induces a Strebel differential, which can be further utilized to generate the hex-mesh. The method has solid theoretic foundation, which guarantees the existence and the uniqueness of the graph-valued harmonic map. The algorithm is capable of handling surfaces with complicated topologies, and producing all possible Strebel differentials on the surface. The user has full control of the combinatorial type and the geometry of the Strebel differential. The computational pipeline is automatic. The experimental results show the efficiency and efficacy of the algorithm, and demonstrate the great potential for automating the structured hexahedral mesh generation. [ABSTRACT FROM AUTHOR]

For the purpose of isogeometric analysis, one of the most common ways is to construct structured hexahedral meshes, which have regular tensor product structure, and fit them by volumetric T-Splines. This theoretic work proposes a novel surface quadrilateral meshing method, colorable quad-mesh , which leads to the structured hexahedral mesh of the enclosed volume for high genus surfaces. The work proves the equivalence relations among colorable quad-meshes, finite measured foliations and Strebel differentials on surfaces. This trinity theorem lays down the theoretic foundation for quadrilateral/hexahedral mesh generation, and leads to practical, automatic algorithms. The work proposes the following algorithm: the user inputs a set of disjoint, simple loops on a high genus surface, and specifies a height parameter for each loop; a unique Strebel differential is computed with the combinatorial type and the heights prescribed by the user’s input; the Strebel differential assigns a flat metric on the surface and decomposes the surface into cylinders; a colorable quad-mesh is generated by splitting each cylinder into two quadrilaterals, followed by subdivision; the surface cylindrical decomposition is extended inward to produce a solid cylindrical decomposition of the volume; the hexahedral meshing is generated for each volumetric cylinder and then glued together to form a globally consistent hex-mesh. The method is rigorous, geometric, automatic and conformal to the geometry. This work focuses on the theoretic aspects of the framework, the algorithmic details and practical evaluations will be given in the future expositions. [ABSTRACT FROM AUTHOR]

Abstract: We developed a facile strategy to obtain a new kind of mesoporous core-shell structured up-conversion nanoparticles (mUCNPs), composed of a NaYbF4:2%Er core and a mesoporous NaGdF4 shell. This mesoporous shell not only enhanced the up-conversion luminescence but also endowed many other functionalities of the nanoparticles such as drug delivery and bio-imaging capabilities. Moreover, after being conjugated with polyethylenimine (PEI) and folic acid (FA), core-shell mUCNPs exhibited good water dispersibility, enhanced drug delivery efficiency, and remarkable targeting ability to cancer cells. To certify the folate receptors (FR)-mediated targeted drug delivery, cell viability assay, cell up-conversion luminescence imaging and flow cytometry analysis were carried out. Furthermore, apart from the application for targeted drug delivery, the as-prepared core-shell mUCNPs could also be employed as the contrast agents for X-ray computed tomography (CT) and magnetic resonance (MR) imaging, because of the strong X-ray attenuation ability of Yb and high longitudinal molar relaxivity (r 1 ) of Gd in the nanoparticles, providing the potential for simultaneously bio-imaging and cancer-targeting therapy. [Copyright &y& Elsevier]

This work proposes a rigorous and practical algorithm for quad-mesh generation based the Abel–Jacobi theory of algebraic curves. We prove sufficient and necessary conditions for a flat metric with cone singularities to be compatible with a quad-mesh, in terms of the deck-transformation, then develop an algorithm based on the theorem. The algorithm has two stages: first, a meromorphic quartic differential is generated to induce a T-mesh; second, the edge lengths of the T-mesh are adjusted by solving a linear system to satisfy the deck transformation condition, which produces a quad-mesh. In the first stage, the algorithm pipeline can be summarized as follows: calculate the homology group; compute the holomorphic differential group; construct the period matrix of the surface and Jacobi variety; calculate the Abel–Jacobi map for a given divisor; optimize the divisor to satisfy the Abel–Jacobi condition by integer programming; compute a flat Riemannian metric with cone singularities at the divisor by Ricci flow; isometrically immerse the surface punctured at the divisor onto the complex plane and pull back the canonical holomorphic differential to the surface to obtain the meromorphic quartic differential; construct a motorcycle graph to generate a T-Mesh. In the second stage, the deck transformation constraints are formulated as a linear equation system of the edge lengths of the T-mesh. The solution provides a flat metric with integral deck transformations, which leads to the final quad-mesh. The proposed method is rigorous and practical. The T-mesh and quad-mesh results can be applied for constructing Splines directly. The efficiency and efficacy of the proposed algorithm are demonstrated by experimental results on surfaces with complicated topologies and geometries. • Optimize the singularities to satisfy Abel–Jacobi condition. • Construct quartic meromorphic differential for quad meshing. • Prove the sufficient and necessary conditions for quad-meshing. [ABSTRACT FROM AUTHOR]

• Switching frequency of switching devices is constrained by power consumption. • Low switching frequency will result in abundant harmonics in the power supply output current. • Cascaded H-bridge topology effectively improves power capacity. • CPS-SPWM control strategy can effectively achieve high equivalent switching frequency. • Combination of CPS-SPWM and H-bridge cascaded inverter improves the performance of output waveform. ITER (International Thermonuclear Experimental Reactor) sensor steady-state test platform needs high power supply with high steady-state precision output voltage. In the field of high voltage power supply applications, there is often a contradiction between the power supply capability and the switching frequency of high power switching devices. Limited by switching loss, the switching frequency of high power switching devices is low, which will generate a lot of harmonic in the output voltage. In order to meet the requirement of power supply for high-precision output voltage, the design of high power supply adopts the method of combining H-bridge cascaded topology with carrier phase shift PWM control scheme, which can effectively improve output voltage waveform in the design of high power supply. The harmonic analysis and simulation are carried out, and the experimental results verify the validity of the experimental scheme. [ABSTRACT FROM AUTHOR]

This work discovers the equivalence relation between quadrilateral meshes and meromorphic quartic differentials. Each quad-mesh induces a conformal structure of the surface, and a meromorphic quartic differential, where the configuration of singular vertices corresponds to the configurations of the poles and zeros (divisor) of the meromorphic differential. Due to Riemann surface theory, the configuration of singularities of a quad-mesh satisfies the Abel–Jacobi condition. Inversely, if a divisor satisfies the Abel–Jacobi condition, then there exists a meromorphic quartic differential whose divisor equals the given one. Furthermore, if the meromorphic quartic differential is with finite trajectories, then it also induces a quad-mesh, the poles and zeros of the meromorphic differential correspond to the singular vertices of the quad-mesh. Besides the theoretic proofs, the computational algorithm for verification of Abel–Jacobi condition is also explained in detail. Furthermore, constructive algorithm of meromorphic quartic differential on genus zero surfaces is proposed, which is based on the global algebraic representation of meromorphic differentials. Our experimental results demonstrate the efficiency and efficacy of the algorithm. This opens up a novel direction for quad-mesh generation using algebraic geometric approach. • Equivalence between a quad-mesh and a meromorphic quartic differential. • Abel–Jacobi condition for singularities of a quad-mesh. • Verification of Abel–Jacobi condition. • Construction of meromorphic differential. [ABSTRACT FROM AUTHOR]

Surface engineering in perovskite solar cells, especially for the upper surface of perovskite, is widely studied. However, most of these studies have primarily focused on the interaction between additive functional groups and perovskite point defects, neglecting the influence of other parts of additive molecules. Herein, additives with ‐NH3+ functional group are introduced at the perovskite surface to suppress surface defects. The chain lengths of these additives vary to conduct a detailed investigation into the impact of molecular size. The results indicate that the propane‐1,3‐diamine dihydroiodide (PDAI2), which possesses the most suitable size, exhibited obvious optimization effects. Whereas the molecules, methylenediamine dihydroiodide (MDAI2) and pentane‐1,5‐diamine dihydroiodide (PentDAI2) with unsuitable size, lead to a deterioration in device performance. The PDAI2‐treated devices achieved a certified power conversion efficiency (PCE) of 25.81% and the unencapsulated devices retained over 80% of their initial PCE after 600 h AM1.5 illumination. [ABSTRACT FROM AUTHOR]

Isogeometric Analysis (IGA) necessitates quadrilateral meshing owing to the utilization of NURBS or other locally tensor-product spline functions as the foundation for its analysis. It is a widely held misconception that the generation of cross fields over the surface domain – a common precursor to quad-mesh construction – establishes equivalence between cross fields and quad-meshes. In this study, we dispel this notion by presenting theorems that distinctly delineate the singularity configurations of both cross fields and quad-meshes. It is posited that these can be viewed as characteristic classes of different fiber bundles, where cross field singularity aligns with the cross fiber bundle and structured mesh singularity corresponds to holomorphic line bundles. As a result, the conditions necessitating quad-mesh singularities are decidedly more stringent than those for cross field singularities. This explains a notable query in the field: the absence of a 3-5 quad-mesh (a quad-mesh with two singularities with topological valence 3 and 5 respectively) on a torus. Additionally, the theoretical framework is broadened to incorporate other types of structured meshes. The formulated theorems give rise to practical algorithms for cross field construction and structured mesh generation. The efficacy and applicability of these algorithms are corroborated through numerical examples that not only validate the theoretical findings but also underscore their practical usability. [ABSTRACT FROM AUTHOR]

This paper is concerned with Smith forms of bivariate polynomial matrices. For a bivariate polynomial square matrix with the determinant being the product of two distinct and irreducible univariate polynomials, we prove that it is equivalent to its Smith form. We design an algorithm to reduce this class of bivariate polynomial matrices to their Smith forms, and an example is given to illustrate the algorithm. Furthermore, we extend the above class of matrices to a more general case, and derive a necessary and sufficient condition for the equivalence of a matrix and one of its all possible existing Smith forms. [ABSTRACT FROM AUTHOR]

Perovskite nanocrystals (PeNCs) deliver size‐ and composition‐tunable luminescence of high efficiency and color purity in the visible range. However, attaining efficient electroluminescence (EL) in the near‐infrared (NIR) region from PeNCs is challenging, limiting their potential applications. Here we demonstrate a highly efficient NIR light‐emitting diode (LED) by doping ytterbium ions into a PeNCs host (Yb3+ : PeNCs), extending the EL wavelengths toward 1000 nm, which is achieved through a direct sensitization of Yb3+ ions by the PeNC host. Efficient quantum‐cutting processes enable high photoluminescence quantum yields (PLQYs) of up to 126 % from the Yb3+ : PeNCs. Through halide‐composition engineering and surface passivation to improve both PLQY and charge‐transport balance, we demonstrate an efficient NIR LED with a peak external quantum efficiency of 7.7 % at a central wavelength of 990 nm, representing the most efficient perovskite‐based LEDs with emission wavelengths beyond 850 nm. [ABSTRACT FROM AUTHOR]

Perovskite nanocrystals (PeNCs) deliver size‐ and composition‐tunable luminescence of high efficiency and color purity in the visible range. However, attaining efficient electroluminescence (EL) in the near‐infrared (NIR) region from PeNCs is challenging, limiting their potential applications. Here we demonstrate a highly efficient NIR light‐emitting diode (LED) by doping ytterbium ions into a PeNCs host (Yb3+ : PeNCs), extending the EL wavelengths toward 1000 nm, which is achieved through a direct sensitization of Yb3+ ions by the PeNC host. Efficient quantum‐cutting processes enable high photoluminescence quantum yields (PLQYs) of up to 126 % from the Yb3+ : PeNCs. Through halide‐composition engineering and surface passivation to improve both PLQY and charge‐transport balance, we demonstrate an efficient NIR LED with a peak external quantum efficiency of 7.7 % at a central wavelength of 990 nm, representing the most efficient perovskite‐based LEDs with emission wavelengths beyond 850 nm. [ABSTRACT FROM AUTHOR]

A mapping between measurable subsets of Euclidean space can be uniquely factorized to the composition of a measure-preserving mapping and an optimal transportation map, the later is also the gradient map of a convex function. This work introduces an algorithm based on variational approach to compute this type of polar factorization for mappings between planar domains and some direct applications. Our method greatly increases the flexibility for surface parameterizations by balancing between area distortion and angle distortion, and improves the accuracy and numerical stability for down steam geometric processing tasks. [ABSTRACT FROM AUTHOR]

Organic-inorganic halide perovskite (OIHP) solar cells with efficiency over 18% power conversion efficiency (PCE) have been widely achieved with lab scale spin-coating method which is however not scalable for the fabrication of large area solar panels. The PCEs of OIHP solar cells made by scalable deposition methods, such as doctor-blading or slot-die coating, have been lagging far behind than spin-coated devices. In this study the authors report composition engineering in doctor-bladed OIHP solar cells with p-i-n planar heterojunction structure to enhance their efficiency. Phase purer OIHP thin films are obtained by incorporating a small amount of cesium (Cs+) and bromine (Br−) ions into perovskite precursor solution, which also reduces the required film formation temperature. Pinhole free OIHP thin films with micrometer-sized grains have been obtained assisted by a secondary grain growth with added methylammonium chloride into the precursor solution. The OIHP solar cells using these bladed thin films achieved PCEs over 19.0%, with the best stabilized PCE reaching 19.3%. This represents a significant step toward scalable manufacture of OIHP solar cells. [ABSTRACT FROM AUTHOR]

Engineering design of plasmonic nanomaterials as on-demand theranostic nanoagents with imaging, drug carrier, and photothermal therapy (PTT) functions have profound impact on treatment of cancer. Here, a facile ‘one-pot’ template-free hydrothermal route was firstly developed for synthesis of plasmonic oxygen deficiency molybdenum oxide hollow nanospheres functionalized by poly(ethylene glycol) (PEG-MoO 3–x HNSs). The as-prepared PEG-MoO 3–x HNSs not only have good biocompatibility but also exhibit obvious localized surface plasmon resonance (LSPR) absorption in the near-infrared (NIR) region. Especially, due to its intrinsic mesoporous properties and effective photothermal conversion efficiency upon 808-nm NIR laser irradiation, the PEG-MoO 3–x HNSs can be applied as a pH/NIR laser dual-responsive camptothecin (CPT) drug delivery nanoplatform for chemotherapy as well as PTT to cancer cells. A remarkably improved synergistic therapeutic effect to pancreatic (PANC-1) tumor-bearing mice was obtained compared to the result of chemotherapy or PTT alone. Apart from its application for drug delivery, the PEG-MoO 3–x HNSs can also be employed as an effective contrast nanoagent for photoacoustic (PAT) imaging because of its high NIR absorption, making it promising as a theranostic nanoagent for PAT imaging-guided chemo-photothermal combinational cancer therapy in the nanomedicine field. [ABSTRACT FROM AUTHOR]

Highlights: [•] CdS and CdS/CdSe quantum dots are assembled on ZnO nanorods by ion exchange process. [•] The CdS/CdSe sensitization of ZnO effectively extends the absorption spectrum. [•] The performance of ZnO/CdS/CdSe cell is improved by extending absorption spectrum. [Copyright &y& Elsevier]

Perovskite quantum dots (QDs) are of interest for solution‐processed lasers; however, their short Auger lifetime has limited lasing operation principally to the femtosecond temporal regime the photoexcitation levels to achieve optical gain threshold are up to two orders of magnitude higher in the nanosecond regime than in the femtosecond. Here the authors report QD superlattices in which the gain medium facilitates excitonic delocalization to decrease Auger recombination and in which the macroscopic dimensions of the structures provide the optical feedback required for lasing. The authors develope a self‐assembly strategy that relies on sodiumd—an assembly director that passivates the surface of the QDs and induces self‐assembly to form ordered three‐dimensional cubic structures. A density functional theory model that accounts for the attraction forces between QDs allows to explain self‐assembly and superlattice formation. Compared to conventional organic‐ligand‐passivated QDs, sodium enables higher attractive forces, ultimately leading to the formation of micron‐length scale structures and the optical faceting required for feedback. Simultaneously, the decreased inter‐dot distance enabled by the new ligand enhances exciton delocalization among QDs, as demonstrated by the dynamically red‐shifted photoluminescence. These structures function as the lasing cavity and the gain medium, enabling nanosecond‐sustained lasing with a threshold of 25 µJ cm–2. [ABSTRACT FROM AUTHOR]

The all‐inorganic nature of CsPbI3 perovskites allows to enhance stability in perovskite devices. Research efforts have led to improved stability of the black phase in CsPbI3 films; however, these strategies—including strain and doping—are based on organic‐ligand‐capped perovskites, which prevent perovskites from forming the close‐packed quantum dot (QD) solids necessary to achieve high charge and thermal transport. We developed an inorganic ligand exchange that leads to CsPbI3 QD films with superior phase stability and increased thermal transport. The atomic‐ligand‐exchanged QD films, once mechanically coupled, exhibit improved phase stability, and we link this to distributing strain across the film. Operando measurements of the temperature of the LEDs indicate that KI‐exchanged QD films exhibit increased thermal transport compared to controls that rely on organic ligands. The LEDs exhibit a maximum EQE of 23 % with an electroluminescence emission centered at 640 nm (FWHM: ≈31 nm). These red LEDs provide an operating half‐lifetime of 10 h (luminance of 200 cd m−2) and an operating stability that is 6× higher than that of control devices. [ABSTRACT FROM AUTHOR]

The all‐inorganic nature of CsPbI3 perovskites allows to enhance stability in perovskite devices. Research efforts have led to improved stability of the black phase in CsPbI3 films; however, these strategies—including strain and doping—are based on organic‐ligand‐capped perovskites, which prevent perovskites from forming the close‐packed quantum dot (QD) solids necessary to achieve high charge and thermal transport. We developed an inorganic ligand exchange that leads to CsPbI3 QD films with superior phase stability and increased thermal transport. The atomic‐ligand‐exchanged QD films, once mechanically coupled, exhibit improved phase stability, and we link this to distributing strain across the film. Operando measurements of the temperature of the LEDs indicate that KI‐exchanged QD films exhibit increased thermal transport compared to controls that rely on organic ligands. The LEDs exhibit a maximum EQE of 23 % with an electroluminescence emission centered at 640 nm (FWHM: ≈31 nm). These red LEDs provide an operating half‐lifetime of 10 h (luminance of 200 cd m−2) and an operating stability that is 6× higher than that of control devices. [ABSTRACT FROM AUTHOR]

The all‐inorganic nature of CsPbI3 perovskites allows to enhance stability in perovskite devices. Research efforts have led to improved stability of the black phase in CsPbI3 films; however, these strategies—including strain and doping—are based on organic‐ligand‐capped perovskites, which prevent perovskites from forming the close‐packed quantum dot (QD) solids necessary to achieve high charge and thermal transport. We developed an inorganic ligand exchange that leads to CsPbI3 QD films with superior phase stability and increased thermal transport. The atomic‐ligand‐exchanged QD films, once mechanically coupled, exhibit improved phase stability, and we link this to distributing strain across the film. Operando measurements of the temperature of the LEDs indicate that KI‐exchanged QD films exhibit increased thermal transport compared to controls that rely on organic ligands. The LEDs exhibit a maximum EQE of 23 % with an electroluminescence emission centered at 640 nm (FWHM: ≈31 nm). These red LEDs provide an operating half‐lifetime of 10 h (luminance of 200 cd m−2) and an operating stability that is 6× higher than that of control devices. [ABSTRACT FROM AUTHOR]

This paper presents a framework for computational generation and conformal fabrication of woven thin-shell structures with arbitrary topology based on the foliation theory which decomposes a surface into a group of parallel leaves. By solving graph-valued harmonic maps on the input surface, we construct two sets of harmonic foliations perpendicular to each other. The warp and weft threads are created afterward and then manually woven to reconstruct the surface. The proposed computational method guarantees the smoothness of the foliation and the orthogonality between each pair of leaves from different foliations. Moreover, it minimizes the number of singularities to theoretical lower bound and produces the tensor product structure as globally as possible. This method is ideal for the physical realization of woven surface structures on a variety of applications, including wearable electronics, sheet metal craft, architectural designs, and conformal woven composite parts in the automotive and aircraft industries. The performance of the proposed method is demonstrated through the computational generation and physical fabrication of several free-form thin-shell structures. • Use foliation theory for woven fabric, link free-form surface with in-plane textiles. • General to surfaces with arbitrary topologies. • Global tensor product structure with minimal singularities, orthogonal crossing angles, no dangling threads. • Computation algorithm is robust, efficient and automatic. [ABSTRACT FROM AUTHOR]

Abstract Catalytic upgrading heavy oil as one of the important in-situ upgrading technologies has attracted worldwide interest for exploitation. Therefore, alkali-treated Fe/ZSM-5 catalyst for upgrading heavy oil was prepared by alkali treatment and ion exchange. 0.4 wt% alkali-treated Fe/ZSM-5, 1 wt% biomass, and 5 wt% glycerol were added into heavy oil (22,300 mPa·s measured at 50 °C) for reaction at 310–370 °C at 10 °C step size for 30 min. Compared with pyrolysis reaction under the same condition, the optimal viscosity reduction was increased by 81% at 350 °C. Physical properties of the catalysts before and after treatments were characterized by BET, ICP, XRD, Pyridine-IR. Besides, the structures and the group compositions of heavy oil samples before and after reactions at 350 °C were analyzed by SARA, FT-IR, EL, 1H NMR, GC–MS. It was found that alkali-treated Fe/ZSM-5 with larger specific area, larger amount of Bronsted acid sites, larger total pore volume, and larger average pore diameter compared with Na/ZSM-5 could have a positive impact on the upgrading heavy oil. Furthermore, it could be concluded that the reduction of its viscosity was mainly caused by the severely destroyed structure of resin in the process of the reaction. Meanwhile, the synergistic effect of alkali-treated Fe/ZSM-5 with glycerol and biomass was proposed and confirmed in this paper. Highlights • Alkaline-treated Fe / ZSM-5, glycerol and biomass as a new system was used for upgrading heavy oil. • Viscosity reduction using this new system was increased by 47%-82% within the temperature range of 310- 350 °C. • The new system is likely to be applied in the field of gathering and transportation on the ground in the future. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) as an emerging photovoltaic technique have achieved exceptional power conversion efficiency (PCE) up to 25.7% after fast development over the past decade. But currently some critical issues are still not well addressed in terms of realizing large-scale fabrication, for example, fast fabrication of high-quality perovskite film with good stability. Here, we demonstrate the use of stable and fast-crystallizing low-dimensional (LD) perovskite thin films as the light absorber with only a 10 s annealing time at 250 °C, delivering a PCE of 18.16%. The crystallization and photoelectric properties of LD perovskite are well illustrated. The reduction in the annealing time will dramatically increase the productivity of PSCs. The PSCs based on rapidly annealed LD perovskite thin films exhibit excellent stability, with only 12% loss of PCE after 1000 h storage at 85 °C and 40–70% relative humidity. • A low-dimensional (LD) perovskite film with high quality is rapidly prepared. • The crystallization of perovskite is controlled by adjusting annealing temperature. • DMAPA2+ organic cations can improve the stability of LD perovskite films. • The PCE of this LD-PSCs is as high as 18.16%. [ABSTRACT FROM AUTHOR]

Semitransparent perovskite solar cells based on smooth perovskite films and ultrathin Cu (1 nm)/Au (7 nm) metal electrode demonstrate an efficiency of 16.5%. When illuminated through the semitransparent perovskite cell, a near‐infrared‐enhanced silicon heterojunction solar cell operates with 6.5% efficiency, leading to a total perovskite/silicon four‐terminal tandem efficiency of 23.0%. [ABSTRACT FROM AUTHOR]

NaYbF4:Tm@NaYF4:Yb/Er upconversion nanoparticles are synthesized and then integrated with light-sensitive nitric oxide (NO) donors (Roussin's black salt) to construct a novel near-infrared (NIR)-triggered on-demand NO delivery platform. This nanocompound can absorb 980 nm NIR photons, convert them into higher energy photons and then transfer the energy to the NO donors, resulting in an efficient release of NO. By manipulating the output power of the 980-nm NIR light, NO-concentration-dependent biological effects for cancer therapy can be fine-tuned, which is investigated and confirmed in vitro. High concentrations of NO can directly kill cancer cells and low concentrations of NO can act as a potent P-glycoprotein (P-gp) modulator to overcome multi-drug resistance (MDR) if combined with chemotherapy. [ABSTRACT FROM AUTHOR]

Hollow-structured nanomaterials with fluorescent properties are extremely attractive for image-guided cancer therapy. In this paper, sub-100 nm and hydrophilic NaYF4 upconversion (UC) hollow nanospheres (HNSs) with multicolor UC luminescence and drug-delivery properties were successfully prepared by a facile one-pot template-free hydrothermal route using polyetherimide (PEI) polymer as the stabilizing agent. XRD, SEM, TEM, and N2-adsorption/desorption were used to characterize the as-obtained products. The growth mechanism of the HNSs has been systematically investigated on the basis of the Ostwald ripening. Under 980 nm excitation, UC emissions of HNSs can be tuned by a simple change of the concentration or combination of various upconverters. As a result, the PEI-coated HNSs could be used as efficient probes for in vitro upconversion luminescence (UCL) cell imaging. Furthermore, a doxorubicin storage/release behavior and cancer-cell-killing ability investigation reveal that the product has the potential to be a drug carrier for cancer therapy. [ABSTRACT FROM AUTHOR]

Ultrafast, high‐sensitivity, visible‐blind ultraviolet (UV) photodetectors are crucial for practical applications, including: optical communication, environmental ozone hole monitoring, and combustion and chemical detection. However, commercial visible‐blind UV photodetectors based on traditional inorganic semiconductor materials involve expensive production processes, while the currently solution‐processed detectors still suffer from issues of low sensitivity or slow response speed. Herein, high‐performance visible‐blind UV photodetectors with simultaneously ultrafast response speed and high detectivity are achieved from solution‐processed micrometer‐thick methylammonium lead trichloride perovskite thin single crystals, grown in high quality with smooth surfaces by judiciously designing the substrate's wettability. The as‐fabricated UV photodetectors exhibit a low noise of 6.5 fA Hz−1/2, a low detection limit of 8.5 pW cm−2, and high specific detectivity of ≈6 × 1012 Jones. A fast response time of 15 ns and a large bandwidth of 25 MHz are obtained when decreasing the crystal thickness to 1 µm. The nanosecond response speed is several orders of magnitude faster than the best ever reported solution‐processed visible‐blind UV photodetectors and is comparable to reported UV photodetectors based on traditional (high‐temperature processed) inorganic semiconductors. The high performance combined with low‐cost fabrication makes these visible‐blind UV photodetectors highly attractive for applications in optical communication and ultrafast detection. [ABSTRACT FROM AUTHOR]

Drug Delivery Hollow ‐ structured nanomaterials with fluorescent properties are extremely attractive for image ‐ guided cancer therapy. In their Full Paper on page 1655   ff. (highlighted on the Back Cover), Wenyan Yin, Zhanjun Gu, Yuliang Zhao et   al. report the fabrication of water ‐ soluble NaYF4 upconversion (UC) hollow nanospheres (HNSs) below 100   nm in size by a facile, one ‐ pot, template ‐ free synthetic route. The UC HNSs are formed through a gas ‐ bubble ‐ assisted Ostwald ripening mechanism under hydrothermal conditions. In vitro UC luminescence cell imaging data, doxorubicin storage/release, and analysis of their therapeutic effects reveal that the UC HNSs could potentially be applied for image ‐ guided drug delivery. [ABSTRACT FROM AUTHOR]