In the SCR systems of heavy-duty diesel engines, urea deposits formed under real operating conditions differ significantly from laboratory-prepared samples in morphology, composition, and structure. Under real operating conditions, the urea solution undergoes multiple dynamic deposition cycles, forming dense and compositionally complex stubborn deposits. Conventional laboratory methodssuch as single evaporation or single-layer liquid film modelsfail to replicate this process. To address this limitation, this study proposes a multilayer liquid-film heating crystallization method. The method is used to investigate the fundamental differences between crystallization on pre-existing crystal layers and static single-layer crystallization. Crystals derived from single-layer and multilayer liquid films of equivalent total thickness were analyzed using thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results indicate that (1) the first urea crystal layer in multilayer crystallization impedes heat transfer to the second liquid film, promoting the formation of lower-temperature crystal components; (2) multilayer urea crystals require higher temperatures for thermal decomposition compared to single-layer crystals; (3) when the temperature decreases (with the first layer's crystallization temperature being not lower than the heating temperature of the second layer), the crystal mass from multilayer crystallization exceeds that from single-layer crystallization of equivalent liquid film thickness; (4) multilayer crystallization, involving secondary deposition and a superimposed thermal history, facilitates the development of ordered columnar or layered microstructures with relatively clean surfaces.
Understanding how crystal fields modify local nonlinear optical responses is essential for the rational design of acentric ionic organic crystals. Here, we investigate a structurally diverse set of noncentrosymmetric push-pull ionic crystals, including classical stilbazolium benchmarks and 6MNEP-related GUR/GUS crystals identified by their CCDC refcodes, to evaluate how electrostatic embedding affects the dipole moment and total static first hyperpolarizability (βtot) of asymmetric units. A self-consistent electrostatic-embedding approach combined with density functional theory (DFT) and time-dependent-DFT (TD-DFT) calculations was used to compare isolated and in-crystal ion-pair responses within a consistent local-descriptor framework. The results show that the crystal field does not act as a uniform amplifier or suppressor of βtot. Instead, its effect depends on the local electrostatic environment, ion-pair organization, and tensor-component balance. Classical stilbazolium salts generally retain large embedded hyperpolarizabilities, with DAPSH, DSTMS, DSCHS, and DSNS-1 among the most responsive systems. In contrast, most 6MNEP-related GUR/GUS crystals show substantial attenuation of βtot upon embedding, while DSCHS, DSNS-1, and the structurally related MBST salt display enhanced embedded responses relative to their isolated counterparts. These results indicate that favorable local crystal-field alignment and contact patterns can reinforce, rather than suppress, the molecular response in selected cases. Overall, explicit crystal embedding provides a useful comparative strategy for analyzing how ion-pair composition and lattice organization modulate local dipolar and hyperpolarizability descriptors in ionic organic Organic nonlinear optical (NLO) crystals.
As the dominant dosage form in clinical practice of TCM, solid preparations face core challenges concerning quality stability and consistent therapeutic efficacy. Clinical observations have revealed efficacy variations among different preparation forms of the same TCM or even among products of the same preparation from different manufacturers. Such variations are attributed not only to the complexity of the production process but also to the physicochemical states of the drug substances, among which crystal forms likely serve as a critical factor influencing the drug state and subsequent efficacy divergence. TCM crystal forms, as a fundamental microscopic attribute of active ingredients in TCM, directly determine physicochemical properties and biological activities of drugs, representing a root cause of quality fluctuation and efficacy variation. Currently, significant progress has been made in the study of TCM crystal forms based on TCM active ingredients and compound preparations. A comprehensive technical framework encompassing preparation, characterization, and property analysis has been established. Its core value lies in revealing the scientific essence of "identical composition but heterogeneous activity", and it is expected to provide quantitative and precise technical support for quality control across the entire TCM industry chain. However, research on the crystal forms of TCM solid preparations remains a major challenge. Whether it concerns the discovery, characterization, and identification of preferred crystal forms in Chinese patent medicines, or the quality control of crystal forms of Chinese patent medicines and their impact on clinical efficacy, these areas remain largely unexplored territory awaiting further investigation. This article proposed the crystal form issues in TCM solid preparations. It comprehensively reviewed the research landscape of TCM crystal forms, spanning from single components to compound preparations, systematically elucidated the associated technical systems and category characteristics of TCM crystal forms, and innovatively proposed a crystal form-based strategy for quality control. This perspective provides a novel research framework for enhancing the quality control of TCM solid preparations and discovering new formula-derived nanoparticle drugs, holding significant importance for enhancing the standardization of TCM solid preparations, ensuring clinical efficacy, and advancing the development of TCM nanoscience.
The crystal-Stellate interaction is the first known example of piRNA-mediated regulation between heterochromatin (the crystal/Suppressor of Stellate [Su(Ste)] locus on the Y chromosome) and euchromatin (the Stellate locus on the X chromosome) in Drosophila melanogaster. Here, we comprehensively annotate the Y-linked crystal/Su(Ste) sequences using Release 6 and heterochromatin-enriched scaffolds and contigs. In Release 6, we mapped two distinct crystal/Su(Ste) repeat regions with different molecular organizations. Beyond the ordered, tandem "classical" region, we identified a novel, disorganized region containing sequence fragments in both orientations derived from both crystal/Su(Ste) repeats and transposable elements. This disorganized locus displays structural features of a piRNA cluster that regulates both Stellate repeats and transposons. Furthermore, we identified at least four additional loci with organized crystal/Su(Ste)-like repeats within heterochromatin-enriched sequences not included in Release 6. We also conducted a detailed examination of the complex relationship between Release 6 sequences and more recent scaffolds and contigs. Alongside the classic crystal/Su(Ste) repeat containing hoppel/1360 fragments, we discovered two new repeat types structurally organized like crystal/Su(Ste) but carrying portions of HetA and gypsy12 transposons. Overall, these findings provide structural insights into the crystal-Stellate system, refining the Drosophila melanogaster Y chromosome map.
Proteins are increasingly used to guide the crystallization of metal-organic frameworks (MOFs), yielding protein@MOFs (p@MOFs) that encapsulate fragile biomacromolecules within stable crystalline hosts. These biohybrid materials offer tunable porosity and spatial organization that are difficult to achieve with conventional synthesis. Despite their growing importance, the mechanisms by which proteins influence MOF nucleation, crystal growth, and defect formation remain poorly understood. Here, we use a distributed electron microscopy approach to follow the full crystallization pathway of ferritin@ZIF-8 (Fn@ZIF-8). The method combines cryogenic transmission electron microscopy (cryo-TEM), cryogenic electron tomography (cryo-ET), and liquid-phase TEM (LP-TEM) to capture structural transitions over time. Using the ferritin iron oxide core as an intrinsic nanoscale tracer, we visualize the transformation of protein-rich amorphous precursors into crystalline particles that ripen, aggregate, and develop large, surface-accessible cavities. These cavities emerge only during later stages of growth, where localized dissolution and recrystallization restructure the framework. Concurrently, proteins become enriched near the crystal periphery and depleted from cavity-rich regions. Our results suggest that protein organization and dissolution-driven restructuring both contribute to defect formation. This work provides a mechanistic framework for understanding how hierarchical porosity develops in p@MOFs and establishes distributed electron microscopy as an approach for investigating biohybrid crystallization pathways.
We investigate the stability of crystalline undulator radiation (CUR) peaks emitted by 530 MeV positron channelling in periodically bent C(110) crystals with varying bending amplitudes and bending periods. Relativistic molecular dynamics simulations were performed to quantify how these parameters affect the intensity and position of the CUR peak. The continuous potential approximation was used to identify isolines of constant peak energy, providing a reference for regions of spectral stability. MD results show that increasing the bending amplitude shifts the CUR peak to lower photon energies, while decreasing the period shifts it to higher energies, with both trends accompanied by enhanced dechannelling. For crystal parameters similar to recent experiments conducted at the Mainz Mikrotron (MAMI), the simulated CUR peak appears near 0.515 MeV. These results demonstrate that the CUR peak remains stable across a broad range of bending amplitudes and periods, providing quantitative estimates of the sensitivity of the emitted radiation to variations in the crystal bending parameters. Spectral distributions of crystalline undulator radiation for 530 MeV positrons for different bending profiles. The top row corresponds to the emission cone θ 0 = 133.8 μ rad ≈ 0.139 / γ , and the bottom row 5 / γ ≈ 4821 μ rad . The left column corresponds to a bending period of λ = 8.0 μ m , the middle column 6.5 μ m , and the right column 5.0 μ m . All cases show the same range of bending amplitudes a. The online version contains supplementary material available at 10.1140/epjd/s10053-026-01227-7.
Selective laser sintering (SLS) of polyamide 12 (PA12) generates large quantities of thermally aged powder whose altered crystallization behavior limits its complete reuse in additive manufacturing. In the present study, the feasibility of repurposing SLS-degraded PA12 powder in conventional melt-processing techniques is investigated. Thermo-analytical, diffraction, spectroscopic, and microscopic techniques were employed to investigate the crystallization kinetics, crystal morphology, and mechanical properties of PA12 materials prepared from different SLS-processed powder grades, namely nondegraded (as purchased), degraded (recycled), and mixed (blended) PA12 powders. The mixed material (made from nondegraded and degraded powders in the weight ratio of 25/75) exhibited markedly slower crystallization, especially during isothermal and slow-cooling conditions, attributed to molecular incompatibility and impaired cocrystallization between long, irregular degraded chains and shorter nondegraded chains. Advanced kinetic modeling using the temperature-dependent M-catalytic Hoffman-Lauritzen framework confirmed increased nucleation barriers and distinct shifts in autocatalytic and growth-related kinetic parameters. Hot-stage microscopy further revealed distinct differences in the crystal growth kinetics, explaining the variable lamellae packing within forming spherulites. Mechanical properties of the melt-processed PA12 materials significantly differed below the glass transition temperature (T g) - stiffness of the degraded material increased, while it decreased for the mixture. On the contrary, above T g, the mechanical behavior was practically identical for the nondegraded material and for the blend with 75% of degraded material, which introduces an interesting alternative utilizing the SLS-processed PA12 powders in melting-based technologies, and provides guidance for optimizing compositions to balance processability, cost-effectiveness, and performance of the corresponding recycling.
Atmosphere evaporation crystallization of stannous sulfate (SnSO4) is constrained by low efficiency. Although negative-pressure evaporation accelerates solvent removal, the resulting abrupt increase in supersaturation often triggers uncontrolled explosive nucleation, forming irregular agglomerates with broad particle size distributions. To address this issue, this study proposes a novel synergistic ultrasonic-negative pressure crystallization strategy. Under optimized conditions (80 °C, 40 kHz, 107 W, 0.03 MPa, 150 rpm), the synergistic process achieved an exceptional 88.6 %±1.6 % efficiency and produced rod-shaped crystals with a uniform unimodal particle size distribution (D50 = 38.42 ± 0.27 μm). In-situ high-speed visualization revealed a unique transformation in bubble behavior under the synergistic field, negative pressure reduced the cavitation threshold, generating two distinct bubble populations-transient bubbles enhanced by negative pressure (boosting volumetric mass transfer) and stable oscillating bubbles (serving as heterogeneous nucleation sites). This study elucidates the effects of negative pressure coupled with ultrasonic on solution cavitation behavior and crystal growth, providing a theoretical foundation for controlled crystallization under negative-pressure and ultrasonic synergy.
This study employs microwave plasma chemical vapor deposition (MPCVD) to systematically investigate the synergistic effects of deposition temperature (793-925 °C) and methane concentration (0.5-2.0%) on the homoepitaxial growth of (111)-oriented single-crystal diamond. Through comprehensive characterization, the intrinsic relationships between process parameters and crystal surface morphology, crystalline quality, and internal stress were revealed. Results indicate that the growth rate increases significantly with rising temperature and methane concentration, reaching a maximum of 1.73 µm h-1. Under low temperature and low methane conditions, cracks and etch pits along the <110> direction were observed. These morphological features transitioned into wavy and eventually straight step-flow structures as process parameters were optimized, while sharp step structures emerged at high methane concentrations. XRD and Raman analyses demonstrated that samples grown in the medium-temperature range (861-875 °C) exhibited the best crystalline quality and the lowest stress, attributed to a balance between atomic migration capability and stress relaxation, which is crucial for high-quality epitaxial growth. This work provides key process windows and theoretical support for the controlled growth of (111) single-crystal diamond for electronic device applications.
The electronic properties of solids are determined by their crystal structure and electron interactions, giving rise to phenomena such as superconductivity, strange metals and correlated insulators. Many of these effects remain poorly understood, motivating efforts to create artificial crystals that mimic real materials while allowing controlled tuning of key parameters. Cold atoms in optical lattices offer flexibility but cannot reproduce the long-range Coulomb interactions and hopping present in solids. Solid-state systems naturally support these features, although they suffer from tunability and flexibility issues. Here we demonstrate a highly tunable artificial crystal formed by superimposing a periodic electrostatic potential onto a two-dimensional electron gas in a shallow GaAs quantum well. This engineered lattice exhibits a band structure characteristic of the artificial triangular lattice, distinct from that of the underlying cubic crystal. Electronic transport measurements show a sign change in the Hall coefficient as the chemical potential sweeps through the artificial bands. The band structure can be continuously tuned to realize linear graphene-like and flat kagome-like bands within a single device. A strong insulating state emerges at half filling of the kagome flat band, consistent with interaction-driven behaviour. This tunability provides an opportunity to explore correlated quantum states in a controlled setting.
As the power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) approaches the Shockley-Queisser theoretical limit, perovskite-based tandem solar cells (TSCs) have been widely recognized as a key pathway to surpass single-junction PSCs and enable next-generation high-performance photovoltaics. However, wide-bandgap (WBG) perovskites, particularly mixed-halide systems, still face significant challenges, including photoinduced phase segregation, high defect densities, and interfacial mismatches. These issues largely stem from their complex crystallization processes. This review describes how inhomogeneous crystallization of WBG perovskites underlies the following challenges: initial phase segregation, defect formation, and stability issues. Following this, a comprehensive review of recent advances in crystallization modulation was carried out. Strategies such as interface engineering, composition engineering, solvent engineering, process optimization, and additive engineering are discussed, with a focus on precisely modulating nucleation and growth to achieve high-quality WBG perovskites. Finally, the development of large-area fabrication of WBG perovskites and stability issues are summarized, and future research directions are outlined.
Achieving uniform and high-quality perovskite crystallization across large substrates is a prerequisite for transitioning perovskite solar cells (PSCs) from laboratory scale to industrial production. Herein, we systematically regulate perovskite crystallization kinetics by using polyfluoroarene molecules featured with distinct electronic effects. We demonstrate that 3,4,5-trifluorobenzonitrile (TFBN) containing a strong electron-withdrawing cyano group creates an electron-deficient conjugation system. This configuration enhances anion-π interactions with I- and forms strong coordination with Pb2+ framework. Synergizing with intermolecular hydrogen bonding, TFBN increases the effective nucleation barrier, converting rapid nucleation into a controlled, uniform growth process. Consequently, this multidimensional regulation yields pinhole-free perovskite films with significantly suppressed non-radiative recombination. The TFBN-optimized small area device (aperture area: 0.09 cm2) achieves a champion power conversion efficiency (PCE) of 27.01% along with a low non-radiative voltage loss of only 55 mV. Furthermore, we demonstrate excellent scalability, achieving PCEs of 25.56% for 1 cm2 (aperture area) cells, 24.51% for 14.63 cm2 (active area) modules, and 21.05% for 58.51 cm2 (active area) modules, respectively. Moreover, the resulting devices exhibit improved long-term operational stability under maximum power point tracking and thermal stress. Overall, this synergistic regulation approach provides molecular-level design principles for scalable fabrication of efficient and durable perovskite photovoltaics.
Transfer of energy and linear momentum between lattice vibrations via anharmonic coupling is an important concept in solid-state physics. However, it remained difficult to directly observe how angular momentum is exchanged and conserved among lattice modes, even though these processes are thought to play an important role in achieving magnetization equilibrium and in spin relaxation effects like the Einstein-de Haas effect. Here we demonstrate and coherently control angular momentum transfer between two lattice modes using the inverse process of anharmonic decay. The observed rotational phonon-phonon Umklapp scattering enforces the conservation of quantized crystal angular momentum, as dictated by the discrete rotational symmetry of the crystal. We thereby experimentally confirm the fundamental analogy between linear and angular momentum conservation in solids. Moreover, we establish axial nonlinear phononics as a promising handle for the ultrafast control of material properties.
Cyanobacteriochromes (CBCRs) are bilin-binding photoreceptors with remarkable spectral versatility. Using phycocyanobilin (PCB) as a chromophore, CBCRs regulate diverse light-dependent processes in cyanobacteria, ranging from photosynthesis to chromatic acclimation. Although extensive studies have uncovered multiple spectral tuning mechanisms in bilin-binding proteins, recent structural studies of far-red CBCRs suggest the existence of additional tuning strategies in both the 15Z and 15E states. Here we report crystal structures of the representative far-red CBCR Anacy_2551g3 in three distinct light-absorbing states, all of which adopt a compact all-syn PCB conformation. These structures demonstrate that 15Z/15E photoisomerization in Anacy_2551g3 involves minimal chromophore rotation relative to the GAF domain, in stark contrast to other characterized bilin-based photoreceptors. To investigate the molecular basis of its far-red absorption, we examined the protonation and tautomeric states of PCB in the Pfr state using resonance Raman (RR) spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Comparisons of experimental and calculated RR spectra support a bilin lactam as the predominant tautomeric form in the Pfr state. Integrating structural, spectroscopic, computational and mutational analyses, we propose that specific protein-chromophore interactions play critical roles in modulating chromophore conjugation beyond bilin coplanarity. Structural analyses further suggest a signaling model in which light regulation by Anacy_2551g3 is mediated through reversible switching between a high-affinity Pfr state and a low-affinity Po state that does not involve large chromophore motions. Together, these results provide new insights into how protein-chromophore coupling governs spectral tuning and light signaling in bilin-based photoreceptors. Bilins are widespread biological pigments that mediate photoreception, light harvesting, and photosynthesis across diverse light environments. In a phenomenon known as spectral tuning, the optical properties of bilin-binding proteins are profoundly influenced by protein-chromophore interactions. Mechanistic understanding of spectral tuning and light signaling is important not only for advancing fundamental knowledge of light-sensitive proteins but also for developing new engineering strategies in synthetic biology and biotechnology. Recently discovered cyanobacteriochromes (CBCRs) exhibit remarkable spectral diversity and structural versatility, providing excellent model systems for dissecting the mechanisms of bilin-based photoreceptors. By integrating crystallography, spectroscopy and computational methods, this work examines three distinct light absorbing states of a representative far-red CBCR. Our findings reveal previously unrecognized mechanisms of spectral tuning and light signaling, highlighting the critical roles of protein-chromophore coupling and electrostatic interactions in regulating photoreceptor function.
Mycobacterium haemophilum is an uncommon nontuberculous mycobacterium that primarily affects immunocompromised hosts and may present with cutaneous and musculoskeletal manifestations that mimic inflammatory or infectious disorders. Its specialized growth requirements often delay diagnosis, particularly in solid organ transplant recipients. A 59-year-old man with a history of deceased donor kidney transplantation presented with progressive bilateral ankle pain, lower extremity swelling, and painful nodular skin lesions. Initial evaluation suggested erythema nodosum and inflammatory arthritis, with nondiagnostic musculoskeletal imaging and arthrocentesis. Corticosteroid therapy resulted in only transient improvement. Persistent low-titer serum cryptococcal antigenemia with negative cerebrospinal fluid studies further complicated the diagnostic evaluation and prompted empiric fluconazole therapy. Progressive disease led to recurrent hospitalization and inability to bear weight. Initial synovial fluid aspiration demonstrated acid-fast bacilli, whereas repeat bilateral aspirations demonstrated concomitant monosodium urate crystals and acid-fast bacilli. Skin biopsy demonstrated rod-shaped acid-fast organisms with negative fungal staining. Routine cultures were unrevealing, but independent polymerase chain reaction testing performed at two reference laboratories identified M. haemophilum. Mycophenolate mofetil was withheld because of active infection, whereas tacrolimus therapy was continued with therapeutic drug monitoring. Prolonged multidrug antimicrobial therapy was individualized according to susceptibility testing and medication tolerance. Despite treatment-related complications, the patient experienced substantial clinical improvement with healing of cutaneous lesions, restoration of mobility, and preservation of kidney allograft function. This case highlights the diagnostic complexity of M. haemophilum infection in kidney transplant recipients. Simultaneous erythema nodosum-like lesions, crystal arthropathy, and persistent serum cryptococcal antigenemia obscured the diagnosis, whereas conventional microbiologic studies remained largely unrevealing. Early consideration of opportunistic nontuberculous mycobacterial infection and the use of molecular diagnostics may facilitate timely diagnosis and appropriate management in immunocompromised patients.
In this study, we have established an empirical 25Mg chemical shift scale for silicates based on experimentally determined isotropic shift δiso values for Mg sites in crystalline compounds spanning coordination numbers from four to eight. These data reveal a robust linear correlation between δiso and the average Mg-O bond distance in the coordination polyhedra, defining approximate δiso ranges of 50 to 30, 27 to 17, 17 to -5, and ≤ -15 ppm for MgIV, MgV, MgVI, and MgVIII environments, respectively. This scale is applied to a comprehensive slice-by-slice analysis of previously reported ultra-high field (35.2 T) 25Mg 3QMAS NMR spectra of three glasses of composition CaMgSi2O6, Na2MgSi3O8, and K2MgSi5O12, revealing a positive correlation between the quadrupolar coupling constant CQ and δiso within two structurally distinct Mg environments assignable to MgVI and MgIV. Quantitative analysis indicates that ∼70-75% of Mg is present as MgIV in all three glasses, yielding an average Mg-O coordination number of ∼4.6 for CaMgSi2O6 glass, in close agreement with the value of ∼4.4 reported in a recent isotope-substituted neutron diffraction study. The finding of the lack of any significant dependence of the Mg-O coordination number on the field strength of the second network modifying cation in these glasses is in sharp contrast with previous reports of a preference of Mg for fourfold coordination in silicate glasses containing low field strength alkali cations.
Fluorinated liquid crystal monomers (FLCMs) have been identified as emerging organic pollutants because of their persistence, bioaccumulation potential, and toxicity. They have been observed in various environmental matrices and have attracted significant public concern. However, research on the development of functional materials and reliable methods for the highly efficient extraction and sensitive determination of FLCMs for assessing the risk levels in soil remains limited. Herein, two types of pentadecafluorooctanoyl (PF)-functionalized hyper-crosslinked polymers (HCPs), namely HCPPF-TPB and HCPPF-TPC, were synthesized by a facile and cost-effective Friedel-Crafts reaction. HCPPF-TPB demonstrated superior extraction performance and was selected to prepare fiber coating for the efficient solid-phase microextraction (SPME) of FLCMs. In addition, the underlying adsorption mechanism was systematically revealed through experiments and density functional theory (DFT) calculations. Under optimal SPME conditions, HCPPF-TPB coated SPME fiber combined with gas chromatography-mass spectrometry (GC-MS) method was proposed for sensitive detection of nine FLCMs in soil, affording high enrichment factors (1091-1760), wide linear range (0.05-100 μg kg-1), and low detection limits (0.010-0.028 μg kg-1). This work provides a simple strategy for the synthesis of perfluoroalkyl-functionalized HCPs and offers a reliable method for the efficient extraction and sensitive quantification of FLCMs in complex environmental matrices, thus promoting the resolution of FLCMs critical problems in the environment.
Polymeric materials capable of undergoing reversible shape change can be used as soft actuators to create low-density, compliant machines. Liquid crystal elastomers (LCEs) are a promising class of soft actuators that undergo large, reversible shape change by heating and cooling, but the fabrication of these materials requires molecular alignment to be trapped by crosslinking. LCEs with dynamic crosslinks can dramatically simplify materials processing and allow for reprogramming of the material after synthesis. However, thermally labile dynamic crosslinks can break during actuation, leading to a degradation of actuator performance over time. Herein, we developed LCEs with dynamic crosslinks with well-separated actuation and processing temperature regimes. Diels-Alder (DA) crosslinks based on 3-substituted furans are more thermally stable, achieving an actuation strain of 35.2% ± 0.5% and an actuation stress of 213.7 ± 20.1 kPa. These values are higher than those obtained from DA bonds formed with 2-substituted furans, which have been commonly used in LCE systems with DA crosslinks. The introduction of 3-substituted furan allowed reversible actuation and improved thermal stability relative to 2-substituted furan, while maintaining reprogrammability and reprocessability. We leverage the combination of thermal stability and facile reprocessability to create multiple, dynamic diffraction gratings in a single material.
In this study, the simultaneous rheology and in situ microscopy measurements, as well as the microfluidic technique, were employed to investigate the dynamic formation law of the gelled system in waxy crude oil emulsions, the mesoscopic influencing factors of gel strength, and their corresponding mechanisms under different water cuts, stirring rates, and temperature conditions. The results show that the mesoscopic structural evolution of the emulsion follows a distinct three-stage pathway: wax crystal/water droplet monomers → homogeneous/heterogeneous aggregates → wax crystal-water droplet floc structure, and each evolutionary stage corresponds to the variation of the macroscopic storage modulus. During the structural evolution, emulsified water droplets act as filling units that strengthen the interfacial connection, and their specific surface area is the primary mesoscopic parameter affecting the structural strength of the gelled system, which directly determines the scale of the oil-water interface and the interfacial interaction between wax crystals and water droplets. Wax crystals constitute the continuous network skeleton of the gelled system, and their quantity governs the compactness and continuity of the three-dimensional floc structure, playing a more dominant role in the macroscopic gel strength. Individual regulation of either the specific surface area of water droplets or the quantity of wax crystals can significantly alter the gel strength of the system. The simultaneous optimization of the two parameters produces an obvious synergistic strengthening effect, leading to an exponential rise in gel strength; conversely, the rheological properties of the emulsion can be remarkably improved. The dual-phase synergistic enhancement and weakening model proposed from a topological perspective clarifies that the "small and abundant" mesoscopic morphology featured by high-specific-surface-area water droplets and a large number of wax crystals is the core cause for the strengthened gel structure and deteriorated rheological properties of the emulsion. This model can systematically explain the influence mechanisms of various working conditions on the gel strength of water-in-oil (W/O) waxy crude oil emulsions. The conclusions of this research are well applicable to waxy crude oil emulsions characterized by high saturates, low aromatics, and low heavy polar components, and can provide theoretical references for the rheological regulation and pipeline transportation optimization of waxy crude oil emulsions.
Vacuum-deposited perovskite emitters provide precise control over thickness and composition, making them inherently compatible with established organic light-emitting diode evaporation infrastructure. However, vacuum deposition suffers from limited crystallization control compared with solution processing, which usually results in suboptimal device performance. The external quantum efficiency (EQE) of near-infrared vacuum-deposited perovskite LEDs remains approximately 10%. In particular, vacuum-deposited 3D perovskites typically undergo rapid nucleation and poor crystal growth, leading to defect-rich films with low photoluminescence quantum efficiencies (PLQEs). Although various passivation strategies have been explored to mitigate defect densities, the underlying growth processes and crystallization mechanisms under vacuum-deposition conditions remain insufficiently understood. Here we demonstrate an interlayer-directed crystallization strategy in a sequential vacuum deposition process, where a zwitterionic interlayer, 5-aminovaleric acid (5AVA), directs the self-assembly of perovskite precursors into oriented submicron-scale domains. This approach produces high-quality perovskite films with significantly enhanced PLQE and improved morphology. Perovskite light-emitting diode (PeLED) fabricated via this route achieves a record EQE of 16.6% with a high radiance of 224 W sr- 1 m- 2. These findings establish interlayer-directed crystallization as a promising strategy for efficient vacuum deposited PeLEDs, showing potential in industrial evaporation technologies.