For a century ferroelectricity has attracted widespread interest from science and industry. Inorganic ferroelectric ceramics have dominated multibillion dollar industries of electronic ceramics, ...ranging from nonvolatile memories to piezoelectric sonar or ultrasonic transducers, whose polarization can be reoriented in multiple directions so that they can be used in the ceramic and thin-film forms. However, the realization of macroscopic ferroelectricity in the polycrystalline form is challenging for molecular ferroelectrics. In pursuit of low-cost, biocompatible, and mechanically flexible alternatives, the development of multiaxial molecular ferroelectrics is imminent. Here, from quinuclidinium perrhenate, we applied fluorine substitution to successfully design a multiaxial molecular ferroelectric, 3-fluoroquinuclidinium perrhenate (3-F-QReO4), whose macroscopic ferroelectricity can be realized in both powder compaction and thin-film forms. The fluorination effect not only increases the intrinsic polarization but also reduces the coercive field strength. More importantly, it is also, as far as we know, the softest of all known molecular ferroelectrics, whose low Vickers hardness of 10.5 HV is comparable with that in poly(vinylidene difluoride) (PVDF) but almost 2 orders of magnitude lower than that in BaTiO3. These attributes make it an ideal candidate for flexible and wearable devices and biomechanical applications.
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IJS, KILJ, NUK, PNG, UL, UM
Materials with circularly polarized luminescence (CPL) activity have immense potential applications in molecular switches, optical sensors, information storage, asymmetric photosynthesis, 3D optical ...displays, biological probe, and spintronic devices. However, the achiral architectures of most of the luminophores severely limit their practical needs. Within this context, molecular ferroelectrics with striking chemical variability and structure–property flexibility bring light to the assembly of CPL-active ferroelectric materials. Herein, we report organic–inorganic perovskite enantiomorphic ferroelectrics, (R)- and (S)-3-(fluoropyrrolidinium)MnBr3, undergoing a 222F2-type ferroelectric phase transition at 273 K. Their mirror relationships are verified by both single-crystal X-ray diffraction and vibrational circular dichroism (VCD). Furthermore, the corresponding Cotton effect for two chiral crystals was captured by mirror CPL activity. This may be assigned to the inducing interaction between the achiral luminescent perovskite framework and chiral organic components. As far as we know, this is the first molecular ferroelectric with CPL activity. Accordingly, this will inspire intriguing research in molecular ferroelectrics with CPL activity and holds great potential for the development of new optoelectronic devices.
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Organic–inorganic hybrid perovskite‐type multiferroics have attracted considerable research interest owing to their fundamental scientific significance and promising technological applications in ...sensors and multiple‐state memories. The recent achievements with divalent metal dicyanamide compounds revealed such malleable frameworks as a unique platform for developing novel functional materials. Herein, two 3D organic–inorganic hybrid perovskites Et3P(CH2)2FMn(dca)3 (1) and Et3P(CH2)2ClMn(dca)3 (2) (dca=dicyanamide, N(CN)2−) are presented. Accompanying the sequential phase transitions, they display a broad range of intriguing physical properties, including above room temperature ferroelastic behavior, switchable dielectricity, and low‐temperature antiferromagnetic ordering (Tc=2.4 K for both 1 and 2). It is also worth noting that the spontaneous strain value of 1 is far beyond that of 2 in the first ferroelastic phase, as a result of the precise halogen substitution. From the point view of molecular design, this work should inspire further exploration of multifunctional molecular materials with desirable properties.
Ferroelastic behavior: By using halogen substitution, two 3D organic–inorganic hybrid perovskite‐type materials Et3P(CH2)2FMn(dca)3 (1) and Et3P(CH2)2ClMn(dca)3 (2) (dca=dicyanamide, N(CN)2−, see figure) are reported. These materials display a broad range of intriguing physical properties, including above room temperature ferroelastic behavior, switchable dielectricity, and low‐temperature antiferromagnetic ordering.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Single‐crystalline diamond wafers are synthesized, and all‐carbon solar‐blind photodetectors are constructed based on the diamond with interdigitated graphite as electrodes. The graphite electrodes ...are made by laser‐induced graphitization of the diamond. The peak responsivity of the photodetector is 21.8 A W−1, and detectivity is 1.39 × 1012 cm Hz1/2 W−1 when the bias voltage is 50 V, it is noted that both of these are among the best values ever reported for diamond‐based photodetectors. The photodetectors are employed as the sensing pixels in an imaging system, and a clear image is obtained, which is the first report on solar‐blind imaging of diamond photodetectors. The results reported in this paper provide a facile approach to high‐performance diamond solar‐blind photodetectors and their applications in solar‐blind imaging, thus may address a significant step toward the preparation and application of diamond photodetectors.
All‐carbon solar‐blind photodetectors are constructed based on single‐crystalline diamond with interdigitated graphite as electrodes, which are realized by laser‐induced local graphitization of the diamond. The photodetectors can be employed as the sensing pixels in an imaging system, and a clear image is obtained, which is the first report on solar‐blind imaging of diamond‐based photodetectors.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Conus, a highly diverse species of venomous predators, has attracted significant attention in neuroscience and new drug development due to their rich collection of neuroactive peptides called ...conotoxins. Recent advancements in transcriptome, proteome, and genome analyses have facilitated the identification of conotoxins within Conus' venom glands, providing insights into the genetic features and evolutionary patterns of conotoxin genes. However, the underlying mechanism behind the extraordinary hypervariability of conotoxins remains largely unknown. We analyzed the transcriptomes of 34 Conus species, examining various tissues such as the venom duct, venom bulb, and salivary gland, leading to the identification of conotoxin genes. Genetic variation analysis revealed that a subset of these genes (15.78% of the total) in Conus species underwent positive selection (Ka/Ks > 1, p < 0.01). Additionally, we reassembled and annotated the genome of C. betulinus, uncovering 221 conotoxin-encoding genes. These genes primarily consisted of three exons, with a significant portion showing high transcriptional activity in the venom ducts. Importantly, the flanking regions and adjacent introns of conotoxin genes exhibited a higher prevalence of transposon elements, suggesting their potential contribution to the extensive variability observed in conotoxins. Furthermore, we detected genome duplication in C. betulinus, which likely contributed to the expansion of conotoxin gene numbers. Interestingly, our study also provided evidence of introgression among Conus species, indicating that interspecies hybridization may have played a role in shaping the evolution of diverse conotoxin genes. This study highlights the impact of adaptive evolution and introgressive hybridization on the genetic diversity of conotoxin genes and the evolution of Conus. We also propose a hypothesis suggesting that transposable elements might significantly contribute to the remarkable diversity observed in conotoxins. These findings not only enhance our understanding of peptide genetic diversity but also present a novel approach for peptide bioengineering.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The accurate prediction of ship trajectory has great significance in maritime transportation. Among all the prediction methods, multi-step prediction has received increasing attention because it can ...predict both time and position information in the future period. However, the existing methods are either complex or have low prediction accuracy. In order to overcome the limitations, a physical hypothesis is introduced to balance the complexity and the accuracy. The cubic spline interpolation and historical trajectories are used to realize it. The advantages of TPNet and LSTM are combined in the proposed method and four parts are involved: the AIS data preprocessing method, the solutions of destination point and support point, and the uncertainty analysis. The proposed method is not only easy to implement and suitable for real-time analysis, but also has a high prediction accuracy. The case study on a ferry ship in the Jiangsu section of the Yangtze River indicates the validity of the method.
•Complex mapping relationships and large data requirements for multi-step prediction is solved.•A physical constraint is used in the construction of the model.•An automatic generation method of reference trajectory based on ship motion parameters is proposed.•The effectiveness of the method is verified by making predictions under four different navigation states.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Freestanding and flexible graphene/polyaniline composite paper was prepared by an in situ anodic electropolymerization of polyaniline film on graphene paper. This graphene-based composite paper ...electrode, consisting of graphene/polyaniline composite sheets as building blocks, shows a favorable tensile strength of 12.6 MPa and a stable large electrochemical capacitance (233 F g−1 and 135 F cm−3 for gravimetric and volumetric capacitances), which outperforms many other currently available carbon-based flexible electrodes and is hence particularly promising for flexible supercapacitors.
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Mesoporous carbon with homogeneous boron dopant was prepared by co-impregnation and carbonization of sucrose and boric acid confined in mesopores of SBA-15 silica template. Low-level boron doping ...shows catalytic effect on oxygen chemisorption at edge planes and alters electronic structure of space charge layer of doped mesoporous carbon. These characteristics are responsible for substantial improvement of interfacial capacitance by 1.5−1.6 times higher in boron-doped carbon than that in boron-free carbon with alkaline electrolyte (6 M KOH) and/or acid electrolyte (1 M H2SO4). This finding should be very useful for developing new doped carbon electrode materials for supercapacitors.
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Piezoelectric sensors that can work under various conditions with superior performance are highly desirable with the arrival of the Internet of Things. For practical applications, a large ...piezoelectric voltage coefficient g and a high Curie temperature T c are critical to the performance of piezoelectric sensors. Here, we report a two-dimensional perovskite ferroelectric (4-aminotetrahydropyran)2PbBr4 (ATHP)2PbBr4 with a saturated polarization of 5.6 μC cm–2, high T c of 503 K above that of BaTiO3 (BTO, 393 K), and extremely large g 33 of 660.3 × 10–3 V m N–1 much beyond that of Pb(Zr,Ti)O3 (PZT) ceramics (20 to 40 × 10–3 V m N–1), more than 2 times higher than that of poly(vinylidene fluoride) (PVDF, about 286.7 × 10–3 V m N–1). Combined with the advantages of molecular ferroelectrics, such as light weight, easy and environmentally friendly processing, and mechanical flexibility, (ATHP)2PbBr4 would be a competitive candidate for next-generation smart piezoelectric sensors in flexible devices, soft robotics, and biomedical devices.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
Artificially performing chemical reactions in living biosystems to attain various physiological aims remains an intriguing but very challenging task. In this study, the Schiff base reaction ...was conducted in cells using Sc(OTf)
3
as a catalyst, enabling the in situ synthesis of a hollow covalent organic polymer (HCOP) without external stimuli. The reversible Schiff base reaction mediated intracellular Oswald ripening endows the HCOP with a spherical, hollow porous structure and a large specific surface area. The intracellularly generated HCOP reduced cellular motility by restraining actin polymerization, which consequently induced mitochondrial deactivation, apoptosis, and necroptosis. The presented intracellular synthesis system inspired by the Schiff base reaction has strong potential to regulate cell fate and biological functions, opening up a new strategic possibility for intervening in cellular behavior.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
