Despite increasing interest in the molecular mechanisms of floral diversity, few studies have investigated the developmental and genetic bases of petaloid bracts. This study examined morphological ...patterns of bract initiation and expression patterns of B-class MADS-box genes in bracts of several Cornus species. We suggest that petaloid bracts in this genus may not share a single evolutionary origin.
Developmental pathways of bracts and spatiotemporal expression of B-class genes in bracts and flowers were examined for four closely related dogwood species.
Divergent morphological progressions and gene expression patterns were found in the two sister lineages with petaloid bracts, represented by Cornus florida and Cornus canadensis. Phylogeny-based analysis identified developmental and gene expression changes that are correlated with the evolution of petaloid bracts in C. florida and C. canadensis.
Our data support the existence of independent evolutionary origins of petaloid bracts in C. canadensis and C. florida. Additionally, we suggest that functional transference within B-class gene families may have contributed to the origin of bract petaloidy in C. florida. However, the underlying mechanisms of petaloid bract development likely differ between C. florida and C. canadensis. In the future this hypothesis can be tested by functional analyses of Cornus B-class genes.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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•PPL was immobilized on organic-inorganic nanocomposites.•Immobilized PPL showed high immobilization yield and activity recovery.•Immobilized PPL exhibited superior environmental ...tolerance and stability.•Immobilized PPL presented improved reusability.
An organic–inorganic nanocomposite which combined mesoporous silica SBA-15 and chitosan using a carboxyl functionalized ionic liquid as the bridging agent (SBA@CS) was successfully fabricated, and was used to immobilize porcine pancreas lipase (PPL) by physical adsorption, cross-linking and metal–organic coordination, respectively. The as-prepared carriers were characterized by scanning electron microscopy, Fourier transform infrared and energy-dispersive X-ray spectroscopy. Compared with immobilization onto the pure mesoporous silicon material SBA-15, all the batches of PPL immobilized onto organic–inorganic nanocomposites showed higher activity, improved stability and reusability as well as better resistance to pH and temperature changes. Among the immobilized PPLs, immobilization based on Co2+ coordination (SBA@CS-Co-PPL) produced the best enzymatic properties. The maximum immobilization efficiency and specific activity of 79.6% and 1975.8 U g−1 were obtained with SBA@CS-Co, separately. More importantly, the activity of immobilized enzyme can still maintain 84.0% after 10 times of reuse. These results demonstrated that thus prepared organic–inorganic nanocomposite could be an ideal carrier for enzyme immobilization by metal–organic coordination.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the last two decades, nanogenerators have been studied inorder to solve the power supply problems of electronic devices. Triboelectric nanogenerators (TENGs) have gained widespread attention due ...to their excellent properties and wide range of applications. However, previous studies frequently ignored numerous application-related issues and even wasted some of the benefits of the TENG itself in favor of enhanced performance. Here, we propose a TENG based on BaTiO
3
(BTO)-polydimethylsiloxane (PDMS) composite films with low cost and simple preparation, where its maximum output performance is obtained when the mass proportion of BTO to PDMS is 40%. In addition, we demonstrate how the single-electrode TENG may be used as a self-powered touch sensor that can communicate with a microcontroller unit (MCU) to turn LED lights on and off. This practical example will provide a valuable reference for the application of low-cost self-powered sensors in wearable devices, Internet of Things, human-machine interactions and other fields. Furthermore, we discovered a number of issues that were rarely or never addressed in previous studies and provide some solutions, such as a signal processing method for a TENG-based self-powered sensor. It serves as a foundation for future investigations on the performance assessment and application of TENGs.
The signal of a self-powered touch sensor based on a TENG is processed to control LEDs.
The unique properties and great variety of relaxer ferroelectrics make them highly attractive in energy-storage and solid-state refrigeration technologies. In this work, lanthanum modified lead ...titanate ceramics are prepared and studied. The giant electrocaloric effect in lanthanum modified lead titanate ceramics is revealed for the first time. Large refrigeration efficiency (27.4) and high adiabatic temperature change (1.67 K) are achieved by indirect analysis. Direct measurements of electrocaloric effect show that reversible adiabatic temperature change is also about 1.67 K, which exceeds many electrocaloric effect values in current direct measured electrocaloric studies. Both theoretical calculated and direct measured electrocaloric effects are in good agreements in high temperatures. Temperature and electric field related energy storage properties are also analyzed, maximum energy-storage density and energy-storage efficiency are about 0.31 J/cm
and 91.2%, respectively.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
(Pb1−xBax)ZrO3 (x = 0, 0.025, 0.05, 0.075, 0.1) ceramics were synthesized by a traditional solid‐state reaction method, and the pure phase was obtained of all sintered samples. For all compositions, ...substitution of Pb2+ by Ba2+ reduced the phase transition temperature of antiferroelectric to ferroelectric and Curie temperature. Polarization–electric field hysteresis loops were conducted and typical ferroelectric hysteresis loops were observed in higher temperature range. Impedance and dielectric measurements were studied on the high temperature relaxation. Relaxation behavior could be suppressed after annealing treatment in oxygen atmosphere. Value of activation energy calculated from impedance was lower than that calculated from conduction measurements. It was concluded that short‐range hopping of oxygen vacancy contributes to the dielectric relaxation and long‐distance movement of doubly ionized oxygen vacancies contributes to the conduction.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
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•Tin doping significantly improves the energy storage performance of PbHfO3 ceramics.•PbHf0.925Sn0.075O3 ceramics achieve high recoverable energy density of 10.1 J/cm3.•The ...outstanding charge–discharge performance is closer to the practical application.•The discharge energy density and rate(t0.9) were 7.81 J/cm3 and 360 ns, respectively.•The discharge current and power density were 1556A/cm2 and 233 MW/cm3, respectively.
Dielectric capacitors with high energy density, high power density, fast charging-discharge rate and good thermal stability have potential applications in advanced electronics and electric power systems. In this work, the PbHf1-xSnxO3 (PHS) antiferroelectric (AFE) ceramics are prepared via solid-state method. The field-induced AFE to ferroelectric transitions are observed in polarization–electric field (P-E) hysteresis loops. The energy storage capacity increases due to the increase of AFE-ferroelectric switching field despite the field-induced ferroelectric polarization decreases. A high recoverable energy storage density of 10.2 ± 0.4 J/cm3 with high energy efficiency of 78.9% is achieved at 320 kV/cm for x = 0.075 (PHS-0.075) ceramic, which is superior to other systems reported recently. Furthermore, the sample also exhibits excellent stability against testing temperature and frequency. The pulsed charge–discharge process is measured to elucidate the actual operation performance in the PHS ceramic. The PHS-0.075 ceramic possesses a high current density of 1556 A/cm2, a giant power density of 233 MW/cm3 and a fast discharge rate (t0.9 < 360 ns). Delightfully, a remarkable discharge energy density of 7.81 J/cm3 is obtained at 300 kV/cm, which is closer to the actual result for the capacitors operating. This great improvement gives a guideline to further promote the commercialization of AFE materials for energy storage applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
East Asian subtropical evergreen broad-leaved forests (EBLFs) are composed of western and eastern subregions with different topographical and environmental conditions. The distribution shifts over ...time of plants in the two subregions are predicted to be different, but the difference has seldom been investigated.
Potential distributions of 53 Magnoliaceae species (22 in the western and 31 in the eastern subregion) during the last glacial maximum (LGM), present, and the 2070s were predicted using MaxEnt based on 58 environmental variables. The changes in the distribution range size and centroid over time were analyzed. Species-level potential habitats were overlaid to uncover species diversity distribution, and the distributions over time were overlaid to discover long-term refugia.
At present, the potential distributions are significantly larger than those shown by the occurrence points. During the LGM, 20/22 species in the western subregion experienced increases in range size through downwards and southward migrations, while decreases in range size in the eastern subregion (27/31 species) were accompanied by northward and eastward migrations. In the future, range size declines and northward shifts will both be found; northwestward shifts will exist in most (20/22 species) species in the western subregion, while both northwest- and northeastward shifts will occur in the eastern subregion. The diversity hotspots experienced a slight southward shift in the past and upwards to the mountain region in the future in the western subregion; in the eastern subregion, shrinks occurred in eastern China in the past and shrinks were shown in all regions in the future. Long-term refugia-preserving diversity was found in the mountains across the entire EBLFs region.
Significant differences in distribution shifts from past to present and similar distribution shifts from present to future are revealed in the two subregions. Species diversity in both subregions experienced no significant shifts from past to future, and Magnoliaceae plants could be preserved in mountainous regions throughout the EBLFs.
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•A multifunctional MXene-coated textile was prepared by a facile dip-coating method.•Lightly cross-linked PDMS network endowed the textile stable adhesive properties.•The adhesive ...textile showed good electro-/photo-thermal conversion performance.•The smart textile showed good electromagnetic interference shielding properties.•The adhesive textile showed stable pressure-sensing response for motion detection.
Adhesion between flexible devices and skin surface facilitates portability of devices and reliable signal acquisition from human body, which is essential for medical therapy devices or monitoring systems. Here, we utilize a simple, cost-effective, and scalable layer-by-layer dip-coating method to fabricate a skin-adhesive multifunctional textile-based device, consisting of three parts: low-cost and easily available airlaid paper (AP) substrate, conductive MXene sensitive layer, and adhesive polydimethylsiloxane (PDMS). The adhesive layer of lightly cross-linked PDMS enables the device to form conformal contact with skin even during human joint bending. The smart textile device exhibits excellent electro-thermal and photo-thermal conversion performance with good cycling stability and tunability. Furthermore, the textile electronics show good electromagnetic interference (EMI) shielding properties due to the good electrical conductivity, as well as sensitive and stable pressure sensing properties for human motion detection. Consequently, this efficient strategy provides a possible way to design multifunctional and wearable electronic textiles for medical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and ...water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73 800 mol mol −1 h −1 . A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.
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