Hybrid metal halides (HMHs) based phase transition materials have received widespread attention due to their excellent performance and potential applications in energy harvesting, optoelectronics, ...ferroics, and actuators. Nevertheless, effectively regulating the properties of phase transitions is still a thorny problem. In this work, two chiral lead‐free HMHs (R‐3FP)2SbCl5 (1; 3FP=3‐fluoropyrrolidinium) and (R‐3FP)2SbBr5 (2) were synthesized. By replacing the halide ions in the inorganic skeleton, the phase transition temperature of 2 changes with an increase of about 20 K, compared with 1. Meanwhile, both compounds display reversible dielectric switching properties. Through crystal structure analysis and Hirshfeld surface analysis, their phase transitions are ascribed to the disorder of the cations and deformation of the inorganic chains.
This article reports a pair of 1D lead‐free hybrid metal halides: (R‐3FP)2SbCl5 (1; 3FP=3‐fluoropyrrolidinium) and (R‐3FP)2SbBr5 (2) exhibit high temperature triggered structural phase transition and dielectric switching properties. By halogen substitution in the inorganic framework, the dielectric switch temperature of 2 increased about 20 K, compared with 1.
Semiconductor quantum-well structures and superlattices are key building blocks in modern optoelectronics, but it is difficult to simultaneously realize defect-free epitaxial growth while fine tuning ...the chemical composition, layer thickness and band structure of each layer to achieve the desired performance. Here we demonstrate the modulation of the electronic structure-and consequently the optical properties-of organic semiconducting building blocks that are incorporated between the layers of perovskites through a facile solution processing step. Self-aggregation of the conjugated organic molecules is suppressed by functionalization with sterically demanding groups and single crystalline organic-perovskite hybrid quantum wells (down to one-unit-cell thick) are obtained. The energy and charge transfers between adjacent organic and inorganic layers are shown to be fast and efficient, owing to the atomically flat interface and ultrasmall interlayer distance of the perovskite materials. The resulting two-dimensional hybrid perovskites are very stable due to protection given by the bulky hydrophobic organic groups.
We report the effect of Bi3+ doping on both electron and phonon transport properties of BixCu1.8-xS (x = 0, 0.004, 0.01, 0.014, 0.02) superionic conductors. An enhanced ZT value in different degrees ...with x is mainly attributed to an improved electrical conductivity owing to an increased carrier mobility with an undegrated Seebeck coefficient when 0 ≤ x ≤ 0.01, and a reduced thermal conductivity to a low level (0.71–1.00 Wm−1K−1) at x = 0.02 benefiting by the formation of the low-conductive Cu3BiS3 and Cu1.96S second phases. The highest ZT value of 0.61 at 673 K obtained for the Bi0.01Cu1.79S (x = 0.01) sample, which is twice as large as that of the pure Cu1.8S sample. Our result indicates that the introduction of Bi3+ in thermoelectric materials is an effective and convenient strategy to improve ZT by improving the power factor and/or decreasing thermal conductivity.
•Subtle tailoring Bi3+ content in Cu1.8S improves the σ with an undegrated α.•The formation of the low-conductive second phases produces a low κ (0.71–1 Wm−1K−1).•The highest ZT up to 0.61 at 673 K is twice as large as that of the pure Cu1.8S.
Meaning in life can be understood as how much people experience life meaning (i.e., presence of meaning, POM) and how intensely they seek life meaning (i.e., search for meaning, SFM). Previous ...research has related POM and SFM to the subjective well-being (SWB) of individuals, but the findings are inconsistent. This meta-analysis investigates the overall relationship between POM/SFM and SWB by examining previous studies that have used Steger et al.’s (J Couns Psychol 53:80–93, 2006.
https://doi.org/10.1037/0022-0167.53.1.80
)
Meaning in Life Questionnaire
to assess POM and SFM. Results of 147 studies, reporting 726 effect sizes (
N
= 92,169), suggest the effect size for the “POM–SWB” relationship is close to medium (
ES
z
= .418,
p
< .001, 95% CI .390, .446). The effect is larger in life satisfaction and cross-sectional studies. The effect size for the “SFM–SWB” association is small (
ES
z
= − .121,
p
< .001, 95% CI − .155,− .087), with the effect being larger for negative affect, cross-sectional studies, and older participants. Interestingly, SFM is related to more SWB in participants from countries that are more collectivistic. This study shows a robust link between presence of life meaning and greater SWB, and that while search for life meaning may be adverse to SWB, the effect is small and conditional.
AgPbmSbTem+2 (abbreviation as LAST) is a promising thermoelectric material based on PbTe for mid-temperature applications. The electrical and thermal transport properties of LAST alloys are greatly ...affected by the formation of nanostructured precipitation depending on the processing conditions, especially for spark plasma sintering (SPS) combined with mechanical alloying (MA). This study was focused on the optimization of SPS temperature (TSPS) and found that its variation in a narrow range (100 K) leads to apparent differences of thermoelectric performances. The sample sintered at an optimized temperature (TSPS = 923 K) shows a low κtotal (0.829 Wm−1K−1) and a high PF (14.9 Wm−1K−2), which is mainly attributed to the nanoscale composition segregation of Ag and Sb. The highest ZT value of 1.28 at 773 K was obtained when TSPS = 923 K, along with the highest ZTeng value of 0.26 and the corresponding ηmax value of 5.8% at the range of 323 K (Tcold)–773 K (Thot), which were increased almost twice by the optimization of sintering temperature.
•Effect of sintering temperature (TSPS) is investigated for AgPbmSbTem+2 alloys.•The influence of composition segregation on its thermoelectric performance is proved.•The maximum ZT value of 1.28 was obtained at 773 K for optimized TSPS.•The ZTeng value was greatly enhanced due to formation of composition segregation.
Sodium metal anode (SMA) is one of the most favored choices for the next-generation rechargeable battery technologies owing to low cost and natural abundance. However, the poor reversibility resulted ...from dendrite growth and formation of unstable solid electrolyte interphase has significantly hindered the practical application of SMAs. Herein, we report that a nucleation buffer layer comprising elaborately-designed core-shell C@Sb nanoparticles (NPs) enables the homogenous electrochemical deposition of sodium metal for long-term cycling. These C@Sb NPs can increase active sites for initial sodium nucleation through Sb-Na alloy cores, and keep these cores stable through carbon shells. The assembled cells with this nucleation layer can deliver continuously repeated sodium plating/stripping cycles for nearly 6000 h at a high areal capacity of 4 mA h cm-2 with an average Coulombic efficiency 99.7%. This ingenious structure design of alloy-based nucleation agent opens up a promising avenue to stabilize sodium metal with targeted properties.
According to Modern-Era Retrospective Research Analysis for Research and
Applications (MERRA-2) temperature and wind datasets in 2019, this
study presents the global variations in the ...eastward-propagating wavenumber
1 (E1), 2 (E2), 3 (E3) and 4 (E4) planetary waves (PWs) and their diagnostic
results in the polar middle atmosphere. We clearly demonstrate the eastward
wave modes exist during winter periods with westward background wind in both
hemispheres. The maximum wave amplitudes in the Southern Hemisphere (SH) are
slightly larger and lie lower than those in the Northern Hemisphere (NH).
Moreover, the wave perturbations peak at lower latitudes with smaller
amplitudes as the wavenumber increases. The period of the E1 mode varies between 3–5 d in both hemispheres, while the period of the E2 mode is slightly longer in
the NH (∼ 48 h) than in the SH (∼ 40 h). The
periods of the E3 are ∼ 30 h in both the SH and the NH, and the period
of E4 is ∼ 24 h. Despite the shortening of wave periods with
the increase in wavenumber, their mean phase speeds are relatively stable, ∼ 53, ∼ 58, ∼ 55 and ∼ 52 m/s at 70∘ latitudes for E1, E2, E3 and
E4, respectively. The eastward PWs occur earlier with increasing zonal
wavenumber, which agrees well with the seasonal variations in the critical
layers generated by the background wind. Our diagnostic analysis also
indicates that the mean flow instability in the upper stratosphere and upper
mesosphere might contribute to the amplification of the eastward PWs.
The design and construction of flexible electrodes that can function at high rates and high areal capacities are essential regarding the practical application of flexible sodium‐ion batteries (SIBs) ...and other energy storage devices, which remains significantly challenging by far. Herein, a flexible and 3D porous graphene nanosheet/SnS2 (3D‐GNS/SnS2) film is reported as a high‐performance SIB electrode. In this hybrid film, the GNS/SnS2 microblocks serve as pillars to assemble into a 3D porous and interconnected framework, enabling fast electron/ion transport; while the GNS bridges the GNS/SnS2 microblocks into a flexible framework to provide satisfactorily mechanical strength and long‐range conductivity. Moreover, the SnS2 nanocrystals, which chemically bond with GNS, provide sufficient active sites for Na storage and ensure the cycling stability. Consequently, this flexible 3D‐GNS/SnS2 film exhibits excellent Na‐storage performances, especially in terms of high areal capacity (2.45 mAh cm−2) and high rates with superior stability (385 mAh g−1 at 1.0 A g−1 over 1000 cycles with ≈100% retention). A flexible SIB full cell using this anode exhibits high and stable performance under various bending situations. Thus, this work provide a feasible route to prepare flexible electrodes with high practical viability for not only SIBs but also other energy storage devices.
Ultraflexible 3D porous graphene nanosheet/SnS2 (3D‐GNS/SnS2) film, prepared from preassembled GNS/SnS2 microblocks, possesses a 3D porous graphene framework and a structure of SnS2 nanocrystals chemically bonded on GNS, which integrates fast ion/electron diffusion dynamics with robust utilization of active materials, thus leading to high areal capacity and high rate performance as flexible sodium‐ion battery anodes.
It is vital to dynamically regulate S activity to achieve efficient and stable room‐temperature sodium–sulfur (RT/Na−S) batteries. Herein, we report using cobalt sulfide as an electron reservoir to ...enhance the activity of sulfur cathodes, and simultaneously combining with cobalt single atoms as double‐end binding sites for a stable S conversion process. The rationally constructed CoS2 electron reservoir enables the straight reduction of S to short‐chain sodium polysulfides (Na2S4) via a streamlined redox path through electron transfer. Meanwhile, cobalt single atoms synergistically work with the electron reservoir to reinforce the streamlined redox path, which immobilize in situ formed long‐chain products and catalyze their conversion, thus realizing high S utilization and sustainable cycling stability. The as‐developed sulfur cathodes exhibit a superior rate performance of 443 mAh g−1 at 5 A g−1 with a high cycling capacity retention of 80 % after 5000 cycles at 5 A g−1.
Engineering CoS2 as electron reservoirs overcomes the limited length of the electron diffusion tunnel over an insulating sulfur cathode and thus achieves fast reaction kinetics in sodium–sulfur batteries. With the assistance of Co1 single atoms, this strategy provides streamlined redox paths, which reduce the formation of unstable polysulfides and enable stable sodium–sulfur batteries.
Cytochrome P450 1A (CYP1A), one of the most important phase I drug-metabolizing enzymes in humans, plays a crucial role in the metabolic activation of procarcinogenic compounds to their ultimate ...carcinogens. Herein, we reported the development of a ratiometric two-photon fluorescent probe NCMN that allowed for selective and sensitive detection of CYP1A for the first time. The probe was designed on the basis of substrate preference of CYP1A and its high capacity for O-dealkylation, while 1,8-naphthalimide was selected as fluorophore because of its two-photon absorption properties. To achieve a highly selective probe for CYP1A, a series of 1,8-naphthalimide derivatives were synthesized and used to explore the potential structure–selectivity relationship, by using a panel of human CYP isoforms for selectivity screening. After screening and optimization, NCMN displayed the best combination of selectivity, sensitivity and ratiometric fluorescence response following CYP1A-catalyzed O-demetylation. Furthermore, the probe can be used to real-time monitor the enzyme activity of CYP1A in complex biological systems, and it has the potential for rapid screening of CYP1A modulators using tissue preparation as enzyme sources. NCMN has also been successfully used for two-photon imaging of intracellular CYP1A in living cells and tissues, and showed high ratiometric imaging resolution and deep-tissue imaging depth. In summary, a two-photon excited ratiometric fluorescent probe NCMN has been developed and well-characterized for sensitive and selective detection of CYP1A, which holds great promise for bioimaging of endogenous CYP1A in living cells and for further investigation on CYP1A associated biological functions in complex biological systems.
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