Information encryption has become increasingly important in recent years; however, information encryption materials, especially those encrypting on a time scale, are still in fancy. Herein, a ...“time‐lock” information encryption material is developed based on a time‐dependent fluorescent hydrogel. The fluorescence color of this hydrogel can be regulated between green and yellow, with distinctive changes in intensity, on a time scale by controlling the concentration of urea/urease and HCl. By taking advantage of this feature, “time‐locked” information can be encoded. Such information self‐erases with time, and moreover, fake or even opposing information is generated during this process. The correct information can only be recognized at a specified time, i.e., using a “time‐key” to decrypt the information. This time‐dependent feature endows the material with a higher level of security and provides new insight for information encryption.
A time‐dependent fluorescent hydrogel driven by the hydrolysis of urea is developed to achieve information encryption. Information is encoded in this material that self‐erased with time, and moreover, false information is generated during the erasing process. The correct information can only be recognized at a specific time.
With the advent of intelligent society and the popularity of electronic equipment, the protection and treatment of electromagnetic (EM) radiation have become hot research topics all over the world. ...Herein, novel 2D carbon‐based nanoplates with uniformly embedded Co nanoparticles are prepared, with unique hierarchical structure and integrated magnetic‐dielectric components. The obtained hierarchical nanoplates exhibit a wide range of tunable EM properties (ε′ for 3.38 to 34.67 and ε″ for 0.13 to 31.45) by manipulating the dispersed states inside wax system, which can achieve an effective switch from microwave absorption to EM interference shielding performance. The optimal reflection loss reaches −55.6 dB, and the shielding efficiency is 93.5%. Meanwhile, the hierarchical nanoplates also exhibit impressive capacitive performance, with a specific capacitance of 1654 F g−1 at 1 A g−1. Based on this, a creative device is constructed with the nanoplates, which can convert harmful EM radiation to useful electric energy for recycling. This work offers a new idea for the development of EM materials and functional devices, powerfully promoting the advance of energy and environmental fields.
Novel 2D carbon‐based nanoplates with uniformly embedded Co nanoparticles are prepared, with highly tunable electromagnetic properties and excellent electrochemical performance. Based on this, a creative energy conversion device is constructed, which can convert harmful EM radiation to useful electric energy for recycling. This work offers a new horizon for the development of advanced electromagnetic materials and functional devices.
Convenient generation of stable superatomic silver clusters and their systematic site-specific tailoring and directional assembly present an enduring and significant challenge. In this work, we ...prepared a face-centered cubic (fcc) array of Ag14 superatoms protected by face-capping 1,2-dithiolate-o-carborane (C2B10H10S2) ligands, each produced from 1-thiol-o-carborane in crystallization with simultaneous reduction of Ag+ to Ag0. We find that the corner N-donor ligands contribute predominately to the stability and luminescence of the Ag14 superatom. As the first-formed nanocluster Ag14(C2B10H10S2)6(CH3CN)8·4CH3CN (NC-1) with labile vertex-coordinated CH3CN ligands is highly unstable, monodendate pyridine ligands were used to replace these CH3CN species site-specifically, giving Ag14(C2B10H10S2)6(pyridine/p-methylpyridine)8 (NCs-2,3) in gram scale with its core structure intact, which features ultrastability up to 150 °C in air. Moreover, using bidentate N-containing ligands to bridge the superatomic Ag14 building blocks, we constructed an unprecedented hierarchical series of 1D-to-3D superatomic silver cluster-assembled materials (SCAM-1,2,3,4), and SCAM-4 is air-stable up to 220 °C. Furthermore, this series of stable solid-state superatomic-nanocluster materials exhibit tunable dual emission with wide-range thermochromism. The present study constitutes a major step toward the development of ligand-modulation of the structure, stability, assembly, and functionality of superatomic silver nanoclusters.
Abstract Metal single‐atoms implanted on nitrogen‐doped carbon matrices (M‐N x Cs) can effectively adjust local surface electrons and polarization relaxation through coordination structures to ...significantly enhance the electromagnetic wave (EMW) absorption properties of the materials. However, the precise construction of the geometric and electronic structures of metal single atoms and the discovery of the structure‐absorption relationship at the atomic level confront a huge challenge. Herein, this work summarizes the latest progress in metal single‐atom engineering of EMW absorbing materials via a comprehensive analysis of M‐N x Cs in terms of design principles, modulation strategies, and structure‐performance correlations. Subsequently, it highlights the recent progress of several typical M‐N x Cs as the EMW absorbing materials, aiming to achieve a complete understanding of the physical effects and atomic‐level absorption mechanisms. Finally, current key challenge and future directions of M‐N x Cs are presented by focusing on the electromagnetic functional materials. This work provides new insights for the development of atomically dispersed absorbing materials for efficient electromagnetic response functionalities.
The identification of aroma composition and key odorants contributing to aroma characteristics of white tea is urgently needed, owing to white tea's charming flavors and significant health benefits. ...In this study, a total of 238 volatile components were identified in the three subtypes of white teas using headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). The multivariate statistical analysis demonstrated that the contents of 103 volatile compounds showed extremely significant differences, of which 44 compounds presented higher contents in Baihaoyinzhen and Baimudan, while the other 59 compounds exhibited higher contents in Shoumei. The sensory evaluation experiment carried out by gas chromatography-olfactometry/mass spectrometry (GC-O/MS) revealed 44 aroma-active compounds, of which 25 compounds were identified, including 9 alcohols, 6 aldehydes, 5 ketones, and 5 other compounds. These odorants mostly presented green, fresh, floral, fruity, or sweet odors. Multivariate analyses of chemical characterization and sensory evaluation results showed that high proportions of alcohols and aldehydes form the basis of green and fresh aroma characteristic of white teas, and phenylethyl alcohol, γ-Nonalactone, trans-β-ionone, trans-linalool oxide (furanoid), α-ionone, and cis-3-hexenyl butyrate were considered as the key odorants accounting for the different aroma characteristics of the three subtypes of white tea. The results will contribute to in-depth understand chemical and sensory markers associated with different subtypes of white tea, and provide a solid foundation for tea aroma quality control and improvement.
The role of hydrogen sulphide (H2S) in angiogenesis has been widely demonstrated. Vascular endothelial growth factor (VEGF) plays an important role in H2S‐induced angiogenesis. H2S promotes ...angiogenesis by upregulating VEGF via pro‐angiogenic signal transduction. The involved signalling pathways include the mitogen‐activated protein kinase pathway, phosphoinositide‐3 kinase pathway, nitric oxide (NO) synthase/NO pathway, signal transducer and activator of transcription 3 (STAT3) pathway, and adenosine triphosphate (ATP)‐sensitive potassium (KATP) channels. H2S has been shown to contribute to tumour angiogenesis, diabetic wound healing, angiogenesis in cardiac and cerebral ischaemic tissues, and physiological angiogenesis during the menstrual cycle and pregnancy. Furthermore, H2S can exert an anti‐angiogenic effect by inactivating Wnt/β‐catenin signalling or blocking the STAT3 pathway in tumours. Therefore, H2S plays a double‐edged sword role in the process of angiogenesis. The regulation of H2S production is a promising therapeutic approach for angiogenesis‐associated diseases. Novel H2S donors and/or inhibitors can be developed in the treatment of angiogenesis‐dependent diseases.
Hydrogen sulphide and nitric oxide interact and depend on each other to jointly regulate angiogenesis.
Cadmium (Cd) is a serious heavy metal (HM) soil pollutant. To alleviate or even eliminate HM pollution in soil, environmental-friendly methods are applied. One is that special plants are cultivated ...to absorb the HM in the contaminated soil. As an excellent economical plant with ornamental value and sound adaptability, V. bonariensis could be adapted to this very situation. In our study, the Cd tolerance in V. bonariensis was analyzed as well as an overall analysis of transcriptome.
In this study, the tolerance of V. bonariensis to Cd stress was investigated in four aspects: germination, development, physiological changes, and molecular alterations. The results showed that as a non-hyperaccumulator, V. bonariensis did possess the Cd tolerance and the capability to concentration Cd. Under Cd stress, all 237, 866 transcripts and 191, 370 unigenes were constructed in the transcriptome data of V. bonariensis roots. The enrichment analysis of gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed that differentially expressed genes (DEGs) under Cd stress were predominately related to cell structure, reactive oxygen species (ROS) scavenging system, chelating reaction and secondary metabolites, transpiration and photosynthesis. DEGs encoding lignin synthesis, chalcone synthase (CHS) and anthocyanidin synthase (ANS) were prominent in V. bonariensis under Cd stress. The expression patterns of 10 DEGs, validated by quantitative real-time polymerase chain reaction (qRT-PCR), were in highly accordance with the RNA-Sequence (RNA-Seq) results. The novel strategies brought by our study was not only benefit for further studies on the tolerance of Cd and functional genomics in V. bonariensis, but also for the improvement molecular breeding and phytoremediation.
Based on the active substructure combination principle, twenty-four novel 5-chloro-pyrazole derivatives containing a phenylhydrazone moiety were designed, synthesized, and evaluated for their ...antifungal activity. Their structures were confirmed using 1 H NMR, 13 C NMR, and HR-MS spectra. The single-crystal structure of compound 8a was analyzed emphatically using X-ray diffraction. The antifungal activities against Fusarium graminearum , Botrytis cinerea , and Rhizoctonia solani were evaluated in vitro . The results of the bioassays revealed that most of the target compounds showed obvious fungicidal activity. Strikingly, the compound 7c exhibited the most potent activity with EC 50 values of 0.74, 0.68, and 0.85 μg mL −1 against the above three plant pathogenic fungi, respectively. The compounds 7c , 8d , and 8g showed significant bioactivity against R. solani with EC 50 values of 0.85, 0.25, and 0.96 μg mL −1 , respectively. In addition, CoMFA and CoMSIA molecular modeling was performed for a 3D-QSAR study, and presented a good predictive ability with q 2 values of 0.575 and 0.667, and r 2 values of 0.961 and 0.962, respectively. The results provide useful information for guiding the design and synthesis of novel potent pyrazole derivatives with good antifungal activity.
Layered nickel oxides have been focused with intense research interests as high-performance lithium-ion batterie (LIB) anode. However, it is hard to obtain few layered nickel oxides material directly ...as it easily forms bulk material with the strong interaction between the interlayer. In this work, two-dimensional (2D) nickel-based coordination polymers were successfully prepared according to aqueous phase copolymerization approach. And then uniform carbon-doped NiO nanosheets were successfully obtained from facile solution assembly and post-thermal treatment. The detailed electrochemical testing shows that the uniform NiO nanocrystals encapsulated into porous N-doped carbon (NiO@NC) nanosheets present much higher rate capability with the discharge specific capacity of 782.7 mAh·g
−1
at high current density of 2.0 A·g
−1
than pure NiO (690 mAh·g
−1
). It also shows long-term cycling performance with 91% retention after 50 cycles at 1.0 A·g
−1
. The high rate capability, cycling stability and the easy synthesis make NiO@NC nanosheets as a promising candidate for LIB anode and build up new way for the fabrication of metal oxides anode materials.
Graphical abstract
AbstractIt is well known that fire-induced spalling usually occurs to high-strength and ultra-high performance concretes. However, experiments have shown that thermal spalling can also occur to ...normal strength concrete (NSC) and the high moisture content is conducive to the occurrence of spalling of specimens and structures of NSC. In view of the fact that the spalling analysis of NSC is still lacking and the spalling mechanism of NSC is still not well understood, in this paper, the thermo-chemo-hydro-mechanical behavior of a NSC cube specimen with 90% moisture content exposed to fire is numerically studied at a mesoscale based on the experiment reported in the literature. By analyzing the nonlinear mechanical effects of the vapor pressure and the thermal stress, the spalling mechanism is investigated. It is concluded that, instead of explosive spalling, surface spalling induced by the vapor pressure occurs to the specimen. This conclusion is also confirmed by a strain energy analysis. Furthermore, with the energy analysis, the feature of non-explosive spalling of NSC under fire heating is also explained.
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