The perfect control over the constituent and architecture of porous nanomaterials is still a significant challenge in developing high performance electromagnetic wave absorption materials. In this ...work, we have designed and prepared a novel lightweight electromagnetic wave absorption material with the combination of hollow structure and bimetallic constituents by the thermal decomposition of metal−organic framework (MOF) ZIF-67. We found that by introducing additional metal Nickle into the porous Co/C composites, the CoNi/C-800-PVDF nanocomposite could yield an excellent reflection loss of −61.02 dB at 13.68 GHz and simultaneously possess effective absorbing bandwidth of 5.2 GHz with lower filler loading as 10 wt%, which corresponding to a less absorber thickness of 2 mm. These results demonstrate that the synergistic effects between the bimetallic components and hollow structure of novel CoNi/C composite optimize impedance matching, and thus improve the absorption performance greatly. The properties of specific surface area, interface polarization, dipole polarization, ferromagnetic resonance, eddy current loss and multiple scattering are investigated to further explain the high performance of materials.
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•Hollow porous structure bimetallic carbon-based nanocomposite (CoNi/C) with excellent electromagnetic wave absorption properties was successfully synthesized.•An excellent reflection loss (RL) of −61.02 dB at 13.68 GHz with a low filler loading (10 wt%) and ultra-thin thickness (2.00 mm).•Effective absorption bandwidth (<−10 dB) up to 5.2 GHz under a single thickness (2.00 mm).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The problem of unstable structure and poor impedance matching of single metal-organic framework (MOF) can be avoided by sintering MOFs and melamine composites to fabricate carbon nanotubes-coated ...cobalt/carbon nanoparticles (Co@C/CNTs). By regulating the mixing ratio of MOF and melamine, different lengths and amount of carbon nanotubes coated porous cobalt/carbon polyhedrons can be obtained, and the catalytic capability of cobalt can be affected to obtain carbon with different degrees of graphitization. The appropriate ratio can change the dielectric magnetic parameters to optimize the impedance matching of the material. As the result, when the mixing ratio of ZIF-67 and melamine was 1:1, the product Co@C/CNTs/PVDF-1:1 shows the lowest reflection loss (−57.6 dB) at the filling amount of 15 wt% with the thickness of 3.01 mm. The effective absorbing bandwidth (EAB) could achieve 5.4 GHz from 12.6 GHz to 18.0 GHz under the filler loading of 10 wt% with the thickness of 2 mm. These results inaugurate a new avenue for obtaining excellent absorbing composites with lightweight, wide EAB and strong absorbing performance.
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•Carbon nanotubes-coated cobalt/carbon nanoparticles (Co@C/CNTs) with excellent performance was successfully synthesized.•An excellent reflection loss (RL) of −57.6 dB with a low filler loading (15 wt%) and thin thickness (3.01 mm).•Effective absorption bandwidth (<−10 dB) can be up to 5.4 GHz under a single thickness (2.00 mm).•The synergistic effect between magnetic components and carbon-based show up good impedance matching.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A design approach to a novel wideband circular sector patch antenna is proposed. Design guidelines are laid down based on an approximate 1.5-wavelength, multimode magnetic dipole, and the cavity ...model. Then, the flared angle of the circular sector patch and the corresponding usable resonant modes for wideband radiation are determined. It is demonstrated that the resonant TM 4/3,1 and the TM 8/3,1 modes within a 270° circular sector patch radiator can be simultaneously excited, perturbed, and employed to form a wideband unidirectional radiation characteristic with two resonances. Prototype antennas are designed and fabricated to experimentally validate the dual-resonant wideband property on a single-layered substrate. It is further demonstrated that the antenna designed on a 5-mm-thick air substrate exhibits an available radiation bandwidth (ARB) of 14.5%, while the printed one designed on a 2-mm-thick modified Teflon substrate exhibits an ARB of 6.5%. It is evidently validated that the proposed approach can be employed to effectively enhance the operational bandwidth of microstrip patch antennas without increasing antenna profile, inquiring multiple radiators or employing reactance compensation techniques.
Costly data movement in terms of time and energy in traditional von Neumann systems is exacerbated by emerging information technologies related to artificial intelligence. In‐memory computing (IMC) ...architecture aims to address this problem. Although the IMC hardware prototype represented by a memristor is developed rapidly and performs well, the sneak path issue is a critical and unavoidable challenge prevalent in large‐scale and high‐density crossbar arrays, particularly in three‐dimensional (3D) integration. As a perfect solution to the sneak‐path issue, a self‐rectifying memristor (SRM) is proposed for 3D integration because of its superior integration density. To date, SRMs have performed well in terms of power consumption (aJ level) and scalability (>102 Mbit). Moreover, SRM‐configured 3D integration is considered an ideal hardware platform for 3D IMC. This review focuses on the progress in SRMs and their applications in 3D memory, IMC, neuromorphic computing, and hardware security. The advantages, disadvantages, and optimization strategies of SRMs in diverse application scenarios are illustrated. Challenges posed by physical mechanisms, fabrication processes, and peripheral circuits, as well as potential solutions at the device and system levels, are also discussed.
This review summarizes the research progress in self‐rectifying memristors (SRM) and SRM‐based applications including 3D memory, in‐memory computing, neuromorphic computing, and hardware security. Through a comprehensive analysis of the advantages and disadvantages of SRMs in different application scenarios, as well as challenges at the device, 3D integration, and peripheral circuit levels, corresponding research ideas and potential solutions are proposed.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lightweight, broad-band, and highly efficient microwave-absorbing materials (MAMs) with tunable electromagnetic properties are in high demand. However, the absorption properties are limited by the ...simple loss mechanism in commonly used absorbing materials. Here, we tested the microwave-absorbing properties of Fe–NiS2/NiS/poly(vinylidene fluoride) (PVDF) in the frequency range of 2–18 GHz. For the 2.5% Fe–NiS2/NiS/PVDF with the filling content of 20 wt %, the maximum reflection loss can reach −61.72 dB at 14.88 GHz, and the bandwidth can reach 3.8 GHz with the reflection loss value below −10 dB. Loss mechanisms of different composites were analyzed on the basis of their magnetic and dielectric properties using both experimental and computational methods. The results indicate that strong microwave absorption property is achieved through a balancing of dielectric loss and magnetic loss. These findings present a new strategy for the future design of MAMs.
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IJS, KILJ, NUK, PNG, UL, UM
DNA/RNA strand displacement is one of the most fundamental reactions in DNA and RNA circuits and nanomachines. In this work, we reported an exploration of the dynamic process of the toehold-mediated ...strand displacement via core–satellite plasmon rulers at the single-molecule level. Applying plasmon rulers with unlimited lifetime, single-strand displacement triggered by the invader that resulted in stepwise leaving of satellite from the core was continuously monitored by changes of scattering signal for hours. The kinetics of strand displacement in vitro with three different toehold lengths have been investigated. Also, the study revealed the difference in the kinetics of strand displacement between DNA/RNA and DNA/DNA duplexes. For the kinetics study in vivo, influence from the surrounding medium has been evaluated using both phosphate buffer and cell lysate. Applying core–satellite plasmon rulers with high signal/noise ratio, kinetics study in living cells proceeded for the first time, which was not possible by conventional methods with a fluorescent reporter. The plasmon rulers, which are flexible, easily constructed, and robust, have proven to be effective tools in exploring the dynamical behaviors of biochemical reactions in vivo.
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IJS, KILJ, NUK, PNG, UL, UM
Crocodilians are diving reptiles that can hold their breath under water for long periods of time and are crepuscular animals with excellent sensory abilities. They comprise a sister lineage of birds ...and have no sex chromosome. Here we report the genome sequence of the endangered Chinese alligator （Alligator sinensis） and describe its unique features. The next-generation sequencing generated 314 Gb of raw sequence, yielding a genome size of 2.3 Gb. A total of 22 200 genes were predicted in Alligator sinensis using a de novo, homology- and RNA-based combined model. The genetic basis of long-diving behavior includes duplication of the bicarbonate-binding hemoglobin gene, co-function- ing of routine phosphate-binding and special bicarbonate-binding oxygen transport, and positively selected energy metabolism, ammonium bicarbonate excretion and cardiac muscle contraction. Further, we elucidated the robust Alligator sinensis sensory system, including a significantly expanded olfactory receptor repertoire, rapidly evolving nerve-related cellular components and visual perception, and positive selection of the night vision-related opsin and sound detection-associated otopetrin. We also discovered a well-developed immune system with a considerable num- ber of lineage-specific antigen-presentation genes for adaptive immunity as well as expansion of the tripartite motif- containing C-type lectin and butyrophilin genes for innate immunity and expression of antibacterial peptides. Mul- tifluorescence in situ hybridization showed that alligator chromosome 3, which encodes DMRT1, exhibits significant synteny with chicken chromosome Z. Finally, population history analysis indicated population admixture 0.60-1.05 million years ago, when the Qinghai-Tibetan Plateau was uplifted.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abdominal Aortic aneurysm (AAA) is associated with chronic inflammation, cells apoptosis, and impairment of autophagy. BP-1-102, a novel potent STAT3 inhibitor, has been recently reported to ...significantly block inflammation-related signaling pathways of JAK2/STAT3 and NF-κB, as well as regulate autophagy. However, its role in vascular inflammation and AAA progression remains to be elucidated. In the present study, the effect and potential mechanisms of BP-1-102 on angiotensin II (AngII) induced AAA in ApoE
mice were investigated. AAA was induced in ApoE
mice with infusion of AngII for 28 days. BP-1-102 was administrated orally to mice every other day. Mice were sacrificed on day 7, day 14, and day 28 to evaluate the treatment effects. BP-1-102 markedly decreased AAA incidence and aortic diameter, maintained elastin structure and volume, reduced the expression of pro-inflammatory cytokines and MMPs, and inhibited inflammatory cells infiltration. Moreover, BP-1-102 dramatically reduced the expression of JAK2, p-STAT3, p-NF-κB, and Bcl-xL but maintained the expression of LC3B and Beclin in AAA tissues. In vitro, vascular smooth muscle cells (VSMCs) were treated with AngII and/or BP-1-102 at indicated time and concentration. BP-1-102 inhibited AngII-induced JAK2/STAT3 and NF-κB signaling activation and maintained autophagy-related proteins expression in VSMCs. Taken together, our findings suggest that BP-1-102 inhibits vascular inflammation and AAA progression through decreasing JAK2/STAT3 and NF-κB activation and maintaining autophagy.
Understanding the dynamics and underlying mechanism of carbon exchange between terrestrial ecosystems and the atmosphere is one of the key issues in global change research. In this study, we ...quantified the carbon fluxes in different terrestrial ecosystems in China, and analyzed their spatial variation and environmental drivers based on the long‐term observation data of ChinaFLUX sites and the published data from other flux sites in China. The results indicate that gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem productivity (NEP) of terrestrial ecosystems in China showed a significantly latitudinal pattern, declining linearly with the increase of latitude. However, GEP, ER, and NEP did not present a clear longitudinal pattern. The carbon sink functional areas of terrestrial ecosystems in China were mainly located in the subtropical and temperate forests, coastal wetlands in eastern China, the temperate meadow steppe in the northeast China, and the alpine meadow in eastern edge of Qinghai‐Tibetan Plateau. The forest ecosystems had stronger carbon sink than grassland ecosystems. The spatial patterns of GEP and ER in China were mainly determined by mean annual precipitation (MAP) and mean annual temperature (MAT), whereas the spatial variation in NEP was largely explained by MAT. The combined effects of MAT and MAP explained 79%, 62%, and 66% of the spatial variations in GEP, ER, and NEP, respectively. The GEP, ER, and NEP in different ecosystems in China exhibited ‘positive coupling correlation’ in their spatial patterns. Both ER and NEP were significantly correlated with GEP, with 68% of the per‐unit GEP contributed to ER and 29% to NEP. MAT and MAP affected the spatial patterns of ER and NEP mainly by their direct effects on the spatial pattern of GEP.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
•We have reviewed a good number of POM-based coordination polymers with entangled structures.•Different topological concepts are employed to describe the various types of these polymers.•Further ...classification is based on the dimensionalities of the individual motifs and the roles of the POMs.•The unique characteristics of the POMs make them perfect templates and linkers in the formation of these structures.
Polyoxometalates (POMs) have attracted a lot of interest due to their novel structure characteristics and various connection modes. POM-based coordination polymers with entangled structures, an indispensable branch of entangled networks, take advantage of the features of POMs, and have received increasing attention. Much effort has been devoted over the past few decades toward their preparation and the analysis of their unusual entangled topology. In this review, we will summarize a number of examples of POM-based coordination polymer that have been described according to their different entangled characteristics. Different concepts, such as interpenetration, polycatenation, polyrotaxane, polypseudo-rotaxane and self-penetration, are employed to describe the various types of POM-based coordination polymers with entangled structures. In addition, we further classify POM-based coordination polymers with entangled structures based on the dimensionalities of the individual motifs and the roles of the POMs. Combining the advantages of the attractive potential applications of the POMs and structure diversities of the entangled frameworks, the investigation of POM-based coordination polymers with entangled structures will be a sustainable research field in coordination chemistry.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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