The Chinese pine genome and methylome unveil key features of conifer evolution

Conifers dominate the world's forest ecosystems and are the most widely planted tree species. Their giant and complex genomes present great challenges for assembling a complete reference genome for evolutionary and genomic studies. We present a 25.4-Gb chromosome-level assembly of Chinese pine (Pinus tabuliformis) and revealed that its genome size is mostly attributable to huge intergenic regions and long introns with high transposable element (TE) content. Large genes with long introns exhibited higher expressions levels. Despite a lack of recent whole-genome duplication, 91.2% of genes were duplicated through dispersed duplication, and expanded gene families are mainly related to stress responses, which may underpin conifers' adaptation, particularly in cold and/or arid conditions. The reproductive regulation network is distinct compared with angiosperms. Slow removal of TEs with high-level methylation may have contributed to genomic expansion. This study provides insights into conifer evolution and resources for advancing research on conifer adaptation and development

A Novel Dual-Ion Capacitive Deionization System Design with Ultrahigh Desalination Performance

Capacitive deionization is an emerging desalination technology with mild operation conditions and high energy efficiency. However, its application is limited due to the low deionization capacity of traditional capacitive electrodes. Herein, we report a novel dual-ion capacitive deionization system with a lithium-ion battery cathode LiMn2O4/C and a sodium-ion battery anode NaTi2(PO4)3/C. Lithium ions could enhance the charge transfer during CDI desalination, while NaTi2(PO4)3/C provided direct intercalation sites for sodium ions. The electrochemical capacities of the battery electrodes fitted well, which was favorable for the optimization of the desalination capacity. The low potential of the redox couple Ti3+/Ti4+ (−0.8 V versus Ag/AgCl) and intercalation/deintercalation behaviors of sodium ions that suppressed hydrogen evolution could enlarge the voltage window of the CDI process to 1.8 V. The novel CDI cell achieved an ultrahigh desalination capacity of 140.03 mg·g−1 at 1.8 V with an initial salinity of 20 mM, revealing a new direction for the CDI performance enhancement

Efficient Removal of Chlorine Ions by Ultrafine Fe₃C Nanoparticles Encapsulated in a Graphene/N-Doped Carbon Hybrid Electrode: Redox and Confinement Effect

Developing a high-performance Cl-storage electrode is a crucial issue for capacitive deionization (CDI). Iron-/nitrogen-doped carbon hybrid composites with densely dispersed ultrafine Fe-based nanoparticles are promising candidates for Cl-storage electrodes, yet further improvement of Fe-based nanoparticles prone to agglomeration is strongly desired. Hereby, a hybrid electrode with ultrafine iron carbide nanoparticles encapsulated in graphene/chitosan-derived N-doped carbon (Fe3C@GNC) is successfully constructed via facile one-step pyrolysis of aerogel composites. The encapsulation effect of graphene can effectively confine Fe3C nanoparticles in the carbon matrix, enabling stable and dispersive ultrafine Fe3C nanoparticles, and chitosan also enables N-doping. Also, a satisfactory conductive system with synergistically long- and short-range conductive networks is successfully generated by the graphene/N-doped carbon matrix. The Fe3C@GNC electrode exhibits a typical pseudocapacitive behavior, with a specific capacitance of up to 305.33 F g–1 and a dominant capacitive contribution of up to 96%. As a Cl-storage electrode for CDI, it delivers a Cl– adsorption capacity as high as 82.08 mg g–1 with a retention rate of 74.2% for 150 cycles. Furthermore, it is revealed that the Cl– storage mechanism of Fe3C@GNC is a pseudocapacitance effect induced by the reversible Fe2+/Fe3+ redox couple, which can achieve fast reaction kinetics and structural stability in the CDI process