Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

Material-SAM:Adapting SAM for Material XCT

X-ray Computed Tomography(XCT)enables non-destructive acquisition of the internal structure of materials,and image segmentation plays a crucial role in analyzing material XCT images.This paper proposes an image segmentation method based on the Segment Anything model(SAM).We constructed a dataset of carbide in nickel-based single crystal superalloys XCT images and preprocessed the images using median filtering,histogram equalization,and gamma correction.Subsequently,SAM was fine-tuned to adapt to the task of material XCT image segmentation,resulting in Material-SAM.We compared the performance of threshold segmentation,SAM,U-Net model,and Material-SAM.Our method achieved 88.45%Class Pixel Accuracy(CPA)and 88.77%Dice Similarity Coefficient(DSC)on the test set,outperforming SAM by 5.25%and 8.81%,respectively,and achieving the highest evaluation.Material-SAM demonstrated lower input requirements compared to SAM,as it only required three reference points for completing the segmentation task,which is one-fifth of the requirement of SAM.Material-SAM exhibited promising results,highlighting its potential as a novel method for material XCT image segmentation.

Diverse O-methyltransferases catalyze the biosynthesis of floral benzenoids that repel aphids from the flowers of waterlily Nymphaea prolifera

Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.

Genetic diversity of wild barley (Hordeum vulgare ssp. spontaneum) and its utilization for barley improvement

Wild barley （Hordeum vulgare spp. spontaneum） is the undisputed progenitor of cultivated barley and offers considerable poten- tial as a genetic resource for barley improvement. Naturally occurring populations are distributed primarily across the Fertile Crescent, but secondary areas of diversity are also found in central Asia and Tibet. The pattern of its genetic diversity is non-random, and is structured on a global, regional and local scale. On a global scale, diversity follows ecogeography, while on a regional and local scale, it is more strongly determined by ecology. Populations growing in areas where the climate is unreliable and/or the soil is heterogeneous tend to retain the most diversity. A large number of accessions are currently conserved ex situ, but a high proportion of these have originated fi：om the Fertile Crescent. Given the likelihood of future climate change, conserving germplasm both in situ and ex situ in the various regions where the species＇ currently existing is a research priority. The value of H. vulgare spp. spontaneum for the improvement of cultivated barley lies largely in its potential contribution to the levels of attaina- ble pathogen resistance and abiotic stress tolerance.

Preliminary Study on Shelf Life of Artificial Feed of Chilo suppressalis

In order to preliminarily explore the preservation effect of ordinary refrigerator( 4℃) on artificial diet of Chilo suppressalis,the effects of artificial feed preserved at refrigerator for different time on percentage of pupation and pupa weight of C. suppressalis were investigated to understand the impact of long-term storage of artificial feed on the growth and development of C. suppressalis. The results showed that the percentage of pupation of C. suppressalis fed with artificial diet that had been stored in refrigerator for 40 d( T40) was highest( 67. 1%),followed by CK( 1 d,63. 5%),and the percentage of pupation of C. suppressalis fed with artificial diet that had been stored in refrigerator for10 d( T10) was 61. 9%. No significant difference was found in percentage of pupation among the treatment groups( P > 0. 05). The female pupa weight of the short-term preservation treatment group( 71. 9 mg) was significantly larger than that of the long-term preservation treatment group( 66. 1 mg)( P < 0. 05),and was insignificantly different from that of CK( P > 0. 05). The male pupa weight of the short-term preservation treatment group( 51. 2 mg) was significantly larger than that of CK( 47. 7 mg)( P < 0. 05),and the male pupa weight of the long-term preservation treatment group was slightly larger than that of CK( P > 0. 05). In conclusion,the artificial diet of C. suppressalis can be stored for at least 40 d in refrigerator( 4℃).

Asymmetric side-chain engineering of organic semiconductor for ultrasensitive gas sensing

Molecular structure of organic semiconductor plays a critical role in determining the performance and functionality of organic electronic devices,by optimizing the electrical,optical and physicochemical properties.Substituted alkyl chains are fundamental units in tailering the solubility and assemblability,among which the asymmetric properties have been reported as key element for controlling the packing motifs and intrinsic charge transport.Here,we expanded the scope of molecular asymmetry dependent sensing features based on a new series of naphthalene diimides(NDI)-based derivatives substituted with a same branching alkyl chain but various linear-shaped alkyl chains(Cn-).A clear molecular stacking change,from head-to-head bilayer to head-to-tail monolayer packing model,is observed based on the features of anisotropic molecular interactions with the change in the chain length.Most importantly,a unique LUMO level shift of 0.17 eV is validated for NDI-PhC4,providing a record sensitivity up to 150%to 0.01 ppb ammonia,due to the desired molecular reactivity and device amplification properties.These results indicate that asymmetric side-chain engineering opens a route for breath healthcare.

Removal of Hg^0 with sodium chlorite solution and mass transfer reaction kinetics

The absorption behavior of Hg0 was studied experimentally by using sodium chlorite solution(NaClO2) as the absorbent in a bubble reactor.Primary influencing factors on removal efficiency of Hg0 such as NaClO2 concentration,pH,reaction temperature and the concentration of Hg0 were investigated.The results indicated that 72.91% of Hg0 removal efficiency could be achieved in acidic NaClO2 solution.The removal mechanism of Hg0 was proposed by analyzing of Hg2+ concentration in ab-sorption solution after reaction and comparing the electrode potentials between NaClO2 species and Hg2+/Hg0.The experimental results of mass transfer-reaction kinetics on oxidation of Hg0 by NaClO2 solution showed that with the increase of NaClO2 concentration and the decrease of pH value,the enhancement factor(E) and ratio of KG(Hg0)/kG(Hg0) increased and the liquid phase mass transfer resistance decreased,which is benefit to the mass transfer adsorption reaction.Although the increase of reaction temperature could improve the enhancement factor(E),but the ratio of KG(Hg0)/kG(Hg0) decreased;as a result,the liquid phase mass transfer resistance increased,therefore,the reaction rate for removal of Hg0 decreased.

中国苔藓植物多样性研究进展

苔藓植物是生物多样性的重要组成部分,包括角苔植物、苔类植物和藓类植物三大类群,其物种数量仅次于被子植物,是高等植物的第二大类群。我国是世界苔藓植物多样性最丰富的国家。自2017年以来,我国苔藓学者在世界范围发现了10个新属, 40个新种,建立了新的地钱纲分类系统;更新了我国苔藓植物物种名录,完成了数本分类学专著,并在苔藓系统发育基因组、苔藓植物多样性与环境关系、苔藓植物多样性保护等领域取得了可喜的进展。对未来的研究,我们提出5点建议:(1)加强对重要生态系统、国家公园和关键类群的物种多样性调查;(2)加快基于基因组的苔藓植物多样性研究;(3)加强苔藓植物保护研究;(4)加强西北地区苔藓植物多样性研究人才的培养;(5)进一步加强国际合作,努力构建“一带一路”国家苔藓植物多样性平台。

层状双金属氧化物材料对放射性核素的去除研究

层状双金属氧化物材料(LDHs)作为最常见的二维材料,在环境污染治理领域展现出巨大的优势. LDHs具有来源广泛、易于制备、较大的表面积、可调控的化学结构、环境友好等优点,最近几年其改性材料多用于放射性核素的高效去除.本文介绍了常用的LDHs材料及其衍生物的制备方法以及它们在放射性核素处理方面的应用及其相互作用机制,最后对LDHs材料的应用和挑战给出了个人见解.本综述为高效去除放射性核素的LDHs材料的设计指明了方向,为放射性核素的高效处理处置提供了新材料.

A Multiresponsive Hydrophobic Associating Hydrogel Based on Azobenzene and Spiropyran

Summary of main observation and conclusion Stimuli-responsive hydrogels crosslinked by weak noncovalent bonds such as hydrogen bonds,ionic interactions,host-guest interactions and hydrophobic interactions have been extensively investigated.Herein,azobenzene and spiropyran acting as two hydrophobic pendant groups were introduced into a hydrophilic polyacrylamide (PAM) via free radical copolymerization to construct a hydrophobic interaction based thermo-,light-responsive polymer hydrogel.Its viscosity and color could be reversibly regulated by heating and cooling.Meanwhile,its color could be specifically switched by light without obvious viscosity change.The gel was also capable of being transited to sol by addition of β-cyclodextrin (β-CD),which encaged the hydrophobic groups and then increased the solubility of polymer in water.The hydrogel could be regained after UV irradiation at λ=365 nm,and after irradiation at λ=440 nm,the hydrogel changed into a clear sol again.

有机晶体管生物传感器的探针接枝及其功能化

随着材料开发和溶液加工技术的不断发展,有机电子器件在生物传感领域得到了广泛关注.其中,有机晶体管不仅具备信号转化和信号放大的功能,还可以在溶液环境中低电压、稳定工作,成为发展生物传感器的理想载体之一.为构建高灵敏和高选择性的生物传感器,往往需要对器件进行探针接枝和功能化处理,提高待测物的信号转换效率和降低其他生物物质对待测物的信号干扰.本文从生物识别探针的种类、接枝方式和组装策略出发,概述了有机晶体管生物传感器的特异性传感机制和功能化应用进展,并对新一代有机晶体管传感器的发展做了总结和展望.