Visual experimental study of nanofluids application to promote CO_(2) absorption in a bubble column

The addition of dispersed-phase nanoparticles in the liquid phase can enhance the gas-liquid transfer process as the suspended nanoparticles affect the transfer process inside the fluid through microdisturbance or micro-convection effects.In this article,a high-speed digital camera was used to visualize the bubble behavior of CO_(2) in pure water and nanofluids to examine the effects of CO_(2) gas flow rate,nanoparticle solid content and type on the bubble behavior in the fluids.The CO_(2) absorption performance in three water-based nanofluids were compared in a bubbler.And the mass transfer characteristics during CO_(2) bubble absorption and the reasons for the enhanced gas-liquid mass transfer effect of nanoparticles were analyzed.The results showed that the presence of nanoparticles affected the formation process of bubbles in the fluid,shortened the bubble detachment time,reduced the detachment diameter,effectively increased the gas-liquid contact area,and improved the bubbles detachment frequency.The system with MCM-41 corresponded to a higher overall mass transfer coefficient.Uncalined MCM-41 contained surfactant that enhanced foaming behavior in water.This prevented the transfer of CO_(2) to some extent,and the CO_(2) absorption by uncalined MCM-41/H_(2)O was 5.34%higher than that by pure water.Compared with SiO_(2) nanoparticles with the same particle size and the same composition,MCM-41 had a higher adsorption capacity and better hydrophilicity due to its larger specific surface area and rich porous structure,which was more favorable to accelerate the collision between nanoparticles and CO_(2) bubbles to cause micro-convection.Under the condition of 0.1%(mass)solid content,the enhancement of CO_(2) absorption process by MCM-41 nanoparticles was more significant and improved by 16.9%compared with pure water.

Electronic Instability of Kagome Metal CsV_(3)Sb_(5) in the 2×2×2 Charge Density Wave State

Recently discovered kagome metals AV_(3)Sb_(5)(A=K,Rb,and Cs)provide an ideal platform to study the correlation among nontrivial band topology,unconventional charge density wave(CDW),and superconductivity.The evolution of electronic structures associated with the change of lattice modulations is crucial for understanding of the CDW mechanism,with the combination of angle-resolved photoemission spectroscopy(ARPES)measurements and density functional theory calculations,we investigate how band dispersions change with the increase of lattice distortions.In particular,we focus on the electronic states around M point,where the van Hove singularities are expected to play crucial roles in the CDW transition.Previous ARPES studies reported a spectral weight splitting of the van Hove singularity around M point,which is associated with the 3D lattice modulations.Our studies reveal that this“splitting”can be connected to the two van Hove singularities at k_(z)=0 and k_(z)=π/c in the normal states.When the electronic system enters into the CDW state,both van Hove singularities move down.Such novel properties are important for understanding of the CDW transition.

The phase behavior of n-ethylpyridinium tetrafluoroborate and sodium-based salts ATPS and its application in 2-chlorophenol extraction

In this paper,the aqueous two-phase systems(ATPS)containing n-ethylpyridinium tetrafluoroborate([EPy]BF_(4)),sodium-based salts,and water were studied and the extraction efficiency of 2-chlorophenol was measured to study the ATPS performance in extracting phenolic compounds.The binodal curves of[EPy]BF_(4)+sodium carbonate(Na_(2)CO_(3))ATPS and[EPy]BF_(4)+sodium dihydrogen phosphate(NaH_(2)PO_(4))ATPS have been determined at 308.15 K,318.15 K,and 328.15 K and atmospheric pressure.After getting good correlation with Merchuk equation,the binodal curves together with gravimetric method were used to calculate the tie-lines data.Furthermore,the reliability of tie-lines data was verified using Othmer-Tobias and Bancroft equations.Then,the salt influence and temperature influence on the phase behavior were discussed and the results show the salt-outing ability of Na_(2)CO_(3) is better than NaH_(2)PO_(4).With the aim of studying the ATPS performance in extracting phenolic compounds,extraction efficiency for 2-chlorophenol at different temperatures were studied and the results show that[EPy]BF_(4)+Na_(2)CO_(3) ATPS is preferred than[EPy]BF_(4)+NaH_(2)PO_(4) ATPS in applications.

Tailoring of Bandgap and Spin-Orbit Splitting in ZrSe_(2) with Low Substitution of Ti for Zr

Tuning the bandgap in layered transition metal dichalcogenides(TMDCs) is crucial for their versatile applications in many fields. The ternary formation is a viable method to tune the bandgap as well as other intrinsic properties of TMDCs, because the multi-elemental characteristics provide additional tunability at the atomic level and advantageously alter the physical properties of TMDCs. Herein, ternary Ti_(x)Zr_(1-x)Se_(2) single crystals were synthesized using the chemical-vapor-transport method. The changes in electronic structures of ZrSe_(2) induced by Ti substitution were revealed using angle-resolved photoemission spectroscopy. Our data show that at a low level of Ti substitution, the bandgap of Ti_(x)Zr_(1-x)Se_(2) decreases monotonically, and the electronic system undergoes a transition from a semiconducting to a metallic state without a significant variation of dispersions of valence bands. Meanwhile, the size of spin-orbit splitting dominated by Se 4p orbitals decreases with the increase of Ti doping. Our work shows a convenient way to alter the bandgap and spin-orbit coupling in TMDCs at the low level of substitution of transition metals.

热消融治疗肺部亚实性结节专家共识(2021年版)

局部热消融技术在肺部结节治疗领域正处在起步与发展阶段,为了肺结节热消融治疗的临床实践和规范发展,由"中国医师协会肿瘤消融治疗技术专家组""中国医师协会介入医师分会肿瘤消融专业委员会""中国抗癌协会肿瘤消融治疗专业委员会""中国临床肿瘤学会消融专家委员会"组织多学科国内有关专家,讨论制定了"热消融治疗肺部亚实性结节专家共识(2021年版)"。主要内容包括:(1)肺部亚实性结节的临床评估;(2)热消融治疗肺部亚实性结节技术操作规程、适应证、禁忌证、疗效评价和相关并发症;(3)存在的问题和未来发展方向。

简便方法制备氮掺杂的碳球用作高效非金属氧还原催化剂（英文）

随着人们环保意识的不断增强,社会对清洁能源的需求也日益增加.燃料电池具有效率高,燃料来源丰富,可直接将化学能转化成电能且污染小等优点,因而受到了广泛关注.然而,燃料电池的阴极氧还原反应(ORR)速率较慢,成为提高燃料电池整体效率的制约因素.因此,开发高性能的ORR催化剂,加快ORR反应速率具有非常重要的意义.目前,Pt基催化剂被认为是活性最好的商用ORR电催化剂.尽管此类催化剂具有较高的催化活性和良好的稳定性,但Pt的储量有限,价格高昂,抗燃料毒化性能差,限制了其大规模应用.近年来,为了减小Pt的用量,降低催化剂成本,人们除了致力于研究贵金属合金催化剂及非贵金属催化剂外,还把目光聚焦在了非金属催化剂,特别是碳及其复合材料的研究上.在众多碳材料中,碳球因具有良好的表面渗透性和较高的机械稳定性而被广泛应用于催化、吸附、药物输送和能量存储及转化等领域中.然而,碳球的表面化学惰性较强,比表面积较低,使其部分应用受到了限制.因此,人们采用了多种方法来调控碳球的物理化学性质.其中,向碳材料中掺入杂原子,尤其是氮原子的方法广受青睐.因为杂原子的掺入会显著增强作为主体的碳原子给电子的能力和表面吸附性质,从而对ORR表现出优异的催化活性和稳定性.本文以蔗糖作为碳源,三聚氰胺作为氮源,采用水热法及高温热解法制备了一系列氮掺杂的生物质碳球.并对氮掺杂量及热解温度进行了优化.结果表明,石墨化程度及石墨氮含量的提高,能有效地提高催化剂的活性.在优化了的条件下得到的催化剂N0.1C1.9S-900,表现出了比商业Pt/C催化剂更好的ORR催化性能.在0.1 mol/L KOH中,该催化剂催化ORR的起始电位和半波电位分别为–22.6和–133.6 mV(vs.Ag/AgCl),极限电流密度为4.6 mA/cm^2,分别比商业Pt/C高出7.2 mV,5.9 mV和0.2 mA/cm^2.同时,在经过30000 s的稳定性测试中,N0.1C1.9S-900催化剂的电流损失也远低于Pt/C,表明该催化剂具有良好的稳定性.此外,在抗甲醇毒化实验中,相比于商业Pt/C,N0.1C1.9S-900催化剂对甲醇有更好的耐受性.另外,该催化剂催化的ORR属于高效的4e~–途径.可见,该催化剂作为燃料电池的阴极氧还原反应催化剂具有广阔的前景.

Genome-wide association study of vitamin E in sweet corn kernels

Vitamin E,consisting of tocopherols and tocotrienols,serves as a lipid-soluble antioxidant in sweet corn kernels,providing nutrients to both plants and humans.Though the key genes involved in the vitamin E biosynthesis pathway have been identified in plants,the genetic architecture of vitamin E content in sweet corn kernels remains largely unclear.In the present study,an association panel of 204 inbred lines of sweet corn was constructed.Seven compounds of vitamin E were quantified in sweet corn kernels at 28 days after pollination.A total of 119 loci for vitamin E were identified using a genome-wide association study based on genotyping by sequencing,and a genetic network of vitamin E was constructed.Candidate genes identified were involved mainly in RNA regulation and protein metabolism.The known gene ZmVTE4,encodingγ-tocopherol methyltransferase,was significantly associated with four traits(α-tocopherol,α-tocotrienol,theα/γ-tocopherol ratio,and theα/γ-tocotrienol ratio).The effects of two causative markers on ZmVTE4 were validated by haplotype analysis.Finally,two elite cultivars(Yuetian 9 and Yuetian 22)with a 4.5-fold increase in the sum ofα-andγ-tocopherols were developed by marker-assisted selection,demonstrating the successful biofortification of sweet corn.Three genes(DAHPS,ADT2,and cmu2)involved in chorismate and tyrosine synthesis were significantly associated with theα/γ-tocotrienol ratio.These results shed light on the genetic architecture of vitamin E and may accelerate the nutritional improvement of sweet corn.

Advances on Theory and Experiments of the Energy Applications in Graphdiyne

After years of development,graphdiyne(GDY)has demonstrated the characteristics of transformative materials in many fields and has promoted great progress in fundamental and applied research.In practice,some important new concepts have been proposed,such as natural surface charge distribution inhomogeneity,multicavity space limiting effect,incomplete charge transfer effect on the atomic level,alkyne-alkene conversion of a chemical bond,in situ induction of constrained growth,reversible transition from high to low valence state,and so on.These characteristics originating from the special electronic structure and chemical structure of GDY have rapidly promoted the development of GDY science in recent years and produced many exciting results in fundamental and applied science.Therefore,we systematically introduce the recent theoretical and experimental progress of GDY in terms of its new structural,electronic,mechanical,thermal,and optical properties and its promising applications in the energy fields of membrane sciences,catalysis,energy storage,and conversion.Specifically,the great breakthrough of GDY zero-valence atomic catalysts,quantum dots catalysts,and heterostructure catalysts for catalytic applications are discussed in detail.We believe this review will provide some significant guidelines for the design and development of GDYbased high-performance materials and devices in energy fields.

Experimental Observation of Electronic Structures of Kagome Metal YCr6Ge6

Using angle-resolved photoemission spectroscopy,we study electronic structures of a Kagome metal YCr6Ge6.Band dispersions along kz direction are significant,suggesting a remarkable interlayer coupling between neighboring Kagome planes.Comparing ARPES data with first-principles calculations,we find a moderate electron correlation in this material,since band calculations must be compressed in the energy scale to reach an excellent agreement between experimental data and theoretical calculations.Moreover,as indicated by band calculations,there is a flat band in the vicinity of the Fermi level at the Г–M–K plane in the momentum space,which could be responsible for the unusual transport behavior in YCr6Ge6.

Advances of graphdiyne-supported metal catalysts in thermocatalytic reactions

Supported metal catalysts are widely used in the modern chemical industry.The electronic interaction between supports and active components is of great significance for heterogeneous catalysis.Graphdiyne(GDY),a new type of carbon allotrope with sp-hybridized carbon atoms,πconjugate structure,and electron transmission capability,is a promising candidate as catalyst support.Recent years have witnessed the rapid progress of GDY-supported metal catalysts for different catalysis reactions.Considering that most processes in the current chemical industry are thermocatalytic reactions,we herein give an overview about the advances and particular characteristics of GDY-supported catalysts in these reactions.The geometric structure and electronic properties of GDY are first introduced.Then,the synthesis methods for GDY-supported metal catalysts and their applications in thermocatalytic reactions are discussed,in which the effect of electronic interaction on catalytic performance is highlighted.Finally,the current challenges and future directions of GDY-supported metal catalysts for thermocatalysis are proposed.It is expected that this review will enrich our understanding of the advances of GDY as a superior support for metal catalysts in thermocatalytic reactions.

Persistence of charge density wave against variation of band structures in V_(x)Ti_(1−x)Se_(2)(x=0–0.1)

Charge density wave(CDW)is a phenomenon that occurs in materials,accompanied by changes in their intrinsic electronic properties.The study of CDW and its modulation in materials holds tremendous significance in materials research,as it provides a unique approach to controlling the electronic properties of materials.TiSe_(2) is a typical layered material with a CDW phase at low temperatures.Through V substitution for Ti in TiSe_(2),we tuned the carrier concentration in V_(x)Ti_(1-x)Se_(2) to study how its electronic structures evolve.Angle-resolved photoemission spectroscopy(ARPES)shows that the band-folding effect is sustained with the doping level up to 10%,indicating the persistence of the CDW phase,even though the band structure is strikingly different from that of the parent compound TiSe_(2).Though CDW can induce the band fold effect with a driving force from the perspective of electronic systems,our studies suggest that this behavior could be maintained by lattice distortion of the CDW phase,even if band structures deviate from the electron-driven CDW scenario.Our work provides a constraint for understanding the CDW mechanism in TiSe_(2),and highlights the role of lattice distortion in the band-folding effect.

Preface to special issue on celebrating the 100th anniversary of Xinjiang University

Xinjiang University originated from Xinjiang College of Russian Language,Political Science and Law in 1924.In 1935 and 1960,the college was re-organized and re-named as Xinjiang College and Xinjiang University,respectively.In 1978,Xinjiang University was appointed by the State Council as the only national key university in Xinjiang.In 1997,it was designated as one of the first batch of key construction universities in the“211 Project”of China.In 2000,Xinjiang University was rebuilt through merging with Xinjiang Institute of Technology.

Denitration of Nitroarenes Under Ambient Physiological Conditions Catalyzed by Graphdiyne-Supported Palladium

The direct cleavage of C–NO_(2)bonds for reductive denitration of nitroarenes remains a challenging transformation in synthetic organic chemistry.Herein,we report a biocompatible palladium-deposited graphdiyne nanocatalyst(Pd@GDY/DSPE-PEG)that can catalyze reductive denitration of nitroarenes under ambient physiological conditions.Mechanistic studies support this transformation via the oxidative addition of nitroarenes with Pd(0)and subsequent ligand exchange to form arylpalladium hydride.This one-step reductive denitration via Pd@GDY/DSPE-PEG successfully facilitates the repair of the nitrated proteins arising from endogenic ONOO−and restores their physiological function,including blocking the apoptosis pathway in living cells.Moreover,Pd@GDY/DSPE-PEG was further successfully applied for catalytic denitration to reduce the level of 3-nitrotyrosine residues of proteins located in the mouse brain hippocampus in vivo.This study provides an ideal strategy for designing highly active enzymatic mimicking synthetic catalysts for the regulation of the nitrated protein level and the detoxification of nitrative damage of living cells and tissues.

国家自然科学基金区域创新发展联合基金改革与实践

2018年国家自然科学基金委员会(以下简称“自然科学基金委”)启动了新时期联合基金改革,统筹设立区域创新发展联合基金。经过四年的不断探索与完善,新时期联合基金规模快速发展,改革初显成效。本文回顾和总结了国家自然科学基金区域创新发展联合基金的发展历程和改革进展,梳理分析了其设立以来的实施成效,并对区域创新发展联合基金管理运行举措进行了归纳。

Influence of organic acids on UV-Vis spectra of pyrrolidino-[60]fullerene derivatives

A pyrrolidino[60]fullerene 1 with pyrrolidine group was synthesized and characterized. The UV-Vis spectra showed that the blue shift of absorption peaks was first observed when strong organic acids such as p-toluene sulfo-nic or trifluoroacetic acid were added to the solution of pyr-rolidino[60]fullerene 1 in dichloromethane. The results indicated that the pyrrolidino[60]fullerene derivatives without pyrrolidine group also possess the same phenomenon. Experiments and computation with the MOPAC 7.0 semi-empirical PM3 method demonstrated the reason that some energy gaps on [60]fullerene skeleton were increased because electronic charges on [60]fullerene framework transferred to pyrrolidine ring when strong organic acids were added into pyrrolidino[60]fullerene derivatives’ solution; as the result, the complexes could be formed and some absorption wavelengths blue shifted in the UV-Vis spectrum.

Single molecule fluorescence spectroscopy for quantitative biological applications

Single molecule techniques emerge as powerful and quantitative approaches for scientific investigations in last decades. Among them, single molecule fluorescence spectroscopy （SMFS） is able to non-invasively characterize and track samples at the molecular level. Here, applications of SMFS to fundamental biological questions have been briefly summarized in catalogues of single-molecule counting, distance measurements, force sensors, molecular tracking, and ultrafast dynamics. In these SMFS applications, statistics and physical laws are utilized to quantitatively analyze the behaviors of biomolecules in cellular signaling pathways and the mechanisms of biological functions. This not only deepens our understanding of bio-systems, but also provides a fresh angle to those fundamental questions, leading to a more quantitative thinking in life science.

The preparation of whole sp-C composed alkyne rich carbon materials

For the high content of sp-hybridized carbon atoms,carbyne based materials can express superior conductivity and ultra-high theoretical capacity,which are key factors of high-performance anode.However,the poor stability of synthetic intermediates and unwanted side reactions lead to huge challenge to synthesis carbyne alternating carbon–carbon triple and single bonds.Here,we rationally designed a smart“Greedy Snake”strategy to synthesize the alkyne rich carbon materials named Si capped alkyne rich carbon(Si-Alkyne-C)which comprised of sp-hybridized carbon atoms.The as-prepared Si-Alkyne-C generated on the copper surface through a carbon–carbon coupling,in which Si can effectively protect the intermediates generated by the reaction.The C–Si bond can constantly generate copper-alkyne intermediates to couple with other terminal alkynes to continuously elongate like"Greedy Snake",forming a long alkyne chain structure.The as-prepared Si-Alkyne-C can be applied as anode electrodes,exhibited very high reversible capacity of up to 2776 mAh/g at a current density of 50 mA/g and an average capacity around 1202 mAh/g at a high current density of 5000 mA/g for 5000 cycles,which are the best results among the reported carbon materials and better than many other anode materials.These results not only provide a facile strategy to prepare carbyne based materials,but also open a broad avenue for the preparation of high-capacity anode materials.

Controlled Growth of Multidimensional Interface for High-Selectivity Ammonia Production

The efficient production of ammonia by reducing nitrates at room temperature and ambient pressure is a promising alternative to the Haber-Bosch process and can effectively overcome the attendant water pollution issues.Herein,a new idea has been realized for rational and selective construction of the sp-carbon-metal-carbon interface,comprised of electronic-donating triple bonds in graphdiyne and electron-withdrawing iron carbides,for a highly efficient nitrate reduction reaction.The as-prepared sp-carbon-metal-carbon interfacial structures greatly increase the charge transfer ability and electrical conductivity of the system.The proposed concept of incomplete charge transfer has demonstrated significantly high selectivity,activity,and stability in catalytic system.The catalyst exhibits high Faradaic efficiency of over>95%and a NH3 yield rate up to 205.5μmolNH_(3) cm^(-2) h^(-1) in dilute nitrate conditions without any contaminant.

Controlled Growth Interface of Charge Transfer Salts of Nickel- 7,7,8,8-Tetracyanoquinodimethane on Surface of Graphdiyne

Here we report an in situ assembly growth method that controls the growth of NiTCNQ on the surface of graphdiyne(GDY).The catalytic system of donor–acceptor–donor(GDY/TCNQ/Ni)structure with multiple charge transfer(CT)was achieved by controlling the growth of NiTCNQ on the surface of GDY.Significantly,a controlled double layer interface of GDY/TCNQ/Ni was formed.This system implemented simultaneously the two elements we expected(1)an incomplete CT,and(2)the infinite distribution of active sites originating from highly asymmetric surface charge distribution.The high conductivity and typical semiconductor characteristics of the catalyst endows it with high catalytic activity.We found that an electrolytic cell consisting of the CT salt as a catalyst provided a 1.40 V ultra-small cell voltage up to 10 mA cm−2 and the outer GDY film effectively prevented the corrosion of the catalyst.Our study is the first to introduce CT complexes to a novel catalytic material platform for high selectivity of catalysts,and undoubtedly demonstrates the high selectivity,stability,and activity of such catalytic systems,which provides a new space for the development of novel conceptual catalysts.

2D graphdiyne materials:challenges and opportunities in energy field

Graphdiyne(GDY),a novel two-dimensional(2D)carbon allotrope featuring one-atom-thick planar layers of sp andhybridized carbon network,is a rapidly rising star on the horizon of materials science.Because of its unparalleled structural,electronic,chemical and physical properties,it has been receiving unprecedented increases from fundamental studies to practical applications,particularly the field of energetic materials.In this review,we aim at providing an up-to-date comprehensive overview on the state-of-the-art research into GDY,from theoretical studies to the key achievements in the development of new GDY-based energetic materials for energy storage and conversion.By reviewing the state-of-the-art achievements,we aim to address the benefits and issues of GDY-based materials,as well as highlighting the existing key challenges and future opportunities in this exciting field.