Luminescence regulation of Sb^(3+)in 0D hybrid metal halides by hydrogen bond network for optical anti-counterfeiting

The Sb^(3+) doping strategy has been proven to be an effective way to regulate the band gap and improve the photophysical properties of organic-inorganic hybrid metal halides(OIHMHs).However,the emission of Sb^(3+) ions in OIHMHs is primarily confined to the low energy region,resulting in yellow or red emissions.To date,there are few reports about green emission of Sb^(3+)-doped OIHMHs.Here,we present a novel approach for regulating the luminescence of Sb^(3+) ions in 0D C_(10)H_(2)_(2)N_(6)InCl_(7)·H_(2)O via hydrogen bond network,in which water molecules act as agents for hydrogen bonding.Sb^(3+)-doped C_(10)H_(2)2N_(6)InCl_(7)·H_(2)O shows a broadband green emission peaking at 540 nm and a high photoluminescence quantum yield(PLQY)of 80%.It is found that the intense green emission stems from the radiative recombination of the self-trapped excitons(STEs).Upon removal of water molecules with heat,C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7) generates yellow emis-sion,attributed to the breaking of the hydrogen bond network and large structural distortions of excited state.Once water molecules are adsorbed by C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7),it can subsequently emit green light.This water-induced reversible emission switching is successfully used for optical security and information encryption.Our findings expand the under-standing of how the local coordination structure influences the photophysical mechanism in Sb^(3+)-doped metal halides and provide a novel method to control the STEs emission.

Insights on advanced g‐C_(3)N_(4)in energy storage:Applications,challenges,and future

Graphitic carbon nitride(g‐C_(3)N_(4))is a highly recognized two‐dimensional semiconductor material known for its exceptional chemical and physical stability,environmental friendliness,and pollution‐free advantages.These remarkable properties have sparked extensive research in the field of energy storage.This review paper presents the latest advances in the utilization of g‐C_(3)N_(4)in various energy storage technologies,including lithium‐ion batteries,lithium‐sulfur batteries,sodium‐ion batteries,potassium‐ion batteries,and supercapacitors.One of the key strengths of g‐C_(3)N_(4)lies in its simple preparation process along with the ease of optimizing its material structure.It possesses abundant amino and Lewis basic groups,as well as a high density of nitrogen,enabling efficient charge transfer and electrolyte solution penetration.Moreover,the graphite‐like layered structure and the presence of largeπbonds in g‐C_(3)N_(4)contribute to its versatility in preparing multifunctional materials with different dimensions,element and group doping,and conjugated systems.These characteristics open up possibilities for expanding its application in energy storage devices.This article comprehensively reviews the research progress on g‐C_(3)N_(4)in energy storage and highlights its potential for future applications in this field.By exploring the advantages and unique features of g‐C_(3)N_(4),this paper provides valuable insights into harnessing the full potential of this material for energy storage applications.

In situ luminescence measurements of GaN/Al_(2)O_(3) film under different energy proton irradiations

Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within the material.The energies of H^(+)were set to 500 keV,640 keV and 2 MeV,the Bragg peaks of which correspond to the GaN film,GaN/Al_(2)O_(3) heterojunction and Al_(2)O_(3) substrate,respectively.A photoluminescence measurement at 250 K was also performed for comparison,during which only near band edge(NBE) and yellow band luminescence in the GaN film were observed.The evolution of the luminescence of the NBE and yellow band in the GaN film was discussed,and both exhibited a decrease with the fluence of H^(+).Additionally,the luminescence of F centers,induced by oxygen vacancies,and Cr^(3+),resulting from the ^(2)E →^(4)A_(2) radiative transition in Al_(2)O_(3),were measured using 2 MeV H^(+).The luminescence intensity of F centers increases gradually with the fluence of H^(+).The luminescence evolution of Cr^(3+)is consistent with a yellow band center,attributed to its weak intensity,and it is situated within the emission band of the yellow band in the GaN film.Our results show that IBIL measurement can effectively detect the luminescence behavior of multilayer films by adjusting the ion energy.Luminescence measurement can be excited by various techniques,but IBIL can satisfy in situ luminescence measurement,and multilayer structural materials of tens of micrometers can be measured through IBIL by adjusting the energy of the inducing ions.The evolution of defects at different layers with ion fluence can be obtained.

Cs_(2)NaGdCl_(6)∶Sb^(3+)荧光粉制备及发光性能

无铅双钙钛矿材料具有高效、稳定的自陷激子发射,在下一代固态照明中显示出巨大的潜力。本文采用微波固相法制备出系列新型的Cs_(2)NaGdCl_(6)∶Sb^(3+)蓝色荧光粉。通过X射线衍射仪、扫描电子显微镜和荧光光谱仪对所制备样品的结晶性、微观形貌和发光性能进行了表征和分析。结果表明,所制备的双钙钛矿型Cs_(2)NaGdCl_(6)∶Sb^(3+)样品属于立方晶系,空间群Fm3m,大小为10μm的不规则颗粒。在336 nm激发光下,荧光粉在460 nm处发射出极强的蓝光,且不同Sb^(3+)离子掺杂浓度的样品色坐标均在蓝光区域。当Sb^(3+)离子掺杂浓度超过0.015时,发生浓度猝灭,归因于电偶极⁃电偶极相互作用。此外,Cs2NaGd0.985Cl6∶0.015Sb^(3+)样品具有较佳的热稳定性,当温度升高至423 K时,发光积分强度仍为323 K时的72.6%。基于上述研究结果,Sb^(3+)离子激活Cs_(2)NaGdCl_(6)蓝色荧光粉在发光二极管领域具有潜在的应用价值。

Sb^(3+)/Bi^(3+)掺杂对Cs_(3)DyCl_(6)钙钛矿光学性能的影响

A_(2)B′BCl_(6)双钙钛矿因其极强的空气稳定性、出色的光学性能而被应用于发光材料。以Cs^(+)作为A^(+)、Dy^(3+)替代Pb^(2+)、Cl^(-)作为卤素合成新的镝基钙钛矿纳米晶体Cs_(3)DyCl_(6),以Sb^(3+)/Bi^(3+)作为激发剂掺杂,成功制备了非铅钙钛矿材料,研究了Sb^(3+)/Bi^(3+)掺杂对钙钛矿发光特性的影响。结果表明:Cs_(3)DyCl_(6)是一种具有高效激发和宽带发射特性的基质,在不添加任何激发剂的情况下就能够发出蓝绿光。在Sb^(3+)掺杂下,材料的发光向黄光方向移动,随着Sb^(3+)掺杂浓度的继续提高,发光强度开始下降,最佳掺杂比例为5%;Bi^(3+)掺杂时的Cs_(3)DyCl_(6)光学性能与Sb^(3+)掺杂下非常相似,当Bi^(3+)掺杂比例为1%时,发光强度达到最大值,Sb^(3+)/Bi^(3+)掺杂能够有效地改善Cs_(3)DyCl_(6)的光学性能。

In^(3+)、Sb^(3+)、Bi^(3+)掺杂对双钙钛矿Cs_(2)NaDyCl_(6)发光性能的调控

A2B′BCl_(6)型双钙钛矿因其极强的空气稳定性和出色的光学性能而被应用于发光材料。使用Na离子替代式掺杂合成非铅体系钙钛矿材料Cs_(2)NaDyCl_(6),引入In^(3+)、Sb^(3+)和Bi^(3+)等掺杂元素对双钙钛矿Cs_(2)NaDyCl_(6)发光性能进行调控。结果表明:通过In^(3+)的掺杂,拓宽了材料的发射区间,进一步提高了其光学性能;Bi^(3+)掺杂能够使钙钛矿的发射光发生红移现象,Sb^(3+)掺杂可以使钙钛矿的发射光发生蓝移现象,Sb^(3+)和Bi^(3+)共同掺杂能够平衡钙钛矿在可见光区域的发射;在In^(3+)、Sb^(3+)、Bi^(3+)三种元素的共同掺杂下,Cs_(2)NaDy_(0.445)In_(0.445)Cl_(6)∶0.1Bi 0.01Sb成功实现了白光发射,在265 nm波长激发下,其CIE色坐标为(0.34,0.35),色温达到5314 K,显色指数高达94。

Sb^(3+)/Bi^(3+)掺杂对Cs_(2)ADyCl_(6)(A=Li,Na,K)发光性能的影响

A2B′BCl_(6)型双钙钛矿因其极强的空气稳定性和出色的光学特性而被应用于发光材料。以Cs^(+)作为A^(+),Dy^(3+)替代Pb^(2+),Cl^(-)作为卤素制备新的镝基钙钛矿纳米晶体Cs_(3)DyCl_(6),使用Li、Na、K离子替代式掺杂合成Cs_(2)ADyCl_(6)(A=Li,Na,K)非铅体系钙钛矿材料,通过掺杂Sb^(3+)/Bi^(3+)作为激发剂实现了不同发光性能的调控。结果表明:Cs_(2)NaDyCl_(6)发射曲线更加平滑且在蓝光与黄光区域均可实现发射,表现出优异的光学特性;通过Sb^(3+)/Bi^(3+)掺杂,双钙钛矿的光学特性得到显著提升,Na^(+)和Sb^(3+)的共同作用可以使钙钛矿材料发光产生蓝移,而Na^(+)与Bi^(3+)的共同作用则可以使其发光产生红移。

Polypyride intercalation boosting the kinetics and stability of V_(3)O_(7)·H_(2)O cathodes for aqueous zinc-ion batteries

V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)intercalated VO with nanoribbon structure was prepared by a simple in-situ pre-intercalation,which is noted VO-PPyd.The total density of states(TDOS)shows that after the pre-intercalation of PPyd,an intermediate energy level appears between the valence band and conduction band,which provides a step that can effectively reduce the band gap and enhance the electron conductivity.Furthermore,the density functional theory(DFT)results found that Zn^(2+)is more easily de-intercalated from the V-O skeleton,which proves that the embeddedness of PPyd improves the diffusion kinetics of Zn^(2+).Electrochemical studies have shown that VO-PPyd cathode materials exhibit excellent rate performance(high specific capacity of 465 and 192 mA h g^(-1)at 0.2 and 10 A g^(-1),respectively)and long-term cycling performance(92.7%capacity retention rate after 5300 cycles),due to their advantages in structure and composition.More importantly,the energy density of VO-PPyd//Zn at 581 and 5806 W kg^(-1)is 375 and 247 W h kg^(-1),respectively.VO-PPyd exhibits excellent electrochemical properties compared to previously reported vanadium based cathodes,which makes it highly competitive in the field of high-performance cathode materials of AZIBs.

Solid-state NMR study on sodium intercalation at low voltage window for Na_(3)V_(2)(PO_(4))_(3) as an anode

In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.

Robust Cross-Linked Na_(3)V_(2)(PO_(4))_(2)F_(3) Full Sodium-Ion Batteries

Sodium-ion batteries(SIBs)have rapidly risen to the forefront of energy storage systems as a promising supplementary for Lithium-ion batteries(LIBs).Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)as a common cathode of SIBs,features the merits of high operating voltage,small volume change and favorable specific energy density.However,it suffers from poor cycling stability and rate performance induced by its low intrinsic conductivity.Herein,we propose an ingenious strategy targeting superior SIBs through cross-linked NVPF with multi-dimensional nanocarbon frameworks composed of amorphous carbon and carbon nanotubes(NVPF@C@CNTs).This rational design ensures favorable particle size for shortened sodium ion transmission pathway as well as improved electronic transfer network,thus leading to enhanced charge transfer kinetics and superior cycling stability.Benefited from this unique structure,significantly improved electrochemical properties are obtained,including high specific capacity(126.9 mAh g^(-1)at 1 C,1 C=128 mA g^(-1))and remarkably improved long-term cycling stability with 93.9%capacity retention after 1000 cycles at 20 C.The energy density of 286.8 Wh kg^(-1)can be reached for full cells with hard carbon as anode(NVPF@C@CNTs//HC).Additionally,the electrochemical performance of the full cell at high temperature is also investigated(95.3 mAh g^(-1)after 100 cycles at 1 C at 50℃).Such nanoscale dual-carbon networks engineering and thorough discussion of ion diffusion kinetics might make contributions to accelerating the process of phosphate cathodes in SIBs for large-scale energy storages.

Interfacial built-in electric field and crosslinking pathways enabling WS_(2)/Ti_(3)C_(2)T_(x) heterojunction with robust sodium storage at low temperature

Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.

Extending the solid solution range of sodium ferric pyrophosphate:Off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)as a novel cathode for sodium‐ion batteries

Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.

Effects of anti-CD4 antibody treatment on calcium ions influx in peanut-sensitized C3H/HeJ mice

The precise mechanism underlying the effects of anti-CD4 antibody and calcium ions(Ca^(2+)) in peanut allergy remains unknown.C3 H/HeJ mice sensitized with peanut protein extract(PPE)were injected with anti-CD4 antibodies for 4 weeks.Stimulation with PPE increased the specific immunoglobulin E(IgE),cytokine,histamine,and mMcp-1 levels,upregulated decorin(Dcn)expression,induced Ca^(2+) inflow in the spleen,and augmented the expression of the transcription factors GATA-3 and Foxp3,which resulted in Th2 and Treg cell activation.Notably,the Ca^(2+) levels were positively correlated with the histamine,interleukin(IL)-4,IL-5,and IL-13 levels,and negatively correlated with IL-10 levels.However,administration of anti-CD4 antibodies markedly alleviated allergic symptoms,activated T cells,and reduced Ca^(2+) inflow,cytokine,histamine,mMcp-1,and the IgHG3,CXCLI2,MMP2 and FABP4 gene.Our results indicated that anti-CD4 antibodies can ameliorate PPE-induced allergy,which is probably related to the suppression of Ca^(2+) inflow,and inhibiting histamine,cytokine and IgHG3,CXCL12,MMP2,and FABP4,thus exerting a protective effect against PPEsensitized food allergy.

Sb_(2)S_(3)/石墨烯负极材料的制备及其储钠性能研究

钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量高被认为是较好的钠离子电池负极材料。本文使用简单水热法将Sb_(2)S_(3)与石墨烯复合,制备Sb_(2)S_(3)/石墨烯复合材料(Sb_(2)S_(3)/Gr)。结果表明:Sb_(2)S_(3)/Gr作为钠离子电池负极时,不仅表现出良好的电导率(3.5×10~(-3)S/cm)和钠离子扩散速率(4.853×10~(-13)cm~2/s),而且在0.5 A/g的电流密度下,首圈库伦效率为76.27%,经150次循环后的比容量稳定在488 m A·h/g,表现出较高的比容量。Sb_(2)S_(3)/Gr复合材料表现出了极大的应用潜力,为高性能钠离子电池负极材料的研发提供了一定的参考价值。

P2X7R过表达的巨噬细胞MSU晶体诱导痛风炎症反应过程中IL-1β、TNF-α、NLRP3表达观察

目的观察嘌呤能受体P2X配体门控离子通道7的配体(P2X7R)过表达白血病细胞诱导分化的巨噬细胞单钠尿酸盐(MSU)晶体诱导痛风炎症反应过程中NOD样受体家族3(NLRP3)蛋白、IL-1β、TNF-α表达情况。方法取人单核细胞白血病细胞系THP-1,并随机分为过表达组、空白组、模型组、对照组;过表达组和空白组分别转染P2X7R过表达质粒、空白载体质粒,转染5 d,将过表达组、空白组、模型组THP-1细胞用100 ng/mL的PMA刺激3 h后分化为巨噬细胞,另将MSU晶体用氢氧化钠溶解配制成浓度为100μg/mL的MSU乳糜状悬液加入培养液中孵育6 h;对照组正常培养。分别采用RT-PCR法和Western blot法测算巨噬细胞P2X7R mRNA、蛋白,ELISA法检测巨噬细胞上清液IL-1β、TNF-α,Western blot法测算巨噬细胞NOD样受体家族3(NLRP3)蛋白。结果与对照组比较,过表达组、空白组、模型组P2X7R mRNA和蛋白相对表达量升高,细胞上清液IL-1β、TNF-α水平升高,细胞NLRP3蛋白相对表达量升高(P均<0.05);与模型组、空白组比较,过表达组P2X7R mRNA、蛋白相对表达量升高,细胞上清液IL-1β、TNF-α水平升高,细胞NLRP3蛋白相对表达量升高(P均<0.05)。结论P2X7R过表达白血病细胞诱导分化的巨噬细胞MSU晶体诱导痛风炎症反应过程中IL-1β、TNF-α、NLRP3表达增加,IL-1β、TNF-α水平升高可能通过激活NLRP3蛋白来实现。

原子层沉积Al_(2)O_(3)对尖晶石LiNi_(0.5)Mn_(1.5)O_(4)正极材料的影响机理

为提升尖晶石相LiNi_(0.5)Mn_(1.5)O_(4)正极材料在深度荷电状态下的界面稳定性,采用原子层沉积法在单晶LiNi_(0.5)Mn_(1.5)O_(4)正极材料表面可控沉积了纳米级Al_(2)O_(3)层。改性后的LiNi_(0.5)Mn_(1.5)O_(4)正极材料表现出优异的长循环耐腐蚀性能(1C电流密度下循环500次的容量保持率高达94.7%)。进一步的表界面解析结果表明:原子层沉积技术构建的纳米级Al_(2)O_(3)包覆层能够明显抑制材料本体与电解液的腐蚀反应,降低过渡金属离子的不可逆溶解与析出;另外,基于HF表面刻蚀产生的AlF_(3)具有增强的耐刻蚀性能,可显著提升LiNi_(0.5)Mn_(1.5)O_(4)正极材料在长循环及高电压下的服役性能。

Ti_(3)C_(2)T_(x)超薄纳米片高效率去除废水中重金属的研究

通过刻蚀剥离法制备了Ti_(3)C_(2)T_(x)超薄纳米片,探究了其对废水中重金属离子的吸附特性。通过SEM、XRD、AFM、FT-IR、Raman对Ti_(3)C_(2)T_(x)超薄纳米片的形貌和结构进行了表征,通过ICP-MS对处理前后水体中重金属离子的含量进行了测试。结果表明剥离的Ti_(3)C_(2)T_(x)超薄纳米片表面含有结构缺陷和羟基,当水体中Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)初始浓度为50 mg/L时,47.5 mg Ti_(3)C_(2)T_(x)超薄纳米片对其的去除效率高达90%以上,尤其是对Pb(Ⅱ)的去除效率达到了98.81%,吸附性能远高于大孔树脂、硅藻土和活性炭等常见吸附试剂。在Na(Ⅰ)、Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)4种离子共存溶液中,Ti_(3)C_(2)T_(x)超薄纳米片对于Pb(Ⅱ)和Cr(Ⅵ)的去除依然可以达到92%以上。通过动力学和吸附等温拟合,Ti_(3)C_(2)T_(x)纳米片对Pb(Ⅱ)的吸附符合拟二级动力学模型和Langmuir等温模型,对Pb(Ⅱ)的最大吸附量和最低检出限分别为81.7 mg/g和0.0094 mg/L。Ti_(3)C_(2)T_(x)超薄纳米片对重金属离子的吸附特性在化学工业、食品加工的废水处理中具有良好的应用前景。

封装包覆结构多孔Fe_(3)O_(4)长循环锂电池负极材料

本文通过封装与包覆结构共同作用抑制多级孔Fe_(3)O_(4)在循环过程中的体积膨胀,提高Fe_(3)O_(4)电极材料的电化学性能。通过采用硬模板法将葡萄糖和尿素作为造孔剂合成具有多级孔结构的Fe_(3)O_(4)材料,再利用醛脂包覆系统在多级孔Fe_(3)O_(4)上均匀的包覆一层碳材料,随后使用氢化工程对体积膨胀率仅为~4%的TiO_(2)进行氢化处理并提高TiO_(2)的导电率,将氢化TiO_(2)作为封装材料对碳包覆多级孔Fe_(3)O_(4)进行封装处理,制备出具有三维网络传输结构的H-TiO_(2)-C-Fe_(3)O_(4)电极材料。结果表明,封装与包覆结构较好的缓解了H-TiO_(2)-C-Fe_(3)O_(4)电极材料在充放电过程中的体积膨胀,在0.2 A·g^(-1)的电流密度下循环500圈之后的放电比容量为599.61 mAh·g^(-1),以1 A·g^(-1)的电流密度循环700圈后的比容量为542.64 mAh·g^(-1),即使在6 A·g^(-1)的大电流密度下比容量也能够达到168.7 mAh·g^(-1),当电流返回0.2 A·g^(-1)循环100圈后的比容量为671.91 mAh·g^(-1),优异的倍率性能为H-TiO_(2)-C-Fe_(3)O_(4)样品在大电流储能设备上使用提供了可能性。

Bi/Bi_(3)Se_(4) nanoparticles embedded in hollow porous carbon nanorod:High rate capability material for potassium-ion batteries

Considering their superior theoretical capacity and low voltage plateau,bismuth(Bi)-based materials are being widely explored for application in potassium-ion batteries(PIBs).Unfortunately,pure Bi and Bibased compounds suffer from severe electrochemical polarization,agglomeration,and dramatic volume fluctuations.To develop an advanced bismuth-based anode material with high reactivity and durability,in this work,the pyrolysis of Bi-based metal-organic frameworks and in-situ selenization techniques have been successfully used to produce a Bi-based composite with high capacity and unique structure,in which Bi/Bi_(3)Se_(4)nanoparticles are encapsulated in carbon nanorods(Bi/Bi_(3)Se_(4)@CNR).Applied as the anode material of PIBs,the Bi/Bi_(3)Se_(4)@CNR displays fast potassium storage capability with 307.5 m A h g^(-1)at 20 A g^(-1)and durable cycle performance of 2000 cycles at 5 A g^(-1).Notably,the Bi/Bi_(3)Se_(4)@CNR also showed long cycle stability over 1600 cycles when working in a full cell system with potassium vanadate as the cathode material,which further demonstrates its promising potential in the field of PIBs.Additionally,the dual potassium storage mechanism of the Bi/Bi_(3)Se_(4)@CNR based on conversion and alloying reaction has also been revealed by in-situ X-ray diffraction.

HL-3装置上离子回旋波加热对中子产额的影响

离子回旋射频(Ion Cyclotron Range of Frequencies,ICRF)波加热是托卡马克装置上至关重要的辅助加热方式之一。托卡马克装置中国环流三号(HL-3,原名HL-2M)拟安装加热功率为6 MW的ICRF加热系统。本工作利用TRANSP程序,模拟并研究了ICRF加热的频率和功率对聚变中子产额以及快离子分布的影响。研究结果表明:ICRF的频率和功率对中子产额有显著影响,固定ICRF频率时,中子产额与加热功率成正比关系,而在固定ICRF加热功率的情况下,中子产额的增加幅度显著依赖ICRF的频率,在研究参数范围内,30 MHz的ICRF对中子产额的增加具有最显著的增强作用。快离子分布的模拟结果显示,在考虑ICRF加热后,中性束和ICRF的协同加热机制能够将快离子加热至最高1 MeV,有效地提高了中子产额。此外,基于中子相机诊断的概念对中子信号进行了仿真。结果表明,中子相机能够有效地测量到由ICRF加热导致的中子产额高低和分布剖面的变化,这为将来优化中子相机诊断系统设计和测量中子空间分布提供了一定的参考。