In this work, we take into account the dual objective control issue for an energy storage system (ESS). For one thing, the total ESS’s power output ought to meet a certain reference value. For another, all energy storage units (ESUs) must have a balanced state-of-energy (SOE) in order to preserve the system power capacity at its highest level. To this end, a sampled-data distributed control scheme is proposed so as to achieve both state-ofenergy balancing and power tracking subject to the reliable and fixed communication network, where the range of sampling period is obtained by the standard procedure. An illustrative example is offered to support the efficacy of the provided control approach.

水合硅酸镁是炼钢连铸过程中间包用镁质浇注料的重要结合相,其含量多少决定着浇注料的强度大小.本工作以Na2SiO3·9H2O和MgCl2·6H2O为原料,采用水热法合成水合硅酸镁(MgO-SiO2-H2O,M-S-H),研究了焙烧温度和焙烧次数对水合硅酸镁的"结构记忆"特性;随后将预合成M-S-H复合硅微粉制备镁质浇注料,研究其对镁质浇注料性能的影响.结果表明:当焙烧温度低于400℃时,水合硅酸镁具有"结构记忆"特性,焙烧次数增加有利于M-S-H凝胶中层间羟基的插入,促进其层状结构晶粒的长大和结构稳定性的提高;在镁质浇注料制备过程中引入一定量的预合成水合硅酸镁和少量的硅微粉,使浇注料具有很好的施工性能和足够的早期结合强度;同时减少了高温热处理后浇注料缺陷形成,提高了材料力学性能,为开发低硅微粉镁质浇注料提供支撑.

We report on investigations of the complex magnetostructural and spin-state transitions in the breathing pyrochlore LiFeCr$_{4}$O$_{8}$ by means of magnetization, M\"ossbauer spectroscopy, and density functional theory (DFT) calculations. Three transitions corresponding to the ferrimagnetic transition at $T_N\sim94$ K, the spin-gap transition at $T_{SG}\sim50$ K, and the magnetostructural transition at $T_{MS}\sim19$ K were observed from the $\chi$(T) curve, whereas only $T_N$ and $T_{MS}$ were evidenced for the Fe site from our M\"ossbauer measurements, suggesting that the spin-gap transition is absent at the Fe site. This indicates that the spin-gap transition is an effect of the breathing Cr$_4$ lattice, in agreement with our DFT calculations from which we see nearly decoupled electronic states for the FeO$_4$ and CrO$_6$ units. From the temperature dependence of the hyperfine magnetic field we also observed a spin-state transition for the Fe spins at $T_{MS}$ consistent with earlier neutron diffraction measurements. These local characteristics are believed to be important for a complete understanding of the complex magnetostructural coupling effects observed in similar systems.

Very recently, a 3d based honeycomb cobaltate Na2Co2TeO6 has garnered tremendous attention due to the proposed proximity to the Kitaev spin-liquid state as its 4d/5d counterparts. Here, we use Zn to substitute Co in a broad range and perform systematic studies on Na2Co2-xZnxTeO6 by structural, magnetic, and thermodynamic measurements, and track the doping evolution of its magnetic ground states. Due to the extremely close radii of Zn2+ and high-spin Co2+ ions, the substitution can be easily achieved. X-ray diffractions reveal no structural transition but onlyminor changes on the lattice parameter c over a wide substitution range 0 <= x <= 1.5. Magnetic susceptibility and specific heat measurements both suggest an antiferromagnetic ground state which is gradually suppressed with doping. It can survive with x up to similar to 1.0. Then it evolves into a spin-glass phase with short-range order that is rapidly supplanted by a magnetically disordered state when x >= 1.3. By summarizing all these data, we construct a magnetic phase diagram of Na2Co2-xZnxTeO6. Our results demonstrate that the Zn doping can effectively suppress the magnetic order and induce a possible quantum paramagnetic state. These may serve as a platform to investigate the Kitaev physics in this system.

在复合相变材料中引入碳纳米纤维(CNFs)提高相变体系的导热系数,以实现相变材料与外界环境进行快速有效的热量交换.本文采用熔融共混法将Na2 SO4·10H2 O和Na2 HPO4·12H2 O制备成共晶盐相变材料,借助聚丙烯酸钠构筑三维聚合物网络封装相变材料,利用CNFs提升复合材料的导热系数.通过Raman、XPS等测试方法,研究了CNFs经高能球磨、湿化学氧化处理后,其表面含氧官能团的变化;借助Raman、DSC、Hot disk、TG等测试方法,分析了CNFs对复合材料化学相容性、相变行为、热稳定性、潜热容量、导热系数的影响.结果表明:CNFs经过功能化处理,氧、碳原子比增大至0.140,氧化效果显著;CNFs引入至复合相变材料中,体系内各组分之间存在良好的化学相容性;当CNFs的添加量达到3％(质量分数),复合材料的固、液态导热系数分别达到1.05 W/(m·K)、0.88 W/(m·K),相较于未添加CNFs的复合材料,固、液态导热性能分别提升了69.4％、60.0％;经过1000次循环试验,复合材料的熔融焓和结晶焓相较循环前分别下降了56.2％、65.3％,相变体系仍然具备一定的储热能力,表明将相变材料嵌入三维网络结构是一种有效的封装策略.

To solve the problem of the shortened cycle life of phase-change latent heat storage due to the large subcooling degree and serious phase stratification of mirabilite phase-change materials, a graphene oxide/mirabilite composite phase-change material (GO–MCPCM) was prepared with Na2SO4·10H2Na2CO3·10H2–NaCl phase-change composite as a matrix and graphene oxide (GO) as additives. The microstructure and properties of GO and GO–MCPCMs were characterized by scanning electron microscopy, transmission electron microscopy Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetry-Differential scanning calorimetry, respectively. The results show that the O/C ratio in oxidized graphene oxide is increased by 65.75%, the structural defect level is increased from 0.224 to 1.088, indicating that the oxidation–treated graphene has no agglomeration phenomenon and has good hydrophilicity and compatibility. The crystalline phase transition temperature of GO–MCPCMs is 23 ℃, the degree of subcooling reduces to 0 ℃, only sodium sulfate decahydrate releases heat, and the crystalline hydrate is Na2SO4·10H2O with a grain length of approximately 2 cm. The maximum latent heat of GO–MCPCMs crystallization at a mass fraction of 0.075% is 156.7 J/g, and the attenuation rate of the latent heat of GO–MCPCMs crystallization at a mass fraction of 0.075% is 4.3% after 500 solid–liquid cycles. Therefore, the addition of GO can improve the thermal stability of the mirabilite composite phase-change material, and graphene oxide/mirabilite composite phase-change material prepared has a good thermal cycle stability and a long service life.

Carbon sponge can be used as a carrier for phase-change materials due to its advantages of low density, large pore volume, and high thermal conductivity. A carbon sponge with certain graphitization characteristics and a porosity of 96.30% was synthesized as a carrier with absorbent cotton and MgO as raw materials, and a composite phase-change material encapsulated by a porous carbon sponge was prepared with Na2SO4·10H2O/Na2HPO4·12H2O as a phase-change medium. The results show that the adsorption amount of carbon sponges prepared at 700, 800 ℃ and 900 ℃ to the phase-change materials is 60, 75 and 102 times greater than their weights, respectively. Also, the solid-liquid phase-change cycle performance of the carbon sponge-encapsulated materials prepared at different temperatures was discussed at 5–60 ℃. After 5 000 cycles, the latent heat of the phase-change material is still > 200 J·g–1, which is reduced by 13%, and the thermal conductivity increasing rate is > 50%. The composite phase-change material encapsulated by porous carbon sponge has promising application prospects in the field of solar energy storage.

Photo-assisted Cu–Co/CeO2 in the Fischer–Tropsch synthesis to achieve high value-added alcohol production. Under light, the excited Cu and the electron transfer behavior of CeO2 promote the adsorption of CO and rapid hydrogenation.

为了形成全员育人、全过程育人的良好态势,文章首先对过程装备CAD课程中的思政元素进行了分析,然后明确了过程装备CAD课程思政教学目标,接着论述了过程装备CAD课程思政教学实践,最后说明了过程装备CAD课程思政教学的考核标准.

A Fe doped TiO2 catalyst (Fe-TiO2) was evaluated for NO oxidation reaction under visible light irradiation. The Fe-TiO2 not only exhibited better catalytic activity and stability, but also suppressed the production of nitrogen dioxide (NO2) than the undoped TiO2. The results of in situ DRIFTS indicated that visible light benefited the adsorption and activation of NO at Fe sites (Fe-(NO)(2)) and Ti sites (Ti-3-NO) as well as the formation of active intermediates (e.g. Fe3+-NO3- and Ti4+-NO-). After EPR, DRS, PL and XPS testing, it was proposed that incorporating Fe ions into TiO2 induced the formation of more oxygen vacancies (OVs), while visible light further facilitated this process, resulting in an enhanced adsorption & activation of NO and also a promoted formation of reactive oxygen species (ROS). Thus, a strengthened photo-driven effect for oxidizing NO into NO2- and NO3- occurred on Fe-TiO2.

以硝酸铋、偏钒酸铵、硝酸铜、氢氧化钠、硝酸等为主要原料,采用水热法合成Cu掺杂BiVO4光催化剂.主要研究了Cu的掺杂量对合成BiVO4光催化剂性能的影响.采用XRD、SEM、BET、紫外—可见分光光度计等检测仪器对合成试样的物相组成、微观形貌、比表面积及光催化性能进行了表征.结果 表明:Cu掺杂改变了合成产物的物相组成,产物中出现Bi2O3、V2O5等杂质,并且产物的形貌发生了较大变化.光催化降解亚甲蓝结果表明,随着Cu掺杂量的增加,合成光催化剂的光催化性能呈现先增加后减小趋势,当Cu掺杂量为5 wt％时,合成产物的光催化性能达到最佳,在高压汞灯照射240 min时,对亚甲蓝(1 0 mg/L)的降解率达87.8％,比同条件下纯BiVO4的光催化效率提高16.4％.

Design and preparation of dual-role anode materials with extraordinary performance for rechargeable Li/Na-ion batteries(LIBs/NIBs)re-mains highly challenging.Herein,three-dimensional(3D)pomegranate-like porous bimetallic NiCo2Se4 spheres with N-doped carbon(termed as NC@NiCo2Se4)are synthesized by solvothermal method and annealing.Microstructure investigations reveal that the NC@NiCo2Se4 spheres include nano-sized NiCo2Se4 particles as inner core and NiCo2Se4 with the modification of thin-walled N-doped carbon layer as inner/outer shell.The bimetallic NC@NiCo2Se4 spheres possess synergistic interaction of Ni/Co atoms to enhance intrinsic conductivity and electro-chemical activity,unique pomegranate-like structure with an inner void space and robust shell to mitigation volume expansion,and intimate contact of N-doped carbon layer to improve interface effect and accelerate conversion kinetics.As anode materials,the NC@NiCo2Se4 exhibits superior lithium/sodium storage performances(1401.6 and 794.8 mA h g-1 at current density of 0.5 and 5 A g-1 after 500 cycles for LIBs as well as 433.9 mA h g-1 at 3 A g-1 after 1000 cycles and a high capability of 306.6 mA hg-1 at 20 A g1 for NIBs).This work represents an impressive strategy for future research of bimetallic selenides as anode materials for advanced high-performance LIBs/NIBs.

采用水热法制备了一系列不同的CeO2/Bi2MoO6纳米复合材料,分别考察了pH值(2～9)和Ce/Bi摩尔比(3％～10％)等因素对其光催化性能的影响.利用X射线粉末衍射、扫描电镜、红外光谱、紫外-可见漫反射光谱、光致发光光谱、瞬态光电流-时间响应等一系列分析测试手段对催化剂的组成、结构、光电性能等进行表征.结果表明,当pH=6时,所制备的Bi2MoO6(BMO)晶体形貌为细针状,复合CeO2后形貌为厚片状,比表面积减小、晶体颗粒增大.在实验室模拟太阳光条件下(300 W氙灯)进行光催化活性测试,分别以罗丹明B(RhB)、亚甲基蓝(MB)和苯酚为模拟污染物,对复合光催化剂的光催化活性进行考察,结果表明,当CeO2的含量为5％时呈现出最高的光催化降解活性.5％CeO2/BMO对RhB、MB和苯酚的光催化反应的速率常数分别为0.037 min-1、0.016 min-1和0.007 min-1,相对于纯的BMO分别提高了3.19倍、1.70倍和4.58倍.其光催化性能增强主要原因是CeO2与Bi2MoO6复合后形成异质结有利于光生电子-空穴的有效分离,从而提高了活性自由基的含量.在自由基捕获实验中,超氧根离子自由基(·O2-)、羟基自由基(·OH)和空穴(h+)参与了光催化降解,其影响顺序为:·O2->·OH>h+.

用醇盐法制备了铈和铂元素掺杂的钙钛矿催化材料.用扫描电子显微镜(SEM)、X射线衍射(XRD)和透射电子显微镜(TEM)对材料进行了表征.结果 表明,催化材料颗粒均匀,直径约30nm,以钙钛矿(CaTiO3)和烧绿石(Ca2Ti2O6)共存,铈和铂元素分散均匀并形成掺杂的固溶体结构.构建了Pt(111)和铂铈原子替代钛原子的钙钛矿掺杂模型,并采用基于密度泛函理论的第一性原理对CaTixPtyCezO3材料的形成能、态密度和吸附性能进行了对比研究.结果 表明,CaTi0.9Pt0.05Ce0.05O3对NH3的吸附能与Pt(111)最接近,掺杂使体系吸附能降低,有利于氨氧化催化的吸附和脱附.

采用复合芒硝(SCNa)为相变材料,以强氧化剂多步氧化法氧化石墨粉,然后采用物理共混法制备出具有优异相变热性能的氧化石墨/复合Na2SO4·10H2O相变材料.结果 表明:加入1％石墨粉,相变温度降低到26.5℃,相变潜热提高到195.8 J·g-1.加入强氧化剂氧化石墨粉,相变温度降低至25.4℃,对相变材料相变潜热提高较大,相比于SCNa材料增加了23％,达到216.5 J·g-1,具备较好的相变热性能.

High ionic conductivity electrolyte and intimate interfacial contact are crucial factors to realize high-performance all-solid-state sodium batteries. Na2.9PS3.95Se0.05 electrolyte with reduced particle size of 500 nm is first synthesized by a simple liquid-phase method and exhibits a high ionic conductivity of 1.21 × 10-4 S cm-1, which is comparable with that synthesized with a solid-state reaction. Meanwhile, a general interfacial architecture, that is, Na2.9PS3.95Se0.05 electrolyte uniformly anchored on Fe1- xS nanorods, is designed and successfully prepared by an in situ liquid-phase coating approach, forming core-shell structured Fe1- xS@Na2.9PS3.95Se0.05 nanorods and thus realizing an intimate contact interface. The Fe1- xS@Na2.9PS3.95Se0.05/Na2.9PS3.95Se0.05/Na all-solid-state sodium battery demonstrates high specific capacity and excellent rate capability at room temperature, showing reversible discharge capacities of 899.2, 795.5, 655.1, 437.9, and 300.4 mAh g-1 at current densities of 20, 50, 100, 150, and 200 mA g-1, respectively. The obtained all-solid-state sodium batteries show very high energy and power densities up to 910.6 Wh kg-1 and 201.6 W kg-1 based on the mass of Fe1- xS at current densities of 20 and 200 mA g-1, respectively. Moreover, the reaction mechanism of Fe1- xS is confirmed by means of ex situ X-ray diffraction techniques, showing that partially reversible reaction occurs in the Fe1- xS electrode after the second cycle, which gives the obtained all-solid-state sodium battery an exceptional cycling stability, exhibiting a high capacity of 494.3 mAh g-1 after cycling at 100 mA g-1 for 100 cycles. This contribution provides a strategy for designing high-performance room temperature all-solid-state sodium battery.

文章在研究孔子"志于道,据于德,依于仁""己所不欲,勿施于人""与其进也,不与其退也"等思想的基础上,探讨了孔子德育为先、以人为本、注重发展的学生观,并提出了孔子的学生观对高校辅导员工作的启示.

High density SiC ceramic was fabricated with pure SiC micro- and nano-powders in a hinge-type cubic-anvil press method at 4.5GPa and 1250℃ for an optimum heat-preserving time of 6 min. SiC ceramic was sinterred at a ultrahigh pressure and different amounts of Al2O3, Y2O3(0-15%in mass fraction) as sintering aids. The samples were characterized by X-ray diffraction, field emission electron microscopy, X-ray energy spectroscopy, micro-hardness and density tests, respectively. The result shows that the Al2O3and Y2O3 are effective in low-temperature sintering. At a low temperature and a ultrahigh pressure, SiC ceramic can appear a phase of Al2Y4O9. The relative density of sample sintered with Al2O3of 7.5% and Y2O3of 7.5% at 4.5GPa and 1250℃ for 6 min is 99.9%, and the micro-hardness can reach HV9.802570.

可降解液体地膜具有吸热增温、保墒、保苗作用,具有无污染可降解特性.适合推广应用于高海拔、干早、寒冷、丘陵地区农作物早期地膜覆盖,同时也应用于道路护坡、固沙造林绿化和渠道防渗、树木防冻,用于荒地、沙地、盐碱地和滩涂整治改良.本文从可降解液体地膜材料分类和特性,作用机理以及应用效果进行概述,提出存在问题和下一步研究展望.

采用失重法,并对腐蚀产物的物质组成和显微结构进行X射线衍射和扫描电镜分析,对十水硫酸钠基复合相变储能材料相变循环对不锈钢、铝合金、纯铜和黄铜等金属封装材料的腐蚀动力学特性进行了研究.结果表明:金属封装材料的耐腐蚀性为不锈钢最佳,紫铜的耐腐蚀性最差,其顺序为:不锈钢304＞不锈钢201＞铝合金1060＞铝合金5052＞铝合金6061＞铝合金7075＞黄铜＞紫铜,纯铜的腐蚀主要以点蚀形式存在,蚀孔表面有Cu2O膜的存在,Cl-的存在与氧竞争吸附,加速腐蚀;黄铜也存在点蚀,同时黄铜与相变材料反应,生成物质粘附在黄铜表面.铝合金腐蚀以点蚀形式存在,腐蚀产物呈开裂状附着于基体表面.铜及合金和铝合金不适合做芒硝基复合相变储能材料的封装材料,不锈钢201和304呈现良好的耐腐蚀状态,适宜作为芒硝基复合相变储能材料的金属封装材料.