铈对16Mn钢中夹杂物和组织的影响

在高温钼丝炉内向16Mn钢中加入不同含量的铈进行脱氧,分析了钢中夹杂物和组织的变化,并探讨了含铈夹杂物诱发晶内铁素体形核的机制.结果表明:随钢中铈含量的增加,夹杂物依次转变为CeAlO3,Ce2O2S和Ce2S3.经铈处理后,钢液在1873 K时保温300 s,夹杂物最为细小弥散.钢中晶内铁素体随铈含量的增加而增加,但最佳的铈含量约为0.032%(质量分数).钢中Ce2O2S和Ce2S3夹杂与α-Fe相之间的错配度分别只有1.2%和0.5%,均可作为IGF非常有效的形核核心,促进其形成.     

Preparation and properties of ZnMoO4 anode materials with polymer network gel method

Polymer network gel method combines the advantages of solid-phase method and liquid phase method, triggering acrylamide (AM) radical polymerization in aqueous solution and N, N′- methylene bis acrylamide (MBAM) active double bond cross-linking reaction, forming polymer chains to form a three-dimensional network. The polymer network space formed by the gel is bound and evenly distributed to the ions in the solution, thereby reducing the contact and aggregation of molecules and achieving the purpose of uniform particle size and small particle size. The principle diagram of network gel is shown in Figure. Using cubic zinc acetate and ammonium molybdate tetrahydrate as raw materials, cubic ZnMoO₄ negative electrode materials were prepared with polymer network gel method. The polymer network gel method has various effects on the structure, morphology and electrochemical properties of materials. Besides, the calcination temperature and calcination time were also the key factors to the electrochemical properties of the materials. In this paper, the effects of the ratio of monomer and crosslinker, calcination temperature and calcination time on ZnMoO₄ materials were studied by single variable method, the preparation process was optimized, and its characterization and electrochemical tests were carried out. After 100 cycles, the optimized ZnMoO₄ electrode has a discharge capacity of 374.0 mAh· g^?1, 332.5, 263.5 and 177.1 mAh · g^?1 at current densities of 0.1, 0.5, 1.0 and 2.0 A g^?1, respectively. The electrochemical results show that the optimized ZnMoO₄ has high capacity, large rate capability and excellent cycle stability.     

Excellent UV-absorbing cotton fabric with high durability and hydrophobicity based on surface-initiated ATRP of polymerizable organic UV-absorber

Cellulose - Ultraviolet (UV) protective cotton fabric is a convenient and reliable way to protect human body from sunlight. Herein, a polymerizable UV-absorber,...     

Novel WS2/Fe0.95S1.05 Hierarchical Nanosphere as a Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction

Fe_0.95S_1.05 with high reactivity and stability was incorporated into WS₂ nanosheets via a one-step solvothermal method for the first time. The resulted hybrid catalyst has much higher catalytic activity than WS₂ and Fe_0.95S_1.05 alone, and the optimal WS₂/Fe_0.95S_1.05 hybrid catalyst was found by adjusting the feed ratio. The addition of Fe_0.95S_1.05 was proven to be able to enhance the hydrogen evolution reaction (HER) activity of WS₂, and vice versa. At the same time, it was found that the catalytic effect of the hybrid catalyst was the best when the feed ratio was W : Fe=2 : 1. In other words, we confirmed that there is a synergistic effect between W- and Fe-based sulfide hybrid catalysts, and validated that the reason for the improved HER performance is the strong interaction between the two in the middle sulfur. WS₂/Fe_0.95S_1.05-2 hybrid catalyst leads to enhanced HER activity, which shows a low overpotential of ∼0.172 V at 10 mA cm⁻², low Tafel slope of ∼53.47 mV/decade. This study supplies innovative synthesis of a highly active WS₂/Fe_0.95S_1.05 hybrid catalyst for HER.     

A new three‐dimensional cobalt(II) coordination polymer based on V‐shaped 3,4′‐oxydibenzoate: synthesis,crystal structure and magnetic properties

A new coordination polymer (CP), namely poly[(μ‐4,4′‐bipyridine)(μ₃‐3,4′‐oxydibenzoato)cobalt(II)], [Co(C₁₄H₈O₅)(C₁₀H₈N₂)]_n or [Co(3,4′‐obb)(4,4′‐bipy)]_n ( 1 ), was prepared by the self‐assembly of Co(NO₃)₂·6H₂O with the rarely used 3,4′‐oxydibenzoic acid (3,4′‐obbH₂) ligand and 4,4′‐bipyridine (4,4′‐bipy) under solvothermal conditions, and has been structurally characterized by elemental analysis, IR spectroscopy, single‐crystal X‐ray crystallography and powder X‐ray diffraction (PXRD). Single‐crystal X‐ray diffraction reveals that each Co^II ion is six‐coordinated by four O atoms from three 3,4′‐obb^2? ligands, of which two function as monodentate ligands and the other as a bidentate ligand, and by two N atoms from bridging 4,4′‐bipy ligands, thereby forming a distorted octahedral CoN₂O₄ coordination geometry. Adjacent crystallographically equivalent Co^II ions are bridged by the O atoms of 3,4′‐obb^2? ligands, affording an eight‐membered Co₂O₄C₂ ring which is further extended into a two‐dimensional [Co(3,4′‐obb)]_n sheet along the ab plane via 3,4′‐obb^2? functioning as a bidentate bridging ligand. The planes are interlinked into a three‐dimensional [Co(3,4′‐obb)(4,4′‐bipy)]_n network by 4,4′‐bipy ligands acting as pillars along the c axis. Magnetic investigations on CP 1 disclose an antiferromagnetic coupling within the dimeric Co₂ unit and a metamagnetic behaviour at low temperature resulting from intermolecular π–π interactions between the parallel 4,4′‐bipy ligands.     

An E1-Catalyzed Chemoenzymatic Strategy to Isopeptide-N-Ethylated Deubiquitylase-Resistant Ubiquitin Probes

Triazole-based deubiquitylase (DUB)-resistant ubiquitin (Ub) probes have recently emerged as effective tools for the discovery of Ub chain-specific interactors in proteomic studies, but their structural diversity is limited. A new family of DUB-resistant Ub probes is reported based on isopeptide-N-ethylated dimeric or polymeric Ub chains, which can be efficiently prepared by a one-pot, ubiquitin-activating enzyme (E1)-catalyzed condensation reaction of recombinant Ub precursors to give various homotypic and even branched Ub probes at multi-milligram scale. Proteomic studies using label-free quantitative (LFQ) MS indicated that the isopeptide-N-ethylated Ub probes may complement the triazole-based probes in the study of Ub interactome. Our study highlights the utility of modern protein synthetic chemistry to develop structurally and new families of tool molecules needed for proteomic studies.     

磷酸盐聚酯型水性聚氨酯/纳米SiO2的合成与性能

以2-磷酸基-1,2,4-三羧酸丁烷(PBTCA)、新戊二醇(NPG)为原料,制得数均相对分子质量为1500并含有磷酸基团的聚酯多元醇。将其与异佛尔酮二异氰酸酯(IPDI)反应,经1,4-丁二醇(BDO)扩链后得到水性聚氨酯,再以KH550为偶联剂,加入纳米SiO2,合成了纳米改性的磷酸型水性聚氨酯(PWPU)。通过红外光谱(FI-IR)、热重分析(TGA)对PWPU的结构和热稳定性进行了研究,使用透射电子显微镜(TEM)对乳液的形貌进行了观察。通过TEM发现,大量粒径在110 nm左右的化合物合成,并与红外光谱联合分析得出,SiO2通过化学键与PWPU相连接。热重分析、残炭量分析和拉伸测试表明,经过纳米SiO2改性的PWPU其阻燃性、热稳定性以及力学性能均有明显的提升,具有很好的应用前景。     

Photocatalytic activities of C–N-doped TiO2 nanotube array/carbon nanorod composite

A C–N-doped TiO₂ nanotube (NT)/carbon nanorod composite is fabricated by chemical vapor deposition (CVD). Carbon nanorods are grown from the TiO₂ NTs, and partly graphitized, while TiO₂ is in the mixture of anatase and rutile. The C–N doping shifts the absorption edge of TiO₂ NTs to the visible light region; the formed carbon nanorods promote the charge carrier transfer from the TiO₂ surface to the electrolyte. Under the simulated solar light irradiation, the C–N-doped TiO₂ NTs show higher photocatalytic activity in the degradation of methyl orange (MO) than the undoped TiO₂ NTs.