Surface Engineering Stabilizes Rhombohedral Sodium Manganese Hexacyanoferrates for High-Energy Na-Ion Batteries

The rhombohedral sodium manganese hexacyanoferrate (MnHCF) only containing cheap Fe and Mn metals was regarded as a scalable, low-cost, and high-energy cathode material for Na-ion batteries. However, the unexpected Jahn-teller effect and significant phase transformation would cause Mn dissolution and anisotropic volume change, thus leading to capacity loss and structural instability. Here we report a simple room-temperature route to construct a magical Co_xB skin on the surface of MnHCF. Benefited from the complete coverage and the buffer effect of Co_xB layer, the modified MnHCF cathode exhibits suppressed Mn dissolution and reduced intergranular cracks inside particles, thereby demonstrating thousands-cycle level cycling lifespan. By comparing two key parameters in the real energy world, i.e., cost per kilowatt-hours and cost per cycle-life, our developed Co_xB coated MnHCF cathode demonstrates more competitive application potential than the benchmarking LiFePO₄ for Li-ion batteries.     

Manganese-Catalyzed Redox-Neutral Thiolation of Alkyl Halides with Thioformates

Transition metal-catalyzed C−S cross-coupling has emerged as an important strategy to furnish thioethers; however, the dominant utilization of noble metal catalysts as well as the construction of challenging C(sp³)−S bonds by transition metal-catalysis remain highly problematic. Earth-abundant manganese has gathered increasing interest as an attractive catalyst for new reaction development; nevertheless, C(sp³)−S cross-coupling reaction by manganese catalysis has not been reported. Herein, we disclose a highly efficient manganese-catalyzed redox-neutral thiolation of a broad range of alkyl halides with thioformates as practical sulfuration agents. Strategically, employing easily synthesized thioformates as thiyl radical precursors allows access to various aryl and alkyl thioethers in good to excellent yields. Notably, this redox-neutral method avoids the utilization of strong bases, external ligands, forcing reaction conditions, and stoichiometric manganese, thus presenting apparent advantages, such as broad substrate scope, excellent functional group compatibility, and mild reaction conditions. Finally, the utilities of this method are also illustrated by downstream transformations and late-stage thiolation of structurally complex natural products and pharmaceuticals.     

ICP－AES法同时测定电解金属锰中的硅、铁、硒和磷

本文研究了用ＩＣＰ－ＡＥＳ直接测定电解金属锰中的Ｓｅ、Ｐ、Ｓｉ、Ｆｅ等元素的方法，方法简便、快速，精密度和准确度均能满足对出口电解金属锰的检验要求。     

高血脂大鼠摄入富硒饲料对血清中铜,锌,钙,镁含量的影响

将４０只雄性ＳＤ大鼠随机分成两组，采用猪油（Ｌ）或玉粮米油（Ｍ）加胆固醇饲料诱导出大高血脂模型后，再分出两组、分别加入亚硒酸钠（Ｌ－Ｓｅ，Ｍ－Ｓｅ），观察大鼠补硒后血清中锌铜、锌、钙、镁等元素的变化。结果表明，高血脂大鼠补硒后血 锌的含量明显下降，铜／锌比值长高。相关分析显示：血硒水平与血清锌含量呈负相关，各组大鼠血清铜、钙、镁的浓度未观察到显著性差异。     

Automorphisms for Skew PBW Extensions and Skew Quantum Polynomial Rings

In this work, I study the automorphisms of skew PBW extensions and skew quantum polynomials. I use Artamonov's works as reference for getting the principal results about automorphisms for generic skew PBW extensions and generic skew quantum polynomials. In general, if I have an endomorphism on a generic skew PBW extension and there are some x _i , x _j , x _u such that the endomorphism is not zero on these elements and the principal coefficients are invertible, then endomorphisms act over x _i as a _i x _i for some a _i in the ring of coefficients. Of course, this is valid for quantum polynomial rings, with r = 0, as such Artamonov shows in his work. We use this result for giving some more general results for skew PBW extensions, using filtred-graded techniques. Finally, I use localization to characterize some class the endomorphisms and automorphisms for skew PBW extensions and skew quantum polynomials over Ore domains.     

氧化电位溶出法测定水质和生物样品中的铜、铅、镉、锌、锰

在潭石酸-NaOH(pH=9)底液中,用银基汞膜电极作工作电极,以底液中的溶解氧作氧化剂,Cu~(2+)、pb~(2+)、Cd~(2+)、Zn~(2+)分别能产生灵敏的溶出峰。峰电流对浓度的线性范围依次为0.2～2800ng/ml、0.1～3400ng/ml、0.05～1400ng/ml、0.2～6100ng/ml。往上述底液中再加入适量的对氨基苯磺酸,Mn~(2+)亦可产生灵敏的电位溶出峰,线性范围为0.5～4800ng/ml。     

Synthesis and Antibacterial Activity of Metal Complexes of Cephalothin

The interactions of cephalothin (Hcephalo) with transition metal(II) ions and imidazole have been investigated. The complexes [M(cephalo)Cl], (where M=Mn(II), Co(II), Ni(II), Pd(II)) and [M(cephalo)(Im)Cl] (where M=Ni(II), Cu(II), Zn(II), Im=Imidazole) were obtained and characterized by physicochemical and spectroscopic methods. The IR and the ¹H-NMR spectra of the complexes suggest that the cephalothin behaves as a monoanionic tridentate ligand. They have been screened for antibacterial activity against several bacteria, and the results are compared with the activity of cephalothin.     

Structures of Mn(II) complexes of bis(2-pyridylmethyl)amine (bpa) and (2-pyridylmethyl)(6-methyl-2-pyridylmethyl)amine (Mebpa): geometric isomerism in the solid state

The crystal structures of [Mn(bpa)₂](ClO₄)₂ (1), [bpa?=?bis(2-pyridylmethyl)amine], and Mn(6-Mebpa)₂(ClO₄)₂ (2), [6-Mebpa?=?(6-methyl-2-pyridylmethyl)(2-pyridylmethyl)amine] have been determined. In 1, two facial [Mn(bpa)₂]²⁺ isomers are observed in the same unit cell, one with C _i (1a) and the other with C₂ (1b) symmetries. In 2, only the isomer with C₂ symmetry is observed. The structure of [Mn(bpa)₂]²⁺ with only C₂ symmetry has been reported previously (Inorg. Chem., 31, 4611 (1992)). The bond length order Mn–N_amine?>?Mn–N_pyridyl, observed in the C₂ and the C _i isomers in the crystals of 1, is the reverse of the order observed in the structure of [Mn(bpa)₂](ClO₄)₂ which contains only the C₂ isomer in the unit cell. The structure of 2 in which only the C₂ isomer is found, also shows the bond length order Mn–N_pyridyl?>?Mn–N_amine. In cyclic voltammetric experiments in acetonitrile solutions, 1 and 2 show irreversible anodic peaks at E _p?=?1.60 and 1.90?V respectively, (vs. Ag/AgCl), assigned to the oxidation of Mn(II) to Mn(III). The substantially higher oxidation potential of 2 is attributable to a higher rearrangement energy in complex 2 due to the steric effect of the methyl substituent.     

分光光度法测定家兔体内铁和锰的代谢

为探讨补铁和补锰药物的代谢情况,我们对家兔灌胃中剂量金施尔康多维元素片,每小时对家兔取血,利用邻二氮菲分光光度法测定血样中铁与锰的含量。结果显示:7h铁在家兔血液中含量达到峰值37.86μg·mL-1,10h基本代谢完毕,恢复至正常值28.72μg·mL-1;5h锰在家兔血液中含量达到峰值1.31μg·mL-1,但代谢缓慢,16h后代谢完毕,恢复至正常值0.008μg·mL-1。本实验可为科学补铁、补锰提供一定依据。     

Enantioselective Sulfoxidations Catalyzedby Horseradish Peroxidase, ManganesePeroxidase, and Myeloperoxidase

Summary.  Horseradish peroxidase (HRP), myeloperoxidase (MPO), and manganese peroxidase (MnP) have been shown to catalyze the asymmetric sulfoxidation of thioanisole. When H₂O₂ was added stepwise to MPO, a maximal yield of 78% was obtained at pH 5 (ee 23%), whereas an optimum in the enantiomeric excess (32%, (R)-sulfoxide) was found at pH 6 (60% yield). For MnP a yield of 18% and a high enantiomeric excess of 91% of the (S)-sulfoxide were obtained at pH 5 and a yield of 36% and an ee of 87% at pH 7.0. Optimization of the conversion catalyzed by horseradish peroxidase at pH 7.0 by controlled continuous addition of hydrogen peroxide during turnover and monitoring the presence of native enzyme as well as of intermediates I, II, and III led to the formation of the sulfoxide in high yield (100%) and moderate enantioselectivity (60%, (S)-sulfoxide). Received November 18, 1999. Accepted January 21, 2000