The fine structure of coelomocytes in the sipunculid Phascolosoma esculenta

Ultrastructural characteristics of coelomocytes of the sipunculid Phascolosoma esculenta were studied by transmission electron microscopy. There are several cell types in the coelomic fluid, including three kinds of granulocytes, vesicular cells, germ cells, amoebocytes, phagocytes, and erythrocytes; there are also a new cell complex which is composed of podocytes and granular cells. And several other cell types (erythrocyte and different kinds of granulocytes) gathering together was discovered in the coelomic fluid of P. esculenta. Functional interpretations were provided for these cells using morphological evidence. The coelomocytes from different sipunculid genera and Annelida were compared. The structural diversity of coelomocytes provides both taxonomic characteristics for discriminative identification and phylogenetic markers in Phascolosoma and other sipunculid taxa.     

模拟移动床色谱技术研究进展

根据模拟移动床色谱技术的发展历程,对其工艺研发,包括异步切换模拟移动床和间歇式模拟移动床等新型操作工艺,以及模拟移动床色谱反应器等进行了综述。总结了近几年模拟移动床色谱技术在手性化合物拆分和糖醇分离中的应用研究进展;展望了模拟移动床色谱的研究方向和发展趋势。     

Target-based design,synthesis and biological activity of new pyrazole amide derivatives

Based on the similarities in the conformation of VS008 (N-(4-methylphenyl)-3-(tert-butyl)-1-(phenylmethyl)-1H-pyrazole-5-carboxamide) and BYIO6830 (N'-(3,5-dimethylbenzoyl)-N'-tert-butyl-5-methyl-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide) bound to the active site of the EcR subunit of the ecdysone receptor (EcR)-ultraspiracle protein (USP) heterodimeric receptor, a series of new pyrazole amide derivatives were designed and synthesized. Their structures were confirmed by IR, ¹H NMR, ¹³C NMR and elemental analysis. Results from a preliminary bioassay revealed that two of the pyrazole derivatives exhibited promising insecticidal activity. Specifically, compounds 6e and 6i exhibited good activity against Helicoverpa armigera (cotton bollworm) at low concentration. Symptoms displayed by tebufenozide-treated H. armigera were identical with those displayed by its treated counterpart. 6i showed the same poisoning symptoms as those of tebufenozide. In addition, results from molecular docking result indicated that the binding modes of 6e and 6i at the active site of the EcR subunit of the heterodimeric receptor were similar to that of the bound tebufenozide.     

Effect of SO<Subscript>2</Subscript> on SCR activity of MnOx/PG catalysts at low temperature

Palygorskite (PG)-supported manganese oxide catalysts (MnOx/PG) were prepared for the selective catalytic reduction (SCR) of NO with ammonia in the presence of SO₂ at low temperature. The influence of gaseous SO₂ on the performance of the catalyst was studied by means of specific surface area (Brunauer-Emmett-Teller, BET) analysis, scanning electron microscopy (SEM), thermogravimetric (TG) analysis, temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). The results showed that the SCR activity of Mn10/PG was significantly inhibited by gaseous SO₂ at temperatures below 300°C. However, the SCR activity of Mn10/PG was markedly promoted by SO₂ in a higher temperature range of 300°C to 500°C. The sulphating of surface active species (MnOx) was suggested to inhibit the oxidation of NH₃ to NO leading to enhancement of the SCR activity at a higher temperature range of 300°C to 500°C and decrease in the SCR activity at temperatures below 300°C.     

掺杂Co2+和Sm3+对纳米ZnFe2O4铁氧体的电磁损耗性质的影响

采用NaHCO3与FeCl3?6H2O,ZnSO4?7H2O,Co(NO3)2?6H2O和Sm(NO3)3?6H2O进行室温固相反应制得碱式碳酸盐和氢氧化铁混合前驱物,先微波加热,再热分解分别制得复合氧化物ZnFe2O4,Co0.5Zn0.5Fe2O4和Co0.5Zn0.5Fe1.95-Sm0.05O4.由激光粒度分析仪、XRD和SEM表征:获得了颗粒分布均匀、平均粒度为62nm左右的立方晶系尖晶石结构的纳米铁氧体粉体.并测试样品的相对介电常数和相对磁导率,研究了它们的电磁损耗特性.结果表明:在ZnFe2O4中,掺入Co2 ,Sm3 元素可以在100～1800MHz测试频率范围内不同程度提高材料的电磁损耗特性.     

铬掺杂的锂离子电池正极材料LiVPO4F的制备以及电化学行为的研究

采用高温固相法2步合成了掺Cr的锂离子电池正极材料LiV_1-xCr_xPO₄F(x=0，0.01，0.03，0.05，0.07)，XRD测试表明LiV_1-xCr_xPO₄F属三斜晶系。通过恒电流充放电，循环伏安和交流阻抗实验表明：掺Cr后LiVPO₄F正极材料更有利于锂离子的嵌入和嵌出，材料的放电容量和循环性能进一步提高，例如，铬掺杂的LiVPO₄F样品在室温、0.2 C倍率下充放电，循环50周后容量在110 mAh·g^-1以上。文中还讨论了充放电容量随掺Cr量的关系，n_Cr含量为0.03的LiV_1-xCr_xPO₄F有着较高的放电平台和良好的循环稳定性。     

球型Ni(OH)2表面包覆Y(OH)3及其高温充放电性能

应用共沉淀的方法在球型Ni(OH)₂的表面包覆了一层Y(OH)₃,并研究了包覆不同含钇量后的球型Ni(OH)₂的高温充放电性能。研究结果表明:包覆Y(OH)₃的球型Ni(OH)₂具有良好的高温充放电性能。其中1C充放电条件下,包覆量为0.3%的Ni(OH)₂较好,0.2C充放电条件下,包覆量为1%的Ni(OH)₂较好。     

思维导图在仪器分析实验教学中的应用——以电化学分析实验为例

在电化学分析实验教学中引入思维导图,探讨了思维导图在仪器分析实验教学中的应用方法及效果评价。实验原理的教学依托“比较与对比图”和“逻辑思维图”,强调相关方法原理之间的联系,突出新方法的特点;实验步骤则以清晰易懂的“流程图”方式呈现。教学实践表明,思维导图有利于学生对实验基本原理的理解和掌握,提高了学生的实验兴趣,促进了学生的独立思考能力和解决问题的能力,显著提升了实验教学效果。     

Breit-Wigner formula for the scattering phase in the Stark effect

Near resonance energy, we study the asymptotic behavior of the derivative of the scattering phase as the applied electric field tends to zero. We obtain the leading asymptotics of the spectral function near a simple resonance, and as an application we rigorously prove the Breit-Wigner formula which relates the width of resonances to the time delay of particles in a homogeneous electric field.Supported by Alexander von Humboldt Stiftung