DA201树脂对伊枯草菌素A动态吸附性能的研究

伊枯草菌素A是一种具有代表性的微生物源两性环脂肽类化合物。采用DA201大孔吸附树脂从枯草芽孢杆菌发酵液中分离提取伊枯草菌素A,考察了不同吸附、解吸条件对其动态吸附性能的影响。结果表明,DA201型树脂对发酵液中伊枯草菌素A的饱和吸附容量可达到3.48mg/g;动态吸附中最佳吸附流速为1BV/h,其吸附率可以达到95.56%;采用95%乙醇作为洗脱剂,以1BV/h的流速洗脱,其洗脱率可以达到92.41%;DA201型树脂是一种从发酵液中分离和提取伊枯草菌素A的较理想的吸附剂。     

大孔吸附树脂对莲房原花青素吸附纯化性能的研究

比较了14种大孔吸附树脂对莲房中原花青素(proanthocyanidins of lotus seedpod,LSPAs)的吸附及解吸性能,在研究静态吸附的基础上,筛选出效果较好的树脂进行动态实验研究,并对所得组分LSPAs含量及其相对分子量进行初步分析.结果表明,DM130大孔吸附树脂分离纯化LSPAs效果最佳,上样浓度为2.5mg/mL,流速为3BV/h时,饱和吸附量为4～4.5个BV;当用体积分数为50%乙醇以3BV/h的流速洗脱5BV时,LSPAs的累积回收率可达96.43%,含量从22.54%提高到95.31%;经质谱分析,(M+H)分子量范围为291.1～1155.3,聚合度≤4.     

大孔吸附树脂分离提取多杀菌素

采用大孔吸附树脂法分离提取多杀菌素.从11种大孔吸附树脂中筛选出DM11进行了静态、动态吸附性能实验,并考察了不同吸附、解吸条件的影响.结果表明,DM11的静态吸附容量为25.63mg/g(wet resin),其吸附等温线符合Langmuir吸附等温式.采用丙酮做洗脱剂,洗脱率为97.5%,动态吸附最佳吸附pH为9.5,吸附流速为6BV/h,穿透吸附容量为21.2mg/ml(wet resin),洗脱流速1.5BV/h.     

A222型阴离子交换树脂脱除HPP水溶液中SO_4~(2-)的研究

论文研究了A222树脂在N,N'-二(2-羟丙基)哌嗪(HPP)脱硫胺液中对SO42-的离子交换性能,优化条件为振荡温度50℃、交换时间2h,HPP浓度0.5mol/L、SO42-浓度0.3mol/L、p H值5.1、固液比80g/L,此条件下,树脂的交换量达163.57mg/g。在HPP-SO42-中,A222树脂具有优良的稳定性和脱盐效果,在循环交换-解吸过程中,对SO42-的平均交换量为136.25mg/g、平均交换率51.37%、平均脱附率96.48%、室温下的动态交换量可达196.90mg/g。FT-IR和TG研究结果表明,HPP能通过物理吸附作用附着在A222树脂上,而树脂对SO42-的离子交换过程中有化学键生成。树脂对SO42-的吸附过程更好地遵循Freundlich等温吸附规律。     

D301R树脂吸附-解吸钼的行为研究

对D301R型阴离子交换树脂吸附-解吸钼的条件进行了研究，采用静态法试验了pH值、钼的浓度等因素对该树脂吸附钼的影响；采用动态法讨论了该树脂对钼的饱和吸附量、解吸剂及其浓度对解吸钼的影响。结果表明在pH2．5，钼的浓度为20g/L时吸附效果最好，树脂对钼的饱和吸附量为1020mg／g，而采用150g/L NaOH溶液解吸钼效果最佳。     

蚕砂总生物碱提取物的脱色研究

通过动态吸附实验,考察了D296R(-Cl型)、D296R(-OH型)、D2040、X-5、D380(-Cl型)和D380(-OH型)6种树脂对蚕砂提取液的脱色作用,筛选出分离效果较好的树脂并确定了其分离条件,在此基础上使用正交设计法对它进行树脂再生条件的探究。通过对比这6种树脂对色素及活性物质的分离效果,发现D296-R(-Cl型)大孔阴离子交换树脂脱色效果最为理想,以95%乙醇溶液稀释的蚕砂提取液,经该树脂上样分离后,用3BV70%的乙醇溶液洗脱,所得洗脱液吸光度0.1,活性成分保留较多。正交设计法得出该树脂的适宜再生条件:乙醇浓度为80%,流速为3BV/h,NaOH溶液浓度为3%。     

大孔吸附树脂纯化迷迭香脂溶性总酚酸的研究

从X-5、D4020、AB-8、H1020、NKA-Ⅱ、HPD-100A、SIPI、HPD800和D3520大孔吸附树脂中筛选出H1020树脂,研究了其对迷迭香脂溶性总酚酸的静态与动态吸附和解吸性能.结果表明,H1020树脂对迷迭香脂溶性总酚酸的饱和吸附量为19.84mg/g干树脂,饱和吸附时间为3h,适宜的解吸荆为体积分数90%的乙醇溶液;以质量浓度为4.45m/mL的迷迭香提取液上柱,流速为1.0mL/min,当吸附平衡后,2.7BV体积分数90%的乙醇溶液可将吸附的总酚酸完全洗脱.经动态纯化后,脂溶性总酚酸质量分数从47.74%提高到70.46%,该组分清除DPPH自由基的IC50值为0.0469mg/mL.     

用离子交换法从植物水提液中纯化分离左旋多巴的研究

本文比较了D290、D296、D370、D301、201×4、201×7等6种树脂对植物水提液中左旋多巴的静态交换和动态交换性能。筛选出D296用以研究不同pH、不同流速、不同解吸剂对吸附交换或解吸交换的影响。实验结果表明：用此工艺得到的产品，有关质量符合药典要求，收率可达4．0％以上。     

树脂吸附法纯化赤霉素

对比了几种大孔吸附树脂对赤霉素发酵液的吸附、解吸性能,实验发现,自制R4树脂的动态饱和吸附容量高达58.38mg/g干树脂,自制R5树脂的动态饱和吸附容量高达96.46mg/g干树脂,R5树脂的吸附容量明显高于R4,这与树脂的比表面积一致.50%(VIV)甲醇水溶液具有较好的解吸性能,收率高达95%以上,经过树脂一步吸附-解吸,赤霉素的浓度可平均提高5倍以上,集中收集最高可提高15倍以上,这对于工业化生产中,赤霉素的进一步结晶析出具有重要意义.     

离子交换法脱除柠檬酸中的硫酸根离子和氯离子

基于动态法研究了D315树脂吸附柠檬酸溶液中硫酸根离子(SO42-)和氯离子(Cl-)的性能,考察了单柱工艺与串柱工艺吸附分离柠檬酸溶液中SO42-和Cl-的效果。研究表明,溶液相中亲和力强的SO42-和Cl-可置换树脂相中柠檬酸,串柱工艺可提高溶液相中SO42-、Cl-与树脂中柠檬酸的交换频率,树脂对SO42-和Cl-的穿透吸附容量达到5.17mmol/g干树脂。另外,改变进料液流速和组成等因素后,串柱工艺中树脂的利用率>85%,高于同等条件下单柱工艺且具有良好的稳定性。     

Solvent extraction separation of In/III/-Tl/III/ and Hg/II/-Cd/II/-Co/II/ with sulphoxides

Solvent extraction studies have been made on some metals: In/III/-Tl/III/ and Hg/II/-Cd/II/-Co/II/, from ammonium thiocyanate solutions by dialkyl sulphoxides. Separation of these metals from one another can be achieved by suitable choice of the extracted conditions. The nature of the extractable metal species has been elucidated.     

Synthesis of chlorobis/β-diketonato/oxotechnetium/V/ and tris/β-diketonato/technetium/III/ complexes

Chlorobis/-diketonato/ oxotechnetium/V/ complexes [TcOCl/-dik/₂, -diketone=acetylacetone, benzoylacetone and dibenzoylmethane] were newly synthesized using macroamount of⁹⁹Tc. These complexes were further separated into geometrical isomers. Furthermore, an improvement of the yields for the syntheses of tris/-dike-tonato/technetium/III/ complexes [Tc/-dik/₃, -diketone=acetylacetone, benzoylacetone and 2-thenoyltrifluoroacetone] was examined using Tc/III/-thiourea complexes as a starting material.     

Crystal structure of Na3PO4 · 12H2O

The crystal structure of trisodium monophosphate hemihydrate was determined. The space group is $\text{C2}\text{c}$ and a unit cell contains eight formula units. The unit cell dimensions of $\text{Na}{}_3\text{PO}{}_4\text{·}\text{1}\text{2}\text{H}{}_2\text{O}$ are a = 9.631(3), b = 5.416(2), c = 16.938(8) Å, β = 102.60(5)°. The final R value is 0.027 for a set of 1430 independent reflections. This atomic arrangement is mainly a three-dimensional network of distorted NaO₆ octahedra. The hydrogen bonding scheme is given.     

Simultaneous propane dehydrogenation andco2hydrogenation overCrOx/SiO2catalyst

Summary Single reverse water-gas shift (RWGS) and dehydrogenation of propane with CO₂(DH-CO₂) reactions in the presence and absence of the CrO_x/SiO₂ catalyst have been studied between 673 and 873 K. It was found that the CrO_x/SiO₂ catalyst is active both in the dehydrogenation of propane and in the RWGS reactions. The obtained results suggest that the dehydrogenation of propane to propene in the presence of CO₂on CrO_x/SiO₂can be facilitated by the RWGS reaction.</o:p>     

Direct synthesis of dimethyl carbonate ?from CH3OH AND CO2 by H3PW12O40/CexTi1-xO2 catalyst

Summary Ce_xTi_1-xO₂ and H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ catalysts were prepared using a sol-gel method, and applied to the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ showed a better catalytic performance than the corresponding Ce_xTi_1-xO₂, due to the bifunctional catalysis of Br?nsted acid sites (provided by H₃PW₁₂O₄₀) and base sites (provided by Ce_xTi_1-xO₂). H₃PW₁₂O₄₀/Ce_0.1Ti_0.9O₂ showed the highest catalytic performance among the H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ catalysts.     

Oxygen defect K2NiF4-type oxides: The compounds La2−xSrxCuO4−x2+δ

Oxygen defect K₂NiF₄-type oxides $\text{La}{}_{\mathrm{2?x}}\text{Sr}{}_{\mathrm{x}}\text{CuO}{}_{\mathrm{<mtext>4?</mtext><mtext>x</mtext><mtext>2</mtext><mtext>+\delta </mtext>}}$ have been synthesized for a wide composition range: 0 ≤ x ≤ 1.34. From the X-ray and electron diffraction study three domains have been characterized: orthorhombic compounds with La₂CuO₄ structure for 0 ≤ x < 0.10, tetragonal oxides similar to LaSrCuO₄ for 0.10 ≤ x < 1 and several superstructures derived from the tetragonal cell ( with n = 3, 4, 4.5, 5, 6) for 1 ≤ x ≤ 1.34. The compounds corresponding to 0 < x < 1 differ from the other oxides in that they are characterized by the presence of copper with two oxidation states: + 2 and + 3. A model structure for La_0.8Sr_1.2CuλO_3.4, in which copper has only the + 2 oxidation state, and for which the actual cell is tegragonal—a = 18.80₄ Å and c = 12.94 Å—has been established. The particular structural evolution of these compounds is discussed in terms of a competition between the capability of Cu(II) to be oxidized to Cu(III) and the ordering of oxygen vacancies.     

An investigation of the promotional effect of propylene or propane traces on the activity of sulfatedPt/g-Al2O3andPt-Sn/g-Al2O3inCH4combustion

Summary A strong promoting effect of the presence of C₃H₈or C₃H₆was determined for the combustion of CH₄in excess oxygen, over pre-sulfated 1%Pt/g-Al₂O₃and pre-sulfated 1%Pt-2%Sn/g-Al₂O₃catalysts.</o:p>     

A study of the spinel materials LiTi2O4 and Li43Ti53O4 by photoelectron spectroscopy

HeI-excited valence-band ultraviolet photoelectron spectra and MgKα-excited Ti-2p X-ray photoelectron spectra are reported for the spinel materials LiTi₂O₄ and $\text{Li}{}_{\mathrm{<mtext>4</mtext><mtext>3</mtext>}}\text{Ti}{}_{\mathrm{<mtext>5</mtext><mtext>3</mtext>}}\text{O}{}_4$. The presence of a Fermi edge in the ultraviolet photoelectron spectrum of LiTi₂O₄ confirms the metallic nature of this material, although the measured density of states at the Fermi energy is much lower than that expected from an independent-electron interpretation of the magnetic susceptibility. This difference is attributed to a strong interaction of the conduction electrons with the lattice vibrations. The localization of conduction electrons that occurs in the final state in the Ti-2p X-ray photoelectron spectrum of LiTi₂O₄ is attributed to a Coulomb interaction with a core hole.     

LixNi0.8-yCo0.2ZnyOp的合成及电化学性能研究

A series of single-phase Li_xNi_0.8-yCo_0.2Zn_yO_p(0.96 ≤x≤ 1.10， 0 ≤y≤ 0.05， 2 ≤p≤ 2(1+y) ) (different in the y values) were synthesized by a two-step solid state reaction method， in which LiOH·H₂O， Zn-doped spherical Ni(OH)₂ and Co₂O₃ were used as the precursors. The ICP-AES analyses proved that the Zn-doped compounds synthesized had the nonstoichiometric form. The results of the XRD， SEM identified that the uniform particles of the as-prepared materials having a good layered structure were fine， narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as-prepared Zn-doped materials had not only a high capacity， but also a better cycling stability characterization than the un-doped one. The Li_1.06Ni_0.75Co_0.22Zn_0.03O_2.03 material has an initial reversible capacity as high as 160.5mAh·g^-1; and a first discharge efficiency 89.2%， and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.     

Synthesis and characterization of Ti1−2xNbxNixO2−x/2 solid solutions

Doped-rutile has been traditionally used in ceramic pigments for its intense optical properties. In this paper, we compare the classical ceramic synthesis of Ti_1−2xNb_xNi_xO_2−x/2 system with the sol-gel methodology, which allows a reduction of the anatase-rutile transformation temperature. The composition was optimised in order to obtain a unique rutile phase with the minimum amount of pollutant Ni(II) and enhanced chromatic coordinates. Incorporation of the doping ions in the rutile structure was corroborated by XRD and Rietveld refinements. The species responsible for the colour mechanism were studied by different techniques. UV-VIS spectroscopy showed the characteristic features of Ni²⁺ ions, whose existence was corroborated by EPR and magnetic measurements. From these results, (Ni,Nb)doped-TiO₂ powder samples can be now shaped as thin films, monoliths, etc. by using sol-gel methodology without modifying their properties. This study introduces new possibilities of coloured TiO₂-based solid solutions in new combined advanced applications (colouring agent and photocatalyst, etc.).