Solvothermal Route to Prepare the Metastable Phase 3c-Fe_7S_8 with Hexagonal Platelet Morphology

The metastable phase 3c-Fe7S8 with the hexagonal platelet morphology has been prepared by using solvothermal route. The product was characterized by means of X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). The experiment results show that the as-prepared Fe7S8 is a metastable phase with the hexagonal platelet morphology.

制剂中利福平晶型的确定

目的 确定制剂中利福平的晶型。方法 利用粉末 X-射线衍射方法测定不同晶型的利福平原料 ,结合文献数据 ,总结出利福平各晶型的主要特征衍射峰 ;直接测定利福平胶囊内容物或片剂研细的固体粉末的粉末 X-射线衍射图谱 ,根据图谱中存在的利福平主要特征衍射峰 ,确定制剂中利福平的晶型。结果 利福平晶体的主要特征衍射峰 (2 θ)分别为 8.79°和 14.48°(I型结晶 ) ,15 .84°和 2 0 .0 6°(II型结晶 ) ,18.36°(SV型结晶 ) ;制剂中的辅料不干扰对主要特征衍射峰的判断 ;国内 5个企业的 12批利福平片和 37个企业的 88批利福平胶囊中的利福平均为 I型结晶。结论 本方法可方便地判断制剂中利福平的晶型。

盐酸林可霉素晶型研究

药物的多晶型对药品质量和临床药效有较大的影响,药物多晶型的研究方法有x—射线单晶结构分析,x—射线粉末法,差热分析,红外光谱分析等。影响晶型转变的因素很多,如研磨,结晶溶剂不同或改变结晶条件,所得产品晶型即有变化。本实验通过盐酸林可霉素针、片剂红外光谱测定,x—射线衍射分析,差示扫描量热法,晶型转化实验等手段,证明盐酸林可霉素为一多晶型药物,晶型之间存在互变,晶型的不同是由于精制浓度及速度不同所致,其中晶B、晶C为稳定型晶态,晶A为亚稳态晶型。

Characterization of ultrafine copper powder prepared by novel electrodeposition method

The auto-evolved ultrafine copper powders were synlhesized via a novel electrodeposition route performed by ultrasonic dispersion of the electrolyte. The properties of the samples obtained were characterized by X-ray powder diffractometry （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM） and laser size distribution analyzer （SL） respectively. The formation mechanisms of the powders and the efficiency of the elctrodeposition were discussed. The results show that the as-prepared powders are high-purity copper nanoparticles with the fcc structure taking a mixture of fishbone-like and irregular shapes When the concentration of Cu^2＋ increases from 0.03 to 0.09 mol/L, the average size of copper particles increases from 0.92 to 1.80 μm, and current efficiency of electrodeposition linearly changes from 66.5% to 91.3%.

Preparation of microsized single-crystalline Co_3O_4 by high-temperature hydrolysis

Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCD2H20 at 600℃. The samples were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results reveal that the as-prepared powders are microsized single-crystalline CO3O4 with cubic spinel structure. An increase in the high-temperature hydrolysis time results in the evolution of particle shapes from cube to quasi-sphere, and then to octahedron. The effect of NaCl additive on the surface morphologies of Co3O4 particles was experimentally investigated. The results indicate that the NaCl additive acts as an inert disperse phase in the high-temperature hydrolysis, and prevents the aggregation of Co3O4 particles effectively.

中国部分地区滑石粉矿物组成的分析与分类

本文提出的改进后滑石粉分析方法,是以X-射线粉末晶体衍射法,进行矿物成分定性和以化学分析方法进行定量,不仅可得到滑石矿的矿物组成,而且绝大部分样品均得到其中所含纯滑石和共存矿物的含量,分析手续大大简化,分析结果表明,十二种滑石粉产品中按其主要共存物,可分为纯滑石、滑石-绿泥石、滑石-白云石、滑石-蛇纹石—白云石、滑石-方解石、滑石-菱镁矿等六种类型。其它杂质还有透闪石、石英、氧化铁、氧化铝等。由于各种共存物与纯滑石具有相差很大的物理和化学性能,当然会给滑石粉在造纸涂料、填料、树脂吸附剂等方面的应用造成很大影响。其次,滑石粉杂质含量的多少直接与其价格相联系,在选用滑石粉时应与其适用性综合考虑。

Determination the content of gypsum fibrosum in Xiaokening tablets by powder X ray diffraction method

The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quantitative peaks are not well solved, and the accuracy and precision of the results are not satisfactory. This study employed the concept of mass absorption coefficient based on the internal standard method, and the full spectrum fitting and quantitative methods were used to solve the above technical problems. The sample was blended. the internal standard substance of zinc oxide was fully ground, and tablets were prepared by positive pressure method. Under certain instrumental conditions, the PXRD pattern was obtained by scanning. The percentage of gypsum fibrosum in Xiaokening tablet was obtained by quantitative analysis of full spectrum fitting internal standard by TOPAS software. The method was investigated by methodology. At the same time, the method was compared by ion chromatography, and SPSS software was used to make a significant t test on the results of the two methods. After the investigation, the average standard recovery rate of CaSO4-2H2O was 99.06%(RSD = 3.02%);and the recovery rate for simulated samples was 96.7%. The method had good specificity. After statistical analysis, there was no significant difference between the new PXRD method and the traditional method of ion chromatography.

Surface Na2CO3 etching induced activity enhancement of 2D BiOI photocatalyst working under visible light

The visible light photocatalytic activity of two-dimensional （2D） BiOl microplates was intensively enhanced through simply dipping in Na2CO3 solutions at room temperature. The X-ray powder diffrac- tion （XRD） and scanning electron microscopy （SEM） investigations suggest that little amount of （BiO）2CO3 phase was formed on the surface of 2D BiOI via the in situ chemical conversion. The concen- tration of Na2CO3 solutions affected the structure, morphology, light absorption and surface element component of 2D BiOl. The surface loaded （BiO）2CO3 mainly trapped the photoinduced electrons of BiOI, improved the separation efficiency of photocharges and finally raised the photocatalytic activity of BiOl under visible light （λ 〉 420 nm）. Furthermore, the product of the as-prepared （BiO）2CO3/BiOI displayed excellent stability in the repeated experiment. This study provides a facile way to improve the photocatalytic activity of BiOX （X = CI, Br, I） by means of surface treatment with Na2CO3 solutions.

Green and low temperature synthesis of nanocrystalline transition metal ferrites by simple wet chemistry routes

Crystalline and nanostructured cobalt （CoFe2O4）, nickel （NiFe2O4）, zinc （ZnFe2O4） and manganese （MnFe2O4） spinel ferrites are synthesized with high yields, crystallinity and purity through an easy, quick, reproducible and low-temperature hydrothermal assisted route starting from an aqueous suspension of copredpitated metal oxalates. The use of water as a reaction medium is a further advantage of the chosen protocol. Additionally, the zinc spinel is also prepared through an alternative route combining copredpitation of oxalates from an aqueous solution with thermal decomposition under reflux conditions. The nanocrystalline powders are obtained as a pure crystalline phase already at the extremely low tem- perature of 75 ℃ and no further thermal treatment is needed. The structure and microstructure of the prepared materials is investigated by means of X-ray powder diffraction （XRPD）, while X-ray photoelectron spectroscopy （XPS） and inductively coupled plasma-atomic emission spectroscopy （ICP-AES） analyses are used to gain information about the surface and bulk composition of the samples, respectively, confirming the expected stoichiometry. To investigate the effect of the synthesis protocol on the morphology of the obtained ferrites, transmission electron microscopy （TEM） observations are performed on selected samples. The magnetic properties of the cobalt and manganese spinels are also investigated using a superconducting quantum device magnetometer （SQUID） revealing hard and soft ferrimagnetic behavior, respectively.