溶剂萃取法制备Co(PO_3)_2超细微粉

本文用溶剂萃取法成功地制备了偏磷酸钴超细微粉并通过ＸＲＤ，ＩＲ，ＴＧ，ＤＴＡ，ＴＥＭ等实验对超细微粉的组成、结构进行了表征。     

用N2O-C2H2火焰原子吸收光谱法测定羰基镍粉中钼含量

运用了N2O—C2H2火焰原子吸收光谱法进行羰基镍粉钼含量的测定。介绍了钼最佳测定条件及呈良好线性范围的浓度,同时对样品消化处理条件及在测定中样品的干扰因素进行了综合考虑．该方法的相对标准偏差均小于1.0％(n=6)，回收率均在97．0％～102．0％(n=6)之间．达到了实验室分析质量控制的要求．     

High Performance Varistor Discs Obtained from Chemically Synthesized Doped Zinc Oxide Powder

The ceramic microstructure, the chemical homogeneity of specific dopants and the mechanical integrity of a varistor disc are critical parameters in determining the transient voltage suppression features of these devices. The material properties and overall quality of the starting ceramic powders used to produce such components are essential in achieving the desired properties. The present work describes a novel chemical method developed to produce doped zinc oxide powders and an industrial scale manufacturing process for the production of final varistor blocks for surge arrester applications. The results are compared with those obtained when using standard varistor powder made by the mixed oxide route is used. All the fundamental electrical properties of the discs have been determined and correlated with the relevant manufacturing steps.     

粉末化学镀法制备的NiB／TiO2非晶态合金催化剂对环丁烯砜加氢反应的催化性能

 采用诱导沉积法及粉末化学镀法分别制备了纯态NiB及负载型NiB／TiO2非晶态合金催化剂．用XRD，ICP，SEM，TEM和DSC等手段对催化剂的物性及TiO2载体与NiB非晶态合金之间的相互作用进行了表征，考察了非晶态合金的结构、组成、形貌和热稳定性，并将其用于环丁烯砜加氢反应中．结果表明，相对于NiB而言，NiB／TiO2催化剂具有优良的热稳定性和催化活性，这缘于NiB和TiO2载体之间的相互作用及载体的分散作用．     

Thermal properties of rare earth elements complexes with 1,3,5-benzenetricarboxylic acid

Summary Rare earth elements 1,3,5-benzenetricarboxylates were prepared as solids of the general formula Ln(C₉H₃O₆)·nH₂O, where n=6 for La-Dy and n=4 for Ho-Lu,Y. Their solubilities in water at 293 K are of the order 10^-4-10^-6 mol dm^-3. The IR spectra of the complexes indicate that the carboxylate groups are bridging and bidentate chelates. Hydrated 1,3,5-benzenetricarboxylates lose water molecules during heating in one step (La-Tb), two steps (Y, Ho-Tm) or three steps (Dy, Yb, Lu). The anhydrous complexes are stable up to 573-742 K and decompose to oxides (Ce-Lu) at higher temperatures.     

Astragalus membranaceus ultrafine powder alleviates hyperuricemia by regulating the gut microbiome and reversing bile acid and adrenal hormone biosynthesis dysregulation

Ethnopharmacological relevanceMetabolic syndrome is closely related to the intestinal microbiota and disturbances in the host metabolome. Hyperuricemia (HUA), a manifestation of metabolic syndrome, can induce various cardiovascular diseases and gout, seriously affecting a patient’s quality of life. Astragalus membranaceus has a long history as a commonly used traditional Chinese medicine to treat kidney disease in China and East Asia.Materials and methodsWe compared the therapeutic effect of benzbromarone and two different doses Astragalus membranaceus ultrafine powder (AMUP) in rats with HUA. Ultra-performance liquid chromatography-mass spectrometer was used to analyze the AMUP metabolism in the plasma, urine, and feces. Further, 16S ribosome RNA sequencing and feces metabolomic were performed to capture the variation of the gut microbiota and metabolites changes before and after drug administration.ResultsAMUP had a notable impact on reducing blood uric acid levels while protecting the liver and kidney. Drug metabolism analysis demonstrated that effective constituent flavonoids are distributed in the blood, whereas saponins remain in the intestine. Gut microbiota analysis showed that low-dose AMUP ameliorated HUA-induced gut dysbiosis by reducing the abundance of harmful bacteria and increasing that of some beneficial bacteria with anti-inflammatory properties, such as Clostridia, Lachnospiraceae, and Muribaculaceae. In addition, HUA-induced changes in metabolite contents in bile acid and adrenal hormone biosynthesis pathways were restored after treatment with AMUP.ConclusionLow-dose AMUP exerts remarkable therapeutic effects on HUA by regulating the gut microbiome and mediating gut metabolism pathways associated with uric acid excretion.     

High-temperature transformations of Cu-rich hydrotalcites

CuM(II)Al ternary hydrotalcites (M(II) = Ni, Co and Mg) with a (Cu+M(II))/Al atomic ratio of 3.0 and Cu/M(II) atomic ratio of 5.0 were synthesized by coprecipitation under low supersaturation. Powder X-ray diffraction of the as-synthesized samples showed a pattern characteristic of hydrotalcite-like (HT-like) structure (JCPDS: 41-1428). Thermal analyses of these samples showed four stages of weight loss/heat change when recorded in nitrogen. Analysis of the evolved gases characterized the nature of these transformations. The thermoanalytical effects differed significantly especially for the high-temperature transformations, when the treatment was performed in oxygen. In situ powder X-ray diffraction of the samples was carried out to elucidate the phase evolution of these compounds. Surprisingly formation of CuO was noted at temperatures around 200°C well below the destruction of the layered network. The nature of the resulting phases varied with both the nature of the co-bivalent metal ion and the heating atmosphere. FT-IR spectroscopy confirmed the retention of carbonate ions at higher temperatures (above 700°C), although the concentration of carbonate anion (most likely unidentate) varied with the calcination temperature. The crystallinity of CuO increased significantly above 600°C, probably through dissociation of copper oxycarbonate. Significant differences in the thermal transformation temperatures (for the third and the fourth transformations) of these samples containing different co-bivalent metal ions were not observed. This suggests that an association of the co-bivalent metal ions and/or trivalent metal ion in this phase is unlikely. A plausible thermal evolution scheme of these hydrotalcites is proposed.     

X-Ray Powder Diffraction Studies of Polyhydrates of Cross-Linked Tetraisoamylammonium Polyacrylates

X-ray powder diffraction studies were performed of the polyhydrates, formed at positive temperature in swelled grains of carboxylic cation-exchange resins in the form of tetraisoamylammonium (cross-linked tetraisoamylammonium polyacrylates, differing in the degree of cross-linking: 1, 2 and 3%). It was shown that the polyhydrates exist as the crystalline phase under specific conditions, determined earlier by DTA technique. Diffraction patterns of the samples, recorded at the temperature +3 ± 1 °C, indicate that the polyhydrates crystallize in hexagonal symmetry, the unit cell parameters are close to a=12.25 Å, c=12.72 Å and do not depend significantly upon the degree of cross-linking. The suppositions were made concerning the size of hydrate crystallites, formed in the swelled grains of the studied resins.This revised version was published online in July 2005 with a corrected issue number.     

液相色谱-串联质谱法检测雄蜂蛹粉中50种抗生素残留

建立了液相色谱-串联质谱检测雄蜂蛹粉中50种抗生素残留（大环内酯类、喹诺酮类、磺胺类、四环素类、硝基咪唑类、林可霉素和氯霉素）的方法。样品经高氯酸溶液和醋酸铅溶液提取沉淀蛋白质，清液用磷酸氢二钾溶液调节pH值至8，经固相萃取净化后进行仪器分析。采用多反应监测正离子或负离子模式检测，可以一次完成对雄蜂蛹粉中50种目标化合物的定性和定量测定。50种抗生素的加标回收率为70.2%~118.3%，相对标准偏差（RSD）为1.8%~13.6%。该方法操作简便，灵敏度高，适用于雄蜂蛹粉中多种兽药残留的分析确证。