蒸氨法制备铜硅催化剂的二甲醚水蒸气重整制氢性能

采用蒸氨法制备出不同Cu负载量的xCu/SiO_2-AE催化剂,并将其用于二甲醚水蒸气重整制氢反应。当Cu负载量为30%(w)时,30Cu/SiO_2-AE催化剂表现出最佳的催化性能。结果显示,该方法制备的催化剂表面具有高度分散的CuO和层状硅酸铜物相,经还原后分别形成Cu~0和Cu~+物种。与常规浸渍法制备的30Cu/SiO_2-IM催化剂相比,蒸氨法制备的30Cu/SiO_2-AE催化剂具有优异的催化稳定性和活性,这与其独特的层状结构和表面Cu~0与Cu~+之间的协同作用相关。     

光合释氧机理的ABEEM/MM/MD和BS-DFT理论研究

建立了S₂态光合释氧络合物（OEC）的原子-键电负性均衡模型（ABEEMσπ）的电荷参数,并使用ABEEM/MM/MD可极化力场的分子动力学模拟和对称性破损的DFT研究了光合作用制造氧气的微观机制.HF/STO-3G（采用此基组的原因请见引用文献）水平下的电荷拟合结果证明了ABEEMσπ模型计算电荷分布的合理性和高效性.MD模拟显示,S₂态Mn₄CaO₅的双向异构化过程伴随Ca上的水分子W3转移至Mn1（III）/Mn4（III）,它很可能作为底物水之一,与O5在S₄态结合产生O₂.基于此,考察了全自旋态下两种异构体形式中O－O键形成的自由基耦合机理.BS-DFT计算结果表明,开立方结构的释氧活性大大优于闭立方结构,金属锰和氧自由基的自旋耦合方式也是反应性的决定性因素,同时,OEC的结构灵活性对于S态循环和光合水分解至关重要.     

Stereochemistry of planarchiral compounds,part X

2,7-Dibromo-1,6-methano[10]anulene (3) and 2,9-Dibromo-syn-1,6:8,13-diimino[14]anulene (9) were quantitatively separated into their enantiomers by chromatography on triacetylcellulose (TAC) in ethanol. X-ray structure analysis (Bijvoet technique) established the chiralities (+)(R)-3 and (+)(S)-9 for the dextrorotatory enantiomers.Comparison of the CD spectra allowed the configurational assignment to further optically active [10] and [14] anulenes which were also accessible by chromatography onTAC. Conversion of (+)(R)-2-bromo-1,6-methano[10]anulene (2) into the corresponding methylester (–)-4 confirmed its previously proposed chirality (–)(R).2,7-Dibromo-1,6-oxido[10]anulene (7) and 2,9-dibromo-syn-diimino[14]anulene (9) are in contrast to the 2,9-dibromo-syn-dioxido[14]anulene (10) optically stable until 250°C. Consequently their inversion barriers are higher than 42 kcal (176 kJ) mol^–1.The CD spectra of mono and disubstituted anulenes (with C₁ and C₂ symmetry, resp.) are compared: For the [10]anulenes theCotton effect around 330 nm seems to be specific for their configuration with a positive effect indicating (S)-chirality and vice versa. Some regularities concerning the chromatographic resolutions are discussed.

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Stereochemie planar chialer Verbindungen, 10. Mitt.: Röntgenkristallstruktur und absolute Chiralität überbrückter [10]- und [14] Anulene

Zusammenfassung 2,7-Dibrom-1,6-methano[10]anulen (3) und 2,9-Dibrom-syn-1,6:8,13-diimino[14]anulen (9) wurden durch Chromatographie an Triacetylcellulose (TAC) in Ethanol quantitativ in ihre Enantiomeren getrennt. Röntgenstruktur-analyse (Bijvoet-Technik) bewies für die rechtsdrehenden Enantiomeren die Chiralität (+)(R)-3 bzw. (+)(S)-9.Ein Vergleich der CD-Spektren ermöglichte die Konfigurationszuordnung weiterer optisch aktiver [10]- und [14]Anulene, die gleichfalls durch Chromato-graphie anTAC erhalten worden waren. Umwandlung von (+)(R)-2-Brom-1,6-methano[10]anulen (2) in den entsprechenden Methylester (–)-4 bestätigte dessen schon früher vorgeschlagene Chiralität (–)(R).Dibrom-1,6-oxido[10]anulen (7) und Dibrom-diimino[14]anulen (9) sind im Gegensatz zum Dioxido[14]anulen (10) bis 250°C optisch stabil. Ihre Inver-sionsbarrieren liegen somit über 42 kcal (176kJ) mol^–1.Die CD-Spektren von mono- und disubstituierten Anulenen (mit C₁ bzw. C₂-Symmetrie) werden verglichen: Für die [10]Anulene scheint derCottoneffekt um 330 nm konfigurationsspezifisch zu sein, wobei ein positiver Effekt (S)-Chiralität anzeigt — und vice versa. Einige Regelmäßigkeiten bezüglich der chromatographischen Enantiomerentrennung werden diskutiert.

     

希土硝酸盐冠醚配合物--Ⅸ.La(NO3)3·4H2O-NO2B15C5-CH3CN三元体系在25℃和15℃时溶解度的研究

改进了半微量相平衡研究方法,研究了La(NO_3)_3·4H_2O-NO_2B15C5-CH_3CN三元体系在25℃和15℃时的溶解度,测定了25℃各饱和溶液的折光率。结果表明,在该体系中只有一种计量配合物La(NO_3)_3·NO_2B15C5·4H_2O生成,该配合物的溶解度随温度的降低而减小,溶解度曲线覆盖的范围很大。利用不同方法获得了固态配合物La(NO_3)_3·NO_2B15C5·4H_2O。通过化学分析、紫外光度分析、红外光谱和差热与热重分析等研究了它的组成和性质,考查了它的水合度与后处理条件的关系。制得了二水合物La(NO_3)_3·NO_2B15C5·2H_2O及无水物。     

Validated HPLC method for simultaneous quantification of mutant IDH1/2 inhibitors (enasidenib,ivosidenib and vorasidenib) in mouse plasma: Application to a pharmacokinetic study

Isocitrate dehydrogenase (IDH) inhibitors comprise a novel class of anticancer drugs, which are approved to treat acute myeloid leukemia patients having mutations on IDH1/2. We report the development and validation of a high‐performance liquid chromatography (HPLC) method for the simultaneous quantitation of IDH inhibitors, namely enasidenib (EDB), ivosidenib (IDB) and vorasidenib (VDB), in mouse plasma as per the US Food and Drug Administration regulatory guidelines. The method involves extraction of EDB, IDB and VDB along with internal standard (IS; phenacetin) from mouse plasma (100 μl) using a simple protein precipitation process. The chromatographic analysis was performed on an HPLC system using a gradient mobile phase (comprising 10 mm ammonium acetate and acetonitrile in a flow‐gradient) and an X‐Terra Phenyl column. The UV detection wave length was set at λ_max 265 nm. EDB, IDB, VDB and the IS eluted at 7.36, 8.60, 9.50 and 5.12 min, respectively, with a total run time of 10 min. The calibration curve was linear over a concentration range of 0.20–12.5 μg/ml for EDB and 0.50–12.5 μg/ml for IDB and VDB (r² = ≥0.998 for all of the analytes). Validation results met the acceptance criteria. The validated HPLC method was successfully applied to a pharmacokinetic study in mice.     

Quantitative ultra‐high‐performance liquid chromatography–tandem mass spectrometry for determination of dexmedetomidine in pediatric plasma samples: Correlation with genetic polymorphisms

Dexmedetomidine is an important sedative agent administered as premedication to achieve procedural sedation in children. To describe the correlation between the genetic state and the concentration of dexmedetomidine, it is necessary to develop a specific, time‐saving and economical method for detection of dexmedetomidine in plasma samples. In this work, an ultra‐high‐performance liquid chromatography (UHPLC)–tandem mass spectrometry method has been established and validated for detection of dexmedetomidine in plasma from pediatric population. After a simple liquid–liquid extraction with an organic solution, the analytes were separated on an ACQUITY BEH C₁₈ column (2.1 mm × 50 mm, 1.7 μm particle size) by gradient elution with the mobile phase of acetonitrile and 1‰ aqueous formic acid (flow rate 0.3 mL min^?1). Mass spectrometry measurements were performed under the positive selected reaction monitoring and the mass transitions monitored were m/z 201.3 → 95.1, 204.2 → 98.0 for dexmedetomidine and deuterated medetomidine (internal standard), respectively. Validation of the method based on China Food and Drug Administration guidelines showed acceptable selectivity. The UHPLC method employed a stable isotope‐labeled internal standard, showed good specificity and was successfully used to detect dexmedetomidine in plasma samples from 260 pediatric patients. A subsequent application of this method to a pharmacogenetic study was also described. Importantly, this is the first study to report the correlation between CYP2A6 rs835309 activity and concentration of dexmedetomidine.     

自由基浓度测定方法的再验证及其在煤化学中应用

对前人建立的标准曲线法测煤中自由基浓度进行优化,以DPPH标准样品和基准样品的二次积分面积比值为新参数,结果显示新参数标准曲线法的实测值与理论值相对误差都在5%以内;重复性、复现性实验的相对标准偏差都小于3%。将新参数标准曲线法用于分析不同煤化程度煤和新疆黑山煤(HS)沥青质的自由基浓度,发现随着煤化程度增加,其煤中自由基浓度逐渐增大,从低阶褐煤的8.531×10~(17)/g上升到高阶无烟煤3.37899×10~(19)/g;而在HS煤液化过程中,随着加氢液化温度的升高,其沥青质自由基浓度逐渐下降,从290℃的1.5793×10~(18)/g降到450℃的7.410×10~(17)/g,沥青质自由基浓度变化趋势与其产率变化趋势相一致。     

化学职前教师PCK的结构与水平研究

本研究基于定量的研究方式测查189名化学职前教师PCK的结构与水平,结果表明（1）化学职前教师的PCK结构主要包括KoC、KoL、KoS、KoA等4个组分,且该结构具有良好的信度与效度;（2）化学职前教师PCK的4个组分之间存在显著相关,且显性的PCK教学方式比隐性的更有利于职前教师对PCK组分间的整合;（3）化学职前教师的PCK水平除KoS组分水平较为理想,其他知识组分水平均处于中等或中下水平;（4）在不同的PCK教学方式（显性或隐性）下,化学职前教师的PCK水平存在显著性差异。     

晶面可控BiOCl光催化剂的制备及其催化反应活性研究

以五水合硝酸铋和氯化钾为原料,通过水热法合成了BiOCl光催化剂,并对其结构进行表征,考察了前驱体的pH对催化剂结构和降解8-羟基喹啉活性的影响。结果表明,随前驱体pH的增加,催化剂[001]晶面暴露程度下降,带隙能减小,且催化反应活性降低,这可归因于低的带隙能和高的光生载流子复合效率。进一步考察降解体系pH对催化剂反应活性的影响,结果表明,降解体系pH影响8-羟基喹啉在催化剂表面的吸附行为,进而影响催化剂的反应活性。     

离子色谱法测定皂粒中葡萄糖酸钠含量

建立了离子色谱检测皂粒中葡萄糖酸钠含量的分析方法。样品经METROSEP CARB 1糖分析色谱柱(150 mm×4.0 mm,5μm)分离,以150 mmol·L~(-1) NaOH+20 mmol·L~(-1)NaAc水溶液为流动相进行等度洗脱,流速1.0 mL·min~(-1),采用瑞士万通850型离子色谱仪,选择脉冲安培检测器进行测定,外标法定量。结果显示:葡萄糖酸钠在0.5～200 mg·L~(-1)质量浓度范围内呈良好的线性,相关系数(r~2)为0.999 6,检出限为0.25 mg·L~(-1),定量下限为0.63 mg·L~(-1)。葡萄糖酸钠在1～20 mg/g加标范围内的回收率为80.7%～104%。该方法无需衍生化处理,操作简单方便,灵敏度高,可用于皂粒产线葡萄糖酸钠含量的监控与测定。