Partial Oxidation of Methane to Synthesis Gas over Hexaaluminates LaMAl11O19-δ catalysts

A series of M-substituted hexaaluminates LaMAl11O19-δ (M=Fe, Co, Ni, Mn, and Cu)were prepared and characterized by XRD, XPS, TPR and TGA techniques, respectively. They exhibited different reducibility and catalytic activity for partial oxidation of methane (POM) to synthesis gas. Among the LaMAl11O19-δ samples, LaNiAl11O19-δ showed the best catalytic activity for the topic reaction and selectivity for synthesis gas at 780 ℃ for 2 h. The conversion of CH4 was over 99.2%, and the product selectivity for both CO and H2 was above 90.3%.     

三亚甲基环碳酸酯及2,2-二甲基三亚甲基环碳酸酯开环均聚合*

生物降解聚合物聚三亚甲基环碳酸酯（PTMC）及聚2,2-二甲基三亚甲基环碳酸酯（PDTC）在药物控释载体及其它生物医学技术领域有着良好的应用前景。与脂肪族聚酯不同,PTMC、PDTC降解时,不会产生有害的酸性化合物。PTMC、PDTC主要由三亚甲基环碳酸酯（TMC）及2,2-二甲基三亚甲基环碳酸酯（DTC）开环均聚合制备。本文总结了催化TMC、DTC开环均聚合的不同催化剂及其聚合机理,综述了近年来国内外在TMC、DTC均聚合催化剂开发上的研究进展,并对生物相容性催化剂如稀土催化剂、Ca、Mg、Zn、Fe催化剂以及酶催化剂催化TMC、DTC开环聚合的优缺点进行了比较。     

微囊藻毒素-LR免疫亲和层析柱的研制和应用

用CNBr-activated Sepharose4B和微囊藻毒素-LR的单克隆抗体制备了免疫亲和层析柱,测得抗体偶联率在75.7%~94.1%之间。制得的免疫亲和层析柱最大柱容量在76~95ng之间,柱空白为0,回收率在90.8%~105.1%之间。柱子再生重复使用6次后,回收率不低于75%。建立了免疫亲和层析柱-高效液相色谱测定水样中的微囊藻毒素-LR的方法。该法检出限为5ng/L;线性定量范围为10~500ng/L。实验结果显示,免疫亲和层析柱特异性好,一次净化能除去绝大部分干扰物,净化效果明显优于现有的固相萃取柱。     

乙醛酸和草酸的毛细管区带电泳分析

建立了同时测定乙醛酸和草酸的毛细管区带电泳法。考察了缓冲溶液的种类、浓度和pH以及分离电压等因素对分离结果的影响。在缓冲溶液为20 mmol/L硼砂-5.5 mmol/L邻苯二甲酸氢钾(pH 9.0)、分离电压20 kV、检测波长212 nm的优化条件下,11 min内即可实现对目标物的分离。乙醛酸和草酸分别在0.8～20 g/L和1.2～20 g/L范围内线性关系良好,相关系数分别为0.9993和0.9975;方法的检出限分别为0.2和0.4 g/L(信噪比为3);样品的加标回收率为98.3%～102.5%,相对标准偏差为0.35%～0.61%。该方法操作简便、快速、成本低廉,已应用于实际样品的分析,并获得了令人满意的结果。     

高效液相色谱法同时测定忍冬中7种成分

建立了在不同时间段内转换使用不同波长同时测定忍冬花和叶中7种化学成分(绿原酸、咖啡酸、芦丁、木犀草苷、异绿原酸A、异绿原酸B、异绿原酸C)的高效液相色谱分析方法,同时应用该方法分析了忍冬花、忍冬老叶和新叶中成分含量的差异。色谱柱为Agilent Eclipse Plus C18(250 mm×4.6 mm, 5 μm);流动相为0.3%甲酸水溶液(A)和乙腈(B),梯度洗脱,流速1 mL/min;采用VWD紫外检测器转换波长(330 nm、350 nm)检测。应用所建立的方法测定忍冬新叶中绿原酸、木犀草苷含量分别为2.572%、1.498‰,均比药典中规定的含量高,有必要进一步的研究和开发利用。该方法准确、简便、灵敏度高,适用于忍冬中7种化学成分含量的同时测定和忍冬的质量控制及综合评价。     

BODIPY‐Bridged Push–Pull Chromophores for Nonlinear Optical Applications

A set of linear and dissymmetric BODIPY‐bridged push–pull dyes are synthesized. The electron‐donating substituents are anisole and dialkylanilino groups. The strongly electron‐accepting moiety, a 1,1,4,4‐tetracyanobuta‐1,3‐diene (TCBD) group, is obtained by insertion of an electron‐rich ethyne into tetracyanoethylene. A nonlinear push–pull system is developed with a donor at the 5‐position of the BODIPY core and the acceptor at the 2‐position. All dyes are fully characterized and their electrochemical, linear and nonlinear optical properties are discussed. The linear optical properties of dialkylamino compounds show strong solvatochromic behavior and undergo drastic changes upon protonation. The strong push–pull systems are non‐fluorescent and the TCBD‐BODIPY dyes show diverse photochemistry and electrochemistry, with several reversible reduction waves for the tetracyanobutadiene moiety. The hyperpolarizability μβ of selected compounds is evaluated using the electric‐field‐induced second‐harmonic generation technique. Two of the TCBD‐BODIPY dyes show particularly high μβ (1.907 μm) values of 2050×10^?48 and 5900×10^?48 esu. In addition, one of these dyes shows a high NLO contrast upon protonation–deprotonation of the donor residue.     

Ultra‐performance liquid chromatography coupled with electrospray ionization/quadrupole time‐of‐flight mass spectrometry for the rapid analysis of constituents in the traditional Chinese medical formula Danggui San

In this work, ultra‐performance LC with ESI quadrupole TOF‐MS (UPLC–ESI‐Q‐TOF‐MS) and automated MetaboLynx analysis was used to rapidly separate and identify the chemical constituents of Danggui San, a traditional Chinese medical formula. The analysis was performed on a Waters UPLC BEH C₁₈ column using a gradient elution system. A hyphenated ESI and Q‐TOF analyzer was used for the determination of the accurate mass of the protonated or deprotonated molecule and fragment ions in both positive and negative modes. Based on retention times, accurate mass, and the mass spectrometric fragmentation characteristics, a total of 47 compounds distributed over the chemical groups of phthalides, flavonoids, monoterpene glycosides, sesquiterpenoids, phenolics, and alkaloids, were simultaneously separated within 18 min and identified or tentatively elucidated in Danggui San for the first time. UPLC–ESI‐Q‐TOF‐MS analysis revealed the complexity of the chemical composition of this formula. The method developed is rapid, accurate, reliable, and highly sensitive to characterize the chemical constituents of Danggui San.     

反相离子对高效液相色谱法测定硫酸软骨素

以四甲基氯化铵作为离子对试剂，采用乙腈-2.28mmol/L四甲基氯化铵水溶液（5:95)作为流动相，选用C18色谱柱分离硫酸软骨素和杂质，建立了测定硫酸软骨素含量的反相离子对高效液相色谱方法。该方法的线性范围为0.4-8.0μg，回收率为98.8%-100.3%，相对标准偏差为0.17%-0.53%。该方法的精密度和准确度较高。     

L—组氨酸和色氨酸三元体系中稀土（Ⅲ）,钙（Ⅱ）的化学形态

在模拟生理条件下（３７℃,Ｉ＝０．１５ｍｏｌ／ＬＮａＣｌ）,用ｐＨ电位滴定与计算机模拟计算相结合的方法研究了镨（Ⅲ）、钆（Ⅲ）、铽（Ⅲ）、镱（Ⅲ）４ｔｋｈ ｔｑｄ ｆｆｆｆｙｂ ｂｂ ｔ ｑｇｈ （Ⅱ）、锌（Ⅱ）离子在Ｌ－组氨酸、色氨酸三元体系中的化学形态。讨论了稀土（Ⅲ）、钙（Ⅱ）和锌（Ⅱ）的物种分布特点。