查询词典 pyridine

A high performance liquid chromatographic method was studied for the simultaneous determination of pesticide imidacloprid and its two intermediates (2-chloro-5-methyl pyridine and 2-chloro-5-chloromethyl pyridin).

研究了用高效液相色谱法同时分离测定农药吡虫啉原粉和中间体2-氯-5-甲基吡啶及2-氯-5-氯甲基吡啶含量的方法。

The design and synthesis of a new unsymmetric 2, 6-bis pyridine iron catalyst and its use in ethylene polymerization.

新型不对称结构双亚胺吡啶铁系催化剂的设计、合成及其催化乙烯聚合反应研究。

Methods: fudr was esterified with acetic anhydride in the presence of pyridine and 4 dimethylaminopyridine.

在吡啶和4 二甲氨基吡啶存在时，fudr与乙酸酐反应，制备氟尿苷二乙酸酯，并测定其核磁共振氢谱。rp hplc测定其在正辛醇和磷酸盐缓冲液中的分配系数及不同ph缓冲液和组织匀浆中的稳定性。

The eluent was evaporated to near-dry under nitrogen and then redissolved with methanol-0.1% formic acid(1∶1,by volume),finally determined by HPLC-MS/MS.The linear range of the calibration curve was 0-50 μg/L for all pyridine herbicides.

在大白菜和橙子2种基质中分别添加5.0、10.0和20.0μg/kg3个水平，玉米基质中添加5.0、10.0、20.0和40.0μg/kg 4个水平的4种吡啶类除草剂混合标准溶液，平均回收率为70%~117%，方法的相对标准偏差小于15%。

The results showed that Kaidimycin was chemically neutral, macrocylic polylactones, stable and liable to dissolve into water and pyridine, slight to dissolve into methanol, ethanol and N-butanol, difficult to dissolve into ethyl acetate, acetone, benzene and chloroform. Chemical reaction of functional group of Kaidimycin showed that it had glycoside, amino acid and aldehyde, no reducing sugar, polypeptide and phenol.

凯地菌素属中等极性的、中性抗生素，极性纸层析结果与多烯类抗生素的纸层析结果相似：易溶于水、吡啶，微溶于甲醇、乙醇、正丁醇，不溶于乙酸乙酯、丙酮、苯、三氯化碳；对高温、光照和紫外处理有很好的稳定性；官能团反应试验结果发现，凯地菌素可能含有糖苷键、氨基酸伯氨基和醛基，不含有还原糖、多肽和酚基，高锰酸钾、浓硫酸反应与多烯大环内酯类抗生素的特性相似；并且依据纯品，采用生物法和分光光度法对摇床发酵液进行了效价的测定。

Penicillin G sulphoxide is esterified by N,N′-bistrimethylsilyl urea under the temperature 55℃ with a molar ratio 2.5∶1 between BSU and sulphoxide,and the ester obtained is ring-enlarged in the toluene under refluxing with the exist of catalyst-pyridine acetyl bromide.

摘 要 本文在制得青霉素G亚砜的基础上，完成了重排酸的扩环反应，重点探讨了扩环反应的最优化条件。青霉素G亚砜与N，N′-双脲在55℃下反应，得到亚砜的酯化物。

Advances on the development of new oxidation reagents and methodologies and their applications in both target-and diversity-oriented synthesis have been regularly surveyed and constituted one of the most extensively and actively investigated areas of current organic synthesis.1 In this context,a plethora of oxidants,including those small organic molecule-based reagents (such as Dess-Martin periodinane,Swern oxidation,Moffatt oxida- tion,Corey-Kim oxidation,and 三氧化硫/pyridine)and metal-based systems(such as Jones reagent,Collins reagent,pyridinium chlorochromate,pyridinium dichromate,barium permanganate, manganese dioxide,ruthenium tetroxide,silver carbonate,and Oppenauer oxidation),have been identified to be powerful tools promoting conversion of various alcohols into their corresponding aldehyde or ketone products and thus evolved as a most important class of tools in synthetic chemists'arsenal.

关于新的氧化试剂和方法，在两个目标和多样性为导向的发展及其应用合成的进步定期调查，构成一个最广泛，积极探讨在这方面，过多的地区目前有机合成。1氧化剂，包括有机小分子为基础的试剂（如Dess - Martin氧化剂，斯文氧化反应，氧化法特，科里，金氧化，三氧化硫/吡啶）和金属为基础的系统（如琼斯试剂，柯林斯试剂，吡啶氯铬，吡啶铬，钡锰，二氧化锰，四氧化钌，银碳酸盐和开瓶器氧化），已被证实为推动中相应的醛或酮醇转化的各种产品，功能强大的工具，因而作为一个最重要的阶级演变在阿森纳的工具合成化学家。

The fixation of CO2 carried out by these autotrophs, in addition to ATP, requires reduced pyridine nucleotide

除ATP外，由这些自养生物进行的CO2固定，需要还原的吡啶核苷酸。

A chiral phase transfer catalyst, N-benzyl quinine bromide, was synthesized from natural chiral compound. And 2,5-bimethyl-4-(3-nitrobenzene)-1,4-bihydrogenation pyridine-3--4-methyl formate (viz. nitrendipine) was synthesized by this chiral phase transfer catalysis, and characterized by elemental analysis, infrared spectrum,1H nuclear magnetic resornace, and X-ray single-crystal diffraction.Key words: ammonium; chiral phase transfer catalyser; crystal structure

通过对天然手性物质进行修饰合成手性相转移催化剂N-苄基溴化奎宁，并对目标分子2，5-二甲基-4-(3-硝基苯)-1，4-二氢吡啶-3-甲酸乙酯-5-甲酸甲酯进行不对称催化合成，并通过红外光谱和核磁共振氢谱对化合物进行了表征，用X射线单晶衍射法测定了该化合物的晶体结构。

(NH_4)_2GeF_6·H_2O is obtained as light-green single crystal from the low-temperature solvothermal reaction of GeO_2, NH_4VO_3 and HF in pyridine-water and characterized by the IR, elemental analysis, TG-DTA and single crystal X-ray diffraction.

化合物(NH_4)_2GeF_6·H_2O由GeO_2，NH_4VO_3和HF在吡啶-水体系中低温溶剂热条件下合成，并用IR、元素分析、TG-DTA和X射线单晶衍射进行了表征。

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。