查询词典 pyridinium

The floatation rate of Pd (superscript 2+) reaches 100% when the concentrations of NaNO3, KBr and cetyl pyridinium bromide in solution are 0.05 g/mL, 3.0×10^(-2) mol/L, 5.0×10^(-4) mol/L(pH 4.0), respectively. Pd (superscript 2+) could be separated from Ru (superscript 3+), Al (superscript 3+), Cr (superscript 3+), Ni (superscript 2+), Ga (superscript 3+), Fe (superscript 3+) and Zn (superscript 2+) by floatation quantiatively. A method of flotation separation and enrichment of Pd (superscript 2+) was established.

当溶液中硝酸钠、溴化钾、溴化十六烷基吡啶的浓度分别为0.05 g/mL，3.0×10^(-2)mol/L，5.0×10^(-4)mol/L，在pH 4.0时，Pd(上标 2+)的浮选率达到100%，Pd(上标 2+)可与Ru(上标 3+)，Al(上标 3+)，Cr(上标 3+)，Ni(上标 2+)，Ga(上标 3+)，Fe(上标 3+)，Zn(上标 2+)定量分离，据此建立了浮选分离和富集Pd(上标 2+)的新方法。

Cyclophos phamide SBQ.pVA SBQ.pVA + polymer emulsion added styryl pyridinium salt pVA's acronym.

SBQ.pVA＋高分子乳剂 SBQ.pVA是加进了苯乙烯吡啶盐的pVA之缩略词。

The pyridinium salts was transformed by the base to 1-hydroxy or 3-hydroxy-quinolizinylides, which undergo 1,3-dipolar cycloadditionreaction with alkenes,and then aromatizated to cycl[3,3,2]azinone in thepresence of oxidant.

实验证明，这是一个连续进行的多步反应：2-羰基吡啶鎓盐在反应中先生成1-羟基或3-羟基喹嗪叶立德，然后与烯烃起1，3—偶极加成反应，最后在氧化剂作用下脱氢芳构化而生成Cycl[3，3，2]azinone。

TheMn complexes with internal quaternary ammonium and/or pyridinium salt, either formed in-situ or isolated, displayedsignificantly higher activities than analogous complexes and Jacobsens catalyst in theaforementioned reaction.

通过研究发现，含有分子内季铵盐和／或吡啶盐的手性吡咯烷Mn配合物，无论是原位生成的还是分离的，都比类似的配合物以及Jacobsen催化剂的活性明显高。

The enhancement of the reaction activity is attributed to the phasetransfer capability of the built-in quaternary ammonium and pyridinium salts of theMn catalyst. The effect of the internal quaternary ammonium and/or pyridiniumsalt on the epoxidation of substituted chromenes is similar to that of the externalpyridinium salts and ammonium halides.

分子内季铵盐和吡啶盐具有相转移能力，对于取代色烯不对称环氧化的作用与外加的吡啶盐和卤化铵的作用相似，使Mn催化剂催化取代色烯环氧化反应的活性明显提高。

Three kinds of ionic liquid were used to support the acetylacetone at the C3 position directly according to the method indicated above. These synthesized ionic liquid supported acetylacetone catalysts include imidazolium salts ionic liquid supported acetylacetone catalysts, pyridinium salts ionic liquid supported acetylacetone catalysts and ammonium salts ionic liquid supported acetylacetone catalysts. All these catalysts were characterized by ~1H-NMR,~(13)C-NMR, IR and elementary analysis.

采用设计过程中预期能够提高乙酰丙酮金属催化剂催化氧化活性的修饰方式，合成了三类离子液体支载的乙酰丙酮金属催化剂：咪唑型离子液体支载乙酰丙酮金属催化剂、吡啶型离子液体支载乙酰丙酮金属催化剂、胺型离子液体支载乙酰丙酮金属催化剂，并采用核磁共振氢谱、碳谱，红外光谱及元素分析来对这些新型的催化剂进行了表征。

A general method for preparing multi-cyclic indolizine compounds(1a—1c, 2a—2b and 3) in moderate yields(45%—71%) by a 1,3-dipolar cycloaddition reaction of pyridinium N-ylides, isoquinolinium N-ylides or quinolinium N-ylides to 1,4,4a ,8a-tetrahydro-1,4-methanonaphthalene-5,8-dione, followed by an aromatization, in the presence of tetrakispyridine cobalt dichromate is described.

在 [ 4Co( HCr O4 ) 2 ]存在下，吡啶叶立德、喹啉叶立德或异喹啉叶立德分别和 1 ，4，4a，8a-四氢-1 ，4-桥亚甲基萘-5 ，8-二酮反应，一步法合成了中氮茚类多环化合物( 1 a～ 1 c，2 a～ 2 b，3 )。该方法原料易得，反应条件容易控制，为合成这类化合物提供了新方

The invention uses the fermentation liquor of one Escherichia coli generating polysialic acid as material, filters and removes thallus, adds some solvents as sodium chloride and alcohol into supernatant to deposit polysialic acid, dissolves the polysialic acid deposits via deionized water, filters to remove modified protein, uses alkali prolease to treat filtrate, complexes deposits via cetyl pyridinium chloride or cetyltrimethylammonium bromide, and dissociates, uses over alcohol to deposit polysialic acid, dissolves the deposits via ultra-pure water, grades and purifies via chromatography column, collects and dialyzes eluent, cools and dries to obtain polysialic acid.

本发明以一株产聚唾液酸大肠杆菌的发酵液为原料，经过过滤去除菌体，上清液加入适量氯化钠和乙醇等溶剂沉淀出聚唾液酸，聚唾液酸沉淀用去离子水溶解，再用过滤去除变性蛋白质，滤液经过碱性蛋白酶处理、氯代十六烷基吡啶或十六烷基三甲基溴化铵络合沉淀并解离后，再用过量乙醇沉淀出聚唾液酸，聚唾液酸沉淀用超纯水溶解，用层析柱进行分级纯化，收集洗脱液经过透析，冷冻干燥得聚唾液酸产品。

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。