缩酮

Any of various carbohydrates containing a ketone group.

任何一种含有酮基或其半缩醛的单糖。

Jiangmen City, Czech Run Chemical Trading Co., Ltd. operating chemical raw materials, mainly toluene, xylene, a rough, crude dimethyl, mixed aromatics, mesitylene, crude Sanjia, mixed dimethoxy, methylal, n-butyl, B ester, n-butyl alcohol, isobutyl alcohol, vinyl acetate, styrene, butyl ether, cyclohexanone, 6 #, 120 #, 200 #, titanium dioxide, phthalic anhydride, DOP, isopropanol for Main Product, Quality Assurance , the price advantage of abundant supply.

江门市捷润化工贸易有限公司经营化工原料，主要为甲苯、二甲苯、粗甲、粗二甲、混合芳烃、三甲苯、粗三甲、混二甲、甲缩醛、正丁酯、乙酯、正丁醇、异丁醇、醋酸乙烯、苯乙烯、丁醚、环己酮、6#、120#、200#、钛白粉、苯酐、DOP、异丙醇为主营产品，质量保证，价格优势，货源充足。

Therefore, studies and applications of the ring-opening reaction of 1, 3-dithiolancycolpentyl moiety should be a valuable research project.

因此，α-羰基环二硫缩烯酮的1， 3-二硫戊环的开环反应及其在合成中的应用研究是一重要的研究课题。

Organic substances (diethylene glycol, glycol methyl ether and methyl ethyl ketone) were used as nonsolvent additives and N-methyl-2-pyrrolidone used as a solvent in membrane preparation. The effects of PPESK concentration, the type of additives and the NSA concentration in casting solution on the morphology and performance of the PPESK hollow fiber ultrafiltration membrane were systematically investigated.

以PPESK为膜材料，NMP为溶剂，水为凝胶剂，选用乙二醇甲醚、一缩二乙二醇和丁酮为非溶剂添加剂，系统研究了聚合物浓度、添加剂种类和含量对PPESK中空纤维超滤膜结构和性能的影响，制备了一系列具有不同孔径和通量的中空纤维超滤膜。

The phase separation behavior of different nonsolvent additives (methyl ethyl ketone, glycol methyl ether and diethylene glycol) on PPESK casting solution was studied at 20℃according the linerized cloud point correlation.

结合线性浊点关系，根据浊点滴定试验，通过三元相图研究了20℃下非溶剂添加剂(丁酮，乙二醇甲醚，一缩二乙二醇)对PPESK铸膜液体系的相分离行为。

It shown that PDC does not only catalyze the production of acetaldehyde (PDC's main activity), but also catalyzes an aldoltype condensation reaction in which the hydroxyethyl-ThDP intermediate of enzyme is condensed with a second acetaldehyde to form acetoin.

在研究中发现PDC不仅能催化产生乙醛，还具有醛连接酶的活性。即将二个乙醛分子缩合成3-羟基丁酮，尽管这个活性比产生乙醛的活性低得多。

Under high dilution,the cross-coupling reactions of 4,5-dicyano-1,3-dithiol-2-one(6) and dithia crown-ether annulated tetrathiafulvalenes(3a～3c) in toluene gave asymmetrical dicyano tetrathiafulvalene derivatives(7a～7c) in the presence of triethyl phosphite.The compounds 7a～7c were characterized by(~1HNMR,EA,MS and IR.

在甲苯溶液中，在亚磷酸三乙酯存在下，采取高度稀释的方法，使4，5-二氰基-1，3-二硫杂环戊二烯-2-酮分别和多缩硫杂冠醚进行交叉偶联反应，成功地得到了不对称的2，3-二氰基四硫富瓦烯衍生物。

Quinone methides, generated in situ from the reaction of 4-hydroxycoumarin with benzaldehyde, formaldehyde and pentanal, underwent the Diels-Alder reaction with silyl enol ethers to give a series of 3,4-dihydro-2H,5H-pyrano[3,2-c][1]benzopyran derivatives in high yields.

通过4-羟基香豆素与苯甲醛、甲醛和戊醛缩合产生的quinone methide与烯醇硅醚的Diels-Alder反应，以较高产率合成了一系列含有硅氧基的3，4-二氢-2H，5H-吡喃并[3，2-c][1]苯并吡喃-5-酮衍生物。

Title compounds were synthesized by condensation of 3 benzylidene isochroman 4 one with 5 substituted 4 amino 3 mercap to 4 1,2,4 triazoles.

通过异色满酮－4的3－位苯亚甲基取代衍生物与4－氨基－3－巯基－1，2，4－三唑的缩合反应得异色满并［3，4－f］硫氮杂奥。

Sulfonated poly are prepared by direct polymerization of biphenol A, disodium 4, 4"-difluoro-3, 3"-disulfonate-1, 1-diphenylsulfone and 1, 3-(4-difluorophenyl)benzene. The polymers are characterized with ~1H-NMR, FT-IR.

以双酚A，1，3-二(4-氟苯基)苯和4，4′-二氟-3，3′-二磺酸钠-1，1′-二苯砜采用直接缩合法合成了不同磺化度的磺酸型聚芳醚酮砜，通过FT-IR和~1H-NMR对聚合物进行了表征，证明其结构正确。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。