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尿素-甲醛的成环化反应 被引量:7
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作者 禄树晖 张艳全 +1 位作者 郭如振 高振华 《东北林业大学学报》 CAS CSCD 北大核心 2008年第12期69-70,86,共3页
采用在脲醛树脂合成初期对尿素—甲醛衍生物进行Uron化反应后,再进行UF树脂合成的技术方法,通过FTIR定量分析,研究了不同pH值、反应温度、反应时间及催化剂种类对尿素与甲醛成环化反应的Uron相对值的影响。结果表明:通过在脲醛树脂合成... 采用在脲醛树脂合成初期对尿素—甲醛衍生物进行Uron化反应后,再进行UF树脂合成的技术方法,通过FTIR定量分析,研究了不同pH值、反应温度、反应时间及催化剂种类对尿素与甲醛成环化反应的Uron相对值的影响。结果表明:通过在脲醛树脂合成中引入Uron环等环状结构物质能够有效提高脲醛树脂胶黏剂的耐水性;当反应温度高于75℃时,反应产物都生成了一定量的Uron环物质;在pH值为8左右、温度控制在85℃、不使用催化剂、尽可能延长反应时间的条件下,尿素与甲醛成环化反应生成的Uron相对值最多。 展开更多
关键词 脲醛树脂 环化反应 FTIR Uron环
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尤戎(Uron)树脂及其用法对脲醛树脂性能的影响 被引量:7
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作者 高伟 李建章 +2 位作者 周文瑞 卢振雷 雷得定 《中国胶粘剂》 CAS 2007年第1期23-25,33,共4页
以不同工艺制备了三种含尤戎结构的脲醛树脂(Uron树脂),通过其与普通脲醛树脂的混合制得多种混合脲醛树脂。研究了Uron树脂及其使用方法对降低脲醛树脂胶粘剂游离甲醛含量及胶接胶合板甲醛释放量的作用与效果。结果表明:1)三种不同摩尔... 以不同工艺制备了三种含尤戎结构的脲醛树脂(Uron树脂),通过其与普通脲醛树脂的混合制得多种混合脲醛树脂。研究了Uron树脂及其使用方法对降低脲醛树脂胶粘剂游离甲醛含量及胶接胶合板甲醛释放量的作用与效果。结果表明:1)三种不同摩尔比的Uron树脂对脲醛树脂游离甲醛含量及胶接胶合板甲醛释放量都有明显的降低作用,游离甲醛含量最多可降低43%,甲醛释放量最多可降低61%;2)Uron树脂的添加量在10%-20%时对胶合强度的提高有利,强度最大可提高29%;3)低摩尔比Uron树脂对脲醛树脂的改性效果优于高摩尔比Uron树脂。 展开更多
关键词 Uron树脂 脲醛树脂 游离甲醛含量 甲醛释放量 胶合强度
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Chicory(Cichorium intybus L.) and cereals differently affect gut development in broiler chickens and young pigs 被引量:3
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作者 Haoyu Liu Emma Ivarsson +1 位作者 Torbjrn Lundh Jan Erik Lindberg 《Journal of Animal Science and Biotechnology》 SCIE CAS 2014年第2期230-235,共6页
Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastric... Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastrics. Furthermore, it can be used as in-feed antibiotic alternative. Chicory (Cichorium intybus L.) forage with high content of pectin (uronic acids as building blocks) is a novel class of dietary fiber that is chemically different from cereal grains (with high content of arabinoxylans). In the present study, we investigated effects of dietary inclusion of chicory forage on digestibility, gut morphology and microbiota in broilers and young pigs. In the chicken experiment, 160 1-d old broiler chicks were fed 3 nutritionally balanced diets for 30 d including a cereal-based diet and 2 diets with part of the cereals substituted with 60 and 120 g/k9 chicory forage (CF60 and CF120], whereas in the pig experiment, 18 seven-wk old Yorkshire pigs were fed 3 diets for 18 d including a cereal-based diet and 2 diets with 80 and 160 g/kg chicory forage inclusion (CF80 and CF160). Our results showed that young pigs were capable to utilize chicory forage well with higher total tract apparent digestibility (TTAD) of all fiber fractions, particularly uronic acid, compared with the control (P 〈 0.01). In contrast, a decreased TTAD of all fiber fractions was observed in chickens fed on diet CF120 (P 〈 0.05). Moreover, diet induced changes in gut morphology were observed in the large intestine of chickens. The alteration of cecal mucosal thickness was further positively correlated with TTAD of non-starch polysaccharides (NSP) and its constituent sugars (P 〈 0.05). In addition, in pigs, terminal restriction fragment length polymorphism (T-RFLP) analysis of intestinal microbiota revealed substantial dietary effects (cereal control diet vs. chicory forage inclusion) on the relative abundance of 2 dominant bacterial phylotypes (Prevotella sp. vs. Roseburia sp.) respectively (P 〈 0.05). In conclusion, our data showed that chicory forage (Cichorium intybus L.), a novel dietary fiber source in animal nutrition, have potential beneficial properties as fiber ingredient in diets for both pigs and chickens. 展开更多
关键词 Broiler Cereal arabinoxylans Chicory uronic acids Digestibility Gut development Microbiota PECTIN Young pigs
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Uron型和三聚氰胺改性脲醛树脂胶粘剂的对比研究 被引量:1
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作者 孙丰文 董云丹 张茜 《中国胶粘剂》 CAS 北大核心 2014年第12期18-21,共4页
在强酸条件下,以尿素(U)和甲醛(F)为原料合成Uron(尤戎)环衍生化合物,然后与采用常规碱-酸-碱工艺合成的三聚氰胺(M)改性脲醛树脂(UF)胶粘剂进行了性能对比,同时还根据市场原料价格估算了两者的成本。研究结果表明:强酸条件下合成的UF... 在强酸条件下,以尿素(U)和甲醛(F)为原料合成Uron(尤戎)环衍生化合物,然后与采用常规碱-酸-碱工艺合成的三聚氰胺(M)改性脲醛树脂(UF)胶粘剂进行了性能对比,同时还根据市场原料价格估算了两者的成本。研究结果表明:强酸条件下合成的UF胶粘剂含有Uron型环状结构(可明显提高胶合板的胶接强度,降低F释放量),具有胶接性能优异、生产成本低廉等特点。 展开更多
关键词 脲醛树脂 胶粘剂 改性 Uron环化合物 三聚氰胺 甲醛释放量 胶接强度
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Fecal microbiome of growing pigs fed a cereal based diet including chicory(Cichorium intybus L.) or ribwort(Plantago lanceolata L.) forage 被引量:1
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作者 Johan Dicksved Janet K.Jansson Jan Erik Lindberg 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2016年第2期167-175,共9页
Background: The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community(microbiome) in newly weaned(35 days of age... Background: The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community(microbiome) in newly weaned(35 days of age) piglets.The piglets were fed a cereal-based diet without(B) and with inclusion(80 and 160 g/kg air-dry forage) of vegetative shoots of chicory(C) and leaves of ribwort(R) forage in a 35-day growth trial. Fecal samples were collected at the start(D0), 17(D17) and 35(D35) days after weaning and profiles of the microbial consortia were generated using terminal restriction fragment length polymorphism(T-RFLP). 454-FLX pyrosequencing of 16 S r RNA gene amplicons was used to analyze the microbial composition in a subset of the samples already analyzed with T-RFLP.Results: The microbial clustering pattern was primarily dependent on age of the pigs, but diet effects could also be observed. Lactobacilli and enterobacteria were more abundant at D0, whereas the genera Streptococcus, Treponema,Clostridium, Clostridiaceae1 and Coprococcus were present in higher abundances at D35. Pigs fed ribwort had an increased abundance of sequences classified as Treponema and a reduction in lactobacilli. However, the abundance of Prevotellaceae increased with age in on both the chicory and the ribwort diet. Moreover, there were significant correlations between the abundance of Bacteroides and the digested amount of galactose, uronic acids and total non-starch polysaccharides, and between the abundance of Bacteroidales and the digested amount of xylose.Conclusion: This study demonstrated that both chicory and ribwort inclusion in the diet of newly weaned pigs influenced the composition of the fecal microbiota and that digestion of specific dietary components was correlated with species composition of the microbiota. Moreover, this study showed that the gut will be exposed to a dramatic shift in the microbial community structure several weeks after weaning. 展开更多
关键词 Amplicon sequencing Chicory Microbiome Ribwort uronic acid Weaning 16S
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Uron环改性SBS胶粘剂的研制与应用
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作者 樊亚娟 汤豪 吴菲 《中国胶粘剂》 CAS 北大核心 2018年第7期32-34,共3页
以尿素与甲醛通过环化反应生成Uron环衍生物,Uron环衍生物与一定比例的SBS(802型)胶粘剂、SBS(796 S/B-20/80型)胶粘剂共同制备成Uron环改性SBS胶粘剂。探讨了pH对尿素与甲醛树脂化和成环化的条件影响,并对该胶粘剂进行FT-IR、DSC、光... 以尿素与甲醛通过环化反应生成Uron环衍生物,Uron环衍生物与一定比例的SBS(802型)胶粘剂、SBS(796 S/B-20/80型)胶粘剂共同制备成Uron环改性SBS胶粘剂。探讨了pH对尿素与甲醛树脂化和成环化的条件影响,并对该胶粘剂进行FT-IR、DSC、光学显微镜图片分析、力学性能测试及应用情况分析。实验结果表明:以Uron环为改性基团,对SBS型复合胶粘剂进行共混改性可有效提升产品性能。 展开更多
关键词 Uron环 SBS胶粘剂 改性
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Carbohydrate analysis by methanolysis method and application to compositional analysis of transparent exopolymer particles
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作者 Shigeki Wada Kazuo Iseki Takeo Hama 《Advances in Bioscience and Biotechnology》 2013年第9期11-17,共7页
Measurement of uronic acids (URAs) which are a group of acidic sugar, would be useful for the understanding of dynamics of bacterial extracellular polymeric substances (EPS) in marine environments. However, the URA an... Measurement of uronic acids (URAs) which are a group of acidic sugar, would be useful for the understanding of dynamics of bacterial extracellular polymeric substances (EPS) in marine environments. However, the URA analysis using traditional hydrolysis method which is used for neutral sugar analysis poses serious problems in URA that is unstable under hydrolysis. We developed the methanolysis method, which deploymerizes polysaccharides while retaining quantitative information. Our method was applied to coastal seawater, and the URAs distribution was compared with that of transparent exopolymer particles (TEP) which are acidic sugar containing particles. Since the relationship of URA with TEP was relatively weak, URA-containing polysaccharides present in bacterial EPS would not participate as a structural component of TEP. 展开更多
关键词 uronic Acid TRANSPARENT Exopolymer PARTICLES METHANOLYSIS Gas CHROMATOGRAPHY MASS SPECTROMETRY
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Uron环结构化合物的合成与稳定性研究 被引量:2
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作者 田雨 刘亚青 +3 位作者 赵贵哲 孙友谊 曹杨 朱福田 《绝缘材料》 CAS 2007年第5期19-21,25,共4页
在弱碱性条件下,以尿素和多聚甲醛为原料进行加成反应合成Uron环结构化合物。利用^13CNMR、FTIR研究弱碱性环境下产物结构特征。结果表明:多聚甲醛在弱碱性条件下尿素的取代主要以多取代为主,产物中有高含量的Uron环结构存在。环境... 在弱碱性条件下,以尿素和多聚甲醛为原料进行加成反应合成Uron环结构化合物。利用^13CNMR、FTIR研究弱碱性环境下产物结构特征。结果表明:多聚甲醛在弱碱性条件下尿素的取代主要以多取代为主,产物中有高含量的Uron环结构存在。环境温度为25℃,pH值为8~9时,产物稳定性好、贮存期长、游离甲醛含量低;DSC-TG结果表明产物有较好的热稳定性,适合后续反应。 展开更多
关键词 尿素 多聚甲醛 Uron环化合物
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碱性条件下Uron环结构化合物的合成与结构研究 被引量:1
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作者 田雨 赵贵哲 +2 位作者 刘亚青 朱福田 曹杨 《中国胶粘剂》 CAS 2007年第3期8-10,共3页
在弱碱性条件下,用尿素和多聚甲醛进行加成反应合成Uron环化合物。用13CNMR、FTIR研究弱碱性环境下产物结构特征。结果表明:多聚甲醛法在弱碱性条件下尿素的取代主要以多取代为主,产物中有高含量的Uron环结构存在。环境温度为25℃,pH值... 在弱碱性条件下,用尿素和多聚甲醛进行加成反应合成Uron环化合物。用13CNMR、FTIR研究弱碱性环境下产物结构特征。结果表明:多聚甲醛法在弱碱性条件下尿素的取代主要以多取代为主,产物中有高含量的Uron环结构存在。环境温度为25℃,pH值为8-9时,产物稳定性好、贮存期长、游离甲醛含量低。 展开更多
关键词 羟甲基 合成 表征 尿素 甲醛 Uron环
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Activity of Acetolactate Synthase from Maize (Zea mays L.) as Influenced by Chlorsulfuron and Tribenuron-methyl 被引量:5
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作者 FANZhi-jin CHENJun-peng 《Agricultural Sciences in China》 CAS CSCD 2003年第2期176-182,共7页
Study on relative sensitivity of maize (Zea mays L.) Nongda108 and Nongda3138 to sulfony-lurea herbicide chlorsulfuron and tribenuron-methyl using maize taproot length by sand bioassy indicated that, Nongda3138 had hi... Study on relative sensitivity of maize (Zea mays L.) Nongda108 and Nongda3138 to sulfony-lurea herbicide chlorsulfuron and tribenuron-methyl using maize taproot length by sand bioassy indicated that, Nongda3138 had higher tolerance to chlorsulfuron and tribenuron-methyl than Nongda108 did. Chlorsulfuron had stronger growth inhibition to maize Nongda108 and Nongda3138 than tribenuron-methyl did. Study on target enzyme of sulfonylurea herbicide acetolactate synthase (ALS) showed that, chlorsulfuron and tribenuron-methyl inhibited ALS in vitro strongly, and non-competitively. In the same concentration of inhibitors, chlorsulfuron had stronger ALS activity inhibition than tribenuron-methyl did. Lower level of chlorsulfuron and tribenuron-methyl has no ALS activity inhibition in vivo, the ALS inhibition only occurred in the condition of high concentration of chlorsulfuron and tribenuron-methyl in vivo. 展开更多
关键词 Chlorsulf uron TRIBENURON-METHYL Acetolactate synthase (ALS) Maize (Zea mays L.)
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