甲基丙烯酰胺丙基二甲基胺的合成

以甲基丙烯酸甲酯和N,N-二甲基丙二胺为原料,二丁基二月桂酸锡为催化剂,对苯二酚为阻聚剂合成了甲基丙烯酰胺丙基二甲基胺(DMAPMA)。确定了合成的最佳工艺为:n(甲基丙烯酸甲酯)∶n(N,N-二甲基丙二胺)=3∶1,催化剂用量为反应液总质量的2.0%,阻聚剂用量为反应液总质量的0.1%,反应温度为体系回流温度,反应时间为3h,在此条件下,产率达96%以上,二丁基二月桂酸锡可重复使用。     

N-羟甲基丙烯酰胺的合成及其工艺改进途径

介绍了N 羟甲基丙烯酰胺的基本性能以及合成N 羟甲基丙烯酰胺的丙烯酰胺法、丙烯腈水解法 ;从催化剂的选择及加量、丙烯酰胺与甲醛投料比、反应时间及反应温度、阻聚剂的选用以及甲醛中杂质含量等几个方面综述了合成N 羟甲基丙烯酰胺的工艺改进途径。     

丙烯酰胺提纯过程中阻聚剂的有效控制

丙烯酰胺水剂在提纯过程中通过调整阴阳树脂比例及提纯终点的确定，可有效地控制丙烯酰胺水剂中阻聚剂的含量。     

一种压裂液的制备与性能研究

为满足压裂液的高温环境应用要求,以丙烯酰胺聚合物为增稠剂,有机硼锆化合物为交联剂,复合多羟基醇为催化剂,制备改性阳离子聚合物压裂液。通过研究丙烯酰胺聚合物用量、有机硼锆交联剂用量、复合多羟基醇用量、反应温度及溶液pH值对压裂液的耐温与抗剪切性能影响,确定改性阳离子聚合物压裂液的最佳组成为:丙烯酰胺聚合物用量0.7%、有机硼锆交联剂用量2.0%、复合多羟基醇用量1.0%、反应温度50℃、溶液pH值为5.0。该阳离子聚合物压裂液经连续剪切,粘度仍维持在80mPa·s以上,可满足150℃高温环境的应用要求。     

聚牛磺酸丙烯酰胺的合成及表征

以牛磺酸丙烯酰胺为原料采用水溶液聚合法合成聚牛磺酸丙烯酰胺。采用L9(3)4正交设计法考察单体浓度,引发剂用量,反应时间,反应温度对产物黏度的影响,确定聚牛磺酸丙烯酰胺的最佳合成条件为单体浓度为20%,引发剂用量为0.4%,反应时间为6h,反应温度为50℃。并利用红外光谱、核磁共振氢谱对产物结构进行表征。     

阳离子聚丙烯酰胺的研制

阳离子聚丙烯酰胺是一种用途广泛的有机高分子聚合物,其分子量和阳离子度是决定其性能的重要指标。在氧化-还原引发体系中,以丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体共聚合成了阳离子型聚丙烯酰胺聚合物(CPAM),考察了反应温度、酸碱度、引发剂、单体及阳离子单体浓度等因素对CPAM分子量和阳离子度的影响。结果表明,较高分子量和阳离子度CPAM的最佳聚合条件为:聚合单体浓度为35%,阳离子单体的含量约15%,引发剂0.4%,反应体系温度35℃,pH值为6左右。     

UV-H_2O_2协同降解水中聚丙烯酰胺研究

采用UV-H2O2氧化降解水中聚丙烯酰胺,研究了H2O2浓度、反应温度、时间、pH值和水质对降解聚丙烯酰胺的影响。结果表明,在H2O2的质量浓度为330mg/L、反应时间为90min,反应温度为50℃和pH值为4.6的最佳条件下,对聚丙烯酰胺的质量浓度为250mg/L的配制水去除率为100%;对聚丙烯酰胺的质量浓度分别为250、276mg/L的模拟地层水和油田含聚污水去除率分别为68.9%和56.0%。水质对UV-H2O2降解聚丙烯酰胺有影响。     

黄原胶基高性能絮凝剂的合成研究

在水溶性引发剂过硫酸钾的引发下,使丙烯酰胺(AM)在黄原胶(XG)分子链上接枝聚合制备黄原胶/丙烯酰胺接枝共聚物(XG-g-AM).研究了单体量,引发剂量、反应温度对接枝反应的影响,利用红外光谱(FT-IR)、热重分析(TGA)对接枝产物进行表征.结果表明,最佳合成条件黄原胶质量浓度为10 g·L~(-1),丙烯酰胺与黄原胶质量比为3:1,引发剂与黄原胶质量比为0.06,反应温度为65℃,用该絮凝剂处理高岭土悬浊液时,絮凝效率能达到90%.     

疏水缔合改性丙烯酰胺共聚物的合成

采用自由基胶束聚合法合成了丙烯酰胺（AM）/丁基苯乙烯（BS）/2-甲基-2-丙烯酰胺基丙磺酸钠（NaAMPS）疏水缔合水溶性共聚物PASA,PASA避免了目前疏水缔合聚合物溶液热稳定性差的问题.研究得到了适宜的反应条件,包括NaAMPS、BS和引发剂加量相对于单体总量的摩尔分数分别为10%、2.5%和0.07%,总单体在水里的质量分数为10%,SDS在水里的质量分数为6.0%,反应温度50℃,pH=6～7,反应时间12 h.采用以上反应条件得到PASA的临界缔合质量浓度为0.05 g·dL^-1,对应的水溶液表观黏度为283 mPa·s,质量浓度为0.1 g·dL^-1的水溶液表观黏度为1020 mPa·s.采用元素分析、UV、FT-IR和¹HNMR证实了共聚物的分子结构;DSC分析表明了共聚物分子链中存在疏水嵌段.     

阳离子淀粉、壳聚糖与丙烯酰胺接枝共聚研究

以硝酸铈铵为引发剂,合成了阳离子淀粉-壳聚糖-丙烯酰胺接枝共聚物,讨论了反应温度、引发剂浓度、单体用量、反应时间以及壳聚糖用量对接枝共聚反应的影响.结果表明,[AGU]=0.20 mol·L-1,mCTS/mCS=1/6,[AM]=1.0 mol·L-1,[Ce4 ]=5 mmol·L-1,T=60 ℃,t=3 h,转化率和接枝效率可分别达到88%和92%以上.壳聚糖与阳离子淀粉质量比增大,转化率增大,接枝效率则随着壳聚糖用量增大一直降低,说明壳聚糖的存在,丙烯酰胺均聚的几率增大.     

季铵化硅烷的合成与应用

利用γ-氯丙基三甲氧基硅烷与N，N-二甲基十八胺反应，合成了N，N-二甲基-N-十八烷基氨丙基三甲氧基硅烷季铵盐(BFS)，对其抑菌性能及与氨基硅微乳同浴使用的效果进行了测定和研究。结果表明：BFS用量为10g／L条件下，能使整理后的棉织物对金黄色葡萄球菌、大肠杆菌的抑菌率分别达到99．82％和99．12％；而与氨基硅微乳同浴使用，所整理的织物不仅抑菌效果显著，柔软性良好，而且具有舒适的手感；另外，弱酸性使用条件有助于BFS和氨基硅微乳的协同效应，表现出最佳的整理效果。     

N-芳基-N-异丙基-2-羟基乙酰胺的合成

以 4个不同结构的芳胺为原料 ,经过N 烷基化 ,N 氯乙酰化 ,酯化 ,酯交换反应合成了 4个 2 羟基乙酰胺类化合物 ,它们都是重要的农药中间体。其中N (4 三氟甲基苯基 ) N 异丙基 2 羟基乙酰胺的合成 :控制温度在 10～ 2 0℃ ,向 4 三氟甲基苯胺 ,冰醋酸与丙酮的混合液中慢慢加入硼氢化钾 ,加完后 2 0℃反应 2h得到产品N 异丙基 4 三氟甲基苯胺 ,产率 86 .0 %。升温至40℃ ,向N 异丙基 4 三氟甲基苯胺、甲苯混合液中滴加氯乙酰氯 ,滴完后升温至 75℃ ,通氮气反应 2h得到产品N (4 三氟甲基苯基 ) N 异丙基 2 氯乙酰胺 ,产率 92 .9%。N (4 三氟甲基苯基 ) N 异丙基 2 氯乙酰胺 ,甲醇 ,醋酸钾 ,三乙胺 ,碳酸钾 ,回流反应 17h ,得到产品N (4 三氟甲基苯基 ) N 异丙基 2 羟基乙酰胺 ,产率 88.2 % ,总收率为 70 .5 %。产品结构经质谱和核磁确定     

The effect of delaying autumn incorporation of green manure crop on N mineralization and spring wheat (Triticum aestivum L.) performance

The use of legumes as green manuring crops does involve a potential riskof N leaching losses over the winter period. The susceptibility of cropresidue-derived N to losses and the pre-crop value of a green manuring crop canbe manipulated by proper timing of incorporation into soil. In this study,mineralization of C and N was investigated in a range of low temperatures,including thawing and freezing, that are characteristic to autumn green manureincorporation and its decomposition. The pre-crop effect of green manuring wasfurther tested with spring wheat under field conditions. We hypothesized thatdelaying green manure incorporation in the autumn would reduce the risk of Nlosses from the field and maximize the N transfer to a successive spring wheatcrop. To test the hypothesis, N mineralization was followed in alaboratory experiment where red clover (Trifoliumpratense L.) shoots were incubated at 4–8 °Cfor 40–80 days to simulate early autumn, delayed autumn and late autumnincorporation of a green manuring crop, followed by an incubation at–2 °C or at –2 °C to+4 °C for 25 days to simulate winter conditions. In asimultaneous field experiment, we measured the effect ofdelayed autumn incorporation of common vetch (Vicia sativaL.) green fallow on spring wheat performance. In the laboratoryexperiment, significant N mineralization during incubation wasdetected when simulating both early autumn and delayed autumn incorporation. Incontrast, no net N mineralization was detected when simulating lateincorporation. In the field experiment, the N supply fromsoil to spring wheat was higher in the late and delayed incorporationtreatmentsthan in early or spring incorporation of green manure. Late incorporationalso produced most wheat grain. We conclude that different amounts of N becomeavailable to wheat, depending on the time of incorporation of green manureresidues in soil. This difference is due to temperature. Late or delayedincorporation of green manure residues has the potential to reduce thesusceptibility of mineral N to leaching and yields more N available to asubsequent crop.     

Nitrogen concentration in cottonseed as an indicator of N availability

Research on corn and winter wheat has shown that a critical N concentration in the grain exists above which a yield response to N fertilizer is unlikely. This indicator can be used for post-harvest evaluation of N sufficiency and for mapping N availability in the field, which may be helpful for making future N fertilizer decisions. The purpose of this study was to determine if a critical N concentration in the seed exists for cotton. The study was conducted in the Georgia Coastal Plain during 1998, 1999, and 2001, using a different variety of cotton in each year. In 1998, 12 N fertilizer rates ranging from 38 to 203 kg ha^–1 were applied to Delta Pineland 90 at three locations within one field that differed in soil organic matter and clay concentration, and in 1999 and 2001, 6 N fertilizer rates ranging from 22 to 179 kg ha^–1 were applied to Stoneville 474 and Delta Pineland 458 in a different field. At all locations, the N concentration in the cottonseed increased linearly with increasing N fertilizer rates. Maximum yields were obtained at less than maximum seed N concentration. Lower seed N concentrations indicated some degree of N deficiency. Based on these results, it appears that a critical N concentration of 35 g kg^–1 exists for cottonseeds, above which no yield response to N fertilizer is likely. Information on the spatial distribution of cottonseed N concentrations could therefore help to evaluate the adequacy of N fertilization for cotton, thereby providing a basis for adjustment of N fertilization rates in future crops.     

Rational nitrogen fertilization in intensive cropping systems

The objective of a rational N fertilization program is to account for the sources and fate of N while estimating crop N needs. Efficiency of N use will vary with cropping systems and N sources. Management technologies that affect N use efficiency include the amount of N applied, timing and placement of N fertilizer, and use of inhibitors. One of the main problems in making a fertilizer N recommendation is to account for the contribution of N mineralization to plant available N. Most laboratory procedures do not account for the environmental factors that affect N mineralization and only estimate the size of the mineralizable N pool. However, changes in soil moisture and temperature can dramatically affect the amount and rate of release of mineralized N. Field and modeling techniques are two possible techniques to estimate N mineralization. Field techniques can be divided into soil and plant approaches. Soil incubations in the field provide a quantitative approach while soil nitrate tests during the growing season provide a qualitative approach to estimating N mineralization. The plant is the ultimate integrator of N mineralization. Plant N uptake by an unfertilized crop can provide a quantitative approach with certain precautions. This approach may be costly, labor intensive, and site specific. Crop N uptake during the growing season can be estimated by measuring the tissue N content or using a chlorophyll meter. The chlorophyll meter measures the greenness of the plant and has been shown to be positively correlated to plant N status. Modeling may provide another option by including the factors that affect the rate of N mineralization from a known pool. The two most important variables include soil moisture and temperature. Realistic yield expectations and accounting for existing and projected amounts of available N can improve the accuracy of N recommendations.     

Extraction of Uranium(VI) and Thorium(IV) from Nitric Acid Solution by N,N,N′,N′ – Tetraoctylglutaricamide

Synthesis and characterization of N,N,N′,N′-tetraoctylglutaricamide (TOGA) was carried out and used for extraction of U(VI) and Th(IV) from nitric acid solutions. The processes of extraction were determined by the slope analysis and by analyzing a function that allows the simultaneous treatment of all the experimental points obtained in different conditions. The different factors affecting the extraction distribution ratio(D) of U(VI) and Th(IV) (extraction concentration, concentrations of nitric acid, salting-out agent NaNO₃ concentration, equilibration time, temperature, and types of diluents) were investigated. The results obtained indicated that the extraction species of U(VI) and Th(IV) are mainly extracted as UO₂(NO₃)₂·1.0TOGA and Th(NO₃)₄·1.5TOGA. The apparent equilibrium constant of U(VI) and Th(IV) extraction determined are 3.35 ± 0.03 L³/mol³ and 1.87 ± 0.01 L⁵/mol⁵ at 298 ± 1 K. Thermodynamic parameters such as the free energy(ΔG), enthalpy(ΔH), and entropy(ΔS) changes associated with the extraction processes could be evaluated. Back-extraction of U(VI) and Th(IV) from organic phases was also studied.     

Response to N-fertilizer of Italian ryegrass grown alone and in mixture with berseem clover under continental irrigated mediterranean conditions

In a field experiment over three growing seasons, the potential benefits of planting berseem clover (Trifolium alexandrinum L) with Westerwold Italian ryegrass (Lolium multiflorum Lam.) were examined under irrigated continental Mediterranean conditions.Similar N rates (0, 30, 60, 90 and 120 kg N ha^–1 cut^–1) were applied to both pure Italian ryegrass stands and mixtures, each given three successive cuts. One previously unfertilized cut was performed in late winter. Species in the mixture were established at 50:50 seed ratio but the mean proportion of berseem clover was 14%. Mean winter survival of berseem was 87% but 88% of the plants had leaves damaged by the frost. Forage production varied with both N rate and cutting sequence in both the pure stand and the mixture but differences between the two types of swards were significant only at low levels of fertilizer N. Total DM production over the four cuts in plots with N applications of 0,90, 180, 270 and 360 kg N ha^–1 a^–1 were 7.14, 9.51, 11.66, 13.91 and 14.36 t DM ha^–1 a^–1 in pure stand, respectively. Corresponding values for the mixture were 8.80, 10.94, 12.90, 14.05 and 13.64 t DM ha^–1 a^–1. The mean response of Italian ryegrass in the range of 0–360 kg N ha^–1 a^–1 was 20 kg DM per kg N applied. The corresponding value for the mixture was 13 kg DM per kg N applied. At the berseem clover proportions reached in this work, N equivalence showed values of about 80 kg N ha^–1 a^–1. As rates of N increased from 0 to 120 kg N ha^–1 cut^–1, nitrogen concentration increased by 78%. In the applied range of N fertilizers, N0₃-N was not affected.

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Résumé Dans un essai réalisé au cours de trois saisons agricoles, on a étudié le potentiel de 1'association du bersim avec le raygrass italien. Les cultures ont été emenées et irrigué dans des conditions continentales méditerranéennes. On a appliqué, aussi bien pour la culture pure du raygrass que pour l'association, une fertilisation azotée avec les doses suivantes (0, 30, 60, 90 et 120 kg N/ha/coupe) après chacune des trois coupes successives. Une autre coupe avant fertilisation a été faite à la fin de 1'hiver. Les proportions du bersim et du raygrass dans le mélange de graines étaient de 50:50. Cependant, dans la culture en association, les plantes du bersim n'étaient préentés qu'avec un 14 pourcent. 87% des plantes du bersim ont pu survivre en hiver, dont 88% avaient des feuilles endommagées par les gelées. La production d'herbe a été proportionnelle aux doses de fertilisation pour la culture pure et l'association. Néanmoins, différence entre les rendements de chacune de ces dernières était d'autant plus nette que les doses d'azote incorporées dans le sol étaient faibles. La production de la MS pour les quatre coupes dans les parcelles avec les applications de 0, 90, 180, 270 et 360 kg N ha^–1 a^–1 étaient de 7.14, 9.51, 11.66, 13.51, 14.36 tMS ha^–1 a^–1. Le rendement moyen du raygrass italien dans un intervalle de 0-360 kg N ha^–1 a^–1 a été de 20 kg MS par kg de N de fertilisation. Concernant le bersim, les valeurs équivalentes de N étaient de 1'ordre de 80 kg N ha^–1 a^–1. Au fur et à mesure que les doses de fertilisation azotée augmente de 0 à 120 kg ha^–1 coupe, la concentration en azote augmente de 78%. Dans l'intervalle de la fertilisation azotée appliqué NO₃ -N n'a pas été affectée.

     

正丁基脒合成工艺的改进

以N、N，N-二丁基戊酰胺和三氟甲磺酸酐为原料，合成正丁基脒。以物料比、反应温度、反应时间为考察因素，采用正交化实验方法筛选最优工艺条件。结果表明，当N、N，N-二丁基戊酰胺与Tf20的投料比为1：2，反应温度0℃，反应时间2h时，产品收率达45％。采用。HNMR和IR对产品结构进行了表征。     

月桂酰胺丙基甜菜碱的合成及其性能

以自制的N ,N 二甲基 N′ 月桂酰基 1 ,3 丙二胺和氯乙酸钠为原料合成月桂酰胺丙基甜菜碱 ,通过改变反应温度、反应时间和氯乙酸钠的酸度 ,探索反应的优化条件 ,并对合成产品的起泡性、稳泡性和增稠性进行研究。结果显示 ,当反应温度为 70℃、反应时间为 5h ,氯乙酸钠的酸度为pH =6 0时 ,产物的活性物质量分数最高 ,为 (30 0± 1 6) % ;产物的起泡、稳泡、增稠性能高 ,与香波中的其他组分的相容性好     

N,N-二乙基-氨丙基甲基二甲氧基硅烷的合成及结构表征

以γ-氯丙基甲基二甲氧基硅烷和二乙胺为原料，经过胺化反应制得N，N-二乙基-氨丙基甲基二甲氧基硅烷，确定最佳反应条件为温度110℃。二乙胺与γ-氯丙基甲基二甲氧基硅烷的量之比4：1，反应时间20h，产品产率可达80%以上；并通过IR，^1HNMR光谱对产品结构进行了表征。应用HF/6-31G*量子化学从头算方法计算了分子构型。