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751.
Retention behavior of size and aluminum components in handsheets prepared in rosin soap size-alum systems 总被引:2,自引:0,他引:2
Handsheets were prepared with rosin soap size and aluminum sulfate under various conditions, and the retention behavior of the rosin size and aluminum components in the handsheets was studied. Pyrolysis-gas chromatography and X-ray fluorescence analysis were used to determine the size and aluminum contents in the handsheets, respectively. When the addition level of rosin soap size varied from 0% to 4% and that of aluminum sulfate was fixed at 2%, the rosin size content increased with the increase in the size addition level, whereas aluminum and calcium contents were roughly constant. Under these conditions, handsheets prepared from fines-free pulp had aluminum contents less than those for the original beaten pulp, probably because the former pulp had a carboxyl content less than that of the latter pulp. Not only the conventional rosin retention mechanism but also mechanism proposed below must exist in the rosin soap size-alum systems. That is, some aluminum compounds originating from aluminum sulfate are adsorbed on pulp fibers immediately after the aluminum sulfate addition. These adsorbed aluminum compounds form cationic sites on pulp fibers, and free rosin acid components with anionic charges are then adsorbed onto the cationic sites of pulp fibers at the wet-end.This research was presented in part at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996 相似文献
752.
753.
J.-P. Carmouze S.G. Galvão L. Nishiara H. de S.L. Mesquita 《Mangroves and Salt Marshes》1998,2(1):43-49
Chemical changes in anoxic tidal waters, emerging from the mangrove forest of Cananeia, (48° W, 25° S; Brazil), were interpreted using a stoichiometric approach. Significant depletion of magnesium and sulphates were observed and were apparently due to magnesium-iron replacement in octahedral sheets of clay minerals, and sulphate reduction, respectively. Iron release from clays, after bacterial-mediated reduction, apparently reacted with sulphides produced by sulphate reduction to form nono- and di-sulphides. Production of 41.5% of FeS and 58.5% of FeS2satisfactorily explained all the stoichiometric relations between concentration changes of magnesium, sulphates, sulphides, iron and alkalinity expected by the model. As a consequence, the decomposition rate of organic matter in these prevailing anoxic conditions, would mainly stem from sulphate reduction (90% against 10% for ferrireduction). The simultaneous bacterial processes of uptake and release of ammonium included in the model would explain why the mangrove forest does not export significant amounts of nitrogen toward the adjacent lagoon. 相似文献
754.
The distribution of aluminum components in cross sections of pulp fibers for alum-treated handsheets was successfully measured by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. In this case, gas-phase osmium coating of paper samples is necessary for the samples to have improved stability to long-term irradiation by electron beams at high magnification during the SEM-EDX measurements. The EDX line-analysis method was superior to the elemental mapping image method in the quantification of aluminum components. According to the SEM-EDX measurement for handsheets prepared from a pulp suspension by adding 2% (on dry weight of pulp) aluminum sulfate, the aluminum components were distributed almost homogeneously in the cross sections of pulp fibers. Aluminum species with smaller sizes than those of A1(OH)3 flocs could probably penetrate the pulp fibers. Thus, aluminum components present only at the pulp fiber surfaces may contribute to retention of colloidal substances in pulp suspensions. From this aspect, a large amount of aluminum components present in the inside pulp fibers may be wasted.This report was presented at the 49th annual meeting of the Japan Wood Research Society at Tokyo, April 1997 相似文献
755.
对刈割后初花期紫花苜蓿(Medicago sativa),分别喷洒不同浓度十二烷基硫酸钠(CK:0%、D1:0.5%、D2:1%、D3:1.5%、D4:2%、D5:2.5%、D6:3%),测定其水分含量变化和干燥后粗蛋白(CP),中性洗涤纤维(NDF),酸性洗涤纤维(ADF)及能量(GE)含量的变化。结果表明:喷洒不同浓度的十二烷基硫酸钠可以不同程度的提高紫花苜蓿的干燥速度,并改善其干草营养品质。除D5外,其余各处理组间紫花苜蓿的CP含量差异不显著(p0.05),其中D5(2.5%)处理组CP含量最高(20.42%);D4(2%)NDF含量(33.77%)显著低于其他各处理组(p0.05);除D3外,其他各处理组ADF含量显著低于CK(p0.05);CK组GE含量极显著低于其余各处理(p0.01),其中D6(3%)GE含量最高(17 671.00 J/g)。综合考虑,7个处理组中以D4(2%)处理组的干燥效果最好,能有效的改善紫花苜蓿干草品质。 相似文献
756.
【目的】研究不同肥料对柳杉幼苗生长及养分吸收的影响,为制定柳杉壮苗施肥措施及其人工林经营提供参考依据。【方法】盆栽柳杉幼苗,采用随机区组试验,设不施肥(CK,处理1)、施硫酸造粒肥(处理2)、施蒸汽造粒肥(处理3)和施有机肥(处理4)4个处理,1年后测定各处理苗高、地径、地上和地下部分干物质及氮、磷、钾养分含量、盆栽土壤水解性氮、速效磷、速效钾含量。【结果】各施肥处理的柳杉苗木生长、养分积累及土壤速效养分含量差异较大,且均极显著高于CK(P<0.01),其中处理2的苗高最高、地径最粗,分别比CK增加24.4%和40.7%,处理3的植株干物质、氮、磷、钾养分含量最高,分别比CK高216.0%、119.4%、192.0%和198.8%,处理4的幼苗盆栽土壤有效养分含量最高,显著高于其他处理(P<0.05)。【结论】施用硫酸造粒肥能加快柳杉苗木出圃,施用蒸汽造粒肥培育的柳杉苗木更适用于多风易致苗木损伤弯折林地造林,施用有机肥可活化土壤中的氮、磷、钾明显提高土壤有效氮、速效磷及速效钾含量。 相似文献
757.
钾肥品种与用量对黄瓜养分吸收和分配的影响 总被引:7,自引:1,他引:7
在大棚栽培条件下,研究了不同钾肥品种与用量对黄瓜养分吸收和分配的影响.结果表明:钾肥可明显提高黄瓜含钾量,而降低其他大、中量元素含量,钾-钙和钾-镁拮抗作用明显;施用氯化钾提高黄瓜组织含钾量的效果优于硫酸钾.低量钾肥可提高黄瓜养分吸收量,继续增施钾肥可明显降低养分元素吸收量.硫酸钾有利于果实养分分配比例的提高,而氯化钾有利于营养体养分分配比例的提高.钾肥品种与用量对黄瓜养分吸收和分配的影响与产量和品质呈密切相关. 相似文献
758.
[目的]为硫酸软骨素的工业化生产提供依据。[方法]以鸡胸软骨为原料,通过单因素优化试验研究影响硫酸软骨素产率的显著性因素,探索碱液水解法提取硫酸软骨素的最佳工艺条件。[结果]料液比、提取温度和碱液浓度对硫酸软骨素的产率有较大影响。料液比是影响硫酸软骨素产率的最显著因素,提取温度为次显著因素,而碱液浓度也是影响产率的显著因素。碱液水解法提取硫酸软骨素的最佳工艺条件为:料液比1∶6.75,反应温度40℃,碱液浓度6%。[结论]在该条件下,所得硫酸软骨素产品的最高产率为19.75%,纯度为82.59%,氮含量为3.35%,符合国家标准。 相似文献
759.
基于日因子和表观残碱浓度对蒸煮温度和时间,以及初始活性碱用量(AA)、硫化度(5)和黑液残碱浓度的统一性表达,分析了日因子和表观残碱浓度与纸浆细浆得率之间的关系,提出可预测纸浆细浆得率经验模型的表达式;经最小二乘法拟合以及实验值与模型预测值的对比,评价模型的适用性和准确性.结果表明,在桉木硫酸盐法蒸煮条件范围内,该模型实验值与预测值之间的相似度高达95%,说明模型可准确预测细浆得率.另外,由于模型所需参数可直接在蒸煮过程中获得,因此,该模型对实际生产过程中细浆得率的预测具有实用性. 相似文献
760.
通过 3种模拟酸沉降溶液对福建和贵阳两种森林土壤样品的连续浸泡试验 ,研究了土壤对酸沉降中 SO42 -和 NO3-的吸附 ,以及盐基离子输入对这种吸附的影响 .结果表明 ,2种土壤对 SO42 -均有一定的吸附能力 ,但福建土壤的吸附量比贵阳土壤大 .土壤对 SO42 - 的吸附与酸沉降中 SO42 - 浓度及土壤水溶性 SO42 - 含量有关 ,但高浓度的盐基离子输入会降低 SO42 -的吸附量 .土壤对 NO3-的吸附主要发生在表土中 ,且比 SO42 -的吸附量低 ,但比预料的要高 相似文献