参数自整定模糊控制器在稀土萃取过程控制中的应用

针对稀土串级萃取生产的工艺特点,设计了参数自整定模糊控制器,并用RBF神经网络实现了对控制器参数的自整定,使萃取生产中回路流量的设定接近并达到控制要求。仿真结果表明该控制策略的可行性。     

不同贮藏方法及光照对马尾松花粉活力的影响

对马尾松花粉在不同贮藏方法及光照下花粉发芽率和花粉和长度变化的分析。结果表明：１．在干燥的状态下,贮藏的温度越低、保存花粉生活力的效果越好;２;在黑光条件下,马尾松花粉发芽率较其它光照条件下高,但它们的差异未达到显著水平;３．在黑光条件下,马尾松花粉和长度较其它光照条件下长,它们之间差异在到极显著水平。最后,对马尾松花粉贮藏方法及光照对花粉萌发的影响进行了讨论。     

球铁曲轴稀土软氮化工艺的研究

笔者研究了稀土对球铁曲轴软氮化工艺及渗层硬度分布的影响.结果表明:加入稀土对球铁曲轴软氮化有明显的催渗作用,软氮化时间可缩短30%; 稀土催渗后,渗层硬度梯度趋向平缓.稀土催渗浮的球铁曲轴使用寿命提高10%.     

Effect of continuous illumination on secretion of pregnane compounds by the rat ovary

Summary Differences in the secretion of pregnance compounds from rats with follicular polycystic ovaries under constant light and with normal preovulatory ovaries under light-dark conditions were compared. The injection of LH greatly increased the secretion of progesterone. 5-pregnane-3,20-dione and 3-hydroxy-5-pregnan-20-one, in both types of ovaries, but the response of the two progesterone metabolites in the polycystic ovaries was low, suggesting low 5-reductase activity.Acknowledgments. The authors thank the Endocrinology Study Section, NIADDK, Bethesda, MD, USA. for their gift of LH. This study was supported by Research Grant No. 466 154 from the Ministry of Education, Science, and Culture, Japan.     

Bifunctional enzyme FBPase/SBPase is essential for photoautotrophic growth in cyanobacterium Synechocystis sp. PCC 6803

From a random insertion mutant library of Synechocystis sp. PCC 6803, a mutant defective in photoautotrophic growth was obtained. The interrupted gene was identified to be slr2094 （fbpl）, which encodes the fructose-1,6-biphosphatase （FBPase）/sedoheptulose-1,7-biphosphatase （SBPase） bifunctional enzyme （F-I）. Two other independently constructed slr2094 mutants showed an identical phenotype. The FBPase activity was found to be virtually lacking in an slr2094 mutant, which was sensitive to light under mixotrophic growth conditions. These results indicate that slr2094 is the only active FBPase-encoding gene in this cyanobacterium. Inactivation of photosystem II by interrupting psbB in slr2094 mutant alleviated the sensitiveness to light. This report provides the direct genetic evidence for the essential role of F-I in the photosynthesis of Synechocystis sp. PCC 6803.     

稀土固体超强酸Ce(Ⅳ)-SO_4~(2-)/TiO_2催化合成柠檬酸三丁酯

采用浸渍法制备了负载稀土的固体超强酸Ce(Ⅳ)-SO4 2-/TiO2催化剂,以柠檬酸三丁酯的合成为探针反应进行了单因素测试.实验结果表明,当Ce(SO4)2·4H2O的质量分数(占浸渍液)为2.0%,H2S04浸渍液浓度为0.6mol/L,酸醇摩尔比1:4,催化剂用量为1.2 g,反应时间为3.0h时,酯化率为86.5%.重复使用5次后,其酯化率仍达78.7%.     

Mineral magnetism of quaternary red earth in Eastern China and Its paleoenvironmental significance

Mineral magnetic measurements have been made on Quaternary Red Earth profiles from Zhejiang Province, Eastern China. Three distinctive magnetic stratigraphic horizons have been identified on the basis of magnetic susceptibility, anhysteretic remanent magnetization, saturation isothermal remanent magnetization and magnetization parameters measurements. Magnetic measurements revealed that there were great variations in ferrimagnetic mineral concentration, mineralogy assemblages and grain size in Quaternary Red Earth profiles, suggesting that these variations reflect pedogenic processes fluctuation and environmental changes. The preliminary results indicate that mineral magnetic measurement of Quaternary Red Earth is useful for studying the Quaternary environmental changes recorded in paleosols.     

氮化硅结合碳化硅材料掺入稀土烧结机理的研究

对氮化硅结合碳化硅材料进行了掺入稀土的系统实验,并对产品进行了力学性能测试和X射线衍射测试,对掺入稀土的氮化硅结合碳化硅材料的烧结热力学,动力学和反应机理等进行了理论研究,简单服掺入稀土的氮化硅结合碳化硅材料性能优于普通氮化硅结合碳化硅材料的原因。     

稀土生产硫酸废液含氟量的测定研究

研究了以高氯酸为介质,用水蒸气将氟分离出来,以碱液吸收,然后以氟试剂分光光度法测定稀土硫酸废液中的氟含量的方法,讨论了络合物显色体系的最佳条件,对稀土硫酸废液中氟含量作了实际测定,并作了加标回收率实验,结果表明,氟的加标回收率在94.5%-100.2%之间,变异系数为0.96%-2.43%。     

稀土对杉木、杨树幼林生长的影响

对杉木[Cuninghamia Lancelata(Lamb)Hook]杨树（Populus cv.‘Lux’施用稀土后幼树的根系吸收等指标进行的观测结果表明,用不同浓度的稀土处理苗木,其单株幼树根系的总吸收面积,活跃吸收面积差异显,根系的比表面差异不显。杨树以500mg/kg的稀土溶液浸根时根系的吸收指标最高,杉木以800mg/kg浓度叶面喷施最高。经不同浓度稀土处理后,与对照相比,杉木,杨树在同时期所测得的高生长量,地径生长量,根系干重均有不同程度的提高。