光强在鱼腥藻7120培养液中的衰减及其对藻细胞生长的影响

研究了光强的衰减与鱼腥藻７１２０细胞浓度和光程的关系，并通过回归分析，得出了光强基于细胞密度和光路长度衰诂的关联式，为预测培养过程中的光强变化和调控提供了依据。同时，在１５Ｌ气升式反应器中，研究了恒定光强下藻细胞的生长情况，探讨了光强变化对藻细胞生长的影响，并对培养过程中细胞倍增时间作了比较，进一步说明了光强在藻细胞培养中的重要作用。     

镧对塔玛亚历山大藻生长的影响

随着稀土的大规模使用 ,天然水体中的稀土积累越来越多 ,稀土对水生态体系的影响引起了人们的广泛关注。本文模拟稀土镧积累的水体环境 ,研究此种情况对塔玛亚历山大藻生长的影响 ,结果显示低浓度镧的积累对塔玛亚历山大藻的生长有促进作用 ,并呈一定的时间、剂量效应关系。     

镧对黑曲霉生长代谢的影响

研究了单一稀土离子La3+对黑曲霉生长代谢的影响。结果表明:在培养基中添加适宜浓度的La3+后,固体平板上菌体生长速率提高,液体培养基中菌体生长量增大。当La3+浓度为40mg/L时,菌体生长速率、生长量及CMC酶活力均达到最大值,此后随离子浓度的增大而逐渐减小。滤纸酶活力则在La3+浓度为20mg/L时达到峰值,随后也随离子浓度的升高而逐渐降低。     

镧对三种植物病原真菌生长的影响

研究了单一稀土氧化镧 ( L a2 O3)对小麦纹枯病菌 ( Rhizoctonia cerealis,Rc)、棉花枯萎病菌 ( Fusariumoxysporum f.sp.vasinfectum,3- 2 )和水稻纹枯病菌 ( Rhizoctonia solani,Rs)三种植物病原真菌生长的影响。结果表明 ,在固体平板培养基中 ,L a2 O3浓度在 1 2 0～ 1 80 mg/L时对 Rc有明显刺激作用 ;浓度≤ 2 1 0 mg/L时 ,对 Rs有明显刺激作用。浓度 >30 0 mg/L时 ,对 Rc和 Rs均有较强抑制作用。La2 O3浓度在 30～ 450 mg/L时对 3- 2均表现为明显的抑制作用。     

外源镧在红壤中的有效性及其对土壤酸度的影响

通过培养试验及盆栽试验研究了外源镧在红壤中的有效性及其对土壤酸度的影响。结果表明,土壤有效态镧随外源镧的增加而增加,两者呈显著的正相关;外源镧在土壤中具有较高的有效性,随着时间的延长有效性逐渐降低;土壤pH随外源镧的增加不断降低,pH和外源镧及有效态镧均呈显著的负相关;过量的镧对土壤生态环境将产生破坏作用。     

镧对青枯假单胞菌生长及若干生化性状的影响

单一稀土氧化镧Ｌａ２Ｏ３对青枯假单胞菌的生长有明显抑制作用。当Ｌａ３＋质量浓度为５０,１００,１５０,２００,２５０,３００,３５０ｍｇ／Ｌ时,与对照相比,固体平板上病菌初生长时间延迟,７天后的菌落直径减小,生长量也减少。液体培养中的生物量也比对照显著下降。当Ｌａ３＋质量浓度大于３５０ｍｇ／Ｌ时,病菌停止生长。浓度为２００ｍｇ／Ｌ的Ｌａ３＋明显刺激该病菌的胞外蛋白酶、果胶酶及纤维素酶活性。     

硝酸镧影响枯草芽孢杆菌生长及细胞壁结构的机理

培养基中添加硝酸镧、溶菌酶和青霉素,探讨硝酸镧影响枯草芽孢杆菌生长及细胞壁结构的机理.采用光电比浊法表征细菌生长;红外光谱法表征细菌细胞壁结构;扫描电镜观察菌体形态.结果表明,溶菌酶和青霉素抑制了枯草芽孢杆菌的生长,硝酸镧逆转了溶菌酶和青霉素的抑制作用,硝酸镧浓度为160.0 mg/L时可明显逆转溶菌酶抑制细菌生长的作...     

镧对纯净钢夹杂物和耐腐蚀的影响

通过观察纯净钢中稀土夹杂物的形态，测试电化学腐蚀EIS谱和极化曲线，研究稀土元素镧对纯净钢耐腐蚀性能的影响。试验结果表明，镧加入纯净钢中，可变质夹杂物和改善夹杂物形态，从而提高了纯净钢耐腐蚀性能。     

钼镧合金重复成型对烧结的影响

为了研究钼镧合金重复成型对烧结的影响,对钼镧合金的形貌、化学及物理指标进行了测试,结果表明:重复成型与正常成型的钼镧合金烧结后的宏观及微观组织形态没有差异。碾压钼粉与正常钼粉相比,粒度变化不大为3.8μm,松比是正常钼粉的2倍为2.46 g/cm3。烧结后,重复成型合金密度为9.76 g/cm3,相比正常合金提高了0.16 g/cm3。碾压钼粉氧含量是正常钼粉的两倍,其他化学元素含量与正常钼粉基本接近。重复成型合金烧结后的化学元素含量与正常合金无显著差异。     

硬脂酸镧对LLDPE热氧化分解行为的影响

通过热失重和氧化诱导期方法研究了硬脂酸镧对LLDPE(线性低密度聚乙烯)热氧化分解行为的影响,在添加一定浓度的硬脂酸镧时,LLDPE的50%失重温度可大幅提高。研究表明,硬脂酸镧不能阻止LLDPE在热氧化分解温度较低阶段时的氧化反应,但可对高温阶段的断链反应有抑制作用,这可能是由硬脂酸镧对LLDPE氧化过程中产生的交联结构有稳定作用而造成的。硬脂酸镧和抗氧剂1010的复合使用对LLDPE热稳定性的提高存在加合效应,可使LLDPE的综合性能得到提高。     

用P507-煤油-HCl体系从YCl3溶液中萃取分离La3+和Ca2+

在生产高纯Y2O3中,YCl3溶液中的Ca2 与La3 均可以用P507萃取分离。经萃取分离后,产品中Ca2 与La3 的质量分数分别低于7×10-6与1×10-6,符合要求。     

Biosorption of La^3＋ and Ce^3＋ by Agrobacterium sp.HN1

The Agrobacterium sp.HN1 was isolated from the soil and used to adsorb rare earth ions La3+ and Ce3+.The results showed that the pretreatments of Agrobacterium sp.HN1 did not enhance the adsorption of La3+ and Ce3+.The pH,temperature,time and bacterial age affected the dynamics of adsorption of La3+ and Ce3+.The optimum adsorption conditions for Agrobacterium sp.HN1 were as follows:15 mg/L La3+ of initial concentration,10 mg/L Ce3+,300 mg/L(dry wt.cell) biomass for sorption,6.8 pH,30 oC temperature,150 r/min rotational speed,2 h adsorption time and 28 h bacterial age.The adsorption kinetics of La3+ and Ce3+ for Agrobacterium sp.HN1 followed the pseudo-second order equation.     

La3+对小球藻异养生长及叶绿素含量的影响

０．１～１００ｍｇ·Ｌ－１Ｌａ（ＮＯ３）３均能促进小球藻的异养生长,有助于葡萄糖的利用。异养培养时间≤３６ｈ时,Ｌａ３＋显著抑制小球藻对ＮＯ－３的吸收,之后则加速ＮＯ－３的吸收。Ｌａ３＋还能提高小球藻的叶绿素ａ、叶绿素ｂ及总叶绿素含量,最大促进百分率分别为２３．４％、２７．１％及２４．７％。     

Effect of La3+ on seed germination and seedling growth of Salvia miltiorrhiza

The purpose of this study is to determine the effect of La³⁺ solution on seed germination and seedling growth of Salvia miltiorrhiza. Different concentrations of La³⁺ were used on seed by soaking treated to determine which concentration is the most suitable for the growth of S. miltiorrhiza. Results show that the low concentration of La³⁺ displays the promotion effect on S. miltiorrhiza seed germination rate and germination potential, and the promotion effect reaches the highest level when the concentration of La³⁺ solution is 30 mg/L, the germination index and vigor index are the highest in 20 mg/L, and it can also increase the contents of soluble sugar, soluble protein and chlorophyll. Meanwhile, the activity of antioxidant enzyme system (CAT and SOD) are improved, thus the photosynthesis and resistance of plant are enhanced. On the contrary, when the La³⁺ concentration is high, La³⁺ can inhibit plant growth. Thus La³⁺ displays the "homesis effect" on S. miltiorrhiza growth.     

铈对黄绿木霉菌拮抗大豆菌核病菌能力的影响

利用室内菌落生长速度测定与对峙试验的方法研究了铈对拮抗菌黄绿木霉菌(T richoderm aaureov iride)拮抗大豆菌核病菌能力的影响,同时测定了添加铈后黄绿木霉菌发酵液抑菌能力的变化。实验结果表明:对黄绿木霉菌敏感的硝酸铈含量为240μg/mL,高于1200μg/mL的硝酸铈含量可完全抑制黄绿木霉菌的生长,低于390μg/mL的硝酸铈浓度可刺激黄绿木霉菌的生长;而大豆核盘菌对硝酸铈的敏感浓度高于黄绿木霉菌,为420μg/mL,在1200μg/mL的浓度下还未完全抑菌。硝酸铈的添加对黄绿木霉菌拮抗大豆菌核病菌(Sclerotin ia sclerotiorum)无影响,对峙培养抑菌率可达100%;不同硝酸铈浓度的发酵液抑制菌核菌的中浓度不同,低浓度下可促进抑菌作用的发挥。     

Fluorimetric study of the interaction between ATP and ciprofloxacin-Y3+ complex and its application

A simple spectrofluorimetric method was developed for determination of trace amount of adenosine disodium triphosphate(ATP).Under the optimum conditions,we studied the interaction between CIP-Y3+-ATP complex by using absorption and fluorescence spectra.It was observed that ATP remarkably enhanced the fluorescence intensity of the CIP-Y3+ complex at λem=415 nm and the enhanced fluorescence intensity of Y3+ ion remained proportional to the concentration of ATP.The developed method was successfully applied for...     

Effect of fluxes on structure and luminescence properties of Y3Al5O12：Ce^3＋ phosphors

Ce3+-activated yttrium aluminum garnet (YAG) was prepared by the solid-state reaction, in which H3BO3, LiF, NaF, KF and BaF2 were used as the fluxes. The effect of fluxes on optical properties of phosphors was studied in detail, especially the fluxes of alkali fluorides, which could enhance the emission intensity and change the wavelength of emission peaks. Among these YAG:Ce phosphors, the phosphor sintered with H3BO3 and NaF exhibited the strongest emission. The emission peaks of phosphors prepared with fluxes from LiF to KF were shifted to long wavelength. The effect of NaF concentration on the emission intensity of YAG:Ce was also investigated. The value of emis-sion intensity reached the maximum when the concentration of NaF was 0.5%.     

固溶参数对热轧Cu-3Si-2Ni合金晶粒长大的影响

研究了固溶温度和保温时间对热轧Cu-3Si-2Ni合金晶粒长大的影响。在875℃固溶处理时,合金晶粒长大缓慢,晶粒长大动力学指数很小,只有0.153。n值随固溶温度的提高而增大。Cu-3Si-2Ni合金在850℃到875℃范围内,保温60min,晶粒均匀长大,晶粒粗化不明显。晶粒长大的表现激活能为Q=80.11kJ/mol,晶粒长大是通过晶界空位扩散的晶界迁移机制;当固溶温度超过875℃,晶粒明显粗化。     

稀土对HAl62-3-3-0.7合金组织和性能的影响

通过对合金成分的调整分别配制了添加不同量稀土元素的试验用HAl62-3-3-0．7合金。借助金相与扫描电镜观察和分析了各合金的显微组织结构,运用模拟设备测试了各合金的力学性能。文章阐述了稀土元素对该类高强度耐磨黄铜的组织和性能的影响,试验表明适量加入稀土会显著细化晶粒,过量的稀土会导致在合金显微组织中形成线形富稀土相。随着合金中稀土含量的增加,合金的硬度升高,但当稀土含量超过0．1％时,由于线形富稀土相的形成,反而会使合金的力学性能下降。     

Effect of Rare Earths on Mechanical Properties and Microstructures of Si3N4-based Ceramics

Si3N4-hased ceramics exhibit excellentproperties such as high strength, high corro..sion resistance, high fire resisting property andhigh thermal shock resistance. However, up tonow, the application of St3N4-based ceramicsis still limited by their poor ductility, lowtoughness and stability. Adding fiber or whisher into ceramic matrix is a useful tougheningmethod, but fiber and whisker are costly and itis difficult to homogenize them in ceramic matrix. Furthermore, ceramic powders can not fill…