Accumulation of Rare Earth Elements in Various Microorganisms

The removal of rare earth elements （REEs） from solution in various microorganisms was examined. Seventy-six strains from 69 species （22 bacteria, 20 actinomycetes, 18 fungi, and 16 yeasts） were tested. Initially, Sm was used to test the removal capabilities of the various organisms. Gram-positive bacteria, such as Bacillus licheniformis, B. subtilis, Brevibacterium helovolum, and Rhodococcus elythropolis, exhibited a particularly high capacity for accumulating Sm. In particular, the B. lichemiformis cells accumulated approximately 316 μmol Sm per gram dry wt. of microbial cells. A full suite of screenings was then conducted to compare the abilities of the organisms to remove Se, Y, La, Er, and, Lu from solution. Tests were done with solutions containing one REE at a time. Accumulation was nearly identical for the various metals and organisms. However, when solutions with equimolar amounts of two REEs were used, preferential removal from solution was observed. When an Eu/Gd solution was used, gram-positive bacteria removed more Eu and Gd as compared to actinomycetes. When Eu/Sm combination was used, gram-positive bacteria removed equal mounts of both metals and some actinomycetes removed more Eu. The selective removal was quantified by calculating separation factors （S. F.）, which indicated that Streptomyces levoris cells accumulated the greatest proportion of Eu. The removal of REEs from a solution containing five metals （Y, La, Sm, Er, and Lu） was then examined. Mucorjavanicus preferentially accumulated Sm and S. flavoviridis preferentially accumulated Lu. The effects of pH and Sm concentration on the accumulation of Sm by B. licheniformis were also examined. Accumulation increased at higher pH and at greater solution concentrations.     

Accumulation and Fractionation of Rare Earth Elements in Soil-Rice Systems

Rare earth elements(REEs)have been widelyapplied in agriculture as micro-fertilizer in China,andit has become an urgent taskto understand their cont-ents,distribution,translocation and accumulation inthe soil-crop systems and their ecological effects,inor…     

Accumulation of REEs in Field Wheat and Comparison between Two Kinds of REEs Dressing Methods

Ｉｎｔｈｅｐａｓｔｙｅａｒｓ ,ｍｏｓｔｏｆｔｈｅａｐｐｌｉｃａｔｉｏｎｓｏｆＲＥＥｓｉｎａｇｒｉｃｕｌｔｕｒｅｗｅｒｅｂａｓｅｄｏｎｆｏｌｉａｇｅｄｒｅｓｓｉｎｇ .Ｒｅｃｅｎｔｌｙ ,ＲＥＥｓｗｉｔｈｏｔｈｅｒｆｅｒｔｉｌｉｚｅｒｓａｒｅｄｒｅｓｓｅｄｉｎｔｏｓｏｉｌｄｉｒｅｃｔｌｙａｓｂａｓｉｃｆｅｒｔｉｌｉｚｅｒ .ＧｅｎｅｒａｌｌｙｓｏｉｌｄｒｅｓｓｉｎｇａｍｏｕｎｔｏｆＲＥＥｓｉｓｔｅｎｔｉｍｅｓｈｉｇｈｅｒｔｈａｎｆｏｌｉａｇｅｄｒｅｓｓｉｎｇａｍｏｕｎｔ .Ｒｅ ｓｅａｒｃｈｅｓｄｅａｌｉ…     

Distribution and Accumulation of Neodymium and Its Effect on Secretion of Progesterone in Mice

Rareearthelementshavebeenincreasinglyusedinagriculture ,animalhusbandryandfisheryinChinasinceREcanpromotegrowthofcropsandani mals[1,2 ] .However ,studieshaveshownthatoverex posureofREmayhavenegativeortoxiceffectsonor ganisms ,forexample ,inhibitingenzymeactivityandinterferinginmetabolism ,havinghighaffinitytoCa2 bindingsitesanddown regulatingabsorptionandfunc tionofCa2 ,blockingbloodclotting ,inducingpatho histologicallesionsofliver ,aswellasaffectinggo nadalfunction[3～6 ] .Furthermore ,…     

Accumulation of Rare Earth Elements in Spinach and Soil under Condition of Using REE and Acid Rain Stress

Ｔｈｅｒｅａｒｅｍａｎｙｒｅｐｏｒｔｓｏｆｓｔｕｄｉｅｓｏｎｔｈｅｅｆｆｅｃｔｓｏｎｐｌａｎｔｓｂｙａｃｉｄｒａｉｎ[1～ 3 ] ａｎｄｕｔｉｌｉｚａ ｔｉｏｎｏｆＲＥＥ[4～ 7] ａｎｄａｆｅｗｓｔｕｄｉｅｓｏｎＲＥＥｕｓ ｉｎｇａｓｃｈｅｍｉｃａｌａｄｊｕｓｔｍｅｎｔｔｏｐｒｏｔｅｃｔｉｎｇｐｌａｎｔｓｆｒｏｍｂｅｉｎｇｄａｍａｇｅｄｂｙａｃｉｄｒａｉｎｓｔｒｅｓｓｕｎｄｅｒｎａｔｕｒａｌｃｏｎｄｉｔｉｏｎ .ＴｈｉｓｓｔｕｄｙｗａｓｆｏｃｕｓｅｄｏｎｔｈｅａｃｃｕｍｕｌａｔｉｏｎｏｆＲＥＥｉｎｓｐｉｎ…     

稀土萃取分离过程三相乳化物的研究Ⅰ——无机杂质富集沉淀导致的乳化

对中钇富铕稀土矿萃取分离过程中产生的三相乳化物进行了物相分离和组成分析,确认第一分离段发生累积性三相物乳化的主要原因是原料中的难溶性固体物质累积,后续各分离段发生累积性三相物乳化的主要原因则是由于氟离子富集后生成了较多稀土氟化物沉淀。     

HDEHP在硫酸溶液中萃取分离轻稀土性能研究

研究了 HDEHP在硫酸溶液中萃取分离轻稀土离子时有机相浓度、皂化剂类型、有机相皂化率、料液酸度对萃取饱和容量、分配比、分离系数的影响 ,确定了最佳萃取工艺参数 ,测定了轻稀土离子的分配比和分离系数。     

Survival of Pseudomonas fluorescence X16 （luxAB） Strain in Soils Accumulated with Mixed Rare Earth Elements

Theresearchandapplicationofrareearthele ments(REE)inagricultureinChinahasbeenformorethan 2 0years .RecentlytheconsumptionofREEin creasesbecauseoftheapplicationofREE ammoniacarbonateinlargescale .REEaddedintosoilprinci pallyaccumulatesinsoilasthemigratingrateofREEinsoilisextremelylow[1] .AlltheseattractthepublicattentiontowardstheecotoxiceffectandenvironmentalsafetyofREE′sagriculturalapplication .Heavymetalsaddedintosoilprimarilyaffectsoilmicrobialflora ,andthequantityandactivityofsoil…     

Concentrations and Distribution Patterns of Rare Earth Elements in Water Body from Intertidal Flat of Tianjin and Influence of Various Factors

Concentrations and distribution patterns of rare earth elements(REEs)in the intertidal flat of Tianjin were studied using P507 resin and ICP-MS analytical technology. The results show that average concentrations of REEs in the filtered(dissolved REEs), unfiltered and interstitial water are 0.461 μg·L-1, 4.98 μg·L-1 and 0.845 μg·L-1, respectively. Their distribution patterns are similar to those in inland natural rivers, but quite different from those in oceans. The average concentrations of REEs in sediments and suspended matters are 161.2 mg·L-1 and 168.1 mg·L-1, respectively, which are much lower than those in sediments of natural rivers but higher than those in sediments of the continental shelf of East China Sea. It is suggested that REEs in sediments and suspended matters of intertidal flat can have mainly originated from terrestrial soils and thus their transportation and transformation processes are similar with those in rivers, and different from those in continental shelves. Pollutants discharged into the Bohai Bay do·not cause significant effect on REEs in the intertidal flat of Tianjin yet.     

Effects of lanthanum on abscisic acid regulation of root growth in Arabidopsis

Rare earth elements(REEs) were reported to have adverse biology effects on plant growth and production. However, whether REEs are involved in plant hormone abscisic acid signal is not clear. Here we reported that REE lanthanum(La) interacted with abscisic acid(ABA) in the regulation of seed germination and root growth in model plant Arabidopsis. La3+at a concentration of 10 μmol/L alleviated ABA depression of seed germination and reversed ABA inhibition of root elongation growth in Arabidopsis. Previous studies showed that ABA could promote root hair development. In the present study, La3+inhibited root hair development promoted by ABA. Moreover, La3+inhibited H2 O2 generation induced by ABA in root cells. Therefore we inferred that La3+might interact with ABA upstream of H2 O2 generation.     

Optical and magnetic properties of GaN epilayers implanted with ytterbium

We have studied the optical and magnetic properties of ytterbium implanted GaN epilayer grown on(0001)sapphire by metalorganic chemical vapor by deposition(MOCVD).Samples were implanted at room temperature with Yb ions at dose 4x1015 cm-2 and energy of 150 keV.The implanted samples were annealed at 1000 ℃ in N2 at atmospheric pressure to recover implantation damages.The photoluminescence (PL),PL excitation(PLE),and PL kinetics have been studied with continuous and pulse photo-excitations in 360-1100 nm spectral range at different temperatures.The characteristic Yb3+ion emission spectra were observed in the spectral range between 970-1050 nm.Theoretical fittings of the experimental PL temperature and PL kinetics data suggest that Yb3+ions are involved in at least two major luminescence centers.The PLE spectra indicate that excitation of the Yb3+ion occurs via electron-hole pair generation and complex processes.Magnetization versus magnetic field curves shows an enhancement of magnetic order for Yb-implanted samples in 5 K to 300 K temperature range.The Yb-implanted GaN sample showing weak ferromagnetic behavior was compared with the ferromagnetic in situ doped GaYbN material.     

Cr3+离子在不同介质中的光谱特征及晶格场强度

研究Cr3+离子掺杂固体物质的制备工艺以及光谱特性有助于开发新的光学材料.本研究分别用提拉法技术生长了Cr3+∶BeAl2O4晶体, 用坩埚下降法技术生长了Cr3+∶LiNbO3晶体, 以及用高温熔融法技术研制了ZnO-Al2O3-SiO2微晶玻璃.获得了生长优质Cr3+∶BeAl2O4与Cr3+∶LiNbO3的工艺参数.分别测定与讨论了Cr3+离子在上述不同介质中的吸收光谱与荧光光谱特征.实验发现Cr3+离子在不同介质中, 其吸收光谱与荧光光谱的位置与形状在不同基质中发生很大的差异.在Cr3+∶BeAl2O4与Cr3+∶LiNbO3晶体中均观测到尖锐的R线荧光.从其相应的光谱特性大致估算了Cr3+离子在不同介质中的晶格场参数.从Dq/B值数据判断Cr3+∶BeAl2O4与Cr3+∶LiNbO3晶体属于强晶格场, Cr3+∶ZnO-Al2O3-SiO2与其微晶玻璃属于弱晶格场.     

偶氮氯膦—mA分光光度法测定钢中的稀土总量

本文提出了大量铁存在时间ＥＤＴＡ做隐蔽剂，选择６５８ｎｍ波长，用偶氮氯膦－ｍＡ（ＣＰＡ－ｍＡ）的分光光度法直接测定钢中的稀土总量，在试验条件下偶氮氯膦－ｍＡ与各等量的单一稀土配俣物的吸光度基本接近，此时，各等量稀土配合物之间吸光度的差别也大大小于用草酸做隐蔽剂时的差别，从而减小了由于试样中各稀土元素的配合分未知而引起的测定误差。     

稀土(Ⅲ)硝酸盐与4-羟基-3-甲氧基苯甲醛缩乙二胺双希夫碱配合物的合成与性质

由双希夫碱４－羟基－３－甲氧基苯甲醛缩乙二胺与稀土（Ⅲ）硝酸盐（Ｌａ，Ｎｄ，Ｇｄ，Ｔｂ，Ｈｏ），合成了五种固体配合物。对配合物进行了元素分析、摩尔电导、红外光谱、紫外光谱、差热—热重分析。确定了配合物的组成为ＬｎＬ（ＮＯ３）３。     

Effects of Rare Earths and Its Complex with Extract from Seaweed（Laminaria japonica ） on Growth and Immunization of Penaeid Shrimp （ Penaeus vannamei ）

In China, scientists have applied inorganic com pounds of rare earths (RE), which act as a microele ment fertilizer, to agricultural crops since 1970s[1~3].Recent works have proved that RE can increase aquat ic production. RE has been widely applied i…     

PMMA with Long-Persistent Phosphors and Its Behavior of Luminescence

A new kind of rare earth material with high efficient long-persistent phosphors, such as SrAl2O4:Eu, Dy, has been developed in recent years. The PMMA with long-persistent phosphors is typical one of applications for the phosphors. In this work, we try to probe into the affection of the manufacture process on the PMMA with long-persistent phosphors, to analyze its performance, and its luminescence behavior, especially to study the self-excitation of the PMMA with long-persistent phosphors.     

不同稀土掺杂聚苯乙烯力学性能研究

选择了几种功能不同的Pr，Eu，Gd，Th，Dy，Ho和Er的三异丙氧基化合物与苯乙烯本体聚合获得稀土掺杂聚苯乙烯，采用ESEM，DMTA，冲击强度测试研究了不同稀土对聚合物力学性能的影响，结果表明不同稀土引入聚苯乙烯中均能使韧性得以提高，它们的力学性能与稀土的原子序数、原子半径大小有关。     

Phase Analysis of Cemented Carbide WC—Co Boronised with Yttrium

Phase analysis for the coated surface with B4Cand Y2O3of cemented carbide WC-20Co in vacuum-heating was carried out by high-temperature X-ray diffraction from ambient temperature to 1300℃，The results show that,the high-concentration active boron atoms are released from the boron-supply agent B4Clocated on the alloy surface and diffused into the γphase,leading to forming the three-element boron-bearing compound W2Co21B6beside forming boron-bearins compounds on the blank surface.By contrast with boronising only,the element yttrium in boronization broadens the boronising temperature range during vacuum-sistering,catalyzes the decarbonisation decomposition of B4C and promotes diffusion of active boron atoms into the bulk of WC-Co.     

稀土锗钨钼杂多配合物的合成及表征

合成了十二种稀土锗钨钼酸根多元杂多配合物。利用元素化学分析和ICP相结合方法、IR等手段对配合物进行了初步表征。     

Enthalpies of Solution of Complexes of Rare Earth Nitrate with L-α-Histidine in Water

The enthalpies of solution in water of complexes of RE(NO3)3(RE = La - Nd, Sm- Lu, Y) with L-α-Histidine (His) were measured at 298.15 K. The standard enthalpies of formation of RE(His)^3 (aq) were calculated. The “tetrad effect” regularity was observed from the curve, which is the enthalpies of solution plotted against the atomic numbers of the elements in lanthanide series.