Effect of La-Gly on Physiological and Biochemical Characteristics of Glycine max Seedling under Pb Stress

ＴｈｅｒｅｈａｖｅｂｅｅｎｓｏｍｅｒｅｐｏｒｔｓｏｎｔｈｅｍｅｃｈａｎｉｓｍｏｆｔｈｅｓｔｒｅｓｓｉｎｊｕｒｙｂｙＰｂｐｏｌｌｕｔｉｏｎｉｎｐｌａｎｔ[1～ 4] .ＴｈｅｉｎｊｕｒｙｕｎｄｅｒＰｂｓｔｒｅｓｓｗａｓｒｅｌａｔｅｄｔｏｔｈｅｄｅｓｔｒｏｙｏｆｓｕｐｅｒｍｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆｃｅｌｌｎｕｃｌｅｕｓｅｓ,ｍｉｔｏｃｈｏｎｄｒｉｏｎ ,ｃｈｌｏｒｏｐｈａｓｔ[5] ,ｓｏｔｈａｔｔｈｅｃｏｎｔｅｎｔｓｏｆｔｈｅｃｈｌｏｒｏｐｈｙｌｌａｎｄａｓｃｏｒｂｉｃａｃｉｄ[1 ,4,5] ,ｔｈｅａｃｔｉｖｉ…     

Alleviation Effects of Rare Earth on Cd Stress to Rape

Using rapes as test materials, the fastness expression and alleviation effect of rapes were studied under Cd stress condition, as the rapeseeds were dipped in the single element( La, Ce, Nd, Pr)and mixed rare earth (RE). The results indicate that, under Cd stress, the dry and fresh weight are increased by both the single element and mixed rare earth treatment, and the fastness of rape is improved. The single element of rare earth decreases the Cd content in rape roots and transmits Cd to the edible parts above the ground in which the alleviation effect of Ce is most significant. La treatment takes the second place, so that the poisonous effect of heavy metal Cd is eased. The mixed rare earth doesnt alleviate the assimilation of Cd in rape roots, but accelerates the transfer of Cd to the parts above the ground. The research puts forward that the alleviation of rare earth on Cd stress has connection with the decrease of Ca content.     

Aging Effect on Lanthanum Doped Ferroelectric Lead Titanate Ceramics

Ferroelectric devices are widely applied in many fields, such as energy conversion and communication. The aging effect in ferroelectric materials plays a central role in the reliability of the related equipments. But it is very difficult to understand the origin of aging effect in ferroelectrics because these materials possess different defects and exhibit various aging behavior. The reverse transition temperature in lead titanate doped with lanthanum increases during aging at ferroelectric phase was reported. It is well known that lattice defects, such as vacancies and solute atoms, are ubiquitous in crystalline solids. These point defects affect physical properties in ferroelectrics significantly. The abnormal increase of the reverse transition temperature was discussed in terms of diffusion of point defects during aging. Dielectric performance in the material after aging was measured and discussed as well.     

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。     

Effect of Lanthanum on Plants under Supplementary Ultraviolet-B Radiation： Effect of Lanthanum on Flavonoid Contents in Soybean Seedlings Exposed to Supplementary Ultraviolet-B Radiation

The effects of solar ultraviolet-B (UV-B,280 ~320 nm) radiation on plants have been studiedintens-ively over the last two decades ,associated withthe re-search onthe biological i mpacts of stratospheric ozonedepletion .There are a large number of reports aboutthe effects of UV-B radiation on crops[1 ~5].Flavonoidcompounds , as secondary metabolites are consideredto play a major role in protecting plants from UV-Bdamage[6].These flavonoids generally absorbthe lightinthe region of 280 ~320 n…     

Inducement of Salicylic Acid in Cucumber Cotyledons by Neodymium and Lanthanum

The cotyledons of cucumber were used to investigate the effects of Nd^3＋ and La^3＋ on physiological characters in respect of plant resistance. The cucumber cotyledons were sprayed with 15 μg · ml^-1· Nd^3＋ and La^3＋, and the changers on salicylic acid （SA） and SA 2-O-β-glucoside （SAG） contents, the generation of ·O2^-, and β-1,3-glucanase and chitinase activities were measured. The results demonstrated that the yields of endogenous SA and SAG in cucumber cotyledons were enhanced significantly in a short time in response to Nd^3＋ and La^3＋ treatments. At 3 h after La^3＋ treatment, the levels of SA and SAG reached the maximum, with 4.3 and 3.3-fold of that in control （CK）, respectively. At 12 h after Nd3＋ treatment, the contents of SA and SAG reached peak levels, increased by 4.5 and 3.0-fold of that in control （CK）, respec- tively. These two components were kept in a higher level up to 72 h after treatment. The generation rate of · O2^- increased gradually in the treatments of Nd^3＋ or La^3＋, and then decreased in cucumber at 12 h. β-1,3-glucanase activity reached peak at 3 h, while chitinase activity reached peak at 12 h, and then both decreased gradually in Nd^3＋ or La^3＋ treatments. At 72 h after treatment, activities of β-1, 3-glucanase and chitinase increased by about 30% and 50%, as compared with CK. Therefore, these results suggested that both Nd^3＋ and La^3＋ could increase the contents of endogenous SA and its related factors which induce plant resistance through the signal pathway of the salicylic acid.     

Chemical States of Lanthanum in Carbonized La2O3-Mo Thermionic Cathode Materials

The chemical reaction between lanthanum oxide and molybdenum carbide was studied by thermodynamic calcu-lation, thermal analysis and in-situ X-ray Photoelectron Spectroscopy. The theoretical results show that at the environment allowing for the evaporation of lanthanum, such as in high vacuum, La2O3 in the La2O3-Mo materials can be reduced to metallic lanthanum by molybdenum carbide (Mo2C). To confirm the conclusion, many analysis methods such as XRD, SPS, and TG-DTA were taken. The experimental results show that the chemical state of lanthanum changes during heat-ing. It was proved, for the first time, that reacted metallic lanthanum appears at the surface of this kind of material at high temperature.     

Effect of Lanthanum on Acid Secretion from Isolated Mouse Stomach in Vitro

Rareearthshavebeenextensivelyusedinindus try ,agricultureandmodernbiologicalmedicine ,andmoreandmoreREelementsareenteringintothebio logicalcircle .Manystudieshaveindicatedthattheyhavesignificanteffectsonallsystemsofhumanandanimalorganisms[1～5] .Previousarticlesreportedthatrareearthsmayaffectthedigestivefunctionandmaypromotedevelopmentofanimals .Thegastricacidandpepsinsecretionsareelevatedatadministrationoflow erdosesofrareearth ,whereasmarkedlydecreasesatadministrationofhigherdosesinratsandr…     

La(Ⅲ)对UV-B辐射胁迫下大豆幼苗内源激素的影响

为了探索La(Ⅲ)对UV-B辐射胁迫下大豆幼苗内源激素的影响,试验以大豆幼苗为材料,采用水培实验的方法研究了La(Ⅲ)对UV-B辐射胁迫下大豆幼苗生长素(IAA)、生长素氧化酶(IAAO)、脱落酸(ABA)、赤霉素(GA)的影响.结果表明,UV-B辐射(T1:0.15W·m-2和T2:0.45W·m-2)胁迫下,大豆幼苗IAA、IAAO、ABA、GA含量在胁迫期(1d～5d)和恢复期(6d～11d)分别呈现"先下降后有所回升"、"先升后降再升"、"先升后降"、"下降"趋势.而各处理组IAA和GA含量La(Ⅲ)+UV-B>UV-B,La(Ⅲ)>CK,La(Ⅲ)+T1>La(Ⅲ)+T2;LAAO活性和ABA含量恰与之相反.表明La(Ⅲ)可减缓UV-B辐射对大豆幼苗的伤害,且对低剂量(T1)的防护效果优于高剂量(T2),进而在防御系统层面实现了La(Ⅲ)对UV-B辐射伤害大豆幼苗的防护效应.     

Effects of Rare Earth on Oxidative Damage and Redox System of Wheat Seedling Leaves under Water Stress

The leaf is the most sensitive site in plant underwater stress . With lengthening in duration of waterstress ,cell membrane of leaf will be damaged .Dhind-sa et al[1]found that when drought tolerant moss lostwater slowly , the activities of SOD and CAT de…     

Study on Interaction between Lanthanum and Phosphor in Purity Steel

Using SEM and EDS some particles containing La and P were discovered in low oxygen and sulfur purity steel with lanthanum. In these particles low melting point elements such as As and Sb also were detected. According to the result of simulative calculation of segregation, it is shown that La and P enrich so strongly in the process of solidification that their concentrations can satisfy thermodynamic condition to forme LaP compound or meet the requirements to forme eutectic phase in the last stage of solidification. Therefore, the particles are concluded as LaP compound or eutectics, which exist on grain boundary mainly.     

Nano Lanthanum Oxide Preparation by Alkalescent Ammonium Citrate System and Its Primary Biological Effect

Nanomaterialshavebacteriostaticandbacterici dalactivityonplant[1,2 ] .Rareearthmaterialsnoton lypossessbacteriostaticandbactericidalactivity ,butalsohavetheactionofnutrientbearerandactasnu trientregulator[3] .Becausetheparticlesizeandho mogeneityofmaterialshavenotbeenrequiredexactly ,nanorareearthmaterialwhichisfrom 1nmto 10 0nmforbiologyapplicationisalsopreparedbyamethodhomogeneousprecipitant[4 ,5] .Currently ,generalpre cipitatorsaremostlyammonia ,urea ,oxalicacidandammoniumbicarbonateaswell…     

Effect of Lanthanum on Rice Growth and Physiological Parameters with Split-Root Nutrient Solution Culture

Ａｌｏｔｏｆｗｏｒｋｈａｓｂｅｅｎｄｏｎｅｏｎｔｈｅｅｆｆｅｃｔｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｏｎｐｌａｎｔｇｒｏｗｔｈａｎｄｐｈｙｓｉｏｌｏｇｉｃａｌａｃｔｉｖ ｉｔｉｅｓ .ＲｅｓｕｌｔｓｈａｖｅｓｈｏｗｎｔｈａｔＲＥＥｓａｐｐｌｉｅｄｂｙｆｏｌｉａｒｓｐｒａｙｓ ,ｓｅｅｄｔｒｅａｔｍｅｎｔｓｏｒａｄｄｉｔｉｏｎｔｏｔｈｅｓｏｉｌｓａｎｄｓｏ ｌｕｔｉｏｎｍｅｄｉａｃａｎｉｎｃｒｅａｓｅｇｒａｉｎｃｒｏｐｓ ,ｅｃｏｎｏｍｉｃｃｒｏｐｓ ,ａｎｄｖｅｇｅｔａｂｌｅｓｂｙ 5 0 %～ 12 % ,8 0 %…     

Effect of Lanthanum(Ⅲ) on Cytosolic Free Calcium in Isolated Rabbit Mature Osteoclasts

The effect of lanthanum(Ⅲ) (La3 ) on cytosolic free calcium ([Ca2 ]i) in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluorescent probe by using a confocal laser scanning microscope. La3 does not alter basal [Ca2 ]i levels and cell spread area at the concentration of 1.00×10-8 mol·L-1. However, La3 at higher concentrations ( 1.00×10-5 and 1.00×10-7 mol·L-1) decreases [Ca2 ]i levels and cell spread area, and greater decreases are observed for the higher concentrations of La3 . Since [Ca2 ]i affects cytoskeleton and the adhesion properties of osteoclasts, our results seem to suggest that La3 inhibit bone resorption by decreasing [Ca2 ]i in rabbit mature osteoclasts.     

Effect of La2O3 on granular bainite microstructure and wear resistance of hardfacing layer metal

The purpose of this work was to investigate the effect of La2 O3 on the granular bainite microstructure and wear resistance of hardfacing layer metal. The hardfacing layer metals with different contents of La2 O3 were prepared. The microstructures of the hardfacing layer metals were observed by field emission scanning electron microscopy(FESEM) and transmission electron microscopy(TEM). The hardness and wear resistance of the hardfacing layer metals were measured respectively. The results indicated that with the increasing content of La2 O3, the amount of granular bainite increased, while that of martensite decreased and that of retained austenite did not change obviously. When the content of La2 O3 was 2.55 wt.%, the volume fraction of the granular bainite in the hardfacing layer metal was 73.2%. Meanwhile, the wear resistance of the hardfacing layer metal was the largest, which was 12100 min/g. The mismatch between the face(100) of LaAlO3 and the face(100) of δ-Fe was 7.1%. Therefore, LaAlO3 could act as moderate effective heterogeneous nuclei of δ-Fe and the granular bainite could be refined.     

Effects of Lanthanum on Redox Systems in Plasma Membranes of Casuarina equisetifolia Seedlings Under Acid Rain Stress

Theplasmamembraneisapenetrablebarrier ,whichcancontroltheexchangeofsubstancesacrossmembranesincells ,andalsoistheintermediumandreceptorofenergyorinformationtransferencebetweencellsandenvironment.Theplasmamembraneredoxsystem(PMRS)meanstheelectrontransferchainsonplasmamembrane .Owingtohavethepossibilityofejectingprotons ,energizingplasmamembraneandhavingthefunctionofacceleratingtransportationofsoluteacrossmembrane ,theplasmamembraneredoxsystemswerepaidmuchattentionto[1] .Acidrainisoneofthemost…     

Preparation and Compressive Stress Effect of Polymer Matrix RE-Fe Giant Magnetostrictive Composite

Polymer matrix RE-Fe giant magnetostrictire composite （GMPC） was prepared using bonding and magnetic field forming technique, and magnetostriction of samples was measured for different compressive stress. The experimental results show thai there is certain compressive effect in GMPC. And the influence of compressive stress on magnetostriction of sample was investigated. It offers essential reference for application and device design of GMPC.     

Effect of La2O3 on Microstructure and Transmittance of Transparent Alumina Ceramics

Optically transparent alumina ceramics were fabricated by conventional process and sintered without pressure in H2 atmosphere. The results indicate that relative densities of alumina specimens increase to theoretical densities （T. D. ） with increasing content of La2O3. With increasing holding time during sintering, much less pores and larger grains were found in the sintered alumina samples. Higher transmittance was achieved in alumina codoped with MgO and La2O3 as compared with that doped with MgO only. The total-transmittance of alumina sample is up to 86% at twavelength range of 300 - 800 nm.     

Effect of La_2O_3 on the wear behavior of MoSi_2 at high temperature

Wear behaviors of MoSi2 doped with La2O3 against SiC under different loads at 1000 oC in air were investigated by using an XP-5 type high temperature friction and wear tester. The worn surfaces and phases of the samples were analyzed by scanning electron microscopy (SEM) and X-ray diffraction, respectively. Results showed that the addition of La2O3 could obviously improve wear resistance of MoSi2. Because of the formation of MoO3 phase on the worn surface, La2O3/MoSi2 composite mainly exhibited oxidation and abrasive wear, which was different from the wear form of MoSi2 such as adhesion, oxidation and abrasion.     

Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys

Ｔｈｅｒｅａｒｅａｌｗａｙｓｓｏｍｅｇｅｏｍｅｔｒｉｃａｌｄｉｓｃｏｎ ｔｉｎｕｉｔｉｅｓ ,ｓｕｃｈａｓｆａｓｔｅｎｅｒｈｏｌｅｓ ,ｆｉｌｌｅｔｓａｎｄｇｒａｖｅｓ ,ｉｎｐｒａｃｔｉｃａｌａｉｒｃｒａｆｔｃｏｎｓｔｒｕｃｔｉｏｎｃｏｍ ｐｏｎｅｎｔｓ .Ｉｎｔｈｅｖｉｅｗｏｆｍａｔｅｒｉａｌｍｅｃｈａｎｉｃｓ ,ｔｈｅｓｅｇｅｏｍｅｔｒｉｃａｌｄｉｓｃｏｎｔｉｎｕｉｔｉｅｓｃａｎｂｅｃｏｎ ｓｉｄｅｒｅｄａｓｎｏｔｃｈｅｓ .Ｓｔｒｅｓｓｃｏｎｃｅｎｔｒａｔｉｏｎｕｓｕａｌ ｌｙｏｃｃｕｒｓａｔｎｏｔｃｈ…