氯化镧与丙氨酸配位反应的热化学研究

用新型的具有恒温环境的反应热量计 ,以溶解量热法分别测定了 2 5℃时 (LaCl·7H2 O 3Ala)和Al(Ala) 3 Cl3 ·3H2 O在 2mol·L-1HCl溶剂中的溶解焓。通过设计的热化学循环得到七水氯化镧与丙氨酸配位反应的反应焓ΔrHm=9 738kJ·mol-1,并计算出配合物La(Ala) 3 Cl3 ·3H2 O在 2 98 2K时的标准生成焓ΔfH0m=- 3713 8kJ·mol-1。     

Effect of Lanthanum on Quantity of Major Microorganism Groups in Yellow Cinnamon Soil

Ｔｈｅｈｉｓｔｏｒｙｏｆａｐｐｌｉｃａｔｉｏｎｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓ（ＲＥＥ）ｉｎａｇｒｉｃｕｌｔｕｒｅｉｓｍｏｒｅｔｈａｎ２０ｙｅａｒｓｉｎＣｈｉｎａ．ＲｅｃｅｎｔｌｙｔｈｅｃｏｎｓｕｍｐｔｉｏｎｏｆＲＥＥｉｓｉｎｃｒｅａｓｅｄｂｙ...     

Segregation and Action of Lanthanum in NiCrCoW Alloys

ＴｈｅｐｒｏｐｅｒｔｉｅｓｏｆｈｏｔｄｅｆｏｒｍａｔｉｏｎａｎｄｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅｏｆＮｉＣｏＣｒＷａｌｏｙａｒｅｉｍｐｒｏｖｅｄｂｙａｄｄｉｔｉｏｎｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓ［１～４］ｂｕｔｔｈｅｍｅｃｈａ...     

Study on Pt/KL Zeolite Catalyst for n-Hexane Aromatization Modified by Lanthanum

Pt/KLze0litecatalystwasfoundtobeahighlyactiveandselectivecatalystf0rthearoma-tizationofn-hexane,onwhichtheselectivitytobenzenewas6~8timeshigherthanthatofcon-venti0nalbifuncti0nalref0rmingcatalyst(Pt/Re/Al,O,-Cl)[lj.However,thiskindofmonofunc-tionalcatalystshowedd0zens0ftimespoorerthantheconventionalcatalystinsulfur-resistance,whichpreventeditfr0m-beingappliedinindus-try['j.Recently,othermetalcomponentssuchasRe,W[3j,F.[4jandrareearth(LaandDy)[5'6JetcwereintroducedtothePt-supportedKLzeo-li…     

Preparation of Polystyrene Doped with Ytrium Ethoxide and Study on Their Coordination

ＰｒｅｐａｒａｔｉｏｎｏｆＰｏｌｙｓｔｙｒｅｎｅＤｏｐｅｄｗｉｔｈＹｔｒｉｕｍＥｔｈｏｘｉｄｅａｎｄＳｔｕｄｙｏｎＴｈｅｉｒＣｏｏｒｄｉｎａｔｉｏｎＳｈｅｎｇＹｕ（生瑜），ＺｈａｎｇＷｅｎｇｏｎｇ（章文贡）（ＩｎｓｔｉｔｕｔｅｏｆＰｏｌｙｍｅｒＳｃ...     

Effects of Lanthanum on Egg Hatching and Nauplius Metamorphosis of Penaeus Chinensis

ＥｆｅｃｔｓｏｆＬａｎｔｈａｎｕｍｏｎＥｇｇＨａｔｃｈｉｎｇａｎｄＮａｕｐｌｉｕｓＭｅｔａｍｏｒｐｈｏｓｉｓｏｆＰｅｎａｅｕｓＣｈｉｎｅｎｓｉｓＸｉｎＦｕｙａｎ（辛福言），ＹｕａｎＹｏｕｘｉａｎ（袁有宪），ＱｕＫｅｍｉｎｇ（曲克明）（Ｙｅｌｏｗ...     

Synthesis and Electrocatalytic Properties of Complex Oxides Containing Lanthanum

Ａｓａｎｅｗｔｙｐｅｃａｔａｌｙｓｔ,ｃｏｍｐｌｅｘｏｘｉｄｅｓｏｆｐｅｒｏｖｓｋｉｔｅｔｙｐｅｈａｖｅｗｏｎｅｘｔｅｎｓｉｖｅａｔｔｅｎｔｉｏｎｉｎｔｈｅｆｕｎｄａｍｅｎｔａｌａｎｄａｐｐｌｉｅｄｒｅｓｅａｒｃｈ．Ｆｏｒｔｈｉｓｒｅａｓｏｎｔｈｅｙａｒｅｏｆｗｅｌｌｄｅｆｉｎｅｄｓｔｒｕｃｔｕｒｅ,ｓｐｅｃｉａｌｃａｔａｌｙｔｉｃｐｒｏｐｅｒｔｉｅｓａｎｄｈｉｇｈｓｔａｂｉｌｉｔｉｅｓ［１］．Ｆｏｒｅｘａｍｐｌｅ,ＬａＮｉＯ３ｉｓｔｈｅｏｎｌｙｍｅｔａｌｌｉｃｃｏｍｐｏｕｎｄｗｉｔｈｏｒｄ…     

Effects of Lanthanum on Liquid Culture and Contents of Amino Acids ofNostoc Commune Flagelliforme Cells

NotoccommunefiagellghrmebelongstoNostocfamilyofprocary0te,andmainlygrOwsinInnermongoliaAuton0mousRegion,NingXiaHuiAutonom0usRegion,GanshuProvinceandXin-jiangWeiwuerAutonomousRegionetcinChina-Nostoccommunefiagelldormecontainsthehighercontentsofprotein,manykindsofaminoacidsandmineralelementsslichasCa,P,Fe,Mn,Zn,CuandCo.Uptonow,theec0l0gical.i....t....[lj,...[2,3]maincomp0sitionandgrOWth...diti..[4jofN0toccommunefiagelldonnehavebeenstudiedsystematically,buttherehavebeennorep0rts0ntheliq…     

Study on RE-Modiffied Mordenite Catalysts for Amination Reaction

Ｉｎｏｒｄｅｒｔｏｉｍｐｒｏｖｅｔｈｅａｃｔｉｖｉｔｙａｎｄｓｅｌｅｃｔｉｖｉｔｙｔｏｄｉｍｅｔｈｙｌａｍｉｎｅ（ＤＭＡ）ｉｎａｍｉｎａｔｉｏｎｒｅａｃｔｉｏｎ，ｍａｎｙｒｅｓｅａｒｃｈｅｒｓｈａｖｅｄｏｎｅｍａｎｙｗｏｒｋｓｍａｉｎｌｙｏｎｔｈｅ...     

Lanthanum elicitation on hypocrellin A production in mycelium cultures of Shiraia bambusicola is mediated by ROS generation

Rare earth elements(REEs)have been widely applied as efficient elicitors to improve production of biologically important secondary metabolites in plants.However,their effects on microbial secondary metabolites were seldom reported.In this study,lanthanum(LaCl_3)was used as an elicitor in mycelium cultures of Shiraia bambusicola to stimulate the production of hypocrellin A(HA),a promising photosensitizer for anticancer photodynamic therapy.La~(3+)at 1.0 g/L not only increases HA content by 2.50-fold in mycelia,but stimulates HA exudation to the medium with the highest production(225.05 mg/L)on day 6.Further analysis shows that La~(3+) can induce the intracellular ROS(reactive oxygen species)accumulation with 2.33-fold higher contents of H_2O_2 in mycelium.HA production induced by La~(3+)treatment can be suppressed by ROS scavengers.Further analysis reveals that the elicitation of La~(3+)on HA accumulation is mediated by ROS generation to enhance expression of HA biosynthetical genes.The expression of ATP-binding cassette transporter gene(SbABC)for HA exudation is also regulated partially via ROS generated by NADPH oxidase.These results indicate that the enhanced HA production by La~(3+)might be mediated by ROS signaling pathway.Our results provide a basis for understanding REE elicitation on fungal metabolites and a practical biotechnological process for enhanced production of HA.     

Studies on Solvent System of Cesium Chloride and Lanthanum Chloride and Synthesization of Four Types of New Compounds

ＳｔｕｄｉｅｓｏｎＳｏｌｖｅｎｔＳｙｓｔｅｍｏｆＣｅｓｉｕｍＣｈｌｏｒｉｄｅａｎｄＬａｎｔｈａｎｕｍＣｈｌｏｒｉｄｅａｎｄＳｙｎｔｈｅｓｉｚａｔｉｏｎｏｆＦｏｕｒＴｙｐｅｓｏｆＮｅｗＣｏｍｐｏｕｎｄｓＬｉＹａｈｏｎｇ（李亚红），ＲａｎＸｉｎｑｕａｎ...     

Effect of Lanthanum on Growth and Extracellular Enzyme Acitivty of Erwinia Chrysanthemi in vitro

Ａｌｏｎｇｗｉｔｈｔｈｅｌａｒｇｅｓｃａｌｅａｐｐｌｉｃａｔｉｏｎｏｆｒａｒｅｅａｒｔｈｉｎａｇｒｉｃｕｌｔｕｒｅ，ｇｒｅａｔａｍｏｕｎｔｏｆｒａｒｅｅａｒｔｈｃｏｍｐｏｕｎｄｓｅｎｔｅｒｅｄｅｎｖｉｒｏｎｍｅｎｔｔｏｒｅｓｕｌｔｉｎａｃｕｍｕｌａｔ...     

Mechanochemical Reaction of Lanthanum Carbonate with Sodium Hydroxide and Preparation of Lanthanum Oxide Nanoparticle

Ｔｈｅｉｍｐｏｒｔａｎｃｅｏｆｎａｎｏｓｉｚｅｄｒａｒｅｅａｒｔｈｏｘｉｄｅｐｏｗｄｅｒｓｉｎｖａｒｉｏｕｓｔｅｃｈｎｉｃａｌａｐｐｌｉｃａｔｉｏｎｓｍａｋｅｓｔｈｅｉｒｐｒｅｐａｒａｔｉｏｎｔｅｃｈｎｏｌｏｇｙａｎｉｎｔｅｒｅｓｔ ｉｎｇｓｕｂｊｅｃｔｆｏｒｒｅｓｅａｒｃｈｗｏｒｋ[1 ] .Ｏｖｅｒｔｈｅｐａｓｔｄｅｃａｄｅｓ,ｍａｎｙｐｒｅｐａｒａｔｉｏｎｍｅｔｈｏｄｓｏｆｎａｎｏ ｓｉｚｅｄｒａｒｅｅａｒｔｈｏｘｉｄｅｓｈａｖｅｂｅｅｎｄｅｖｅｌｏｐｅｄ ,ｉｎｃｌｕｄｉｎｇｐｈｙｓｉｃａｌａｎｄ…     

皂化法制备硬脂酸钇及其动力学研究

采用皂化法制备了PVC热稳定剂-硬脂酸钇，并进行了动力学研究。采用单因素实验方法对反应时间、反应温度、盐碱比、氢氧化钠浓度等因素分别对硝酸钇／氢氧化钠盐碱反应和氢氧化钇／硬脂酸皂化反应的稀土转化率的影响进行了考察，并确定了最优工艺条件，建立了动力学模型。实验结果表明，采用改进的新工艺，稀土转化率高达99．50％以上，硬脂酸钇的熔点为118℃。经实验验证，第一阶段硝酸钇／氢氧化钠盐碱反应为二级反应，动力学方程为-dcA／dt=8．56cA^2。第二阶段近似看作氢氧化钇／硬脂酸的皂化反应，符合二级反应特征，动力学方程为-dcA／dt=1666cA^2。采用称重法测定稀土转化率比化学法简单、快速。     

Influence of La and RE on the Underside Shrinkage of ZA27 Alloy

Ｗｉｔｈｌｏｗｅｒｃｏｓｔ,ｇｏｏｄｆｏｕｎｄｒｙｃｈａｒａｃｔｅｒｉｓｔｉｃｓａｎｄｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓ,ＺＡ２７ａｌｏｙｈａｓａｃｈｉｅｖｅｄｃｏｎｓｉｄｅｒａｂｌｅｓｕｃｅｓｉｎｔｈｅｎｏｎｆｅｒｏｕｓｆｏｕｎｄｒｙｉｎ...     

Effect of Lanthanum Chloride on Membrane Permeability of Corn Root Tissue

The effect of lanthanum ion on membrane permeability of corn root segment is studied.Results shows thattreatment of the root segments with LaCl_3·7H_2O can decrease the ion leakage of the root tissue.The leakagedecreases hy increasing the concentration of lanthanum,and the concentration has no further dependence on ionleakages above 25 μmol/L.After treating the root tissue for one hour with lanthanum ion,the amount of leak-age has linear dependence on time within the first 2 h and after two hours the leakage increases.The ion leakageof the tissue dependes on the time of lanthanum treatment.When the duration of treatment is prolonged,theleakage decreases rapidly and the leakage reaches a minimum at 30 minutes.Other rare earth elements can alsodecrease ion leakage.There is no significant difference in the ion leakage among these elements.     

Synthesis of Mg-based composite material with in-situ formed LaH3 and its hydrogen storage characteristics

In this work, a Mg-based composite material with in-situ formed LaH₃, Mg₂NiH₄-LiBH₄ + 20 wt% LaH₃, was prepared by ball milling LiBH₄ and hydrogenated LaMg₂Ni and Mg₂Ni powder mixture, followed by heat treatment at 573 K. The onset dehydrogenation temperature of the composite is reduced by 50 K compared with that of Mg₂NiH₄-LiBH₄. The LaH₃-doped composite shows faster kinetics, absorbing 1.43 wt% hydrogen within 100 s at 423 K, which is 6.5 times faster than Mg₂NiH₄-LiBH₄. Moreover, the composite releases 1.24 wt% hydrogen within 500 s at 573 K, 0.69 wt% higher than Mg₂NiH₄-LiBH₄. The activation energy of the composite is reduced by 8.2 and 80 kJ/mol compared with that of Mg₂NiH₄-LiBH₄ and commercial MgH₂, respectively. The improvement in hydrogen storage properties is attributed to the fact that LaH₃ promotes the generation of nano-sized spongy Mg structure, which has good catalytic activity during the subsequent hydrogenation/dehydrogenation process.     

Voltammetric Study on the Complexes of the Rare Earths with Tetraphenylporphyrin

Fifteen rare earth-tetraphenylporphyrin(RE-TPP)complexes were directly prepared by mixing equalmolar concentrations of RE(ClO_4)_3 and H_2TPP in acetone media.The electrochemical behaviors of these com-plexes and the influence of dissolved oxygen were investigated by voltammetry.Althrough there are some differ-ence between the behaviors of light and heavy rare earth-porphyrins,the central RE ions of the all fifteen com-plexes were reduced from tervalent to divalent state,meanwhile the dissovled oxygen was reduced as superoxideion O~-.which readily combined with the complex forming peroxide additive complex such as RE-TPP·O~(2-)_2.     

Reaction between tetravalent cerium ion and chloride ion and effect of thiourea using cyclic voltammetry

To monitor the reaction between Ce⁴⁺ ion and Cl^– ion at the electron level, an electrochemical experiment was designed in this work. Herein, the intermediate and final products that may be produced during the redox reaction are directly tracked by using cyclic voltammetry, and the influences of Ce⁴⁺ ion concentration, temperature and F^– ion on the reduction peak potential of Ce⁴⁺ ion were investigated. The results show that Ce⁴⁺ ion reacts with Cl^– ion through an irreversible reaction without any intermediate products, and the rate-determining step of the reaction is diffusion during the electrode reaction. The effects of temperature (20–40 °C) and Ce⁴⁺ ion concentration (0.04–0.12 mol/L) on the reduction peak potential of Ce⁴⁺ ion can be ignored, but the higher the molar ratio of F^– to Ce⁴⁺ (0–3 mol/mol), the more easily the reduction of Ce⁴⁺ ion to Ce³⁺ ion occurs. Additionally, the Ce⁴⁺ ions are preferentially reduced by thiourea when thiourea is added in the HCl solution, and thiourea inhibits the oxidation of Cl^– ions to Cl₂ by forming a complex with Cl^– ions. This work provides a theoretical basis for the role of thiourea in inhibiting Cl₂ production and offers a new way to find new reductants.     

Effects of lanthanum on the growth and essential oil components of lavender under osmotic stress

The effects of lanthanum on growth, soluble sugar content, essential oil contents and quality were studied in lavender plant (Lavandula Angustifolia Mill, Variety 701) under osmotic stress by means of PEG-6000 solution. The results show that osmotic stress could reduce the growth rate of lavender, and increase the content of SSC (soluble sugar concentration) to some extent. Compared with control group, the contents of essential oil in flowers and leaves respectively increase by 45.6% and 48.3% in the osmotic stress group induced by 15% PEG-6000. However, the presence of lanthanum can make the contents of essential oil in the flowers and leaves of stressed lavender plants enhance by 19.4% and 18.6%, respectively. Under osmotic stress, the relative contents of four kinds of lavender essential oil compositions of camphor, linalool, linalyl acetate and lavandulol acetate in the lavender flowers were successively 22.63%, 0.61%, 25.46%, 7.03%, and 20.17%, 0.62%, 20.72%, 10.80%, respectively in the presence and absence of lanthanum. The contents of all four main components of lavender essential oils meet the requirements of the national standard under osmotic stress in the presence of lanthanum. However, in the absence of lanthanum, the contents of linalyl acetate and lavandulol acetate does not meet the requirements of the national standard under osmotic stress. Moreover, the contents of five components of borneol, camphor, eudesmol, caryophyllene oxide and bicyclic sesquiphellandrene from the essential oil of lavender leaves are 12.89%, 3.84%, 8.76%, 11.30% and 8.10%, respectively. The total content of above five components accounts for 44.89% of the essential oil of the lavender leaves. Particularly, the borneol content in leaf essential oil is up to 12.89%. It is 125.2 times the amount of borneol in the flower essential oil. In conclusion, the suitable concentration of lanthanum can improve the adaptability of lavender plants, and heighten the content and quality of lavender essential oil to some extent under osmotic stress.