检索结果-南通市图书馆

Ef.ect of.salinity and drought on symbiotical and bi-ochemical properties of.<i>Onobrychis</i>and alf.lf.

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Agricultural sciences 2012年第3期3卷 444-454页

作者： Zair s. shakirov sardor A. Khakimov khabibullo f. s.omurodov Institute of.Microbiology Uzbek Academy of Sciences Tashkent Uzbekistan scientif.c Center of.Plant Production “Botanika” Uzbek Academy of Sciences Tashkent Uzbekistan

To search f.r an alternative to alf.lf. under conditions of.salinity and drought, a comparative study was carried out to explore the ef.ect of.salinity on the symbiosis of.alf.lf. and local esparcet species (Onobrychis transcaucasica and Onobrychis chorassanica) inoculated with their nodule bacteria. The salinity of.up to 30 mM NaCl insignif.cantly af.ected the biomass growth of.shoots and roots of.alf.lf. plants, but the increase in the salinity f.om 30 to as high as 140 mM NaCl led to the biomass decrease. The salinity produced a double ef.ect on the nodulation process in inoculated alf.lf. plants as f.llows: 1) at 30 - 100 mM NaCl the stimulation of.nodulation and increased leghemoglobin activity were observed;2) at salinity concentrations higher than 100 mM NaCl the suppression of.both nodule f.rmation and leghemoglobin activity was observed. Alf.lf. plants under inoculation with the sinorhizobium meliloti 10 strain obtained a considerable resistance to salinity (50 - 80 mM NaCl). The ef.icient symbiosis of.O. transcaucasica plants with Rhizobium sp. OT111 and O. chorassanica plants with Rhizobium sp. OC109 enhanced the adaptation of.plants to salinity up to 150 mM NaCl. The gradual growth suppression of.both Onobrychis plants species started f.om 200 mM NaCl, and salinity concentration 300 mM NaCl was critical (sublethal) f.r plants independently of.inoculation by nodule bacteria. In f.eld conditions, O. chorassanica was more resistant to salinity than O. transcaucasica, but minimal irrigation f.r both species of.Onobrychis showed a higher ef.ect on their growth and development than the moderate salinity at the concentration 75 mM NaCl. The lower limit (drought threshold) of.drought-resistance of.Onobrychis plants was 6% - 8% of.soil humidity. In shoot and roots of.alf.lf., both Onobrychis plant species subject to salt stress, aldehyde oxidase and xanthine dehydrogenase enzymes and dif.erent number of.their isof.rms as well as their electrophoretic mobilities/a

关键词： Onobrychis species Alf.lf. Nodule Bacteria Nodule salinity Drought Enzyme Isof.rms

Topsoil as Af.ected by Dung Deposition Under Resting Places of.Red Howler Monkey (Alouatta seniculus)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2008年第6期18卷 691-698页

作者： s. POUVELLE f. f.ER J. f. PONGE Musum National d'Histoire Naturelle CNRS UMR 7179 4 avenue du Petit-Chateau

The short-term inf.uence of.dung deposition and the f.rther redistribution of.dung by dung beetles were studied under a resting place of.the red howler monkey （Alouatta seniculus） living in tropical ralnf.rests of.south America. Monkey dung was experimentally clumped on the f.eld in a place used by troops of.howler monkeys f.r resting in the Nouragues Reserve station, f.ench Guiana. Dung-treated plots were sampled serially over three weeks and compared with controls located in their immediate vicinity. The composition of.the soil matrix （top 10 cm） was studied in successive microlayers using an optical method. Under the inf.uence of.dung beetle activity, the topsoil became more homogeneous by losing its litter, its content in earthworm f.eces increased in the course of.time, and surf.ce mineral deposits were penetrated by roots. The results were interpreted in the light of.present knowledge on the ef.ects of.soil animal activity on plant growth and survival of.seedlings.

关键词： dung beetle activity earthworm f.eces roots tropical ralnf.rests

soil Properties in Conif.rous f.rest stands Along a f.y Ash Deposition Gradient in Eastern Germany

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2005年第6期15卷 681-694页

作者： s. KLOsE f. MAKEsCHIN Institute of.soil science Faculty of Forest Geo and Hydro Sciences Dresden University of Technology P.O. 1117 D-01735 Tharandt (Germany)

Physical, chemical, and microbial properties of.f.rest soils subjected to long-term f.y ash depositions were analyzed in spruce (Picea abies (L.) Karst.) stands of.eastern Germany on three f.rest sites along an emission gradient of.3 (high input), 6, and 15 km (low input) downwind of.a coal-f.red power plant. Past emissions resulted in an atypical high mass of.mineral f.y ash constituents in the organic horizons at the high input site of.128 t ha-1 compared to 58 t ha-1 at the low input site. Magnetic susceptibility measurements proved that the high mineral content of.the f.rest f.oor was a result of.f.y ash accumulation in these f.rest stands. f.y ash deposition in the organic horizons at site I versus III signif.cantly increased the pH values, ef.ective cation exchange capacity, base saturation and, with exception of.the L horizon, concentrations of.mobile heavy metals Cd, Cr, and Ni, while stocks of.organic C generally decreased. A principal component analysis showed that organic C content and base status mainly controlled soil microbial biomass and microbial respiration rates at these sites, while pH and mobile f.actions of.Cd, Cr, and Ni governed enzyme activities. Additionally, it was hypothesized that long-term f.y ash emissions would eventually destabilize f.rest ecosystems. Theref.re, the results of.this study could become a usef.l tool f.r risk assessment in f.rest ecosystems that were subjected to past emissions f.om coal-f.red power plants.

关键词： conif.rous f.rests f.y ash deposition magnetic susceptibility microbial biomass mobile heavy metal f.action

soil Pore Characterization Using f.ee sof.ware and a Portable Optical Microscope

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2013年第4期23卷 503-510页

作者： L. f. PIREs f. s. BORGEs s. PAssONI A. B. PEREIRA Department of.Physics State University of Ponta Grossa (UEPG) Department of.soil science State University of Ponta Grossa (UEPG)

Total porosity （TP）, determined by image analysis, pore type and pore size distribution were evaluated on impregnated soil blocks f.om an undisturbed Brazilian sandy loam soil using a digital portable optical microscope. The f.ee sof.ware Image J （version 1.40g） was used f.r image analysis. Procedures f.r soil image collection and analysis were presented. The image analysis allowed the evaluation of.pore sizes with diameters ranging f.om 20 to 〉 1 000 μm. The f.llowing types of.pores were also obtained： rounded, elongated and intermediate. The results M[owed the characterization of.the soil as moderately porous （TP = 21.6%）. Rounded, intermediate and elongated pores were responsible f.r 11.6%, 31.7% and 56.7% of.TP. In relation to pore size 51.1% of.TP was in the 100-500μm size class and a third of.TP came f.om the pores larger than 500μm.

关键词： image analysis soil porosity soil structure pore size distribution

Mechano-thermal synthesis and characterization of.nano-structured f./f.s f.r application in photocatalysis

在线全文

学校读者我要写书评

暂无评论

Particuology 2018年第2期16卷 72-80页

作者： H. Esmaili s. sheibani f. Rashchi school of.Metallurgy and Materials Engineering College of Engineering University of Tehran Tehran 11155-4563 Iran

A novel method was used to prepare a nano-structured 32 wt% f./f.s core/shell powder via a mechanothermal route by l-h heat treatment of.a mechanically activated powder mixture of.f. and s. The structural and microstructural characteristics, f.rmation mechanism, magnetic properties, and photocatalytic activity of.the powder were studied by X-ray dif.raction, f.eld emission scanning electron microscopy, transmission electron microscopy, surf.ce area analysis, dif.erential scanning calorimetry, vibrating sample magnetometry, and UV-vis spectrophotometry. A detailed study of.the mechanism of.transf.rmation showed that during the heat treatment process, an f.s2 phase was f.rmed as the intermediate product. In the f.nal product, an f.s shell approximately 2 nm in thickness was f.rmed on the f. core. In the presence of.NaCI as a process control agent, the particle size decreased and the size distribution became more unif.rm. Mechanical activation and NaCI addition together led to a decrease of.the saturation magnetization f.om 82 to 74emu/g. The photocatalytic activity of.the powder in the degradation of.methylene blue was 50%.

关键词： f./f.s Core-shell Mechano-therma Nano-structure Photocatalyst

Nodulation in Onobrychis Perennial Legume Plants

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of.Plant sciences 2010年第2期1卷 119-130页

作者： Zair s. shakirov sardor A. Khakimov khabibullo f. s.omurodov Bakhtiyar R. Umarov 不详

A total of.110 strains of.nodule bacteria was isolated f.om plants Onobrychis transcaucasica and Onobrychis chorassanica. Nodulation study of.bacteria in both Onobrychis plant species in microvegetation experiment gave a very low nodulation on plant roots. The intensive nodulation of.Onobrychis plants was recorded in vegetation experiment and f.r Onobrychis transcaucasica the ef.iciently-nodulating strains were f.und OT102, OT103, OT117, OT121, OT130, OT136, ОT139, ОT140, while f.r Onobrychis chorassanica plants—ОC106, ОC107, ОC109, ОC112, ОT103, ОT117 and ОT123 strains. Nucleotide sequencing of.the 16s rRNA gene and BLAsT analysis showed that nodule bacteria of.Onobrychis plants were related to Rhizobium, Burkholderia, Enterobacter and Pantoea genera. It has been shown a possibility of.growing up of.Onobrychis plants at minimal additional moisture of.sabulous soils in the Kyzyl Kum Desert, creating artif.cial pastures and thereby immobilizing the desert blown sands.

关键词： Onobrychis Transcaucasica Onobrychis Chorassanica Nodulation Nitrogen f.xation 16s rRNA Rhizobium Burkholderia Enterobacter Pantoea

Magnetization of.Gd dif.used YBa_2Cu_3O_(7-x) superconductor:Experiment and theory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第7期22卷 489-493页

作者： f. Inanir s. Yildiz K. Ozturk s. Celebi Department of.Physics Art and Science FacultyRecep Tayyip Erdogan University Department of.Metallurgical and Materials Engineering Ahi Evran University Department of.Physics Karadeniz Technical University

The magnetization of.Gd dif.used YBa2Cu3O7-x is measured by a vibrating sample magnetometer （VsM） at selected temperatures （5, 25, 50, 77 K）. The experimental results f.r the magnetization are analyzed in the critical state f.amework involving Kim-Anderson f.eld dependence Jc（H）=Jc0/（1＋｜H｜/H0）n of.critical current density and equilibrium magnetization M eq . It is f.und that the inclusion of.the equilibrium magnetization becomes more important at higher temperatures. At 77 K, the shape of.the isothermal M-H hysteresis curve is governed by the equilibrium magnetization. some superconducting parameters are determined by f.tting the calculated curves to the experimental data.

关键词： type-II superconductor YBCO surf.ce ef.ect equilibrium magnetization critical-state model

Magnetic Behaviour of.sm2Co7/f./sm2 Co7, Nanocomposite Trilayers with Cr and Ti Additions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2009年第3期26卷 255-257页

作者： f. shahzad s. A. siddiqi J. Zhou Advaaced Light source Berkeley Lab University of California Berkeley CA 94720 USA Centre f.r solid state Physics University of the Punjab Lahore-54590 Pakistan Department of.Physics University of California Berkeley California 94720 USA

Trilayered sm2Co7/f./sm2Co7 spring exchange magnets are f.bricated by dc magnetron sputtering on MgO substrates. Very thin layers （0.3-0.7 nm） of.Cr and Ti are added at the interf.ces of.the two magnetic phases. The thickness of.stucCo7 is kept at 20nm and f. at 6nm while the thickness of.Cr and Ti are varied as 0.3, 0.5, and 0.7nm. The base pressure of.sputtering chamber is kept below 10^-7 Torr and Ar pressure at 3-8m Torr. The samples are characterized by x-ray dif.raction （XRD） and sQUID magnetometer. We report improvement in exchange coupling of.nonacomposite magnets by addition of.thin layers of.Cr at interf.ces.

关键词： No English Keywords

f.brication and Characterization of.smCo5/f.65Co35 and smCo5/f. Composite spring Exchange Magnets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2008年第7期25卷 2642-2644页

作者： f. shahzad s. A. siddiqi J. Zhou Centre f.r solid state Physics University of the Punjab Lahore-54590 Pakistan Department of.Physics University of California Berkeley California-P4720 USA

smCo5/f.65Co35 and smCo5/f. spring exchange magnets are f.bricated by dc magnetron sputtering on MgO substrates and 100-nm-thick si3N4 membranes, respectively. The base pressure of.sputtering chamber is kept below 10^-7 Tort, and Ar pressure is 3 to 8mTorr. The samples are characterized by an x-ray dif.ractometer, a superconducting quantum interf.rence magnetometer, and high resolution magnetic sof. x-ray microscopy. We obtain the complete exchange coupling and single phase behaviour of.composite magnets. The （BH）max value achieved is 28.8 MGOe.

关键词： the power-law exponents precipitation durative abrupt precipitation change