LiSr1.65 square 0.35B1.3B ' O-1.7(9) (B = Ti, Zr; B ' = Nb, Ta): New lithium ion conductors based on the perovskite structure

We describe the design and synthesis of new lithium ion conductors with the formula, LiSr(1.65)rectangle(0.35)B(1.3)B'O-1.7(9) (rectangle = vacancy; B = Ti, Zr; B' = Nb, Ta), on the basis of a systematic consideration of the composition-structure-property correlations in the well-known lithium-ion conductor, La-(2/3-x)Li(3x)rectangle((1/3)-2x)TiO3 (I), as well as the perovskite oxides in Li-A-B,B'-O (A = Ca, Sr, Ba; B = Ti, Zr; B' = Nb, Ta) systems. A high lithium-ion conductivity of ca. 0.12 S/cm at 360 degrees C is exhibited by LiSr(1.65)rectangle(0.35)Ti(1.3)Ta(1.7)O(9) (III) and LiSr(1.65)rectangle(0.35)Zr(1.3)Ta(1.7)O(9) (IV), of which the latter containing stable Zr(IV) and Ta(V) oxidation states is likely to be a candidate electrolyte material for all-solid-state lithium battery application. More importantly, we believe the approach described here could be extended to synthesize newer, possibly better, lithium ion conductors.

One step synthesis of monoclinic VO2 (B) bundles of nanorods: Cathode for Li ion battery

One of the metastable phases of vanadium dioxide, VO2(B) bundles of nanorods and microspheres have been synthesized through a simple hydrothermal method by dispersing V2O5 in aqueous quinol. The obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and electrochemical discharge-charge test for lithium battery. It was found that the morphologies of the obtained VO2(B) can be tuned by manipulating the relative amount of quinol. The electrochemical test found that the bundles of nanorods exhibit an initial discharge capacity of 171 mAh g(-1) and its almost stabilized capacity was reached to 108 mAh g(-1) after 47 cycles at a current density of 0.1 mA g(-1). The formation mechanism of the VO2(B) bundles of nanorods and microspheres was also discussed. (C) 2012 Elsevier Inc. All rights reserved.

Ferrimagnetism and magnetic phase separation in Nd1-xYxMnO3 studied by magnetization and high frequency electron paramagnetic resonance

Ferrimagnetism and metamagnetic features tunable by composition are observed in the magnetic response of Nd1-xYxMnO3, for x=0.1-0.5. For all values of x in the series, the compound crystallizes in orthorhombic Pbnm space group similar to NdMnO3. Magnetization studies reveal a phase transition of the Mn-sublattice below T-N(Mn) approximate to 80 K for all compositions, which, decreases up on diluting the Nd-site with Yttrium. For x=0.35, ferrimagnetism is observed. At 5 K, metamagnetic transition is observed for all compositions x < 0.4. The evolution of magnetic ground states and appearance of ferrimagnetism in Nd1-xYxMnO3 can be accounted for by invoking the scenario of magnetic phase separation. The high frequency electron paramagnetic resonance measurements on x=0.4 sample, which is close to the critical composition for phase separation, revealed complex temperature dependent lineshapes clearly supporting the assumption of magnetic phase separation. (C) 2014 Elsevier B.V. All rights reserved.

Frecuencia y grado de cubrimiento de las malezas presentes en el Ingenio Azucarero Javier Guerra B. Nandaime

El presente estudio se llevó a cabo de junio de 1992 a junio 1993 en áreas del Ingenio Javier Guerra, ubicado en el municipio de Nandaime, departamento de Granada, con el propósito de determinar la composición florística de las malezas que compiten en el cultivo de la caña de azúcar, el grado de cubrimiento y frecuencia de aparición de las mismas en general y por tipo de suelo. Para el estudio se seleccionaron siete lotes de producción representativos de las condiciones de suelo predominantes en las áreas cañeras. En cada lote de muestreo se seleccionaron de forma sistemática cinco puntos, los cuales estaban separados 200 metros el uno del otro. En cada una de las estaciones se anotaron por separado las malezas y el grado de cubrimiento, seleccionándose las especies con mayores distribuciones en base a la frecuencia y grado de cubrimiento promedio en total de sub-estaciones evaluados. El método utilizado fue el de observación visual, tomando como base los grados fijados en la escala de Braun-Blanquet (1964). Se realizó selección de especies de malezas que aparecieron en los tipos de suelo en estudio (TX a 3 III), (NNc IV), (AA a II), (VCa 4 IV), (TXa 2 II) y (Sta II). El análisis de los resultados se realizó de forma descriptiva, con el auxilio de Figuras y Tablas. Los resultados pueden ser resumidos de !a siguiente forma: se determinaron 79 especies de malezas, el 68.35 por ciento corresponden a dicotiledóneas y el 31.65 por ciento a monocotiledóneas. Se determinaron en total 24 familias de plantas, cuatro de las cuales pertenecen a la clase monocotiledóneas. Del total de monocotiledóneas, el 72 por ciento pertenecen a la familia poaceae Las especies de malezas pertenecientes a la clase dicotiledóneas presentaron un porcentaje superior en relación a las malezas monocotiledóneas. Del total de malezas dicotiledóneas el 14.8 por ciento corresponde a la familia asteraceae. La familia poaceae es la familia con mayor representación en número de especies presentes, ya que presenta 22.8 por ciento del total de especies determinadas. Las especies de malezas con clase de frecuencia 5 fueron ixophorus unicetus (Presl) Schlecht, Phyllanthus amarus Schum y Amaranthus Spinosus L. Las dos primeras especies aparecieron en el 100 por ciento de las muestras realizadas y la última en el 85 por ciento de las muestras. La especie Cyperus rotundus L. presenta frecuencia N, y grado de cubrimiento de 4, lo cual constituye un parámetro importante para considerar a asta especie como una de las más problemáticas en el área del cultivo. La mayor cantidad de especies se encontró en los suelo TX a 3 III, y NNc IV. El suelo Sta II, presentó el menor número de especies de malezas. Las especies de malezas dicotiledóneas y monocotiledóneas, predominantes en tos seis tipos de suelo fueron: A. spinosus, Lunicetus, P. amaras. En cambio, las malezas con distribución en cinco y cuatro tipos de suelos fueron: Baltimora recta , Cleome viscosa , Cyperus rotundas , Cucumisdipsacum , y Echinochloacolonum.

Efecto de diferentes niveles y fraccionamientos de nitrógeno, sobre el crecimiento y rendimiento del cultivo del ajonjoli (Sesamum indicum L.) variedad mejicana y análisis económico de los tratamientos

El presente trabajo se planificó con la finalidad de determinar el efecto de diferentes niveles (0. 65, 130 y 195 kg/ha) y fraccionamiento (100% a los 20 dds; 50% a los 20 dds y 50% a los 35 dds; 50% a los 20 dds y 50% a los 45 dds y 100% a los 45 dds) de urea 46% de N sobre el crecimiento y rendimiento del cultivo del ajonjolí (Sesamum indicum L.) variedad Mejicana y análisis económicos de los tratamientos, bajo las condiciones ecológicas de la Hacienda Las Mercedes. El ensayo se estableció en la siembra de primera de 1997 (10 de Junio al 10 de Septiembre), se utilizó un diseño en bloques completos al azar con arreglos en parcelas divididas, estableciéndose cuatro repeticiones. Los resultados estadísticos mostraron efecto real de los niveles del Factor A (dosis) en las variables número de capsulas por planta y rendimiento de grano; para el Factor B (fraccionamiento) no se encontró diferencias estadísticas entre las variables evaluadas y para el efecto de la interacción de los factores solamente las variables altura de planta, numero de hojas por planta, numero de capsulas por planta y rendimiento de grano resultaron ser significativamente diferentes. La mejor dosis fue la de 195 kg de urea 46% DE n /ha y el mejor momento de aplicación fue cuando se fracciono 50% a los 20 dds Y 50% a los 45 dds, y cuando se combinaron ambos niveles se obtuvo el mayor rendimiento de 1,716.07 kg de grano por hectárea. El tratamiento que resulto económicamente más rentable fue la combinación a4b2 con una tasa de retorno marginal de 1,108.9%.

A study of T = 2 states in ^(12)B, ^(12)C, ^(20)F and ^(28)Al

The lowest T = 2 states have been identified and studied in the nuclei ¹²C, ¹²B, ²⁰F and and ²⁸Al. The first two of these were produced in the reactions ¹⁴C(p,t)¹²C and ¹⁴C (p,³He)¹²B, at 50.5 and 63.4 MeV incident proton energy respectively, at the Oak Ridge National Laboratory. The T = 2 states in ²⁰F and ²⁸Al were observed in (³He,p) reactions at 12-MeV incident energy, with the Caltech Tandem accelerator.

The results for the four nuclei studied are summarized below:

(1) ¹²C: the lowest T = 2 state was located at an excitation energy of 27595 ± 20 keV, and has a width less than 35 keV.

(2) ¹²B: the lowest T = 2 state was found at an excitation energy of 12710 ± 20 keV. The width was determined to be less than 54 keV and the spin and parity were confirmed to be 0⁺. A second ¹²B state (or doublet) was observed at an excitation energy of 14860 ± 30 keV with a width (if the group corresponds to a single state) of 226 ± 30 keV.

(3) ²⁰F: the lowest T = 2 state was observed at an excitation of 6513 ± 5 keV; the spin and parity were confirmed to be 0⁺. A second state, tentatively identified as T = 2 from the level spacing, was located at 8210 ± 6 keV.

(4) ²⁸Al: the lowest T = 2 state was identified at an excitation of 5997 ± 6 keV; the spin and parity were confirmed to be 0⁺. A second state at an excitation energy of 7491 ± 11 keV is tentatively identified as T = 2, with a corresponding (tentative) spin and parity assignment J^π = 2⁺.

The results of the present work and the other known masses of T = 2 states and nuclei for 8 ≤ A ≤ 28 are summarized, and massequation coefficients have been extracted for these multiplets. These coefficients were compared with those from T = 1 multiplets, and then used to predict the mass and stability of each of the unobserved members of the T = 2 multiplets.

Optical properties of the organic substances from aqueous humus surface waters. [Translation from: Gidrochim. Mat. 23, 31-35, 1955]

Dissolved organic matter, especially turf and peat, is repsonsible for the colouration of water. The reported study tried to determine the nature of the colouring agent or organic matter by the establishment of a relationship between the intensity of colouration and the total organic matter content. 44 waters from different sources were examined.

COMPARISON OF MILLISECOND ANNEALING OF B IMPLANTS AND ISOTHERMAL ANNEALING FOR TIMES OF A FEW SECONDS.

The annealing behaviour of B implants in the millisecond time regime using a combination of swept line beam and background heating is compared with isothermal annealing with heating cycles of a few seconds. Carrier concentration profiles show that under annealing conditions which restrict diffusion, millisecond processing gives higher activation of B implants than isothermal heating. Transmission electron microscopy shows that millisecond annealing also results in a lower defect density.

Cyt b-559 链Arg18和Ser24的定点突变及其对PSII功能的影响

Cyt b-559是光系统II反应中心的成分之一，它由亚基和亚基组成的。在Cyt b-559中，血红素辅基与两个亚基中的组氨酸连接成有功能的蛋白，并维持PSII的功能稳定性。前人曾将与血红素相连的His突变，导致Cyt b-559功能和PSII稳定性的丧失。基于此研究，本文采用定点突变技术，将亚基中与His23位置最近的上游氨基酸Arg18分别用Gly和Glu取代，下游氨基酸Ser24用Phe取代，获得了衣藻Cyt b-559的突变体。对突变体的分析，有以下新结果：突变体都能进行光合自养，但无论在异养培养基上还是自养培养基上，和对照相比，其生长速度非常缓慢; PSII的活性分析，表明PSII的放氧活性为野生衣藻细胞的50%～80%， Fv/Fm 的荧光参数为40%～70%;对突变体进行强光（1000μE•m-2•s-1）照射，10min后，其放氧活性都降低为0，而野生型衣藻还保持35%的活性;提取类囊体膜蛋白，进行SDS-PAGE电泳和Western-blotting分析，显示突变体的膜蛋白与对照无显著差异。这些结果说明对围绕血红素环境的固有氨基酸的改变，虽然并没有明显影响类囊体膜蛋白的表达和组成，但是却影响了衣藻细胞的生长和PSII的活性，增加了衣藻细胞对强光的敏感性，降低了衣藻细胞自身的光保护能力。这说明靠近血红素配位环境的氨基酸Arg和Ser，尤其是Arg，对Cyt b-559的功能维持不可缺少，对于维持PSII的活性也很重要。

Phylogeny and biogeography of Chinese sisorid catfishes re-examined using mitochondrial cytochrome b and 16S rRNA gene sequences

The family Sisoridae is one of the largest and most diverse Asiatic catfish families, most species occurring in the water systems of the Qinhai-Tibetan Plateau and East Himalayas. To date published morphological and molecular phylogenetics hypotheses of sisorid catfishes are part congruent, and there are some areas of significant disagreement with respect to intergeneric relationships. We used mitochondrial cytochrome b and 16S rRNA gene sequences to clarify existing gaps in phylogenetics and to test conflicting vicariant and dispersal biogeographical hypotheses of Chinese sisorids using dispersal-vicariance analysis and weighted ancestral area analysis in combination with palaeogeographical data as well as molecular clock calibration. Our results suggest that: (1) Chinese sisorid catfishes form a monophyletic group with two distinct clades, one represented by (Gagata (Bagarius, Glyptothorax)) and the other by (glyptosternoids, Pseudecheneis); (2) the glyptosternoid is a monophyletic group and Glyptosternum, Glaridoglanis, and Exostoma are three basal species having a primitive position among it; (3) a hypothesis referring to Pseudecheneis as the sister group of the glyptosternoids, based on morphological evidence, is supported; (4) the genus Pareuchiloglanis, as presently defined, is not monophyletic; (5) congruent with previous hypotheses, the uplift of Qinghai-Tibetan Plateau played a primary role in the speciation and radiation of the Chinese sisorids; and (6) an evolutionary scenario combining aspects of both vicariance and dispersal theory is necessary to explain the distribution pattern of the glyptosternoids. In addition, using a cytochrome b substitution rate of 0.91% per million years and 0.23% for 16S rRNA, we tentatively date that the glyptosternoids most possibly originated in Oligocene-Miocene boundary (19-24Myr), and radiated from Miocene to Pleistocene, along with a center of origin in the Irrawaddy-Tsangpo drainages and several rapid speciation in a relatively short time. (c) 2005 Elsevier Inc. All rights reserved.

1.35 mu m photoluminescence from In0.5Ga0.5As/GaAs islands grown by molecular beam epitaxy via cycled (InAs)(1)/(GaAs)(1) monolayer deposition

1.35 mum photoluminescence (PL) with a narrow linewidth of only 19.2 meV at room temperature has been achieved in In0.5Ga0.5As islands structure grown on GaAs (1 0 0) substrate by solid-source molecular beam epitaxy. Atomic force microscopy (AFM) measurement reveals that the 16-ML-thick In0.5Ga0.5As islands show quite uniform InGaAs mounds morphology along the [ 1(1) over bar 0] direction with a periodicity of about 90 nm in the [1 1 0] direction. Compared with the In0.5Ga0.5As alloy quantum well (QW) of the same width, the In0.5Ga0.5As islands structure always shows a lower PL peak energy and narrower full-width at half-maximum (FWHM), also a stronger PL intensity at low excitation power and more efficient confinement of the carriers. Our results provide important information for optimizing the epitaxial structures of 1.3 mum wavelength quantum dots devices. (C) 2000 Elsevier Science B.V. All rights reserved.

硅中Rh-B络合物性质的理论研究

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