Sr2ZnWO6:Eu3+,Bi3+,Li+: a potential white‐emitting phosphor for near‐ultraviolet white light‐emitting diodes

A series of Sr₂ZnWO₆ phosphors co‐doped with Eu³⁺, Bi³⁺ and Li⁺ were prepared using the Pechini method. The samples were tested using X‐ray diffraction and luminescence spectroscopy. The results show that the samples can be effectively excited by near‐ultraviolet (UV) and UV light. The introduction of Bi³⁺ and Li⁺ significantly enhances the fluorescence emission of Sr₂ZnWO₆:Eu³⁺ and changes the light emitted by the phosphors from bluish‐green to white. When excited at 371 nm, Sr_2–x–zZn_1–yWO₆:xEu³⁺,yBi³⁺,zLi⁺ (x = 0.05, y = 0.05, z = 0.05, 0.1 and 0.15) samples emit high‐performance white light. Intense red–orange emission is also observed when excited by UV light. The obtained phosphor is a potential white‐emitting phosphor that could meet the needs of excitation sources with near‐UV chips. In addition, this phosphor might have promising application as a red–orange emitting phosphor for white light‐emitting diodes based on UV light‐emitting diodes. Copyright © 2015 John Wiley & Sons, Ltd.     

The concentration of free Ca(2+) in the sarcoplasmic reticulum of frog cut twitch skeletal muscle fibers estimated with tetramethylmurexide

One aim of this article was to determine the resting concentration of free Ca²⁺ in the sarcoplasmic reticulum (SR) of frog cut skeletal muscle fibers ([Ca²⁺]_SR,R) using the calcium absorbance indicator dye tetramethylmurexide (TMX). Another was to determine the ratio of [Ca²⁺]_SR,R to TMX's apparent dissociation constant for Ca²⁺ (K_app) in order to establish the capability of monitoring [Ca²⁺]_SR(t) during SR Ca²⁺ release – a signal needed to determine the Ca²⁺ permeability of the SR. To reveal the properties of TMX in the SR, the surface membrane was rapidly permeabilized with saponin to rapidly dissipate myoplasmic TMX. Results indicated that the concentration of Ca-free TMX in the SR was 2.8-fold greater than that in the myoplasm apparently due to binding of TMX to sites in the SR. Taking into account that such binding might influence K_app as well as a dependence of K_app on TMX concentration, the results indicate an average [Ca²⁺]_SR,R ranging from 0.43 to 1.70 mM. The ratio [Ca²⁺]_SR,R/K_app averaged 0.256, a relatively low value which should not depend on factors influencing K_app. As a result, the time course of [Ca²⁺]_SR(t) in response to electrical stimulation is well determined by, and approximately linearly related to, the active TMX absorbance signal.     

Die Verwertung reiner Nährstoffe

Auf der Grundlage einer Analyse von Energieumsatzmessungen an ausgewachsenen Rindern (Ochsen) bei Verfütterung von 110 Rationen sehr heterogener Nährstoffzusammensetzung werden folgende Vorhersagegleichungen für Brutto‐ (y₁), verdauliche (y₂) und umsetzbare Energie (y₃) sowie für die Energieansatzwirkung von Rationen (y) (kJ) mitgeteilt:

y₁ ‐ 23.6z₁ + 34.0z₂ + 17.3z₃ + 16,0z₄ + 19, 1z₅

y₂ = 23.6x₁ + 34.0x₂ + 17.3x₃ + 16.0x₄ + 18.0x₅

y₃‐ 17.3x₁ + 34.0x₂+15.9x₃+ 15.1x₄+15.4x₅

y = (6.5x₁ + 26.6x₂ + 10.1x₃ + 7.5x₄ + 8.9x_s)( ‐ 0.5574 + 0.04050x₆ ‐ 0,0002633x₆ ²)

z₁ = Rohprotein(g) x, ‐ verdl. Rohprotein(g)

z₂ ‐ Rohfett(g) x₂ = verdl. Rohfett(g)

z₃ ‐ Stärke(g) x₃ = verdl. Stärke(g)

z₄ ‐ Zucker(g) x₄ = verdl. Zucker(g)

z₅ ‐ N‐freie Reststoffe(g) x₅ = verdl. N‐freie Reststoffe(g)

x₆ ‐ Verdaulichkeit der Energie der Ration(%) (x₆ ≤ 77)     

Use of Transformed Auxiliary Variable in Estimating the Finite Population Mean

For estimating the finite population mean Y- of the study character y, an estimator using a transformed auxiliary variable has been defined. The bias and mean-squared error (MSE) of the proposed estimator have been obtained. The regions of preference have been obtained under which it is better than usual unbiased estimator y-, the ratio estimator y-_R = y-X-/x-, Sisodia and Dwivedi (1981) estimator y-_s = y-(X- + C_x)/(x- + C_x) and Singh and Kakran (1993) estimator y-_k = y[X- + β₂(x)]/[x- + β₂(x)]. An empirical study has been carried out to demonstrate the superiority of the suggested estimator over the others.     

Boundaries of the universal K3 region and plateau region of the dynamic structure factor for DNA

A sufficiently long semiflexible filamentous macromolecule is theroretically expected to exhibit three different domains of behavior of its apparent diffusion coefficient D_app(K) as a function of scattering vector K: (1) the small wave vector limit, where D_app(K) = D₀ is the translational diffusion coefficient of the center-of-mass; (2) the universal K³ region, where D_app(K) = (k_BT/6πη)K is a universal function of K independent of any property of the molecule itself; (c) the plateau region at large K², where D_app(K) approaches either a plateau, or gradually sloping quasiplateau, characteristic of local (elastic) rigid-body motions of the filament. The existence of each of these different domains has now been established experimentally for at least some polymers. The boundaries of the universal K³ region and the plateau region are determined theoretically here using precise quantitative criteria for universal or plateau behavior of D_app(K) for a Rouse-Zimm model containing N + 1 subchains with rms subchain extension b. Allowing a maximum of 13% nonuniversal behavior, the domain of the universal K³ region is given by K²R²_G = K²Nb²/6 ≥ 7 and K²b² ? 0.54. Allowing as much as 10% nonplateau behavior, the boundary for onset of plateau behavior is K²b² = 18.3. D_app(K) is at least 50% nonuniversal when K²b²/6 = 6 ln 3. Extension of these results to DNA is examined theoretically, and good agreement of the pertinent predictions with published experimental data is demonstrated. It is concluded that no truly universal K³ region exists for DNA with M_r ? 10⁷ and persistence length a ≥ 450 Å, although marginally (?17% nonuniversal) universal behavior, is exhibited in a very narrow domain 0.64 × 10¹⁰ ? K² ? 0.84 × 10¹⁰ cm^?2 for ?29 DNA (M_r = 11.5 × 10⁶). More than 50% of D_app(K) is governed by local (elastic) rigid-body motions when K² = 5.23 × 10¹⁰ cm^?2. The existence of a very wide region of nonuniversal apparent K³ behavior extending up to very large K², far into the plateau region, is demonstrated in a plot of D_app(K)/K vs K² for the Rouse-Zimm model. This is shown to stem in part from visual artifacts of plotting D_app(K)/K vs K², even for rigid species.     

秃病蚤蒙冀亚种与长爪沙鼠密度的状态空间模型

 给出了一个描述秃病蚤蒙冀亚种Nosopsyllus laeviceps kuzenkovi与长爪沙鼠M eriones unguiculatus密度的状态空间模型,模型为x_t+1=-0.336x_t+0057y _t+0107z_t, y_t+1=0.586x_t-0369y_t-0274z_t, z_t+1=0.189x _t+0247y_t-0309z_t, 其中x_t,y_t和z_t分别为t月份的沙鼠密度, 巢秃病蚤 和体秃病蚤指数。结果表明,模型能够较好地描述野外秃病蚤蒙 冀亚种与长爪沙鼠间的关系,并发现沙鼠密度显著地影响巢秃病蚤指数。     

Stabilized Co3+/Co4+ Redox Pair in In Situ Produced CoSe2−x‐Derived Cobalt Oxides for Alkaline Zn Batteries with 10 000‐Cycle Lifespan and 1.9‐V Voltage Plateau

In aqueous alkaline Zn batteries (AZBs), the Co³⁺/Co⁴⁺ redox pair offers a higher voltage plateau than its Co²⁺/Co³⁺ counterpart. However, related studies are scarce, due to two challenges: the Co³⁺/Co⁴⁺ redox pair is more difficult to activate than Co²⁺/Co³⁺; once activated, the Co³⁺/Co⁴⁺ redox pair is unstable, owing to the rapid reduction of surplus Co³⁺ to Co²⁺. Herein, CoSe_2?x is employed as a cathode material in AZBs. Electrochemical analysis recognizes the principal contributions of the Co³⁺/Co⁴⁺ redox pair to the capacity and voltage plateau. Mechanistic studies reveal that CoSe_2?x initially undergoes a phase transformation to derived Co_xO_ySe_z, which has not been observed in other Zn//cobalt oxide batteries. The Se doping effect is conducive to sustaining abundant and stable Co³⁺ species in Co_xO_ySe_z. As a result, the battery achieves a 10 000‐cycle ultralong lifespan with 0.02% cycle^?1 capacity decay, a 1.9‐V voltage plateau, and an immense areal specific capacity compared to its low‐valence oxide counterparts. When used in a quasi‐solid‐state electrolyte, as‐assembled AZB delivers 4200 cycles and excellent tailorability, a promising result for wearable applications. The presented effective strategy for obtaining long‐cyclability cathodes via a phase transformation‐induced heteroatom doping effect may promote high‐valence metal species mediation toward highly stable electrodes.     

From Surface ZrO2 Coating to Bulk Zr Doping by High Temperature Annealing of Nickel‐Rich Lithiated Oxides and Their Enhanced Electrochemical Performance in Lithium Ion Batteries

One of the major hurdles of Ni‐rich cathode materials Li_1+x(Ni_xCo_zMn_z)_wO₂, y > 0.5 for lithium‐ion batteries is their low cycling stability especially for compositions with Ni ≥ 60%, which suffer from severe capacity fading and impedance increase during cycling at elevated temperatures (e.g., 45 °C). Two promising surface and structural modifications of these materials to alleviate the above drawback are (1) coatings by electrochemically inert inorganic compounds (e.g., ZrO₂) or (2) lattice doping by cations like Zr⁴⁺, Al³⁺, Mg²⁺, etc. This paper demonstrates the enhanced electrochemical behavior of Ni‐rich material LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) coated with a thin ZrO₂ layer. The coating is produced by an easy and scalable wet chemical approach followed by annealing the material at ≥700 °C under oxygen that results in Zr doping. It is established that some ZrO₂ remains even after annealing at ≥800 °C as a surface layer on NCM811. The main finding of this work is the enhanced cycling stability and lower impedance of the coated/doped NCM811 that can be attributed to a synergetic effect of the ZrO₂ coating in combination with a zirconium doping.     

Tunable white light emission from single‐phased Li2SrSiO4:Dy3+ phosphors by co‐doping with Eu3+

A series of single‐phase full‐color emitting Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ phosphors were synthesized by solid‐state reaction and characterized by X‐ray diffraction and photoluminescence analyses. The samples showed emission peaks at 488 nm (blue), 572 nm (yellow), 592 nm (orange) and 617 nm (red) under 393 nm excitation. The photoluminescence excitation spectra, comprising the Eu–O charge transfer band and 4f–4f transition bands of Dy³⁺ and Eu³⁺, range from 200 to 500 nm. The Commission Internationale de I'Eclairage chromaticity coordinates for Li₂Sr_0.98−xSiO₄:0.02Dy³⁺,xEu³⁺ phosphors were simulated. By manipulating Eu³⁺ and Dy³⁺ concentrations, the color points of Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ were tuned from the greenish‐white region to white light and eventually to reddish‐white region, demonstrating that a tunable white light can be obtained by Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ phosphors. Li₂Sr_0.98−xSiO₄:0.02Dy³⁺, xEu³⁺ can serve as a white‐light‐emitting phosphor for phosphor‐converted light‐emitting diode. Copyright © 2014 John Wiley & Sons, Ltd.     

Evaluation of the Shape Symmetry of Bilateral Normal Corneas in a Chinese Population

Purpose

To investigate the bilateral symmetry of the global corneal topography in normal corneas with a wide range of curvature, astigmatism and thickness values

Design

Cross-Sectional Study

Methods

Topography images were recorded for the anterior and posterior surfaces of 342 participants using a Pentacam. Elevation data were fitted to a general quadratic model that considered both translational and rotational displacements. Comparisons between fellow corneas of estimates of corneal shape parameters (elevation, radius in two main directions, R_x and R_y, and corresponding shape factors, Q_x and Q_y) and corneal position parameters (translational displacements: x₀, y₀ and z₀, and rotational displacements: α, β and γ) were statistically analyzed.

Results

The general quadratic model provided average RMS of fit errors with the topography data of 1.7±0.6 µm and 5.7±1.3 µm in anterior and posterior corneal surfaces. The comparisons showed highly significant bilateral correlations with the differences between fellow corneas in R_x, R_y, Q_x and Q_y of anterior and posterior surfaces remaining insignificantly different from zero. Bilateral differences in elevation measurements at randomly-selected points in both corneal central and peripheral areas indicated strong mirror symmetry between fellow corneas. The mean geometric center (x₀, y₀, z₀) of both right and left corneas was located on the temporal side and inferior-temporal side of the apex in anterior and posterior topography map, respectively. Rotational displacement angle α along X axis had similar distributions in bilateral corneas, while rotation angle β along Y axis showed both eyes tilting towards the nasal side. Further, rotation angle γ along Z axis, which is related to corneal astigmatism, showed clear mirror symmetry.

Conclusions

Analysis of corneal topography demonstrated strong and statistically-significant mirror symmetry between bilateral corneas. This characteristic could help in detection of pathological abnormalities, disease diagnosis, measurement validation and surgery planning.     

3种酰胺类稻田除草剂对克氏原螯虾的急性毒性

[目的] 研究稻虾共作模式条件下,稻田封闭除草剂对克氏原螯虾产生的急性毒性。[方法] 采用半静态试验方法,研究3种酰胺类除草剂（乙草胺、丙草胺和丁草胺）对克氏原螯虾的急性毒性,计算3种酰胺类除草剂对克氏原螯虾的安全浓度,并分析其LC₅₀衰减规律。[结果] 随着暴露时间和除草剂浓度的增加,虾体侧躺,步行足和游泳足活动频率降低,最终死亡。乙草胺对克氏原螯虾的96 h半致死浓度（LC₅₀）和安全浓度（SC）分别为0.0707和0.0146 mL·L^-1;丙草胺对克氏原螯虾的96 h LC₅₀和SC分别为0.0119和0.0021 mL·L^-1;丁草胺对克氏原螯虾的96h LC₅₀和SC分别为0.0073和0.0014 mL·L^-1。乙草胺、丙草胺及丁草胺除草剂LC₅₀随着暴露时间延长呈下降趋势,符合双曲线衰减模型,回归方程分别为：① y₁=2.0840x^-0.7380（R²=0.9973）;② y₂=0.1106x^-0.4930（R²=0.9872）;③ y₃=0.2236x^-0.7480（R²=0.9990）。克氏原螯虾对3种除草剂的敏感性由高到低依次为：丁草胺 > 丙草胺 > 乙草胺。[结论] 乙草胺和丙草胺可在稻田综合种养生产过程中按常规剂量使用,而丁草胺按常规剂量使用可能存在较大的风险。     

Site‐Selective In Situ Electrochemical Doping for Mn‐Rich Layered Oxide Cathode Materials in Lithium‐Ion Batteries

Various doped materials have been investigated to improve the structural stability of layered transition metal oxides for lithium‐ion batteries. Most doped materials are obtained through solid state methods, in which the doping of cations is not strictly site selective. This paper demonstrates, for the first time, an in situ electrochemical site‐selective doping process that selectively substitutes Li⁺ at Li sites in Mn‐rich layered oxides with Mg²⁺. Mg²⁺ cations are electrochemically intercalated into Li sites in delithiated Mn‐rich layered oxides, resulting in the formation of [Li_1?xMg_y][Mn_1?zM_z]O₂ (M = Co and Ni). This Mg²⁺ intercalation is irreversible, leading to the favorable doping of Mg²⁺ at the Li sites. More interestingly, the amount of intercalated Mg²⁺ dopants increases with the increasing amount of Mn in Li_1?x[Mn_1?zM_z]O₂, which is attributed to the fact that the Mn‐to‐O electron transfer enhances the attractive interaction between Mg²⁺ dopants and electronegative O^δ? atoms. Moreover, Mg²⁺ at the Li sites in layered oxides suppresses cation mixing during cycling, resulting in markedly improved capacity retention over 200 cycles. The first‐principle calculations further clarify the role of Mg²⁺ in reduced cation mixing during cycling. The new concept of in situ electrochemical doping provides a new avenue for the development of various selectively doped materials.     

Ni[TCNE]2 · zCH2Cl2 (Tc = 13 K) and VxNi1 − x[TCNE]y · zCH2Cl2 solid solution room temperature magnets

Magnetically ordered Ni[TCNE]₂ · zCH₂Cl₂ (T_c = 13 K) is reported for the first time from the reaction of Ni(CO)₄ with tetracyanoethylene (TCNE). A family of new solid solution room temperature magnets of V_xNi_1 − x[TCNE]_y · zCH₂Cl₂ (0 ? x < 1; y ? 2) composition has been characterized by IR spectrometry, elemental analysis, and magnetic measurements (ac and dc susceptibility). Substitution of Ni^II for V^II in V[TCNE]_y · zCH₂Cl₂ does not alter the T_c significantly for x ? 0.05 and does not alter H_cr significantly for x > 0; however, the magnitude of M increases with x, as does the broadness of the peaks in the χ′(T) and χ″(T) ac susceptibilities. Hence, the magnetic properties of the room temperature V[TCNE]_y · zCH₂Cl₂ magnet can be finely tuned via synthetic chemistry methodology, making this material more amenable in future technologies.     

A promising RVO4:Eu3+,Li+@SiO2 (R = Gd,Y and Gd/Y) red‐emitting phosphor with improved luminescence (cd/m2) and colour purity for optical display applications

Red emission intensity was optimized in three stages, by investigating the effects of: (i) host composition (Gd, Y and Gd/Y), (ii) codoping Li⁺ as a sensitizer and, finally, (iii) with a SiO₂ shell coating as a protecting layer. Lanthanide vanadate powder phosphors were synthesized using a modified colloidal precipitation technique. The effects of SiO₂ coating on phosphor particles were characterized using scanning electron microscopy (SEM)‐EDAX, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and photoluminescence (PL) measurements. An improvement in the PL intensity on Li codoping was due to improved crystallinity, which led to higher oscillating strengths for the optical transitions, and also a lowering of the inversion symmetry of Eu³⁺ ions. Red emission intensity due to ⁵D₀ → ⁵D₂ transition of the phosphor Y_0.94VO₄:Eu³⁺_0.05,Li⁺_0.01 was enhanced by 22.28% compared with Y_0.95VO₄:Eu³⁺_0.05, and was further improved by 58.73% with SiO₂ coating. The luminescence intensity (I) and colour coordinates (x, y) of the optimized phosphor Y_0.94VO₄:Eu³⁺_0.05,Li⁺_0.01@SiO₂, where I = 13.07 cd/m² and (x = 0.6721, y = 0.3240), were compared with values for a commercial red phosphor (Y₂O₂S:Eu³⁺), where I = 27 cd/m² and (x = 0.6522, y = 0.3437). The measured colour coordinates are superior to those of the commercial red phosphor, and moreover, match well with standard NTSC values (x = 0.67, y = 0.33). Copyright © 2015 John Wiley & Sons, Ltd.     

Grafting Benzenediazonium Tetrafluoroborate onto LiNixCoyMnzO2 Materials Achieves Subzero‐Temperature High‐Capacity Lithium‐Ion Storage via a Diazonium Soft‐Chemistry Method

Subzero‐temperature Li‐ion batteries (LIBs) are highly important for specific energy storage applications. Although the nickel‐rich layered lithium transition metal oxides(LiNi_xCo_yMn_zO₂) (LNCM) (x > 0.5, x + y +z = 1) are promising cathode materials for LIBs, their very slow Li‐ion diffusion is a main hurdle on the way to achieve high‐performance subzero‐temperature LIBs. Here, a class of low‐temperature organic/inorganic hybrid cathode materials for LIBs, prepared by grafting a conducting polymer coating on the surface of 3 µm sized LiNi_0.6Co_0.2Mn_0.2O₂ (LNCM‐3) material particles via a greener diazonium soft‐chemistry method is reported. Specifically, LNCM‐3 particles are uniformly coated with a thin polyphenylene film via the spontaneous reaction between LNCM‐3 and C₆H₅N₂⁺BF₄^?. Compared with the uncoated one, the polyphenylene‐coated LNCM‐3 (polyphenylene/LNCM‐3) has shown much improved low‐temperature discharge capacity (≈148 mAh g^?1 at 0.1 C, ?20 °C), outstanding rate capability (≈105 mAh g^?1 at 1 C, ?20 °C), and superior low‐temperature long‐term cycling stability (capacity retention is up to 90% at 0.5 C over 1150 cycles). The low‐temperature performance of polyphenylene/LNCM‐3 is the best among the reported state‐of‐the art cathode materials for LIBs. The present strategy opens up a new avenue to construct advanced cathode materials for wider range applications.     

Optimal Fixing of the Bandwidth-Parameter for the Empirical Regression1,2

The estimator ?₀(x) of the regression r(x) = E (Y | × = x) from measured points (x_i, y_i), i = 1(1) n, of a continuous two-dimensional random variable (X, Y) with unknown continuous density function f(x, y) and with moments up to the second order can be made with the help of a density estimation f?₀(x, y) (see e.g. SCHMERLING and PEIL, 1980). Here f?₀(x, y) still contains free parameters (so-called band-width-parameters), the values of which have to be optimally fixed in the concrete case. This fixing can be done by using a modification of the maximum-likelihood principle including jackknife techniques. The parameter values can be also found from the estimators for r(x). Here the cross-validation principle can be applied. Some numerical aspects of these possibilities for optimally fixing the bandwidth-parameter are discussed by means of examples. If ?₀(x) is used as a smoothing operator for time series the optimal choice of the parameter values is dependent on the purpose of application of the smoothed time series. The fixing will then be done by considering the so-called filter-characteristic of ?C₀(x).     

Relationships between phoma leaf spot and development of stem canker (Leptosphaeria maculans) on winter oilseed rape (Brassica napus) in southern England

Models were constructed to describe the relationships between incidence of phoma leaf spot at different growth stages in autumn/winter or early spring and incidence of stem canker (basal canker or stem lesions) in summer on winter oilseed rape in southern England. Model 1, describing the phoma leaf spot/basal canker relationship, was y₁=β₀+β₁x₁+β₂(x₂ ‐ x₁) if x₂ > x₁, and y₁=β₀+β₁x₁ if x₂≤x₁, in which y₁ was the incidence (% plants affected) of basal canker at harvest, x₁ was the maximum incidence of phoma leaf spot during the period from sowing to growth stage (G.S.) 1,6‐1,7 (about 100 days after sowing) and x₂ was the maximum incidence of phoma leaf spot between G.S. 1,7 and G.S. 2,0 (start of stem extension). Model 2, describing the phoma leaf spot/stem lesion relationship, was y₂=α₀+α₁x₃+α₂x₄, in which y₂ was the incidence of stem lesions at harvest, x₃ was the incidence of phoma leaf spot at G.S. 3,3–3,5 (flower buds visible) and x₄ was the incidence of phoma leaf spot at G.S. 4,5–5,5 (flower buds opening). Data from field experiments with four winter oilseed rape cultivars at Boxworth or Rothamsted in the 1992/93, 1993/94, 1996/97, 1997/98 or 1998/99 seasons were used to test the models. The values of R² for the regression equations testing model 1 for the phoma leaf spot/basal canker relationship were 0.75, 0.93, 0.91 and 0.89 for cvs Apex, Bristol, Capitol and Envol, respectively. The values of R² for the regression equations testing model 2 for the phoma leaf spot/stem lesion relationship were 0.58, 0.57, 0.54 and 0.71 for cvs Apex, Bristol, Capitol and Envol, respectively. The phoma leaf spot/basal canker relationship (model 1) could also be fitted to the combined data set for all four cultivars (R²= 0.65), whereas the phoma leaf spot/stem lesion relationship (model 2) could not to be fitted to the combined data set for the four cultivars. The relationships between incidence and severity of stem canker were examined and the values of R² for the regressions of severity on incidence were 0.91 for basal canker and 0.89 for stem lesions.     

Synthesis and luminescent properties of novel BaGd2O4:Eu3+ scintillating phosphor

BaGd_2‐xO₄:xEu³⁺ and Ba_1‐yGd_1.79‐2yEu_0.21Na_3yO₄ phosphors were synthesized at 1300°C in air by conventional solid‐state reaction method. Phosphors were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence excitation (PLE) spectra, photoluminescence (PL) spectra and thermoluminescence (TL) spectra. Optimal PL intensity for BaGd_2‐xO₄:xEu³⁺ and Ba_1‐yGd_1.79‐2yEu_0.21Na_3yO₄ phosphors at 276 nm excitation were found to be x = 0.24 and y = 0.125, respectively. The PL intensity of Eu³⁺ emission could only be enhanced by 1.3 times with incorporation of Na⁺ into the BaGd₂O₄ host. Enhanced luminescence was attributed to the flux effect of Na⁺ ions. However, when BaGd₂O₄:Eu³⁺ phosphors were codoped with Na⁺ ions, the induced defects confirmed by TL spectra impaired the emission intensity of Eu³⁺ ions. Copyright © 2012 John Wiley & Sons, Ltd.     

Multidimensional profiling of components in complex mixtures of natural products for metabolic analysis,proof of concept: Application to Quillaja saponins

A method for separation and detection of major and minor components in complex mixtures has been developed, utilising two-dimensional high-performance liquid chromatography (2D-HPLC) combined with electrospray ionisation ion-trap multiple-stage mass spectrometry (ESI-ITMSⁿ). Chromatographic conditions were matched with mass spectrometric detection to maximise the number of components that could be separated. The described procedure has proven useful to discern several hundreds of saponin components when applied to Quillaja saponaria Molina bark extracts. The discrimination of each saponin component relies on the fact that three coordinates (x, y, z) for each component can be derived from the retention time of the two chromatographic steps (x, y) and the m/z-values from the multiple-stage mass spectrometry (z_n, n = 1, 2, …). Thus an improved graphical representation was obtained by combining retention times from the two-stage separation with +MS¹ (z₁) and the additional structural information from the second mass stage +MS² (z₂, z₃) corresponding to the main fragment ions. By this approach three-dimensional plots can be made that reveal both the chromatographic and structural properties of a specific mixture which can be useful in fingerprinting of complex mixtures.