不同倍性小麦材料对水分和密度条件的响应

以栽培一粒(2n)、栽培二粒(4n)和长武134(6n)为材料在大型活动防雨棚条件下研究不同倍性小麦材料在不同密度和水分条件下的产量适应性变化。结果发现,在两种水分条件下随着染色体倍性从2n→6n的增加,产量、千粒重、水分利用效率(WUE)和收获指数均呈增加趋势,在水分胁迫下各材料穗粒数和穗数则呈降低趋势,而在正常供水下穗粒数则呈增加趋势。在水分胁迫下栽培一粒、栽培二粒和长武134最高产量分别出现在中、低、高密度群体,而同一材料不同密度群体间变异系数分别为6.73%,1.98%,9.07%;不同倍性材料千粒重均随着密度增加而减小,而穗数则逐渐增加,二倍体的穗粒数以中密度最高,四倍体的穗粒数随着群体密度的增加而减小,六倍体则相反;三种材料WUE和收获指数分别以低、高、低密度最高。正常供水下随着染色体倍性从2n→6n的增加,三个倍性材料最高产量分别出现在高、低、低密度群体,而同一材料不同密度群体间变异系数分别为6.01%,17.12%,2.46%;千粒重表现为中密度>低密度>高密度,而穗粒数均以低密度群体最高,二倍体和四倍体以高密度群体最低,六倍体则以中密度群体最低,穗数则随着密度群体增加而增加;二倍体WUE以高...

作物非充分灌溉决策指标研究进展

为了有效地进行非充分灌溉,通过不同方面研究土壤和作物水分亏缺的诊断方法,从而制定科学有效的灌水指标。对目前非充分灌溉的土壤、灌溉、作物等指标的研究现状及存在的问题进行了的阐述,讨论了非充分灌溉决策指标今后研究发展的方向。从目前国内外研究情况来看,应用叶水势、茎直径变化、冠层温度等作物指标来精确诊断作物的水分状况,已逐渐成为非充分灌溉研究领域关注的热点,但其基础理论、监测方法及不同作物的应用效果仍需进一步研究完善。因此,单纯从一种灌溉决策指标出发确定灌溉量是不全面的,如何建立非充分灌溉条件下不同地区、作物的灌溉指标体系将是今后中国重要的研究内容。

容器苗质量评定指标的研究

In this paper,the assessing indices of container seedlings quality were synthesized in accordance with growth and physiological factors. The results showed that the seedling quality might be determined by the dormancy state of terminal bud,nutrient condition of plant,and the state of root system. The critical quality indices should include stem diameter at soil surface,dry weight of terminal bud,and soluble sugar content. Moreover,some indices such as root system vitality and dry weight of plant were also important.

Radiation-use efficiency and the harvest index of winter wheat at different nitrogen levels and their relationships to canopy spectral reflectance

Radiation-use efficiency (RUE, g/MJ) and the harvest index (HI, unitless) are two helpful characteristics in interpreting crop response to environmental and climatic changes. They are also increasingly important for accurate crop yield simulation, but they are affected by various environmental factors. In this study, the RUE and HI of winter wheat and their relationships to canopy spectral reflectance were investigated based on the massive field measurements of five nitrogen (N) treatments. Crop production can be separated into light interception and RUE. The results indicated that during a long period of slow growth from emergence to regreening, the effect of N on crop production mainly showed up in an increased light interception by the canopy. During the period of rapid growth from regreening to maturity, it was present in both light interception and RUE. The temporal variations of RUEAPAR (aboveground biomass produced per unit of photosynthetically active radiation absorbed by the canopy) during the period from regreening to maturity had different patterns corresponding to the N deficiency, N adequacy and N-excess conditions. Moreover, significant relationships were found between the RUEAPAR and the accumulative normalised difference vegetation index (NDVI) in the integrated season (R-2 = 0.68), between the HI and the accumulative NDVI after anthesis (R-2 = 0.89), and between the RUEgrain (ratio of grain yield to the total amount of photosynthetically active radiation absorbed by the canopy) and the accumulative NDVI of the whole season (R-2 = 0.89) and that after anthesis (R-2 = 0.94). It suggested that canopy spectral reflectance has the potential to reveal the spatial information of the RUEAPAR, HI and RUEgrain. It is hoped that this information will be useful in improving the accuracy of crop yield simulation in large areas.

Separation of ternary systems of hydrophilic ionic liquid with miscible organic compounds by RPLC with refractive index detection

A rapid and simple analytical method was developed for the simultaneous and quantitative determination and separation of hydrophilic imidazolium ionic liquids (ILs) (1-butyl-3-methylimidazolium chloride, [C(4)mim]Cl; 1-hexyl-3-methylimidazolium chloride, [C(6)mim]Cl; 1-octyl-3-methylimidazolium chloride, [C(8)mim]Cl; 1-allyl-3-methylimidazolium chloride, [Amim]Cl; or 1-allyl-3-methylimidazolium bromide, [Amim]Br) with miscible ethyl acetate and EtOH and their mixtures using reverse phase liquid chromatography coupled with refractive index detection (RPLC-RI). The influence of 60 to 100% (volume percentage) methanol in the mobile phase on the IL systems ([C(4)mim]Cl, [C(6)mim]Cl, [C(8)mim]Cl, [Amim]Br, or [Amim]Cl)-ethyl acetate-EtOH was investigated.

Reduction of Eu3+ to Eu2+ in MAl2Si2O8 (M = Ca, Sr, Ba) in air condition

In general, the reduction of Eu3+ to Eu2+ in solids needs an annealing Process in a reducing atmosphere. in this paper, it is of great interest and importance to find that the reduction of Eu3+ to Eu2+ can be realized in a series of alkaline-earth metal aluminum silicates MAl2Si2O8 (M = Ca, Sr, Ba) just in air condition. The Eu2+-doped MAl2Si2O8 (M = Ca, Sr, Ba) powder samples were prepared in air atmosphere by Pechini-type sol-gel process. It was found that the strong hand emissions of 4f(6)5d(1)-4f(7) from Eu2+ were observed at 417, 404 and 373 nm in air-annealed CaAl2Si2O8, SrAl2Si2O8 and BaAl2Si2O8, respectively, under ultraviolet excitation although the Eu3+ precursors were employed. In addition, under low-voltage electron beam excitation, Eu2+-doped MAl2Si2O8 also shows strong blue or ultraviolet emission corresponding to 4f(6)5d(1)-4f(7) transition.

Shape-Controlled Synthesis of Wurtzite ZnS Microstructures Under Mild Solvothermal Condition

Through a facile solvothermal route using zinc chloride and thiourea as reactants, wurtzite ZnS and its precursor ZnS center dot (en)(0.5) (en = ethylenediamine) with various morphologies and sizes were grown, which were characterized by XRD, SEM, TEM and N-2 adsorption and so on. The phase evolution, composition and morphologies of the products are highly dependent on the concentration of en. By keeping the en-water volume ratio at 1/2 to 1, the nanostripes-flower or nanorod-spheric wurtzite ZnS were easily obtained under 120 degrees C for 6-24 h, which possess relatively higher specific surface area and larger total pore volume.

Surface-enhanced Raman scattering of 4-aminothiophenol self-assembled monolayers in sandwich structure with nanoparticle shape dependence: Off-surface plasmon resonance condition

A universal metal-molecule-metal sandwich architecture by the self-assembly of Ag nanoparticles (NPs) and Au NPs of various shapes interconnected with 4-aminothiophenol (4-ATP) molecules was presented. These Ag NPs/4-ATP/Au NPs sandwich structures were characterized by surface enhanced Raman scattering (SERS) using an off-surface plasmon resonance condition. Enhancement factors (EF) on the order of 10(8) for 9b(b(2)) vibration mode were observed for the 4-ATP self-assembled monolayers (SAMs) in such sandwich structures. The factors are 2 orders of magnitude larger than that on the monolayer of Au NPs of various shapes under similar condition. More importantly, remarkable increase in the intensity of b(2) vibrational modes, which is characteristic of the charge transfer (CT) behavior between metal NPs and 4-ATP molecules, was observed in these sandwich structures under 1064 nm excitation. The obtained EF on these sandwich structure for 9b(b(2)) is larger than that for 7a vibration mode by a factor of similar to 10(2), demonstrating the importance of the contribution of the CT mechanism and the CT behavior of metal contacts, which play a significant role in metal-molecule-metal nanosystems.

Reversible B/Z-DNA transition under the low salt condition and non-B-form polydApolydT selectivity by a cubane-like europium-L-aspartic acid complex

We report here that a cubane-like europium-L-aspartic acid complex at physiological pH can discriminate between DNA structures as judged by the comparison of thermal denaturation, binding stoichiometry, temperature-dependent fluorescence enhancement, and circular dichroism and gel electrophoresis studies. This complex can selectively stabilize non-B-form DNA polydApolydT but destabilize polydGdCpolydGdC and polydAdTpolydAdT. Further studies show that this complex can convert B-form polydGdCpolydGdC to Z-form under the low salt condition at physiological temperature 37 degrees C, and the transition is reversible, similar to RNA polymerase, which turns unwound DNA into Z-DNA and converts it back to B-DNA after transcription. The potential uses of a left-handed helix-selective probe in biology are obvious. Z-DNA is a transient structure and does not exist as a stable feature of the double helix. Therefore, probing this transient structure with a metal-amino acid complex under the low salt condition at physiological temperature would provide insights into their transitions in vivo and are of great interest.

White polymeric light-emitting diodes with high color rendering index

The efficient white polymeric light-emitting diodes based on a white emissive polymer doped with a red phosphorescent dopant were fabricated by spin-coating method. The emission spectrum of the device is broadened to cover the full visible region by doping the red phosphorescent dye and thereby realizes white emission with high color-rendering index (CRI). By controlling the contents of the doped electron-transporting 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole and the red phosphorescent dopant, a luminous efficiency as high as 5.3 cd/A and a power efficiency of 3 lm/W were obtained with a CRI of 92.

Study on QSPR of alcohols with a novel edge connectivity index F-m

A novel edge degree f(i) for heteroatom and multiple bonds in molecular graph is derived on the basis of the edge degree delta(e(r)). A novel edge connectivity index F-m is introduced. The multiple linear regression by using the edge connectivity index F-m and alcohol-type parameter delta, alcohol-distance parameter L can provide high-quality QSPR models for the normal boiling points (BPs), molar volumes (MVs), molar refraction (MRs), water solubility(log(1/S)) and octanol/water partition (logP) of alcohols with up to 17 non-hydrogen atoms. The results imply that these physical properties may be expressed as a liner combination of the edge connectivity index and alcohol-type parameter, 6, alcohol-distance parameter, L. For the models of the five properties, the correlation coefficient r and the standard errors are 0.9969,3.022; 0.9993, 1.504; 0.9992, 0.446; 0.9924,0.129 and 0.9973,0.123 for BPs, MVs, MRs, log(1/S) and logP, respectively. The cross-validation by using the leave-one-out method demonstrates the models to be highly reliable from the point of view of statistics.

On characterization of organic structures - A highly discriminating molecular topological index

A new molecular topological index, EATI is proposed based on the extended adjacency matrix, It has a hitherto unheard of power of discrimination and can be applied to discriminate various kinds of organic compounds, such as structures containing heteroatoms, etc.. Thus EATI might be possibly used as supplementary reference for CAS Registry Numbers for structure documentation.

On highly discriminating molecular topological index

A highly discriminating molecular topological index, EAID, is proposed based on the extended adjacency matrix. A systematic search for degeneracy was performed for 3 807 434 alkane trees, 202 558 complex cyclic or polycyclic graphs, and 430 472 structures containing heteroatoms. No counterexamples (two or more nonisomorphic structures with the same EAID number) were found. This is a hitherto unheard of power of discrimination. Thus EAID might be possibly used as supplementary reference for CAS Registry Numbers for structure documentation.

A new topological index for the Changchun institute of applied chemistry C-13 NMR information system

A method to assign a single number representation for each atom (node) in a molecular graph, Atomic IDentification (AID) number, is proposed based on the counts of weighted paths terminated on that atom. Then, a new topological index, Molecular IDentification (MID) number is developed from AID. The MID is tested systematically, over half a million of structures are examined, and MID shows high discrimination for various structural isomers. Thus it can be used for documentation in the Changchun Institute of Chemistry C-13 NMR information system.