Structural Noise Analysis of Longitudinal Stiffened Concrete Cylindrical Shell in Air

Structural noises induced by urban viaduct box beam basically comes from the vibration responses with low frequency noises, which may affect the surrounding buildings’ security, the common using of high precision instruments and the living of human beings etc.In order to study the principles of structural noise of railway box beams, the infinite longitudinal stiffened concrete cylindrical shell in air was actively investigated.Aimed at the fluid structure interaction, the characteristics of sound radiation of coupling system were investigated by the wave number domain approach and transfer matrix method.And the effects of various parameters on the properties of concrete cylindrical shell, including the position of observation point, the size of the external excitation force, structural damping and the amount of longitudinal ribs, were numerically simulated based on the proposed analytical model.It is found that the increase of longitudinal ribs can effectively reduce the vibration and structural noises of concrete cylindrical shell.The observations would be provided as beneficial guidelines for the noise mitigation of pipeline structures and railway box beams.     

A model for simulating plant N accumulation,growth and yield of diverse rice genotypes grown under different soil and climatic conditions

The objective of this study was to develop a whole-process model for explaining genotypic and environmental variations in the growth and yield of irrigated rice by incorporating a newly developed sub-model for plant nitrogen (N) uptake into a previously reported model for simulating growth and yield based on measured plant N. The N-uptake process model was developed based on two hypotheses: (1) the rate of root system development in the horizontal direction is proportional to the rate of leaf area index (LAI) development, and (2) root N-absorption activity depends on the amount of carbohydrate allocated to roots. The model employed two empirical soil parameters characterizing indigenous N supply and N loss. Calibration of the N-uptake process sub-model and validation of the whole-process model were made using plant N accumulation, and growth and yield data obtained from a cross-locational experiment on nine rice genotypes at seven locations in Asia, respectively. Calibration of the N-uptake process sub-model indicated that a large genotypic difference exists in the proportionality constant between rate of root system development and that of LAI development during early growth stages. The whole-process model simultaneously explained the observed genotypic and environmental variation in the dynamics of plant N accumulation (R² = 0.91 for the entire dataset), above-ground biomass growth (R² = 0.94), LAI development (R² = 0.78) and leaf N content (R² = 0.79), and spikelet number per unit area (R² = 0.78) and rough grain yield (R² = 0.81). The estimated value of the site (field)-specific soil parameter representing the rate of N loss was negatively correlated with cation exchange capacity of the soil and was approximated by a logarithmic function of cation exchange capacity for seven sites (R² = 0.95). Large yearly and locational variations were estimated in the soil parameter for representing the rate of indigenous N supply at 25 °C. With the use of these two soil parameters, the whole-system model explained the observed genotypic and environmental variations in plant N accumulation, growth and yield of rice in Asia.     

The S-RNase-based gametophytic self-incompatibility system in Prunus exhibits distinct genetic and molecular features

Most Prunus fruit tree species exhibit a homomorphic gametophytic self-incompatibility (GSI) system, in which specificity of self/nonself-recognition is controlled by products encoded within the S locus. In the pollination event, a self-incompatibility (SI) reaction is triggered when the same “S allele” specificity is expressed in both the pollen and pistil. During the last two decades, much progress has been made in our understanding of the molecular basis of the gametophytic self-incompatibility system in Prunus. Identification of the pistil S and pollen S determinants led to the development of PCR-based S genotyping and marker-assisted selection for self-compatible (SC) individuals. Molecular and genetic analyses of Prunus SC S haplotypes and polyploid sour cherry (Prunus cerasus) reveal the possible existence of a distinct SI/SC recognition mechanism in the S-RNase-based GSI system of Prunus. This review summarizes the current molecular knowledge of the S-RNase-based GSI system in Prunus with reference to data collected for S-RNase-based GSI in other plants and its potential usefulness in SC breeding.     

青花菜基因型和环境互作对花球4–甲基亚磺酰丁基硫苷含量的影响

为深入了解青花菜基因型、环境及其互作对花球4–甲基亚磺酰丁基硫苷含量的影响,分析了生长在2006—2008年3个不同栽培年度和2008年内3个不同栽培地点共5种不同栽培环境条件下,11个基因型青花菜花球的4–甲基亚磺酰丁基硫苷含量,基因型、栽培年份、栽培地点等环境因素对4–甲基亚磺酰丁基硫苷含量的影响及基因与环境互作效应进行了方差分析。结果表明,在不同环境中,各参试材料间的4–甲基亚磺酰丁基硫苷含量均存在差异。同年份不同地点硫苷含量的稳定性普遍较不同年份不同地点的稳定性高。在3年内5种不同环境条件下,基因型、地点、年份、基因型与地点互作、基因型与年份互作效应的变异来源分别占总变异的67.3%、0.8%、0.2%、3.8%和1.4%。基因型对青花菜4–甲基亚磺酰丁基硫苷含量的影响极显著(P0.01),栽培地点的影响及与基因型的互作效应均显著(P0.05),而栽培年份的影响及其相关互作效应均不显著。研究结果为筛选稳定性好的高4–甲基亚磺酰丁基硫苷含量材料来培育具保健功能的优质青花菜新品种提供了参考。     

基于AMMI模型的烤烟品种丰产性和稳定性评价

对2010年湖南省烤烟品种区域试验结果进行方差分析,利用AMMI模型进行品种稳定性分析,发现HY-9J、C6212两品种在3个试验点产量均较高,具有稳定丰产的特性,品种HY-5X有较好的丰产性,对各地的适应性很好,HY-9X和HY-9CH丰产性和稳定性较差,利用价值不大;湖南农业大学基地环境对品种的鉴别力较高,而永州烟科所环境对品种的适应性较强。     

Differential Pathogenic Response in Strawberry Tissues and Organs by Colletotrichum acutatum

The susceptibility of different tissues and organs from strawberry plants, cv ＂Camarosa＂, to Colletotrichum acutatum was tested using a severity index based on infection response. Symptoms developed on inoculated tissues were characterized along 30 days. Flowers, except sepals, petioles and fruits were the most susceptible organs to the pathogen and they became necrotic tissues at 30 days post inoculation （dpi）. Also, well-developed acervuli, which produced masses of orange-pink spores, were observed on these infected organs. An asymptomatic stage or latency phase was observed in green and white strawberry fruits. In spite of they were inoculated anthracnose symptoms were observed only when they became red fruits. On the other hand, strawberry leaves and sepals were resistant to infection by C. acutatum and only small flecks or light brown spots were observed reaching a size of 1 to 5 mm at 30 dpi. Likewise, the susceptibility of stolons and crowns to C. acutatum was evaluated as intermediate at 30 dpi. Finally, the infection process of the fungus on strawberry leaves and petioles was studied using light and electron microscopy. Pre-penetration events were similar on both, leaves and petioles： However, differences between colonization of strawberry leaves and petioles by C. acutatum were observed.     

Analysis of Genetic Effects for Heterosis of Erucic Acid and Glucosinolate Contents in Rapeseed （Brassica napus L.）

The embryo,cytoplasmic,and maternal heterosis for erucic acid content (EAC) and glucosinolate content (GLS) of rapeseed (Brassica napus L.) were studied by using the genetic models for quantitative traits of seeds in diploid crops.Eight parents were included in a diallel mating design in two years.It was found that the heterosis of EAC and GLS was simultaneously controlled by genetic main effects and genotype×environment (GE) interaction effects.The general heterosis of most crosses for EAC was significantly positive,while it was not for GLS.The general heterosis was more important for two quality traits of rapeseed because of the low GE interaction heterosis in both years,especially for GLS.Among different genetic systems,significant positive embryo general heterosis and the negative maternal general heterosis were found for EAC and GLS in most hybrid crosses.Some hybrids with significant negative interaction heterosis were detected for either of EAC or GLS.In general,maternal general and interaction heterosis was more important for reducing EAC and GLS of rapeseed.     

水稻抽穗期基因定位及其环境互作研究

为构建SSR分子标记技术构建其遗传图谱,利用由小穗小粒型品种‘密阳46’和大穗大粒型品种FJCD建立的一个包含130个家系F10的重组自交系群体,测定武夷山和莆田环境下水稻群体的抽穗期,并进行了QTL的定位及环境互作研究。结果表明,在武夷山环境下仅检测到一个与抽穗期相关的加性QTL,位于6号染色体上,解释了25.63%;1个位点存在显著的加性×环境互作效应,而GE互作效应对表型变异贡献几乎为0,表明控制水稻抽穗期基因的表达有显著的环境特异性。     

城乡一体化背景下农产品加工业促进城乡产业互动的特征分析

农产品加工业能够促进城乡产业互动。文章用实证分析方法分析了农产品加工业在成长初期农业的关联最强,与工业和服务业的关联较弱,产业互动的要素主要是自然资源和资本。在成长期,农产品加工业产业集群的趋势增强,产业互动的要素主要是知识和技术。进入成熟期,其与其它产业互动的能力增强,且产业互动的要素更高级、互动模式更多样。文章并以合肥市为例进行阐述。最后提出政府应根据农产品加工业不同发展阶段的特征,出台相应的政策和措施,促进农业结构的调整和农民收入的提高。     

水氮互作对结实期水稻衰老和物质转运及产量的影响

以杂交稻冈优527为试材,通过淹水灌溉（W1）、“湿润灌溉（前期）+浅水灌溉（孕穗期）+干湿交替灌溉（抽穗至成熟期）”（W2）和旱种（W3）3种灌溉方式及不同的施氮量,研究了水氮互作对水稻衰老生理指标、物质转运及产量的影响及各指标间的相互关系。结果表明,W2处理下,施氮量为180 kg/hm2的水氮运筹相对于其他处理,能发挥水氮交互效应优势,使剑叶中O2-、H2O2和MDA增幅较慢,具有较高的光合速率,有利于可溶性蛋白等渗透调节物质的积累和SOD、CAT、POD活性及根系活力的提高,促进结实期物质的转运及产量的增加;施氮量达270 kg/hm2各水氮处理交互效应优势减弱,不仅影响结实期水稻正常的生理机能,还会导致物质转运和产量的下降。旱作（W3）条件下,施氮量以90～180 kg/hm2为宜,可缓解水氮互作的负效应,为生产中水资源不足的情况下参考。此外,水氮互作下各指标间有显著的相关性,剑叶中O2-、H2O2和MDA间呈极显著正相关,与保护酶活性、Pn及可溶性蛋白均呈显著或极显著负相关。各指标在抽穗后7～14 d与产量呈极显著相关,衰老过程中地下与地上部也密切相关;根系活力与剑叶保护酶活性、Pn及可溶性蛋白呈显著或极显著正相关,与O2-、H2O2和MDA呈显著负相关。