Genotypic Variability in Biomass Protein and Nucleic Acids in Four Linum Species to Sodicity Stress

Differences in gas exchange parameters i.e. carbon exchange rate (CER), transpiration (Tr), water vapor conductance (g) were investigated, under a controlled environment, in a semi-dwarf (SD) Triticum aestivum line, its tall (TL) near isoline and the Payne (PA) variety characterized by small leaves. The plants were maintained in: (a) optimal substrate moisture condition (CTR); (b) salinized by watering with a 0.12 m NaCl solution (SLT); (c) water stressed by withholding waterings during a period of six days (STR); (d) stressed and salinized during the same period and with the same saline solution (S + S). CER and Tr were negatively affected by the stresses; SLT and S + S treatments had a higher WUE compared to their respective controls CTR and STR.
SD line had a better performance in terms of CER and WUE, particularly when water and salt stresses interacted. Leaf anatomy and assimilation/internal CO₂ concentration curves contributed to explaining the SD performance.     

对图书馆人文类下架报刊的再利用有感——报刊阅览室改革收效

报刊管理是一项有益于学生身心的事业。学生们就像即将绽放的花蕾般需要浇灌,而我们则像园丁。只有让他们明白报刊的重要性,再从中提炼知识的精华,才能成为坚强,忠诚,理智的人。走入图书馆,无异于走进灵魂的加油站。而我们驻守在这里,也身负重要的责任。它的精粹,足以涤荡人心。报刊的循环利用,更是使这一作用良性循环,生生不息。     

基于VBA的道路交通事故现场图绘制系统开发

为了达到公安部新标准“GA49-2009”的制图要求,利用Excel VBA( visual basic for application)二次开发技术,开发了一套简单适用的道路交通事故现场图计算机绘制系统,通过与徒手绘图对比,系统绘制的现场图制图规范,客观、准确地再现现场情况,满足了交警需求.     

Diazotroph community structure and abundance in wheat–fallow and wheat–pea crop rotations

Biological input of nitrogen (N) from the atmosphere by free-living diazotrophs can help alleviate fertilizer use in agricultural systems. In this study, we investigated the effect of N fertilizer and winter pea (Pisum sativum L.) crop on the community structure and abundance of free-living diazotrophs in a two year study of dryland winter wheat (Triticum aestivum L.) no-till production system in Eastern Oregon, USA. Based on quantification of the nifH gene, diazotroph abundance was strongly influenced by plant species and the crop year in which the soil samples were collected. A greater amount of nifH copies was recovered in 2012 compared to 2011 either as copies per gram soil or normalized to the abundance of bacterial 16S rRNA genes. The quantity of genes was greater under pea than wheat in 2012 although no difference was observed in the preceding year. The nifH gene abundance was positively correlated to ammonium concentration in 2011 and bacterial abundance in 2012. Nitrogen application did not influence diazotroph abundance in the top 0–5 cm; however the abundance was reduced by application at the lower 5–10 cm depth under wheat crop. The diazotroph community structure appeared to be influenced more by N fertilization rather than plant species with the exception of wheat in 2012. Changes in the community structure over the two years were greater for fertilized than unfertilized soil. Collectively, these data suggest that year-to-year variability had a greater influence on diazotroph communities rather than specific parameters of plant species, fertilization, total N, total organic C, or soil pH. Multi-year studies are necessary to define the specific drivers of diazotroph abundance, community structure and function.     

路桥过渡段施工问题研究

在路桥过渡段施工时,会因基础不同、防水措施不足、施工质量等问题产生显著的沉降差异,从而引起桥头跳车现象。路桥过渡段的施工,应做好施工勘察设计工作、处理好软性地基、选好台后填筑材料、做好台背排水、压实填土,减少台后路基的沉降,提高路基的刚度,尽力实现路桥刚柔平稳过渡,达到防治桥台跳车的目的。     

Methods for measuring N2O flux from water surface and N2O dissolved in water from agricultural land

A new chamber method and a stripping method were developed for field measurements of the rate of N₂O emission from the water surface and for determinations of dissolved N₂O in water from agricultural land.

These methods were used for the measurement of drainage canal water and flooded water of rice fields during the period of June 1982 to January 1983. The results demonstrate that aquatic systems of agricultural land may provide both source and sink for atmospheric N₂O.     

Research and field monitoring on transgenic crops by the Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT)

The International Maize and Wheat Improvement Center (CIMMYT) aims to genetically enhance both crops and generate public sector-provided products for the resource poor, e.g., drought tolerant wheat and insect resistant maize, and through international–national partnerships facilitate the acquisition of improved germplasm for non-mandate crops in the cropping systems where maize and wheat thrives; e.g., GM-papaya through a national food security undertaking in Bangladesh. The Center also engages in public awareness campaigns in projects such as Insect Resistance Maize for Africa (IRMA), which includes food, feed and environmental safety, monitoring of resistance and establishment of refugia, non-target effects and gene flow. Monitoring of genetic resources is a wide concern among the centers of the Consultative Group on International Agricultural Research (CGIAR), with an emphasis on the quality of gene banks. Decisions, policies and procedures about monitoring should be science-based, and this requires education, an area where CIMMYT and other CGIAR centers can play an important role. There will be a need to continue to evaluate the need for, and type of monitoring, as new (and unique) products are developed and released in the emergent economies of the world.     

我国水稻育插秧机械化进入快速发展阶段

我国水稻生产综合机械化水平最低,特别是栽植环节机械化成为推进水稻生产机械化最突出、最薄弱的环节.发展水稻育插秧机械化具有节省秧田、节约水肥、省工节本、高产稳产等优势,对提高水稻综合生产能力,保障粮食安全,增加农民收入意义重大.近几年,水稻育插秧机械化发展迅速,进入了快速发展阶段.