豫西地区不同类型农田化肥增产效益及增产潜力研究

 【目的】探讨化肥在豫西地区不同地形农田的增产效益与增产潜力，为引导和实现化肥的优化配置和合理施用、提高豫西地区粮食产量提供参考依据。【方法】采用田间试验，研究了豫西地区平川地、坡平地、坡地等3种典型地形农田化肥施用量对作物产量的影响；并对3种典型农田化肥消费量与粮食产量的多年统计资料进行了分析，提出了二者之间的关系，并由此对豫西地区粮食增产潜力进行了预测。【结果】作物单产以平川地最高，坡平地次之，坡地最低。尽管在3种类型农田上使用化肥均可大幅度增加作物产量，但化肥增产效益以坡地最高，坡平地次之，平川地最低；对3种典型地形农田化肥消费量与粮食产量多年统计资料的分析也获得相同结论。根据田间试验结果对未来豫西地区粮食产量及增产潜力进行的预测表明，当采用本研究中最大施肥量时，豫西地区粮食总产量可达到4.24×109 kg，是2003年该地区粮食产量的2.1倍；并预测在增加粮食产量中，坡地贡献率占50.1%、坡平地占33.7%、平川地占16.2%，坡地和坡平地粮食生产对该地区粮食总产量具有决定作用。【结论】豫西地区3种典型地形农田中化肥增产效益存在差异，以坡地化肥增产效益最大。因此，加强坡地化肥投入，可有效地提高本区粮食总产量，对今后本区粮食的增产具有重要意义。     

豫西地区石粉矿物元素含量分析

对豫西地区石粉中矿物元素的含量进行检测,结果表明,石粉中含有丰富的钙和铁等元素。其中龙门山石粉中钙的含量为18.00%,铁含量为4 357.36 mg/kg;新安县石粉中钙的含量为32.77%,铁含量为5 398.06 mg/kg。2种石粉是补充禽用饲料中钙、铁等元素的良好来源。     

自拟中草药复方防治蛋雏鸡大肠杆菌病的研究

用自拟中草药复方对蛋雏鸡大肠杆菌病进行了病原菌体外药物敏感试验、中西药疗效对比试验及临床治疗和预防试验,并对自拟中草药复方进行了有效治疗剂量筛选试验和安全性试验。结果表明,自拟中草药复方对各生长阶段蛋雏鸡的安全性高,对大肠杆菌中度敏感;在饲料中有效治疗添加量为10g/kg,在治疗蛋雏鸡大肠杆菌病时获得了较好的治疗效果(有效率88.3%),但采取中西医合并治疗效果最好(有效率96.7%),与西药组和中药组相比差异显著(P<0.05);使用自拟中草药复方在临床上预防大肠杆菌病,发病率明显低于西药组,且二者差异显著(P<0.05);按8倍剂量使用仍较安全,未出现异常表现,剖检和组织切片检查也未发现异常变化。     

澳大利亚国内大学排名及优势学科分布

本文归纳分析了澳大利亚国内大学的整体概况、国内八所名牌大学、国内各大学排名、高等教育十大领域以及在各大学中的分布、和悉尼大学的某些学科专业情况。     

西部农村信息化建设的思考

农村信息化建设是国家信息化战略的重要组成部分，是加速实现农业现代化的重要途径。本文从信息化的定义、农村信息化与建设社会主义新农村的关系出发，分析了西部农村信息化建设中存在的问题，进而提出促进西部农村信忠化建设的几点建议。     

牛叠朊编码基因缺失突变体的构建及在大肠杆菌中的表达

本实验室已制备出多株针对牛叠朊的单克隆抗体,为充分鉴定这些单克隆抗体针对的抗原表位,通过基因克隆表达的策略获取牛叠朊基因缺失突变体的重组蛋白,以期为单克隆抗体的表位鉴定提供物质材料。经过对牛成熟叠朊编码基因及预测蛋白结构特征的分析,设计表达9个缺失突变体的引物。以PCR扩增出叠朊基因的缺失突变体,与pET-30a（＋）表达载体连接后转入E.coli DH5α中,经双酶切和测序鉴定后将重组质粒转入E.coliJM109和E.coli BL21表达宿主菌中,经IPTG诱导表达后,以SDS-PAGE、Western blot和ELISA检测表达产物的相对分子质量、相对表达量和反应原性。结果表明,成功构建了9个牛叠朊编码基因的缺失突变体,通过IPTG的诱导表达,其中有6个缺失突变体被大肠杆菌高效表达,并且具有较好的反应原性,这为其单克隆抗体表位的进一步鉴定奠定了物质基础。     

抗伪狂犬病病毒gC抗体制备及其gC蛋白表达

用纯化的重组蛋白His-gCN813制备抗PRV-gC抗体,并分析伪狂犬病病毒（pseudorabies virus,PRV）gC蛋白在真核细胞的表达情况。本研究以提取的病毒基因组为模板,PCR克隆PRV gC全长基因,构建gC真核表达质粒p3xFLAG-gC,在真核细胞中表达gC基因;纯化蛋白His-gCN813制备的抗体,Western blotting和间接免疫荧光（IFA）检测到p3xFLAG-gC转染真核细胞和PRV感染细胞中的gC蛋白。结果表明本试验成功构建了PRV gC基因真核表达系统,获得了特异性抗PRV gC抗体,重组gC真核表达质粒p3xFLAG-gC转染Vero细胞,表达的重组蛋白gC为72 ku,PRV感染Vero细胞,表达的gC蛋白为55、72和94 ku,主要定位在细胞浆,gC蛋白可以作为PRV感染的指示分子,为下一步研究PRV和宿主相互作用及PRV的复制奠定了基础。     

基于生态修复理念的西汉帝陵大遗址生态景观规划设计研究

通过分析挖掘西汉五陵塬地区的历史、民俗文化,以恢复生态学理论为指导,总结出西汉帝陵大遗址区生态景观设计原则,探讨了如何在城郊大遗址保护中运用生态设计手法创造出具有生态效应和持久魅力的遗址区景观规划设计案例。     

Quantifying the contribution of dissolved organic matter to soil nitrogen cycling using N isotopic pool dilution

Dissolved organic matter (DOM) has been recognised as a key carbon and nitrogen (N) pool involved with soil-plant-microbe interactions. Yet few studies have quantified this contribution in agricultural soils. In this study we leached DOM from a sandy loam and sandy clay loam soil under either grassland or arable cropping. Two weeks after DOM removal microbial respiration from soils was not altered. However, a significant (P<0.05) decline in microbial biomass-N, potentially mineralizable-N, gross N mineralization and gross nitrification occurred after leaching. This data illustrate that whilst DOM is a small component of the soil OM it contributed up to 25% of microbial N supply within these agricultural soils.     

Prioritisation of conservation areas in the Western Ghats, India

Areas of high conservation value were identified in the Western Ghats using a systematic conservation planning approach. Surrogates were chosen and assessed for effectiveness on the basis of spatial congruence using Pearson’s correlations and Mantel’s tests. The surrogates were, threatened and endemic plant and vertebrate species, unfragmented forest areas, dry forests, sub-regionally rare vegetation types, and a remotely sensed surrogate for unique evergreen ecosystems. At the scale of this analysis, amphibian richness was most highly correlated with overall threatened and endemic species richness, whereas mammals, especially wide-ranging species, were better at capturing overall animal and habitat diversity. There was a significant relationship between a remote sensing based habitat surrogate and endemic tree diversity and composition. None of the taxa or habitats served as a complete surrogate for the others. Sites were prioritised on the basis of their irreplaceability value using all five surrogates. Two alternative reserve networks are presented, one with minimal representation of surrogates, and the second with 3 occurrences of each species and 25% of each habitat type. These networks cover 8% and 29% of the region respectively. Seventy percent of the completely irreplaceable sites are outside the current protected area network. While the existing protected area network meets the minimal representation target for 88% of the species chosen in this study and all of the habitat surrogates, it is not representative with regard to amphibians, endemic tree species and small mammals. Much of the prioritised unprotected area is under reserve forests and can thus be incorporated into a wider network of conservation areas.