作物品种区域试验非平衡资料的分析方法——综合性状的分析

运用混合线性模型的分析原理,提出了作物区域试验非平衡数据的综合分析方法,用MINQUE法估算各性状的方差分量和成对性状的协方差分量,然后对品种效应的综合线性对比作显著性测验。对品种综合性状稳定性分析,用Jackknife数值重复抽样方法计算回归参数的估计值及其标准误,并通过分析回归参数置信区间来综合评价品种稳定性。作为综合分析区域试验非平衡数据的实例,分析了黄河流域棉花区域试验的纤维强度和皮棉产量。     

从个案调查辨析改进院校图书馆管理服务

通过对某专业院校图书馆文献借阅情况调查,就改进院校图书馆管理,优化读者服务谈了一些看法。侧重于研究教学型的专业院校图书馆作讨论。     

Fields of Cultural Contradictions: Lessons from the Tobacco Patch

Why do tobacco farmers continue to produce tobacco in light of the bleak future of this crop? Given the changing political economy of tobacco, we might expect producers to respond by diversifying their enterprises. This study of Kentucky burley tobacco farmers finds that farmers express contradictory values toward the economic role of production and the social value of tobacco consumption. The economic value of tobacco is articulated by drawing upon experiential lessons with the crop. These, in turn, are used to inform production processes (reproduction of tobacco farming), all the while castigating the consumption of their commodity. Farmers persist in producing tobacco because of the structural and historical conditions of the region that have engendered a culture of tobacco production. The contradiction in production and consumption values suggests that the “cultural turn” in agro-food studies needs to move away from a linear approach of cultural values as determinants of social action and become sensitive to the differential ways commodity actors produce, use, and reproduce a culture of commodity production and a culture of commodity consumption. This unproblematic and linear association between values and economic activity misinforms social science research about seemingly “individual” motivations that are shaped by historical and structural conditions.     

作物品种区域试验非平衡资料的分析方法——单一性状的分析

本文运用混合线性模型的分析原理,提出了作物区域试验非平衡数据的统计分析方法。用MINQUE法估算各项方差分量,然后对品种效应的线性对比作显著性测验。品种稳定性分析采用Jackknife数值重复抽样方法,计算回归参数的估计值及其标准误,并通过分析回归参数置信区间来评价稳定性。作为分析区域试验非平衡数据的实例,分析了黄河流域棉花区域试验的皮棉产量。     

广西浦北县1967～2006年降水量特征统计分析

采用累积距平和线性趋势等方法,对广西浦北县1967-2006年逐旬降水量进行了分析。结果表明：近40 a来浦北县年降水极不稳定,年际变化明显;年平均降水量的总变化趋势是每年减少5.697 0 mm,原因主要是由春、秋2季降水量减少引起的。     

秦岭神安沟矿区沟道地表水和沉积物中重金属分布形态研究

为了探讨重金属在矿山水体环境中的富集规律,以秦岭神安沟矿区沟道地表水、沉积物中的重金属为研究对象,测试了各类重金属含量.并利用Tessier五步连续萃取法分析了沉积物中重金属的5种形态.旨在为该矿区环境恢复治理提供参考.结果显示,未受采矿活动影响的对照区地表水与沉积物均未检出Zn、Pb、Cd,对照区未受污染.受开采活动影响的上、中、下游地表水、沉积物受到Pb、Cd不同程度的污染,下游地表水Pb、Cd分别超标5.3倍、43.3倍,不符合农田灌溉用水水质要求;上、中、下游沉积物中重金属污染负荷指数均达Ⅲ级,沟道沉积物已受到严重污染.沉积物中重金属形态分布特征为:Zn、Cd以有机结合态所占比例最高,Pb以铁锰氧化物结合态所占比例最高,Zn、Pb的生物有效性高.由此得出下游地表水不适于灌溉.由于矿方目前已终止尾矿库淋滤水向沟道排放,沉积物中各类萤金属含量已趋于稳定,矿区神安沟地表水、沉积物重金属污染严重,亟需治理恢复.     

基于能值与生命周期评价耦合模型的农业系统生态效率评估——以北京市郊区为例

结合能值分析和生命周期评价模型,从期望产出效率和非期望产出效率两个角度构建生态效率计量方法,评价京郊3种典型农作物生产系统的可持续性,为北京市农业内部结构优化提供科学的决策依据。研究表明:玉米、蔬菜和桃的能值投入产出比分别是6.61×10~4、1.47×10~5、1.92×10~5sej·J~(-1),玉米的期望产出效率最高,蔬菜其次,桃最低;玉米、蔬菜和桃生产系统的非期望产出效率分别是1.29×10~6、1.60×10~5和2.59×10~5,玉米的非期望产出效率最高,桃其次,蔬菜最低;玉米的生态效率最高,为2.95×10~(-4),蔬菜其次,为7.42×10~(-6),桃最低,为7.05×10~(-6);以蔬菜为例进行敏感性分析表明,投入要素中对生态效率敏感性最大的是电能(用于农田灌溉),氮肥次之,再次是有机堆肥和农药。调整种植业结构不仅要考虑农产品的产量及经济收益,还需要考虑生态效率。有机肥替代化肥能够显著提高农作物生产系统的生态效率,但要注意有机肥中重金属含量对人体健康的影响。总之,发展节水型粮食作物种植、加强农业节水和提高有机肥比例是改善北京市农田生态系统生态效率的重要措施。     

Identification,Characterization, and Expression of P450 Gene Encoding CYP6BQ13v2 from the Red Flour Beetle,Tribolium castaneum （Herbst） （Coleoptera： Tenebrionidae）

An allele of CYP6BQI3, named CYP6BQ 13v2 （GenBank accession no. FJ209361）, was isolated from the red flour beetle, Tribolium castaneum （Herbst） （Coleoptera： Tenebrionidae） by RT-PCR. The cDNA sequence of CYP6BQ13v2, 1 563 bp in length, contains an open reading frame of 1 554 nucleotides encoding a putative protein of 518 amino acid residues with a predicted molecular weight of 59.92 kDa and a theoretical pl of 7.60. The putative protein contains the classic hemebinding sequence motif F××G×××C×G （residues 456-465） conserved among all P450 enzymes as well as other characteristic motifs of all cytochrome P450s. It shares 98% identity with the previously published sequence of CYP6BQ13 （GenBank accession no. XP967146） from the T. castaneum genome project. Phylogenetic analysis of amino acid sequences from members of various P450 families indicated that there was closer phylogenetic relationship of CYP6BQ 13v2 with CYP302A1 and CYP307A1 mediating synthesis of the insect molting hormone, distant relationship with CYP6B1 metabolizing plant allelochemicals, CYP6D 1 linking to pyrethroid resistance and other members of CYP6 family. Expression test of the gene in the adults and immature stages of T. castaneum by quantitative real-time PCR revealed that CYP6BQ13v2 is expressed in all life stages investigated. The mRNA expression level in 1st instar larvae was 14.9- and 3.86-fold higher than those in pupae and adults, respectively. The CYP6BQ13v2 expression levels appeared in the order of 1st instar larvae, followed by 4th instar larvae, 7th instar larvae, adult, and pupae from high to low. The more bioinformation of CYP6BQ 13v2 was also analyzed.