进境美国大豆杂草和杂质含量研究

自装载美国大豆的外轮货舱中取样,研究进口美国大豆携带杂草和杂质的含量关系:取样量为5 kg/1 000 t,是能反映进口大豆中杂草和杂质含量关系的最低取样量;把进口美国大豆杂质含量划分为1.5%、1.5%~2.0%和2.0%3个区间,其携带杂草含量和种类与杂质含量呈显著的正相关;进口大豆中携带杂草含量高的,检出频率也相对高,但检出的杂草总种类数少于杂草含量低的;杂草含量低的,检出频率也相对低,但检出的杂草总种类数多于杂草含量高的。     

离子液体2-甲基咪唑四氟硼酸盐分子结构与氢键关系的研究

离子液体作为一种新型绿色溶剂,已引起广泛关注。采用密度泛函理论,在B3LYP/6-311++G(d,p)水平下,计算2-甲基咪唑与四氟硼酸结合能为-1 100.09 kJ/mol,并且采用NBO理论与AIM研究其结构与分子内氢键作用。     

不同生育期水稻干物质量与产量的关系研究

为明确不同生育期的干物重对粤晶丝苗2号、粤农丝苗、合美占3个水稻(Oryza sativa L.)品种的产量及产量构成因素的影响,设置了早造和晚造两次不同氮肥梯度随机区组栽培试验。结果表明,叶片干物质的分配比例在拔节孕穗期时最高,且其随着生育进程逐渐降低,在乳熟期达到最低值;茎干物质的分配比例在乳熟期降至最低;齐穗期的穗干物质分配比例不到20%,而乳熟期的穗干物质量将近占总干物质量的43%;早造和晚造水稻的结实率差异极显著,总干重差异显著,而穗数、每穗粒数、千粒重、产量差异不显著;齐穗期以后,结实率和千粒重均与干物重呈负相关,而叶干重与穗数呈显著正相关,且相关性较大,茎干重与各产量性状密切相关,总干重与产量呈正相关。水稻干物重是决定高产的重要因素。     

基于服务关系为核心的图书馆服务模式研究

通过对图书馆服务工作过程的分析，建立以服务中形成的关系为核心的服务模式。揭示在服务工作过程中所形成的人与物、人与人的几种相互关系，指出这些关系是否处于和谐发展状态，对服务质量以及服务效益的提高，具有一定的影响。同时，对反馈信息进行评价，找出差距，理顺关系，进一步优化服务过程，使服务工作处于一种良性循环状态。     

Response of Maize and Cowpea Grown Sequentially to Application of Phosphate Rock in the Humid Tropics

Field trials were conducted at the Institute of Agricultural Research and Training Ibadan in 2000 and 2001 cropping seasons to evaluate the efficiency of some phosphorus (P) sources, rates, and frequency of application on grain yields of maize and cowpea grown sequentially. The experiment was laid out in a split–split plot arrangement using randomized complete block design, with three replications. The main plot was frequency of fertilizer application (seasonal and annual). Source of P [single superphosphate (SSP: 18% P₂O₅)]; Ogun rock phosphate (OPR: 20.21% P₂O₅), and crystallizer super (CS: 31.4% P₂O₅) constituted the subplots. The P rates (0, 20, 40, and 60 kg P ha^?1) were the sub-subplots. An early maize cropping followed by a late-season cowpea was the sequential cropping, while an early maize followed by a late-season maize was the continuous cropping. The croppings were repeated the second year. Frequency of P application and source of P were significantly different while rates of application were not. Maize and cowpea grain yields from the control treatment were significantly less than yields from P-treated plots. Maize grain yields were slightly greater in plots alternated with cowpea, compared to continuous maize. Relative agronomic efficiency (RAE) values of OPR and CS were 67% and 75%, respectively, in annual application and 140% and 134% in seasonal applications, respectively, in 2000. In 2001, the trend was almost similar to 2000 except that there was a decline in RAE values of cowpea. Each Naira invested in the annual application returned about ?3.12 while about ?2.13 was returned with the seasonal application (?125.00 is the equivalent of USD$1.00). The OPR and CS can serve as alternatives to water-soluble sources such as SSP.     

几种苹果矮化砧木的抗寒性研究

以71-3-150、GM256、SH6及M9 4种苹果(Malus)矮化砧木的1年生枝条为试材,进行-20℃、-25℃、-30℃、-35℃、-40℃低温处理,用电导法配合Logistic方程,求得拐点温度(LT50)即半致死温度,并对其电导率、可溶性蛋白含量和POD酶活性等指标进行了测定比较。结果表明:测得的电解质渗出率呈典型的S型曲线,与相应的低温呈极显著负相关;71-3-150、GM256、SH6及M9的半致死温度分别为-40.63℃、-39.29℃、-34.10℃、-30.10℃;抗寒性强的71-3-150和GM256能保持较高的可溶性蛋白含量和POD酶活性。     

基于食品安全的供应链合作伙伴关系研究

针对国内近年来频繁的食品安全问题,从食品供应链角度进行分析,查找现有食品供应链影响食品安全的隐患,指出构建食品供应链合作伙伴关系对于保障食品安全的重要意义,并提出构建食品供应链合作伙伴关系的措施,更有效保证食品安全。     

Developmental Dynamics and Early Growth Vigour in Rice. I. Relationship Between Development Rate (1/Phyllochron) and Growth

Achieving early vigour, that is, rapid dry matter accumulation, is a priority in rice crop improvement, but this trait is complex and not well understood genetically and physiologically. This study tested the hypothesis that the development rate (DR) contributes to early vigour. Two diversity panels were phenotyped during vegetative stage for traits constituting early vigour (shoot dry weight, SDW; relative growth rate, RGR) or contributing to early vigour (tillering, leaf size, DR). The first panel comprised 169 genotypes from all major genetic groups of Oryza sativa and was phenotyped under irrigated upland conditions in the field (Philippines, Exp1). The second panel with 190 genotypes representing the diversity of the tropical japonica group was phenotyped in pots in a greenhouse (Montpellier, France, Exp2). Results from field and pot experiment pointed out that DR, tillering and leaf size were positively correlated with RGR and SDW, although the contribution of leaf size was small. DR was positively correlated with tillering but both were negatively correlated with leaf size. DR vs. RGR correlation was conserved in subsets of genotypes with similar leaf size and tillering, suggesting an effect of DR on RGR independent of the other traits. DR is a promising, still underexploited trait contributing to rice early vigour, requiring further genetic and physiological characterization.     

高效凝胶过滤色谱法测定肽的相对分子量分布

采用高效凝胶过滤色谱法,对肽粉、酵母核苷酸和自溶酵母粉三种肽类产品的相对分子量大小及分布进行了测定。结果表明,此三种产品的相对分子量分布范围集中在2000Da以下,寡肽含量丰富,其中含有一定量的游离氨基酸和氨基酸残基。该方法简便快捷、准确性高、重复性好,适合肽类产品分子量(<1 0KD)分布的分析检测。     

妊娠早期蒙古绵羊子宫内膜enJSRV及IFN-τ基因表达水平的分析

本研究旨在检测内源性绵羊肺腺瘤反转录病毒(enJSRV)与干扰素-τ(IFN-τ)在妊娠早期蒙古绵羊子宫内膜组织的表达以及enJSRV的表达与外周血孕酮水平变化的关系。运用TaqMan实时荧光定量PCR技术和电化学发光法对enJSRV和IFN-τ在妊娠早期蒙古绵羊子宫内膜组织相对表达及孕酮水平进行了测定。实时荧光定量PCR结果显示,enJSRV和IFN-τmRNA在妊娠早期绵羊子宫内膜组织有不同程度的表达。SAS统计学软件分析得出,子宫内膜组织中enJSRV mRNA在妊娠12～14d(交配日为0d)表达较高,2～10、16～30d的表达均低于前者。IFN-τmRNA仅在妊娠12～25d表达,14d达其峰值,30d就不能检出,且差异都极显著(P<0.01)。电化学发光法结果显示,孕酮水平在妊娠2d为0.4ng·mL-1,以后升高,妊娠8～16d维持在8.3ng·mL-1左右,在妊娠19～30d孕酮水平有所下降,30d为2.5ng·mL-1。以上结果提示,子宫内膜组织中enJSRV mRNA的表达与外周血孕酮含量及IFN-τ的变化高度相关,且enJSRV在胎盘的形态发生及生殖生物学方面发挥重要作用。