气力轮式精密排种器大豆充种过程试验研究

采用均匀设计和高速摄像方法,研究气力轮式精密排种器在常压和加气条件下大豆种子在充种过程中的运动。试验结果表明:常压下,充种角小于45o时,种子面随充种包角增加而提高,无带动层;充种角大于45o时,排种轮上部出现带动层,带动层种子随排种轮转动到达清种位置;气力条件下,吹嘴进口压力>1.0kPa时,在充填区上部逐渐形成一个比较明显的回旋流动区,种子群在该区域形成沿逆时针方向运动的种子环流群,扩大了种子的充填范围。     

饲料中添加发酵豆粕对仔猪生长性能的影响

试验选择母猪胎次、初生体重相近的杜长大三元杂交哺乳仔猪24窝,随机分为对照组,试验Ⅰ、Ⅱ组,每组八窝。对照组饲喂常规乳猪料,试验Ⅰ、Ⅱ组分别饲喂添加10%、20%发酵豆粕的乳猪料,研究发酵豆粕对仔猪生长性能的影响。结果表明试验Ⅰ、Ⅱ组仔猪平均日增重、平均日采食量均显著高于对照组(P<0.05),而料肉比、腹泻率显著低于对照组(P<0.05);试验组Ⅱ平均日增重、平均日采食量高于试验组Ⅰ,料肉比、腹泻率低于试验组Ⅰ,但二者之间差异不显著(P>0.05)。     

偏重亚硫酸钠钝化生豆粕胰蛋白酶抑制因子的研究

试验用不同浓度的Ｎａ２Ｓ２Ｏ５处理生豆粕，进行适宜水平研究。结果表明，当生豆粕ＴＩＡ和ＵＡ分别为２９．７２酶活单位和１．９５△ｐＨ时，分别用０．３％、０．４％、０．５％和０．６％ＮａＳ２Ｏ５处理ＲＳＢＭ，ＴＩＡ依次降低了５１．８％、５５．９６％、５９．８３％和５２．０５％，均极显著地低于ＲＳＢＭ（Ｐ＜０．０１）。０．３％Ｎａ２Ｓ２Ｏ５对ＵＡ无影响，其它处理ＵＡ提高约０．０６△ｐＨ。     

棉子油中不饱和脂肪酸的分离

本文论述了从棉子油或棉子油皂脚中分离不饱和脂肪酸的可能性和必要性,以及脂肪酸分离的不同方法。详细阐述了不饱和脂肪酸尿素包合分离法的原理、操作过程及各种因素对分离效果的影响。不饱和脂肪酸尿素包合分离法具有操作方便、设备要求简单。及防止不饱和脂肪酸在分离过程中发生氧化和异构化的特点,是一种较理想的制备高纯度不饱和脂肪酸的方法。     

中国海洋捕捞渔船油污水产生量估算及对策研究

为获知中国海洋捕捞渔船底舱中油污水的产生量,对东部沿海主要渔区海洋捕捞渔船的底舱油污水状况进行了调研和取样,并进行了测算和分析,以进一步推算中国海洋捕捞渔船油污水的年排放总量,并对其进行探讨和对策建议。推算数据显示：全国海洋渔船年总排水量约为136 118 t,全国海洋渔船年总排油量约为5 238 t。研究认为：油污水产生量与船龄不直接相关,船龄在5年以下的渔船情况较好;油污水含油率基本在5%以下,长时间静置后下层水含油率仍高于排放标准;海洋捕捞渔船的油污水产生与日常管理水平关系较大。建议：加强宣传,提高渔民的环保意识;加强监管,减少渔船污染物排放;采取措施,鼓励渔船污染物收集;加强合作,建立各部门协同机制;加强研发,推进渔船底舱油污水技术革新。     

不同播种季节对早熟菜用大豆农艺性状的影响

对12个早熟菜用大豆品种(系),进行春夏播试验,研究不同播季对主要农艺性状的影响,分析不同播季性状之间的相关性。结果表明,春季播种条件下几乎所有性状均高于夏播;农艺性状的变异系数小于夏播;单株荚数、全生育期等2个性状与单株产量达显著或极显著相关,而夏播条件下单株荚数、单株粒数等2个性状与单株产量达显著相关。初步探讨了产生遗传差异的原因及分季播种条件下有关性状的选择,为早熟菜用大豆育种在不同环境条件下的性状选择与鉴定提供依据。     

不同遮光处理对菜用大豆产量的影响

设置遮双层网、遮单层网和不遮网3种处理,对32个菜用大豆品种(系)各小区的标准荚数、标准荚重、百粒重、产量等指标进行比较。结果表明:筛选出了3种处理条件下平均小区产量均超过1 300 g的上海红皮、灵川吕竹豆等菜用大豆品种(系)6个;各处理小区平均产量与标准荚数、标准荚重呈极显著的正相关;耐阴性较强的菜用大豆品种(系)在遮光和正常条件下平均产量均较高。     

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。     

鱼油对仔猪生产性能、炎性介质和下丘脑-垂体-肾上腺轴激素的影响

本试验研究了鱼油对断奶仔猪生产性能、炎性介质和下丘脑-垂体-肾上腺轴激素的影响.选用32头(28±3)日龄、体重(8.91±0.74)kg的杜洛克×长白×大白仔猪,随机分为4组,每组4个重复,每个重复2头猪,1公1母.采用双因子设计,主因子包括:1)饲粮处理(5%鱼油或5%玉米油);2)免疫应激[注射脂多糖(LPS)或...     

Seasonal critical concentration and relationships of leaf phosphorus and potassium status with biomass and yield traits of soybean

Analysis of uppermost fully expanded leaves is useful to detect a deficiency of mineral nutrients such as phosphorus (P) and potassium (K) in soybean. Although, the leaf P or K status aids in fertilizer management, information on nutrient seasonal relationships with growth and yield traits at maturity are limited. To investigate this, soybean was grown under varying P or K nutrition under ambient and elevated CO₂ concentrations. Results show significant relationships of the relative total biomass and yield‐related traits with the foliar P and K concentrations measured several times in the season across CO₂ levels. However, the relationships established earlier in the season showed that the growth period between 25 and 37 d after planting (DAP), representing the beginning of flowering and pod, respectively, is the best for leaf sampling to determine the foliar P or K status. The leaf P and K status as well as the critical leaf P (CLPC) and K (CLKC) concentrations for traits such as seed yield peaked around 30 DAP (R2 stage) and tended to decline thereafter with the plant age. The CLPC and CLKC of seed yield indicate that the leaf P and K concentration of at least 2.74 mg g^?1 and 19.06 mg g^?1, respectively, in the uppermost fully expanded leaves are needed between 25 and 37 DAP for near‐optimum soybean yield. Moreover, the greatest impact of P and K deficiency occurred for the traits that contribute the most to the soybean yield (e.g., relative total biomass, seed yield, pod and seed numbers), while traits such as seed number per pod, seed size, and shelling percentages were the least affected and showed smaller leaf critical concentration. The CLPC or CLKC for biomass and seed yield was greater under elevated CO₂ 24–25 DAP but varied thereafter. These results are useful to researchers and farmers to understand the dynamics of the relationship of pre‐harvest leaf P and K status with soybean productivity at maturity, and in the determination of suitable growth stage to collect leaf samples.