新植蔗施肥模式与宿根蔗产量及糖分关系的研究

本文研究了新植蔗不同施肥模式对宿根蔗的后续效应,旨在探讨新植蔗不同施肥模式下,宿根蔗产量和蔗糖分差异及其原因,为进一步优化甘蔗三高施肥模式提供理论依据。试验结果表明,在新植蔗不同施肥模式下,就模式间进行比较,宿根蔗蔗茎产量和收获株数存在显著差异,其规律与新植蔗的结果相一致;宿根蔗的株高在施肥情况下存在显著差异;宿根蔗茎径差异不显著;株高的变异系数存在明显差异,且施肥与否规律相同;生长中后期的叶片Ｎ含量存在明显差异,在施肥情况下差异更加明显;蔗汁锤度无显著差异;叶片Ｐ和Ｋ含量无明显差异。试验结果也表明,在新植蔗不同施肥模式下,宿根蔗施肥比不施肥,蔗茎产量和株数显著增加;叶片含Ｎ、Ｐ、Ｋ量明显增加;株高的变异系数明显较低;而其他性状则无明显的差异。分析试验结果可以看出,新植蔗不同施肥模式下宿根蔗产量的差异主要是由于株数、株高、叶片含氮量、株高整齐度的差异所致,宿根蔗的株数,乃至产量又与新植蔗的有效茎数有密切关系     

电喷雾萃取及电离质谱法分析大豆水提液快速鉴别种子活力

为快速评价大豆种子活力,该文以人工加速老化后的大豆种子为原料,采用电喷雾萃取电离质谱（extractive electrospray ionization-mass spectrometry,EESI-MS）直接检测不同活力大豆种子水提液,获得其正离子模式下指纹图谱,结合主成分分析（principal component analysis,PCA）、聚类分析（cluster analysis,CA）和判别分析（discriminant analysis, DA）,建立鉴别大豆种子活力的方法。结果表明,在正离子模式下,电喷雾萃取电离质谱结合多变量分析方法可以有效鉴别不同活力大豆种子。主成分分析提取了前3个主成分因子,累计贡献率达到94.80%,聚类分析和判别分析的正确率都为100%,对外部验证样本进行判别分析,正确率为95%。电喷雾萃取电离质谱能快速鉴别不同活力大豆种子,为种子活力检测提供了一种快速、准确、高效的新方法。     

乌鲁木齐河下游地区湖泊沉积物的粒度特征与沉积环境

根据乌鲁木齐河下游尾癌湖泊东道海子钻孔沉积物＾１４Ｃ年代和粒度分析,表明沉积物的粒度特征随着入湖水量的波动而发生有规律的变化。最近３０ｋａＢＰ以来该钻孔基本上处于比较稳定的湖泊沉积环境,说明东道海子至少有３万年的发育历史,这也说明古尔班通古特沙漠边缘地带的纵向沙垄具有相当程度的稳定性。最后几十年的湖泊变４干、环境退化过程主要是人类活动造成的。     

利用SSR和SRAP标记分析花椰菜自交系的遗传多样性

为选育优质花椰菜新品种,指导种质资源引进和利用,本研究采用简单重复序(simple sequence repeat,SSR)标记和相关序列扩增多态性(sequence-related amplified polymorphism,SRAP)标记对38份花椰菜自交系进行了遗传多样性分析,分别从48对SSR引物、48对SRAP引物中各筛选出4对有效引物。4对SSR引物扩增的总条带数为47个,多态性条带为39个,平均多态性比率达83.0%;4对SRAP引物扩增的总条带数为86个,多态性条带为51个,平均多态性比率为59.3%,该结果显示花椰菜自交系间具有较丰富的遗传多样性。UPGMA聚类分析揭示了花椰菜自交系的熟期与其遗传差异相关。     

Genetic analysis of ORF5 of recent Korean porcine reproductive and respiratory syndrome viruses (PRRSVs) in viremic sera collected from MLV-vaccinating or non-vaccinating farms

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.     

姑婆山国家森林公园景观格局变化分析

根据姑婆山国家森林公园1999年和2009年森林调查资料,在ArcGIS和Fragstas 3.3的支持下对姑婆山国家森林公园景观格局动态变化进行研究。结果表明：研究期间,研究区主要景观类型没有变化,阔叶树、灌木林、杉木林3种主要景观类型面积占总面积的比例由80.44%提高到94.51%;景观基质均为阔叶林,占总面积比例由63.63%提高到75.82%;总斑块数量由301块下降到174块;平均形状指数呈下降趋势;多样指数由1.233下降到0.862;优势度指数则由0.846升高至1.217。总体表现为针叶林向针阔混交林,进而向阔叶林演替,景观趋向连续和稳定。     

Effects of dietary protein to carbohydrate ratios on growth and body composition of juvenile yellow catfish, Pelteobagrus fulvidraco (Siluriformes, Bagridae, Pelteobagrus)

The present experiment was conducted to investigate the effects of dietary protein to carbohydrate ratios on growth and body composition of juvenile yellow catfish, Pelteobagrus fulvidraco . Nine diets were formulated to contain three protein levels (30%, 36% and 42%), each with three carbohydrate levels (24%, 30% and 36%). Each diet was randomly assigned to triplicate groups of 20 fish (initial mean body weight: 8.24±0.20 g) in indoor flow – through fibreglass tanks. The experiment continued for 8 weeks. Weight gain and specific growth rate were similar for the fish fed the 36% and 42% protein diets but higher than that fed the 30% protein diet. At the 36% protein level, carbohydrate contents varying from 24% to 36% ( P / E ratio of 24.0–28.2 mg protein kJ⁻¹) had no significant effects on growth performance and feed utilization ( P >0.05). Protein efficiency ratio tended to increase with dietary carbohydrate level at the same protein level. Dietary treatments significantly influenced body composition ( P <0.05), but not the condition factor, viscerosomatic index, hepatosomatic index and intraperitoneal fat ratio ( P >0.05). Based on these observations, 36% protein and 24–36% carbohydrate with the P / E ratio of 24.0–28.2 mg protein kJ⁻¹ seemed suitable for optimal growth and feed utilization, and carbohydrate could cause protein-sparing effect in diets for juvenile yellow catfish.     

高压气动比例减压阀设计与仿真

提出一种高压气动比例减压阀,该阀由比例电磁铁控制的二位三通型滑阀式先导阀和活塞提升式主阀组成,通过压力传感器和控制器构成闭环电反馈控制,最高工作压力为31.5 MPa。该阀虽然存在少量先导耗气,但保证了压力调整的快速性和稳定性,克服了先导泄漏对减压阀的影响,避免了先导阀意外结冰的发生。在介绍结构及工作原理的基础上分析了该减压阀的特点,利用AMESim建立了考虑气源压力和负载流量波动的仿真模型。仿真结果表明:该阀在气源压力缓慢下降且负载流量大范围波动的情况下能实现稳定的压力输出,在不改变控制参数的前提下,当气源压力为31.5 MPa时输出压力可在1~30 MPa范围内稳定;先导阀预开口形式对压力精度影响较小,但应避免正开口以减少气体浪费;先导阀环形间隙高度控制在10μm左右较为合适。     

不同地面结构育肥猪舍的恶臭排放影响因素分析

研究了冷、暖季节下生物发酵床、水泥实心、全缝隙3种不同地面结构的机械通风育肥猪舍的恶臭浓度、排放系数及地面结构、舍内温湿度、猪体重对恶臭浓度的影响.研究表明:猪舍的恶臭浓度与舍内温度、猪体重呈显著正相关(p＜0.05),恶臭浓度与相对湿度无显著相关性(p＞0.1);地面结构不同,恶臭浓度存在显著差异(p＜0.05);生物发酵床猪舍有助于恶臭减排,恶臭浓度最低,水泥实心地面猪舍的恶臭浓度最高,全缝隙地面猪舍的恶臭浓度居中;生物发酵床、全缝隙、水泥实心地面育肥猪舍的恶臭排放系数分别为(3.39±3.33)、(3.70±1.31)、(4.33±2.39) OU/(m2·s).     

鸡粪厌氧发酵沼液混凝处理投药量预测

对某养鸡场沼气工程全混式发酵罐出水沼液混凝投药量预测模型进行了研究.采用回归分析法确定了混凝剂最优投加量的模型参数;通过回归正交试验研究了助凝剂最优投加量影响因素,建立了助凝剂最优投加量预测模型;通过中试试验,对所得投药量模型进行了验证.结果表明,混凝处理沼液混凝剂最优投加量模型为A=0.000 06C1.41;助凝剂最优投加量模型为B=0.000 148CN -0.014 2C -0.277N+ 26.7,原水CODcr及搅拌强度是影响助凝剂PAM投加量的重要因素;经统计检验及中试试验验证,表明所建预测模型准确可靠.