小水电科技发展领域的系统分析

该文用层次分析法(AHP)和德尔菲法(Delphi)相结合的系统分析法,对江西省上饶地区小水电科技发展领域分析模型作了探索,提出了小水电科技发展领域的优先度及重点,为“八五”、“九五”小水电科技规划的制定提供了依据,同时也为水利水电同行在科技规划中提供一点参考。     

饲粮中添加抗菌肽对肉鸭增重及血清尿素氮、总蛋白水平的影响

240只1日龄肉鸭随机成分4组,每组设3个重复,对照组用基础日粮,试验组在基础日粮上每千克分别添加1、2、3mL抗菌肽制剂。结果显示:1)2、3mL/kg添加量组增重效果显著(P<0.05),3mL/kg添加量组最佳;净肉率升高,达到显著水平(P<0.05),其中主要是胸肌率上升;腹脂率降低但差异不显著(P>0.05);料重比无显著变化(P>0.05)。2)血清总蛋白浓度差异不显著(P>0.05),但尿素氮浓度下降,2、3mL/kg添加量组达显著水平(P<0.05),3mL/kg添加量组最低。     

TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION IN A FOAL

An 8-day-old Arabian-Morgan cross colt underwent cardiac evaluation. The foal was tachycardic, tachypneic, exercise intolerant and had a loud right-sided heart murmur and cyanotic mucous membranes. Total anomalous pulmonary venous connection was diagnosed with echocardiography and confirmed at postmortem examination. Total anomalous pulmonary venous connection is a very rare congenital cardiac abnormality that has not been reported before in the horse.     

苜蓿冠层温度与农艺性状的相关分析

对从国内外引进的31个苜蓿品种分枝期—结英期的冠层温度及其农艺性状指标进行了相关分析和偏相关分析。结果表明，苜蓿冠层温度与分枝期和现蕾期的茎叶比、开花期的叶面积和产量间存在显著的偏相关关系，可作为产量高低的间接或直接指标；由于农艺性状指标间互相关的影响，冠层温度与农艺性状指标间的单相关系数可靠性差，且与偏相关系数有明显的差异；排除农艺性状指标间互相关影响后，偏相关系数可靠性大，可作为变量间关系密切程度的量化指标。     

Effect of take-all root infections on nitrate uptake in winter wheat

The effect of take-all root lesions on nitrate uptake of wheat was investigated in two experiments under controlled conditions. Plants were supplied with a nutrient solution labelled with ¹⁵N during stem elongation and flowering to assess the distribution of the isotopic tracer in the different plant organs, and particularly in root segments located on both sides of take-all lesions. The ¹⁵N atom percentage excess measured in root segments located below lesions longer than 1 cm was reduced on average by half compared with that in healthy roots and root segments above lesions, reflecting a reduction in nitrogen uptake by these root segments. This reduction probably resulted from the invasion and breakdown of phloem vessels by the fungus hyphae, interrupting energy supply and thus the uptake process. Severely infected plants showed an increase in the uptake rate per unit of efficient root, which appeared to be a compensatory response to reduction of efficient root biomass in order to satisfy shoot nitrogen demand. However, this compensatory response was insufficient to ensure nitrogen accumulation equivalent to that of healthy plants, as reductions in nitrogen accumulated in roots and aerial parts at flowering were up to 56 and 49%, respectively, for plants with more than 50% of the root system below lesions longer than 1 cm.     

Weed:spring barley competition for applied nitrogen in pig slurry

Summary The experiments were carried out in the two spring barley fields of the organic six-course cattle:crop rotation at Foulumgaard, Denmark. The weed density was 300 and 1800 plants m⁻² respectively. Pig slurry was applied by hand in microplots by four methods: broadcasting followed by incorporation, or injected in bands to depths of 5, 10 or 15 cm. Spring barley and weeds were sampled separately six times during the tillering and elongation phase of the spring barley. The effect of application method on dry-matter (d.m.) production, nitrogen uptake and recovery of applied nitrogen in the spring barley and the weeds is reported. Slurry banding halved the weed d.m. and weed N uptake compared with broadcasting, irrespective of weed density. Weeds recovered up to 12% of the applied nitrogen, which made them a significant competitor when the slurry was broadcast and incorporated. Banding by direct injection reduced the slurry:soil contact and the weed:crop competition balance for applied nitrogen moved in favour of the crop. Thus, the crop recovery of applied nitrogen at the end of the sampling period was increased from approximately 45% for broadcast and incorporated to approximately 50% for injected slurry, and coincidental weed recovery was reduced to a maximum of 5%. As the nitrogen supply normally affects plant d.m. production, banding of slurry might well improve crop competitiveness and its tolerance to mechanical weed control.     

不同地域环境对枸杞蛋白质和药用氨基酸含量的影响

根据2000～2001年我国北方六省(区)多点枸杞采样资料和田间试验资料,利用K-均值聚类方法和非线性回归方法,对比分析了宁杞1号枸杞蛋白质和9种药用氨基酸含量的差异和特点,以及生态因子对它们的影响。分析结果表明,不同地域栽种的宁杞1号枸杞蛋白质和9种药用氨基酸含量的变异系数分别为16.58%和16.22%,除品种因子的决定作用以外,环境条件对枸杞蛋白质含量有一定作用,其中土壤水解氮含量对蛋白质和氨基酸合成有一定作用,二者呈对数关系。     

丝状霉形体丝状亚种SC型脂蛋白LppQ N末端基因克隆与序列分析

脂蛋白LPPQ是丝状霉形体丝状亚种SC型(MmmSC)非洲株、欧洲株和疫苗株所特有的。LPPQ N末端域具有良好的免疫原性，在牛体内可诱导产生强大、特异、早期、持续的免疫反应。本研究根据已发表的LPPQ基因序列设计引物，用Pyrobest^TM高保真DNA聚合酶从MmmSC HVRI X株中扩增出了LPPQ N末端基因序列，并进行了克隆与序列测定。核苷酸序列比较结果显示，HVRI X株的LPPQ N末端基因序列与国外发表的序列同源性为99．7％，由其推导的氨基酸序列同源性为99，1％，为脂蛋白LPPQ N末端基因体外表达奠定了基础。     

体外试验中不同粗精比对山羊瘤胃细菌氨态氮利用效率的影响

利用体外发酵法研究了4种粗精比(10∶0、8∶2、6∶4和4∶6)底物对山羊瘤胃细菌产量、15NH3-N利用效率的影响。结果表明:混合培养液的pH值与氨态氮浓度在8h内急剧下降,而后至24h呈缓慢下降;经24h培养的细菌产量在8∶2、6∶4和4∶6组中差异不显著(P>0.05),但都极显著地高于10∶0组(P<0.01);细菌体15N丰度以8∶2及4∶6组较高,显著高于10∶0和6∶4组(P<0.05);细菌体15N富集量以8∶2组最高,底物547.43μg15N中有120.44μg被细菌体富集,显著高于10∶0组(P<0.05),但6∶4、4∶6组与10∶0组间差异均不显著(P>0.05)。细菌赖氨酸的相对百分组成随精饲料比例的增加而显著增加,胱氨酸在粗饲料组(10∶0)显著高于其它组,但各精饲料添加组间差异不显著,组氨酸以8∶2组为最高,显著高于10∶0组,但与其它精饲料添加组间差异不显著(P>0.05)。     

Visualization of the effect of a surfactant on the uptake of xenobiotics into plant foliage by confocal laser scanning microscopy

A radiolabelling method is generally used to determine the foliar uptake of xenobiotics. This technique cannot provide any information on the localization of chemicals inside leaf tissues. The influence of an alcohol ethoxylate surfactant on the uptake of three fluorescent dyes, difluorofluorescein (hydrophilic), rhodamine B (moderately lipophilic) and a naphthalimide dye (lipophilic), into the leaves of three contrasting species, bean (Vicia faba), wheat (Triticum aestivum) and cabbage (Brassica oleracea), at 16 h after treatment was measured using a conventional wash‐off method and also visualized in vivo by confocal laser scanning microscopy (CLSM). Whereas the lipophilic dyes showed greater intrinsic uptake than the hydrophilic one, the enhancing effect of the surfactant on uptake was more pronounced for the latter. CLSM revealed that the presence of the surfactant increased the transport of difluorofluorescein into the epidermal cells of bean and wheat leaves, but not cabbage leaves. Rhodamine B showed greatest transcuticular diffusion in all three species, but most of the dye moved into the vacuole of the epidermal cells. The naphthalimide dye was strongly retained by the wax–cuticle layer of all species, even in the presence of the surfactant. CLSM has proven to be an attractive tool for studying xenobiotic diffusion. The results obtained using fluorescent dyes are believed to be applicable to the foliar uptake of herbicides.