肉鸡和蛋鸡心肌易颤性的比较研究

以常规饲养的肉鸡和蛋鸡作为试验动物,通过电刺激诱颤阈和输钾诱颤阈的测定以及进行冷加压试验,对同体重肉鸡和蛋鸡的心肌易颤性进行了比较研究。结果表明:(1)同体重肉鸡和蛋鸡相比,电刺激诱颤阈和输钾诱颤阈肉鸡均极显著低于蛋鸡(P<0.01);(2)在电刺激诱发室颤的过程中,开胸时室颤的发生率肉鸡(14%)显著高于蛋鸡(0%)(P<0.05);(3)冷加压试验:冷加压5min内,心率和PT波宽出现了显著的变化,而且变化幅度肉鸡均明显大于蛋鸡。上述试验结果从不同方面均表明肉鸡心肌易颤性高于蛋鸡。     

鄂尔多斯高原中部5.8～4.5 Cal kaBP气候旋回的地层记录

通过对鄂尔多斯高原现代风成砂与PJHZ剖面沉积物粒度特征的对比分析,确定了剖面中4个层位(290~210,190~160,153.5~123.5,50~40 cm)基本属于风成砂沉积。结合粒度参数、碳酸钙含量、总有机碳含量及年代序列,认为此区域在5.8~4.5 Cal kaBP存在以下沉积旋回:~5 749 Cal aBP,沉积风成砂,反映该时期风砂活动强烈,气候干燥,冬季风强盛;5 749 Cal aBP前后,沉积物为灰绿色湖相层,表明这一时期存在短暂的湖面扩展,沙漠退缩;5 749~5 370 Cal aBP,沉积风成砂,反映了湖泊的退缩和沙漠的扩展;5 370~4 895 Cal aBP,湖相沉积物,反映了流域降水量的增多;4 895~4 580 Cal aBP沉积风成砂后,4 580 Cal aBP前后又出现了短暂的湖相沉积,之后又是风砂沉积。     

不同方法提取牛心朴子基因组DNA效果的比较研究

以牛心朴子的叶片、茎段、根为试材,采用改良的CTAB法Ⅰ、CTAB法Ⅱ和SDS法对其进行了基因组DNA提取效果的比较分析.结果表明.CTAB法Ⅰ从3个部位都能提出较高浓度的DNA,电泳条带完整清晰;CTAB法Ⅱ从3个部位都能提出DNA,条带明亮,但有明显拖尾现象;SDS法从叶片中能提出较高的DNA,但从茎和根中所提的DNA含量较小,电泳条带暗;3种方法所提的DNA其RAPD扩增效果以CTAB法Ⅰ最好,CTAB法Ⅱ次之,SDS法最差.叶片提取的DNA平均纯度、浓度和得率为最高,RAPD扩增效果最好,茎次之,根最低.说明CTAB法工是牛心朴子DNA的高效提取方法,不同部位以牛心朴子叶子提取的DNA得率高,扩增效果最好.     

瘤胃微生物总DNA快速提取法研究

本文介绍了一种简便快速地提取瘤胃微生物细胞总DNA的方法,该法是对提取植物的CTAB法进行改进而成。与经典反复冻融 SDS/蛋白酶K裂解法相比,该法可在数小时内高效地提取瘤胃内容物总DNA,经琼脂糖凝胶电泳对所提取瘤胃微生物总DNA进行检测,证明所获得的瘤胃总DNA符合分子生物学操作要求。     

投加硅藻土对城镇污水处理厂出水水质影响研究

对好氧池出水混合液进行了加药絮凝试验，探讨了加药量、污泥浓度对絮凝沉淀效果的影响，并通过生产性试验，验证了试验结果的正确性，从而解决了某污水处理厂因进水水质波动影响，出水SS不能稳定达标的问题。     

Study on Optimum Design of Rectangular Sedimentation Tanks

In this paper,the flow velocity fields,suspended solids concentration fields and flow-through curves in rectangular sedimentation tanks with different reaction baffles location,inlet horizontal velocity and length height ratio are simulated in detail using a developed mathematical model given in Reference 2.According to the numerical results,the influence of different reaction baffles location,inlet horizontal velocity and length height ratio on the operating efficiency is analyzed.Finally,the rational reaction baffles location,inlet horizontal velocity and length height ratio are presented.     

Study on the Sedimentation Rule of the Particles in Debris Flow

In this paper, according to the study on a great number of experiments and data analyses, the sedimentation rule of solid particles in debris flow is set up. Three main factors that influence the particle sedimentation in debris flow were studied; the basic reasons to influence the particle sedimentation were analyzed. The particle sedimentation in debris flow could be divided into three stages,i, e. the starting stage, the quick sedimentation stage and the accumulation stage,and detailed analysis on the sedimentation process each stage was made. The liquid viscosity, particle quality and additional water pressure have an important role on the sedimentation rule of the particle in debris flow.     

籼稻体细胞胚胎发生特异性蛋白质研究

以籼稻Oryza sativa L.subsp. indica品种“广陆矮4号”幼穗和种子为外植体，在含有2，4-D2.0mg/L的MS培养基上，分别形成胚性和非胚性愈伤组织，建立体细胞胚胎发生实验系统。应用Native/SDS双向凝胶电泳分析，结果表明，非胚性愈伤组织分化培养前后均存在一种分子量为45kD的非胚性蛋白质N1，另一种非胚性蛋白质N2（54kD）仅     

平面二维数模研究闸下淤积的缺陷

以姚江大闸和武障河闸为例，对河口水域建闸后的闸下淤积的机理进行了研究。通过应用二维悬沙模型的模拟计算，分析了数学模型在模拟近闸段的淤积时存在的缺陷，对产生问题的原因进行了初步探讨。由于闸下淤积问题存在明显的时空性和区域性特征，应积极研究解决措施。     

Evidence of sedimentation inequality along riparian areas colonised by Impatiens glandulifera (Himalayan balsam)

Soil loss from riparian areas supporting the annual invasive weed, Impatiens glandulifera (Himalayan balsam), was measured and compared with equivalent values recorded at nearby, topographically similar areas supporting perennial vegetation over a cumulative seven-year period, along sections of two separate river systems; one in Switzerland, and one in the UK. Soil loss from colonised locations was significantly greater than from reference locations in four of the seven measurement periods. Despite contrasting results, standard deviations, based on soil losses and gains, were predominantly higher for colonised areas at both rivers over most monitoring periods. These findings indicated that areas colonised by Himalayan balsam experience higher sediment flux in comparison with areas free of invasion. Here, we test those original interpretations by reinterrogating the datasets using a more robust analysis of inequality. Nine datasets were tested, five of which (i.e. 56%) showed that sediment flux was significantly greater at Himalayan balsam-invaded areas than at reference areas. Three datasets showed no difference in sediment flux between invaded and reference areas (33%), and one (11%) showed higher sediment flux at reference areas. Most results uphold our original interpretations and support our hypothesis that hydrochory probably dictates where colonisation initially occurs, by depositing Himalayan balsam seeds in slack or depressional areas along river margins. Once Himalayan balsam becomes established and sufficient perennial vegetation is displaced, seasonal die-off and depleted vegetation cover may increase the risk that some areas will experience significantly higher sediment flux.