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771.
Barium sulfate bronchograms were performed on four 454-kg (1000-lb), adult, mixedbreed horses. Approximately 100 ml of 100% w/v premixed barium sulfate suspension was insufflated into a caudodorsal portion of one lung. Excellent bronchograms were obtained through six generations of bronchial divisions. Bronchograms of diagnostic quality were present for at least 30 minutes. Radiographs at 24 hours showed that most of the barium had been removed from the lung. At 48 hours, tiny barium nodules were essentially all that remained. One hundred and thirty milliliters of barium sulfate initially resulted in overfilling of the bronchial tree and prolonged retention of the contrast medium. Six weeks after bronchography, histopathologic examination of the perfused fixed lungs of two horses showed a very mild inflammatory response to the barium. One of the four horses received two barium sulfate bronchograms. This horse was observed and found to be free of any side effects for 15 months after the second bronchogram.  相似文献   
772.
气体水合物储存甲烷促进技术研究   总被引:4,自引:1,他引:3  
气体水合物储气技术是世界上正在研究开发的天然气储存新技术.针对含表面活性剂水溶液体系中甲烷水合物的形成过程进行了试验研究,发现微量的表面活性剂可以使甲烷水合物在静止的系统中快速形成,并且可以提高气体水合物储存甲烷的能力.在300 mg/L十二烷基硫酸钠水溶液中,在0.9℃、5.54 MPa时,甲烷水合物储气量达到162.63 m3/m3,是理想储气量的90%.  相似文献   
773.
774.
日摄食钼250ppm[15mg/(kg·d)]的成年绵羊,加喂硫酸钠7g/d能显著减少其血浆、被毛及组织中的钼蓄积,显著增加脾、肝、肾等组织的铁含量;而单纯摄入高钼则对体内铁状态无显著影响。硫酸盐对摄食高钼绵羊体内铜状态的影响与单纯投钼羊类似,表现为肝、肾等组织铜、血浆总铜以及铜蓝蛋白氧化酶(CP)活性增加;对血浆铜的组分构成具有显著影响,表现为降低三氯醋酸(TCA)不溶铜而升高TCA可溶铜。在实验期间,加喂硫酸盐并未引起钼诱导的铜缺乏。  相似文献   
775.
Dynamic interactions between cells and underlying extracellular matrices are crucial for development, maintenance of cellular function, and response of tissure to injury and infection. Heparan sulfate proteoglycans (HSPG) are found in extracelular matrices and on the surface of most nuclrarated cells,and play critical roles in cell-cell and cell-matrix signal transduct ion by binding many molecules, such as growth factors and cytokines. Most of the biological properties of HSPG are conferred by heparan sulfate side chains, which can be degraded by heparanase. Changes of heparanase expression and activity may affect the biological processes above, which enables extravasation of inflammation cells, metastasis and neoangiogenesis of tumor cells invasion.  相似文献   
776.
777.
通过对青海尕斯油田、跃进2号油田矿物组成和流体性质及油藏条件等进行分析,表明这两个油田管线极易产生硫酸钡锶垢.采用离子发射光谱(ICP-AES)和X-射线衍射方法(XRD)分析垢组成及面分布图获得垢矿物成分和细微形貌,表明尕斯E13、跃进2号油田管线垢样主要成分为硫酸钡和硫酸锶垢,并且它们是伴生的(约占60%),其余成分为碳酸钙和碳酸亚铁.  相似文献   
778.
Yield decline resulting from continuous cropping of aerobic rice is a constraint to the widespread adoption of aerobic rice technology. Shifts in water management from flooded to aerobic conditions are known to influence the availability and form of N present in the soil and might require a different approach to N management in aerobic rice. The present study was conducted to determine the effects of different N sources on the plant growth and grain yield of aerobic rice. Four pot experiments were conducted in which rice was aerobically grown in soil that was taken from fields where aerobic rice has been cultivated for 11 consecutive seasons and an adjacent field where flooded rice has been grown continuously. Nitrogen was applied as ammonium sulfate, urea, ammonium chloride, ammonium nitrate and potassium nitrate at four N rates of 0.3, 0.6, 0.9 and 1.2 g N pot−1. Two unfertilized controls consisting of soil that was either untreated or oven heated at 120°C for 12 h were also included. Plants were sampled during the vegetative stage or at maturity to measure plant growth, N uptake, grain yield and the yield components. Growth of aerobic rice in aerobic soil was generally better with the application of ammonium-N than nitrate-N. Potassium nitrate decreased plant growth and caused plant death at the high N rate. Ammonium sulfate was more effective in improving the vegetative plant growth, N nutrition and grain yield of aerobic rice than urea at the high N rates. The application of ammonium sulfate achieved the same and even better plant growth than the soil oven-heating treatment. These results suggest that there is a possibility of reversing the yield decline observed in the continuous aerobic rice system by using the right source of N fertilizer at the optimal rate.  相似文献   
779.
秸秆和硫酸铝改良剂对苏打盐碱土吸附腐殖酸性能的影响   总被引:2,自引:1,他引:1  
为了揭示硫酸铝改良剂对苏打盐碱土在秸秆还田条件下固碳性能的影响,研究了添加秸秆和硫酸铝并于恒温条件下培养300天后的盐碱土对腐殖酸的吸附性能。结果表明:在腐殖酸吸附动力学中,秸秆和硫酸铝不同添加量条件下,盐碱土对腐殖酸的吸附均在120min时达到平衡,准二级动力学方程拟合效果最好,R2值最高(0.936)。Langmuir方程和Freundlich方程均可较好地拟合盐碱土对腐殖酸的等温吸附。添加相同比例的玉米秸秆条件下,Langmuir方程拟合获得的最大吸附量分别表现为69.335,42.830,40.498,42.593mg/g。而添加同等比例的硫酸铝改良剂条件下,最大吸附量分别表现为21.358,32.647,69.335,49.232,62.375,42.830mg/g。  相似文献   
780.
硫酸安普霉素对哺乳仔猪黄白痢的预防试验   总被引:4,自引:1,他引:3  
为了解国产硫酸安普霉素对哺乳仔猪黄痢和白痢发病率、成活率及体重的影响 ,用国产硫酸安普霉素对 2 0头哺乳母猪和 1 55头哺乳仔猪分别进行了为期 3 0 d的饲喂试验 ,结果表明 :在母猪或仔猪或同时添加硫酸安普霉素 ,均能提高仔猪成活率 ,降低仔猪黄痢、白痢发生率 ,促进仔猪生长。  相似文献   
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