近43年黄河上游来水来沙变化特点

选取黄河头道拐站实测水沙序列(1960-2002年)资料,对水沙序列进行了多时间尺度和趋势识别的小波分析。结果表明:①黄河上游来水来沙量汛期所占比例减少,而非汛期所占比例增加;在年际变化上,水沙量逐年减少;同时,水沙相关关系具有一定的变化;②黄河上游水沙序列具有相同的多时间尺度(准周期)变化,但同一尺度下,水沙所处的丰枯变化并不一致;③年水沙序列趋势变化基本一致,20世纪80年代以来,两者存在明显减少趋势;但在非汛期,两者的趋势变化有较大区别。     

基于ASP的期刊分类发送系统的设计与实现

介绍了数字化期刊分类发送系统的功能与结构,该系统实现了通过电子邮件按订阅读者的学科专业兴趣,有选择地发送期刊文章。可供科技期刊编辑部向读者有针对性地自动发送带论文附件的邮件。     

奶牛人工授精的优缺点和技术要点

奶牛人工授精技术加速了奶牛品种改良进程,实现了将优秀种公牛精液跨区域、超时限的利用共享,极大地促进了养牛业的发展.以奶牛人工授精应用现状为出发点,介绍了人工授精技术的优点和不足,最后结合自身工作经验,从发情鉴定、适时配种、精液解冻、精液检测、输精、精液保存和妊娠检测等技术要点进行概述,以期更好地促进奶牛人工授精技术的应...     

注射用硫酸链霉素细菌内毒素检查法的探讨

按照《中国兽药典》二○○五年版一部[1]中注射用硫酸链霉素细菌内毒素检查法对样品复核检验,试验表明该方法是可行的;并与《美国药典》进行了比较,结果说明《中国兽药典》注射用硫酸链霉素细菌内毒素检查法对细菌内毒素的限值表达比《美国药典》29版[2]更合理、更科学。     

牧草种质资源繁殖更新技术规程

依照《农作物种质资源整理技术规程》,结合国家种质牧草中期库和多年生牧草圃在牧草种质资源繁殖更新技术方面取得的丰富经验,并针对存在问题制定“牧草种质资源繁殖更新技术规程”,使得牧草种质资源进行更科学的繁殖更新,为遗传完整且稳定的活种质的保存和利用提供依据。     

COMPARISON OF UPPER GASTROINTESTINAL RADIOGRAPHIC FINDINGS TO HISTOPATHOLOGIC OBSERVATIONS: A RETROSPECTIVE STUDY OF 41 DOGS AND CATS WITH SUSPECTED SMALL BOWEL INFILTRATIVE DISEASE (1985 to 1990)

It was the intent of this study to define which, if any, radiographic observations corresponded with specific causes of diffuse infiltrative small bowel disease and if radiographic findings could differentiate inflammatory disease from neoplastic disease and either of them from normal. Bowel spasticity, luminal narrowing, and thumbprinting tend to indicate the presence of tumor more often than inflammatory disease. Increased bowel gas in cats and barium adhesion in dogs and cats suggest that a component of enteritis is present. Decreased bowel gas in dogs is more often associated with obstructive disease, but is not helpful in differentiating diffuse inflammatory disease from diffuse neoplastic disease. While several observations that can foster differentiation of neoplastic from inflammatory disease were found, this study also indicated that the UGI lacks a high degree of predictive value other than to indicate the presence of infiltrative small bowel disease.     

Characterization of an intravenous lipopolysaccharide inflammation model in calves with respect to the acute-phase response

Our objective was to develop a lipopolysaccharide (LPS) inflammation model in calves to evaluate the acute-phase response with respect to the release of pro-inflammatory cytokines and acute-phase proteins, fever development and sickness behaviour. Fourteen 4-week-old male Holstein Friesian calves were included and randomly assigned to a negative control group (n = 3) and an LPS-challenged group (n = 11). The latter received an intravenous bolus injection of 0.5 μg of LPS/kg body weight. Blood collection and clinical scoring were performed at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 12, 18, 24, 28, 32, 48, 54 and 72 h post LPS administration (p.a.). In the LPS group, the following clinical signs were observed successively: tachypnoea (on average 18 min p.a.), decubitus (29 min p.a.), general depression (1.75 h p.a.), fever (5 h p.a.) and tachycardia (5 h p.a.). Subsequent to the recovery from respiratory distress, general depression was prominent, which deteriorated when fever increased. One animal did not survive LPS administration, whereas the other animals recovered on average within 6.1 h p.a. Moreover, the challenge significantly increased plasma concentrations of tumour necrosis factor-α, interleukin 6, serum amyloid A and haptoglobin, with peaking levels at 1, 3.5, 24 and 18 h p.a., respectively. The present LPS model was practical and reproducible, caused obvious clinical signs related to endotoxemia and a marked change in the studied inflammatory mediators, making it a suitable model to study the immunomodulatory properties of drugs in future research.     

黑河上游冰沟流域3种林地土壤有机碳分布特征与土壤特性的关系

研究了青海省祁连县黑河上游冰沟流域3种林地的土壤有机碳分布特征与土壤特性的关系,以期为黑河上游冰沟流域水源涵养研究提供科学依据。结果表明,3种林地0-60mm土层有机碳密度表现为针叶林森林灌丛阔叶林,针叶林有机碳密度为7.18kg·m-2,是森林灌丛、阔叶林的1.24和1.58倍,针叶林、森林灌丛、阔叶林0-10mm土层有机碳密度分别为13.22、9.49和8.62kg·m-2,是剖面有机碳密度均值的1.84、1.63和1.89倍。3种林地0-60mm土层自然含水量、团聚体、全氮均值表现为针叶林森林灌丛阔叶林,而容重、物理性沙粒、pH均值表现为针叶林森林灌丛阔叶林。3种林地土壤有机碳含量与自然含水量、团聚体、全氮之间呈显著的正相关关系(P0.05),与容重、物理性沙粒、pH之间呈显著的负相关关系。