浅谈油气管道完整性管理模式

本文基于国内外油气管道完整性管理(PIM)成果的基础，从数据收集和研究、高后果区分析、完整性评估、管道检测与执行、管道维护修复、效能分析等方面进行具体PIM描述，从体系文件、标准规范、系统平台、支持技术、实施应用五个层面构建PIM管理体系框架。     

Effect of ammonia and nitrite on vigour,survival rate,moulting rate of the blue swimming crab <Emphasis Type="Italic">Portunus pelagicus</Emphasis> zoea

The effects of ammonia and nitrite on vigour, survival rate, moulting rate of zoea of blue swimming crab, Portunus pelagicus, were studied. A total of five nitrite-N treatments (26.67, 53.34, 106.68, 213.36, 426.72 mg/l) and a control (no nitrite-N added) were set up for the acute nitrite-N toxicity experiment; a total of five ammonia-N treatments (8.43, 16.86, 33.72, 67.44, 134.88 mg/l) and a control (no ammonia-N added) were set up for the acute ammonia-N toxicity experiment. The results showed that the vigour, survival rate and moulting rate of zoea of the blue swimming crabs exposed to over 53.34 mg/l were significantly different (P < 0.05) from the control group. The zoea LC₅₀ values (mg/l) of nitrite-N were 179.47, 76.56, 66.70, 37.49, 25.01, 25.35, 25.34 mg/l for 24, 36, 48, 60, 72, 84, 96 h, respectively. The vigour, survival rate and moulting rate of zoea of the blue swimming crabs exposed to over 16.86 mg/l were significantly different (P < 0.05) from the control group. The zoea LC₅₀ values (mg/l) of ammonia-N were 51.04, 39.62, 38.72, 24.43, 16.90, 13.42, 11.16 mg/l for 24, 36, 48, 60, 72, 84, 96 h, respectively. The zoeae are highly sensitive to ammonia and nitrite, and the toxicity of ammonia and nitrite on Portunus pelagicus decrease with development of this crab.     

多元文化对语言歧义理解及运用的影响——以新疆农业垦区为例

一.引言在新疆农业垦区,多民族杂居、多元文化并存。自西汉至清末,历代王朝出于戍边和维护地方治安的考虑,均非常重视在西域屯田。新疆生产建设兵团进驻新疆后,大力发展屯垦经济,进一步增强了汉民族农耕文化在新疆地区的吸纳力和包容力。     

禁抗前后规模鸡场环境中金黄色葡萄球菌和大肠杆菌对15种抗菌药的敏感性比较

为了解规模鸡场两种环境细菌在禁抗前后耐药性的变化,以评估使用抗菌药对养殖场用药的影响,通过对禁抗前以及禁抗6个月后规模鸡场的环境进行采样,培养分离大肠杆菌和金黄色葡萄球菌(金葡菌),然后针对15种常见抗菌药物开展药敏试验,并对敏感性进行比对。结果显示:禁抗前规模鸡场分离的大肠杆菌对妥布霉素、林可霉素、头孢拉定、卡拉霉素等较敏感,而对磺胺异噁唑、土霉素、头孢唑林和青霉素等耐药;金葡菌对头孢曲松、卡拉霉素、头孢唑啉、氟苯尼考等较敏感,而对土霉素、磺胺异噁唑、庆大霉素、妥布霉素等耐药。禁抗6个月后,两种细菌对大部分抗菌药的敏感性都有不同程度的增加,但对土霉素、磺胺异噁唑、氟苯尼考、青霉素等的敏感性增加不多甚至有降低。结果表明禁抗总体上可以增强鸡场环境中两种细菌对抗菌药的敏感性,降低耐药性。本文为指导规模鸡场禁用和科学使用抗菌药物提供了数据支持。     

红薯秧茎破碎还田机的研制

针对红薯秧茎的蔓生性及北方红薯种植模式,研制了适合于垄作红薯秧茎破碎还田机。该机主要由挑秧机构、秧茎破碎装置、刀轴总成、碎秧输送装置和地轮总成等组成。该机由轮式拖拉机牵引,可一次完成秧茎的收割、粉碎、还田等项作业。工作时,动力通过万向节从拖拉机的动力输出轴传出,经过锥齿轮减速器变向增速后,动力分成两路,分别传给秧茎破碎装置、碎秧输送装置和嫩秧切断装置。随着拖拉机前进,秧茎先被挑秧机构挑起,然后被机器前部高悬的旋转圆盘刀切断,高速旋转的破碎刀轴产生负压将切断的秧茎及剩余主干上的薯叶吸进破碎刀轴和护罩间破碎,碎秧落入碎秧输送装置的输送带,被均匀输送抛撒至垄沟。     

2BQM-6型免耕播种机设计及播种深度控制研究

根据北方地区免耕作业的农艺要求,设计了2BQM-6型气吸式免耕播种机,实现了破茬、开沟施肥、播种及覆土镇压等联合作业。在此基础上,针对免耕条件下作业地面平整度较差等因素所造成的播种深度变动大的问题,研究了播种深度调节机构和相应的参数。通过ADAMS软件对播种单体进行建模分析,研究其仿形机构不同参数对仿形效果的影响,寻求最佳仿形时的最优参数范围,以满足不同农作物种植深度不同的要求。该调节装置具有调节范围广、灵活及易于操作等特点。