站控、通信及网络系统的防雷措施

论述了输油泵站控制系统及微波通信系统遭受雷击的危害及原因,有针对性地采取了各种防雷的有效措施,完善微波通讯和站控及网络防雷保护系统,为确保输油安全生产提供了有利保证.     

Efficacy of natural biocide on control of microbial induced corrosion in oil pipelines mediated by Desulfovibrio vulgaris and Desulfovibrio gigas

We compared the efficacy of a natural biocide with four chemical tetrakishydroxymethyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, and formaldehyde, glutaraldehyde, to control microbial induced corrosion in oil pipelines. The efficacy of biocides were monitored against Desulfovibrio vulgaris and Desulfovibrio gigas in experimental pipes by measuring cell counts, H2S production, Fe(II) production, production of extracellular polymeric substances and structure of biofilm. The treatment with cow urine had minimum planktonic cell counts of 3 102 CFU/mL as well as biofilm cell counts of 9 101 CFU/mL as compared with tetrakishydroxyl methyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, formaldehyde and glutaraldehyde. Sulfide production was the lowest with cow urine (0.08 mmol/L), followed by tetrakishydroxymethyl phosphonium sulfonate 0.72 mmol/L. On day 90 of treatment, Fe(II) production was also found to be the lowest with cow urine. The scanning electron microscopic studies indicated that the biofilm bacteria were killed by cow urine. These results demonstrate the cow urine mediated control of microbially induced corrosion, and this is indicative of its potential as a viable substitute of toxic biocides. To the best of our knowledge, this seems to be the first report which screens possible biocidal activity by cow urine as compared to the most common biocides which oil industry is currently using.     

预腐蚀LY12CZ铝合金的疲劳寿命预测模型

目的研究铝合金预腐蚀疲劳的寿命评估模型。方法利用损伤力学模型,建立预腐蚀构件疲劳寿命预测模型,并利用LY12CZ铝合金进行预腐蚀疲劳的验证性实验。结果利用损伤力学建立的模型所得到的预腐蚀铝合金试件的疲劳寿命与实验结果吻合程度良好。结论基于损伤力学的铝合金预腐蚀疲劳寿命预测模型合理有效。     

基于疲劳累积破坏机制的储罐结构动力可靠度分析

针对随机风载荷作用下储罐结构动力可靠性问题,以300 m3的中小型立式低温储罐为研究对象,利用AR模型进行数值模拟得到风载荷的脉动风速时程与脉动功率谱密度函数。采用ANSYS建立储罐三维有限元模型,并对储罐进行动力学分析,计算出储罐结构的随机响应,进而求出随机风载荷作用下储罐结构动力可靠性所需全部数字特征,最后利用疲劳累积损伤机制计算得到储罐的动力可靠度。结果表明:假设结构强度不随时间退化,前5 a动力可靠度基本保持不变,随着使用年限的延长,动力可靠度下降速度明显增大。研究方法可为储罐的动力可靠性及寿命预测提供一定的理论依据。     

电气柜疲劳强度校核及结构优化

针对多孔闭孔型发泡硅橡胶D型空心密封条的超弹性特性,通过试验找出了密封条回弹力与压缩量之间的关系,提出了密封条满足IP X5的判别方程式,同时对方程式进行了试验验证,最后对密封条进行了阿累尼乌斯图寿命推算,为变流器柜门IP防护设计提供了重要参考。     

Immunotoxicity of bisphenol a to Carassius auratus Lymphocytes and macrophages following in vitro exposure

Bisphenol A （BPA） is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical （EDC）. The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA （0.054-5.4 mg/L）, estradiol （0.0002-2.0 mg/L） and hydrocortisone （5-50 mg/L） significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone （500-5000 mg/L） appeared to be inhibitory. BPA （0.005-50 mg/L）, estradiol （0.005-800 mg/L） and hydrocortisone （0.005-500 mg/L） markedly enhanced macrophage proliferation, whereas higher doses of BPA （500-1000 mg/L） appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA （50 mg/L） and hydrocortisone （50 and 500 mg/L） suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested （0.05-500 mg/L）. In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.     

Oxidative stress and DNA damages induced by cadmium accumulation

Experimental evidence shows that cadmium （Cd） could induce oxidative stress and then causes DNA damage in animal cells, however, whether such effect exists in plants is still unclear. In the present study, Vicia faba plants was exposed to 5 and 10 mg/L Cd for 4 d to investigate the distribution of Cd in plant, the metal effects on the cell lipids, antioxidative enzymes and DNA damages in leaves. Cd induced an increase in Cd concentrations in plants. An enhanced level of lipid peroxidation in leaves and an enhanced concentration of H2O2 in root tissues suggested that Cd caused oxidative stress in Vicia faba. Compared with control, Cd-induced enhancement in superoxide dismutase activity was significant at 5 mg/L than at 10 mg/kg in leaves, by contrast, catalase and peroxidaseactivities were significantly suppressed by Cd addition. DNA damage was detected by neutral/neutral, alkaline/neutral and alkaline/alkaline Comet assay. Increased levels of DNA damages induced by Cd occurred with reference to oxidative stress in leaves, therefore, oxidative stress induced by Cd accumulation in plants contributed to DNA damages and was possibly an important mechanism of Cd-phytotoxicity in Vicia faba plants.     

高铁扣件弹条疲劳断裂原因分析

通过对WJ-7型扣件中60Si2MnA弹条在拉伸-扭转试验过程发生断裂的原因进行分析和数值模拟研究,得出弹条断裂的原因.对60Si2MnA弹条承受的荷载进行分析可知,WJ-7型扣件在铁垫板与弹条后端接触区域内弯处应力集中最大,是造成弹条断裂破坏的主要原因之一,而弹条断裂的根本原因是弹条长期处于极限强度下工作,使弹条最终...     

一种高压油管焊接质量评价方法

阐述了高压油管疲劳破坏的原理及危害,建立高压油管焊接质量评价力学模型,通过有限元分析技术对其许用位移输入进行计算,并结合应变测量技术,利用电动振动台,对高压油管焊接处的疲劳特性进行了试验验证。结果表明,此高压油管焊接质量评价方法是可行的,有限元分析技术和应变测量技术的结合使用,保证了试验的安全性和结果准确性,此外,利用电动振动台进行疲劳耐久试验,操作方便简单,成本相对较低,具有通用性。     

焊点热疲劳失效原因分析

某PCBA样品在使用约半年后出现功能失效,该PCBA在封装后进行整体灌胶,将失效样品剥离,发现部分器件直接脱落,通过表面观察、切片分析、EBSD分析、应力分析、热膨胀系数测试等手段对样品进行分析,结果表明:各封装材料存在热失配,且焊点缺陷较多且存在应力集中区,加速焊点的疲劳失效进程,导致PCBA功能失效。