水下隧道穿越管道保护效果测试评价

本文通过对四川气田北干线涪江隧道穿越管道阴极保护电参数的现场测试，取得了实际可信的基础数据，验证了处于水下隧道洞内的穿越段管道，能得到陆上强制电流阴极保护系统的有效保护，保护电流所必经的岩石层和锚喷钢筋混凝土层对保护电流没有构成屏蔽的结论，对管道工程设计和运行管理具有指导作用。     

4-methoxy-2,6-bis(3,5-dimethylpyrazoyl)-1,3,5-triazine modified carbon paste electrode for trace Cu(Ⅱ) determination by differential pulse volt-ammetry

A differential pulse voltammetric method was developed for the sensitive and selective determination of Cu(Ⅱ) at 4-methoxy-2,6-bis(3,5-dimethylpyrazoyl)-l,3,5-triazine modified carbon paste electrode in 0.05 mol/L KHC8H4O4 solution (pH = 4.02). The oxidation peak of Cu(Ⅱ) was observed at 0.065 V(vs Ag/AgCl) by scanning the potential in positive direc-tion. The analysis procedure consisted of an open circuit accumulation step in stirred sample solution. It was followed by medium exchange to a clean solution and subsequently an anodic potential scan was affected to obtain the voltammetric peak. The current was proportional to the concentration of the Cu(Ⅱ) ion in a range of 1× 10-7-1×10-4 mol/L for 6 min accumulation; the most of metal ions did not interfere with the determination. The developed method was applied to Cu(Ⅱ) determination in coal-ash sample, the results agreed with that of atomic adsorption spectroscopy(AAS).     

油井缓蚀剂研究与应用

油井缓蚀剂研究与应用崔忠兴(中原油田设计院,濮阳457001)1.前言中原油田已进入高含水期,油井系统腐蚀严重,直接影响了油田的正常生产l’].为了解决油井系统腐蚀问题,在中科院腐蚀所的专种“基础f,联合开发研制了!MC—SDeZS油井缓蚀剂.该剂以合成炔氧甲基胺和炔氧甲基季法盐衍生物,以这两种衍生物为主体成分复配辅助成分而成的水溶油分散吸附成股型缓蚀剂l’1.通过室内高温高压模拟评价试验.ZI口油井加药试验及测试表明l‘],平?...     

Intraspecific variation and interspecific differences in sex pheromones of sibling species inCtenopseustis obliquana complex

The specific status ofCtenopseustis obliquana pheromone-types I, II, and III has been more fully examined. Females of types I and III produce a mixture of (Z)-8- and (Z)-5-tetradecenyl acetates (Z8-14:Ac, Z5-14: Ac). The previously reported different ratios of these two components in females of the two types (type I=8020, III=9010) have been reinvestigated. The median ratios of each type differed significantly, although there was some overlap in the ranges of these ratios. A field cage trial showed that males of type III are attracted to females of type I, so the observed differences may be ascribed to intraspecific variation. In contrast to females of types I or III, females of type II produce Z5-14Ac but no Z8-14Ac. The electroantennogram (EAG) profile of antennae of type II males shows a maximum response to Z5-14Ac, while the EAG profiles of types I and III show a strong response to Z8-14Ac. In wind tunnel tests using mixtures of these two compounds, type II males prefer blends consisting of all or mostly Z5-14: Ac, while type I males showed a preference to a mix of 70% Z8-14Ac plus 30% Z5-14Ac. We found that type I males are attracted to type I females when offered a choice between type I and type II females in a field cage test and that type II males similarly prefer type II females. Males of types I and II have specialist cells for Z8-14Ac and Z5-14Ac but differ with respect to relative densities of these cells and to further cell types responsive to other alkenyl acetates. Type IIC. obliquana is considered therefore a sibling species of types I and III. In addition, the amount of Z5-14Ac produced by type II females varied geographically. Females from the North Island produced significantly less (median=1.2 ng) Z5-14Ac than females from the South Island (median=2.2 ng). Type II populations in the North Island morphologically resembled sympatric type I, rather than type II from the South Island and are designated as type II (North Island). Type II (North Island) populations have so far been found only at Rukuhia (near Hamilton) and from Kerikeri. In contrast, type II populations are sympatric with type III populations over much of the South Island. In a field cage trial, males of types II and II (North Island) were attracted to females of both II and II (North Island). We tentatively ascribe the differences between type II and type II (North Island) to intraspecific variation.     

Evaluation of oxidative stability of canola oils by headspace analysis

Lipid oxidation is a major factor affecting flavor quality and shelf life of vegetable oils. Oxidative stability is therefore an important criterion by which oils are judged for usefulness in various food applications. In this study a method based on headspace analysis was developed to evaluate relative oxidative stability of canola oils. The method does not require the use of chemicals, involves minimal sample preparation, and can be performed on a relatively small sample size in comparison with traditional wet chemical methods. Canola oils freshly extracted in the laboratory from different seed samples were subjected to accelerated oxidation and analyzed for PV by standard methods and headspace volatiles by solid phase microextraction/GC-MS. Forward stepwise regression analysis of the data revealed a relationship between PV and headspace concentration of the volatile lipid oxidation products hexanal and trans,trans-2,4-heptadienal. The PV calculated using this formula correlated (R ²=0.73) with those measured by conventional methods. Presented in part at the 96th Annual Meeting of the AOCS, 1–4 May 2005, Salt Lake City, UT.     

哈氏合金设备的设计与施工

介绍哈氏合金的类型及耐腐蚀性能,从设计、成型、焊接和机械加工等方 面提出了制造哈氏合金设备的有关注意事项。     

改性丙烯酸-环氧树脂纳米乳液的制备及应用

介绍了水性丙烯酸-环氧树脂纳米乳液的制备及其在油罐防腐工程中的应用。讨论了亲水侧链聚乙二醇相对分子质量大小对涂膜性能的影响以及乳化剂各组分的用量对乳液粒径的影响。     

针状纳米级碳酸钙工业制备新工艺

在复合结晶导向剂存在条件下，在碳化温度30～75℃、氢氧化钙初始质量分数8％～12％的高温高浓的工艺条件下，制备出了直径为20nm、长径比为10～15、粒径分布均匀的针状纳米碳酸钙。同时研究了结晶导向剂加入量、碳化温度、氢氧化钙初始浓度等对针状纳米碳酸钙的粒径和形貌的影响，并进行了工业化试验，取得良好结果。     

饲料级磷酸氢钙标准样品的研制

简述了饲料级磷酸氢钙标准样品的研制过程，并对样品作了稳定性试验，对搅拌设备的搅拌均匀性和物料的均匀性进行了测定，并由国家认可实验室进行了定值数据的监测。通过对比实验证明了国家实验室之间的无差异性。实验数据表明了所测定的饲料级磷酸氢钙产品是稳定和均匀的，同时简要介绍标准样品的研制程序，为开发其他化工行业标准样品奠定了基础。     

氧化还原反应式配平中可能差错的几种情况

本文通过许多实例，指出了氧化还原反应式配平中可能出现的得失电子数不等或电荷数未配平、得失电子关系不对及反应式中酸碱性介质有错误等几种差错，并归纳了在酸碱性水溶液中平衡介质的方法。