An investigation of some Schiff bases as corrosion inhibitors for austenitic chromium–nickel steel in H2SO4

The corrosion inhibition of austenitic chromium–nickel steel by two Schiff bases, N-(1-toluidine)salicylaldimine and N-(2-hydroxyphenyl)salicylaldimine, was investigated in sulphuric acid medium. The effect of concentration and temperature on inhibition properties was determined. It was found that when the concentrations of inhibitor were increased the inhibition efficiencies () and surface coverage () increased. Some thermodynamic parameters such as free energy of adsorption, G _ads, and enthalpy, H, were determined for the Schiff bases. Experimental results agree with the Temkin isotherm for N-(1-toluidine)salicylaldimine, but the Langmuir isotherm is more appropriate for N-(2-hydroxyphenyl)salicylaldimine.     

多酚氧化酶催化单宁的氧化聚合反应研究

研究了多酚氧化酶催化单宁的氧化聚合反应情况 ,探索了反应条件及 7种化合物对酶活性的抑制效果 ,对产物进行了红外光谱和紫外光谱测试 ,相对粘度法测定了产物的分子量。结果表明 ,反应的最佳条件是pH为 5 .2 9,温度为 3 0℃ ,在所用抑制剂中 ,硫酸铜的抑制作用最强 ,与单宁酸的IR图相比 ,产物的 -OH吸收带变窄 ,在 12 60cm-1处吸收峰增强 ,而紫外吸收无变化。产物平均分子量为 3 5 41,说明多酚氧化酶能催化单宁的氧化聚合     

Silphinene Sesquiterpenes as Model Insect Antifeedants

Silphinene sesquiterpenes are established chrysomelid antifeedants. In this work, nine silphinene analogs, 11-acetoxy-5-angeloyloxysilphinen-3-one (1), 11-acetoxy-5-tigloyloxysilphinen-3-one (2), 11-acetoxy-5-iso- butyryloxysilphinen-3-one (3), 11-hydroxy-5-angeloyloxysilphinen-3-one (4), 11,5-dihydroxysilphinen-3-one (5), 11,5-diacetoxysilphinen-3-one (6), 5,11-diisobutyryloxysilphinen-3-one (7), silphinen-3,5,11-trione (8), and O-methyl-5-epicantabrenolic acid methyl ester (10), and a presilphiperfolane sesquiterpene (9) were tested against several divergent insect species, including the lepidopteran Spodoptera littoralis, the chrysomelid Leptinotarsa decemlineata, and five aphid species, and their antifeedant effects were compared with those of picrotoxinin, a GABA-antagonist, and thymol, an allosteric modulator for insect GABA receptors. All insects tested responded to at least one silphinene analog and/or GABA antagonist. Compound 3 and thymol were effective antifeedants against all species tested except S. littoralis, with varying potencies according to their feeding ecologies. The toxicity of these compounds was species-dependent and did not correlate with their antifeedant effect.     

聚天冬氨酸与含磷阻垢剂复配产品的阻垢性能

聚天冬氨酸作为阻垢剂具有可完全生物降解的优越特性，但聚天冬氨酸本身的阻垢效果无法达到市售阻垢剂的水平。研究了聚天冬氨酸与市售的含磷阻垢剂复配产品的阻垢性能。结果表明，在相同阻垢剂用量的条件下，用质量分数为50％的聚天冬氨酸与50％的HEDP或ATMP，PBTCA复配产品的阻碳酸钙垢性能分别与100％的HEDP或ATMP，PBTCA的性能一致，说明用聚天冬氨酸可以取代这些含磷阻垢剂的50％。     

增塑聚丙烯结晶行为和力学性能的研究

以液体石蜡（LP）为增塑剂，采用双螺杆挤出机对无规共聚聚丙烯（PP）进行了增塑，研究了LP用量对PP力学性能和结晶性能的影响。研究结果表明：PP经过增塑后，冲击强度可提高150％，拉伸强度提高80％，断裂伸长率提高110％；增塑PP的结晶度和热变形温度也有所提高。     

硅整流元件纯水冷却系统换热设备的化学清洗

介绍了硅整流元件的纯水冷却系统换热设备化学清洗中药剂的评定筛选原则。质量标准，清洗工艺等。并对其清洗效果加以评定。     

石蜡的国内外市场

石蜡在国际市场上相对稳定，预计２０００年的需求量为３５０万ｔ，价格仍将维持在目前的水平。１９９５年我国石蜡的产量为８４．５万ｔ，预计２０００年国内需求量约６０万ｔ，出口量将达５０万ｔ     

新型高效水处理剂的研制

本文简单介绍了2－丙烯酰胺－2－甲基丙磺酸（AMPS）的性能及应用，工业循环冷动水处理中阻垢剂的发展历史与最新进展。并首次以马来酸酐（MA）、AMPS、NaH2PO2为单体，水为溶剂、过硫酸氨为引发剂合成低磷含量的膦羧酸共调聚物，探讨了单体配比为n(MA):n(AMPS)=2:1,m(NaH2PO2):m(MA AMPS)=10:100时反应温度，反应时间对合成产品的影响。     

石蜡沉积对储层渗透率的影响研究

油气开采过程中的蜡质、沥青质等有机固相沉积。严重影响着油田的正常生产。固相沉积物不仅堵塞油井、输油管线,而且也给油藏多孔介质造成一系列的伤害。如堵塞油藏孔隙、降低孔隙度和渗透率,改变油藏岩石的润湿性,从而影响原油采收率的提高。本文采用热力学理论建立了液固两相相平衡方程,模拟计算石蜡沉积量对储层孔隙度和渗透率影响,进而求出对油井产能的影响。     

绿色金属缓蚀剂及其应用

金属缓蚀剂是工业领域内应用非常广泛的助剂，也是金属腐蚀防护的重要方法之一。本文介绍了几种常用的绿色金属缓蚀剂及其缓蚀机理，并对环保型金属缓蚀剂的发展进行了展望。