有机磷农药——敌敌畏时间分辨化学发光分析的研究

文中根据鲁米诺-H2O2体系中敌敌畏与Co2+化学发光动力学性质的不同,建立了敌敌畏的时间分辨化学发光分析法.该法可对存在于一些金属离子的混合溶液中的敌敌畏进行测定,在最优条件下,混和溶液中的敌敌畏浓度在2×10-8～3×10-6g@mL-1范围内(Co2+浓度小于3.0×10-2μg·mL-1)呈较好的线性关系.     

Generation process of FeS and its inhibition mechanism on iron mineral reduction in selective direct reduction of laterite nickel ore

Numerous studies have demonstrated that Na₂SO₄ can significantly inhibit the reduction of iron oxide in the selective reduction process of laterite nickel ore. FeS generated in the process plays an important role in selective reduction, but the generation process of FeS and its inhibition mechanism on iron reduction are not clear. To figure this out, X-ray diffraction and scanning electron microscopy analyses were conducted to study the roasted ore. The results show that when Na₂SO₄ is added in the roasting, the FeO content in the roasted ore increases accompanied by the emergence of FeS phase. Further analysis indicates that Na₂S formed by the reaction of Na₂SO₄ with CO reacts with SiO₂ at the FeO surface to generate FeS and Na₂Si₂O₅. As a result, a thin film forms on the surface of FeO, hindering the contact between reducing gas and FeO. Therefore, the reduction of iron is depressed, and the FeO content in the roasted ore increases.     

High plastic Zr-Cu-Fe-Al-Nb bulk metallic glasses for biomedical applications

Four Zr-Cu-Fe-Al-based bulk metallic glasses (BMGs) with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr-Cu-Fe-Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson's ratio and low Young's and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316L steel in phosphate buffer solution (PBS, pH 7.4). The combination of the optimized composition with high deformation ability, low Young's modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.     

基于通径系数分析的细菌脱硫实验条件优化

 为探明金属硫化矿细菌脱硫的影响因素与作用机理,采用嗜酸细菌进行柱浸实验。实验方案采用均匀设计法,分析了溶液初始pH 值、布液强度和矿石平均粒径3 个因素对脱硫效果的影响。脱硫实验结果表明,布液强度对矿石脱硫率的影响最大,矿石粒径次之,pH 值最小。对脱硫率进行回归分析,结果表明,布液强度、pH 值与脱硫率为正相关,矿石粒径与脱硫率为负相关,脱硫率预测最大值可达到19.66%。此外,电镜扫描显示,细菌脱硫作用使矿石表面由致密变为疏松,矿石表面的硫含量由43%左右降低至15%左右,表面脱硫率为65%,矿石的可燃性降低。     

退火对Cu46Zr47Al7块体非晶合金的力学性能 与电子功函数的影响

测定了大块非晶合金Cu46Zr47Al7晶化前后的力学性能,使用先进的扫描开尔文探针技术对其表面功函数做了研究.结果表明晶体相的析出使非晶合金的力学性能和功函数都降低.对于退火后的非晶合金,随着退火温度的升高,晶体相与非晶基体之间的界面减少,晶界处的缺陷减少,从而导致电子逃离物体表面需要更多的能量,其功函数不断增大.随着退火温度升高,Cu46Zr47Al7非晶合金的压缩变形和断裂行为表现为从延展性到脆性的变化.     

Ti的变化对Cu-Zr-Ti大块非晶合金热塑性的影响

采用铜模铸造法制备尺寸为2 mm×2 mm×55 mm的Cu60Zr40-xTix(x=9,11)块体非晶合金,利用三点压弯式粘度仪测定了合金在过冷液区附近的粘度,通过计算得到非晶合金的脆性参数m和流变激活能E.通过合金动力学参数比较研究表明,Cu60Zr29Ti11非晶合金相对于Cu60Zr31Ti9非晶合金具有更好的热塑性性能.而少量Ti元素的适量增加使合金内部自由体积大量增加,是提高Cu-Zr-Ti非晶合金热塑性的主要原因.     

填充大孔载体的生物滴滤塔脱除H2S的研究

在生物滴滤塔反应系统中,利用大孔聚氨酯载体固定渗滤液处理厂活性污泥中的自养菌,进行为期1年的脱除H?2S臭气的试验研究。结果表明：污泥经过预曝气、选择驯化、挂膜固定化和直流驯化4个阶段共18 d的培养后,系统成功启动;最佳运行条件pH为2.16,营养液喷淋速率为70 mL/min,空塔停留时间为25 s;当H₂S去除率为100%时,系统所允许的最大污染物容积负荷为114 gH₂S/(m³载体?h),是鲍尔环滴滤系统的5倍。试验还发现：H₂S脱除反应的最终产物以SO₄^2-为主,且SO₄^2-4浓度与pH、氧化还原电位有很好的相关性。     

高效硫化亚铁钝化剂在常减压装置的应用

本文通过对化工生产装置发生硫化亚铁卣燃的危害性,硫化亚铁垢的形成及存在形式进行的探讨,介绍了FZC-1硫化亚铁化学清洗剂的性能特点及在兰州石化常减压装置的应用情况。应用结果表明,FZC-1硫化亚铁化学清洗剂对防止硫化亚铁自燃效果明显．且不会造成环境污染。     

Cu60 Zr29 Ti11大块非晶合金的粘度特征和强液体行为

采用铜模铸造法制备了Cu60 Zr29 Ti11大块非晶合金,用x射线衍射仪（XRD）、三点压弯式粘度仪对该非晶合金的动力学性质进行了研究．测定了大块非晶合金Cu60 Zr29 Ti11在过冷液相区的粘度,得到了它的动力学脆性系数m=30．848,以及流变激活能E=63．437kJ／mol．表明大块非晶合金Cu60 Zr29 Ti11是一种强液体．分析了合金在过冷态的流变激活能变化规律,发现流变激活能的变化并不符合Kivelson的super—Arrhenius公式．     

硫化物夹杂形态对硅锰钢冲击韧性的影响

针对硅锰钢履带板冲击韧性波动范围大、冲击韧性低这一生产中急待解决的问题,主要研究了硫化物夹杂对冲击性能的影响,发现硫化物的形态是影响冲击性能的主要因素。当钢中硫化物形态以球形、多角形的Ⅰ、Ⅲ为主时,钢的冲击性能良好;当钢中硫化物形态长务链形、网状的Ⅱ型析出时,将会对钢的冲击韧性产生不利的影响。硫化物的形态主要受钢中稀土残余含量的影响,当稀土残余含量ｗ（Ｒｅ）〉０．０４％、残余稀土与Ｓ含量的比值ｗ（