Structural dependences of the <Emphasis Type="Italic">η</Emphasis><Superscript>6</Superscript> complexes of 3-amino-9-ethylcarbazole with chromium tricarbonyl fragment on third-order optical nonlinearities

Degenerate four-wave mixing measurements, using the 35 ps pulses at 532 nm, have been employed to investigate the third-order nonlinear optical parameters of two chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring （1） or the unsubstituted ring （2） and their precursor 3-amino-9-ethylcarbazole （AECz）. The second-order hyperpolarizability y of the compounds 1 and 2 were found to be 42.9×10^-31 and 35.9×10^-31 esu, respectively, approximately one order of magnitude greater than AECz. The relation between the molecular structure and second-order hyperpolarizability of the compounds I and 2 was explored in detail based on the three-level model and the density functional theory （DFT） calculation. The theoretical results indicate that the spatial distribution of electron density has the profound role in the third-order nonlinear optical properties.     

聚乙二醇—硫酸铵双水相萃取分离测定铬(Ⅵ)的研究

利用聚乙二醇-硫酸铵双水相体系,研究二苯偕肼-铬(Ⅵ)配合物的显色和萃取分离条件,建立了萃取、分离、测定于一身的非有机溶剂(水相)萃取光度法,并用于钢中微量铬的测定.实验表明,在0.18-0.35 mol/L的硫酸溶液中,在硫酸铵存在下,Cr(Ⅵ)与二苯偕肼的配合物可被聚乙二醇(PEG)相萃取,且最大吸收峰为550 nm,表观摩尔吸光系数ε550=3.0×104L.mol-1.cm-1铬(Ⅵ)浓度在0~55μg/25 ml范围内符合比耳定律.此法用于测定钢中铬,操作简便,安全无毒,分析速度快,是一种集萃取分离与测定为一体的测定结果准确的测铬新方法.     

煤对含铬废水的净化

用煤对含铬废水进行了净化,得到了最佳的固液化,酸度等吸附条件,考察了温度对净化的影响,在水溶液中,煤对Ｃｒ（Ⅵ）的吸附主要为物理过程,并遵从Ｆｅｕｎｄｌｉｃｈ经验公式;吸附量与时间的定量关系为：ｍ＝３．７０ｔ（１＋２．０６ｔ）＾－１。     

An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr<Superscript>3+</Superscript> removal capacity

A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investigations were carried out regarding the capacity of zeolite 4A to remove Cr(Ⅲ) from aqueous solutions with relatively low initial concentrations of Cr(Ⅲ) (5–100 mg·L-1). It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environmental pollution caused by the dumping of bauxite tailings. The Cr(Ⅲ) removal capacity highly depends on the initial pH value and concentration of Cr(Ⅲ) in the solution. The maximum removal capacity of Cr(Ⅲ) was evaluated to be 85.1 mg·g-1 for zeolite 4A, measured at an initial pH value of 4 and an initial Cr(Ⅲ) concentration of 5 mg·L-1. This approach enables a higher removal capacity at lower concentrations of Cr(Ⅲ), which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr(Ⅲ) by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr(Ⅲ).     

FeO影响CaO-SiO_2-MgO-Al_2O_3-Cr_2O_3体系中含铬尖晶石晶体析出的热力学分析

不锈钢渣中的铬以尖晶石矿物相状态赋存时不易溶出,有利于钢渣的资源化利用。本文基于熔体非平衡凝固理论,采用热力学数据库FactSage 7.0研究了FeO添加量对CaO-SiO_2-MgO-Al_2O_3-Cr_2O_3不锈钢渣体系中尖晶石晶体析出温度、析出量、化学组成及铬元素赋存状态的影响规律。模拟计算结果表明,尖晶石晶体为高温析出相,主要由MgCr_2O_4和FeCr_2O_4组成;随着FeO添加量不断增多,尖晶石晶体的析出温度逐渐降低,其最终析出量逐渐增加,析出物中FeCr_2O_4所占比例增加而MgCr_2O_4相对减少;铬元素的赋存状态未受FeO添加量变化影响,仍以尖晶石固溶体形式存在。     

用综合加权评分法优化高铬型钒钛矿电热熔分工艺

以气基竖炉还原得到的金属化率为95%的高铬型钒钛磁铁矿球团为原料,在高频感应炉内进行电热熔分深度还原.设计了三因素三水平正交试验,重点考察熔分温度、熔分时间及二元碱度对熔分效果的影响,并运用综合加权评分法对试验结果进行分析,发现熔分后可获得含钒、铬铁块和高钛渣.适宜的高铬型钒钛磁铁矿电热熔分参数为:二元碱度1.1,熔分温度1 650℃,熔分时间45 min.对熔分综合指标影响大小依次为二元碱度熔分温度熔分时间.另外,分析二元碱度对熔分效果的影响规律及作用机理可知,随碱度增大,铁、钒、铬及钛的收得率呈先上升后下降的趋势,在二元碱度为1.1时,高铬型钒钛矿熔分效果最好.     

羊毛染色新型Cr（Ⅲ）媒染剂的开发与性能研究

在原有Cr(Ⅲ）媒染剂的基础上,开发了性能更优,价格低廉的新型媒染剂CTA-Cr,讨论了媒染剂合成中的性质变化,分析了影响媒染的因素,通过对比证实了Cr(Ⅲ）媒染剂的“携铬”作用,确定了最佳染色工艺,结果证明CTA-Cr媒染样品泛色正常,牢度优良,残浴不含六价铬。     

电镀废铬液回收利用技术的研究

应用化学处理技术将电镀废铬槽液经过絮凝、沉淀、分离等过程,提纯为高纯度的Cr(Ⅳ）液,复配为高浓度的鞣革铬液,并应用于鞣革。结果表明,应用化学处理技术可将电镀废铬液回收为铬鞣剂,用于鞣革,各项技术指导已达到与国内标准铬粉的同等水平,实现了电镀污水零排放。     

Intergranular corrosion behavior of high nitrogen austenitic stainless steel

The intergranular corrosion (IGC) behavior of high nitrogen austenitic stainless steel (HNSS) sensitization treated at 650-950℃ was investigated by the double loop electrochemical potentiodynamic reactivation (DL-EPR) method. The effects of the electrolytes, scan rate, sensitizing temperature on the susceptibility to IGC of HNSS were examined. The results show that the addi-tion of NaCl is an effective way to improve the formation of the cracking of a passive film in chromium-depleted zones during the reactivation scan. Decreasing the scan rate exhibits an obvious effect on the breakdown of the passive film. A solution with 2 mol/L H₂SO₄+1 mol/L NaCl+0.01 mol/L KSCN is suitable to check the susceptibility to IGC of HNSS at a sensitizing temperature of 650-950℃ at a suitable scan rate of 1.667 mV/s. Chromium depletion of HNSS is attributed to the precipitation of Cr₂N which results in the susceptibility to IGC. The synergistic effect of Mo and N is suggested to play an important role in stabilizing the passive film to prevent the attack of IGC.     

不锈钢中磷和铬的联合测定

提出一种快速分析不锈钢中磷和铬的联合测定的方法,针对不锈钢中高铬含量的情况,采用王水和高氯酸溶解后,准确控制发烟时间可使磷和铬全部氧化完全.试样溶解后磷的测定采用酸性介质中用抗坏血酸为还原剂的铋磷钼蓝光度法,在波长660 nm处测定其吸光度,铬的测定采用高氯酸氧化亚铁容量法,实现了磷和铬的联合测定.通过研究与应用认为,此法对磷含量在0.005%～0.050%之间,铬含量在10%～35%的之间合金钢、不锈钢皆适用,试验结果满意.