Electrochemical and spectroscopic study of interfacial interactions between chalcopyrite and typical flotation process reagents

Comparative voltammetry and differential double-layer capacitance studies were performed to evaluate interfacial interactions between chalcopyrite (CuFeS₂) and n-isopropyl xanthate (X) in the presence of ammonium bisulfite/39wt% SO₂ and caustic starch at different pH values. Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, contact angle measurements, and microflotation tests were used to establish the type and extent of xanthate adsorption as well as the species involved under different mineral surface conditions in this study. The results demonstrate that the species that favor a greater hydrophobicity of chalcopyrite are primarily CuX and S0, whereas oxides and hydroxides of Cu and Fe as well as an excess of starch decrease the hydrophobicity. A conditioning of the mineral surface with ammonium bisulfite/39wt% SO₂ at pH 6 promotes the activation of surface and enhances the xanthate adsorption. However, this effect is diminished at pH ≥ 8, when an excess of starch is added during the preconditioning step.     

界面裂纹的Cell-Based光滑有限元法研究

为提高求解含界面裂纹结构断裂参数的精度,基于界面断裂力学和Cell-Based光滑有限元法,提出了求解双材料界面裂纹断裂参数的Cell-Based光滑有限元法,给出了求解应力强度因子的光滑子域交互积分法,对含中心界面裂纹双材料无限板进行了模拟,并与FEM计算结果和解析解进行了对比,讨论了光滑子元数和单元个数与正则应力强度因子的关系及其收敛性.数值算例结果表明该方法具有很好的收敛性和精度,可为研究人员和工程师设计制造多层材料提供必要参考.     

Conductive and corrosion behaviors of silver-doped carbon-coated stainless steel as PEMFC bipolar plates

Ni–Cr enrichment on stainless steel SS316L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was deposited in situ to prepare a thin continuous Ag-doped carbon film on a porous carbon-coated SS316L substrate. The corrosion resistance of this film in 0.5 mol·L-1 H₂SO₄ solution containing 5 ppm F- at 80℃ was investigated using polarization tests. The results showed that the surface treatment of the SS316L strongly affected the adhesion of the carbon coating to the stainless steel. Compared to the bare SS316L, the Ag-doped carbon-coated SS316L bipolar plate was remarkably more stable in both the anode and cathode environments of proton exchange membrane fuel cell (PEMFC) and the interface contact resistance between the specimen and Toray 060 carbon paper was reduced from 333.0 mΩ·cm2 to 21.6 mΩ·cm2 at a compaction pressure of 1.2 MPa.     

考虑燃烧过程的航天器用液体火箭发动机动态特性分析

研究了考虑惯性等因素的集液腔充填过程以及考虑喷雾燃烧的发动机动态特性数学模型的建立,结合发动机的喷雾燃烧过程以及燃烧室的集中参数模型,分析了航天器用双组元(一甲基肼/四氧化二氮)液体火箭发动机推力室的脉冲工作特性、启动特性以及关机特性。     

血影膜与荧光探针ANS间的能量转移

血影膜与荧光探针ANS间存在非辐射共振能量转移。能量转移效率随ANS浓度的增大而增加。甲胺磷对血影膜的荧光有强烈的猝灭作用。     

一种优良的泡沫排水剂—CZP

CZP是以农副产品为原料制取的一种气井用发泡剂。本文通过对CZP性能的室内评价和现场试验说明,在气井条件下,CZP的起泡力高,泡沫稳定性好、携液量大,适应性强,可用于凝析油含量达70-80%的油气同产的气水井和300m以上的含硫气井的排液,也可用于一般气井中,是一种综合性能优良的气井用发泡剂。     

除泥旋流器试验分析

油井产液除砂用旋流器与钻井液处理用旋流器,在工作条件和使用要求上都存在很大差异。根据这些差异,通过室内模型旋流器试脸,讨论了影响油井产液除砂旋流器分离效果的主要因素,指出了其主要设计、使用特点。     

球孢白僵菌产几丁质酶液态发酵研究

对球孢白僵菌Bb174产几丁质酶的液态发酵条件进行了试验研究。选择麸皮和蚕蛹粉作为培养基的基本成分。以不同比例的麸皮和蚕蛹粉进行试验,结果显示:麸皮和蚕蛹粉分别为5％,培养温度28℃,接种量10％,装液量10mL,起始pH6.0,添加0.3％NaNO_3对产儿丁质酶有利,最高酶活力为4664U/mL。     

高效液相色谱测定鸟氨酸脱羧酶活性方法的改进

对柴彪新等报道的高效液相色谱测定鸟氨酸脱羧酶(ODC)活性的方法作了改进.结果表明,改进后的方法更灵敏,更简便,线性范围明显扩大,相关系数为0.9998,显著高于柴彪新等报道的0.9939.同时,新方法还可使苯甲酸和苯甲酰氯降到很低.     

热致性液晶聚合物对PET冷结晶行为的影响

用ＤＳＣ法研究了两种不同结构热致性液晶共聚酯（ＰＥＴ／６０ＰＨＢ和ＨＴＨ６）分别对ＰＥＴ冷结晶行为的影响．结果表明,随共混体系中ＨＴＨ６含量的增加,ＰＥＴ冷结晶温度逐渐下降,而共混体系中ＰＥＴ／６０ＰＨＢ的加入使ＰＥＴ冷结晶温度突然下降,而后基本不再随ＰＥＴ／６０ＰＨＢ含量的增加而变化．对此两种不同结构的热致性液晶聚合物对ＰＥＴ冷结晶行为的不同影响提出了解释