镍钴草酸盐共沉淀体系的过饱和态演变规律

对Ni(Ⅱ)-Co(Ⅱ)-C2O4-H2O体系镍、钴溶解度[M]T(M指金属离子)和过饱和度(S)进行了热力学分析,绘制出pH-lg[M]T图和pH-lgS图。结果表明:当2pH3时,镍、钴的溶解度最小;当pH2时,镍、钴的过饱和度均随pH的上升而增大,此后继续提高pH值,其过饱和度基本保持恒定。加料方式也对镍、钴过饱和度和体系平衡pH值影响显著,正加(沉淀剂加入金属剂)过程的过饱和度和pH值均波动较小,反加(金属剂加入沉淀剂)过程则变化很大。共沉淀试验结果进一步证实了热力学分析。pH≈1时,共沉淀粉体呈现2种形貌,粒度分布较广;当pH≥2时,共沉淀粉体粒度均匀,形貌单一。采用正加的加料方式,更有利于得到粒度均匀、形貌单一的镍钴草酸盐共沉淀粉体。     

低温合成NaTaO3纳米微粒

以草酸钠和氢氧化钽为原料,少量水为溶剂,在红外灯下充分研磨烘干后得到前驱体。利用热重分析（TG）技术对前驱体进行分析。将制备的前驱体分别在500℃、600℃、700℃、800℃下焙烧3 h,得到的产物均为单相的NaTaO3粉体。通过X-射线衍射仪（XRD）、扫描电镜（SEM）及FTIR对产物进行表征。在500℃焙烧下得到的NaTaO3粉体,XRD分析计算其晶粒直径为43 nm,通过扫描电镜（SEM）证实其颗粒小于100 nm。在FT-IR谱图中615cm-1处存在Ta-O键的特征吸收峰,经紫外-可见漫反射光谱（UV-Vis）表征、计算得出NaTaO3粉体的能隙为3.96 eV。     

Synthesis and optical properties of nanostructured Ce(OH)4

Nanocrystalline cerium hydroxide (NCs-Ce(OH)4) is a intermediate product of CeO2, synthesized successfully using by a novel and simple wet chemical rout at ambient temperature for the preparation of NCs CeO2 powder and film on mass scale for various purposes. The synthesized NCs-Ce(OH)4 was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), Fourier transform infrared (FTIR), UV-Visible and photoluminescence (PL) spectroscopy. The average crystallite size of NCs-Ce(OH)4 has been estimated by Scherrer equation was to be 3-4 nm. The SEM examinations show that the surface texture was very uniformly agglomerated and homogeneous. Thermal analysis suggests that cerium (IV) ion is in the tetra hydrated form. Absorption and luminescence spectroscopic studies have been examined for future application in the development of optical devices.     

电沉积纳米镍-钻合金在金刚石工具制备中的应用研究

采用纳米镍一钴镀层制备电镀金刚石工具以期提高工具的性能。通过考察脉冲参数、细化添加剂、硫酸钴对镀层显微硬度的影响,得出结论：细化添加剂、硫酸钴都能细化晶粒,两者有竞争关系;改变峰值电流密度和开通时间可以细化晶粒,脉冲周期过短会造成晶粒粗化。镀层中钴的质量分数为9％,表面较光整,平均晶粒尺寸在14nm左右,显微硬度达到609HV。确定了制造金刚石工具最佳的电镀工艺参数,由其制得的工具平均寿命比纳米镍镀层材料工具高16％。     

用氢氧化镁基过氧化物漂白机械浆

加拿大New Brunswick大学制浆和造纸研究与教育中心科技人员的最新研究结果表明，在过氧化物漂白机械浆过程中，以Mg（OH）：代替NaOH，可明显降低废水中COD和阴离子垃圾含量。据文献报道，在云杉热磨机械浆（TMP）过氧化物漂白过程中以Mg（OH）2代替NaOH，浆料白度为68％-70％，槭木化学热磨机械浆（CTMP）过氧化物漂白过程中以Mg（OH）2代替NaOH，浆料白度为80％，而漂白机械浆强度没有降低。试验采用槭木CTMP、槭木PGW（加压磨木浆）和云杉TMP等3种纸浆在不同游离度下经过氧化物漂白，在各种不同漂白条件下。采用Mg（OH）2或NaOH作为碱来源，对漂白浆强度的影响进行了研究。     

Influences of stoichiometric ratio B/A on structures and electrochemical behaviors of Lao.75Mg0.25Ni3.5Mx （M=Ni,Co; x=0-0.6） hydrogen storage alloys

In order to investigate the influences of the stoichiometric ratio ofB/A （A： gross A-site elements, B： gross B-site elements） and the substitution of Co for Ni on the structures and electrochemical performances of the AB3.5-4.1-type electrode alloys, the La-Mg-Ni-Co system La0.75Mg0.25Ni3.5Mx （M=Ni, Co; x= 0, 0.2, 0.4, 0.6） alloys were prepared by induction melting in a helium atmosphere. The structures and electrochemical performances of the alloys were systemically measured. The results show that the structures and electrochemical performances of the alloys are closely relevant to the B/A ratio. All the alloys exhibit a multiphase structure, including two major phases, （La, Mg）2Ni7 and LaNis, and a residual phase LaNi2, and with rising ratio B/A, the （La,Mg）2Ni7 phase decreases and the LaNi5 phase increases significantly. When ratio B/A-3.7, the alloys obtain the maximum discharge capacities. The high rate discharge（HRD） capability of the alloy （M=Ni） monotonously rises with growing B/A ratio, but that of the alloy （M=Co） first mounts up then declines. The cycle stability of the alloy （M-Co） monotonously increases with rising B/A ratio, but it first decreases slightly then increases for the alloy （M=Ni）. The discharge potential of the alloy （M=Ni） declines with increasing B/A ratio （x〉0.2）, but for the alloy （M-Co）, the result is contrary. The substitution of Co for Ni significantly ameliorates the electrochemical performances. For a fixed ratio B/A=3.7, the Co substitution enhances the discharge capacity from 365.7 to 401.8 mA.h/g, the capacity retention ratio （S100） after 100 charging-discharging cycles from 50.32% to 53.26% and the HRD from 88.65% to 90.69%.     

青海夏日哈木镍钴矿区露天采场工程地质条件与岩体质量评价

通过对青海夏日哈木镍钴矿区的现场调查,获得矿区工程地质特征,对调查数据进行分析。根据矿区工程地质调查统计资料、矿岩岩石力学性质试验结果等,采用工程岩体分级标准,对矿区分布的主要岩组进行岩体质量分析评价。将区内岩体工程地质类型划分为4个工程地质岩组,根据岩体基本质量的定性特征和岩体基本质量指标BQ两者相结合确定岩体基本质量级别,为矿区稳定性分析提供了理论依据。     

高活性镍钴铁三元合金电极的制备及析氢性能研究

为进一步提高镍基电极的析氢性能,采用恒电位沉积法,通过改变镀液中各合金的质量浓度比、沉积电位、沉积时间等条件,制备出一种高活性的镍钴铁三元合金电极。通过测定电极在1 mol/L的NaOH溶液中的极化曲线,得到最佳的沉积工艺条件为:36.25 g/L NiSO_4·6H_2O,1.25 g/L NiCl_2·6H_2O,5 g/L CoSO_4·7H_2O,7.5 g/L FeSO_4·7H_2O,10 g/L H_3BO_3,0.5 g/L抗坏血酸,1 g/L十二烷基硫酸钠,pH=4.0,电沉积电位-1.45 V,电沉积时间300 s。阴极极化曲线测试结果表明在5 A/dm^2的条件下,镍钴铁三元合金电极的析氢过电位降低至121 mV,相比于纯镍电极过电位降低近50%,相比于镍钴电极过电位降低近35%。     

高频脉冲电镀镍钴合金耐蚀性的研究

用电化学的方法研究了高频脉冲电镀Ni-Co复合镀层在NaCl溶液中的耐蚀性,结果表明:随着频率的增加,沉积速率提高,沉积层表面更加致密、均匀,在3.5%NaCl溶液中Ni-Co镀层的腐蚀失重明显减小,腐蚀失重速率变慢;高频和直流电铸Ni-Co复合镀层的阳极极化曲线形状相似,随频率增加,自腐蚀电位正移,自腐蚀电流降低.可见,高频率对沉积层的细化有重要影响,并使镀层的耐蚀性提高.