一种2-苯基吡啶铱配合物的合成及结构表征

采用无水无氧真空线技术(Schlenk),以氯桥二聚体(ppy)_2Ir(μ-Cl_2)Ir(ppy)_2为原料,在碱性条件下与配体苯甲酰丙酮反应合成出磷光材料配合物Ir(ppy)_2(bza)。通过调整反应物比例,缩短了反应时间,产率提高至83%。采用元素分析、核磁共振谱(~1H-NMR、~(13)C-NMR)、质谱和红外光谱等表征手段,确定了产物的分子结构。     

侵蚀性阴离子对A3钢腐蚀电化学行为的影响

利用电化学阻抗谱和极化曲线研究了A3钢在不同浓度的Cl^-、SO4^2-、S^2-溶液中的腐蚀行为。结果表明,阴离子Cl^-、SO4^2-、S^2-对A3钢腐蚀速率影响较大。且在相同浓度下腐蚀速率的排序为：S^2-〉Cl^-〉SO4^2-。随着Cl^-、SO4^2-、S^2-浓度的增加,腐蚀电位负移,腐蚀电流逐渐增大,...     

Removal of iron from ilmenite by KOH leaching-oxalate leaching method

Oxalic acid was used for the removal of iron from the intermediates of ilmenite leached by KOH liquor. Various parameters, such as pH, temperature, initial oxalate concentration, and illumination were investigated. Meanwhile, it was found that orthorhombic crystal Ti2O2(OH)2(C2O4)·H2O formed as the leaching proceeded. Scanning electronic microscope (SEM) images implied that the formation of Ti2O2(OH)2(C2O4)·H2O with good crystallinity proceeded through three stages. Calcining Ti2O2(OH)2(C2O4)·H2O, anatase (350°C) or rutile (550°C) type TiO2 was obtained, respectively. Element analysis found that the calcined product contained 94.9% TiO2 and 2.5% iron oxide, but only about 1600 ppm dissolvable iron oxide was left, which indicates that oxalic acid was comparatively effective on iron oxide removal from the intermediates. Finally, an improved route was proposed for the upgrading of ilmenite into rutile.     

铈盐和镧盐对铝合金阳极氧化膜性能的影响

通过对铝合金在含有稀土盐的硫酸电解液中进行阳极氧化所得到氧化膜性能的研究，发现加入硫酸铈比无稀土盐其厚度、硬度及耐蚀性均好，最佳含量为0．5g／L；硫酸铈和硫酸镧复合稀土盐比单一硫酸铈稀土盐好。     

Effects of electrolyte components on properties of Al alloy anode

The effects of Na2SnO3, In(OH)3 and Na2SnO3+In(OH)3 on the properties of Al alloy anode were studied in alkaline medium at 25 ℃. The self-corrosion rate of Al alloy anode was studied by method of H2 immersed in aqueous medium, and the electrochemical properties of Al alloy anode were tested via galvanostatic discharge and dynamic potential methods. The results show that the self-corrosion rate of Al alloy anode in 4 mol/L NaOH+3 mol/L NaAlO2 medium can be minimized by adding Na2SnO3, In(OH)3 and Na2SnO3+ In(OH)3. Na2SnO3, In(OH)3 and Na2SnO3+In(OH)3 make Al anodic potential shift positively in galvanostatic discharging. The most effective additive of Al alloy anode in 4 mol/L NaOH+3 mol/L NaAlO2 medium is 0.075 mol/L Na2SnO3+0.005 mol/L In(OH)3, integrating self-corrosion rate and electrochemical properties.     

Synthesis of barium mercaptides and application of antimony/barium mercaptides

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｎｔｉｍｏｎｙｍｅｒｃａｐｔｉｄｅｓ[1～ 4 ] ｕｓｅｄａｓｈｅａｔｓｔａｂｉｌｉｚ ｅｒｉｓａｔｔｒａｃｔｉｖｅｎｏｔｏｎｌｙｆｏｒｉｔｓｒｅｌａｔｉｖｅｌｙｌｏｗｃｏｓｔ ,ｂｕｔａｌｓｏｆｏｒｉｔｓｓｉｍｉｌａｒｓｔａｂｉｌｉｚｉｎｇｅｆｆｅｃｔｃｏｍｐａｒｅｄｗｉｔｈｔｈａｔｏｆｔｈｅｍｏｓｔｅｘｃｅｌｌｅｎｔｏｎｅ ｏｒｇａｎｏｔｉｎ .Ｂｙｍａｋｉｎｇｆｕｌｌｕｓｅｏｆｔｈｅｐｌｅｎｔｉｆｕｌａｎｔｉｍｏｎｙｒｅｓｏｕｒｃｅ ,ｄｅｖｅｌｏｐｉｎｇａｎｔｉｍｏｎｙｍ…     

ZrVxFe（2-x）合金的制备及其显微组织

利用非自耗真空电弧熔炼技术,制得了Zr系吸氢合金ZrVxFe(2-x)合金,其中x=0.2、0.3、0.4、0.5。采用SEM、EDS并结合XRD分析了合金的显微组织。结果表明,合金主要由ZrFe2(V)和ZrV2(Fe)两相组成,在熔炼过程中,Zr首先析出,随后ZrFe2(V)和ZrV2(Fe)开始形核并析出;随着合金成分中V含量的增加,ZrFe2(V)相的含量减少,ZrV2(Fe)相的含量增加。     

Effect of the partial substitution of Mg by Al on the crystal structure and hydrogenation behavior of La2Mg17

The effect of the partial substitution of Mg by A1 on the crystal structure of La2Mg17 has been investigated. It was found that the LaEMgl7 phase disappears after the partial substitution of Mg by Al. The LaE（Mgo.gAl0.1）17 alloy contains La（Mg,AI）12 and La（Mg,Al）2. Further increasing the Al content, the La2（Mg0.8Al0.2）17 alloy consists of La（Mg,Al）12, La（Mg,Al）2, and Mg. The La（Mg0.93Al0.07）12 phase in the La2（Mg0.9Al0.1）17 alloy crystallizes with the ThMn12-type structure in space group 14/mmm （No. 139）. The lattice parameters were determined to be a = 1.03246（7） nm and c = 0.59410（6） nm. In the ThMn12-type structure, AI atoms occupy 8f site but the A1 content is limited. Moreover, the hydrogenation character- istics have also been compared. La2Mgl7 decomposes into LaH3 and MgH2 under hydrogen, but the La（Mgo.93Alo.o7）12 phase can be hydrogenated into LaH3, MgH2, and La3Al11 at 473 K.     

ZrO2(n)、SiC(W)的分散及与MoSi2基质的均匀混合工艺研究

通过沉降实验并借助SEM观察探讨了不同分散剂、不同分散介质对纳米ZrO2颗粒分散效果的影响。介绍了SiC晶须分散工艺,探讨了多相悬浮液混合法制备ZrO2(n)／MoSi2复合粉体及SiC(w)／ZrO2(n)／MoSi2复合粉体的均匀混合工艺。结果表明：以PEG为分散剂、水为分散介质可以有效地分散纳米ZrO2并能与基体MoSi2粉末均匀混合;通过调节乙醇悬浮液的pH值,可将SiC晶须均匀分散在ZrO2(n)／MoSi2复合粉体中,获得分布均匀的SiC(w)／ZrO2(n)／MoSi2复合粉。     

Reaction mechanism of hydriding combustion synthesis of Mg2NiH4

A previous study suggested that the process of combustion synthesis of Mg₂NiH₄ from the compact of magnesium and nickel mixture in pressurized hydrogen cannot be expressed by a single reaction formula such as 2Mg+Ni+2H₂=Mg₂NiH₄. In this paper, our attention is addressed to studying the reaction mechanism during the process of hydriding combustion synthesis of Mg₂NiH₄ by means of a differential scanning calorimeter (DSC) and an X-ray diffractometer (XRD). The results show that this process is consisted of seven distinguished reactions: (1) Mg+H₂→MgH₂; (2) MgH₂→Mg+H₂; (3) 2Mg+Ni→Mg₂Ni; (4) 2Mg+Ni→Mg₂Ni (L); (5) Mg₂Ni+0.15H₂→Mg₂NiH_0.3; (6) Mg₂Ni+2H₂→Mg₂NiH₄ (HT); and (7) Mg₂NiH₄ (HT)→Mg₂NiH₄ (LT).     

Partial phase diagram of Au-Ag-Dy ternary system

On the basis of Au-Ag, Au-Dy and Ag-Dy binary phase diagrams, the 700 ℃ isothermal section of Au-Ag-Dy ternary system（Dye≤35 %, mole fraction） was established by X-ray diffraction analysis, differential thermal analysis and optical microscopy. It is found that there is a long single-phase region, Au（Ag） or Ag（Au）, along the Au-Ag binary isomorphous system on the gold-silver-rich side of the 700 ℃ isothermal section and between the binary compound Au2Dy and Ag2 Dy there is the all proportional solid solution, （Au2 Dy） or （Ag2 Dy）. It is confirmed that the partial 700 ℃ isothermal section consists of six single-phase regions： solid solution Au（Ag） or Ag （Au）, （Au2 Dy） or （Ag2 Dy）, Au6 Dy, Au51 Dy14, Au3 Dy and Ag51 Dy14 ; nine binary-phase regions; （Au2 Dy） ＋ Au （Ag）, Au6Dy＋ Au（Ag）, Au（Ag） ＋Ag51 Dy14 , Ag51 Dy14 ＋ （Au2Dy）, Au3Dy＋（Au2Dy）, Au3Dy＋ Au51 Dy14, Au51 Dy14＋Au6Dy, Au51 Dy14＋Au（Ag） and Au（Ag） ＋Au3Dy; four ternary regions： Ag51 Dy14＋ （Au2Dy）＋ Au （Ag）, （Au2 Dy） ＋ Au（Ag） ＋ Au3 Dy, Au（Ag） ＋ Au3 Dy＋ Au51 Dy14 and Au51 Dy14＋ Au （Ag）＋ Au6 Dy. No new ternary compound is formed in the gold-silver-rich field（Dy≤35 %） of the Au-Ag-Dy ternary system.     

TiO2的制备及表面修饰工艺对其光电化学阴极保护性能的影响

采用连续离子层吸附反应法在TiO2表面沉积Co(OH)2,并将Co(OH)2热处理转化为CoOx的表面修饰方法制备高性能Co(OH)2/CoOx协同修饰TiO2纳米管光阳极材料。通过探讨Co(OH)2修饰次数、热处理温度以及保温时间,确定光阳极最佳性能的制备工艺条件,从光催化原理出发,阐明Co(OH)2/CoOx修饰提高光电性能机理。     

添加Li2O对陶瓷CBN砂轮结合剂性能的影响研究

本文主要研究了添加Li2O对Na2O-B2O3-Al2O3-SiO2陶瓷结合剂性能的影响.实验结果表明:随着Li2O添加量的增加,结合剂的耐火度显著降低;在0～6wt% Li2O添加量范围内,结合剂的耐火度下降较快,之后耐火度变化趋于平缓.随着Li2O添加量的增加,结合剂的高温流动性增大.随着温度升高,相同组成结合剂的流动性明显增大.当添加6% Li2O时,磨具试样的抗弯强度出现一个最大值.当Li2O添加量低于6wt%时,随着Li2O含量增大,结合剂玻化程度逐渐改善,结合剂与磨粒结合紧密,磨具试样的强度增大;Li2O含量高于6wt%时,会因结合剂本身结构的变化和磨具显微结构的变坏,使磨具强度降低.磨具显微结构与磨具强度变化有着一致的对应关系.     

玻璃组分与Cu—Ni熔体过冷稳定性

在高真空下,研究了５０ ％ （７９ ％ Ｓｉ Ｏ２ ＋ １２ ．５ ％ Ｂ２ Ｏ３ ＋ ２ ．２ ％ Ａｌ２ Ｏ３ ＋ ０ ．６ ％ Ｃａ Ｏ ＋ ５ ．７ ％ Ｎａ２ Ｏ） （ 简写为 Ｎａ Ｃａ Ａｌ Ｂ Ｓｉ） ＋ ５０ ％ （ Ｎａ２ Ｂ７ Ｏ４） 对 Ｃｕ５０ Ｎｉ５０ 和 Ｃｕ７０ Ｎｉ３０ 合金熔体循环过热过程中过冷度稳定性的影响。结果表明,５０ ％（ Ｎａ Ｃａ Ａｌ Ｂ Ｓｉ） ＋ ５０ ％ （ Ｎａ２ Ｂ７ Ｏ４） 玻璃对合金熔体的净化过程为物理—化学复合净化, 且在（ Ｎａ Ｃａ Ａｌ Ｂ Ｓｉ） 净化剂中加入（ Ｎａ２ Ｂ７ Ｏ４） 玻璃形成的净化剂粘度适中,因此合金熔体在２ ～５ 次循环过热过程中可以获得稳定深过冷。     

合金化对MoSi_2室温韧性的影响

配制和电弧熔炼了MoSi2、(Mo,2at%Nb)Si2、(Mo,6at%Nb)Si2、Mo(Si,2at%Al)2、Mo(Si,4at%Al)2和(Mo,2at%Cr)Si2六种合金,用XRD、SEM-EDS、EPMA、维氏硬度计及压痕法研究了Nb、Al、Cr合金化对MoSi2组织结构、室温硬度及断裂韧性的影响.结果表明,2at%Al、4at%Al和2at%Cr三种合金均得到了单一四方C11b相;6at%Nb合金因Nb含量高,导致部分四方C11b相转变为六方C40相,合金出现灰色C11b基体相与亮白色层片状C40第二相双相组织,部分C40相中存在几乎平行排列的宽度贯穿裂纹.Nb、Al、Cr合金化都降低了MoSi2的维氏硬度,提高断裂韧性,其中2at%Nb、4at%Al合金的断裂韧性最高,达到了5.90 MPa·m1/2,提高了69%.     

Determination of Isothermal Section of Fe-Ni-Zr Ternary System at 1198K

The isothermal section of Fe-Ni-Zr ternary system at 1198K was experimentally determined using diffusion triple technique together with scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The results indicate that there are seven binary intermetallic phases, Fe2Zr, FeZr2, NiZr2, NiZr, Ni10Zr7, Ni7Zr2, and Ni5Zr, found in the ternary system, the binary compounds NiZr2 and FeZr2 show a homogeneity range and form a continuous solid solution, namely (Fe, Ni)Zr2. Five three-phase sections, γ(Fe,Ni) Ni7Zr2 Ni5Zr, γ(Fe,Ni) Ni7Zr2 Ni10Zr7, γ(Fe,Ni) Fe2Zr Ni10Zr7, (Fe,Ni)Zr2 Fe2Zr Ni10Zr7, and (Fe,Ni)Zr2 NiZr Ni10Zr7, exist in the isothermal section. No ternary compound is observed.     

Effect of K_2TiO(C_2O_4)_2 Addition in Electrolyte on the Microstructure and Tribological Behavior of Micro-Arc Oxidation Coatings on Aluminum Alloy

Micro-arc oxidation(MAO)coatings with different concentrations of K_2TiO(C_2O_4)_2 in the sodium silicate base electrolyte were prepared on 6061 aluminum alloy with the aim of promoting a better understanding of the formation mechanisms and tribological behaviors of the coatings.Scanning electron microscopy(SEM)assisted with energy-dispersive X-ray spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS)and friction test were employed to characterize the MAO processes and microstructure of the resultant coatings.Results showed that the composition and microstructure of the coatings were significantly affected by the addition of K_2TiO(C_2O_4)_2.A sealing microstructure of MAO coating was obtained with the addition of K_2TiO(C_2O_4)_2.Ti element from K_2TiO(C_2O_4)_2 was only absorbed into the defects of micropores under surface energy in the early stage,while in the later stage,Ti element was predominant in the micropores and distributed on the coatings under plasma discharge to form TiO_2.It was demonstrated that Ti and Si elements from the electrolyte could interact with each other during the MAO process and the interaction mechanism was systematically analyzed.Wear resistance of the MAO coatings with K_2TiO(C_2O_4)_2 addition was significantly improved compared with that of the MAO coatings without K_2TiO(C_2O_4)_2 addition.     

Corrosion resistance of nanostructured magnesium hydroxide coating on magnesium alloy AZ31: influence of EDTA

A hexagonal nanosheet Mg(OH)_2 coating was prepared through a one-step hydrothermal method using LiOH solution as mineralizer and then modified by ethylenediaminetetraacetic acid(EDTA) to minimize the rapid corrosion of AZ31 Mg alloy.The performance of the coating was evaluated using electrochemical technique,hydrogen evolution measurements, nanoscratch test,Fourier-transform infrared spectroscopy(FTIR), X-ray diffraction(XRD) patterns and field-emission scanning electron microscopy(FESEM).The results suggested that the corrosion rate of bare AZ31 Mg alloys was significantly reduced by one and two orders of magnitude through the protection from Mg(OH)_2 coating and modification with EDTA(i.e., EDTA-Mg(OH)_2 coating), respectively.FESEM micrographs indicated that the modification in EDTA elicits to the formation of an EDTA-Mg(OH)_2 composite with a thickness as twice as that of as-prepared Mg(OH)_2 coating.Nanoscratch tests revealed strong adhesion between the composite or Mg(OH)_2 coating and the substrate.The study of formation and corrosion mechanisms of the coatings manifested that Mg(OH)_2 was first formed near the intermetallic compound AlMn particles and gradually covered the entire surface, wherein the AlMn particles played an important role in the coating growth process.And it also proved that EDTA accelerated the formation of Mg(OH)_2.     

Identification of Complex Ions of Nb(V)in FLINAK-O~(2-)System by Infrared Spectra

The FT-IR spectra for K_2NbF_7-FLINAK-O~(2-) solution were measured and compared with the spectraof crystalline K_2NbF_7 and K_2NbOF_6.The results show that the niobium fluoro-complex and/oroxyfluoro-complex ions are presented in these solutions.NbF_7~(2-) complex ion is the predominant species inNb(V)-FLINAK solution(not considering oxide impurity).The influence of O~(2-) on the oxyfluoro-complexions shows that NbOF_6~(3-) as a stable monooxyfluoro-complex anion presented in FLINAK-O~(2-) systemsand the number of NbOF_6~(3-) species are increased with increasing of O~(2-) when molar ratio of O~(2-)/Nb(V)is less than 1.     

Decomposition of supersaturated sodium aluminate solution

1　INTRODUCTIONThecrystallizationofgibbsite(Al(OH) 3)fromsu persaturatedsodiumaluminatesolutionisanimportantpartofcommercialalumina production .However ,longperiodandlargeburdenoftheprocessmakeitbecomebottleneckofalumina production .Thede compositionofsupersaturatedsodiumaluminatesolu tionintogibbsite ,whichinvolvesinthetransforma tionoftetrahydroxy ,Al(Ⅲ ) containingspeciesinso lutionintooctahedralcoordinateAl(OH) 3inthepres enceofNa+andOH- ions ,areasyetunknown .Specially ,intensi…