Properties of non-aqueous solutions of Zn(CF3SO3)2

Elemental analysis of the crystals produced in the solutions prepared by dissolving a considerable amount of Zn(CF₃SO₃)₂ in the non-aqueous solvents MeOH, EtOH, HCONH₂, CH₃CN and HCON(CH₃)₂ was performed. The crystals obtained from the MeOH and EtOH solutions are the solvated compound with four molecules and those obtained from the HCONH₂, CH₃CN and HCON(CH₃)₂ solutions are the solvated compound with six molecules of the respective solvent.The apparent molecular volume ø of Zn(CF₃SO₃)₂ (zinc salt) in the non-aqueous solutions were determined at 30 °C. ø is affected by both the solvent in the solution and the concentration of the zinc salt. Although ø for the zinc salt in every solvent solution reaches a constant value at or above a specific concentration, the constant value becomes higher with increasing molecular weight of solvent, except for the HCONH₂ solution, and becomes lower with increasing electrical conductivity of the solution, except for the EtOH solution. It seems that the constant value of ø in Zn(CF₃SO₃)₂-non-aqueous solutions is in the range 67 – 175 cm³ mol^-1.     

Properties of non-aqueous solutions of Cu(CF3SO3)2

Elemental analysis was made of the crystals produced in solutions prepared by dissolving a considerable amount of Cu(CF₃SO₃)₂ in non-aqueous solvents such as MeOH, EtOH, HCONH₂, CH₃CN and HCON(CH₃)₂. Apart from the crystal produced in the HCONH₂ solution, each crystal is the solvated compound with four molecules of the respective solvent.The apparent molecular volume φ of Cu(CF₃SO₃)₂ in the non-aqueous solutions was determined at 30 °C. φ is affected by the solvent in the solution and the concentration of the copper salt as well. Although φ for the copper salts in every solvent solution reaches a constant value at a specified concentration of the copper salt or higher, the constant value increases with increasing molecular weight of solvent, except for the HCONH₂ solution, and decreases with increasing electrical conductivity of the solution, except for the EtOH solution. It seems that the constant value of φ for non-aqueous solutions of Cu(CF₃SO₃)₂ will be in the range 80 – 200 cm³ mol^-1.     

Intermolecular interactions in the structure of new molecular semiconductor [Pd(dddt)2]2CF3SO3

An X-ray structural investigation of a new molecular semiconductor, [Pd(dddt)₂]₂CF₃SO₃ (1), where dddt²⁻ is 5,6-dihydro-1,4-dithiin-2,3-dithiolate, is made. Crystal data of 1:a = 6.521(7) Å, b = 8.354(4) Å, c = 16.113(6) Å, α = 87.12(4)°, β = 85.51(6)°, γ = 67.94(7)°, V = 811(1) ų, triclinic, space group P. Crystal structure 1 is characterized by layers of [Pd(dddt)₂]^1/2+ radical cations, with [CF₃SO₃]⁻ anions located between them. In these layers, [Pd(dddt)²]^1/2+ cations form dimers with strongly shortened intermolecular contacts Pd…Pd 3.031 (2) Å. The [CF₃SO₃]⁻ anion in the structure of 1 is disordered.     

Effects of applied stress and long-term stability on PPy(CF3SO3) linear actuators

The actuation performance of PPy(CF₃SO₃) films, in the free-standing form, has been characterized in aqueous NaPF₆ electrolytes during potential step experiments. Actuation strains of up to 7.5% were observed due to anion insertion at more positive potentials. The actuation strain decreased as the applied stress was increased up to 12 MPa, and then remained constant at above 4% up to the maximum applied stress of 28.8 MPa. A relatively large creep was observed in the case of an applied stress of 28.8 MPa. The film could be cycled more than 1500 times with the retention of 18% of the initial strain level.     

Conductivity and magnetoconductivity below 1 K in films of poly(3,4-ethylenedioxythiophene) doped with CF3SO3

The temperature dependence of the electrical conductivity σ(T) and the magnetoconductivity σ(B,T) of poly(3,4-ethylenedioxythiophene) (PEDOT) films heavily doped with CF₃SO₃ has been measured down to T = 150 mK in magnetic fields up to B = 9 T. It is shown that, below 1 K, σ(T) α ln T and σ(B,T) depends significantly on the orientation of B parallel or perpendicular to the film surface. These facts are interpreted as a manifestation of two-dimensional character of electron transport in highly doped PEDOT films because of the possible formation of strongly graphitized layers with plane structure of polymer chains or fibrils.     

Luminescence study of lanthanide(III) ions in non-aqueous solutions containing azide ions

Luminescence lifetime and intensity measurements of lanthanide(III) ions, Ln³⁺ (Eu, Gd and Tb), in non-aqueous solutions containing azide ions (N₃⁻) have been performed to study the quenching effect of N₃⁻ using time-resolved laser-induced luminescence spectroscopy and conventional luminescence spectroscopy. The luminescence Stern–Volmer quenching constants K_sv^Φ and azide non-radiative decay constants k_N3 of the excited Eu(III) ion in the presence of N₃⁻ were measured in N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylformamide (NMF), formamide (FA) and methanol (MeOH). The obtained quenching effect of the Ln³⁺ luminescence by azide in the non-aqueous solvents shows the order: Gd>Eu>Tb, which does not obey the energy gap law, ΔE, between the emitting and the ground state of the Ln³⁺ ion (Gd>Tb>Eu). The anomaly in the quenching pattern observed in the case of Eu³⁺ can be attributed to its partial reduction to Eu²⁺, additionally to the energy transfer from excited state of Eu³⁺ to N₃⁻. The values of quenching rate constants k_N3measured for Eu³⁺ in various solutions depend on the acceptor number (AN) of the solvents used.     

Enthalpies of Formation of (Cu,Ni)3Sn, (Cu,Ni)6Sn5-HT and (Ni,Cu)3Sn2-HT

Standard enthalpies of formation of ternary phases in the Cu-Ni-Sn system were determined along sections at 25, 41 and 45.5 at.% Sn applying tin solution drop calorimetry. Generally, the interaction of Ni with Sn is much stronger than that of Cu with Sn. Along all sections the enthalpy of formation changes almost linearly with the mutual substitution of Cu and Ni within the respective homogeneity ranges. Thus no additional ternary interaction promoting the formation of further Cu-Ni-Sn phases can be assumed. The results are discussed and compared with literature values relevant to this system.     

Electrochemical Properties of the Amorphous Ti3Ni2 Alloy in Ni/MH Batteries

采用机械球磨晶态Ti3Ni2 (Ti2Ni/TiNi)合金的方法制备非晶态的Ti3Ni2合金,并研究其电化学性能.充放电测试结果显示,非晶态Ti3Ni2合金成功地解决了晶态Ti3Ni2合金在高温下(333 K)循环寿命极短的缺点.在333K循环19次后,相对于晶态Ti3Ni2合金较低的容量保持率(39.47％),其非晶态合金有效的将容量保持率提高到88.83％.通过Tafel极化,线性极化以及交流阻抗测试,发现这种改善源于非晶态Ti3Ni2合金的耐蚀性远优于其晶态合金.     

Ordering in mechanically alloyed Ni(Ga) and Ni(Ga,C) solid solutions during heating

Nonequilibrium Ni(Ga) and Ni(Ga, C) solid solutions are fabricated by mechanical alloying. The ordering in the solid solutions, which is accompanied by the formation of the Ni₃Ga intermetallic compound and the Ni₃GaC _x carbide, is studied by X-ray diffraction, differential scanning calorimetry, and calculating model X-ray diffraction patterns. A procedure is proposed for determining the carbon content in the binary Ni₃GaC _x carbide with a perovskite structure (structure type E2₁) from the intensity ratio of superlattice lines. The equilibrium carbon content in the carbide synthesized by mechanical alloying is shown to be 0.25 atom per unit cell.     

Ti2Ni3Si/NiTi金属间化合物合金在H2SO4溶液中的腐蚀行为

利用激光熔炼材料制备技术,制得了由三元金属硅化物Ti2Ni3Si初生枝晶和枝晶间Ti2Ni3Si/Ti共晶组成的金属间化合物耐磨耐蚀合金;采用极化曲线、塔菲尔图(Tafel Plot)和交流阻抗(EIS)等技术,研究了合金在1 mol/L H2SO4溶液中的电化学腐蚀行为以及Ti含量对合金组织与耐蚀性的影响.结果表明:由于表面形成的稳定钝化膜及Ti2Ni3Si和NiTi的高化学稳定性,使合金在1 mol/L H2SO4溶液中具有优异的耐蚀性,且随着Ti含量的升高,合金的耐蚀性略有提高.     

Pb[(Mg1/3Nb2/3)0.536(Ni1/3Nb2/3)0.128Ti0.336]O3陶瓷的结构和电学性能

通过铌铁矿预产物法制备出了Pb[(Mgq/3Nb2/3)0.536(Ni1/3Nb2/3)0.128Ti0.336]O3铁电陶瓷,并对其结构和电学性能进行了研究.结果表明,该三元体系组成处在准同型相界区域,1kHz时的介电常数极值达到45540,剩余极化强度为37uC/gm2,压电系数d33也达到780pC/N.烧结时有效地抑制PbO的挥发对于获得高性能的铅系铁电陶瓷有决定性的影响.     

Pitting corrosion of intermetallic compound Ni3(Si,Ti) with 2 at% Mo in sodium chloride solutions

The pitting corrosion of Ni₃(Si,Ti) with 2 at% Mo consisting of a single intermetallic compound Ni₃(Si,Ti) phase of L1₂ structure and a two phase mixture of L1₂ and fcc nickel solid solution was investigated as functions of test temperature and chloride concentration in sodium chloride solutions by using a potential step method and compared with that of intermetallic compound, Ni₃(Si,Ti). The pitting potential obtained for the Ni₃(Si,Ti) with 2 at% Mo decreased with increasing chloride concentration and test temperature. A critical chloride concentration below which no pitting corrosion took place was found to exist and to decrease with increasing test temperature. The specific pitting potential at the critical chloride concentration also decreased with increasing test temperature. The pitting potential of Ni₃(Si,Ti) with 2 at% Mo was higher than pure nickel, but lower than that of Ni₃(Si,Ti). A critical chloride concentration was found to be lower than that of Ni₃(Si,Ti), whereas the specific pitting potentials at the critical chloride concentration was found to be higher than that of Ni₃(Si,Ti). Pitting corrosion occurred in the two phase mixture region.     

Effects of SO2 and SO3 on the Na2SO4 induced corrosion of nickel

The effects of SO₂ and SO₃ in the environment on the hot corrosion behavior of Ni in the temperature range 750–950°C has been studied. Below the melting point of Na₂SO₄ (884°C), rapid corrosion takes place by formation of a Na₂SO₄-NiSO₄ melt, which can penetrate the porous oxide scale and give rise to sulfide information by coming in contact with the metal. The distribution of the sulfides depends on the SO₂ level in the ambient gas. Continued corrosion occurs by a sulfidation-oxidation mechanism. At temperatures above the melting point of Na₂SO₄, accelerated degradation occurs via dissolution of the surface scale, followed by reprecipitation of the oxide in a nonprotective form.Deceased     

采用Na2SO3溶液从硒渣中选择性浸出Se及其动力学

采用SO2还原沉金后液制得硒渣,再用Na2SO3选择性浸出硒渣,使Se得到有效分离;通过研究浸出过程中Se浸出率随时间的变化,建立该反应的动力学方程,确定Na2SO3溶液浓度、液固比、搅拌速度及反应温度对Se浸出率的影响,并计算相应的表观活化能。结果表明:增加Na2SO3溶液浓度和升高反应温度可以较大幅度提高Se的浸出率,液固比和搅拌速度对浸出Se的影响较小;Na2SO3浸出Se过程为Avrami模型混合控制,其特征参数n和表观活化能E分别为0.235和20.847 kJ/mol,Se的浸出率受反应温度的影响较大。     

The anodic dissolution of beryllium in non-aqueous solutions

The anodic dissolution of Be was studied in Cl^? and Cl0₄^? solutions of methanol, ethanol and N,N-dimethylformamide with water contents < 0.1 g/l at 25°C. The apparent valences of Be ions going into solution ranged from 0.37 to 1.8. The lower values were obtained in alcohol solutions with Cl^?. Considerable gas evolution was noted from the Be surface. The low and anomalous valences are attributed mainly to a chemical dissolution of the metal by reaction with the solution. This reaction is reported to be catalysed by Cl^?. Theeffect of the low watercontent is to hinder the reforming of an oxide or hydroxide film that protects the Be from chemical attack. The numerical value of the valence is mainly dependent on the rate that the Be will chemically react with the media once a current flows that disrupts the surface film.     

层状Li(Ni0.5Mn0.5)1-xTixO2材料的合成及性能研究

以Li2CO3,Ni(OH)2,MnCO3,TiO2为原料,采用高温固相合成法制备了层状Li(Ni0.5Mn0.5)1-xTixO2。通过X射线衍射确定了不同钛掺杂量样品的相组成。用扫描电镜对组织形貌进行了观测。对用所制样品组装的电池的充放电和循环性能进行了测试。实验结果得出:所制备的Li(Ni0.5Mn0.5)1-xTixO2的结构为α-NaFeO2型层状结构,当x=0.02时,L(iNi0.5Mn0.5)1-xTixO2的首次放电容量为161mA·h/g,25次循环后容量仍保持在144mA·h/g,具有较高的比容量和良好的循环性。     

Properties of ausformed austempered ductile iron (AADI) containing Ni

Abstract

The abrasion wear behaviours of Ausformed Austempered Ductile Iron (AADI) and conventional Austempered Ductile Iron (ADI) were investigated. The effects of both Ni content and rolling reduction during the ausforming process on the wear resistance of AADI and ADI were studied. The ausforming process created a finer and more homogeneous ausferrite structure that had a direct influence on the mechanical properties of AADI. Maximum hardness and tensile strength were obtained with 35% rolling reduction. On the other hand, ductility and impact strength were reduced with increasing rolling reduction during the ausforming process. AADI showed superior abrasion wear resistance because of its finer and harder structure.     

稀土CeCl3对耐热钢Ni2Al3/Ni复合涂层抗氧化性的影响

本文采用电镀镍、低温包埋渗铝在P92铁素体耐热钢表面制备不同稀土Ce含量的Ni-Al化合物复合涂层,并对复合涂层进行650 ℃&#215;132 h的抗氧化实验。利用OM、SEM、EDS、XRD,分析涂层氧化前后的截面微观形貌,化学元素分布及物相变化规律。结果表明：涂层的氧化动力学曲线均符合抛物线规律。不含Ce的复合涂层平均氧化速率为0.4412&#215;10-6 g/cm2/s,渗铝剂中加入2%CeCl3的涂层抗氧化性明显增强,平均氧化速率为0.2957&#215;10-6 g/cm2/s,而加入过量CeCl3（4%、6%）则会在氧化过程中产生更多的孔洞,恶化了涂层的高温抗氧化性能,氧化速率相对加入2 % CeCl3的涂层有所升高。另外涂层中加入Ce元素增加了氧化膜的粘附性,对Al元素的向内扩散具有抑制作用。     

PMN-PNN-PT陶瓷晶粒异常长大研究

采用两步法和等离子放电烧结技术制备出了致密的单一钙钛矿相的PMN-PNN-PT陶瓷,对其高温热处理后晶粒异常长大进行了研究.发现添加5%(质量分数)过量PbO有助于晶粒的异常长大,观察到了3种典型的异常长大晶粒,为下一步固态法制备该组成单晶打下了基础.     

掺杂Al的(In2Te3)0.09(SnTe)0.91化合物热电性能

以等摩尔分数的Al元素替代(In2Te3)0.09(SnTe)0.91中的In元素,利用放电等离子烧结技术、采用相同的工艺制备了(In2Te3)0.09(SnTe)0.91和(In1.9Al0.1Te3)0.09(SnTe)0.912种化合物,并对两者的微观结构和热电性能进行对比。结果表明,掺杂Al元素后,材料的Seebeck系数降低很小,电导率为1×1052.3×1051·m1,是掺杂前的2.43倍,晶格热导率L值大幅度降低。在693K时,掺杂Al后的化合物ZT值达到最大值0.4,是同温度下掺杂前ZT值的2倍。