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1.
草酸铂薄层层析方法研究   总被引:2,自引:0,他引:2  
对草酸铂的薄层色谱进行实验性研究,获得草酸酸的最佳色谱条件(1)硅胶H板为吸附剂;(2)甲醇-四氢呋喃(THF)-二乙胺)DEA)_水(20:2:0.05:1)为展开剂;(3)碘蒸气显色。该色谱条件下,点样40μg只出现一主斑点(Rf=0.50),且重现性好。杂质Ag、「Pt(DACH)Cl2」「Pt(DACH)(H2O)2」(NO3)2和C2O4^2_的Rf值为0.00,最步检出限分别为0.01  相似文献   

2.
抗癌药物卡铂薄层色谱分析方法研究   总被引:8,自引:0,他引:8  
研究抗癌药卡铂薄层色谱分析方法,采用硅胶G板为吸附剂,苯:丙酮:水(3:17.5:4)为展开剂,碘蒸气显色,卡铂的Rf值为0.45±0.03,杂质二碘二氨合铂(Ⅱ)、1,1-环丁二羧酸银及水解产物的Rf值分别为0.83±0.02、0.00和0.00,最小检出限量分别为0.24、0.20和0.02μg,本法分离效果好、操作简便、灵敏、快速。  相似文献   

3.
本文研究了稀土金属镧(La)对FecuNbSiB系软磁合金结构与性能的影响。结果表明:当La含量为0.5at%时,纳米晶Fe(73)Cu1Nb3Si(13.5)B9La(0.5)合金经470℃×1h晶化退火后具有最佳软磁性能,其起始磁导率μ(0.001)为8.3×104,矫顽力Hc为0.70A/m。过高或过低的La含量均不利于提高合金软磁性能。  相似文献   

4.
针对二重集团公司钢包精炼炉(LRF)完成的十炉冶炼转子钢的工业性实验进行了研究。实验结果表明:钢水初始硫「S」在0.020%以下炉渣采用下列组成:CaO=55%~65%,SiO2=13%~15%,MgO=4.0%~6.0%,Al2O3=3%~5%,FeO〈0.5%;Fe2O3〈0.3%,Σ(FeO)〈1.0%,B=3.5~5.5和真空搅拌功εM·t=(70~100)×^3J/t可获得良好的脱硫效果  相似文献   

5.
配体交换动力学法测定痕量银的研究   总被引:3,自引:0,他引:3  
在酸性条件下痕量Ag(I)对K4[Fe(CN)60361-尿素间的配体交换反应具有显著的催化效应,催化反应的表观活化能为18.12kJ·mol^-1。本文据此建立了测定痕量银的配体交换动力学分析法,测定条件为K4[Fe(CN)6]:8.0×10^-4mol·L^-1,[CH3COOH]:0.12mol·L^-1,[CO(NH2)2]:6.0×10^-4mol·ml^-1,80℃。线性测定范围为10  相似文献   

6.
在碱性介质中,铈(Ⅲ)能显著地阻抑H2O2氧化水扬基荧光酮(SAF)褪色的指示反应,研究表明该动力学反应对铈(Ⅲ)为一级,测得反应的表观活化能为28.75kJ/mol。据此建立了测定痕量铈的动力学分析法,测定条件为SAF:4.0×10-5mol/l,H2O2:0.010%,NaOH:2.0×10-2mol/l,50℃。线性测定范围0.04μg/ml~0.44μg/ml,方法检测限为0.02μg/ml(Ce)。当溶液中的铈含量为0.16μg/ml时,3~8倍量的轻稀土,5~11倍量的重稀土和同倍量的铀和钍等不干扰测定。测定了按不同稀土矿的稀土元素配分合成的样品中的铈含量,结果满意。  相似文献   

7.
本文对用Fe、Al替代Co的La(Fe(0.73)-xCoxAl(0.27))(13)系和用R(Ce,Pr,Nd,Sm,Dy,Gd)替代La的La1-zRz(Fe(0.71)Co(0.02)Al(0.27))(13)系的结构、磁性及磁熵变特性进行了研究。实验发现,La(Fe(0.78)-xCoxAl(0.27))(13)系的晶体结构均保持LaCo(13)的立方结构,每3d原子的饱和磁矩与其电子数nd的关系在富Co侧符合刚性能带模型,而在富Fe侧则与该模型不符。当x=0.02时该化合物的居里温度在室温并有较高的磁熵变△SM,在1.11MA/m(1.4T)磁场下的(△SM)max为13kJ/m3·K。对于La1-zRz(Fe(0.71)Co(0.02)Al(0.27))(13)系,实验发现除Ce外,其它稀土元素均不能与La、Fe、Co、Al形成1:13相,而是形成了2:17相。  相似文献   

8.
研究了 Fe-28Al-5Cr(原子分数)与 Fe-28Al-5Cr-0.5Nb-0.1C合金的高温变形行为,结果表明,在 850 ℃左右,应变速率为 8.3×10-4 s-1时,呈现一定的超塑性变形能力,延伸率分别达到 145%和 254%;应变速率敏感指数 m分别为 0.4与 0.35;激活能分别为: 243 kJ/mol与 218 kJ/mol.在变形过程中,位错堆积形成小角度晶界,并逐渐转变成大角度晶界,使粗大的原始晶粒细化.  相似文献   

9.
在pH4.30的HAc-NaAc缓冲液中,Au(Ⅲ)与5-Br-PADAP经沸水浴加热形成1:I紫色配合物,在示波极谱仪上-0.60V(vs,SCE)产生一灵敏的配合物吸附波。线性范围5.0×10 ̄(-8)~2.00×l0 ̄(-6)mol/L检出限2.0×108mol/L.研究30多种离子的干扰及分离条件。用聚氨酯泡沫塑料分离金用于矿样中金的测定,结果良好。  相似文献   

10.
Rh(III)—5—Br—PADAP配合物吸附波研究   总被引:4,自引:0,他引:4  
刘桂华  张淑云 《贵金属》1993,14(4):40-49
Rh(Ⅲ)在0.1mol/L HAc-0.1mol/L NaAc,1。60×10^-5mol/L5-Br-PADAP和0.0025%OP溶液(PH≈4.7)中,良好的极谱波,峰电位Ep=-0.64V(vs.SCE).Rh(Ⅲ)浓度在3.90×10^-9~6.80×10^-7mol/L(即0.40~70ppb)与峰电流成线性关系;检出下限为1.9×10^-9mol/L。作直线法测定配合比为:Rh(Ⅲ  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

13.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

14.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

15.
The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).  相似文献   

16.
The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.  相似文献   

17.
This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.  相似文献   

18.
Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.  相似文献   

19.
A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.  相似文献   

20.
韩磊 《腐蚀与防护》2015,36(1):84-90,94
综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。  相似文献   

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