ICP—AES techniques applied to analysis of precious metals in ores

A method for the simultaneous determination of precious metals and matrix elements in Fe and Cu ores is studied.The instrument used is ICAP-9000 polychromator and its accessory monochromator(N 1),Interferences of matrix are eliminated by matrix matching method,i.e.the influence of matrix was corrected by minus equivalent concentration method,The experiments show that the method is simple,sensitive and reliable;especially,suitable for determination of Au in Cu-Au ores.     

MULTI—ELEMENT DETERMINATION OF SOIL SOLUTION BY INAA

One factor of influencing crop growth is the effective elemental contents, especially trace elements, under the circumstances of the same concentrations of N, P and K in soil. In order to obtain the data of effective elemental contents in soil, a novel method was introduced. In this method, soil solution was extracted by a squeezer. The concentrations of elements in soil solution were determined by INAA. Study on the compositions and the contents of elements in soil solution will provide information on making a suitable soil environment for plant growth and for rational and economical manure.     

Calibrating the linearity between grayscale and element content for X-ray KES imaging of alloys

Doped elements in alloys significantly impact their performance. Conventional methods usually sputter the surface material of the sample, or their performance is limited to the surface of alloys owing to their poor penetration ability. The X-ray K-edge subtraction(KES)method exhibits great potential for the nondestructive in situ detection of element contents in alloys. However,the signal of doped elements usually deteriorates because of the strong absorption of the principal component and scatt...     

Synchrotron radiation X-ray fluorescence analysis on altered mineral muscovite in gold deposit

Synchrotron radiation X-ray fluorescence (SRXRF) microprobe was used to ananlyse altered mineral muscovite and its surrounding feldspar in Yuerya gold deposit. The major, minor and trace elements of the two minerals were detected and analyzed. SRXRF analysis showed that the Yuerya muscovite had a complex chemical composition. containing K, Fe, Ca, Ti, Cr, Mn, Co, Cu, Zn and many trace or ultra-trace elements. Since muscovite resulted from the alteration of hydrothermal ore fluid acting on feldspar (plagioclase), the difference of chemical composition between the two minerals shows the components of ore fluid, which are characterized by the enrichment of alkaline and alkaline-earth metal elements K, Ca and ore-associated elements Fe, Cu, Zn. And gold. silver and platinum, invisible under microscope, were detected in some areas of muscovite but not found in feldspar. Especially platinum, a mantle material is rarely seen in the earth crust but now found in the gold deposit of magmatic sources; its appearance approves the idea of mantle flux participating in the gold mineralization, which suggests that the tectonic event controlling gold mineralization in the Yuerya district is a mantle phenomenon.     

Study of Effect of Mn on Hardening Induced by Cu Precipitates in bcc Fe Matrix

<正>Cu precipitate is one of the major contributors to the hardening and embrittlement in pressurized water reactor pressure vessels steels(RPV).As the research going,solute elements were observed in rich Cu precipitates by 3Datomprobe tomography,such as Ni,and Mn.The appearance of Ni and Mn in RPV can significantly affect the formation and stability of rich Cu precipitates.Up to now,the influence of Ni atoms     

Synchrotron radiation X-ray fluorescence analysis of Fe,Zn and Cu in mice brain associated with Parkinson’s disease

The contents and distributions of metal elements in the brain are closely related to neurodegenerative diseases.In this study, we examined Fe, Cu and Zn contents in the brain section associated with Parkinson‘s disease(PD)using synchrotron radiation X-ray fluorescence(SRXRF). PD mouse model induced by 1-methyl-4-phenyl-1,2,3,6-terahydropyridine(MPTP) was used for the elemental analysis(e.g., Fe, Cu and Zn) in the substantia nigra pars compacta(SNpc) region of mice brain tissue samples. We found that mice in the MPTP group had higher contents of Fe, Cu and Zn in the SNpc than the control group. After treating the PD mice with rapamycin, the contents of Fe, Cu and Zn were reduced, the dopamine neurons and motor function were rescued correspondingly. The results prompted that the SRXRF provided an ideal method for tracing and analyzing the metal elements in the brain section to assess the pathological changes of PD model and the therapeutic effect of drugs.     

NAA OF SOME ANCIENT INDIAN COINS

The radioactivity induced in the coins from satvahanas,Ahmadshah Bahamani,Gujrat Sultan,Nizamshahi and Marathas after(n,γ) reactions for the elements of interest is measured on multichannel analyzer coupled to high purity germanium detector and percentage of these elements is determined by comparator method of NAA.All these coins are found to be copper based with the presence of As,Sb,In,Au,Sn and Mn.     

Accurate quantitative CF-LIBS analysis of both major and minor elements in alloys via iterative correction of plasma temperature and spectral intensity

The chemical composition of alloys directly determines their mechanical behaviors and application fields.Accurate and rapid analysis of both major and minor elements in alloys plays a key role in metallurgy quality control and material classification processes.A quantitative calibration-free laser-induced breakdown spectroscopy (CF-LIBS) analysis method,which carries out combined correction of plasma temperature and spectral intensity by using a secondorder iterative algorithm and two boundary standard samples,is proposed to realize accurate composition measurements.Experimental results show that,compared to conventional CF-LIBS analysis,the relative errors for major elements Cu and Zn and minor element Pb in the copperlead alloys has been reduced from 12％,26％ and 32％ to 1.8％,2.7％ and 13.4％,respectively.The measurement accuracy for all elements has been improved substantially.     

CALCULATION AND OPTIMIZATION OF EXPERIMENTAL PARAMETERS IN ELASTIC RECOIL DETECTION (ERD)

Elastic recoil detection (ERD) proposed for the analysis of light elements in a heavier matrix is an appropriate method for its specialities. Optimization of experimental parameters in ERD such as scattering geometry and incident beam energy is very important when using a small accelerator with energy lower than 10 MeV. In this paper a computer program ERDAl is developed for the purpose, and is proved to be useful for practical handling of ERD experiments.     

Micro—PIXE analysis of trace element composition and their distribution in minerals of mantle peridotite

The proton microprobe and the quantitative micro-PIXE analysis technique are used to determine trace element composition and distribution in minerals of mantle peridotite,therefore,additional useful information is provided on the study of upper mantle mineral phase transformation.An example reported here is the study on the geochemical behavior of trace elements in minerals of Suoluoshu mantle peridotite from Shandong province,which was in the process of mineral phase transformation from spinel to garnet.The study shows that trace element composition and distribution display obvious change in minerals while the mineral phase is transformed from spinel to garnet.Most of the trace elements analyzed reside in clinopyroxene and spinel.However,garnet is nearly poor in all of these elements.This phenomenon is associated with the infiltration of soultion and the existence of micropgrained inclusions in minerals in the process of mantle metasomatism.     

A study of quasi-absolute method in photon activation analysis

Relative methods, which are performed with the assistance of reference materials, are widely used in photon activation analysis(PAA). On the contrary, absolute methods, which are conducted without any reference material, are rarely applied due to the difficulty in obtaining photon flux. To realize absolute measurement in PAA,we retrieve photon flux in the sample via Monte Carlo simulation and raise a novel procedure—quasi-absolute method. With simulated photon flux and cross section data from existing databases, it is possible to calculate the concentration of target elements in the sample straightforwardly. A controlled experiment indicates that results from the quasi-absolute method for certain elements are nearly comparable to relative methods in practice.This technique of absolute measurement has room for improvement in the future and can serve as a validation technique for experimental data on cross sections as well.     

ELASTIC RECOIL DETECTION ANALYSIS OF LIGHT ELEMENTS IN THIN FILMS USING 35 MeV~(35) Cl~(6+) BEAM

In this paper, an elastic recoil detection analysis method is described using 35 MeV ~(35)Cl as incident ions. This method can determine and profile simultaneously H, D, He, C and O or in the other case, H, C, N and O. The depth resolution for the elements heavier than He is better than 20 nm. It has been applied to study the Co/Si and TiN thin films, and the depth profiles of He implanted in monocrystal silicon.     

The Analysis of Technetium in Purex

The concentration analysis of Tc is the basis of the research of behavior of Tc. Tc is a P radiation nuclide. It's half-life is 2.13 × 105 a. The concentration of Tc can be determined by its activity or by spectroscopic method using its complex with other substance. Tc samples in Purex may contain a large amount of U, Np and Pu. The disturbance of them should be eliminated when the concentration of Tc is analyzed. As collidine can extract heptavalent, Tc nearly quantitatively and the extraction ability for other elements is very low, it is possible to separate Tc from U, Np,     

Analysis of Impurity Element Content in Uranium Ore Concentrate

<正>In the nuclear forensic research of uranium ore concentrate (UOC),the content of impurity elements is one of the very important characteristic fingerprint information.Compared with other nuclear materials in the nuclear fuel cycle,UOC is rich in various impurity elements (REE,Fe,     

Determination of Uranium,Neptunium and Plutonium in 1AW

正The solution in 1AW is the waste of the first separation unit in Purex process.The composition of the aqueous waste of the co-decontaminating unit is very complex.It contains almost all the radioactive fragment elements,and the spe-     

Progress of ^151Sm Measurement With Accelerator Mass Spectrometry

^151Sm is a fission product nuclide with the life-time of 90 a. ^151Sm is also a kind of rare earth elements. They have come into extensive use rapidly in a number of fields. As a result, more and more lanthanides are getting into the environment and food chains. In recent years much interest has been addressed to study on the effects of lanthanides. It is very difficult to measure the content of ^151Sm with routine methods. Accelerator Mass Spectrometry （AMS） may be the method to measure ultra-trace ^151Sm with high sensitivity.     

Instrumental neutron activation analysis of beachrock samples of South East Coast of Tamilnadu, India

Element profiles of some beach rock samples collected from South East Coast of Tamilnadu, India have been determined using single comparator method of INAA. The geo-chemical behavior of the elements in the region is discussed. The irradiations were done at thermal neutron flux of ~ 1011 cm-2·s-1 at 20kW power using Kalpakkam Mini Reactor (KAMINI), IGCAR, Kalpakkam, Tamilnadu, India. Around 19 elements have been determined from 15 samples by high-resolution gamma spectrometry. The accuracy and precision were evaluated by assaying the irradiated Standard Reference Material (SRM 1646a Estuarine sediment) and were found to be in good agreement with certified values.     

MATRIX ABSORPTION CORRECTION OF MEDIUM THICK TARGETS IN XRF

This paper deals with the matrix absorption and enhancement effects of thick targets in energy dispersive X-ray fluorescence analysis. Two kinds of absorption correction methods are studied especially for medium thick targets (5-10 mg/cm2). For analysis of hair samples, both the measurement of absorption correction coefficients and the determination of sensitivity factors using an addition method are introduced. Quantitative analysis of medial thick samples is established. The relative deviation between different methods for most of the elements is found to be less than 5 %.     

The Study Programm Report of the Corrosion Behavior of New Zirconium-based Alloys

The corrosion of fuel cladding in PWR limits the extension of burnup. To compare the corrosion resistance of Zr-4 and new zirconium-based alloys, the out-of-pile water-side corrosion test has been conducted for these materials.To study the effects of heat flux on the corrosion of cladding, and keep the surface of cladding as an original 'as-received' statement, the heat elements are introduced into the inside of the cladding tubes.The materials have been exposed for 205 d till now. The oxide film performed on the surface of cladding is black and glossy. The thickness of oxide is measured by the method of eddy current.     

A NEW APPROACH TO THE CURVE FITTING OF IN VITRO RADIOASSAYS BASED ON THE MASS ACTION LOW

A new curve fitting method with its mathematical models derived from the mass action law is presented which is applicable to several in vitro radioassays including RIA and RBA. Experiments revealed that the robustness of this method is better than the conventional methods like Woolf plot in RBA and 4- parameter logistic plot in RIA. However, the robustness of this method is only relative: in some cases of RIA and RBA, the bias of the results may still be too large to be acceptable. Further improvement is expected to be studied.