The dielectric properties of LaMn1−xFexO3 (LMFO, 0.1≤x≤0.5) under magnetic fields and electrical biases have been studied. A considerable low‐field magnetodielectric (MD) effect is observed for x≤0.2, but it is suppressed by further Fe substitution. Besides the giant MD effect, the dielectric constants can also be tuned by dc electrical bias, and a reduction of more than 70% for x≤0.2 under a low bias of 40 V/cm is achieved. These results together with the impedance characteristics can be explained by the contributions of barrier layers at interfacial and grain boundaries as well as the magnetoelectric coupling. The giant dielectric response and tunability under both low magnetic and electric fields in the nonferroelectrics may be advantageous for applications.

Aluminium concentrations in NIST (formally NBS) Standard Reference Material Tomato Leaves and Citrus Leaves were determined by ICP-AES after acid digestion. The normal 'total' acid attack (nitric and perchloric acids) gave very low recovery (40%) of Al in NIST tomato leaves, but not for citrus leaves. The contribution of Al from Al-rich 'soil' particles in both tomato leaves and citrus leaves was estimated semi-quantitatively by computer-controlled EPMA. The Al held in these particles corresponded in approximate concentration to the shortfall between the acid soluble component determined in this study and the certified value. Analysis by EPMA can provide, therefore, a method of estimating Al contributed by soil contamination to plant materials. The limitations of the NIST tomato and citrus leaf reference material for the validation of methods for the determination of Al in vegetation are demonstrated.

Hydrogen sulfide reacts with the corrosion products (Fe 2 O 3 ) in oil tanks to form iron sulfides. The oxidation and released heat of iron sulfides can lead to spontaneous combustion of iron sulfides and fire of oil tanks. In this article, the simulating production process of iron sulfides in oil tanks and the effects of flow rate of hydrogen sulfide, environmental temperature and setting time on the quantities and types of iron sulfides are studied.