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141.
R. Singh R. M. Misra D. C. Gupta D. D. Shukla M. N. Sharma M. P. Madan 《Zeitschrift für Physik B Condensed Matter》1985,58(2):83-89
The parameterC
1=[(1/K
T
)/P]
T
, which describes the pressure variation of the compressibility, has been examined correlating the thermodynamical and interatomic potential approaches employing fewer approximations than has been usual heretofore. General expressions have been derived forC
1 by including the thermal correction terms, which have generally been ignored in previous studies concerning thermal properties of ionic crystals. The parameterC
1 has also been related to the Grüneisen parameter, , using a relation given earlier. The applicability of the derived equations is investigated and discussed for alkali halides employing few realistic potential forms. A good general accord is found with the available experimental data, which exhibits an essential improvement over other theoretical determinations. 相似文献
142.
Using the Wigner-Kirkwood expansion and bare Lennard-Jones (LJ) (12-6) potential, an effectiveLJ potential is derived, which includes the quantum effects through the expressions of the effective diameter∂(T, λ) and well-depth
(T, λ). We use theWCA perturbation theory to calculate the free energy and pressure for theLJ and effectiveLJ potentials. Simple analytic expressions are given for the reference system and the first order correction calculated. The
results are quite good at high density. The quantum effects on the free energy and pressure are also discussed. 相似文献
143.
K. Nagarajan M. Bhupathy Rajendra Prasad Ziley Singh V. Venugopal D.D. Sood 《Thermochimica Acta》1980,36(1):85-89
The thermal decomposition kinetics of Pr2(SO4)3 to Pr2O2SO4 have been studied by isothermal weight change determination. The reaction was found to obey a linear law up to α = 0.5; beyond α = 0.5 it could be described as a phase-boundary controlled process. A dependence of the activation energy upon the sample weight was observed. The changes in surface area and density which occur during the decomposition are also given. 相似文献
144.
Biosensors for environmental pollutants and food contaminants 总被引:4,自引:0,他引:4
Baeumner AJ 《Analytical and bioanalytical chemistry》2003,377(3):434-445
This review article provides an overview of the most recent literature on biosensors for environmental pollutants and food contaminants. Due to the large number of publications, only papers published between 2000 and January 2003 were considered. Also, while not all of the published literature could be reviewed here, over 200 references are cited to provide a good overview of research undertaken in the last two years. Older publications are covered by a number of earlier review articles. This article provides an introduction into the field including specific consideration of the application areas, describes the typical biosensor assay format used, and is subsequently structured according to the biorecognition elements used (i.e., nucleic acids, enzymes, whole cells, tissue and whole organisms, antibodies and receptors, and biomimetic materials). In addition, a section on microbiosensing systems is provided. Since only very few microbiosensors with applications in environmental and food systems have been published, enabling technology is also covered in this article.Abbreviations BOD biological oxygen demand - cfu colony forming units - DNP dinitrophenol - GFP green fluorescent protein - NASBA nucleic acid sequence-based amplification - PCR polymerase chain reaction - ppt parts per trillion - QCM quartz crystal microbalance - SPR surface plasmon resonance 相似文献
145.
146.
Surface tension measurements can be used to investigate molecular complex formation in liquid solutions for strong and weak
complexes. The association constant and epthalpy for triethylamine-iodine, hexamethylbenzene-tetracyanoethylene and ethanol-iodine
in cyclohexane are 4·55×103, 218 and 0.93M−1 at 25° C and 12·5, 7·7 and 5·1 kcal/mol respectively. These values compare well with those reported in the literature by
other methods. 相似文献
147.
Complete Separation of ternary mixtures of Ca, Mg and Sr or Ba ions with ammonium chloride and less complete but detectable separation of the same mixtures with ammonium nitrate have been achieved, as well as a few binary separations of the type Ca-Ba, Ca-Sr, Ca-Mg, Mg-Sr and Mg-Ba. 相似文献
148.
Compatibilities of various PVC blends with chlororubber-20 and its graft polyblends have been studied on the basis of our previous findings. It has been found that chlororubber-20 makes compatible blends with PVC, while grafting of styrene, ethyl acrylate or acrylonitrile onto chlororubber-20 generates heterogeneity in their blends with PVC. The behaviour of these blends at the molecular level is reflected in the changes of ultrasonic velocity and absolute viscosity with composition. 相似文献
149.
Maria Merces Marques C. Costa F. Lemos F. Ram?a Ribeiro A. R. Dias 《Reaction Kinetics and Catalysis Letters》1997,62(1):9-15
In this paper we present a kinetic approach to the analysis of steady-state homogeneous Ziegler-Natta polymerization activity
data. The influence of the number of monomeric species that are coordinated to the active site on the apparent rate law is
discussed and the equations are fitted to the experimental results. 相似文献
150.
The Mössbauer spectrum of ferrous zirconium double sulphate FeZrO(SO4)2·8H2O shows a quadrupole split doublet at room temperature. The results are discussed in terms of high-spin Fe(II) in distorted octahedral symmetry. 相似文献