In this paper，the principle of immunoassay is restated in terms of reagent analysis. Three types and four key links of label immunoassay are discussed，and some commenu are made on antibody as an analytical reagent. The current situation of immunoassays is reviewed and five hot topics of nowaday immunoassays are. introduced，they are:recombination antibody，biotin-aviding labeling system，time-resolved fluoroimmunoassay，multianalyte immunoassay，and automatic immunoassay. The trend of immunoassay is also discussed.

The research progress of MRI contrast agents has been reviewed with 93 references.More than 70 compounds of gadolinium(III) have been discussed in categories

This paper deals with the synthetic methods of crown other cyanine dyes and their key intermediates. The studies on their properties such as complexation，light/heat stability and spectral sensibilization are presented systematically.,It also describes the recent progresses in studies of crown ether compounds in photographic materials and of crown ether cvanines in other aspects,and shows their potential applications in these fields.

The theoretical procedure of the (iaussian一2 Theory has been reviewed in detail. This includes the Gaussian-1 Theory，the Gaussian一2 Theory，the simplified Gaussian-2(MP2 and MP3)Theories. Results of these theories have been compared and analyzed. Applications of the G2 on reproducing，assessing，predicting experimental data and the applications in the research of reaction pathways in recent years have been reviewed. The applications of the G2 and G2 (MP2)energies for the isoelectronic-isogyric，valence isoelectronic-isogyric，isogyric and non-isogyric reactions have been discussed according t6 our recent work. Meanwhile，the G2 prediction of the standard enthalpies of formation at 298K for a number of chemical species we have studied recently has also been included.

The magnetocaloric effect (MCE) of rare earth metals and their alloys is introduced in the present paper. The discussion of thermodynamic theoiy of the magnetocaloric effect，the experimental methods of measuring the MCE，the reported results of MCE in some rare earth metals and their alloys and their applications in magnetic refrigerators are reviewed.

Dimethyl sulfide emitted from the oceans is the main natural source of sulfur emissions. This paper reviews the current trends and developments of studies }on DMS oceanic emission，its oxidation in the atmosphere and its impacts on precipitation's natural acidity and climate change.