The paper discussed the preparation of rare earth europium complexes ultraviolet rays (UV) photochromic ink and the influences of factors, such as europium complexes using a rare earth ternary complex of Eu ion with 3-benzoylbenzoic acid and phenathrolinephen [Eu(BA)3Phen] content upon printing ink formula. In the experiment, we utilized fluorescence spectrophotometer to make quantitative deter...

The effects of barometric pressure and earth tide changes are often observed in ground water level measurements. These disturbances can make aquifer test interpretation difficult by masking the small changes induced by aquifer testing at late times and great distances. A computer utility is now available that automatically removes the effects of barometric pressure and earth tides from water le...