thermal demagnetizer heats the sample to make the magnetic field disappear. Demagnetization in alternating magnetic field: the remanence of sample disappears in alternating magnetic field.
1. Working Principle: GC mainly uses differences in boiling point, polarity and adsorbability of substances to separate mixtures. The process is shown in FIG. 1 gas phase analysis flow chart. Actually, chromatography was first discovered by the Russian botanist M.S.Tswett in 1901. In March 1903, M.S.Tswett formally proposed the word “chromatography” in his report at an academic conference at the University of Warsaw, marking the birth of chromatography. Therefore, he was nominated as candidate for the Nobel Prize in chemistry in 1917. Gas chromatography appeared in the 1940s. At that time, Tswett was studying the separation technology of liquid chromatography (LC). In the process of studying the theory of distribution chromatography, British people A.J.P. Martin and R.L.M. Synge confirmed the possibility of gas as chromatography flowing and predicted the birth of GC. Coincidentally, the two scientists awarded Nobel Prize for Chemistry. Although the achievement represented their contribution to distributive chromatography theory, some descendants believed that they got the prize because…
1.Conception Paleontological fossils are the remains, relics and traces of life activities of organisms in geological history preserved in rock strata through natural processes. Paleontological fossil can be divided into remains fossil, mold fossil, relic fossil, relic fossil, chemical fossil five kinds. Remains fossils refer to the remains of paleontology themselves preserved in rocks, including whole and partial fossils.Such as mammoth, dinosaur bones, human skulls, siliceous wood and other fossils.Cast fossils are impressions and replicas of biological remains left in strata or surrounding rocks.Such as leaf impressions, shells and other fossil.Relic fossils are traces of ancient life that remain in rock formations.Such as footprints, climb marks, holes, apertures and other fossils. 2. Instruments Equipmets: microscope, electronic scales(0g~100g,±0.01g), adjustable temperature heating plate(50C~300C), ultrasonic cleaner(power:75W~100W), refrigerator, oven. 3. Carry Out Testing Projects 1 Identification of slake fossil rocks 6 Sporopollen analysis 2 Analysis and identification of calcareous ultramicrofossils 7 Analysis and identification of micropalaeobotany 3 analysis and identification of Foraminifera 8…
1、Examination and adjustment of polarizing microscope 1.1 power Turn on the power of the polarizing microscope, check and confirm that the lighting system is intact, and gradually adjust the light intensity from weak to strong. 1.2 Adjustment of objective center 1.2.1 The adjustment of the objective lens is from low power to high power 1.1.2 Specific regulation way is that put some of the rock slices on the stage, adjust the focal length of eyepiece, select a tiny particles to the crosshair center, rotate the object stage to observe the small particles trajectory, then use objective correct screw to adjust for the center, keeping tiny particles remains at the center of the cross wire.Finally, the adjustment is finished. Adjustment of the high power objective lens shares the same way with the low power objective. 1.3 Adjustment of polarizer 1.3.1 The thin section containing biotite is placed under the eyepiece, the strip section of biotite is selected under the plan polarized…
1、Equipment (1)Polarizing, reflection microscope or emission polarizing microscope, and equipped with computer or mechanical station, counter, image analyzer (2)Microphotographic system 2、Rock flake The area of flake is 40mm×25mm with 10mm thickness and smooth surface, mirror-like bright. 3、Preparatory work before identification 3.1 Pressure flat piece Place the back side of the slide on the glue (3.2.2) that adheres to the slide and press the smooth surface horizontally with a hand press (3.2.1). 3.2 Power supply Turn on the power supply of the reflector polarizing microscope, turn the transformer knob, gradually adjust the brightness degree from weak to strong, to achieve the required lighting effect. 3.3 Adjustment of reflection polarizing microscope 3.3.1 Center correction of objective lens Methods Center correction was performed with the same polarizing light microscope (see 5.3 in DZ/T 0275.4-2015). 3.3.2 Adjustment of reflector First, place the polished section on the microscope platform; Then, after setting the microscope in focus, the light with the shape of circle is cast…