The ornamental design for an electronmicroscope, as shown and described.
FIG. 1 is a front, top and right side perspective view of an electron microscope according to the design;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is an enlarged view of the portion shown in BOX 8 in FIG. 1;
FIG. 9 is cross-sectional view taken along line 9-9 of FIG. 2; and,
FIG. 10 is an enlarged view of the portion shown in BOX 10 in FIG. 9.
The dashed broken lines in the drawings show portions of the electron microscope that form no part of the claimed design. The dot-dash broken lines in the drawings indicate boundaries of the claimed subject matter that form no part of the claimed design. The dot-dot-dash broken lines in the drawings indicate boundaries of the view indicators that form no part of the claimed design.