Adenoviruses tend to turn out very beautiful after negative staining with either PTA or UA, with a nicely defined capsid structure. It is hard to see on these low-res images, however, some of the darker round/hectagonal shapes look like virus particles (see: first image center right, third image very top at the 72nm measurement) . Certainly those elongated shapes are not adenoviruses.

Martin Schauflinger thank you, Martin. What do you think those elongated particles are if they are not viruses? For me, those are viruses but they are aggregated.

You're welcome. Cannot tell without high-resolution image. Definitely not adenovirus. Could be impurities in the stain, the film, or the sample. Focus on the roundish particles, these are most likely your sample. Look at the literature for example images.

Edit: Here is a image I took recently of PTA stained adenovirus. The adenovirus particle has a very defined structure, it should be very obvious if you are looking at one.

Martin Schauflinger, what about this one?? is it look like a virus to you ??

No. Way too irregular and too large. By the way, adenoviruses are non enveloped, they do not feature membranes.

Very importantly, please note that these objects are out of focus. A strong defocus will lead to the kind of black and white lines around an object as is seen in your image. I'm pretty certain, that once in focus these "membranes" will disappear. I'd strongly recommend you get proper training by an experienced EM operator if this is something you plan to do regularly.