passive mass造句

• Passive mass shielding of four metric tons per square meter of surface area will reduce radiation dosage to several high natural background areas on Earth.
• Alternative concepts based on active shielding are untested yet and more complex than such passive mass shielding, but usage of magnetic and / or electric fields to deflect particles could potentially greatly reduce mass requirements.
• The supposedly active popular culture versus the passive mass culture ( in fact, later in the book Kammen cites opinions that the most recent artifacts of mass culture, like computer games, are not passive at all ) is not the only difference.
• None of these strategies currently provide a method of protection that would be known to be sufficient For passive mass shielding, the required amount could be too heavy to be affordably lifted into space without changes in economics ( like hypothetical non-rocket spacelaunch or usage of extraterrestrial resources )  many hundreds of metric tons for a reasonably-sized crew compartment.