design principfes of nuclear explosives. fhe evolution of atelivery systens seetrslike1y to carry nore practical import ance in the future, as it has alreadlr done fnz cnna rroavcA/35/392 English Annex Page 38 C, Nuclear testing Bf. A most crueial question is vhat influence nuclear-weapon tests nay have onthe fut're developnent of varheads, as the s.nsver is of central inportlnce to theefforts to achieve a comprehensive test ban. The nuc]ear test activity is stilr_considerable. Since the first nucl_ear explosion in l9)+5 the nuclear plwers haveperforraed more than 1,200 nuclear tests. The exact nrimber is not officiallyknovn, but some more detailed figures are given in chapter fV. 87- According to Anerican sources, 11/ united states tests during the late fg70swere conducted for the fol_l,owing naii--purposes: (a) Tmprovement of yield-to-weight ratiosr (b) Reduction of varhead cost anal special nuclear naterial and consumption: (c) Enhancement of warhead safetyi (d) fncrease of veaI)on controL to prevent unauthorized use; (") Tailoxing of weapons effects to specific nilitary needs: (f) Understanding of long-tern cb.emical and structu"al stability. This reflects the technofogicar trends d.escribed. above. The list contains thep'rloses fox advanced crevel-op'ent and testing stated to be important iu view ofthe possibility of a comprehensive test ban. A naJor purpose for testing isnormarly the requirenxents caused. by adaptation of l./arhead.s to nel, or nodif.iedlrcapon systenrs or vehicles. BB: The distribution, by percentage, of tests made in the United States from theend of 1963 to 19?1 ( exctuding 21 "pr.ovshare " tests for civir obJectives) h.; ;;;"presented 12/ as foltovs. 1]/ Effgcts of a gonprehensirre test ban treaty on united states nationslthe Strategic Arms LinitationTalks and the comprehensive ?est Ban treaty of the rntelligence and Mir-itaryApplication of Nucrear Energy subcomnittee of the conmittee on Arms services,House of Rep"esent at ives , 95th Congress, Second Session, August 19T8.
**Analysis**
The text appears to be discussing the development and testing of nuclear weapons, which is a critical aspect of military technology and defense strategy. The text mentions various purposes of nuclear testing, such as improving yield-to-weight ratios, reducing costs, enhancing safety, and understanding long-term chemical and structural stability. This suggests that the text is related to the development and maintenance of military capabilities, rather than other areas such as economic development, natural resources, or education.

**Category**
Science and Technology, Industry