scientific american - 1997 10 - special issue - the future of transportation
scientific american - 1997 10 - special issue - the future of transportation
... spend most of their travel time on the ground. The Past and Future of Global Mobility Scientific American October 1997 61 The Authors ANDREAS SCHAFER and DAVID VICTOR col- laborate on long-term and ... Mokhtarian 54 58 64 70 75 80 86 93 94 1 0 1 0 October 1997 Volume 277 Number 4 STOP THE FUTURE OF TRANSPORTATION THE FUTURE OF TRANSPORTATION...
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scientific american - 1994 10 - special issue - life in the universe
... understanding of the laws of nature. T he present gaps in our knowl- edge of the laws of nature stand in the way of explaining the ini- tial conditions of the universe, at 10 Ð12 second after the nominal ... distribution of matter are inti- mately linked; the observed expansion of the system of galaxies reveals the un- folding of space itself. An essent...
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scientific american - 2002 09 - special issue - a matter of time
... Meanwhile the floors tie the inner frame to the outer one, bracing the entire edifice. In the case of the World Trade Center, which was a state -of -the- art design in the late 1960s, the steel-mesh ... remember. The fact that we remember the past, rather than the future, is an observa- tion not of the passage of time but of the asymmetry of time. Nothing...
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scientific american - 1993 09 - special issue - life, death, and the immune system
... millions of women for more than 20 years beginning in the 1940s to pre- vent miscarriages. Use of the drug end- ed with the discovery that the daugh- ters of DES mothers are unusually like- ly to ... preexist in the fertilized egg. In- stead the code resides in four sets of mini-genes located in widely separated parts of the nucleus. Antibody diversi- ty springs from...
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scientific american - 1996 09 - special issue - what you need to know about cancer
... of- fered proof that ungulates—hoofed vertebrates related to deer—lived be- fore the Cretaceous-Tertiary extinc- tion, which wiped out the dinosaurs 65 million years ago. Eighty-five-million- year-old ... Bern- ers-Lee, PICS resolves the moral contra- diction that lies at the heart of existing schemes to regulate the Net. Because they inherit the assumptions of broad- castin...
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scientific american - 2003 09 - special issue - better brains
... pro- posed second-generation system known as Computer-Assisted Passenger Pre-Screening, or CAPPS II. In terms of the variety of in- formation, the sys- tem goes much fur- ther than the 1.0 ver- sion —and ... number, en- joyed high wages relative to those of their fa- thers. Well-off, they could afford to raise fam- ilies. When their children the baby boomers— came of age begin...
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scientific american special edition - 1999 vol 10 no1 - the future of space exploration
... MANAGER 31 0-4 7 7-9 299 fax 31 0-4 7 7-9 179 lcarden@sciam.com SAN FRANCISCO Debra Silver SAN FRANCISCO MANAGER 41 5-4 0 3-9 030 fax 41 5-4 0 3-9 033 dsilver@sciam.com DALLAS THE GRIFFITH GROUP 97 2-9 3 1-9 001 fax 97 2-9 3 1-9 074 lowcpm@onramp.net CANADA FENN ... S.A. ul. Garazowa 7 0 2-6 51 Warszawa, POLAND tel: +4 8-0 2 2-6 0 7-7 6-4 0 swiatnauki@pro...
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scientific american - 1993 10 - is los angeles winning the war on smog
... the velocity of seismic waves changes abruptly, probably be- cause of a change in the mineral struc- ture of the mantle rocks. The issue of whether the whole mantle mixes or whether the upper and ... that in almost one Þfth of all the vehicles on the road, the emissions-control equip- ment was either removed by the own- er or damaged by the use of leaded fu...
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scientific american - 1997 03 - the rising seas - how much of a threat
... the way from the sun’s in- terior to the earth and out to the farthest reaches of the solar wind. Some of its in- struments are now poised to resolve sev- eral other mysteries. Two of them, the GOLF ... polydiacety- lene film, which happens to be blue. But the binding of E. coli toxin to the other part of the molecule (the cell-surface re- ceptor) breaks the link...
Ngày tải lên: 12/05/2014, 15:21
scientific american - 1997 05 - the 100 - year weather forecast
... preda- tors. Once the cubs can move, though, the mothers bring them out into the open to join the rest of the pride. If any of the other females have cubs, they form a crèche and remain in near-con- stant ... cycles. It all depends on the risk, on the speed of the machine, on the cost of communication, on the importance of the problem —on a mil- lion variable...
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