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(B)  “At a time when a bomb smuggled by terrorists is as big a concern as one from a foreign power, delivered by missile or airplane, an attack at a port is definitely a more likely scenario,” says Thomas Cartledge, a nuclear engineer with the U.S. Defense Threat Reduction Agency (DTRA) in Fort Belvoir, Virginia. But forensic experts, who rely largely on nuclear test data collected years ago in Western deserts, lack a clear picture of how energy from a detonation would propagate in the highly saturated geology of many U.S. port cities. To remedy that, DTRA last October quietly staged Humming Terrapin: a 2-week test series at the Aberdeen Proving Ground in Mainland that detonated nearly 2 metric tons of conventional explosives to simulate nuclear blast effects in shallow water.  Since the 9/11 attacks, the U.S. government has mounted a major effort lo prevent a nuclear bomb from being smuggled into a port. It has outfitted points of entry with radiation detectors, and it is working with foreign ports toward a goal of having all U.S.-bound cargo scanned for nuclear materials before departure. But it’s well nigh impossible to track the myriad small craft flitting in and out of the 361 U.S. ports and 153,000 kilometers of open shoreline.“There are a zillion fishing boats that leave U.S. ports and nobody inspects them when they come home,” says Matthew Bunn, a specialist on nuclear terrorism at Harvard University’s Belfer Center for Science and International Affairs. “If there is highly enriched uranium metal that’s shielded and below the water line, it’s going to be really tough to detect at long range.”  In case the unthinkable happens, a sensor array called Discreet Oculus that is being installed in major U.S. cities would capture key forensic information. The array, which DTRA is still developing, would record radiation and seismic waves emanating from the blast “Discreet Oculus is up and running in several U.S. cities now,” Cartledge says. A sister system— a portable array that runs on battery or solar power called Minikin Echo—will be deployed at major events such as the Olympics or the Super Bowl. Data from Cold War-era nuclear testing and simulations are being used to calibrate the sensors.  Yet past U.S. testing is a poor proxy for detonations at a port, says Tamara VanHoose, a U.S. Army major and nuclear engineer at DTRA. A closer analog is a little-known campaign in 1963-64 in which the U.S. Air Force conducted a series of detonations of as much as 10 tons of chemical explosives at the bottom of Lake Superior. The tests offered a wealth of data on how seismic waves traverse the land-water interface, but they “were not instrumented to meet our needs,”VanHoose says.  Humming Terrapin aims to fill that gap. VanHoose and colleagues set up Discreet Oculus and two Minikin Echo arrays at Aberdeen, adding hydrophones, which are not currently included in either array. Another set of sensors probed how seismic signals ripple through East Coast rock layers.“These are wel-type geologies versus the granite geologies that we see out at the typical desert sites where we’ve done historic testing,” VanHoose says.   All of the following are true EXCEPT______.

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(A)  Board games are growing as a popular hobby in mainstream culture and academic circles, thanks, in part, to the rise of “Eurogames,” which emphasize strategy and individual development over luck and conflict. Given their wide appeal, board games also represent a media form ripe with potential for science education. This review presents two board games with environmentally themed expansions that can help kick-start discussions on the effects of climate change.   Evolution: Climate is the newest stand-alone expansion by North Star Games, released on 1 November 2016. In the titular base game (Evolution), players create new animal species by combining trait cards designed to maximize survival. The result is a frenzied evolutionary arms race, as players add and discard traits in response to starvation risk and predation by other species.  The game even comes with a sheet of proposed scientific names that tip their hat to traditional Latin nomenclature while borrowing from modem vernacular. A climbing carnivore, for instance, may have the cheeky name of Ascendo non-nom.   In the new expansion, climate oscillates between an “Ice Age” and “Scorching”temperatures, driving evolution by selectively reducing populations of maladapted species that are too large or small in body size. One-time events, such as volcanic eruptions and glacial thaws, reduce food availability or select for certain body sizes. New trait cards bring with them new trade-offs and decisions: Should one invest in heavy fur for freezing temperatures or horns to discourage an opponent’s carnivore?  The species created in this game may raise questions during and after play. Just how adaptive is a long neck on a burrower? How can an ambush carnivore realistically cooperate with a hibernating climber. Another game is when players discover the Red Queen hypothesis on their own. “I’m just trying to keep up!” is a common refrain, as players struggle to keep their species alive amidst ever-evolving predators and prey.  The addition of climate not only adds another layer of complexity to players’ strategies but also emphasizes its role as a vehicle for evolution. Players witness firsthand how species with small populations suffer greater extinction risks when climate changes, especially with major shifts.  Evolution: Climate positions players to discuss current challenges to conservation efforts. Biotic and abiotic factors regularly place pressure on populations, and environmental stochasticity can be the proverbial nail in the coffin for maladapted species. Extinctions can spell further changes in community assemblage, a reminder of the interlinked nature of living systems.  Catan Scenarios: Oil Springs, by Mayfair Games, is an expansion of the critically acclaimed game The Settlers of Catan. The base game centers on a race to colonize the fictional island of Catan. Placement of a player’s initial settlements determines his or her access to resources, which in tum fuel further development of roads, settlements, and, eventually, cities. The first player to cinch 10 victory points wins.  Oil Springs introduces a new resource (oil) to the mix. One unit of oil can be converted to two of the original resources or spent to upgrade cities to metropolises, allowing for faster development. The flip side is that its overuse wreaks disasters, either by flooding coastal settlements or corrupting resource tiles into unproductive wastelands. Too many disasters will prematurely end the game with an island-wide deluge, encouraging players to stem their collective usage.   What does the passage mainly discuss?

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