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Himalaya' s Receding Glaciers The great majority of the world's glaciers appear to be declining at rates equal to or greater than long-established trends, according to early results from a joint NASA and United States Geological Survey (USGS) project designed to provide a global assessment of glaciers. At the same time, a small minority of glaciers are advancing. Scientists monitor only a few of India's vital glaciers, which are receding by as much as 100 feet each year. Billions of people in China and the Indian subcontinent rely on South Asia's Himalayan glaciers the world's largest store of fresh water outside the polar ice caps. The massive ice floes feed seven of the world's greatest Asian rivers in one of the world's most densely populated regions. Yet as global climate change slowly melts glaciers from Africa to the Andes, scientists say the glaciers in the Himalayas are retreating air a rate of about 33 to 49 feet each year—faster than in any other part of the world. In the Himalayas, the Gangotri Glacier, one of India's largest, is entitled to an even more dubious distinction. Recent studies reveal that the Gangotri, which forms a mass of ice about 18 miles long, is retreating at a rate of more than 100 feet a year. But according to government officials and environmental groups like Greenpeace, very little has been done in the way of a rigorous scientific study. Scientists are monitoring glacial melting on only a handful of the 7,000 glaciers that cover the Indian Himalayas. While ice reflects the sun's rays, lake water absorbs and transmits heat more efficiently to the underlying ice, kicking off a feedback that creates further melting. And at such a rapid retreat, a gradual increase in droughts, flash floods, and landslides are not the only issue to worry about, say environmentalists. Glacier changes in the next 100 years could significantly affect agriculture, water supplies, hydroelectric power, transportation, mining, coastlines, and ecological habitats. Just when power companies are planning more energy sources to power India's growing economy, a rising level of sediment in regional rivers is creating havoc for many grids. 'The power grid in Uttarkashi is constantly breaking down and that's because of the rise in sediment in the water being used at the hydro-power projects,' says Joseph Thsetan Gergan from the WADIA Institute of Himalayan Glaciology, a part of the Indian Department of Science and Technology. 'When the power breaks down, the people blame the Geological Survey of India or the Central Water Commission for not doing its work properly, but that's like thinking of digging a well when your house is already on fire.' While the Gangotri has been retreating since measurements began in 1842, the rate of retreat, which was around 62 feet per year between 1935 and 1971, has almost doubled. Global warming is causing Himalayan glaciers to rapidly retreat, threatening to cause water shortages for hundreds of millions of people who rely on glacier-dependent rivers in China, India and Nepal. In northwest China, the Qinghai Plateau's wetlands have seen declining lake water levels, lake shrinkage, the absence of water flow in rivers and streams and the degradation of swamp wetlands An added difficulty, says Mr. Gergan, is the lack of a sustained research effort since the 1970s. The Indian government's own recommendations, issued in March 2002 by the standing committee on Science and Technology, noted that glacial melting required immediate implementation of a program to measure and monitor the changes to the Gangotri and its impact on the Ganges river systems. 'It's not enough to just note the fact that the glaciers are melting,' Gergan says. 'The impact of that is not being focused on at all.' Melting ice may cause serious problems and all these impacts will change with time.
A.
Y
B.
N
C.
NG
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【单选题】企业以银行存款支付销售A产品运费3000元,支付产品广告费1000元。会计 分录为( )
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【单选题】要用于止咳而少用其镇痛的是
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【简答题】下图所示为一个支架,杆①为直径d=16mm的圆形钢杆,许用应力[σ] 1 =140MPa;杆②为边长a=100mm的方形截面木杆,许用应力[σ] 2 =4.5MPa。已知结点B处挂一重物G=40kN,试校核两杆的强度。
【单选题】图示支架杆 ① 为直径 d=16mm 的圆截面钢杆,许用应力 [ σ ]₁=140 Mpa 。杆 ② 为边长 a=100mm 的正方形截面木杆,许用应力 [ σ ]₂=4.5Mpa, 已知结点 B 处挂一重物 G=36KN ,试求两杆件的应力。(    )
A.
σ₁=140MPa,σ₂=9.0MPa
B.
σ₁=140MPa,σ₂=4.5MPa
C.
σ₁=105.5MPa,σ₂=4.5MPa
D.
σ₁=4.5MPa,σ₂=140MPa
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