已知:①C(石墨,s)=C(金刚石,s)△H=QkJ•mol-1(Q>0)②在稀

题型:选择题

问题:

已知:①C(石墨,s)=C(金刚石,s)△H=Q kJ•mol-1(Q>0)②在稀溶液中,H+(aq)+OH-(aq)=H2O(l)△H=-57.3kJ•mol-1,下列有关说法正确的是(  )

A.金刚石比石墨稳定

B.石墨比金刚石稳定

C.浓硫酸与氢氧化钠溶液反应生成1molH2O时放出的热量也为57.3kJ

D.1mol醋酸与1mol氢氧化钠的稀溶液混和反应完全放出的热量等于57.3kJ

考点:能量的相互转化
题型:选择题

There is no question that the academic enterprise has become increasingly global, particularly in the sciences. Nearly three million students now study outside their home countriesa 57% increase in the last decade. Foreign students now dominate many U.S. doctoral programs, accounting for 64% of Ph. D. s in computer science, for example.
Faculty members are on the move, too. Half of the world’s top physicists no longer work in their native countries. And major institutions such as New York University are creating branch campuses in the Middle East and Asia. There are now 162 satellite campuses worldwide, an increase of 43% in just the past three years.
At the same time, growing numbers of traditional source countries for students from South Korea to Saudi Arabia (沙特阿拉伯), are trying to improve both the quantity and quality of their own degrees, engaging in a fierceand expensiverace to recruit students and create world-class research universities of their own.
Such competition has led to considerable hand-wringing in the West. During a 2008 campaign stop, for instance, then—candidate Barack Obama expressed alarm about the threat that such academic competition poses to U. S. competitiveness. Such concerns are not limited to the United States. In some countries, worries about educational competition and brain drains have led to academic protectionism. India, for instance, places legal and bureaucratic barriers in front of Western universities that want to set up satellite campuses to enroll local students.
Perhaps some of the anxiety over the new global academic enterprise is understandable, particularly in a period of massive economic uncertainty. But educational protectionism is as big a mistake as trade protectionism is. The globalization of higher education should be embraced, not fearedincluding in the United States. There is every reason to believe that the worldwide competition for human talent, the race to produce innovative research, the push to extend university campuses to multiple countries, and the rush to train talented graduates who can strengthen increasingly knowledge-based economies will be good for the United States, as well.

A feature of the globalization of the academic enterprise is that more students ______.

A. study in foreign countries
B. major in computer science
C. take joint doctoral programs
D. return home after studying abroad

题型:选择题

对化学反应限度的叙述,不正确的是(  )

A.任何可逆反应都有一定的限度

B.化学反应达到限度时,正逆反应速率相等

C.达到化学平衡状态也就达到化学反应的最大限度

D.化学反应的限度是不可改变的

题型:选择题

二极管最大反向电流一般不超过()。

A、几十微安

B、几十毫安

C、1安培

D、5安培

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治疗肾阳不足,肠燥津枯便秘的药物是()

A.巴戟天

B.肉苁蓉

C.仙茅

D.淫羊藿

E.胡芦巴

题型:选择题

急性乳腺炎的主要致病菌为

A.金黄色葡萄球菌
B.大肠杆菌
C.溶血性链球菌
D.表皮葡萄球菌
E.肺炎双球菌

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