共查询到20条相似文献，搜索用时 15 毫秒
1.
Europe's terrestrial biosphere absorbs 7 to 12% of European anthropogenic CO2 emissions 总被引：2，自引：0，他引：2
Janssens IA Freibauer A Ciais P Smith P Nabuurs GJ Folberth G Schlamadinger B Hutjes RW Ceulemans R Schulze ED Valentini R Dolman AJ 《Science (New York, N.Y.)》2003,300(5625):1538-1542
Most inverse atmospheric models report considerable uptake of carbon dioxide in Europe's terrestrial biosphere. In contrast, carbon stocks in terrestrial ecosystems increase at a much smaller rate, with carbon gains in forests and grassland soils almost being offset by carbon losses from cropland and peat soils. Accounting for non-carbon dioxide carbon transfers that are not detected by the atmospheric models and for carbon dioxide fluxes bypassing the ecosystem carbon stocks considerably reduces the gap between the small carbon-stock changes and the larger carbon dioxide uptake estimated by atmospheric models. The remaining difference could be because of missing components in the stock-change approach, as well as the large uncertainty in both methods. With the use of the corrected atmosphere- and land-based estimates as a dual constraint, we estimate a net carbon sink between 135 and 205 teragrams per year in Europe's terrestrial biosphere, the equivalent of 7 to 12% of the 1995 anthropogenic carbon emissions. 相似文献
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Agriculture is facing great challenge in meeting global food security and is expected to face even greater challenge under climate change. The overall goal of this paper is to examine how finance can be used to achieve the joint objectives of development, mitigation of and adaptation to climate change in agriculture in developing world based on literature review. The results show that agriculture is much under invested and foreign aid also has not increased appropriately to assist developing countries to maintain sustainable agriculture under climate change. There are a wide range of areas in mitigation of and adaptation to climate change that need substantial investment. Major areas and successful cases mitigation of and adaptation to climate change in agriculture that have worked in developing countries are examined. A list of areas that have worked, could work and be scaled up or transferred is identified and discussed. This study concludes that mainstreaming agricultural mitigation and adaptation into agricultural development programs, enhancing local capacity, and considering different stakeholders＇ needs are major experiences for successfully financing sustainable agriculture under climate change. 相似文献
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Koenig R 《Science (New York, N.Y.)》2000,289(5487):2019b
Disaffection with the European Union's (E.U.'s) flagship research effort has found a sympathetic ear in the program's upper echelons. Last week, the E.U.'s top two research officials said they are pushing for big changes in the successor to Europe's 5-year, $17 billion Framework 5, including stronger efforts to coordinate research across the continent and to support innovative projects. 相似文献
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Watson A 《Science (New York, N.Y.)》2000,290(5495):1287b
Space is too important to Europe to be left to scientists alone, according to a report on the future of the European Space Agency (ESA) released last week. The report (available at www.esa.int) concludes that better coordination between ESA and the business and defense sectors is essential to Europe's development. 相似文献
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自然灾害下的农业保障体系构建 总被引：3，自引：1，他引：2
自然灾害是人类经济生产所面对的巨大问题,特别是对农业生产,具有极大的破坏性。一般在自然灾害之后,当地农业的经济效益便会大幅降低,甚至为零。从事农业生产的农民便成为自然灾害的直接受害者,付出的劳动不但得不到收益,可能还要承担巨大的损失。这时便需要一个有力的保障体系在自然灾害来袭之后,减少农业生产者的损失,能使他们迅速地在自然灾害之后恢复生产能力,保障经济的顺利运行。 相似文献
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Lenoir N 《Science (New York, N.Y.)》2000,287(5457):1425-1427
Europe's historic plurality and the lack of a commonly accepted definition of the moral status of the embryo have led to varying regulation in European countries. Council of Europe and European Union legislation, based on fundamental ethical principles, does exist for specific issues, such as prohibition against producing embryos solely for research. Such principles have recently been elucidated by the European Group on Ethics in Science and New Technologies. Newly emerging research techniques are beginning to cause reconsideration of the regulation of embryo research in Europe. 相似文献
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温室凯特杏园明亮熊蜂和意大利蜜蜂的传粉生物学比较 总被引：1，自引：0，他引：1
对明亮熊蜂和意大利蜜蜂在温室凯特杏园的传粉生物学特性进行研究.结果表明,这2种蜂都可以代替人工弹花为温室杏园提供有效的传粉服务,但其传粉生物学特性不同.明亮熊蜂的趋光性差,适应温室环境能力强,活动起点温度为8.3℃,晴天日工作时间为7.85 h,访花速度为10.70朵.min-1;偏爱采集花粉,平均携粉率为31.59%.意大利蜜蜂的趋光性强,喜欢访问树冠上部的花朵;其活动受温度和光照条件的影响较大,在温度低于15℃的阴雪天气传粉活动停止,晴天日工作时间为5.34 h,访花速度为8.80朵.min-1;偏爱采集花蜜,平均携粉率仅为11.08%.因此,在低温条件下明亮熊蜂的传粉效果比意大利蜜蜂好. 相似文献
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土壤深松技术的应用研究 总被引：23，自引：0，他引：23
郭新荣 《山西农业大学学报(自然科学版)》2005,25(1):74-77
以铧式犁为主的传统耕作制度制约着我国农业的发展。通过对土壤深松技术的分析, 结果表明: 该技术克服了以铧式犁为主的传统耕作制度的弊端, 有利于作物生长、可防止水土流失。通过对土壤深松机具的工作原理及其在田间的试验研究, 结果表明: 在土壤深松机具中, 全方位深松机优越于其它类型的深松机具, 应是我国保护性耕作中首选的优良机型。 相似文献
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A test of climate, sun, and culture relationships from an 1810-year Chinese cave record 总被引：15，自引：0，他引：15
Zhang P Cheng H Edwards RL Chen F Wang Y Yang X Liu J Tan M Wang X Liu J An C Dai Z Zhou J Zhang D Jia J Jin L Johnson KR 《Science (New York, N.Y.)》2008,322(5903):940-942
A record from Wanxiang Cave, China, characterizes Asian Monsoon (AM) history over the past 1810 years. The summer monsoon correlates with solar variability, Northern Hemisphere and Chinese temperature, Alpine glacial retreat, and Chinese cultural changes. It was generally strong during Europe's Medieval Warm Period and weak during Europe's Little Ice Age, as well as during the final decades of the Tang, Yuan, and Ming Dynasties, all times that were characterized by popular unrest. It was strong during the first several decades of the Northern Song Dynasty, a period of increased rice cultivation and dramatic population increase. The sign of the correlation between the AM and temperature switches around 1960, suggesting that anthropogenic forcing superseded natural forcing as the major driver of AM changes in the late 20th century. 相似文献
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郭如灼 《福建农林大学学报(自然科学版)》1987,(3)
本文提出一种农业生产规划中编制初始方案的新方法。通过实例计算对比,证实采用该新方法编制的初始方案比采用现在常用的最小(大)元素法编制的初始方案更合理,能更快地训整到最优方案,使计算量大大减少. 相似文献
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《Science (New York, N.Y.)》1989,243(4893):876
Because of a transmission error, the West German government's position on Europe's genome program was incorrectly stated in David Dickson's News & Comment article "Genome project gets rough ride in Europe" (3 Feb., p. 599). The Bundestag has given its qualified approval to the program. It has not endorsed the views of a parliamentary committee that opposes the effort, as the article stated. 相似文献
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本设计将红外遥控与单片机AT89C51相结合实现一款多功能红外遥控开关,利用单片机AT89C51的编程实现的控制电路,实现按键显示,工作状态显示,自动报警等功能。以遥控小车为例,利用红外遥控器使小车能够前行、倒退、左转、右转、高低档、停止和启动,以及小车的工作状态和小车速度显示,使用PWM对小车进行调速。力求将理论联系实际结合,并通过实践验证理论的可行性,设计一款多功能红外遥控开关,使人们的生活方式更加便利。 相似文献
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Balter M 《Science (New York, N.Y.)》2000,288(5475):2298-2299
In the next few weeks, Europe's most advanced high-security pathogen lab is expected to open for business in the southern French city of Lyons, but the long-anticipated debut of this "hot" lab is not turning out to be a joyous occasion for some of those involved. Last week, the Marcel Mérieux Foundation, which paid for the lab's construction, announced that the Pasteur Institute will take over its "scientific direction" and gave Pasteur the authority to name the lab's director. The leading candidate is a Pasteur scientist, which would leave the lab's current director out in the cold. 相似文献
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Frutkin AW 《Science (New York, N.Y.)》1970,169(3943):333-339
NASA has developed an extensive program of international cooperation, which opens the entire range of its space activities to foreign participation and benefit. The program has involved developing as well as advanced countries in activities that are fruitful scientifically, technically, economically, and (it may be hoped) politically. "Gaps" or limitations in the program are found in the areas of manned space flight and large booster development and in cooperation with the Soviet Union. In the first case, the low level of European budgeting is the prime explanation, perhaps reflecting Europe's late start in the space business and an early underestimate of its values and possibilities. In the second case, the explanation seems to rest with Soviet political views rather than with technical problems or any lack of interest by the United States. Openhanded efforts are currently under way to raise the level of foreign participation in the space programs of the next decade, but it is too early to estimate their chances of major success. Public commentary could undoubtedly assist these efforts more effectively if it were directed more clearly to the actual sources of restriction on foreign participation. Despite the restricting factors abroad, however, there is every reason to persevere with existing and improved programs for international cooperation. 相似文献
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陕北马海毛山羊选育方案 总被引：1，自引：0，他引：1
在分析陕北发展马海毛山羊的必要性与可能性的基础上,提出选育陕北马海毛山羊新品种的选育指标、杂交方案。计划从1988年开始,用安哥拉山羊为父本、陕北黑山羊为母本,采取级进杂交方式,开展大规模改良工作,要求在15～20年内选育出陕北马海毛山羊新品种,并提出相应的选种、饲养、管理、繁殖等一系到配套技术。 相似文献
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陈曦 《信阳农业高等专科学校学报》2007,17(3):70-72
绝大多数的固始人,特别是文化程度较高的以及18~30岁年龄段的人,对普通话的实用价值认同度非常高,但对普通话的情感价值认同度却较低。不同年龄、不同性别、不同文化程度的人们对普通话实用性价值的评价不同,有过外出打工、经商经历或与外界接触较多的人们对学习和掌握普通话情有独钟。今后在该地区推广普通话,应着重提高普通话的情感价值。 相似文献
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ELLSA反应板的利用,目前仅为一次性的。本试验采取5种不同清洗液对其进行洗涤处理,对比试验结果表明:不同浓度浓硫酸和重铬酸钾配制的清洗效果好,尤以高浓度的效果最佳,可行性强。 相似文献