第7届国际树木年轮大会

2006年6月12-17日，第7国际树木年轮学大会（the 7th International Conference on Dendrochronology）在北京隆重召开。     

Effects of historical land cover changes on climate

In order to explore the influence of anthropogenic land use on the climate system during the last mil- lennium, a set of experiments is performed with an Earth system model of intermediate complexity—— the McGill Paleoclimate Model (MPM-2). The present paper mainly focuses on biogeophysical effects of historical land cover changes. A dynamic scenario of deforestation is described based on changes in cropland fraction (RF99). The model simulates a decrease in global mean annual temperature in the range of 0.09-0.16℃, especially 0.14-0.22℃ in Northern Hemisphere during the last 300 years. The responses of climate system to GHGs concentration changes are also calculated for comparisons. Now, afforestation is becoming an important choice for the enhancement of terrestrial carbon sequestration and adjustment of regional climate. The results indicate that biogeophysical effects of land cover changes cannot be neglected in the assessments of climate change.     

Impacts of climate warming on heating energy consumption and southern boundaries of severe cold and cold regions in China

Impacts of climate warming on heating energy consumption and southern boundaries of severe cold and cold regions of China in the past 20 years are analyzed by using daily and monthly average tem- perature data from 590 weather stations in China and based on regulations of Heating Ventilation and Air Conditioning Design Rules (GB50019-2003) and Thermal Design Rules for Civil Building (GB50175-93) (China National Standard). The contribution of climate warming to coal saving for heating during cold seasons in major cities is calculated according to indices of coal consumption for heating in major cities during cold seasons defined in Energy Conservation Design Standard for New Heating Residential Buildings (JCJ26-95). Comparing with the period before 1980, southern boundaries of se- vere cold and cold regions shift toward north up to 2 degrees in latitude since the mid-1980s. Theo- retically, climate warming could contribute to 5%―10% coal savings for heating since the mid-1980s in major cities, and even more since the mid-1990s.     

The orbital scale evolution of regional climate recorded in a long sediment core from Heqing, China

Based on the analysis of carbonate content and loss on ignition for a long sediment core (737 m in length) drilled in Heqing, the orbital scale evolution of the Southwest Monsoon is revealed, by using overlapped spectral analysis and filter methods. It is shown that the obliquity cycle and precession cycle are the key factors for the Southwest Monsoon evolution and that the change of the global ice volume and the uplift of the Qinghai-Tibetan Plateau also impose great influences on it.     

蚕室温湿度的调控措施

养蚕季节气候差异大，而温湿度变化直接影响着蚕的生长发育。春蚕和晚秋蚕期气温低，不能满足蚕生长发育所需的温度，而夏秋蚕期常出现高温高湿和干旱的饲养环境，对蚕体的生长发育极为不利。在高温环境下，当温度超过30％时，蚕体内大多数酶的活性降低，蚕体变弱，抗病力下降。如再加高湿，蚕体水分散发困难，体温升高，不利于蚕的生长发育，而有利于多种真菌滋生，引起僵病发生。     

中共中央、国务院隆重举行国家科学技术奖励大会

中共中央、国务院2月27日上午在北京隆重举行国家科学技术奖励大会。党和国家领导人胡锦涛、温家宝、曾庆红、李长春出席大会并为获奖代表颁奖。温家宝代表党中央、国务院在犬会上讲话。李长春主持大会。     

中科大创世界第一 量子密码确保网络安全

国际上第一个量子密码网络系统近日在京测试运行。记者从中国科技大学获悉，由郭光灿院士领导的中科院量子信息重点实验室，利用自主创新的量子路由器，在北京网通公司商用通信网络上率先完成四用户量子密码通信网络的测试运行，确保了网络通信的安全。     

“锯”出金藏立潮头——记厦门金藏机电有限公司

锯,或许是目前世界上最普通的工具,有哪个人不知道它?有哪个人没使用过它?可是,锯,或许也是目前世界上最奇妙的工具,又有多少人能够说清楚它?又有多少人能造得好它?     

技术市场与现代服务业相关指标的对应关系

大力发展现代服务业，是实现首都经济结构调整、优化、升级，以及落实中央对北京“世界城市、国家首都、文化名城、宜居城市”的城市功能定位的重要选择。市科委研究制定“北京现代服务业促进”主题计划实施方案的目的，也是力图在下一个五年计划内，发挥首都科技资源优势，为北京现代服务业的发展提供科技促进指导，建设北京现代服务业创新体系，加快科技在北京现代服务业发展中的广泛应用，     

人体自然之谜

真实事件还是凭空捏造？ 我们生活在一个危险的世界里，身边有各种易燃，易爆的东西。那么，我们的身体会不会突然起火？这种想法存在己久，一些莫名其妙的燃烧现象似乎也证实了人体自燃的发生。[编者按]