200兆赫高功率CW锁模YAG激光泵浦源研究

本文报导一台200MHz 12W平均功率的CW锁模Nd:YAG激光泵浦源,输出脉宽约100ps,能够可靠地长期稳定运转。     

稀土元素添加剂在导电铝中的作用机理

研究了在导电铝中添加不同稀土元素后,对脱硫、脱氧、细化晶粒、抑制高温下晶粒长大等作用;分析了稀土元素对导电率、抗冲击、显微硬度等影响的原因。通过实验证实,在所研究的几种稀土元素添加剂中,以稀土元素钇的效果为最佳。     

分光计调整的成像演示

介绍一种演示分光计调整的方法，可以在屏幕上演示分光计调整过程反射十字像的移动和成像系统的结构。     

黑龙江省科技成果推广方法得力效益显著

黑龙江省科技成果推广方法得力效益显著黑龙江省科技成果推广工作，紧密结合资源开发和产业结构调整，逐步引入市场机制，取得了显著的经济效益和社会效益。１９９１～１９９３年，全省共实施推广计划项目３０８项，其中国家重点推广计划项目１０３项，占３３．４％３累计...     

PALEOMONSOONS OF CHINA OVER THE LAST 130,000 YEARS——PALEOMONSOON VARIATION

Based upon the effect of land-sea interaction on the paleomonsoon variation and the time series of climatic proxy-indicators, the historical Asian monsoon variation over the last 130,000 and 18,000 years has been reconstructed with an emphasis on the basic characteristics of summer monsoon circulation. The monsoon-climatic cycles and associated model of environmental development over the central and eastern China are proposed and the mechanism of paleomonsoon variation of China preliminarily discussed. The variation of East Asian monsoon circulation should be regarded as a regional result of both solar-radiation changes and the global glacial-interglacial cycles. The episodic uplifting of the Qinghai-Xizang Plateau since the late Miocene has to a large extent controlled the forming and evolution of the paleomonsoon circulation of China.     

函数的图象与性质

函数的图象与性质是函数部分的主要内容，在高中数学竞赛中应用广泛．本讲主要研究函数图象变换及应用，利用函数的单调性、奇偶性、周期性解决竞赛中的问题．