付费电视频道营销思路探讨

数字电视整体转换是目前全国广电行业的一件大事，对于已经完成整体转换的城市和地区来说，开展有别于传统业务的增值业务是网络运营商需要不懈努力的目标，尤其是付费电视节目的营销显得更为重要，从付费节目的现状、付费节目的特点、付费节目营销的实践等方面，阐述对付费节目营销的一些理念和理解，期望我国付费电视节目市场有更大的发展。     

国产Yb:YAG透明陶瓷实现激光输出

YAG单晶是高功率激光的重要材料,近年来高透明度多晶陶瓷作为激光介质引起人们广泛的注意.     

Numerical investigation of the nonlinear spectral broadening aiming at a few-cycle regime for 10 ps level Nd-doped lasers

We present a cascaded nonlinear spectral broadening scheme for Nd-doped lasers, featuring with long pulse duration and high average power. This scheme is based on two multi-pass cells (MPCs) and one multiple-plate supercontinuum generation (MPSG), and the numerical investigation is driven by a home-made Nd-doped fiber laser with 12 ps pulse duration, 50 kHz repetition rate and 100 W average power. The MPC-based first two stages allow us to broaden the pulse spectrum to 4 nm and 43 nm respectively, and subsequently, the MPSG-based third stage allows us to reach 235 nm spectral bandwidth. This broadened spectrum can support a Fourier-transfer-limited pulse duration of 9.8 fs, which is shorter than three optical cycles. To the best of our knowledge, it is the first time to demonstrate the possibility of few-cycle pulses generation based on the 10 ps level Nd-doped lasers. Such few-cycle and high average power laser sources should be attractive and prospective, benefiting from the characteristics of structure compact, low-cost and flexibility.     

c-Ha-ras反义RNA对细胞恶性表型逆转作用的研究

本文应用表达反义c-Ha-ras癌基因上游区第一外显子2.0kb片段的RNA质粒,转染经c-Ha-ras转染的恶性细胞系GCM-3T3与REF-4.3,造成恶性行为的改变.表现在生长速度减慢,软琼脂克隆形成能力下降、裸鼠中致瘤力减小和肿瘤的病理分化程度增加,其中原来可造成转移的GCM-3T3细胞经反义RNA转染后肺转移率从60％降至12.5％,同时,两种细胞经转染后分离的克隆都有显著的ras癌基因产物p21蛋白表达的减少.本工作证明了反义RNA在癌基因表达上的调控和抑制细胞恶性行为的作用.