典型炭材料微观结构及SO2吸附机理研究

采用SEM和低温氮吸附方法研究了碳纳米管和活性炭的表面微观形貌及孔隙结构,通过固定床研究了炭材料SO₂吸附机理。研究结果表明:活性炭大孔直接暴露于表面,中孔和微孔分布于大孔内部,"聚合"是碳纳米管的重要特征;椰壳活性炭是微孔型吸附剂,煤基活性炭孔隙主要由微孔和大孔组成,碳纳米管氮吸附有明显的毛细凝聚现象,中孔和大孔是其孔隙主要组成;活性炭SO₂吸附过程受物理吸附控制,碳纳米管SO₂吸附不同于活性炭,同时受到物理吸附和化学吸附控制;孔径小于0.7 mm的微孔是炭材料SO₂吸附的主要场所。     

十堰电视台播出系统备份和应急措施

播出系统完善的备份和应急措施是保障安全播出的必要手段.详细介绍了十堰电视台为确保安全播出,对硬盘播出系统的信号源、硬件、软件、电源和节目存储等采取的备份和应急措施.总结了在实践过程中积累的经验,对于市级电视台同行具有一定的借鉴意义.     

某型模块的热设计及仿真

以某型模块热设计为例,首先按自然散热方式进行理论计算,然后应用FloTHERM软件对导航模块的散热性能进行仿真分析,为电子设备的散热设计提供了设计依据和参考,最后对仿真分析的结果进行了分析总结。     

十堰电视台新闻数字直播系统

【】 本文描述了十堰电视台新闻直播系统的组成及功能。分享了Blackmagic Design数字切换台、数字矩阵、大洋科技的图文在线包装系统、迪乐普的虚拟演播室系统和极速studio播出视频服务器等关键技术。分析了直播系统的视音频信号流程,介绍了视音频信号的调度、分配、应急措施。运用音频混嵌技术,简化了信号流程,节省了设备资源。     

一种8点FFT算法的逻辑电路实现

文章讲述了一种8点FFT的verilog HDL设计实现，着重阐述了有符号的复数加／减法器的设计，并给出了整个系统仿真的结果，该设计可以在4个时钟内计算一个数据，最后该系统在Altera公司在FLEX10K的FPGA上成功地实现了综合，实验结果证明这种设计方法不但具有设计方法简单的优点，而且吞吐量可以达到2M／s的变换速度，已经完全能够满足目前一些系统的要求（如OFDM系统）。     

Coherent Acoustic Phonon and Its Chirping in Dirac Semimetal Cd_3As_2

Ultrafast optical spectroscopy of a single crystal of a Dirac semimetal Cd_3As_(2 )is carried out.An acoustic phonon(AP)mode with central frequency f=0.037 THz(i.e.,1.23 cm~(-1)or 0.153 meV)is unambiguously generated and detected,which we attribute to laser-induced thermal strain.An AP chirping(i.e.,variation of the phonon frequency)is clearly detected,which is ascribed to heat capacity variation with time.By comparing our experimental results and the theoretical model,we obtain a chirping time constant,which is 31.2 ps at 6 K and 19.8 ps at 300 K,respectively.Significantly,we identify an asymmetry in the AP frequency domain peak and find that it is caused by the chirping,instead of a Fano resonance.Moreover,we experimentally demonstrate that the central frequency of AP is extremely stable with varying laser fluence,as well as temperature,which endows Cd_3As_2application potentials in thermoelectric devices.     

Estimation of the chiral magnetic effect considering the magnetic field response of the QGP medium

The magnetic field plays a major role in searching for the chiral magnetic effect in relativistic heavy-ion collisions. If the lifetime of the magnetic field is too short, as predicted by simulations of the field in vacuum, the chiral magnetic effect will be largely suppressed. However, the lifetime of the magnetic field will become longer when the QGP medium response is considered. We give an estimate of the effect, especially considering the magnetic field response of the QGP medium, and compare it with the experimental results for the background-subtracted correlator H at RHIC and LHC energies. The results show that our method explains the experimental results better at the top RHIC energy than at the LHC energy.     

Analysis of Temperature Dependence of Silicon-on-Insulator Thermo-Optic Attenuator

The temperature dependence of silicon-on-insulator thermo-optic attenuators is analysed, which originates from the temperature dependence of characteristics of multimode interference. The attenuator depth and power consumption are independent of temperature while the insertion loss depends on the temperature heavily. The variation of the insertion loss decreases from 4.3 dB to i dB as the temperature increases from 273K to 343K.     

向列相液晶中的耦合自相位调制现象

通过实验研究了C60掺杂的向列相液晶(5CB)在低光强下的自相位调制现象。样品经过二波耦合实验之后液晶分子进行一定的取向,这时在水平和竖直偏振光的照射下可观察到明显的自相位调制现象。改变入射光的偏振方向可以看到自相位调制的衍射图样也随之改变,原因就是液晶折射率变化的各向异性。可见,液晶盒中的分子取向与光束的偏振方向有很强的依赖关系。