从松节油中高效分离α-蒎烯

设计出一种从松节油中高效分离α-蒎烯的蒸馏-分馏工艺，对工艺条件进行了优化研究，产物经气相色谱-质谱联用测定、红外光谱结构表征，确证为α-蒎烯，纯度为98．76％，收率达到72．92％。     

Structure, thermal-stability and reducibility of Si-doped Ce–Zr–O solid solution

The Si-doped Ce–Zr–O solid solutions have been prepared by the reverse microemulsion method. The effects of Si and its content on the structure characters, thermal-stability and reducibility of the Ce–Zr–O solid solution have been studied by N₂ adsorption, XRD, laser Raman (LR), TPR, FT-IR, NMR and XPS methods. The results indicate that, there are the bonds of Si–O–M (Ce or Zr) in the Ce–Zr–Si–O solid solutions, and the presence of Si can increase obviously the surface area, thermal-stability, crystal lattice distortion rate, and reducibility of the solid solution. The surface area of the sample with 20 wt.% Si reaches 153 m² g⁻¹ after being calcined at 900 °C for 6 h. The Ce–Zr–O solid solution with 5.2–10 wt.% Si shows excellent thermal-stability and reducibility.     

基于PCI和LVDS的高速数据存储系统的设计

针对某系统图像数据量大、传输速率快的特点,提出了采用PCI总线协议完成PC与高速数据存储系统之间的通信,利用LVDS总线协议传输数据并进行混合编帧的解决方案。为提高数据存储速率,使用Flash交叉双平面页编程技术,将写入速度提高到30 MB/s,有效地满足了图像高速存储的要求。针对数据的码率匹配,通过构建片内FIFO缓存来实现。测试结果表明,所设计的数据存储系统能够稳定地接收并存储图像数据,而且具有很高的可靠性。     

气相法合成纳米颗粒的制备技术进展

本文综述了气相法合成纳米颗粒材料的主要制备技术，并介绍了制备方法的最新进展－化学气相冷凝技术制备纳米颗粒材料，提出了制备纳米颗粒技术研究中面临的问题及今后的发展方向。     

基于超高温光谱的C/C材料烧蚀产物研究

用“星形”等离子发生器及国产的等离子体火炬进行了炭基复合材料烧蚀实验，采用实验中光谱检测对烧蚀产物进行了分析。经分析发现：在“星形”等离子发生器产生的3500K以下烧蚀环境的光谱中，产物以CO为主，而在国产的等离子体火炬产生的5500K以上烧蚀环境的光谱中，产物以CN、C2、C1和CO为主。光谱检测结果与热化学烧蚀计算的产物吻合得很好，验证了热化学计算的正确性。     

Surface morphology and nodule formation mechanism of cellulose acetate membranes by atomic force microscopy

By the use of atomic force microscopy (AFM), formation mechanism of nodular structure in cellulose acetate membranes was systematically investigated. Elementary factors affecting the nodule formation were delineated on the basis of both kinetic and thermodynamic considerations. It was shown that (1) the exact nature of nodular structure is thermodynamic equilibrium glassy state; nodular structure will vanish in the rubbery state; (2) the thermodynamic factor affecting nodule formation is the membrane formation temperature; with the membrane formation temperature decreasing, more chain segments are able to form nodular structures; (3) nodule formation is dependent on the segment rearrangement; variation of the solvent environment is the major kinetic factor affecting the segment rearrangement and nodule formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1328–1335, 2003     

An energy conservation replica placement strategy for Dynamo

With the fast development of cloud computing and wide application of cloud storage, the energy efficiency of cloud storage system is drawing significant attention from researchers or specialists. For the typical Dynamo cloud storage system, we design a new policy instead of the consistent hashing policy which is a combination of consistent hashing and sequential policy. The basic idea of this policy is that it divides the nodes into groups and allows each other to be mirror modes so it can find the full coverage subset of data items easily. Also we use autoregressive-moving-average model to estimate the task numbers of servers so that when under low utilization period, certain numbers of servers can be turned off to save energy. Based on the model, we demonstrate that it can save up to 23.7 % energy and maintain load balancing of servers. Furthermore, we compare our policy with Heuristic which is a classical energy conservation policy for cloud storage system that is based on consistent hash table. And we find several advantages of our policy which include finding the minimum subset of full coverage as well as other aspects.     

基于BACnet/IP的设备与实时数据库通信实现

针对不同厂商、不同系统的楼宇自控设备互操作、互通信的局限性,分析了BACnet/IP技术和实时数据库,设计开发了一种基于BACnet/IP技术的实时数据库DasRdb的设备驱动程序。该设备驱动程序采用UDP通信方式,通过调用每个BACnet/IP设备的标准接口函数来驱动实时数据库DasRdb分别进行写操作和读操作,能够有效地实现BACnet/IP设备与实时数据库DasRdb之间的通信,从而使楼控设备的互操作成为可能。现场工程应用表明,该程序的运行契合BACnet的一致性要求,具有简单、高效、精确度高、实时性好的特点。