温度敏感葡聚糖凝胶的合成及其细胞相容性研究

合成了N-异丙基丙烯酰胺（NIPAAm）与葡聚糖的共聚水凝胶，利用红外光谱表征了单体和凝胶结构，研究了水凝胶在去离子水和细胞培养基中的温度响应性，并对凝胶进行了细胞培养和脱附研究．结果表明，共聚凝胶具有很好的温度敏感性和细胞相容性，可以通过控制温度变化，实现对细胞的无损伤脱附．     

Frequency shift keyed narrowband interference rejection: optimal exponential weighting factor for the RLS algorithm

Cochannel narrowband interference can limit the performance of direct sequence spread spectrum (DSSS) and high frequency (HF) systems. Narrowband interference (NBI) can be single tone, chirped or frequency shift keyed (FSK) in nature and numerous techniques for its removal have been proposed. Linear adaptive prediction filters based on autoregressive modelling have been suggested owing to their ability to perform in a non-stationary environment. In the FSK narrowband interference case, adaptive filters are susceptible to excess residual errors owing to instantaneous frequency step changes and the finite convergence time required for the filter to adapt to a new interference frequency. The signal degradation owing to this type of interference becomes greater in high SNR regimes and has been found to be a function of the frequency parameters of the FSK interference signal. The paper discusses the convergence and frequency tracking properties of the recursive least squares (RLS) adaptive lattice filter using a posteriori estimation errors in the presence of FSK narrowband interference. An optimal exponential weighting factor that balances convergence time and steady state error is derived for this case of NBI. Results are compared to those of a previously proposed fast converging minimum frequency error (FCMFE) RLS lattice filter.     

光度法测定药品和食物中的微量VC

采用一种简单、快速的方法测定VC,该方法基于在室温下,抗坏血酸能快速地将Fe3 还原成Fe2 ,Fe2 与2,2’-联吡啶反应生成红色配合物,配合物的最大吸收峰位于520 nm波长处,VC的质量浓度在0.088~7.0 mg/L范围内符合比尔定律,该方法用于食品和药片中VC含量的测定,结果的相对标准偏差小于1.5%,回收率在96.3%~105.0%之间.     

Effect of Wall Surface Properties at Different Drying Kinetics on the Deposition Problem in Spray Drying

Current methods in alleviating the wall deposition problem in spray drying emphasize mainly controlling the stickiness of the drying particles and less attention is placed on the properties of the dryer wall. In this experimental study, the effect of wall surface properties on the deposition mechanism has been investigated. Properties considered in classifying different wall materials were surface energy, roughness, and dielectric properties. The model solution contained sucrose, representing low-molecular-weight sugars commonly encountered in spray drying of fruit and vegetable juices. The effect of wall properties on deposition was explored at different drying rates producing particles of different surface rigidity. Larger surface roughness produced higher deposition fluxes for particles with high impact velocity and moisture. Surface energy and surface roughness were found to have no significant effect for dry rigid particles at the middle and bottom elevation of the drying chamber. However, material with lower surface energy (Teflon) exhibited less deposition for rubbery particles at such elevations. Analysis shows that dielectric wall material (Teflon) tends to enhance deposition of dry particles because of attrition at the surface. Higher wall temperature was found to produce slightly more deposition. The results of this work give a general indication of the effect of wall material on the deposition problem and provide the fundamental understanding for further studies along this line. Proper selection of dryer wall material will provide potential alternatives for reducing the deposition problem.     

基于遗传算法的土钉支护结构优化设计研究

通过建立三维有限元模型,对土钉支护的变形和受力性能进行分析,得出土钉力的合理分布。在此基础上,考虑土钉支护的水平位移,采用遗传算法,对土钉支护的结构优化设计进行研究,建立了土钉支护结构的优化设计数学模型,并编制了相应的计算程序。通过算例分析,并与基于极限平衡分析的优化结果相比较,得出合理的土钉支护结构设计的参考结论。     

工程钻机在沙卵石地区的物探钻井

川西平原属沉积平原，不到2m厚的表土下面全是沙卵石，沙卯石厚度达二、三十米。地面覆盖农田，沟垄纵横，限制了车载钻机的进入。以往地震勘探多采取浅井组合方式激发，所获得的地震资料能量差、面波强，对农田破坏面积大。若使用SH30—2A型轻便工程钻机，配上自制的冲击管，采取冲击钻进，从管中下药柱的方式，可实现沙卵石地区的深井激发，提高资料采集质量，且效率高、成本低。     

One-to-Many and Many-to-One Optical Chaos Communications Using Semiconductor Lasers

A theoretical construction of one-to-many (OTM) and many-to-one (MTO) chaos synchronization communications using semiconductor lasers is presented. One center laser provides strong injections (strong link) to other side lasers, and the side lasers also provide weak injections (weak link) to the center one. Simulation results show that the side lasers synchronize with the center laser through injection-locking. In addition, messages transmitted via the strong links or the weak links experience strong chaos pass filtering, enabling us to realize OTM and MTO communications.     

美国火灾报警系统的新技术需要更多的培训

如今市场上大多数火灾报警系统的运行需要程序化的软件。随着软件技术的发展，消防行为已担心在安装的可靠性上可能下降。 如今的软件技术为火灾报警系统提供了更多灵活的和可操作的控制，安装维修系统的技艺更灵活更可操作控制需要更多的投资。但是这种灵活的和可操作的控制是需要成本的，还需要安装和维修系统的技术人员掌握一定的工程技巧。     

影响道路沥青低温抗裂性能的因素

用弯曲梁流变仪、直接拉伸试验机对7种国内外油源沥青样品进行了低温抗裂性能的评价，从沥青的四组分、相对分子质量及其分布来分析其对沥青低温抗裂性能的影响，结果表明，沥青的相对分子质量分布宽，对沥青的低温抗裂性能有利。