基因芯片技术分析20 cGy γ射线照射人淋巴母细胞中差异表达的基因谱

应用基因芯片技术对20 cGy ^60Coγ射线照射的人淋巴母细胞和对照细胞中的mRNA表达水平进行对比杂交分析,探索差异表达基因。结果发现在所分析的14112条日的基因中差异表达显著的基因（2倍以上差异）有83条,其中表达上调的有21条,表达下降的有62条,这些基因表达产物涉及到信号转导、细胞周期调节、免疫相关蛋白、细胞骨架与运动等功能基因。表明低剂量辐射对多种功能基因表达产生了影响,是调控细胞辐射反应最基本的分子基础。     

Research on the dyeing behavior of wool fabric with natural phytolacca berry dyes北大核心

The natural dyes was extracted from mature Phytolacca berries for wool fabric dyeing, the influence of different dyeing process parameters on the dyeing depth was investigated in the case of direct dyeing, Al3+ as mordant was applied to improve the dyeing fastness, the antibacterial properties of dyed wool fabric was tested. The results showed that: the dyeing depth K/S value increased with the ratio of solid to liquid and tended to flatten when the ratio was 1 : 8. 33. The K/S value increased with temperature, the dyed fabric color changed from red to pale yellow when the temperature was over 60 °C. The K/S value declined with NaCl concentration increased. The K/S had maximum color yield when the pH value was 3.5. Al3+ could improve the washing and rubbing fastness of dyed fabric. The dyed fabric had good antimicrobial properties.     

Crystallinity of biodegradable polymers reinforced with functionalized carbon nanotubes

Well-dispersed multiwall carbon nanotubes (MWCNTs) were prepared by grafting poly(L-lactide-co-ε-caprolactone) (PLACL) biodegradable copolymer onto the sidewall of hydroxylated MWCNTs using oligomeric L-lactide (LA) and ε-caprolactone (CL). After preparation of MWCNT/PLACL composites, the effect of functionalized MWCNTs on crystallinity of PLACL was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and polarized light optical microscopy (POM). The surface functionalization effectively improved the dispersion and adhesion of MWCNTs which acted as reinforcing filler in the PLACL polymer matrix and hence improved the physical and thermomechanical properties of the nanocomposites. The glass transition temperature (T _g) and the crystallinity of nanocomposites decreased in comparison with those of neat PLACL when the concentration of functionalized MWCNTs in nanocomposites was 0.5 wt%. With further increment in concentration of functionalized MWCNTs, the T _g of composites increased until the T _g of neat PLACL, and also the crystallinity of composites increased. The functionalized MWCNTs have no significant effect on the melting point of nanocomposites. The MWCNTs acted as heterogeneous nucleation points and increased the lamella size and therefore the crystallinity of PLACL. Furthermore, the larger agglomerated clusters of both kinds of MWCNTs (i.e., MWCNT-grafted-PLACL and pristine MWCNTs) are more effective than small clusters as nucleation points for growing the spherulites.     

单相并联型APF双环控制技术的仿真研究

分析了系统谐波的危害,提出了有源电力滤波器抑制谐波的有效性,以单相并联型有源电力滤波器为背景,介绍了其工作原理并建立数学模型。详细分析了基于电压外环电流内环的单相并联型有源电力滤波器双环控制系统,并给出了电压外环以及电流内环PI控制参数的具体设计过程。最后通过MATLAB仿真对所设计的系统控制参数进行了验证。仿真结果表明,该种基于电压外环电流内环的双环PI控制器的单相并联型有源电力滤波器能保证直流母线电压的稳定,并对中低频带的谐波进行有效的补偿。     

以稻壳为原料制取氟硅酸钠

稻壳燃烧后的灰分中含硅酸酐和无定形硅达９５％，与萤石粉充分混合，在浓硫酸的作用下生成气态ＳｉＦ４和硫酸钙ＳｉＦ４经水吸收得固相硅胶和氟硅酸溶液，氟硅酸溶液与食盐作用生成氟硅酸钠和盐酸，因过程中的中间产品为气相，故最终产品的纯度一步可达９９％，收率为６２％，本法对以稻壳为燃料装置中灰渣的利用有很大的意义。     

醇相法生产甘氨酸

介绿醇相法制备甘氨酸，用氯乙酸、氨、乌洛托品在醇相中制备甘氨酸，其甘氨酸最高收率为７８．８％，醇相法中乌洛托品用量是水相法的１／３，醇相法比水相法具有原料消耗低，生产周期短等优点。     

装配线传送带驱动用控制式无级变速器的设计

本文根据装配线传送带运行的要求，设计了一种控制式无级变速器，给出了其传动参数，并进行了运动学、动力学计算．     

纯棉阻燃织物中磷—氮协同效应初探

通过一种国产纯棉阻燃剂，对阻燃织物中磷－氮协同效应的一些规律进行了初步探讨，认为并非所有的含氮化合物都有磷－氮协同效应。对有协合能力的含氮化合物来讲，也并非其用量越多协同效应越 大。     

Preparation and characterization of amphiphilic block copolymer of polyacrylonitrile‐block‐poly(ethylene oxide)

The synthesis of polyacrylonitrile‐block‐poly(ethylene oxide) (PAN‐b‐PEO) diblock copolymers is conducted by sequential initiation and Ce(IV) redox polymerization using amino‐alcohol as the parent compound. In the first step, amino‐alcohol potassium with a protected amine group initiates the polymerization of ethylene oxide (EO) to yield poly(ethylene oxide) (PEO) with an amine end group (PEO‐NH₂), which is used to synthesize a PAN‐b‐PEO diblock copolymer with Ce(IV) that takes place in the redox initiation system. A PAN‐poly(ethylene glycol)‐PAN (PAN‐PEG‐PAN) triblock copolymer is prepared by the same redox system consisting of ceric ions and PEG in an aqueous medium. The structure of the copolymer is characterized in detail by GPC, IR, ¹H‐NMR, DSC, and X‐ray diffraction. The propagation of the PAN chain is dependent on the molecular weight and concentration of the PEO prepolymer. The crystallization of the PAN and PEO block is discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1753–1759, 2003