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41.
应用原子吸收光谱法测定了内蒙古地产的笃斯茎、叶中的Cu,Fe,Zn,Mn,Ca,Mg等六种人体必需微量元素及宏量元素的含量。从而为评价笃斯的品质及其药理、药效提供了具有一定价值的数据。 相似文献
42.
氩离子激光固化环氧树脂制作三维微结构 总被引:1,自引:0,他引:1
利用激光束进行三维成像是通过逐层光引发聚合形成宏观尺度的三维实体 .最近出现的激光全息光刻技术是利用激光束的干涉产生三维全息图案 ,让感光树脂在全息图案中曝光 ,从而一次形成三维周期有序微结构 .通过调节激光干涉及波长可控制三维结构的形状及尺寸 .利用该技术获得亚微米尺度上周期性重复的三维微结构 ,可用于制作三维光子晶体 [1,2 ]等具有独特性能的聚合物材料 .本文用铁芳烃化合物与特种环氧树脂配制成阳离子型可见光固化树脂 ,在氩离子激光器产生的多束可见连续激光相干形成的空间干涉光场中曝光 ,成功地制备出亚微米量级的三… 相似文献
43.
HPLC determination of four active saponins from Panax notoginseng in rat serum and its application to pharmacokinetic studies 总被引:1,自引:0,他引:1
Four main active saponins (ginsenosides Rg1, Rb1, Rd and notoginsenoside R1) in Panax notoginseng in rat serum after oral and intravenous administration of total saponins of P. notoginseng (PNS) to rats were determined using a simple and sensitive high-performance chromatographic method. The serum samples were pretreated with solid-phase extraction before analysis. The calibration curves for the four saponins were linear in the given concentration ranges. The intra-day and inter-day assay coefficients in serum were less than 10.0% and the recoveries of the method were higher than 80.0% in the high, middle and low concentrations. This method was applied to study the pharmacokinetics following oral and intravenous administration of PNS. 相似文献
44.
胶原-磺化羧甲基壳聚糖/硅橡胶皮肤再生材料的制备及其对小型猪烫伤创面全层皮肤缺损的修复研究 总被引:3,自引:0,他引:3
制备了一种胶原-磺化羧甲基壳聚糖/硅橡胶皮肤再生材料,并以小型猪为模型,考察了其对烫伤全层皮肤缺损的修复性能.首先合成了磺化羧甲基壳聚糖,并对其结构进行了表征.制备了胶原-磺化羧甲基壳聚糖多孔支架,采用扫描电子显微镜(SEM)研究了磺化羧甲基壳聚糖含量对支架微结构的影响.随着磺化羧甲基壳聚糖含量的增大,胶原-磺化羧甲基壳聚糖支架从纤维结构向片状结构转化,且支架的孔径相对变大.采用体外成纤维细胞培养实验证明胶原-磺化羧甲基壳聚糖支架无明显细胞毒性.进一步将胶原-磺化羧甲基壳聚糖支架与硅橡胶膜复合,构建具有双层结构的皮肤再生材料.以小型猪为模型,评价了其对深度烫伤创面的修复性能.大体观察和组织学分析结果显示,胶原-磺化羧甲基壳聚糖/硅橡胶皮肤再生材料具有更快的血管化性能,且经该材料处理的创面能有效支持薄自体皮片的移植成活,实现深度烫伤创面的全层修复. 相似文献
45.
Sn掺杂二氧化锰超级电容器电极材料 总被引:3,自引:0,他引:3
用化学液相法制备了超级电容器用的Sn掺杂二氧化锰电极材料. 采用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)光谱对电极材料的形貌和物相进行表征. 结果表明, 所得样品由直径约10 nm, 长约100 nm的棒状物粘结成200-500 nm的球状物, 晶型为δ-MnO2. 循环伏安、电化学交流阻抗和恒流充放电测试表明, 化学掺杂的比例对材料的电化学性能有较大的影响. 当Mn:Sn的摩尔比为50:1时, 电极材料的比电容达到293 F·g-1, 比未掺杂的提高了64.6%. 600次充放电循环后, 比电容稳定在275 F·g-1, 表现出良好的容量保持能力. 相似文献
46.
N,N,N-Trimethylchitosan chloride with different degrees of quaternization has been synthesized and characterized by (1)H NMR spectroscopy. The particle size ranges from 150 to 600 nm, which is dependent on the N/P ratio and is less influenced by the degree of quaternization. The majority of the particles have a spherical morphology. The zeta potential of the particles increases with the N/P ratio and the quaternization degree of TMC. Short-term contact experiments show good biocompatibility of TMC, but long-term contact experiments reveal its high toxicity. This study suggests that TMC is a promising gene carrier, but further modification is still required to improve its cytocompatibility. 相似文献
47.
以十四酸根阴离子柱撑Zn-Al水滑石Zn0.77Al0.22(OH)2.0.22C13H27COO.0.81 H2O(记为ZnAl-14A)为预撑前体,在水溶液中用离子交换法将以2∶17缺位杂多酸根离子(P2Mo16VO61)11-记为(P Mo V)为配体的稀土杂多配阴离子Ce(P2Mo16VO61)219-(记为Ce(PMoV)2)插层组装到水滑石层板间,合成了一种具有大的层间距(3.37 nm)的超分子插层材料Zn0.77Al0.23(OH)2.0.0105[Ce(P1.9Mo15.7V1.1O61)2].0.011C13H27COO.0.83H2O(记为ZnAl-Ce(PMoV)2)。用ICP,IR,XRD和DTA对产物的组成和结构进行了表征。结果表明,该产物中Ce(PMoV)2配阴离子沿其长轴垂直于层板的方向分布于水滑石层间;产物具有规整的层状结构和热稳定性;产物对乙酸与正丁醇的酯化反应,二甘醇的脱水-环化反应和H2O2氧化环己烷的反应有良好的催化性能,且易于回收重复使用。 相似文献
48.
Emulsion copolymerization of poly(methacrylic acid) and poly(2-(diethylamino)ethyl methacrylate) (PMAA/PDEA) yielded pH-responsive polyampholyte microgels of 200-300 nm in diameter. These microgels showed enhanced hydrophilic behavior in aqueous medium at low and high pH, but formed large aggregates of approximately 2500 nm at intermediate pH. To achieve colloidal stability at intermediate pH, a second batch of microgels of identical monomer composition were synthesized, where monomethoxy-capped poly(ethylene glycol)methacrylate (PEGMA) was grafted onto the surface of these particles. Dynamic light-scattering measurements showed that the hydrodynamic radius, Rh, of sterically stabilized microgels was approximately 100 nm at intermediate pH and increased to 120 and 200 nm at pH 2 and 10, respectively. Between pH 4 and 6, these microgels possessed mobility close to zero and a negative second virial coefficient, A2, due to overall charge neutralization near the isoelectric pH. From the Rh, mobility, and A2, cross-linked MAA-DEA microgels with and without PEGMA retained their polyampholytic properties in solution. By varying the composition of MAA and DEA in the microgel, it is possible to vary the isoelectric point of the colloidal particles. These new microgels are being explored for use in the delivery of DNA and proteins. 相似文献
49.
Muliadi Ramli Nasrullah Idris Kenichi Fukumoto Hideaki Niki Fujio Sakan Tadashi Maruyama Koo Hendrik Kurniawan Tjung Jie Lie Kiichiro Kagawa 《Spectrochimica Acta Part B: Atomic Spectroscopy》2007,62(12):1379-1389
A TEA CO2 laser (350 mJ–1.5 J, 10.6 μm, 200 ns, 10 Hz) was focused onto a metal sub-target under He as host gas at 1 atmospheric pressure with a small amount of impurity gas, such as water and ethanol vapors. It was found that the TEA CO2 laser with the help of the metal sub-target is favorable for generating a strong, large volume helium gas breakdown plasma at 1 atmospheric pressure, in which the helium metastable-excited state was then produced overwhelmingly. While the metal sub-target itself was never ablated. The helium metastable-excited state produced after the strong helium gas breakdown plasma was considered to play an important role in exciting the atoms. This was confirmed by the specific characteristics of the detected H emission, namely the strong intensity with low background, narrow spectral width, and the long lifetime. This technique can be used for gas and solid samples analysis. For nonmetal solid analysis, a metal mesh was introduced in front of the nonmetal sample surface to help initiation of the helium gas breakdown plasma. For metal sample, analysis can be carried out by combining the TEA CO2 laser and an Nd–YAG laser where the Nd–YAG laser is used to ablate the metal sample. The ablated atoms from the metal sample are then sent into the region of helium gas breakdown plasma induced by the TEA CO2 laser to be excited through the helium metastable-excited state. This technique can be extended to the analysis of other elements, not limited only to hydrogen, such as halogens. 相似文献
50.
Chun Lei Sheng‐Xiong Huang Ji‐Jun Chen Jian‐Xin Pu Li‐Mei Li Wei‐Lie Xiao Jin‐Ping Liu Li‐Bin Yang Han‐Dong Sun 《Helvetica chimica acta》2007,90(7):1399-1405
Four new, highly oxygenated nortriterpenoids with the unique schisanartane skeleton, propindilactones A–D ( 1 – 4 ), were isolated from the aerial parts of Schisandra propinqua var. propinqua, together with four known schisanartane‐type compounds. The structures of the new plant constituents were established on the basis of extensive spectroscopic methods. 相似文献