松杉灵芝多糖的抗突变作用

通过小鼠骨髓细胞微核试验、 小鼠睾丸染色体畸变和Ames 试验观察了松杉灵芝多糖的抗突变作用. 结果表明, 松杉灵芝多糖对TA98, TA100两株试验菌株, 加与不加S-9均对阳性物致突变作用有抑制作用; 口服不同剂量的药液30 d, 能明显拮抗环磷酰胺所致小鼠骨髓细胞微核率, 但对于丝裂霉素C诱发小鼠睾丸染色体畸变无明显抑制作用.     

钙镁硅酸盐溶度积常数的测定

借助高频等离子体发射光谱分别测定了一定温度下钙镁硅酸盐(CaO.mSiO2、MgO.mSiO2,其中m为模数)饱和溶液中Ca2 、Mg2 的平衡浓度,从而计算该温度下钙镁硅酸盐的溶度积常数,并研究了温度及水玻璃模数对钙镁硅酸盐溶度积常数的影响。结果表明,在同一温度下钙硅酸盐溶度积常数比镁硅酸盐溶度积常数小,在30℃下,水玻璃模数m为3.29时,钙硅酸盐的溶度积常数为1.14×10-8,而镁硅酸盐的溶度积常数为2.29×10-5;随着温度升高钙镁硅酸盐溶度积常数减小,当温度升高至90℃时,钙硅酸盐的溶度积常数减小至0.92×10-8,而镁硅酸盐的溶度积常数减小至1.68×10-5;在同一温度下随着水玻璃模数的增加,与其对应钙镁硅酸盐溶度积常数减小,由于模数的增加使沉淀中硅酸根离子直径变大,与钙镁离子反应生成钙镁硅酸盐晶体更易于沉淀,且更不易溶解,从而使钙镁硅酸盐的溶度积常数减小。     

昌黎沿海野生大豆分布及其耐盐性

对河北省昌黎县沿海地区生长在河沿岸、低洼地、苇塘、沟边、海滩等潮湿环境下的野生大豆进行了实地考察。该地区野生大豆茎纤细、缠绕攀援生长 ;其种子具有硬实现象 ;在株型、叶片、生长势、抗逆性等方面差异较大。经种子耐盐萌发试验和盐池鉴定发现 :昌黎沿海地区野生大豆芽期耐盐性达 0 .9% ,植株在盐的质量分数为 0 .0 0 5～ 0 .0 0 6的土壤中可以生长。     

汽车覆盖件模具CAD/CAM集成系统设计简介

本文主要介绍国内外汽车覆盖件模具的发展概况 ,针对国内汽车发展状况 ,提出了汽车覆盖件模具CAD/CAM集成系统的框架     

Microwave-assisted Extraction of Rutin and Quercetin from Flos Sophorae

Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction (SMOBE). The third procedure was microwave resonant cavity dynamic extraction (MRCDE). The results obtained by the three microwave-assisted extraction procedures were compared with those obtained by using traditional Soxhlet extraction. The results indicate that the MAE not only took a shorter time, but also simplified the procedure, and made the extraction a higher yield. At the same time the results obtained by the three MAE procedures were also compared with each other.     

Syntheses of 2- or 6-Substituted Chromones and Chromone Ring-opening Reaction in Polyphosphoric Acid

In an attempt to find new antitumor agents, a novel class of chromone compounds with a benzimidazoleor a benzoxazole ring in positions 2 or 6 were synthesized νia condensation in polyphosphoric acid(PPA) byusing chromone acids as the starting materials. During the preparation process, it was found that PPA couldcleave the chromone ring to produce a ring-opening compound(6). The molar ratio of the chromone com-pound (5) to the ring-opening compound (6) varied with the change of reaction temperature and time. Basedon MTT protocol, the antitumor activity of each of the compounds obtained was evaluated against three hu-man cancer cell lines: KB(oral epidermal), A2780(ovary) and Be17402 (liver). The IC50 varied from 54.7μmol/L to more than 180 μmol/L.     

铌酸锂晶体高温拉曼光谱研究

采用高温拉曼光谱法,对铌酸锂晶体高温下的结构特征进行了研究.结果显示,室温下较强的拉曼振动模式主要是由[NbO6]八面体的振动所引起的;随着温度升高,频率减小,谱峰位置向低波数方向移动,可观测到的谱峰数目减少.这主要是由晶体内模所对应的Nb-O键合强度随着温度升高而减弱引起的.     

手性丙三醇衍生物的合成

以天然酒石酸为原料,设计并合成了一个未见文献报道的手性丙三醇衍生物即R-2-苯甲氧基-3-(2-四氢吡喃氧基)丙醇,及用新方法制备了R-2-苯甲氧基-3-(4-甲氧基苯甲氧基)丙醇。它们是合成溶血磷脂酸(LPA),血小板活性因子(PAF),脂肪胞壁酸以 及其他具有手性丙三醇骨架化合物的手性源。     

基于计算机视觉的钢轨磨耗自动测量技术的研究

在各种决定钢轨伤损的参数中,钢轨头部的磨耗值是最主要的参数之一.钢轨磨耗是否超限直接决定钢轨是否需要更换或打磨,因此,精确快速地测量出磨耗值对于钢轨的维护及行车安全是非常重要的.本文讨论了光取断面法在钢轨磨耗的自动测量系统中的应用,全面地阐述了系统的工作原理及解决方案.实践证明:本系统具有实时测量、速度快、精度高等特点.     

烯烃光敏顺反异构化反应

烯烃光顺反异构化是一个重要的基元有机光化学反应.本文从垂直中间态理论和势能面的角度对烯烃光敏顺反异构化反应机理进行了综述,并介绍了这些理论在异构体激发三重态能量的确定和敏化剂筛选中的应用.