神经二肽N-乙酰天门冬氨酰谷氨酸的合成

The synthesis process of N-acetyl-aspartyl-glutamate (NAAG) was studied, in which L-aspartic acid was used as the raw material, and the dipeptide was first prepared by esterification,acylation and the reaction with L-glutamic acid, and then the product NAAG was finally obtained by hydrolyzation and purification.The product and the intermediate were analyzed and identified by melting point measuring, elemental analysis, polarimeter and IR analysis.The effects of mixture ratio of raw materials, reaction temperature and reaction time were investigated.The results showed that the total yield was 50.02% when the esterification temperature was controlled at 20℃, esterification time 10 h, acylation temperature 70℃, acylation time 2 h, and DCC was used as the addition reagent to synthesize dipeptide.The hydrolization temperature was 60℃, the hydrolization time was 4 h.The product was purified by ion-exchange resin.The purity detected by HPLC was 97.5%.     

光干涉膜阻隔红外线的研究

研究了光学干涉膜对光的选择性,根据其厚度会影响最大反射峰,采用在一个干涉膜上叠加另一个或多个不同厚度的干涉膜,制成梯度干涉膜,能形成更宽的反射带,可阻隔更多的红外线。采用自制的隔热效果测试装置对梯度干涉膜的隔热效果进行了测定。结果表明,干涉膜反射光的波长范围主要由其厚度决定,随着光学厚度的增加,主要反射光波波长位置逐渐从较短区域向较长区域迁移;梯度干涉膜随着梯度数的增加,反射峰叠加变宽;在红外灯照射下梯度干涉膜和空白玻璃之间的温差最高可达8 ℃。     

Phase Separation Inducing Controlled Crystallization of GeSe2–Ga2Se3–CsI Glasses for Fabricating Infrared Transmitting Glass–Ceramics

Infrared transmitting glass–ceramics based on the selected glass of 65GeSe₂–25Ga₂Se₃–10CsI were obtained by a two-stage heat-treatment method. Results of X-ray diffraction and scanning electronic microscopy indicated that droplet-like nanoparticles containing cubic Ga_2−δGe_δSe₃ crystals are homogeneously generated in the glass–ceramics and that the whole glass–ceramic process is composed of phase separation, nucleation, and crystal growth. Evolutions of the optical and mechanical properties of glass–ceramics versus annealing time at the first-stage heat treatment were also investigated. Compared with the parent glass, the fabricated glass–ceramics show considerably enhanced fracture toughness, practicable infrared transparence, and microhardness, which confer them with considerable competitive advantages over currently used infrared materials.     

天然短纤维/聚合物复合材料研究进展

综述了国内外有关天然短纤维增强聚合物复合材料的最新研究成果。针对天然短纤维与聚合物相容性较差及在聚合物基质中分散难这两大问题,对短纤维改性作了较详细的论述。展望了天然短纤维/聚合物复合材料的发展方向和前景。     

新建本科院校化工类学生科研素质的培养

新建本科院校面临着为本地区经济发展培养和造就高素质的化工类创新型人才的重任,而具备一定的科研素质是创新型人才的最要特征。文章就目的新建本科院校化工类学生科研训练活动中存在的问题进行分析,并提出了相应的建议．以逐步提高学生的科研素质。     

二氧化碳增能解堵技术在下寺湾采油厂的应用

介绍了二氧化碳增能解堵原理、在下寺湾采油厂油井的施工方法和程序以及所用工作液的组成.该技术作为油井增产措施应用于下寺湾采油厂26口井作业后采油时间为4个月的基础上实现平均单年增油41.49吨,当年可完全收回投资成本,实现投入与产出比为1:3.     

High-Temperature Thermoelectric Properties in the La2−xRxCuO4 (R: Pr, Y, Nb) Ceramics

La_{2− x} R _x CuO₄ (R: Pr, Y, Nb) polycrystalline ceramics have been prepared by a spark plasma sintering process. Analysis of the microstructure and phase composition shows that pure La₂CuO₄ ceramics with a high density can be obtained, and no impurity phases appear. All the samples exhibit a metal–semiconductor transition behavior at ∼750 K, which could be ascribed to the decreasing charge density as a result of loss of oxygen atoms and various conduction mechanisms in these La₂CuO₄-based ceramics. Our results indicate that the La_1.98Y_0.02CuO₄ ceramics show large thermoelectric power ∼1.0 × 10⁻³μW·(m·K²)⁻¹, and the evaluated ZT can reach 0.17 at 330 K, which potentially make them useful for thermoelectric applications.     

粉煤灰的引入及表面处理对陶瓷远红外性能的影响

对工业废渣粉煤灰在远红外功能陶瓷的应用进行了相关实验和讨论分析.通过引入粉煤灰的单因素实验和表面处理实验后发现:粉煤灰能够作为一种陶瓷原料引入红外功能陶瓷的坯体配方中,其加入能大大降低坯体的烧结温度,但随着量的加大坯体的远红外辐射性能会有所下降;材料的烧结程度和表面采取不同的处理方式(抛光与否)皆会影响其红外发射率值.     

羧甲基壳聚糖离子配位微球的制备及性能研究

以羧甲基壳聚糖(CMCHS)为主要原料,采用静电脉冲液滴发生器制备羧甲基壳聚糖离子配位微球。光学显微镜观察微球具备规整形貌,扫描电镜分析显示干球粒径约为100μm且表面呈多孔结构;红外光谱证明其内部具有由CMCHS上的羧酸根与Ca^2 配位形成的羧酸盐结构。溶胀实验表明,CMCHS溶液浓度、金属离子种类及其浓度等制备条件均影响微球的溶胀性能．且其溶胀行为对pH值较敏感。药物体外释放初步研究表明,CaCl2浓度和释放介质pH值均对微球的释放性能产生影响。研究对其进一步应用于药物释放等领域具有重要意义。     

聚甲基丙烯酰氧乙基二甲基丁烷基溴化铵共振光散射法测定核酸

通过光谱法研究聚甲基丙烯酰氧乙基二甲基丁烷基溴化铵(PMDB)和核酸的作用。结果表明通过共振光散射法用PMDB检测微量的DNA可靠、准确和简单。