2,6-二氨基-3-硝基甲苯的合成

以2,6-二氨基甲苯为原料,酰化反应得到2,6-二乙酰氨基甲苯,混酸硝化,水解得到2,6-二氨基-3-硝基甲苯（DANT）目标产品。纯度97.6%、总收率达62%以上。考察了溶剂用量、反应时间,反应温度等因素的影响,优化选择了各反应的较佳工艺参数。酰化反应中,乙酸酐与乙酸的体积比为 1∶2,温度80℃,反应时间2h;硝化反应中,浓硝酸与2,6-二乙酰氨基甲苯的摩尔比1.38∶1,温度为10℃。105℃回流,酸性水解,得产品。产品经13C-NMR、MS 进行了结构表征。     

Controlled synthesis and formation mechanism of sodium yttrium fluoride nanotube arrays

Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate, sodium fluoride and poly-ethanediol in propanetriol solvent under a facile hydrothermal route. By regulating the molar ratio of yttrium and fluoride, hydrothermal tem-perature and reaction time, the phase and shape of sodium yttrium fluoride were commendably controlled. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS) techniques. It was revealed that the hollow-structured Na(Y1.5Na0.5)F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped. The for-mation of hexagonal Na(Y1.5Na0.5)F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening. This study provided a simple method to prepare hexagonal bamboo raft-shaped Na(Y1.5Na0.5)F6 on a large scale, which broadened their practical applications.     

离散电流对精密线圈磁场影响的研究

研究了通常用电流片模型来近似计算线圈磁场时被忽略的由于导线电流的离散而引起的附加磁场的变化规律,指出此种附加磁场会随着离开导线距离的增加而迅速衰减.此结论可用于指导精度要求较高的线圈磁场系统的设计,如用于质子回旋磁比γp′测量的高精度亥姆霍兹线圈的设计和用于普朗克常数h测量的焦耳天平系统中的精密互感线圈的设计等.     

Fluorophore-gold nanoparticle complex for sensitive optical biosensing and imaging

Fluorophores have been extensively used as the signal mediator in biosensing and bioimaging for a long time. Enhancement of fluorescence can amplify the signal, thus improving the sensitivity, enabling earlier and accurate disease detection and diagnosis. Some metal nanoparticles, such as gold and silver, can generate a strong electromagnetic field on their surface (surface plasmon field) upon receiving photonic energy. When a fluorophore is placed in the field, the field can affect the fluorophore electrons participating in fluorescence emission and change the fluorescence output. The change can be from complete quenching to significant enhancement, depending on the metal type, particle size and shape, excitation/emission wavelengths and quantum yield of the fluorophore, and the distance between the fluorophore and the particle surface. In this study, the effects of these parameters on the fluorescence enhancement of commonly used fluorophores by gold nanoparticles (GNPs) are theoretically analyzed. Experimentally, an NIR contrast agent with enhanced fluorescence was developed by carefully tailoring the distance between Cypate (ICG based fluorophore) and a GNP, via biocompatible spacer constructs. The effect of the GNP size (3.7-16.4 nm) and spacer length (3.2-4.6 nm) on fluorescence enhancement was studied, and the spacer length that provided the significant enhancement was determined. The spacer of 3.9 nm with 16.4 nm GNP provided the fluorescence of 360% of the control. The experimental data qualitatively agreed with the theoretical results and, thus, the theoretical analysis can be used as a guide for significantly improving the sensitivity of existing fluorescent contrast agents by properly utilizing GNPs and spacers.     

Synthesis of high-purity 2-hydroxyterephthalic acid

系统地研究了以间羟基苯甲酸（HBA）为原料、经改进的Koble-Schmitt法常压合成2-羟基对苯二甲酸（HTA）的新工艺及其精制方法,并与2-溴对苯二甲酸（BTA）催化水解法制备HTA技术进行了比较。结果表明：以HBA为原料,甲酸钾为溶剂,在碳酸钾存在下,反应温度为230～240 ℃时,CO₂常压羧化反应6 h制得纯度约90%的HTA粗品,采用二次酸碱精制法可使HTA质量达聚合级单体的水平（纯度>99.5%,金属离子<50 mg/kg）,总收率56%以上。产品经FT-IR和MS表征确认。该技术具有常压反应、操作方便、产品质量优异、经济性良好及易于产业化等优点,能为进一步合成羟基改性的新型高性能材料及新单体提供原料。     

渤海海域新近系河流相油田储量参数精度分析

针对渤海海域6个已投产的新近系河流相油田储量复算前后的变化,开展了储量参数精度分析,结果表明:含油面积是影响储量评价质量的最关键参数,其次为有效厚度,这2个关键参数变化引起的探明储量变化百分比分别为80%和10%;含油面积变化原因主要为流体界面变化和储层描述的精度,有效厚度变化主要取决于反演资料可靠程度及泥质夹层发育模式。在明确了关键储量参数及其精度影响因素的基础上,提出了现阶段提高参数取值精度的对策,有利于提高河流相油藏储量评价质量及开发效果。     

锈蚀钢筋混凝土梁受弯承载力与自发漏磁相关性试验研究

为探索锈蚀钢筋混凝土梁受弯承载力与自发漏磁的相关性,同时开展了锈蚀钢筋混凝土梁受弯承载力和自发漏磁检测试验。基于法拉第电解第一定律对试件进行不同程度电化学加速锈蚀,并采集了试件锈蚀后的自发漏磁信号,最后采用四点弯曲试验测定试件受弯承载力。结果表明：随着锈蚀加深,试件自发漏磁分量曲线出现愈发明显磁异变峰的同时,受弯承载力逐渐衰减,通过该磁异变峰可确定锈蚀区域并判断受弯承载力大致衰减程度。随着试件受弯承载力持续衰减,漏磁曲线梯度与邻增量均非线性单调增加,且该梯度和邻增量增长快慢均与受弯承载力损失快慢一致。梯度和邻增量均能昭示受弯承载力的大幅衰减,邻增量出现峰值点可作为受弯承载力为零的判据。     

2-羟基-4-甲氧基-5-磺酸基二苯甲酮的合成

采用间苯二甲醚为原料,经酰化、脱甲基、磺化一系列的反应合成2-羟基-4-甲氧基-5-磺酸基二苯甲酮,并对其物料配比、催化剂用量、反应温度以及反应时间等因素作了探索.结果表明酰化反应较佳条件为:以二氯甲烷为溶剂,n(间苯二甲醚)∶n(苯甲酰氯)∶n(无水AlCl3)=1∶1.05∶1.05,反应温度0～5℃,反应时间3 ...     

Bridgman法制备塑性钛基轻质非晶复合材料

通过Bridgman定向凝固法成功制备了内生枝晶增塑的轻质钛基非晶复合材料. 与传统的Cu模吸铸法相比, Bridgman法有效消除了铸态组织中的孔洞, 得到了更均匀的微观组织, 且能通过调节抽拉速度来控制枝晶相的尺寸和分布, 进而优化其力学性能. 当抽拉速度为1.4 mm/s时, 合金压缩屈服强度、断裂强度和断裂塑性分别达到1956 MPa, 2706 MPa和18.0%, 且有明显的加工硬化现象. 进一步讨论了枝晶跨越长度$L$和枝晶间距$S$与力学性能的关系, 发现L在约40 μm时对材料的塑性贡献最大.     

Loofah sponge activated by periodate oxidation as a carrier for covalent immobilization of lipase

Cellulose in loofah sponge was first oxidized by sodium periodate at positions 2 and 3 of anhydroglucose unit to introduce aldehyde groups, which were able to react with amino groups of lipase to form Schiff’s base, and result in loofah sponge immobilized lipase. The result of periodate oxidation was confirmed by determination of aldehyde group content and analysis of Fourier transform infrared spectra. The optimal pH for both free and immobilized lipases was approximately 7.5. The maximum activity of immobilized lipase was observed at 40 °C, while the free lipase exhibited maximum activity at 37 °C. The immobilized lipase presented improved thermal stability, storage stability, and reusability.