TS和PTS单晶体的热刺激电流

测定了双(对甲基磺酸)2,4-己二炔-1,6-二醇酯(TS)及其不同聚合程度TS-PTS混合体和完全聚合的聚合物PTS在100-300K温度范围内的热刺激电流。在沿分子堆砌方向上(对PTS则是大分子链方向)上观察到了它们的热刺激电流,并在相应于它们相变152K和192K处呈现热刺激电流峰。研究了聚合程度对相变的影响,绘制了TS-PTS体系的相图。对另三个热刺激电流峰的归属作了定性解释。     

输入输出共轴的三弯曲型TM01-TE11模式转换器

 通过采用相位重匹配技术，设计了一种输入输出共轴的三弯曲型TM₀₁-TE₁₁模式转换器，该转换器由三段常曲率弯曲波导和两段直波导组成。用模式耦合理论建立了该类模式转换器的数值计算和优化设计方法，并设计了一个中心频率为7.0 GHz的模式转换器。该转换器的TM₀₁-TE₁₁转换效率在中心频率上大于99％，在6.5~7.5 GHz的频率范围内大于90％。应用时域有限差分法和有限元方法对所设计的模式转换器进行了仿真，仿真结果验证了设计理论和设计结果。     

苯与溴取代反应的实验改进

人教版《化学2》中苯的溴代反应实验[1],人们已做了不少探究改进,但仍然存在一些不足[2~8]:(1)用磁铁吸引铁粉的改进方法不仅操作不方便,而且难以保证把铁屑全部吸住,稍有不慎操作就会失败;(2)装置中用直玻璃导管不利于苯和Br2蒸气的充分冷凝回流;(3)向反应后的混合物中直接注入NaOH溶液,除去未反应的Br2来观察溴苯的真实     

一种氮烷基化的2-(5-溴-4-甲基噻吩)-咪唑[4，5-f]-[1，10]-菲咯啉三羰基铼(Ⅰ)配合物的聚集诱导荧光增强效应

本文旨在探索基于2-噻吩-咪唑[4,5-f]-[1,10]-菲咯啉（TIP）结构的三羰基铼（Ⅰ）配合物的聚集诱导荧光增强（AIEE）性质。研究了2-（5-溴-4-甲基噻吩）-咪唑[4,5-f]-[1,10]-菲咯啉（1）与不同溴代烷烃之间的氮烷基化反应,并成功制备了3种具有不同氮烷基链结构的TIP衍生物（2a~2c）。氮烷基链引入可以明显提高其在有机溶剂中的溶解性以及不同程度影响TIP中相邻咪唑环和噻吩环的二面角。通过配体2a与五羰基氯化铼的配位反应成功制备了一个具有AIEE性质的三羰基铼（Ⅰ）配合物3。通过对三羰基铼（Ⅰ）配合物3进行X射线单晶衍射的分析,发现该配合物的AIEE活性取决于其松弛的分子堆积结构以及多重的分子间氢键作用。     

大面积均匀电子束产生实验研究

 在电子束泵浦气体激光实验中,大面积均匀电子束是获得高效能激光输出的必要条件。介绍了利用SPG-200脉冲功率源产生大面积均匀电子束的实验。SPG-200是基于SOS的全固态重复频率脉冲功率源,其开路电压大于350 kV。用于产生电子束的真空二极管阴极长294 mm,宽24 mm,两端均为半径为12 mm的半圆,栅网平面为阳极面,两者之间的距离在0~49 mm可调,阴极发射的电子束通过用于隔离激光气室和二极管真空室的压力膜及其支撑栅网引出。分别以石墨和天鹅绒为阴极材料,获得了大面积电子束输出,给出了二极管参数的测量结果,并对电子束发射均匀性进行了诊断。实验结果表明：在阴极材料为石墨、阴阳极间隙为5~9 mm时,二极管电压为240~280 kV,二极管电流为0.7~1.8 kA,输出的电子束很不均匀;在阴极材料为天鹅绒、阴阳极间隙为31~46 mm时,二极管电压为200~250 kV,二极管电流为1.5~1.7 kA,输出的电子束均匀性较好。     

用直接法测定黄河矿晶体的超结构

本文分析了黄河矿晶体超结构中赝对称性的特点,详述了用于测定黄河矿晶体超结构的直接法。 关键词：     

Highly selective synthesis of single-walled carbon nanotubes from methane in a coupled Downer-turbulent fluidized-bed reactor

For the synthesis of single-walled carbon nanotubes (SWCNTs) from CH₄ over a Fe/MgO catalyst, we proposed a coupled Downer-turbulent fluidized-bed (TFB) reactor to enhance the selectivity and yield (or production rate) of SWCNTs. By controlling a very short catalyst residence time (1–3 s) in the Downer, only part of Fe oxides can be reduced to form Fe nano particles (NPs) available for the growth of SWCNTs. The percentage of unreduced Fe oxides increased and the yield of SWCNTs decreased accordingly with the increase of catalyst feeding rate in Downer. SWCNTs were preferentially grown on the catalyst surface and inhibited the sintering of the Fe crystallites which would be formed thereafter in the downstream TFB, evidenced by TEM, Raman and TGA. The coupled Downer-turbulent fluidized-bed reactor technology allowed higher selectivity and higher production rate of SWCNTs as compared to TFB alone.     

Inhibitory Effect and Mechanism of Chitosan–Ag Complex Hydrogel on Fungal Disease in Grape

Hydrogel antibacterial agent is an ideal antibacterial material because of its ability to diffuse antibacterial molecules into the decayed area by providing a suitable microenvironment and acting as a protective barrier on the decay interface. The biocompatibility and biodegradation make the removal process easy and it is already widely used in medical fields. However, there have been few reports on its application for controlling postharvest diseases in fruit. In this study, the Chitosan–silver (CS–Ag) complex hydrogels were prepared using the physical crosslinking method, which is used for controlling postharvest diseases in grape. The prepared hydrogels were stable for a long period at room temperature. The structure and surface morphology of CS–Ag composite hydrogels were characterized by UV-Vis, FTIR, SEM, and XRD. The inhibitory effects of CS–Ag hydrogel on disease in grape caused by P. expansum, A. niger, and B. cinerea were investigated both in vivo and in vitro. The remarkable antibacterial activity of CS–Ag hydrogels was mainly due to the combined antibacterial and antioxidant effects of CS and Ag. Preservation tests showed that the CS–Ag hydrogel had positive fresh-keeping effect. This revealed that CS–Ag hydrogels can play a critical role in controlling fungal disease in grapes.     

基于近红外光谱技术的石油组分定量分析新方法

针对石油化工产品生产控制和质量检查的需要,为提高测定产品组成的效率,将近红外光谱法作为基础测定方法,以直馏柴油、加氢精制柴油和催化裂化柴油为校正模型的训练样本,测定其中饱和烃、胶质、单环芳烃、双环芳烃、三环芳烃和环烷烃的组成,论述了采用模糊神经网络建立校正模型测定石油化工产品组成的可行性。基于dSPACE硬件平台,用验证样本对模糊神经网络校正模型进行了检验,实验结果表明,该方法响应快、误差小、鲁棒性强,在近红外长波区内,校正样品和验证样品的均方误差小于10-6。该方法可用于石油化工产品的生产工艺研究中。     

互花米草定植的养殖尾水处理人工湿地中古菌群落的组成与分布

为探究凡纳滨对虾养殖尾水处理过程中互花米草湿地的净化效果和沉积物古菌群落的组成与分布,基于16S rRNA基因的高通量测序技术,从沉积物环境因子、古菌群落结构和多样性、环境因子与古菌群落间的相互关系进行分析.结果表明:互花米草人工湿地深层沉积物的古菌群落多样性显著高于表层和根际沉积物;门水平上,互花米草人工湿地优势古菌为泉古菌门、广古菌门和奇古菌门;纲水平上,优势古菌为深古菌纲、甲烷微菌纲和热源体纲;目水平上,互花米草人工湿地中含3种氨氧化古菌和7种产甲烷古菌.非度量多维尺度分析(NMDS)表明,互花米草根际沉积物与深层沉积物古菌群落差异显著(P<0.05),与表层更为相似.冗余分析(RDA)及Mantel检验表明,影响古菌群落的主要环境因子包括p H、铵氮(NH₄⁺-N)、总有机碳(TOC)和总磷(TP).相关性热图表明奇古菌门和其中的亚硝基菌纲与环境因子的相关性最强.氨氧化古菌群落与pH、NH₄⁺-N、总氮(TN)和TP呈显著相关(P<0.01),产甲烷古菌与环境因子则无显著相关性....