用于金属腐蚀防护聚苯胺薄膜的研究

聚苯胺作为一种新型的金属腐蚀防护材料,成为当前的一个研究热点.分别用原位聚合法和恒电位法在不锈钢表面合成导电聚苯胺,采用阳极极化曲线和电化学阻抗谱测试等方法研究它对不锈钢在3.5%NaCl溶液中的抗腐蚀能力,并用红外光谱和X射线衍射分析其结构.结果表明,覆有聚苯胺的不锈钢在3.5%NaCl溶液中的自腐蚀电位和极化电阻都明显增大,说明聚苯胺膜的存在明显减慢了不锈钢在氯化钠溶液中的腐蚀速度.     

α，α＇-邻苯二甲基桥联双茚基钐二苯胺化物催化丙烯腈聚合

以α,α＇-邻苯二甲基桥联双茚基钐二苯胺化物为催化剂,对丙烯腈聚合反应进行了研究,考察了催化剂用量、反应时间及反应温度对丙烯腈聚合的影响,并且用粘度法对聚合产物的粘均分子量进行了表征。发现α,α＇-邻苯二甲基桥联双茚基钐二苯胺化物对丙烯腈聚合反应具有极高的催化活性。随着催化剂用量增加聚合反应转化率增大,聚合产物的粘均分子量下降;延长反应时间,转化率和分子量都增大。     

大型WebSphere应用性能故障分析实例

针对大型WebSphere应用系统经常遇到的某些问题,如响应变慢,多个线程长时间挂起等情况,以某电信运营商的CRM系统为例,详细分析了应用系统性能故障,并提出优化解决方案,以作为解决类似问题的参考.     

线形缩聚反应聚合度计算的解析

线形缩聚是高分子化学的重要内容,该部分内容存在聚合度计算公式适用条件复杂的问题。本文推导了2-2-1缩聚反应体系和双官能团物质aRb加少量单官能团物质Cb缩聚反应体系中产物聚合度的计算公式,明确了不同线形缩聚体系中基团数比计算公式的适用条件,举例阐明了线形缩聚体系中基团数比及聚合度的计算方法,深化了对线形缩聚的教与学。     

天津子牙河大桥上部结构安装施工工艺

文章以天津子牙河大桥上部结构安装施工为例,说明自锚式悬索桥上部结构包括塔顶索鞍底板及索鞍安装;主缆施工工艺;吊杆安装的工艺及配套附属件的安装工艺。     

Three-dimensional nonlinear flutter analysis of long-span suspension bridges during erection

In this work, the aerodynamic stability of the Yichang Suspension Bridge over Yangtze River during erection was determined by three-dimensional nonlinear flutter analysis, in which the nonlinearities of structural dynamic characteristics and aeroelastic forces caused by large deformation are fully considered. An interesting result obtained was that the bridge was more stable when the stiffening girders were erected in a non-symmetrical manner as opposed to the traditional symmetrical erection schedule. It was also found that the severe decrease in the aerodynamic stability was due to the nonlinear effects. Therefore, the nonlinear factors should be considered accurately in aerodynamic stability analysis of long-span suspension bridges during erection. Project supported by National Natural Science Foundation of China(No. 598954410), and China Postdoctoral Science Foundation (No. 2002031245)     

手性氨基酸对DNA链式聚合反应的影响

构成天然蛋白质的氨基酸为L构型,D构型氨基酸虽然不是构成蛋白质的基本结构单元,但许多植物、微生物甚至在人体中都有D-氨基酸的存在.DNA聚合酶链式反应广泛发生在生物体内及PCR实验中,首次探究手性氨基酸及其与金属离子协同条件下对Taq-DNA聚合酶催化下的DNA链式聚合反应的影响情况,为进一步研究手性氨基酸及金属离子对...     

课堂教学结尾小议

课堂教学结尾是一种艺术.总结归纳法、练习法、悬念法、讨论法、文艺法,是我们在课堂教学结尾中常用的几种基本方法.根据实际情况,灵活运用这些方法,对于激发学生学习兴趣,培养学生能力等方面,具有不可忽视的作用.     

高磁含量聚合物的合成

提出一种制备高磁含量聚合物的方法 .首先用乙醇对共沉淀法制备的磁流体进行处理 ,然后在处理过的 Fe3O4粒子存在情况下 ,以聚乙二醇为分散剂 ,偶氮二异丁腈为引发剂 ,乙醇为分散介质 ,进行丙烯酰胺的分散聚合 .讨论了分散介质、搅拌强度、磁性粒子性质及用量等因素对聚合反应及聚合物磁含量的影响 .制备出了磁含量高达 3 2 .2 % (质量比 )的聚丙烯酰胺微球     

Identification and characterization of profilin gene family in rice

BackgroundProfilin proteins (PRFs) are small (12–15 kD) actin-binding protein, which play a significant role in cytoskeleton dynamics and plant development via regulating actin polymerization. Profilins have been well documented in Arabidopsis, Zea mays L. as well as Phaseolus vulgaris, however no such fully characterization of rice (Oryza sativa L.) profilin gene family has been reported thus far.ResultIn the present study, a comprehensive genome-wide analysis of rice PRF genes was completed and three members were identified. OsPRF1 and OsPRF2 shared 98.5% similarity (6 nucleotide divergence), but the deduced amino acid sequences of OsPRF1 and OsPRF2 are fully identical. In contrast, the OsPRF3 presents relatively lower similarity with OsPRF1 and OsPRF2. Phylogenetic analysis also support that OsPRF1 has a closer relationship with OsPRF2. Expression pattern analysis revealed the differential expression of OsPRFs in tissues of mature plant, which suggested the potential spatial functional specificity for rice profilin genes. Subcellular localization analysis revealed the OsPRFs were localized in cytoplasm and nucleus and all of them could bind actin monomers. Furthermore, abiotic stresses and hormones treatments assay indicated that the three OsPRF genes could be differentially regulated, suggesting that OsPRF genes might participate in different stress processes in rice.ConclusionsTaken together, our study provides a comprehensive analysis of the OsPRF gene family and will provide a basis for further studies on their roles in rice development and in response to abiotic stresses.How to cite: Zhang Y, Dong G, Wu L, et al. Identification and characterization of profilin gene family in rice. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.08.004.