Sinorhizobium meliloti nifA gene exerts a pleiotropic effect on nodulation through the enhanced plant defense response

Sinorhizobium meliloti nifA gene is required for the expression of a bunch of nif and fix genes. Here, we report its pleiotropic effects on the nodule formation. Compared with wild type strain, nifA mutant sig- nificantly reduced nodule suppression rate in split-root system. The plants inoculated with mutant strain produced lower amount of daidzein and less necrotic cells on their roots. In addition, the defense genes failed to be evoked by nifA mutant at the early nodulation stage. These findings indicated that host defense response was one of the mechanisms mediated by nifA gene to regulate nodule formation during symbiosis. Even though nifA mutant could increase the number of nodules in host plant, it synthesized lower Nod factors than wild type. This suggested that nifA gene mediated multiple and diverse instances in nodulation formation.     

基于石墨烯/聚苯胺纳米线阵列复合薄膜的柔性超级电容器

该文报道了基于石墨烯/聚苯胺纳米线阵列自支撑薄膜的柔性超级电容器.首先通过抽滤方法制备了柔性的石墨烯自支撑薄膜,然后在石墨烯薄膜表面原位生长聚苯胺纳米线阵列,得到了石墨烯/聚苯胺纳米线阵列柔性复合薄膜.同时,基于该柔性薄膜组装出三明治结构的柔性超级电容,并测试了其电化学性能.结果表明复合的薄膜具有优异的比电容（278Fg？1）和循环稳定性（循环8000次,容量保持80%）.     

新型N-取代-1,6-亚甲基桥[10]轮烯-3,4-二甲酰亚胺的合成

以1,6-亚甲基桥[10]轮烯-3,4-二羧酸乙酯为原料,经皂化、酸化直接得到了一种新型中间体1,6-亚甲基桥[10]轮烯-3,4-二甲酸酐,该酸酐与相应的伯胺(苯胺,苄胺,苯乙胺,正丁胺)在醋酸中回流3 h,简便的合成了新型N-取代-1,6-亚甲基桥[10]轮烯-3,4-二甲酰亚胺,并用1H-NMR,13C-NMR,MS及HRMS等波谱进行了表征验证。     

从社会支持理论谈优化校园心理健康教育环境

社会支持对心理健康有积极的促进作用，高校是大学生社会支持的重要来源之一。从教学、管理、心理辅导等方面向学生提供有力的社会支持是优化校园心理健康教育环境的有效措施。     

Use of photoelectron energy spectrum transfer equation for the measurement of a narrowband XUV pulse

To study the time evolution of a molecular state in an ultra-fast chemical reaction,the use of shorter pulses with higher photon energy and narrower bandwidth for both pump and probe is necessary.However,quick and precise measurement of their detailed time structures is a challenge.Over the last decade,great efforts have been made to measure an attosecond extreme ultraviolet (XUV) pulse.To date,several methods have been developed to measure the pulse duration and completely reconstruct it.The attosecond spectral phase interferometry for direct electric field reconstruction (SPIDER) and attosecond frequency-resolved optical gating (FROG) techniques are often used.However,these methods use state-of-the-art experimental set-ups and complicated data analysis procedures.To develop attosecond metrology for practical use (e.g.timing,measurement,evaluation,calibration,optimization,pumping,probing),we propose a quick and analytical method to precisely observe an attosecond XUV pulse with laser-assisted photo-ionization.The method is based on determining the laser-related phase of each streaked electron and using a transfer equation for one-step pulse reconstruction without any time-resolved measurements,iterative calculations,or data fitting procedures.Temporal errors of the pulse reconstruction are calculated from the XUV bandwidth.Because the transfer equation establishes a direct connection between the XUV pulse properties,the crucial laser parameters (peak intensity,phase,carrier envelope phase),the atomic ionization potential,and the measured photoelectron energy spectrum,we can use it to study any one of these properties from other known information and probe the dynamic processes of an ultra-fast reaction.     

高职高专学生职业生涯规划教育的重要意义及其实施对策

本文试就萍乡地区两所高职高专院校学生职业生涯规划的调查现状,来谈高职高专学生职业生涯规划教育的重要意义及其实施对策。     

Averaging method of particulate systems and its application to particle-fluid flow in a fluidized bed

A particulate system can be described through the discrete approach at the microscopic level or through the continuum approach at the macroscopic level. It is very significant to develop the method to link the two approaches for the development of models allowing a better understanding of the fundamentals of particulate systems. Several averaging methods have been proposed for this purpose in the past, but they mainly focused on cohesionless particle systems. In this work, a more general averaging method is proposed by extending it for cohesionless particle systems. The application of the method to the particle-fluid flow in a gas fluidized bed is studied. The density, velocity and stress of this flow are examined. A detailed discussion has been conducted to understand the dependence of the averaged variables on sample size.