棉纤维发育相关转录因子的研究进展

 转录因子在棉纤维细胞分化发育过程中起重要的调节作用。近年来已经有多个与棉纤维发育相关的转录因子被研究报道,主要包括MYB、HD-ZIP、MADS、TCP等家族成员,其中研究最为广泛的为MYB类转录因子。GL1类的MYB转录因子和MIXTA类的MYB转录因子通过不同的调控方式参与对棉纤维细胞发育的调控。对这些转录因子的深入研究,对于揭示棉纤维细胞分化发育的分子机理具有重要的意义。本文就这方面的研究进展作一简要概述。     

集群成长:我国木工机械产业发展转型升级的思考

我国木工机械产业目前正处在"转方式,调结构"的关键时期,集群发展是其转型升级的必由之路。在对产业集群概念、特征及其成长模式和成长动力机制等一般理论进行阐述的基础上,对我国木工产业集群发展的现状和存在的问题进行了系统分析,并据此提出了我国木工机械产业集群未来发展的思路和对策。     

Research on Mechanical Characteristics of the Cemented Sandstone Based on 3Dimensional PFC Numerical Model

Sandstone is sediment rock composed of many cemented sand particles, and corresponding particle constraint and force bearing capacity are greatly controlled by the cemented property. In order to better reflect the cemented property influencing on the mechanical characteristics of the sandstone, take the oil sandstone reservoir for instance, a numerical model based on 3Dimensional Particle Flow Code (PFC3D) considering the parallel bond model was brought forward to simulate the failure mechanism during shearing process. The sandstone cemented property is modeled based on random mathematics and advanced development of Particle Flow Code (PFC), and the relation of the stress ratio, volume strain, coordination number and bond-broken number and the axial strain is analyzed in detail, especially the contact network evolution indicated the force chain is important to transfer the external force, which verifies the feasibility of the numerical model. Based on the above PFC3D model, a series of researches on changing the cemented radius ratio, parallel bond stiffness and cemented volume of the particles have been done to clearly illuminate the importance of cemented property for the bearing capacity of the sandstone structure, which provides a scientific base for research on the failure mechanism of the sandstone under special conditions. Therefore, the above numerical method is more efficient and applicable for comparatively large scale and complex experiments, and the obtained research results can bring a new thought for the real cemented sandstone to research on its macro-micromechanical response and the structure failure mechanism, and also is significant for the sand production mechanism, sand volume prediction and sand control measures for the sandstone reservoir.     

Meeting time aware community routing mechanism in opportunistic network

Making use of the meeting opportunity raised by the movement of nodes, the messages are transmitted with the manner of “store-carry-forward” in opportunistic network. So these networks have a feature of longer delay than conventional ad hoc network. Current routing schemes try their best to deliver packet but leading to definitely network delay and are based on random movement model. According to the social character of nodes in network, the distributed predicting scheme on the expectation of meeting time between nodes is proposed; moreover, according to the estimating results, the relay node can be selected reasonably. With this manner, the message can be forwarded to the destination. Simulations show that the proposed estimating method is accurate; furthermore, comparing with the widely used routing mechanism, the performance on the delay can be improved more than 30%.     

关于江西省林产品质量安全问题的几点思考

产品质量一直是党和国家以及广大公众比较关注的焦点问题,江西作为全国林产品重要供应基地之一,林产品质量安全形势也不容乐观,已在一定程度上对公众身体健康、林产品竞争力和林业产业可持续发展的态势造成了影响。笔者从江西省林产品的现状谈起,分析林产品质量安全的概念和内涵,以及全省林产品质量安全保障机制的不足,并提出几点建议。     

创新治安管理机制 维护科研、旅游平安环境

以中国热带农业科学院香料饮料研究所(以下简称“香饮所”)的安全工作为例,从创新体制,优化社会治安综合治理;树立和落实科学发展观,维护科研、旅游稳定;建立严格的管理体系,提出旅游景点治安管理工作等3个方面,通过实例说明管理体制的不断创新可提高人与自然的和谐相处,并对单位和旅游景点的人、财、物安全提供了强有力的保障措施,对维护香饮所安全、稳定、健康的持续发展具有重要意义。     

蛋白质影响水稻米饭食味品质的机理

 以杂交中籼丰两优1号组合为材料,设置不同的播期和收获期,分析稻米主要品质指标(直链淀粉、总蛋白含量、RVA特征值等)和米饭食味品质,并用二硫苏糖醇 (DTT)或蛋白酶(Trypsin)分别打破样品蛋白质二硫键或酶解蛋白质后,观察RVA特征谱和膨胀势的变化,旨在明确蛋白质对不同食味品质样品RVA的影响,进而探索蛋白质影响米饭食味品质的机理。结果表明,第3播期(6月13日)稻米品质主要指标（直链淀粉、总蛋白、膨胀势、RVA特征值）与第4播期（6月23日）样品差异不显著,但食味品质明显好于后者;分别经蛋白酶处理后,第3和第4播期样品RVA上升段斜率差异不显著,但前者后段冷却后回升斜率明显小于第4播期。由于影响RVA特征谱后段凝胶刚性的主要因素是淀粉与水之比,刚性随淀粉凝胶中含水量减少而提高,食味品质较好的第3播期米粉经蛋白酶处理后,凝胶刚性小且减弱程度大,这可能是蛋白质酶解后形成蛋白质碎片的持水能力弱,即淀粉与水之比低,由此推测蛋白质影响米饭食味品质可能在米饭蒸煮后阶段,即可能与蛋白质水合后持水能力差异有关。     

水稻抗稻瘟病分子遗传研究进展

了解水稻对稻瘟病的抗性机制,选育对稻瘟病具有广谱、持久抗性的水稻品种是水稻稻瘟病研究的重点与难点。从水稻抗稻瘟R基因和稻瘟菌Avr基因的定位与克隆、功能和结构特点、两者之间的互作机制等方面综述了目前稻瘟病的研究进展,并对稻瘟病需要进一步研究的问题进行了讨论和展望。     

牛支原体耐药性研究进展

在对国内外牛支原体的耐药性研究进展做以综述的基础上,对近年来支原体的耐药机制进行了概述,以期为养牛业生产中牛支原体病的防治和耐药机制的研究提供参考.     

泡生法制备蓝宝石缺陷产生机理及改进方法分析

指出了在采用泡生法制备蓝宝石晶体的过程中,常见的晶体缺陷主要有位错、杂质原子及色心、气泡与空腔、晶体裂纹等。缺陷的产生极大影响了晶体的光学性能和使用性能,因此对于晶体缺陷产生机理的研究很有必要。分析表明:通过改善晶体生长的物质条件和工艺条件可有效降低晶体中各种缺陷的产生,对于生长大尺寸、高质量蓝宝石晶体具有重要意义。