Prophages domesticated by bacteria promote the adaptability of bacterial cells

Prophages are temperate phages integrated into the host bacterial genome. They play an important role in theadaptation and the pathogenicity of bacteria, especially pathogenic bacteria. In this review, we described the distributionof prophages in different hosts and different environments, and focused on the significance of prophages. At the singlecell level, prophages can help the host adapt to harsh external environments by directly carrying virulence genes, encodingregulatory factors and activating lysogeny. At the population level, prophages can influence the overall evolutionarydirection and ecological function of the host bacterial community. This review will help us understand the importantrole of prophages as unique organisms in individual bacteria and microbial populations.     

高碳钢线材轧制组织和性能模型的应用

开发了用于模拟高碳钢高速线材生产过程中断面温度分布,奥氏体组织演变和产品性能的系统数学模型组。由实验确定的临界应变、奥氏体再结晶、斯太尔摩冷却线上奥氏体相变、组织和力学性能关系子模型耦合轧件温度场,构建了一个组织性能预报系统。该系统所计算出的轧制线上关键点钢材温度,奥氏体晶粒度和力学性能与实测值吻合较好。     

差分进化算法在变压器故障诊断中应用

针对典型小样本数据的变压器故障诊断,文章提出了一种基于差分进化算法优化的支持向量机构建电力变压器故障诊断方法。该方法是采用差分进化算法来优化支持向量机核函数参数g和惩罚因子C,将优化过的支持向量机对小样本故障数据进行故障诊断。实验结果表明,该方法比网格搜索优化算法和粒子群优化算法具有更高的准确率,非常适合于电力变压器的故障诊断。     

Electrochemical cell current requirements for toxic organic waste destruction in Ce(IV)-mediated electrochemical oxidation process

The electrochemical cell for cerium oxidation and reactor for organic destruction are the most important operation units for the successful working mediated electrochemical oxidation (MEO) process. In this study, electrochemical cells with DSA electrodes of two types, single stack and double stack connected in series, were used. The performances towards the electrochemical generation of Ce(IV) in nitric acid media at 80 °C were studied. The current-voltage curves and cerium electrolysis kinetics showed the dependence on number of cell stacks needed to be connected in series for the destruction of a given quantity of organic pollutant. The presence of an optimum region for Ce(III) oxidation with a contribution of oxygen evolution, especially at low Ce(III) concentration (high conversion ratios), was found. The cells were applied for the Ce(IV) regeneration during the organic destruction. The cell and reactor processes were fitted in a simple model proposed and used to calculate the current needed in terms of Ce(III) oxidation rate and the number of cell stacks required for maintaining Ce(IV)/Ce(III) ratio at the same level during the organic destruction. This consideration was based on the kinetic model previously developed by us for the organic destruction in the MEO process.     

Odor Detection in Insects: Volatile Codes

Insect olfactory systems present models to study interactions between animal genomes and the environment. They have evolved for fast processing of specific odorant blends and for general chemical monitoring. Here, we review molecular and physiological mechanisms in the context of the ecology of chemical signals. Different classes of olfactory receptor neurons (ORNs) detect volatile chemicals with various degrees of specialization. Their sensitivities are determined by an insect-specific family of receptor genes along with other accessory proteins. Whereas moth pheromones are detected by highly specialized neurons, many insects share sensitivities to chemical signals from microbial processes and plant secondary metabolism. We promote a more integrated research approach that links molecular physiology of receptor neurons to the ecology of odorants.     

植物基因多态性的系统分类学研究（Ⅱ）凝集素基因的分子进化

通过选择豆科植物的几种凝集素，求得其核苷酸替换率（Ｋｎｕｃ值）．结果显示，蚕豆、兵豆、和豌豆的Ｋｎｕｃ值较小，而大豆、刀豆、菜豆的Ｋｎｕｃ值较大．由此确定蚕豆、兵豆和豌豆之间具有较近的亲缘关系，而其它则较远．由Ｋｎｕｃ值绘制的系统树支持恩格勒被子植物分类系统．     

论地球化学外能与内能的转换

岩石在地表条件下具有q值增大规律。岩浆岩和变质岩在地表条件下,吸收太阳等宇宙能转化成沉积岩;在地壳深处,沉积岩释放这些能量转化成岩浆岩或变质岩。能量的上述转换,是通过内生的低晶格能矿物与外生的高晶格能矿物负载者实现的;是通过硅、铝主导控制元素,以及氧、钠、钾、钙、镁和铁等实现的。外能补充内能并通过内能起作用,从而成为改造地球面貌的宏伟运动。     

Rethinking the design of real-coded evolutionary algorithms: Making discrete choices in continuous search domains

Although real-coded evolutionary algorithms (EAs) have been applied to optimization problems for over thirty years, the convergence properties of these methods remain poorly understood. We discuss the use of discrete random variables to perform search in real-valued EAs. Although most real-valued EAs perform mutation with continuous random variables, we argue that EAs using discrete random variables for mutation can be much easier to analyze. In particular, we present and analyze two simple EAs that make discrete choices of mutation steps.     

强流微束斑电子束系统的研究和设计计算

本文研究了强流微束斑电子束的形成问题。提出了一种采用新型磁透镜的电磁复合聚焦系统，这种新型电子束系统的轴上磁场在电子束束腰附近达到极大值，并且轴上磁场分布关于其极大值不对称。利用附加电极在磁场较强的区域构成具有拒斥电场的电透镜，以充分抑制空间电荷推斥力的散焦作用。利用描述电流密度分布演化的变态伏拉索夫方程，研究了强流微束斑电子束系统，数值分析研究了透镜激励和电子束初始条件对于电流密度分布演化的影响。发现侧极靴透镜和相应电极形成的电磁复合聚焦场对于强电流电子束具有优秀的聚焦效果，设计出了利用侧极靴磁透镜的新型电子光学系统，这种系统可以形成电流达到1．96mA、束斑半径仅为4．2μm的强电流微束斑电子束。     

Theoretically-based algorithms for robustly tracking intersection curves of deforming surfaces

This paper applies singularity theory of mappings of surfaces to 3-space and the generic transitions occurring in their deformations to develop algorithms for continuously and robustly tracking the intersection curves of two deforming parametric spline surfaces, when the deformation is represented as a family of generalized offset surfaces. The set of intersection curves of two deforming surfaces over all time is formulated as an implicit 2-manifold I in an augmented (by time domain) parametric space R⁵. Hyperplanes corresponding to some fixed time instants may touchI at some isolated transition points, which delineate transition events, i.e. the topological changes to the intersection curves. These transition points are the 0-dimensional solution to a rational system of five constraints in five variables, and can be computed efficiently and robustly with a rational constraint solver using subdivision and hyper-tangent bounding cones. The actual transition events are computed by contouring the local osculating paraboloids. Away from any transition points, the intersection curves do not change topology and evolve according to a simple evolution vector field that is constructed in the Euclidean space in which the surfaces are embedded.