线粒体D-loop序列变异与东方鲀属鱼类系统发育

东方鲀属的红鳍东方鲀(Takifugu rubripes)是后基因组时代的一种重要模式生物。本研究中,利用东方鲀属11种鱼类(18尾)的D-loop基因序列,对东方鲀属鱼类的系统发育关系进行研究。经序列比对排定后,分析中D-loop序列有841个位点,其中395个位点为可变位点,267个位点为系统发育信息位点。分别采用邻接法(NJ)、最大简约法(MP)、最大似然法(ML)和贝叶斯方法构建了分子系统树。研究结果表明:(1)东方鲀属鱼类为一单系类群;(2)由横纹东方鲀(T. oblongus)和铅点东方鲀(T

Investigation of DyBa2Cu3O7-d superconducting domains grown by the infiltration technique starting with small size Dy-211 particles

An infiltration and growth process is here used as an alternative to the classical top-seeded melt-textured growth process for the production of Dy-123 single-domains with finely dispersed small size Dy-211 particles. The starting materials are the 211-particles and a barium and copper rich liquid phase precursor. The infiltration and growth process allows for controlling both the spatial and size distribution of the 211-particles in the final superconducting 123-single-domain. The main parameters (set-ups, maximum processing temperature with respect to the peritectic temperature, nature of reactant, porosity of the 211-preform) of the infiltration and growth process are discussed. Moreover, different processes of chimie douce are shown in order to produce Dy-211 particles with controlled shape and size, particles that can be used as precursors for the infiltration and growth process. © 2005 IOP Publishing Ltd.

线粒体DNA d-loop序列变异与鳅鮀亚科鱼类系统发育

对鳅鮀亚科(Gobiobotinae)2个属8个种10个个体线粒体控制区d-loop全序列进行了测定.以(鱼丹)亚科斑马鱼为外类群,对鳅鮀及鲤科(Cyprinidae)一些亚科代表种鱼类进行了系统发育分析.结果显示,鳅鮀鱼类是一个单系类群,与鮈和细鲫有较近的亲缘关系.从系统发育的角度看,鳅鮀亚科应归属于鮈亚科(Gobioninae).研究结果支持鳅鮀亚科分为异鳔鳅鳅属(Xenophyso-gobio)和鳅鮀属(Gobiobtia).

Assessing boost-assist options for turbocharged engines using 1-D engine simulation and model predictive control

Delivering acceptable low end torque and good transient response is a significant challenge for all turbocharged engines. As downsized gasoline engines and Diesel engines make up a larger and larger proportion of the light-duty engines entering the market, the issue takes on greater significance. Several schemes have been proposed to improve torque response in highly boosted engines, including the use of electrical assist turbochargers and compressed air assist. In this paper we examine these methods with respect to their effectiveness in improving transient response and their relative performance along with some of the practical considerations for real world application. Results shown in this paper are from 1-D simulations using the Ricardo WAVE software package. The simulation model is based on a production light-duty Diesel engine modified to allow the introduction of compressed air at various points in the air-path as well as direct torque application to the turbocharger shaft (such as might be available from an electrical assist turbocharger). Whilst the 1-D simulation software provides a suitable environment for investigating the various boost assistance options, the overall air path performance also depends upon the control system. The introduction of boost assistance complicates the control in two significant ways: the system may run into constraints (such as compressor surge) that are not encountered in normal operation and the assistance introduces an additional control input. Production engine controllers are usually based on gain-scheduled PID control and extensive calibration. For this study, the non-linear nature of the engine together with the multiple configurations considered and the slower than real-time execution of 1-D models makes such an approach time consuming. Moreover, an ad-hoc approach would leave some doubt as to the fairness of comparisons between the different boost-assist options. Model Predictive Control has been shown to offer a convenient approach to controlling the 1-D simulations in a close to optimal manner for a typical Diesel VGT-EGR air path configuration. We show that the same technique can be applied to all the considered assistance methods with only modest calibration effort required. Copyright © 2012 SAE International.

Model based control for closed loop testing of 1-D engine simulation models

1-D engine simulation models are widely used for the analysis and verification of air-path design concepts and prediction of the resulting engine transient response. The latter often requires closed loop control over the model to ensure operation within physical limits and tracking of reference signals. For this purpose, a particular implementation of Model Predictive Control (MPC) based on a corresponding Mean Value Engine Model (MVEM) is reported here. The MVEM is linearised on-line at each operating point to allow for the formulation of quadratic programming (QP) problems, which are solved as the part of the proposed MPC algorithm. The MPC output is used to control a 1-D engine model. The closed loop performance of such a system is benchmarked against the solution of a related optimal control problem (OCP). As an example this study is focused on the transient response of a light-duty car Diesel engine. For the cases examined the proposed controller implementation gives a more systematic procedure than other ad-hoc approaches that require considerable tuning effort. © 2012 IFAC.

2,4-D���鱼腥藻增殖的效应

本文在实验室批量培养,室外小池大量培养和塑料大棚大面积培养的基础上,研究了植物激素2,4-D���激鱼腥藻增殖的效应。浓度在0.01—2.00μg/mL范围内都具有刺激鱼腥藻增殖的效果,随着浓度增加,这种效果降低。品质分析结果表明,0.01μg/mL2.4-D���提高蛋白质和叶绿素a的含量;浓度为0.05μg/mL时,二者的含量与对照相差不大;浓度达到0.1μg/mL时,二者的含量降低。本文提出,2,4-D���激鱼腥藻增殖的应用浓度应在0.05μg/mL以下,以0.01μg/mL效果最佳。

气单胞菌(Aeromonassp.D-4)降解LAS的研究

Aeromonas sp.D-4不能以LAS作为唯一碳源,它对LAS的利用是通过共代谢来完成的。LAS对D-4具有毒害作用,而且,起始LAS浓度越高,毒害作用越大。LAS的最大去除率与起始LAS浓度呈负相关。当起始LAS在40—120mg/L之间时,去除率较高;如果起始LAS在40mg/L左右,则去除率可达80％以上。研究还表明,Aeromonas sp.D-4纯培养对LAS的去除率(最大值84.97％)大于混合菌(最大值78.57％)。耗氧呼吸测定证实了Aeromonas sp.D-4对于LAS的共代谢