Growth Performance and Genetic Diversity Analysis of Hybrids Between Selective Lines of Litopenaeus vannamei

对2个凡纳滨对虾(Litopenaeus vannamei)选育系(A和B)的自繁与杂交后代的生长性状及遗传多样性进行了分析.养殖对比实验结果表明,杂交组合AB生长性状优于其他各组,表现出较好的杂种优势.使用11对荧光标记的微卫星引物对4个凡纳滨对虾自繁与杂交群体以及1个从美国引进的初代亲本SIS群体的基因组DNA进行扩增,结果显示除AA群体外,其余4个群体均表现出较丰富的遗传多样性,观测到的平均等位基因数(Na)为4.273~5.636,平均期望杂合度(He)为0.586~0.629,平均多态信息含量(PIC)为0.512~0.556.遗传距离分析结果显示,SIS群体和AA群体的遗传距离最远(0.670 4),而与AB群体的最近(0.131 4).研究结果表明,引自美国的凡纳滨对虾群体经多代自繁后,其遗传多样性水平降低;而选育系间杂交则可使杂交后代的生长性状和遗传多样性水平得到改善.The growth performance and genetic diversity of the inbred and crossbred progenies of two Litopenaeus vannamei selective lines( A and B) were analyzed in this study.The results indicated that AB group showed the best growth performance and heterosis.Eleven fluorescently labeled microsatellite markers were used to amplify microsatellite DNA from five L. vannamei populations.The results showed that four populations( except for AA) displayed higher genetic diversity with average numbers of alleles( Na = 4. 273-5. 636),average expected heterozygosity( He = 0. 586-0. 629),and average polymorphism information content( PIC = 0. 512-0. 556). Nei' s unbiased genetic distance( Ds) indicated a close genetic relationship between populations SIS and AB( Ds= 0. 131 4),while populations SIS and AA showed the farthest genetic relationship( Ds = 0. 670 4).The results demonstrated that the genetic diversity decreased after several generations of selection,while hybridization between different selective lines could improve the growth performance and genetic diversity of L. vannamei.厦门市海洋经济创新发展区域示范项目(13PZY001SF25

中能重离子在位置灵敏CsI（Tl)探测器中能损与光输出响应的关系

In this paper, we describe the structure and readout system of a two-dimension positional sensitive CsI(Tl) detector, and investigates the relation between energy lose and light output of the CsI(Tl) detector with secondary beams in intermediate energy.Bρ+(ΔE-TOF) method was used to distinguish the secondary beam.Linearity of the position signals of the CsI(Tl) was corrected.Energy signals from the CsI(Tl) detector were calibrated using the relationship of the Z, A and the light output response of the incid...中文摘要：描述了一种双维位置灵敏CsI(Tl)探测器的结构及其读出系统,用中能次级束研究其能损与光输出关系。使用Bρ+(ΔE-TOF)方法鉴别次级束,刻度了CsI(Tl)探测器位置信号的线性,并用其光输出与入射粒子的A、Z关系刻度其能量。结果表明,CsI(Tl)探测器输出信号的ADC读出与QDC读出(即其光输出)有很好的线性关系

基于扭摆的微冲量测量方法及实验研究

超高微重力水平的卫星平台在空间引力波探测、地球重力场测量中发挥着重要的作用,脉冲微推力器可以帮助微重力卫星实现姿态控制.微冲量是评价脉冲微推力器性能的重要指标之一,常用的基于扭摆的微冲量测量方法有两种,方法一是根据单个冲量元瞬间作用于无阻尼扭摆后,扭摆转动最大角位移计算冲量,方法二是根据高固定频率的连续脉冲作用于有阻尼扭摆后,扭摆转动的平均角位移计算冲量.为了在地面实现对脉冲微推力器的微冲量测量,利用已有的基于扭摆的亚微牛级推力测量系统,进行了实验研究.利用静电梳齿产生的标准静电力标定已有的扭摆推力测量系统,通过电容式位移传感器测量扭摆角位移,进而得到推力与角位移的关系,以及其他扭摆系统参数;然后,根据两种冲量测量方法,再以电磁螺线圈与永磁体分别产生瞬时磁力与固定频率的磁力作用于扭摆,研究推力测量系统微冲量测量性能.实验结果表明:使用方法一时,推力测量系统冲量测量范围为0.05～220μN·s,分辨力可达到0.02μN·s;而利用方法二测量微冲量相比于方法一而言,能够扩大冲量测量范围,提高冲量分辨能力

A Design Method for Redundant Microthruster Layout With Allocation Error

The microthruster is generally chosen as the actuator of the drag-free satellite control system, and the layout directly affects the stability of the satellite control. Due to the extremely rigorous objectives of drag-free control, a design method for the redundant thruster layout is proposed in this paper to improve the control stability of the satellite and reduce the allocation error of the control system. First, the factors corresponding to the allocation errors of redundant thruster layouts are analyzed. And the minimum number of thrusters required for satellite control is determined through the calculation method of thruster redundancy. Then, the design criterion of reducing the allocation error and increasing the satellite control stability is put forward. To demonstrate the effectiveness and feasibility of the design method proposed in this paper, the space gravitational wave detection satellite is taken as a simulation case. Thrust distribution models corresponding to the designed thruster layouts are established, and the results show that a proper layout can not only improve stability but also reduce fuel consumption. The research is looking forward to providing a reference for designing the microthruster layout of the gravitational wave detection satellite in the future

一种基于悬挂摆的单自由度无拖曳控制仿真系统

本发明公开了一种基于悬挂摆的无拖曳半物理仿真系统,包括环形筒状真空环境模拟子系统、隔振台、悬挂摆子系统、悬挂及隔振子系统、静电梳推力子系统、测控子系统；该悬挂及隔振子系统通过钨丝两端配对安装的钨丝绕线环和夹具锁头将钨丝和悬挂摆子系统的摆杆紧固连接,从而提高无拖曳半物理仿真系统的灵敏度和精度；所述测控子系统用于监测悬挂摆子系统状态变化并输入该控制器中,控制器用于计算并输出静电梳推力子系统所需的静电力信号；本发明按照动力学及主要物理量等效原则设计一种单自由度无拖曳控制半物理仿真方法。该方法模拟各项载荷在无拖曳控制回路中的性能并且验证在地面上控制回路可以达到的无拖曳控制性能指标

一种基于Roberval平衡结构的微推力测量装置

本发明公开了一种基于Roberval平衡结构的微推力测量装置,该装置包括扭摆型测量机构、位移传感器、标准力标定装置、水平底座及防尘罩、以及测控子系统5；该扭摆型测量机构包括平行四边形测量台架、限位机构与阻尼器、以及配重机构；在该平行四边形测量台架的一条侧边联动杆的上表面安装有推力器安装台,该推力器安装台上分别装有推力器、位移传感器、标准力标定装置,推力器的推力方向为沿着联动杆的长度方向；本发明有效消除了推力器力臂测量误差、标准力力臂测量误差和传感器位置测量误差,提高了测量精度；位移测量表现为一维位移测量模式,提高了推力测量系统线性度；仅需调节扭摆一维质心位置,简化了推力器装配和调试过程

一种无拖曳控制半物理仿真系统

本发明公开了一种无拖曳控制半物理仿真装置,包括质量块模拟子系统、冷气微推力子系统、测量与控制子系统、气浮台子系统；该气浮台子系统整体悬浮布设在大理石平台上方,用于模拟在轨卫星的本体运动；该气浮台子系统设有第一级台面和第二级台面,该第一级台面上布设有两套质量块模拟子系统、用于模拟在轨卫星敏感轴方向的运动；该第一级台面上还布设有冷气微推力子系统；该第二级台面上布设有测量与控制子系统,该测量与控制子系统用于测量气浮台子系统的气浮台运动状态和质量块模拟子系统的质量块运动状态,并输出控制指令给微推力器,控制系统状态。本发明解决了之前的卫星模拟内部都是没有活动部件的,现有技术没有先例可以借鉴的难题