延迟投饵对厚颌鲂仔鱼的影响

在室内养殖条件下,研究厚颌鲂仔鱼的摄食、耐饥饿和恢复生长能力。试验结果表明:(1)仔鱼在孵出后2～3d开口摄食,卵黄囊在之后的2d耗尽,饥饿仔鱼在12～13日龄达到不可逆点(PNR);(2)饥饿仔鱼的初次摄食率在卵黄囊耗尽时达到最高,保持在80%以上的时间为7d;(3)仔鱼在PNR后死亡率急剧增加,PNR后第3d仔鱼全部死亡;(4)经恢复生长试验,延迟3d投饵对仔鱼的存活率影响不大,延迟3～6d投饵对仔鱼全长生长影响不大。

垂直流人工湿地系统中不同组合填料净化能力研究

在较高水力负荷(1～2.5 m/d)下,选取沸石、无烟煤、蛭石、高炉钢渣、生物陶粒等5种填料,采用不同组合方式构建了4个模拟垂直流人工湿地并处理污水。结果表明:组合填料的种类、装填顺序和装填方式对净化效果产生了较大影响;与单一填料相比,4种组合填料对COD的平均去除率都有所提高,对BOD5的净化能力则略有降低;由上至下依次填充无烟煤、生物陶粒、沸石的组合填料具有较好的脱氮功能,对TN和NH4+-N的平均去除率分别达到85%和91%;由上至下依次填充无烟煤、蛭石、钢渣的组合填料具有较好的除磷功能,对TP和T

鳜肿瘤坏死因子相关的凋亡诱导配体Trail基因的原核表达

中国科学院“百人计划”项目([2005]192)资助

Change propagation analysis in complex technical systems

Understanding how and why changes propagate during engineering design is critical because most products and systems emerge from predecessors and not through clean sheet design. This paper applies change propagation analysis methods and extends prior reasoning through examination of a large data set from industry including 41,500 change requests, spanning 8 years during the design of a complex sensor system. Different methods are used to analyze the data and the results are compared to each other and evaluated in the context of previous findings. In particular the networks of connected parent, child and sibling changes are resolved over time and mapped to 46 subsystem areas. A normalized change propagation index (CPI) is then developed, showing the relative strength of each area on the absorber-multiplier spectrum between -1 and +1. Multipliers send out more changes than they receive and are good candidates for more focused change management. Another interesting finding is the quantitative confirmation of the "ripple" change pattern. Unlike the earlier prediction, however, it was found that the peak of cyclical change activity occurred late in the program driven by systems integration and functional testing. Patterns emerged from the data and offer clear implications for technical change management approaches in system design. Copyright © 2007 by ASME.

马口鱼和宽鳍(鱼巤)鳃上发现寄生桡足类一新种(杯口水蚤目,鳋科)(英文)

在湖北省丹江口水库的马口鱼和宽鳍(鱼巤)的鳃上发现的寄生桡足类1新种丹江鳋。形态观察的结果表明,丹江鳋与鳋属的其他种类有很多共同特征,尤其是与博氏鳋和膨大鳋。与其它所有鳋属种类不同的是丹江鳋的第2触肢内缘光滑无刺,及其楔形第2节的外缘呈明显的弧状。以核糖体内转录间隔区(ITS)为标记进行系统进化分析,结果表明,与膨大鳋相比,博氏鳋与丹江鳋的亲缘关系更近些。无论是形态还是系统进化分析的结果都支持丹江鳋为鳋属1个独立的新种。

柱状黄杆菌强毒株和弱毒株胞外蛋白中差异蛋白的初步鉴定

柱状黄杆菌(Flavobacterium columnare)是一种世界范围的水产动物致病菌,是中国重要养殖鱼类草鱼(Ctenopharyngodon idellus)、鳜(Siniperca chuatsi)等烂鳃病的病原。本研究以1972年从患"烂鳃病"草鱼上分离的两株冻干柱状黄杆菌G4和G18菌株为研究对象,并将G4株再次分离纯化得纯化菌株,命名为G4R3。对草鱼鱼苗浸泡攻毒结果显示,G4R3的LD50至少比G18的高3个数量级,因此G4R3为"强毒株",G18为"弱毒株"。利用蛋白质组学方法分析柱

从18S rRNA基因序列探讨盾腹吸虫的系统发育关系

盾腹亚纲吸虫被认为是寄生扁形动物中古老的类群,包括盾腹科、多萼科、裂杯科和皱腹科,科间系统发育关系尚存争议。本研究收集GenBank数据库中所有的盾腹吸虫18S rRNA基因序列,测定了三种盾腹吸虫的相应序列,分别采用最大简约法和最大似然法构建分子系统发育树。结果显示,多萼科的分类地位不成立,多萼属应还原到盾腹科;盾腹科的盾腹亚科和杯盾亚科均非单系,吸槽列数可能是平行进化特征,不能反映盾腹科各亚科间的系统发育关系。建议将具有边缘器的吸槽型腹吸盘,以及不具边缘器的吸杯型和皱褶型腹吸盘分别鉴定为盾腹科、裂杯科