凡纳对虾小触角表面结构的显微观察   总被引：3，自引：0，他引：3  

曾嶒  戴立贤  刘永红  李红  李琦  王珺 《华中农业大学学报》2002,21(4):371-378

应用光学显微镜和扫描电子显微镜观察了凡纳对虾小触角的表面结构。结果发现：小触角上广泛着生着700根以上的羽状刚毛；外鞭片状隆起腹面平均约具280根无顶孔但有细分支的化感刚毛，这类有分支的化感刚毛在其它十足目种类上未见有报道，而且其刚毛数也较其它种类少；内侧附肢前端与柄节上直立的羽状刚毛毛簇顶相接触，推测该结构可能对相邻的复眼具某种作用。  相似文献   

神农架地区虫草寄主记述     

曾宪顺  刘治根  陈启武 《华中农业大学学报》1985,(4)

对神农架林区已发现的粉被虫草菌、珊瑚虫草菌、霍克斯虫草菌、蛹虫草菌和巴恩斯虫草菌的寄主昆虫种类作了调查,描述了寄主被寄生后的虫体形态。  相似文献   

基于CFD的储粮装具设计及其仿真     

胡耀华  曾智伟  陈康乐  张强  侯俊才 《粮食储藏》2012,41(6):18-21

粮食储藏直接关系着人们所食用粮食的质与量,先进的、适用的储藏技术能最大限度降低储藏期间的粮食损耗,而性能合理的粮仓则是优越储藏技术发挥作用的基础。我国粮食存储的主体是农户,但目前农户储粮在我国是最薄弱的环节,因此,研究适合农户使用的储粮装具就显得至关重要。本研究是在参考现有粮仓的基础上,设计了一种适合农户家用的储粮仓。通过CFD软件对不同温湿度条件下粮仓内部温度场和湿度场的模拟,对于在不同环境条件下的储粮安全性进行了分析。研究表明,在低温和中温条件下,该装具有较好的储粮效果,在极端高温或者高湿条件下,由于粮食的呼吸作用加强,容易导致粮食发生霉变和虫害,发生储粮损失。  相似文献   

Molecular characterization,tissue distribution,and expression regulation from fasting and re-feeding of two growth hormone receptors in mandarin fish Siniperca chuatsi     

Xue Lu  Yongming Gu  Xiaocui Hou  Haifang Wang  Pengfei Wang  Peng Xu  Lei Zeng  Lei Zhou  Guifeng Li 《Fisheries Science》2016,82(1):155-169

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微生物营养剂对峨眉蔷薇种子萌发的影响     

韩倩  王泽翻  郑燕  杨恒  曾凡景  李亚奇  赵惠恩  赵世伟  刘恒星 《东北林业大学学报》2012,40(11)

以峨眉蔷薇种子为材料,低温冷藏后取出,利用不同质量浓度的微生物营养剂进行暖温催芽处理,以零添加、零处理为对照,研究探讨了不同碳、氮质量浓度的微生物营养剂对种子萌发的影响,结果显示,不同质量浓度的营养剂均可不同程度地提高种子萌发率,促进种子快速萌发;较适宜营养剂,即蔗糖、酵母膏质量浓度分别为5、1.0g· L-1;质量浓度最高的组合效果最差,较低的碳源、氮源质量浓度组合表现出较好的综合促进作用,推测可能与微生物的活动周期有关,最适的营养剂质量浓度等仍有待进一步研究.  相似文献   

Comparison of physiological and yield traits between purple- and white-pericarp rice using SLs     

Zhi-Juan Ji  Xiao-Guang Wang  Yu-Xiang Zeng  Liang-Yong Ma  Xi-Ming Li  Bing-Xin Liu  Chang-Deng Yang 《Breeding Science》2012,62(1):71-77

Five physiological and eleven yield traits of two pairs of sister lines generated from a high generation with similar genetic background (SLs) for purple pericarp were investigated to explore the reasons behind low-yield production of colored rice. Of the five physiological traits examined, except grain anthocyanin content, there were generally similar trends between the P (purple-pericarp) lines and the corresponding W (white-pericarp) lines over two seasons (in the year 2009 and 2010 separately). The results demonstrated that the chlorophyll content of flag leaves, the net photosynthetic rate of flag leaves, and the grain anthocyanin content could be easily influenced by the environment. The physiological functions of the traits for the P lines were more active than those of the corresponding W lines in the year 2010. The grain anthocyanin content of the P lines was much greater in the year 2010 than in the year 2009 during the growth period. The investigation of yield traits revealed that the P lines had reduced 1000-grain weight, yield per plot and grain/brown rice thickness compared to the W lines. A difference comparison of these traits and a source-sink and transportation relationship analysis for these SLs suggested that small sink size was a key reason behind yield reduction of purple pericarp rice.  相似文献   

The Innovativeness and Heterogeneity of Foreign‐Invested High‐Tech Companies in Shanghai     

Ingo Liefner  Yehua Dennis Wei  Gang Zeng 《Growth and change》2013,44(3):522-549

China has taken a foreign direct investment‐based approach toward increasing its capital and knowledge base, and developing into an innovative economy. However, little quantitative evidence exists about the factors that drive innovations of foreign‐invested enterprises (FIEs) there. This paper uses survey data from high‐technology firms in Shanghai to discuss factors affecting their innovativeness. It takes the concepts of absorptive capacity, export orientation, and innovation‐related cooperation as a starting point. It highlights how the interplay of strategies and resources affects innovativeness and heterogeneity of FIEs. The most innovative FIEs are endowed with a strong human capital base and R&D activities, which at the same time target export markets and whose cooperative partners involve firms other than their parent company. The results underline the necessity to differentiate between the different types of FIEs when examining their innovativeness.  相似文献   

火炬水封罐溢流口位置的设置     

曾一斐  于安峰 《油气储运》2013,32(1)

水封罐是火炬系统防回火的重要设备之一,其溢流方式直接影响凝缩油的排放,而水封罐撇油、换水操作亦会对火炬系统产生影响.对典型的水封罐结构及溢流方式进行总结分析,结果表明:采用带挡板的水封罐可以明显减少换水量,而将溢流口设置在罐壁上可以有效撇油,并且能够避免撇油过程中的安全隐患.通过具体实例,给出典型罐壁开孔的水封罐结构及运行参数,并提出对于火炬水封罐溢流口位置设置的建议:设计中,优选在水封罐壁不同高度开口的方法,若采用连通管溢流方式,则需制定详细的撇油、换水作业操作规程,并严格执行.  相似文献   

我国蓖麻良种选育研究现状及发展策略   总被引：2，自引：0，他引：2  

曾祥艳  王东雪  马锦林 《广西热带农业》2010,(6)

通过分析我国蓖麻当前的良种选育和推广应用的现状和趋势,提出了蓖麻良种选育研究发展的若干策略,为今后我国蓖麻的发展提供参考.  相似文献   

福建省连江县沿海防护林体系建设成效与对策     

曾庆旻 《亚热带水土保持》2011,23(1):50-52

根据连江县沿海防护林体系建设情况,结合"十二五"林业发展规划,提出加强县域防护林体系建设的应对措施,为科学经营防护林提供依据,对建设海峡西岸经济区最前沿的一道绿色屏障具有重要的战略意义.  相似文献