在水下光通信中,信号在海水信道中衰减极大,严重影响通信系统的可靠性,因此必须采用优秀的纠错码来降低数据传输的误码率。将低密度奇偶校验码(LDPC)与脉冲位置调制(PPM)相结合,建立
According to the documental accounts,the distri- bution of wild rice(O.perennis),the ancestor spe- cies of cultivated rice in ancient China is possiblymore nor
利用花药培养诱导单倍体,可以缩短育种年限,提高育种效率。花药培养的后代是单倍体加倍的纯合单株,由于花粉母细胞在减数分裂时染色体的随机交换,理论上可以出现新基因型植株
香蕉系芭蕉科芭蕉属,是我国海南、广东、广西等南方地区的重要经济作物之一。香蕉叶面积大,根系浅,生长迅速,需水量大,而我国一些光热条件十分适合种植香蕉的地区因季节性缺
随着我国市场经济的快速发展,社会整体水平得到了明显的改善,园林绿化逐渐在城市发展中发挥了积极的作用.近年来,我国对植物景观园林绿化的建设更加重视,改善和提升环境质量
Natal rearing experience of animals may affect their behaviors,such as habitat selection and oviposition decision.As part of the overall fitness of insect paras
Predatory mites of the Phytoseiidae family are considered one of the most important groups of natural enemies used in biological control.The behavioral pattes o