Studies on the Characteristics of Nitrogen and Phosphorus Pollution of Natural Outcrop Springs in Wudalianchi

Objective] The research aimed to study the characteristics of nitrogen and phosphorus pollution of 30 natural outcrop springs in Wudalianchi, which provides a theoretical basis for the sustainable development and utilization and protection of Wudalianchi natural mineral resources. [Method] Choosing the 30 natural outcrop spring representatives in different regions, samples were collected in low water period, normal water period, wet period respectively, and the content of nitrogen, phosphorus and other contaminants in the samples were determined. Besides, the pollution characteristics of nitrogen and phosphorus in Wudalianchi natural outcrop spring were analyzed. [Result] The 30 natural outcrop spring in Wudalianchi area were seriously polluted by nitrogen. Total nitrogen and nitrate nitrogen were the main forms of nitrogen pollution. The content of total phosphorus and ammonia nitrogen were low. [Conclusion] The natural outcrop spring is mainly caused by agricultural non-point source pollution.

Joint Network and Fountain Codes Design for RelayAssisted Multi-User System

In relay-assisted multi-user system, relay coding is important to enhance the robustness and reliability of cooperative transmission. For better adaptability and efficiency, two joint network and fountain coding(JNFC) schemes are proposed. When the condition of all direct channels is worse, JNFC scheme based on distributed LT(DLT) codes is used. Otherwise, JNFC scheme based on multi-dimensional LT(MD-LT) codes is suited. For both two above-mentioned schemes, the united degree distribution design method for short-length fountain codes is proposed. For the latter scheme, MD-LT codes are proposed for equal error protection(EEP) of each user. Simulation results and analysis show that the united degree distribution need less decoding overhead compared with other degree distribution for short-length fountain codes. And then, all users are protected equally in despite of asymmetric uplinks.

再谈“垄种千口羊”

高昂《征行诗》:“垄种千口羊,泉连百壶酒。”其中的“垄种”和“泉连”,张春雷认为当读为“龙钟”和“蝉连”,为叠韵联绵词。我们从“垄种”的文献记载情况、“龙钟”的语义与词语搭配、《征行诗》的整体内容和结构等三个方面,对“垄种”“泉连”及《征行诗》的语义进行了探讨。我们认为“垄”为“高丘;山坡”之义,而“种”表“养殖;养育”,“垄种”就是“山坡高丘上蓄养”,“泉连”即“泉水相连”。这两句诗的大意为“山坡高丘上蓄养着群羊,百壶美酒如泉水相连”,以本字解之,语义顺畅无碍,无需求之于通假联绵。