The problem of food shortage is one of the most important problems facing many countries in the world. Various factors affect the decline in crop productivity. Where weeds are the most important reasons that cause a h...The problem of food shortage is one of the most important problems facing many countries in the world. Various factors affect the decline in crop productivity. Where weeds are the most important reasons that cause a huge loss in crop productivity. Studying agricultural ecosystems, knowing their components and explaining the relationship between all of their components, helps a lot in achieving the highest productivity of different crops in addition to benefiting from some types of weeds, as well as, identifying appropriate methods to control the growth of weeds. In this study, 60 species were listed. The most frequent plant families were Asteraceae, Poaceae and Zygophyllaceae. Annuals were the most common life span, as well as, therophytes were the most frequent life form. The most frequent floristic categories were Saharo-Sindian-Sudano-Zambezian and Saharo-Sindian regions. The most famous indicators of biodiversity (species richness, species evenness and species diversity) have been calculated. For managing and classifying data PC-ORD program (TWINSPAN and DCA analyses) was used.展开更多
针对语音通信的实时性特点,在50 kHz带宽的超短波(Very High Frequency,VHF)通信信道上采用动态时分复用接入、高压缩语音编码方式,基于多点中继(Multipoint Relaying,MPR)广播协议的Ad-Hoc网络,提出一种低延时高覆盖率的多跳语音广播...针对语音通信的实时性特点,在50 kHz带宽的超短波(Very High Frequency,VHF)通信信道上采用动态时分复用接入、高压缩语音编码方式,基于多点中继(Multipoint Relaying,MPR)广播协议的Ad-Hoc网络,提出一种低延时高覆盖率的多跳语音广播通信方案,以满足应急、户外探险以及军用班排级团队的无线通信需求。展开更多
文摘The problem of food shortage is one of the most important problems facing many countries in the world. Various factors affect the decline in crop productivity. Where weeds are the most important reasons that cause a huge loss in crop productivity. Studying agricultural ecosystems, knowing their components and explaining the relationship between all of their components, helps a lot in achieving the highest productivity of different crops in addition to benefiting from some types of weeds, as well as, identifying appropriate methods to control the growth of weeds. In this study, 60 species were listed. The most frequent plant families were Asteraceae, Poaceae and Zygophyllaceae. Annuals were the most common life span, as well as, therophytes were the most frequent life form. The most frequent floristic categories were Saharo-Sindian-Sudano-Zambezian and Saharo-Sindian regions. The most famous indicators of biodiversity (species richness, species evenness and species diversity) have been calculated. For managing and classifying data PC-ORD program (TWINSPAN and DCA analyses) was used.
文摘针对语音通信的实时性特点,在50 kHz带宽的超短波(Very High Frequency,VHF)通信信道上采用动态时分复用接入、高压缩语音编码方式,基于多点中继(Multipoint Relaying,MPR)广播协议的Ad-Hoc网络,提出一种低延时高覆盖率的多跳语音广播通信方案,以满足应急、户外探险以及军用班排级团队的无线通信需求。
