面对未来无人水下航行器(UUV)等设备探测通信一体化需求,本文提出一种基于Costas序列频率调制和差分相移键控(Frequency modulation of Costas Sequence and Differential Phase Shift Keying,Costas-DPSK)的水下探测通信一体化波形,并...面对未来无人水下航行器(UUV)等设备探测通信一体化需求,本文提出一种基于Costas序列频率调制和差分相移键控(Frequency modulation of Costas Sequence and Differential Phase Shift Keying,Costas-DPSK)的水下探测通信一体化波形,并给出后续基于双曲调频信号和单频连续波信号(Hyperbolic Frequency Modulation Wave and Continue Wave, HFM+CW)导引信号设计和信息处理方案。该信号利用Costas跳频调制保证了波形的探测能力,结合DPSK调制通信信息序列。仿真实验结果表明,该信号同时具备不输于线性调频信号(Line Frequency Modulation,LFM)信号的目标探测能力以及DPSK调制的通信能力,兼顾了水下探测和通信功能。展开更多
This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer inciden...This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer incidence rates, placing Costa Rica at the forefront within Central America. While prostate cancer and breast cancer dominate, disparities emerge when scrutinizing gender-specific trends. Notably, stomach and cervical cancers show declines, potentially attributed to targeted interventions. However, colorectal and liver cancers witness mortality increases, necessitating strategic responses. Geographical disparities persist across provinces, highlighting the need for equitable healthcare access. In conclusion, this commentary underscores the urgency of addressing the burgeoning cancer burden in Costa Rica, calling for evidence-based interventions and collaborative efforts on a global scale.展开更多
该文在步进频信号的基础上,把基于混沌调制的多载波相位编码(Multi-Carrier Phase Coded,MCPC)信号作为子脉冲,用Costas跳频代替频率的线性步进,设计出脉间Costas跳频脉内多载波混沌相位编码(Inter-Pulse Costas frequency hopping and ...该文在步进频信号的基础上,把基于混沌调制的多载波相位编码(Multi-Carrier Phase Coded,MCPC)信号作为子脉冲,用Costas跳频代替频率的线性步进,设计出脉间Costas跳频脉内多载波混沌相位编码(Inter-Pulse Costas frequency hopping and intra-pulse Multi-Carrier Chaotic Phase Coded,IPC-MCCPC)雷达信号,并对其模糊函数及自相关性能进行了研究。仿真分析表明,该文设计的信号继承了步进频信号用较小的瞬时带宽合成较大的工作带宽的优点,同时有效克服了步进频信号存在的距离-速度耦合的缺点。脉内多载波特性使得这种信号在保持总带宽和步进频信号相等的条件下减少跳频阶数,从而提高信号处理的数据率;混沌调相的引入使得这种信号具有更强的保密性;脉间频率的随机跳变使其模糊函数具有更低的周期性旁瓣。这种信号众多的参数、灵活的结构及较大的调制复杂度,增加了侦察接收机匹配和识别的难度,从而提高雷达的反截获性能。展开更多
Two long carbon chain alkyl (aqua) Costa type organocobalt complexes (R=C 6H 13 and C 8H 17 ) have been synthesized for the first time and characterized by elemental analysis, UV Vis and 1H NMR. Their inclusion behavi...Two long carbon chain alkyl (aqua) Costa type organocobalt complexes (R=C 6H 13 and C 8H 17 ) have been synthesized for the first time and characterized by elemental analysis, UV Vis and 1H NMR. Their inclusion behavior with β cyclodextrin was studied by 1H NMR methods. It was indicated that in aqueous solution supramolecular adducts have been formed, in which the alkyl groups of the guests were included into the cavity of β CD. Cyclic voltammetry methods was also used to study the electrochemical properties of organocobalt complexes in the absence and presence of β CD. [WT5HZ]展开更多
文摘面对未来无人水下航行器(UUV)等设备探测通信一体化需求,本文提出一种基于Costas序列频率调制和差分相移键控(Frequency modulation of Costas Sequence and Differential Phase Shift Keying,Costas-DPSK)的水下探测通信一体化波形,并给出后续基于双曲调频信号和单频连续波信号(Hyperbolic Frequency Modulation Wave and Continue Wave, HFM+CW)导引信号设计和信息处理方案。该信号利用Costas跳频调制保证了波形的探测能力,结合DPSK调制通信信息序列。仿真实验结果表明,该信号同时具备不输于线性调频信号(Line Frequency Modulation,LFM)信号的目标探测能力以及DPSK调制的通信能力,兼顾了水下探测和通信功能。
文摘This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer incidence rates, placing Costa Rica at the forefront within Central America. While prostate cancer and breast cancer dominate, disparities emerge when scrutinizing gender-specific trends. Notably, stomach and cervical cancers show declines, potentially attributed to targeted interventions. However, colorectal and liver cancers witness mortality increases, necessitating strategic responses. Geographical disparities persist across provinces, highlighting the need for equitable healthcare access. In conclusion, this commentary underscores the urgency of addressing the burgeoning cancer burden in Costa Rica, calling for evidence-based interventions and collaborative efforts on a global scale.
文摘Two long carbon chain alkyl (aqua) Costa type organocobalt complexes (R=C 6H 13 and C 8H 17 ) have been synthesized for the first time and characterized by elemental analysis, UV Vis and 1H NMR. Their inclusion behavior with β cyclodextrin was studied by 1H NMR methods. It was indicated that in aqueous solution supramolecular adducts have been formed, in which the alkyl groups of the guests were included into the cavity of β CD. Cyclic voltammetry methods was also used to study the electrochemical properties of organocobalt complexes in the absence and presence of β CD. [WT5HZ]
