In this paper, we have studied a general kind of n-species Lotka-Volterra network- like food-chain system with delays and impulses on time scales. Applying Mawhin＇s continuation theorem of coincidence degree theory a...In this paper, we have studied a general kind of n-species Lotka-Volterra network- like food-chain system with delays and impulses on time scales. Applying Mawhin＇s continuation theorem of coincidence degree theory and some skills of inequalities, some sufficient criteria have been established to guarantee the existence of at least 2n periodic solutions to this model. One example is given to illustrate the effectiveness of our results.展开更多
The crystallization behavior, rheological behavior, mechanical properties and microstructures of injection molded isotactic polypropylene （iPP）, polypropylene random copolymer （co-PP） and iPP/co-PP blends were inv...The crystallization behavior, rheological behavior, mechanical properties and microstructures of injection molded isotactic polypropylene （iPP）, polypropylene random copolymer （co-PP） and iPP/co-PP blends were investigated. Differential scanning calorimetry （DSC） and dynamic rheological analysis illustrated that iPP and co-PP were compatible in the blends and co-PP uniformly dispersed in the/PP phase. Polarizing optical microscope （POM） was adopted to observe the crystal size and morphology evolution. The results of mechanical properties and scanning electron microscopy （SEM） indicated that the crystal size of iPP in iPP/co-PP blends （10 wt% co-PP ＋ 90 wt% iPP and 30 wt% co-PP ＋ 70 wt% iPP） radically decreased after the incorporation of co-PP. During crystallization, the molecular chain segments of co-PP could penetrate iPP spherulites and form a network-like crystalline structure. The network-like crystal structure could effectively transmit stress and consume more energy to overcome intermolecular forces to resist stretching. In this way, the strength would improve to a certain degree. The impact fracture mechanism of iPP/co-PP blends is quasi ductile fracture by multiple crazes. Our work discovered that the blends containing 10 wt% and 30 wt% ofco-PP exhibited prominent toughness and reinforcement.展开更多
基于类Kuramoto模型,对链式电网中的任意两个节点添加新的输电线,利用微扰动方法进一步分析链式电网的稳定性.理论结果表明:当电网中新加传输线中间节点相位差的取值范围给定时,拉普拉斯矩阵的最大非零特征值的领头阶修正(leading order...基于类Kuramoto模型,对链式电网中的任意两个节点添加新的输电线,利用微扰动方法进一步分析链式电网的稳定性.理论结果表明:当电网中新加传输线中间节点相位差的取值范围给定时,拉普拉斯矩阵的最大非零特征值的领头阶修正(leading order correction)的符号由新加传输线两端对应节点的相位差决定,且当新加传输线对应的节点与其中间节点的相位差同时在第一象限或者第四象限时,整体网络的稳定性能提高.展开更多
目的整合生物信息学挖掘并分析与基底型乳腺癌(basal-like breast cancer,BLBC)的预后相关的核心基因。方法首先,从GEO数据库中遴选与乳腺癌分子分型相关的数据集,数据处理后利用WGCNA筛选与BLBC相关的模块。然后,借助蛋白-蛋白互作(pro...目的整合生物信息学挖掘并分析与基底型乳腺癌(basal-like breast cancer,BLBC)的预后相关的核心基因。方法首先,从GEO数据库中遴选与乳腺癌分子分型相关的数据集,数据处理后利用WGCNA筛选与BLBC相关的模块。然后,借助蛋白-蛋白互作(protein-protein interaction,PPI)网络和cytohubba筛选出模块中差异最大的前10%基因作为候选基因,对候选基因进行生存分析和表达分析得到核心基因。最后,利用TIMER、TISIDB等生信工具探索核心基因表达和肿瘤免疫浸润、趋化因子及免疫调节剂的相关性并构建核心基因转录调控网络。结果利用WGCNA筛选出与BLBC相关的黑色模块中共891个基因,从差异性最大的80个候选基因中分析获得ESPL1和CCNB2两个核心基因。结果显示,两个核心基因与BLBC免疫细胞浸润有关,主要包括Th2细胞、CD8+T细胞、内皮细胞和肿瘤相关成纤维细胞。而且,核心基因表达水平与趋化因子、免疫刺激因子、免疫抑制因子及MHC分子相关。核心基因上游转录调控网络表明22种转录因子同时调控两个核心基因。结论ESPL1和CCNB2是BLBC的预后标志物且与肿瘤免疫相关。展开更多
文摘In this paper, we have studied a general kind of n-species Lotka-Volterra network- like food-chain system with delays and impulses on time scales. Applying Mawhin＇s continuation theorem of coincidence degree theory and some skills of inequalities, some sufficient criteria have been established to guarantee the existence of at least 2n periodic solutions to this model. One example is given to illustrate the effectiveness of our results.
文摘The crystallization behavior, rheological behavior, mechanical properties and microstructures of injection molded isotactic polypropylene （iPP）, polypropylene random copolymer （co-PP） and iPP/co-PP blends were investigated. Differential scanning calorimetry （DSC） and dynamic rheological analysis illustrated that iPP and co-PP were compatible in the blends and co-PP uniformly dispersed in the/PP phase. Polarizing optical microscope （POM） was adopted to observe the crystal size and morphology evolution. The results of mechanical properties and scanning electron microscopy （SEM） indicated that the crystal size of iPP in iPP/co-PP blends （10 wt% co-PP ＋ 90 wt% iPP and 30 wt% co-PP ＋ 70 wt% iPP） radically decreased after the incorporation of co-PP. During crystallization, the molecular chain segments of co-PP could penetrate iPP spherulites and form a network-like crystalline structure. The network-like crystal structure could effectively transmit stress and consume more energy to overcome intermolecular forces to resist stretching. In this way, the strength would improve to a certain degree. The impact fracture mechanism of iPP/co-PP blends is quasi ductile fracture by multiple crazes. Our work discovered that the blends containing 10 wt% and 30 wt% ofco-PP exhibited prominent toughness and reinforcement.
文摘基于类Kuramoto模型,对链式电网中的任意两个节点添加新的输电线,利用微扰动方法进一步分析链式电网的稳定性.理论结果表明:当电网中新加传输线中间节点相位差的取值范围给定时,拉普拉斯矩阵的最大非零特征值的领头阶修正(leading order correction)的符号由新加传输线两端对应节点的相位差决定,且当新加传输线对应的节点与其中间节点的相位差同时在第一象限或者第四象限时,整体网络的稳定性能提高.
文摘目的整合生物信息学挖掘并分析与基底型乳腺癌(basal-like breast cancer,BLBC)的预后相关的核心基因。方法首先,从GEO数据库中遴选与乳腺癌分子分型相关的数据集,数据处理后利用WGCNA筛选与BLBC相关的模块。然后,借助蛋白-蛋白互作(protein-protein interaction,PPI)网络和cytohubba筛选出模块中差异最大的前10%基因作为候选基因,对候选基因进行生存分析和表达分析得到核心基因。最后,利用TIMER、TISIDB等生信工具探索核心基因表达和肿瘤免疫浸润、趋化因子及免疫调节剂的相关性并构建核心基因转录调控网络。结果利用WGCNA筛选出与BLBC相关的黑色模块中共891个基因,从差异性最大的80个候选基因中分析获得ESPL1和CCNB2两个核心基因。结果显示,两个核心基因与BLBC免疫细胞浸润有关,主要包括Th2细胞、CD8+T细胞、内皮细胞和肿瘤相关成纤维细胞。而且,核心基因表达水平与趋化因子、免疫刺激因子、免疫抑制因子及MHC分子相关。核心基因上游转录调控网络表明22种转录因子同时调控两个核心基因。结论ESPL1和CCNB2是BLBC的预后标志物且与肿瘤免疫相关。
