TWR(Two Way Ranging)和SDS-TWR(Symmetric Double Side-Two Way Ranging)是IEEE802.15.4a中定义的两种TOA测距方案,主要用于无基础设施和额外同步机制条件下的节点定位/跟踪等应用.通过分析指出:TWR测距方案具有较高的测距容量且对节...TWR(Two Way Ranging)和SDS-TWR(Symmetric Double Side-Two Way Ranging)是IEEE802.15.4a中定义的两种TOA测距方案,主要用于无基础设施和额外同步机制条件下的节点定位/跟踪等应用.通过分析指出:TWR测距方案具有较高的测距容量且对节点移动的敏感度低,但其测距误差较大;SDS-TWR虽然能有效降低时钟频偏带来的测距误差,但其测距容量较低并且对节点移动的敏感度高.在此基础上,提出一种基于时钟频率比的TOA测距新方案R-TWR(Frequency Ratio BasedTWR).分析及仿真证明,该方案能达到SDS-TWR方案的测距准确度,并和TWR一样对节点移动的具有较高的测距容量和较低的移动敏感度.展开更多
No, Isaac Newton did not “explain” gravitation. What he did, and this certainly constituted all and by itself a great achievement, was to recognize (to “assert”) the universal character of gravitation: all materia...No, Isaac Newton did not “explain” gravitation. What he did, and this certainly constituted all and by itself a great achievement, was to recognize (to “assert”) the universal character of gravitation: all material objects (bodies) attract each other by gravitation. But how does gravitation perform its deeds? This remained a mystery to Newton. In a “desperate move” at the end of his life, he introduced the concept of “Particles which are moved by certain active Principles [our emphasis]—such as is that of Gravity” he said. We resurrect this scheme, we provide it with a quantum structure—a stunning new insight into the workings of gravitation obtains.展开更多
The result of mathematical and physical analysis of the daily change in gravity is presented. The subject of consideration was the manifestation of semi-daily factors in diurnal variations of gravity. The assumption i...The result of mathematical and physical analysis of the daily change in gravity is presented. The subject of consideration was the manifestation of semi-daily factors in diurnal variations of gravity. The assumption is investigated, according to which the cause of the half-day factors is the gravitational shielding of the planet Earth. Gravitational shielding is considered as a function of the size and thickness of celestial bodies and growing with distance from their poles. It is concluded that the planet Earth has the property of partial gravitational shielding, and the Moon does not have enough thickness to exhibit a tangible gravitational shielding. The obtained mathematical results correspond to the existing experimental data. It is suggested that gravitational shielding is the cause of the precession of the perihelion of Mercury and the peculiarities of the manifestation of tidal processes. It is assumed that gravitational shielding is one of the main reasons for the presence of hidden substances in the Universe. It is concluded that the physical picture with mutual shielding of interaction elements corresponds to the classical ideas of Fatio and Lesage. This approach is proposed as an alternative point of view to the existing theory on the description of tidal processes. It is shown that the existing basic approach to the description of tidal forces is unsatisfactory: the factors underlying the existing approaches have values 10 times less than those observed and cannot be considered as the reason for the manifestation of half-day manifestations in the daily change in gravity. The work is a continuation of the implementation by the author of P. Dirac’s ideas about accounting for the size of microparticles in physical theory.展开更多
目的:探索血浆中人类白细胞抗原FAT10(humanleukocy teantigen-Fadjacent transcript 10,HLA-FAT10)m RNA表达水平,评估其对肝癌和结肠癌的诊断价值.方法:收集70例肝癌、60例肝硬化、64例结肠癌和64例健康对照者的血浆,应用实时荧光定量...目的:探索血浆中人类白细胞抗原FAT10(humanleukocy teantigen-Fadjacent transcript 10,HLA-FAT10)m RNA表达水平,评估其对肝癌和结肠癌的诊断价值.方法:收集70例肝癌、60例肝硬化、64例结肠癌和64例健康对照者的血浆,应用实时荧光定量PCR(RT-PCR)和酶联吸附试验(E L I S A)法检测FAT10 mRNA和甲胎蛋白(a-fetoprotein,AFP)蛋白的表达水平.采用SPSS21.0统计软件进行数据分析.结果:FAT10 mRNA在肝癌、肝硬化、健康对照组中的阳性表达率分别为72.85%,28.3%和12.5%,三者之间差异显著(P<0.05),其高表达与肝癌TNM分期及淋巴结转移有关(P<0.05).FAT10 mRNA在结肠癌的阳性表达率明显高于健康对照组(P<0.05),其上调表达与结肠癌Duke's分期和远处转移相关(P<0.05).在AFP阴性肝癌中FAT10 m RNA的诊断灵敏度为66.6%.小肝癌与非肝癌组(肝硬化和健康组)比较时,FAT10 mRNA的灵敏度为68.8%,特异度为79.8%,联合AFP蛋白后,诊断灵敏度提高至84.4%.结论:FAT10 m RNA有可能成为肝癌和结肠癌诊断中的一个新的血清学指标,且可以应用于AFP阴性肝癌的辅助诊断,联合FAT10 mRNA和AFP蛋白可以提高肝癌的诊断率.展开更多
文摘TWR(Two Way Ranging)和SDS-TWR(Symmetric Double Side-Two Way Ranging)是IEEE802.15.4a中定义的两种TOA测距方案,主要用于无基础设施和额外同步机制条件下的节点定位/跟踪等应用.通过分析指出:TWR测距方案具有较高的测距容量且对节点移动的敏感度低,但其测距误差较大;SDS-TWR虽然能有效降低时钟频偏带来的测距误差,但其测距容量较低并且对节点移动的敏感度高.在此基础上,提出一种基于时钟频率比的TOA测距新方案R-TWR(Frequency Ratio BasedTWR).分析及仿真证明,该方案能达到SDS-TWR方案的测距准确度,并和TWR一样对节点移动的具有较高的测距容量和较低的移动敏感度.
文摘No, Isaac Newton did not “explain” gravitation. What he did, and this certainly constituted all and by itself a great achievement, was to recognize (to “assert”) the universal character of gravitation: all material objects (bodies) attract each other by gravitation. But how does gravitation perform its deeds? This remained a mystery to Newton. In a “desperate move” at the end of his life, he introduced the concept of “Particles which are moved by certain active Principles [our emphasis]—such as is that of Gravity” he said. We resurrect this scheme, we provide it with a quantum structure—a stunning new insight into the workings of gravitation obtains.
文摘The result of mathematical and physical analysis of the daily change in gravity is presented. The subject of consideration was the manifestation of semi-daily factors in diurnal variations of gravity. The assumption is investigated, according to which the cause of the half-day factors is the gravitational shielding of the planet Earth. Gravitational shielding is considered as a function of the size and thickness of celestial bodies and growing with distance from their poles. It is concluded that the planet Earth has the property of partial gravitational shielding, and the Moon does not have enough thickness to exhibit a tangible gravitational shielding. The obtained mathematical results correspond to the existing experimental data. It is suggested that gravitational shielding is the cause of the precession of the perihelion of Mercury and the peculiarities of the manifestation of tidal processes. It is assumed that gravitational shielding is one of the main reasons for the presence of hidden substances in the Universe. It is concluded that the physical picture with mutual shielding of interaction elements corresponds to the classical ideas of Fatio and Lesage. This approach is proposed as an alternative point of view to the existing theory on the description of tidal processes. It is shown that the existing basic approach to the description of tidal forces is unsatisfactory: the factors underlying the existing approaches have values 10 times less than those observed and cannot be considered as the reason for the manifestation of half-day manifestations in the daily change in gravity. The work is a continuation of the implementation by the author of P. Dirac’s ideas about accounting for the size of microparticles in physical theory.
文摘目的:探索血浆中人类白细胞抗原FAT10(humanleukocy teantigen-Fadjacent transcript 10,HLA-FAT10)m RNA表达水平,评估其对肝癌和结肠癌的诊断价值.方法:收集70例肝癌、60例肝硬化、64例结肠癌和64例健康对照者的血浆,应用实时荧光定量PCR(RT-PCR)和酶联吸附试验(E L I S A)法检测FAT10 mRNA和甲胎蛋白(a-fetoprotein,AFP)蛋白的表达水平.采用SPSS21.0统计软件进行数据分析.结果:FAT10 mRNA在肝癌、肝硬化、健康对照组中的阳性表达率分别为72.85%,28.3%和12.5%,三者之间差异显著(P<0.05),其高表达与肝癌TNM分期及淋巴结转移有关(P<0.05).FAT10 mRNA在结肠癌的阳性表达率明显高于健康对照组(P<0.05),其上调表达与结肠癌Duke's分期和远处转移相关(P<0.05).在AFP阴性肝癌中FAT10 m RNA的诊断灵敏度为66.6%.小肝癌与非肝癌组(肝硬化和健康组)比较时,FAT10 mRNA的灵敏度为68.8%,特异度为79.8%,联合AFP蛋白后,诊断灵敏度提高至84.4%.结论:FAT10 m RNA有可能成为肝癌和结肠癌诊断中的一个新的血清学指标,且可以应用于AFP阴性肝癌的辅助诊断,联合FAT10 mRNA和AFP蛋白可以提高肝癌的诊断率.
