In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic pro...In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic properties. Here we present a single frequency modulation method based on a torsion pendulum to measure the remanent magnetic moment mr of 1.1 kg dummy copper test mass, and the measurement result is(6.45 ± 0.04(stat) ± 0.07(syst)) × 10^(-8)A · m^(2). The measurement precision of the mr is about 0.9 n A · m^(2), well below the present measurement requirement of Tian Qin. The method is particularly useful for measuring extremely low magnetic properties of the materials for use in the construction of space-borne gravitational wave detection and other precision scientific apparatus.展开更多
对4根玄武岩纤维布加固的混凝土 T 形截面连续梁和1根对比梁进行抗弯试验，分析了试验梁的破坏模式和各控制截面的弯矩调幅系数.试验结果表明：加固梁跨中截面纵筋屈服前，加固梁和对比梁各控制截面荷载-挠度曲线基本重合；跨中截面纵...对4根玄武岩纤维布加固的混凝土 T 形截面连续梁和1根对比梁进行抗弯试验，分析了试验梁的破坏模式和各控制截面的弯矩调幅系数.试验结果表明：加固梁跨中截面纵筋屈服前，加固梁和对比梁各控制截面荷载-挠度曲线基本重合；跨中截面纵筋屈服后，加固梁发生了明显的弯矩重分布，跨中截面弯矩调幅系数为0.09~0.22，中支座截面弯矩调幅系数为0.15~0.38；1~3层纤维布加固梁荷载-挠度曲线具有屈服平台，表现出明显的延性破坏特征.展开更多
In this study, we theoretically investigate the strain effect on the orientation-dependent high-order harmonic generation(HHG) of monolayer aluminum nitride(Al N) by solving the multiband semiconductor Bloch equations...In this study, we theoretically investigate the strain effect on the orientation-dependent high-order harmonic generation(HHG) of monolayer aluminum nitride(Al N) by solving the multiband semiconductor Bloch equations in strong laser fields. Our simulations denote that the efficiency of the orientation-dependent HHG is considerably enhanced when a 15% biaxial tensile strain is applied to Al N, which is attributed to the downshifting energy level of the conduction band. Furthermore, the odd-even feature in the orientation-dependent high harmonic spectra owing to the strain is considerably different when compared with that in the case without strain. The enhanced quantum interference between different energy bands in strained Al N around the Γ-M direction is responsible for the observed odd-even distributions of the orientation-dependent HHG. This study helps to better understand the HHG in solids by tuning their electronic structures.展开更多
基金supported by the National Key R&D Program of China (Grant No. 2020YFC2200500)the National Natural Science Foundation of China (Grant Nos. 12075325, 12005308, and 11605065)。
文摘In Tian Qin spaceborne gravitational-wave detectors, the stringent requirements on the magnetic cleanliness of the test masses demand the high resolution ground-based characterization measurement of their magnetic properties. Here we present a single frequency modulation method based on a torsion pendulum to measure the remanent magnetic moment mr of 1.1 kg dummy copper test mass, and the measurement result is(6.45 ± 0.04(stat) ± 0.07(syst)) × 10^(-8)A · m^(2). The measurement precision of the mr is about 0.9 n A · m^(2), well below the present measurement requirement of Tian Qin. The method is particularly useful for measuring extremely low magnetic properties of the materials for use in the construction of space-borne gravitational wave detection and other precision scientific apparatus.
文摘对4根玄武岩纤维布加固的混凝土 T 形截面连续梁和1根对比梁进行抗弯试验，分析了试验梁的破坏模式和各控制截面的弯矩调幅系数.试验结果表明：加固梁跨中截面纵筋屈服前，加固梁和对比梁各控制截面荷载-挠度曲线基本重合；跨中截面纵筋屈服后，加固梁发生了明显的弯矩重分布，跨中截面弯矩调幅系数为0.09~0.22，中支座截面弯矩调幅系数为0.15~0.38；1~3层纤维布加固梁荷载-挠度曲线具有屈服平台，表现出明显的延性破坏特征.
基金supported by the National Natural Science Foundation of China(Grant Nos.11974185,11704187,11774175,and 11834004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20170032)。
文摘In this study, we theoretically investigate the strain effect on the orientation-dependent high-order harmonic generation(HHG) of monolayer aluminum nitride(Al N) by solving the multiband semiconductor Bloch equations in strong laser fields. Our simulations denote that the efficiency of the orientation-dependent HHG is considerably enhanced when a 15% biaxial tensile strain is applied to Al N, which is attributed to the downshifting energy level of the conduction band. Furthermore, the odd-even feature in the orientation-dependent high harmonic spectra owing to the strain is considerably different when compared with that in the case without strain. The enhanced quantum interference between different energy bands in strained Al N around the Γ-M direction is responsible for the observed odd-even distributions of the orientation-dependent HHG. This study helps to better understand the HHG in solids by tuning their electronic structures.
