Emerging trends in the use of smartphones, online mapping applications, and social media, in addition to the geo-located data they generate, provide opportunities to trace users' socio-economic activities in an unprecedentedly granular and direct fashion and have triggered a revolution in empirical research. These vast mobile data offer new perspectives and approaches to measure economic dynamics, and they are broadening the social science and economics fields. In this paper, we explore the potential for using mobile data to measure economic activity in China from a bottom-up view. First, we build indices for gauging employment and consumer trends based on billions of geo-positioning data. Second, we advance the estimation of offline store foot traffic via location search data derived from Baidu Maps, which is then applied to predict Apple's revenues in China and to accurately detect box-office fraud. Third, we construct consumption indicators to track trends in various service sector industries and verify them with several existing indicators. To the best of our knowledge, this is the first study to measure the world's second-largest economy by mining such unprecedentedly large-scale and fine-granular spatial-temporal data. In this way, our research provides new approaches and insights into measuring economic activity.

Previous research has explored the impact of political ties on corporate innovation performance, yet with controversial results. This study proposes that political ties has a curvilinear impact on innovation performance, and the resulting curvilinear relationship is moderated by absorptive capacity and external environment. We conduct examination based on a survey among Chinese manufacturing firms, which demonstrates an inverted U-shape relationship between political ties and corporate innovation performance. This inverted U-shape relationship is moderated by the absorptive capacity, which means the positive effect of political ties on corporate innovation performance is strong when the absorptive capacity of a firm is high. Furthermore, political ties, absorptive capacity and external environment (i.e. dynamism, munificence, and complexity) have a three-way interactive effect on corporate innovation, which means firms with strong political ties exhibit the highest innovation performance when their absorptive capacity and external environmental condition (dynamism or munificence or complexity) stand at high level simultaneously. The research findings provide a comprehensive understanding for firms, especially for those with different characteristics and under different external environments, to exploit political ties to facilitate corporate innovation performance.

In this paper, we applied the modal expansion method (MEM) to investigate the wave behaviors inside a step-modulated subwavelength metal slit. The physical mechanism of the surface plasmon polariton (SPP) transmission is investigated in detail for slit structures with either dielectric or geometric modulation. The applicability of the effective index method is discussed. Moreover, as a special case of the geometric modulation, the evanescent-wave assisted transmission is demonstrated in a thin-modulated slit. We emphasize that a complete set is necessary in order to expand the wave functions in these kinds of structures. All the calculated results by the MEM are well retrieved by the finite-difference time-domain calculation.

This paper reports a newly developed high current transformer-rectifier High-T c Superconducting (HTS) flux pump switched by dynamic resistance. A quasi-persistent current of over 1.1 kA has been achieved at 77 K using the device, which is the highest reported operating current by any HTS flux pumps to date. The size of the device is much smaller than traditional current leads and power supplies at the same current level. Parallel YBCO coated conductors are used in the transformer secondary winding as well as in the superconducting load coil to achieve high current. The output current is limited by the critical current of the load rather than the flux pump itself. Moreover, at over 1 kA current level, the device can maintain high flux injection accuracy, and the overall flux ripple is less than 0.2 mili-Weber. The work has shown the potential of using the device to operate high field HTS magnets in ultra-high quasi-persistent current mode, thus substantially reducing the inductance, size, weight, and cost of high field magnets, making them more accessible. It also indicates that the device is promising for powering HTS NMR/MRI magnets, in which the requirement for magnetic field satiability is demanding.

Compared with the data from the 1993 survey, illicit drug use has continued to escalate across the areas, calling for priority concern in various sections of the country.