Anisotropic low field behavior and the observation of flux jumps in CeCoIn5

The magnetic behavior of the heavy fermion superconductor CeCoIn5 has been investigated. The low field magnetization data show flux jumps in the mixed state of the superconducting phase in a restricted range of temperature. These flux jumps begin to disappear below 1.7 K, and are completely absent at 1.5 K. The magnetization loops are asymmetric, suggesting that surface and geometrical factors dominate the pinning in this system. The lower critical field (Hc1), obtained from the magnetization data, shows a linear temperature dependence and is anisotropic. The calculated penetration depth is also anisotropic, which is consistent with the observation of an anisotropic superconducting gap in CeCoIn5. The critical currents, determined from the high field isothermal magnetization loops, are comparatively low (around 4000 A/cm2 at 1.6 K and 5 kOe).Comment: 4 pages 3 figure

Critical fields and Landau-Ginzburg parameters of the heavy-fermion superconductor UPt\u3csub\u3e3\u3c/sub\u3e

Measurements of both the lower and upper critical fields along all three principal axes of the heavy-fermion superconductor UPt3 have been performed. A kink in the temperature dependence of the lower critical field, Hci, is observed for all three orientations, which is in agreement with a recent theory by Hess, Tokuyasu, and Sauls. Also, an anisotropy of the temperature dependence of the lower critical field is observed at low temperatures (T \u3c290 \u3emK). The Landau-Ginzburg parameters are estimated from the experimental results

Exploring tourist spatiotemporal behavior differences and tourism infrastructure supply–demand pattern fusing social media and nighttime light remote sensing data

ABSTRACTIncreased tourism forms subdivide the tourism market. Therefore, distinguishing spatiotemporal behaviors of different types of tourists is of great significance for tourism marketing and planning. In this study, we constructed a Spatial–Temporal-Preference model based on spatial clustering, seasonal-trend decomposition and statistical analysis, using multi-source data. It provides a novel frame for comparing tourist behavioral characteristics from a new perspective. Meanwhile, providing a method to rapidly identify the Tourism Infrastructure Supply and Demand Pattern (TISDP) fusing nighttime light and social media data. Then the framework was applied to analyze the differences between sightseeing tourists (STs) and cycling tourists (CTs) in Yunnan Province, China. The results showed clear spatial differences in location popularity and flow data with STs favoring northwestern Yunnan, and CTs favoring eastern Yunnan. Tourist behavior varied also seasonally and tourists preferred visiting minority areas or areas with better infrastructure. The tourism industry in the study area developed rapidly after 2013, although still with an unbalanced infrastructure supply and demand. The CTs loss areas were greater in northeastern and northwestern Yunnan and south of Kunming. The proposed methods help to identify differences in tourism activities and has important implications to tourism infrastructure planning and sustainable development

JDry-100-ASTRA, a cryogen-free 3He-4He dilution refrigerator for ground-based cosmic microwave background astronomy

A new custom cryogen-free dilution refrigerator with base temperature of 17 mK and cooling power of 120 μW@100mK was developed in collaboration with the University of Roma, Italy; and Janis Research Company, Inc. (USA). The design is specifically geared for integrating with an existing telescope on alt-azimuth mount. The first lab-based test results show that the system is maintaining its design specifications in its tilted position up to as much as -20 degree and +50 degree from the cryostat vertical axis. © Published under licence by IOP Publishing Ltd