All-solid highly sensitive fiber-tip magnetic field sensor based on a Fabry-Perot interferometer with a breakpoint structure.

An all-solid fiber-tip Fabry-Perot interferometer (FPI) coated with a nickel film is proposed and experimentally verified for magnetic field sensing with high sensitivity. It is fabricated by splicing a segment of a thin-wall capillary tube to a standard single-mode fiber (SMF), then inserting a tiny segment of fiber with a smaller diameter into the capillary tube, and creating an ultra-narrow air-gap at the SMF end to form an FPI. When the device is exposed to magnetic field, the capillary tube is strained due to the magnetostrictive effect of the nickel film coated on its outer surface. In addition, owing to the unique breakpoint sensitivity-enhancement structure of the air-gap FPI, the elongation of the capillary tube whose length is over 100 times longer than the air-gap width is entirely transferred to the cavity length change of the FPI, and the sensor is extremely sensitive to the magnetic field as proved by our experiments, achieving a high sensitivity of up to 2.236 nm/mT for a linear magnetic field range from 40 to 60 mT, as well as a low-temperature cross-sensitivity of 56 µT/°C. The all-solid stable structure, compact size (total length of ∼3.0 mm), and reflective working mode with high magnetic field sensitivity indicate that this sensor has good application prospects.

Analysis on the Path of Digital Villages Affecting Rural Residents' Consumption Upgrade: Based on the Investigation and Research of 164 Administrative Villages in the Pilot Area of Digital Villages in Zhejiang Province.

The weak consumption of rural residents has become an important factor restricting the healthy development of the Chinese economy. With the continuous development of digital construction in rural areas, its role in the upgrading of rural residents' consumption is becoming more and more important. Based on the mechanism of 164 administrative villages in the pilot area of Zhejiang Province, and using staggered cluster analysis, MLR analysis, mediation effect model, etc., this paper discusses the impact and transmission mechanism of digital villages on rural residents' consumption upgrade. The results show that farmers' wage income, property income, and total income all play a significant positive mediating role in the process of promoting consumption upgrading in digital villages; information literacy is a latent variable in the process of promoting consumption upgrading in digital villages. It also played a significant positive mediating role. The research provides the micromechanism of the digital village affecting the consumption upgrade of rural residents and puts forward to promote the process of infrastructure construction, improve the construction of e-commerce system, pay attention to the differences among residents and other suggestions.