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In this work, an arc-shaped Metglas/polyvinylidene fluoride (PVDF)/Ni laminate is proposed, which exhibits a large self-biased magnetoelectric (ME) effect due to the internal magnetization gradient field between the two magnetic layers and the built-in stress formed from the arc-shaped structure. The ME coefficients reach 38.24 and 15.0 V cm−1 Oe−1 without a DC bias magnetic field at resonance and nonresonant frequencies, respectively. The sample shows a high sensitivity, resolution and linearity with values of 210.07 mV Oe−1, 1 nT and 0.9999 at the resonance frequency, respectively. The sample was then used to detect AC magnetic fields with different nonresonant frequencies (ranging from 1 to 25 kHz), resulting in the measured data being in good agreement with the actual data. Under a zero bias magnetic field and at frequencies of 40 and 1 Hz, the limit of detection can reach 2 and 8 nT, and the resolution can reach 1 and 4 nT, respectively. The results indicate that the arc-shaped Metglas/PVDF/Ni laminate shows a large self-biased ME effect and good AC magnetic sensing performance in the bending state, which provides a new way to develop a wide frequency range AC magnetic sensor.

Air-resource heat pump, as a Green energy-saving equipment, which converts low potential energy into high potential energy, is commonly used as an auxiliary heat source of solar energy. Air-resource heat pump is driven by electric energy, makes heat (cold) quantity with ambient air as cold (hot) source. It can not only refrigerate in summer, but also heat in winter [1]. This article analyzes the current situation of the public bathroom in a university, updates and selects the equipment according to the new requirements, and reasonably adjusts and uses the original system device, and adds an automatic control system. After reconstruction, it meets the use requirement and achieves the purpose of energy conservation. Finally, the article also gives some advice of further modification.

On June 10, 2015, Beijing Municipal Environmental Protection Bureau issued “Boiler Atmospheric Pollutant Emission Standard” DB11/139-2015. Starting from April 1, 2017, NOx emissions from newly built boilers must be below 30mg/m3 and from in-use boilers must be below 80mg/m3. For implementing the emission reduction work in Beijing, according to current situation of boiler room in Beijing University of Chemical Technology, the school authorities do a series of work, including visits, market research and data analysis, attend academic conferences. On how to deal with the problem of air pollutant discharge standard of boilers in our university, we analyse the relevant emission standards at home and abroad, pollution prevention and control technology, low-nitrogen combustion principle of gas-fired industrial boilers and its technical development status, and put forward three solutions[1][2]. Through the comparison of advantages and disadvantages, the optimal solution is obtained.

Flexible magnetic sensors are attracting more and more attention because of their application in wearable devices. In this paper, Metglas/polyvinylidene fluoride (PVDF) bilayer composite with good flexibility was fabricated to evaluate its applicability as a flexible in-plane magnetic sensor. The magnetoelectric (ME) coupling characteristics and sensing performance of the sample were investigated under different test conditions, including different AC and DC magnetic field, and changing the direction of the magnetic field and the bending degree of the sample. The sample shows a large ME coefficient with a value of 176.41 V cm−1 Oe. The sensitivity, linearity and deviation of the sample are 892.96 mV Oe−1, 0.99965 and ±2% for the AC magnetic field, and 157.6 mV Oe−1, 0.99444 and ±5% for the DC magnetic field, respectively, and it shows excellent stability over repetitions. Moreover, the sample was gradually rotated anticlockwise in the magnetic fields. The output voltage of the sample varies with the rotation angle and has a good symmetry in plane, which is described well by a sine function. In addition, the clamping effect of the sample was studied. Even when bent, the sample still maintains an excellent and stable performance. The sensitivity and linearity of the sample with a bent angle of 23.5° are 254.37 mV Oe−1 and 0.99975 for the AC magnetic field, and 28.07 mV Oe−1 and 0.99309 for the DC magnetic field, respectively. The deviation of measurements is small for both the AC and DC magnetic sensors. In summary, the present study shows that the Metglas/PVDF bilayer composite has a good sensing performance and is suitable for = flexible in-plane resonant magnetic sensors.