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The data of neutron capture cross section are very important for the research of nuclear astrophysics, advanced nuclear energy development. Owing to the limitation of neutron source and detector, the experimental data of neutron capture cross section in an energy range of 1 eV–10 keV were almost blank in China. The first Chinese gamma-ray total absorption facility has been constructed in the key laboratory of nuclear data at China institute of atomic energy, which consists of 40 BaF2 detector units. The BaF2 crystal shell with a thickness of 15 cm and an inner radius of 10 cm covers 95.2% of the solid angle. On-line measurement method of neutron capture reaction cross section is established on the back-streaming white neutron source of China spallation neutron source by using the upgraded facility. The cross section of 197Au neutron capture reaction is measured for the first time under the experimental condition of irregular 30 mm neutron beam spot. The measured position of resonance peak is well consistent with the relevant data of ENDF evaluation database, which verifies the reliability of the measurement device and measurement technology, and thus laying the foundation for the acquisition of high precision cross section in future.

The back-streaming neutron beam line (Back-n) was built in the beginning of 2018, which is part of the China Spallation Neutron Source (CSNS). The Back-n is the first white neutron beam line in China, and its main application is for nuclear data measurement. For most of neutron-induced nuclear reaction measurements based on white neutron facilities, the beam of gamma rays accompanied with neutron beam is one of the most important experimental backgrounds. The back streaming neutron beam is transported directly from the spallation target to the experimental station without any moderator or shielding, the flux of the in-beam gamma rays in the experimental station is much larger than those of these facilities with neutron moderator and shielding. Therefore, it is necessary to consider the influence of in-beam gamma rays on the experimental results. Studies of the in-beam gamma rays are carried out at the back-n. Monte-Carlo simulation is employed to obtain the energy distribution and the time structure of the in-beam gamma rays. According to the simulation results, when the neutron flight time is longer than 1.0 μs the energy distribution of the in-beam gamma rays does not vary with flight time. Therefore, the time structure of these gamma rays can be measured without the correction of the detection efficiency. In this work, the time structure of the in-beam gamma rays in the low neutron energy region is measured by both direct and indirect methods. In the direct measurement, a 6Li loaded ZnS(Ag) scintillator is located on the neutron beam line and the time of flight method is used to determine the time structure of neutrons and gamma rays. The gamma rays are separated from neutrons with pulse-shape discrimination. The black filter method is used to verify the particle discrimination results. In the indirect measurement, the C6D6 scintillation detectors are used to measure the gamma rays scattered off a Pb sample on the way of the neutron beam. The time structure of the in-beam gamma rays is derived from that of the scattered gamma rays. The experimental results are in good agreement with the simulations with the time-of-flight between 12 μs and 2.0 ms. Besides, according to the simulation results, the intensity of the in-beam gamma rays is 1.21 × 106 s–1·cm–2 in the center of the experimental station 2 of Back-n, which is 76.5 m away from the spallation target of CSNS.

Wind energy is a renewable energy that growing fast across the whole world, but its subsystems experience premature failures during its 20-year design life, leading downtime and costly maintain and repair. Since gearbox is the subsystem who causes the longest downtime, condition monitoring (CM) of the gearbox to prevent catastrophic failures is critical to wind energy. Based on vibration analysis, this paper presents a practical CM technique for faulty gear and faulty bearing detection of wind turbine gearbox. The algorithms studied in this paper have been successfully applied on signals from a field test of a full-size wind turbine gearbox who sustained gear and bearing damage, showing a good engineering prospect.

When rolling bearing has mechanical localized faults in its various components, pseudo-cyclostationary transient impact signal will be generated. But when in transient faults, this weak impact signal may submerge in strong background noise and gear vibration signal. In this paper, adaptive threshold wavelet de-noising method is used to reduce background noise, then Kurtosis of the noise-reduction signal is calculated in time domain. By comparing the calculation result with a given threshold, a conclusion can be made that whether the bearing is healthy or having mechanical localized faults. When the bearing is diagnosed as faulty in time domain, Kurtogram is used to find out a most suitable pass-band in frequency domain by maximizing the Kurtosis value. Band-pass filtering and do demodulation to this band-pass signal, the faulty component can be positioned precisely and reliably.

Order tracking analysis has been demonstrated to be suitable for wind turbine gearbox fault diagnosis, but in traditional way, a keyphasor signal is indispensable. In some real cases, due to harsh working environment and installation space limitation, it's hard to acquire this keyphasor signal. To overcome this problem, raw speed profile is used in this paper to synthesize the keyphasor, by assuming that the first pulse signal is at time zero, once the arriving time of the ith pulse is known, calculate the next pulse arrival time in two different ways, then minimizing the difference of these two results to get the next pulse arrival time. By assuming the shaft angular acceleration is constant between three consecutive pulses and using the synthesized keyphasor above, this paper successfully fulfill order tracking analysis on a United Stated MW-class wind turbine gearbox without keyphasor signal, which shows a very good engineering practicability.

The atmospheric pressure plasma deposition of hydroxyl functionalized hydrocarbon films is reported in this work, with a reactor fed with water aerosol and ethylene. The effects of power and feed flow rates onto film chemistry have been investigated. Coatings produced with this approach can find application in the biomedical field, among others, as platforms for cell adhesion and proliferation. Results show that operating at 4 kHz provides a much higher amount of hydroxyl group in the coating compared with samples obtained at 11 kHz. After water immersion, the stability of the films and their amount of hydroxyl groups remain high. A simplified deposition mechanism is proposed.

Limited by materials and process stability, the nano-scale IC manufacturing process is still based on the 193 nm light technology and the wavelength is larger than the feature size of layout, thus the induced interference and diffraction greatly reduce the resolution, which affect the quality of the chip. So the layout needs to be checked by the design-for-manufacturability (DfM) model before manufacturing. Traditional DfM models describe the process steps using physical models, and deduce the convolution kernels by decomposing the matrix in corresponding physical models, which are not only complicated but also hard to use; thus combined with the insufficiency of physical models, it is difficult to describe the process with thousands of parameters. This paper uses convolution form as the framework of DfM model, and deduces the relationship, represented as convolution kernels, between layout and contour by an optimization method. Every element in the convolution kernels is optimized based on the input and output data of the process and is also a dimension to describe the process. This model overcomes the disadvantages of the traditional model which needs confidential information such as process parameters, and it has more powerful capability to describe the process. Moreover, the model can contain the layout correction information, and describe the process from layout to contour. Experiment results for 65 nm process show that the model has an accuracy of 8 nm.