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Abstract Monoculture croplands are a major source of global anthropogenic emissions of nitrous oxide (N2O), a potent greenhouse gas that contributes to ozone depletion. Agroforestry has the potential to reduce N2O emissions. Presently, there is no systematic comparison of soil N2O emissions between cropland agroforestry and monoculture systems in Central Europe. We investigated the effects of converting the monoculture cropland system into the alley cropping agroforestry system on soil N2O fluxes at three sites (each site has paired agroforestry and monoculture) in Germany, where agroforestry combined crop rows and poplar short‐rotation coppice (SRC). We measured soil N2O fluxes monthly over 2 years (March 2018–January 2020) using static vented chambers. Annual soil N2O emissions from agroforestry ranged from 0.21 to 2.73 kg N ha−1 year−1, whereas monoculture N2O emissions ranged from 0.34 to 3.00 kg N ha−1 year−1. During the rotation of corn crop, with high fertilization rates, agroforestry reduced soil N2O emissions by 9% to 56% compared to monocultures. This was mainly caused by low soil N2O emissions from the unfertilized agroforestry tree rows. Soil N2O fluxes were predominantly controlled by soil mineral N in both agroforestry and monoculture systems. Our findings suggest that optimized fertilizer input will further enhance the potential of agroforestry for mitigating N2O emissions.

Alley-cropping agroforestry enhances carbon sequestration compared to open cropland and open grassland, and improves soil biological habitat and erosion resistance relative to open cropland, based on measured ecosystem functions at five sites in Germany.

Brazed diamond abrasive drill was suitable for drilling holes in carbon fiber reinforced silicon carbide ceramic matrix composites, but a large amount of chips could adversely affect the drilling process of the holes. Therefore, according to the chip discharge process, the chip morphology was analyzed, and the effects of chips on the axial drilling force, the hole processing quality and the drill wear during drilling were studied. The results show that the chips have an effects on the axial drilling forces, especially when drilling deep holes. The chips have little effects on the machining quality of the hole inlet, only a slight edge collapses at the hole inlet. The chips have a significant impacts on the processing quality of the hole outlet, which can cause serious fiber breakage, tear defects, and large areas of the matrix shedding. At the same time, the chip intensifies the drill wear, which not only causes slight wear such as edge collapse and micro crack, but also produces serious wear behaviors such as matrix peeling and diamond peeling.

The measurement of nitric oxide (NO) concentration in power plant flue gas by tunable diode laser absorption spectroscopy (TDLAS) is susceptible to fly ash particles. The presence of fly ash particles causes laser intensity fluctuations and leads to the second harmonic (2f) signal amplitude changes. In this manuscript, we analyzed the influence of particles on the 2f signal and corrected the measurement error of NO concentration by the wavelength modulation-second harmonic (WMS-2f) technique. Specifically, the 2f signal error caused by quartz sand and fly ash particles were measured, and the exponential function representing the peak-to-peak error of the 2f signal was obtained by fitting. Finally, the peak-to-peak value of the 2f signal and the NO concentration were corrected according to the exponential function. After correction, the NO concentration error under the fly ash influence (the particle size in the range of 10–200 μm and the mass concentration is less than 18.26 g/m3) was no more than 2%. This correction method effectively improves the measurement accuracy of NO concentration by the WMS-2f technique in the fly ash environment.

In order to study the bearing capacity of high-strength steel screw anchors, six groups of screw anchors with different parameters are carried out in in situ construction and tensile capacity test, and the load-displacement curves of screw anchors with different parameters are obtained. The bearing mechanism, design method, and key design parameters of screw anchors are analyzed. Meanwhile, the test results are compared with theoretical calculation and numerical simulation, respectively. The results show that the drawing capacity of high-strength screw anchor calculated by the existing standard theoretical calculation formula is conservative. The load capacity of high-strength steel screw anchor is significantly higher than that of ordinary strength steel screw anchor. Taking steel strength, buried depth, quantity, distance, and diameter as the influencing factors, parametric analysis is conducted on the uplift capacity of high-strength steel screw anchor in this paper. The embedding depth of screw anchor, the number, spacing, and diameter of anchor plates have significant influence on the drawing capacity of screw anchor. The construction technology of high-strength steel screw anchor is reliable, and the bearing capacity is good, which can be applied in the soft-soil power transmission line projects, such as bog and coastal beach. Meanwhile, the research results can provide reference for the design and construction of screw anchor foundation.

To analyze the bearing capacity of high-cap inclined pile foundations based on foundation design in practical engineering, finite element models of single cap foundations and multi-cap foundations are established. The influence of the inclination direction and angle of the inclined pile on the lateral displacement of the foundation and internal force of the pile body is investigated. The influence of uneven settlement on inclined pile foundations is examined by weakening the soil strength. This paper suggests that the lateral bearing capacity of a negatively inclined pile is better than that of a positively inclined pile. When the inclination angle of a negatively inclined pile changes within a certain range, it can significantly affect the lateral displacement of the pile body. Under uneven settlement, the change in the internal force of the inclined pile is larger than that of the vertical pile, the horizontal displacement difference of each bearing platform is small, and the vertical displacement is quite different.