The study on the strength characteristics of slip zone soils is an important part of landslide stability analysis. Current research on slip zone soils has concentrated on fine-grained slip zone ...soils. Meanwhile, investigations on slip zone soils that contain coarse particles are scarce. This study focuses on a review and analysis of the influence of specific factors, such as coarse-grained content, moisture content, and mineral composition, as well as the micro and meso aspects and numerical simulations on the strength characteristics of slip zone soils, based on a brief summary of the distribution range and geological characteristics of this type of slip zone soil. The concept of coarse-grained slip zone soils is proposed and compared with soil–rock mixtures. Research showed that the content, shape, size of the coarse particles, moisture content, and the composition and proportion of the clay minerals have an influence on the strength parameters of the slip zone soil. The deformation mechanism of the slip zone soil is further revealed from the perspective of particle deformation and movement at the micro- and meso-level, and the research method of combining macro, meso, and micro is emphasized. Finally, several aspects that should be strengthened in the research work are pointed out, such as the influence of coarse particle difference (content, shape, etc.) on the mechanical properties of the slip zone soil, the development process from meso-deformation to macro-deformation, the internal relationship between macro-parameters and meso-parameters, and the mechanical properties of weak layers of landslides in the permafrost regions.
In this work, the friction and galling properties of 7075 aluminum alloy sheet at different temperatures from ambient to 400 °C have been investigated by performing linear unlubricated reciprocating ...sliding tests on a ball-on-plate tribometer. It was found that a compacted layer could be formed on the worn surface and its effect on the friction behavior of the alloy was determined. Thereafter, coupled with dissolution-precipitation of the hard phase, a friction evolution model of the alloy was established and the friction mechanism at different temperatures was revealed. At 25 °C and 150 °C, the friction mechanism of 7075 aluminum alloy sheet is mainly ploughing friction. When higher than 300 °C, the dominant friction mechanism becomes the adhesive peeling-off.
•The friction and galling properties of 7075 aluminum alloy sheet were studied.•The formation and destruction mechanism of a compacted layer on the worn surface was determined.•The friction evolution model coupled with the dissolution-precipitation of hard phase was established.•The friction mechanism at different temperatures was revealed.•The dominant friction mechanism is ploughing at 25 °C and 150 °C and adhesive peeling-off higher than 300 °C.
Two kinds of hundred-watt-level random distributed feedback Raman fiber have been demonstrated. The optical efficiency can reach to as high as 84.8%. The reported power and efficiency of the random ...laser is the highest one as we know. We have also demonstrated that the developed random laser can be further used to pump a Ho-doped fiber laser for mid-infrared laser generation. Finally, 23 W 2050 nm laser is achieved. The presented laser can obtain high power output efficiently and conveniently and opens a new direction for high power laser sources at designed wavelength.
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•Porous ZnMn2O4 hollow microrods have been constructed with the assistance of SDS.•A plausible morphology evolution mechanism for Zn1/3Mn2/3C2O4·2H2O precursors was proposed.•Porous ...ZnMn2O4 hollow microrods exhibit outstanding electrochemical performances.
Porous ZnMn2O4 hollow microrods have been constructed through a facile co-precipitation method followed by an annealing process. The plausible formation mechanism for the unique architecture of ZnMn2O4 microrods was proposed and discussed in detail. It is found that the calcination temperature plays a key role in determining the microstructures of ZnMn2O4. On the whole, 700 °C is the optimal temperature, which not only makes the as-constructed ZnMn2O4 microrods (denoted as ZMO-700) the porous and hollow architecture, but also owns a good crystallinity, high porosity and large specific surface area. When used as anode materials for lithium ion batteries, the ZMO-700 exhibits outstanding electrochemical performances. It both possesses a high reversible capacity of 902 mAh g−1 after 320 cycles at 0.5 C, and presents an excellent rate capability in the current rate region of 0.1–5 C, especially deliveries a high capacity of 223 mAh g−1 at 5 C. The significant enhancement in the electrochemical performances should be attributed to the synergistic effect of the porous hollow architecture and the micro-nano hierarchical structure for the as-constructed ZnMn2O4 anode.
Edge-preserving image smoothing is a fundamental step for many computer vision problems, and so far, countless algorithms have been proposed. Among these algorithms, bilateral filtering and its ...extensions are widely used in image preprocessing. However, several difficulties are hindering its further development. First, the phenomenon of "halo artifact" occurs along the edges. Second, most of the existing algorithms work only with a fixed filtering kernel and cannot accurately distinguish the edges and textures which leads to inappropriate filtering. To address these issues, we present a novel edge-preserving image smoothing via adaptive side window joint bilateral filtering. As a local optimized-based algorithm, different from the traditional filtering, the position of the target pixel in the filtering kernel is changed from the center to the optimal edge and the filtering kernel size of each pixel is effectively estimated. Combined side window filtering with the joint bilateral filter, the capability of texture removal and edge preservation is improved and the halo artifacts are alleviated. Experimental results show that the proposed method outperforms existing state-of-the-arts in removing the texture information while preserving the main image content.
We present theoretical study of wavelength dependence of mode instability (MI) in high power fiber lasers, which employs an improved semi-analytical theoretical model. The influence of pump/seed ...wavelength and photodarkening on threshold has been studied. The results indicate promising MI suppression through pumping or seeding at an appropriate wavelength. Small amounts of photodarkening can lead to a significant impact on MI.
The superfluorescent fiber source (SFS) has the unique features of broadband emission, low coherence, high brightness, and high temporal stability, thereby being applicable to a wide variety of ...situations such as sensing, medical imaging, and material processing. In this paper, a spectrum-manipulable hundred-watt-level high-power SFS with both wavelength and linewidth tunability is demonstrated for the first time to our knowledge. By inserting a bandwidth-adjustable tunable optical filter after a broadband SFS seed and amplifying through a three-stage fiber amplifier, the operating wavelength of the SFS can be tuned over a range of ~25 nm, and the output power can exceed 106 W over the whole tuning range, corresponding to a slope efficiency of ~77% with respect to the launched pump power. The full width at half maximum linewidth of the SFS can also be continuously tuned from ~0.4 to ~15.2 nm. The developed high-power SFS with flexible spectral manipulation property may have potential applications in the industrial production and scientific research.
Neurodegenerative diseases are disorders that are characterized by a progressive decline of motor and/or cognitive functions caused by the selective degeneration and loss of neurons within the ...central nervous system. The most common neurodegenerative diseases are Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Neurons have high energy demands, and dysregulation of mitochondrial quality and function is an important cause of neuronal degeneration. Mitochondrial quality control plays an important role in maintaining mitochondrial integrity and ensuring normal mitochondrial function; thus, defects in mitochondrial quality control are also significant causes of neurodegenerative diseases. The mitochondrial deacetylase SIRT3 has been found to have a large effect on mitochondrial function. Recent studies have also shown that SIRT3 has a role in mitochondrial quality control, including in the refolding or degradation of misfolded/unfolded proteins, mitochondrial dynamics, mitophagy, and mitochondrial biogenesis, all of which are affected in neurodegenerative diseases.
We present a hundred-watt-level linearly-polarized random fiber laser (RFL) pumped by incoherent broadband amplified spontaneous emission (ASE) source and prospect the power scaling potential ...theoretically. The RFL employs half-opened cavity structure which is composed by a section of 330 m polarization maintained (PM) passive fiber and two PM high reflectivity fiber Bragg gratings. The 2nd order Stokes light centered at 1178 nm reaches the pump limited maximal power of 100.7 W with a full width at half-maximum linewidth of 2.58 nm and polarization extinction ratio of 23.5 dB. The corresponding ultimate quantum efficiency of pump to 2nd order Stokes light is 86.43%. To the best of our knowledge, this is the first demonstration of linearly-polarized high-order RFL with hundred-watt output power. Furthermore, the theoretical investigation indicates that 300 W-level linearly-polarized single-mode 1st order Stokes light can be obtained from incoherently pumped RFL with 100 m PM passive fiber.
The power scaling of linearly polarized random fiber lasers (RFLs) is investigated in detail based on master oscillator power amplifier configuration. A 442-W linearly polarized output with a narrow ...3-dB linewidth of 0.28 nm and a 621-W linearly polarized output with a relatively wider 3-dB linewidth of 2.7 nm are realized. Besides, near-diffraction-limited beam quality and high polarization extinction ratio are obtained in both situations, and further power scaling is limited by the onset of mode instability (MI). To the best of our knowledge, these results are highest output powers of linearly polarized RFLs for the time being, in the narrow-linewidth and wide-linewidth situations, respectively. Meanwhile, the differences in the spectral broadening factor and the MI threshold between the narrow-linewidth linearly polarized RFL and the wide-linewidth one are discovered and discussed for the first time. It is experimentally demonstrated that relatively wider linewidth of the RFL seed is in favor of reducing the spectral broadening and increasing the MI threshold, providing significant reference for power scaling of linearly polarized RFL.
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