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This article extracts the Qiantang River tidal bore, analyzing the water environment characteristics in front of the tidal line of the Qiantang River tidal bore and behind it. The Qiantang River tidal bore Index (QRI) was established using HY-1C, HY-1D, and Gao Fen-1 wide field-of-view (GF-1 WFV) satellite data to precisely determine the location and details of the Qiantang River tidal bore. Comparative analyses of the changes on the two sides of the Qiantang River tidal bore were conducted. The results indicate the following: (1) QRI enhances the visibility of tidal bore lines, accentuating their contrast with the surrounding river water, resulting in a more vivid character. QRI proves to be an effective extraction method, with potential applicability to similar tidal lines in different regions. (2) Observable roughness changes occur at the tidal bore location, with smoother surface textures observed in front of the tidal line compared to those behind it. There is a discernible increase in suspended sediment concentration (SSC) as the tidal bore passes through. (3) This study reveals the mechanism of water environment change induced by the Qiantang River tidal bore, emphasizing its significance in promoting vertical water body exchange as well as scouring the bottom sediments. This effect increases SSC and surface roughness. [ABSTRACT FROM AUTHOR]

The wettability of coal is an important factor influencing hydraulic stimulation. Field-trial data has proven that high-pressure N2 injection plays a positive role in increasing the coalbed methane (CBM) production rate. For the purpose of investigating the mechanism by which N2 promotes the gas rate, multiple experiments were conducted sequentially on the wettability of anthracite under different N2 pressures. Testing of the coal surface contact angle was conducted under 0.1–8 MPa nitrogen pressure using a newly built contact angle measuring device. The coal samples were collected from the Xinjing Coal Mine in the Qinshui Basin, China. The test results revealed that the contact angle increased with increasing N2 pressure. That is, the contact angle was 77.9° at an N2 pressure of 0.1 MPa and gradually increased to 101.4° at an infinite N2 pressure. In contrast, the capillary pressure decreased with an increasing N2 pressure, from 0.298 MPa to −0.281 MPa. The relationship between contact angle and N2 pressure indicated that the wettability was reversed at a N2 pressure of 5.26 MPa, with a contact angle of 90° and a capillary pressure of 0 MPa. The capillary pressure reversed to a negative value as the N2 pressure increased. At the microlevel, a high N2 pressure increases the surface roughness of coal, which improves the ability of the coal matrix to adsorb N2, forming the gas barrier that hinders the intrusion of water into the pores of the coal matrix. The results of this study provide laboratory evidence that high-pressure N2 injection can prevent water contamination and reduce the capillary pressure, thus benefiting coalbed methane production. [ABSTRACT FROM AUTHOR]

Through analyzing the triggering factors and activity characteristics of avalanches in Aerxiangou in the Western Tianshan Mountains, the formation and disaster-causing process of avalanches were studied to provide theoretical support and a scientific basis for avalanche disaster prevention. In this paper, based on remote sensing interpretation and field investigation, a spatial distribution map of avalanches was established, and the induced and triggering factors in disaster-prone environments were analyzed using the certainty factor model. The degree of influence (E) of the disaster-causing factors on avalanche triggering was quantified, and the main control conditions conducive to avalanche occurrence in different periods were obtained. The RAMMS-avalanche model was used to analyze the activity characteristics at points where multiple avalanches occurred. Research results: (1) The E values of the average temperature, average snowfall, and surface roughness in February were significantly higher than those of other hazard-causing factors, reaching 1.83 and 1.71, respectively, indicating strong control. The E values of the surface cutting degree, average temperature, and average snow depth in March were all higher than 1.8, indicating that these control factors were more prominent than the other factors. In contrast, there were four hazard-causing factors with E values higher than 1.5 in April: the mean temperature, slope, surface roughness, and mean wind speed, with clear control. (2) Under the influence of the different hazard-causing factors, the types of avalanches from February–April mainly included new full-layer avalanches, surface avalanches, and full-layer wet avalanches. (3) In the RAMMS-avalanche simulation test, considering the deposition effect, compared to the previous avalanche movement path, the secondary avalanche flow accumulation area impact range changes were slight, while the movement area within the avalanche path changes was large, as were the different categories of avalanches and their different movement characteristic values. Overall, wet snow avalanches are more hazardous, and the impact force is larger. The new snow avalanches start in a short period, the sliding rate is fast, and the avalanche sliding surface (full-snow surface and face-snow) of the difference is mainly manifested in the differences in the value of the flow height. [ABSTRACT FROM AUTHOR]

The pantograph–catenary system is one of the most commonly used power-receiving modes of metro trains. Its friction and wear performances are related to the safety and stability of train operation. In this study, a copper-impregnated carbon slide plate material, widely used in numerous metro lines in China, is considered as the research object. The problem of abnormal wear of slide plates caused by the decrease in relative humidity in the autumn and winter in tunnels is studied. Current-carrying friction and wear tests under humidity conditions of 20%, 30%, and 40% relative humidity (RH) are performed to reveal the mechanism of seasonal abnormal wear of slide plates and provide a reference for the service of pantograph slide plates under low-humidity conditions. The results reveal that relative humidity significantly influences the wear process of slide plates; further, the wear rate decrease with an increase in relative humidity. As observed by laser scanning confocal microscopy, with an increase in the relative humidity, the mechanical wear of the slide surface is weakened, arc erosion is enhanced, and surface roughness is increased. The Raman spectral scan showed that with the increasing humidity, the graphitization of the surface material decreased significantly, and the molecular structure changed greatly. Scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analysis reveal that under high humidity conditions, a relatively complete oxide film forms on the slide plate and plays a role in lubrication and protection. [ABSTRACT FROM AUTHOR]

Soil surface roughness is an important factor affecting hydrology and soil erosion processes, and its development is influenced by precipitation, topography, and tillage practices. In this study, the typical mollisol area in northeast China was taken as the research object. Then, the variation in soil surface roughness with time was analyzed under different terrains, as well as different tillage methods, and the effect of the precipitation condition on roughness was also discussed in detail. Through the design of field experiments, the height information of the soil surface was measured using a probe-type roughness plate. Two parameters, the root-mean-square height (RMSH) and the correlation length (CL), were selected to quantitatively characterize the soil surface roughness. In addition, the dynamic change patterns of surface roughness resulting from five tillage methods, including rotary tillage, combined tillage, no tillage, conventional tillage, and reduced tillage, under both sloping and flat land, were compared and analyzed throughout the soybean growing season, under the influence of rainfall. The results show that with the increase in rainfall, the RMSH of the soil surface, under different tillage methods, showed a trend of first decreasing, and then increasing. The results also showed that the RMSHs under rotary tillage, combined tillage, conventional tillage, and reduced tillage in flat land were greater than those in sloping land, and that the CLs of the soil surface under different tillage methods in flat land were smaller than those in sloping land. In addition, the degree of variation in the soil surface roughness was greater in flat land than that in sloping land under all tillage practices, indicating that this study is of great practical importance in the rational selection of tillage methods, and in the scientific quantification of soil erosion, which also show obvious significance for soil and water conservation. [ABSTRACT FROM AUTHOR]

• The morphology of differential weathering is digitized by 3D laser scanning. • The differential weathering features are characterized by the roughness indexes. • How spatial features of walls affect the differential weathering is discussed. • The classification of differential weathering degree is explored preliminarily. Earthen heritage sites have been undergoing lengthy surface weathering since they were built, which can pose a severe threat to the protection and utilization of these cultural treasures. Especially for differential weathering, one of the most common surface weathering patterns of earthen heritage sites in northwestern China, has not been well studied yet. Hence, in this paper, Suoyang Ancient City was selected as the study area, and six analysis domains (S1 to S6) exhibiting various differential weathering degrees were determined on wall faces and their morphological data were collected by a 3D laser scanner. Based on the point cloud data, the morphology of each domain was digitalized and reconstructed, and ten typical profiles were selected for roughness analysis. Concretely, for these profiles, six roughness parameters, including average asperity inclination (A i), mean curvature (R′da), textural slope parameter (Z 2), roughness coefficient (R p), self-affine fractal dimensions (A and D) and directional roughness metric (G (i)) were calculated to characterize their differential weathering features. The results show that the wall with a higher differential weathering degree has greater values of R p , G (i), A and D. It can also be found that different roughness indicators can reflect different wall surface morphological characteristics. In addition, the main driver of differential weathering developing is the prevailing sediment-laden wind, and the degree of differential weathering is also affected by the building techniques, wall endowment environment, wall orientation and morphology. Finally, according to the roughness values and wall surface morphology, the differential weathering degrees were classified into five grades (from level I to level V). In this case, the differential weathering degrees of S2 (level IV) and S5 (level IV) are the highest, followed by S3 (level III), S6 (level III), S1 (level II) and S4 (level II) respectively. Overall, the proposed approach based on 3D scanning and surface roughness is feasible to characterize the differential weathering degree, contributing to better prevention and mitigation of damage on earthen heritage sites. [ABSTRACT FROM AUTHOR]

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Roads are a type of typical artificial terrain, and are key components of urban terrain. Road networks formed by connections between different roads not only form the skeleton of urban terrain, but also plays an important role in transmitting energy and matter on the urban surface. Therefore, how to consider characteristics when constructing the digital road elevation model (DEM) has become an important research topic in the field of geographic information and mapping. Using high-definition unmanned aerial vehicle (UAV) images as the basic data source, this study proposes a new method for constructing the road DEM by analyzing semantic features such as road shape and function. This method first takes the sideline and centerline of the road as the macroscopic undulation morphological constraints. It uses the shape control equation of the local domain to constrain the morphological change characteristics of the road surface in the transverse and longitudinal directions, in order to construct the road DEM with high fidelity to the surface shape characteristics. Then, in terms of the water catchment function of the road surface, a road DEM correction method considering surface flow direction characteristics is designed to ensure that the water catchment path of the road surface conforms to the actual situation. For this paper, several typical roads in Chuzhou University in Anhui Province, China, were selected as the experimental objects to carry out a DEM construction experiment. The results indicate the following: (1) compared with the traditional construction method, the DEM shape of the road constructed by this research method is more consistent with the actual road shape, and the smoothness of the road surface is better; (2) due to the high density and high elevation accuracy of the point cloud used in modeling, the elevation adjustment strategy of the sideline and centerline of the road implemented in this study does not reduce elevation accuracy, indicating that an adjustment to the elevation information is necessary for constructing the DEM of special artificial terrain; and (3) the DEM correction method proposed in this paper to find the correct catchment path can ensure that the processed DEM can accurately simulate the surface catchment process, and the correction of the elevation of the road DEM is also controlled within a small range without affecting the elevation accuracy of the regional DEM. This study has reference value for implementing projects such as urban terrain expression in the construction of 3D China. [ABSTRACT FROM AUTHOR]

The long-term trends in the occurrence frequency of pre-summer daytime and nocturnal extreme hourly rainfall (EXHR) during 1988-2018 in Hong Kong and their spatial distributions are examined and analyzed. Despite a significant increasing trend observed in the occurrence frequency of pre-summer EXHRs during the investigated period, the increase in daytime and nocturnal EXHRs show distinct spatial patterns. Nocturnal EXHRs show uniform increasing trends over the entire Hong Kong. However, the increase in daytime EXHRs is concentrated over the northern or eastern areas of Hong Kong, indicating a downstream shift of pre-summer EXHRs in Hong Kong with regard to the prevailing southwesterly monsoonal flows in south China. The clustering of weather types associated with daytime and nocturnal EXHRs further reveals that the increase in EXHRs over Hong Kong are mainly contributed by the increase of the events associated with southwesterly monsoonal flows with relatively high speeds. During the past few decades, the southwesterly monsoonal flows at coastal south China have undergone a substantial weakening due to the increased surface roughness induced by the urbanization over the Guangdong-Hong Kong-Macau Greater Bay Area since 1990s, leading to enhanced low-level convergence and thus significant increase in EXHRs at coastal south China. Meanwhile, daytime sea-wind circulation at coastal south China is markedly enhanced during the investigated period, which is the main reason for the northward shift of daytime EXHRs in Hong Kong. In addition, the blocked southwesterly monsoonal flows at coastal south China are detoured eastward, leading to stronger convergence and increase in EXHRs at eastern coast of Hong Kong, especially during daytime, when the easterly sea winds prevail at the region. [ABSTRACT FROM AUTHOR]

The Mo/Si multilayer mirror has been widely used in EUV astronomy, lithography, microscopy and other fields because of its high reflectivity at the wavelength around 13.5 nm. During the fabrication of Mo/Si multilayers on large, curved mirrors, shadow mask was a common method to precisely control the period thickness distribution. To investigate the effect of shadow mask on the microstructure of Mo/Si multilayers, we deposited a set of Mo/Si multilayers with and without the shadow mask on a curved substrate with aperture of 200 mm by direct current (DC) magnetron sputtering in this work. Grazing incidence X-ray reflectivity (GIXR), diffuse scattering, atomic force microscope (AFM) and X-ray diffraction (XRD) were used to characterize the multilayer structure and the EUV reflectivity were measured at the National Synchrotron Radiation Laboratory (NSRL) in China. By comparing the results, we found that the layer microstructure including interface width, surface roughness, layer crystallization and the reflectivity were barely affected by the mask and a high accuracy of the layer thickness gradient can be achieved. [ABSTRACT FROM AUTHOR]

Abrasive waterjet, which is capable of machining all kinds of materials without generating obvious heat and dust, was proposed for treating rail for the first time. With the employment of China's U71Mn heavy rail of 60 kg/m, the fitting method for the cross-section profile of the rail head and the compensation cutting strategy of abrasive waterjet were proposed. The feasibility of rail surface treatment using abrasive waterjet and the influence of jet pressure and traverse speed on the profile deviation and surface roughness were studied. Moreover, both the macro-morphology and micromorphology of the rail surface before and after abrasive waterjet treatment were analyzed using the scanning electron microscope. Results show that abrasive waterjet could effectively remove the surface defects like pits, rust, and microcracks under the experimental conditions. Jet pressure and traverse speed greatly affect the surface roughness and profile deviation. In addition, the profile deviations and the surface roughness of the rail surface treated by abrasive waterjets could satisfyingly meet the acceptance standard (Chinese TJ/GW170-2021). To be more specific, the rail profile and surface roughness after treating can reach 0.337 mm and 2.691 μm, respectively, at jet pressure of 400 MPa and traverse speed of 200 mm/min. [ABSTRACT FROM AUTHOR]

Due to the continuous intensification of human activities in the ocean, the frequent outbreaks of red tide have caused great harm to the marine environment and ecology. Thus, the rapid detection and monitoring of red tide become particularly important. At present, the main monitoring methods depend on artificial and buoy data, as well as optical satellite remote sensing. However, these methods may not be able to effectively deal with the characteristics of red tide bloom, such as suddenness and unpredictability. The global navigation satellite system-reflectometry (GNSS-R) is an emerging technology that makes use of navigation signals as a remote sensing opportunity to obtain Earth surface information. GNSS-R has already been proved to be capable of retrieving sea surface parameters (e.g., dielectric constant and sea surface roughness) closely related to the outbreak of a red tide. In this article, we proposed a new method to estimate red tide density, which utilizes an all-new model associating GNSS-R observations with sea surface red tide density. This method can remove the weather influence and greatly decrease the revisit period, which is much longer for optical red tide remote sensing methods. The Landsat-8 near-infrared data and TechDemoSat-1 (TDS-1) GNSS-R data of a red tide outbreak in the sea off the Tsingtao coast in China are used to build and test the proposed method. The results demonstrate that the correlation coefficient is 0.73, and the root mean square error of retrieved red tide density is 2.84%, which shows that the GNSS-R technology shows great potential to perform the rapid and preliminary red tide monitoring and judgment. [ABSTRACT FROM AUTHOR]

Morphometrics are fundamental for the analysis of size and shape in fossils, particularly because soft parts or DNA are rarely preserved and hard parts such as shells are commonly the only source of information. Geometric morphometrics, that is, landmark analysis, is well established for the description of shape but it exhibits a couple of shortcomings resulting from subjective choices during landmarking (number and position of landmarks) and from difficulties in resolving shape at the level of micro‐sculpture.With the aid of high‐resolution 3D scanning technology and analyses of fractal dimensions, we test whether such shortcomings of linear and landmark morphometrics can be overcome. As a model group, we selected a clade of modern viviparid gastropods from Lake Lugu, with shells that show a high degree of sculptural variation. Linear and landmark analyses were applied to the same shells in order to establish the fractal dimensions. The genetic diversity of the gastropod clade was assessed.The genetic results suggest that the gastropod clade represents a single species. The results of all morphometric methods applied are in line with the genetic results, which is that no specific morphotype could be delimited. Apart from this overall agreement, landmark and fractal dimension analyses do not correspond to each other but represent data sets with different information. Generally, the fractal dimension values quantify the roughness of the shell surface, the resolution of the 3D scans determining the level. In our approach, we captured the micro‐sculpture but not the first‐order sculptural elements, which explains that fractal dimension and landmark data are not in phase.We can show that analyzing fractal dimensions of gastropod shells opens a window to more detailed information that can be considered in evolutionary and ecological contexts. We propose that using low‐resolution 3D scans may successfully substitute landmark analyses because it overcomes the subjective landmarking. Analyses of 3D scans with higher resolution than used in this study will provide surface roughness information at the mineralogical level. We suggest that fractal dimension analyses of a combination of differently resolved 3D models will significantly improve the quality of shell morphometrics. [ABSTRACT FROM AUTHOR]

Terrain classification involves essential tasks in geomorphology, landscape investigation, regional planning, and hazard prediction. Most existing methods are based on a simple thresholding approach. However, such an approach is limited in terms of accuracy and robustness, especially for large‐scale tasks. To overcome this limitation, this article proposes an object‐based framework combined with the random forest. Six terrain factors, namely terrain relief, surface roughness, elevation, elevation coefficient variation, shaded relief, and accumulative curvature, are first selected by correlation analysis using Sheffield's entropy. The obtained segmentation result is then optimized by Moran's I and the weighted variance, combining both terrain factors and textures derived from digital elevation models. Then, the features are selected among both terrain factors and their gray‐level co‐occurrence matrix textures. Finally, the features are fed into the random forest classifier. Seven landform types are classified, including plain, hill, low mountain, low‐middle mountain, high‐middle mountain, high mountain, and extremely high mountain. A case study in China was conducted and achieved an overall accuracy of 80.53% compared with the official landform atlas, which is better performance over the compared semi‐automatic methods. The transferability of our framework was further confirmed by an additional application in provincial‐scale mapping with a different classification system. [ABSTRACT FROM AUTHOR]

The surface slope and roughness of the Moon have been investigated extensively over a wide baseline range except millimeter to decimeter scales. In this study, we present for the first time millimeter‐to decimeter‐scale surface slope and roughness of the Moon at China's Chang'e‐4 landing regions (∼20 m across) using the Digital Terrain Model (DTM) with a resolution of 5 mm/pixel. The bidirectional slope at the 7 mm scale can be larger than 40° with a median value of ∼10°. The root‐mean‐square (RMS) height within a window size of 125 mm varies from ∼1 mm to ∼18 mm with a median value of ∼4 mm. Both the bidirectional slope and RMS height show scale‐dependent behaviors and the parameter of scale dependence, the Hurst exponent, is ∼0.6–0.85. We also synthesized the bidirectional slope at baseline from micrometer to kilometer, showing that bidirectional slope decreases from ∼60° at micrometer to ∼1° at a kilometer. At millimeter‐scale, surface roughness is mainly controlled by small impact craters, rocks, and regolith properties. Our roughness results not only bridge the gap in understanding surface roughness from traditional topographic data sets to radar and thermal observations, but also provide valuable information about lunar regolith characteristics, and small‐scale geological processes. Plain Language Summary: The roughness of a planetary body quantitively describes terrain surface topographic undulation at a horizontal scale and is widely used in geological and geomorphological studies. Roughness is an important parameter in radar observations due to its modulation of radar wave behaviors. Lunar surface roughness at a wide baseline range has been investigated before, but not in the baseline range of millimeter to decimeter. The Panoramic Camera onboard the Yutu‐2 rover collected millimeter‐scale resolution stereo images over China's Chang'e‐4 landing region. We generated a 5 mm/pixel resolution DTM covering an area of ∼20 m wide and then calculated three roughness parameters. We found that small impact craters, rocks, and regolith properties are the controlling factors affecting the millimeter‐scale roughness of the lunar surface. Combining with previous roughness results, we obtained lunar surface roughness versus baseline at scales ranging from micrometer to kilometer, which can be applied in a variety of studies. Key Points: We investigated millimeter to decimeter scale topographic roughness of the Moon in the Chang'e‐4 exploration region of ∼20 m wideThe median bidirectional slope is ∼10° at 7 mm scale and the median RMS height is ∼4 mm at 125 mm window size, and both show scale dependent behaviorsSmall impact craters, rocks, and regolith properties mainly affect millimeter‐scale topographic roughness of the Moon [ABSTRACT FROM AUTHOR]

Tamusu mudstone, located in Inner Mongolia, is being recognized to be the potential host formation in deep HLW disposal across China. This paper describes diverse laboratory experiments performed using the fractured Tamusu mudstone, with concern to the study of the combined mechanical and thermal effects on its hydraulic properties, as well as its self-sealing effect. A single rough fracture is generated down the sample diameter direction before the sample's installation. Considering a heating-cooling cycle, the evolution of the samples' hydraulic properties under different stress conditions has been monitored. The hydraulic conductivity is proved to be not only related to the temperature-induced water viscosity and density variation but also the change of stress state. At the same thermal conditions, the increase of confining pressure (or deviatoric stress) may weaken the flow capacity of the fractures and thus reduce the permeability. The non-coincidence for the curve of permeability versus temperature at the heating and cooling stage indicates that the permeability alterations in the fractures are irreversible. Fracture zone changes were observed by X-ray computer tomography (CT) before and after the tests. The self-sealing behavior, which may be beneficial from high confining pressure, was detected for fractured Tamusu mudstone. Morphologies of fracture surfaces were detected by the 3D scanning technique, which shows that the fracture surface roughness, due to the alteration of asperity contacts and void spaces under high stress, may take an important part of the responsibility to the change of permeability. [ABSTRACT FROM AUTHOR]

To better understand how surface roughness affects soil erosion, we investigated the rill distribution of sloping farmland under tillage practices in China's Loess Plateau region. Four tillage treatments (three tillage practices and a non-tillage control) were simulated manually using five slope gradient levels (3°-20°) and two rainfall intensities (90 and 120 mm h-1). The spatial distribution of rills was extracted and four indices were derived based on Strahler's stream ordering. With increasing slope gradient, random roughness exhibited a decreasing effect on sediment yield, and the interaction effect changed from negative to positive at a critical slope gradient of ~10°. Low-order rills gradually merged into high-order rills, forming a complete rill network toward higher slope gradients. The bifurcation ratio of different treatments did not differ considerably. With increasing surface roughness, the length of first-order rills and their longitudinal river slope decreased. For example, on the 10° slope under 90 mm h-1 rainfall intensity, the longitudinal river slope of contour plowing, manual hoeing, and contour drilling treatments decreased respectively by 29.4, 38, and 48.9% relative to the value of smooth surface (control) with a rise in rill order. Yet a greater surface roughness had the least effect on the number, length, and longitudinal river slope of third-order rills. A similar result was obtained in that correlation between sediment yield and the length of third-order rills was the weakest overall. The results indicate that surface roughness affects rill distribution and soil erosion on sloping farmland via its effect upon low-orderrill development. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cover management factor (C‐factor) has become one of the most sensitive and complex parameters in the revised universal soil loss equation (RUSLE) because of its sensitivity to anthropogenic activities. However, due to the regionally limited scope of conventional models, direct applications of the C‐factor prediction have been hindered in China. Alternative C‐factor estimation approaches often consider vegetation coverage alone. This can decrease the accuracy of the estimation to an extent. In this study, several cropping systems were established to investigate the coupling effect of surface changes under different management practices and crop cover in preventing soil loss at the plot scale. Five experimental (CP, cropped; SSR, roughened; SC, crusted; CP‐SSR, cropped‐roughened; CP‐SC, cropped‐crusted) plots were set, compared to bare plot (BP). The impact of cropping systems on soil loss was estimated by SLR (soil loss ratio), according to the universal soil loss equation (USLE). The SLR estimation models were provided via identifying the related sub‐factors, subsequently, combined with the distribution curve of rainfall erosivity to allow the novel C‐factor estimation. The results showed that compared with SLRCP, the decrease in SLRCP − SSR varied from 12% to 43% with a mean of 25.50%; and the decrease in SLRCP − SC varied from 24% to 51% with a mean of 34.75%. Crop coverage, plant height, root weight density, < 0.5 mm root length density (both at 0–5 cm depth), initial roughness, and initial crust thickness were significantly correlated with SLR. For cropped plot, SLRCP − estimated can achieve more accurate simulation result than conventional models obtained from literature findings, with RMSE (root mean square error) coefficient of 0.17. For a comprehensive understanding of the C‐factor, multiple crops should be considered, and more experiments in the experimental group to better verify SLRCP − SSR − estimated and SLRCP − SC − estimated are recommended. [ABSTRACT FROM AUTHOR]

Plant leaves can accumulate particulate matter (PM) from the air, thus mitigating air pollution. Nine plant species from the central part of Shanxi Province, China, were investigated to characterize differences in their PM retention capacity and the grain sizes of the collected PM. Styphnolobium japonicum, Syringa oblata, and Cerasus serrulata demonstrated strong retention capacity for PM particles of diverse size fractions. Philadelphus incanus, Viburnum opulus, and Yulania biondii had relatively weak retention capacity for overall and fine PM. Generally, species with smaller leaves and roughness surfaces, waxy leaves, or leaves with hair had strong PM retention capacity. Leaves with suitable groove widths better retained fine PM. Foliar dust observed on leaves presented multimodal distribution curves, including bimodal, trimodal, and four-peak distributions, which differed from the trimodal distribution of natural dustfall. The different PM retention capacities of the nine investigated species and the differing grain sizes between foliar dust and atmospheric dustfall indicated that plant leaves could selectively retain PM. The results of this study provide a scientific basis for the use of the plant to mitigate particulate air pollution. [ABSTRACT FROM AUTHOR]

Soil erosion in sloping cropland is a key water and soil conservation issue in the Loess Plateau region, China. How surface roughness influences soil detachment remains unclear due to the inconsistent results obtained from existing studies. The objectives of the present study were to evaluate the effects of tillage practices on soil detachment rate in sloping cropland and establish an accurate empirical model for the prediction of soil detachment rates. A series of movable bed experiments were conducted on sloping surfaces under three different tillage practices (manual dibbling, manual hoeing, and contour drilling), with a smooth surface (non‐tillage) as a control. The research indicated that soil detachment rate significantly increased with roughness (p < 0.05) since the average soil detachment rate was the highest under the contour drilling treatment (6.762 g m−2 s−1), followed by manual hoeing (4.180 g m−2 s−1), and manual dibbling (3.334 g m−2 s−1); the lowest detachment rate was observed under the non‐tillage treatment (3.214 g m−2 s−1). Slope gradient and unit discharge rate were positively correlated with soil detachment rate and proved to be more influential than soil surface roughness. Four composite hydraulic parameters were introduced to estimate soil detachment rate on tilled surfaces. Regression analyses revealed that stream power was the most effective predictor of soil detachment rate compared with unit length shear force, shear stress, and unit stream power. By integrating surface roughness as a variable, the detachment rate could be accurately described as a nonlinear function of stream power and surface roughness. The results of the present study indicate that tillage practice could influence soil loss on sloping cropland, considering the higher soil detachment rates under all tillage practices tested compared with non‐tillage. The results are attributed mainly to concentrated flow caused by the high water storage levels on tilled surfaces, which could damage surface microtopography and, subsequently, the development of headcuts. [ABSTRACT FROM AUTHOR]

Coastal beaches are mostly distributed in the silt-type muddy coastal zone, particularly in the Yellow River Delta of China. The typical ecologically fragile areas have suffered from severe soil degradation, where the ground vegetation is scarce. Furthermore, the tides and evaporation have also posed great damage to forming bare beaches with dry surface and flat terrain. In this study, four types of micro-topography transformation models were established in the flat terrain of the Yellow River Delta beach, in order to explore suitable vegetation restoration. Specifically, S-, strip-, pin-, and crescent-shaped topographies were selected in the bare land of the light beach. The specific parameters were then measured to analyze the engineering quantity in the four micro-terrain reconstructions, including the surface roughness, vegetation growth, and soil improvement. A principal component and fuzzy mathematics membership functions were used to comprehensively evaluate the vegetation restoration and soil improvement in the four micro-terrain reconstructions. The results showed that the surface roughness increased, but the wind speed reduced under the various micro-topography of bare land in the light beach. The probability of seed retention increased in this case, where a warm zone formed at the bottom of the pit, thereby to promoting seed germination and growth. It was found that the micro-topography significantly enhanced the physical and chemical properties of soil for the growth of vegetation (P<0.05). Meanwhile, the micro-topography significantly reduced the soil bulk density, salinity, and pH value, whereas, it increased soil nutrients, porosity, and water-holding capacity, compared with the bare land of the light beach. The indicators were systematically evaluated in the four micro-terrain reconstructions. The Crescent-shaped model significantly reduced the soil salinity by 44.19% (P<0.05), indicating a much more excellent performance to promote the vegetation restoration, compared with the bare land in the four micro-terrain reconstructions. The content of soil organic matter in the striped transformation model significantly increased by 65.11% (P<0.05), indicating a significant effect on the soil improvement, compared with the bare land of the bare beach. The pattern of the pin-shaped model greatly increased the soil porosity, while reduced the soil bulk density by 15.24% (P<0.05), indicating a better improvement in the physical properties of soil. Nevertheless, the S-shaped pattern performed a relatively weak correlation on vegetation restoration and soil improvement. Therefore, four micro-topography modification modes were ranked in a descending order: crescent-shaped, strip-shaped, pin-shaped, S-shaped, and bare land, after the comprehensive evaluation on the plant growth and soil improvement. A strong recommendation was that the crescent-shaped should be considered firstly, when carrying out the micro-topography transformation on the beaches of the Yellow River Delta, followed by the stripe-shaped and pin-shaped ones, where the S-shaped one cannot be adopted. There were still some limitations here, where the moist area at the bottom of the pit was first used to promote the growth of Suaeda salsa. It is also expected to measure the environmental changes at the bottom of pits in a long term, due mainly to the short testing period here. The finding can provide insightful technical support to the vegetation restoration for the coastal beaches of the Yellow River Delta in China. [ABSTRACT FROM AUTHOR]

The technology of pulse-plasma modification of the working surface of the die of 4Kh5MF1S tool steel (analogues are X40CrMoV5-1 in the EU and 4Cr5MoSiV1 in China) was considered. The mentioned tool is used for stamping billets of titanium VT6 alloy (wt.%: Al -- 3.0--6.8; V -- 3.5--5.0; Ti -- base), which is performed at temperatures of up to 700 °C. The die surface is heated, which leads to its oxidation and diffusion redistribution of alloying elements. Pulse-plasma stamping leads to the formation of elastic-plastic deformations of the surface layer in a tool steel, which in combination with pulsed thermal and electromagnetic effects provides a refinement of the alloy structure and intensifies the diffusion mechanisms of alloying elements. The studies showed that the modified layer (over 80 µm thickness) in 4Kh5MF1S steel, formed in the process of pulse-plasma treatment, contains up to 2.5 % carbon, up to 12 % oxygen and up to 3 % tungsten. In the mentioned layer the presence of nanocrystalline structures with a size of less than 100 nm was revealed. The hardness of the modified layer is more than 700 HV0.025. The surface roughness after pulse-plasma treatment did not change. Experience of industrial use of this technology showed that modification of a surface of the die from 4Kh5MF1S steel provided its high serviceability at a deep drawing of products from the heated (to 700 °C) sheet of VT-6 titanium of 3 mm thickness. [ABSTRACT FROM AUTHOR]

• Abrasion tests were performed to investigate the friction degradation of the sliding layer. • Dust incursion under the baseplate significantly affected friction performance. • Influence of dust particle size on the friction performance analyzed. • Surface roughness of the geomembrane was highly correlated with μ of the sliding layer. The track-bridge interaction force in the China Railway Track System II slab track can be significantly reduced due to the effect of the sliding layer, thus its friction performance is crucial for the operational safety of the track. However, because of the micro delamination between the base plate and bridge deck under certain conditions, the dust inevitably infiltrates the sliding layer. This study performed abrasion experiments to investigate the influence of dust incursion on the friction performance of the sliding layer. The experimental apparatus was designed to simulate repeated sliding and normal pressure between the base plate and the bridge under actual working conditions. Different sizes of dust particles were employed, and the friction performance, characterized by the friction coefficient and surface topography of the geomembrane, was obtained and analyzed. The experimental results show that the growth rate of the friction coefficient was 1.46–2.88 times greater than that without dust incursion. The results of this study can serve as a reference for the actual friction performance degradation of the sliding layer and shed light on maintenance decision-making. [ABSTRACT FROM AUTHOR]

As part of the efforts to establish a reliable fabrication process of superconducting integrated circuits at Center for Excellence in Superconducting Electronics (CENSE) in China, we investigated the influences of various deposition conditions on the properties of molybdenum (Mo) thin films. Thin-film resistors were fabricated based on these films by using a lift-off process. It was found that Mo structures made from films peeled off easily from the substrate after lift-off. We have optimized the deposition conditions to grow Mo films with compressive or weakly tensile stress. Mo thin-film resistors with a sheet resistance of several ohm/square and surface roughness of less than 1 nm were successfully fabricated and were used in the fabrication of superconducting quantum interference devices and small-scale superconducting integrated circuits. [ABSTRACT FROM AUTHOR]

Wind speed and variability are the most critical climatic factors affecting sand/dust storms, which have not been sufficiently studied in the middle reaches of the Yarlung Tsangpo River (MYR). In this study, wind speed variability was investigated using the moving average over shifting horizon method (MASH), combined with the modified Mann–Kendall test and Sen's slope based on data from the Tsetang, Lhasa, and Nyêmo meteorological stations during 1960–2015. The results indicated that annual wind speeds for the MYR wide valley regions declined significantly at decadal rates of − 0.216 m/s and underwent three stages from 1960 to 2015: an increasing trend from 1960 to 1975 (0.44 m/s per decade), a weakening until 2006 (− 0.46 m/s per decade), and a remarkable subsequent recovery (1.05 m/s per decade). Different variability trends were observed for the three stations: wind speed decreased significantly during all months at the Tsetang and Nyêmo stations, particularly in the spring, while for Lhasa, a non-significant wind speed increase was detected in summer, and the highest decline occurred in winter. The MASH method resulted in the effective visualization of different patterns, making seasonal process analysis and trend detection easier. In addition, the possible main causes for wind speed change were also discussed. The wind speed change in the study region was strongly associated with the large-scale atmospheric patterns, and the surface pressure gradient variability between the mid and low latitudes may have been a primary driving force. Positive/negative phases of the Pacific Decadal Oscillation (PDO) corresponded well with wind speed decreases/increases and were regarded as an indicator of wind speed variations. The effects of human activities associated with surface roughness change in the MYR were minor compared with the climatic changes. [ABSTRACT FROM AUTHOR]

Characterizing geomorphological patterns based on digital elevation models (DEMs) has become a basic focus of current geomorphology. A new DEM upscaling method based on the high-accuracy surface modelling method (HASM-US method) has been developed to improve the accuracy of current models and the subjectivity of macroscopic geomorphological patterns. The topographic variables of elevation (EL), slope (SL), aspect (AS), relief amplitude (RA), surface incision (SI), surface roughness (SR), and profile curvature (PC) with a spatial resolution of 1 km × 1 km in the Beijing-Tianjin-Hebei (BTH) area of China have been obtained by using the HASM-US method combined with the principal component analysis (PCA) method in terms of the elevation data of the SRTM-4 DEM, meteorological station location information, and field measurements with a GPS receiver. A geomorphological regionalization pattern has been developed to quantitatively classify the geomorphological types in the BTH area by combining the seven topographic factors of EL, SL, AS, RA, SI, SR, and PC that have significant spatial variation. The results show that the upscaling accuracy of elevation (mean difference only −2.32 m) with the HASM-US method is higher than that with the bilinear interpolation method and nearest neighbour interpolation method. The geomorphologic distribution in the BTH area includes 11 types: low plain, low tableland, low hill, low basin, middle plain, middle hill, low mountain with low RA values, low mountain with medium RA values, middle mountain with low RA values, middle mountain with medium RA values, and middle mountain with high RA values. The low plain is the dominant geomorphological type that covers 40.58% of the whole BTH area. The geomorphological distribution shows the different significant characteristics: the elevation rapidly decreases from the Taihang Mountains to the eastern area, gradually decreases from the Yanshan Mountains to the southern area, and first increases and then decreases from the Bashang Plateau to the southeastern area in the whole BTH area. [ABSTRACT FROM AUTHOR]

BACKGROUND: Our previous study confirmed that BTO/P(VDF-TrFE) piezoelectric nanocomposita membrane containing 5%BTO (BaTO3, BTO) nanoparticles could significantly promote bone marrow mesenchymal stem cells (BMSCs) adhesion, growth, osteogenic differentiation and repair of bone defects due to its bionic potential. However, for clinical applications, it is not clear whether there is any difference between the bone repair effect of this material as a guide for tissue regeneration and that of the existing clinically non-degradable membrane products. OBJECTIVE: To compare the effects of BTO/P(VDF-TrFE) piezoelectric nano-composne membrane materials with commercial PTFE membrane in repairing critical-sized defects of SD rat skull. METHODS: BTO/P(VDF-TrFE) piezoelectric nanocomposne membrane containing 5% BTO nanoparticles was prepared by solution casting method. Scanning electron microscope, atomic force microscope and water contact angle measuring instrument were used to observe the surface morphology, measure the surface roughness and surface hydrophilicity and hydrophobicity of the material. In SD rats (purchased from the Laboratory Animal Center, Beijing University Hospital of Stomatology, China), a 5-mm sized full-thick bone defect was made on both sides of the sagittal suture of the skull. The left bone defect was covered with PTFE membrane (control group). The right bone defect was covered with BTO/P(VDF-TrFE) piezoelectric nano-composita membrane (experimental group). At postoperative 4 and 12 weeks, micro-CT and histological methods were used to evaluate the repair of the skull defect in rats. This study was approved by Animal Ethics Committee, Beijing University Hospital of Stomatology. RESULTS AND CONCLUSION: The piezoelectric nanocomposite membrane had smooth and dense surface and BTO nanoparticles were evenly distributed. PTFE membrane was composed of loose coarse fibers. The piezoelectric nanocomposite membrane had lower surface roughness (P< 0.001) and higher hydrophilicity (P< 0.001) than PTFE membrane. Micro-CT and histological results showed that at 4 weeks after surgery, new bone formation was found in both groups, but new bone formation was more obvious in the center of the defect in the experimental group than in the control group. At 12 weeks after surgery, bone defects healed in both groups, but the maturity of newly formed bone in the experimental group was greater than that in the control group. These results suggest that BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5%BTO (BaTO3, BTO) nanoparticles can be used as a membrane guiding tissue regeneration. [ABSTRACT FROM AUTHOR]

The aerodynamic roughness of glacier surfaces is an important factor governing turbulent heat transfer. Previous studies rarely estimated spatial and temporal variation in aerodynamic surface roughness (z0) over a whole glacier and whole melting season. Such observations can do much to help us understand variation in z0 and thus variations in turbulent heat transfer. This study, at the August-one ice cap in the Qilian mountains, collected three-dimensional ice surface data at plot scale, using both automatic and manual close-range digital photogrammetry. Data were collected from sampling sites spanning the whole ice cap for the whole of the melting season. The automatic site collected daily photogrammetric measurements from July to September of 2018 for a plot near the center of the ice cap. During this time, snow cover gave way to ice and then returned to snow. z0 was estimated based on micro-topographic methods from automatic and manual photogrammetric data. Manual measurements were taken at sites from the terminals to the top of the ice cap; they showed that z0 was larger at the snow and ice transition zone than in areas that are fully snow or ice covered. This zone moved up the ice cap during the melting season. It is clear that persistent snowfall and rainfall both reduce z0. Using data from a meteorological station near the automatic photogrammetry site, we were able to calculate surface energy balances over the course of the melting season. We found that high or rising turbulent heat, as a component of surface energy balance, tended to produce a smooth ice surface and a smaller z0 and that low or decreasing turbulent heat tended to produce a rougher surface and larger z0. [ABSTRACT FROM AUTHOR]

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Surface roughness and slope gradient are two important factors influencing soil erosion. The objective of this study was to investigate the interaction of surface roughness and slope gradient in controlling soil loss from sloping farmland due to water erosion on the Loess Plateau, China. Following the surface features of sloping farmland in the plateau region, we manually prepared rough surfaces using four tillage practices (contour drilling, artificial digging, manual hoeing, and contour plowing), with a smooth surface as the control measure. Five slope gradients (3°, 5°, 10°, 15°, and 20°) and two rainfall intensities (60 and 90 mm/hr) were considered in the artificial rainfall simulation experiment. The results showed that the runoff volume and sediment yield increased with increasing slope gradient under the same tillage treatment. At gentle slope gradients (e.g., 3° and 5°), the increase in surface roughness prevented the runoff and sediment production, that is, the surface roughness reduced the positive effect of slope gradient on the runoff volume and sediment yield to a certain extent. At steep slope gradients, however, the enhancing effect of slope gradient on soil erosion gradually increased and surpassed the reduction effect of surface roughness. This study reveals the existence of a critical slope gradient that influences the interaction of surface roughness and slope gradient in controlling soil erosion on sloping farmland. If the slope gradient is equal to or less than the critical value, an increase in surface roughness would decrease soil erosion. Otherwise, the increase in surface roughness would be ineffective for preventing soil erosion. The critical slope gradient would be smaller under higher rainfall intensity. These findings are helpful for us to understand the process of soil erosion and relevant for supporting soil and water conservation in the Loess Plateau region of China. [ABSTRACT FROM AUTHOR]

The engineering classification of rock masses is the basis of rock engineering design and construction. We propose and apply a quick basic quality (BQ) classification method based on the standard BQ method of China to classify the quality grade of the rock mass around tunnels along the Ningguo-Huangshan Expressway during the construction period. Moreover, the joint continuity and surface roughness of the controlled key joint are added to the classification indices of the quick BQ method to address shortcomings of the standard BQ classification method. Therefore, an improved BQ classification method for rock mass is proposed. According to the BQ method, different personnel might select different values of correction coefficient that result in divergences in the result of rock mass classification. In order to solve this problem, the Genetic algorithm (GA) and support vector classification (SVC) coupling algorithm is introduced into the field of engineering rock mass classification. GA is used to automatically search for the optimal SVC parameters during the training process of samples. By training the classification samples of rock mass around a tunnel using the improved BQ method during the tunnel construction period, an intelligent SVC classification model is constructed with inputs based on eight classification indices and an output of the BQ quality grade. To verify the reliability and accuracy of the model, the SVC model is used to evaluate the quality grade of the rock mass around tunnel in other cross sections of the tunnels along the Ningguo-Huangshan Expressway. Only one section classification result differed from those of the improved BQ method in a total of 20 sections. In contrast, three section classification results based on the BP neural network (BPNN) model were inconsistent with those of the improved BQ method. Therefore, the proposed SVC model displays a higher rate of correct classification relative to that of the BPNN model. Meanwhile, the use of this SVC model can avoid the divergence among different people on the classification result of rock mass around a tunnel, which provides an effective new method for the rapid classification of rock mass around a tunnel during tunnel construction. [ABSTRACT FROM AUTHOR]

• The coupling effect between erosion processes and soil surface roughness. • Soil surface roughness exerts an important effect on the hydrodynamic parameters. • Flow velocity and roughness as the parameters can predict collapsing gully slope erosion well. The colluvial deposits, resulting from the collapsing gully erosion, provide a large amount of sediment for subsequent water erosion in southeastern China. Previous studies have shown the apparent effects of rainfall, runoff and slope gradient on erosion of colluvial deposits, but paid little attention to the effect of soil surface roughness. The objective of this study was to investigate the relationship between surface roughness and erosion processes under continuous rainfall conditions. For this purpose, we repeated an indoor rainfall experiment 20 times on a colluvial deposit slope of 30°. The rainfall intensity was 3.33 mm min−1 and the rainfall lasted 60 min. We measured the sediment yield for each rainfall experiment and the related hydrodynamic parameters, including the flow velocity, Froude number, Reynolds number, Runoff power and Darcy-Weisbach resistance coefficient. We found that the gradual enrichment of coarse particles and gravel on the surface of the colluvial deposits led to an exponential decrease in sediment yield. The water erosion consists of three processes: (1) The emergence of the falling-sill, followed by the formation and rapid expansion of the rill; (2) The frequent expansion of the rill; and (3) The random landslide of the rill wall. The flow velocity, Froude number (Fr), Reynolds number (Re) and runoff power (ω) all showed a power decrease in contrast to a power increase of Darcy-Weisbach resistance coefficient (f) due to the influence of the roughness of colluvial deposits. The roughness and flow velocity can be used as good indicators for characterizing the water erosion intensity of the colluvial deposits. The findings will facilitate further research into the effect of roughness on the water erosion of colluvial deposits. [ABSTRACT FROM AUTHOR]

The shear behavior of rock mass significantly depends upon the surface roughness of rock joints which is generally characterized by the anisotropy characteristic and the scale effect. The large-scale natural rock joint surfaces, at Qingshi Town, southeast of Changshan County, Zhejiang Province, China, were used as a case study to analyze the roughness characteristics. A statistical assessment of joint roughness coefficient (JRC) indicated the roughness anisotropy of different sized rock joints. The lower limit (JRCmean-σ) was regarded as the determinate information, and the difference between lower and upper limits represented indeterminate information. The neutrosophic number (NN) was calculated to express the various JRC values. The parametric equations for JRC anisotropic ellipse were presented based on the JRC statistical assessment of joint profiles of various orientations. The JRC values of different sized joint samples were then quantitatively described by the neutrosophic function. Finally, a neutrosophic parameter ψ for evaluating the scale effect on the surface roughness anisotropy was introduced using the ratio of maximum directional roughness to minimum directional roughness. The case study indicates that the proposed method has the superiority in moving forward from subjective assessment to quantitative and objective analysis on anisotropy characteristic and scale effect of joint surface roughness. [ABSTRACT FROM AUTHOR]

Offshore wind resource assessment seems to be urgently needed due to the rapid development of offshore wind energy in the coming decades. Technical potential of offshore wind energy over the sea area shallower than 250 m along China coast is investigated. To avoid erroneous estimation of wind power density, a statistical model considering sea state effect is proposed. Long-term CCMP wind field data are examined using that model to reduce uncertainties. Further, influential factors including wind power density, water depth, wind turbine size, wind farm layout and various spatial constraints are analyzed on the GIS platform. Technical potential under different scenarios are presented and discussed. It shows that wind resource at Taiwan Strait is particularly abundant, where wind power density at 70 m height can be above 900 W/m 2 . Technical potential is quite sensitive to the size of wind turbine. Taking the layout S1 (8 × 15 turbines in each farm, 8 rotor diameters apart between wind turbines, 20 km buffer region between neighboring farms) as an example: the total technical potential of the study area is 613 GW for rotor radius 60 m, and that for rotor radius 90 m is 1264 GW; the growth rates of technical potential with rotor radius is 19.3 GW/m roughly. Spatial constraints has significant impact on the region with water depth less than 50 m, where only 48.1% of area is available for developing wind energy and the technical potential there is about 23% of that of the study area. [ABSTRACT FROM AUTHOR]

The great Zhangbei-Bohai fault (ZBF) is an important seismic active zone in Northeastern China, which intersects with another great fault, namely Tancheng-Lujiang fault (TLF), in the Central Bohai Sea. Most of the previous studies only investigated the earthquakes (EQs) happened in the west section of ZBF and anomalies appeared in the land area, but few researchers focused on the EQs happened in the east section of ZBF and studied the anomalies appeared above the Bohai Sea. Recently, we have investigated the disturbances on and above the Bohai Sea associated with the Zhangbei Mb5.6 EQ in 1998, whose epicenter located in the west section of ZBF, and found that there was seismicity induced gas release from submarine TLF. To study further the multi-parameter anomalies of EQs near ZBF during past decades and their relationship with ZBF and TLF, a scrutiny strategy for seismic anomaly in the sea area was proposed in this study. After comprehensive screening of EQs occurred near ZBF from 1998 to 2022 using multi-source remote sensing data, potential seismic anomalies including the anomalies of microwave brightness temperature and sea surface roughness on Bohai Sea were found correlated with 6 of the 23 investigated EQs, and there were commonly anomalies of CO and CH 4 concentration in the atmosphere. All these seismic anomalies were found developing mainly along the TLF in Bohai Sea, and started usually before shocking, appeared co-seismically and in the next few days. Regional inconsistencies among the distribution of CO and CH 4 anomalies could be owning to the specific underwater reservoir in the Bohai Bay Basin. Though analyzing the focal mechanism solutions of the selected EQ cases, we found that the seismic anomaly existed only when the TLF was in a stress state of tensile relaxation. • A scrutiny strategy for seismic anomalies in the sea area was proposed. • The earthquakes near Zhangbei-Bohai fault were comprehensively investigated. • The general features were summarized from the seismic anomalies of 6 earthquakes. • The geo-mechanism of the seismic anomalies was analyzed by centroid moment tensors. [ABSTRACT FROM AUTHOR]

• Tillage-induced SSR played an important role in soil and water conservation. • Rough surface generated lesser surface flow and more subsurface flow. • Rough surface reduced sediment yield during light rain and the sheet erosion stage. • Rough surface was more inclined to transport clay particles than smooth surface. • Stream power fitted best with the soil loss rate. Tillage-induced soil surface roughness (SSR) and rainfall interactions determine the process of water erosion. In this study, long-duration rainfall simulations were conducted to investigate the effect of SSR on the processes of surface–subsurface flow generation and soil loss, flow hydrodynamics, sediment sorting and transport on the steep red soil sloping farmland, southern China. Rainfalls with intensities of 30, 60, and 90 mm h−1 with duration of 180 min were applied to two soil surfaces (smooth and rough) with the slope gradient of 15°. Lesser surface flow and more subsurface flow were generated on the rough surface, which also accelerated the initial flow response and erosion stage advancement. The reduction effect of SSR on the sediment yield was significant under light rain or in the sheet erosion stage, while was limited when the rainfall intensity became stronger or entering the rill erosion stage. Differences in the spatial variability of soil crusts and the spatial distribution of rill networks were the main agents. Stream power took roughness factor into consideration well, thus was identified as the best hydraulic parameter for the prediction of soil loss rate. The investigation of particle size distribution of the eroded sediment showed the contents of sand, silt and clay changed from 15.9%, 64.9%, and 19.2% (average value of the original soil) to 22.9%, 53.1%, and 24% for the smooth surface, and to 37.8%, 42.1%, and 20.2% for the rough surface (average value of the eroded sediment). The selective and degrading effects of SSR on sediment particles were represented well. The rough surface was more inclined to transport clay particles than the smooth surface in the former period of erosion. Sand particles instead become more enriched with the extension of rainfall time. The results are beneficial for controlling the water erosion on agricultural sloping farmland. [ABSTRACT FROM AUTHOR]

The special climate environment creates a distinctive air-lake interaction characteristic in the Tibetan Plateau (TP) lakes, where the variations of surface roughness lengths also differ somewhat from those of other regions. However, how different categories of roughness lengths affect the lake surface energy exchange and the planetary boundary layer height (PBLH) remains unclear in the TP lakes. In this study, we used a tuned Weather Research and Forecasting (WRF) model version 3.6.1 to investigate the responses of the freeze-up date, turbulent fluxes, meteorological variables, and PBLH to surface roughness length variations in Ngoring Lake. Of all meteorological variables, the lake surface temperature responded to roughness length variations most sensitively; increasing roughness lengths can put the lake freeze-up date forward. The effect of momentum roughness length on wind speed was significantly affected by the fetch length. The increase in the roughness length for heat can induce the increment of the nightly PBLH in most months, especially for the central lake area in autumn. The primary factors that contribute to sensible heat flux (H) and latent heat flux (LE) were the roughness lengths for heat and momentum during the ice-free period, respectively. Increasing roughness length for heat can increase the nightly PBLH, and decreasing roughness length for moisture can also promote growth of the PBLH, but there was no obvious correlation between the momentum roughness length and the PBLH. [ABSTRACT FROM AUTHOR]

High temporal resolution water distribution maps are essential for surface water monitoring because surface water exhibits significant inner-annual variation. Therefore, high-frequency remote sensing data are needed for surface water mapping. Dongting Lake, the second-largest freshwater lake in China, is famous for the seasonal fluctuations of its inundation extents in the middle reaches of the Yangtze River. It is also greatly affected by the Three Gorges Project. In this study, we used Sentinel-1 data to generate surface water maps of Dongting Lake at 10 m resolution. First, we generated the Sentinel-1 time series backscattering coefficient for VH and VV polarizations at 10 m resolution by using a monthly composition method. Second, we generated the thresholds for mapping surface water at 10 m resolution with monthly frequencies using Sentinel-1 data. Then, we derived the monthly surface water distribution product of Dongting Lake in 2016, and finally, we analyzed the inner-annual surface water dynamics. The results showed that: (1) The thresholds were -21.56 and -15.82 dB for the backscattering coefficients for VH and VV, respectively, and the overall accuracy and Kappa coefficients were above 95.50% and 0.90, respectively, for the VH backscattering coefficient, and above 94.50% and 0.88, respectively, for the VV backscattering coefficient. The VV backscattering coefficient achieved lower accuracy due to the effect of the wind causing roughness on the surface of the water. (2) The maximum and minimum areas of surface water were 2040.33 km² in July, and 738.89 km² in December. The surface water area of Dongting Lake varied most significantly in April and August. The permanent water acreage in 2016 was 556.35 km², accounting for 19.65% of the total area of Dongting Lake, and the acreage of seasonal water was 1525.21 km². This study proposed a method to automatically generate monthly surface water at 10 m resolution, which may contribute to monitoring surface water in a timely manner. [ABSTRACT FROM AUTHOR]

Urbanization has a significant influence on climate and meteorological conditions through altering surface aerodynamic characteristics. Based on observational data collected at 15 levels on a 325 m meteorological tower in Beijing during 1991-2011, changes in wind speed, vertical profile, aerodynamic roughness length (z0), and zero-plane displacement height (zd) were analyzed. Decreasing trends were observed predominantly during this period, especially for levels between 65 and 140 m where the largest decreasing rates often occur. The annual and seasonal (spring, summer, autumn, and winter) mean wind speeds at 15 levels all present decreasing trends with average rates of 0.029, 0.024, 0.023, 0.040, and 0.019 m s−1 a−1, respectively. The decreases in strong wind categories contribute most to the reduction of mean wind speed. Furthermore, in 2005-2011, the diurnal maximum wind speeds at lower levels tend to appear earlier as compared to those in 1991-1997, while the patterns of diurnal cycle between different levels become more similar in these periods. Besides, the phenomena of “kink” in wind profiles are visible in various atmospheric stabilities, and the average height of a kink has increased from about 40 m to nearly 80 m associated with urbanization during 1991-2011. In addition, the results of z0 and zd calculated using the wind profile method vary with wind directions due to surface heterogeneity and that larger values often occur along with southerly winds. Both z0 and zd show increasing trends in different sectors during 1991-2011, and the annual mean z0 and zd have increased from less than 1 m to greater than 2 m, and from less than 10 m to greater than 20 m, respectively. [ABSTRACT FROM AUTHOR]

In this paper, terminal diameter and expansion velocity of the three-phase contact (TPC) line on the low-rank coal surfaces with different surface roughness were investigated. To eliminate the heterogeneity effect on the hydrophilic surfaces of low-rank coal particles, experimental samples with low ash content were adopted. Moreover, the analysis result of XPS indicated that there were few hydrophilic mineral particles on the low-rank coal surface. Furthermore, from the analyses of SEM and AFM measurements there are many crevices (pillars, protrusions) of different sizes (height and width) in different local areas of low-rank coal surfaces. Therefore, the three-phase contact lines on the low-rank coal surfaces presented different wetting behaviors. It demonstrated that the wetting film diameter became smaller and the expansion velocity of the three-phase contact line was faster while the surface roughness of low-rank coal samples increased. [ABSTRACT FROM AUTHOR]

A novel method for centimeter level high surface roughness copper nanoparticles (CuNPs)/silver nanowires (AgNWs) heterostructures prepared by vacuum thermal evaporation method and solid-state ionics method under 6 ​μA direct current electric field (DCEF) using fast ionic conductor KAg 4 I 5 was developed. The fractal dimension of the CuNPs/AgNWs heterostructures was calculated by grid-coverage method and the surface-enhanced Raman scattering (SERS) performance was detected by melamine aqueous solution as probe molecules. The results indicate that the macroscopic dendritic CuNPs/AgNWs heterostructures arranged neatly near cathode with the longest length of 6.3 ​cm were prepared, the diameters of CuNPs/AgNWs heterostructures ranged from 40 to 100 ​nm and many regularly arranged CuNPs with the diameter from 10 to 30 ​nm lie in the prepared nanoheterostructures, which lead to the CuNPs/AgNWs heterostructures have high surface roughness. The molar ratio of Ag:Cu is 11.87:1 and the fractal dimension of CuNPs/AgNWs heterostructures was 1.64 which means that there were more dentritic nanoheterostructures. The limiting concentration of melamine for the prepared high surface roughness CuNPs/AgNWs heterostructures SERS substrates is 10−16 ​mol/L, which is far below the strictest safety limits required of melamine in US and China. The EF for R6G/CuNPs/AgNWs heterostructures is estimated to be 4.82 ​× ​1012. These results indicate that the prepared CuNPs/AgNWs heterostructures with facile material synthesis, high surface roughness, low detection concentration and simple detection procedure has promising and strong application prospect for SERS detection in food safety. CuNPs/AgNWs heterostructures with the longest length of 6.3 ​cm were prepared by vacuum thermal evaporation method and solid-state ionics method, the diameters of CuNPs/AgNWs heterostructures ranged from 40 to 100 ​nm. The limiting concentration of melamine for the prepared high surface roughness CuNPs/AgNWs heterostructures SERS substrates is 10−16 ​mol/L and the EF for R6G/CuNPs/AgNWs heterostructures is estimated to be 4.82 ​× ​1012. [Display omitted] • Centimeter level high surface roughness CuNPs/AgNWs heterostructures were prepared. • The longest length is 6.3 ​cm and the diameters ranged from 40 to 100 ​nm. • Many regularly CuNPs with the diameter from 10 to 30 ​nm lie in the nanomaterials. • The limiting concentration of melamine for the nanomaterials is 10−16 ​mol/L. [ABSTRACT FROM AUTHOR]

• We quantify the correlation between urban morphology and heat island. • 1D surface roughness emerges as a good indicator of urban morphology. • Urban planning needs to consider potential nonlinearity in the correlation. As important determinants of urban thermal environment, surface roughness and morphology have been extensively studied for sustainable urban development. In this study, we quantify the effect of urban roughness and morphology on the surface urban heat island (SUHI) intensity and its spatiotemporal patterns, over seventeen major cities in six urban agglomerations of China. We employ multisource dataset and derive multiple measures, representative of the roughness and horizontal/vertical indicators of urban morphology. The results show that the correlation between the SUHI intensity and urban morphological indices is significantly strengthened with the heat island intensity, manifested by the contrasting Pearson's r in summer (r = 0.59 ± 0.13) and winter (0.11 ± 0.35). In general, the impact assessed using different measures of surface morphology is consistent on the SUHI intensity, while the one-dimensional (1D) roughness emerges as an adequate index not inferior to more complex morphological parameters. Our study also shows that the impact of urban morphology varies in different geographic and climatic regions, as well as with different urban management, which highlights the importance of locality and site-specific design in implementing effective urban heat mitigation strategies. [ABSTRACT FROM AUTHOR]

Passive microwave remote sensing of soil moisture is an underdetermined problem, as observed microwave emission from the landscape is affected by a variety of unknown surface parameters. Increasing observation information is an effective means to make retrievals more robust. In this study, a multi-temporal and multi-angular (MTMA) approach is proposed using SMOS (Soil Moisture and Ocean Salinity) satellite L-band data for retrieving vegetation optical depth (VOD p , p indicates the polarization with H for horizontal and V for vertical)), effective scattering albedo (ω p eff ), soil surface roughness (Z p s ), and soil moisture (SM p). The advantage of the MTMA approach is that it does not need auxiliary data as inputs or constraints. SMOS polarization-dependent VOD are produced and compared at a global scale for the first time, and it is found that the polarization difference of vegetation effects should not be ignored in the SM retrieval algorithm. The MTMA VOD retrievals are found to have a reasonable global spatial distribution, which is generally consistent with the VOD retrievals obtained from the SMOS Level 3 (SMOS-L3) and SMOS-IC Version 2 (V2) (referred to as SMOS-IC), except for showing relatively lower values over densely vegetated areas compared with the other two SMOS products. The spatial distribution of retrieved ω p eff generally shows a dependence on both VOD and land cover types. In addition, the values of MTMA - ω V eff are higher than that of MTMA - ω H eff , indicating stronger microwave scattering of V-pol in the vegetation layer than that of H-pol. The retrieved surface roughness parameter (Z p s ) ranges from 0.04 to 0.22 cm, and its spatial distribution is partially different from the existing roughness products/auxiliary data from SMOS and SMAP. The retrieved MTMA SM shows generally high correlations with in-situ measurements (11 dense observation networks) with overall correlation coefficients of > 0.75. The overall ubRMSE of MTMA - SM H and MTMA - SM V are < 0.055 m3/m3 and lower than that of SMOS-IC and SMOS-L3 products. SMOS-IC generally presents higher correlation coefficients compared to MTMA in most sites outside China; in China, RFI filtering is crucial and makes it very difficult when comparing algorithms based on different brightness temperature products. The number of effective retrievals of MTMA - SM H and MTMA- SM V ranges from 1409 to 1640 and 1104 to 1603 respectively, which is more than that from SMOS-IC (from 236 to 1358) over the selected 11 networks. Therefore, it is concluded that by incorporating multi-temporal SMOS data, the proposed method of MTMA can be used to systematically retrieve SM, VOD and additional surface parameters (effective scattering albedo and surface roughness) with comparable or better performance of SM than that of SMOS-IC and SMOS-L3. Moreover, this paper for the first time produced a polarization-dependent SMOS VOD product at a global scale. • A multi-temporal and multi-angular retrieval algorithm is developed for SMOS. • Vegetation optical depth and single scattering albedo are simultaneously retrieved. • The first retrieval of vegetation optical depth at V/H polarization, respectively. • Soil moisture and surface roughness are simultaneously retrieved. • The number of effective soil moisture retrievals is significantly increased. [ABSTRACT FROM AUTHOR]

Many studies have been carried out to investigate the scale effect on the shear behavior of rock joints. However, existing methods are difficult to determinate the joint roughness coefficient (JRC) and the shear strength of rock joints with incomplete and indeterminate information; the nature of scale dependency of rock joints is still unknown and remains an ongoing debate. Thus, this paper establishes two neutrosophic functions of the JRC values and the shear strength based on neutrosophic theory to express and handle the incomplete and indeterminate problems in the analyses of the JRC and the shear strength. An example, including four rock joint samples derived from the pyroclastic rock mass in Shaoxing city, China, is provided to show the effectiveness and rationality of the developed method. The experimental results demonstrate that the proposed neutrosophic functions can express and deal with the incomplete and indeterminate problems of the test data caused by geometry complexity of the rock joint surface and sampling bias. They provide a new approach for estimating the JRC values of the different-sized test profiles and the peak shear strength of rock joints. [ABSTRACT FROM AUTHOR]

Current land surface models (LSMs) tend to largely underestimate the daytime land surface temperature for high-altitude regions. This is partly because of underestimation of heat transfer resistance, which may be resolved through adequate parameterization of roughness lengths for momentum and heat transfer. In this paper, the regional-scale effects of the roughness length parameterizations for alpine grasslands are addressed and the performance of the Noah LSM using the updated roughness lengths compared to the original ones is assessed. The simulations were verified with various satellite products and validated with ground-based observations. More specifically, four experimental setups were designed using two roughness length schemes with two different parameterizations of (original and updated). These experiments were conducted in the source region of the Yangtze River during the period 2005-10 using the Noah LSM. The results show that the updated parameterizations of roughness lengths reduce the mean biases of the simulated daytime in spring, autumn, and winter by up to 2.7 K, whereas larger warm biases are produced in summer. Moreover, model efficiency coefficients (Nash-Sutcliffe) of the monthly runoff results are improved by up to 26.3% when using the updated roughness parameterizations. In addition, the spatial effects of the roughness length parameterizations on the simulations are discussed. This study stresses the importance of proper parameterizations of and for LSMs and highlights the need for regional adaptation of the and values. [ABSTRACT FROM AUTHOR]

The influence of shear rate on the mechanical behavior of rough rock joints prepared using a molding method was examined by testing jointed samples of four rock joint groups, which were obtained from the underground caverns of the Huangdao State Oil Reserves in China. The tests were performed using a JAW-600 coupled shear-flow machine under constant normal load (CNL) conditions. Shear rate and joint roughness coefficient (JRC) were the two primary considerations in this study. The results indicate that the peak shear strength is controlled by shear rate and joint roughness. Shear rate has a nonlinear relationship with the peak shear strength, whereas joint roughness exhibits good linearity with a high correlation coefficient (>0.97, except for results under a shear rate of 24.0 mm/min). Furthermore, shear rate affects the damage incurred by the rock joints, as illustrated by the acoustic emission of rock joints monitored by a PAC acoustic emission system. The joint surface breaks earlier with increased shear rate. Furthermore, because of the more rapid generation of macrocracks under higher shear rate, the corresponding cumulative acoustic emission (AE) count and AE energy are inversely proportional to the shear rate. A new shear strength criterion that considers both shear rate and joint roughness was developed based on the experimental results and Barton’s shear strength criterion. Then, the validity of this proposed criterion was verified with an average estimated error of 10.539% using the shear strength values of rock joints proposed by Barton, indicating that the new criterion is capable of providing an accurate estimate of shear strength for rough rock joints under different shear rates. [ABSTRACT FROM AUTHOR]

Soil moisture plays a critical role in the energy exchange and water redistribution of the land-atmosphere system. Knowledge of the temporal variations in soil moisture is vital in agricultural applications. Microwave indices are often used to characterize the temporal variations in soil moisture. In this study, we evaluate the temporal variations in soil moisture based on the microwave polarization difference index (MPDI) using ground-based measurements in China.In situsoil moisture at six test sites during the crop-growing season from 2009 to 2011 is obtained. The consistency of the temporal variations between the MPDI values and thein situsoil moisture is analysed in terms of (1) microwave frequencies, (2) satellite overpass times, and (3) measurement depths of soil moisture. The results show that the accuracies of the consistency vary from approximately 40% to 90%. Compared with thein situsoil moisture at 0–10 cm, the temporal variations in soil moisture are best characterized by the 6.9 GHz MPDI values from the ascending overpasses (MPDI_06A). Furthermore, the accuracies of the consistency between MPDI_06A and thein situsoil moisture at 0–10 cm are greater than those between MPDI_06A and thein situsoil moisture at 10–20 cm. [ABSTRACT FROM PUBLISHER]

Most land surface models require information on aerodynamic roughness length and its temporal and spatial variability. This research presents a practical approach for determining the aerodynamic roughness length at fine temporal and spatial resolution over the landscape by combining remote sensing and ground measurements. The basic framework of Raupach, with the bulk surface parameters redefined by Jasinski et al., has been applied to optical remote sensing data collected by the HJ-1A/1B satellites. In addition, a method for estimating vegetation height was introduced to derive the aerodynamic roughness length, which is preferred by users over the height-normalized form. Finally, mapping different vegetation classes was validated taking advantage of the data-dense field experiments conducted in the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) project. Overall, the roughness model performed well against the measurements collected at most HiWATER flux tower sites. However, deviations still occurred at some sites, which have been further analyzed. [ABSTRACT FROM AUTHOR]

The statistics of momentum exchange in the urban roughness sublayer are investigated. The analysis focuses on the characteristics of the dimensionless friction velocity, $${u_{*}}/U$$ , which is defined as the square root of the drag coefficient. The turbulence observations were made at a height of 47 m above the ground on the 325-m meteorological tower, which is located in a very inhomogeneous urban area in Beijing. Under neutral conditions, the dependence of the drag coefficient on wind speed varies with wind direction. When the airflow is from the area of densely built-up buildings, the drag coefficient does not vary with wind speed, while when the airflow is from the area covered by vegetation, the drag coefficient appears to decrease with increasing wind speed. Also, the drag coefficient does not vary monotonically with the atmospheric stability. Both increasing stability and increasing instability lead to the decrease of the drag coefficient, implying that the roughness length and zero-plane displacement may vary in urban areas. [ABSTRACT FROM AUTHOR]