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Forests, serving as natural barriers in mountainous regions, can reduce surface erosion, enhance water flow resistance and facilitate sedimentation. While extensive research has been conducted for forests and their capacity to withstand debris flows, there has been relatively little investigation into the interactions between riparian forests and debris flows. In this paper, a field investigation of Keze gully was conducted through section surveys, quadrat surveys and unmanned aerial vehicle field investigations. Based on the flow calculation results, analysis of sediment characteristics, gully morphology change and analysis of stand characteristics, the interaction model between the riparian forest and debris flow in the complex channel was discussed. The results further emphasise the role of forests in mitigating debris flows. Furthermore, the results show that the identified critical slope for the study area provides a threshold to explain two different flow interaction dynamics with riparian forests. Above the critical slope, debris flows predominantly follow the main channel, where the root-soil complex of riparian forests reduces channel bank erosion. However, this erosion can also lead to the uprooting and destruction of trees. Below the critical slope, floodplains are vital in accommodating overflow. Debris flows interact not only with the roots of trees near the riverbank but also with the trunks of trees on floodplains. Trees with a diameter less than 30 cm may also suffer damage due to broken stems. [ABSTRACT FROM AUTHOR]

The loose material in the mountain gullies is prone to form serious debris flow disasters under appropriate hydrodynamic conditions. The various compositions of these loose materials often lead to very large differences in the runout distances and the inundated areas. However, the mechanisms of the influence of material composition on the deposition characteristics of debris flow remain unclear, and studies are lacking on the influence of material composition on the deposition characteristics of runoff-generated debris flows. This study conducted experiments using different water discharges, flume slopes, and grain size distributions. The deposition processes of debris flows were observed, and their deposition patterns were explored. The effects of material composition on flow regimes, runout distances, inundated areas, and deposit geometries are revealed. The results showed that there are three types of debris flow, and their deposition patterns are different. The relationships of the Bagnold number and Friction number concerning the volume solid concentration were exponential. The mean mobility angle, a function of the upstream terrain slope, was established to assess the runout distance of debris flows with different flow regimes. Additionally, a criterion for identifying debris flow types was established by combining dimensionless runout distance and dimensionless slope. This study not only improved the observation of experimental phenomena in the deposition process of runoff-generated debris flows but also deepened the understanding of the mechanism of the influence of material composition on the deposition characteristics. [ABSTRACT FROM AUTHOR]

The debris flow dam is a common type of barrier dams, which shows significant differences from other types of barrier dam such as landslide dam, moraine dam in their formation processes, dam body shapes, and internal compositions. The basic breaching parameters such as flood peak discharge are vital indicators of risk assessment. In this study, we elucidated the failure process of the debris flow dam through the flume experiment, and built the calculation equation of the breaching parameters by selecting critical factors. The result shows that the overtopping failure process of the debris flow dam is capable of forming significantly retrogressive scarps, and the failure process experiences three stages, the formation of the retrogressive scarp, the erosion of the retrogressive scarp, and the decline of the retrogressive scarp. Five factors used for establishing the calculation equations for peak discharge (QP), final width (Wb) of the breach, and duration (T) of the debris flow dam failure are dam height (h), reservoir capacity (V), the fine grain content (P0.075) of the soil, the nonuniformity coefficient (Cu) of the soil, and the upper limit grain size (D90) of the soil, respectively. In the three equations, the correlation coefficients between Qp, Wb, T and the five factors were 0.86, 0.70, 0.63, respectively. The equations still need to be modified and verified in actual cases. [ABSTRACT FROM AUTHOR]

Debris flows pose great threats to people's safety and cause catastrophic damage to infrastructure. Accurate prediction of debris flow runout distance provides a scientific basis for delineating hazard zones and formulating disaster mitigation countermeasures. As a analytical model, the leading-edge model is widely used to predict debris flow runout distance in practice. The flow regime determines the stress state of the debris flow, which ultimately affects the debris flow runout distance. Particle collision stress, Coulomb friction stress, and viscous stress are three common stresses in debris flows. However, only the effect of Coulomb friction is considered in the leading-edge model. In this study, a modified debris flow runout distance model incorporating the effects of particle collision, Coulomb friction, and viscous drag is established. This study innovatively introduces the Bagnold number and Savage number into the runout distance model to establish the link between micro and macro variables, which provides a new approach for predicting the debris flow runout distance. The modified model is also validated and analyzed based on data from flume experiments and actual debris flow events. The results show that the modified model performed well in predicting debris flow runout distance. In addition, this study provides an open-ended discussion of the factors affecting debris flow runout distance and the shortcomings of the modified model, thus providing a basis for further study in the future. [ABSTRACT FROM AUTHOR]

Damage to rural buildings in mountainous regions caused by flash floods accounts for a significant proportion of economic losses from disasters. The unreinforced masonry (URM) wall is the most vulnerable structural element of rural buildings exposed to flash floods. The failure of a URM wall indicates damage to rural buildings in flash floods. Based on the yield line theory of out-of-plane damage of URM walls and the virtual work method, brittle failure criteria for URM walls under the impact of flash floods were established. According to the field investigation data of the 26 June 2020 flash flood event in Damawu Gully and the corresponding simulation results of FLO-2D, the disaster-causing process was analysed, and the failure criteria were validated. Three building parameters were identified to influence the flood-resistance of URM walls, including the mortar grade, the span-to-height ratio of the wall, and the number of floors of the rural building. The results showed that the cause of the 26 June disaster was the diversion of a 50-year flash flood into the residential community on the alluvial fan. The affected buildings were constructed with hollow blocks and lacked flood-resistance reinforcement. The critical failure depth of a URM wall restrained at the top by ring beams (RBs) under hydrostatic load conditions is 1.17 to 1.20 times greater than that of a URM wall without RBs, and the difference is even more pronounced when lower-strength mortar is used. The flood-resistance of a URM wall constructed with Mb 7.5 mortar and restrained by RBs is almost as strong as that of a URM wall constructed with Mb 20 mortar and without RBs. The span-to-height ratio of a URM wall should not be greater than 1.875 in this case. However, the flood-resistance of a URM wall with RB restraint is almost independent of the span-to-height ratio. The brittle fracture energy of masonry mortar is more crucial to the flood-resistance of 4-edge restrained URM walls if L/Z > 1.875. The flood-resistance of the URM wall of the first storey increases linearly with the number of floors. Single-storey rural buildings should be given priority to the use of high-grade masonry mortar and high-density blocks to improve flood-resistance. The failure criteria and the influence laws of building parameters on the flood-resistance of URM walls can provide references for flash flood mitigation and flood-resistance reinforcement of rural buildings in mountainous regions of Southwest China. [ABSTRACT FROM AUTHOR]

The impact force of large boulders carried by flash floods and debris flows is one of the main causes of structural damage. The elastoplastic modification model of the impact force was derived, and it was found that the impact force was significantly affected by large boulders with irregular shapes. However, a large boulder with an irregular shape is often simplified as an isovolumetric sphere or ellipsoid, which may lead to inaccurate calculation of the impact force. In this paper, a method to obtain the irregular shape of a large boulder in the field is proposed by combining field investigation, image processing, and graphic analysis. The irregular shape is described by a nonuniform rational B-spline (NURBS) curve. The curvature radii corresponding to the potential impact contact points on the surface of a large boulder, which can reflect the influence of the irregular shape, are extracted according to the concavity and convexity analysis. The results demonstrate that NURBS curves can describe irregular shapes both conveniently and accurately. The impact force was corrected by the elastic—plastic model, the impact force increased with increasing curvature radius, and the increase ratio of the impact force gradually decreased with increasing velocity. Compared with the isovolumetric sphere model and ellipsoid model, the impact force calculated by the ellipsoid model is closer to the results obtained in this paper. The reduction factor of the impact force is 0.03–0.16, which first increases significantly and then linearly increases with increasing curvature radius. In addition, the reduction factor of the impact force initially exhibits a significant decline with increasing velocity and then gradually stabilises. To simplify parameter selection, we suggest using the maximum curvature radius in the ellipsoid model as the calculation parameter in calculating the impact force of large boulders. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature 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.)

Objective: Sonographic features are associated with pathological and immunohistochemical characteristics of triple-negative breast cancer (TNBC). To predict the biological property of TNBC, the performance using quantitative high-throughput sonographic feature analysis was compared with that using qualitative feature assessment. Methods: We retrospectively reviewed ultrasound images, clinical, pathological, and immunohistochemical (IHC) data of 252 female TNBC patients. All patients were subgrouped according to the histological grade, Ki67 expression level, and human epidermal growth factor receptor 2 (HER2) score. Qualitative sonographic feature assessment included shape, margin, posterior acoustic pattern, and calcification referring to the Breast Imaging Reporting and Data System (BI-RADS). Quantitative sonographic features were acquired based on the computer-aided radiomics analysis. Breast cancer masses were manually segmented from the surrounding breast tissues. For each ultrasound image, 1688 radiomics features of 7 feature classes were extracted. The principal component analysis (PCA), least absolute shrinkage and selection operator (LASSO), and support vector machine (SVM) were used to determine the high-throughput radiomics features that were highly correlated to biological properties. The performance using both quantitative and qualitative sonographic features to predict biological properties of TNBC was represented by the area under the receiver operating characteristic curve (AUC). Results: In the qualitative assessment, regular tumor shape, no angular or spiculated margin, posterior acoustic enhancement, and no calcification were used as the independent sonographic features for TNBC. Using the combination of these four features to predict the histological grade, Ki67, HER2, axillary lymph node metastasis (ALNM), and lymphovascular invasion (LVI), the AUC was 0.673, 0.680, 0.651, 0.587, and 0.566, respectively. The number of high-throughput features that closely correlated with biological properties was 34 for histological grade (AUC 0.942), 27 for Ki67 (AUC 0.732), 25 for HER2 (AUC 0.730), 34 for ALNM (AUC 0.804), and 34 for LVI (AUC 0.795). Conclusion: High-throughput quantitative sonographic features are superior to traditional qualitative ultrasound features in predicting the biological behavior of TNBC. Key Points: • Sonographic appearances of TNBCs showed a great variety in accordance with its biological and clinical characteristics. • Both qualitative and quantitative sonographic features of TNBCs are associated with tumor biological characteristics. • The quantitative high-throughput feature analysis is superior to two-dimensional sonographic feature assessment in predicting tumor biological property. [ABSTRACT FROM AUTHOR]

Forestry has played an important role in hazard mitigation associated with debris flows. Most forest mitigation measures refer to the experience of soil and water conservation, which disregard the destructive effect of debris flows, causing potentially serious consequences. Determination of the effect of a forest on reducing debris-flow velocity and even stopping debris flows requires distinguishing between when the debris flow will destroy the forest and when the trees will withstand the debris-flow impact force. In this paper, we summarized two impact failure models of a single tree: stem breakage and overturning. The influences of different tree sizes characteristics (stem base diameter, tree weight, and root failure radius) and debris-flow characteristics (density, velocity, flow depth, and boulder diameter) on tree failure were analyzed. The observations obtained from the model adopted in this study show that trees are more prone to stem breakage than overturning. With an increase in tree size, the ability to resist stem breakage and overturning increases. Debris-flow density influences the critical failure conditions of trees substantially less than the debris-flow velocity, depth, and boulder diameter. The application conditions of forests in debris-flow hazard mitigation were proposed based on the analysis of the model results. The proposed models were applied in the Xiajijiehaizi Gully as a case study, and the results explain the destruction of trees in the forest dispersing zone. This work provides references for implementing forest measures for debris-flow hazard mitigation. [ABSTRACT FROM AUTHOR]

This study presents a novel angle-based contact detection method to address the concave contact problem of arbitrary polyhedra, including convex and concave polyhedra, those with cavities and/or holes, and likely their unions. First, the most important mathematical concept in this study, the angle, is introduced to represent a general polyhedron. Using angles, the topologies of the polyhedra can be far more complex and universal than those previously studied, allowing for the coplanarity of faces and collinearity of edges, and not limiting the polyhedra to simple homeomorphic to closed three-dimensional (3-D) spheres. Second, all the local entrances of two general angles, which are either vertex angle to half-space or crossing edge angle to edge angle entrances, are identified using the entrance formulas. Third, local convex decomposition (LCD) is proposed to decompose any arbitrarily concave angle into a set of convex subangles, making the method easy to implement and naturally compatible with detection of entrance angles. Fourth, the proposed entrance angle method (EAM) is implemented in 3-D discontinuous deformation analysis (DDA) to compute arbitrarily convex/concave contacts. Finally, the EAM-based 3-D DDA method is validated and then employed to investigate the discontinuous mechanical behaviors of complex polyhedral block systems. Overall, the extended 3-D DDA program is sufficiently developed to meet the analysis requirements of complex rock mass projects. [ABSTRACT FROM AUTHOR]

On August 8, 2017, a Ms = 7.0 magnitude earthquake occurred in the Jiuzhaigou Valley, in Sichuan Province, China (N: 33.20°, E: 103.82°). Jiuzhaigou Valley is an area recognized and listed as a world heritage site by UNESCO in 1992. Data analysis and field survey were conducted on the landslide, collapse, and debris flow gully, to assess the coseismic geological hazards generated by the earthquake using an unmanned aerial vehicle (UAV), remote-sensing imaging, laser range finders, geological radars, and cameras. The results highlighted the occurrence of 13 landslides, 70 collapses, and 25 potential debris flow gullies following the earthquake. The hazards were classified on the basis of their size and the potential property loss attributable to them. Consequently, 14 large-scale hazards, 30 medium-sized hazards, and 64 small hazards accounting for 13%, 28%, and 59% of the total hazards, respectively, were identified. Based on the variation tendency of the geological hazards that ensued in areas affected by the Kanto earthquake (Japan), Chi-chi earthquake (Taiwan China), and Wenchuan earthquake (Sichuan China), the study predicts that, depending on the rain intensity cycle, the duration of geological hazard activities in the Jiuzhaigou Valley may last over ten years and will gradually decrease for the following five to ten years before returning to pre-earthquake levels. Thus, necessary monitoring and early warning systems must be implemented to ensure the safety of residents, workers and tourists during the construction of engineering projects and reopening of scenic sites to the public. [ABSTRACT FROM AUTHOR]

Debris flow can cause serious damages to roads, bridges, buildings and other infrastructures. Arranging several rows of deceleration baffles in the flow path can reduce the flow velocity and ensure better protection of life and property. In debris flow prevention projects, deceleration baffles can effectively reduce the erosion of the debris flow and prolong the running time of the drainage channel. This study investigated the degree to which a 6 m long flume and three rows of deceleration baffles reduce the debris flow velocity and affect the energy dissipation characteristics. The influential variables include channel slope, debris flow density, and spacing between baffle rows. The experimental results demonstrated that the typical flow pattern was a sudden increase in flow depth and vertical proliferation when debris flow flows through the baffles. Strong turbulence between debris flow and baffles can contribute to energy dissipation and decrease the kinematic velocity considerably. The results showed that the reduction ratio of velocity increased with the increase in debris flow density, channel slope and spacing between rows. Tests phenomena also indicated that debris flow density has significant influence on the mobility and deposition characteristic of debris flow. The deposit amount first increased then decreased when the flow density rises, and the deposit amount of debris flow density of 1500 kg/m reached the maximum when the experimental flume slope is 12°. [ABSTRACT FROM AUTHOR]

Previously, we developed and validated a multiplex assay of 27 ancestry-informative markers (AIMs) for analyzing African (AFR), European (EUR), and East Asian (EAS) ancestry components. In this study, we typed and collectively analyzed a large Uyghur sample of 979 individuals to estimate the genetic coefficients of the 27 AIMs and investigate differentiation parameters between Uyghur and Han. The Uyghur allele frequencies ranged from 0.243 to 0.952, and heterozygosities ranged from 0.091 to 0.500. Values of F3 and I3 for EUR, Uyghur, and EAS ranged from 0.028 to 0.550 and 0.0002 to 0.345, respectively. The Uyghur population displays a substantial ancestry contribution of 50.3:49.7 (EUR:EAS) and was efficiently discriminated from Han Chinese with an accuracy of 99.285 %. All populations were clustered into AFR, EUR, EAS, and admixture groups of these three ancestries. Central Asian was obviously stratified from the other admixture populations of South Asians, North Asians, and the Americans. The 27 SNPs yield a circle with an average distance of 0.936 from the center (0, 0) in PCA analysis. Using this set, Chinese Uyghur and Han populations achieved accurate differentiation, and our updated genotype database (by citing 1000 Genomes data) of 43 worldwide populations is a useful resource for forensic applications and disease association studies. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science B is the property of Springer Nature 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.)

A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas. Experimental studies were performed to determine the characteristics of viscous debris flow in a drainage channel of this type with a slope of 15%. The velocity and depth of the viscous debris flow were measured, processed, and subsequently used to characterize the viscous debris flow in the drainage channel. Observations of this experiment showed that the surface of the viscous debris flow in a smooth drainage channel was smoother than that of a similar debris flow passing through the energy dissipation section in a channel of the new type studied here. However, the flow patterns in the two types of channels were similar at other points. These experimental results show that the depth of the viscous debris flow downstream of the energy dissipation structure increased gradually with the length of the energy dissipation structure. In addition, in the smooth channel, the viscous debris-flow velocity downstream of the energy dissipation structure decreased gradually with the length of the energy dissipation structure. Furthermore, the viscous debris-flow depth and velocity were slightly affected by variations in the width of the energy dissipation structure when the channel slope was 15%. Finally, the energy dissipation ratio increased gradually as the length and width of the energy dissipation structure increased; the maximum energy dissipation ratio observed was 62.9% (where B = 0.6 m and L/ w = 6.0). [ABSTRACT FROM AUTHOR]

Debris flows are one of the common natural hazards in mountainous areas. They often cause devastating damage to the lives and property of local people. The sabo dam construction along a debris flow valley is considered to be a useful method for hazard mitigation. Previous work has concentrated on the different types of sabo dams such as close-type sabo dam, open-type sabo dam. However, little attention has been paid to the spillway structure of sabo dam. In the paper, a new type of spillway structure with lateral contraction was proposed. Debris flow patterns under four different spillway structures were investigated. The projection theory was employed to predict trajectory of debris flow out from the spillway and to estimate the incident angle and terminal velocity before it plunged into the scour hole behind the sabo dam. The results indicated that the estimated data were in good agreement with the experimental ones. The discrepancy between the estimated and experimental values of main parameters remained below 21.82% (relative error). Additionally, the effects of debris flow scales under different spillway structures were considered to study the scour law. Although the debris flow pattern and scour law behind the sabo dam under different operating conditions was analyzed in this paper, further study on the scour mechanism and the maximum scour depth estimation based on scour theory is still required in the future. [ABSTRACT FROM AUTHOR]

A single-tube multiplex assay of a small set of ancestry-informative markers (AIMs) for effectively estimating individual ancestry and admixture is an ideal forensic tool to trace the population origin of an unknown DNA sample. We present a newly developed 27-plex single nucleotide polymorphism (SNP) panel with highly robust and balanced differential power to perfectly assign individuals to African, European, and East Asian ancestries. Evaluating 968 previously described intercontinental AIMs from three HapMap population genotyping datasets (Yoruban in Ibadan, Nigeria (YRI); Utah residents with Northern and Western European ancestry from the Centre de'Etude du Polymorphism Humain (CEPH) collection (CEU); and Han Chinese in Beijing, China (CHB)), the best set of markers was selected on the basis of Hardy-Weinberg equilibrium ( p > 0.00001), population-specific allele frequency (two of three δ values >0.5), according to linkage disequilibrium ( r < 0.2), and capable of being multiplexed in one tube and detected by capillary electrophoresis. The 27-SNP panel was first validated by assigning the ancestry of the 11 populations in the HapMap project. Then, we tested the 27-plex SNP assay with 1164 individuals from 17 additional populations. The results demonstrated that the SNP panel was successful for ancestry inference of individuals with African, European, and East Asian ancestry. Furthermore, the system performed well when inferring the admixture of Eurasians (EUR/EAS) after analyzing admixed populations from Xinjiang (Central Asian) as follows: Tajik (68:27), Uyghur (49:46), Kirgiz (40:57), and Kazak (36:60). For individual analyses, we interpreted each sample with a three-ancestry component percentage and a population match probability sequence. This multiplex assay is a convenient and cost-effective tool to assist in criminal investigations, as well as to correct for the effects of population stratification for case-control studies. [ABSTRACT FROM AUTHOR]

Debris flows are among the most common geological disasters in China, and have been particularly frequent in Sichuan Province since the Wenchuan earthquake on 12 May 2008. The construction of debris flow drainage channels is a countermeasure used to distribute debris flow fans, and these channels play a critical role in the mitigation and prevention of damage resulting from debris flows. Under field conditions, the useful life of drainage channels can be greatly shortened as a result of strong abrasions to the drainage structure caused by the debris flow. Field investigations have shown that the types of damage to drainage channels include (a) erosion caused by hyper-concentrated silt flow, (b) impact fractures and foundation scour at the groundsills of the drainage channel, (c) destruction of the drainage channel outlet, and (d) destruction of the drainage channel caused by debris flow abrasion. In addition, based on the destruction of the drainage channel during the debris flow drainage process, a new type of drainage channel with energy dissipation components was proposed and applied in a steep, narrow gully for debris flow mitigation. Moreover, design and engineering repair recommendations for drainage channels are provided as a reference for repairing the damage to the channel. The results can provide an important reference for the effective repair and optimal design of drainage channels. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Prediction for pathological and immunohistochemical characteristics of triple‑negative invasive breast carcinomas" which appeared in the 14 September 2021 issue.

The characteristics of a new type of drainage channel with staggered indented sills for controlling debris flows were studied. The intermediate fluid in the non-viscous debris flow exhibited a helical movement, whereas the fluid near the sidewall had a stop-start movement pattern; the viscous debris flow exhibited a stable structure between the indented sills. The experimental results indicate that the mean velocity of the debris flow increased with increasing channel gradients, and the debris flow velocity was slightly affected by the angle of the sills. The average velocity of the non-viscous debris flow increased in the range of (0.5-1.5) interval between the indented sills, whereas the average velocity of the viscous debris flow increased initially and then decreased in the range of (0.75-1.25) interval between the indented sills. The depth of the non-viscous debris flow tended to gradually increase as the channel gradients increased, whereas the depth of the viscous debris flow gradually decreased as the channel gradients increased. When the discharge of the debris flow was constant, the angle and the interval between the indented sills had a slight effect on the depth of the viscous debris flow, whereas the depth of the non-viscous debris flow exhibited a different trend, as the sill angles and intervals were varied. [ABSTRACT FROM AUTHOR]

TiO 2 was prepared by a hydrothermal method. It was chemically combined with carboxymethyl cellulose prepared from biodegradable ramie fiber to obtain the TiO 2/ramie fiber composite. The TiO 2/ramie fiber composites were characterized by an X-ray diffractometer, an environmental scanning electron microscope, and a Fourier-transform infrared spectra. The results indicate that TiO 2 is chemically combined with ramie fiber, and it can be reused more than five times without obvious TiO 2 loss. The photocatalytic performances of TiO 2 and TiO 2/ramie fiber composite used to degrade both a methyl orange (MO) anionic dye and a rhodamine B (RB) cationic dye solution indicate that the photocatalytic activities of TiO 2 for the degradation of the above described solutions are greatly improved when the TiO 2 is dispersed on ramie fiber. When 0.5 g of the TiO 2/ramie fiber composite is added to a dye solution for 3 h, the degradation rates for the initial concentrations (20 mg/L of MO and 12 mg/L of RB) are greater than 90 %. The photocatalytic degradation of MO can be described as a zeroth order reaction. [ABSTRACT FROM AUTHOR]

Measurements of turbulent flow fields in a stilling basin of multi-horizontal submerged jets were made with the singlecamera Particle Image Velocimetry (PIV). The particle images were captured, processed, and subsequently used to characterize the flow in terms of the 2-D velocity and vorticity distributions. This study shows that the maximum close-to-bed velocity in the stilling basin is approximately reduced by 60%, comparing to the jet velocity at the outlet of orifices. The jet velocity is distributed evenly at the latter half of the stilling basin and the time-averaged velocity of the cross section is reduced by 77%-85%, comparing to the jet velocity at the outlet of orifices. These results show that the vortices with horizontal axes are continuously repeated during the form-merge-split-disappear process. The vertical vortices are continuously formed and disappeared, they appear randomly near the slab and intermittently reach the slab of the stilling basin. The range of these vortices is small. Vortices with horizontal axes and vertical vortices do not coincide in space and the vortices with horizontal axes only affect the position of the tail of the vertical vortices attached to the slab of the stilling basin. [ABSTRACT FROM AUTHOR]

For sudden expansion pipes, experiments were carried out to study the cavitation inception for various enlargement ratios in high speed flows. The flow velocity of the prototype reaches 50 m/s in laboratory. The relationship between the expansion ratio and the incipient cavitation number is obtained. The scale and velocity effects are revealed. It is shown that Keller’s revised formula should be modified to calculate the incipient cavitation number when the forecasted velocity of the flows in the prototype exceeds the experimental velocity. [ABSTRACT FROM AUTHOR]

Air entrainment is known to be one of efficient and inexpensive methods to prevent cavitation damages in hydropower projects. The shape of sudden expansion-fall is used as a common device for mitigating cavitation erosions. The complex flow patterns with cavitation are numerically simulated by using the realizable k - ε turbulence model and the air-water mixture model. The calculated results are compared well with the experimental results as well as those obtained with the k - ε turbulence model with the Volume Of Fluid (VOF) Model. The calculated results agree well with the experimental data for the aeration cavity and wall pressure. Moreover, the air concentration near sidewall is simulated by a mixture model. It is found that the mixture turbulence model is superior to the VOF turbulence model. [ABSTRACT FROM AUTHOR]

A series of experiments were carried out on multi-horizontal submerged jets with four different model scales of 1:36, 1:57, 1:80, 1:200. In routine tests, scale effects have to be considered, due to complex vortex structure and strong air entrainment in stilling basin. Our focus was laid on measuring and analyzing the time-averaged pressure distribution, water depth and closed-to-bed velocity in the stilling basin of multi-horizontal submerged jets. The experiments results show that the model scale has but a slight effect on the time-averaged hydraulic characteristics in the stilling basin of multi-horizontal submerged jets, which indicates that the results of time-averaged hydraulic characteristics for a normal pressure model are reliable. However, the scale effects of air entrainment, fluctuation pressure and vortex structure call for further investigations in order to make the results of experiments serve as scientific references for practical engineering. [ABSTRACT FROM AUTHOR]

3-D numerical simulation was carried out for the water flow in a stilling basin with multi-horizontal submerged jets by using two different turbulence models, namely, the VOF RNG k-ε and Mixture RNG k-ε turbulence models. The calculated water depth, velocity profile and pressure distribution are in good agreement with the data obtained in experiments. It indicates that the numerical simulation can effectively be used to study the water flow movement and the energy dissipation mechanism. The numerical simulation results show that the turbulent kinetic energy distribution obtained by using the Mixture turbulence model covers a region about 18% larger than that calculated by using the VOF turbulence model, and is in better agreement with the actual situation. Furthermore, the Mixture turbulence model is better than the VOF turbulence model in calculating the air entrainment. [ABSTRACT FROM AUTHOR]

The Kazak ethnic minority is a large ethnic group in the Xinjiang Uygur Autonomous Region of China and is valuable resource for the study of ethnogeny. In the present study, 24 Y-chromosomal short tandem repeat (Y-STR) loci were analyzed in 201 unrelated Kazak male individuals from Ili Kazak Autonomous Prefecture, Xinjiang, China. The gene diversity of the 24 Y-STR loci in the studied Kazak group ranged from 0.0050 to 0.9104. According to haplotypic analysis of the 24 Y-STR loci, 113 different haplotypes were obtained, 96 of which were unique. The haplotype diversity and discrimination capacity in Kazak group were 0.9578 and 0.5622 at 24 STR loci, respectively. The haplotype diversity and discrimination capacity at Y-filer 17 loci, extended 11 loci, and minimal 9 loci were reduced to 0.9274 and 0.4279, 0.8459 and 0.3284, and 0.8354 and 0.2985, respectively, which could indicate that the more loci were detected, the higher forensic efficacy was obtained. We evaluated the application value of the 24 loci in forensic sciences and analyzed interpopulation differentiations by making comparisons between the Kazak1 (represent our samples from Ili Kazak Autonomous Prefecture) group and other 14 groups. The results of pairwise genetic distances, multidimensional scaling plot, and neighbor-joining tree at the same set of 17 Y-filer loci indicated that the Kazak1 group had the closer genetic relationships with Kazak2 (represent samples from the whole territory of Xinjiang Uygur Autonomous Region), Mongolian, and Uygur ethnic groups. The present results may provide useful information for paternal lineages in forensic cases and can also increase our understanding of the genetic relationships between Kazak1 and other groups. [ABSTRACT FROM AUTHOR]

A Co/ZrO /SiO catalyst active for synthesis of heavy hydrocarbons from syngas was subjected to a stability test of 500 h on a laboratory scale. The catalyst showed a considerable decrease in CO conversion, while the hydrocarbon distribution hardly changed with time on stream. The regeneration of deactivated catalyst with H at 673 K partially restored the activity. XRD, FT-IR and TGA identified a hydrated cobalt silicate species in the catalyst near the reactor outlet. Thus, the cause of deactivation was proposed mainly to be the formation of inactive hydrated silicate between Co metal and silica in presence of high partial pressure of water. [ABSTRACT FROM AUTHOR]

The article discusses the organocatalytic asymmetric domino reaction between 2-sulfanylbenzaldehyde and 3-phenylprop-2-enal in the presence of L-proline as catalyst. The investigation of the effect of pressure on the domino reaction in supercritical carbon dioxide (scCO2) is outlined. The enantioselectivity as determined not only by the pressure but also by the temperature is also cited.