Finite element analysis of steep excavation slope failure by CFS theory

The distribution of Coulomb failure stress （CFS） change in the steep excavation slope is calculated by finite element method in this paper, and the failure mechanics under different conditions have been investigated. Comparing the CFSs before and after the slope excavation （stress loading and unloading processes）, the dangerous internal zone and the most likely failure external area are attained. Given the shear cracks on the top surface while tensile stress or cracks along the toe of the slope, we analyze the high cutting-angle steep slope in Kaixian county of the Three Gorges Reservoir region. We bring forward that the peak value of CFS after excavation can reach to the order of 0.1 MPa, which is greatly higher than that of before. Our preliminary results are useful for optimizing the reinforcement structure during the steep slope stabilization engineering.

Preprocessing photospheric vector magnetograms for nonlinear force-free field extrapolation of the global corona

Nonlinear force-free magnetic field （NLFFF） extrapolation based on the observed photo- spheric magnetic field is the most important method to obtain the coronal magnetic field nowadays. However, raw photospheric magnetograms contain magnetic forces and small-scale noises, and fail to be consistent with the force-free assumption of NLFFF models. The procedure for removing the forces and noises in observed data is called preprocessing. In this paper, we extend the preprocessing code of Jiang ＆ Feng to spherical coordinates for a full sphere. We first smooth the observed data with Gaussian smoothing, and then split the smoothed magnetic field into a potential field and a non-potential field. The potential part is computed by a numerical potential field model, and the non-potential part is prepro- cessed using an optimization method to minimize the magnetic forces and magnetic torques. Applying the code to synoptic charts of the vector magnetic field from SDO/HMI, we find it can effectively reduce the noises and forces, and improve the quality of data for a better input which will be used for NLFFF extrapolations applied to the global corona.

On numerical earthquake prediction

Can earthquakes be predicted？ How should people overcome the difficulties encountered in the study of earthquake prediction？ This issue can take inspiration from the experiences of weather forecast. Although weather forecasting took a period of about half a century to advance from empirical to numerical forecast, it has achieved significant success. A consensus has been reached among the Chinese seismological community that earth- quake prediction must also develop from empirical fore- casting to physical prediction. However, it is seldom mentioned that physical prediction is characterized by quantitatively numerical predictions based on physical laws. This article discusses five key components for numerical earthquake prediction and their current status. We conclude that numerical earthquake prediction should now be put on the planning agenda and its roadmap designed, seismic stations should be deployed and observations made according to the needs of numerical prediction, and theoretical research should be carried out.

Active tectonics in Taiwan:insights from a 3-D viscous finite element model

Taiwan is a young orogenic belt with complex spatial distributions of deformation and earthquakes. We have constructed a three-dimensional finite element model to explore how the interplays between lithospheric struc- ture and plate boundary processes control the distribution of stress and strain rates in the Taiwan region. The model assumes a liberalized power-law rheology and incorporates main lithospheric structures; the model domain is loaded by the present-day crustal velocity applied at its bound- aries. The model successfully reproduces the main features of the GPS-measured strain rate patterns and the earth- quake-indicated stress states in the Taiwan region. The best fitting model requires the viscosity of the lower crust to be two orders of magnitude lower than that of the upper crust and lithospheric mantle. The calculated deviatoric stress is high in regions of thrust faulting and low in regions of extensional and strike-slip faulting, consistent with the spatial pattern of seismic intensity in Taiwan.

Establishment of Integrated Diagnosis and Treatment and Whole-Course Management Model of Major Depressive Disorder

Integrated diagnosis,treatment and whole-course management model of major depressive disorder(MDD)is an integrated drug-psychological-physical comprehensive treatment model based on rapid biological-psychological-social evaluation for treating patients with major depressive disorder.This paper comprehensively evaluates the clinical efficacy and biochemical indexes of patients,and carries out symptom evaluation,problem classification,disease diagnosis and etiological analysis of visitors from the three dimensions about physiology,psychology and society.Then,according to the symptoms and causes of different dimensions,this paper formulates personalized drug,psychological and physical therapy programs,and constantly optimizes and adjusts the treatment plan in the treatment process,so as to cure both the symptoms and the root causes,providing a reliable strategy for the treatment of clinical MDD,and establishing a standardized characteristic model for further promotion and application of this technology.At present,the project has been used in the member units of Taihe Medical Group and Shiyan City and its surrounding areas,the market response is good,and will be gradually promoted to the whole country in the later stage.

Hepatocyte apoptosis fragment product cytokeratin-18 M30 level and non-alcoholic steatohepatitis risk diagnosis:an international registry study

Background:Liver biopsy for the diagnosis of non-alcoholic steatohepatitis(NASH)is limited by its inherent invasiveness and possible sampling errors.Some studies have shown that cytokeratin-18(CK-18)concentrations may be useful in diagnosing NASH,but results across studies have been inconsistent.We aimed to identify the utility of CK-18 M30 concentrations as an alternative to liver biopsy for non-invasive identification of NASH.Methods:Individual data were collected from 14 registry centers on patients with biopsy-proven non-alcoholic fatty liver disease(NAFLD),and in all patients,circulating CK-18 M30 levels were measured.Individuals with a NAFLD activity score(NAS)≥5 with a score of≥1 for each of steatosis,ballooning,and lobular inflammation were diagnosed as having definite NASH;individuals with a NAS≤2 and no fibrosis were diagnosed as having non-alcoholic fatty liver(NAFL).Results:A total of 2571 participants were screened,and 1008(153 with NAFL and 855 with NASH)were finally enrolled.Median CK-18 M30 levels were higher in patients with NASH than in those with NAFL(mean difference 177 U/L;standardized mean difference[SMD]:0.87[0.69–1.04]).There was an interaction between CK-18 M30 levels and serum alanine aminotransferase,body mass index(BMI),and hypertension(P<0.001,P=0.026 and P=0.049,respectively).CK-18 M30 levels were positively associated with histological NAS in most centers.The area under the receiver operating characteristics(AUROC)for NASH was 0.750(95%confidence intervals:0.714–0.787),and CK-18 M30 at Youden’s index maximum was 275.7 U/L.Both sensitivity(55%[52%–59%])and positive predictive value(59%)were not ideal.Conclusion:This large multicenter registry study shows that CK-18 M30 measurement in isolation is of limited value for non-invasively diagnosing NASH.

Numerical simulation of landslide-generated tsunamis in lakes:A case study of the Xiluodu Reservoir

China has planned and built several world-class cascade high dams in Jinsha River,Dadu River,Lancang River,and Yarlung Zangbo River.The complex geological conditions in the reservoir area and numerous large-scale landslide bodies make the potential disaster risk of overflowing and cascade dam failure caused by landslide-generated tsunami under increasing severe situations.However,the study on describing and predicting the complex dynamic processes of generation,propagation,overflowing,wave setup,and the interaction between tsunami and lakeshore has not been systematically carried out.Based on the high-order Boussinesq-type equations,the development of the dynamic system of tsunamis in lakes coupled with the landslide process is realized using the finite volume method in this paper.To verify the accuracy and reliability of the study,the Xiluodu Reservoir is selected as the object to simulate the potential landslide-generated tsunamis.The factors such as the generation and propagation of tsunamis,dam overflowing,and wave setup in the downstream river are quantitatively evaluated and analyzed.The constructed landslide with a total volume of 24×10^(6)m^(3)generates a near-field wave amplitude of about 28 m.The maximum wave run-up height is about 95 m,the volume of the dam overflowing water up to 2.13×10^(6)m^(3),and the maximum wave height above the dam crest presents an M-shaped distribution.This LGWs event raises the downstream water level by nearly 40 m.The results show that the risk of landslide-generated tsunamis in the reservoir area in China cannot be ignored.The developed Boussinesq-type equations coupled with the landslide dynamics can simulate the whole process of generation,propagation,runup,and estimating the overflowing water volume of the tsunamis in the lake,laying a foundation for the quantitative risk assessment of tsunamis in lakes of high cascade dams in China.

Numerical simulation of tectonic stress and strain rate fields in the northeastern margin of the Tibetan Plateau in association with major fault zones

A series of large strike-slip and thrust faults have developed in the northeastern margin of the Tibetan Plateau since the Late Cenozoic,with strong and active tectonic activity and frequent occurrences of large earthquakes.Modulation of regional tectonic stress distribution,strain fields,and seismic hazards has not been well studied.This study introduces a three-dimensional viscoelastic finite element numerical model to calculate crustal stress and strain rate fields under current tectonic loading.The preliminary results show that the direction of the horizontal principal compressive stress rate and compressive horizontal principal strain rate in the northeastern margin of the Tibetan Plateau rotate clockwise as a whole,and this rotation is more significant in the southeast direction because of the block of the Alxa and the Ordos blocks.The NE-SW horizontal principal compressive stress rate and SE horizontal tensile stress rate dominate the entire study region.The maximum value of the horizontal principal compressive strain rate at a depth of 0 km in the model is approximately 4×10^(-8)yr^(-1)near the East Kunlun fault and is smaller in the stable Alxa and Ordos blocks at approximately 1×10^(-8)yr^(-1).The calculated regional stress state is in good agreement with the actual focal mechanism solution,indicating that strike-slip and thrust stress fields dominate the northeastern margin of the Tibetan Plateau.The Altyn Tagh,East Kunlun,and Haiyuan faults demonstrate that the maximum shear strain rate gradually decreases eastward,and the decrease in the maximum shear strain rate value is absorbed by orogenic uplift and crustal shortening at its boundaries.The western section of the Altyn Tagh fault,west-to-middle sections of the East Kunlun fault,and west-to-middle sections of the Haiyuan fault will have high seismic hazards in the future.

Element migration and phase distribution characteristics during crystallization of rare earth phase in rare earth slag

The crystallization experiment of molten rare earth(RE)slag under different cooling rates was carried out.The characteristics of element migration and phase distribution during RE phase crystallization were studied by using different equipment.The experimental results show that there are two RE phases in the RE slag,namely(Ca,Ce,La)_(5)(SiO_(4))6F and(Ca,Ce,La,Mg)_(3)(Ti,Al,Nb)_(2)O_(7).During the cooling crystallization process of molten RE slag,Ca and P elements in the RE phase of(Ca,Ce,La)_(5)(SiO_(4))_(6)F migrate from inside to outside,and finally gather at the outer edge of the phase to form phase Ca_(3)(PO4)2.The RE phase(Ca,Ce,La)_(5)(SiO_(4))_(6)F is distributed inside the furnace-cooled slag,and the RE phase(Ca,Ce,-La,Mg)_(3)(Ti,AI,Nb)_(2)O_(7)is distributed in the surface layer of the furnace-cooled slag.And based on the phase distribution characteristics,the central hollowing method is proposed to realize the preliminary enrichment of valuable elements Ti,Nb and RE in RE slag.

Magnetic skyrmions:materials,manipulation,detection,and applications in spintronic devices

Magnetic skyrmions are vortex-like spin configurations that possess nanometric dimensions,topological stability,and high controllability through various external stimuli.Since their first experimental observation in helimagnet MnSi in 2009,magnetic skyrmions have emerged as a highly promising candidate for carrying information in future high-performance,low-energy-consumption,non-volatile information storage,and logical calculation.In this article,we provide a comprehensive review of the progress made in the field of magnetic skyrmions,specifically in materials,manipulation,detection,and application in spintronic devices.Firstly,we introduce several representative skyrmion material systems,including chiral magnets,magnetic thin films,centrosymmetric materials,and Van der Waals materials.We then discuss various methods for manipulating magnetic skyrmions,such as electric current and electric field,as well as detecting them,mainly through electrical means such as the magnetoresistance effect.Furthermore,we explore device applications based on magnetic skyrmions,such as track memory,logic computing,and neuromorphic devices.Finally,we summarize the challenges faced in skyrmion research and provide future perspectives.

Higher consumption of animal organ meat is associated with a lower prevalence of nonalcoholic steatohepatitis

Background:Animal organ meat(offal)is a food with high nutrient density that is popular in different parts of the world,but its relationship with nonalcoholic steatohepatitis(NASH)is unclear.We aimed to examine whether daily animal organ meat consumption is associated with the presence of NASH in individuals with nonalcoholic fatty liver disease(NAFLD).Methods:A total of 136 Chinese adults with biopsy-proven NAFLD were included.Definite NASH was defined as NAFLD activity score≥4 and at least one point for steatosis,ballooning,and lobular inflammation.Daily animal organ meat consumption was estimated using a self-administered validated food frequency questionnaire.Logistic regression analysis was performed to assess the association between animal organ meat intake and liver disease severity.Results:The 136 participants(80.9%men)of the study had a mean±standard deviation(SD)age of 39.0±12.5 years and body mass index of 27.4±3.6 kg/m2.Prevalence of definite NASH was 65.4%.Daily median organ meat consumption was 1.30 g/1,000 kcal.Animal organ meat consumption was inversely associated with the presence of NASH even after adjustment of demographics,lifestyle variables,metabolic and dietary factors,as well as liver fibrosis stage;adjusted-odds ratios(95%confidence intervals)for NASH were 0.15(0.03,0.69)for the highest tertile and 0.18(0.05,0.70)for the medium tertile,compared to the lowest(reference)tertile of animal organ meat intake(P value for trend=0.024).Conclusions:Our results suggest for the first time that higher animal organ meat consumption is associated with a lower prevalence of NASH in Chinese individuals with biopsy-proven NAFLD.

Seismic and geological evidence of hidden faults in the Yinpan Reservoir area based on a dense seismic array

1.Introduction.On November 23,2017,an M_(S)5.0 earthquake occurred in Wulong,Chongqing,China,resulting in tens of casualties and considerable economic loss.Geologically,the epicenter of this earthquake was located in the transition zone from the Central Chongqing Fold Belt to the southeast,characterized by a low tectonic loading rate.

对我国月球科研站开展特定固体月球动力学研究的一些思考

我国在月球探测空间技术方面近年来取得了里程碑性的突破,在科学研究方面也将开展国际月球科研站的研究和部署,此时确定一些既有重大科学意义、又在我国目前研究基础上具备可行性,能够培养队伍、取得突出成果的关键科学问题十分重要。本文仅对我国拟建设的国际科研站在固体月球动力学研究方面的一些关键科学问题提出一些设想。在几年时间内,建议开展月球现今热状态的国家自然科学基金重大项目类研究,通过它培养科研队伍,在地球物理、大地测量、地球化学、矿物学、高温高压实验、地球动力学等学科交叉和集成研究中取得突出进展;在十几年时间内,可以进行月震学的研究和部署,如果能在月震台站布设技术方面做出原始创新,则能在月球内部结构、组成和状态的研究中取得里程碑性的进展;最后,在几十年的时间内,开展熔岩管洞穴科研站的先导性研究,为在月球上建立长期有人科研站奠定基础。期待国家自然科学基金委员会发挥顶层设计和队伍组织作用,建立多学科融合平台,助力实现我国月球科学研究跨越式发展。

Coupled Models and Parallel Simulations for Three-Dimensional Full-Stokes Ice Sheet Modeling

A three-dimensional full-Stokes computational model is considered for determining the dynamics,temperature,and thickness of ice sheets.The governing thermomechanical equations consist of the three-dimensional full-Stokes system with nonlinear rheology for the momentum,an advective-diffusion energy equation for temperature evolution,and a mass conservation equation for ice-thickness changes.Here,we discuss the variable resolution meshes,the finite element discretizations,and the parallel algorithms employed by the model components.The solvers are integrated through a well-designed coupler for the exchange of parametric data between components.The discretization utilizes high-quality,variable-resolution centroidal Voronoi Delaunay triangulation meshing and existing parallel solvers.We demonstrate the gridding technology,discretization schemes,and the efficiency and scalability of the parallel solvers through computational experiments using both simplified geometries arising from benchmark test problems and a realistic Greenland ice sheet geometry.

Metabolic Dysfunction-associated Fatty Liver Disease is Associated with Greater Impairment of Lung Function than Nonalcoholic Fatty Liver Disease

Background and Aims:We compared lung function parameters in nonalcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease(MAFLD),and examined the association between lung function parameters and fibrosis severity in MAFLD.Methods:In this cross-sectional study,we randomly recruited 2,543 middle-aged individuals from 25 communities across four cities in China during 2016 and 2020.All participants received a health check-up including measurement of anthropometric parameters,biochemical variables,liver ultrasonography,and spirometry.The severity of liver disease was assessed by the fibrosis(FIB)-4 score.Results:The prevalence of MAFLD was 20.4%(n=519)and that of NAFLD was 18.4%(n=469).After adjusting for age,sex,adiposity measures,smoking status,and significant alco-hol intake,subjects with MAFLD had a significantly lower predicted forced vital capacity(FVC,88.27±17.60%vs.90.82±16.85%,p<0.05)and lower 1 s forced expiratory volume(FEV1,79.89±17.34 vs.83.02±16.66%,p<0.05)than those with NAFLD.MAFLD with an increased FIB-4 score was significantly associated with decreased lung function.For each 1-point increase in FIB-4,FVC was diminished by 0.507(95%CI:-0.840,-0.173,p=0.003),and FEV1 was diminished by 0.439(95%CI:-0.739,-0.140,p=0.004).The results remained unchanged when the statistical analyses was performed separately for men and women.Conclusions:MAFLD was significantly asso-ciated with a greater impairment of lung function param-eters than NAFLD.

Accelerating the HS-type Richardson Iteration Method with Anderson Mixing

The Accelerated Hermitian/skew-Hermitian type Richardson(AHSR)iteration methods are presented for solving non-Hermitian positive definite linear systems with three schemes,by using Anderson mixing.The upper bounds of spectral radii of iteration matrices are studied,and then the convergence theories of the AHSR iteration methods are established.Furthermore,the optimal iteration parameters are provided,which can be computed exactly.In addition,the application to the model convection-diffusion equation is depicted and numerical experiments are conducted to exhibit the effectiveness and confirm the theoretical analysis of the AHSR iteration methods.

Finite element simulation of deformation and stress changes of Kalpin-Kemin fault system in the Southwest Tianshan Orogenic Belt

Under the shadow of the far-field effect of the India-Eurasia collision,the Tianshan orogenic belt underwent tectonic re-activation in the Cenozoic,accompanied by strong tectonic deformation and frequent large earthquakes.Bounded by two rigid cratonic blocks located in its north and south,a series of marginal foreland fold-and-thrust belts are developed within the Tianshan orogenic belt and continue to develop to the bilateral pull-apart basins.Meanwhile,the faults in the orogenic belt are reactivated.The deformation caused by thrust-related structure accounts for larger than 50%of the total convergence of the Tianshan Mountains,which results in the most active structure with large earthquakes in the Tianshan area.Therefore,it is of great significance to study the dynamic process of the newly generated and reactivated thrust-nappe structures in Tianshan orogen via numerical modeling.This paper selects a classical cross-section profile in the western segment of the Southwest Tianshan Mountains,which contains the Kalpin-Maidan-Nalati-Kemin fault system from the south to the north.We attempt to establish a two-dimensional plane strain,viscoelastic finite element model,by treating the regional faults as a whole fault system and considering the topography,fault geometry,and GPS data.The displacement and stress fields of the model are retrieved,the short-term cumulative deformation field of the overall fault system is analyzed,and the rate of Coulomb failure stress change of each fault is also considered.The results show that the deformation is concentrated in the middle and southern parts of the Southwest Tianshan Mountains.In contrast,the deformation of the Kemin fault in the north is relatively small.According to the Coulomb failure stress changes of these four faults and the historical earthquake catalog,the potential seismicity of each fault is qualitatively analyzed.Our preliminary results suggest that the possibility of large earthquake occurrence is higher in the Kalpin fault,Maidan fault,and Nalati fault but lower in the Kemin fault in the near future。

Mildly elevated serum bilirubin is associated with a lower risk of hearing loss in Chinese adults

To the Editor:Hearing loss is the most common sensory deficit in humans,affecting daily communication and the overall quality of life.Oxidative stress plays a critical role in the development and progression of age-related hearing loss.Studies show that endogenous antioxidant deficiency or insufficient dietary antioxidant nutrient intake increased hearing loss risk,while antioxidant supplementation could prevent age-related hearing loss development.

Fiber-Shaped Triboiontronic Electrochemical Transistor

Contact electrification-activated triboelectric potential offers an efficient route to tuning the transport properties in semiconductor devices through electrolyte dielectrics,i.e.,triboiontronics.Organic electrochemical transistors(OECTs)make more effective use of ion injection in the electrolyte dielectrics by changing the doping state of the semiconductor channel.However,the mainstream flexible/wearable electronics and OECT-based devices are usually modulated by electrical signals and constructed in conventional geometry,which lack direct and efficient interaction between the external environment and functional electronic devices.Here,we demonstrate a fiber-shaped triboiontronic electrochemical transistor with good electrical performances,including a current on/off ratio as high as≈1286 with off-current at~nA level,the average threshold displacements(D_(th))of 0.3 mm,the subthreshold swing corresponding to displacement(SS_(D))at 1.6 mm/dec,and excellent flexibility and durability.The proposed triboiontronic electrochemical transistor has great potential to be used in flexible,functional,and smart self-powered electronic textile.