28 research outputs found
Reliability of base-isolated structures with sliding hydromagnetic bearings considering stochastic ground motions
Stochastic seismic response analysis and reliability assessment of a base-isolated structure with sliding hydro-magnetic bearings are performed combining the probability density evolution method and the stochastic func-tion model of seismic ground motions. The reliability assessments are based on the extreme value distribution of the inter-story drifts of the base-isolated structure. Compared with the responses of the base-fixed struc-ture, the superstructure of the base-isolated structure almost behaves like a rigid body. The sliding hydromag-netic bearing is efficient in reducing the responses by one degree of seismic intensity. Finally, the dynamic re-liability of the base-isolated structure is evaluated, which provides an index for decision making in practice
IOS Enabled Business Process Transformation: A Case Study in China
Abstract. Taking China's two successful IOSs as study subject, this paper investigated inter-firm business process transformation enabled by IOS from four aspects, namely, integration, transfer, elimination and creation of inter-firm business processes. This study argues that IOS must be seen as the enabler of organizational structure and business process changes rather than a mere implementation tool for existing organizations and processes inside enterprises and between enterprises. Enterprises should focus on their core capability, collaborate with each other with IOS and actively achieve inter-firm business process integration and innovation
Visualizing the Zhang-Rice singlet, molecular orbitals and pair formation in cuprate
The parent compound of cuprates is a charge-transfer-type Mott insulator with
strong hybridization between the Cu and O orbitals.
A key question concerning the pairing mechanism is the behavior of doped holes
in the antiferromagnetic (AF) Mott insulator background, which is a
prototypical quantum many-body problem. It was proposed that doped hole on the
O site tends to form a singlet, known as Zhang-Rice singlet (ZRS), with the
unpaired Cu spin. But experimentally little is known about the properties of a
single hole and the interplay between them that leads to superconductivity.
Here we use scanning tunneling microscopy to visualize the electronic states in
hole-doped , aiming to establish the atomic-scale local
basis for pair formation. A single doped hole is shown to have an in-gap state
and a clover-shaped spatial distribution that can be attributed to a localized
ZRS. When the dopants are close enough, they develop delocalized molecular
orbitals with characteristic stripe- and ladder-shaped patterns, accompanied by
the opening of a small gap around the Fermi level (). With
increasing doping, the molecular orbitals proliferate in space and gradually
form densely packed plaquettes, but the stripe and ladder patterns remain
nearly the same. The low-energy electronic states of the molecular orbitals are
intimately related to the local pairing properties, thus play a vitally
important role in the emergence of superconductivity. We propose that the
Cooper pair is formed by two holes occupying the stripe-like molecular orbital,
while the attractive interaction is mediated by the AF spin background
A 13-Gene Metabolic Prognostic Signature Is Associated With Clinical and Immune Features in Stomach Adenocarcinoma
Patients with advanced stomach adenocarcinoma (STAD) commonly show high mortality and poor prognosis. Increasing evidence has suggested that basic metabolic changes may promote the growth and aggressiveness of STAD; therefore, identification of metabolic prognostic signatures in STAD would be meaningful. An integrative analysis was performed with 407 samples from The Cancer Genome Atlas (TCGA) and 433 samples from Gene Expression Omnibus (GEO) to develop a metabolic prognostic signature associated with clinical and immune features in STAD using Cox regression analysis and least absolute shrinkage and selection operator (LASSO). The different proportions of immune cells and differentially expressed immune-related genes (DEIRGs) between high- and low-risk score groups based on the metabolic prognostic signature were evaluated to describe the association of cancer metabolism and immune response in STAD. A total of 883 metabolism-related genes in both TCGA and GEO databases were analyzed to obtain 184 differentially expressed metabolism-related genes (DEMRGs) between tumor and normal tissues. A 13-gene metabolic signature (GSTA2, POLD3, GLA, GGT5, DCK, CKMT2, ASAH1, OPLAH, ME1, ACYP1, NNMT, POLR1A, and RDH12) was constructed for prognostic prediction of STAD. Sixteen survival-related DEMRGs were significantly related to the overall survival of STAD and the immune landscape in the tumor microenvironment. Univariate and multiple Cox regression analyses and the nomogram proved that a metabolism-based prognostic risk score (MPRS) could be an independent risk factor. More importantly, the results were mutually verified using TCGA and GEO data. This study provided a metabolism-related gene signature for prognostic prediction of STAD and explored the association between metabolism and the immune microenvironment for future research, thereby furthering the understanding of the crosstalk between different molecular mechanisms in human STAD. Some prognosis-related metabolic pathways have been revealed, and the survival of STAD patients could be predicted by a risk model based on these pathways, which could serve as prognostic markers in clinical practice
Influences on Antislide Piles Used for Slope Reinforcement: Numerical Simulation Based on the Soil Arching Effect
This study explores the pile-soil interaction mechanism and the optimal use of antislide piles for slope reinforcement based on finite difference numerical modelling. The force and displacement principles of slopes and antislide piles are analysed. The influences of various factors are investigated, such as postpile filling parameters, pile embedding methods, and pile cross-sectional shapes. Numerical modelling is used to determine the optimal layouts of antislide piles for push and traction landslides. The findings indicate that the cohesive force of the fill has a greater influence on the piles and slope than the friction angle and is the primary control factor. Fully buried antislide piles provide a better antisliding effect than semiburied ones. With fully buried piles, the best controlling effect is obtained when the ratio of the length of the pile’s free section to the height of the sliding body is approximately 4/5. Moreover, stepped-cross-section piles provide better slope reinforcement than those with rectangular, T-shaped, or trapezoidal cross-sections. In practical applications, end-bearing arches can be utilized as the primary control structures, with friction arches used for secondary control to improve the soil arching effect as much as possible, thereby enhancing the stability of the piles and slope. To control landslides of various thrust forms, antislide piles should be set in the active section, the core sliding section, or both, as required. This paper provides guidance for improving the design of antislide piles
Mesostructural Modeling of Dynamic Modulus and Phase Angle Master Curves of Rubber Modified Asphalt Mixture
The main objective of this paper was to develop a mesostructure-based finite element model of rubber modified asphalt mixture to predict both the dynamic modulus master curve and phase angle master curve under a large frequency range. The asphalt mixture is considered as a three-phase material consisting of aggregate, asphalt mortar, and air void. The mesostructure of the asphalt mixture was digitized by a computed tomography (CT) scan and implemented into finite element software. The 2S2P1D model was used to obtain the viscoelastic information of an asphalt mortar under a large range of frequencies and temperatures. The continuous spectrum of the 2S2P1D model was converted to a discrete spectrum and characterized by the generalized Maxwell model for numerical simulation. The Prony series parameters of the generalized Maxwell model and the elastic modulus of the aggregates were inputted into the finite element analysis as material properties. The dynamic modulus tests of a rubber modified asphalt mortar and asphalt mixture were conducted under different temperatures and loading frequencies. The dynamic modulus master curve and phase angle master curve of both asphalt mortar and asphalt mixture were constructed. The frequency of the finite element simulations of the dynamic modulus tests ranged from 10−6 to 104. The dynamic modulus and phase angle of the asphalt mixture was calculated and the master curves were compared with the master curves obtained from the experimental data. Furthermore, the effect of the elastic modulus of aggregates on the master curves was analyzed. Acceptable agreement between dynamic modulus master curves obtained from experimental data and simulation results was achieved. However, large errors between phase angle master curves appeared at low frequencies. A method was proposed to improve the prediction of the phase angle master curve by adjusting the equilibrium modulus of the asphalt mortar
Modified approximate proximal point algorithms for finding roots of maximal monotone operators
Short-term survival and safety of apatinib combined with oxaliplatin and S-1 in the conversion therapy of unresectable gastric cancer
Abstract Background We conducted a single-arm phase II trial to investigate the short-term efficacy and safety of apatinib combined with oxaliplatin and S-1 in the treatment of unresectable gastric cancer. Patients and methods Previously untreated patients with unresectable HER-2-negative advanced gastric cancer were selected. All the patients received six cycles of S-1 and oxaliplatin and five cycles of apatinib, which were administered at intervals of three weeks. The surgery was performed after six cycles of drug treatment. The primary endpoints were radical resection (R0) rate and safety. This study was registered with the China Trial Register, number ChiCTR-ONC-17010430 (01/12/2016–01/12/2022). Results A total of 39 patients were enrolled. Efficacy evaluation was feasible for 37 patients. One patient achieved complete response (CR, 2.7%), 26 patients achieved partial response (PR, 70.3%), three patients had stable disease (SD, 8.1%) and seven patients had progressive disease (PD, 18.9%). The objective response rate (ORR) was 73.0% and the disease control rate (DCR) was 81.1%. 22 patients underwent surgery, among which 14 patients underwent radical resection (R0), with a R0 resection rate of 63.6%. The 1-year survival rate of the surgical group (22 patients) was 71.1% and the 2-year survival rate was 41.1%. The median survival time was 21 months. The incidence of adverse events (AEs) was 100%. Leucopenia (65.3%) and granulocytopenia (69.2%) were the most common hematological AEs. The most common non-hematological AEs were fatigue (51.3%) and oral mucositis (35.9%). Conclusion Apatinib combined with oxaliplatin and S-1 showed good short-term survival and acceptable safety in the conversion therapy of unresectable gastric cancer
Assessment of Modulus Attenuation of Cement and Lime-Fly Ash Semi-Rigid Road Base Materials
For asphalt pavement structures, semi-rigid road base course has to sustain repeated high-axle load during its service life and the performance of semi-rigid road base materials directly influences the durability of pavement structures. The dynamic compressive resilience modulus of two commonly used semi-rigid road base materials, cement stabilized aggregates (CSG) and lime-fly ash stabilized aggregates (LFSG) were evaluated at different frequencies using a Universal Testing Machine (UTM). The results showed that LFSG had higher dynamic modulus than that of CSG and the load frequency had less influence on the dynamic modulus of these two semi-rigid road base materials. The four-point bending test was applied to measure the flexural-bending strength and the fatigue life of these two semi-rigid materials. A higher flexural-bending strength of LFSG indicated its better bearing capacity than that of CSG. The fatigue life of LFSG and CSG decreased with the increase of stress–strength ratio and the LFSG performed better in terms of fatigue resistance. The fatigue damage models of CSG and LFSG based on Stress-Life (S-N) curve are established. As per incremental-recursive mechanics, a general modulus degradation model was established and verified by the results of full-scale accelerate loading test. This model cannot only be used to predict the fatigue deterioration of semi-rigid road base materials under different stress levels, but is also able to calculate the current bending elastic modulus based on its initial modulus value