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In this paper, we study the mixed virtual element approximation to an elliptic optimal control problem with boundary observations. The objective functional of this type of optimal control problem contains the outward normal derivatives of the state variable on the boundary, which reduces the regularity of solutions to the optimal control problems. We construct the mixed virtual element discrete scheme and derive an a priori error estimate for the optimal control problem based on the variational discretization for the control variable. Numerical experiments are carried out on different meshes to support our theoretical findings. [ABSTRACT FROM AUTHOR]

Accurate prediction of the remaining useful life (RUL) of energy storage batteries plays a significant role in ensuring the safe and reliable operation of battery energy storage systems. This paper proposes an RUL prediction framework for energy storage batteries based on INGO-BiLSTM-TPA. First, the battery's indirect health index is extracted by combining principal component analysis and the Pearson correlation coefficient in the battery charge/discharge cycle data. Second, for the problem that the Northern Goshawk Optimization (NGO) algorithm is prone to falling into local optimum, the Gaussian variation mechanism and nonlinear hunting radius are introduced to improve the NGO algorithm, and the Improved Northern Goshawk Optimization (INGO) algorithm is proposed. Finally, the temporal pattern attention (TPA) mechanism is introduced in the bi-directional long short-term memory (BiLSTM), which makes the model weighted to focus on the features of important time steps, and the INGO algorithm is applied to it to build the RUL prediction framework. Based on the CALCE battery dataset, the root-mean-square error (RMSE) of RUL prediction based on the proposed framework is controlled within 1.3%, which provides better prediction accuracy and generalization. [ABSTRACT FROM AUTHOR]

Accurate cannulation of the adrenal vein is challenging during adrenal venous sampling (AVS) because of the variations in adrenal vein anatomy. This study aimed to investigate the adrenal venous morphology in Chinese and improve the success rate of AVS. A total of 221 participants with primary aldosteronism (PA) who underwent AVS were enrolled. Compare the morphology among subgroups divided according to sex, body mass index (BMI), and with or without adenoma. The success rate of right, left, and bilateral AVS was 98.60%, 97.20%, and 96.85%, respectively. The triangular pattern was the most common (39.37%) on the right side, while the glandlike pattern (70.14%) on the left. The proportion of adrenal venous morphology varies among patients with different sexes (χ2 = 21.335, P <.001), BMI (χ2 = 10.642 P =.031), and with or without adenoma (χ2 = 10.637, P =.031) on the right side, and the male, obese and adenoma group showed a higher proportion of glandlike pattern than triangular pattern. If only dependent on computed tomography, 9.05% of patients incorrectly diagnose the dominant side, 14.48% of patients would have inappropriate surgery meanwhile 25.34% of patients would miss the surgical opportunity. In conclusion, the most common types of right and left adrenal venous morphology were triangular pattern and glandlike pattern, respectively. Sex, BMI, and the presence of adenoma affected right adrenal venous morphology. Adequate knowledge of the adrenal venous morphology is critical for improving the success rate of AVS and making an appropriate treatment for PA. [ABSTRACT FROM AUTHOR]

Three new nitrides La3MN5 (M=Cr, Mn, and Mo) have been synthesized using a high pressure azide route. These are the first examples of ternary Cs3CoCl5‐type nitrides, and show that this (MN4)NLa3 antiperovskite structure type may be used to stabilise high oxidation‐state transition metals in tetrahedral molecular [MN4]n− nitridometallate anions. Magnetic measurements confirm that Cr and Mo are in the M6+ state, but the M=Mn phase has an anomalously small paramagnetic moment and large cell volume. Neutron powder diffraction data are fitted using an anion‐excess La3MnN5.30 model (space group I4/mcm, a=6.81587(9) Å and c=11.22664(18) Å at 200 K) in which Mn is close to the +7 state. Excess‐anion incorporation into Cs3CoCl5‐type materials has not been previously reported, and this or other substitution mechanisms may enable many other high oxidation state transition metal nitrides to be prepared. [ABSTRACT FROM AUTHOR]

Three new nitrides La3MN5 (M=Cr, Mn, and Mo) have been synthesized using a high pressure azide route. These are the first examples of ternary Cs3CoCl5‐type nitrides, and show that this (MN4)NLa3 antiperovskite structure type may be used to stabilise high oxidation‐state transition metals in tetrahedral molecular [MN4]n− nitridometallate anions. Magnetic measurements confirm that Cr and Mo are in the M6+ state, but the M=Mn phase has an anomalously small paramagnetic moment and large cell volume. Neutron powder diffraction data are fitted using an anion‐excess La3MnN5.30 model (space group I4/mcm, a=6.81587(9) Å and c=11.22664(18) Å at 200 K) in which Mn is close to the +7 state. Excess‐anion incorporation into Cs3CoCl5‐type materials has not been previously reported, and this or other substitution mechanisms may enable many other high oxidation state transition metal nitrides to be prepared. [ABSTRACT FROM AUTHOR]

To reveal complex causes of aircraft events, this paper aims to mine association rules between the trigger probability and relative strength via a modified Apriori algorithm. Clustering is adopted for data preprocessing and TF–IDF value calculation. Causative item sets of aircraft events are obtained based on the accident causation 2–4 model and are coded to establish code indicators. By avoiding the use of statistical methodologies to resolve not-a-number (NaN) values for altering the interrelations among causes, an enhancement in the Apriori algorithm is proposed by considering frequent items. By extracting frequent patterns, in this paper, all the association rules that satisfy three perspectives (support, confidence and lift) are determined by constantly generating and pruning candidate item sets. A network graph is used to visualize the association rules between different unsafe events and all types of causes. Finally, 9835 representative pieces of data, including general unsafe events, general incidents and serious incidents from the Southwest Air Traffic Management Bureau, are selected for analysis. The results show that improper energy allocation, poor conflict resolution ability, inadequate onsite management duties, adoption of a luck mentality, and occurrence of controller oversight are highly correlated with general unsafe events, and failure to rectify incorrect recitation is notably correlated with general incidents, while inadequate manual promotion, lack of conflict judgement and insufficient safety management are strongly correlated with serious incidents. This study quantitatively reveals the potential patterns and characteristics of mutual interactions among various types of historical aircraft events and highlights directions for controllable prevention and prediction of aircraft events. [ABSTRACT FROM AUTHOR]

Biomolecules are fundamental for various chemical and biological processes of living organisms. High‐resolution in situ imaging of the dynamics and local distribution of biomolecules may facilitate better interpretation of diverse complex cell events in the biomedicine field. In different advanced imaging tools, fluorescence imaging‐based activatable organic probes can be noninvasively and effortlessly internalized into cells and can be easily modified, which is essential for the in situ imaging of targets in living organisms. We here briefly summarize the existing general design strategies of activatable organic probes for retaining the fluorescence signal inside cells. We particularly describe the bioapplication of these probes for the in situ bioimaging. This review is expected to promote the development of new molecular tools for extending the application of these in situ imaging strategies to other biomolecules. [ABSTRACT FROM AUTHOR]

Porous SiC ceramics have been used in high temperature flue gas filtration fields because of their excellent properties such as high strength, high temperature resistance, corrosion resistance, and long service time. This work reports the porous SiOC‐bonded SiC ceramics prepared at low temperature. The properties of porous SiC ceramics were first investigated with silicone resin content from 10 to 25 wt%, and then the effects of different pore‐forming agent contents on the behaviors of porous SiC ceramics were discussed by adjusting poly (methyl methacrylate) PMMA microbeads from 5 to 20 wt%. The prepared porous SiC ceramics showed apparent porosity from 17.3% to 57.7%, compressive strength from 6 to 216 MPa, and Darcy permeability k1 ranging from 7.02 × 10−14 to 1.45 × 10−12 m2. The corrosion behavior of porous SiC ceramics was investigated in acidic and alkaline media. The porous SiC ceramics showed better corrosion resistance in acidic solutions. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to investigate mixed lubrication performances of stern bearing in a misaligned state considering turbulence and bearing deformation impacts. Design/methodology/approach: A mixed lubrication model of stern bearing is established. The generalized average Reynolds equation governing the turbulent flow of lubricant is analyzed by considering the interaction of bearing elastic deformation, asperity contact pressure and film pressure. The bearing behaviors including minimum film thickness, hydrodynamic pressure, asperity friction force and frictional coefficient are studied under different models. The correctness of this model is verified by comparing it with that of the published data. Findings: Numerical results indicate that elastic deformation noticeably decreases the maximum film pressure, the asperity contact force and the friction coefficient in the mixed lubrication stage. The effect of elastic deformation and turbulence reduces the transition speed from mixed to liquid lubrication. Originality/value: This model includes both turbulence and bearing deformation impacts on journal bearing performances. It is expected that the numerical results can provide useful information to establish a stern bearing exposed to mixed lubrication conditions. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2022-0352/ [ABSTRACT FROM AUTHOR]

In this article, we study mixed virtual element methods for a distributed optimal control problem governed by a fourth order partial differential equation. By introducing an auxiliary variable, the fourth order equation can be transformed into systems of second order equations. A mixed virtual element discrete scheme for the optimal control problem is established. Moreover, a priori error estimates for auxiliary, state, adjoint state and control variable in and norms are derived. Finally, the theoretical finding is verified by numerical experiments. [ABSTRACT FROM AUTHOR]

Background: Various maneuvers have been introduced to address anterior shoulder dislocations. Chair method allows the patient to sit comfortably and feel less pain during the reduction procedure. However, the rarity of comparative studies led to a lack of evidence to popularize. The present study aimed to introduce a modified chair (MOC) reduction method for anterior shoulder dislocation and explore its effectiveness compared with the traditional Hippocratic approach.Methods: This is a single-center retrospective study of 257 patients with anterior shoulder dislocation from September 2020 and July 2021. Patients were divided into two groups according to the reduction method they received (either the Hippocratic method or the MOC method). Success rate, reduction time, visual analog scale (VAS) pain score, satisfaction level, and a new indicator, pain index (reduction time (s)* VAS/ 10), were compared.Results: One hundred sixteen patients (43 females, 73 males) underwent the Hippocratic method, and 141 (65 females, 76 males) MOC method. A significantly higher success rate was seen in the MOC group (96.5%(136/141) vs. 84.5%(98/116) in the Hippocratic group; OR 5, 95%CI 1.79 ~ 13.91; p = 0.002). Pain index of the patients in the MOC group was much lower than that in the Hippocratic group (3.20 (2.10, 4.53) vs. 36.70 (22.40, 47.25), p <  0.001). The reduction time, VAS pain score, and satisfaction level also favored the MOC method.Conclusions: The MOC method is an easy and efficient reduction method with minimum assistance for anterior shoulder dislocations. Physicians can skillfully perform this procedure with the help of their body weight. The MOC method could be attempted for shoulder dislocations in the emergency department. [ABSTRACT FROM AUTHOR]

In this study, an egg white dual cross-linked hydrogel was developed based on the principle that the external stimulus can denature proteins and cause them to aggregate, forming hydrogel. The sodium hydroxide was used to induce gelation of the egg white protein, subsequently introducing calcium ions to cross-link with protein chains, thereby producing a dual cross-linked hydrogel. The characteristics of the dual cross-linked hydrogels—including the secondary structure, stability, microstructure, swelling performance, texture properties, and biosafety—were investigated to determine the effects of calcium ion on the egg white hydrogel (EWG) and evaluate the potential application in the field of tissue engineering. Results showed that calcium ions could change the β-sheet content of the protein in EWG after soaking it in different concentrations of CaCl2 solution, leading to changes in the hydrogen bonds and the secondary structure of polypeptide chains. It was confirmed that calcium ions promoted the secondary cross-linking of the protein chain, which facilitated polypeptide folding and aggregation, resulting in enhanced stability of the egg white dual cross-linked hydrogel. Furthermore, the swelling capacity of the EWG decreased with increasing concentration of calcium ions, and the texture properties including hardness, cohesiveness and springiness of the hydrogels were improved. In addition, the calcium cross-linked EWG hydrogels exhibited biocompatibility and cell-surface adhesion in vitro. Hence, this work develops a versatile strategy to fabricate dual cross-linked protein hydrogel with biosafety and cell-surface adhesion, and both the strategy and calcium-egg white cross-linked hydrogels have potential for use in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Objectives: Concerns about the coronavirus disease 2019 (COVID‐19) pandemic resulted in unprecedented challenges to the management of geriatric hip fractures. We aimed to evaluate the effects of the COVID‐19 surge on the time to surgery and 1 year mortality in geriatric patients with hip fracture at a large, urban Level 1 trauma center in Beijing, and to guide the management of geriatric hip fracture patients throughout the COVID‐19 pandemic. Methods: This single‐center retrospective study included consecutive patients aged ≥65 years and injured 3 weeks prior to admission. Demographic and surgical data were collected between January 20 and May 31, 2020, and from the same period in 2019. Mortality data and functional status were collected at follow‐up of 1‐year after surgery. The primary outcomes were time to surgery and 1 year mortality. Results: There were no significant differences in sex, fracture type, and surgical pattern between the 2020 (n = 261) and 2019 time‐matched (n = 307) cohorts. The time from admission to surgery was significantly delayed in the 2020 cohort compared with that in the 2019 cohort (48.9 h vs 20.5 h, p < 0.001). Fewer patients underwent surgery within 48 h in the 2020 cohort (65.5% vs 87.6%, p < 0.001). Surgical delay was also associated with an increased risk of inpatient complications (30.2% vs 20.8%, p = 0.010), however there was no significant difference in the 1‐year mortality rate, nor between pre‐injury and 1 year follow‐up mobility as assessed by Parker score. Only approximately half of the patients in both groups completely returned to their pre‐injury mobility levels. Conclusions: The COVID‐19 pandemic has significantly increased the surgery waiting time for geriatric patients with hip fractures, which resulted in increased inpatient complications without a higher mortality rate within 1 year. This reinforces the importance of maintaining timely and protocolized care for geriatric hip fractures throughout any subsequent waves of the pandemic. [ABSTRACT FROM AUTHOR]

To analyze the treatment of elderly femoral intertrochanteric fracture (EFIF) using InterTan intramedullary nail (InterTanIN) and proximal femoral nail antirotation (PFNA). A total of 75 patients suffering from EFIF receiving intramedullary fixation were retrospectively collected. According to intramedullary fixation methods, the patients were separated into InterTanIN group and PFNA group. Parameters including the surgery time, blood loss, number of X-ray fluoroscopy, hospital stays, bone-healing time, postoperative Harris hip score (HIS) (1 month, 3 months, 6 months, and 12 months), and complications were collected and analyzed. The results showed surgery time, blood loss, and number of X-ray fluoroscopy in InterTanIN group were higher than those in PFNA group (P < 0.05). The mean hospital stay in the InterTanIN group was comparable to that in the PFNA group (P > 0.05). There was no significant difference in bone-healing time between the InterTanIN group and PFNA group (P > 0.05). The postoperative HIS of InterTanIN group was statistically better than PFNA group at the 3rd month and the 6th month (P < 0.05). With the extension of recovery time, the gap between the two groups gradually narrowed. The postoperative implant displacement happened more often in the PFNA group than in the InterTanIN group. EFIF treated with InterTanIN or PFNA could achieve good long-term efficacy. Although InterTanIN has the disadvantages of increased operative time, blood loss, and radiation exposure compared to PFNA, the postoperative hip function recovery of InterTanIN seems to be more reliable and stable than PFNA. [ABSTRACT FROM AUTHOR]

Common calculation methods of passive earth pressure, such as the Rankine or Coulomb earth pressure theory, assume that the width of the fill behind the wall is sufficient for the development of the slip surface and that after the passive earth pressure reaches the limit state, its value remains unchanged with the increase of displacement of the retaining wall. Nevertheless, cases with narrow backfill width should be considered when retaining walls must be built close to existing stabilization walls in urban areas or near rock faces in mountainous areas. Furthermore, for sand, especially dense sand, when the displacement of the retaining wall is large, a strain-softening behavior similar to the triaxial test will appear, resulting in a decrease in passive earth pressure. In this regard, a practical model for strain-softening of dense sand is proposed firstly and verified by the discrete element method (DEM) using the Particle Flow Code (PFC-2D) software. Then, based on the sliding surface shape obtained by DEM, a simplified method for determining the passive earth pressure distribution of retaining walls using limit equilibrium analysis was proposed. Finally, the passive earth pressures calculated by the proposed method agree well with those from PFC results, and the effects of the width of the backfill and displacement of retaining wall on the distribution of active earth pressure were discussed. [ABSTRACT FROM AUTHOR]

• Generative pre-training network can better do feature embedding of normal pattern. • Anomaly simulation can assist in the learning of one-class classification. • Self-attention-based GCN can enhance the detection of model for logical anomaly. • SLSG achieves SOTA performance and faster speed in detecting comprehensive anomaly. Industrial image anomaly detection under the setting of one-class classification has significant practical value. However, most existing models face challenges in extracting separable feature representations when performing feature embedding and in constructing compact descriptions of normal features when performing one-class classification. One direct consequence is that most models perform poorly in detecting logical anomalies that violate contextual relationships. Focusing on more effective and comprehensive anomaly detection, we propose a network based on self-supervised learning and self-attentive graph convolution (SLSG). SLSG uses a generative pre-training network to assist the encoder in learning the embedding of normal patterns and the reasoning of positional relationships. Subsequently, we introduce pseudo-prior knowledge of anomalies in SLSG using simulated abnormal samples. By comparing the simulated anomalies, SLSG can better summarize the normal patterns and narrow the hypersphere used for one-class classification. In addition, with the construction of a more general graph structure, SLSG comprehensively models the dense and sparse relationships among the elements in an image, which further strengthens the detection of logical anomalies. Extensive experiments on benchmark datasets show that SLSG achieves superior anomaly detection performance, demonstrating the effectiveness of our method. [ABSTRACT FROM AUTHOR]

Conventional approach for evaluation of the stability of geosynthetic-reinforced soil structures (GRSSs) is performed under either completely dry or saturated conditions, whereas soils are usually unsaturated in practice. Owing to the suction-induced effect, the behavior of soil is quite different, consequently leading to various stability conditions of GRSSs. This study presents a useful analytical solution for assessing the reinforcement effect of geosynthetics on the internal stability of unsaturated GRSSs under steady infiltration conditions using the kinematical approach of limit analysis, aiming at determining the reinforcement strength required for preventing slope failure. This analytical solution can take the effect of suction stress, unit weight of soil and tensile strength cut-off simultaneously into account. By comparing with the results of other solutions, the validity of the analytical solution is verified. An extensive parametric study is conducted in this paper. The obtained results show that the suction stress has a more significant effect than the tensile strength cut-off on the required normalized reinforcement; additionally, the required normalized reinforcement obtained by the extended M-C yield criterion is more conservative than that of the tension cut-off model in the presence of suction stress, and the hysteresis effect should be considered in the routine design. [ABSTRACT FROM AUTHOR]

The calculation of two-electron repulsion integrals (ERIs) is a crucial aspect of Hartree–Fock calculations. In computing the ERIs of varying angular momentum, both the central processing unit (CPU) and the graphics processing unit (GPU) have their respective advantages. To accelerate the ERI evaluation and Fock matrix generation, a hybrid CPU/GPU method has been proposed to maximize the computational power of both CPU and GPU while overlapping the CPU and GPU computations. This method employs a task queue where each task corresponds to ERIs with the same angular momentum. The queue begins with ERIs of low angular momentum, which are computationally efficient on GPUs, and ends with ERIs of high angular momentum, which are better suited for CPU computation. CPUs and GPUs dynamically grab and complete tasks from the start and end of the queue using OpenMP dynamic scheduling until all tasks are finished. The hybrid CPU/GPU computation offers the advantage of enabling calculations with arbitrary angular momentum. Test calculations showed that the hybrid CPU/GPU algorithm is more efficient than "GPU-only" when using a single GPU. However, as more GPUs are involved, the advantage diminishes or disappears. The scaling exponents of the hybrid method were slightly higher than "GPU-only," but the pre-exponent factor was significantly lower, making the hybrid method more effective overall. [ABSTRACT FROM AUTHOR]

Bioactive NAD+ mediated multiple biocatalytic pathways in metabolic networks. Refining the structure of NADH oxidase-like (NOX) mimics to efficiently replenish NAD+ has been promising but challenging in NAD+-dependent dehydrogenase electrochemical cascade biosensing. Herein, we discovered that PtOx structures, formed via lattice oxygen translocation from WO3 to Pt NPs at the interface, potentially activate and modulate the NOX-like functionality in Pt@WO3 nanosheets. Incorporating PtOx leads to a more positive valence of Pt species within Pt/PtOx@WO3−x, where the PtO2 species serve as preeminent reaction sites for NADH coordination, activation, and dehydrogenation. Consequently, such nanozymes display enhanced NOX-like activity towards NADH oxidation in comparison to Pt@WO3. Ultimately, the 650-Pt/PtOx@WO3−x nanozyme is employed in an electrochemical cascade biosensor for β-hydroxybutyrate (HB) detection, achieving a calculated detection limit of 25 μM. This study offers insights into PtOx activation in Pt-based NOX mimics and supports the future development of NAD+/NADH-dependent electrochemical biosensors. [ABSTRACT FROM AUTHOR]

• A new method is proposed for diversified recommendation. • The method considers the influence of imbalanced data distribution on diversity. • An enhanced negative sampling strategy is designed. • Self-supervised auxiliary task is constructed based on counterfactual learning. • Experimental results prove the effectiveness of the method. Consumers' needs present a trend of diversification, which causes the emergence of diversified recommendation systems. However, existing diversified recommendation research mostly focuses on objective function construction rather than on the root cause that limits diversity—namely, imbalanced data distribution. This study considers how to balance data distribution to improve recommendation diversity. We propose a novel self-supervised graph model based on counterfactual learning (SSG-CL) for diversified recommendation. SSG-CL first distinguishes the dominant and disadvantageous categories for each user based on long-tail theory. It then introduces counterfactual learning to construct an auxiliary view with relatively balanced distribution among the dominant and disadvantageous categories. Next, we conduct contrastive learning between the user–item interaction graph and the auxiliary view as the self-supervised auxiliary task that aims to improve recommendation diversity. Finally, SSG-CL leverages a multitask training strategy to jointly optimize the main accuracy-oriented recommendation task and the self-supervised auxiliary task. Finally, we conduct experimental studies on real-world datasets, and the results indicate good SSG-CL performance in terms of accuracy and diversity. [ABSTRACT FROM AUTHOR]

Water level drawdowns that occur outside and inside a fully, or partially, submerged slope will change the hydraulic gradient and enhance seepage forces, and may thus lead to slope instability and collapse. Existing research on this stability issue has primarily focused on the use of linear failure criteria and the associated flow rule. Little attention has been given to the effects of nonlinearity and the nonassociated plasticity of geomaterials, and of surcharge loading on slope stability. However, these conditions are more realistic for real-world cases. This study addresses this knowledge gap. The limiting surcharge on the top of submerged slopes subjected to water drawdown is analyzed in terms of nonlinearity and dilation effects using a limit analysis method. The optimal solutions were sought through optimization. The proposed method and its assumed failure mechanism were validated by comparing the results of the proposed method with results from finite element and finite element limit analysis. Parametric analysis and a case study are presented and indicate that as the water level difference increases, the bearing capacity of the slope decreases. In addition, it was found that the dilatancy effect has an effect on slope bearing capacity and that the inclusion of nonlinear effects enables better results. [ABSTRACT FROM AUTHOR]

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) at the end of 2019 has caused a large global outbreak and now become a major public health issue. However, there is currently a lack of data underlying how the human host interacts with SARS-CoV-2 virus. In the current study, We performed Venn-analysis, Gene ontology (GO), KEGG pathway analysis and Protein-protein interaction analysis of whole transcriptome studies with the aim of clarifying the genes and pathways potentially altered during human respiratory tract cell infection with SARS-CoV-2. We found 36 overlapping upregulated genes among different types of cells after viral infection. Further functional enrichment analysis revealed these Differential Expressed Genes (DEGs) are most likely involved in biological processes related to inflammatory response and response to cytokine, cell component related to extracellular space and I-kappa B/NF-kappa B complex, molecular function related to protein binding and cytokine activity. KEGG pathways analysis highlighted altered conical and casual pathways related to TNF, NF-kappa B, Cytokine-cytokine receptor interaction and IL-17 signaling pathways during SARS CoV-2 infection with CXCL1, CXCL2, CXCL3, CXCL8, CXCL10, IL32, CX3CL1, CCL20, IRF1, NFKB2 and NFKB1A up-regulated which may explain the inflammatory cytokine storms associated with severe cases of COVID-19. [ABSTRACT FROM AUTHOR]

We study the k -error linear complexity of subsequences of the d -ary Sidel'nikov sequences over the prime field 𝔽 d . A general lower bound for the k -error linear complexity is given. For several special periods, we show that these sequences have large k -error linear complexity. [ABSTRACT FROM AUTHOR]

Most classical predictive models of relative permeability conceptualize the pores in porous media as assemblies of uniform capillary tubes with different sizes. However, this simplification may overestimate the transport capacity of porous media due to overlooking the effects of the pore nonuniformity. This study presents a simple way to quantify the effect of the nonuniformity of pore cross section on the transport characteristic of unsaturated porous media. The way is based on the index relationship between the porosity of a newly defined reference cross section and that of porous media, which satisfies the intrinsic constraints for the nonuniform porosity of cross sections in porous media. Moreover, the index factor can be captured by a newly defined parameter, called the nonuniformity factor, which is used to establish an extended Darcy's law. Based on these, a fractal-based continuous analytical model and a fractal-based Monte Carlo model of relative permeability as well as a permeability-porosity model are established. Experimental data of five wetting-nonwetting phase systems, including the water-air, water-steam, water-nitrogen, water-oil, and oil-gas systems, are selected to assess the performance of the proposed model. The results confirm the proposed model's capacity in capturing the transport properties of various porous media. It is found that the nonuniformity of pores can significantly increase the resistance of fluid flow and thus reduce the transport capacity of porous media. [ABSTRACT FROM AUTHOR]

Intervertebral disc degeneration (IDD) and ligamentum flavum hypertrophy (LFH) are major causes of degenerative spinal disorders. Comparative and proteomic analysis was used to identify differentially expressed proteins (DEPs) in IDD and LFH discs compared with normal discs. Subsequent gene ontology term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of the DEPs in human IDD discs or LFH samples were performed to identify the biological processes and signaling pathways involved in IDD and LFH. The PI3K-AKT signaling pathway, advanced glycation endproducts-receptor for advanced glycation endproducts signaling pathway, p53 signaling pathway, and transforming growth factor-b signaling pathway were activated in disc degeneration. This review summarizes the recently identified DEPs, including prolargin, fibronectin 1, cartilage intermediate layer protein, cartilage oligomeric matrix protein, and collagen types I, II and IV, and their pathophysiological roles in degenerative spinal disorders, and may provide a deeper understanding of the pathological processes of human generative spinal disorders. The present review aimed to summarize significantly changed proteins in degenerative spinal disorders and provide a deeper understanding to prevent these diseases. [ABSTRACT FROM AUTHOR]

In this work we report an ab initio intermolecular potential energy surface and theoretical spectroscopic studies for Xe–H2O complex. The ab initio energies are calculated with CCSD(T) method and large basis sets (aug-cc-pVQZ for H and O and aug-cc-pVQZ-PP for Xe) augmented by a {3s3p2d2f1g} set of bond functions. This potential energy surface has a global minimum corresponding to a planar and nearly linear hydrogen bonded configuration with a well depth of 192.5 cm-1 at intermolecular distance of 4.0 Å, which is consistent with the previous determined potential by Wen and Jäger [J. Phys. Chem. A 110, 7560 (2006)]. The bound state calculations have been performed for the complex by approximating the water molecule as a rigid rotor. The theoretical rotational transition frequencies, isotopic shifts, nuclear quadrupole coupling constants, and structure parameters are in good agreement with the experimental observed values. The wavefunctions are analyzed to understand the dynamics of the ground and the first excited states. [ABSTRACT FROM AUTHOR]

The initial state selected time-dependent wave packet method has been extended to calculate the total reaction probability for atom-triatom reactions with total angular momentum J > 0 by treating both bonds in the triatom reagent reactively. The total exchange and abstraction reaction probabilities for the title reaction with J = 15 calculated with 2 K-blocks (the projection of the total angular momentum on the body-fixed axis) show that one has to treat both OH bonds in the H[SUB2]O reagent reactively for the exchange reaction, but for the abstraction reaction one can treat one OH bond as a spectator bond to get accurate results. This is in accord with what had been found for the total reaction probabilities for J=0 [Phys. Rev. Lett. 89, 103201 (2002)]. The J= 15 reaction probabilities also show that the CS (centrifugal sudden) approximation is inadequate for the title reaction, in particular for the abstraction reaction. The integral cross sections for the abstraction reaction, calculated without the CS approximation but by freezing one OH bond in the H[SUB2]O reagent for the ground and first vibrationally excited states, are found to be substantially larger than the corresponding CS integral cross sections. However, the integral cross section for the ground vibrational state is still much smaller than the existing experimental result. Since the treatment of freezing OH bond is not expected to introduce any noticeable error, it is conceivable that the experiments overestimated the integral cross section for the abstraction reaction. [ABSTRACT FROM AUTHOR]

The initial state selected time-dependent wave packet method has been developed to study the H+ CH[sub 4] reaction in seven dimensions by employing the model developed by Palma and Clary [J. Chem. Phys. 112, 1859 (2000)]. The latter eight-dimensional model only assumes that the nonreacting CH[sub 3] group keeps a C[sub 3V] symmetry in reaction. The CH bond lengths in the nonreacting CH[sub 3] group were fixed in the study to reduce the number of degrees of freedom to seven. Our calculations reveal that it is very important to accurately deal with the umbrella motion of the CH[sub 3] group while studying this reaction. We investigated the effects of the fundamental vibrational excitations of CH[sub 4] on the reaction. Finally, we compare our rate constant for the ground rovibrational initial state with available experimental and other theoretical results. [ABSTRACT FROM AUTHOR]

This paper presents fully converged integral cross sections for the D[sub 2](j[sub 1]=0,2,4)+OH(j[sub 2]=0,2,4)→HOD+D reaction on the YZCL2 potential energy surface. It is found that the influence of reagent rotation excitation on reactivity is relatively mild compared with that of the D[sub 2] vibration excitation, but is fairly important to the thermal rate constant at low temperature. In general, the OH rotation excitation tends to hinder the reaction, and the D[sub 2] rotation excitation tends to enhance the reactivity. The simultaneous reagent rotation has some correlated effect, with the influence of the D[sub 2] rotation excitation considerably dependent on the OH rotation excitation. It is also found that the reaction is strongly dependent on j[sub 12] (the coupled angular momentum between j[sub 1] and j[sub 2]), K[sub 0] (the projection of the reagent rotation on the body fixed axis), and the parity of the system, in particular for either the OH or D[sub 2] rotationally excited initial states, but this dependence becomes relatively weaker as the collision energy increases. Excellent agreement achieved between theory and experiment on the thermal rate coefficients for temperatures up to 400 K clearly shows that the YZCL2 potential energy surface is capable of producing “quantitatively” accurate results for the title reaction. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report dynamics on two interpolated global potential energy surfaces (PES) for the H[sub 2]+OH reaction. The first PES is based on both QCISD(T)/6-311++G(3df,2pd) and MRCI/aug-cc-pVTZ ab initio calculations. In the second version, the energies at the interpolation data points are improved to the UCCSD(T)/aug-cc-pVQZ level. Fully converged integral cross sections were calculated on these two PESs for the title reaction for the ground rovibrational and two rotationally excited initial states. Good agreement between theory and experiment for rate coefficients for temperatures up to 1050 K are only achieved on the second PES. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Aims: In addition to pineal gland, many cells, tissues, and organs also synthesize melatonin (N-acetyl-5-methoxytryptamine). Embryos are a group of special cells and whether they can synthesize melatonin is still an open question. However, melatonin application promoted embryo development in many species in in vitro condition. The purpose of this study was to investigate whether embryos can synthesize melatonin; if it is so, what are the impacts of the endogenously produced melatonin on embryo development and the associated molecular mechanisms. These have never been reported previously. Results: Melatonin synthesis was observed at different stages of embryonic development. Aanat (aralkylamine N-acetyltransferase), a rate-limiting enzyme for melatonin production, was found to mostly localize in the mitochondria. Aanat knockdown significantly impeded embryonic development, and melatonin supplementation rescued it. The potential mechanisms might be that melatonin preserved mitochondrial intact and its function, thus providing sufficient adenosine 5′-triphosphate for the embryo development. In addition, melatonin scavenged intracellular reactive oxygen species (ROS) and reduced the DNA mutation induced by oxidative stress. In the molecular level, Aanat knockdown reduced tet methylcytosine dioxygenase 2 (Tet2) expression and DNA demethylation in blastocyst and melatonin supplementation rescued these processes. Innovation: This is the first report to show that embryos synthesize melatonin, and its synthetic enzyme Aanat was located in the mitochondria of embryos. An effect of melatonin is to maintain Tet2 expression and normal methylation status, and thereby promote embryonic development. Conclusion: Embryos can produce melatonin that reduces ROS production, preserves mitochondrial function, and maintains Tet2 expression and the normal DNA methylation. [ABSTRACT FROM AUTHOR]

Abstract In this study, based on the log-spiral upper bound limit analysis method that integrated with the generalized effective stress, a new formula for calculating the lateral stabilizing force provided by a row of piles required to increase the slope safety factor to a desired value under vertical steady unsaturated flow was developed, and the most critical solutions were obtained by the optimization method. Moreover, the proposed method can be simplified to the case without piles for computing the stability number for a slope in the limit state of failure. By comparing the results of the proposed method to others for some examples, its feasibility was verified. Numerical study for the parametric effects was presented, indicating that limit lateral stabilizing force depends strongly on the soil types, the slope geometry, the seepage conditions and that in routine design without consideration of suction stress can lead to a less conservative result in clay and sand, but can obtain a relatively safe result in silt and loess. This paper gives some useful suggestions for engineering application and provides a useful method for further study. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the surface damage mechanism of monocrystalline silicon in micro ball-end milling with polycrystalline diamond (PCD) and natural diamond tools. Machining-induced surface damages such as surface fracture, phase transition, and residual stress are studied under different machining conditions. It is found that under a small feed rate and cutting depth and high spindle speed, PCD micro ball-end mill is a potential candidate in manufacturing low-damage surfaces that are distributed uniformly with the amorphous layer of several-nanometer thickness and the average compressive residual stress that does not exceed 150 MPa. Additionally, the influences of feed rate on surface damages in PCD micro milling are more significant than those in micro milling with a natural diamond tool. The experimental results reveal the surface damage mechanism: (i) the current cutting region comprises the subsurface layer after machining in the last tooth period, the previously produced surface/subsurface defects can affect the damages of the current machined surface, (ii) the cutting edge closer to the tool tip acts primarily on amorphous silicon generated in the previous tooth period, part of the amorphous phase remains on the machined surface, and the formation of metastable phases (Si-III, Si-XII, and Si-IV) occurs away from the machined surface. [ABSTRACT FROM AUTHOR]

TiBw/TA15 composites are featured by the network-structured distribution of the reinforced phase quasi-continuously. The multiphase microstructure including the TiB ceramic whisker reinforcement, the titanium alloy matrix and the interface plays a significant role in cutting processes. In this paper, multiscale finite element (FE) cutting models in accordance with the structural characteristics of TiBw/TA15 composites are established. Then, the interfacial mechanical parameters of TiBw/TA15 composites are recognized by the microcolumn compression approach, and the thermoplastic equivalent constitutive parameters (ECP) of the TiBw-rich region in the model are obtained by a two-step FE simulation. The cutting model is validated by orthogonal turning experiments. Finally, the formation of segmented chips can be visualized by the cutting models, which is caused by the compressive stress and the TiB whiskers failure. In addition, the mapping relationship between the critical equivalent strain (CES) and the hardened layer depth (HLD) is established. The results indicate that the HLD reduces with the decrease of cutting speed (V C) and depth of cutting (h). The findings in this paper facilitate a further understanding of the TiBw/TA15 composites cutting mechanism. [ABSTRACT FROM AUTHOR]

MicroRNAs play a crucial role in regulating the epithelial barrier and immune response, which are implicated in the pathogenesis of ulcerative colitis (UC). This study aimed to investigate the role and molecular mechanism of miR-30c in the pathogenesis of UC using a dextran sulfate sodium salt (DSS)-induced colitis model, which is similar to ulcerative colitis. Wild-type (WT) and miR-30c knockout (KO) mice were assigned to either control or DSS-treated groups to evaluate the influence of aberrant miR-30c expression on UC pathogenesis. The disease activity index, inflammatory factors, and the extent of pathological and histological damage in colon tissues were analyzed. The effect of miR-30c on vasoactive intestinal peptide (VIP) gene expression was validated through luciferase reporter assay, qRT-PCR, Western blotting, and immunohistochemistry. The results showed that miR-30c KO mice with DSS-induced colitis model showed more severe phenotypes: significantly higher disease activity indices, significant body weight loss, reduced length of the colon of mice, increased number of aberrant crypt structures, reduced mucus secretion, and significant differences in inflammatory factors. These findings suggested that the absence of miR-30c might promote DSS-induced colitis, and the targe-regulatory effect of miR-30c on VIP might play an important role in the development of colitis. [ABSTRACT FROM AUTHOR]

The detection of botulinum neurotoxin A (BoNT/A) endopeptidase activity by pregnancy test paper based on human chorionic gonadotropin (hCG)-functionalized peptide-modified magnetic nanoparticles (MNs) is described for the first time. HCG-functionalized SNAP-25 peptide substrate with hydrolysis recognition sites was optimally designed. HCG can be recognized by pregnancy test strips. BoNT/A light chain (BoNT-LcA) is the central part of the endopeptidase function in holotoxin, which can specifically hydrolyze SNAP-25 peptide to release the hCG-peptide probe, and the hCG-peptide probe released can be quantitatively detected by pregnancy test strips, achieving indirect determination of BoNT/A. By quantifying the T-line color intensity of test strips, the visual detection limit for BoNT-LcA is 12.5 pg/mL, and the linear range of detection for BoNT-LcA and BoNT/A holotoxin was 100 pg/mL to 1 ng/mL and 25 to 250 ng/mL. The ability of the method to quantify BoNT/A was validated in human serum samples. This method shows the potential for sensitive detecting BoNT/A and has prospects for the diagnosis and prognosis of clinical botulism. [ABSTRACT FROM AUTHOR]

Biodegradability and toxicity are two important indexes in considering the feasibility of a chemical process for environmental remediation. The acetylacetone (AA) mediated photochemical process has been proven as an efficient approach for dye decolorization. Both AA and its photochemical degradation products had a high bioavailability. However, the biocompatibility and ecotoxicology of the UV/AA treated solutions are unclear yet. In the present work, we evaluated the biocompatibility and toxicity of the UV/AA treated solutions at both biochemical and organismal levels. The biodegradability of the treated solution was evaluated with the ratio of 5-d biological oxygen demand (BOD 5 ) to chemical oxygen demand (COD) and a 28-d activated sludge assay (Zahn-Wellens tests). The UV/AA process significantly improved the biodegradability of the tested dye solutions. Toxicity was assessed with responses of microorganisms (microbes in activated sludge and Daphnia magna ) and plants (bok choy, rice seed, and Arabidopsis thaliana ) to the treated solutions, which showed that the toxicity of the UV/AA treated solutions was lower or comparable to that of the UV/H 2 O 2 counterparts. The results are helpful for us to determine whether the UV/AA process is applicable to certain wastewaters and how the UV/AA process could be effectively combined into a sequential chemical-biological water treatment. [ABSTRACT FROM AUTHOR]

Abstract: The near‐UV and visible light induced interfacial electron transfer (IFET) process between aqueous solution of [Fe(bipy)2Cl2][FeCl4] complex and TiO2 NPs has been proved at first time and the photochemical products were mainly characterized by electronic absorption, Fe K‐edge X‐ray absorption fine structure, electron paramagnetic resonance and 57Fe Mössbauer spectroscopic method. This study makes in comprehending for the combination of semiconductor NPs and metal complex, in‐particularly ionic salt like complex has potential in environmental friendly synthesis and remediation process. [ABSTRACT FROM AUTHOR]

The deformation of the overlying pipeline caused by the soil tunnel excavation cannot be ignored in the case of the small spacing between the pipeline and the tunnel. Based on the rigid bar method, the pipeline-soil interaction model was established, with the simply supported beam as the basic system, and the loads acting on the pipeline by the soil are considered to be linearly distributed. Calculation methods for continuous and discontinuous pipeline deformations were established. The results calculated by the proposed method agree well with the experimental data of centrifuge tests and field data. Parametric study on the effect of the volume loss (η = 1%, 2%,3 %), rotational stiffness (β0 = 4.47 × 106N⋅m/rad, 4.47 × 108N⋅m/rad, 4.47 × 1010N⋅m/rad), ratio of pipeline section length to inflection point of soil settlement curve (L/is = 0.5, 1.0, 1.5, 2.0) and soil elastic modulus (E = 10 MPa, 30 MPa, 50 MPa) on the deflection and joint rotation angle of the discontinuous pipeline were carried out. Results show that: (1) the maximum pipeline deflection and the maximum rotation angle of the joint increase as η increases and decrease as β0 increases; (2) in the "odd" case, the maximum pipeline deflection and the maximum rotation angle of the joint first increase and then decrease as L/is increases, reaching a peak at L/is = 1.5, while in the "even" case, the maximum pipeline deflection decreases as L/is increases and the maximum rotation angle of the joint first increases and then decreases as L/is increases; (3) in the "odd" case, the maximum pipeline deflection and the maximum angle of rotation of the joint decrease as E increases, while the opposite trend is observed in the "even" case. Additionally, the maximum pipeline deflection and the maximum rotation angle of the joint are always greater in the "odd" case than that in the "even" case. [ABSTRACT FROM AUTHOR]

Light source is a crucial factor in the application of a photochemical process, which determines the energy efficiency. The performances of acetylacetone (AA) in conversion of aqueous contaminants under irradiation with a low-pressure mercury lamp, a medium-pressure mercury lamp, a xenon lamp, and natural sunlight were investigated and compared with those of H 2 O 2 as reference. In all cases, AA was superior to H 2 O 2 in the degradation of Acid Orange 7. Using combinations of the different light sources with various cut-off and band-pass filters, the spectra responses of the absorbed photons in the UV/AA and UV/H 2 O 2 processes were determined for two colored and two colorless compounds. The photonic efficiency ( φ ) of the two photochemical processes was found to be target-dependent. A calculation approach for the inner filter effect was developed by taking the obtained φ into account, which provides a more accurate indication of the reaction mechanisms. [ABSTRACT FROM AUTHOR]

• The TTG, sanukitoids, and plagioclase-amphibolite gneiss were formed at ∼ 2.51–2.46 Ga. • The NOB might be in a transition stage from a compressional regime to an extensional regime during ∼ 2.51–2.46 Ga. • The NOB is in a long-term active continental margin setting during ∼ 2.51–1.95 Ga. The most poorly exposed and least understood in the North China Craton (NCC) lies largely hidden beneath the Ordos Basin, severely limiting the cognition of the Precambrian tectonic evolution in the western NCC and the tectonic division. Diverse orthogneiss samples collected from four boreholes drilled into the basement of the north side of Hangjinqi Fault Zone (HFZ) in the North Ordos Basin (NOB) are investigated by integrating zircon U-Pb dating, Hf-Nd isotopes, and whole-rock geochemical analyses. The TTG gneiss, quartz-monzonite gneiss, granodiorite gneiss, and amphibolite were emplaced at ca. 2.51–2.46 Ga, of which the amphibolite also recorded the metamorphic age of ca. 1.95 Ga. The TTG gneisses display low MgO, Mg#, Cr, and Ni, high HREE and Rb/Sr, enrichment of LILEs and depletion of Nb, Ta, and Ti, and positive εNd(t) (2.04–4.06) and εHf(t) (3.04–7.59) values, suggesting that they were mainly originated from partial melting of the tectonically thickened mafic island-arc crust. In contrast, the quartz monzonite gneisses and granodiorite gneisses show the geochemical features of Archean sanukitoids with higher MgO, Mg#, Cr, and Ni, and similar ε Nd (t) (1.34–3.82) and ε Hf (t) values (3.94–7.32), suggesting that they were derived from the partial melting of the mantle metasomatized by fluids and melts of the subduction. The amphibolites exhibit a mixed characteristic of E-MORB and arc-like geochemical affinities resembling the Mariana back-arc basin, which was derived from the partial melting of spinel lherzolite. The arc and arc-back lithological assemblages suggest that the north margin of the NOB might be in a geodynamic transition period from a compressional regime correlated with plate subduction to an extensional regime correlated with slab rollback during ca. 2.51–2.46 Ga. Combined with previous analytical results, the northern margin of the NOB was most likely in a long-term active continental margin setting during 2.51–1.95 Ga and involved in the collision event between the Yinshan Block and Ordos Block at ca. 1.95 Ga. [ABSTRACT FROM AUTHOR]

Oil pollution has seriously affected the ecological balance, and the development of an efficient and low-cost sorbent material to treat oil pollution is work with practical applications. In this work, a novel hydrophobic sorbent based on natural sepiolite was obtained by modifying with four saturated fatty acids with different carbon chain length and used for oil removal from water. The original and modified samples were tested for SEM, XRD, FTIR, CA, XPS and BET analysis. The results showed that the functional groups of the modifier were successfully grafted onto the sepiolite surface. The sepiolite fibers changed from the original agglomerative morphology to more dispersed with a coarser surface. The contact angle of modified sepiolite was improved greatly compared with the original sepiolite. Among them, octadecanoic acid modified sepiolite (O-SEP), with a lower water contact angle showed the best diesel removal efficiency, indicating that there was no significant positive correlation between the oil sorption efficiency and the value of the contact angle. This study presented a simple and feasible method to produce hydrophobic-based sorbents with good performance based on clay minerals that could be used for oil spill cleaning up. • The highly hydrophobic sorbent based on sepiolite was prepared. • The carbon chain lengths of the modifier influenced the value of the contact angle. • The oil removal efficiency of modified samples was higher than original sepiolite. • The enhanced oil sorption was attributed to hydrophobic forces and rough surfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • Block copolymers synthesised through sequential NIR LED light-controlled BIT-RDRP and purple LED light induced ROP strategy. • The dispersity value of the block copolymers can be as low as to 1.06. • The "one pot" strategy greatly simplified the operation process and improved the synthesis efficiency. Photoinduced reversible-deactivation radical polymerization (RDRP) has attracted great interest in virtue to their unique inherent advantages, such as low activation energy, environmentally benign reaction conditions and precision synthesis of designable functional polymeric materials. In this work, a facile and efficient strategy for preparing block copolymers was developed by the combination of near-infrared (NIR) light-controlled in-situ bromine-iodine transformation reversible-deactivation radical polymerization (BIT-RDRP) and purple LED light induced ring-opening polymerization (ROP). Herein, the macroinitiator was first synthesized via NIR light-controlled BIT-RDRP by using a bifunctional 2-hydroxyethyl 2-bromo-2-phenylacetate (EBP-OH) as the initiator at room temperature. Subsequently the block copolymers with narrow dispersity (low up to 1.06) were prepared by combination of purple LED light induced ROP through "two step" or "one pot" process. Importantly, the "one pot" strategy can greatly simplify the operation process and improve the synthesis efficiency, which will facilitate the batch preparation of block copolymers. [ABSTRACT FROM AUTHOR]

High-accuracy and real-time semi-supervised image surface defect detection is extensively needed in industrial scenarios. However, existing methods do not provide a good balance between accuracy and speed of defect detection, so this paper proposes an end-to-end memory-based segmentation network (MemSeg) to better accomplish this task. Considering the small intra-class variance of products in the same production line, from the perspective of differences and commonalities, MemSeg introduces artificially simulated abnormal samples and memory samples to assist the model learning. In the training phase, MemSeg explicitly learns the potential differences between normal and simulated abnormal images to obtain a robust classification hyperplane. At the same time, inspired by the mechanism of human memory, MemSeg uses a memory pool to store the general patterns of normal samples. By comparing the similarities and differences between input samples and memory samples in the memory pool to give effective guesses about abnormal regions; In the inference phase, MemSeg directly determines the abnormal regions of the input image in an end-to-end approach. Simple but high-performance, MemSeg achieves state-of-the-art (SOTA) performance on MVTec AD datasets with AUC scores of 99.56% and 98.84% at the image level and pixel level, respectively, while also meeting the real-time requirements in industrial scenarios. [ABSTRACT FROM AUTHOR]

There is a gap that should be filled in a deeper understanding of the potential role played by multiple microstructures in the material mechanical properties during the machining of network-structured TiBw/TA15 composites. In view of this, a comprehensive constitutive model is established coupled with the shear lag theory and Weibull distribution for the TiBw/TA15 composites. Whereby, the multi-step finite element (FE) simulations considering the multiphase microstructures are adopted to determine the local equivalent (LE) constitutive function of network boundary region (NBR). And the initial parameter identification and model modification are completed with the SHPB data and the DIC-based analytical results of the micro-scale orthogonal machining process, respectively. The proposed constructive model with high fitting precision enables the quantification of the effective strengthening effect from TiBw and the equivalent stress from TA15 matrix. Subsequently, the established constructive model can be utilized to construct the theoretical yield strength field in the machined subsurface with the help of the conventional analytical modeling method. And the semi-analytical modeling technique is developed and validated using the theoretical yield strength as an index to predict the subsurface microhardness. Furthermore, the internal mechanism derived from the constitutive model provides some explanation for the microhardness variation analysis. [ABSTRACT FROM AUTHOR]

Smart and precise sensing is very important for the protection of both environment and personal security in modern civilized society. There are numerous sensing devices for detecting physical and chemical changes such as temperature, humidity, pressure, and chemical species. In this regard, conducting polymers is at the core of attention for the fabrication of next-generation sensor applications. Polypyrrole (PPy), is one of the emerging intelligent materials with a wide range of applications in the field of optical, electronic, and electrochromic devices and sensors. The stability in a different environment, ease of deposition from aqueous and non-aqueous media, adherence to diverse substrates, and high electrical conductivity made PPy a unique choice for sensor development. In recent years, PPy has proven an excellent candidate for sensing volatile organic compounds (VOCs) due to its selectivity and sensitivity towards target gas molecules, and detection of inorganic gases and VOCs. Consequently, to develop outstanding sensing devices attempts have been dedicated to developing PPy-based sensors for excellent mechanical and electrochemical performance. This review aims to provide a recent overview of progress in PPy-based advanced sensing devices. This review aims to provide a recent overview of progress in PPy-based advanced sensing devices. We have systematically discussed the challenges and future development of various sensing devices. Furthermore, the current understanding and performance evaluation of gas sensing mechanisms in PPy-based sensors are discussed theoretically and experimentally. We have also identified gaps in the state-of-the-art and hope that this study would lead to further research works into using PPy to make gas sensors. Finally, the future directions of various sensors with advanced PPy-based sensing systems have been prospected. [Display omitted] • Polypyrrole (PPy) was an excellent candidate for capturing a broad range of VOCs. • Doping, surface modification, side-chain selection, and PPy-chain-arrangements were reported. • The complementary roles of experimental and theoretical studies were clearly described. • Reported families of PPy and their current utilities were elaborated. • Gaps were identified both from fundamental and applied standpoints. [ABSTRACT FROM AUTHOR]

Dissociative chemisorption is the initial and often rate-limiting step in many heterogeneous processes. As a result, an in-depth understanding of the reaction dynamics of such processes is of great importance for the establishment of a predictive model of heterogeneous catalysis. Overwhelming experimental evidence has suggested that these processes have a non-statistical nature and excitations in various reactant modes have a significant impact on reactivity. A comprehensive characterization of the reaction dynamics requires a quantum mechanical treatment on a global potential energy surface. In this review, we summarize recent progress in constructing high-dimensional potential energy surfaces for polyatomic molecules interacting with transition metal surfaces based on the plane-wave density functional theory and in quantum dynamical studies of dissociative chemisorption on these potential energy surfaces. A special focus is placed on the mode specificity and bond selectivity in these gas–surface collisional processes, and their rationalization in terms of the recently proposed Sudden Vector Projection model. [ABSTRACT FROM AUTHOR]

The Pennsylvanian Taiyuan Formation of the Shenmu Field in the northeastern Ordos Basin of China contains tight sandstone reservoirs that have recently been commercially produced. An evaluation of the reservoir quality of the Taiyuan sandstones will play a critical role in the development of the field. An investigation was conducted to explore possible effects of the sequence stratigraphy, depositional facies and diagenetic alterations on the reservoir quality of the Taiyuan sandstones based on core descriptions, the examination of thin-sections, and core plug and scanning electron microscope analyses. The Taiyuan Formation consists of lowstand system tracts (LST), transgressive system tracts (TST) and highstand system tracts (HST). The LST sandstones are principally medium-to coarse-grained and are interpreted to have been deposited in the dominant distributary channels of a delta plain. The early TST fine-to coarse-grained sandstones were largely deposited in the underwater distributary channel and mouth bar of a delta front, and the middle TST fine-to medium-grained sandstones were deposited in the shoreface to foreshore environment. The HST silt to medium-grained sandstones were mostly deposited in the mouth bar of a delta front and shoreface to foreshore. The Taiyuan sandstones, which are composed of sublitharenites, quartzarenites and litharenites, suffered from extensive compaction that resulted in a large loss of intergranular porosity before the sandstones were further cemented severely. The sandstone cements are mostly composed of illite, ankerite, calcite and quartz. The Taiyuan sandstones have a particularly low average core plug porosity of 7.41% and horizontal permeability of 0.916 mD, which results from that most of the pores of the sandstones are micropores and secondary pores with poor connectivity. The LST dominant distributary channel, early TST underwater distributary channel and proximal mouth bar, and HST shoreface to foreshore sandstones with relatively coarser grain sizes (mostly medium-to coarse-grained) have relatively higher porosities and permeabilities than the sandstones with relatively finer grain size, which is ascribed to a widespread early dissolution by meteor water leaching and lower content of cements within the coarser-grained sandstones. However, the LST dominant distributary channel sandstones had undergone a more effectively early dissolution and less carbonate cementation than the TST underwater distributary channel and proximal mouth bar and HST shoreface and foreshore sandstones had, which lead to the relatively best reservoir quality of the LST dominant distributary channel sandstones among the Taiyuan sandstones. The study revealed that the reservoir quality of the tight Taiyuan sandstones was controlled by sequence stratigraphy framework, depositional facies, grain size and diagenetic alterations together. The sequence stratigraphy framework played a key role in controlling the reservoir quality of the Taiyuan sandstones by governing the depositional facies and corresponding diagenetic products while the grain size affected the reservoir quality of the sandstones by controlling the content of cement within the sandstones. [ABSTRACT FROM AUTHOR]