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Graph convolutional networks (GCNs), an emerging type of neural network model on graphs, have presented state-of-the-art performance on the node classification task. However, recent studies show that neural networks are vulnerable to the small but deliberate perturbations on input features. And GCNs could be more sensitive to the perturbations since the perturbations from neighbor nodes exacerbate the impact on a target node through the convolution. Adversarial training (AT) is a regularization technique that has been shown capable of improving the robustness of the model against perturbations on image classification. However, directly adopting AT on GCNs is less effective since AT regards examples as independent of each other and does not consider the impact from connected examples. In this work, we explore AT on graph and propose a graph-specific AT method, Directional Graph Adversarial Training (DGAT), which incorporates the graph structure into the adversarial process and automatically identifies the impact of perturbations from neighbor nodes. Concretely, we consider the impact from the connected nodes to define the neighbor perturbation which restricts the perturbation direction on node features towards their neighbor nodes, and additionally introduce an adversarial regularizer to defend the worst-case perturbations. In this way, DGAT can resist the impact of worst-case adversarial perturbations and reduce the impact of perturbations from neighbor nodes. Extensive experiments demonstrate that DGAT can effectively improve the robustness and generalization performance of GCNs. Specially, GCNs with DGAT can provide better performance when there are rare few labels available for training.

The low-frequency unsteady motions behind a backward-facing step (BFS) in a turbulent flow at $Ma=1.7$ and $Re_\\infty =1.3718\\times 10^7 \\ {\\rm m}^{-1}$ are investigated using a well-resolved large-eddy simulation. The instantaneous flow field illustrates the unsteady phenomena of the shock wave/boundary layer interaction (SWBLI) system, including vortex shedding in the shear layer, the flapping motions of the shock and breathing of the separation bubble, streamwise streaks near the wall and arc-shaped vortices in the turbulent boundary layer downstream of the separation bubble. A spectral analysis reveals that the low-frequency behaviour of the system is related to the interaction between shock wave and separated shear layer, while the medium-frequency motions are associated with the shedding of shear layer vortices. Using a three-dimensional dynamic mode decomposition (DMD), we analyse the individual contributions of selected modes to the unsteadiness of the shock and streamwise-elongated vortices around the reattachment region. Görtler-like vortices, which are induced by the centrifugal forces originating from the strong curvature of the streamlines in the reattachment region, are strongly correlated with the low-frequency unsteadiness in the current BFS case. Our DMD analysis and the comparison with an identical but laminar case provide evidence that these unsteady Görtler-like vortices are affected by fluctuations in the incoming boundary layer. Compared with SWBLI in flat plate and ramp configurations, we observe a slightly higher non-dimensional frequency (based on the separation length) of the low-frequency mode.

The flow over a forward-facing step (FFS) at $Ma_\\infty =1.7$ and $Re_{\\delta _0}=1.3718\\times 10^{4}$ is investigated by well-resolved large-eddy simulation. To investigate effects of upstream flow structures and turbulence on the low-frequency dynamics of the shock wave/boundary layer interaction (SWBLI), two cases are considered: one with a laminar inflow and one with a turbulent inflow. The laminar inflow case shows signs of a rapid transition to turbulence upstream of the step, as inferred from the streamwise variation of $\\langle C_f \\rangle$ and the evolution of the coherent vortical structures. Nevertheless, the separation length is more than twice as large for the laminar inflow case, and the coalescence of compression waves into a separation shock is observed only for the fully turbulent inflow case. The dynamics at low and medium frequencies is characterized by a spectral analysis, where the lower frequency range is related to the unsteady separation region, and the intermediate one is associated with the shedding of shear layer vortices. For the turbulent inflow case, we furthermore use a three-dimensional dynamic mode decomposition to analyse the individual contributions of selected modes to the unsteadiness of the SWBLI. The separation shock and Görtler-like vortices, which are induced by the centrifugal forces in the separation region, are strongly correlated with the low-frequency unsteadiness in the current FFS case. Similarly as observed previously for the backward-facing steps, we observe a slightly higher non-dimensional frequency (based on the separation length) of the low-frequency mode than for SWBLI in flat plate and ramp configurations.

Introduction Anti-programmed cell death-ligand 1 (Anti-PD-L1) blockades have become the first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC) from CASPIAN and IMpower133 trials. SCLC has a high incidence of brain metastasis (BM) and brain radiotherapy (BRT) is the main local treatment method, but there is limited data on the BRT-immunotherapy scheme. The aim of the retrospective study is to investigate the clinical efficacy and safety of the first-line anti-PD-L1 blockades combined with BRT in ES-SCLC with BM. Methods Patients with newly diagnosed ES-SCLC with baseline BMs at Shandong Cancer Hospital and Research Institute between 2017 and 2021 were selected. Patients were divided into the anti-PD-L1+BRT group and BRT group. We also assessed the leukoencephalopathy in both groups. Results A total of 46 patients were selected. Fifteen were divided into anti-PD-L1+BRT group and 31 to BRT group. The median overall survival (OS) was not reached (NR) vs 15.9 m ( P  = 0.172). Progression-free survival (PFS) was numerically prolonged with anti-PD-L1 blockades, but the significance was not reached (median: 9.4 m vs 7.4 m, P  = 0.362). The median intracranial PFS was not improved, neither (median: 8.2 m vs 8.9 m, P  = 0.620). Objective response rate (ORR) in the two groups was 73.33% vs 77.42% ( P  = 0.949) and disease control rate (DCR) was both 100%. Intracranial ORR and DCR were 53.33% vs 70.97% ( P  = 0.239) and 73.33% vs 80.65% ( P  = 0.855), respectively. There was no significant difference in leukoencephalopathy incidence between the two groups. Conclusion The combination of first-line anti-PD-L1 blockades with BRT did not confer a significant survival benefit in ES-SCLC with BM, without enhancing cranial neurotoxicity.

Among the four candidate algorithms in the fourth round of NIST standardization, the BIKE (Bit Flipping Key Encapsulation) scheme has a small key size and high efficiency, showing good prospects for application. However, the BIKE scheme based on QC-MDPC (Quasi Cyclic Medium Density Parity Check) codes still faces challenges such as the GJS attack and weak key attacks targeting the decoding failure rate (DFR). This paper analyzes the BGF decoding algorithm of the BIKE scheme, revealing two deep factors that lead to DFR, and proposes a weak key optimization attack method for the BGF decoding algorithm based on these two factors. The proposed method constructs a new weak key set, and experiment results eventually indicate that, considering BIKE’s parameter set targeting 128-bit security, the average decryption failure rate is lowerly bounded by . This result not only highlights a significant vulnerability in the BIKE scheme but also provides valuable insights for future improvements in its design. By addressing these weaknesses, the robustness of QC-MDPC code-based cryptographic systems can be enhanced, paving the way for more secure post-quantum cryptographic solutions.

This paper presents a self‐protected wide‐range bi‐directional voltage‐to‐current (V–I) converter. The proposed V–I converter is a self‐contained cell that operates independently and implements high precision conversion with a transconductance set by resistors. Compared with conventional structures, the proposed scheme features safety and reliability. The conversion range is widened since the internal biasing current is not starved and is adaptively set based on the input voltage. The proposed V–I structure was fabricated in a 0.18‐µm Bipolar‐CMOS‐DMOS (BCD) process with a die area of 0.0825 mm2. The measured non‐linearity across an input voltage range from −70 to 70 V was within ±0.2%. The total harmonic distortion was −63 dB at 1 kHz and the delay of conversion was within 3 µs.

This article studies the influence of structural parameters of the optimization model for the gas–liquid mixing device of a fire truck (compressed air foam lift fire truck, model JP21/G2, made in China) on the liquid phase volume fraction, static pressure, velocity streamline, and the influence of smaller flow rates on the mixing effect. By using the computational fluid dynamics (CFD) software FLUENT 2021 R2, numerical simulations were conducted on the fluid domain model of the gas–liquid mixing device of the JP21/G2 fire truck. The changes in the mixing effect time dimension, liquid phase volume fraction, static pressure, and velocity streamline inside the gas–liquid mixing device were obtained. The optimal mixer structure combination in practical applications was inferred through orthogonal experiments, and the influence of flow rate on the optimal pipe diameter and shortest mixing distance was obtained through variable flow rate simulation experiments. The numerical simulation results show that the presence of bent pipes in the JP21/G2 real vehicle model hinders the gas–liquid mixing process. A straight pipe section of at least 8 m was added after the bent pipe to ensure the mixing effect. The optimal parameter combination for orthogonal experiments had an accurate value of 50°-50°-220 mm. Under the same pipe diameter, using a larger flow rate can achieve better mixing effects.

In this paper, we reported a technique for the surface modification of poly-( p -phenylene terephthamide) (PPTA) powder coated with polydopamine (PDOPA). We used air oxidation to self-polymerize dopamine (DOPA) to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reaction time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride (EPDM- g -MAH), and it proved that this method can enhance the strength and electric insulativity of EPDM- g -MAH.

In this paper, we report a technique for the surface modification of poly-（p-phenylene terephthamide） （PPTA） powder coated with polydopamine （PDOPA）. We used air oxidation to self-polymerize dopamine （DOPA） to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reac- tion time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride （EPDM-g-MAH）, and it proved that this method can enhance the strength and electric insulativity of EPDM-g-MAH.

A novel and efficient synthesis of pyrazole fused[6-7-5]tricyclic derivatives via AlCl 3 -catalysed intramolecular Friedel–Crafts reaction of the Morita–Baylis–Hillman adducts was described and a plausible mechanism was given.