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Insight into the Role of Isolated Gold Atoms-Ceria Conjunction in Catalyzing the Water-Gas Shift Reaction

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Chinese Journal of Chemistry 2024年第6期42卷 636-644页

作者： Xin-Pu Fu Hui-Zhao wei-wei Wang Chun-Jiang Jia Key Laboratory for Colloid and Interface Chemistry Key Laboratory of Special Aggregated MaterialsSchool of Chemistry and Chemical EngineeringShandong UniversityJinanShandong250100 China

As the promising catalysts for the water-gas shift(WGS)reaction,the activity of Au-CeO_(2) composites is susceptible to the aggregation size and electronic state of Au *** reports were extensively focused on the discrepancy between nonmetallic Au and metallic Au nanoparticles,whereas the understanding of the authentic role of the isolated Au atoms was ***,we investigated the catalytic behavior and structural information over two types of Au/CeO_(2) catalysts,in which the predominant conjunctions were isolated Au1.CeO_(2) and Aun-CeO_(2),*** on comprehensive characterizations,particularly by in-situ Raman and in-situ DRIFTS,we found that the isolated Au atoms were responsible for enhancing the reducibility of the CeO_(2) *** CO adsorption ability on the isolated Au sites was significantly inferior to clustered Au atoms,especially at relatively high temperatures(>200°C).As a result,the boosted O vacancy on the isolated Au1.CeO_(2) conjunctions could improve the H2O activation ability for the Au-CeO_(2) catalysts and demonstrate a comparable activity to the clustered Aun-CeO_(2) *** work might deepen understanding of the catalytic function for the isolated Au1.site within Au/CeO_(2) systems while catalyzing the WGS reaction.

关键词： Isolated Au atoms Ceria-based catalysts Water-gas shift reaction Defect Adsorption

Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

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Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng Sheng-Jie wei Guang-Qing Zhang Da-wei Zhou Chuang-Chao Xu School of Petroleum Engineering China University of Petroleum PetroChina Changqing Oilfield Company

Pulsating hydraulic fracturing(PHF) is a promising fracturing method and can generate a dynamic periodic pressure. The periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of fracture. If the frequency of periodic pressure exceeds 1. Hz, the distribution of pressure along the main fracture will be heterogeneous, which is much different from the one induced by the common fracturing method. In this study, the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated. A coupled numerical simulation model is first proposed and verified through experimental and theoretical solutions. The mechanism of secondary fracture initiation around the main fracture is then discovered. In addition, sensitivity studies are conducted to find out the application potential of this new method. The results show that(1. this coupled numerical simulation model is accurate. Through comparison with experimental and theoretical data, the average error of this coupled model is less than 1.01..(2) Even if a reservoir has no natural fracture, this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3) The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4) Through adjusting the stimulation parameters, the stimulation efficiency can be improved. The average and amplitude of pressure can increase possibility of secondary fracture initiation. The frequency of this periodic pressure can increase number of secondary fractures. Even 6 secondary fractures along a 1.0 m-length main fracture can be generated.(5) The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties, therefore, this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

Long-time Asymptotics for the Reverse Space-time Nonlocal Hirota Equation with Decaying Initial Value Problem:without Solitons

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 708-727页

作者： wei-qi PENG Yong CHEN School of Mathematical Sciences East China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this work,we mainly consider the Cauchy problem for the reverse space-time nonlocal Hirota equation with the initial data rapidly decaying in the solitonless *** from the Lax pair,we first construct the basis Riemann-Hilbert problem for the reverse space-time nonlocal Hirota ***,using the approach of Deift-Zhou nonlinear steepest descent,the explicit long-time asymptotics for the reverse space-time nonlocal Hirota is *** the reverse space-time nonlocal Hirota equation,since the symmetries of its scattering matrix are different with the local Hirota equation,the v(λ_(i))(i=0,1.would like to be imaginary,which results in theδ_(λi)^(0)contains an increasing t(±Imv(λ_(i)))/2,and then the asymptotic behavior for nonlocal Hirota equation becomes differently.

关键词： Riemann-Hilbert problem reverse space-time nonlocal Hirota equation long-time asymptotics nonlinear steepest descent method

HEN:a novel hybrid explainable neural network based framework for robust network intrusion detection

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Science China(Information Sciences) 2024年第7期67卷 72-90页

作者： wei wei Sijin CHEN Cen CHEN Heshi WANG Jing LIU Zhongyao CHENG Xiaofeng ZOU School of Computer Science and Engineering Xi'an University of TechnologyShaanxi Key Laboratory for Network Computing and Security Technology School of Computer Science and Technology Wuhan University of Science and Technology School of Future Technology South China University of Technology Shenzhen Research Institute of Hunan University School of Computer Science Hunan University of Technology and Business Institute for Infocomm Research (I2R) Agency for Science Technology and Reseach (A*STAR)

With the rapid development of network technology and the automation process for 5G, cyberattacks have become increasingly complex and threatening. In response to these threats, researchers have developed various network intrusion detection systems(NIDS) to monitor network traffic. However, the incessant emergence of new attack techniques and the lack of system interpretability pose challenges to improving the detection performance of NIDS. To address these issues, this paper proposes a hybrid explainable neural network-based framework that improves both the interpretability of our model and the performance in detecting new attacks through the innovative application of the explainable artificial intelligence(XAI)method. We effectively introduce the Shapley additive explanations(SHAP) method to explain a light gradient boosting machine(Light GBM) model. Additionally, we propose an autoencoder long-term short-term memory(AE-LSTM) network to reconstruct SHAP values previously generated. Furthermore, we define a threshold based on reconstruction errors observed during the training phase. Any network flow that surpasses the specified threshold is classified as an attack flow. This approach enhances the framework's ability to accurately identify attacks. We achieve an accuracy of 92.65%, a recall of 95.26%, a precision of 92.57%,and an F1.score of 93.90% on the dataset NSL-KDD. Experimental results demonstrate that our approach generates detection performance on par with state-of-the-art methods.

关键词： explainable artificial intelligence light gradient boosting machine machine learning network intrusion detection Shapley additive explanation hybrid explainable neural network (HEN)

EPR-Net: constructing a non-equilibrium potential landscape via a variational force projection formulation

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National Science Review 2024年第7期11卷 135-147页

作者： Yue Zhao wei Zhang Tiejun Li Center for Data Science Peking University Zuse Institute Berlin Department of Mathematics and Computer Science Freie Universit?t Berlin Laboratory of Mathematics and Applied Mathematics(LMAM)and School of Mathematical Sciences Peking University Center for Machine Learning Research Peking University

We present EPR-Net, a novel and effective deep learning approach that tackles a crucial challenge in biophysics: constructing potential landscapes for high-dimensional non-equilibrium steady-state ***-Net leverages a nice mathematical fact that the desired negative potential gradient is simply the orthogonal projection of the driving force of the underlying dynamics in a weighted inner-product ***, our loss function has an intimate connection with the steady entropy production rate(EPR),enabling simultaneous landscape construction and EPR estimation. We introduce an enhanced learning strategy for systems with small noise, and extend our framework to include dimensionality reduction and the state-dependent diffusion coefficient case in a unified fashion. Comparative evaluations on benchmark problems demonstrate the superior accuracy, effectiveness and robustness of EPR-Net compared to existing methods. We apply our approach to challenging biophysical problems, such as an eight-dimensional(8D)limit cycle and a 52D multi-stability problem, which provide accurate solutions and interesting insights on constructed landscapes. With its versatility and power, EPR-Net offers a promising solution for diverse landscape construction problems in biophysics.

关键词： high-dimensional potential landscape non-equilibrium system entropy production rate dimensionality reduction deep learning

Nearly degenerate ground states of a checkerboard antiferromagnet and their bosonic interpretation

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 84-89页

作者： Haiyuan Zou Fan Yang wei Ku Key Laboratory of Polar Materials and Devices(MOE) School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China Department of Physics Beijing Institute of TechnologyBeijing 100081China Tsung-Dao Lee Institute Shanghai 200240China Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) Shanghai 200240China Shanghai Branch Hefei National LaboratoryShanghai 201315China

The spin-1.2 model system with antiferromagnetic(AF) couplings on a J1.J2checkerboard lattice, known as the planar pyrochlore model, is strongly frustrated and associated with a two-to-one dimensional crossover. Using the Projected Entangled Simplex States tensor network ansatz, we identify a large number of nearly degenerate states in the frustrated region(J_(1.1.≤J_(2), while various 1. AF correlated states take over the rest. We verify the stability of the VBS state against nematic perturbation. The corresponding bosonic picture provides an intuitive understanding of the low-energy physics. Particularly, it predicts weaker VBS states in the easy-plane limit, which we confirm numerically. Our results clarify the most essential ground state properties of this interesting system and demonstrate the usefulness of bosonic picture in dealing with frustrated magnetism.

关键词： tensor networks frustrated magnetism dimensional crossover degenerate states

Wireless multisite sensing systems for continuous physiological monitoring

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Science China Materials 2024年第6期67卷 2045-2047页

作者： Ruilai wei Qilin Hua Guozhen Shen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China Institute of Flexible Electronics Beijing Institute of TechnologyBeijing 102488China

Respiratory diseases rank as the third leading cause of adult mortality[1.,while cardiopulmonary and gastrointestinal issues are the primary cause of death within the first five years of a child’s life[2].The monitoring of cardiac,respiratory,and gastrointestinal sounds plays a vital role in routine care,as alterations or absence of these body sounds can serve as indicators of underlying diseases.

关键词： routine continuous monitoring

Cardiac infiltration of diffuse large B-cell lymphoma manifesting as sustained ventricular tachycardia:a case report

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Journal of Geriatric Cardiology 2024年第2期21卷 242-245页

作者： wei CHEN Kun HUANG wei-wei GUO Fan ZHOU De-Ning LIAO Department of Cardiology Shanghai Jingan District Zhabei Central HospitalShanghaiChina Department of Cardiology Shanghai Changzheng HospitalShanghaiChina Department of Hematology Shanghai Jingan District Zhabei Central HospitalShanghaiChina

Cardiac tumors are ***,cardiac metastases can occur in up to 1.%of patients with *** cardiac neoplasms,metastases are much more common than primary cardiac tumors.[1.Metastatic cardiac neoplasms most frequently metast... 详细信息

关键词： neoplasms sustained cardiac

Contribution of Surface Waves to Sea Surface Temperatures in the Arctic Ocean

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Journal of Ocean University of China 2024年第5期23卷 1151-1162页

作者： wei Meng SHAO weizeng SHEN wei HU Yuyi ZHANG Yu ZUO Juncheng College of Oceanography and Ecological Science Shanghai Ocean UniversityShanghai 201306China China Waterborne Transport Research Institute Ministry of Transport of the People’s Republic of ChinaBeijing 100088China

The aim of our study was to examine the contribution of surface waves from WAVEWATCH-III(WW3)to the variation in sea surface temperature(SST)in the Arctic *** simulated significant wave height(SWH)were validated against the products from Haiyang-2B(HY-2B)in 2021.obtaining a root mean squared error(RMSE)of 0.45 with a correlation of 0.96 and scatter index of *** wave-induced effects,i.e.,wave breaking and mixing induced by nonbearing waves resulting in changes in radiation stress and Stokes drift,were calculated from WW3,ERA-5 wind,SST,and salinity data from the National Centers for Environmental Prediction and were taken as forcing fields in the Stony Brook Parallel Ocean *** results showed that an RMSE of 0.81. with wave-induced effects was less than the RMSE of 1.1.℃ achieved without the wave term compared with the simulated SST with the measurements from *** the four wave effects and sea ice freezing,the SST in the Arctic Ocean decreased by up to 1. in *** analysis revealed that the SWH was linear in SST(values without subtraction of waves)in summer and autumn,but this behavior was not observed in spring or winter due to the presence of sea *** interannual variation also presented a negative relationship between the difference in SST and SWH.

关键词： sea surface wave sea surface temperature Arctic Ocean