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Science China Chemistry 2005年第z1期48卷 93-96页

作者： CHANG jianhua zheng Shuzhan jian Yajun bai Yinjuan ZHANG Shiping Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China Department of Chemistry Northwest University Xi'an 710069 China

A novel ligand of DTPA-dihydropyridine derivative was synthesized by reaction of DTPA-dianhydride with 4-aniline-1,4-dihydropyridine. Its complexes of gadolinium, manganese and iron were prepared. Their spin-lattice relaxivities (T1) were investigated. The results show that the NMR T1 relaxivitives (R1) for complexes of Fe(Ⅲ), Mn(Ⅱ) are less than that of Gd(Ⅲ) complex,which has a high relaxivity (R1) on the surrounding water protons, indicating that the Gd(Ⅲ) complex possesses the precondition to be contrast agents for magnetic resonance imaging.

关键词： diethylenetriaminepentaacetic acid, dihydropyridine, magnetic resonance imaging contrast agent, relaxivity.

A Coordinate Gradient Descent Method for Nonsmooth Nonseparable Minimization

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Numerical Mathematics(Theory,Methods and Applications) 2009年第4期2卷 377-402页

作者： zheng-jian bai Michael K. Ng Liqun Qi School of Mathematical Sciences Xiamen University Xiamen 361005 China Centre for Mathematical Imaging and Vision and Department of Mathematics Hong Kong Baptist University Kowloon Tong Hong Kong Department of Applied Mathematics The Hong Kong Polytechnic University Hung Horn Hong Kong

This paper presents a coordinate gradient descent approach for minimizing the sum of a smooth function and a nonseparable convex *** find a search direction by solving a subproblem obtained by a second-order approximation of the smooth function and adding a separable convex *** a local Lipschitzian error bound assumption,we show that the algorithm possesses global and local linear convergence *** also give some numerical tests(including image recovery examples) to illustrate the efficiency of the proposed method.

关键词： Coordinate descent global convergence linear convergence rate

How do high-voltage cathode and PEO electrolyte get along well?EIS analysis mechanism&potentiometric control strategy

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Journal of Energy Chemistry 2024年第9期96卷 424-436页

作者： Xiaodong bai Chaoliang zheng Heng Zhang jian Liu Panpan Wang Baojia Xia jianling Li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 201800China

PEO-based all-solid-state electrolytes are extensively utilized and researched owing to their exceptional safety,low-mass-density,and ***,the low oxidation potential of PEO makes the interface problem with the high-voltage cathode extremely *** this work,the impedance of PEO-based all-solid-state batteries with high-voltage cathode(NCM811)was studied at different *** Nyquist plots displayed a gyrate arc at low-frequencies for NCM811/PEO *** on the kinetic modeling,it was deduced that there is a decomposition reaction of PEO-matrix in addition to de-embedded reaction of NCM811,and the PEO intermediate product(dehydra-PEO)adsorbed on the electrode surface leading to low-frequency inductive ***,the distribution of relaxation time shows the dehydra-PEO results in the kinetic tardiness of the charge transfer process in the temporal ***,an artificial interface layer(CEI_(x))was modified on the surface of NCM811 to regulate the potential of cathode/electrolyte interface to prevent the high-voltage deterioration of ***/CEI_(x)/PEO batteries exhibit capacity retentions of 96.0%,84.6%,and 76.8%after undergoing 100 cycles at cut-off voltages of 4.1,4.2,and 4.3 V,***,here the failure mechanism of high-voltage PEO electrolyte is investigated by EIS and a proposed solving strategy is presented.

关键词： PEo-based electrolyte High-voltage cathode Electrochemical impedance spectroscopy Mechanism research Electrochemical characteristic

Evaluating CMIP6 models in simulating the North Pacific decadal variability in sea surface salinity

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Science China Earth Sciences 2024年第8期67卷 2661-2680页

作者： jian CHEN Hailong LIU Pengfei LIN Wenrong bai Chengzu bai Lu WANG Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China State Key Laboratory of Geo-Information Engineering Xi’an 710054China Beijing Municipal Climate Center Beijing Meteorological BureauBeijing 100089China Space System Department Equipment Department Beijing 100096China

The North Pacific sea surface salinity(SSS)decadal variability(NPSDV)and its potential forcing were evaluated from 25 coupled models of the Coupled Model Intercomparison Project phase 6(CMIP6)considering the prospects for decadal climate *** results indicated that the CMIP6 models generally reproduced the spatial patterns of *** large standard deviation of the SSS anomaly over the strong current regions,such as the Kuroshio-Oyashio Extension(KOE),North Pacific Current(NPC),California Current System(CCS),and Alaskan Coastal Current(ACC),is reflected in the two leading modes of NPSDV:a dipole with out-of-phase loadings in the KOE-NPC versus CCS-ACC and a monopole with positive loading over the *** order of modes is sensitive to individual models that exhibit discrepancies,especially in temporal phases and power *** autoregressive model of order-1 was used to reconstruct the NPSDV with several forcing *** generally weaker influence of forcings in an autoregressive model of order-1 is partly related to the overestimated response time of NPSDV relative to *** NPSDV variances originate from the persistence of SSS anomalies,but the dominant forcing factors are diverse among *** model diversity for the NPSDV simulation mainly arises from the influence of the tropical El Ni?o-Southern Oscillation through teleconnection on the North Pacific Oscillation or Aleutian Low with timescale ***,models that can reproduce the NPSDV well are not dependent on those with larger impacts from the North Pacific oceanic processes.

关键词： North Pacific Sea surface salinity Decadal variability CMIP6 Leading mode

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A review of reservoir damage during hydraulic fracturing of deep and ultra-deep reservoirs

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Petroleum Science 2024年第1期21卷 384-409页

作者： Kun Zhang Xiong-Fei Liu Dao-Bing Wang Bo zheng Tun-Hao Chen Qing Wang Hao bai Er-Dong Yao Fu-jian Zhou National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing102249China School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing102617China Tuha Downhole Operation Company CNPC Xibu Drilling Engineering Company LimitedShanshan838200XinjiangChina

Deep and ultra-deep reservoirs have gradually become the primary focus of hydrocarbon exploration as a result of a series of significant discoveries in deep hydrocarbon exploration *** reservoirs present unique challenges due to their deep burial depth(4500-8882 m),low matrix permeability,complex crustal stress conditions,high temperature and pressure(HTHP,150-200℃,105-155 MPa),coupled with high salinity of formation ***,the costs associated with their exploitation and development are exceptionally *** deep and ultra-deep reservoirs,hydraulic fracturing is commonly used to achieve high and stable *** hydraulic fracturing,a substantial volume of fluid is injected into the ***,statistical analysis reveals that the flowback rate is typically less than 30%,leaving the majority of the fluid trapped within the ***,hydraulic fracturing in deep reservoirs not only enhances the reservoir permeability by creating artificial fractures but also damages reservoirs due to the fracturing fluids *** challenging“three-high”environment of a deep reservoir,characterized by high temperature,high pressure,and high salinity,exacerbates conventional forms of damage,including water sensitivity,retention of fracturing fluids,rock creep,and proppant *** addition,specific damage mechanisms come into play,such as fracturing fluid decomposition at elevated temperatures and proppant diagenetic reactions at HTHP ***,the foremost concern in deep oil and gas development lies in effectively assessing the damage inflicted on these reservoirs by hydraulic fracturing,comprehending the underlying mechanisms,and selecting appropriate ***'s noteworthy that the majority of existing studies on reservoir damage primarily focus on conventional reservoirs,with limited attention given to deep reservoirs and a lack of systematic *** light of this,our approach entails initially summarizin

关键词： Artificial fracture Deep and ultra-deep reservoir Fracture conductivity Fracturing fluid Hydraulic fracturing Reservoir damage

Diffractive neural networks with improved expressive power for gray-scale image classification

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Photonics Research 2024年第6期12卷 1159-1166页

作者： MINJIA zheng WENZHE LIU LEI SHI jian ZI State Key Laboratory of Surface Physics Key Laboratory of Micro-and Nano-Photonic Structures(Ministry of Education)and Department of PhysicsFudan UniversityShanghai 200433China Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China Shanghai Research Center for Quantum Sciences Shanghai 210315China

In order to harness diffractive neural networks(DNNs)for tasks that better align with real-world computer vision requirements,the incorporation of gray scale is ***,DNNs are not powerful enough to accomplish gray-scale image processing tasks due to limitations in their expressive *** our work,we elucidate the relationship between the improvement in the expressive power of DNNs and the increase in the number of phase modulation layers,as well as the optimization of the Fresnel number,which can describe the diffraction *** demonstrate this point,we numerically trained a double-layer DNN,addressing the prerequisites for intensitybased gray-scale image ***,we experimentally constructed this double-layer DNN based on digital micromirror devices and spatial light modulators,achieving eight-level intensity-based gray-scale image classification for the MNIST and Fashion-MNIST data *** optical system achieved the maximum accuracies of 95.10%and 80.61%,respectively.

关键词： process mirror limitations

Image Inpainting Technique Incorporating Edge Prior and Attention Mechanism

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Computers, Materials & Continua 2024年第1期78卷 999-1025页

作者： Jinxian bai Yao Fan Zhiwei Zhao Lizhi zheng College of Information Engineering Xizang Minzu UniversityXianyang712000China

Recently,deep learning-based image inpainting methods have made great strides in reconstructing damaged ***,these methods often struggle to produce satisfactory results when dealing with missing images with large holes,leading to distortions in the structure and blurring of *** address these problems,we combine the advantages of transformers and convolutions to propose an image inpainting method that incorporates edge priors and attention *** proposed method aims to improve the results of inpainting large holes in images by enhancing the accuracy of structure restoration and the ability to recover texture *** method divides the inpainting task into two phases:edge prediction and image ***,in the edge prediction phase,a transformer architecture is designed to combine axial attention with standard *** design enhances the extraction capability of global structural features and location *** also balances the complexity of self-attention operations,resulting in accurate prediction of the edge structure in the defective *** the image inpainting phase,a multi-scale fusion attention module is *** module makes full use of multi-level distant features and enhances local pixel continuity,thereby significantly improving the quality of image *** evaluate the performance of our *** experiments are conducted on several datasets,including CelebA,Places2,and *** experiments show that our method outperforms the other mainstream ***,it improves Peak Signal-to-Noise Ratio(PSNR)and Structure Similarity Index Measure(SSIM)by 1.141~3.234 db and 0.083~0.235,***,it reduces Learning Perceptual Image Patch Similarity(LPIPS)and Mean Absolute Error(MAE)by 0.0347~0.1753 and 0.0104~0.0402,*** experiments reveal that our method excels at reconstructing images with complete structural information and c

关键词： Image inpainting transformer edge prior axial attention multi-scale fusion attention

Ellagic acid inhibits gastric cancer cells by modulating oxidative stress and inducing apoptosis

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Asian Pacific Journal of Tropical Biomedicine 2024年第4期14卷 162-169页

作者： jian zheng Chun-Feng Li Department of Diagnostic Radiology Division Harbin Medical University Cancer HospitalHeilongjiangChina Department of Gastrointestinal Surgical Ward Harbin Medical University Cancer HospitalHeilongjiangChina

Objective:To evaluate the anticancer effect of ellagic acid on gastric cancer ***:MTT assay was used to evaluate the effect of ellagic acid at different concentrations(0.5-100μg/mL)on gastric cancer AGS ***-qPCR and Western blot analyses were applied to assess apoptosis(BCL-2,CASP-3,and BAX)and autophagy(LC3,ATG5,and BECN1)in AGS cells treated with ellagic *** expression of invasion-related markers including TP53,CDKN2A,and PTEN was *** addition,cell cycle markers including cyclin A,B,D,and E were measured by *** stress markers were evaluated using ***:Ellagic acid inhibited the proliferation of AGS cells in a concentration-and time-dependent *** expression of BCL-2 was significantly decreased(P0.05).Moreover,the oxidative stress markers including SOD,TAC,and MDA were increased by ellagic acid(P<0.01).Conclusions:Ellagic acid can inhibit cell proliferation,induce apoptosis,and modulate oxidative stress in AGS ***,further in vivo and molecular studies are needed to verify its anticancer efficacy.

关键词： Ellagic acid Gastric cancer Apoptosis Autophagy Metastasis Proliferation

Recent Advances in Asymmetric Structural Composites for Excellent Electromagnetic Interference Shielding: A Review

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Chinese Journal of Polymer Science 2024年第6期42卷 693-710页

作者： Ying Zhou bai Xue Lan Xie Chang-Mei Wu Qiang zheng Department of Polymer Materials and Engineering College of Materials and Metallurgy Guizhou University National Engineering Research Center for Compounding and Modification of Polymer Materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane Processes State Key Laboratory of Public Big Data Guizhou University Department of Polymer Science and Engineering Zhejiang University

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness(EMI SE) via designing the hierarchical structures for electromagnetic interference(EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the “absorption-reflection-reabsorption” shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation(5G) technology.

关键词： Asymmetric structure Microano functional filler Polymer composite Electromagnetic interference shielding

Simulation of RFI Cancellation Using Subspace Projection Algorithm for PAF Receiver

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Research in Astronomy and Astrophysics 2024年第1期24卷 237-244页

作者： Peng Wu jian Li Mao-zheng Chen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The simulation of radio frequency interference(RFI) cancellation by applying a spatial filtering technique for phased array feed(PAF) is presented. In order to better reflect the characteristics of PAF, a new signal model is to add the coupling coefficient among elements of PAF to the conventional array signal model. Then the subspace projection(SP) algorithm is used to cancel RFI from the correlation matrix of the signal, and finally, the 2D power image is drawn. The power variation of signal-of-interest direction and RFI direction before and after using the SP algorithm is analyzed. The new signal model and simulation strategy can be used to test and verify the beamformer.

关键词： methods:analytical techniques:radar astronomy telescopes