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A convenient preparation of ethoxymethoxymethane and its effect on the solubility of methanol/gasoline blends

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Chinese Chemical Letters 2009年第8期20卷 973-976页

作者： Shan Jian Cao Ai you Hao hong Yuan sun Tao sun School of Chemistry and Chemical Engineering Shandong University Jinan 250100 China

Ethoxymethxoymethane （EMM） was conveniently prepared by acetalization of aqueous formaldehyde with methanol andethanol in a batch reactive distillation mode using a cation-exchange resin catalyst for the first time. EMM was found tO be asignificant cosolvent of methano1/gasoline blends, ？ 2009 Ai you Hao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.

关键词： Ethoxymethoxymethane Cation-exchange resin catalyst Batch reactive distillation Methano1/gasoline Cosolvent

Hydrocarbon gas huff-n-puff optimization of multiple horizontal wells with complex fracture networks in the M unconventional reservoir

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Petroleum Science 2024年第2期21卷 1018-1031页

作者： Hao-Chuan Zhang Yong Tang you-Wei He Yong Qin Jian-hong Luo Yu sun Ning Wang De-Qiang Wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina CNPC Research Institute of Petroleum Exploration&Development Beijing100083China Southwest Oil&Gas Field Company PetroChinaChengdu610051SichuanChina State Key Laboratory of Offshore Oil Exploitation CNOOC Research Institute Co.LtdBeijing100027China

The oil production of the multi-fractured horizontal wells(MFHWs) declines quickly in unconventional oil reservoirs due to the fast depletion of natural energy. Gas injection has been acknowledged as an effective method to improve oil recovery factor from unconventional oil reservoirs. Hydrocarbon gas huff-n-puff becomes preferable when the CO_(2) source is limited. However, the impact of complex fracture networks and well interference on the EOR performance of multiple MFHWs is still unclear. The optimal gas huff-n-puff parameters are significant for enhancing oil recovery. This work aims to optimize the hydrocarbon gas injection and production parameters for multiple MFHWs with complex fracture networks in unconventional oil reservoirs. Firstly, the numerical model based on unstructured grids is developed to characterize the complex fracture networks and capture the dynamic fracture ***, the PVT phase behavior simulation was carried out to provide the fluid model for numerical simulation. Thirdly, the optimal parameters for hydrocarbon gas huff-n-puff were obtained. Finally, the dominant factors of hydrocarbon gas huff-n-puff under complex fracture networks are obtained by fuzzy mathematical method. Results reveal that the current pressure of hydrocarbon gas injection can achieve miscible displacement. The optimal injection and production parameters are obtained by single-factor analysis to analyze the effect of individual parameter. Gas injection time is the dominant factor of hydrocarbon gas huff-n-puff in unconventional oil reservoirs with complex fracture networks. This work can offer engineers guidance for hydrocarbon gas huff-n-puff of multiple MFHWs considering the complex fracture networks.

关键词： Unconventional oil reservoir Complex fracture network Hydrocarbon gas huff-n-puff Parameter optimization Numerical simulation

Special issue:Catenary optics and catenary electromagnetics

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Opto-Electronic Advances 2024年第5期7卷 1-4页

作者： Qian sun Minghui hong Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

As a natural mathematical form,a catenary is the curve that a hanging chain or cable adopts under its own weight when supported at its ends in a homogeneous gravitational *** unique shape arises from the balance of forces acting on each segment of the chain,resulting in a curve described by hyperbolic cosine *** functions play pivotal roles in describing the electromagnetic field,intensity distribution,and dispersion of structured light on the sub-wavelength scale^(1).

关键词： functions field optics

Laser manufacturing of spatial resolution approaching quantum limit

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Light(Science & Applications) 2024年第3期13卷 421-428页

作者： Xiao-Jie Wang hong-Hua Fang Zhen-Ze Li Dan Wang hong-Bo sun State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

Atomic and close-to-atom scale manufacturing is a promising avenue toward single-photon emitters,single-electron transistors,single-atom memory,and quantum-bit devices for future communication,computation,and sensing *** manufacturing is outstanding to this end for ease of beam manipulation,batch production,and no requirement for *** is,however,suffering from optical diffraction ***,we report a spatial resolution improved to the quantum limit by exploiting a threshold tracing and lock-in method,whereby the two-order gap between atomic point defect complexes and optical diffraction limit is surpassed,and a feature size of<5 nm is *** underlying physics is that the uncertainty of local atom thermal motion dominates electron excitation,rather than the power density slope of the incident *** show that the colour centre yield in hexagonal boron nitride is transformed from stochastic to deterministic,and the emission from individual sites becomes polychromatic to *** a result,single colour centres in the regular array are deterministically created with a unity yield and high positional accuracy,serving as a step forward for integrated quantum technological applications.

关键词： quantum limit resolution

Rapid Energy Exchange between In Situ Formed Bromine Vacancies and CO_(2)Molecules Enhances CO_(2)Photoreduction

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Research 2024年第2期2023卷 763-771页

作者： Qin Ren Ye He hong Wang Yanjuan sun Fan Dong Research Center for Environmental and Energy Catalysis Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China

Photocatalytic reduction of CO_(2)into fuels provides a prospective tactic for regulating the global carbon balance utilizing renewable solar ***,CO_(2)molecules are difficult to activate and reduce due to the thermodynamic stability and chemical *** this work,we develop a novel strategy to promote the adsorption and activation of CO_(2)molecules via the rapid energy exchange between the photoinduced Br vacancies and CO_(2)*** in situ continuous wave-electron paramagnetic resonance(cw-EPR)and pulsed EPR technologies,we observe that the spin-spin relaxation time(T_(2))of BiOBr is decreased by 198 ns during the CO_(2)photoreduction reaction,which is further confirmed by the broadened EPR *** result reveals that there is an energy exchange interaction between in situ formed Br vacancies and CO_(2)molecules,which promotes the formation of high-energy CO_(2)molecules to facilitate the subsequent reduction *** addition,theoretical calculations indicate that the bended CO_(2)adsorption configuration on the surface of BiOBr with Br vacancies caused the decrease of the lowest unoccupied molecular orbital of the CO_(2)molecule,which makes it easier for CO_(2)molecules to acquire electrons and get *** situ diffuse reflectance infrared Fourier transform spectroscopy further shows that the activated CO_(2)molecules are favorably converted to key intermediates of COOH*,resulting in a CO generation rate of 9.1μmol g^(-1)h^(-1)and a selectivity of 100%.This study elucidates the underlying mechanism of CO_(2)activation at active sites and deepens the understanding of CO_(2)photoreduction reaction.

关键词： reaction. adsorption activation

Dietary Supplementation of β-Carotene Reveals miRNAs Involved in the Regulation of Carotenoid Metabolism in Crassostrea gigas

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Journal of Ocean University of China 2024年第4期23卷 1045-1053页

作者： sun Dongfang WAN Sai YU hong KONG Lingfeng LI Qi Key Laboratory of Mariculture Ministry of EducationOcean University of ChinaQingdao 266003China Laboratory for Marine Fisheries Science and Food Production Processes Laoshan LaboratoryQingdao 266237China

Carotenoids play crucial physiological roles in animals.A comprehensive investigation into the mechanism of carotenoid metabolism in oysters will establish a theoretical foundation for further development of its carotenoid-rich ***,the information on the function of miRNA in β-carotene metabolism in oysters is *** elucidate the mechanisms underlying miRNA regulation of carotenoid metabolism in oysters,we compared the expressions of miRNA in digestive gland tissues of Pacific oyster(Crassostrea gigas)fed with aβ-carotene supplemented diet and a normal diet,respectively.A total of 690 candidate miRNAs in the Pacific oyster digestive gland tissues were identified,including 590 known miRNAs and 111 unknown *** differentially expressed miRNAs were obtained in the carotenoid-fed and normal groups,associated to 137 differentially expressed target ***,the GO enrichment analysis revealed that the differentially expressed target genes were mainly involved in transmembrane transport *** enrichment showed that the differentially expressed target genes were involved in ABC *** of the mRNA-miRNA network revealed that novel0025 played a central role in carotenoid metabolism,and it was negatively correlated with the expression of 46 *** addition,down-regulated expression of novel0025 upregulated the expression of the lipoprotein gene LOC105342186,suggesting a potential regulatory role in carotenoid *** results provide useful information for elucidating the miRNA regulation mechanism during carotenoids metabolism in the Pacific oyster.

关键词： Crassostrea gigas β-carotene microRNA carotenoid metabolism

Prediction and interpretation of photocatalytic NO removal on g-C_(3)N_(4)-based catalysts using machine learning

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Chinese Chemical Letters 2024年第2期35卷 477-483页

作者： Jing Li Xinyan Liu hong Wang Yanjuan sun Fan Dong School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China Research Center for Carbon-Neutral Environmental & Energy Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China

Predictive modeling of photocatalytic NO removal is highly desirable for efficient air pollution ***,great challenges remain in precisely predicting photocatalytic performance and understanding interactions of diverse features in the catalytic ***,a dataset of g-C_(3) N_(4)-based catalysts with 255 data points was collected from peer-reviewed publications and machine learning(ML)model was proposed to predict the NO removal *** result shows that the Gradient Boosting Decision Tree(GBDT)demonstrated the greatest prediction accuracy with R 2 of 0.999 and 0.907 on the training and test data,*** SHAP value and feature importance analysis revealed that the empirical categories for NO removal rate,in the order of importance,were catalyst characteristics>reaction process>preparation ***,the partial dependence plots broke the ML black box to further quantify the marginal contributions of the input features(e.g.,doping ratio,flow rate,and pore volume)to the model output *** ML approach presents a pure data-driven,interpretable framework,which provides new insights into the influence of catalyst characteristics,reaction process,and preparation conditions on NO removal.

关键词： Machine learning g-C_(3)N_(4)-based catalysts NO removal Interpretability Catalytic informatics

Electrolyte Design for Low‑Temperature Li‑Metal Batteries:Challenges and Prospects

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Nano-Micro Letters 2024年第2期16卷 365-382页

作者： Siyu sun Kehan Wang Zhanglian hong Mingjia Zhi Kai Zhang Jijian Xu Department of Chemistry City University of Hong KongHong Kong 999077People’s Republic of China State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China State Key Laboratory of Advanced Chemical Power Sources Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)Haihe Laboratory of Sustainable Chemical TransformationsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)College of ChemistryNankai UniversityTianjin 300071People’s Republic of China Department of Chemical and Biomolecular Engineering University of Maryland College ParkCollege ParkMD 20742USA

Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature *** get the most energy storage out of the battery at low temperatures,improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode ***,this review critically outlines electrolytes’limiting factors,including reduced ionic conductivity,large de-solvation energy,sluggish charge transfer,and slow Li-ion transportation across the electrolyte/electrode interphases,which affect the low-temperature performance of Li-metal *** theoretical derivations that explain the explicit influence of temperature on battery performance are presented to deepen *** improvement strategies from the aspects of electrolyte design and electrolyte/electrode interphase engineering are summarized and rigorously *** on future research are proposed to guide the ongoing exploration for better low-temperature Li-metal batteries.

关键词： Solid electrolyte interphase Li metal Low temperature Electrolyte design Batteries

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： Yong-Chao Li Rui-Sheng Jia Ying-Xiang Hu hong-Mei sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning