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Recent advances in switchable surfactants for heavy oil production:A review

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Energy Geoscience 2024年第4期5卷 75-88页

作者： qi Li Lingfei Liu Dejun Sun Zhenghe xu Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical EngineeringShandong UniversityJinanShandong250100PR China Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials Department of Materials Science and EngineeringSouthern University of Science and TechnologyShenzhenGuangdong518055PR China Key Laboratory of Tertiary Oil Recovery and Oilfield Chemistry PetroChina Dagang Oilfield CompanyTianjin300280PR China

Surfactants are extensively employed in the cold production of heavy ***,producing heavy oil emulsions using conventional surfactants poses a challenge to spontaneous demulsification,necessitating the addition of demulsifiers for oil-water *** inevitably increases the exploitation cost and environmental pollution *** surfactants have garnered much attention due to their dual capabilities of underground heavy oil emulsification and surface *** study focuses on the fundamental working principles and classification of novel switchable surfactants for oil displacement developed in recent *** offers a comprehensive overview of the latest advances in the applications of switchable surfactants in the fields of enhanced oil recovery(EOR),oil sand washing,and oil-water ***,it highlights the existing challenges and future development directions of switchable surfactants for heavy oil recovery.

关键词： Heavy oil Switchable surfactant Cold production Emulsification Demulsification

Effects of Different Concentrations of Sulfate Ions on Carbonate Crude Oil Desorption:Experimental Analysis and Molecular Simulation

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1731-1741页

作者： Nannan Liu Hengchen qi Hui xu Yanfeng He School of Petroleum and Natural Gas Engineering Changzhou UniversityChangzhou213164China

Low salinity water containing sulfate ions can significantly alter the surface wettability of carbonate ***,the impact of sulfate concentration on the desorption of oil film on the surface of carbonate rock is still *** study examines the variations in the wettability of the surface of carbonate rocks in solutions containing varying amounts of sodium sulfate and pure *** problem is addressed in the framework of molecular dynamics simulation(Material Studio software)and *** experiment’s findings demonstrate that sodium sulfate can increase the rate at which oil moisture is turned into water *** final contact angle is smaller than that of pure *** results of the simulations show that many water molecules travel down the water channel under the influence of several powerful forces,including the electrostatic force,the van der Waals force and hydrogen bond,crowding out the oil molecules on the calcite’s surface and causing the oil film to *** relative concentration curve of water and oil molecules indicates that the separation rate of the oil film on the surface of calcite increases with the number of sulfate ions.

关键词： Carbonate rocks wettability sulfate ions concentration molecular simulation desorption

A star-like photodetector for angle-based light sensing in 3D space

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Nano Research 2024年第8期17卷 7567-7573页

作者： qi Pan Sisi Chen Hongfei Xie qiling xu Meng Su Yanlin Song College of Chemistry Zhengzhou UniversityZhengzhou 450051China Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(ICCAS)Beijing Engineering Research Center of Nanomaterials for Green Printing TechnologyBeijing National Laboratory for Molecular Sciences(BNLMS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The development of three-dimensional(3D)space light angle detection is vital in optical technology for applications such as 3D imaging,computer vision,and augmented *** methods involve advanced sensors and algorithms,including time-offlight cameras,which need multiple cameras and light sources to improve ***,it is a great challenge to integrate these complex components into compact *** semiconductor structures offer optical resonance characteristics,enabling precise light–matter interaction regulation.A 3D star-like photodetector,fabricated using a template assistant printing strategy,demonstrates optical resonances of the subwavelength facade and the shielding effect of spatial *** achieves light angle detection with the resolution of 10°in vertical space and the resolution of 36°in horizontal space,making it a promising prototype for various applications.

关键词： photodetector light angle detection printing subwavelength structure shielding effect

Hybrid HMX multi-level assembled under the constraint of 2D materials with efficiently reduced sensitivity and optimized thermal stability

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Defence Technology（防务技术） 2024年第9期39卷 123-132页

作者： Xiaomin Song Longjin Huang Rufang Peng qi Huang Jinjiang xu Jie Sun Institute of Chemical Materials China Academy of Engineering PhysicsMianyang621900China State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive ***,screening suitable coating agents to enhance the interfacial effect to obtain high-energy and low-sensitivity explosives has long been a major *** this work,HMX-PEI/rGO/g-C_(3)N_(4)(HPrGC)composites were innovatively prepared by a multi-level coating strategy of two-dimensional graphite rGO and g-C_(3)N_(4).The g-C_(3)N_(4) used for desensitization has a richπ-conjugated system and shows outstanding ability in reducing friction *** hierarchical structure of HPrGC formed by electrostatic self-assembly andπ-πstacking can effectively dissipate energy accumulation under heat and mechanical stimulation through structural evolution,thus exhibiting a prominent synergistic desensitization effect on *** results show that rGO/gC_(3)N_(4) coating has no effect on the crystal structure and chemical structure of *** importantly,the perfect combination of g-C_(3)N_(4) and rGO endows HPrGC with enhanced thermal stability and ideal mechanical sensitivity(IS:21 J,FS:216 N).Obviously,the new fabrication of HPrGC enriches the variety of desensitizer materials and helps to deepen the understanding of the interaction between explosives and coatings.

关键词： HMX-PEI/rGO/g-C_(3)N_(4) Electrostatic self-assembly π-πstacking Synergistic desensitization

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Crystal facet-dependent CO_(2) cycloaddition to epoxides over ZnO catalysts

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 49-59页

作者： Yongjian wei Ying Li Yunfei xu Yinghui Sun Tong xu Haiou Liang Jie Bai Inner Mongolia Key Laboratory of Industrial Catalysis Hohhot 010051China College of Chemical Engineering Inner Mongolia University of TechnologyHohhot 010051China

With regard to green chemistry and sustainable development,the fixation of CO_(2) into epoxides to form cyclic carbonates is an attractive and promising pathway for CO_(2) *** oxides,renowned as promising eco-friendly catalysts for industrial production,are often undervalued in terms of their impact on the CO_(2)addition *** this work,we successfully developed ZnO nanoplates with(002)surfaces and ZnO nanorods with(100)surfaces via morphology-oriented regulation to explore the effect of crystal faces on CO_(2) *** quantitative data obtained from electron paramagnetic resonance spectroscopy indicated that the concentration of oxygen vacancies on the ZnO nanoplate surfaces was more than twice that on the ZnO nanorod *** functional theory calculations suggested that the(002)surfaces have lower adsorption energies for CO_(2) and epichlorohydrin than the(100)*** a result,the yield of cyclochloropropene carbonate on the ZnO nanoplates(64.7%)was much greater than that on the ZnO nanorods(42.3%).Further evaluation of the reused catalysts revealed that the decrease in the oxygen vacancy concentration was the primary factor contributing to the decrease in catalytic *** on these findings,a possible catalytic mechanism for CO_(2) cycloaddition with epichlorohydrin was *** work provides a new idea for the controllable preparation of high-performance ZnO catalysts for the synthesis of cyclic carbonates from CO_(2) and epoxides.

关键词： carbon dioxide cycloaddition zinc oxide crystal face oxygen vacancy

Optical coherence tomography angiography metrics in different stages of diabetic macular edema

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Eye and Vision 2024年第3期10卷 13-20页

作者： Ruyi Han Ruowen Gong wei Liu Gezhi xu Eye Institute and Department of Ophthalmology Eye and ENT Hospital of Fudan University83 Fenyang RoadShanghai200031People’s Republic of China Key Laboratory of Visual Impairment and Restoration Fudan UniversityShanghaiPeople’s Republic of China Key Laboratory of Myopia(Fudan University) Chinese Academy of Medical SciencesNational Health CommissionShanghaiPeople’s Republic of China

Background To investigate the optical coherence tomography angiography(OCTA)characteristics of diabetic macular edema(DME)at different *** This study was a cross-sectional *** diagnosed with DME were *** was classified into early,advanced,and severe *** vessel density(VD)in the superficial vascular plexus(SVP),deep vascular plexus(DVP)and foveal avascular zone(FAZ)parameters,including FAZ area,FAZ perimeter,acircularity index and foveal VD in a 300-μm-wide region around the FAZ(FD-300),were calculated by the AngioVue software.A multivariate generalized estimating equation was used to evaluate the associations between visual acuity and OCTA *** Ninety-two eyes from 74 patients with DME were included in this *** to early(P=0.006)and advanced DME(P=0.003),the acircularity index was higher in severe *** whole and parafoveal VD in the DVP decreased in eyes with severe DME compared to early DME(P=0.018,P=0.005,respectively)and advanced DME(P=0.035,P=0.012,respectively).In the multivariate generalized estimating equation,DME severity,FAZ area and foveal thickness were positively associated with worse visual acuity(P=0.001,P=0.007 and P=0.001,respectively).Conclusion Compared to early and advanced DME,severe DME showed increased irregularity in the FAZ and more extensive vessel damage in the *** severity level of DME,larger FAZ area,and increased foveal thickness could be risk factors for poor visual *** registration The protocol was published in the Chinese Clinical Trial Registry(ChiCTR2000033082).

关键词： Optical coherence tomography angiography Diabetic macular edema Vessel density Acircularity index

14-bit SAR ADC with On-Chip Digital Bubble Sorting Calibration Technology

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Chinese Journal of Electronics 2024年

作者： Hua FAN Zhuorui CHEN Tongrui xu Franco Maloberti qi wei Quanyuan FENG School of Integrated Circuit Science and Engineering (Exemplary School of Microelectronics) University of Electronic Science and Technology of China (UESTC) Shenzhen Institute for Advanced Study Chongqing Institute of Microelectronics Industry Technology Department of Electrical Computer and Biomedical Engineering University of Pavia Department of Precision Instrument Tsinghua University Institute of Microelectronics Southwest Jiaotong University

This article designs a 14-bit successive approximation register analog-to-digital converter(SAR ADC).A novel digital bubble sorting calibration method is proposed and applied to eliminate the effect of capacitor mismatch on the linearity of the SAR ADC. To reduce the number of capacitors, a hybrid architecture of a high 8-bit binary-weighted capacitor array and a low 6-bit resistor array is adopted by the digital-to-analog(DAC). The common-mode voltage VCM-based switching scheme is chosen to reduce the switching energy and area of the DAC. The time-domain comparator is employed to obtain lower power consumption. Sampling is performed through a gate voltage bootstrapped switch to reduce the nonlinear errors introduced when sampling the input signal. Moreover, the SAR logic and the whole calibration is totally implemented on-chip through digital integrated circuit(IC) tools such as Design Compiler, IC compiler, etc. Finally, a prototype is designed and implemented using 0.18 μm Bipolar-complementary metal oxide semiconductor(CMOS)-double-diffused MOS 1.8 V CMOS technology. The measurement results show that the SAR ADC with on-chip bubble sorting calibration method achieves the signal-to-noise-and-distortion ratio of 69.75 dB and the spurious-free dynamic range of 83.77 dB.

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Molecular dynamics simulation study of nitrogen vacancy color centers prepared by carbon ion implantation into diamond

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Nanotechnology and Precision Engineering 2024年第3期7卷 71-78页

作者： wei Zhao Zongwei xu Pengfei Wang Hanyi Chen State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

Nitrogen vacancy(NV)color centers in diamond have useful applications in quantum sensing andﬂuorescent *** can be gen-erated experimentally by ion implantation,femtosecond lasers,and chemical vapor ***,there is a lack of studies of the yield of NV color centers at the atomic *** the molecular dynamics simulations described in this paper,NV color centers are pre-pared by ion implantation in diamond with pre-doped nitrogen and subsequent *** differences between the yields of NV color centers produced by implantation of carbon(C)and nitrogen(N)ions,respectively,are *** is found that C-ion implantation gives a greater yield of NV color centers and superior location *** effects of different pre-doping concentrations(400–1500 ppm)and implantation energies(1.0–3.0 keV)on the NV color center yield are analyzed,and it is shown that a pre-doping concentra-tion of 1000 ppm with 2 keV C-ion implantation can produce a 13%yield of NV color centers after 1600 K annealing for 7.4 ***,a brief comparison of the NV color center identiﬁcation methods is presented,and it is found that the error rate of an analysis utiliz-ing the identify diamond structure coordination analysis method is reduced by about 7%compared with conventional identiﬁcation+methods.

关键词： NV color center Ion implantation Molecular dynamics(MD)simulation Yield enhancement

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A new monitoring index for ecological vulnerability and its application in the Yellow River Basin,China from 2000 to 2022

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Journal of Arid Land 2024年第9期16卷 1163-1182页

作者： GUO Bing xu Mei ZHANG Rui LUO wei School of Civil Engineering and Geomatics Shandong University of TechnologyZibo 255000China Key Laboratory of Remote Sensing of Gansu Province Heihe Remote Sensing Experimental Research StationNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China North China Institute of Aerospace Engineering Langfang 065000China

The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade ***,the change mechanisms of ecological vulnerability in different sub-regions and periods vary,and the reasons for this variability are yet to be ***,in this study,we proposed a new remote sensing ecological vulnerability index by considering moisture,heat,greenness,dryness,land degradation,and social economy indicators and then analyzed and disclosed the spatial and temporal change patterns of ecological vulnerability of the Yellow River Basin,China from 2000 to 2022 and its driving *** results showed that the newly proposed remote sensing ecological vulnerability index had a high accuracy,at 86.36%,which indicated a higher applicability in the Yellow River *** 2000 to 2022,the average remote sensing ecological vulnerability index of the Yellow River Basin was 1.03,denoting moderate vulnerability *** intensive vulnerability area was the most widely distributed,which was mostly located in the northern part of Shaanxi Province and the eastern part of Shanxi *** 2000 to 2022,the ecological vulnerability in the Yellow showed an overall stable trend,while that of the central and eastern regions showed an obvious trend of *** gravity center of ecological vulnerability migrated southwest,indicating that the aggravation of ecological vulnerability in the southwestern regions was more severe than in the northeastern regions of the *** dominant single factor of changes in ecological vulnerability shifted from normalized difference vegetation index(NDVI)to temperature from 2000 to 2022,and the interaction factors shifted from temperature∩NDVI to temperature∩precipitation,which indicated that the global climate change exerted a more significant impact on regional *** above results could provide decision support for the ecological protection and restoration of the Y

关键词： ecological vulnerability spatio-temporal pattern gravity center migration trajectory interaction factors geodetector green index q-value

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