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A molecular insight into coke formation process of vacuum residue in thermal cracking reaction

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Petroleum Science 2024年第3期21卷 2130-2138页

作者： Ji-Guang Li xin Guo Huan-Di hou Heavy Oil Processing Department Sinopec Research Institute of Petroleum Processing Co. Ltd

Understanding the coking behaviors has been considered to be really essential for developing better vacuum residue processing technologies. A battery of thermal cracking tests of typical vacuum residue at410°C with various reaction time were performed to evaluate the coke formation process. The total yields of ideal components including naphtha, atmospheric gas oil(AGO) and vacuum gas oil(VGO) of thermal cracking reactions increased from 10.89% to 40.81%, and the conversion ratios increased from8.05% to 43.33% with increasing the reaction time from 10 to 70 min. The asphaltene content increased from 12.14% to a maximum of 22.39% and then decreased, and this maximum of asphaltene content occurred at the end of the coking induction period. The asphaltenes during the coking induction period,at the end and after coking induction period of those tested thermal cracking reactions were characterized to disclose the structure changing rules for coke formation process, and the coke formation pathways were discussed to reveal the coke formation process at molecular level.

关键词： Vacuum residue Thermal cracking Asphaltene Coking induction period Sulfur Nitrogen

A novel profile modification HPF-Co gel satisfied with fractured low permeability reservoirs in high temperature and high salinity

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Petroleum Science 2024年第1期21卷 683-693页

作者： Ya-Kai Li Ji-Rui hou wei-Peng Wu Ming Qu Tuo Liang wei-xin Zhong Yu-Chen Wen Hai-Tong Sun Yi-Nuo Pan China University of Petroleum Beijing Beijing102249China PetroChina Tarim Oilfield Company Korla 841000XinjiangChina Key Laboratory of Improving Oil and Gas Recovery of Ministry of Education Northeast Petroleum University Daqing 163318HeilongjiangChina Xi'an Shiyou University Xi'an 710065ShaanxiChina Northwest Oilfield Company SINOPECUrumqi 830011XinjiangChina

Conformance control and water plugging are a widely used EOR method in mature oilfields.However,majority of conformance control and water plugging agents are unavoidable dehydrated situation in high-temperature and high-salinity low permeability reservoirs.Consequently,a novel conformance control system HPF-Co gel,based on high-temperature stabilizer(CoCl_(2)·H_(2)O,CCH)is developed.The HPF-Co bulk gel has better performances with high temperature(120℃)and high salinity(1×10^(5)mg/L).According to Sydansk coding system,the gel strength of HPF-Co with CCH is increased to code G.The dehydration rate of HPF-Co gel is 32.0%after aging for 150 d at 120℃,showing excellent thermal stability.The rheological properties of HPF gel and HPF-Co gel are also studied.The results show that the storage modulus(G′)of HPF-Co gel is always greater than that of HPF gel.The effect of CCH on the microstructure of the gel is studied.The results show that the HPF-Co gel with CCH has a denser gel network,and the diameter of the three-dimensional network skeleton is 1.5-3.5μm.After 90 d of aging,HPF-Co gel still has a good three-dimensional structure.Infrared spectroscopy results show that CCH forms coordination bonds with N and O atoms in the gel amide group,which can suppress the vibration of cross-linked sites and improve the stability at high temperature.Fractured core plugging test determines the optimized polymer gel injection strategy and injection velocity with HPF-Co bulk gel system,plugging rate exceeding 98%.Moreover,the results of subsequent waterflooding recovery can be improved by 17%.

关键词： Low permeability reservoir High-temperature resistant gel Complexation reaction Polymer gel injection strategy Plugging rate Enhanced oil recovery

Probiotics administration alleviates cognitive impairment and circadian rhythm disturbance induced by sleep deprivation

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Food Science and Human Wellness 2024年第4期13卷 1951-1961页

作者： Peijun Tian Yunfei hou Zheng Wang Jiaona Jiang xin Qian Zhihao Qu Jianxin Zhao Gang Wang wei Chen State Key Laboratory of Food Science and Resources Jiangnan UniversityWuxi 214122China School of Food Science and Technology Jiangnan UniversityWuxi 214122China National Engineering Research Center for Functional Food Jiangnan UniversityWuxi 214122China Institute of Food Biotechnology(Yangzhou) Jiangnan UniversityYangzhou 225004China

Gut microbiome is indispensable for maintaining normal brain function.Specifically,gut microbiota plays a causal role in sleep deprivation(SD)-induced cognitive impairment.In this study,neurobehavioral effects of the Bifidobacterium breve strain(CCFM1025)were assessed in sleep-deprived mice.CCFM1025 improved the body weight and food and water intake of the mice.It also alleviated SD-induced cognitive behavioural abnormalities(in the novel object recognition test),but did not show beneficial effects on mood-and spatial memory-related behaviours.CCFM1025 significantly altered the gut microbial composition and genome function.Key microbial metabolites that may regulate sleep function were also identified,such as isovaleric acid andγ-aminobutyric acid in the gut and purine metabolites in the serum.Those metabolites may participate in gutbrain communication by acting on the striatal melatonin system,for example to increase melatonin levels,and by regulating the expression of circadian clock genes such as those encoding the adenosine A2A receptor and period circadian regulator 1.Collectively,administration of probiotics alleviated cognitive impairment and circadian rhythm disturbance induced by SD via modulation of gut microbiome and its metabolites.These findings may help guide the treatment of insomnia or other sleep disorders via dietary strategies.

关键词： Bifidobacterium Sleep Circadian rhythm Purine Gut microbiome

A novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite oxide with surface doping of Y and its application in Pd-only three-way catalyst

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Rare Metals 2024年第2期43卷 749-757页

作者： Zheng Zhao wei-xin Zhao Yong-Qi Zhang Mei-Sheng Cui Yong-Ke hou Dong-Ming Chen Juan-Yu Yang Zong-Yu Feng Xiao-wei Huang National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.GRINM Group Corporation LimitedBeijing100088China Griem Hi-Tech Co.Ltd. Langfang065000China Rare Earth Functional Materials(Xiong’an)Innovation Venter Co.Ltd. Baoding071700China

The ceria-zirconia compound oxide-supported noble metal Pd(Pd@CZ)is widely used in three-way catalyst.Moreover,the surface structure of CZ plays an important role in catalytic activity of Pd.However,how to regulate the surface structure of CZ and clarify the structure–activity relationship is still a challenge.In this paper,a strategy is proposed to develop high activity Pd@CZ nanocatalysts by tuning Y doping sites in CZ.The precipitate-deposition method is developed to prepare the novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite with surface doping of Y(CZ-Y-S).In addition,the Pd@CZ-Y-S(Pd supported on CZ-Y-S)exhibits superior catalytic activity for HC,CO,and NO oxide,wherein,for CO and C_(3)H_(6) oxidation,the low-temperature activity of Pd@CZ-Y-S is still 20%higher than that of Pd@CZ-Y-B(Y bulk doping)and commercial Pd@CZ after 1000℃/4 h aging.The effect mechanism is further studied by density functional theory(DFT)calculation.Compared with Pd@CZ-Y-B,Pd@CZ-Y-S shows the lower CO oxide reaction energy barriers due to the weaker adsorption strength of O2.The Y surface doping strategy could provide valuable insights for the development of highly efficient Pd@CZ catalyst with extensive applications.

关键词： Rare earth Ceria-zirconia-supported Pd Surface doping Experiment and theory Catalytic application

Two thin middle-crust low-velocity zones imaged in the Chuan-Dian region of southeastern Tibetan Plateau and their tectonic implications

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Science China Earth Sciences 2024年第5期67卷 1675-1686页

作者： Long LI xin WANG Guangbing hou Yuan LING Yinshuang AI Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

Intracrustal low-velocity zones(LVZs)indicate a mechanically weak crust and are widely observed in the southeast margin of the Tibetan Plateau.However,their spatial distributions and formation mechanisms remain controversial.To investigate their distribution and detailed morphology of the LVZs in the southeastern Tibetan Plateau,here we used teleseismic events and continuous waveform data recorded by 40 broadband seismic stations newly deployed in the Sichuan-Yunnan region from December 2018 to October 2020.A total of 12,924 high-quality P-wave receiver functions and 5–40 s fundamental Rayleigh surface wave phase velocity dispersion curves from ambient noise cross-correlation functions were obtained.The Swave velocity model at a depth interval of 0–100 km in the study area was inverted by using the trans-dimensional Markov chain Monte Carlo strategy to jointly invert the complementary data of the receiver function waveform and Rayleigh surface wave phase velocity dispersion.Our results show that there are two separate LVZs(~3.5 km/s)surrounding the rigid Daliangshan subblock at crustal depths of approximately 30–40 km,providing new constraints on the geometry of the LVZs in our study region.The two LVZs obtained in this study may represent the middle crustal flow channels,through which the material in the center of the Tibetan Plateau extrudes to its southeast margin.Blocked by the rigid Sichuan Basin and the spindle-like Daliangshan subblock,the material continues to flow southward through the mechanically weak middle crustal channels surrounding the Daliangshan subblock.In addition,the existence of thin LVZs in the middle crust plays an important role in understanding the decoupling between the upper and lower crust in the study area.It also provides new constraint on the complex tectonic deformation process of the southeastern margin of the Tibetan Plateau caused by the collision and compression of the Indian and the Eurasian plates.

关键词： Southeastern Tibetan Plateau Joint inversion Intracrustal low-velocity zone Mid-crustal channel flow

First Digit Distributions of Gamma-Ray Bursts

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Research in Astronomy and Astrophysics 2024年第5期24卷 70-75页

作者： hou-Yu Lai Jun-Jie wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s law.In this work,we perform a comprehensive investigation on the first digit distributions of the duration,fluence,and energy flux of gamma-ray bursts (GRBs) for the first time.For a complete GRB sample detected by the Fermi satellite,we find that the first digits of the duration and fluence adhere to Benford’s law.However,the energy flux shows a significant departure from this law,which may be due to the fact that a considerable part of the energy flux measurements is restricted by lack of spectral information.Based on the conventional duration classification scheme,we also check if the durations and fluences of long and short GRBs (with duration T_(90)>2 s and T_(90)≤2 s,respectively) obey Benford’s law.We find that the fluences of both long and short GRBs still agree with the Benford distribution,but their durations do not follow Benford’s law.Our results hint that the long–short GRB classification scheme does not directly represent the intrinsic physical classification scheme.

关键词： (stars:)gamma-ray burst general-methods statistical-astronomical databases miscellaneous

Evolution of chemistry and selection technology for DNA-encoded library

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Acta Pharmaceutica Sinica B 2024年第2期14卷 492-516页

作者： Peixiang Ma Shuning Zhang Qianping Huang Yuang Gu Zhi Zhou wei hou wei Yi Hongtao Xu Shanghai Key Laboratory of Orthopedic Implants Department of OrthopedicsShanghai Ninth People’s HospitalShanghai Jiao Tong UniversitySchool of MedicineShanghai 200025China Shanghai Institute for Advanced Immunochemical Studies ShanghaiTech UniversityShanghai 201210China Guangzhou Municipal and Guangdong Provincial Key Laboratory of Molecular Target&Clinical Pharmacology The NMPA and State Key Laboratory of Respiratory DiseaseGuangzhou Medical UniversityGuangzhou 511436China College of Pharmaceutical Science and Institute of Drug Development&Chemical Biology Zhejiang University of TechnologyHangzhou 310014China

DNA-encoded chemical library(DEL)links the power of amplifiable genetics and the nonself-replicating chemical phenotypes,generating a diverse chemical world.In analogy with the biological world,the DEL world can evolve by using a chemical central dogma,wherein DNA replicates using the PCR reactions to amplify the genetic codes,DNA sequencing transcripts the genetic information,and DNA-compatible synthesis translates into chemical phenotypes.Importantly,DNA-compatible synthesis is the key to expanding the DEL chemical space.Besides,the evolution-driven selection system pushes the chemicals to evolve under the selective pressure,i.e.,desired selection strategies.In this perspective,we summarized recent advances in expanding DEL synthetic toolbox and panning strategies,which will shed light on the drug discovery harnessing in vitro evolution of chemicals via DEL.

关键词： DNA-encoded library Drug discovery High-throughput selection DNA-compatible synthesis In vitro evolution Chemical central dogma

Deep learning for joint channel estimation and feedback in massive MIMO systems

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Digital Communications and Networks 2024年第1期10卷 83-93页

作者： Jiajia Guo Tong Chen Shi Jin Geoffrey Ye Li xin Wang Xiaolin hou National Mobile Communications Research Laboratory Southeast UniversityNanjing210096China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZUK DOCOMO Beijing Communications Laboratories Co. LtdBeijingChina

The great potentials of massive Multiple-Input Multiple-Output(MIMO)in Frequency Division Duplex(FDD)mode can be fully exploited when the downlink Channel State Information(CSI)is available at base stations.However,the accurate CsI is difficult to obtain due to the large amount of feedback overhead caused by massive antennas.In this paper,we propose a deep learning based joint channel estimation and feedback framework,which comprehensively realizes the estimation,compression,and reconstruction of downlink channels in FDD massive MIMO systems.Two networks are constructed to perform estimation and feedback explicitly and implicitly.The explicit network adopts a multi-Signal-to-Noise-Ratios(SNRs)technique to obtain a single trained channel estimation subnet that works well with different SNRs and employs a deep residual network to reconstruct the channels,while the implicit network directly compresses pilots and sends them back to reduce network parameters.Quantization module is also designed to generate data-bearing bitstreams.Simulation results show that the two proposed networks exhibit excellent performance of reconstruction and are robust to different environments and quantization errors.

关键词： Channel estimation CSI feedback Deep learning Massive MIMO FDD

To explore the pathogenesis of anterior resection syndrome by magnetic resonance imaging rectal defecography

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 529-538页

作者： Ling-hou Meng Xian-wei Mo Bing-Yu Yang Hai-Quan Qin Qing-Zhou Song xin-xin He Qiang Li Zheng Wang Chang-Lin Mo Guo-Hai Yang Department of Gastrointestinal Surgery Guangxi Clinical Research Center for Colorectal CancerGuangxi Medical University Cancer HospitalNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Colorectal and Anal Surgery Guangxi Medical University Cancer HospitalNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Radiology Guangxi Medical University Cancer HospitalNanning 530021Guangxi Zhuang Autonomous RegionChina First Department of Chemotherapy Guangxi Medical University Cancer HospitalNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND Over 90%of rectal cancer patients develop low anterior resection syndrome(LARS)after sphincter-preserving resection.The current globally recognized evaluation method has many drawbacks and its subjectivity is too strong,which hinders the research and treatment of LARS.AIM To evaluate the anorectal function after colorectal cancer surgery by quantifying the index of magnetic resonance imaging(MRI)defecography,and pathogenesis of LARS.METHODS We evaluated 34 patients using the standard LARS score,and a new LARS evaluation index was established using the dynamic images of MRI defecography to verify the LARS score.RESULTS In the LARS score model,there were 10(29.41%)mild and 24(70.58%)severe cases of LARS.The comparison of defecation rate between the two groups was 29.36±14.17%versus 46.83±18.62%(P=0.004);and MRI-rectal compliance(MRI-RC)score was 3.63±1.96 versus 7.0±3.21(P=0.001).Severe and mild LARS had significant differences using the two evaluation methods.There was a significant negative correlation between LARS and MRI-RC score(P<0.001),and they had a negative correlation with defecation rate(P=0.028).CONCLUSION MRI defecography and standard LARS score can both be used as an evaluation index to study the pathogenesis of LARS.

关键词： Anterior resection syndrome Colorectal cancer Diagnostic evaluation system Magnetic resonance imaging defecography Pathogenesis