检索结果-南通市图书馆

Fabrication of supported acid catalytic composite fibers by a simple and low-cost method and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2022年第1期7卷 165-171页

作者： Yinhua Yan Huiqin Guo Kexin Li liushui Yan Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle NanChang Hangkong UniversityNanChang330063China National-Local Joint Engineering Research Center of Heavy Metals Polluants Control and Resource Utilization NanChang Hangkong UniversityNanChang330063China

In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles.

关键词： Acid catalysis Waste Camellia oleifera shells Sulfonic groups Polytetrafluoroethylene fibers 5-Ethoxymethylfurfural

m^(6)A regulator-mediated methylation modification patterns and tumor immune microenvironment characterization in endometrial cancer

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2023年第6期10卷 2278-2281页

作者： Kexin Li Shanrong Shu Jiahua Zou Manmei li Zhong liu Guangdong Provincial Key Laboratory of Bioengineering Medicine National Engineering Research Center of Genetic MedicineInstitute of BiomedicineCollege of Life Science and TechnologyJinan UniversityGuangzhouGuangdong 510632China Department of Gynecology and Obstetrics The First Afﬁliated Hospital of Jinan UniversityGuangzhouGuangdong 510630China International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education(MOE) School of PharmacyJinan UniversityGuangzhouGuangdong 510632China

Endometrial cancer(EC)is the second most prevalent female reproductive system tumor after cervical cancer and its incidence is rising globally.1 Recently,N6-methyladenosine(m^(6)A)has emerged as an important regulator of a variety of physiological and pathological processes,especially in promoting EC progression.2,3 However,the potential roles of m^(6)A modification in EC and its immune landscape remain unknown.Here,the correlation between m^(6)A modification patterns and tumor microenvironment(TME)cell-infiltrating characteristics was comprehensively evaluated based on 21 m^(6)A regulators of 1301 endometrial cancer samples.We identified four m6Aclasses characterized by distinct TME cell infiltration.We used principal component analysis algorithms to construct m6Ascore to quantify m^(6)A modification patterns of endometrial cancer individuals.Our results showed that lower m6Ascore may be closely related to immune-inflamed phenotype and displayed immune-activated characteristics and better prognosis.

关键词： endometrial cancer m^(6)A

Improved edge lightweight YOLOv4 and its application in on-site power system work

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Global Energy Interconnection 2022年第2期5卷 168-180页

作者： Kexin Li liang Qin Qiang li Feng Zhao Zhongping Xu Kaipei liu School of Electrical Engineering and Automation Wuhan UniverstiyWuhan430072P.R.China State Grid Information&Telecommunication Group Co. LtdBeijing102211P.R.China Beijing State Grid Information&Telecommunication Accenture Information Technology Co. Ltd.Beijing 100052P.R.China

A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and alert.Owing to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively low.This study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the speed.Specifically,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature utilization.Moreover,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved algorithm.Finally,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on it.According to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%.

关键词： On-site power system work YOLOv4-Tiny Convolution block attention mechanism Efficient channel attention Optimized training methods.

One-step fabrication of mesoporous sulfur-doped carbon nitride for highly selective photocatalytic transformation of native lignin to monophenolic compounds

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第1期34卷 440-445页

作者： Conghao Ku Huiqin Guo Kexin Li Qiong Wu liushui Yan Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource utilization Nanchang Hangkong UniversityNanchang 330063China Jiangxi Provincial Experimental Teaching Demonstration Center of Environmental Science and Engineering Nanchang Hangkong UniversityNanchang 330063China

Photocatalytic selective transform native lignin into valuable chemicals is an attractive but challenging task.Herein,we report a mesoporous sulfur-doped carbon nitride(MSCN-0.5)which is prepared by a facile one-step thermal condensation strategy.It is highly active and selective for the cleavage Cα-Cβbond inβ-O-4 lignin model compound under visible light radiation at room temperature,achieving 99%substrate conversion and 98%Cα-Cβbond cleavage selectivity.Mechanistic studies revealed that the Cβ-H bond of lignin model compounds activated by holes and generate key Cβradical intermediates,further induced the Cα-Cβbond cleavage by superoxide anion radicals(·O2-)to produce aromatic oxygenates.Waste Camellia oleifera shell(WCOS)was taken as a representative to further understand the reaction mechanisms on native lignin.33.2 mg of monophenolic compounds(Vanillin accounted for 22%and Syringaldehyde for 34%)can be obtained by each gram of WCOS lignin,which is 2.5 times as that of the pristine carbon nitride.The present work offers useful guidance for designing metal-free heterogeneous photocatalysts for Cα-Cβbond cleavage to harvest monophenolic compounds.

关键词： Mesostructure Sulfur-doped carbon nitride Photocatalysis lignin model compound Native lignin Monophenolic compounds

El Niño and the AMO Sparked the Astonishingly Large Margin of Warming in the Global Mean Surface Temperature in 2023

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第6期41卷 1017-1022页

作者： Kexin Li Fei ZHENG Jiang ZHU Qing-Cun ZENG International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China

In 2023,the majority of the Earth witnessed its warmest boreal summer and autumn since 1850.Whether 2023 will indeed turn out to be the warmest year on record and what caused the astonishingly large margin of warming has become one of the hottest topics in the scientific community and is closely connected to the future development of human society.We analyzed the monthly varying global mean surface temperature(GMST)in 2023 and found that the globe,the land,and the oceans in 2023 all exhibit extraordinary warming,which is distinct from any previous year in recorded history.Based on the GMST statistical ensemble prediction model developed at the Institute of Atmospheric Physics,the GMST in 2023 is predicted to be 1.41℃±0.07℃,which will certainly surpass that in 2016 as the warmest year since 1850,and is approaching the 1.5℃ global warming threshold.Compared to 2022,the GMST in 2023 will increase by 0.24℃,with 88%of the increment contributed by the annual variability as mostly affected by El Niño.Moreover,the multidecadal variability related to the Atlantic Multidecadal Oscillation(AMO)in 2023 also provided an important warming background for sparking the GMST rise.As a result,the GMST in 2023 is projected to be 1.15℃±0.07℃,with only a 0.02℃ increment,if the effects of natural variability—including El Niño and the AMO—are eliminated and only the global warming trend is considered.

关键词： record-breaking temperature global mean surface temperature El Niño AMO global warming

A binder-free CF|PANI composite electrode with excellent capacitance for asymmetric supercapacitors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2023年第3期44卷 95-103页

作者： Kexin Li Gentian Yue Furui Tan Henan Key Laboratory of Photovoltaic Materials and Laboratory of Low-Dimensional Materials Science Henan UniversityKaifeng 475004China

In this work,carbon fiber and polyaniline(CF|PANI)composites are prepared by using an electrochemical polymeriza-tion method.The morphology and composition characterization results show that the PANI nanospheres are successfully syn-thesized and uniformly coated on the CF.When the electrodeposition period is 300 cycles,the as-prepared CF|PANI electrode ex-hibits good specific capacitance of 231.63 F/g at 1 A/g,high performance of 98.14%retention rate from 0.5 to 20 A/g,and excel-lent cycle stability with only 0.96%capacity loss after 1000 cycles.This is ascribed to the internal resistance that was signific-antly reduced without binders,which helps to the CF|PANI electrode maintains high operating potential and pseudo-capacit-ance performance at high current density.The symmetrical supercapacitor based on two CF|PANI electrodes connecting by acid-ic PVA-H2SO4 gel electrolyte exhibits an energy density of 6.55 W·h/kg at a power density of 564.37 W/kg.In addition,the asym-metric supercapacitor based on MoS2|MWCNTs and CF|PANI electrodes with neutral PVA-Na2SO4 gel electrolyte shows an en-ergy density of 16.12 W·h/kg at a power density of 525.03 W/kg.These results indicate that the low internal resistance contrib-utes to the high energy density of symmetrical supercapacitors and asymmetric supercapacitors at high current density and high power density,which is significant for its practical application.

关键词： quasi-solid state supercapacitor carbon fibers binder-free polyaniline

Bureaucratic Culture and Innovation

在线全文

学校读者我要写书评

暂无评论

China & World Economy 2024年第3期32卷 31-66页

作者： Shigang li kexin She li Zhang International School of Business and Finance Sun Yat-sen UniversityChina National School of Development Peking UniversityChina International School of Business and Finance Key Laboratory of Mesoeconomics and Coordinated Development of Regions and IndustriesSun Yat-sen UniversityChina

This study explores the effects of bureaucratic culture on innovation.We define bureaucratic culture as a culture in which power and officials are held in the highest regard.Using panel data of publicly listed Chinese manufacturing firms from 2007 to 2015,we found that bureaucratic culture negatively correlated with firms'patent output.A mechanism analysis shows that bureaucratic culture hindered corporate innovation by reducing firms'research and development inputs and decreasing innovation efficiency.Furthermore,we provided evidence that anti-corruption campaigns and the development of formal institutions could neutralize the negative impact of bureaucratic culture on corporate innovation.This study is the first to investigate quantitatively the causal effect of bureaucratic culture on corporate innovation and it can deepen the understanding of the relationship between culture and innovation in China.We speculate that promoting a creative culture,particularly one that fosters entrepreneurial spirit,is of utmost importance.

关键词： bureaucratic culture corporate innovation economic growth talent allocation

A high-concentrated and nonflammable electrolyte for potassium ion-based dual-graphite batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2023年第5期16卷 6353-6360页

作者： Kexin Li Guiyou Ma Dandan Yu Wen Luo Jiaxin li Laishun Qin Yuexiang Huang Da Chen College of Materials and Chemistry China Jiliang UniversityHangzhou 310018China liangxin College China Jiliang UniversityHangzhou 310018China

Potassium ion-based dual-graphite batteries(KDGBs)emerge as promising devices for large-scale applications due to their high voltage,low cost,environmental friendliness.However,conventional KPF6/carbonate-based electrolytes suffer from severe oxidation decomposition,low concentration,flammability,which limit the capacity and cyclability of KDGBs.Herein,a nonflammable potassium bis(fluorosulfonyl)imide/triethyl phosphate(KFSI/TEP)electrolyte was designed for KDGBs.When the salt-to-solvent molar ratio increases to 1:1.3,graphite cathode operated at the cut-off potential of 5.2 V exhibits much enhanced capacity,excellent rate capability(26.4 mAh∙g^(−1) at 1.0 A∙g^(−1)),superior cyclability with 98%capacity retention after 350 cycles.Inorganic compounds-rich electrode/electrolyte interphase layers derived from the preferential decomposition of FSI−anions ensure good compatibility of the 1:1.3 KFSI/TEP electrolyte with K metal and graphite anodes.Based on this electrolyte,asassembled KDGBs show high operation voltage of 4.3 V and good cycling performance.This work provides feasibility for developing long-life and safe-operation DGBs.

关键词： dual-ion batteries graphite high voltage high-concentrated electrolytes phosphates

Acoustic response characteristics and sensitivity of briquette and raw coal under temperature and pressure control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2023年第1期17卷 170-179页

作者： Hewei ZHANG Jian SHEN Kexin Li Xiaojie FANG Ziwei WANG Lei DU Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process(Ministry of Education) China University of Mining and TechnologyXuzhou 221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China Huabei Oilfield CBM Branch Company Changzhi 046000China Shaanxi Coalfield Geophysical Exploration and Mapping Co. Ltd.Xi᾽an 710000China

Acoustic testing is a widely used technique to measure the coal mechanical properties under high temperature and pressure in situ conditions.This study compared the acoustic wave characteristics of briquette and raw coal under various temperature and pressure conditions.The results show that the longitudinal wave velocity(Vp)decreases with an increasing vitrinite content.A large number of the vitrinite content enhances the process in which the temperature and pressure changed the Vp.The Vp of briquette decreases approximately linearly with the temperature compared to raw coal.The Vp of raw coal experiences initially a rapid,then gradual,and finally the moderate increasing trend with the increase in confining pressure.However,in briquette,the Vp increases approximately linearly with the confining pressure.The results indicate that the Vp is more sensitive to temperature under low confining pressure and peaks at 50℃−60℃ than high confining pressure.However,the Vp is less sensitive to temperature under higher confining pressure,and the positive effect of high confining pressure is dominant.Understanding the mechanical properties of coal under high pressure and temperature develops better insight into coalbed methane(CBM)exploration from deep reservoirs.

关键词： high-rank coal P-wave velocity temperature pressure microscopic components sensitivity