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Quantification of Central and Eastern China's atmospheric CH_(4) enhancement changes and its contributions based on machine learning approach

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Journal of Environmental Sciences 2024年第4期138卷 236-248页

作者： Xinyue Ai Cheng Hu Yanrong Yang Leying Zhang Huili Liu Junqing Zhang Xin Chen Guoqiang Bai Wei Xiao college of Biology and the Environment Joint Center for sustainable Forestry in Southern ChinaNanjing Forestry UniversityNanjing 210037China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Guang’an vocational&technical college Guangan 638550China HuaNan Meteorological Administration Huanan 154400China

Methane is the second largest anthropogenic greenhouse gas,and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and ***,the monitoring of CH_(4) concentration changes and the assessment of underlying driving factors can provide scientific basis for the government’s policy making and *** is the world’s largest emitter of anthropogenic ***,due to the lack of ground-based observation sites,little work has been done on the spatial-temporal variations for the past decades and influencing factors in China,especially for areas with high anthropogenic emissions as Central and Eastern *** to quantify atmospheric CH_(4) enhancements trends and its driving factors in Central and Eastern China,we combined the most up-to-date TROPOMI satellite-based column CH_(4)(xCH_(4))concentration from 2018 to 2022,anthropogenic and natural emissions,and a random forest-based machine learning approach,to simulate atmospheric xCH_(4) enhancements from 2001 to *** results showed that(1)the random forest model was able to accurately establish the relationship between emission sources and xCH_(4) enhancement with a correlation coefficient(R^(2))of 0.89 and a root mean-square error(RMSE)of 11.98 ppb;(2)The xCH_(4) enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018,with a relative change of 3.27%±0.13%;(3)The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH_(4) enhancement,contributing 68.00% and 31.21%,respectively,and the decrease of animal ruminants contributed-6.70% of its enhancement trend.

关键词： TROPOMI Methane column concentrations Anthropogenic sources Random Forest model

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Contact Stress Reliability Analysis Model for Cylindrical Gear with Circular Arc Tooth Trace Based on an Improved Metamodel

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 593-619页

作者： Qi Zhang Zhixin Chen Yang Wu Guoqi Xiang Guang Wen Xuegang Zhang Yongchun Xie Guangchun Yang School of Intelligent Manufacturing&Automobile Chengdu Industrial Vocational Technical CollegeChengdu610218China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua617000China School of Electrical Engineering Chengdu Industry and Trade CollegeChengdu601165China School of Mechanical Engineering Sichuan UniversityChengdu601165China Chengdu Technological University Chengdu611730China

Although there is currently no unified standard theoretical formula for calculating the contact stress of cylindrical gears with a circular arc tooth trace(referred to as CATT gear),a mathematical model for determining the contact stress of CATT gear is essential for studying how parameters affect its contact stress and building the contact stress limit state equation for contact stress reliability *** this study,a mathematical relationship between design parameters and contact stress is formulated using the *** enhance the model’s accuracy,we propose a new hybrid algorithm that merges the genetic algorithm with the Quantum Particle Swarm optimization algorithm,leveraging the strengths of ***,the“parental inheritance+self-learning”optimization model is used to fine-tune the KrigingMetamodel’s *** this,amathematicalmodel for calculating the contact stress of Variable Hyperbolic Circular-Arc-Tooth-Trace(VH-CATT)gears using the optimized Kriging model was *** then examined how different gear parameters affect the VH-CATT gears’contact *** simulation results show:(1)Improvements in R2,RMSE,and RMAE.R2 rose from0.9852 to 0.9974(a 1.22%increase),nearing 1,suggesting the optimized Kriging Metamodel’s global error is ***,RMSE dropped from3.9210 to 1.6492,a decline of 57.94%.The global error of the GA-IQPSO-Kriging algorithm was also reduced,with RMAE decreasing by 58.69%from 0.1823 to 0.0753,showing the algorithm’s enhanced *** a comparison of ten experimental groups selected randomly,the GA-IQPSO-Kriging and FEM-based contact analysis methods were used to measure contact *** revealed a maximum error of 12.11667 MPA,which represents 2.85%of the real value.(2)Several factors,including the pressure angle,tooth width,modulus,and tooth line radius,are inversely related to contact *** descending order of their impact on the contact stress is:tooth line radius>modulus

关键词： CATT gear contact stress finite element method metamodel hybrid algorithm influencing factors

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Study on How to Improve Tourism English Major Students’English Communicative Ability in Higher vocational college

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Journal of Literature and Art Studies 2024年第8期14卷 726-729页

作者： SHEN Hua-ying School of Digital and Cultural Tourism Sichuan Vocational and Technical CollegeSuining 629000China

Tourism English Major students’English communicative ability is very important for students’to promote professional *** is necessary for students to improve the commnunicative ability and It is one of the teachers’... 详细信息

关键词： communicative ability professional skills cultivate

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Maternal supplementation with mulberry-leaf flavonoids improves the development of skeletal muscle in the offspring of chickens

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Animal Nutrition 2024年第3期18卷 72-83页

作者： Zhenwu Huang Hongjian Dai Simeng Li Zhe Wang Quanwei Wei Zhonghua Ning Yuming Guo Fangxiong Shi Zengpeng Lv State Key Laboratory of Animal Nutrition and Feeding College of Animal Science and TechnologyChina Agricultural UniversityBeijing100193China college of Animal Science and Technology Nanjing Agricultural UniversityNanjing210095China State Key Laboratory of Animal Nutrition and Feeding Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijing100193China School of Biotechnology Aksu Vocational and Technical CollegeAksu843000China

The development of skeletal muscle is a crucial factor in determining the meat yield and economic benefits of broiler *** research has shown that mulberry leaves and their extracts can be used to significantly improve the growth performance of livestock and *** present study aims to elucidate the mechanisms involved in the regulation of skeletal muscle development in broiler offspring by dietary mulberry-leaf flavonoids(MLF)supplementation from the perspective of maternal effect theory.A total of 270 Qiling broiler breeder hens were randomly assigned to 3 treatments with different doses of MLF(0,30,60 mg/kg)for 8 weeks before collecting their fertilized *** chicken offspring at 13 and 19 d of embryonic stage,and from 1 to 28 d old after hatching were included in this *** results showed that maternal supplementation increased the breast muscle weight and body weight of the offspring at the embryo and chick stages(P<0.05).This was followed by increased cross-sectional area of pectoral muscle fibres at 14 d(P<0.05).Further determination revealed a tendency towards increased serum levels of insulin-like growth factor 1(IGF-1)(P=0.092)and muscle fibre count(P=0.167)at 1 d post-hatching following maternal MLF treatment,while serum uric acid(UA)was decreased at 14 d after hatching(P<0.05).Moreover,maternal MLF supplementation significantly up-regulated the mRNA expression of the myogenic regulatory factor Myf5 in skeletal muscle at the both embryonic and growth stages(P<0.05).The relative abundance of the downstream protein of BMPR2,Smad1 and p-Smad1/5/9 in the TGFβsignalling pathway was significantly increased by maternal MLF ***,the increased expression of the target protein p-mTOR in the breast muscle of the offspring chicks is in accordance with the improved growth rate of the breast and the *** conclusion,maternal MLF supplementation can promote muscle protein metabolism and muscle fibre development of chick embryos

关键词： Broiler breeder hen Mulberry-leaf flavonoids Offspring Protein metabolism Skeletal muscle

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A survey on semantic communications:Technologies,solutions,applications and challenges

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Digital Communications and Networks 2024年第3期10卷 528-545页

作者： Yating Liu Xiaojie Wang Zhaolong Ning MengChu Zhou Lei Guo Behrouz Jedari School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Baotou vocational&technical college Baotou 014035China School of Information and Electronic Engineering Zhejiang Gongshang UniversityHangzhou 310018China Department of Electrical and Computer Engineering New Jersey Institute of TechnologyNewarkNJ 07102USA Nokia Finland

Semantic Communication(SC)has emerged as a novel communication paradigm that provides a receiver with meaningful information extracted from the source to maximize information transmission throughput in wireless networks,beyond the theoretical capacity *** the extensive research on SC,there is a lack of comprehensive survey on technologies,solutions,applications,and challenges for *** this article,the development of SC is first reviewed and its characteristics,architecture,and advantages are ***,key technologies such as semantic extraction,semantic encoding,and semantic segmentation are discussed and their corresponding solutions in terms of efficiency,robustness,adaptability,and reliability are *** of SC to UAV communication,remote image sensing and fusion,intelligent transportation,and healthcare are also presented and their strategies are ***,some challenges and future research directions are presented to provide guidance for further research of SC.

关键词： Semantic communication Semantic coding Semantic extraction Semantic communication framework Semantic communication applications

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Exposure to ephedrine attenuates Th1/Th2 imbalance underlying OVA-induced asthma through airway epithelial cell-derived exo-somal lnc-TRPM2-AS

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Chinese Journal of Natural Medicines 2024年第6期22卷 530-540页

作者： HU Yan WANG Mengqing XIE Jing JIAO Luojia DING Yi LUO Yinhe Department of Pediatrics The First Hospital of Hunan University of Chinese MedicineChangsha 410007China Hunan University of Chinese Medicine Changsha 410208China Department of Rehabilitation Medical CollegeChangsha Civil Affairs Vocational and Technical CollegeChangsha 410004Hunan ProvinceChina Teaching and Research Office of Chinese and Western Combination Hunan University of Chinese MedicineChangsha 410208China

Although various anti-inflammatory medications,such as ephedrine,are employed to manage cough-variant asthma,their underlying mechanisms are yet to be fully *** studies suggest that exosomes derived from airway epithelial cells(AECs)contain components like messenger RNAs(mRNAs),micro-RNAs(miRNAs),and long noncoding RNA(lncRNA),which play roles in the occurrence and progression of airway *** study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant *** established a mouse model of asthma and measured airway resist-ance and serum inflammatory cell ***-time polymerase chain reaction(RT-qPCR),Western blotting,and enzyme-linked im-munosorbent assay(ELISA)analyses were used to assess gene and protein expression *** were isolated and *** immunoprecipitation(RIP)and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and *** the ovalbumin(OVA)-challenged mouse model,ephedrine treatment reduced inflammatory responses,air-way resistance,and Th1/Th2 cell *** from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1,which were diminished following ephedrine *** exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4^(+)T cells,with its packaging into exosomes being facilitated by *** study unveils a novel mechanism by which ephedrine ameli-orates OVA-induced CD4^(+)T cell imbalance by suppressing AEC-derived exosomal *** findings could provide a theoretical framework for using ephedrine in asthma treatment.

关键词： Asthma Ephedrine Exosomal lnc-TRPM2-AS1 Th1/Th2 imbalance HnRNPA2B1 Airway epithelial cells

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Simulation of temperature distribution in double-row potato ridges mulched with plastic film covered with soil

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 185-197页

作者： Quandong Liu Wei Sun Yongmei Wang Juanling Wang Xinglong Che Mechanical and Electrical Engineering college Gansu Agricultural UniversityLanzhou 730070China Agricultural Machinery Branch of Longxi County vocational and technical School Dingxi 748100China Institute of Dryland Agriculture Shanxi Agricultural UniversityTaiyuan 030031China

In Northwest China,potatoes are cultivated on double-rows of each ridge which is mulched with plastic film,and the film is covered with some of *** effective in retaining soil moisture,this technique can render the potato seedlings prone to be burned if they are not released from the plastic film in *** this study,the model of convective heat transfer of potato ridge under solar radiation and atmospheric radiation is established by the Fluent *** processes of the heat transfer of potato ridge was simulated for a certain day,and the temperature distribution in the potato ridge was monitored over *** temperature distribution of soil in the growth layer of potato plants was analyzed under different thickness and widths of the covering soil on the *** results showed that with the increase of covering soil thickness and width,the time for soil at different depth to reach the peak-temperature was delayed,and the daily temperature change of soil where the different depths layer of potato plants growth was *** that time,a binary regression equation of offset temperature was constructed by using the Response Surface *** best parameter combination for covering soil on the plastic film is a thickness of 50 mm and a width of 280 mm in the cold and arid areas of Northwest ***,the offset temperature(PT)first decreased and then almost remained unchanged with the increase of covering soil *** the operational efficiency and power consumption of soil covering devices in the field,the unchanged width of the covering soil is 200 *** field experiments have shown that a 50 mm thick of soil covering is beneficial for the growth of potato plants and a 200 mm width of soil covering is beneficial for the growth of potato *** height of potato plants was 21 cm,and the natural emergence rate of potatoes was 95.8%on June 9,*** environment of soil covered could provide theoretical support for the mechanized pla

关键词： potato growth plastic mulching soil covered with film temperature distribution natural emergence rate

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Effect of rare earth on primary carbides in H13 die steel and their addition method:a review

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Journal of Iron and Steel Research International 2024年第3期31卷 531-551页

作者： Jing-feng Wang Lin-zhu Wang Chao-yi Chen Xiang Wang Fei Zhao School of Materials and Metallurgy Guizhou UniversityGuiyang 550025GuizhouChina Zhengzhou Railway vocational and technical college Zhengzhou 450000HenanChina Guizhou Provincial University Key Laboratory of High Performance Battery Materials Guizhou UniversityGuiyang 550025GuizhouChina Shougang Guiyang Special Steel Co. Guiyang 550005GuizhouChina

Larger-sized primary carbides lead to stress concentration during the application of H13 hot-work die steel,resulting in microcracks and fatigue *** earth was usually added to modify the carbides and *** existing literature is reviewed on the effect of rare earth on primary carbides in H13 steel.A comprehensive review on the effect of rare earth on the characteristics of primary carbides,i.e.,number,size,morphology,and thermal stability in H13 steel,was *** precipitation mechanism and nucleation of primary carbides with rare earth were *** position and form of rare earth in steel and their effects on alloying elements segregation were *** addition techniques of rare earth in H13 steel were compared,and the prospects for other uncommon rare earth and emerging technology were *** on the current references,it can be known that adding rare earth facilitated refined and dispersed primary *** size of primary carbides would be reduced,and their morphology would be improved because the rare earth inclusions formed in H13 steel can act as nucleation cores forγ-Fe orδ-Fe,refining the dendritic ***,the number of primary carbides at grain boundaries would be significantly ***,rare earth had little impact on thermal *** nucleation of primary carbides tended to be inhibited due to the modification of inclusions by rare earth which were likely to be nucleation cores for primary *** earth had been reported to affect the mechanism and process of primary carbide ***,the addition of rare earth can inhibit the segregation of alloying elements and carbon diffusion by ***,laboratory experiments and theoretical calcu-lations need to be conducted to study the states and evolution of rare earth steels.

关键词： Rare earth H13 die steel Primary carbide Nucleation Dendritic structure

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A Railway Fastener Inspection Method Based on Abnormal Sample Generation

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 565-592页

作者： Shubin Zheng Yue Wang Liming Li Xieqi Chen Lele Peng Zhanhao Shang Higher vocational and technical college Shanghai University of Engineering ScienceShanghai200437China School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China Shanghai Engineering Research Centre of Vibration and Noise Control Technologies for Rail Transit Shanghai University of Engineering ScienceShanghai201620China

Regular fastener detection is necessary to ensure the safety of ***,the number of abnormal fasteners is significantly lower than the number of normal fasteners in real *** supervised inspectionmethods have insufficient detection ability in cases of imbalanced *** solve this problem,we propose an approach based on deep convolutional neural networks(DCNNs),which consists of three stages:fastener localization,abnormal fastener sample generation based on saliency detection,and fastener state ***,a lightweight YOLOv5s is designed to achieve fast and precise localization of fastener ***,the foreground clip region of a fastener image is extracted by the designed fastener saliency detection network(F-SDNet),combined with data augmentation to generate a large number of abnormal fastener samples and balance the number of abnormal and normal ***,a fastener inspection model called Fastener ResNet-8 is constructed by being trained with the augmented fastener *** show the effectiveness of our proposed method in solving the problem of sample imbalance in fastener *** and quantitative comparisons show that the proposed F-SDNet outperforms other state-of-the-art methods in clip region extraction,reaching MAE and max F-measure of 0.0215 and 0.9635,*** addition,the FPS of the fastener state inspection model reached 86.2,and the average accuracy reached 98.7%on 614 augmented fastener test sets and 99.9%on 7505 real fastener datasets.

关键词： Railway fastener sample generation inspection model deep learning

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Site-directed mutagenesis of bifunctional riboflavin kinase/FMN adenylyltransferase via CRISPR/Cas9 to enhance riboflavin production

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Synthetic and Systems Biotechnology 2024年第3期9卷 503-512页

作者： Bing Fu Meng Chen Xianfeng Bao Jiajie Lu Zhiwen Zhu Fuyao Guan Chuyang Yan Peize Wang Linglin Fu Ping Yu college of Food Science and Biotechnology Zhejiang Gongshang University149 Jiaogong RoadHangzhouZhejiang Province310035People’s Republic of China college of Forestry Science and Technology Lishui Vocational and Technical College357 Zhongshan Street NorthLishuiZhejiang Province323000People’s Republic of China Lishui Institute for Quality Inspection and Testing 395 Zhongshan StreetLishuiZhejiang Province323000People’s Republic of China

Vitamin B_(2)is an essential water-soluble *** most prokaryotes,a bifunctional enzyme called FAD synthase catalyzes the successive conversion of riboflavin to FMN and *** this study,the plasmid pNEW-AZ containing six key genes for the riboflavin synthesis was transformed into strain R2 with the deleted FMN riboswitch,yielding strain *** R5 strain could produce 540.23±5.40 mg/L riboflavin,which was 10.61%higher than the R4 strain containing plasmids pET-AE and pAC-Z harboring six key *** further enhance the production of riboflavin,homology matching and molecular docking were performed to identify key amino acid residues of FAD *** point mutation sites were *** comparing riboflavin kinase activity,mutations of T203D and N210D,which respectively decreased by 29.90%and 89.32%compared to wild-type FAD synthase,were selected for CRISPR/Cas9 gene editing of the genome,generating engineered strains R203 and ***-AZ was transformed into R203,generating R6.R6 produced 657.38±47.48 mg/L riboflavin,a 21.69%increase compared to *** study contributes to the high production of riboflavin in recombinant *** BL21.

关键词： Vitamin B_(2) FAD synthase Escherichia coli BL21 Riboflavin kinase CRISPR/Cas9

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