检索结果-南通市图书馆

Recent advances in transition-metal catalyzed nitrene transfer reactions with carbamates

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第3期35卷 76-86页

作者： Yanshu Luo xinyu zhang Yuanzhi Xia College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China

Nitrene transfer reactions are powerful tools in synthetic organic *** recent years,transitionmetal catalyzed nitrene transfer reactions with carbamates as the nitrene precursors have been widely *** species undergoes facile C-H amination,aziridination,and bifunctionalization of alkenes under the catalysis of different transition metals including Rh,Fe,Ru and others,enabling the efficient construction of various nitrogen-containing *** this review,the recent developments in nitrene transfer reactions with carbamates via N-O bond cleavage were introduced based on different types of reaction,and the key mechanistic information and synthetic applications of the methodologies were discussed.

关键词： Transition-metal catalysis Nitrene transfer Carbamate C—H amination Aziridination Bifunctionalization

Kriging Model Averaging Based on Leave-One-Out Cross-Validation Method

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第5期37卷 2132-2156页

作者： FENG Ziheng ZONG Xianpeng XIE Tianfa zhang.xinyu School of Mathematics Statistics and Mechanics Beijing University of Technology Academy of Mathematics and Systems Science Chinese Academy of Sciences

In recent years, Kriging model has gained wide popularity in various fields such as space geology, econometrics, and computer experiments. As a result, research on this model has *** this paper, the authors propose a model averaging estimation based on the best linear unbiased prediction of Kriging model and the leave-one-out cross-validation method, with consideration for the model uncertainty. The authors present a weight selection criterion for the model averaging estimation and provide two theoretical justifications for the proposed method. First, the estimated weight based on the proposed criterion is asymptotically optimal in achieving the lowest possible prediction ***, the proposed method asymptotically assigns all weights to the correctly specified models when the candidate model set includes these models. The effectiveness of the proposed method is verified through numerical analyses.

关键词： Asymptotic optimality best linear unbiased prediction cross-validation Kriging model model averaging

Phenology of different types of vegetation and their response to climate change in the Qilian Mountains,China

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第2期21卷 511-525页

作者： ZHAO Kaixin LI Xuemei zhang Zhengrong LIU xinyu Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring Lanzhou 730070China Gansu Provincial Engineering Laboratory for National Geographic State Monitoring Lanzhou 730070China

The Qilian Mountains(QM)possess a delicate vegetation ecosystem,amplifying the evident response of vegetation phenology to climate *** relationship between changes in vegetation growth and climate remains *** this end,we used MODIS NDVI data to extract the phenological parameters of the vegetation including meadow(MDW),grassland(GSD),and alpine vegetation(ALV))in the QM from 2002 to ***,we employed path analysis to reveal the direct and indirect impacts of seasonal climate change on vegetation ***,we decomposed the vegetation phenology in a time series using the trigonometric seasonality,Box-Cox transformation,ARMA errors,and Trend Seasonal components model(TBATS).The findings showed a distinct pattern in the vegetation phenology of the QM,characterized by a progressive shift towards an earlier start of the growing season(SOS),a delayed end of the growing season(EOS),and an extended length of the growing season(LOS).The growth cycle of MDW,GSD,and ALV in the QM species is clearly *** SOS for MDW and GSD occurred earlier,mainly between late April and August,while the SOS for ALVs occurred between mid-May and mid-August,a one-month delay compared to the other *** EOS in MDW and GSD were concentrated between late August and April and early September and early January,*** phenology exhibits distinct responses to seasonal temperature and precipitation *** advancement and delay of SOS were mainly influenced by the direct effect of spring temperatures and precipitation,which affected 19.59%and 22.17%of the study area,*** advancement and delay of EOS were mainly influenced by the direct effect of fall temperatures and precipitation,which affected 30.18%and 21.17%of the area,*** the contrary,the direct effects of temperature and precipitation in summer and winter on vegetation phenology seem less noticeable and were mainly influenced by indirect *** indirec

关键词： Vegetation phenology Time series decomposition Path Analysis Climate change

Printed Circuit Board (PCB) Surface Micro Defect Detection Model Based on Residual Network with Novel Attention Mechanism

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 915-933页

作者： xinyu Hu Defeng Kong Xiyang Liu Junwei zhang Daode zhang School of Mechanical Engineering Hubei University of TechnologyWuhan430068Chain

Printed Circuit Board(PCB)surface tiny defect detection is a difficult task in the integrated circuit industry,especially since the detection of tiny defects on PCB boards with large-size complex circuits has become one of the *** improve the performance of PCB surface tiny defects detection,a PCB tiny defects detection model based on an improved attention residual network(YOLOX-AttResNet)is ***,the unsupervised clustering performance of the K-means algorithm is exploited to optimize the channel weights for subsequent operations by feeding the feature mapping into the SENet(Squeeze and Excitation Network)attention network;then the improved K-means-SENet network is fused with the directly mapped edges of the traditional ResNet network to form an augmented residual network(AttResNet);and finally,the AttResNet module is substituted for the traditional ResNet structure in the backbone feature extraction network of mainstream excellent detection models,thus improving the ability to extract small features from the backbone of the target detection *** results of ablation experiments on a PCB surface defect dataset show that AttResNet is a reliable and efficient *** Torify the performance of AttResNet for detecting small defects in large-size complex circuit images,a series of comparison experiments are further *** results show that the AttResNet module combines well with the five best existing target detection frameworks(YOLOv3,YOLOX,Faster R-CNN,TDD-Net,Cascade R-CNN),and all the combined new models have improved detection accuracy compared to the original model,which suggests that the AttResNet module proposed in this paper can help the detection model to extract target *** them,the YOLOX-AttResNet model proposed in this paper performs the best,with the highest accuracy of 98.45% and the detection speed of 36 FPS(Frames Per Second),which meets the accuracy and real-time requirements for the detection of tiny defect

关键词： Neural networks deep learning ResNet small object feature extraction PCB surface defect detection

Application of electromagnetic metallurgy in continuous casting: A review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2024年第1期34卷 1-11页

作者： Jiale Li Yi Nian Xiang Liu Youcheng Zong xinyu Tang Chaojie zhang Liqiang zhang The Intelligent Metallurgy Research Institute School of Metallurgical Engineering Anhui University of Technology

The standards within the global steel industry are constantly advancing, necessitating increasingly rigorous quality control protocols during the continuous casting process. Central to the challenges faced in this domain are persistent defects such as central segregation, V-shaped segregation, and center porosity, which significantly impede the production of high-caliber steel products. The discipline of electromagnetic metallurgy has emerged as a critical solution in reducing these defects, thereby enhancing the efficiency and stability of continuous casting operations. Its demonstrated effectiveness has led to its widespread implementation across global and domestic steel production industries. This paper aims to deliver a comprehensive examination of electromagnetic metallurgy's impact on the final stages of solidification in continuous casting, along with its contributions to the heating and purification processes within the tundish. Additionally, it will explore the potential advancements and applications of this technology in the evolving sphere of continuous casting.

关键词： continuous casting Quality control Final electromagnetic stirring Induction heating Electromagnetic purification

Tracing the sources of nutrients through the Tsushima/Korea Strait

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第6期43卷 142-152页

作者： Jing zhang.xinyu Guo Lei Zhu Jianlong Feng Liang Zhao Key Laboratory of Marine Resource Chemistry and Food Technology Ministry of EducationTianjin 300457China College of Marine and Environmental Science Tianjin University of Science and TechnologyTianjin 300457China Center for Marine Environmental Studies Ehime UniversityMatsuyama 790-8577Japan

The nutrients from the East China Sea(ECS) through the Tsushima/Korea Strait(TS) strongly impact the eco system of the Japan Sea(JS).The complex origins of the Tsushima Warm Current and the various nutrient sources in the ECS result in complex spatial-temporal variations in nutrients in the *** a physical-biological model with a tracking technique,we studied the effects of nutrient sources from the ECS on the *** all the nutrient sources,the Kuroshio has the highest nutrient concentrations in the *** maximum concentration occurs at the bottom,while those of rivers and atmospheric depo sition occur at the surface,and that of the Taiwan Strait occurs in the middle *** nutrient transport through the TS exhibits similar seasonal variations,as does the volume *** transport of nutrients from the Kuroshio accounts for more than 85% of the *** transport of nutrients from the Taiwan Strait is greater during autumn and *** transport of dissolved inorganic nitrogen(DIN) from both rivers and atmospheric deposition through the TS peak in *** transport cannot be equated with volume *** DIN in the less saline zone originates not only from rivers but also from atmospheric deposition and the *** transport of nutrients from the Taiwan Strait is not as significant as its volume transport in the TS.

关键词： dissolved inorganic nitrogen dissolved inorganic phosphate East China Sea Japan Sea nutrient transport

Defusing Triple Pressure to Promote High-Quality Economic Development Rapidly

在线全文

学校读者我要写书评

暂无评论

Frontiers of Economics in China-Selected Publications from Chinese Universities 2024年第1期19卷 30-58页

作者： WANG Hongju zhang.xinyu Schoolof Applied Economics University of Chinese Academyof Social SciencesBeijing 12488China National Academy of Economic Strategy Chinese Academy of Social SciencesBeijing 100006China School of Finance Zhejiang University of Finance&EconomicsHangzhou 310018China

Since the 18th National Congress of the Communist Party of China(CPC),the quality of China's economic development has been continuously ***,the year 2022 witnessed a subdued economic growth *** triple pressures continue to evolve,with contraction in demand as the primary contradiction facing China's macro economy in the short *** contrast to major economies in the world,China grapples with a low economic growth-inflation index combination,a pace of economic expansion trailing behind its potential,and a mounting unemployment *** impact of supply on price increases weakens,while the global industrial and supply chains are amidst continuous *** the consumer confidence index(Ccl)and the purchasing managers'index(PMl)remain *** expectation for the depreciation of the RMB against US dollar is *** 2023,China will continue to improve the financing environment and carry out a proactive fiscal ***,there is a moderation trend in the trajectory of the interest rate of the Federal Reserve System *** together,these factors(triple pressures)are expected to mitigate the contraction in demand,thereby steering the economy toward robust ***,it is crucial to recognize that low economic growth in the long term may compromise the quality of economic *** year 2023 is the first year of accelerating Chinese modernization after the 2Oth National Congress of the *** should integrate the strategy to expand internal demand with its efforts to deepen supply-side structural *** can foster the coordinated growth of both economic quality and speed,making a good start for Chinese modernization.

关键词： high-quality development output gap strategy to expand domestic demand supply-sidestructuralreform

A CMIP6-based assessment of regional climate change in the Chinese Tianshan Mountains

维普期刊数据库评论

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 Arid Land 2024年第2期16卷 195-219页

作者： LIU xinyu LI Xuemei zhang Zhengrong ZHAO Kaixin LI Lanhai Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring Lanzhou 730070China Gansu Provincial Engineering Laboratory for National Geographic State Monitoring Lanzhou 730070China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China

Climate warming profoundly affects hydrological changes,agricultural production,and human *** and semi-arid areas of China are currently displaying a marked trend of warming and *** Chinese Tianshan Mountains(CTM)have a high climate sensitivity,rendering the region particularly vulnerable to the effects of climate *** this study,we used monthly average temperature and monthly precipitation data from the CN05.1 gridded dataset(1961-2014)and 24 global climate models(GCMs)of the Coupled Model Intercomparison Project Phase 6(CMIP6)to assess the applicability of the CMIP6 GCMs in the CTM at the regional *** on this,we conducted a systematic review of the interannual trends,dry-wet transitions(based on the standardized precipitation index(SPI)),and spatial distribution patterns of climate change in the CTM during *** further projected future temperature and precipitation changes over three terms(near-term(2021-2040),mid-term(2041-2060),and long-term(2081-2100))relative to the historical period(1961-2014)under four shared socio-economic pathway(SSP)scenarios(i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5).It was found that the CTM had experienced significant warming and wetting from 1961 to 2014,and will also experience warming in the future(2021-2100).Substantial warming in 1997 was captured by both the CN05.1 derived from interpolating meteorological station data and the multi-model ensemble(MME)from the CMIP6 *** MME simulation results indicated an apparent wetting in 2008,which occurred later than the wetting observed from the CN05.1 in *** GCMs generally underestimated spring temperature and overestimated both winter temperature and spring precipitation in the *** and wetting are more rapid in the northern part of the *** the end of the 21st century,all the four SSP scenarios project warmer and wetter conditions in the CTM with multiple dry-wet ***,the rise in precipitation fails to counterbal

关键词： climate change Coupled Model Intercomparison Project Phase 6(CMIP6) global climate models(GCMs) shared socio-economic pathway(SSP)scenarios standardized precipitation index(SPI) Chinese Tianshan Mountains

Gas-generating polymersomes-based amplified photoimmunotherapy for abscopal effect and tumor metastasis inhibition

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 456-461页

作者： Chenlu Huang xinyu Yang Qingyu Yu Linhua zhang Dunwan Zhu Tianjin Key Laboratory of Biomedical Materials Key Laboratory of Biomaterials and Nanotechnology for Cancer ImmunotherapyInstitute of Biomedical EngineeringChinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300192China

Due to the heterogeneity of tumors,single phototherapy cannot completely ablate tumors and inhibit tumor *** overcome these,we formulated targeted and multifunctional polymersomes ABC@ICGIMQ-LHRH(AIRL)that encapsulated Toll-like receptor(TLR)7/8 agonist imiquimod(IMQ)and photosensitizer indocyanine green(ICG)in the hydrophobic layer as well as bubble-generator NH_(4)HCO_(3) in the hydrophilic cavity to inhibit the growth of primary and distant tumors,and prevent tumor metastasis through synergistic *** AIRL polymersomes exhibited uniform and stable size,and high drug encapsulation efficiency,acid/reduction/laser responsiveness,excellent photothermal conversion efficiency,effective reactive oxygen species generation,high tumor *** could be effectively internalized by dendritic cells(DCs),achieve lysosome escape and enhance DCs *** synergistic photoimmunotherapy via AIRL polymersomes remarkably promoted the differentiation and activation of T cells,elevated strong systemic immune response to eradicate primary tumors and inhibit the growth of distant ***,the endurable immunological memory prevented tumor metastasis,which provided a promising nanoplatform for the combination therapy of cancer.

关键词： Polymersomes Phototherapy Immunotherapy TLR 7/8 agonist Gas-generating