检索结果-南通市图书馆

General radical difluoromethylation using difluoroacetic anhydride via photoredox catalysis

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2637-2646页

作者： Meng He Yankai Yang Heng Zhang zhipeng guan zhi-Bing Dong hong Yi Aiwen Lei School of Chemistry and Environmental Engineering Wuhan Institute of TechnologyWuhan 430205China College of Chemistry and Molecular Sciences and Institute for Advanced Studies(IAS) Wuhan UniversityWuhan 430072China

CF_(2)H-containing molecules play pivotal roles in diverse fields from medicinal chemistry to materials science. However, the application of existing CF_(2)H reagents as a source of CF_(2)H radical is limited by their reactivity and preparation. Herein, we develop a simple and general visible-light-catalyzed radical difluoromethylation reaction of alkenes, dienes, and heteroaromatics using commercially available, easy-to-handle, and low-cost difluoroacetic anhydride as the CF_(2)H reagent. This scalable protocol enables the convenient synthesis of a range of CF_(2)H-containing compounds under mild conditions, exhibiting a broad substrate scope and functional group tolerance. Potential applications are further demonstrated by gram-scale synthesis, sunlight experiments, derivatization experiments as well as the synthesis of bioactive molecules.

关键词： radical difluoromethylation alkenes/dienes/heteroaromatics difluoroacetic anhydride photoredox

同方期刊数据库

Boundary Points,Minimal L^(2)Integrals and Concavity PropertyⅢ—Linearity on Riemann Surfaces and Fibrations over Open Riemann Surfaces

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第9期40卷 2091-2152页

作者： Qi An guan zhi Tong MI Zheng YUAN School of Mathematical Sciences Peking UniversityBeijing 100871P.R.China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044P.R.China Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China

In this article,we consider a modified version of minimal L^(2) integrals on sublevel sets of plurisubharmonic functions related to modules at boundary points,and obtain a concavity property of the modified *** applications,we give characterizations for the concavity degenerating to linearity on open Riemann surfaces and on fibrations over open Riemann surfaces.

关键词： Minimal L^(2)integrals plurisubharmonic functions boundary points weakly pseudoconvex Kähler manifold

Autoimmune Encephalitis： An Expanding Frontier of Neuroimmunology

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2016年第9期129卷 1122-1127页

作者： hong-zhi guan Hai-Tao Ren Li-Ying Cui Department of Neurology Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100730 China Neuroscience Center Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100730 China

INTRODUCTIONDiscovery of the spectrum ofautoimmune encephalitis （ALE） is among the most attractive events of neurology in the past decade. AIE includes a heterogeneous group of encephalitic syndromes, which generally include two major categories： classic paraneoplastic limbic encephalitis （LE） associated with the so-called well-characterized onconeural autoantibodies against intracellular neuronal antigens （e.g., Hu, Ma2, etc.） and new-type AIE associated with autoantibodies to the neuronal surface or synaptic antigens.

关键词： Antibody Autoimmune Encephalitis Cerebrospinal Fluid Immune Therapy

Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第3期35卷 109-141页

作者： Hui Liu guan-hong Lei He-Fei Huang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research *** paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt *** competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this *** approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.

关键词： Irradiation and corrosion Synergistic effect Austenitic stainless steels Nickel-based alloys Reactors

Climate warming is likely to weaken the performance of two-phase closed thermosyphon on the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 90-100页

作者： guan-Li JIANG Zi-Teng FU Xin-Yu MEN hong-Ting ZHAO Si-Ru GAO Yong-zhi LI Qing-Bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Beiluhe Observation and Research Station on Frozen Soil Engineering and Environment in the Qinghai-Tibet Plateau Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Muli Field Scientific Observation and Research Station for Gas Hydrate China Geological SurveyBeijing 100083China University of Chinese Academy of Sciences Beijing 100049China School of Civil Engineering and Architecture Jiaxing Nanhu UniversityJiaxing 314001China

Over the years,numerous geotechnical approaches have been implemented to mitigate the adverse effects of climate warming on various infrastructures in the permafrost region of the Qinghai-Tibet Plateau(QTP),such as the Qinghai-Tibet Highway and Railway,and achieved the expected engineering ***,little attention has been given to whether the performance of these geotechnical approaches has changed during the ongoing process of climate *** investigate the performance variation of one of these geotechnical approaches,which is two-phase closed thermosyphon(TPCT),during sustained climate warming,we conducted a statistical analysis of soil temperature monitoring data in 2003-2020 from eight regular embankments and six TPCT embankments in our permafrost monitoring *** results indicate that TPCT undeniably has a cooling effect on the permafrost beneath embankments,even rapidly eliminated previously formed taliks beneath ***,further analysis reveals that the performance of TPCT has been weakening during sustained climate warming,which has confirmed by the re-forming of the taliks beneath embankment where they had been previously *** on the current understanding,we attributed the weakening of thermosyphon performance to a significant reduction in the air temperature freezing index caused by ongoing climate *** this study,we aimed to draw attention to the evolving performance of geotechnical approaches in permafrost regions amid climate warming,prompting necessary engineering innovations to address this situation and ensure the sustainable development of the permafrost region on the QTP.

关键词： Two-phase closed thermosyphon Climate warming Supra-permafrost talik Permafrost degradation Qinghai-Tibet Highway

Multi-scale data joint inversion of minerals and porosity in altered igneous reservoirs—A case study in the South China Sea

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

Petroleum Science 2024年第1期21卷 206-220页

作者： Xin-Ru Wang Bao-zhi Pan Yu-Hang Guo Qing-Hui Wang Yao guan College of Geo-exploration Science and Technology Jilin UniversityChangchun130046JilinChina Research Institute CNOOC Ltd.-ShenzhenShenzhen518000GuangdongChina

There are abundant igneous gas reservoirs in the South China Sea with significant value of research,and lithology classification,mineral analysis and porosity inversion are important links in reservoir ***,affected by the diverse lithology,complicated mineral and widespread alteration,conventional logging lithology classification and mineral inversion become considerably *** the same time,owing to the limitation of the wireline log response equation,the quantity and accuracy of minerals can hardly meet the exploration requirements of igneous *** overcome those issues,this study takes the South China Sea as an example,and combines multi-scale data such as micro rock slices,petrophysical experiments,wireline log and element cutting log to establish a set of joint inversion methods for minerals and porosity of altered igneous ***,we define the lithology and mineral characteristics through core slices and mineral data,and establish an igneous multi-mineral volumetric *** we determine element cutting log correction method based on core element data,and combine wireline log and corrected element cutting log to perform the lithology classification and joint inversion of minerals and ***,it is always difficult to determine the elemental eigenvalues of different minerals in *** paper uses multiple linear regression methods to solve this ***,an integrated inversion technique for altered igneous formations was *** results show that the corrected element cutting log are in good agreement with the core element data,and the mineral and porosity results obtained from the joint inversion based on the wireline log and corrected element cutting log are also in good agreement with the core data from X-ray *** results demonstrate that the inversion technique is applicable and this study provides a new direction for the mineral inversion research of altered igneous formation

关键词： Joint inversion Altered igneous rock Element correction method Lithology identification Multi mineral volume model

Further study on the genesis of lamellar calcite veins in lacustrine black shale--A case study of Paleogene in Dongying Depression, China

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1508-1523页

作者： guan-Min Wang Yun-Jiao Zhang Zi-Yuan Yin Rui Zhu zhi-Yao Hou Yu Bai School of Geosciences China University of Petroleum(East China)Qingdao266580ShandongChina

Lamellar calcite veins are prevalent in carbonate-rich,lacustrine dark *** formation mechanisms of these veins have been extensively debated,focusing on factors such as timing,depth,material source,and driving *** paper examines dark lacustrine shale lamellar calcite veins in the Paleogene strata of Dongying Depression,using various analytical techniques:petrography,isotope geochemistry,cathodoluminescence,inclusion thermometry,and electron probe *** distinct types of calcite veins have been identified:granular calcite veins and sparry calcite *** two types differ significantly in color,grain structure,morphology,and *** further investigation,it was observed that vein generation occurred from the shallow burial period to the maturation of organic matter,with a transition from granular calcite veins to sparry calcite *** granular calcite veins exhibit characteristics associated with the shallow burial period,including plastically deformed laminae and veins,the development of strawberry pyrite,the absence of oil and gas,weak fractionation in oxygen isotopes,and their contact relationship with sparry calcite *** granular calcite veins were likely influenced by the reduction of sulfate *** the other hand,sparry calcite veins with fibrous grains are antitaxial and closely linked to the evolution and maturation of organic *** contain oil and gas inclusions and show a distribution range of homogenization temperature between 90℃ and 120℃ and strong fractionation in oxygen isotopes,indicating formation during the hydrocarbon expulsion *** carbon isotope analysis of the surrounding rocks and veins suggests that the material for vein formation originates from the shale itself,specifically authigenic micritic calcite modified by the action of *** opening of horizontal fractures and vein formation is likely driven by fluid overpressure resulting from undercompaction and hydrocarb

关键词： Calcite veins Shale diagenesis Material source Formation period Formation mechanism

Causal role of immune cells in obstructive sleep apnea hypopnea syndrome:Mendelian randomization study

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第7期12卷 1227-1234页

作者： Huang-hong Zhao Zhen Ma Dong-Sheng guan Department of Encephalopathy Henan Provincial Hospital of Traditional Chinese MedicineZhengzhou 450000Henan ProvinceChina Department of Personnel The First Affiliated Hospital of Henan University of Traditional Chinese MedicineZhengzhou 450000Henan ProvinceChina Department of Neurology Henan Provincial Hospital of Traditional Chinese MedicineZhengzhou 450000Henan ProvinceChina

BACKGROUND Despite being one of the most prevalent sleep disorders,obstructive sleep apnea hypoventilation syndrome(OSAHS)has limited information on its immunologic *** immunological underpinnings of certain major psychiatric diseases have been uncovered in recent years thanks to the extensive use of genome-wide association studies(GWAS)and genotyping techniques using highdensity genetic markers(e.g.,SNP or CNVs).But this tactic hasn't yet been applied to *** a Mendelian randomization analysis,we analyzed the causal link between immune cells and the illness in order to comprehend the immunological bases of *** To investigate the immune cells'association with OSAHS via genetic methods,guiding future clinical *** A comprehensive two-sample mendelian randomization study was conducted to investigate the causal relationship between immune cell characteristics and *** statistics for each immune cell feature were obtained from the GWAS *** on 731 immune cell properties,such as morphologic parameters,median fluorescence intensity,absolute cellular,and relative cellular,was compiled using publicly available genetic *** results'robustness,heterogeneity,and horizontal pleiotropy were confirmed using extensive sensitivity *** Following false discovery rate(FDR)correction,no statistically significant effect of OSAHS on immunophenotypes was ***,two lymphocyte subsets were found to have a significant association with the risk of OSAHS:Basophil%CD33dim HLA DR-CD66b-(OR=1.03,95%CI=1.01-1.03,P<0.001);CD38 on IgD+CD24-B cell(OR=1.04,95%CI=1.02-1.04,P=0.019).CONCLUSION This study shows a strong link between immune cells and OSAHS through a gene approach,thus offering direction for potential future medical research.

关键词： Obstructive sleep apnea hypopnea syndrome Immunity Causal inference MR analysis Sensitivity

Remaining Useful Life Prediction Method for Multi-Component System Considering Maintenance:Subsea Christmas Tree System as A Case Study

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

China Ocean Engineering 2024年第2期38卷 198-209页

作者： WU Qi-bing CAI Bao-ping FAN hong-yan WANG guan-nan RAO Xi GE Weifeng SHAO Xiao-yan LIU Yong-hong CNOOC Safety Technology Services Co. Ltd.Tianjin 300456China College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China CNOOC EnerTech Safety&Environmental Protection BranchTianjin 300456China

Maintenance is an important technical measure to maintain and restore the performance status of equipment and ensure the safety of the production process in industrial production,and is an indispensable part of prediction and health ***,most of the existing remaining useful life(RUL)prediction methods assume that there is no maintenance or only perfect maintenance during the whole life cycle;thus,the predicted RUL value of the system is obviously lower than its actual operating *** complex environment of the system further increases the difficulty of maintenance,and its maintenance nodes and maintenance degree are limited by the construction period and working conditions,which increases the difficulty of RUL *** RUL prediction method for a multi-omponent system based on the Wiener process considering maintenance is *** performance degradation model of components is established by a dynamic Bayesian network as the initial model,which solves the uncertainty of insufficient data *** on the experience of experts,the degree of degradation is divided according to Poisson process simulation random failure,and different maintenance strategies are used to estimate a variety of condition maintenance *** example of a subsea tree system is given to verify the effectiveness of the proposed method.

关键词： remaining useful life Wiener process dynamic Bayesian networks maintenance subsea Christmas tree system