检索结果-南通市图书馆

Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

National Science Review 2024年第2期11卷 155-167页

作者： Peng He Meng-Yang Hu Jin-Hong li Tian-Zhang Qiao Yi-lin Lu shou-fei Zhu Frontiers Science Center for New Organic Matter State Key Laboratory and Institute of Elemento-Organic Chemistry Nankai University

Iron catalysts are ideal transition metal catalysts because of the Earths abundant, cheap, biocompatible features of iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively,and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

关键词： spin effect spin-delocalization spin crossover iron-catalysis alkyne hydrosilylation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Trial application of the envelope method to the potential ambiguity problem

引用

Nuclear Science and Techniques 2024年第1期35卷 73-80页

作者： li-Yuan Hu Yu-shou Song Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering UniversityHarbin 150001China College of Nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China Key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information TechnologyHarbin 150001China

The optical potential ambiguity is a long-standing problem in the analysis of elastic scattering data.For a specific collid-ing system,ambiguous potential families can lead to different behaviors in the nearside and farside scattering components.By contrast,the envelope method can decompose the experimental data into two components with negative and positive deflection angles,respectively.Hence,a question arises as to whether the comparison between the calculated nearside(or farside)component and the derived positive-deflection-angle(or negative-deflection-angle)component can help analyze the potential ambiguity problem.In this study,we conducted a trial application of the envelope method to the potential ambiguity problem.The envelope method was improved by including uncertainties in the experimental data.The colliding systems of 16O+28Si at 215.2 MeV and 12C+12C at 1016 MeV were considered in the analyses.For each colliding system,the angular distribution experimental data were described nearly equally well by two potential sets,one of which is“surface transpar-ent”and the other is refractive.The calculated angular distributions were decomposed into nearside and farside scattering components.Using the improved envelope method,the experimental data were decomposed into the positive-deflection-angle and negative-deflection-angle components,which were then compared with the calculated nearside and farside components.The capability of the envelope method to analyze the potential ambiguities was also discussed.

关键词： Elastic scattering Optical potential ambiguities Envelope method Nearside/farside decomposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Self-assembly of perovskite nanocrystals:From driving forces to applications

引用

Journal of Energy Chemistry 2024年第1期88卷 561-578,I0013页

作者： Yi li fei Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell field.This review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are detailed.Subsequently,we summarize the collective optoelectronic properties and application areas of perovskite superlattice structures.Finally,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

关键词： Self-assembly Metal halide perovskite Nanocrystals Driving forces

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impacts of pancreatic exocrine insufficiency on gut microbiota

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第4期25卷 271-279页

作者： Yulin GUO Feng CAO fei li Department of General Surgery Xuanwu Hospital of Capital Medical UniversityBeijing 100053China Acute Pancreatitis Clinical Center of Capital Medical University Beijing 100053China

Pancreatic exocrine insufficiency(PEI)can be induced by various kinds of diseases,including chronic pancreatitis,acute pancreatitis,and post-pancreatectomy.The main pathogenetic mechanism of PEI involves the decline of trypsin synthesis,disorder of pancreatic fluid flow,and imbalance of secretion feedback.Animal studies have shown that PEI could induce gut bacterial overgrowth and dysbiosis,with the abundance of Lactobacillus and Bifidobacterium increasing the most,which could be partially reversed by pancreatic enzyme replacement therapy.Clinical studies have also confirmed the association between PEI and the dysbiosis of gut microbiota.Pancreatic exocrine secretions and changes in duodenal p H as well as bile salt malabsorption brought about by PEI may affect and shape the abundance and composition of gut microbiota.In turn,the gut microbiota may impact the pancreatic exocrine acinus through potential bidirectional crosstalk.Going forward,more and higher-quality studies are needed that focus on the mechanism underlying the impact of PEI on the gut microbiota.

关键词： Pancreatic exocrine insufficiency Gut microbiota Gut microbiome Pancreatic enzyme replacement therapy

来源：

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

Recent Advances in Mn,Fe,Co,and Ni-Catalyzed Organic Reactions

引用

CCS Chemistry 2024年第3期6卷 537-584页

作者： Lu-Jie li Yuli He Yunhui Yang Jun Guo Zhan Lu Congyang Wang Shaolin Zhu shou-fei Zhu College of Chemistry Nankai UniversityTianjin 300071 School of Chemistry and Chemical Engineering Nanjing UniversityNanjingJiangsu Province 210093 Institute of Chemistry Chinese Academy of Sciences and University of Chinese Academy of SciencesBeijing 100190 Department of Chemistry Zhejiang UniversityHangzhouZhejiang Province 310058

This paper reviewed the recent research progress of organic reactions catalyzed by four typical earthabundant and 3d metal catalysts:Mn,Fe,Co,and Ni complexes and mainly focused on the reactions in which these 3d metal catalysts exhibited obvious advantages over other catalysts.The mechanism that makes these 3d metal catalysts show unusual properties is another focus of this paper.An outlook on 3d metal complexes-catalyzed organic reactions was also considered.

关键词： Earth-abundant metal catalysts sustainable organic synthesis structure-function relationships organometallic intermediates hydrocarbon transformations

来源：

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

Considering solid shear stress in MP-PIC simulation of a CFB riser

引用

Particuology 2024年第6期89卷 79-87页

作者： Tagir Kadyrov fei li Atta Ullah Nature-inspired Engineering Center University of TyumenTyumen 625003Russia Laboratory of Theory and Optimization of Chemical and Technological Processes University of TyumenTyumen625003Russia State Key Laboratory of Multi-phase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Department of Chemical Engineering Pakistan Institute of Engineering&Applied SciencesIslamabad 45650Pakistan

To enable successful multi-phase particle-in-cell(MP-PIC)simulations of circulating fluidized beds(CFBs),both the interphase drag force and interparticle collisions need to be carefully modeled.Particle collisions are usually represented by the solid stress consisting of the normal and shear components,in which the normal stress was found to have a leading role in the numerical stability of MP-PIC simulations,whereas the impact of the shear stress has seldom been reported.In this work,the effects of the solid shear stress are investigated by using two-dimensional simulations of the moderately dense laboratory-scale CFB riser with in-house MP-PIC code implemented on MFIX open-source platform.Cases including only normal solid stress and those considering both normal and shear solid stresses are simulated.The results of solids flux,axial and radial solids profiles are compared with available experimental data.The results show that the solid shear stress plays a minor role on the accuracy of simulation,and the increase of PPP(number particles per parcel)leads to a lower accuracy of simulation.

关键词： Simulation Fluidization Multiphase particle-in-cell(MP-PIC) Solid shear stress

来源：

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

Partial linear Model Averaging Prediction for Longitudinal Data

引用

Journal of Systems Science & Complexity 2024年第2期37卷 863-885页

作者： li Na fei Yu ZHANG Xinyu Faculty of Science Kunming University of Science and TechnologyKunming 650500China School of Statistics and Mathematics Yunnan University of Finance and EconomicsKunming 650221China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

Prediction plays an important role in data analysis.Model averaging method generally provides better prediction than using any of its components.Even though model averaging has been extensively investigated under independent errors,few authors have considered model averaging for semiparametric models with correlated errors.In this paper,the authors offer an optimal model averaging method to improve the prediction in partially linear model for longitudinal data.The model averaging weights are obtained by minimizing criterion,which is an unbiased estimator of the expected in-sample squared error loss plus a constant.Asymptotic properties,including asymptotic optimality and consistency of averaging weights,are established under two scenarios:(i)All candidate models are misspecified;(ii)Correct models are available in the candidate set.Simulation studies and an empirical example show that the promise of the proposed procedure over other competitive methods.

关键词： Asymptotic optimality longitudinal data model averaging estimator partially linear model prediction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Homer1a reduces inflammatory response after retinal ischemia/reperfusion injury

引用

Neural Regeneration Research 2024年第7期19卷 1608-1617页

作者： Yanan Dou Xiaowei fei Xin He Yu Huan Jialiang Wei Xiuquan Wu Weihao Lyu Zhou fei Xia li fei fei Department of Neurosurgery Xijing HospitalAir Force Military Medical UniversityXi’anShaanxi ProvinceChina Department of Ophthalmology Xijing HospitalAir Force Military Medical UniversityXi’anShaanxi ProvinceChina

Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in neuroinflammation in the cerebrum.However,the effects of Homerla on NLRP3inflammasomes in retinal ischemia/reperfusion injury caused by elevated IOP remain unknown.In our study,animal models we re constructed using C57BL/6J and Homer1^(flox/-)/Homerla^(+/-)/Nestin-Cre^(+/-)mice with elevated IOP-induced retinal ischemia/repe rfusion injury.For in vitro expe riments,the oxygen-glucose deprivation/repe rfusion injury model was constructed with M uller cells.We found that Homerla ove rexpression amelio rated the decreases in retinal thickness and Muller cell viability after ischemia/reperfusion injury.Furthermore,Homerla knockdown promoted NF-κB P65^(Ser536)activation via caspase-8,NF-κB P65 nuclear translocation,NLRP3 inflammasome formation,and the production and processing of interleukin-1βand inte rleukin-18.The opposite results we re observed with Homerla ove rexpression.Finally,the combined administration of Homerla protein and JSH-23 significantly inhibited the reduction in retinal thickness in Homer1^(flox/-)Homer1a^(+/-)/Nestin-Cre^(+/-)mice and apoptosis in M uller cells after ischemia/reperfusion injury.Taken together,these studies demonstrate that Homer1a exerts protective effects on retinal tissue and M uller cells via the caspase-8/NF-KB P65/NLRP3 pathway after I/R injury.

关键词： caspase-8 Homer1a interleukin-18 interleukin-1β intraocular pressure ischemia/reperfusion injury JSH-23 Müller cells NLRP3 nuclear factor-kB p65 retina

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recent progress in side chain engineering of Y-series non-fullerene molecule and polymer acceptors

引用

Science China Chemistry 2024年第3期67卷 788-805页

作者： li Tian Chunchen liu fei Huang School of Materials Science and Engineering Henan University of TechnologyZhengzhou 450001China Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou 510640China

Organic solar cells(OSCs) have drawn considerable attention in the last decade due to the great potential of light weight,flexibility, and low-cost solution processing. Particularly, Y-series non-fullerene acceptors(NFAs) including small molecular acceptors(SMAs) and polymerized small molecular acceptors(PSMAs) have become research hot spots due to their excellent power conversion efficiency. Side chain engineering is crucial to adjust the solubility and crystallinity of NFAs, which will significantly affect the morphology of active layers and the efficiency of OSCs. However, the understanding of side chain engineering on NFAs is still limited and lacks a systematic review. This review aims to provide a brief summary of the recent developments in side chain engineering of NFAs, with a special focus on the design and application of Y-series SMAs and PSMAs for high-efficiency non-fullerene organic solar cells(NF-OSCs). In addition, the review also points out challenges and provides useful guidance regarding side chain regulation for Y-series NFAs.

关键词： organic solar cell Y-series non-fullerene acceptors side chain engineering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distribution of per-and polyfluoroalkyl substances in blood,serum,and urine of patients with liver cancer and associations with liver function biomarkers

引用

Journal of Environmental Sciences 2024年第5期139卷 418-427页

作者： Cao Dai lin Peng Yanjie li Zhendong li Da Chen fei Wang Nan lin Department of Hepatobiliary Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630China School of Environment Guangdong Key Laboratory of Environmental Pollution and HealthJinan UniversityGuangzhou 510632China State Key Laboratory of Environmental and Biological Analysis Department of ChemistryHong Kong Baptist UniversityHong Kong 999077China South China Institute of Environmental Sciences MEEGuangzhou 510655China

Studies have shown that per-and polyfluoroalkyl substances(PFASs)may be hepatotoxic in animals or humans.However,data on clinical epidemiology are very limited.In this study,21PFASs were determined in patients with liver diseases,with the highest median concentrations detected in the serum sample(26.7 ng/mL),followed by blood(10.7 ng/mL)and urine(5.02 ng/mL).Higher total PFAS concentrations were found in hepatocellular carcinoma(HCC)patients compared to non-HCC patients,with significant discrepancies in serum and blood samples.Besides,significant correlations were also found among PFAS concentrations and age,gender,body mass index(BMI),and liver function biomarkers levels.For example,PFAS concentrations are significantly higher in males than in females;Several serum PFASs concentrations increase with age and BMI,while the serum perfluorohexane sulfonic acid(PFHxS)concentrations are negatively correlated with age.In addition,multiple regression models adjusted for age,gender and BMI found that increased serum perfluorobutane sulfonic acid(PFBS),perfluoroheptane sulfonic acid(PFHpS)and perfluorohexylphosphonic acid(PFHxPA)conentrations are correlated with elevated alkaline phosphatase(ALP),aspartate aminotransferase(AST),and alpha-fetoprotein(AFP)(plinical hepatotoxicity of PFAS.

关键词： Per-and polyfluoroalkyl substances(PFASs) liver cancer Serum Blood Urine liver function biomarkers

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：