检索结果-南通市图书馆

Chinese Chemical Letters 2016年第6期27卷 964-968页

作者： Xue-Dong Zhang Na Gao Zhi Guan yan-hong he Key Laboratory of Applied Chemistry of Chongqing Municipality School of Chemistry and Chemical Engineering Southwest University

An unprecedented enzyme-catalyzed asymmetric domino aza-Michael/aldol reaction of 2-aminobenzaldehyde and a,b-unsaturated aldehydes is achieved. Pepsin from porcine gastric mucosa provided mild and efficient access to diverse substituted 1,2-dihydroquinolines in yields of 38%–97% with 6%–24%enantiomeric excess（ee）. This work not only provides a novel method for the synthesis of dihydroquinoline derivatives, but also promotes the development of enzyme catalytic promiscuity.

关键词： Pepsin Biocatalysis Domino aza-Michael/aldol reaction 1 2-Dihydroquinolines Enzyme catalytic promiscuity

Polyacrylamide hydrogels with phenylboronic acid moieties for the imprinting of proteins

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第12期21卷 1487-1489页

作者： yan Wang Zhi Hua Chai hong yan he Yi Zhe Jiang Guo Qi Fu Key Laboratory of Functional Polymer Materials of Ministry of Education Institute of Polymer Chemistry Nankai University Tianjin 300071 China

In this letter,N-acryloyl-3-aminophenylboronic acid（AAPBA） was synthesized and then examined as a new functional monomer for protein *** was allowed to be copolymerized with acrylamide to produce hemoglobin- or lysozyme-imprinted *** template rebinding tests,the imprinted gels showed significant increase in the specific binding with the increase of the AAPBA amounts in the prepolymerization *** results indicate that AAPBA may be a useful functional monomer for its moderate interactions with protein molecules.

关键词： Protein imprinting Hydrogels hemoglobin Lysozyme 3-Aminophenylboronic acid

Restoring cosmological concordance with axion-like early dark energy and dark matter characterized by a constant equation of state?

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第7期76卷 74-82页

作者： yan-hong Yao Xin-he Meng School of Physics and Astronomy Sun Yatsen University 2 Daxue RoadTangjiaZhuhaiChina School of Physics Nankai University 94 Weijin RoadNankaiTianjinChina

The Hubble tension persists as a challenge in *** early dark energy(EDE)models,initially considered the most promising for alleviating the Hubble tension,fall short of addressing the issue without exacerbating other tensions,such as the S_(8)*** that a negative dark matter(DM)equation of state(EoS)parameter is conducive to reduce the value of the σ_(8)parameter,we extend the axion-like EDE model in this paper by replacing the cold dark matter(CDM)with DM characterized by a constant EoS w_(dm)(referred to as WDM hereafter).We then impose constraints on this axion-like EDE extension model,along with three other models:the axion-like EDE model,ΛWDM,and Λ*** constraints are derived from a comprehensive analysis incorporating data from the Planck 2018 cosmic microwave background,baryon acoustic oscillations,and the Pantheon compilation,as well as a prior on H_(0)(i.e.H_(0)=73.04±1.04,based on the latest local measurement by Riess et al)and a Gaussianized prior on S_(8)(i.e.S_(8)=0.766±0.017,determined through the joint analysis of KID1000+BOSS+2dLenS).We find that although the new model maintains the ability to alleviate the Hubble tension to~1.4σ,it still exacerbates the S_(8)tension to a level similar to that of the axion-like EDE model.

关键词： Hubble tension early dark energy noncold dark matter S8 tension

A new anthraquinone glycoside from seeds of Cassia obtusifolia

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第9期19卷 1083-1085页

作者： Li Ying Tang Zhu Ju Wang Mei hong Fu yan he hong Wei Wu Lu Qi Huang Institute of Traditional Chinese Materia Medica Chinese Academy of Medical Sciences Beijing 100700 China

A new anthraquinone glycoside 1, along with a known anthraquinone glycoside aurantio-obmsin-6-O-β-D-glucopyranoside 2, were isolated from the seeds of Cassia obtusifolia. On the basis of spectral and chemical evidences, the structure of 1 was established as 1-demethylaurantio-obtusin-2-O-β-D-glucopyranoside. Moreover, the 13C NMR of 2 was assigned totally and correctly for the first time based on the two-dimensional NMR.

关键词： ~assia obtusifolia Anthraquinone glycoside 1-Demethylaurantio-obtusin-2-O-β-D-glucopyranoside

Stimuli-Responsive lonic Liquids and the Regulation of Aggrega-tion Structure and Phase Behavior

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第3期39卷 729-744页

作者： Xiao-Qing Yuan Ya-Qin Zhang Zhi-Yong Li Feng Huo Yi-Hui Dong hong-yan he Beijing Key Laboratory of lonic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBejling 100190China Dalian National Laboratory for Clean Energy DalianLiaoning 116023China Collaborative Innovation Center of henan Province for Green Manufacturing of Fine Chemicals Key Laboratory of Green Chermical Media and ReactionsMinistry of EducationSchool of Chemistry and Chemical EngineeringHenan Normal UniversityXinxiangHenan 453007China

lonic liquids with stimuli-responsive characteristics are an essential branch in the comprehensive ionic liquids'family,which can meet the controllable and reversible needs in practical applications with different stimulation *** this review,we summarize the recent research progress of these stimuli-responsive ionic liquids,mainly focusing on their chemical structures,properties,responsive mechanism,aggregation structures,and phase behaviors,which were driven by external stimuli,such as CO2,magnetism,light,temperature,redox,and ***,the particular or potential applications of stimuli-responsive ionic liquids are expounded in various fields of science,including catalytic reaction,extraction,separation,nano-material preparation,and gas *** the end,the challenges and strategies of the subject are briefly *** is expected that this review will contribute to the rational design and applications of stimu-liresponsive ionic liquids in the future.

关键词： lonic liquids Stimuli Responsive Aggregation Phase behavior

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

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

Rare Metals 2024年第6期43卷 2832-2841页

作者： yan Jiang Liang-Liang Wei Jian he hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural Materials and Protective Coatings Ministry of Industry and Information TechnologyBeihang UniversityBeijing 100191China

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in *** comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in *** novel coating has a mass gain of~0.5 mg·cm^(-2)after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional *** oxide scale mostly consisting ofα-Al_(2)O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2)O_(3).Pt content in the novel coating has significant effect on the oxidation *** optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

关键词： γ-γ'NiPtAl coating Platinum Oxidation Al_(2)O_(3) Superalloy

Efficient Pt/KFI zeolite catalysts for the selective catalytic reduction of NOxby hydrogen

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 102-111页

作者： Ligang Zhang Yulong Shan Zidi yan Zhongqi Liu Yunbo Yu hong he School of Rare Earths University of Science and Technology of ChinaHefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341119China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Aiming at purification of NO_(x)from hydrogen internal combustion engines(HICEs),the hydrogen selective catalytic reduction(H_(2)-SCR)reaction was investigated over a series of Pt/KFI zeolite catalysts.H_(2)can readily reduce NO_(x)to N_(2)and N_(2)O while O_(2)inhibited the deNO_(x)efficiency by consuming the reductant H_(2).The Pt/KFI zeolite catalysts with Pt loading below 0.1wt.% are optimized H_(2)-SCR catalysts due to its suitable operation temperature window since high Pt loading favors the H_(2)-O_(2)reaction which lead to the insufficient of *** to metal Pt^(0)species,Pt^(δ+)species showed lower activation energy of H_(2)-SCR reaction and thought to be as reasonable active ***,Eley-Rideal(E-R)reaction mechanism was proposed as evidenced by the reaction orders in kinetic ***,the optimized reactor was designed with hybrid Pt/KFI catalysts with various Pt loading which achieve a high NO_(x)conversion in a wide temperature range.

关键词： Pt/KFI zeolite Pt loading H_(2)-SCR Reaction conditions Kinetics studies

Effects of impregnation sequence on the NH_(3)-SCR activity and hydrothermal stability of a Ce-Nb/SnO_(2) catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 450-457页

作者： Ying Zhu Wenpo Shan Zhihua Lian Jingjing Liu yan Zhang hong he Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control Ningbo Urban Environment Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesNingbo 315800China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Hydrothermal stability is crucial for the practical application of deNO_(x)catalyst on diesel vehicles,for the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR).SnO_(2)-based materials possess superior hydrothermal stability,which is attractive for the development of NH_(3)-SCR *** this work,a series of Ce-Nb/SnO_(2)catalysts,with Ce and Nb loading on SnO_(2)support,were prepared by impregnation *** was found that,the NH_(3)-SCR activities and hydrothermal stabilities of the Ce-Nb/SnO_(2)catalysts significantly varied with the impregnation sequences,and the Ce-Nb(f)/SnO_(2) catalyst that firstly impregnated Nb and then impregnated Ce exhibited the best *** characterization results revealed that CeNb(f)/SnO_(2)possessed appropriate acidity and redox ***,the strong synergistic effect between Nb and Sn species stabilized the structure and maintained the dispersion of acid *** study may provide a new understanding for the effect of impregnation sequence on activity and hydrothermal stability and a new environmental-friendly NH_(3)-SCR catalyst with potential applications for NO_(x)removal from diesel and hydrogenfueled engines.

关键词： NO_(x)emission control NH_(3)-SCR Hydrothermal stability Ce-Nb/SnO_(2)catalyst Impregnation sequence

Channel assignment and power allocation for throughput improvement with PPO in B5G heterogeneous edge networks

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第1期10卷 109-116页

作者： Xiaoming he Yingchi Mao Yinqiu Liu Ping Ping yan hong Han Hu The College of Computer and Information Hohai UniversityNanjingChina The Key Laboratory of Water Big Data Technology of Ministry of Water Resources Hohai UniversityNanjing China The School of Computer Science and Engineering Nanyang Technological UniversitySingapore The College of Textile and Clothing Engineering Soochow UniversitySuzhouChina The College of Internet of Things Nanjing University of Posts and TelecomurunicationsNanjingChina

In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver uses interference ***,uncoordinated radio resource allocation can reduce system throughput and lead to user inequity,for this reason,in this paper,channel allocation and power allocation problems are formulated to maximize the system sum rate and minimum user achievable *** the construction model is non-convex and the response variables are high-dimensional,a distributed Deep Reinforcement Learning(DRL)framework called distributed Proximal Policy Optimization(PPO)is proposed to allocate or assign ***,several simulated agents are trained in a heterogeneous environment to find robust behaviors that perform well in channel assignment and power ***,agents in the collection stage slow down,which hinders the learning of other ***,a preemption strategy is further proposed in this paper to optimize the distributed PPO,form DP-PPO and successfully mitigate the straggler *** experimental results show that our mechanism named DP-PPO improves the performance over other DRL methods.

关键词： B5G heterogeneous edge networks PPO Channel assignment Power allocation Throughput

PDOL-Based Solid Electrolyte Toward Practical Application:Opportunities and Challenges

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

Nano-Micro Letters 2024年第7期16卷 109-141页

作者： Hua yang Maoxiang Jing Li Wang hong Xu Xiaohong yan Xiangming he Institute for Advanced Materials School of Materials Science and EngineeringJiangsu UniversityZhenjiang 212013People’s Republic of China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084People’s Republic of China

Polymer solid-state lithium batteries(SSLB)are regarded as a promising energy storage technology to meet growing demand due to their high energy density and *** conductivity,interface stability and battery assembly process are still the main challenges to hurdle the commercialization of *** the main component of SSLB,poly(1,3-dioxolane)(PDOL)-based solid polymer electrolytes polymerized in-situ are becoming a promising candidate solid elec-trolyte,for their high ion conductivity at room temperature,good battery elec-trochemical performances,and simple assembly *** review analyzes opportunities and challenges of PDOL electrolytes toward practical application for polymer *** focuses include exploring the polymerization mechanism of DOL,the performance of PDOL composite electrolytes,and the application of ***,we provide a perspective on future research directions that need to be emphasized for commercialization of PDOL-based electrolytes in *** exploration of these schemes facilitates a comprehensive and profound understanding of PDOL-based polymer electrolyte and provides new research ideas to boost them toward practical application in solid-state batteries.

关键词： Poly(1,3-dioxolane) Solid electrolyte Polymerization mechanism Composite electrolyte Practical application