检索结果-内蒙古大学图书馆

Selective production of olefins from methanol over a heteroatomic SAPO-34 zeolite

science Bulletin 2025年第5期70卷 694-703页

作者： Zhaodong Zhu Mengtian Fan Meng He Bing An Yinlin Chen Shaojun Xu Tianze Zhou Alena M.Sheveleva Meredydd Kippax-Jones Lutong Shan Yongqiang Cheng Hamish Cavaye Jeff Armstrong Svemir Rudić Stewart F.Parker William Thornley Evan Tillotson Matthew Lindley Shenglong Tian Daniel Lee Shiyu Fu Mark D.Frogley Floriana Tuna Eric J.L.McInnes Sarah J.Haigh Sihai Yang Department of Chemistry University of ManchesterManchesterM139PLUK Departmentof Chemical Engineering University of ManchesterManchesterM139PLUK Photon Science Institute University of ManchesterManchesterM139PLUK The Chemical and Engineering Materials Division(CEMD) Neutron Sciences DirectorateOak Ridge National LaboratoryOak RidgeTN 37831USA ISIS Facility STFC Rutherford Appleton LaboratoryDidcotOX110QXUK Department of Materials University of ManchesterManchesterM139PLUK CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510641China Diamond Light Source Harwell Science CampusDidcotOX110DEUK College of Chemistry and Molecular Engineering Beijing National Laboratory for Molecular SciencesPeking UniversityBeijing 100871China

The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower *** the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO ***,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of ***-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°*** situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in *** tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.

关键词： Methanol-to-olefin SAPO-34 Propylene Inelastic neutron scattering Trimethyloxonium

来源：评论

学校读者我要写书评

暂无评论

Investigating the hyperparameter space of deep neural network models for reaction coordinates: Revisiting the solvent coordinate in alanine dipeptide isomerization

arXiv

引用

arXiv 2024年

作者： Kawashima, Kyohei Sato, Takumi Okazaki, Kei-Ichi Kim, Kang Matubayasi, Nobuyuki Mori, Toshifumi Institute for Materials Chemistry and Engineering Kyushu University Fukuoka Kasuga816-8580 Japan Department of Interdisciplinary Engineering Sciences Interdisciplinary Graduate School of Engineering Sciences Kyushu University Fukuoka Kasuga816-8580 Japan Research Center for Computational Science Institute for Molecular Science Aichi Okazaki444-8585 Japan Division of Chemical Engineering Department of Materials Engineering Science Graduate School of Engineering Science Osaka University Osaka Toyonaka560-8531 Japan

Identifying reaction coordinates (RCs) from many collective variable candidates have been of great challenge in understanding reaction mechanisms in complex systems. Machine learning approaches, especially the deep neural network (DNN), have become a powerful tool in this field, and have actively been applied. On the other hand, the structure of the DNN model is highly flexible, and the hyperparameters that determine the structure is often selected intuitively or in a highly non-trivial and tedious manner. Furthermore, how the choice of hyperparameter affects the quality of the DNN model remains obscure. In this work, we explore the hyperparameter space by developing the hyperparameter tuning approach for the DNN model in RC optimization, and investigate how the choice of parameter sets affect the quality of the RC. The DNN model is constructed from a large number of collective variables to predict the changes of committor along the RC by minimizing the cross-entropy function, and the hyperparameters are determined in an automatic manner using the Bayesian optimization method. The approach is applied to study the isomerization of alanine dipeptide in vacuum and in water, and the features that characterize the RC are extracted using the explainable AI (XAI) tools. The results show that the DNN models with notably different structures can describe the RC with similar accuracy. Furthermore, despite the difference in the hyperparameters, the features analyzed by XAI are highly similar, indicating that the hyperparameter space is multimodal. By studying the reaction in water, it is found that the electrostatic potential from the solvent to the hydrogen (H18), in addition to the dihedral angles and θ, plays an important role in characterizing the RC. The DNN model thus effectively accounts for the torque character suggested previously. The current study shows that the structure of the DNN models can be rather flexible while the suitably optimized model share the same feat

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

Waste-battery-derived multifunctional zinc catalysts for glycolysis and decolorization of polyethylene terephthalate

引用

Applied Catalysis B: Environmental 2023年第1期325卷

作者： Chiao, Yu-Wen Liao, Weisheng Krisbiantoro, Philip Anggo Yu, Bor-Yih Wu, Kevin C.-W. Department of Chemical Engineering National Taiwan University Taipei10617 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei11529 Taiwan International Graduate Program of Molecular Science and Technology National Taiwan University Taipei10617 Taiwan

In this study, novel and easily recyclable catalysts were prepared from waste batteries for efficient glycolysis and decolorization of polyethylene terephthalate (PET) to obtain bis(2-hydroxyethyl) terephthalate (BHET). At 190 °C and 5 h, the PET conversion and BHET yield reach 89.7 and 77.7%, respectively, which are comparable to the values obtained for the commonly used catalyst zinc acetate. Species generated from the reaction between ethylene glycol (EG) and zinc plates (e.g., Zn-glycolate, ZnO, and other metal species on zinc plates) demonstrate excellent catalytic performance. Furthermore, dye molecules released from several commercial-colored PET bottles during glycolysis can be degraded to colorless molecules using zinc plates, thereby facilitating BHET purification. The exposed zero-valent zinc from the zinc plates in EG is responsible for degrading the dye molecules. Finally, the scaled-up PET glycolysis process is conceptually designed using Aspen Plus software. The simulation results suggest that reducing the energy requirement in distillation is necessary for further improvement. © 2022 Elsevier B.V.

关键词： Polyethylene terephthalates

来源：评论

学校读者我要写书评

暂无评论

Exciton diffusion and dissociation in organic and quantum-dot solar cells

引用

SmartMat 2023年第6期4卷 11-30页

作者： Dan He Miao Zeng Zhenzhen Zhang Yang Bai Guichuan Xing Hui-Ming Cheng Yuze Lin Department of Metallurgy and Applied Physical Chemistry College of Chemistry and Chemical EngineeringCentral South UniversityChangshaChina Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijingChina Faculty of Materials Science and Energy Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoMacaoChina University of Chinese Academy of Sciences BeijingChina Australian Institute for Bioengineering and Nanotechnology The University of Queensland BrisbaneSt LuciaQueenslandAustralia

For the process of photovoltaic conversion in organic solar cells(OSCs)and quantum-dot solar cells(QDSCs),three of four steps are determined by exciton behavior,namely,exciton generation,exciton diffusion,and exciton ***,it is of great importance to regulate exciton behavior in OSCs and QDSCs for achieving high power conversion *** to the rapid development in materials and device fabrication,great progress has been made to manage the exciton behavior to achieve prolonged exciton diffusion length and improved exciton dissociation in recent *** this review,we first introduce the parameters that affect exciton behavior,followed by the methods to measure exciton diffusion ***,we provide an overview of the recent advances with regard to exciton behavior investigation in OSCs and QDSCs,including exciton lifetime,exciton diffusion coefficient,and exciton ***,we propose future directions in deepening the understanding of exciton behavior and boosting the performance of OSCs and QDSCs.

关键词： exciton behavior exciton diffusion exciton dissociation organic solar cells quantum-dot solar cells

来源：评论

学校读者我要写书评

暂无评论

NGenE 2021: Electrochemistry Is Everywhere

引用

ACS ENERGY LETTERS 2022年第1期7卷 368-374页

作者： Cabana, Jordi Alaan, Thomas Crabtree, George W. Hatzell, Marta C. Manthiram, Karthish Steingart, Daniel A. Zenyuk, Iryna Jiao, Feng Vojvodic, Aleksandra Yang, Jenny Y. Balsara, Nitash P. Persson, Kristin A. Siegel, Donald J. Haynes, Christy L. Mauzeroll, Janine Shen, Mei Venton, B. Jill Balke, Nina Rodriguez-Lopez, Joaquin Rolison, Debra R. Shahbazian-Yassar, Reza Srinivasan, Venkat Chaudhuri, Santanu Couet, Adrien Hattrick-Simpers, Jason Department of Chemistry University of Illinois at Chicago Chicago Illinois 60607 United States Department of Physics University of Illinois at Chicago Chicago Illinois 60607 United States Joint Center for Energy Storage Research Argonne National Laboratory Lemont Illinois 60439 United States George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta Georgia 30332 United States Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena California 91125 United States Department of Chemical Engineering Columbia University New York New York 10027 United States Columbia Electrochemical Energy Center Columbia University New York New York 10027 United States Department of Earth and Environmental Engineering Columbia University New York New York 10027 United States Department of Chemical and Biomolecular Engineering University of California Irvine California 92697 United States Center for Catalytic Science and Technology Department of Chemical and Biomolecular Engineering University of Delaware Newark Delaware 19716 United States Department of Chemical and Biomolecular Engineering University of Pennsylvania Philadelphia Pennsylvania 19104 United States Department of Chemistry University of California Irvine California 92697 United States Department of Chemical and Biomolecular Engineering University of California Berkeley California 94720 United States Materials Science Division Lawrence Berkeley National Laboratory Berkeley California 94720 United States Molecular Foundry Lawrence Berkeley National Laboratory Berkeley California 94720 United States Department of Materials Science and Engineering University of California Berkeley California 94720 United States Walker Department of Mechanical Engineering University of Texas at Austin Austin Texas 78712 United States Department of Chemistry University of Minnesota Minneapolis Minnesota 55455 United States Department of Chemistry McGill

来源：评论

学校读者我要写书评

暂无评论

Nickel-Catalyzed Reductive Asymmetric Aryl-Acylation and Aryl-Carbamoylation of Unactivated Alkenes

引用

CCS Chemistry 2022年第5期4卷 1510-1518页

作者： Youxiang Jin Pei Fan Chuan Wang Hefei National Laboratory for Physical Science at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefeiAnhui 230026 School of Chemical and Materials Engineering Huainan Normal UniversityHuainanAnhui 232038 Center for Excellence in Molecular Synthesis of CAS HefeiAnhui 230026

Herein we report a nickel-catalyzed asymmetric two-component reductive aryl-acylation and arylcarbamoylation of aryl-iodide-tethered unactivated alkenes,which utilize ortho-pyridinyl esters and isocyanates as the electrophilic acyl sources,*** the catalysis of a nickel–pyrox complex with zinc powder as the reductant,a variety of chiral indanes,indolines,and dihydrobenzofurans bearing a quaternary stereogenic center were prepared in moderate to high efficiency and good to excellent *** utility of this method is demonstrated by various simple derivatizations of the attached carbonyl group,particularly the sequential benzylic oxidation and pinacol coupling,which provide a concise entry to the benzene-fused bicyclic bridged ring framework containing three challenging tetrasubstituted stereocenters in high stereocontrol.

关键词： dicarbofunctionalization reductive crosscoupling acylation carbamoylation nickel

来源：评论

学校读者我要写书评

暂无评论

materials Discovery with Extreme Properties via Reinforcement Learning-Guided Combinatorial Chemistry

arXiv

引用

arXiv 2023年

作者： Kim, Hyunseung Choi, Haeyeon Kang, Dongju Lee, Won Bo Na, Jonggeol School of Chemical and Biological Engineering Seoul National University Korea Republic of Department of Chemical Engineering and Materials Science Ewha Womans University Korea Republic of Graduate Program in System Health Science and Engineering Ewha Womans University Korea Republic of

The goal of most materials discovery is to discover materials that are superior to those currently known. Fundamentally, this is close to extrapolation, which is a weak point for most machine learning models that learn the probability distribution of data. Herein, we develop reinforcement learning-guided combinatorial chemistry, which is a rule-based molecular designer driven by trained policy for selecting subsequent molecular fragments to get a target molecule. Since our model has the potential to generate all possible molecular structures that can be obtained from combinations of molecular fragments, unknown molecules with superior properties can be discovered. We theoretically and empirically demonstrate that our model is more suitable for discovering better compounds than probability distribution-learning models. In an experiment aimed at discovering molecules that hit seven extreme target properties, our model discovered 1,315 of all target-hitting molecules and 7,629 of five target-hitting molecules out of 100,000 trials, whereas the probability distribution-learning models failed. Moreover, it has been confirmed that every molecule generated under the binding rules of molecular fragments is 100% chemically valid. To illustrate the performance in actual problems, we also demonstrate that our models work well on two practical applications: discovering protein docking molecules and HIV inhibitors. © 2023, CC BY-NC-SA.

关键词： Probability distributions

来源：评论

学校读者我要写书评

暂无评论

Construction of high stability indium gallium zinc oxide transistor biosensors for reliable detection of bladder cancer-associated microRNA

引用

Chinese chemical Letters 2022年第2期33卷 979-982页

作者： Jing Guo Ruichen Shen Xuejie Shen Bo Zeng Nianjun Yang Huageng Liang Yanbing Yang Quan Yuan Key Laboratory of Biomedical Polymers of Ministry of Education College of Chemistry and Molecular SciencesSchool of MicroelectronicsWuhan UniversityWuhan 430072China Department of Urology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Institute of Chemical Biology and Nanomedicine State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Institute of Materials Engineering University of SiegenSiegen 57076Germany

Bladder cancer is the most common malignant tumours with high morbidity, mortality and ***, currently developed detection methods for bladder cancer-associated urine biomarkers are hindered by their extremely low abundance. Hence, the exploration of a highly sensitive and selective approach for the detection of trace bladder cancer-associated biomarkers in human urine is of vital importance for the diagnosis of bladder cancer. Herein, we developed a highly reliable indium gallium zinc oxide field effect transistor(IGZO FET) biosensor for the detection of bladder cancer-related biomarker micro RNA. The single-stranded DNA-functionalized IGZO FET biosensors exhibit high sensing reproducibility and stability with an ultralow detection limit of 19.8 amol/L. The device could also be used for quantitative detection of trace micro RNA in human urine samples and can effectively distinguish bladder cancer patients from healthy donors. The development of high performance IGZO FET biosensors presents new opportunities for the achievement of early-stage diagnosis of bladder cancer.

关键词： Bladder cancer Field-effect transistors IGZO miRNA Urine

来源：评论

学校读者我要写书评

暂无评论

An angle-insensitive electromagnetic absorber enabling a wideband absorption

引用

Journal of materials science & Technology 2022年第18期113卷 33-39页

作者： Zhichao Lou Qiuyi Wang Xiaodi Zhou Ufuoma I.Kara Rajdeep S.Mamtani Hualiang Lv Meng Zhang Zhihong Yang Yanjun Li Chenxuan Wang Solomon Adera Xiaoguang Wang Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China Willian G.Lowrie Department of Chemical and Biomolecular Engineering The Ohio State UniversityColumbusOH43210United States of America Institute of Materials Research and Engineering Agency for SciencesTechnology and ResearchSingapore State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences Chinese Academy of Medical SciencesSchool of Basic Medicine Peking Union Medical CollegeBeijing 100005China Department of Mechanical Engineering University of MichiganAnn ArborMI48109United States of America Sustainability Institute The Ohio State UniversityColumbusOH43210United States of America School of Materials Science and Engineering Henan University of Science and TechnologyLuoyang 471023China

Electromagnetic(EM)wave absorbers with wideband absorption capability are proposed as a strategy to mitigate environmental pollution by EM ***,designing an EM absorber with its performance capacity independent of the EM wave incident angle remains elusive to *** this challenge requires development of EM absorbers whose EM absorption performance is insensitive to the EM wave incident ***,we synthesized EM absorbers with a variety of structures with different symme-tries(including micro-/nanospheres,nanoflakes and nanotubes)to study the effect of the EM absorbers’structure and the EM wave incident angle on the EM absorption *** analysis reveals that non-magnetic EM absorbers with spatially symmetric nanostructures exhibit excellent EM wave incident ***,we demonstrate that a class of non-magnetic EM absorbers made from bam-boo derived-carbon nanospheres exhibit EM incident angle-insensitivity and wideband EM absorption performance with an effective absorption band up to 3.5 GHz when the thickness is 1.4 mm,a signif-icant improvement from prior studies which used thicknesses as high as 3-4 mm for comparable EM absorption performance.

关键词： Nanostructure Angle-insensitive EM absorption Biomass derived carbon Wideband

来源：评论

学校读者我要写书评

暂无评论

Ultrahigh zT from strong electron-phonon interactions and a low-dimensional Fermi surface

引用

Energy and Environmental science 2024年第5期17卷 1904-1915页

作者： Ranganayakulu, V.K. Wang, Te-Hsien Chen, Cheng-Lung Huang, Angus Ma, Ma-Hsuan Wu, Chun-Min Tsai, Wei-Han Hung, Tsu-Lien Ou, Min-Nan Jeng, Horng-Tay Lee, Chih-Hao Chen, Kuei-Hsien Li, Wen-Hsien Brod, Madison K. Snyder, G. Jeffrey Chen, Yang-Yuan Institute of Physics Academia Sinica Taipei11529 Taiwan Department of Engineering and System Science National Tsing Hua University Hsinchu30013 Taiwan Taiwan International Graduate Program Taipei11529 Taiwan Department of Physics National Chung Hsing University Taichung City40227 Taiwan Graduate School of Materials Science National Yunlin University of Science and Technology Yunlin64002 Taiwan Bachelor Program in Semiconductor Materials and Fabrication Ming Chi University of Technology New Taipei City243303 Taiwan Department of Physics National Tsing Hua University Hsinchu30013 Taiwan Center for Theory and Computation National Tsing Hua University Hsinchu30013 Taiwan Physics Division National Center for Theoretical Sciences Taipei10617 Taiwan Department of Physics National Central University Jhongli32001 Taiwan National Synchrotron Radiation Research Center Hsinchu Science Park Hsinchu30076 Taiwan Institute of Atomic and Molecular Sciences Academia Sinica Taipei10617 Taiwan Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States Graduate Institute of Applied Physics National Chengchi University Taipei11605 Taiwan

The outstanding thermoelectric performance of GeTe has attracted significant attention in the research community in recent years. However, many of the underlying physical mechanisms that contribute to GeTe's exceptionally high figure of merit (zT) remain not fully understood. In this study, an Sb-Bi codoped GeTe single crystal (Ge0.86Sb0.08Bi0.06)Te with an ultrahigh zT of 2.7 at 700 K and a record high device zT of 1.41 in the temperature range of 300-773 K was synthesized and investigated. The ultrahigh zT is attributed to the extremely low lattice thermal conductivity induced by strong electron-phonon (EP) interactions as revealed by the experimentally observed Kohn anomaly, through inelastic neutron scattering (INS) measurements. First-principles calculations further demonstrate that the remarkable EP interaction arises from the Fermi surface nesting featured in a one-dimensional (double-walled) topology. Our finding unravels the ultrahigh-zT mechanism in GeTe-based materials, serving as an inspiring guide toward high thermoelectric performance. © 2024 The Royal Society of Chemistry.

关键词： Neutron scattering

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：