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Buildingcrystal structures ofconjugatedpolymersthrough X-ray diffraction and molecular modeling

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SmartMat 2021年第3期2卷 378-387页

作者： Ze-Fan Yao Qi-Yi Li Hao-Tian Wu Yi-Fan Ding Zi-Yuan Wang Yang Lu Jie-Yu Wang Jian Pei beijing National Laboratory for Molecular Sciences(BNLMS) Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter of Soft Matter Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijingChina

Crystal structure of conjugated molecules and polymers is fundamentally critical to understand their multilevel microstructures,carrier transport,and diverse ***,to determine the crystal structure of conjugated polymers is a significant challenge,mainly due to the poor crystallinity,weak diffraction,and instability under high-energy ***,we build the possible crystal structures of eight typical conjugated polymers,covering several widely used molecular segments in organic *** model the packing structures of these seed polymers based on synchrotron X-ray diffractions and molecular *** crystal structures provide a new platform to predict the packing structures of more related polymer systems,extending the molecular *** on this polymer crystal structure database,the multiscale microstructures and charge transport properties of conjugated polymers can be predicted before *** study sets up a polymer crystal structure database to eliminate the current trial-and-error approaches and accelerating the design of high-performance conjugated polymers.

关键词： charge transport conjugated polymers crystal structure molecular modeling

Experimental and theoretical insights into copper phthalocyanine-based covalent organic frameworks for highly efficien radioactive iodine capture

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Chinese Chemical Letters 2022年第7期33卷 3549-3555页

作者： Xuewei Liu Anrui Zhang Ran Ma Bo Wu Tao Wen Yuejie Ai Mingtai Sun Jie Jin Suhua Wang Xiangke Wang MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environment and Chemical EngineeringNorth China Electric Power UniversityBeijing 102206China Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China

Exploring efficient materials for capturing radioactive iodine in nuclear waste is of great significance for the progress of nuclear energy as well as the protection of ecological *** organic frameworks(COFs)have emerged as promising adsorbents because of their predesignable and functionalizable skeleton ***,it remains a grand challenge to achieve large scale preparation of *** this work,we developed a mild and efficient microwave irradiation method instead of the traditional solvothermal method to prepare copper phthalocyanine-based covalent organic frameworks(Cu_(x)Pc-COFs)within only 15 *** nitrogen-rich 1,2,4,5-tetracarbonitrilebenzene(TCNB)was selected as the solely organic ligand to construct copper phthalocyanine-based 2D conjugated *** resultant Cu_(x)Pc-COFs exhibited excellent iodine enrichment with 2.99 g/g for volatile iodine and 492.27 mg/g for iodine-cyclohexane solution,respectively,outperforming that of many porous *** indicated by spectroscopic analysis and DFT calculations,this impressive adsorption performance can be attributed to the charge transfer arising from nitrogen-rich phthalocyanine structures and electron-richπ-conjugated systems with iodine ***,the strong electrostatic interaction between Cu(Ⅱ)on chelate centers and polyiodide anions(I_(x)^(-))also play an important role in the firmly trapping radioactive ***,this study provides a facile and intelligent approach to implement metal-based COFs for the remediation of toxic radioactive iodine.

关键词： Cu_(x)Pc-COFs Microwave Iodine adsorption Charge transfer Electrostatic interaction

Characterization of squash polysaccharide and the anti-diabetic effect on type 2 diabetic rat revealed by urine metabolomics analysis

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Food Science and Human Wellness 2024年第5期13卷 2937-2946页

作者： Li Liang Fuming Zhang Quanhong Li Baoguo Sun Yuyu Zhang Robert J.Linhardt beijing Advanced Innovation Center for Food Nutrition and Human Health Beijing Key Laboratory of Flavor ChemistryBeijing Technology and Business University(BTBU)Beijing 100048China Departments of Chemical and Biological Engineering Chemistry and Chemical BiologyBiomedical Engineering and Biological ScienceCenter for Biotechnology and Interdisciplinary StudiesRensselaer Polytechnic InstituteTroy 12180USA College of Food Science and Nutritional Engineering China Agricultural UniversityBeijing 100083China China National Engineering Research Center for Fruit and Vegetable Processing Beijing 100083China

The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from ***-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were likely to contain HG and RG-I domain of pectic polysaccharide,***-F2(Mw=270.4 kDa)was mainly composed of rhamnose,galactose and *** treatment with SPS decreased body weight gain,glucose and TG levels in type 2 diabetes ***,25 differential metabolites were identified based on urinary metabolomics analysis,which are crucial to the anti-diabetic effect of *** regulation of nicotinamide N-oxide,histamine,cis-aconitate,citrate,L-malic acid,3-(3-hydroxyphenyl)propanoic acid and N-acetyl-L-aspartic acid were mainly associated with energy metabolism,gut microbiota and *** of surface plasmon resonance revealed the binding kinetics with galectin-3(Gal-3)and fibroblast growth factor 2(FGF2).The K_(D)values of SPS-F2 and SPS-F3 to Gal-3 were 4.97×10^(-3)and 1.48×10^(-3)mol/L,indicating a weak binding *** 3 fractions showed moderate binding to FGF2 and the affinity was SPS-F3>SPS-F2>***,the metabolomics and SPR approach were proved to be a promising tool in exploring the anti-diabetes effects of SPS and provided a deep understanding of the mechanisms.

关键词： Polysaccharide Metabolomics Type 2 diabetes Surface plasmon resonance

The battle of crops against drought:Genetic dissection and improvement

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Journal of Integrative Plant Biology 2023年第2期65卷 496-525页

作者： Zhirui Yang Feng Qin State Key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBeijing 100193China

With ongoing global climate change,water scarcity-induced drought stress remains a major threat to agricultural *** undergo a series of physiological and morphological changes to cope with drought stress,including stomatal closure to reduce transpiration and changes in root architecture to optimize water *** phenotypic and multi-omics studies have recently identified a number of drought-related genetic resources in different crop *** functional dissection of these genes using molecular techniques has enriched our understanding of drought responses in crops and has provided genetic targets for enhancing resistance to ***,we review recent advances in the cloning and functional analysis of drought resistance genes and the development of technologies to mitigate the threat of drought to crop production.

关键词： crops drought resistance gene cloning genetic improvement

Surface hydrophobic modification enhanced catalytic performance of electrochemical nitrogen reduction reaction

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Nano Research 2022年第5期15卷 3886-3893页

作者： Lijuan Niu Ziwen Liu Guohua Liu Mengxuan Li Xupeng Zong Dandan Wang Li An Dan Qu Xiaoming Sun Xiayan Wang Zaicheng Sun beijing Key Laboratory for Green Catalysis and Separation Center of Excellence for Environmental Safety and Biological EffectsFaculty of Environment and LifeBeijing University of TechnologyBeijing 100124China State Key Laboratory of Chemical Resource Engineering College of Energy Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education Jilin Normal UniversityChangchun 130103China

Electrocatalytic nitrogen reduction reaction(NRR)is a sustainable approach for NH_(3)production with low energy ***,competing hydrogen reduction reaction(HER)in aqueous solution results in low NH_(3)production and Faraday efficiency(FE).Here,MoS_(2)nanostructures with a hydrophobic surface are synthesized by alkyl thiols *** and hydrophobic surface facilitates an efficient three-phase contact of N_(2),H_(2)O,and ***,localized concentrated N_(2)molecules can overcome the mass transfer limitation of N2 and depress the HER due to lowering the proton *** the active-sites decrease with the increase of the alkyl chain since the thiol may cover the active site,the optimized electrocatalyst achieves NH_(3)yield of 12.86×10^(-11)mol·cm^(-2)·s^(-1)at-0.25 V and 22.23%FE,which are 4.3 and 24 times higher than those of MoS2-CP electrocatalyst,*** increased catalytic performance is attributed to the high N_(2)adsorption and depressed HER.

关键词： nitrogen reduction reaction MoS_(2)electrocatalyst hydrophobic modification density functional theory calculations

Function-Oriented Natural Product Synthesis

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Chinese Journal of Chemistry 2021年第4期39卷 838-854页

作者： Kaiqi Chen Fan Wu Xiaoguang Lei beijing National Laboratory for Molecular Sciences State Key Laboratory of Natural and Biomimetic DrugsKey Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationDepartment of Chemical BiologyCollege of Chemistry and Molecular EngineeringSynthetic and Functional Biomolecules CenterPeking UniversityBeijing100871 China Peking-Tsinghua Center for Life Science Academy for Advanced Interdisciplinary StudiesPeking UniversityBeijing100871 China

Natural products and their derivatives have long been used as medicinal agents,and they still make up a significant fraction of clinically approved *** product synthesis provides a rich and unparalleled opportunity to develop new synthetic transformations,conceive novel and general strategies to access complex structures,and study the mechanism of action of bioactive *** combination of the tools and principles of chemistry,together with the tools of modern biology,allows us to create complex synthetic and natural molecules,comprising processes with novel biological,chemical and physical *** account will illustrate the opportunities that lie at this interface between synthetic organic chemistry and chemical biology by describing a series of examples that we are actively working on in our laboratory at Peking *** take the inspiration from mother nature to develop new synthetic strategies to achieve the efficient synthesis of complex natural *** addition,we also conduct chemical biology studies for these bioactive natural products to elucidate their cellular targets and mode of ***,we further use bioactive natural products to explore new biology and develop novel drug candidates for human diseases,such as cancers and infectious diseases.

关键词： Natural products Total synthesis Chemical biology Target identification Drug discovery

Sparse convolutional model with semantic expression for waste electrical appliances recognition

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Science China(Technological Sciences) 2024年第9期67卷 2881-2893页

作者： HAN HongGui LIU YiMing LI FangYu DU YongPing Faculty of Information Technology Beijing University of TechnologyBeijing 100124China beijing Key Laboratory of Computational Intelligence and Intelligent System Beijing 100124China Engineering Research Center of Digital Community Ministry of EducationBeijing 100124China beijing Artificial Intelligence Institute and beijing Laboratory for Intelligent Environmental Protection Beijing 100124China

Deep neural networks play an important role in the recognition of waste electrical appliances. However, deep neural network components still lack reliability in decision-making features. To address this problem, a sparse convolutional model with semantic expression(SCMSE) is proposed. First, a low-rank sparse semantic expression component, combining the benefits of residual networks and sparse representation, is adapted to enhance sparse feature extraction and semantic expression. Second, a reliable network architecture is obtained by iterating the optimal sparse solution, enhancing semantic expression. Finally, the results of visualization experiments on the waste electrical appliances dataset demonstrate that the proposed SCMSE can obtain excellent semantic performance.

关键词： sparse convolutional model deep neural network semantic expression visualization computer vision

LegoDroid: flexible Android app decomposition and instant installation

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Science China(Information Sciences) 2023年第4期66卷 155-173页

作者： Yi LIU Yun MA Xusheng XIAO Tao XIE Xuanzhe LIU School of Computer Science Peking University Key Laboratory of High Confidence Software Technologies(Peking University) Ministry of Education Institute for Artificial Intelligence Peking University Department of Computer and Data Sciences Case Western Reserve University

Current mobile applications(apps) have become increasingly complicated with increasing features that are represented on the graphical user interface associated with application programming interfaces(APIs) to access backend functionality and data. Meanwhile, apps suffer from the “software bloat” in volume. Some app features may be redundant, with respect to those features(from other apps) that the users already desirably and frequently use. However, the current app release model forces users to download and install a full-size installation package rather than optionally choosing only their desired features. Large-size apps can not only increase the local resource consumption, such as CPU, memory, and energy, but also inevitably compromise the user experience, such as the slow load time in the app. In this article, we first conduct an empirical study to characterize the app feature usage when users interact with Android apps,and surprisingly find that users access only a very small subset of app features. Based on these findings,we design a new approach named Lego Droid, which automatically decomposes an Android app for flexible loading and installation, while preserving the expected functionality with a fast and instant app load. With such a method, a slimmer bundle will be downloaded and host the target APIs inside the original app to satisfy users’ requirements. We implement a system for Lego Droid and evaluate it with 1000 real-world Android apps. Compared to the original full-size apps, apps optimized by Lego Droid can substantially improve the load time by reducing the base bundle and feature bundles by 13.06% and 10.93%, respectively,along with the app-package installation size by 44.17%. In addition, we also demonstrate that Lego Droid is quite practical with evolving versions, as it can produce substantial reusable code to alleviate the developers’ efforts when releasing new app versions.

关键词： performance software bloat instant installation mobile applications program analysis

Active Learning Approach to Optimization of Experimental Control

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Chinese Physics Letters 2020年第10期37卷 21-25页

作者： Yadong Wu Zengming Meng Kai Wen Chengdong Mi Jing Zhang Hui Zhai Institute for Advanced Study Tsinghua UniversityBeijing 100084China State Key Laboratory of Quantum Optics and Quantum Optics Devices and Institute of Opto-ElectronicsCollaborative Innovation Center of Extreme OpticsShanxi UniversityTaiyuan 030006China

We present a general machine learning based scheme to optimize experimental *** method utilizes the neural network to learn the relation between the control parameters and the control goal,with which the optimal control parameters can be *** main challenge of this approach is that the labeled data obtained from experiments are not *** central idea of our scheme is to use the active learning to overcome this *** a demonstration example,we apply our method to control evaporative cooling experiments in cold *** have first tested our method with simulated data and then applied our method to real *** is demonstrated that our method can successfully reach the best performance within hundreds of experimental *** method does not require knowledge of the experimental system as a prior and is universal for experimental control in different systems.

关键词： utilize scheme hundreds