检索结果-南通市图书馆

Structural disruption of melanin-like polymers with boosted UV protection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1653-1663页

作者： Zhen yang Xianheng Wang Wanjie Bai Zikun Zou Haoxing Wu yiwen Li Department of Radiology Huaxi MR Research CenterFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceNational Clinical Research Center for GeriatricsWest China HospitalSichuan UniversityChengdu 610041China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Manipulating the energy structure of materials represents an efficient way to regulate their light absorption behaviors. For example, constructing donor-acceptor(D-A) structures to increase the polarizability and reduce the energy bandgap of local molecules has been widely used in the field of organic photovoltaics with ordered structures. Remarkably, even in disordered and chaotic systems such as melanin-like polydopamine(PDA), visible and near-infrared light absorption can be significantly improved using this strategy. However, there has been a noticeable dearth of research on the ultraviolet(UV) light absorption regulation of bioinspired polymers with disordered and chaotic architectures by tailoring the D-A microstructures. In this study, a series of benzoheterocyclic molecules with strong electron-donating features screened by molecular simulation calculations were involved in disrupting the D-A structures within PDA. The destruction of D-A structures promoted the increase of the energy band gap and finally boosted the UV absorption of PDA. The resulting PDA nanoparticles with enhanced UV absorption were further employed to fabricate UV shielding composite films to protect the growth of plants from harmful UV radiation. This research may open up new avenues for structural disruption of bioinspired polymers for enhanced photoprotection applications.

关键词： melanin-like polymers polydopamine D-A structure UV absorption photoprotection

Spatiotemporal variability of rain-on-snow events in the arid region of Northwest China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2024年第4期16卷 483-499页

作者： yang Zhiwei CHEN Rensheng LIU Zhangwen ZHAO Yanni LIU yiwen WU Wentong Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Rain-on-snow(ROS)events involve rainfall on snow surfaces,and the occurrence of ROS events can exacerbate water scarcity and ecosystem vulnerability in the arid region of Northwest China(ARNC).In this study,using daily snow depth data and daily meteorological data from 68 meteorological stations provided by the China Meteorological Administration National Meteorological Information Centre,we investigated the spatiotemporal variability of ROS events in the ARNC from 1978 to 2015 and examined the factors affecting these events and possible changes of future ROS events in the ARNC.The results showed that ROS events in the ARNC mainly occurred from October to May of the following year and were largely distributed in the Qilian Mountains,Tianshan Mountains,Ili River Valley,Tacheng Prefecture,and Altay Prefecture,with the Ili River Valley,Tacheng City,and Altay Mountains exhibiting the most occurrences.Based on the intensity of ROS events,the areas with the highest risk of flooding resulting from ROS events in the ARNC were the Tianshan Mountains,Ili River Valley,Tacheng City,and Altay Mountains.The number and intensity of ROS events in the ARNC largely increased from 1978 to 2015,mainly influenced by air temperature and the number of rainfall days.However,due to the snowpack abundance in areas experiencing frequent ROS events in the ARNC,snowpack changes exerted slight impact on ROS events,which is a temporary phenomenon.Furthermore,elevation imposed lesser impact on ROS events in the ARNC than other factors.In the ARNC,the start time of rainfall and the end time of snowpack gradually advanced from the spring of the current year to the winter of the previous year,while the end time of rainfall and the start time of snowpack gradually delayed from autumn to winter.This may lead to more ROS events in winter in the future.These results could provide a sound basis for managing water resources and mitigating related disasters caused by ROS events in the ARNC.

关键词： rain-on-snow events snowpack snowmelt climate change Spearman's rank correlation arid region of Northwest China

Hydroxysafflor yellow A induced ferroptosis of Osteosarcoma cancer cells by HIF-1α/HK2 and SLC7A11 pathway

在线全文

学校读者我要写书评

暂无评论

Oncology Research 2024年第5期32卷 899-910页

作者： yiwen ZHU LIU yang YING YU YING XIONG PING XIAO XIAO FU XIN LUO Department of Rehabilitation Medicine The Second Affiliated Hospital of Nanchang UniversityNanchang330006China Department of General Practice The Second Affiliated Hospital of Nanchang UniversityNanchang330006China

Osteosarcoma is a very serious primary bone cancer with a high death rate and a dismal prognosis.Since there is no permanent therapy for this condition,it is necessary to develop a cure.Therefore,this investigation was carried out to assess the impacts and biological functions of hydroxysafflor yellow A(HYSA)in osteosarcoma cell lines(MG63).In this investigational study,MG63 cells were utilized.Microarray experiments,quantitative polymerase chain reaction(qPCR),immunofluorescent staining,extracellular acidification rate(ECAR),oxygen consumption rate(OCR),glucose consumption,lactate production,and ATP levels,proliferation assay,5-Ethynyl-2′-deoxyuridine(EDU)staining,and Western blot were performed.In MG63 cells,HYSA lowered cell proliferation and metastasis rates,suppressed EDU cell number,and enhanced caspase-3/9 activity levels.HYSA reduced the Warburg effect and induced ferroptosis(FPT)in MG63 cells.Inhibiting ferroptosis diminished HYSA’s anti-cancer activities in MG63 cells.The stimulation of the HIF-1α/SLC7A11 pathway decreased HYSA’s anti-cancer activities in MG63 cells.HIF-1αis one target spot for HYSA in a model of osteosarcoma cancer(OC).HYSA altered HIF-1α’s thermophoretic activity;following binding with HYSA,HIF-1α’s melting point increased from~55°C to~60°C.HYSA significantly enhanced the thermal stability of exogenous WT HIF-1αwhile not affecting Mut HIF-1α,suggesting that ARG-311,GLY-312,GLN-347,and GLN-387 may be involved in the interaction between HIF-1αand HYSA.Conclusively,our study revealed that HYSA induced FPT and reduced the Warburg effect of OC through mitochondrial damage by HIF-1α/HK2/SLC7A11 pathway.HYSA is a possible therapeutic option for OC or other cancers.

关键词： Hydroxysafflor yellow A Osteosarcoma HIF-1α FPT

Improving the spaceborne GNSS-R altimetric precision based on the novel multilayer feedforward neural network weighted joint prediction model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 271-284页

作者： yiwen Zhang Wei Zheng Zongqiang Liu Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100094China China Academy of Aerospace Science and Innovation Beijing 100176China State Key Laboratory of Space-Ground Integrated Information Technology Beijing Institute of Satellite Information EngineeringBeijing 100194China

Global navigation satellite system-reflection(GNSS-R)sea surface altimetry based on satellite constellation platforms has become a new research direction and inevitable trend,which can meet the altimetric precision at the global scale required for underwater navigation.At present,there are still research gaps for GNSS-R altimetry under this mode,and its altimetric capability cannot be specifically assessed.Therefore,GNSS-R satellite constellations that meet the global altimetry needs to be designed.Meanwhile,the matching precision prediction model needs to be established to quantitatively predict the GNSS-R constellation altimetric capability.Firstly,the GNSS-R constellations altimetric precision under different configuration parameters is calculated,and the mechanism of the influence of orbital altitude,orbital inclination,number of satellites and simulation period on the precision is analyzed,and a new multilayer feedforward neural network weighted joint prediction model is established.Secondly,the fit of the prediction model is verified and the performance capability of the model is tested by calculating the R2 value of the model as 0.9972 and the root mean square error(RMSE)as 0.0022,which indicates that the prediction capability of the model is excellent.Finally,using the novel multilayer feedforward neural network weighted joint prediction model,and considering the research results and realistic costs,it is proposed that when the constellation is set to an orbital altitude of 500 km,orbital inclination of 75and the number of satellites is 6,the altimetry precision can reach 0.0732 m within one year simulation period,which can meet the requirements of underwater navigation precision,and thus can provide a reference basis for subsequent research on spaceborne GNSS-R sea surface altimetry.

关键词： GNSS-R satellite constellations Sea surface altimetric precision Underwater navigation Multilayer feedforward neural network

A review on surface coating strategies for anti-hygroscopic of high energy oxidizer ammonium dinitramide

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 237-269页

作者： Hongyu yang Fuyao Chen yiwen Hu Qiangqiang Lu Lei Xiao Yinglei Wang Fengqi Zhao Wei Jiang Gazi Hao National Special Superfine Powder Engineering Research Center of China School of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing 210094China Xi’an Modern Chemistry Research Institute Xi’an 710065China

Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidizer ammonium perchlorate(AP)in solid propellants,but also a good performance explosive in itself.However,due to the strong hygroscopicity of ADN,its application in solid propellants and explosives is greatly limited.Solving the hygroscopicity of ADN is the key to realize the wide application of ADN.In this paper,we systematically review the research progress of anti-hygroscopic strategies of ADN coating.The surface coating methods are focusing on solvent volatilization,solvent-non-solvent,melt crystallization and atomic layer deposition technology.The characteristics of the different methods are compared and analyzed,and the basis for the classification and selection of the coating materials are introduced in detail.In addition,the feasibility of material for surface coating of ADN is evaluated by several compatibility analysis methods.It is highly expected that the liquid phase method(solvent volatilization method,solvent-non-solvent method)would be the promising method for future ADN coating because of its effective,safety and facile operation.Furthermore,polymer materials,are the preferred coating materials due to their high viscosity,easy adhesion,good anti-hygroscopic effect,and heat resistance,which make ADN weak hygroscopicity,less sensitive,easier to preserve and good compatibility.

关键词： Ammonium dinitramide(ADN) Energetic materials Anti-hygroscopic Surface coating Compatibility analysis

Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第2期16卷 438-449页

作者： Jingyi Xie Fuli Wang Yanan Zhou yiwen Dong Yongming Chai Bin Dong State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580People’s Republic of China

The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge.Herein,an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field(IPF),arising hydroxyl spillover(HOSo)during OER.Facilitated by IPF,the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy,boosting the OER activity(242 mV vs.RHE at 100 mA cm-2)for least 100 h.More interestingly,for the anion exchange membrane water electrolyzer(AEMWE)with low concentration electrolyte,the advantage of HOSo effect is significantly amplified,delivering 1 A cm^(-2)at a low cell voltage of 1.88 V with excellent stability for over 50 h.

关键词： Hydroxyl spillover effect Internal polarization field Heterostructure Oxygen reduction reaction Anion exchange membrane water electrolysis

Intuitive Human-Robot-Environment Interaction With EMG Signals:A Review

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1075-1091页

作者： Dezhen Xiong Daohui Zhang Yaqi Chu yiwen Zhao Xingang Zhao State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016 Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169 University of Chinese Academy of Sciences Beijing 100049China

A long history has passed since electromyography(EMG)signals have been explored in human-centered robots for intuitive interaction.However,it still has a gap between scientific research and real-life applications.Previous studies mainly focused on EMG decoding algorithms,leaving a dynamic relationship between the human,robot,and uncertain environment in real-life scenarios seldomly concerned.To fill this gap,this paper presents a comprehensive review of EMG-based techniques in human-robot-environment interaction(HREI)systems.The general processing framework is summarized,and three interaction paradigms,including direct control,sensory feedback,and partial autonomous control,are introduced.EMG-based intention decoding is treated as a module of the proposed paradigms.Five key issues involving precision,stability,user attention,compliance,and environmental awareness in this field are discussed.Several important directions,including EMG decomposition,robust algorithms,HREI dataset,proprioception feedback,reinforcement learning,and embodied intelligence,are proposed to pave the way for future research.To the best of what we know,this is the first time that a review of EMG-based methods in the HREI system is summarized.It provides a novel and broader perspective to improve the practicability of current myoelectric interaction systems,in which factors in human-robot interaction,robot-environment interaction,and state perception by human sensations are considered,which has never been done by previous studies.

关键词： robot summarized Robot

维普期刊数据库博看期刊

Assessment of the forensic application of 50 Y-STR markers in a large pedigree

在线全文

学校读者我要写书评

暂无评论

Forensic Sciences Research 2022年第2期7卷 207-210页

作者： Yi Ye Yuran An yiwen yang Hao Wu Yuzi Zheng Linchuan Liao West China School of Basic Medical Sciences&Forensic Medicine Sichuan UniversityChengduChina Criminal Technology Department Liupanshui Public Security BureauGuizhouChina

Short tandem repeats on the Y chromosome(Y-STRs),characterized by paternal inheritance,are valuable in forensic practice.Notably,the potential application of Y-STRs in pedigrees should be drawn upon,especially in China’s surname-concentrated natural villages.The study focused on 50 Y-STRs,including 13 rapidly mutating(RM)Y-STRs that largely constitute the current Y-STR commercial kits,and determined the differences in these Y-STRs between branches in a large pedigree and the discriminatory power of these haplotypes in different units for male relatives.As indicated in the results,14 inconsistencies were observed at 9 Y-STRs between 10 father-son pairs.In addition,these 50 Y-STR haplotypes discriminated 10 out of 47 father-son pairs,106 of 148 cousin pairs,70 of 119 uncle-nephew pairs,17 of 39 brother pairs,and 14 out of 33 grandfather-grandson pairs in a large pedigree.The RM Y-STR set is able to differentiate close male relatives in a large pedigree.

关键词： Forensic sciences forensic genetics Y-STR haplotype rapid mutation pedigree

Cu-substituted nickel hexacyanoferrate with tunable reaction potentials for superior ammonium ion storage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第2期169卷 19-27页

作者： Leiyu Fan Guangchang Shu yiwen Liu Haoxiang Yu Lei Yan Liyuan Zhang Jie Shu School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China

In this work,a variety of Cu_(x)Ni_(2-x)Fe(CN)_(6)(x=0,0.4,0.8,1.2,1.6,2)cathodes for ammonium ion batteries are prepared and their electrochemical performances are investigated.During the introduction of copper in nickel hexacyanoferrate,the electrochemical performance varies without changing the structure of nickel hexacyanoferrate.The increase of Cu content in nickel hexacyanoferrate leads to the enhancement of reaction potential and capacity.Electrochemical results suggest that the substitution of Cu for Ni has a positive effect on improving the cycling stability and rate capacity of nickel hexacyanoferrate when x in Cu_(x)Ni_(2-x)Fe(CN)_(6)is less than 0.4.Therefore,Cu_(0.4)Ni_(1.6)Fe(CN)_(6)exhibits the best cycling per-formance(capacity retention of 97.54%at 0.3 C)and the highest rate capacity(41.4 mAh g^(-1)at 10 C)in Cu_(x)Ni_(2-x)Fe(CN)_(6).Additionally,the X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)tests also reveal that the structural evolution of Cu_(0.4)Ni_(1.6)Fe(CN)_(6)is highly reversible upon NH_(4)^(+)storage.Therefore,this work proposes a candidate material for ammoniumion batteries and offers a novel avenue for adjusting the operating potential of the material.

关键词： Nickel hexacyanoferrate Copper hexacyanoferrate NH_(4)^(+)storage Ammonium ion batteries Aqueous batteries