检索结果-南通市图书馆

Glass transition temperature prediction of disordered molecular solids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1633-1639页

作者： kun-han Lin Leanne Paterson Falk May Denis Andrienko Max Planck Institute for Polymer Research Ackermannweg 1055128 MainzGermany Merck KGaA 64293 DarmstadtGermany

Glass transition temperature,Tg,is the key quantity for assessing morphological stability and molecular ordering of films of organic semiconductors.A reliable prediction of Tg from the chemical structure is,however,challenging,as it is sensitive to both molecular interactions and analysis of the heating or cooling *** combining a fitting protocol with an automated workflow for forcefield parameterization,we predict Tg with a mean absolute error of~20℃for a set of organic compounds with Tg in the 50–230℃*** study establishes a reliable and automated prescreening procedure for the design of amorphous organic semiconductors,essential for the optimization and development of organic light-emitting diodes.

关键词： automated prediction transition

A survey on joint-operation application for unmanned swarm formations under a complex confrontation environment

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 Systems Engineering and Electronics 2023年第6期34卷 1432-1446页

作者： ZhanG Jialong han kun ZhanG Pu HOU Zhongxi YE Lei Unit 63768 of the PLA Xi’an 710200China School of Automation Northwestern Polytechnical UniversityXi’an 710072China Test and Training Base National University of Defense TechnologyXi’an 710100China School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China

With the rapid development of informatization,autonomy and intelligence,unmanned swarm formation intelligent operations will become the main combat mode of future *** unmanned swarm formations such as ground-based directed energy weapon formations,space-based kinetic energy weapon formations,and sea-based carrier-based formations have become the trump card for winning future *** a complex confrontation environment,these sophisticated weapon formation systems can precisely strike mobile threat group targets,making them extreme deterrents in joint combat *** on this,first,this paper provides a comprehensive summary of the outstanding advantages,strategic position and combat style of unmanned clusters in joint warfare to highlight their important position in future ***,a detailed analysis of the technological breakthroughs in four key areas,situational awareness,heterogeneous coordination,mixed combat,and intelligent assessment of typical unmanned aerial vehicle(UAV)swarms in joint warfare,is *** in-depth analysis of the UAV swarm communication networking operating mechanism during joint warfare is provided to lay the theoretical foundation for subsequent cooperative tracking and ***,an indepth analysis of the shut-in technology requirements of UAV clusters in joint warfare is provided to lay a theoretical foundation for subsequent cooperative tracking ***,the technical requirements of UAV clusters in joint warfare are analysed in depth so the key technologies can form a closed-loop kill chain system and provide theoretical references for the study of intelligent command operations.

关键词： unmanned swarm operation style weapon formation system mobile group target joint operation

A high power efficiency method using orthogonal signal decomposition in high PAPR system

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2013年第4期56卷 173-179页

作者： REN ZhiYuan LI YongZhao ZhanG HaiLin han kun State Key Laboratory of Integrated Services Network Xidian University Xi'an Communication Institute

To solve the low-power-efficiency problem for high peak to average power ratio systems,such as OFDM,an orthogonal inhomogeneous signal decomposition approach is proposed in this *** novel method decomposes the signal into branch signals orthogonally,which can adapt to the change of saturate power of each branch power ***,the novel method has the advantages of both high power efficiency of power amplifier and low PAPR of branch ***,this is more suitable for practical *** simulation results indicate that the proposed method can increase the power efficiency remarkably without reducing the BER performance in the receiver.

关键词： green radio power amplifier orthogonal inhomogeneous signal decomposed power efficiency energy conservation

Reducing Ammonia Volatilization from Maize Fields with Separation of Nitrogen Fertilizer and Water in an Alternating Furrow Irrigation System

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2014年第5期13卷 1099-1112页

作者： han kun ZHOU Chun-ju WANG Lin-quan College of Resources and Environment Northwest A&F University College of Life Science Northwest A&F University

The objective of this 2-yr field trial, with a central composite rotatable design, was to assess and quantify the effects of separation of nitrogen fertilizer and water with alternating furrow irrigation （SNWAFI） practices on soil ammonia （NH3） emission during the summer maize （Zea mays L.） growing season. Ammonia volatilization after N sidedress and irrigation ranged from 4.8 to 17.0 kg N ha-1 and 6.2 to 20.6 kg N hal, respectively, in 2008 and 2009. The lower N input contributed to lower NH3 loss but lower yield, whereas the higher N input induced higher yield as well as higher NH3 loss. Ammonia intensity （NH3 volatilization per crop yield） after N sidedress and irrigation was 1.2-3.0 kg NH3-N t-1 yield in 2008 and 1.1-3.2 kg NH3-N t1 yield in 2009. The predicted minimum NH3 intensity in 2008 was 1.6 kg NH3-N fl yield and was obtained with the combined application of 127 kg N ha^-1 and 108 mm irrigation water. In 2009, the predicted minimum NH3 intensity was 1.3 kg NH3-N t-j yield and was obtained with the combined application of 101 kg N ha-1 and 83 mm irrigation water. We conclude that SNWAFI practices with optimum rates of water and fertilizer can significantly reduce soil NH3 intensity and maintain yield. It was more beneficial for sustainable farming strategies to minimize the NH3 intensity rather than reduce absolute NH3 emissions alone.

关键词： volatilization rate cumulative volatilization SNWAFI CCRD NH3 intensity

Dye removal by eco-friendly physically cross-linked double network polymer hydrogel beads and their functionalized composites

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第4期31卷 81-91页

作者： Yan Kong Yuan Zhuang Zhiyong han Jianwei Yu Baoyou Shi kun han Haotian Hao Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of Sciences College of Petrochemical Engineering Lanzhou University of Technology University of Chinese Academy of Sciences

Hydrogels have attracted large attention in wastewater treatment fields due to their low-cost and good interaction with pollutants,among which novel double network hydrogel is an outstanding *** expand the application of double network hydrogel in water treatment,in this study,eco-friendly physically cross-linked double network polymer hydrogel beads(DAP)are prepared and studied in depth on the mechanism of Methylene Blue(MB)adsorption;and then the polymer hydrogels are further functionalized by inorganic *** adsorption on DAP favors alkaline condition which is due to the increase of electrostatic attraction and adsorption site,and it reaches equilibrium within 10 hr,which is faster than that of the single network hydrogel beads(SAP).Through thermodynamics study,the process shows to be an exothermic and spontaneous *** adsorption isotherms are well fitted by Langmuir model,with a maximum monolayer adsorption capacity of 1437.48 mg/g,which is larger than SAP(1255.75 mg/g).After being functionalized with common inorganic materials including activated carbon,Fe_3O_4and graphene oxide(GO),the composites show to have larger pore sizes and have obvious increases in adsorption capacity especially the one contains *** the composites contains Fe_3O_4are used as heterogeneous Fenton catalyst which shows to have excellent performance in MB *** results indicate the potential of polymer double network to be functionalized in environmental areas.

关键词： Adsorption Alginate Poly(vinyl alcohol) Hydrogel Methylene Blue

Statistical Analysis of Articles Published in China CDC Weekly——Worldwide,2019-2020

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2021年第31期3卷 669-673页

作者： Zhenwei Zhang kun han Wenhui Shi Editorial Department for Chinese Journal of Preventive Medicine Chinese Medical Association Publishing HouseBeijingChina Division of non-communicable diseases and elderly health management Chinese Center for Disease Control and PreventionBeijingChina

Introduction:This study analyzed views and downloads of articles published in China CDC Weekly from 2019 to 2020 as part of an evaluation of the academic level and quality of the ***:The study included articles published between November 29,2019 and December 25,2020 and evaluated views and downloads through February 9,2021 using standard *** conducted network analysis with VOSviewer ***:There were 283 articles from 101 institutions published in China CDC Weekly during the analysis period,among which 22(21.8%)institutions were overseas *** were 220 unique first authors,with 1.28 articles per first *** were 2,404,882 views and 58,760 downloads in *** article with the highest view and download counts had 1,244,826 views and 38,978 *** types with more than 4,500 views per article were Vital Surveillance,Notes from the Field,and Preplanned *** with more than 3,500 views per article were epidemiology of infectious diseases,epidemiology of non-infectious diseases,and maternal and child *** with descriptive research and articles discussing public health monitoring received more attention,shown by larger average per article page ***:Study results can help the editorial department improve the journal’s international influence through targeted measures,such as adjusting article types according to view and download analyses and increasing the proportion of international manuscripts selected.

关键词： journal Notes institutions

Two New Norsesquiterpenes from Ixeris polycephala

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第7期17卷 913-915页

作者： Yi Feng han kun GAO Zhong Jian JIA State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000

The chemical investigation of Ixeris polycephala afforded two new norsesquiterpenes, named as ixerols A and B （1-2）. Their structures were established based on spectroscopic methods including 2D NMR experiments. The... 详细信息

关键词： Ixeris polycephala Compositae ixerols A and B norsesquiterpene.

Metallographic sample prepared by ion beam etching

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第z1期14卷 282-285页

作者： XU Xiang-yang ZhanG kun han Jian-min CHEN Guang-nan Institute of Materials Science & Engineering Beijing Jiaotong University Beijing 100044 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Materials Science & Engineering Beijing Jiaotong University Beijing 100044 China

Ion beam etching technique was used to reveal the metallograhpic microstructure and interface morphology of electroplating chromium coating, in particular, whose substrate surface layer was treated in advance by laser quenching. Chemical etchings were also conducted for comparison. The reveal microstructures were observed and analyzed by scanning electron microscopy. The results show that ion beam etching can reveal well the whole microstructures of composite coating-substrate materials.

关键词： ion beam etching metallography microstructure electroplating chromium

Synthesis and characterization of monodispersed inorganic/organic core/shell microspheres with fluorescence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2005年第14期50卷 1526-1528页

作者： ZhanG Kai han kun ZhanG Xuehai YANG Bai Key Laboratory of Supramolecular Structure and Materials College ofChemistry Jilin University Changchun 130012 China

In recent years, the semiconductor nanocrystals (NCs) have attracted greatinterest due to their potentials in photonics, electronics, magnetics and catalysis, and themonodispersed organic or inorganic microspheres doped NCs display predominant characteristics in thefabrication and study for photonic crystals, and considerable effort has been devoted to the designand synthesis of CdTe NCs doped colloid with well fluorescence. For example, CdTe NCs werefabricated on the surfaces of silica or polymer microspheres by the methods of layer-by-layerassembly, and CdTe NCs were also doped into inorganic or organic microspheres through sol-gelprocess or swelling. In our previous work, we synthesized monodispersed silica-CdTe compositemicrospheres. Here, we synthesized silica-CdTe/polymer core/shell microspheres by emulsionpolymerization, and silica-CdTe composite microspheres were used as templates. In this paper, wecharacterized the morphology and fluorescence of silica-Cd'Te/polymer core/shell microspheres. Itwas believed that this method is useful to obtain inorganic/organic core/shell microspheres withwell fluorescence, and the fluorescent core/shell microspheres will display broad application inphotonic crystals, biological labels and fluorescent polymer material. The characterization of thesilica-CdTe/polymer core/shell microspheres was taken by TEM, PL, microscope and FTIR.

关键词：微球体荧光性单分散性半导体光电子学