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Chinese Journal of Polymer Science 2020年第7期38卷 704-714,I0005页

作者： Jin-Rui Deng Cong-Lei Zhao Yi-xian wu State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing Laboratory of Biomedical MaterialsBeijing University of Chemical TechnologyBeijing 100029China

The novel quaternized hydroxypropyl cellulose-g-poly(THF-co-epichlorohydrin)graft copolymers,HPC-g-QCP(THF-co-ECH),have been successfully synthesized to combine the properties from hydrophilic hard HPC biomacromolecular backbone and hydrophobic flexible polyether ***,the P(THF-co-ECH)living chains were synthesized by cationic ring-opening copolymerization of THF with ***,P(THF-co-ECH)living chains were grafted onto HPC backbone by reaction with-OH groups along HPC to produce HPC-g-P(THF-co-ECH)graft ***,the mentioned graft copolymers were quaternized by reaction with ternanyamine to generate functionalized HPC-g-QCP(THF-co-ECH).The HPC-g-QCP(THF-co-ECH)graft copolymers exhibited good antibacterial ability against *** or *** *** ibuprofen(IBU)-loaded microparticles of HPC-g-(QC)P(THF-co-ECH)graft copolymers were prepared by *** in vitro pH-responsive drug-release behavior of IBU reached up to 75%of drug-loaded at pH=*** quaternized graft copolymer was beneficial to solving the problems of a burst effect and fast release of HPC as drug carriers.

关键词： Living cationic ring-opening copolymerization Hydroxypropyl cellulose-graft-polyether Antibacterial ability pH-responsive drug-release

JMNet: A joint matting network for automatic human matting

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Computational Visual Media 2020年第2期6卷 215-224页

作者： xian wu Xiao-Nan Fang Tao Chen Fang-Lue Zhang Department of Computer Science and Technology Tsinghua UniversityBeijing100084China AI Center at Visual China Group BurlingameCA94010USA School of Engineering and Computer Science Victoria University of WellingtonWellingtonNew Zealand

We propose a novel end-to-end deep learning framework, the Joint Matting Network(JMNet), to automatically generate alpha mattes for human *** utilize the intrinsic structures of the human body as seen in images by introducing a pose estimation module,which can provide both global structural guidance and a local attention focus for the matting task. Our network model includes a pose network, a trimap network, a matting network, and a shared encoder to extract features for the above three networks. We also append a trimap refinement module and utilize gradient loss to provide a sharper alpha matte. Extensive experiments have shown that our method outperforms state-of-theart human matting techniques;the shared encoder leads to better performance and lower memory *** model can process real images downloaded from the Internet for use in composition applications.

关键词： alpha matting human images deep learning pose estimation

Synergistic effects of vegetation layers of maize and potato intercropping on soil erosion on sloping land in Yunnan Province, China

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Journal of Mountain Science 2020年第2期17卷 423-434页

作者： ZHANG Xiao-yun wu Kai-xian FULLEN Michael A wu Bo-zhi Faculty of Agronomy and Biotechnology Yunnan Agricultural UniversityKunming 650201China Faculty of Technology and Engineering The University of WolverhamptonWulfruna StreetWolverhamptonWV11LYUK

Intercropping, as an overyielding system, can decrease soil erosion on sloping land through the presence of dense canopy covers. However, the structure mechanism in canopy is still unclear. We conducted a two-year field experiment on runoff plots, exploring whether the interaction between vegetation layers reduce soil erosion in maize and potato intercropping systems. The maize, potato, and weed layers in the intercropping system were removed by a single layer, two layers and three layers, respectively(total of 8 treatments including all layers removed as the control). Then, throughfall, runoff and sediment were measured at the plot and row scale on a weekly basis. Based on the difference between each treatment and the control, we calculated and found a relative reduction of runoff and sediment by any combination of the two vegetation layers greater than the sum of each single layer. In 2016 and 2017, the highest relative reduction of runoff reached 15.65% and 46.73%, respectively. Sediment loss decreased by 33.96% and 42.77%, respectively. Moreover, runoffand sediment reduced by the combination of all vegetation layers(no layers removed) was also larger than the sum of that by each single layer. In 2016 and 2017, the highest relative reduction of runoff reached 7.32% and 3.48%, respectively. So, there were synergistic effects among multi-level(two or three layers) vegetation layers in terms of decreasing soil erosion on sloping land. Maize redistributes more throughfall at the maize intra-specific row and the maize and potato inter-specific, which is favorable for the synergistic effect of reducing soil erosion. This finding shows an important mechanism of maize and potato intercropping for soil and water conservation, and may promote the application of diverse cropping systems for sustainable agriculture in mountainous areas.

关键词： Synergistic effect Vegetation layer Soil erosion Intercropping Maize Potato

Estimation of the turbulent viscous shear stress in a centrifugal rotary blood pump by the large eddy particle image velocimetry method

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Journal of Hydrodynamics 2020年第3期32卷 486-496页

作者： Jing-jing Ji Hao-yuan Li Qing-yu wu Yu Zhang xian-wu Luo School of Clinical Medicine Tsinghua UniversityBeijing 100084China State Key Laboratory of Hydroscience and Engineering Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

The non-physiologic turbulent flows in centrifugal rotary blood pumps (RBPs) may result in complications such as the hemolysis and the platelet activation. Recent researches suggest that the turbulent viscous dissipation in the smallest eddies is the main factor of the blood trauma caused by the turbulent flow. The turbulent viscous shear stress (TVSS) was taken as the realistic physical force acting on the cells. However, limited by the temporal and spatial resolutions of the instrumentation currently available, very limited studies are available for the TVSS in the RBPs. In this paper, the large eddy particle image velocimetry (PIV) method is used to estimate the turbulent dissipation rate in the sub-grid scale, to investigate the effect of the TVSS on the blood trauma. Detailed flow characteristics, such as the relative velocity vectors, the estimated TVSS levels and the Kolmogorov length scales, are analyzed in three impeller phases at three constant flow rates (3 L/min, 5 L/min and 7 L/min). Over the measures range in this study, the maximum TVSS in the investigated RBP is lower than the reported critical value of stress. This study demonstrates that the large eddy PIV method is effective to evaluate the flow-dependent force on the cells. On the other hand, it is found that the TVSS is highly dependent on the flow behavior. Under severe off-design conditions, the complex flow characteristics, such as the flow separation and the vortical structures, will increase the TVSS. Thus, in order to reduce the hemolysis in the RBPs, the flow disturbance, induced by the departure of the incidence angle, should be avoided during the design of the RBPs.

关键词： Rotary blood pump turbulent flow turbulent viscous shear stress large eddy particle image velocimetry flow separation

Evaluation of semivariogram features for objectbased image classification

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Geo-Spatial Information Science 2015年第4期18卷 159-170页

作者： xian wu Jianwei PENG Jie SHAN Weihong CUI School of Remote Sensing and Information Engineering Wuhan University129 Luoyu RoadWuhan 430079China Central Southern China Electronic Power Design Institute of China Power Engineering Consulting Group 668 Minzhu RoadWuhan 430071China Lyles School of Civil Engineering Purdue UniversityWest LafayetteIN 47907USA Collaborative Innovation Center of Geospatial Technology Wuhan University129 Luoyu RoadWuhan 430079China

Inclusion of textures in image classification has been shown *** paper studies an efficient use of semivariogram features for object-based high-resolution image ***,an input image is divided into segments,for each of which a semivariogram is then ***,candidate features are extracted as a number of key locations of the semivariogram *** we use an improved Relief algorithm and the principal component analysis to select independent and significant *** the selected prominent semivariogram features and the conventional spectral features are combined to constitute a feature vector for a support vector machine *** effect of such selected semivariogram features is compared with those of the gray-level co-occurrence matrix(GLCM)features and window-based semivariogram texture features(STFs).Tests with aerial and satellite images show that such selected semivariogram features are of a more beneficial supplement to spectral *** described method in this paper yields a higher classification accuracy than the combination of spectral and GLCM features or STFs.

关键词： object based image analysis image segmentation image classification texture feature semivariogram

Bacterial Template Synthesis of Multifunctional Nanospindles for Glutathione Detection and Enhanced Cancer-Specific Chemo-Chemodynamic Therapy

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Research 2020年第1期2020卷 1788-1802页

作者： Yan-Wen Bao xian-wu Hua Jia Zeng Fu-Gen wu State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast University2 Sipailou RoadNanjing 210096China

Biological synthetic methods of nanoparticles have shown great advantages,such as environmental friendliness,low cost,mild reaction conditions,and enhanced biocompatibility and stability of ***,as one of the most important living organisms,have been utilized as bioreducing nanofactories to biosynthesize many metal nanoparticles or ***,inspired by the disinfection process of KMnO_(4),we for the first time introduce bacteria as both the template and the reducing agent to construct a novel tumor microenvironment-responsive MnO_(x)-based nanoplatform for biomedical applications in various *** is found that the bacterium/MnO_(x)-based nanospindles(EM NSs)can efficiently encapsulate the chemotherapeutic agent doxorubicin(DOX),leading to the fluorescence quenching of the *** as-formed DOX-loaded EM NSs(EMD NSs)are proven to be decomposed by glutathione(GSH)and can simultaneously release DOX and Mn^(2+)*** former can be utilized for sensitive fluorescence-based GSH sensing with a limit of detection as low as 0.28μM and selective cancer therapy,while the latter plays important roles in GSH-activated magnetic resonance imaging and chemodynamic *** also demonstrate that these nanospindles can generate oxygen in the presence of endogenous hydrogen peroxide to inhibit P-glycoprotein expression under hypoxia and can achieve excellent tumor eradication and tumor metastasis inhibition *** together,this work designs a multifunctional bacterially synthesized nanomissile for imaging-guided tumor-specific chemo-chemodynamic combination therapy and will have implications for the design of microorganism-derived smart nanomedicines.

关键词： hemodynamic utilized template

Biocompatible,Hemocompatible and Antibacterial Acylated Dextran-g-polyisobutylene Graft Copolymers with Silver Nanoparticles

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Chinese Journal of Polymer Science 2021年第12期39卷 1550-1561页

作者： Cong-Lei Zhao Yu-Zhuang Gao Meng-Ying wu Hang-Tian Zhang Yi-xian wu State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing Laboratory of Biomedical MaterialsBeijing University of Chemical TechnologyBeijing 100029China

The novel amphiphilic acylated dextran-g-polyisobutylene(AcyDex-g-PIB)graft copolymers with different branch lengths(A4nPtB,2600-5800 g/mol)and grafti ng numbers(GN,5-28 per 1000 Dex mono saccharide)were successfully synthesized via the nu cleophilic substitution of the hydroxyl(-OH)side groups along AcyDex backb one by the living PIB-THF4+chai ns prepared through cati onic polymerizatio *** crystallizati on of AcyDex backb one in AcyDex-g-PIB graft copolymers was con fined due to the prese nee of PIB branches and the morphology changed from short rod-like crystals to fragment-like crystals with increasing Mn P|B and *** obvious microphase separation occurred due to the incompatibility between hard AcyDex backbone and soft PIB ***-g-PIB graft copolymers exhibit excellent biocompatibility towards HeLa cells and good hemocompatibility with red blood cells(RBCs),both of which increase with increasing *** in creases of water con tact angle and roughness on the surface of the graft copolymers with in creasi ng A4nP|B and GN manifest the anti-protein adsorption *** amphiphilic AcyDex-g-PIB graft copolymers could self-assemble in aqueous solution into nanospheres,which can be used as pH-sensitive drug carriers and can release 100%of the loaded drug within 72 h at pH=***-g-PIB graft copolymers bearing silver nanoparticles(Ag-NPs,0.8 wt%-3.9 wt%,4.5-9.5 nm)show good antibacterial *** kind of amphiphilic graft copolymer would have a promising prospect in biological and medical fields.

关键词： Dextran Polyisobutylene Cationic polymerization Graft copolymer Biomedical application

Suppression of vortex rope oscillation and pressure vibrations in Francis turbine draft tube using various strategies

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Journal of Hydrodynamics 2021年第3期33卷 534-545页

作者： Lei Zhu Rui-zhi Zhang An Yu Li Lu xian-wu Luo China Institute of Water Resources and Hydropower Research Beijing100038China State Key Laboratory of Hydroscience and Engineering Department of Energy and Power EngineeringTsinghua UniversityBeijing100084China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China

The vortex rope usually occurs in the draft tube of the Francis turbine operated under part-load conditions,to induce strong low-frequency pressure vibrations,and therefore,is very harmful to the safety of the hydropower *** the present work,three kinds of strategies are extensively investigated,i.e.,the installations of the ventilation and the fin,as well as the hybrid strategy of the air admission through a fin,so as to effectively suppress the vortex rope oscillation and the pressure vibration in the draft tube of a Francis turbine,whose specific speed is 125 *** the unsteady flow simulation,the Reynolds averaged Navier-Stokes(RANS)method is applied coupled with the k-ω SST turbulence model and a homogeneous cavitation *** flow analysis confirms that the low-frequency pressure vibrations are originated from the periodical oscillation of the vortex rope,and the cavitation usually enhances the vortex rope oscillation in the draft *** the part-load condition,the dominant component of the pressure vibration in the draft tube has a frequency,for example,f_(1),lower than the runner rotating frequency f_(n).It is shown that all three strategies can be adopted to alleviate the vortex rope oscillation and the pressure vibrations in the draft tube,but their suppression mechanisms are quite *** ventilation of an adequate amount from the turbine runner cone can change the vortex rope geometry from the spiral type to the cylindrical type,suppress the vortex rope oscillation,and consequently create the homogeneous distributions of the pressure and the pressure gradient in the draft *** the other hand,a fin installed at the draft tube wall can induce a small extra rope,and the interaction between the main vortex rope and the extra rope changes the flow field and alleviates the pressure vibration in the draft *** should be noted that a fin is much more effective to suppress the pressure vibration in the draft tube under the cavitation cond

关键词： Francis turbine vortex rope pressure vibration ventilation fin installation

Air combat decision-making of multiple UCAVs based on constraint strategy games

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Defence Technology（防务技术） 2022年第3期18卷 368-383页

作者： Shou-yi Li Mou Chen Yu-hui Wang Qing-xian wu College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing211100China

Game theory can be applied to the air combat decision-making problem of multiple unmanned combat air vehicles(UCAVs).However,it is difficult to have satisfactory decision-making results completely relying on air combat situation information,because there is a lot of time-sensitive information in a complex air combat *** this paper,a constraint strategy game approach is developed to generate intelligent decision-making for multiple UCAVs in complex air combat environment with air combat situation information and time-sensitive ***,a constraint strategy game is employed to model attack-defense decision-making problem in complex air combat ***,an algorithm is proposed for solving the constraint strategy game based on linear programming and linear inequality(CSG-LL).Finally,an example is given to illustrate the effectiveness of the proposed approach.

关键词： Game theory Time-sensitive information Constraint strategy games Polytope strategy games Multiple UCAVs Air combat decision-making

A Novel Efficient Method for Synthesis of β-Organoseleno Substituted Allyl Sulfoxides

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Chinese Chemical Letters 2005年第10期16卷 1333-1334页

作者： Zhi Meng wu Ru Wei SHEN Lu Ling wu xian HUANG Department of Chemistry Zhejiang University （Xixi Campus） Hangzhou 310028

Hydroselenation of 1, 2-allenyl sulfoxides give 2-organoseleno substituted allyl sulfoxides in high yields and the reaction is absolute regioselective.

关键词： Hydroselenation allenyl sulfoxides regioselectivity.