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Now showing items 145 - 160 of 469

  • A highly sensitive fluorescent sensor based on small molecules doped in electrospun nanofibers:detection of explosives as well as color modulation

    Xue, Wei   Zhang, Yang   Duan, Juanjuan   Liu, Dong   Ma, Yawei   Shi, Naien   Chen, Shufen   Xie, Linghai   Qian, Yan   Huang, Wei  

    Fluorescent polymer nanofibers have wide applications in the fields of nano-photonics, nanooptoelectronics, chemical sensors and light-emitting diodes. The doping of small fluorophores into low-cost polymers is a proven alternative route to produce cost-effective and high-performance optical materials. In order to gain deep insight into the photophysical processes of small molecule-doped polymer nanofiber systems and obtain highly sensitive and cost-effective explosive fluorescent sensors, a new type of highly sensitive low-cost sensor for nitro-compounds was synthesized based on PEO/MePyCz (polyethylene oxide/4-(2-(2-(2-methoxyethoxy) ethoxy) ethoxy)-9-(pyren-1-yl)-9H-carbazole) composite nanofibers. It exhibited fast response and high quenching efficiency towards DNT vapor, which may be attributed to an improved exciton migration of MePyCz in PEO in addition to the large driving force of the electron transfer and the nanofibrous structures. Additionally, it promoted a fluorescence resonance energy transfer process in the polymer fibrous matrix with a green-emitting material of 2-(thiophen-2-yl)-fluoren-9-one. The sensing composite nanofibrous film had good sensitivity and selectivity and might be constructed into a portable detector for explosives.
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  • Effect of sintering temperature on the microstructure and performance of a ceramic coating obtained by the slurry method

    Xiao, Kui   Xue, Wei   Li, Zhaoliang   Wang, Jirui   Li, Xueming   Dong, Chaofang   Wu, Junsheng   Li, Xiaogang   Wei, Dan  

    In this paper, SiO2, Cr2O3, A1(2)O(3), and MgO were used as ceramic aggregates, and a small amount of Al powder was added A ceramic coating was prepared on a Q235 steel substrate The effect of the sintering temperature on the coating microstructure, phase structure and wear resistance was studied by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and friction and wear testing The results show that the tensile strength of the ceramic coating is increased after sintering, the structure becomes dense, and the size of coated micropores is increased to release the internal tensile stress. With the increase of the sintering temperature and tensile stress, the micropores begin to release the excess tensile stress in the form of crack initiation and expansion. The mineralization of MgO, Cr2O3, nMgO and mSiO(2) phases can be achieved by sintering the coating at 200 degrees C. the oxygen in the atmosphere migrates along the micropores in the coating to react with Fe in the steel substrate, forming FeO, and the resulting FeO reacts with the SiO2 the coating to form the Fe2SiO4 phase. The coating has the best wear resistance after being sintered at 400 degrees C, and the abrasion resistance of the sample is 6.7 times higher than that of the sample dried at room temperature.
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  • NIR‐Laser‐Controlled Hydrogen‐Releasing PdH Nanohydride for Synergistic Hydrogen‐Photothermal Antibacterial and Wound‐Healing Therapies

    Yu, Siming   Li, Guowei   Zhao, Penghe   Cheng, Qikun   He, Qianjun   Ma, Dong   Xue, Wei  

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  • Insight into silicon-carbon multilayer films as anode materials for lithium-ion batteries: A combined experimental and first principles study

    Zhang, Zhen   Liao, Ningbo   Zhou, Hongming   Xue, Wei  

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  • Role of charge reversal in the hemo/immunocompatibility of polycationic gene delivery systems

    Yang, Qi   Liu, Shuo   Liu, Xin   Liu, Zonghua   Xue, Wei   Zhang, Yi  

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  • Atomic-scale investigation of enhanced lithium, sodium and magnesium storage performance from defects in MoS2/Graphene heterostructure

    Xu, Ke   Liao, Ningbo   Zhang, Miao   Xue, Wei  

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  • Probing Single-Chain Magnets in a Family of Linear Chain Compounds Constructed by Magnetically Anisotropic Metal-Ions and Cyclohexane-1,2-Dicarboxylate Analogues RID A-1917-2011 RID B-4551-2010

    Zheng, Yan-Zhen   Xue, Wei   Tong, Ming-Liang   Chen, Xiao-Ming   Zheng, Shao-Liang  

    Five new metal-carboxylate chain-based laminated compounds, namely, (2)(infinity)[Fe(II)(e,e-trans-1,2-chdc)] (3) (1,2-chdc = cyclohexane-1,2-dicarboxylate), (2)(infinity)[Ni(II)(mu-OH(2))(e,a-cis-1,2-chdc)] (4), (2)(infinity)[Co(II)(mu-OH(2))(1,2-chedc)] (5) (1,2-chedc = cyclohex-1-ene-1,2-dicarboxylate), (2)(infinity)[Co(5)(II)(mu(3)-OH)(2)(OH(2))(2)(1,2-chedc)(4)] (6), and (2)(infinity)[Co(II)(4-Me-1,2-chdc)] (7) (4-Me-1,2-chdc = = trans-4-methylcyclohexane-1,2-dicarboxylate) have been hydrothermally synthesized. In these series of magnetic chain-based compounds, 3 and 7 have the same dimeric paddle-wheel M(II)-carboxylate chain as the previously reported compound, (2)(infinity)[Co(II)(trans-1,2-chdc)] (2). However, compound 3 does not behave as a single-chain magnet (SCM) but simply an alternating ferro-antiferro magnetic chain. Compound 4 has the cis conformation of 1,2-chdc ligand, which leads to a uniform aqua-carboxylate-bridged Ni(II) chain. Such a Ni-O chain exhibits strong antiferromagnetic interactions, leading to a diamagnetic ground state. Compound 5 features a corner-sharing triangular chain, or A-chain, which is part of a Kagome lattice. However, 5 does not exhibit a spin-frustrated effect but simply spin competition. Compound 6 has a unique pentanuclear Coll cluster, which is further connected by the syn-anti carboxylate into a chain structure. Compound 6 exhibits antiferromagnetic interactions among the Co(II) ions, and no SCM behavior is observed. These results might indicate that the dimeric paddle-wheel Co(II)-carboxylate chain is essential in obtaining SCM behavior in this family of compounds. Although 2 and 7 have very similar SCM behavior, alternating current magnetic studies show that 7 has a higher energy barrier than that of 2. Such behavior is probably caused by the larger anisotropic energy barrier in 7.
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  • Redox poly(ethylene glycol)-b-poly(L-lactide) micelles containing diselenide bonds for effective drug delivery.

    Zeng, Xiaolong   Zhou, Xiaoyan   Li, Mengyi   Wang, Changyong   Xu, Jiake   Ma, Dong   Xue, Wei  

    Bioreducible polymers have appeared as the ideal drug carriers for tumor therapy due to their properties of high stability in extracellular circulation and rapid drug release in intracellular reducing environment. Recently, the diselenide bond has emerged as a new reduction-sensitive linkage. In this work, the amphiphilic poly(ethylene glycol)-b-poly(L-lactide) containing diselenide bond has been synthesized and used to load anti-tumor drug, docetaxel (DTX), to form the redox micelles. It was found that the redox micelles showed a rapid response to glutataione (GSH), which resulted in a fast release of DTX in the presence of GSH. In contrast, <40% of DTX was released from the micelles within 72h under the normal condition (absence of GSH). The DTX-loaded redox micelles showed the significant inhibition effect to MCF-7 cells, and the cytotoxicity was dependent on the intracellular GSH concentrations. Moreover, considering the potentially clinical applications of the micelles through intravenous injection, the blood compatibility was also studied by the hemolysis analysis, activated partial thromboplastin time, prothrombin time and thromboelastography assays. These results confirmed that the redox micelles showed good blood safety, suggesting a potential application in tumor therapy. =20
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  • CXCL1-LCN2 paracrine axis promotes progression of prostate cancer via the Src activation and epithelial-mesenchymal transition

    Lu, Yongning   Dong, Baijun   Xu, Fan   Xu, Yunze   Pan, Jiahua   Song, Jiajia   Zhang, Jin   Huang, Yiran   Xue, Wei  

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  • Identification of an active miniature inverted-repeat transposable element mJing in rice

    Tang, Yanyan   Ma, Xin   Zhao, Shuangshuang   Xue, Wei   Zheng, Xu   Sun, Hongying   Gu, Ping   Zhu, Zuofeng   Sun, Chuanqing   Liu, Fengxia   Tan, Lubin  

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  • Biological activity evaluation and action mechanism of chalcone derivatives containing thiophene sulfonate

    Guo, Tao   Xia, Rongjiao   Chen, Mei   He, Jun   Su, Shijun   Liu, Liwei   Li, Xiangyang   Xue, Wei  

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  • Causes of model dry and warm bias over central US and impact on climate projections

    Lin, Yanluan   Dong, Wenhao   Zhang, Minghua   Xie, Yuanyu   Xue, Wei   Huang, Jianbin   Luo, Yong  

    Climate models show a conspicuous summer warm and dry bias over the central United States. Using results from 19 climate models in the Coupled Model Intercomparison Project Phase 5 (CMIP5), we report a persistent dependence of warm bias on dry bias with the precipitation deficit leading the warm bias over this region. The precipitation deficit is associated with the widespread failure of models in capturing strong rainfall events in summer over the central U.S. A robust linear relationship between the projected warming and the present-day warm bias enables us to empirically correct future temperature projections. By the end of the 21st century under the RCP8.5 scenario, the corrections substantially narrow the intermodel spread of the projections and reduce the projected temperature by 2.5 K, resulting mainly from the removal of the warm bias. Instead of a sharp decrease, after this correction the projected precipitation is nearly neutral for all scenarios.
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  • A flexible, porous, cluster-based Zn-pyrazolate-dicarboxylate framework showing selective adsorption properties

    Chen, Kai-Jie   He, Chun-Ting   Liao, Pei-Qin   Wei, Yong-Sheng   Zhang, Peng-Xiang   Xue, Wei   Zhang, Wei-Xiong   Zhang, Jie-Peng   Chen, Xiao-Ming  

    A flexible Zn-pyrazolate-carboxylate framework [Zn7O2(deppy)(2)(oba)(4)]center dot 2.5DMF center dot 2H(2)O (1) (Hdeppy = 3,5-diethyl-4-(4'-pyridyl)pyrazole, H(2)oba = 4,4'-oxobisbenzoic acid) was synthesized by solvothermal reaction. Single-crystal X-ray diffraction indicated that 1 possesses a 10-connected bct topological network based on a rare heptanuclear zinc(II) cluster. Comparison of crystal structures of 1 determined at 300 K and 150 K illustrated the conformational flexibility of deppy ligands. Thermogravimetry analyses and powder X-ray diffraction measurements showed that 1 has high thermal stability and good water stability. Gas and liquid sorption experiments of 1 not only showed stronger adsorption of CO2 compared with N-2, but also demonstrated highly efficient separation of n-propylbenzene from other C9H12 alkylbenzene isomers 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene.
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  • Quadri-directionally anisotropic droplets sliding surfaces fabricated by selective laser texturing of aluminum alloy plates

    Zhou, Xikang   Xue, Wei   Liu, Wenwen   Zhu, Dehua   Cao, Yu  

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  • Insulin Resistance in Polycystic Ovary Syndrome Improved by Chinese Medicine Dingkun Pill (定坤丹): A Randomized Controlled Clinical Trial

    Deng, Yan   Xue, Wei   Wang, Yan-fang   Liu, Xiao-hui   Zhu, Shi-yang   Ma, Xiao   Zuo, Hong-ling   Jiang, Jian-fa   Zheng, Ting-ping   Sun, Ai-jun  

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  • Responsiveness of performance and morphological traits to experimental submergence predicts field distribution pattern of wetland plants

    Luo, Fang-Li   Huang, Lin   Lei, Ting   Xue, Wei   Li, Hong-Li   Yu, Fei-Hai   Cornelissen, Johannes H. C.  

    QuestionPlant trait mean values and trait responsiveness to different environmental regimes are both important determinants of plant field distribution, but the degree to which plant trait means vs trait responsiveness predict plant distribution has rarely been compared quantitatively. Because hydrological regime is a key determinant of wetland plant distribution, we hypothesized that both plant trait means and trait responsiveness to experimental submergence could predict plant adaptation to a wet or a dry part of hydrological gradients in wetlands. LocationBeijing, China. MethodsWe measured mean values for 14 plant traits by growing 30 wetland species both on land (control) and partially submerged in a greenhouse, and calculated log response ratios (LnRRs) of these traits to submergence. A distribution pattern index of wetland plants along the moisture gradient (from the zone furthest from the wetland waterline to that nearest to the waterline) was developed based on plant survey data in 3988 field plots in 24 wetlands in Beijing, China. ResultsLnRRs of performance traits (shoot biomass, root biomass, plant height and total root length; R-2=3D0.249, P=3D0.005) and one out of five morphological traits (i.e. shoot elongation capacity; R-2=3D0.194, P=3D0.015) between partially submerged and control treatments could predict the distribution pattern of the 30 wetland plant species. In contrast, means of plant traits in either control or submergence could not predict species distribution. The trait LnRRs, increasing from very negative to very positive, corresponded positively with the distribution, ranging from the zone furthest from the wetland waterline to that nearest to the waterline. Surprisingly, physiological trait LnRRs that had been expected to underpin performance trait LnRRs did not themselves predict the distribution pattern of these species. Analyses at the level of multivariate trait groups (based on PCA) showed that species LnRRs of the morphological trait group were positively correlated with LnRRs of the performance trait group. ConclusionsOur findings demonstrate that screening wetland plant species for performance and morphological trait LnRRs under experimentally flooded conditions is an effective approach to understand and predict their distribution pattern along moisture gradients in the field.
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