关键词：
Evergreen broad-leaved forest;Tree biomass carbon;Mid-subtropical region
摘要：
Biomass carbon of tree layer in the three successional stages of Pinus massoniana forest (PMF), Pinus massonianaand broad-leaved mixed forest (PBF) and evergreen broad-leaved forest (EBF) was studied. The results showed that the biomass carbon storage of tree layer was the highest in EBF (129.34 t/hm(2), followed by PBF and PMF with 95.83 and 85.27 t/hm(2), respectively. Biomass carbon of various tree components showed the trend as stem> root> branch > leaf >bark. With the succession, the proportion of the stem accounted for the tree biomass carbon reduced, and the root of the proportion had increased. Tree biomass carbon is mainly concentrated in the 20-30cm diameter at breast height (DBH), or more than 30cm DBH.
摘要：
To better understand the effect of forest succession on carbon storage of woody debris (WD), carbon stock and allocation of evergreen broadleaf forest, a major zonal forest in subtropical China was investigated. Three forest types were sampled, pine (Pinus massoniana) forest (PF), pine and broadleaf mixed forest (MF) and evergreen broadleaf forest (BF). The amount of woody debris (WD) biomass was between 1.26-8.82 Mg. hm(-2), under the following order: PF < MF < BF, showed a trend of increase gradually with the succession. Coarse woody debris (CWD) carbon content varies with tree species and its decomposition level, with the improvement of CWD decomposition level, gradually reduce its carbon content. The woody debris carbon storage of PF, MF, and BF were 0.62 Mg . hm(-2), 1.75 Mg . hm(-2) and 3.78 Mg . hm(-2), respectively, corresponded to the tree carbon storage 0.73%, 1.83% and 2.92%.
摘要：
Lenvatinib (LEN), sorafenib (SOR), and sunitinib (SUN) are drugs targeting vascular endothelial growth factor receptor 2 (VEGFR2). Despite sharing similar chemical structures and bioactivities, LEN and SOR bind to different functional states of VEGFR2, viz. DFG-in and DFG-out state, respectively. SUN binds to the DFG-out state of VEGFR2 just like SOR but with less potency. Thus, detail binding mechanisms between VEGFR2 and these drugs, especially dynamic interaction, are valuable for future drug design. In the present work, molecular dynamics simulation, essential dynamic analysis, and molecular mechanics/generalized born surface area were performed to these VEGFR2-drugs systems. Rank of calculated binding affinities is in accordance with the experimental data. The binding free energy calculation suggests that van der Waals interaction plays a vital role in the binding. Per-residue free energy decomposition indicates that residues L840, V848, A866, E885, L889, V899, V916, F918, C919, L1035, C1045, D1046, and F1047 play an important role in the binding between VEGFR2 and LEN/SOR. While residues L840, V848, E917, F918, C919, G922, L1035, and F1047 contribute the major hydrophobic interaction for SUN binding to the receptor. Our results also reveal that residue E885/D1046 plays a vital role in binding via forming hydrogen bonds with drugs.
作者机构：
Hunan Academy of Forestry,Hengshan Research Station of Forest Ecosystem;School of Science,Central South University of Forestry and Technology;Hunan Hengshan National Nature Reserve Administration;School of Life and Health Science,Kaili University;Water Resources Research & Development Center
摘要：
In this paper, secondary forest of Pinus massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest were taken as research objects, to explore carbon reserve of arbor layer and its spatial distribution characteristics. At different succession stages, the sequence of organic carbon content in each organ was secondary forest of P. massoniana > coniferous-broad-leaved mixed forest> broad-leaved evergreen forest. Carbon reserve of arbor layer was the highest in broad-leaved evergreen forest, which was 129.34 t/hm 2, followed by coniferous-broad-leaved mixed forest (95.83 t/hm 2), and the minimum was 85.27 t/hm 2 in secondary forest of P. massoniana . In each stand type, the sequence of carbon reserve of each organ in arbor layer was trunk>root>branch>leaf>bark. Carbon reserve of arbor layer mainly concentrated in trunk, and the proportion to carbon reserve of arbor layer declined from secondary forest of P. massoniana to broad-leaved evergreen forest, while it had increasing relationship in root. In secondary forest of P. massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest, individual with the diameter more than 20 cm accounted for the majority of carbon reserve in the arbor layer.
作者机构：
Hunan Academy of Forestry,Hengshan Research Station of Forest Ecosystem,Changsha 410004,China;School of Science,Central South University of Forestry and Technology,Changsha 410004,China;Hunan Hengshan National Nature Reserve Administration,Nanyue 421999,China;School of Life and Health Science,Kaili University,Kaili 556011,China;Water Resources Research & Development Center,Changsha 410013,China
关键词：
BIOMASS;Model;P.pubescens
摘要：
To accurately calculate carbon fixation capacity of P. pubescens forest in Hunan Province and promote the balanced and stable development of P. pubescens forestry in Hunan Province,standard sample plot was set in major producing area of P. pubescens in Hunan Province,and biomass of 258 P. pubescens was measured according to DBH and age class. Multivariate regression method was used to establish univariate（ DBH as independent variable） and bivariate（ DBH and age class as independent variables） models of total aboveground biomass and organ biomass of P. pubescens. Model evaluation and test showed that each model accorded with the applicable precision and had the appropriate prediction level.
通讯机构：
[Wang, WL; Wang, YL] C;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.
关键词：
Cr(6+) and carmine;Electron beam irradiation;Heterostructure;In(2)S(3)-CdIn(2)S(4)@X(X = Ag, Ag(3)PO(4), AgI);Photocatalysis
摘要：
Ternary heterostructure nanotubes of In2S3-CdIn2S4@X(X=Ag, Ag3PO4, AgI) were synthesized with enhanced photocatalytic activity for efficiently degrading pollutants. Electron beam irradiation was employed to artificially introduce interface defects to the heterostructure nanotubes. The experimental results for degrading carmine and Cr(6+) under visible light irradiation showed that the photocatalytic efficiency of In2S3-CdIn2S4 was improved to some extent by the introduction of silver compounds. DRS results confirmed that the band gaps of In2S3-CdIn2S4 were reduced to 1.62eV and 1.58eV by introducing Ag3PO4 and AgI, respectively. Interestingly, the band gap of In2S3-CdIn2S4@AgI after electron beam irradiation was further reduced to 1.56eV, resulting in that the degradation time of both Cr(6+) and carmine by In2S3-CdIn2S4@AgI after high-energy electron beam irradiation was shortened to only 5min. The XRD spectra of the photocatalysts after five cycles could maintain the original crystal form to a large extent. The OH stretching vibration peaks of In2S3-CdIn2S4@AgI after electron beam irradiation at 3387cm(-1) became wider and sharper, thus indicating that the number of free hydroxyl groups on the heterostructure surface significantly increased. PL results showed that electron beam irradiation could significantly reduce the PL emission peak and enhance the utilization of photogenerated charge carriers. EIS results further confirmed that In2S3-CdIn2S4@AgI processed by electron beam irradiation had higher photogenerated electron-hole separation efficiency. Based on the experimental results, a feasible reaction pathway and photocatalytic mechanism for the degradation of carmine was investigated. ESR results showed that the main active groups in the whole photocatalytic system were *O2(-) and h(+).
摘要：
Adsorption is recognized as one of the most promising technologies applied to remove heavy metals from contaminated water. However, the adsorption efficiency often decreases because of the aggregation and loss of adsorbents. Herein, a novel adsorbent was synthesized by intercalation ethylenediaminetetraacetic acid (EDTA) into layered double hydroxides (LDH) and subsequent encapsulated into PAN polymer matrix using electrospinning. The synthesized electrospun nanofiber membrane (MgAl-EDTA-LDH@PAN) was found to combine the advantages of LDH@PAN nanofiber membrane (high surface area, easy to separate, free from aggregation and loss) and EDTA (powerful chelating agent). The adsorption performance of the MgAl-EDTA-LDH@PAN was evaluated using Cu(II) as target metals by varying experimental conditions such as pH, contact time, initial adsorbent dosage, and temperature. The maximum adsorption capacity of MgAl-EDTA-LDH@PAN was 120.77 mg/g with the initial Cu(II) concentrations ranging from 0.6 to 40 mg/L. MgAl-EDTA-LDH@PAN was also used in real industrial contaminated water treatment, and the final effluent was approximate to class-I criteria of the National Wastewater Discharge Standard of China. (GB 8978-1996). In addition, Cu K-edge XAS and XPS analyses were applied for unraveling the adsorptive performance of MgAl-EDTA-LDH@PAN by revealing the molecular-level mechanism of Cu(II) uptake. (C) 2017 Elsevier B.V. All rights reserved.
通讯机构：
[He, Meng-Dong] C;Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
关键词：
Localized surface plasmon resonance;Plasmon resonance energy transfer;Metallic nanoparticle array;Reduced cytochrome c molecule
摘要：
We investigate the optical properties of a metallic nanoparticle array covered by a reduced cytochrome (Cyt) c molecule layer by using the finite-difference time-domain method. As the wavelength of the surface plasmon resonance of metallic nanoparticle array matches with that of the absorption peak of reduced Cyt c molecules, a pronounced spectral dip forms in extinction spectrum due to the plasmon resonance energy transfer from metallic nanoparticles to Cyt c molecules. The depth of extinction dip can be controlled by the length and width of metallic nanoparticle, the grating constant, and the Cyt c molecule layer number, though the position of extinction dip is unchanged with these parameters. The findings may find applications in molecule identification and detection.
摘要：
Based oil the finite-difference time-domain method, we demonstrate multiple enhanced transmission bands through subwavelength compound periodic array of rectangular holes by adjusting the cutoff wavelength of each hole. The results show that the transmission spectrum of this structure is almost a compound of that of the corresponding periodic hole arrays with simple cell, when the holes lire arranged appropriately. It IS also found that the Surface plasmon resonance peak and the localized resonance peak exhibit different behaviors as the symmetry of compound periodic structure varies. The proposed method provides in effective way to achieve enhanced transmission simultaneously at different selected wavelengths ill the visible and infrared re-ions. (C) 2009 American Institute Physics. [doi:10.1063/1.3254248]
