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Search Results: 1 - 10 of 127116 matches for " Dejun LI "
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Emissions of NO and NH3 from a Typical Vegetable-Land Soil after the Application of Chemical N Fertilizers in the Pearl River Delta
Dejun Li
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0059360
Abstract: Cropland soil is an important source of atmospheric nitric oxide (NO) and ammonia (NH3). Chinese croplands are characterized by intensive management, but limited information is available with regard to NO emissions from croplands in China and NH3 emissions in south China. In this study, a mesocosm experiment was conducted to measure NO and NH3 emissions from a typical vegetable-land soil in the Pearl River Delta following the applications of 150 kg N ha?1 as urea, ammonium nitrate (AN) and ammonium bicarbonate (ABC), respectively. Over the sampling period after fertilization (72 days for NO and 39 days for NH3), mean NO fluxes (± standard error of three replicates) in the control and urea, AN and ABC fertilized mesocosms were 10.9±0.9, 73.1±2.9, 63.9±1.8 and 66.0±4.0 ng N m?2 s?1, respectively; mean NH3 fluxes were 8.9±0.2, 493.6±4.4, 144.8±0.1 and 684.7±8.4 ng N m?2 s?1, respectively. The fertilizer-induced NO emission factors for urea, AN and ABC were 2.6±0.1%, 2.2±0.1% and 2.3±0.2%, respectively. The fertilizer-induced NH3 emission factors for the three fertilizers were 10.9±0.2%, 3.1±0.1% and 15.2±0.4%, respectively. From the perspective of air quality protection, it would be better to increase the proportion of AN application due to its lower emission factors for both NO and NH3.
Nanoscale Multilayered ZrAlN/ZrB2 Coatings Synthesized by Magnetron Sputtering
Dejun LI,
Dejun
,LI

材料科学技术学报 , 2006,
Abstract: Multilayered ZrAlN/ZrB2 coatings containing alternating bilayer periods were synthesized by dc magnetron sputtering technique. The intensities of ZrN (111) or ZrN (200) textures in the structure of the nanolayers depended on the bilayer period as well as N2 gas partial pressure during deposition. Nanoindentation testing showed that hardness and internal stress of the nanolayers varied with the bilayer period and crystallographic orientation in the coatings. The hardness of the nanolayers with bilayer periods of 3~6 nm was enhanced (~27%) over the rule-of-mixture value. A low percent of N2 in processing gas was proved to be benefitial to the synthesis of high hard nanoscale multilayered coatings.
Quasi-invariant flow generated by Stratonovich SDE with BV drift coefficients
Huaiqian Li,Dejun Luo
Mathematics , 2010,
Abstract: We generalize the results of Ambrosio [Invent. Math. 158 (2004), 227--260] on the existence, uniqueness and stability of regular Lagrangian flows of ordinary differential equations to Stratonovich stochastic differential equations with BV drift coefficients. Then we construct an explicit solution to the corresponding stochastic transport equation in terms of the stochastic flow. The approximate differentiability of the flow is also studied when the drift is a Sobolev vector field.
A unified treatment of ODEs under Osgood and Sobolev type conditions
Huaiqian Li,Dejun Luo
Mathematics , 2011,
Abstract: In this paper we present a unified treatment for the ordinary differential equations under the Osgood and Sobolev type conditions, following Crippa and de Lellis's direct method. More precisely, we prove the existence, uniqueness and regularity of the DiPerna-Lions flow generated by a vector field which is "almost everywhere Osgood continuous".
The log-Sobolev inequality for the ground state of a Schr?dinger operator on bounded convex domains
Huaiqian Li,Dejun Luo
Mathematics , 2013,
Abstract: We consider the ground state $\phi_0$ of the Schr\"odinger operator $L=-\Delta+V$ on the bounded convex domain $\Omega\subset\R^n$, satisfying the Dirichlet boundary condition. Assume that $V\in C^1(\Omega)$ and it admits an even function $\tilde V\in C^1([-D/2,D/2])$ as its modulus of convexity, where $D$ is the diameter of $\Omega$. If the first Dirichlet eigenvalue $\tilde\lambda_0$ of $-\frac{\d^2}{\d t^2}+\tilde V$ on the interval $[-D/2,D/2]$ satisfies $\tilde\lambda_0>\tilde V(0)$, then the measure $\d\mu=\phi_0 \d x$ satisfies the log-Sobolev inequality on $\Omega$ with the constant $\tilde\lambda_0-\tilde V(0)$. In particular, if $V$ is convex, then the constant is explicitly given by $\frac{\pi^2}{D^2}$.
Curcumin protects against rotenone-induced neurotoxicity in cell and drosophila models of Parkinson’s disease  [PDF]
Zhaohui Liu, Tianxia Li, Dejun Yang, Wanli W. Smith
Advances in Parkinson's Disease (APD) , 2013, DOI: 10.4236/apd.2013.21004
Abstract: Parkinson’s disease (PD) is a progressive neurodegenerative movement disorder resulting from a selective loss of dopaminergic neurons. The pathogenesis of PD remains incompletely understood, but increasing evidence from human and animal studies has suggested that oxidative damage contributes to the neuronal loss in PD. In this study, we used rotenone (a mitochondrial complex I inhibitor) based cell and Drosophila models that resemble some key pathological features of PD to test whether curcumin, a potent antioxidant compound, derived from the curry spice turmeric, could protect against rotenone-induced neuronal toxicity. We found that curcumin reduced rotenone induced cell death in SH-SY5Y human neuroblastoma cells and alleviated PD-like symptoms in drosophila via reducing the intracellular and mitochondrial reactive oxygen species (ROS) levels and inhibiting the caspase-3/caspase-9 activity. These results suggest that curcumin is a promising therapeutic compound for PD.
Utilizing Transaction to Realize Data Consistency in Multi-tier Database Architecture
在多层数据库结构中利用事务处理保证数据的一致性

Li DeJun,
李德军

计算机系统应用 , 2006,
Abstract: 本文先分析了数据库管理系统中事务的概念,到Delphi中事务处理在多层结构中的实现方法,并且以客户端显式和中间层隐式的事务处理方法作讨论,阐述了在Delphi中如何利用事务处理保证基于多层数据库的数据一致性问题。
Measured and Simulated Nitrous Oxide Emissions from Ryegrass- and Ryegrass/White Clover-Based Grasslands in a Moist Temperate Climate
Dejun Li, Gary Lanigan, James Humphreys
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0026176
Abstract: There is uncertainty about the potential reduction of soil nitrous oxide (N2O) emission when fertilizer nitrogen (FN) is partially or completely replaced by biological N fixation (BNF) in temperate grassland. The objectives of this study were to 1) investigate the changes in N2O emissions when BNF is used to replace FN in permanent grassland, and 2) evaluate the applicability of the process-based model DNDC to simulate N2O emissions from Irish grasslands. Three grazing treatments were: (i) ryegrass (Lolium perenne) grasslands receiving 226 kg FN ha?1 yr?1 (GG+FN), (ii) ryegrass/white clover (Trifolium repens) grasslands receiving 58 kg FN ha?1 yr?1 (GWC+FN) applied in spring, and (iii) ryegrass/white clover grasslands receiving no FN (GWC-FN). Two background treatments, un-grazed swards with ryegrass only (G–B) or ryegrass/white clover (WC–B), did not receive slurry or FN and the herbage was harvested by mowing. There was no significant difference in annual N2O emissions between G–B (2.38±0.12 kg N ha?1 yr?1 (mean±SE)) and WC-B (2.45±0.85 kg N ha?1 yr?1), indicating that N2O emission due to BNF itself and clover residual decomposition from permanent ryegrass/clover grassland was negligible. N2O emissions were 7.82±1.67, 6.35±1.14 and 6.54±1.70 kg N ha?1 yr?1, respectively, from GG+FN, GWC+FN and GWC-FN. N2O fluxes simulated by DNDC agreed well with the measured values with significant correlation between simulated and measured daily fluxes for the three grazing treatments, but the simulation did not agree very well for the background treatments. DNDC overestimated annual emission by 61% for GG+FN, and underestimated by 45% for GWC-FN, but simulated very well for GWC+FN. Both the measured and simulated results supported that there was a clear reduction of N2O emissions when FN was replaced by BNF.
LDN-73794 Attenuated LRRK2-Induced Degeneration in a Drosophila Parkinson’s Disease Model  [PDF]
Dejun Yang, Sharmila Das, Loujing Song, Tianxia Li, Jianqun Yan, Wanli W. Smith
Advances in Parkinson's Disease (APD) , 2015, DOI: 10.4236/apd.2015.43007
Abstract: Parkinson’s disease (PD) is a common neurodegenerative disease with unclear pathogenesis. Currently, there are no disease-modifying neuron-protecting drugs to slow down the neuronal degeneration. Mutations in the leucine-rich repeat kinase 2 (LRRK2) cause genetic forms of PD and contribute to sporadic PD as well. Disruption of LRRK2 kinase functions has become one of the potential mechanisms underlying disease-linked mutation-induced neuronal degeneration. To further characterize the pharmacological effects of a reported LRRK2 kinase inhibitor, LDN-73794, in vitro cell models and a LRRK2 Drosophila PD model were used. LDN-73794 reduced LRRK2 kinase activity in vitro and in vivo. Moreover, LDN-73794 increased survival, improved locomotor activity, and suppressed DA neuron loss in LRRK2 transgenic flies. These results suggest that inhibition of LRRK2 kinase activity can be a potential therapeutic strategy for PD intervention and LDN-73794 could be a potential lead compound for developing neuroprotective therapeutics.
Effect of node deleting on network structure
Ke Deng,Heping Zhao,Dejun Li
Physics , 2007, DOI: 10.1016/j.physa.2007.02.039
Abstract: The ever-increasing knowledge of the structure of various real-world networks has uncovered their complex multi-mechanism-governed evolution processes. Therefore, a better understanding of the structure and evolution of these networked complex systems requires us to describe such processes in a more detailed and realistic manner. In this paper, we introduce a new type of network growth rule which comprises addition and deletion of nodes, and propose an evolving network model to investigate the effect of node deleting on network structure. It is found that, with the introduction of node deleting, network structure is significantly transformed. In particular, degree distribution of the network undergoes a transition from scale-free to exponential forms as the intensity of node deleting increases. At the same time, nontrivial disassortative degree correlation develops spontaneously as a natural result of network evolution in the model. We also demonstrate that node deleting introduced in the model does not destroy the connectedness of a growing network so long as the increasing rate of edges is not excessively small. In addition, it is found that node deleting will weaken but not eliminate the small-world effect of a growing network, and generally it will decrease the clustering coefficient in a network.
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