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Quantifying the Effects of Climate Change and Land Management on Vegetation Dynamics from 1982 to 1985 in the Source Region of Three-Rivers, China [PDF]
Rui Wang, Hao Ma
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.711005

Abstract: Vegetation dynamics under a warming climate in the source region of the Three Rivers (SRTR) and its ecological impacts are a source of serious concern. In this study, we investigated the spatial and temporal variations of normalized difference vegetation index during the growing season (NDVIgr) and the start of the vegetation growing season (SOS) for six ecosystems. We examined the relationships between vegetation parameters, air temperature, precipitation and land management using residual trend method from 1982 to 2015. The NDVIgr increased at a rate of 0.0061/10a, and SOS advanced by 0.96 d/10a during the study period. The NDVIgr increased for the all six vegetation ecosystem from 1982 to 2015. The SOS showed advancing trend for the vegetation types for meadow (0.1236 d/a) and steppe (0.3480 d/a), but showing delaying trends for forest, shrub, barren land and alpine vegetation. The results of the correlation analysis indicate an increase in the air temperature in the SRTR is the main factor explaining increases in the NDVI and advancement of the SOS. In general, awarming-wetting climate and reasonable human activities had positive effects on vegetation growth, while the positive impact of human activities was weaker than that of climatic factors. This study provides a necessary basis for research on and the prediction of vegetation changes and their response to the climate warming of the SRTR in the Qinghai-Tibet Plateau (QTP).

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RETRACTED: Energy Flux Distribution and Thermal Performance of Linear Fresnel Collector System in Cold Region [PDF]
Jing Ma, Zheng Chang, Rui Tian
Energy and Power Engineering (EPE) , 2017, DOI: 10.4236/epe.2017.910039

Abstract:

Short Retraction Notice

Large-scale corrections should be made to the paper.

This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.

Editor guiding this retraction: Dr. Fermin Mallor (EiC of EPE)

The full retraction notice in PDF is preceding the original paper, which is marked \"RETRACTED\".

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Neural Circuit in the Dorsal Raphe Nucleus Responsible for Cannabinoid-Mediated Increases in 5-HT Efflux in the Nucleus Accumbens of the Rat Brain
Rui Tao,Zhiyuan Ma
ISRN Pharmacology , 2012, DOI: 10.5402/2012/276902

Abstract:

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Abstract: In vivo microdialysis was used in this study to reveal the role of cannabinoids in regulating serotonin (5-HT) efflux in the nucleus accumbens (NAcc) and dorsal raphe nucleus (DRN). The cannabinoid CB1 receptor agonists WIN55212-2 and CP55940 systematically administered to rats caused significant increases in 5-HT efflux in the NAcc but failed to have an effect in the DRN. To reveal mechanisms underlying regionally selective responses, we tested the hypothesis that cannabinoids have both direct and indirect effects on 5-HT efflux, depending on the location of CB1 receptors in the neural circuit between DRN and NAcc. We showed that the direct effect of cannabinoids caused a reduction in 5-HT efflux whereas the indirect effect resulted in an increase. Furthermore, the indirect effect was blocked by the GABAA receptor antagonist bicuculline in the DRN, suggesting that the action is likely due to a presynaptic inhibition on GABAergic activity that exerts a tonic influence on neuronal circuits regulating 5-HT efflux. Involvement of GABAergic neurons was confirmed by measuring changes in GABA efflux. Taken together, our study suggests that cannabinoids may have direct and indirect effects on the 5-HT regulatory circuits, resulting in regionally selective changes of 5-HT efflux in the brain. 1. Introduction Cannabinoid CB1 receptors and relevant endocannabinoids are widely distributed throughout the brain in mediating affective, cognitive, and motor behaviors [1, 2]. Much of the current neurochemical evidence suggests that their functional roles are mainly to modulate presynaptic neurotransmission impinging on postsynaptic neurons [3–6]. Midbrain raphe serotonergic neurons are known as an important substrate of cannabinoids, which have been demonstrated operating in a plethora of neurological responses [6–9]. Thus, the explicit understanding of cannabinoid modulations on midbrain raphe serotonergic neuronal activity has been for many years one of the central issues in the cannabinoid research. The dorsal (DRN) raphe nuclei (MRN) are two principal sources of serotonergic projections to the forebrain. The DRN serotonergic projections are likely associated with cognitive and affective activity [10, 11] while MRN serotonergic neurons are more clinging to motor behavior [12, 13]. Some of the forebrain neurons, particularly GABAergic and glutamatergic afferents, in turn innervate raphe nuclei forming feedback circuits that control extreme fluctuations of 5-HT availability [14]. The convergence of evidence suggests that GABAergic and glutamatergic afferents put

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Unconventional Electrochemical Characterization of Nanocomposite Supercapacitor Electrode with High Energy Density
Rui Jia Ma
Physics , 2014,

Abstract: A supercapacitor electrode was fabricated from a nanocomposite consisting of multiwall carbon nanotubes and titanium oxide nanoparticles. Conventional electrochemical characterizations cyclic voltammetry and galvanostatic charge-discharge in a lithium-based electrolyte gave a specific capacitance of 345 F/g at a current density of 0.1 A/g. Unconventional electrochemical characterization techniques that allow one to obtain the peak capacitance associated with intercalation and to distinguish between electrostatic and faradaic charge storage are described and applied to the electrode measurements. The advantages of the unconventional techniques are shown by comparison to the conventional ones. Finally, the maximum energy density obtained was 31 Wh/kg.

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Some groups of order $p^{6}$ with trivial Bogomolov multipliers
Yin Chen,Rui Ma
Mathematics , 2013,

Abstract: Let $G$ be a finite group and $B_{0}(G)$ be its Bogomolov multiplier, i.e., the subgroup of the Schur multiplier $H^{2}(G,\mathbb{Q}/\mathbb{Z})$ consisting of cohomology classes whose restrictions to all bicyclic subgroups are zero. This important invariant can be served as an obstruction to answer the classical Noether's problem over $\mathbb{C}$. For instance, Bogomolov \cite{Bog1988} found a group $G$ of order $p^{6}$ with $B_{0}(G)\neq 0$ for any prime number $p$, so that the classical Noether's problem for $(G, \mathbb{C})$ has a negative answer. Recently, all nonabelian groups of order 64 with nontrivial Bogomolov multiplier was classified by Chu et al. \cite{CHKK2010}. In this paper, we will calculate the Bogomolov multiplier of some nonabelian groups of order $p^{6}$ for any prime $p>3$.

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Superconvergence of both the Crouzeix-Raviart and Morley elements
Jun Hu,Rui Ma
Mathematics , 2014,

Abstract: In this paper, a new method is proposed to prove the superconvergence of both the Crouzeix-Raviart and Morley elements. The main idea is to fully employ equivalences with the first order Raviart-Thomas element and the first order Hellan-Herrmann-Johnson element, respectively. In this way, some special conformity of discrete stresses is explored and superconvergence of mixed elements can be used to analyze superconvergence of nonconforming elements. Finally, a half order superconvergence by postprocessing is proved for both nonconforming elements.

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Guaranteed Lower and upper bounds for eigenvalues of second order elliptic operators in any dimension
Jun Hu,Rui Ma
Mathematics , 2014,

Abstract: In this paper, a new method is proposed to produce guaranteed lower bounds for eigenvalues of general second order elliptic operators in any dimension. Unlike most methods in the literature, the proposed method only needs to solve one discrete eigenvalue problem but not involves any base or intermediate eigenvalue problems, and does not need any a priori information concerning exact eigenvalues either. Moreover, it just assumes basic regularity of exact eigenfunctions. This method is defined by a novel generalized Crouzeix-Raviart element which is proved to yield asymptotic lower bounds for eigenvalues of general second order elliptic operators, and a simple post-processing method. As a byproduct, a simple and cheap method is also proposed to obtain guaranteed upper bounds for eigenvalues, which is based on generalized Crouzeix-Raviart element approximate eigenfunctions, an averaging interpolation from the the generalized Crouzeix-Raviart element space to the conforming linear element space, and an usual Rayleigh-Ritz procedure. The ingredients for the analysis consist of a crucial projection property of the canonical interpolation operator of the generalized Crouzeix-Raviart element, explicitly computable constants for two interpolation operators. Numerics are provided to demonstrate the theoretical results.

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The enriched Crouzeix-Raviart elements are equivalent to the Raviart-Thomas elements
Jun Hu,Rui Ma
Mathematics , 2014,

Abstract: For both the Poisson model problem and the Stokes problem in any dimension, this paper proves that the enriched Crouzeix-Raviart elements are actually identical to the first order Raviart-Thomas elements in the sense that they produce the same discrete stresses. This result improves the previous result in literature which, for two dimensions, states that the piecewise constant projection of the stress by the first order Raviart-Thomas element is equal to that by the Crouzeix-Raviart element. For the eigenvalue problem of Laplace operator, this paper proves that the error of the enriched Crouzeix-Raviart element is equivalent to that of the Raviart-Thomas element up to higher order terms.

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Structural organization and energy storage in crosslinked actin assemblies
Julien Berro,Rui Ma
- , 2018, DOI: 10.1371/journal.pcbi.1006150

Abstract:

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