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Search Results: 1 - 10 of 18779 matches for " Demin Gao "
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Comparative analgesic effect of Ligusticum chuanxiong pieces and its products in mice
GAO Demin,XU Lingchuan
Pharmacognosy Magazine , 2010,
Abstract: The present study was undertaken with the objective of finding out the comparative analgesic effect of Ligusticum chuanxiong (LC) pieces decoction, LC formula granule decoction, liquored LC pieces decoction and liquored LC formula granule decoction. The analgesic effects were analyzed using the hot plate and acetic-induced writhing test in mice, and antidysmenorrheic effect was observed with primary dysmenorrhea model. The results showed that four kinds of LC decoction had definite effect in delaying incubation period and decreasing the writhing frequency within 30 min. They also effectively relieved dysmenorrhea. Moreover, liquored LC had better analgesic effect than crude LC in four decoctions.
Study and Design an Anycast Routing Protocol for Wireless Sensor Networks
Demin Gao,Huanyan Qian,Zheng Wang,Jiguang Chen
Journal of Networks , 2011, DOI: 10.4304/jnw.6.12.1726-1733
Abstract: In wireless sensor networks, there is usually a sink which gathers data from the battery-powered sensor nodes. As sensor nodes around the sink consume their energy faster than the other nodes, several sinks have to be deployed to increase the network lifetime. Anycast is a mechanism that the source node sends the data to the nearest sink node. The paper study and design an anycast service for deploying several sinks in wireless sensor network. A novel anycast tree-based is proposed approach to minimize the path cost. Here the nodes form a tree with a sink node as the root, while the height of the tree integrates multiple metrics to calculate path cost based on diverse selection criteria. This paper discusses and analyzes the model deeply. The experimental data proves its validity and efficiency. Computer simulation shows that the proposed scheme reduces and balances the energy consumption among the nodes effectively, so it significantly extends the network lifetime compared to the existing schemes.
Anycast Routing Protocol for Forest Monitoring in Rechargeable Wireless Sensor Networks
Demin Gao,Yunfei Liu,Fuquan Zhang,Jun Song
International Journal of Distributed Sensor Networks , 2013, DOI: 10.1155/2013/239860
Abstract: In rechargeable wireless sensor networks (R-WSNs), sensors have to adjust their duty cycles continuously owing to sporadic availability of energy and operate in a very low duty cycle because of current energy conversion technical limitations. Even though the network lifetime is not the main problem, packet delivery latency is critical because a sensor is in the dormant state most of the time in R-WSNs. These unique characteristics pose a new challenge for routing protocol design over traditional energy-static sensor networks. In this work, we introduce a routing protocol based on anycast communications technology, a novel design to minimize packet delivery latency for forest monitoring in R-WSNs. The key idea is to let a sender choose a closest neighbor to forward packets from forwarding candidates and a nearest sink node to accept the packet from all sinks. For multiple source nodes, we introduce an anycast technology based on Tabu search for each source establishing a minimal E2E delay routing path to reach anyone sinks. Through extensive simulation and experiments, we demonstrate that our anycast scheme based on Tabu search is efficient to provide smallest packets delivery latency in R-WSNs. 1. Introduction Wireless sensor networks (WSNs), a promising technology, have been a topic of much interest to researchers due to their wide-ranging applications. For example, they have been used for military applications, environmental applications, health applications, and home applications [1, 2]. However, a fundamental problem in WSNs is the limited lifetime of sensor nodes. To this end, a significant amount of work has been carried out across the protocol stack to prolong the lifetime of WSNs. Examples of which include energy-efficient medium access control (MAC) protocols [3], duty-cycling strategies [4], energy-efficient routing [5], and topology control mechanisms [6]. Other examples can be found in [7, 8] and references therein. An interesting approach to extend the lifetime of sensor nodes is the use of energy harvesting, which refers to harness energy from the environment or other source. Sensor nodes will equip them with rechargeable technologies that convert sources such as body heat [9], foot strike [10], and finger strokes [11] into electricity, such as a rechargeable battery or an ultracapacitor [12]. The energy from surrounding environment is free, unlimited, and environment friendly. Assuming energy neutral operation [13], a sensor node can operate perpetually if the harvested energy is used at an appropriate rate. Note that a harvesting node is
Fracture and Damage Behaviors of Concrete in the Fractal Space  [PDF]
Heng Zhang, Demin Wei
Journal of Modern Physics (JMP) , 2010, DOI: 10.4236/jmp.2010.11006
Abstract: The fracture toughness, the driving force and the fracture energy for an infinite plate with a fractal crack are investigated in the fractal space in this work. The perimeter-area relation is adopted to derive the transforma-tion rule between damage variables in the fractal space and Euclidean space. A plasticity yield criterion is introduced and a damage variable tensor is decomposed into tensile and compressive components to describe the distinct behaviors in tension and compression. A plastic damage constitutive model for concrete in the Euclidean space is developed and generalized to fractal case according to the transformation rule of damage variables. Numerical calculations of the present model with and without fractal are conducted and compared with experimental data to verify the efficiency of this model and show the necessity of considering the fractal effect in the constitutive model of concrete. The structural response and mesh sensitivity of a notched unre-inforced concrete beam under 3-point bending test are theoretical studied and show good agreement with the experimental data.
The Infective endocarditis (prevention, diagnosis criteria and treatment): key points 2010
A.A. Demin
Rational Pharmacotherapy in Cardiology , 2010,
Abstract: Key positions of Guidelines on the prevention, diagnosis, and treatment of infective endocarditis issued by the Task Force of ESC in 2009 are explained in the comments. Recent opinions on these items are presented.
Analysis of efficacy of SGLT2 inhibitors using semi-mechanistic model
Oleg Demin Jr
Frontiers in Pharmacology , 2014, DOI: 10.3389/fphar.2014.00218
Abstract: Renal sodium-dependent glucose co-transporter 2 (SGLT2) is one of the most promising targets for the treatment of type 2 diabetes. Two SGLT2 inhibitors, dapagliflozin and canagliflozin, have already been approved for use in USA and Europe; several additional compounds are also being developed for this purpose. Based on the in vitro IC50 values and plasma concentration of dapagliflozin measured in clinical trials, the marketed dosage of the drug was expected to almost completely inhibit SGLT2 function and reduce glucose reabsorption by 90%. However, the administration of dapagliflozin resulted in only 30–50% inhibition of reabsorption. This study was aimed at investigating the mechanism underlying the discrepancy between the expected and observed levels of glucose reabsorption. To this end, systems pharmacology models were developed to analyze the time profile of dapagliflozin, canagliflozin, ipragliflozin, empagliflozin, and tofogliflozin in the plasma and urine; their filtration and active secretion from the blood to the renal proximal tubules; reverse reabsorption; urinary excretion; and their inhibitory effect on SGLT2. The model shows that concentration levels of tofogliflozin, ipragliflozin, and empagliflozin are higher than levels of other inhibitors following administration of marketed SGLT2 inhibitors at labeled doses and non-marketed SGLT2 inhibitors at maximal doses (approved for phase 2/3 studies). All the compounds exhibited almost 100% inhibition of SGLT2. Based on the results of our model, two explanations for the observed low efficacy of SGLT2 inhibitors were supported: 1) the site of action of SGLT2 inhibitors is not in the lumen of the kidney’s proximal tubules, but elsewhere (e.g., the kidneys proximal tubule cells); and 2) there are other transporters that could facilitate glucose reabsorption under the conditions of SGLT2 inhibition (e.g., other transporters of SGLT family).
Geometry Method for the Rotating Navier-Stokes Equations With Complex Boundary and the Bi-Parallel Algorithm
Kaitai Li,Demin Liu
Mathematics , 2011,
Abstract: In this paper, a new algorithm based on differential geometry viewpoint to solve the 3D rotating Navier-Stokes equations with complex Boundary is proposed, which is called Bi-parallel algorithm. For xample, it can be applied to passage flow between two blades in impeller and circulation flow through aircrafts with complex geometric shape of boundary. Assume that a domain in $R^3$ can be decomposed into a series sub-domain, which is called "flow layer", by a series smooth surface $\Im_k, k=1,...,M$. Applying differential geometry method, the 3D Navier-Stokes operator can be split into two kind of operator: the "Membrane Operator" on the tangent space at the surface $\Im_k$ and the "Bending Operator" along the transverse direction. The Bending Operators are approximated by the finite different quotients and restricted the 3D Naver-Stokes equations on the interface surface $\Im_k$, a Bi-Parallel algorithm can be constructed along two directors: "Bending" direction and "Membrane" directors. The advantages of the method are that: (1) it can improve the accuracy of approximate solution caused of irregular mesh nearly the complex boundary; (2) it can overcome the numerically effects of boundary layer, whic is a good boundary layer numerical method; (3) it is sufficiency to solve a two dimensional sub-problem without solving 3D sub-problem.
东昆仑中灶火地区超镁铁质辉石岩的成因
Petrogenesis of the Zhongzaohuo Ultramafic Pyroxenite Pluton, East Kunlun:Constraints from Petrology, Geochemistry and Genetic Mineralogy

罗文行,钱莉莉,李德威,朱云海,刘德民,高成
LUO Wenxing
, QIAN Lili, LI Dewei, ZHU Yunhai, LIU Demin, GAO Cheng

地球科学(中国地质大学学报) , 2018, DOI: 10.3799/dqkx.2013.119
Abstract: 最近在青海东昆北中灶火地区发现超镁铁质岩的岩石学、地球化学以及成因矿物学等方面的研究成果.岩石主要由单斜辉石、斜方辉石和角闪石组成,另有少量斜长石、石英、黑云母和铁质不透明矿物.角闪石和黑云母为后期退变质矿物.斜方辉石成因判别分析结果为岩浆成因,故该超镁铁质岩为辉石岩而非麻粒岩.该辉石岩化学成分上表现为异常的高MgO、高CaO、低Al2O3特征,微量元素表现为Rb、Th富集而Nb、Ti的亏损,表明其来源于富集地幔.通过岩相学、稀土元素等特征与前人研究结果对比认为该辉石岩是俯冲洋壳部分熔融产生的富Si熔体与地幔橄榄岩发生交代反应产生辉石岩岩浆,然后底侵到地壳中部冷却结晶形成的.野外地质特征显示辉石岩的侵位晚于发生糜棱岩化的围岩,即晚于围岩的形成时代,即早二叠世,说明该辉石岩是在中二叠世古特提斯洋向北大规模俯冲及其所导致的弧后伸展的构造背景下形成的.
A ultramafic pyroxenite pluton has been discovered in Zhongzaohuo area in the East Kunlun orogen Recently. This paper reports the results of petrological, geochemical and genetic mineralogy research on the pyroxenite pluton. The rock is mainly composed of clinopyroxene, orthopyroxene and amphibole, and minor plagioclase, quartz, biotite and iron opaque minerals. Amphibole and biotite were formed during retrograde metamorphism. The discriminant analysis results suggest that the Opx are magmatogenic, thus the rock should be named pyroxenite rather than granulite. The rock has high MgO, CaO and low Al2O3 and enriched in Rb and Th and depleted in Nb and Ti, showing clear evidence for an enriched mantle source. Field occurrence of the pyroxenite pluton suggests that the pyroxenite pluton was formed after the mylonization of the surrounding rocks. Combined with the tectonic evolution of East Kunlun, we come to the conclusion that the subduction of an Paleo-Tethys(Anyemaqen) oceanic slab at the Middle Permian led to fluid and Si-rich?melt metasomatism, inducing partial melting of an enriched lithospheric mantle(peridotites) to form the ultramafic pyroxenite magma. The pyroxenite magma underplated the overlying lower crust, captured the metamorphic zircons of the granulite and exchanged some trace elements, but didnt result in the lower crust partial melting to form any felsic magma. The pyroxenite magma emplaced alone eventually
A Cooperative Location Management Scheme for Mobile Ad Hoc Networks  [PDF]
Demin LI, Jiacun WANG, Liping ZHANG, Hao LI, Jie ZHOU
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2009, DOI: 10.4236/ijcns.2009.28084
Abstract: A mobile ad hoc network (MANET) is a kind of wireless ad hoc network. It is a self-configuring network of mobile routers connected by wireless links. Since MANETs do not have a fixed infrastructure, it is a chal-lenge to design a location management scheme that is both scalable and cost-efficient. In this paper, we propose a cooperative location management scheme, called CooLMS, for MANETs. CooLMS combines the strength of grid based location management and pointer forwarding strategy to achieve high scalability and low signaling cost. An indepth formal analysis of the location management cost of CooLMS is presented. In particular, the total location management cost of mobile nodes moving at variable velocity is estimated using the Gauss_Markov mobility model for the correlation of mobility velocities. Simulation results show CooLMS performs better than other schemes under certain circumstances.
Using the Power Control and Cooperative Communication for Energy Saving in Mobile Ad Hoc Networks  [PDF]
Chunjie Chen, Chao Jin, Demin Li, Jiacun Wang, Jianan Fang
Communications and Network (CN) , 2010, DOI: 10.4236/cn.2010.21001
Abstract: In this paper, we investigate the energy saving problem in mobile ad hoc network, and give out an improved variable-range transmission power control algorithm based on minimum spanning tree algorithm (MST). Using previous work by Gomez and Campbell [1], we show that in consider of node's mobility, the previous variable-range transmission power control based on minimum spanning tree algorithm can not support nodes' mobility in mobile ad hoc network. For this reason, we give out an improved variable-range transmission power control algorithm to support node's mobility and solve asymmetric graph problem. To save more energy without changing the topology of the network, we give out two new data transmission mechanisms based on the idea of cooperative communication. The results of this paper enhance the possibility of using variable-range transmission power control in mobile ad hoc networks.
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