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Convergence of Protection and Restoration in Telecommunication Networks   总被引:1,自引:0,他引:1  
This paper argues for the need for convergence of protection and restoration schemes in today's telecommunication networks. Such networks are presented both in a layered context and from an end-to-end perspective. Such convergence is both necessary to ensure inter-working amongst a multitude of technologies deployed and desirable to ensure simplified operations. This paper further identifies the issues and inter-working items that need resolution in today's telecommunication and data networks in order to achieve inter working amongst various existing and emerging restoration and protection schemes in a layered and end-to-end context. End-to-end context covers the access, metro, and long haul dimensions of the network. It also encompasses both the services and the transport layers of the network in the context of multi-domain, multi service provider networks. Layering issues arise from the mix of technologies at several layers for example: optical transmission and CWDM/DWDM at physical layer, SONET/SDH framing and management at layer-1, ATM, MPLS, Ethernet, and resilient packet rings at layer-2, and finally IP and routing protocols at layer-3. Given that some degree of routing and signaling intelligence is migrating down to the optical layer equipment, this whole layering concept is currently in transition. This paper shows the need for convergence in the form of a two level protection and restoration scheme. A service independent layer and a mesh restoration capability at the routing layer.  相似文献   
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This paper presents a computational fluid dynamics (CFD)-based erosion prediction model and its application to oilfield geometries specifically elbows and plugged tees. This comprehensive procedure consists of three major components: flow simulation, particle tracking, and erosion calculation. The effect of the particle rebound model on the particle trajectories as well as erosion pattern in the elbow and plugged tee is also investigated. Experimental erosion tests were performed in both an elbow and a plugged tee to evaluate the simulation results. The results from the model show good agreement of the erosion trend with the erosion data for elbow and plugged tee geometries. Experiment confirms that a stochastic rebound model is required in simulations to give a reasonable estimate of erosion rate and pattern in a plugged tee.  相似文献   
3.
Platelets are involved in tumor angiogenesis and cancer progression. Previous studies indicated that cancer could affect platelet content. In the current study, we investigated whether cancer-associated proteins can be discerned in the platelets of cancer patients, and whether antitumor treatment may affect the platelet proteome. Platelets were isolated from nine patients with different cancer types and ten healthy volunteers. From three patients, platelets were isolated before and after the start of antitumor treatment. Mass spectrometry-based proteomics of gel-fractionated platelet proteins were used to compare patients versus controls and before and after treatment initiation. A total of 4059 proteins were detected, of which 50 were significantly more abundant in patients, and 36 more in healthy volunteers. Eight of these proteins overlapped with our previous cancer platelet proteomics study. From these data, we selected potential biomarkers of cancer including six upregulated proteins (RNF213, CTSG, PGLYRP1, RPL8, S100A8, S100A9) and two downregulated proteins (GPX1, TNS1). Antitumor treatment resulted in increased levels of 432 proteins and decreased levels of 189 proteins. In conclusion, the platelet proteome may be affected in cancer patients and platelets are a potential source of cancer biomarkers. In addition, we found in a small group of patients that anticancer treatment significantly changes the platelet proteome.  相似文献   
4.
A new model is proposed to predict minimum flow rates required to constantly move particles in both intermittent and stratified flow regimes. The new model consists of a single‐phase flow model along with an appropriate length scale to be extended to multiphase flow regime. A comparison of the new model with experimental data in a multiphase air–water flow shows that the new model is able to predict minimum flow rates well for a wide range of operating conditions. The new model can capture the effects of particle size, particle concentration, and pipe size as confirmed by experimental data. A comparison of the new model with previously proposed models in the literature shows that the new model improves critical velocity predictions significantly. Moreover, the new model is the only model that takes into account the effect of particle concentration and can predict critical velocity in both intermittent and stratified flow regimes. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2634–2646, 2015  相似文献   
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Low concentration particle transport in multiphase horizontal pipes in the presence of a viscous liquid is experimentally investigated. The experiments were conducted for a wide range of liquid and gas flow rates in both intermittent and stratified flows. Critical flow rates (velocity) is defined as the minimum required liquid and gas flow rates (velocities) to keep particles constantly moving in the pipe. The effects of physical parameters such as sand concentration, sand size, pipe size, and liquid viscosity are also experimentally investigated. It is observed that that critical velocity is a function of sand concentration and sand size and increases by increasing either within the ranges of particle concentrations and sizes examined. Regarding the effect of carrier liquid viscosity, the experimental data reveal that by increasing viscosity the minimum required flow rates to constantly move sand along the pipe increases within the range examined. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1821–1833, 2016  相似文献   
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