Shanghai, China

University of Shanghai for Science and Technology founded in 1906, is a public university in Shanghai, People's Republic of China. It is colloquially known as Shànghǎi Lǐgōng or Shànglǐ. Wikipedia.


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Luo X.,University of Shanghai for Science and Technology
IEEE Transactions on Wireless Communications | Year: 2017

To meet ever-growing mobile data traffic, network spatial densification with various low-power nodes in addition to the conventional high-power macro base stations, also known as heterogeneous network (HetNet), is regarded as one key enabling solution. Due to the unplanned nature, HetNets are very irregular and severe interference can happen without judicious designs of the user association rules. Most prior works assumed best-effort traffic and sought the optimal association to maximize metrics, such as the sum of log-rates. In the case of bursty traffic with quality-of-service (QoS) requirements, existing association schemes cannot fully release the traffic offloading capabilities of HetNets. In this paper, we model the downlink traffic to individual mobile station explicitly. Aiming to minimize the network-wide packet delay, we investigate the optimal user association scheme and the corresponding resource allocation algorithm. We then propose the QoS-aware user association (QoSA) strategies of different flavors enjoying low complexity and guaranteed convergence. Furthermore, the proposed QoSA algorithms are readily implemented in distributed manners. Extensive network simulations are carried out to corroborate our designs. © 2017 IEEE.


News Article | May 24, 2017
Site: phys.org

When a narrow tube is dipped into granular material and vibrated vertically, the granular material rises inside the tube to reach a terminal vertical level. Credit: Fengxian Fan, Eric Parteli, Thorsten Pöschel Dipping a tube into a container filled with water will make the water rise in the tube. This phenomenon is called liquid capillarity. It is responsible for many natural and technical processes, for example the water absorption of trees, ink rising in a fountain pen, and sponges absorbing dishwater. But what happens if the tube is dipped into a container filled not with water but with sand? The answer is – nothing. However, if the tube is shaken up and down, the sand will also begin to rise. Scientists have now discovered the mechanism behind this effect, the so-called granular capillary effect. Dr Eric J. R. Parteli from the University of Cologne's Department of Geosciences, Professor Fengxian Fan from the University of Shanghai for Science and Technology, and Professor Thorsten Pöschel from Friedrich-Alexander University Erlangen-Nürnberg have now published the results of their study 'Origin of Granular Capillarity Revealed by Particle-Based Simulations' in Physical Review Letters. Liquid capillarity results from the interplay of different molecular forces: the attraction between the liquid molecules keeps it together while the attraction between molecules and tube drives the liquid upward. This explanation precludes the occurrence of capillarity for sand because sand grains are so much bigger than their constituent molecules that inter-molecular forces can be safely neglected compared to gravity and grain inertia. However, surprisingly, granular capillarity has been observed in laboratory experiments in which the granular material was subjected to a tiny vertical vibration of a few grain diameters in amplitude and a frequency of just a few Hertz. The origin of this granular capillary effect was a long-standing mystery the international team of scientists succeed in unveiling. They investigated the problem using a particle-based numerical simulation method called Discrete Element Method. In this method, the trajectory of every single grain is calculated by numerically solving Newton's equations of translational and rotational motion due to the forces that act on each grain. By means of such a numerical experiment, it is thus possible to track the trajectory and velocity of all grains, including those grains that are deep within the granular bulk, which are difficult to assess in the laboratory. The research team observed in their simulations that what makes the sand column ascend in the tube is a convective motion of the sand grains within the recipient that is inherent to granular materials under vertical vibrations. This convective flux causes lateral mass transport within the vibrating granular packing, which leads to an upward pressure on the base of the granular column in the tube, which is why the column ascends. The scientists found that how fast and far the column rises depends on the tube size. Remarkably, the simulations showed that the height of the granular meniscus (the capillary height that the granular column reaches after a long time) is proportional to the inverse of the tube size. This is exactly the same behaviour as for liquid capillarity, although the driving forces in the two systems are so much different. The physicists showed in their study that the same capillary effect can be produced by shaking the tube instead of the container, which opens up promising applications in the handling and transportation sectors. For example, particles could be pumped up from very large containers just by using granular capillarity. They are now studying the process in more depth to understand the effect of system and particle geometry. Explore further: Feeling the force between sand grains More information: Fengxian Fan et al. Origin of Granular Capillarity Revealed by Particle-Based Simulations, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.118.218001


News Article | May 25, 2017
Site: www.sciencedaily.com

Dipping a tube into a container filled with water will make the water rise in the tube. This phenomenon is called liquid capillarity. It is responsible for many natural and technical processes, for example the water absorption of trees, ink rising in a fountain pen, and sponges absorbing dishwater. But what happens if the tube is dipped into a container filled not with water but with sand? The answer is -- nothing. However, if the tube is shaken up and down, the sand will also begin to rise. Scientists have now discovered the mechanism behind this effect, the so-called granular capillary effect. Dr Eric J. R. Parteli from the University of Cologne's Department of Geosciences, Professor Fengxian Fan from the University of Shanghai for Science and Technology, and Professor Thorsten Pöschel from Friedrich-Alexander University Erlangen-Nürnberg have now published the results of their study 'Origin of Granular Capillarity Revealed by Particle-Based Simulations' in the Physical Review Letters. Liquid capillarity results from the interplay of different molecular forces: the attraction between the liquid molecules keeps it together while the attraction between molecules and tube drives the liquid upward. This explanation precludes the occurrence of capillarity for sand because sand grains are so much bigger than their constituent molecules that inter-molecular forces can be safely neglected compared to gravity and grain inertia. However, surprisingly, granular capillarity has been observed in laboratory experiments in which the granular material was subjected to a tiny vertical vibration of a few grain diameters in amplitude and a frequency of just a few Hertz. The origin of this granular capillary effect was a long-standing mystery the international team of scientists succeed in unveiling. They investigated the problem using a particle-based numerical simulation method called Discrete Element Method. In this method, the trajectory of every single grain is calculated by numerically solving Newton's equations of translational and rotational motion due to the forces that act on each grain. By means of such a numerical experiment, it is thus possible to track the trajectory and velocity of all grains, including those grains that are deep within the granular bulk, which are difficult to assess in the laboratory. The research team observed in their simulations that what makes the sand column ascend in the tube is a convective motion of the sand grains within the recipient that is inherent to granular materials under vertical vibrations. This convective flux causes lateral mass transport within the vibrating granular packing, which leads to an upward pressure on the base of the granular column in the tube, which is why the column ascends. The scientists found that how fast and far the column rises depends on the tube size. Remarkably, the simulations showed that the height of the granular meniscus (the capillary height that the granular column reaches after a long time) is proportional to the inverse of the tube size. This is exactly the same behaviour as for liquid capillarity, although the driving forces in the two systems are so much different. The physicists showed in their study that the same capillary effect can be produced by shaking the tube instead of the container, which opens up promising applications in the handling and transportation sectors. For example, particles could be pumped up from very large containers just by using granular capillarity. They are now studying the process in more depth to understand the effect of system and particle geometry.


News Article | May 25, 2017
Site: www.rdmag.com

Dipping a tube into a container filled with water will make the water rise in the tube. This phenomenon is called liquid capillarity. It is responsible for many natural and technical processes, for example the water absorption of trees, ink rising in a fountain pen, and sponges absorbing dishwater. But what happens if the tube is dipped into a container filled not with water but with sand? The answer is - nothing. However, if the tube is shaken up and down, the sand will also begin to rise. Scientists have now discovered the mechanism behind this effect, the so-called granular capillary effect. Dr Eric J. R. Parteli from the University of Cologne's Department of Geosciences, Professor Fengxian Fan from the University of Shanghai for Science and Technology, and Professor Thorsten Pöschel from Friedrich-Alexander University Erlangen-Nürnberg have now published the results of their study 'Origin of Granular Capillarity Revealed by Particle-Based Simulations' in the Physical Review Letters. Liquid capillarity results from the interplay of different molecular forces: the attraction between the liquid molecules keeps it together while the attraction between molecules and tube drives the liquid upward. This explanation precludes the occurrence of capillarity for sand because sand grains are so much bigger than their constituent molecules that inter-molecular forces can be safely neglected compared to gravity and grain inertia. However, surprisingly, granular capillarity has been observed in laboratory experiments in which the granular material was subjected to a tiny vertical vibration of a few grain diameters in amplitude and a frequency of just a few Hertz. The origin of this granular capillary effect was a long-standing mystery the international team of scientists succeed in unveiling. They investigated the problem using a particle-based numerical simulation method called Discrete Element Method. In this method, the trajectory of every single grain is calculated by numerically solving Newton's equations of translational and rotational motion due to the forces that act on each grain. By means of such a numerical experiment, it is thus possible to track the trajectory and velocity of all grains, including those grains that are deep within the granular bulk, which are difficult to assess in the laboratory. The research team observed in their simulations that what makes the sand column ascend in the tube is a convective motion of the sand grains within the recipient that is inherent to granular materials under vertical vibrations. This convective flux causes lateral mass transport within the vibrating granular packing, which leads to an upward pressure on the base of the granular column in the tube, which is why the column ascends. The scientists found that how fast and far the column rises depends on the tube size. Remarkably, the simulations showed that the height of the granular meniscus (the capillary height that the granular column reaches after a long time) is proportional to the inverse of the tube size. This is exactly the same behaviour as for liquid capillarity, although the driving forces in the two systems are so much different. The physicists showed in their study that the same capillary effect can be produced by shaking the tube instead of the container, which opens up promising applications in the handling and transportation sectors. For example, particles could be pumped up from very large containers just by using granular capillarity. They are now studying the process in more depth to understand the effect of system and particle geometry.


News Article | May 24, 2017
Site: www.eurekalert.org

Dipping a tube into a container filled with water will make the water rise in the tube. This phenomenon is called liquid capillarity. It is responsible for many natural and technical processes, for example the water absorption of trees, ink rising in a fountain pen, and sponges absorbing dishwater. But what happens if the tube is dipped into a container filled not with water but with sand? The answer is - nothing. However, if the tube is shaken up and down, the sand will also begin to rise. Scientists have now discovered the mechanism behind this effect, the so-called granular capillary effect. Dr Eric J. R. Parteli from the University of Cologne's Department of Geosciences, Professor Fengxian Fan from the University of Shanghai for Science and Technology, and Professor Thorsten Pöschel from Friedrich-Alexander University Erlangen-Nürnberg have now published the results of their study 'Origin of Granular Capillarity Revealed by Particle-Based Simulations' in the Physical Review Letters. Liquid capillarity results from the interplay of different molecular forces: the attraction between the liquid molecules keeps it together while the attraction between molecules and tube drives the liquid upward. This explanation precludes the occurrence of capillarity for sand because sand grains are so much bigger than their constituent molecules that inter-molecular forces can be safely neglected compared to gravity and grain inertia. However, surprisingly, granular capillarity has been observed in laboratory experiments in which the granular material was subjected to a tiny vertical vibration of a few grain diameters in amplitude and a frequency of just a few Hertz. The origin of this granular capillary effect was a long-standing mystery the international team of scientists succeed in unveiling. They investigated the problem using a particle-based numerical simulation method called Discrete Element Method. In this method, the trajectory of every single grain is calculated by numerically solving Newton's equations of translational and rotational motion due to the forces that act on each grain. By means of such a numerical experiment, it is thus possible to track the trajectory and velocity of all grains, including those grains that are deep within the granular bulk, which are difficult to assess in the laboratory. The research team observed in their simulations that what makes the sand column ascend in the tube is a convective motion of the sand grains within the recipient that is inherent to granular materials under vertical vibrations. This convective flux causes lateral mass transport within the vibrating granular packing, which leads to an upward pressure on the base of the granular column in the tube, which is why the column ascends. The scientists found that how fast and far the column rises depends on the tube size. Remarkably, the simulations showed that the height of the granular meniscus (the capillary height that the granular column reaches after a long time) is proportional to the inverse of the tube size. This is exactly the same behaviour as for liquid capillarity, although the driving forces in the two systems are so much different. The physicists showed in their study that the same capillary effect can be produced by shaking the tube instead of the container, which opens up promising applications in the handling and transportation sectors. For example, particles could be pumped up from very large containers just by using granular capillarity. They are now studying the process in more depth to understand the effect of system and particle geometry.


Zhao B.,University of Shanghai for Science and Technology
Separation and Purification Technology | Year: 2012

Modeling the particle separation efficiency has been a topic of interest since the air cyclones was introduced for gas-particle separation in the fields of environmental science and chemical engineering. In this work, a new simple time-of-flight model is theoretically developed to predict the particle separation efficiency in cyclones. In this model, the equivalent volume method is employed to geometrically modify the cylindrical-conical type cyclone as a right cylindrical cyclone in order to overcome the nonuniform effect on the particle separation distance. Based on the analysis of the gas flow pattern and the particle dynamics in the cyclone separator, the differential equation for the time-of-flight model is established according to the principle of particle mass balance. The model can be finally expressed as a simple explicit function including the main cyclone dimensions and operating parameters, without the need for solving complex equation of mathematical physics. The influences of the short-circuit flow near the bottom of cyclone outlet duct and the exchange flow between outer and inner vortex flow are comprehensively considered to revise the effective residence time of gas flow, a key parameter in the present model. By comparisons with experimental data as well as other classical separation models for the cyclones with different geometrical configurations and operating conditions, the results show that the present model has a relatively high predicted accuracy with the mean squared error of 0.0158. It is demonstrated that the present model has considerable availability for predicting the particle separation efficiency for cyclone separators. © 2011 Elsevier B.V. All rights reserved.


Zhao B.,University of Shanghai for Science and Technology | Su Y.,Donghua University
Renewable and Sustainable Energy Reviews | Year: 2014

Global warming caused by anthropogenic CO2 emission has been one of the most important issues in the fields of science, environment and even international economics and politics. To control and reduce CO2 emissions, intensive carbon dioxide capture and storage (CCS) technologies have been comprehensively developed for sequestration of CO2 especially from combustion flue gas. Microalgae-based CO2 biological fixation is regarded as a potential way to not only reduce CO2 emission but also achieve energy utilization of microalgal biomass. However, in this approach culture process of microalgae plays an important role as it is directly related to the mechanism of microalgal-CO2 fixation and characteristics of microalgal biomass production. The aim of this work is to present a state-of-the-art review on the process effect, especially on the effects of photobiochemical process, microalgal species, physicochemical process and hydrodynamic process on the performance of microalgal-CO2 fixation and biomass production. Also, the perspectives are proposed in order to provide a positive reference on developing its fundamental research and key technology. © 2013 Elsevier Ltd.


Yuan X.,University of Shanghai for Science and Technology
IEEE Transactions on Wireless Communications | Year: 2014

Recently, much research interest has been focused on the design of efficient communication mechanisms for multiple-input-multiple-output (MIMO) multiway relay channels (mRCs). In this paper, we investigate achievable degrees of freedom (DoFs) of the MIMO mRC with L clusters and K users per cluster, where each user is equipped with M antennas and the relay with N antennas. Our analysis is focused on a new data exchange model, termed clustered full data exchange, i.e., each user in a cluster wants to learn the messages of all the other users in the same cluster. Novel signal alignment techniques are developed to jointly and systematically construct the beamforming matrices at the users and the relay for efficient implementation of physical-layer network coding. Based on this, we derive an achievable DoF of the MIMO mRC with an arbitrary network configuration of L and K, as well as with an arbitrary antenna configuration of M and N. We show that our proposed scheme achieves the DoF capacity when M/N \leq 1/(LK-1) and M/N\geq((K-1)L+1)/KL. The DoF results derived in this paper can serve as fundamental benchmarks in evaluating the performance of practical communication systems over MIMO mRCs and provide guidance and insights into the design of wireless relay networks. © 2002-2012 IEEE.


Liao J.,University of Shanghai for Science and Technology
Nature Structural and Molecular Biology | Year: 2016

Na+/Ca2+ exchangers use the Na+ electrochemical gradient across the plasma membrane to extrude intracellular Ca2+ and play a central role in Ca2+ homeostasis. Here, we elucidate their mechanisms of extracellular ion recognition and exchange through a structural analysis of the exchanger from Methanococcus jannaschii (NCX_Mj) bound to Na+, Ca2+ or Sr2+ in various occupancies and in an apo state. This analysis defines the binding mode and relative affinity of these ions, establishes the structural basis for the anticipated 3:1 Na+/Ca2+-exchange stoichiometry and reveals the conformational changes at the onset of the alternating-access transport mechanism. An independent analysis of the dynamics and conformational free-energy landscape of NCX_Mj in different ion-occupancy states, based on enhanced-sampling molecular dynamics simulations, demonstrates that the crystal structures reflect mechanistically relevant, interconverting conformations. These calculations also reveal the mechanism by which the outward-to-inward transition is controlled by the ion occupancy, thereby explaining the emergence of strictly coupled Na+/Ca2+ antiport. © 2016 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.


Yu D.G.,University of Shanghai for Science and Technology
International journal of nanomedicine | Year: 2011

The objective of this investigation was to develop a new type of solid dispersion in the form of core-sheath nanofibers using coaxial electrospinning for poorly water-soluble drugs. Different functional ingredients can be placed in various parts of core-sheath nanofibers to improve synergistically the dissolution and permeation properties of encapsulated drugs and to enable drugs to exert their actions. Using acyclovir as a model drug, polyvinylpyrrolidone as the hydrophilic filament-forming polymer matrix, sodium dodecyl sulfate as a transmembrane enhancer, and sucralose as a sweetener, core-sheath nanofibers were successfully prepared, with the sheath part consisting of polyvinylpyrrolidone, sodium dodecyl sulfate, and sucralose, and the core part composed of polyvinylpyrrolidone and acyclovir. The core-sheath nanofibers had an average diameter of 410 ± 94 nm with a uniform structure and smooth surface. Differential scanning calorimetry and x-ray diffraction results demonstrated that acyclovir, sodium dodecyl sulfate, and sucralose were well distributed in the polyvinylpyrrolidone matrix in an amorphous state due to favoring of second-order interactions. In vitro dissolution and permeation studies showed that the core-sheath nanofiber solid dispersions could rapidly release acyclovir within one minute, with an over six-fold increased permeation rate across the sublingual mucosa compared with that of crude acyclovir particles. The study reported here provides an example of the systematic design, preparation, characterization, and application of a novel type of solid dispersion consisting of multiple components and structural characteristics.

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