University of Shanghai for Science and Technology

www.usst.edu.cn
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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News Article | July 31, 2017
Site: phys.org

In a new study published in EPL, a team of scientists from China whose members study complex systems, data science, and physics has developed a new approach called the credit allocation method (CAM) for ranking research institutes that accounts for all of these factors by using many thousands of directed networks. "Different from other metrics based on citations, our work considers the citation network structure and provides one way to rank the credit for research institutes for different research fields from the viewpoint of academic reputation," coauthor Jian-Guo Liu, at the University of Shanghai for Science and Technology, the Shanghai University of Finance and Economics, and the University of Fribourg in Switzerland, told Phys.org. The basic idea is that each directed network consists of one randomly chosen paper that is linked to all of the papers that have cited that paper. Then each of these citing papers is linked to all of the other papers that it cites, as long as those papers have at least one author from one of the same research institutes as the original paper. By using a formula that accounts for the order of each research institute (those listed first in the paper receive more credit than those listed later), the researchers computed the credit allocated to each research institute due to the original paper. After repeating this process for nearly half a million papers in the field of physics, with authors from approximately 19,000 research institutes, the researchers considered another problem that makes the assessment of research institutes difficult: the citation data is often unreliable. The researchers refer to a recent study that found that more than 30% of research papers had at least one incorrect citation, and that 10% of all citations were incorrect, meaning the papers cited did not clearly support the statements they were meant to support. To address this problem, the researchers randomly rewired some of the citation links in the networks, creating an artificial disturbance intended to model the inaccuracies in the citation data. In the final rankings, many of the top-ranked physics research institutes identified by the new method corresponded to institutes with high reputations. The top four overall were the University of California, Bell Labs, the Max Planck Institute, and MIT. The top four in China were the University of Science and Technology of China, Nanjing University, Peking University, and Tsinghua University. Although the researchers showed that the new method outperforms other methods of assessing research institutes, they note that it has some shortcomings. In particular, it does not account for the fact that older papers tend to have more citations than newer papers, so research institutes with longer histories tend to be ranked higher. The researchers plan to address this detail in the future by accounting for the age of the institution. "In future work, we also plan to investigate the citation networks of some specific research fields, such as management science, complexity, statistical physics, and computer science, in order to rank the research institute credit of these fields," Liu said. "We also plan to develop a website to publish the ranking results for researchers all over the world." More information: J.-P. Wang et al. "Credit allocation for research institutes." EPL. DOI: 10.1209/0295-5075/118/48001


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.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 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 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.


Jia L.Y.,University of Shanghai for Science and Technology
Physical Review C - Nuclear Physics | Year: 2016

The particle-hole symmetry (equivalence) of the full shell-model Hilbert space is straightforward and routinely used in practical calculations. In this work I show that this symmetry is preserved in the subspace truncated up to a certain generalized seniority and give the explicit transformation between the states in the two types (particle and hole) of representations. Based on the results, I study particle-hole symmetry in popular theories that could be regarded as further truncations on top of the generalized seniority, including the microscopic interacting boson (fermion) model, the nucleon-pair approximation, and other models. © 2016 American Physical Society.


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.


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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