Multiple-predators-based capture process on complex networks

The predator/prey （capture） problem is a prototype of many network-related applications. We study the capture process on complex networks by considering multiple predators from multiple sources. In our model, some lions start from multiple sources simultaneously to capture the lamb by biased random walks, which are controlled with a free parameter a. We derive the distribution of the lamb＇s lifetime and the expected lifetime （T）. Through simulation, we find that the expected lifetime drops substantially with the increasing number of lions. Moreover, we study how the underlying topological structure affects the capture process, and obtain that locating on small-degree nodes is better than on large- degree nodes to prolong the lifetime of the lamb. The dense or homogeneous network structures are against the survival of the lamb. We also discuss bow to improve the capture efficiency in our model.

Ab Initio Study of Single-and Double-Electron Capture Processes in Collisions of He^(2+) Ions and Ne Atoms

The single-and double-electron capture(SEC, DEC) processes of He^(2+) ions colliding with Ne atoms are studied by utilizing the full quantum-mechanical molecular-orbital close-coupling method. Total and state-selective SEC and DEC cross sections are presented in the energy region of 2 eV/u to 20 keV/u. Results show that the dominant reaction channel is Ne^(+)(2s2p^(6) ^(2)S) + He^(+)(1s) in the considered energy region due to strong couplings with the initial state Ne(2s^(2)2p^(6)^(1)S) + He^(2+) around the internuclear distance of 4.6 a.u. In our calculations, the SEC cross sections decrease initially and then increase whereby, the minimum point is around 0.38 keV/u with the increase of collision energies. After considering the effects of the electron translation factor(ETF), the SEC cross sections are increased by 15%–25% nearby the energy region of keV/u and agree better with the available results. The DEC cross sections are smaller than those of SEC because of the larger energy gaps and no strong couplings with the initial state. Due to the Demkov-type couplings between DEC channel Ne^(2+)(2s^(2)2p^(4)^(1)S) + He(1s^(2)) and the dominating SEC channel Ne^(+)(2s2p^(6) ^(2)S) + He^(+)(1s), the DEC cross sections increase with increasing impact energies. Good consistency can also be found between the present DEC and the experimental measurements in the overlapping energy region.

An Integrated Carbon Dioxide Capture and Methanation Process

Reducing the ever-growing level of CO_(2)in the atmosphere is critical for the sustainable development of human society in the context of global warming.Integration of the capture and upgrading of CO_(2)is,therefore,highly desirable since each process step is costly,both energetically and economically.Here,we report a CO_(2)direct air capture(DAC)and fixation process that produces methane.Low concentrations of CO_(2)(∼400 ppm)in the air are captured by an aqueous solution of sodium hydroxide to form carbonate.The carbonate is subsequently hydrogenated to methane,which is easily separated from the reaction system,catalyzed by TiO2-supported Ru in the aqueous phase with a selectivity of 99.9%among gas-phase products.The concurrent regenerated hydroxide,in turn,increases the alkalinity of the aqueous solution for further CO_(2)capture,thereby enabling this one-ofits-kind continuous CO_(2)capture and methanation process.Engineering simulations demonstrate the energy feasibility of this CO_(2)DAC and methanation process,highlighting its promise for potential largescale applications.

Charge transfer in low-energy collisions of Be^3+ and B^4+ ions with He

The nonradiative charge-transfer processes of Be3+(1s)/B4+(1s)colliding with He(1s2)are investigated by the quantum-mechanical molecular orbital close-coupling(QMOCC)method from 10 eV/u to 1800 eV/u.Total and state-selective cross sections are obtained and compared with other results available.Although the incident ions have the same number of electrons and collide with the same target,their cross sections are different due to the differences in molecular structure.For Be3+(1s)+He(1s2),only single-electron-capture(SEC)states are important and the total cross sections have a broad maximum around E=150 eV/u.While for B4+(1s)+He(1s2),both the SEC and double-electron-capture(DEC)processes are important,and the total SEC and DEC cross sections decrease rapidly with the energy decreasing.

Comparison of Structured Packings in CO2 Absorber with Chemical Reactions

The objective of this work is to study a comprehensive performance of three types of structured parking in CO2 absorption application. One of them was developed in Mexican National Institute of Nuclear Research （ININ abbreviation in Spanish of Instituto Nacional de lnvestigaciones Nucleates）, and the other two, Sulzer BX and Mellapak 250Y, by Sulzer Brothers Ltd. Aqueous solution of 30 weight % Monoethanolamine was employed as absorption solvent. The performance of the structured packing was evaluated in terms of the pressure drop, holds up, volumetric overall mass transfer coefficient and height of a global transfer unit of gas and liquid side as a function of the process operating parameters including gas and liquid load, by using hydrodynamic and mass transfer models. The pressure drop of ININ packing was higher than Sulzer BX and Mellapak 250Y, and volumetric overall mass transfer coefficient values are similar of Sulzer BX values and higher than Mellapak 250Y, although Sulzer BX and ININI 8 packing had less height of a global transfer unit of gas side values than Mellapak 250Y packing. The above-mentioned are consequences of the geometric characteristics and operational behavior for each packing.

Comprehensive evaluation of an ionic liquid based deep purification process for NH_(3)-containing industrial gas

Ammonia(NH_(3))emission has caused serious environment issues and aroused worldwide concern.The emerging ionic liquid(IL)provides a greener way to efficiently capture NH_(3).This paper provides rigorous process simulation,optimization and assessment for a novel NH_(3)deep purification process using IL.The process was designed and investigated by simulation and optimization using ionic liquid[C_(4)im][NTF_(2)]as absorbent.Three objective functions,total purification cost(TPC),total process CO_(2)emission(TPCOE)and thermal efficiency(ηeff)were employed to optimize the absorption process.Process simulation and optimization results indicate that at same purification standard and recovery rate,the novel process can achieve lower cost and CO_(2)emission compared to benchmark process.After process optimization,the optimal functions can achieve 0.02726$/Nm~3(TPC),311.27 kg CO_(2)/hr(TP-COE),and 52.21%(ηeff)for enhanced process.Moreover,compared with conventional process,novel process could decrease over$3 million of purification cost and 10000 tons of CO_(2)emission during the life cycle.The results provide a novel strategy and guidance for deep purification of NH_(3)capture.

Development of CO2 Selective Poly（Ethylene Oxide）-Based Membranes： From Laboratory to Pilot Plant Scale

Membrane gas separation is one of the most promising technologies for the separation of carbon dioxide （CO2） from various gas streams. One application of this technology is the treatment of flue gases from combustion processes for the purpose of carbon capture and storage. For this application, poly（ethylene oxide）-containing block copolymers such as Pebax or PolyActiveTM polymer are well suited. The thin-film composite membrane that is considered in this overview employs PolyActiveTM polymer as a selective layer material. The membrane shows excellent CO2 permeances of up to 4 m^3（STP）.（m^2·h·bar）^-1 （1 bar = 105 Pa） at a carbon dioxide/nitrogen （CO2/N2） selectivity exceeding 55 at ambient temperature. The membrane can be manufactured reproducibly on a pilot scale and mounted into fiat-sheet membrane modules of different designs. The operating performance of these modules can be accurately predicted by specifically developed simulation tools, which employ single-gas permeation data as the only experimental input. The performance of membranes and modules was investigated in different pilot plant studies, in which flue gas and biogas were used as the feed gas streams. The investigated processes showed a stable separation performance, indicating the applicability of PolyActiveTM polymer as a membrane material for industrialscale gas processing.

A PCR-based Rapid Neutralization Assay for GⅡ.4 Norovirus Infection in HIEC6 Cell Culture

Because of limited viral replication and lack of cytopathic effect in cell culture,a new PCR-based rapid seroneutralization assay for detection of GII.4norovirus neutralized antibodies was developed with serum samples from acute-phase patients,convalescent-phase patients and healthy controls.According to this study,neutralizing antibodies were detected in 100% ofconvalescent-phase sera, and in 2.5% of healthy controls sera. However, all of the acute-phase serum samples could not neutralize virus efficiently. Compared to the results from ELISA （96.2% at sensitivity and 80% at specificity）, the present in vitro neutralization assay is more specific and more sensitive.

Learning from a carbon dioxide capture system dataset: Application of the piecewise neural network algorithm

This paper presents the application of a neural network rule extraction algorithm,called the piecewise linear artificial neural network or PWL-ANN algorithm,on a carbon capture process system dataset.The objective of the application is to enhance understanding of the intricate relationships among the key process parameters.The algorithm extracts rules in the form of multiple linear regression equations by approximating the sigmoid activation functions of the hidden neurons in an artificial neural network(ANN).The PWL-ANN algorithm overcomes the weaknesses of the statistical regression approach,in which accuracies of the generated predictive models are often not satisfactory,and the opaqueness of the ANN models.The results show that the generated PWL-ANN models have accuracies that are as high as the originally trained ANN models of the four datasets of the carbon capture process system.An analysis of the extracted rules and the magnitude of the coefficients in the equations revealed that the three most significant parameters of the CO_(2) production rate are the steam flow rate through reboiler,reboiler pressure,and the CO_(2) concentration in the flue gas.

Advances in alternating electromagnetic field data processing for earthquake monitoring in China

The alternating electromagnetic(EM) field is one of the most sensitive physical fields related to earthquakes. There have been a number of publications reporting EM anomalies associated with earthquakes. With increasing applications and research of artificial-source extremely low frequency EM and satellite EM technologies in earthquake studies, the amount of observed data from the alternating EM method increases rapidly and exponentially, so it is imperative to develop suitable and effective methods for processing and analyzing the influx of big data. This paper presents research on the self-adaptive filter and wavelet techniques and their applications to analyzing EM data obtained from ground measurements and satellite observations, respectively. Analysis results show that the self-adaptive filter method can identify both natural- and artificial-source EM signals, and enhance the ratio between signal and noise of EM field spectra, apparent resistivity, and others. The wavelet analysis is capable of detecting possible correlation between EM anomalies and seismic events. These techniques are effective in processing and analyzing massive data obtained from EM observations.