9,421 research outputs found
Preface to Special Issue on Green Conversion of HMF
No full textIn this Editorial, Guest Editors Stefania Albonetti, Changwei Hu, and Shunmugavel Saravanamurugan introduce the Special Issue of ChemSusChem on Green Conversion of HMF. The significance of and enormous challenges for the sustainable transformation of 5-hydroxymethylfurfural are reviewed, and the contents of the Special Issue with highly interesting contributions from scientists around the world are outlined
Matlab Image Fusion Toolbox for Image Fusion Algorithm Based On Orientation Information Motivated Pulse Coupled Neural Networks
No full textThis toolbox contains Matlab files that implement the image fusion algorithm: orientation information motivated Pulse Coupled Neural Networks in the following paper:
[1]Xiaobo Qu, Changwei Hu, Jingwen Yan, Image Fusion Algorithm Based On Orientation Information Motivated Pulse Coupled Neural Networks, The seventh World Congress on Intelligent Control and Automation-WCICA 2008，Chongqing, China,25-27 June 2008, pp.2437-244
An innovative ‘sea-thermal’ synergetic biorefinery for biofuel production: Co-valorization of lignocellulosic and algal biomasses using seawater under hydrothermal conditions
No full text8 figures, 2 tables.-- Supplementary information available.This study explores the co-hydrothermal treatment (co-HTT) of almond hulls and Chlorella Vulgaris using seawater as an alternative HTT medium. The influence of the feedstock (individual biomass and all the possible binary mixtures) was systematically evaluated under different conditions (reaction temperatures and times). The feedstock mixture and hydrothermal conditions significantly influenced the overall product distribution: gas (1–5%), hydrochar (6–56%), biocrude (6–55%), and aqueous fraction (33–52%), along with the most representative physicochemical and fuel properties of these products. Notably, the biocrude had a calorific value of 24–31 MJ/kg, whereas the hydrochar shifted between 3 and 26 MJ/kg. The degradation of abundant polysaccharides in almond hulls produced acidic species, promoting the degradation of proteins to N-containing species in biocrude. The synergies between microalgae and almond hulls favored the deamination of amino acid and repolymerization of formed monomers. Process optimization revealed that the best biocrude production (59% yield and HHV = 28 MJ/kg) was obtained by treating C. Vulgaris at 268 °C for 180 min. Contrarily, the HTT of almond hulls under optimum processing conditions (300 °C and 112 min) also produced an energy-dense biocrude (29 MJ/kg) but with a much lesser yield (16%). However, such a low biocrude production can be synergistically increased up to 33 %, maintaining the HHV (31 MJ/kg), including up to 61 wt% of C.Vulgaris into the feedstock, with a feedstock energy recovery of 75%. Holistically, the co-HTT of 40 wt% C. Vulgaris and 60 wt% almond hulls at 300 °C for 180 min produced energy-dense liquid (23% yield and HHV = 32 MJ/kg) and solid (29% yield and HHV = 25 MJ/kg) biofuels simultaneously, with a feedstock energy recovery of 80%. Given these excellent prospects, this strategy provides timely and new insights into developing synergetic strategies to utilize microalgal and lignocellulosic biomasses more efficiently, paving the way toward developing holistic and unseasonal biorefinery processes.This work was funded by MCIN/AEI/10.13039/501100011033 (I + D + i project PID2020-115053RB-I00) and by the Aragón Government (Research Group Reference T06-23R). This work was also financially supported by the National Natural Science Foundation of China (No. 21536007), the 111 project (B17030), and the Beijing Nova Program (Z211100002121085). Yingdong Zhou acknowledges the support from the China Scholarship Council (CSC No. 202006240156). Javier Remón is grateful to the Spanish Ministry of Science, Innovation and Universities for the Juan de la Cierva (JdC) fellowship (Grant Number IJC2018-037110-I) and thanks MCIN/AEI/10.13039/501100011033 and the European Union « NextGenerationEU»/PRTR » for the Ramón y Cajal Fellowship (RYC2021-033368-I) awarded, and the Aragón Government (Research Group Reference T22_23R) for providing frame support.Peer reviewe
Experiment and CFD investigation on gravity effects in reverse osmosis
No full textBellevue, WashingtonHU Changwei, Beihang University, ChinaKE Peng, Beihang University, ChinaZHANG Shuguang, Beihang University, ChinaThe 45th International Conference on Environmental Systems was held in Bellevue, Washington, USA on 12 July 2015 through 16 July 2015.The reverse osmosis (RO) technology, due to its less replacement and predictable treatment efficiency, is applicable to the water recovery system, which is necessary for long duration space missions to provide an ongoing, safe and healthy water supply. The objective of this research is to investigate the permeability characteristics of RO membranes by using experiment and computational fluid dynamics (CFD) methods, with a special consideration on the effects of concentration polarization and gravity, where the system performance may be degraded. Permeation coefficient of the certain RO membrane was firstly determined experimentally with the variation of feed flow velocity, trans-membrane pressure and solute concentration. Then the numerical tools based on two dimensional (2D) and three dimensional (3D) CFD method were built to investigate the influence of concentration polarization and gravity on membrane permeability. Such numerical tools were validated by the experiments and theoretical permeation models. It was found that effects of gravity, closely related to the concentration polarization and the direction of gravity, can affect the permeate flux. The gravity influence coefficient was proposed to represent the effects of gravity. The correlations between gravity influence coefficient and affecting factors were further build. This study could be helpful to the measurement and analysis of RO membrane permeability characteristics considering the effects of gravity
Performance Evaluation of Distributed-Antenna Communications Systems Using Beam-Hopping
No full textDigital beamforming (DBF) techniques are capable of improving the performance of communications systems significantly. However, if the transmitted signals are conflicted with strong interference, especially, in the direction of the transmitted beams , these directional jamming signals will severely degrade the system performance. In order to efficiently mitigate the interference of the directional jammers, in this contribution a beam-hopping (BH) communications scheme is proposed. In the proposed BH communications scheme, only one pair of the beams is used for transmission and it hops from one to the next according to an assigned BH pattern. In this contribution a range of expressions in terms of the average SINR performance have been derived, when both the uplink and downlink are considered. The average SINR performance of the proposed BH scheme and that of the conventional single-beam (SB) as well as multiple-beam (MB) assisted beam-processing schemes have been investigated. Our analysis and results show that the proposed BH scheme is capable of efficiently combating the directional jamming, with the aid of utilizing the directional gain of the beams generated by both the transmitter and the receiver. Furthermore, the BH scheme is capable of reducing the intercept probability of the communications. Therefore, the proposed BH scheme is suitable for communications, when several distributed antenna arrays are available around a mobile
Toward developing more sustainable marine biorefineries: A novel ‘sea-thermal’ process for biofuels production from microalgae
No full text5 figures, 4 tables.-- Supplementary information available.This work explores the ‘sea-thermal’ treatment of the aquatic protein-rich microalga Chlorella Vulgaris to produce energy-dense biofuels and value-added, nitrogen-rich liquid products. The impact of the processing conditions (temperature, 200–300 °C; time, 20–180 min) and reaction medium (seawater/(deionized water + seawater) ratio, 0–100 wt%) on the yields and properties of these products has been addressed using a two-level, three-factor (23) Box-Wilson Central Composite, Face Centered (CCF, α: ±1) design. These processing parameters ruled the distribution of the overall reaction products, including gas (1–5 %), biocrude (17–57 %), aqueous product (32–47 %) and hydrochar (3–45 %), and the fuel and chemical properties of these fractions. The calorific values of the hydrochar and biocrude ranged from 2 to 25 MJ/kg and 23 to 32 MJ/kg, respectively. Using low temperatures and/or short reaction times favored biocrude formation, while higher temperatures and/or more prolonged processing times boosted the repolymerization of the biocrude to hydrochar. These transformations depended on the reaction medium, with seawater exerting different influences based on the reaction medium salinity. Diluted seawater promoted the dissolution and depolymerization of polysaccharides and proteins in the alga by disrupting the H-bonding networks within these macromolecules, while enriched seawater media favored the deoxygenation and repolymerization of the biocrude. These variations highlighted the bespoke nature of this ‘sea-thermal’ process to furnish liquid and solid biofuels and/or biochemicals. Process optimization based on the formulae developed from the ANOVA of the experimental data showed that 55–60 wt% of the alga could be converted either to energy-dense (30 MJ/kg) biofuels (36 wt% biocrude, with hydrocarbons and fatty acids/esters in high amount, and 20 wt% hydrochar) at 200 °C for 180 min using enriched seawater (64 wt% seawater) as a solvent or to value-added liquids (a nitrogen-rich (88 %) biocrude, including abundant fatty amides and N-heterocycles) at 237 °C for 169 min in seawater. These results lay the first stone toward developing more sustainable marine biorefineries using marine-based solvents to valorize marine feedstocks.This work is financially supported by the National Natural Science Foundation of China (No. 21536007), the 111 project (B17030), and the I + D + i project PID2020-115053RB-I00, funded by Spanish MCIN/AEI/10.13039/501100011033. Yingdong Zhou acknowledges the support from China Scholarship Council (CSC No. 202006240156). Javier Remón and Jesús Gracia are grateful to the Spanish Ministry of Science, Innovation and Universities for their JdC (IJC2018-037110-I) and FPI (PRE2018-085182) fellowships.Peer reviewe
Tun hu: (du mu ju ji).
No full text復工之前 -- 母女們 -- 囤戶.吳天著.Drama.Wu Tian zhu.Fu gong zhi qian -- Mu nü men -- Tun hu
Superluminal and Instantaneous Physics
No full textThis book is a selection from the papers of the First International Conference on Superluminal Physics as New Fields of Research held at the University of New Mexico, Gallup Campus, USA, in July 2012. The editor have selected seven papers proposed by the following authors and co co-authors Kaizhe Guo Guo, Chongwu Guo Guo, Chen Jianguojianguo, Dong Jingfeng Jingfeng, Mi Haijiang Haijiang, Changwei Hu Hu, Yang Shijiashijia, Guli, and Fu Yuhua Yuhua
Flow dynamics on a U shaped channel flow: a numerical study
No full textThe paper deals with the numerical simulation of river channel flows at laboratory scale. The adopted geometry
consists of a U shaped trapezoidal smooth open channel with fixed slope. The branches, 3m of length each, are linked with a joint, 0.40m long, realizing two 90 degrees bends. The system is fed upstream with a water discharge under critical conditions while a Cipolletti weir is set downstream to control flow profiles.
Steady flow movements are obtained by means of two different softwares: a pure Lagrangian developed by the author, based on the Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) technique and Flow3D®, a commercial CFD software based on a Finite Volume formulation of the Navier Stokes equations in the Eulerian framework. Depending on the assumed boundary conditions, velocity profiles and water interfaces at certain cross sections are deducted by using the codes. Results are discussed and compared, showing a satisfactory agreement
HU Protein Induces Incoherent DNA Persistence Length
No full textHU is a highly conserved protein that is believed to play an important role in the architecture and dynamic compaction of bacterial DNA. Its ability to control DNA bending is crucial for functions such as transcription and replication. The effects of HU on the DNA structure have been studied so far mainly by single molecule methods that require us to apply stretching forces on the DNA and therefore may perturb the DNA-protein interaction. To overcome this hurdle, we study the effect of HU on the DNA structure without applying external forces by using an improved tethered particle motion method. By combining the results with DNA curvature analysis from atomic force microscopy measurements we find that the DNA consists of two different curvature distributions and the measured persistence length is determined by their interplay. As a result, the effective persistence length adopts a bimodal property that depends primarily on the HU concentration. The results can be explained according to a recently suggested model that distinguishes single protein binding from cooperative protein binding.Imaging Science and TechnologyApplied Science
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