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Flow Regimes in Bubble Columns with and without Internals: A Review 被引量:1
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作者 Ayat N.Mahmood Amer A.Abdulrahman +3 位作者 Laith S.Sabri Abbas J.Sultan Hasan Shakir Majdi Muthanna H.Al-Dahhan 《Fluid Dynamics & Materials Processing》 EI 2024年第2期239-256,共18页
Hydrodynamics characterization in terms offlow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related methodologies.This review presents recent studies on the typicalflo... Hydrodynamics characterization in terms offlow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related methodologies.This review presents recent studies on the typicalflow regimes established in bubble columns.Some effort is also provided to introduce relevant definitions pertaining to thisfield,namely,that of“void fraction”and related(local,chordal,cross-sectional and volumetric)variants.Experimental studies involving different parameters that affect design and operating conditions are also discussed in detail.In the second part of the review,the attention is shifted to cases with internals of various types(perfo-rated plates,baffles,vibrating helical springs,mixers,and heat exchanger tubes)immersed in the bubble columns.It is shown that the presence of these elements has a limited influence on the global column hydrodynamics.However,they can make the homogeneousflow regime more stable in terms of transition gas velocity and transi-tion holdup value.The last section is used to highlight gaps which have not beenfilled yet and future directions of investigation. 展开更多
关键词 HYDRODYNAMICS flow regime bubble column heat-exchanging internals
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Enhancing lead-free photovoltaic performance:Minimizing buried surface voids in tin perovskite films through weakly polar solvent pre-treatment strategy
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作者 Dongdong Yan Han Zhang +7 位作者 Chensi Gong Hailong Wang Qing Lu Jun Liu Wenzhen Lv Mingguang Li Runfeng Chen Ligang Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第11期556-561,共6页
Buried interfacial voids have always been a notorious phenomenon observed in the fabrication of lead perovskite films. The existence of interfacial voids at the buried interface will capture the carrier, suppress carr... Buried interfacial voids have always been a notorious phenomenon observed in the fabrication of lead perovskite films. The existence of interfacial voids at the buried interface will capture the carrier, suppress carrier transport efficiencies, and affect the stability of photovoltaic devices. However, the impact of these buried interfacial voids on tin perovskites, a promising avenue for advancing lead-free photovoltaics, has been largely overlooked. Here, we utilize an innovative weakly polar solvent pretreatment strategy(WPSPS) to mitigate buried interfacial voids of tin perovskites. Our investigation reveals the presence of numerous voids in tin perovskites during annealing, attributed to trapped dimethyl sulfoxide(DMSO) used in film formation. The WPSPS method facilitates accelerated DMSO evaporation, effectively reducing residual DMSO. Interestingly, the WPSPS shifts the energy level of PEDOT:PSS downward, making it more aligned with the perovskite. This alignment enhances the efficiency of charge carrier transport. As the result, tin perovskite film quality is significantly improved,achieving a maximum power conversion efficiency approaching 12% with only an 8.3% efficiency loss after 1700 h of stability tests, which compares well with the state-of-the-art stability of tin-based perovskite solar cells. 展开更多
关键词 Tin perovskite Buried interfacial Weakly polar solvent pre-treatment strategy
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THE GLOBAL EXISTENCE AND UNIQUENESS OF SMOOTH SOLUTIONS TO A FLUID-PARTICLE INTERACTION MODEL IN THE FLOWING REGIME
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作者 Lin ZHENG Shu WANG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第5期1877-1885,共9页
This paper is concerned with the Cauchy problem for a 3D fluid-particle interaction model in the so-called flowing regime inℝ3.Under the smallness assumption on both the external potential and the initial perturbation... This paper is concerned with the Cauchy problem for a 3D fluid-particle interaction model in the so-called flowing regime inℝ3.Under the smallness assumption on both the external potential and the initial perturbation of the stationary solution in some Sobolev spaces,the existence and uniqueness of global smooth solutions in H3 of the system are established by using the careful energy method. 展开更多
关键词 fluid-particle flowing regime global existence
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Extending homogeneous fluidization flow regime of Geldart-A particles by exerting axial uniform and steady magnetic field
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作者 Qiang Zhang Wankun Liu +1 位作者 Hengjun Gai Quanhong Zhu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期169-177,共9页
The homogeneous/particulate fluidization flow regime is particularly suitable for handling the various gas–solid contact processes encountered in the chemical and energy industry.This work aimed to extend such a regi... The homogeneous/particulate fluidization flow regime is particularly suitable for handling the various gas–solid contact processes encountered in the chemical and energy industry.This work aimed to extend such a regime of Geldart-A particles by exerting the axial uniform and steady magnetic field.Under the action of the magnetic field,the overall homogeneous fluidization regime of Geldart-A magnetizable particles became composed of two parts:inherent homogeneous fluidization and newly-created magnetic stabilization.Since the former remained almost unchanged whereas the latter became broader as the magnetic field intensity increased,the overall homogeneous fluidization regime could be extended remarkably.As for Geldart-A nonmagnetizable particles,certain amount of magnetizable particles had to be premixed to transmit the magnetic stabilization.Among others,the mere addition of magnetizable particles could broaden the homogeneous fluidization regime.The added content of magnetizable particles had an optimal value with smaller/lighter ones working better.The added magnetizable particles might raise the ratio between the interparticle force and the particle gravity.After the magnetic field was exerted,the homogeneous fluidization regime was further expanded due to the formation of magnetic stabilization flow regime.The more the added magnetizable particles,the better the magnetic performance and the broader the overall homogeneous fluidization regime.Smaller/lighter magnetizable particles were preferred to maximize the magnetic performance and extend the overall homogeneous fluidization regime.This phenomenon could be ascribed to that the added magnetizable particles themselves became more Geldart-A than-B type as their density or size decreased. 展开更多
关键词 FLUIDIZED-BED FLUIDIZATION Geldart-A particles Flow regimes EXTEND Magnetic stabilization
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Some Indicators of the Water Regime in Some Varieties Belonging to the Monarda didyma L. Genus in the Conditions of Tashkent (Uzbekistan)
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作者 Mamadalieva Vakhobjon Kizi Madina Rakhimova Tashkhanim 《American Journal of Plant Sciences》 CAS 2024年第5期374-386,共13页
In this article, the names of 3 varieties of Monarda didyma L., which are considered to be introduced species, some indicators of the water regime in the climatic conditions of Uzbekistan: the amount of water in the l... In this article, the names of 3 varieties of Monarda didyma L., which are considered to be introduced species, some indicators of the water regime in the climatic conditions of Uzbekistan: the amount of water in the leaves, water deficit, water storage capacity were studied in spring and summer, and seasonal changes were determined. According to these indicators of the water regime, the studied varieties belong to the labile water regime, high green mass (centner), seed yield (how many grams), resistance to diseases and pests have been determined, which shows that it is promising for introduction in the conditions of our republic. Therefore, it is recommended to breed these varieties in the foothills and hilly regions of Uzbekistan, where the amount of precipitation is more than 400 - 500 mm. 展开更多
关键词 Uzbekistan Tashkent Monarda didyma Bergama Jar-Ptitsa Cambridge Scarlet Water regime Water Quantity Water Shortage Water Storage Capacity Labile
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Effects of thrombopoietin pre-treatment on peri-liver transplantation thrombocytopenia in a mouse model of cirrhosis with hypersplenism 被引量:2
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作者 Zi-Rong Liu Ya-Min Zhang +1 位作者 Zi-Lin Cui Wen Tong 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第10期2115-2122,共8页
BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resu... BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resulting in hypersplenism and excessive removal of platelets in the spleen,further reducing platelet count.When liver function is decompensated in cirrhotic patients,the decrease of thrombopoietin(TPO)synthesis is the main reason for the decrease of new platelet production.This change of TPO leads to thrombocytopenia and bleeding tendency in cirrhotic patients with hypersplenism.AIM To investigate the clinical efficacy of recombinant human TPO(rhTPO)in the treatment of perioperative thrombocytopenia during liver transplantation in cirrhotic mice with hypersplenism.METHODS C57BL/6J mice and TPO receptor-deficient mice were used to establish models of cirrhosis with hypersplenism.Subsequently,these mice underwent orthotopic liver transplantation(OLT).The mice in the experimental group were given rhTPO treatment for 3 consecutive days before surgery and 5 consecutive days after surgery,while the mice in the control group received the same dose of saline at the same frequency.Differences in liver function and platelet counts were determined between the experimental and control groups.Enzyme-linked immunosorbent assay was used to assess the expression of TPO and TPO receptor(c-Mpl)in the blood.RESULTS Preoperative administration of rhTPO significantly improved peri-OLT thrombocytopenia in mice with cirrhosis and hypersplenism.Blocking the expression of TPO receptors exacerbated peri-OLT thrombocytopenia.The concentration of TPO decreased while the concentration of c-Mpl increased in compensation in the mouse model of cirrhosis with hypersplenism.TPO pre-treatment significantly increased the postoperative TPO concentration in mice,which in turn led to a decrease in the c-Mpl concentration.TPO pre-treatment also significantly enhanced the Janus kinase(Jak)/signal transducers and activators of transcription pathway protein expressions in bone marrow stem cells of the C57BL/6J mice.Moreover,the administration of TPO,both before and after surgery,regulated the levels of biochemical indicators,such as alanine aminotransferase,alkaline phosphatase,and aspartate aminotransferase in the C57BL/6J mice.CONCLUSION Pre-treatment with TPO not only exhibited therapeutic effects on perioperative thrombocytopenia in the mice with cirrhosis and hypersplenism,who underwent liver transplantation but also significantly enhanced the perioperative liver function. 展开更多
关键词 Thrombopoietin pre-treatment CIRRHOSIS Liver transplantation Perioperative period PLATELET
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Wind regime features and their impacts on the middle reaches of the Yarlung Zangbo River on the Tibetan Plateau, China 被引量:1
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作者 ZHANG Yan ZHANG Zhengcai +5 位作者 MA Pengfei PAN Kaijia ZHA Duo CHEN Dingmei SHEN Caisheng LIANG Aimin 《Journal of Arid Land》 SCIE CSCD 2023年第10期1174-1195,共22页
The wide valley of the Yarlung Zangbo River is one of the most intense areas in terms of aeolian activity on the Tibetan Plateau,China.In the past,the evaluation of the intensity of aeolian activity in the Quxu–Sangr... The wide valley of the Yarlung Zangbo River is one of the most intense areas in terms of aeolian activity on the Tibetan Plateau,China.In the past,the evaluation of the intensity of aeolian activity in the Quxu–Sangri section of the Yarlung Zangbo River Valley was mainly based on data from the old meteorological stations,especially in non-sandy areas.In 2020,six new meteorological stations,which are closest to the new meteorological stations,were built in the wind erosion source regions(i.e.,sandy areas)in the Quxu–Sangri section.In this study,based on mathematical statistics and empirical orthogonal function(EOF)decomposition analysis,we compared the difference of the wind regime between new meteorological stations and old meteorological stations from December 2020 to November 2021,and discussed the reasons for the discrepancy.The results showed that sandy and non-sandy areas differed significantly regarding the mean velocity(8.3(±0.3)versus 7.7(±0.3)m/s,respectively),frequency(12.9%(±6.2%)versus 2.9%(±1.9%),respectively),and dominant direction(nearly east or west versus nearly north or south,respectively)of sand-driving winds,drift potential(168.1(±77.3)versus 24.0(±17.9)VU(where VU is the vector unit),respectively),resultant drift potential(92.3(±78.5)versus 8.7(±9.2)VU,respectively),and resultant drift direction(nearly westward or eastward versus nearly southward or northward,respectively).This indicated an obvious spatial variation in the wind regime between sandy and non-sandy areas and suggested that there exist problems when using wind velocity data from non-sandy areas to evaluate the wind regime in sandy areas.The wind regime between sandy and non-sandy areas differed due to the differences in topography,heat flows,and their coupling with underlying surface,thereby affecting the local atmospheric circulation.Affected by large-scale circulations(westerly jet and Indian monsoon systems),both sandy and non-sandy areas showed similar seasonal variations in their respective wind regime.These findings provide a credible reference for re-understanding the wind regime and scientific wind-sand control in the middle reaches of the Yarlung Zangbo River Valley. 展开更多
关键词 wind regime aeolian activity sand-driving winds drift potential atmospheric circulation Yarlung Zangbo River Tibetan Plateau
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Flow characteristics and regime transition of aqueous foams in porous media over a wide range of quality,velocity,and surfactant concentration 被引量:1
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作者 Bin-Fei Li Meng-Yuan Zhang +3 位作者 Zhao-Min Li Anthony Kovscek Yan Xin Bo-Liang Li 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期1044-1052,共9页
Aqueous foam is broadly applicable to enhanced oil recovery(EOR).The rheology of foam as a function of foam quality,gas and liquid velocities,and surfactant concentration constitute the foundation of its application.T... Aqueous foam is broadly applicable to enhanced oil recovery(EOR).The rheology of foam as a function of foam quality,gas and liquid velocities,and surfactant concentration constitute the foundation of its application.The great variations of the above factors can affect the effectiveness of N2 foam in EOR continuously in complex formations,which is rarely involved in previous relevant studies.This paper presents an experimental study of foam flow in porous media by injecting pre-generated N2 foam into a sand pack under the conditions of considering a wide range of gas and liquid velocities and surfactant concentrations.The results show that in a wide range of gas and liquid velocities,the pressure gradient contours are L-shaped near the coordinate axes,but V-shaped in other regions.And the surfactant concentration is a strong factor influencing the trend of pressure gradient contours.Foam flow resistance is very sensitive to the surfactant concentration in both the high-and low-foam quality regime,especially when the surfactant concentration is less than CMC.The foam quality is an important variable to the flow resistance obtained.There exists a transition point from low-to high-quality regime in a particular flow system,where has the maximum flow resistance,the corresponding foam quality is called transition foam quality,which increases as the surfactant concentration increases.The results can add to our knowledge base of foam rheology in porous media,and can provide a strong basis for the field application of foams. 展开更多
关键词 Foam flow regime and transition Porous media Pressure gradient Flow velocity Surfactant concentration Foam quality
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Controlled transition to different proton acceleration regimes:Near-critical-density plasmas driven by circularly polarized few-cycle pulses
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作者 Shivani Choudhary De Marco Sudipta Mondal +1 位作者 Daniele Margarone Subhendu Kahaly 《Matter and Radiation at Extremes》 SCIE EI CSCD 2023年第5期1-18,共18页
A controlled transition between two different ion acceleration mechanisms would pave the way to achieving different ion energies and spectral features within the same experimental set up,depending on the region of ope... A controlled transition between two different ion acceleration mechanisms would pave the way to achieving different ion energies and spectral features within the same experimental set up,depending on the region of operation.Based on numerical simulations conducted over a wide range of experimentally achievable parameter space,reported here is a comprehensive investigation of the different facets of ion acceleration by relativistically intense circularly polarized laser pulses interacting with thin near-critical-density plasma targets.The results show that the plasma thickness,exponential density gradient,and laser frequency chirp can be controlled to switch the interaction from the transparent operating regime to the opaque one,thereby enabling the choice of a Maxwellian-like ion energy distribution with a cutoff energy in the relativistically transparent regime or a quasi-monoenergetic spectrum in the opaque regime.Next,it is established that a multispecies target configuration can be used effectively for optimal generation of quasi-monoenergetic ion bunches of a desired species.Finally,the feasibility is demonstrated for generating monoenergetic proton beams with energy peak atℰ≈20–40 MeV and a narrow energy spread ofΔℰ/ℰ≈18%–28.6%confined within a divergence angle of∼175 mrad at a reasonable laser peak intensity of I0≃5.4×10^(20)W/cm^(2). 展开更多
关键词 ACCELERATION regime CIRCULAR
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Lake regime shift from submerged macrophyte to phytoplankton affected phosphorus speciation in sediment and eutrophic state in Caohai Lake,Guizhou,China
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作者 Jixing DONG Yanmin GUO +5 位作者 Pinhua XIA Yuanbin TIAN Feifei ZHENG Anyan LI Tao LIN Ruiwen LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第6期2262-2275,共14页
To understand the effect of regime shift in Caohai Lake in Yunnan-Guizhou Plateau,SW China from submerged macrophyte dominance to phytoplankton dominance on the specification and distribution of phosphorus and on ecol... To understand the effect of regime shift in Caohai Lake in Yunnan-Guizhou Plateau,SW China from submerged macrophyte dominance to phytoplankton dominance on the specification and distribution of phosphorus and on ecological and environmental states,changes in phosphorus specification in the sediments and water were studied.The form,composition,and distribution of phosphorus in sediment were sampled in July 2020(before regime shift)and July 2021(after regime shift)were analyzed.Results reveal that phosphorus content in sediment was lower than that those of Erhai Lake and Dianchi Lake,Yunnan,SW China,on the same plateau,and was lower than those of Taihu Lake,Chaohu Lake,and Poyang Lake in the middle-lower Changjiang(Yangtze)River Plain.Organic phosphorus(Or-P)was the main form(up to 60%),followed by inactive phosphorus(Ina-P),and the active phosphorus(Act-P),the least,which is opposite to those of Taihu Lake and Poyang Lake in the middle-lower Changjiang River Plain in the eastern China.Or-P content was high,indicating a high potential risk of phosphorous release.After the regime shift,the total phosphorus in sediment decreased from 0.87±0.13 to 0.70±0.13 g/kg.The proportion of Or-P and Act-P decreased from 68.23% to 65.32% and from 5.35% to 4.69%,respectively.In contrast,the proportion of Ina-P increased from 26.42% to 29.99%.The Moran’s I index revealed that the heterogeneity of the spatial distributions of the total phosphorus(S-TP)and Act-P in the sediments before regime shift was significant(P<0.1).However,the heterogeneity of the spatial distributions of S-TP and the various forms of phosphorus after regime shift was not significant(P>0.05).The regime shift aggravated the eutrophication of the lake,the trophic level index(TLI)increased from 48.42 to 54.49(P<0.01),and the previously mesotrophic lake became a mildly eutrophic lake.The results of this study revealed the impact of regime shift in the lake from submerged macrophyte dominance to phytoplankton dominance on the composition and spatial distribution of phosphorus in sediments and provided a basis for the restoration of eutrophicated and aquatic ecosystem degraded lakes. 展开更多
关键词 Caohai Lake SEDIMENT phosphorus specification regime shift
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Predicting and delineating soil temperature regimes of China using pedotransfer function
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作者 BAO Wan-kui LEI Qiu-liang +4 位作者 JIANG Zhuo-dong SUN Fu-jun ZHANG Tian-peng HU Ning WANG Qiu-bing 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第9期2882-2892,共11页
Soil temperature regime(STR)is important for soil classification and land use.Generally,STR is delineated by estimating the mean annual soil temperature at a depth of 50 cm(MAST50)according to the Chinese Soil Taxonom... Soil temperature regime(STR)is important for soil classification and land use.Generally,STR is delineated by estimating the mean annual soil temperature at a depth of 50 cm(MAST50)according to the Chinese Soil Taxonomy(CST).However,delineating the STR of China remains a challenge due to the difficulties in accurately estimating MAST50.The objectives of this study were to explore environmental factors that influence the spatial variation of MAST50 and generate an STR map for China.Soil temperature measurements at 40 and 80 cm depth were collected from 386 National Meteorological Stations in China during 1971–2000.The MAST50 was calculated as the average mean annual soil temperature(MAST)from 1971–2000 between 40 and 80 cm depths.In addition,2048 mean annual air temperature(MAAT)measurements from 1971 to 2000 were collected from the National Meteorological Stations across China.A zonal pedotransfer function(PTF)was developed based on the ensemble linear regression kriging model to predict the MAST50 in three topographic steps of China.The results showed that MAAT was the most important variable related to the variation of MAST50.The zonal PTF was evaluated with a 10%validation dataset with a mean absolute error(MAE)of 0.66°C and root mean square error(RMSE)of 0.78°C,which were smaller than the unified model with MAE of 0.83°C and RMSE of 0.96°C,respectively.This study demonstrated that the zonal PTF helped improve the accuracy of the predicted MAST50 map.Based on the prediction results,an STR map across China was generated to provide a consistent scientific base for the improvement and application of CST and land use support. 展开更多
关键词 soil temperature soil temperature regimes Soil Taxonomy pedotransfer function
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Gas liquid cylindrical cyclone flow regime identification using machine learning combined with experimental mechanism explanation
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作者 Zhao-Ming Yang Yu-Xuan He +6 位作者 Qi Xiang Enrico Zio Li-Min He Xiao-Ming Luo Huai Su Ji Wang Jin-Jun Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第1期540-558,共19页
The flow regimes of GLCC with horizon inlet and a vertical pipe are investigated in experiments,and the velocities and pressure drops data labeled by the corresponding flow regimes are collected.Combined with the flow... The flow regimes of GLCC with horizon inlet and a vertical pipe are investigated in experiments,and the velocities and pressure drops data labeled by the corresponding flow regimes are collected.Combined with the flow regimes data of other GLCC positions from other literatures in existence,the gas and liquid superficial velocities and pressure drops are used as the input of the machine learning algorithms respectively which are applied to identify the flow regimes.The choosing of input data types takes the availability of data for practical industry fields into consideration,and the twelve machine learning algorithms are chosen from the classical and popular algorithms in the area of classification,including the typical ensemble models,SVM,KNN,Bayesian Model and MLP.The results of flow regimes identification show that gas and liquid superficial velocities are the ideal type of input data for the flow regimes identification by machine learning.Most of the ensemble models can identify the flow regimes of GLCC by gas and liquid velocities with the accuracy of 0.99 and more.For the pressure drops as the input of each algorithm,it is not the suitable as gas and liquid velocities,and only XGBoost and Bagging Tree can identify the GLCC flow regimes accurately.The success and confusion of each algorithm are analyzed and explained based on the experimental phenomena of flow regimes evolution processes,the flow regimes map,and the principles of algorithms.The applicability and feasibility of each algorithm according to different types of data for GLCC flow regimes identification are proposed. 展开更多
关键词 Gas liquid cylindrical cyclone Machine learning Flow regimes identification Mechanism explanation ALGORITHMS
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Influence Mechanism of Curing Regimes on Interfacial Transition Zone of Lightweight Ultra-High Performance Concrete
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作者 李洋 张高展 +3 位作者 YANG Jun ZHANG Jian DING Qingjun ZHAO Mingyu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第3期591-603,共13页
This study aims to clarify the effects of curing regimes and lightweight aggregate(LWA)on the morphology, width and mechanical properties of the interfacial transition zone(ITZ) of ultra-high performance concrete(UHPC... This study aims to clarify the effects of curing regimes and lightweight aggregate(LWA)on the morphology, width and mechanical properties of the interfacial transition zone(ITZ) of ultra-high performance concrete(UHPC), and provide reference for the selection of lightweight ultra-high performance concrete(L-UHPC) curing regimes and the pre-wetting degree LWA. The results show that, under the three curing regimes(standard curing, steam curing and autoclaved curing), LWA is tightly bound to the matrix without obvious boundaries. ITZ width increases with the water absorption of LWA and decreases with increasing curing temperature. The ITZ microhardness is the highest when water absorption is 3%, and the microhardness value is more stable with the distance from LWA. Steam and autoclaved curing increase ITZ microhardness compared to standard curing. As LWA pre-wetting and curing temperatures increase, the degree of hydration at the ITZ increases, generating high-density CSH(HD CSH) and ultra-high-density CSH(UHD CSH), and reducing unhydrated particles in ITZ. ITZ micro-mechanical properties are optimized due to hydration products being denser. 展开更多
关键词 curing regime ultra-high performance concrete lightweight aggregate interfacial transition zone meso-mechanical properties micro-mechanical properties
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Anthropogenic activity,hydrological regime,and light level jointly influence temporal patterns in biosonar activity of the Yangtze finless porpoise at the junction of the Yangtze River and Poyang Lake,China
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作者 Peng-Xiang Duan Zhi-Tao Wang +4 位作者 Tomonari Akamatsu Nick Tregenza Guang-Yu Li Ke-Xiong Wang Ding Wang 《Zoological Research》 SCIE CSCD 2023年第5期919-931,共13页
Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neopho... Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis),once commonly observed in the Yangtze River-Poyang Lake junction,is now rarely seen in the river-lake corridor.In this study,static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor.Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation,as well as environmental variables,including hydrological conditions and light levels.Over approximately three consecutive years of monitoring(2020–2022),porpoise biosonar was detected during 93%of logged days,indicating the key role of the corridor for finless porpoise conservation.In addition,porpoise clicks were recorded in 3.80%of minutes,while feeding correlated buzzes were detected in 1.23%of minutes,suggesting the potential existence of localized,small-scale migration.Furthermore,both anthropogenic and environmental variables were significantly correlated with the diel,lunar,monthly,seasonal,and annual variations in porpoise biosonar activities.During the pandemic lockdown period,porpoise sonar detection showed a significant increase.Furthermore,a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity.In addition to water level and flux,daylight and moonlight exhibited significant correlations with porpoise biosonar activities,with markedly higher detections at night and quarter moon periods.Ensuring the spatiotemporal reduction of anthropogenic activities,implementing vessel speed restrictions(e.g.,during porpoise migration and feeding),and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability. 展开更多
关键词 Yangtze finless porpoises Yangtze River Poyang Lake Pandemic lockdown Boat traffic Hydrological regime Light level
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Which return regime induces overconfidence behavior?Artificial intelligence and a nonlinear approach
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作者 Esra Alp Coşkun Hakan Kahyaoglu Chi Keung Marco Lau 《Financial Innovation》 2023年第1期1135-1168,共34页
Overconfidence behavior,one form of positive illusion,has drawn considerable attention throughout history because it is viewed as the main reason for many crises.Investors’overconfidence,which can be observed as over... Overconfidence behavior,one form of positive illusion,has drawn considerable attention throughout history because it is viewed as the main reason for many crises.Investors’overconfidence,which can be observed as overtrading following positive returns,may lead to inefficiencies in stock markets.To the best of our knowledge,this is the first study to examine the presence of investor overconfidence by employing an artificial intelligence technique and a nonlinear approach to impulse responses to analyze the impact of different return regimes on the overconfidence attitude.We examine whether investors in an emerging stock market(Borsa Istanbul)exhibit overconfidence behavior using a feed-forward,neural network,nonlinear Granger causality test and nonlinear impulseresponse functions based on local projections.These are the first applications in the relevant literature due to the novelty of these models in forecasting high-dimensional,multivariate time series.The results obtained from distinguishing between the different market regimes to analyze the responses of trading volume to return shocks contradict those in the literature,which is the key contribution of the study.The empirical findings imply that overconfidence behavior exhibits asymmetries in different return regimes and is persistent during the 20-day forecasting horizon.Overconfidence is more persistent in the low-than in the high-return regime.In the negative interest-rate period,a high-return regime induces overconfidence behavior,whereas in the positive interest-rate period,a low-return regime induces overconfidence behavior.Based on the empirical findings,investors should be aware that portfolio gains may result in losses depending on aggressive and excessive trading strategies,particularly in low-return regimes. 展开更多
关键词 OVERCONFIDENCE Nonlinear Granger causality Artificial intelligence Feedforward neural networks Nonlinear impulse-response functions Local projections Return regime
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Globalization Under the Spells of Breakdowns in Supply Chains, Regime Change, Regime Formation, and Alliance Restructuring: How Much Is Left for Public Goods?
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作者 Ekkart Zimmermann 《International Relations and Diplomacy》 2023年第5期211-216,共6页
In a paper conceived about five years ago(“Globalization and Public Goods:Too Big to Tackle?”)roughly a dozen factors were linked to explain important causal paths from globalization to the potential output of publi... In a paper conceived about five years ago(“Globalization and Public Goods:Too Big to Tackle?”)roughly a dozen factors were linked to explain important causal paths from globalization to the potential output of public goods.The Russian invasion of Ukraine,the corona epidemic,and the increased hegemonic rivalry between China and the U.S.interrupted or even destroyed many of the linkages between globalization and potential public good production.About five important detrimental paths involved in the meantime.In the present article we aim at linking what is left from the previous level of globalization or emerging to form a new and simplified causal model for likely linkages between truncated or(re-)emerging globalization,and the deadly needed output of public goods.These linkages refer to rules of climate control,go to trade linkages and arbitrary tariffs and trade interventions.Regime change,regime formation,and alliance restructuring address aspects of domestic rule and international stability.Selectorate theory,regime type,and exit options for political elites provide key explanatory factors in explaining globalization and public goods productions,or their decay.Where possible we use some data and transformation experiences corroborating our arguments.In other instances need for further empirical macro research will become clear. 展开更多
关键词 hegemonic rivalry new alliances and bloc formation de-globalization and re-globalization selectorate theory regime type and regime change elite exit options public goods
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For a Green Future Why Africa should get a fair climate change funding regime without a debt trap
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作者 MAHASHA RAMPEDI 《ChinAfrica》 2023年第11期36-37,共2页
In the summer of 2022,subtropical storm Issa pounded parts of the KwaZulu-Natal Province in South Africa,claiming 459 lives.It displaced more than 40,000 people and caused 36 billion rand($1.92 billion)worth of infras... In the summer of 2022,subtropical storm Issa pounded parts of the KwaZulu-Natal Province in South Africa,claiming 459 lives.It displaced more than 40,000 people and caused 36 billion rand($1.92 billion)worth of infrastructure damage.Issa-related floods and landslides swept away bridges and more than 4,000 homes,mainly in the coastal city of Durban and the surrounding areas.Researchers from Wits University in Johannesburg and the University of Brighton in the UK called the floods the“most catastrophic natural disaster”ever recorded in KwaZulu-Natal.They also attributed them to global warming. 展开更多
关键词 floods DISASTER regime
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Cyclic feeding regime may delay aging in animals by enhancing the hepatocytes nuclei structure
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作者 Ceasar Dubor Danladi Anatoli Bozhkov Ivanovich Nedime Serakinci 《Aging Communications》 2023年第1期29-34,共6页
Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear... Background:The liver is fundamental for keeping up the entire body’s homeostasis.The liver hepatocytes have been shown to undergo genomic instability with aging.The stability of the hepatocytes depends on its nuclear architecture.Calorie restriction has been shown to extend life-span favorably and this may be through the reorganization of the nuclear structure.Objective:To study the effect of cyclic feeding regime on the chromatin assembly anchored to the nuclear membrane scaffold of rat models hepatocytes nuclei.Method:Rats models underwent cyclic feeding regime,after which nuclei were isolated;then,we investigated the chromatin decondensation and nuclear membrane disintegration of the hepatocytes using fluorescence imaging methods.Results:In 60 seconds,protease decondensed the chromatin and disintegrated the nuclear membrane structure of controls.After the first fasting,the time increased to 145 seconds in 3-month-old rats.The first refeeding increased the time to 156 seconds with a further rise to 340 seconds following the second fasting,then dropped to 116 seconds by the second refeeding.20 months old rats showed 186 seconds increase in the time of chromatin decondensation and nuclear membrane disintegration after the first fasting,with a decrease to 140 seconds observed after first refeeding.The second fasting increased the time to 165 seconds,which then slightly decreased to 163 seconds after the second refeeding.Conclusion:These results show that intermittent fasting may have acted on chromatin histone interactions and the structural lamin networks of the nuclear membranes in bringing about nuclear stability,which is essential for normal cellular function. 展开更多
关键词 AGING hepatocytes nuclei cyclic feeding regime nuclear stability
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Soil Carbon Pool Management Index under Different Straw Retention Regimes 被引量:5
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作者 曾研华 吴建富 +4 位作者 何虎 潘晓华 石庆华 吴自明 邓伟明 《Agricultural Science & Technology》 CAS 2012年第4期818-822,共5页
[Objective] To clarify the effects of different straw retention regimes on soil fertility in double cropping paddy field. [Method] The effects of different straw reten- tion regimes on total organic carbon (CToc), a... [Objective] To clarify the effects of different straw retention regimes on soil fertility in double cropping paddy field. [Method] The effects of different straw reten- tion regimes on total organic carbon (CToc), active carbon (CA) and mineralized carbon (CM) were analyzed, and carbon pool active (A), carbon pool active index (A/), carbon pool index (CPI) and carbon pool management index (CPMi) for each treat- ment were calculated. [Result] Compared with the unfertilized treatment (CK), CToc, CA, CM and the available ratio of soil carbon were increased in the treatment of re- turning early season and late season rice straws to field. With the same nutrient application, CToc, CA and the available ratio of soil carbon in the field with straw re- turned to field were higher than that of straw incineration and no straw returning, and the change in soil CA content was more significant. The difference in CPMI be- tween different treatments reached significant or very significant level, and the value was in the order of straw directly returned to field 〉 straw returned to field after in- cineration 〉 no straw returned to field. [Conclusion] This study provided theoretical bases for the increase of soil CA content and soil fertility in double rice fields. 展开更多
关键词 Double-cropping paddy field Different straw retention regimes Total or- ganic carbon Active carbon Mineralized carbon Carbon pool management index
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聚合物熔体结晶的方式(Regime)理论 被引量:6
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作者 余坚 何嘉松 《高分子通报》 CAS CSCD 2001年第1期25-33,共9页
综述了基于链折叠概念的聚合物熔体结晶的方式理论 ,详述了结晶的三个方式并列举了文献提到的存在方式转变的体系 ,并对理论参数的获得和方式转变与形态变化的关系进行了讨论。
关键词 链折叠 聚合物 熔体结晶 方式 增长速度 温度
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