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Influence and mechanism of xanthan gum on the aggregation and flotation behavior of talc,olivine,and serpentine
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作者 YANG Xu-sheng FENG Bo +1 位作者 WANG Zi-ming JIANG Long-xia 《Journal of Central South University》 2025年第7期2463-2475,共13页
Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xantha... Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xanthan gum(XG)as a non-toxic and environmentally friendly depressant of talc,olivine,and serpentine.The effects and mechanisms of XG on the aggregation and flotation behavior of talc,olivine and serpentine were investigated by flotation tests,sedimentation tests,IC-FBRM particle size analysis tests,adsorption quantity tests,Fourier transform infrared spectroscopy(FTIR)tests,X-ray photoelectron spectroscopy(XPS)analysis tests and Zeta potential tests.The flotation results indicated that when the three minerals were mixed,XG caused the talc-serpentine aggregation in the solution to shift to olivine-serpentine aggregation,with the remaining XG adsorbing on talc to depress its flotation.In addition,combining XPS and zeta potential tests,the-OH(hydroxyl)groups in XG molecules preferentially adsorbed on Mg sites on the surface of olivine through chemical bonding.The surface potential of olivine significantly shifted to a more negative value,with the negative charge on the olivine surface far exceeding that on the talc surface.This resulted in an increased aggregation effect between positively charged serpentine and negatively charged olivine due to enhanced electrostatic forces. 展开更多
关键词 flotation reagents copper-nickel suifide magnesium silicate gangue minerals xanthan gum aggregation MECHANISMS potential
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Impact of radiation,melting,and chemical reaction on magnetohydrodynamics nanoparticle aggregation flow across parallel plates
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作者 Ram Prakash SHARMA J.K.MADHUKESH +3 位作者 Sunendra SHUKLA Amal ABDULRAHMAN B.C.PRASANNAKUMARA K.V.NAGARAJA 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第10期3715-3729,共15页
The heat transfer between two corresponding plates,disks,and concentric pipes has many applications,including water cleansing and lubrication.Furthermore,TiO_(2)-water-based nanofluids are used widely because it is us... The heat transfer between two corresponding plates,disks,and concentric pipes has many applications,including water cleansing and lubrication.Furthermore,TiO_(2)-water-based nanofluids are used widely because it is useful for operating and controlling the temperature,especially in photovoltaic technology and solar panels.Motivated by these applications,the current study is based on the nanoparticle aggregation effect on magnetohydrodynamics(MHD)flow via rotating parallel plates with the chemical reaction.To achieve maximum heat transportation,the Bruggeman model is used to adapt the Maxwell model.Also,melting and thermal radiation effects are considered in the modeling to discuss heat transport.The Runge-Kutta-Fehlberg 4th−5th order method is used to attain numerical solutions.The main focus of this study is to see the thermodynamic behavior considering several aspects of nanoparticle aggregation.The heat transfer rate between the parallel plates is enhanced by improving the thermophoresis,radiation,and Brownian motion parameters.The rise in Schmidt number and chemical reaction rate parameter decreases the concentration distribution.This study will be helpful in enhancing the thermal efficiency of photovoltaic technology in solar plates,water purifying,thermal management of electronic devices,designing effective cooling systems,and other sustainable technologies. 展开更多
关键词 nanoparticle aggregation thermal radiation parallel plates magnetic field chemical reaction
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Analyzing fatigue behaviors and predicting fatigue life of cement-stabilized permeable recycled aggregate material
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作者 YANG Tao XIAO Yuan-jie +6 位作者 LI Yun-bo WANG Xiao-ming HUA Wen-jun HE Qing-yu CHEN Yu-liang ZHOU Zhen MENG Fan-wei 《Journal of Central South University》 2025年第4期1481-1502,共22页
Permeable roads generally exhibit inferior mechanical properties and shorter service life than traditional dense-graded/impermeable roads.Furthermore,the incorporation of recycled aggregates in their construction may ... Permeable roads generally exhibit inferior mechanical properties and shorter service life than traditional dense-graded/impermeable roads.Furthermore,the incorporation of recycled aggregates in their construction may exacerbate these limitations.To address these issues,this study introduced a novel cement-stabilized permeable recycled aggregate material.A total of 162 beam specimens prepared with nine different levels of cement-aggregate ratio were tested to evaluate their permeability,bending load,and bending fatigue life.The experimental results indicate that increasing the content of recycled aggregates led to a reduction in both permeability and bending load.Additionally,the inclusion of recycled aggregates diminished the energy dissipation capacity of the specimens.These findings were used to establish a robust relationship between the initial damage in cement-stabilized permeable recycled aggregate material specimens and their fatigue life,and to propose a predictive model for their fatigue performance.Further,a method for assessing fatigue damage based on the evolution of fatigue-induced strain and energy dissipation was developed.The findings of this study provide valuable insights into the mechanical behavior and fatigue performance of cement-stabilized permeable recycled aggregate materials,offering guidance for the design of low-carbon-emission,permeable,and durable roadways incorporating recycled aggregates. 展开更多
关键词 cement-stabilized permeable recycle aggregate materials PERMEABILITY fatigue life prediction fatigue damage energy dissipation
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Aggregation operators on intuitionistic trapezoidal fuzzy number and its application to multi-criteria decision making problems 被引量:64
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作者 Wang Jianqiang Zhang Zhong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期321-326,共6页
Intuitionistic trapezoidal fuzzy numbers and their operational laws are defined. Based on these operational laws, some aggregation operators, including intuitionistic trapezoidal fuzzy weighted arithmetic averaging op... Intuitionistic trapezoidal fuzzy numbers and their operational laws are defined. Based on these operational laws, some aggregation operators, including intuitionistic trapezoidal fuzzy weighted arithmetic averaging operator and weighted geometric averaging operator are proposed. Expected values, score function, and accuracy function of intuitionitsic trapezoidal fuzzy numbers are defined. Based on these, a kind of intuitionistic trapezoidal fuzzy multi-criteria decision making method is proposed. By using these aggregation operators, criteria values are aggregated and integrated intuitionistic trapezoidal fuzzy numbers of alternatives are attained. By comparing score function and accuracy function values of integrated fuzzy numbers, a ranking of the whole alternative set can be attained. An example is given to show the feasibility and availability of the method. 展开更多
关键词 intuitionistic trapezoidal fuzzy numbers aggregation operators multi-criteria decision making
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Generalization of the linguistic aggregation operator and its application in decision making 被引量:3
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作者 Jose M. Merigo Anna M. Gil-Lafuente +1 位作者 Ligang Zhou Huayou Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第4期593-603,共11页
A generalization of the linguistic aggregation functions (or operators) is presented by using generalized and quasiarithmetic means. Firstly, the linguistic weighted generalized mean (LWGM) and the linguistic gene... A generalization of the linguistic aggregation functions (or operators) is presented by using generalized and quasiarithmetic means. Firstly, the linguistic weighted generalized mean (LWGM) and the linguistic generalized ordered weighted averaging (LGOWA) operator are introduced. These aggregation functions use linguistic information and generalized means in the weighted average (WA) and in the ordered weighted averaging (OWA) function. They are very useful for uncertain situations where the available information cannot be assessed with numerical values but it is possible to use linguistic assessments. These aggregation operators generalize a wide range of aggregation operators that use linguistic information such as the linguistic generalized mean (LGM), the linguistic OWA (LOWA) operator and the linguistic or- dered weighted quadratic averaging (LOWQA) operator. We also introduce a further generalization by using quasi-arithmetic means instead of generalized means obtaining the quasi-LWA and the quasi-LOWA operator. Finally, we develop an application of the new approach where we analyze a decision making problem regarding the selection of strategies. 展开更多
关键词 linguistic aggregation function linguistic orderedweighted averaging (OWA) operator generalized mean linguis-tic decision making strategic decision making uncertainty.
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A novel algorithm for SLAM in dynamic environments using landscape theory of aggregation 被引量:1
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作者 华承昊 窦丽华 +1 位作者 方浩 付浩 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第10期2587-2594,共8页
To tackle the problem of simultaneous localization and mapping(SLAM) in dynamic environments, a novel algorithm using landscape theory of aggregation is presented. By exploiting the coherent explanation how actors for... To tackle the problem of simultaneous localization and mapping(SLAM) in dynamic environments, a novel algorithm using landscape theory of aggregation is presented. By exploiting the coherent explanation how actors form alignments in a game provided by the landscape theory of aggregation, the algorithm is able to explicitly deal with the ever-changing relationship between the static objects and the moving objects without any prior models of the moving objects. The effectiveness of the method has been validated by experiments in two representative dynamic environments: the campus road and the urban road. 展开更多
关键词 mobile robot simultaneous localization and mapping(SLAM) dynamic environment landscape theory of aggregation iterative closest point
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Plasma pharmacological study on Da Huang Zhe Chong capsule on platelet aggregation of normal person 被引量:3
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作者 WANG Dong-sheng CHEN Fang-ping XIAO Chang-jiang HE Shi-lin FU Bin LI Xin CAO Xing-yu CHEN Yan XIE Qin-zhi 《Journal of Central South University of Technology》 2005年第z1期326-330,共5页
Objective To develop a plasma pharmacological method evaluates the effect of Da Huang Zhe Chong capsule on platelet aggregation and its mechanism, which is a representative Traditional Chinese Medicine Patent Prescrip... Objective To develop a plasma pharmacological method evaluates the effect of Da Huang Zhe Chong capsule on platelet aggregation and its mechanism, which is a representative Traditional Chinese Medicine Patent Prescription Promoting blood circulation by removing blood stasis. Methods Platelets specimens from healthy volunteers made serum and plasma with medicine, while platelet PRP were separated, which were divided into 8groups,i.e. auto-serum, allo-serum, serum with Da Huang Zhe Chong capsule , serum with aspirin, auto-plasma, plasma with Da Huang Zhe Chong capsule, plasma with aspirin, every group added to serum and plasma to hatch. After ADP and adrenalin were added into the specimens and hatched, the effects of specimens on platelet aggregation were observed. Results After ADP adrenalin were added, all the serum groups did not present platelet aggregation,while all the plasma group presented platelet aggregation. P1, P5, Pmax, t and TM have no significant difference (P>0. 05) between auto-plasma group and allo-plasma group induced by ADP and adrenalin. P1, P5, t and Pmax have significant differences (P<0. 01) and TM decreased significantly (P<0. 05) comparing plasma group with Da Huang Zhe Chong capsule and plasma group of aspirin to allo-plasma group. P1, t and Pmax have significant difference (P<0.05), and P5 and TM are simulate comparing plasma group with Da Huang Zhe Chong capsule to plasma group of aspirin. P1, P5, t and Pmax have significant differences (P<0. 01), P1, TM have also significant(P<0. 05), comparing plasma group of Da Huang Zhe Chong capsule with plasma of aspirin to allo-plasma group induced by adrenalin. P1 ,P5 and Pmax have significant differences (P<0.05), and t and Pmax are simulate comparing plasma group with Da Huang Zhe Chong capsule with plasma group of aspirin. Conclusion The serum pharmacological study is inappropriate to study platelet aggregation in vitro. The plasma pharmacological study is inappropriate to study platelet aggregation in vitro. The plasma pharmacological study could reflect the pharmacological effect produced in vivo. Da Huang Zhe Chong capsule has better anti artery thrombosis effect than aspirin, and it is an ideal medicine for anti artery thrombosis. 展开更多
关键词 DA HUANG Zhe CHONG CAPSULE PLASMA pharmacology platelet aggregation
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VLAN Aggregation结合DHCP技术在嵌入式系统中实现
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作者 马军华 杜新华 纪林 《电子测量技术》 2005年第2期61-62,共2页
VILAN aggregation技术在节省IPv4地址方面有着非常好的优越性,但是标准的VLAN aggregation技术由于需要将子网和IP地址绑定使得该技术受到限制。本文通过将VLAN aggregation和DHCP技术结合起来,使之在以太网接环境下得到应用,给出在嵌... VILAN aggregation技术在节省IPv4地址方面有着非常好的优越性,但是标准的VLAN aggregation技术由于需要将子网和IP地址绑定使得该技术受到限制。本文通过将VLAN aggregation和DHCP技术结合起来,使之在以太网接环境下得到应用,给出在嵌入式操作系统中的具体程序流程。该技术在一以太网接入设备中运行稳定效果良好。 展开更多
关键词 DHCP 嵌入式系统 嵌入式操作系统 IPV4地址 以太网接入 地址绑定 技术结合 稳定效果 接入设备 程序流程 子网
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Distributed Weighted Data Aggregation Algorithm in End-to-Edge Communication Networks Based on Multi-armed Bandit 被引量:1
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作者 Yifei ZOU Senmao QI +1 位作者 Cong'an XU Dongxiao YU 《计算机科学》 CSCD 北大核心 2023年第2期13-22,共10页
As a combination of edge computing and artificial intelligence,edge intelligence has become a promising technique and provided its users with a series of fast,precise,and customized services.In edge intelligence,when ... As a combination of edge computing and artificial intelligence,edge intelligence has become a promising technique and provided its users with a series of fast,precise,and customized services.In edge intelligence,when learning agents are deployed on the edge side,the data aggregation from the end side to the designated edge devices is an important research topic.Considering the various importance of end devices,this paper studies the weighted data aggregation problem in a single hop end-to-edge communication network.Firstly,to make sure all the end devices with various weights are fairly treated in data aggregation,a distributed end-to-edge cooperative scheme is proposed.Then,to handle the massive contention on the wireless channel caused by end devices,a multi-armed bandit(MAB)algorithm is designed to help the end devices find their most appropriate update rates.Diffe-rent from the traditional data aggregation works,combining the MAB enables our algorithm a higher efficiency in data aggregation.With a theoretical analysis,we show that the efficiency of our algorithm is asymptotically optimal.Comparative experiments with previous works are also conducted to show the strength of our algorithm. 展开更多
关键词 Weighted data aggregation End-to-edge communication Multi-armed bandit Edge intelligence
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Pythagorean probabilistic hesitant triangular fuzzy aggregation operators with applications in multiple attribute decision making 被引量:2
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作者 LIAO Fuping LI Wu +1 位作者 LIU Gang ZHOU Xiaoqiang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第2期422-438,共17页
As a generalization of fuzzy set,hesitant probabilistic fuzzy set and pythagorean triangular fuzzy set have their own unique advantages in describing decision information.As modern socioeconomic decision-making proble... As a generalization of fuzzy set,hesitant probabilistic fuzzy set and pythagorean triangular fuzzy set have their own unique advantages in describing decision information.As modern socioeconomic decision-making problems are becoming more and more complex,it also becomes more and more difficult to appropriately depict decision makers’cognitive information in decision-making process.In order to describe the decision information more comprehensively,we define a pythagorean probabilistic hesitant triangular fuzzy set(PPHTFS)by combining the pythagorean triangular fuzzy set and the probabilistic hesitant fuzzy set.Firstly,the basic operation and scoring function of the pythagorean probabilistic hesitant triangular fuzzy element(PPHTFE)are proposed,and the comparison rule of two PPHTFEs is given.Then,some pythagorean probabilistic hesitant triangular fuzzy aggregation operators are developed,and their properties are also studied.Finally,a multi-attribute decision-making(MADM)model is constructed based on the proposed operators under the pythagorean probabilistic hesitant triangular fuzzy information,and an illustration example is given to demonstrate the practicability and validity of the proposed decision-making method. 展开更多
关键词 pythagorean probabilistic hesitant triangular fuzzy set(PPHTFS) aggregation operator multi-attribute decisionmaking(MADM)
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Components of traditional Chinese medicine inhibit platelet aggregation by blocking ADP receptor subtypes P2Y1 and P2Y12
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作者 Xiao-liangWANG Yi-yingLI +2 位作者 Hong-yanYANG ShaofengXU LingWANG 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2015年第S1期28-29,共2页
Platelets aggregation and thrombosis formation are major reasons of cardiovascular and cerebral vascular diseases.To develop new generative,potent and safe agents for inhibiting platelet aggregation and preventing abo... Platelets aggregation and thrombosis formation are major reasons of cardiovascular and cerebral vascular diseases.To develop new generative,potent and safe agents for inhibiting platelet aggregation and preventing above diseases are urgently required.Some traditional Chinese medicines of″Houxue Huayu″have been shown to inhibit platelet aggregation potently.In the present study the mechanisms and the molecular targets of puerarin,salvianolic acid B and the analogue of 3-n-butylphthalide,dl-PHPB were investigated and compared with ticlopidine.Four platelet aggregation inducers,ADP,arachidonic acid,collagen and thrombin were used in the study.It was found that puerarin and dl-PHPB specifically inhibited ADP induced platelet aggregation like ticlopidine did.However,salvianolic acid B inhibited both ADP and collagen induced platelet aggregations with similar potency.Due to existing two ADP receptor subtypes on platelets,P2Y1 and P2Y12,we studied the action of above compounds on the receptors and the signaling pathways.It was found that dl-PHPB decreased IP1 accumulation produced by ADP,but had no effect on IP1 level induced by m-3M3 FBS,an activator of PLC.M-3M3 FBS might attenuate the inhibitory effect of dl-PHPB on ADP-induced platelet aggregation.In addition,dl-PHPB did not affect cyclic AMP formation in platelets by ADP,which is different from P2Y12 antagonist ticlopidine.Puerarin showed the similar effects of dl-PHPB.Therefore,the actions of dl-PHPB and puerarin might be through P2Y1receptor-PLC-βpathway.Salvianolic acid B did not reduce the IP1 accumulation stimulated by ADP.It might act on the receptor subtype P2Y12.Our results suggest that components of Chinese herb medicine might be a resource for development of novel anti-platelet drugs. 展开更多
关键词 PLATELET aggregation ADP RECEPTORS Houxue Huayu
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Free Energy Change of Micelle Formation for Sodium Dodecyl Sulfate from a Dispersed State in Solution to Complete Micelles along Its Aggregation Pathways Evaluated by Chemical Species Model Combined with Molecular Dynamics Calculations
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作者 YOSHII Noriyuki KOMORI Mika +3 位作者 KAWADA Shinji TAKABAYASHI Hiroaki FUJIMOTO Kazushi OKAZAKI Susumu 《物理化学学报》 SCIE CAS CSCD 北大核心 2018年第10期1163-1170,共8页
Surfactant molecules, when dispersed in solution, have been shown to spontaneously form aggregates. Our previous studies on molecular dynamics(MD) calculations have shown that ionic sodium dodecyl sulfate molecules qu... Surfactant molecules, when dispersed in solution, have been shown to spontaneously form aggregates. Our previous studies on molecular dynamics(MD) calculations have shown that ionic sodium dodecyl sulfate molecules quickly aggregated even when the aggregation number is small. The aggregation rate, however, decreased for larger aggregation numbers. In addition, studies have shown that micelle formation was not completed even after a 100 ns-long MD run(Chem. Phys. Lett. 2016, 646, 36). Herein, we analyze the free energy change of micelle formation based on chemical species model combined with molecular dynamics calculations. First, the free energy landscape of the aggregation, ?G_(i+j)^+, where two aggregates with sizes i and j associate to form the(i + j)-mer, was investigated using the free energy of micelle formation of the i-mer, G_i^+, which was obtained through MD calculations. The calculated ?G_(i+j)^+ was negative for all the aggregations where the sum of DS ions in the two aggregates was 60 or less. From the viewpoint of chemical equilibrium, aggregation to the stable micelle is desired. Further, the free energy profile along possible aggregation pathways was investigated, starting from small aggregates and ending with the complete thermodynamically stable micelles in solution. The free energy profiles, G(l, k), of the aggregates at l-th aggregation path and k-th state were evaluated by the formation free energy ∑_in_i( l,k)G_i^+ and the free energy of mixing ∑_in_i( l,k)k_BTln( n_i( l,k)/n( l,k)), where ni(l, k) is the number of i-mer in the system at the l-th i aggregation path and k-th state, with n(l,k)= ∑_n_i( l,k). All the aggregation pathways were obtained from the initial i state of 12 pentamers to the stable micelle with i = 60. All the calculated G(l, k) values monotonically decreased with increasing k. This indicates that there are no free energy barriers along the pathways. Hence, the slowdown is not due to the thermodynamic stability of the aggregates, but rather the kinetics that inhibit the association of the fragments. The time required for a collision between aggregates, one of the kinetic factors, was evaluated using the fast passage time, t_(FPT). The calculated t_(FPT) was about 20 ns for the aggregates with N = 31. Therefore, if aggregation is a diffusion-controlled process, it should be completed within the 100 ns-simulation. However, aggregation does not occur due to the free energy barrier between the aggregates, that is, the repulsive force acting on them. This may be caused by electrostatic repulsions produced by the overlap of the electric double layers, which are formed by the negative charge of the hydrophilic groups and counter sodium ions on the surface of the aggregates. 展开更多
关键词 Free energy CHANGE aggregation pathway SDS MICELLE Molecular dynamics calculation
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Aggregation of Diesel Contaminated Soil for Bioremediation
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作者 Yu Ying Shi Xiu-hong +1 位作者 Li Song Xu Jing-gang 《Journal of Northeast Agricultural University(English Edition)》 CAS 2014年第4期18-24,共7页
Diesel contaminated soil(DCS) contained a large amount of the hydrocarbons and salt which was dominated by soluble sodium chloride. Aggregation process which made the desired aggregate size distribution could speed ... Diesel contaminated soil(DCS) contained a large amount of the hydrocarbons and salt which was dominated by soluble sodium chloride. Aggregation process which made the desired aggregate size distribution could speed up the degradation rate of the hydrocarbons since the aggregated DCS had better physical characteristics than the non-aggregated material. Artificial aggregation increased pores 〉30 μm by approximately 5% and reduced pores 〈1 μm by 5%, but did not change the percentage of the pores between 1 and 30 μm. The saturated hydraulic conductivity of non-aggregated DCS was 5×10-6 m · s-l, but it increased to 1×10-5 m · s-l after aggregation. The compression index of the non-aggregated DCS was 0.0186; however, the artificial aggregates with and without lime were 0.031 and 0.028, respectively. DCS could be piled 0.2 m deep without artificial aggregation; however, it could be applied 0.28 m deep when artificial aggregates were formed without limiting O2 transport. 展开更多
关键词 diesel contaminated soil aggregation NON-aggregation salt leaching AERATION
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Induced and heavy aggregation operators with distance measures
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作者 José M.Merigó Montserrat Casanovas 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期431-439,共9页
This paper introduces a new aggregation model by using induced and heavy aggregation operators in distances measures such as the Hamming distance.It is called the induced heavy ordered weighted averaging(OWA) dista... This paper introduces a new aggregation model by using induced and heavy aggregation operators in distances measures such as the Hamming distance.It is called the induced heavy ordered weighted averaging(OWA) distance(IHOWAD) operator.This paper studies some of its main properties and a wide range of particular cases such as the induced heavy OWA(IHOWA) operator,the induced OWA distance(IOWAD) operator and the heavy OWA distance(HOWAD) operator.This approach is generalized by using generalized and quasi-arithmetic means obtaining the induced generalized IHOWAD(IGHOWAD) operator and the Quasi-IHOWAD operator.An application of the new approach in a decision making problem regarding the selection of strategies is developed. 展开更多
关键词 distance measures aggregation operators decision making OWA operator.
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Time-effect and dose-effect of prasugrel hydrobromide acetic acid compound inhibiting platelet aggregation
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《中国药理学通报》 CAS CSCD 北大核心 2015年第B11期178-178,共1页
Aim To evaluate the time-effect and dose-effect of prasugrel hydrobromide acetic acid compound (PHAAC) inhibiting platelet aggregation. Methods For the time-effect study, 190 Sprague-Dawley (SD) rats were devided ... Aim To evaluate the time-effect and dose-effect of prasugrel hydrobromide acetic acid compound (PHAAC) inhibiting platelet aggregation. Methods For the time-effect study, 190 Sprague-Dawley (SD) rats were devided into 19 groups (n- 10): the vehicle control group, the PHAAC groups (0.5, 1, 2, 4, 6, 24, 48, 72, 96 h) and the prasugrel hydrochloride groups (0.5, 1, 2, 4, 6, 24, 48, 72, 96 h). Rats were singly intra- gastic administration of the vehicle, the PHAAC (5 mg·kg^-1) or the prasugrel hydrochloride (5 mg · kg^-1 ), re- spectively. Blood samples were taken at each time point for the determination of platelet aggregation rate (PAR). For the dose-effect study, 110 SD rats were devided into 11 groups (n= 10): the vehicle control group, the PHAAC groups (10, 5, 2.5, 1, 0.5 mg · kg^-1, dosage of prasugrel) and the prasugrel hydrochloride groups ( 10, 5, 2.5, 1, 0.5 mg · kg^-1, dosage of prasugrel) . Blood samples were taken at 4 h after drug administration for the determination of PAR. Results Compared with the vehicle group, PHAAC has significant anti-platelet ag- gregative effects (P 〈 0.05) at the time of 0.5, 1, 2, 4, 6, 24, 48 h, and the effect at the time of 4 h was the strongest. There were no obvious differences between the effect of PHAAC (5 mg · kg^-1) and prasugrel hydrochlo- ride (5 mg · kg^-1) at each time point. Compared with the vehicle group, intragastic administration of PHAAC at the doses of 10, 5, 2.5, 1, 0.5 mg · kg^-1 could obviously inhibite the platelet aggregation, and showed a dose- dependent manner. There were no significant differences between the effect of PHAAC and prasugrel hydrochloride at the same dose. Conclusion PHAAC can inhibit platelet aggregation in a dose-dependent manner, and the effect at 4 h after drug administration is the strongest. The action strength and duration of PHAAC are similar with that of the prasugrel hydrochloride. 展开更多
关键词 PRASUGREL hydrobromide acetic acid compound platelet aggregation time-effect DOSE-EFFECT prasug-rel HYDROCHLORIDE
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Elimination of hard aggregation of bismuth-doped tin dioxide nanometer powders prepared by wet chemical method 被引量:7
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作者 何秋星 涂伟萍 胡剑青 《化工学报》 EI CAS CSCD 北大核心 2006年第6期1490-1495,共6页
Bismuth-doped tin dioxide (BTO) nanometer powders were prepared by the wet chemical method using tin tetrachloride (SnCl4), bismuth nitrate [Bi(NO3) 3 ] and ammonia as raw materials. Non-bridge hydroxides and ca... Bismuth-doped tin dioxide (BTO) nanometer powders were prepared by the wet chemical method using tin tetrachloride (SnCl4), bismuth nitrate [Bi(NO3) 3 ] and ammonia as raw materials. Non-bridge hydroxides and capillary force between particles were found to be key factors causing hard aggregation of BTO through analyzing the formation mechanism of hard aggregation. The hard aggregation of BTO was eliminated effectively when the Bi-Sn precursor (BSP) was treated with post processing including dispersing with ultrasonic wave, refluxing and distilling with addition of n-butanol and benzene (DRD) and drying by microwave. Characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM), BTO spherical particles with tetragonal phase structure are well crystallized, dispersed easily and the average size was less than 10 nm. 展开更多
关键词 湿化学法 制备 铋掺杂二氧化锡 纳米粉体 硬团聚控制
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Hydrophobic aggregation of ultrafine kaolinite
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作者 张晓萍 胡岳华 刘润清 《Journal of Central South University of Technology》 EI 2008年第3期368-372,共5页
The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles sh... The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles show the self-aggregation of edge-face in acidic media,the aggregation of edge-face and edge-edge in neutral media,and the dispersion in alkaline media due to electrostatic repulsion. In the presence of the dodecylammonium acetate cationic surfactant and in neutral and alkaline suspension,the hydrophobic aggregation of face-face is demonstrated. The zeta potential of kaolinite increases with increasing the concentration of cationic surfactant. The small and loose aggregation at a low concentration but big and tight aggregation at a high concentration is presented. At pH=7 alkyl quarterly amine salt CTAB has the best hydrophobic aggregation among three cationic surfactants,namely,dodecylammonium acetate,alkyl quarterly amine salts 1227 and CTAB. 展开更多
关键词 ultrafine kaolinite cationic surfactant SEM observation hydrophobic aggregation
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Polycrystalline ZSM-5 Aggregates Induced by Seed and Catalytic Performance in Methanol to Hydrocarbon
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作者 WANG Xuchang JIAO Chuyu +5 位作者 JI Zhuo JIAO Qirui QIN Bo DU Yanze ZHENG Jiajun LI Ruifeng 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第8期945-954,I0010-I0013,共14页
Synthesis of ZSM-5 zeolite typically utilizes small molecule polyamines or quaternary ammonium salts as organic structure guiding agent(OSDA).By contrast,the OSDA-free hydrothermal synthesis system eliminates the use ... Synthesis of ZSM-5 zeolite typically utilizes small molecule polyamines or quaternary ammonium salts as organic structure guiding agent(OSDA).By contrast,the OSDA-free hydrothermal synthesis system eliminates the use of organic templates and the subsequent calcination procedure.This not only reduces the cost of synthesis,but also prevents environmental pollution from the combustion of organic templates,representing an eco-friendly approach.Despite this,literature suggests that even so-called template-free synthesis systems often involve trace amount of organic substances like alcohol.In the present work,a calcined commercial ZSM-5 zeolite was served as seed,with sodium aluminate as aluminum source and silica sol as silicon source,ensuring an entirely template-free synthesis system.Polycrystalline ZSM-5 aggregates consisted of rod-like nanocrystals were successfully prepared in the completely OSDA-free system.Effects of the Si/Al ratio in ZSM-5 seed,dosage and crystallization conditions such as crystallization temperature and crystallization time on ZSM-5 synthesis were investigated.The results show that a highly crystallinity ZSM-5 aggregate consisting of primary nano-sized crystals less than 100 nm is produced from a gel precursor with 5.6%(in mass)seed after hydrothermal treatment for 48 h.Furthermore,the Si/Al ratio in ZSM-5 seed has little effect on the topological structure and pore structure of the synthesized samples.However,the seeds with a low Si/Al ratio facilitate faster crystallization of zeolite and enhance the acidity,especially the strong acid centers,of the catalyst.The catalytic performance of the synthesized polycrystalline ZSM-5 was evaluated during dehydration of methanol and compared with a commercial reference ZSM-5r.The results exhibit that as compared with the reference catalyst,the fabricated sample has a longer catalytic lifetime(16 h vs 8 h)attributed to its hierarchical pores derived from the loosely packed primary nanoparticles.Additionally,the prepared polycrystalline catalyst also exhibits a higher aromatics selectivity(28.1%-29.8%vs 26.5%). 展开更多
关键词 ZSM-5 polycrystalline aggregate crystal seed structure guiding agent
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SCE-YOLO:改进YOLOv8的轻量级无人机视觉检测算法 被引量:1
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作者 张帅 王波涛 +1 位作者 涂嘉怡 陈聪实 《计算机工程与应用》 北大核心 2025年第13期100-112,共13页
针对无人机航拍场景下的目标检测模型计算复杂、检测效果不佳等问题,提出一种改进YOLOv8的轻量级无人机目标检测算法SCE-YOLO。使用STA_C2f替换骨干网络中的C2f模块,提高模型的特征提取能力;将采用渐进重参数化方法改进的AIFI模块作为... 针对无人机航拍场景下的目标检测模型计算复杂、检测效果不佳等问题,提出一种改进YOLOv8的轻量级无人机目标检测算法SCE-YOLO。使用STA_C2f替换骨干网络中的C2f模块,提高模型的特征提取能力;将采用渐进重参数化方法改进的AIFI模块作为空间金字塔池化层,实现高质量的尺度特征交互;提出一种多尺度特征聚合扩散网络UAV_CFDPN,根据航拍小目标的尺度特征优化网络结构,设计特征聚合模块FAM以及新的特征聚合与扩散路径,使得模型获得丰富的多尺度特征和上下文信息,提高目标检测的尺度适应性;设计一种高效共享卷积模块ES-Head,在保持定位和分类能力的同时,使得模型更加轻量高效。在VisDrone2019数据集上进行测试,实验结果表明,相较于YOLOv8s,虽然提出的SCE-YOLO算法mAP50减少0.5个百分点,但参数量和计算量仅为YOLOv8s的10.0%和48.8%,在检测精度和轻量化方面相较于其他先进算法具有明显的优势。 展开更多
关键词 目标检测 YOLOv8 多尺度特征 特征聚合 轻量化
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热带砖红壤果园长期生草对土壤团聚体及有机碳分布的影响
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作者 赵秋芳 魏长宾 +5 位作者 马海洋 王成艳 马智玲 严程明 汤昕明 冼皑敏 《西南农业学报》 北大核心 2025年第1期145-151,共7页
【目的】研究热带砖红壤典型果园生草对土壤团聚体和有机碳固存的影响,为砖红壤果园土壤物理结构改良和有机碳提升提供理论支撑。【方法】以热带砖红壤番石榴果园为研究对象,设置清耕(CK)、自然生草(NG)、热研2号柱花草(Re)、Ubon柱花草... 【目的】研究热带砖红壤典型果园生草对土壤团聚体和有机碳固存的影响,为砖红壤果园土壤物理结构改良和有机碳提升提供理论支撑。【方法】以热带砖红壤番石榴果园为研究对象,设置清耕(CK)、自然生草(NG)、热研2号柱花草(Re)、Ubon柱花草(Ub)4个处理,对果园长期生草下土壤团聚体组成、团聚体稳定性及有机碳分布进行分析。【结果】5年长期果园生草试验的研究结果表明,果园生草处理显著增加0~20 cm土层>2 mm水稳性团聚体含量,降低了0.25~2.00和0.053~0.250 mm水稳性团聚体含量,同时显著增加了R_(0.25)、MWD和GWD,提高了0~20 cm土层团聚体稳定性,但对20~40 cm土层团聚体分布和稳定性影响不显著。果园生草处理显著增加了土壤有机碳含量,Re、Ub和NG处理0~20 cm土层有机碳含量较CK分别提高55.0%、37.3%和24.8%,20~40 cm土层有机碳含量较CK分别提高28.1%、42.7%和25.0%。柱花草(Re和Ub)处理显著提高0~20和20~40 cm土层中>2 mm和0.25~2.00 mm粒级有机碳含量及其对土壤有机碳的贡献率。【结论】研究表明热带果园长期生草特别是种植柱花草可显著提高土壤水稳性团聚体的稳定性,同时增加土壤有机碳含量,显著提高土壤水稳性大团聚体中有机碳分布,提高其对土壤有机碳的贡献率。 展开更多
关键词 砖红壤 果园生草 土壤团聚体 团聚体有机碳
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