通讯机构：
[Dai, YM ] C;Changsha Univ Sci & Technol, Sch Chem & Chem Engn, Hunan Prov Key Lab Mat Protect Elect Power & Tranp, Hunan Prov Key Lab Cytochem, Changsha 410114, Peoples R China.
摘要：
Developing a green adsorbent to deal with Congo red dyes from wastewater was a significative exploration. In the work, we prepared an ionic liquid modified magnetic cellulose/sepiolite composite FSCS-cl-p(MBA-co-BVI) via a simple method, the process including the magnetic sepiolite/cellulose complex grafting the polymer of MBA and BVI. The high specific surface area of sepiolite and cellulose, the electropositivity of ionic liquids [Bvim][Br] and magnetic response of Fe3O4@SiO2 nanoparticles jointly promoted the adsorption performance of adsorbents. The composites were characterized by SEM, XRD, EDS, FTIR, BET, TGA and VSM, the adsorption performances were evaluated containing the influence factors, adsorption kinetics, isotherm and thermodynamics. In brief, the adsorbents were suitable within the pH range of 3-9 and reach adsorption equilibrium during 120 min. Meanwhile, the maximum adsorption capacity for CR was up to 1374.10 mg/g at 45 celcius. Furthermore, the adsorption kinetics and isotherm models were well-fitted to pseudo-second-order model and Langmuir isotherm model, respectively. The adsorption mechanisms of FSCS-cl-p(MBA-co-BVI) for CR could be interpreted as electrostatic attraction, hydrogen bonding and pi-pi stacking interaction. Based on results, the as-obtained adsorbents were effective, inexpensive and expected to be applied to the treatment of dyestuff.
摘要：
Traditional amide-based hydrate inhibitors, vital for preventing blockages, face limitations due to increasingly stringent environmental regulations. This study focuses on modifying poly(N-vinylcaprolactam) (PVCap) to improve its inhibition and biodegradation properties, by introducing -OH, -NH2, or -COOH groups into the molecular structure. The results revealed that the -OH group significantly improved both hydrate inhibition and biodegradability, while the -COOH and - NH2 groups had moderate and counter-effects, respectively. Compared to end hydroxyl modification, multiple -OH groups in the vinylcaprolactam/vinylalcohol copolymer weaken the inhibition effect, despite enhancing biodegradability. Optimal hydrophilicity was found to enhance PVCap's KHI performance, emphasizing the delicate balance needed to optimize stability and effectiveness. PXRD, Raman spectroscopy and interfacial tension tests were used to elucidate the impact of the modified PVCaps on hydrate structure and gas-liquid interfacial properties. The results further highlighted the significance of appropriate amphiphilicity in augmenting the KHI effect of the modified PVCaps.
摘要：
Examining the impacts of accident characteristics and differentiated built environment factors on accident severity at inherent accident hotspots within cities can help managers to adjust traffic control measures through urban planning and design, thereby reducing accident casualties. In this study, time series clustering was used to identify traffic accident hotspots in Changsha City. Based on the hotspot identification results, Kruskal-Wallis tests were used to select differentiated built environment factors among different accident areas within the city. A severity analysis model for road crashes in Changsha's hotspots, taking into account the built environment, was constructed using a Light gradient boosting machine (LightGBM). In addition, Shapley additive explanations (SHAP) were used to reveal the influences of accident characteristics and built environment factors on accident severity. The results showed that different accident characteristics and built environment factors affect accident severity in different urban accident areas. Factors such as type of accident, visibility, period of time, land use mixing degree, population density, density of commercial places, and density of industrial places showed varying degrees of importance in influencing accident severity, while the overall impact trends remained consistent. On the other hand, transportation accessibility, road network density, landform, and accident location showed significant differences in their impacts on accident severity between different accident areas within the city.
关键词：
Reinforcement learning;Periodic structures;dialogue policy;action space inflation;incoherence problem
摘要：
Reinforcement learning (RL) has emerged as a key technique for designing dialogue policies. However, action space inflation in dialogue tasks has led to a heavy decision burden and incoherence problems for dialogue policies. In this paper, we propose a novel decomposed deep Q-network (D2Q) that exploits the natural structure of dialogue actions to perform decomposition on Q-function, realizing efficient and coherent dialogue policy learning. Instead of directly evaluating the Q-function, it consists of two separate estimators, one for the abstract action-value functions and the other for the specific action-value functions, both sharing a common feature layer. The abstract action-value function determines the speech act of the system action, while the specific action-value function focuses on the concrete action. This structure establishes a logical relationship between the user and the system on speech actions, avoiding the problem of incoherence. Moreover, the abstract action-value function shields unreasonable specific actions in the inflated action space, reducing the decision complexity. Our results show that the problem of incoherence is prevalent in existing approaches, which significantly impacts the efficiency and quality of dialogue policy learning. Our D2Q architecture alleviates this problem and performs significantly better than competitive baselines in both evaluated and human experiments. Further experiments validate the generality of our method. It can be easily extended to other RL-based dialogue policy approaches.
期刊：
Journal of Heterocyclic Chemistry,2024年61(4) ISSN：0022-152X
通讯作者：
Liu, Aiping;Lan, SL;Xie, JJ
作者机构：
[Xie, Jianjun; Li, Guojun] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha, Peoples R China.;[Lan, Shilin; Ouyang, Wensen; Liu, Aiping; Long, Chuyun; Li, Jun; Li, Guojun; Li, Jianming; Xiao, Ting; Hu, Li] Hunan Res Inst Chem Ind, Natl Engn Res Ctr Agrochem, Changsha, Peoples R China.;[Liu, Aiping] Hunan Prov Key Lab Agrochem, Changsha, Peoples R China.;[Xiao, Ting] Changsha Univ Sci & Technol, Sch Chem & Chem Engn, Changsha, Peoples R China.;[Lan, Shilin; Liu, Aiping; Liu, AP; Lan, SL] Hunan Res Inst Chem Ind, Natl Engn Res Ctr Agrochem, Changsha 410007, Peoples R China.
通讯机构：
[Liu, AP; Lan, SL ] H;[Xie, JJ ] C;Hunan Res Inst Chem Ind, Natl Engn Res Ctr Agrochem, Changsha 410007, Peoples R China.;Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Peoples R China.
摘要：
By connecting the key intermediate trifluoroethyl sulfide with pyrimidinamine, we obtained T4 with LC50 was 0.19 mg/L against T. urticae and T15 with EC50 was 1.32 mg/L against P. sorghi after active testing and structural optimization. Abstract In order to overcome the problem of pesticide resistance, it is necessary to discover novel pesticides with new mechanisms of action. Herein, a series of novel pyrimidin‐4‐amine derivatives containing trifluoroethyl sulfide moiety were designed and synthesized. Bioassays indicated that the title compounds synthesized possessed excellent acaricidal activity against Tetranychus urticae and fungicidal activity against Erysiphe graminis and Puccinia sorghi. Especially, the acaricidal activity of 5‐chloro‐6‐(difluoromethyl)‐N‐(2‐(2‐fluoro‐4‐methyl‐5‐((2,2,2‐trifluoroethyl)thio)phenoxy)ethyl)pyrimidin‐4‐amine (compound T4, LC50 = 0.19 mg/L) against T. urticae was close to commercial acaricide cyenopyrafen, and the fungicidal activity of 5‐chloro‐6‐(difluoromethyl)‐2‐methyl‐N‐(2‐(3‐((2,2,2‐trifluoroethyl)thio)phenoxy)ethyl)pyrimidin‐4‐amine (compound T15, EC50 = 1.32 mg/L) against P. sorghi. was superior to commercial fungicide tebuconazole. The synthesis and characterization of these compounds were given and the structure–activity relationships were discussed.
作者机构：
[Safari, Farzaneh] Changsha Univ Sci & Technol, Int Coll Engn, Changsha 410004, Peoples R China.;[Nieto, Juan J.] Univ Santiago de Compostela, Dept Stat Math Anal & Optimizat, CITMAga, Santiago De Compostela 15782, Spain.
通讯机构：
[Nieto, JJ ] U;Univ Santiago de Compostela, Dept Stat Math Anal & Optimizat, CITMAga, Santiago De Compostela 15782, Spain.
关键词：
Wu-Zha n g system;Non-linear equatio n s;Dispersion;Surface velocity
摘要：
We study the implementation of a numerical method to solve the time fractional (2 + 1)-dimensional Wu- Zhang system focusing on properties of trigonometric basis functions (TBFs). The approximation of the system describing dispersive long waves by appropriate discretization of the system and Grunwald difference operators is discussed and a linear system of the resulting discrete systems is given. This process includes a presentation of a general framework to approximate the solution by a mesh-free scheme which is stable and converges. Finally, various numerical experiments are present to illustrate the exceptional effect of fractional-order on the WZ system.
摘要：
Bioretention facilities are essential, low-impact development measures to treat roof runoff pollution. To explore the effects of roof runoff pollution control and internal influencing mechanisms of field-scale bioretention facilities, a newly assembled bioretention facility (ABF) comprising volcanic rock and coconut coir was constructed. The results of the 21-month experiment showed that the peak concentrations of total suspended solids (TSS), ammonia nitrogen (NH4+-N), and chemical oxygen demand (COD) of roof runoff were 332.50 mg center dot L-1, 3.46 mg center dot L-1, and 122.33 mg center dot L-1, respectively, indicating that the roof runoff was seriously polluted and needed urgent treatment. The removal rates of TSS, NH4+-N, and COD within the facility were 86.50 +/- 7.31 %, 79.40 +/- 19.28 %, and 51.84 +/- 26.24 %, respectively. However, continuous and high-intensity rainfall decreased pollutant removal performance by weakening the adsorption effect of the media. Continuous pollutant input decreased the abundance of Arthrobacter and Hyphomicrobium within the media, and functional bacteria, such as KD4-96, Roseiflexaceae, Vicinamibacteraceae, and Gaiellales, played dominant roles in NH4+-N and COD removal to ensure the long-term stability of the facility. This study provides theoretical guidance and a practical basis for enhancing the application of ABF in mitigating roof runoff pollution.
关键词：
Molecular dynamics;Dual -phase Cu -Fe alloys;Fe content;Temperature;Strain rate
摘要：
Design: concept of dual-phase copper alloys was attractive to improve the mechanical performance of Cu. However, a systematic understanding of the interactions between second phase, twins, and dislocations in dualphase copper alloys during deformation was urgent for further strengthening their mechanical properties. Herein, models of dual-phase Cu-Fe alloys with different Fe contents were established and simulated to deeply investigate the interaction between Cu matrix and Fe-enriched phase during deformation as well as the dislocation proliferation and structural changes at the atomic scale. It was found that numerous dislocations and twins were produced in Cu matrix during the deformation process, while grain boundaries of Fe-enriched phases were able to effectively impede the movement of dislocations, resulting in an enhancement of the alloy's strength. Furthermore, new grain boundaries were appeared in the Fe-enriched phase of the dual-phase Cu-Fe alloys at higher strain rates, resulting in a certain grain refinement. With the increasing temperature, the main deformation mechanism of dual-phase Cu-Fe alloys were changed from dislocation slip to grain boundary slip. In addition, the additional Fe content can significantly strengthen the alloys, and the changes in the mechanical properties of dual-phase Cu-Fe alloys during deformation were verified via experiments.
作者机构：
[Zhuofan Liao; Wenqiang Deng; Shiming He; Qiang Tang] School of Computer and Communication Engineering, Changsha University of Science and Technology, Changsha 410114, China
通讯机构：
[Zhuofan Liao] S;School of Computer and Communication Engineering, Changsha University of Science and Technology, Changsha 410114, China
摘要：
As Network Function Virtualization (NFV) continues to advance, Virtual Network Functions (VNFs) such as firewalls are increasingly used. Service Function Chains (SFCs) are formed by combining specific VNFs in a particular order, which are then deployed on the physical network to provide dedicated services to end users. Occasionally, partial VNF migration is employed to maintain service and network stability. However, decision-making times and system delays may become unacceptable due to the heterogeneous resource requirements of VNFs and the massive state migration of VNFs, especially in Multi-access Edge Computing (MEC) networks where resources are scarce and demand fluctuations are frequent. To solve these challenges, we first formulate the problem of Minimizing decision Time and system Latency for joint VNF Deployment and Migration (MTLDM) as a multi-objective optimization problem. Then, we propose a Collaborative Filtering-based Fast Delay-aware algorithm (CFFD) to solve this problem. In this algorithm, we introduce an innovative approach, referred to as the collaborative filtering-based method, which utilizes the preference information of deployed/migrated VNFs to assist the current VNF deployment/migration in reducing decision-making time. Additionally, we design a similarity-based method in CFFD to search for suitable hosts for the current VNF, thereby reducing the complexity caused by heterogeneity and minimizing system latency. Furthermore, we implement a heuristic method in CFFD to increase the number of accepted requests. In the end, extensive simulations are conducted to evaluate the performance of CFFD in comparison with baseline algorithms and to select the suitable similarity algorithm. The results of the selection simulation show that Manhattan distance and cosine similarity are superior to Pearson’s correlation. Moreover, the comparison simulation results indicate that CFFD outperforms the baseline algorithms in terms of delay optimization and decision time by up to 22.08% and 99%, respectively.
期刊：
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY,2024年84:102641 ISSN：0364-5916
通讯作者：
Xin, JH;Liss, KD
作者机构：
[Yin, Chongshan; Li, Xi; Zhang, Wei -Bing; Luo, Minsi; Zhu, Ruixiang] Changsha Univ Sci & Technol, Hunan Prov Key Lab Flexible Elect Mat Genome Engn, Changsha 410004, Peoples R China.;[Xin, Jinghua; Xin, JH] MOT, Tianjin Res Inst Water Transport Engn, Safety Energy Conservat & Emergency Technol Res Ct, Tianjin 300000, Peoples R China.;[Shang, Shun -Li; Liu, Zi-Kui] Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA.;[Funakoshi, Ken-Ichi] Comprehens Res Org Sci & Soc, Neutron Sci & Technol Ctr, Tokai, Ibaraki 3191106, Japan.;[Reid, Mark; Liss, Klaus -Dieter; Liss, KD; Dippenaar, Rian Johannes] Univ Wollongong, Sch Mech Mat Mechatron & Biomed Engn, Northfields Ave, Wollongong, NSW 2522, Australia.
通讯机构：
[Liss, KD ] U;[Xin, JH ] M;MOT, Tianjin Res Inst Water Transport Engn, Safety Energy Conservat & Emergency Technol Res Ct, Tianjin 300000, Peoples R China.;Univ Wollongong, Sch Mech Mat Mechatron & Biomed Engn, Northfields Ave, Wollongong, NSW 2522, Australia.
关键词：
Equation of state;Ti-Al alloys;High-pressure;Synchrotron radiation
摘要：
The phase transformations and pressure -volume dependencies of the Ti-45Al alloy with respect to pressure have been investigated by means of in -situ observation using multi anvil -type high-pressure devices and synchrotron radiation. Under hydrostatic compression from 0 to 10.1 GPa, about 2.3 vol % of gamma transforms continuously to alpha 2. Lattice parameters as well as volume fractions of these two phases have been determined as functions of pressure. Bulk moduli estimated using Birch-Murnaghan's equation of state are 146.2 GPa for the gamma phase, 136.7 GPa for the alpha 2 phase, and 145.6 GPa for their two-phase mixture of Ti-45Al alloy. First -principles have also applied to investigate bulk moduli of two single phases, and the deviation between calculations and measurements is discussed and attributed to mainly phase transformation. The present study provides useful insights into thermodynamics of alpha 2 and gamma phases under high pressure.
摘要：
Cement-stabilized macadam materials are widely utilized as semi-rigid base materials in road construction. However, conventional cement-stabilized macadam (CCSM) bases often develop shrinkage cracks during early construction and maintenance due to variations in humidity and temperature. Shrinkage cracks can subsequently result in reflective cracks in the asphalt pavement, significantly reducing the overall service life of the road. This study systematically evaluates the shrinkage and mechanical properties of large-size cement-stabilized macadam (LSCSM). Initially, the mix proportion for LSCSM is determined using the Bailey method. Subsequently, an experimental design based on the response surface method is implemented to comprehensively investigate various properties, including unconfined compressive strength, compressive rebound modulus, flexural strength, and the durability aspects of early drying shrinkage and temperature shrinkage through laboratory experiments. Further, the performance differences between CCSM and LSCSM are analyzed comparatively. The findings reveal that the compressive strength of LSCSM surpasses that of CCSM, albeit with comparatively lower compressive rebound modulus and flexural strength. LSCSM demonstrates a unique blend of characteristics, exhibiting traits of both semi-rigid and flexible materials. Furthermore, LSCSM exhibits favorable crack resistance properties, as evidenced by lower dry shrinkage strain, average dry and temperature shrinkage coefficient compared to CCSM. The proposed LSCSM in this study effectively reduces cement dosage and enhances the crack resistance performance of base materials.
摘要：
The mesoporous carbons with abundant Fe-Co sites were prepared through one-step carbonization of a MOF materials (ZIF-67) with sodium iron ethylenediaminetetraacetic acid [NaFe(III)EDTA], which can facilitate the nucleation and growth of highly dispersed palladium active sites. The robust synergistic interaction between Pd and FeCo metal with moderate work functions is responsible for the enhanced catalytic activity. Interfacing Pd nano-particles with FeCo sites has been demonstrated for the first time to boost the heterogeneous catalysis of hydrogen production from formic acid, affording the high turnover frequency (TOF) value of 1288 h- 1 at 303 K. The Pd-Fe-Co sites also help to achieve outstanding catalysis performance of in situ hydrogenating phenol. The 91.1 % of the conversion of phenol and 92.7 % of the selectivity of cyclohexanone has been obtained with formic acid as H-donor.
摘要：
Modification of fly ash geopolymer with steel slag: Preparation of steel slag-fly ash geopolymer paste using steel slag andvarying dosages of NaOH-Na2SiO3 as variables. The study aims to investigate the workability, strength, and strengthening mechanismof this paste material, as well as to assess its mechanical properties and water stability in stabilized gravel. The results showed thatincorporating steel slag could decrease the fluidity and setting time of fly ash geopolymer while increasing its strength. When the steelslag and activator was 30% and 18%, respectively, the compressive strength at 7 and 28 days was the highest, reaching 19.3 and 24.9MPa, respectively. The strength of geopolymer-stabilized gravel was equivalent to that of cement-stabilized gravel. When thegeopolymer content is modified to 6%, the unconfined compressive strength at 7 and 28 days is 5.2 and 6.1 MPa, respectively. After28 days of curing, the water stability has significantly improved, with a water stability coefficient exceeding 0.9. The addition of steelslag can enhance the reactivity of the reaction system, facilitate the formation of C-(A)-S-H gel, increase the bonding strength, and fillthe internal pores, resulting in a 23.3% reduction in porosity, a denser structure, and improved strength.
关键词：
Preventive maintenance;Two-dimensional warranty;Gamma usage process
摘要：
This study considers a manufacturer performing preventive maintenance (PM) on a product according to a one- or two-dimensional (2-D) policy. The one-dimensional PM policy is based on either time or usage, while in the two-dimensional case, PM is scheduled based on both scales. The product carries a 2-D warranty that offers protection for a certain amount of time and usage. Its cumulative usage is continuously monitored by the manufacturer and is assumed to follow a gamma process. In this context, we first propose a doubly stochastic Poisson process model for product failures where the stochastic intensity is influenced by the gamma usage process in an additive manner. We then explicitly derive the expected total costs of the two one-dimensional PM policies using the concepts of first hitting times and gamma bridges. For the 2-D PM policy, we express the associated cost in terms of the value function of a dynamic programming model. In the numerical experiments, we show how the variability of the usage process affects the costs of the three PM policies and find that the optimal 2-D policy degenerates into a one-dimensional policy.
摘要：
In this paper, a linearized numerical scheme of nonlinear variable-order fractional diffusion equation with time delay is constructed. We apply the L2-1(sigma) formula to discretize the temporal derivative and second-order central difference scheme to discretize the spatial derivative. The proposed method is unconditionally stable and convergent with O(tau(2)+h(2)), where tau and h are the time and space steps, respectively. Numerical experiment demonstrates the effectiveness and accuracy of the numerical scheme.
