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Attention-enhanced multi-time scale LSTM for soft sensor modeling of corn starch liquefaction
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作者 Yu Zhuang Zhongyi Zhang +5 位作者 Jin Tao Yi Li Fan Li Yu Wang Lei Zhang Jian Du 《Chinese Journal of Chemical Engineering》 2026年第1期132-144,共13页
Data-driven deep learning modeling has been increasingly applied to quality prediction in complex chemical processes.However,the data show complex temporal features due to different residence times and strong coupling... Data-driven deep learning modeling has been increasingly applied to quality prediction in complex chemical processes.However,the data show complex temporal features due to different residence times and strong coupling relationships among chemical entities.This study proposes a multi-scale temporal feature extraction module to extract local dynamic temporal features across different time scales and combines it with long short-term memory(LSTM)networks to capture global temporal patterns,thereby taking full advantage of available data.In addition,variable-wise channel attention is integrated into the model to enhance attention on the essential parts of the feature maps and improve predictive performance.Furthermore,by analyzing the attention weights,the model quickly identifies the key variables that significantly affect the predictions.Finally,the model is applied to a real corn starch liquefaction process and achieves an accurate product quality prediction with an R^(2) value of 0.9392,which represents a 4%to 9%improvement over traditional models and demonstrates the superiority of the proposed approach. 展开更多
关键词 Multi-scale dilated causal convolution Neural networks Soft sensor Systems engineering attention mechanism Biochemical engineering
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Promotional effect of silica shell coated NiO physically mixed with Mo/HZSM-5 catalyst on methane dehydroaromatization
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作者 Jangeon Roh Kihun Nam +9 位作者 Yong Hyun Lim Yeseul Hwang Hae Won Ryu Kyoungmin Kim Gyeongmin Seok Yangho Jeong Jong Hun Kang Jungyeop Lee Jong-Ki Jeon Do Heui Kim 《Chinese Journal of Catalysis》 2025年第4期220-233,共14页
In our previous study,the activity and stability of the Mo/HZSM-5 catalyst were enhanced by mixing physically with NiO in methane dehydroaromatization(MDA)reaction.It has been confirmed that the physically mixed NiO n... In our previous study,the activity and stability of the Mo/HZSM-5 catalyst were enhanced by mixing physically with NiO in methane dehydroaromatization(MDA)reaction.It has been confirmed that the physically mixed NiO not only promoted the dispersion of MoC_(x)active sites but also reduced the coke formation on the MoC_(x)owing to the CNTs growth on Ni.However,the promotional effect of NiO was limited when the particle size was reduced,due to the excessive interaction with MoOx(forming NiMoO_(4))which is detrimental to the MoC_(x)dispersion.In this study,to overcome the limitation,silica shell on NiO particles with various sizes(5,15,110 nm)was introduced.The catalyst with silica shell coated NiO with the size of 15 nm exhibited a significant improvement in both BTX yield and stability,and the catalyst with silica shell coated NiO with the size of 5 nm achieved the highest maximum BTX yield,about 7.2%.This study demonstrates that the catalytic performance improved as the NiO particle size decreased with the introduction of the silica shell.Combined transmission electron microscopy-energy dispersive spectroscopy,X-ray diffraction,temperature-programmed surface reaction of methane,CO chemisorption,visible Raman,and thermogravimetric analysis allowed us to confirm that a thin silica shell further enhances the MoC_(x)dispersion while preventing the formation of Ni-Mo complexes.However,when the size of NiO decreased to 5 nm,CNT growth on Ni was limited during the reaction,which is crucial for reducing coke formation on Mo active sites,thereby resulting in the decreased catalyst stabilization ability of Ni.Overall,this study indicates that the introduction of a silica shell in a controlled way can significantly enhance the promotional effect of physically mixed NiO on MDA. 展开更多
关键词 Methane dehydroaromatization MO/HZSM-5 BTX Physical mixing NIO Silica shell Carbon nanotube
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High-throughput and intelligent design of potential GRK2 inhibitor candidates using deep learning and mathematical programming methods
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作者 Yujing Zhao Qilei Liu +3 位作者 Jian Du Qingwei Meng Liang Sun Lei Zhang 《Chinese Journal of Chemical Engineering》 2025年第8期11-22,共12页
G protein coupled receptor kinase 2 (GRK2) is a kinase that regulates cardiac signaling activity. Inhibiting GRK2 is a promising mechanism for the treatment of heart failure (HF). Further development and optimization ... G protein coupled receptor kinase 2 (GRK2) is a kinase that regulates cardiac signaling activity. Inhibiting GRK2 is a promising mechanism for the treatment of heart failure (HF). Further development and optimization of inhibitors targeting GRK2 are highly meaningful. Therefore, in order to design GRK2 inhibitors with better performance, the most active molecule was selected as a reference compound from a data set containing 4-pyridylhydrazone derivatives and triazole derivatives, and its scaffold was extracted as the initial scaffold. Then, a powerful optimization-based framework for de novo drug design, guided by binding affinity, was used to generate a virtual molecular library targeting GRK2. The binding affinity of each virtual compound in this dataset was predicted by our developed deep learning model, and the designed potential compound with high binding affinity was selected for molecular docking and molecular dynamics simulation. It was found that the designed potential molecule binds to the ATP site of GRK2, which consists of key amino acids including Arg199, Gly200, Phe202, Val205, Lys220, Met274 and Asp335. The scaffold of the molecule is stabilized mainly by H-bonding and hydrophobic contacts. Concurrently, the reference compound in the dataset was also simulated by docking. It was found that this molecule also binds to the ATP site of GRK2. In addition, its scaffold is stabilized mainly by H-bonding and π-cation stacking interactions with Lys220, as well as hydrophobic contacts. The above results show that the designed potential molecule has similar binding modes to the reference compound, supporting the effectiveness of our framework for activity-focused molecular design. Finally, we summarized the interaction characteristics of general GRK2 inhibitors and gained insight into their molecule-target binding mechanisms, thereby facilitating the expansion of lead to hit compound. 展开更多
关键词 Mathematical modeling Optimal design Product design GRK2 Mathematical programmingmethod Binding affinity
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Ultrathin Pd based bimetallic nanowires as highly efficient ampere-level pH-universal water splitting
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作者 Yuanwei Ma Jigang Wang +4 位作者 Zhaodi Yan Qiang Liu Lanyan Li Zhongfang Li Likai Wang 《Chinese Chemical Letters》 2026年第1期350-355,共6页
Herein,we have developed a straightforward wet-chemical method to synthesize a series of Pd-based alloy nanowires(NWs),including Pd Pt NWs,Pd Au NWs,Pd Ir NWs,and Pd Ru NWs,which exhibits high mass activity and turnov... Herein,we have developed a straightforward wet-chemical method to synthesize a series of Pd-based alloy nanowires(NWs),including Pd Pt NWs,Pd Au NWs,Pd Ir NWs,and Pd Ru NWs,which exhibits high mass activity and turnover frequency(TOF) for HER,surpassing Pt/C by 4.6-fold and 1.5-fold in acidic and alkaline electrolytes,respectively.It also demonstrates high stability in alkaline electrolyte at a current density of 220 m A/cm^(2) for 280 h,highlighting its potential for practical applications under industrial current conditions.Pd Pt NWs exhibited ultrathin structures with head-to-tail kinks and inherent defects,significantly increasing the density of active sites and precisely tuning the electronic structure,which could accelerate reaction kinetics and boost water-splitting electrocatalytic performance.This study highlights the potential of Pd Pt NWs as highly efficient catalysts,offering outstanding catalytic performance and stability for practical applications. 展开更多
关键词 PdPt ALLOY NANOWIRES Water splitting HER
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Ultrahigh-Mass-Loading Electrodes With Enhanced Homogeneity Using a High-Concentration Slurry for Lithium-Ion Batteries
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作者 Jun Kyu Park Woohyeon Shin +14 位作者 Woohyeon Jo Hyo-Jeong Lee Won-Yong Jeon Jinho Ahn Jihee Yoon Yea-Ji Jeong Joonyoung Oh Minji Kang Min-Jae Choi Jin Joo Jongsoon Kim Seong-Keun Cho Jun Dong Park Jaewook Nam Jung-Keun Yoo 《Carbon Energy》 2026年第1期126-137,共12页
Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity c... Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity carbon nanotubes(CNT)conductive materials,and electrode thickening.However,these methods are still limited due to the limitation in the capacity of high-nickel NCM,aggregation of CNT conductive materials,and nonuniform material distribution of thick-film electrodes,which ultimately damage the mechanical and electrical integrity of the electrode,leading to a decrease in electrochemical performance.Here,we present an integrated binder-CNT composite dispersion solution to realize a high-solids-content(>77 wt%)slurry for high-mass-loading electrodes and to mitigate the migration of binder and conductive additives.Indeed,the approach reduces solvent usage by approximately 30%and ensures uniform conductive additive-binder domain distribution during electrode manufacturing,resulting in improved coating quality and adhesive strength for high-mass-loading electrodes(>12 mAh cm^(−2)).In terms of various electrode properties,the presented electrode showed low resistance and excellent electrochemical properties despite the low CNT contents of 0.6 wt%compared to the pristine-applied electrode with 0.85 wt%CNT contents.Moreover,our strategy enables faster drying,which increases the coating speed,thereby offering potential energy savings and supporting carbon neutrality in wet-based electrode manufacturing processes. 展开更多
关键词 cathodes DISPERSIBILITY dispersion solution high-mass-loading lithium-ion batteries
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An efficient adaptive finite element method algorithm with mass conservation for analysis of liquid face seals 被引量:10
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作者 Xiayg-kai MENG Shao-xian BAI Xu-dong PENG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2014年第3期172-184,共13页
To improve lubrication effect and seal performance, complicated geometrical hydrodynamic grooves or patterns are often processed on end faces of liquid lubricated mechanical seals. These structures can lead to difficu... To improve lubrication effect and seal performance, complicated geometrical hydrodynamic grooves or patterns are often processed on end faces of liquid lubricated mechanical seals. These structures can lead to difficulties in precisely estimating the seal performance. In this study, an efficient adaptive finite element method (FEM) algorithm with mass conservation was presented, in which a streamline upwind/Petrov-Galerkin (SUPG) weighted residual FEM and a fast iteration algorithm were applied to solve the lubrication equations (Reynolds equation). A mesh adaptation technique was utilized to refine the computation domain based on a residual posterior error estimator. Validation, applicability, and efficiency were verified by comparison among different algorithms and by case studies on seals' faces with different groove structures. The study investigated the influence of the order of shape function and the mesh number on the leakage balance. Mesh refinement occurred mainly in cavitation zones when cavitation happened, otherwise it occurred in regions with a high pressure gradient. Numerical experiments verified that the proposed algorithm is a fast, effective, and accurate method to simulate lubrication problems in the engineering field apart from end face seals. 展开更多
关键词 CAVITATION Finite element method (FEM) End face seals Streamline upwind/Petrov-Galerkin (SUPG) Massconservation
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Research on reasonable winding angle of ribbons of Flat Steel Ribbon Wound Pressure Vessel 被引量:4
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作者 郑传祥 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第3期445-449,共5页
Flat Steel Ribbon Wound Pressure Vessels (FSRWPVs) are used in many important industry areas. There is no such kind of pressure vessel exploding on operation for its reasonable structure design. Many explosion experim... Flat Steel Ribbon Wound Pressure Vessels (FSRWPVs) are used in many important industry areas. There is no such kind of pressure vessel exploding on operation for its reasonable structure design. Many explosion experiments on Flat Steel Ribbon Wound Pressure Vessel showed that their limited load pressure is related to the winding angle of the steel ribbons. FSRWPVs with reasonable winding angle have better security and lower cost. Reasonable angels given at the end of this paper facilitate engineering design. 展开更多
关键词 Flat Steel Ribbon Wound Pressure Vessel (FSRWPV) Winding angle RIBBONS
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Recent advances in soft electronic materials for intrinsically stretchable optoelectronic systems 被引量:4
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作者 Ja Hoon Koo Huiwon Yun +3 位作者 Woongchan Lee Sung-Hyuk Sunwoo Hyung Joon Shim Dae-Hyeong Kim 《Opto-Electronic Advances》 SCIE EI 2022年第8期21-49,共29页
In recent years,significant progress has been achieved in the design and fabrication of stretchable optoelectronic devices.In general,stretchability has been achieved through geometrical modifications of device compon... In recent years,significant progress has been achieved in the design and fabrication of stretchable optoelectronic devices.In general,stretchability has been achieved through geometrical modifications of device components,such as with serpentine interconnects or buckled substrates.However,the local stiffness of individual pixels and the limited pixel density of the array have impeded further advancements in stretchable optoelectronics.Therefore,intrinsically stretch-able optoelectronics have been proposed as an alternative approach.Herein,we review the recent advances in soft elec-tronic materials for application in intrinsically stretchable optoelectronic devices.First,we introduce various intrinsically stretchable electronic materials,comprised of electronic fillers,elastomers,and surfactants,and exemplify different in-trinsically stretchable conducting and semiconducting composites.We also describe the processing methods used to fabricate the electrodes,interconnections,charge transport layers,and optically active layers used in intrinsically stretch-able optoelectronic devices.Subsequently,we review representative examples of intrinsically stretchable optoelectronic devices,including light-emitting capacitors,light-emitting diodes,photodetectors,and photovoltaics.Finally,we briefly discuss intrinsically stretchable integrated optoelectronic systems. 展开更多
关键词 stretchable optoelectronics light-emitting capacitors light-emitting diodes PHOTODETECTORS photovoltaics intrinsically stretchable devices
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Synthesis of indirect work exchange networks considering both isothermal and adiabatic process together with exergy analysis 被引量:2
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作者 Yu Zhuang Linlin Liu +1 位作者 Lei Zhang Jian Du 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1644-1652,共9页
In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In co... In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method. 展开更多
关键词 Work exchange networks Transshipment model Adiabatic process Exergy analysis Isothermal process Work cascade
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HYSYS Automation and Its Application on Evaluation of Plate Heat Exchanger 被引量:3
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作者 Dai Yuqiang Liu Wenwei +1 位作者 Wang Shaomin Hu Dapeng 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2008年第3期55-59,共5页
When simulating or designing plate heat exchangers for multicomponent mixtures, most designers are often perplexed with the question on how to choose or estimate the physical property param- eters and hope to have a r... When simulating or designing plate heat exchangers for multicomponent mixtures, most designers are often perplexed with the question on how to choose or estimate the physical property param- eters and hope to have a reliable database that could be adopted. The commercial codes HYSYS supply the physical property package on over 1500 pure substances and over 16 000 binary coefficients for them. This work has briefly presented an efficient communication interface based on the Microsoft Component Object Model (COM) between inner plate heat exchanger simulation codes and the HYSYS package. The application of a custom-made HYSYS-COM interface has shown high efficiency, such as significant reduction of time needed for evaluating each process stream's properties. This automation method can be conveniently extended to further optimization study for any specific operation device such as heat transfers, columns, and other facilities. 展开更多
关键词 HYSYS automation plate heat exchanger Component Object Model (COM)
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Step-wise synthesis of work exchange networks involving heat integration based on the transshipment model 被引量:8
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作者 Yu Zhuang Linlin Liu +1 位作者 Qilei Liu Jian Du 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第8期1052-1060,共9页
Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy effic... Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy efficiency and the influence of lower carbon development.Since work exchange network is a significant part of energy recovery system,its optima design will have dramatically significant effect on energy consumption reduction in chemical process system.With an extension of the developed transshipment model in isothermal process,a novel step-wise methodology for synthesis of direct work exchange network(WEN)in adiabatic process involving heat integration is first proposed in this paper,where a nonlinear programming(NLP)model is formulated by regarding the minimum utility consumption as objective function and optimizing the initial WEN in accordance with the presented matching rules to get the optimized WEN configuration at first.Furthermore,we focus on the work exchange network synthesis with heat integration to attain the minimal total annual cost(TAC)with the introduction of heat-exchange equipment that is achieved by the following strategies in sequence:introducing heat-exchange equipment directly,adjusting the work quantity of the adjacent utility compressors or expanders,and approximating upper/lower pressure limits consequently to obtain considerable cost savings of expanders or compressors and work utility.Finally,a case taken from the literature is studied to illustrate the feasibility and effectiveness of the proposed method. 展开更多
关键词 Work exchange network Transshipment model Adiabatic process Trade-off between work and heat Economic analysis
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ESTIMATE OF BURSTING PRESSURE OF MILD STEEL PRESSURE VESSEL AND PRESENTATION OF BURSTING FORMULA 被引量:3
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作者 ZHENG Chuanxiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第3期421-424,共4页
In order to get more precise bursting pressure formula of mild steel, hundreds of bursting experiments of mild steel pressure vessels such as Q235(Gr.D) and 20R(1020) are done. Based on statistical data of burstin... In order to get more precise bursting pressure formula of mild steel, hundreds of bursting experiments of mild steel pressure vessels such as Q235(Gr.D) and 20R(1020) are done. Based on statistical data of bursting pressure and modification of Faupel formula, a more precise modified formula is given out according to the experimental data. It is proved to be more accurate after examining other bursting pressure value presented in many references. This bursting formula is very accurate in these experiments using pressure vessels with different diameter and shell thickness. Obviously, this modified bursting formula can be used in mild steel pressure vessels with different diameter and thickness of shell. 展开更多
关键词 Bursting pressure Pressure vessel Mild steel
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Towards high-performance and robust anion exchange membranes(AEMs)for water electrolysis:Super-acid-catalyzed synthesis of AEMs 被引量:1
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作者 Geun Woong Ryoo Sun Hwa Park +3 位作者 Ki Chang Kwon Jong Hun Kang Ho Won Jang Min Sang Kwon 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期478-510,I0012,共34页
The increasing demand for hydrogen energy to address environmental issues and achieve carbon neutrality has elevated interest in green hydrogen production,which does not rely on fossil fuels.Among various hydrogen pro... The increasing demand for hydrogen energy to address environmental issues and achieve carbon neutrality has elevated interest in green hydrogen production,which does not rely on fossil fuels.Among various hydrogen production technologies,anion exchange membrane water electrolyzer(AEMWE)has emerged as a next-generation technology known for its high hydrogen production efficiency and its ability to use non-metal catalysts.However,this technology faces significant challenges,particularly in terms of the membrane durability and low ionic conductivity.To address these challenges,research efforts have focused on developing membranes with a new backbone structure and anion exchange groups to enhance durability and ionic conductivity.Notably,the super-acid-catalyzed condensation(SACC)synthesis method stands out due to its user convenience,the ability to create high molecular weight(MW)polymers,and the use of oxygen-tolerant organic catalysts.Although the synthesis of anion exchange membranes(AEMs)using the SACC method began in 2015,and despite growing interest in this synthesis approach,there remains a scarcity of review papers focusing on AEMs synthesized using the SACC method.The review covers the basics of SACC synthesis,presents various polymers synthesized using this method,and summarizes the development of these polymers,particularly their building blocks including aryl,ketone,and anion exchange groups.We systematically describe the effects of changes in the molecular structure of each polymer component,conducted by various research groups,on the mechanical properties,conductivity,and operational stability of the membrane.This review will provide insights into the development of AEMs with superior performance and operational stability suitable for water electrolysis applications. 展开更多
关键词 Green hydrogen production Water electrolysis Anion exchange membrane water electrolyzer(AEMWE) Anion exchange membranes(AEMs) Super-acid-catalyzed condensation(SACC)
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Machine learning methods for developments of binding kinetic models in predicting protein-ligand dissociation rate constants 被引量:1
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作者 Yujing Zhao Qilei Liu +2 位作者 Jian Du Qingwei Meng Lei Zhang 《Smart Molecules》 2023年第3期98-112,共15页
Binding kinetic properties of protein–ligand complexes are crucial factors affecting the drug potency.Nevertheless,the current in silico techniques are insufficient in providing accurate and robust predictions for bi... Binding kinetic properties of protein–ligand complexes are crucial factors affecting the drug potency.Nevertheless,the current in silico techniques are insufficient in providing accurate and robust predictions for binding kinetic properties.To this end,this work develops a variety of binding kinetic models for predicting a critical binding kinetic property,dissociation rate constant,using eight machine learning(ML)methods(Bayesian Neural Network(BNN),partial least squares regression,Bayesian ridge,Gaussian process regression,principal component regression,random forest,support vector machine,extreme gradient boosting)and the descriptors of the van der Waals/electrostatic interaction energies.These eight models are applied to two case studies involving the HSP90 and RIP1 kinase inhibitors.Both regression results of two case studies indicate that the BNN model has the state-of-the-art prediction accuracy(HSP90:R^(2)_(test)=0:947,MAE_(test)=0.184,rtest=0.976,RMSE_(test)=0.220;RIP1 kinase:R^(2)_(test)=0:745,MAE_(test)=0.188,rtest=0.961,RMSE_(test)=0.290)in comparison with other seven ML models. 展开更多
关键词 Bayesian neural network binding kinetics dissociation rate constant machine learning protein-ligand interaction energies
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NiO_(x) Nanoparticle Synthesis by Chemical Vapor Deposition from Nickel Acetylacetonate 被引量:1
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作者 Pavel Moravec Jiri Smolik +3 位作者 Helmi Keskinen Jyrki M.Makela Snejana Bakardjieva Valeri V.Levdansky 《Materials Sciences and Applications》 2011年第4期258-264,共7页
Ni/NiO nanoparticles were synthesized by metal organics chemical vapor deposition of nickel acetylacetonate in an externally heated tube flow reactor at moderate temperatures, up to 500°C. Particle production and... Ni/NiO nanoparticles were synthesized by metal organics chemical vapor deposition of nickel acetylacetonate in an externally heated tube flow reactor at moderate temperatures, up to 500°C. Particle production and characteristics were studied by evaluating the effects of reactor temperature, precursor concentration, and flow rate through the reactor. In addition, two precursor decomposition methods were examined: thermal decomposition and reduction by hydrogen. Particle production was monitored with a scanning mobility particle sizer, and particle characteristics were studied using transmission electron microscopy, high resolution transmission electron microscopy, selected area electron diffraction, and energy dispersive spectroscopy. The presence of hydrogen in the reaction mixture influenced significantly both particle production and their characteristics. 展开更多
关键词 Nickel Nanostructures MOCVD Hot Wall Tube Reactor Electron Diffraction
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Understanding the roles of Brønsted/Lewis acid sites on manganese oxide-zeolite hybrid catalysts for low-temperature NH_(3)-SCR
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作者 Hyun Sub Kim Hwangho Lee +2 位作者 Hongbeom Park Inhak Song Do Heui Kim 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第10期79-88,共10页
Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their s... Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their subsequent reaction mechanism on acid sites is still unclear and requires investigation.In this study,the distribution of Brønsted/Lewis acid sites in the hybrid materials was precisely adjusted by introducing potassium ions,which not only selectively bind to Brønsted acid sites but also potentially affect the formation and diffusion of activated NO species.Systematic in situ diffuse reflectance infrared Fourier transform spectroscopy analyses coupled with selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)reaction demonstrate that the Lewis acid sites over MnO_(x)are more active for NO reduction but have lower selectivity to N_(2)than Brønsted acids sites.Brønsted acid sites primarily produce N_(2),whereas Lewis acid sites primarily produce N_(2)O,contributing to unfavorable N_(2)selectivity.The Brønsted acid sites present in Y zeolite,which are stronger than those on MnO_(x),accelerate the NH_(3)-SCR reaction in which the nitrite/nitrate species diffused from the MnO_(x)particles rapidly convert into the N_(2).Therefore,it is important to design the catalyst so that the activated NO species formed in MnO_(x)diffuse to and are selectively decomposed on the Brønsted acid sites of H-Y zeolite rather than that of MnO_(x)particle.For the physically mixed H-MnO_(x)+H-Y sample,the abundant Brønsted/Lewis acid sites in H-MnO_(x)give rise to significant consumption of activated NO species before their inter-particle diffusion,thereby hindering the enhancement of the synergistic effects.Furthermore,we found that the intercalated K+in K-MnO_(x)has an unexpected favorable role in the NO reduction rate,probably owing to faster diffusion of the activated NO species on K-MnO_(x)than H-MnO_(x).This study will help to design promising metal oxide-zeolite hybrid catalysts by identifying the role of the acid sites in two different constituents. 展开更多
关键词 Hybrid metal oxide-zeolite The role of acid sites Manganese oxides Physical mixing Selective catalytic reduction of NO_(x)with NH_(3)
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Surface doping effect on the optoelectronic performance of 2D organic crystals based on cyano-substituted perylene diimides
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作者 Jaeyong Ahn Zhenping Li +6 位作者 Zhiwei Wang Ke Gao Huagui Zhuo Wanuk Choi Gang Chang Xiaobo Shang Joon Hak Oh 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第9期193-197,共5页
Compared to organic thin films,organic single crystals offer significant potential in organic phototransistors(OPTs)due to their enhanced charge transport,large surface area,and defect-free nature.However,the developm... Compared to organic thin films,organic single crystals offer significant potential in organic phototransistors(OPTs)due to their enhanced charge transport,large surface area,and defect-free nature.However,the development of n-type semiconductors has lagged behind p-type semiconductors.To enhance semiconductor device performance,a doping process can be employed,which typically involves the introduction of charged impurities into the crystalline semiconducting material.Its aim is to reduce the Ohmic losses,increase carrier density,improve transport capabilities,and facilitate effective carrier injection,ultimately enhancing the electrical properties of the material.Traditional doping processes,however,often pose a risk of damaging the structure of single crystals.In this study,we have synthesized novel cyanosubstituted chiral perylene diimides,which self-assemble into two-dimensional single crystals that can be used for n-type semiconductor devices.We have employed a surface doping strategy using diethylamine vapor without disrupting the crystal structure.The fabricated devices exhibit significantly higher charge transport properties after doping,achieving a maximum electron mobility of 0.14 cm^(2)V^(-1)s^(-1),representing an improvement of over threefold.Furthermore,the optoelectronic performance of the doped devices has significantly improved,with the external quantum efficiency increased by over 9 times and the significantly improved response time.These results suggest that our surface doping technology is a promising way for enhancing the performance of 2D organic single-crystal OPTs. 展开更多
关键词 Doping effect PHOTOTRANSISTORS Perylene diimides Organic crystals Cyano substitution
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Apparent Solubility of Natural Products Extracted with Near-Critical Carbon Dioxide
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作者 Helena Sovová 《American Journal of Analytical Chemistry》 2012年第12期958-965,共8页
The apparent solubility controls the initial stage of supercritical fluid extraction of natural products, which is most important for the process economics. Based on the literature, data on CO2 apparent solubility of ... The apparent solubility controls the initial stage of supercritical fluid extraction of natural products, which is most important for the process economics. Based on the literature, data on CO2 apparent solubility of volatile substances from different matrices as leaves, flowers, rhizomes and seeds were collected and compared with their thermodynamic solubility. The adsorption isotherm derived by del Valle and Urrego as a modification of the isotherm proposed by Perrut et al. is universal enough to interpret these data as well as the apparent solubility of vegetable oils from seeds, for which it was originally proposed. When the apparent solubility of minor extract components in CO2 is compared with their thermodynamic solubility, their fraction in the extracted mixture should be taken into account. 展开更多
关键词 SUPERCRITICAL Fluid Extraction Solubility Adsorption ISOTHERM VEGETABLE OILS VOLATILE Compounds
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Characterization of the Effect of Programmed Aeration on Energy Efficiency of Microalgae Cultivation System
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作者 Robert Bocsi Dora Rippel-Petho +2 位作者 Geza Horvath Laszlo Hanak Zoltan Hodai 《World Journal of Engineering and Technology》 2017年第3期481-486,共6页
With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we m... With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we must reckon with the energy balance of the whole process. Densification and processing of microalgae can consume 50% - 70% of the energy that can be extracted from the cells,?therefore the cultivation should use such a little energy as it possible. In closed cultivation systems,?there are three main energy intensive steps: artificial illumination, dissolution of gas compounds and mixing. We have carried out our measurements in our lab-scale screening photobioreactor system for the investigation of the most energy effective program for aeration. We have found the aeration program considerable solution for lower energy consumption in?algae cultivation. 展开更多
关键词 ENERGY EFFICIENCY MICROALGAE CULTIVATION AERATION
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Interface engineering of Co nanoparticles decorated by Ir confined in N-doped carbon nanotubes for flexible Zn-air batteries and pH-universal overall water splitting
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作者 Ying-Gang Sun Xin Du +5 位作者 Ji-Gang Wang Qiang Liu Jing-Lin Mu Zhong-Fang Li He-Qing Jiang Li-Kai Wang 《Rare Metals》 CSCD 2024年第12期6447-6459,共13页
To alleviate the crisis of energy shortages,the scalable fabrication of highly efficient electrocatalysts is highly sought after for metal-air batteries and pH-universal overall water splitting.Hereby,an in situ const... To alleviate the crisis of energy shortages,the scalable fabrication of highly efficient electrocatalysts is highly sought after for metal-air batteries and pH-universal overall water splitting.Hereby,an in situ construction to achieve Co@Ir nanoparticles in N-doped carbon nanotubes has been explored,which were directly fabricated by the pyrolysis and galvanic replacement.The interface engineering of Co@Ir core-shell structures could enhance interfacial and synergistic effects,achieving the tailorable electrocatalytic activities for oxygen reduction reaction,oxygen evolution reaction and hydrogen evolution reaction.Co@Ir-NT demonstrates the outstanding stability for overall water splitting under pH-universal conditions.Co@Ir-NT-based r-ZABs display a high power density of295.1 mW·cm^(-2)and a ultralong cycle stability over 2000continuous charge-discharge cycles,and Co@Ir-NT-based F-ZABs maintain the similar performance at different bending angles,suggesting its promising potential in the application of wearable electronics.The corresponding theoretical calculations also indicate that Co@Ir core-shell structure could improve the adsorption capacity and facilitate the breakage of O-O band.Hence,this work might be helpful for developing multifunctional catalysts for metalair batteries and water splitting under pH-universal conditions. 展开更多
关键词 Co@Ir Carbon nanotubes Electrocatalysts Zn-air batteries Water splitting
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