检索结果-南通市图书馆

International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 358-366页

作者： Yong-xing Zheng Jilai Ning Wei Liu pan-jin hu jin-fang Lü Jie pang State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming 650093China School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

To evaluate the feasibility of recovering Pb and Zn sulfides and Ag-containing minerals from Zn leaching residue by the process of reduction roasting followed by flotation,the reaction behaviors of Pb and Zn sulfates during this process were *** analysis showed that the transformation ratios of PbSO4 and ZnSO4 could reach 65.51%and 52.12%,respectively,after reduction roasting,and the introduction of a sulfidation agent could improve the transformation ratios of these *** electron microscopy-energy dispersive spectroscopy(SEM-EDS)revealed that temperature obviously affects the particle size,crystal growth,and morphology of the artificial Pb and Zn sulfide *** size analysis demonstrated that the particle size of the materials increases after *** tests revealed that a flotation concentrate composed of 12.01wt%Pb,27.78wt%Zn,and 6.975×10^(−2)wt%Ag with recoveries of 60.54%,29.24%,and 57.64%,respectively,could be obtained after roasting.

关键词： zinc leaching residue reduction roasting flotation Pb and Zn sulfates artificial sulfides

A CNN-SVR model for NO_(2)profile prediction based on MAX-DOAS observations:The influence of Chinese New Year overlapping the 2020 COVID-19 lockdown on vertical distributions of tropospheric NO_(2)in Nanjing,China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第7期141卷 151-165页

作者： Xin Tian Zijie Wang Pinhua Xie jin Xu Ang Li Yifeng pan Feng hu Zhaokun hu Mingsheng Chen Jiangyi Zheng Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key laboratory of Environmental Optical and Technology Anhui Institute of optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China School of Environmental Science and Optoelectronic Technology University of Science and Technology of ChinaHefei 230026China

In this study,a hybrid model,the convolutional neural network-support vector regression model,was adopted to achieve prediction of the NO_(2)profile in Nanjing from January 2019to March *** the sudden decline in NO_(2)in February 2020,the contribution of the Coronavirus Disease-19(COVID-19)lockdown,Chinese New Year(CNY),and meteorologi cal conditions to the reduction of NO_(2)was ***_(2)vertical column densities(VCDs) from January to March 2020 decreased by 59.05%and 32.81%,relative to the same period in 2019 and 2021,*** the period of 2020 COVID-19,the average NO_(2)VCDs were 50.50%and 29.96%lower than those during the pre-lockdown and post-lockdown pe riods,*** NO_(2)volume mixing ratios(VMRs)during the 2020 COVID-19 lock down significantly decreased below 400 *** NO_(2)VMRs under the different wind fields were significantly lower during the lockdown period than during the pre-lockdown period This phenomenon could be attributed to the 2020 COVID-19 *** NO_(2)VMRs be fore and after the CNY were significantly lower in 2020 than in 2019 and 2021 in the same period,which further proves that the decrease in NO_(2)in February 2020 was attributed to the COVID-19 *** source analysis of an NO_(2)pollution episode during the lockdown period showed that the polluted air mass in the Beijing-Tianjin-Hebei was trans ported southwards under the action of the north wind,and the subsequent unfavorable meteorological conditions(local wind speed of<2.0 m/sec)resulted in the accumulation o pollutants.

关键词： MAX-DOAS CNN-SVR Nitrogen dioxide COVID-19 Chinese New Year Regional transport

Semi-Varying Coefficient panel Data Model with Technical Indicators Predicts Stock Returns in Financial Market

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第4期37卷 1638-1652页

作者： hu Xuemei pan Ying LI Xiang School of Mathematics and Statistics Chongqing Technology and Business UniversityChongqing 400067China Chongqing Key Laboratory of Social Economy and Applied Statistics Chongqing 400067China Research Center for Economy of Upper Reaches of the Yangtse River Chongqing Technology and Business UniversityChongqing 400067China

Accurately predicting stock returns is a conundrum in financial *** this conundrum can bring huge economic benefits for investors and also attract the attention of all circles of *** this paper the authors combine semi-varying coefficient model with technical analysis and statistical learning,and propose semi-varying coefficient panel data model with individual effects to explore the dynamic relations between the stock returns from five companies:CVX,DFS,EMN,LYB,and MET and five technical indicators:CCI,EMV,MOM,ln ATR,ln RSI as well as closing price(ln CP),combine semi-parametric fixed effects estimator,semi-parametric random effects estimator with the testing procedure to distinguish fixed effects(FE) from random effects(RE),and finally apply the estimated dynamic relations and the testing set to predict stock returns in December 2020 for the five *** proposed method can accommodate the varying relationship and the interactive relationship between the different technical indicators,and further enhance the prediction accuracy to stock returns.

关键词： Fixed effects random effects semi-varying coefficient panel data model stock returns technical indicators

Impact of continuous care on cardiac function in patients with lung cancer complicated by coronary heart disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第2期12卷 314-321页

作者： Ting Gao jin-Lan Luo pan Guo Xi-Wen hu Xiao-Yan Wei Yan hu Division of Cardiovascular First Ward Department of Internal MedicineLiyuan HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430077Hubei ProvinceChina Department of Cardiovascular Medicine Wuhan Wuchang HospitalWuhan 430063Hubei ProvinceChina Cardiovascular Clinical Medical Center Liyuan HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430077Hubei ProvinceChina Department of Second Thoracic Surgery Hubei Cancer HospitalWuhan 430079Hubei ProvinceChina

BACKGROUND Despite sharing similar pathogenic factors,cancer and coronary heart disease(CHD)occur in comparable populations at similar ages and possess similar susceptibility ***,it is increasingly commonplace for patients to experience the simultaneous occurrence of cancer and CHD,a trend that is steadily *** To determine the impacts of continuing care on lung cancer patients with CHD following percutaneous coronary intervention(PCI).METHODS There were 94 lung cancer patients with CHD following PCI who were randomly assigned to the intervention group(n=38)and the control group(n=41).In the intervention group,continuing care was provided,while in the control group,routine care was *** evaluation of cardiac and pulmonary function,medication compliance,a 6-min walk test,and patient quality of life was *** Differences between the two groups were significant in left ventricular ejection fraction,6-min walk test,oxygen uptake,quality of life and medication compliance(P<0.05).In comparison with the control group,the enhancement in the intervention group was more *** intervention group had more patients with high medication compliance than the control group,with a statistically significant difference(P<0.05).CONCLUSION After undergoing PCI,lung patients with CHD could benefit from continued care in terms of cardiac and pulmonary function,medications compliance,and quality of life.

关键词： Lung cancer Continuing care Coronary heart disease Percutaneous coronary intervention

Micro-mechanism Study on the Different Antioxidants Protective Effect of Vegetable Oil by ReaxFF Molecular Dynamics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 1269-1279页

作者： Haoxi Cong Xuefeng hu Hao pan Qingmin Li State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

The aging problem of vegetable oil has severely restricted the popularization and application of vegetable oil *** antioxidants is the most recommended *** present,there is insufficient research on the micromechanism application of the protective effect of antioxidants on vegetable *** this paper,multiple vegetable oil models with different types and concentrations of antioxidants are *** the molecular dynamics simulation based on ReaxFF is carried out at different temperatures and oxygen *** show that the protective mechanism of antioxidants is to release H and combine this with free radicals generated by the decomposition of unsaturated fatty acids(UFA)in the *** addition,the protective effects of four antioxidants show different *** stronger ones are tert-butyl hydroquinone(TBHQ)and butylated hydroxytoluene(BHT),while the weaker ones are butylated hydroxyanisole(BHA)and propyl gallate(PG).TBHQ has a better protective effect at lower concentrations,but the decomposition of UFA is promoted at higher *** the temperature rises,the decomposition of UFA is *** the addition of oxygen,smaller molecular compounds are easily oxidized,and the decomposition of UFA is *** above research could reveal the microscopic mechanism of antioxidant protection on vegetable oil,providing theoretical references for further exploration of effective vegetable oil aging protection technology.

关键词： Antioxidant molecular dynamics transformer vegetable oil

Multi-Objective Equilibrium Optimizer for Feature Selection in High-Dimensional English Speech Emotion Recognition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 1957-1975页

作者： Liya Yue Pei hu Shu-Chuan Chu Jeng-Shyang pan Fanli Business School Nanyang Institute of TechnologyNanyang473004China School of Computer and Software Nanyang Institute of TechnologyNanyang473004China College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao266590China Department of Information Management Chaoyang University of TechnologyTaichung413310Taiwan

Speech emotion recognition(SER)uses acoustic analysis to find features for emotion recognition and examines variations in voice that are caused by *** number of features acquired with acoustic analysis is extremely high,so we introduce a hybrid filter-wrapper feature selection algorithm based on an improved equilibrium optimizer for constructing an emotion recognition *** proposed algorithm implements multi-objective emotion recognition with the minimum number of selected features and maximum ***,we use the information gain and Fisher Score to sort the features extracted from ***,we employ a multi-objective ranking method to evaluate these features and assign different importance to *** with high rankings have a large probability of being ***,we propose a repair strategy to address the problem of duplicate solutions in multi-objective feature selection,which can improve the diversity of solutions and avoid falling into local *** random forest and K-nearest neighbor classifiers,four English speech emotion datasets are employed to test the proposed algorithm(MBEO)as well as other multi-objective emotion identification *** results illustrate that it performs well in inverted generational distance,hypervolume,Pareto solutions,and execution time,and MBEO is appropriate for high-dimensional English SER.

关键词： Speech emotion recognition filter-wrapper high-dimensional feature selection equilibrium optimizer multi-objective

Slippery hydrogel with desiccation-tolerant‘skin’for high-precision additive manufacturing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第2期6卷 486-500页

作者： Desheng Liu pan Jiang Yue hu Yaozhong Lu Yixian Wang Jiayu Wu Danli hu Tao Wu Xiaolong Wang State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000People’s Republic of China CAS Key Laboratory of Chemistry of Northwestern Plant Resources Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000People’s Republic of China Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai Zhongke Research Institute of Advanced Materials and Green Chemical EngineeringYantai 264006People’s Republic of China Key Laboratory of Materials-Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region School of Chemistry and Chemical EngineeringShihezi UniversityShihezi 832003People’s Republic of China

Hydrogels inevitably undergo dehydration,structural collapse,and shrinkage deformation due to the uninterrupted evaporation in the atmosphere,thereby losing their flexibility,slipperiness,and manufacturing ***,we propose a novel bioinspired strategy to construct a spontaneously formed‘skin’on the slippery hydrogels by incorporating biological stress metabolites trehalose into the hydrogel network,which can generate robust hydrogen bonding interactions to restrain water *** contents of trehalose in hydrogel matrix can also regulate the desiccation-tolerance,mechanical properties,and lubricating performance of slippery hydrogels in a wide *** vat photopolymerization three-dimensional printing and trehalose-modified slippery hydrogels enables to achieve the structural hydrogels with high resolution,shape fidelity,and sophisticated architectures,instead of structural collapse and shrinkage deformation caused by *** thus,this proposed functional hydrogel adapts to manufacture large-scale hydrogels with sophisticated architectures in a long-term *** a proof-of-concept demonstration,a high-precision and sophisticated slippery hydrogel vascular phantom was easily fabricated to imitate guidewire ***,the proposed protocol is universally applicable to diverse types of hydrogel *** strategy opens up a versatile methodology to fabricate dry-resistant slippery hydrogel for functional structures and devices,expanding their high-precision processing and broad applications in the atmosphere.

关键词： slippery hydrogel trehalose desiccation tolerance vat photopolymerization 3D printing hydrogen bonding

Synergistic precipitant powered self-assembly of papain for cross-linked enzyme crystals preparation

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第2期85卷 102-112页

作者： Qi Hao pan Guo Honghai Wang Min Su Chunli Li Yuqi hu Weiyi Su School of Chemical Engineering and Technology Hebei University of TechnologyTianjin300130China National-Local Joint Engineering Laboratory for Energy Conservation of Chemical Process Integration and Resources Utilization Tianjin300130China

In this study,we prepared cross-linked enzyme crystals(CLECs)of papain to further broaden the application of the enzyme with high activity in extreme ***,papain crystals were successfully obtained based on the micro-batch,batch,and expanded batch crystallization ***,ammonium sulfate and polyethylene glycol 6000(PEG6000)were synergistically used as the precipitants,while L-cysteine was applied to enhance the activity of ***,the interaction between L-cysteine and papain was modeled by molecular docking *** was found that L-cysteine could form a hydrogen bond with aspartic acid residue(Asp)at site 158,and the electrostatic attraction with lysine residue(Lys)at site 156 was also quite *** the enzyme crystals were cross-linked by glutaraldehyde at optimized *** papain CLECs were identified by various methods,and it was found that the thermal stability and enzymatic activity both increased compared to the raw *** importantly,it could be applied at more rigorous conditions,for example,pH of 4.

关键词： Papain Cross-linked enzyme crystals L-cysteine Molecular docking Crystallization

Uncovering of the formation of rare earth texture and pseudo fiber bimodal microstructure in the high ductility Mg-2Gd-0.4Zr alloy during extrusion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第5期172卷 166-184页

作者： Tianxu Zheng Yaobo hu Chao Zhang Tianshuo Zhao Bin Jiang Fusheng pan Aitao Tang College of Materials Science and Engineering Chongqing UniversityChongqing400044China National Engineering Research Center for Magnesium Alloys Chongqing400044China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240China

The aim of this research was to elucidate the underlying mechanism involved in the formation of rare earth(RE)texture and pseudo fiber bimodal microstructure in the high ductility Mg-2Gd-0.4Zr *** microstructure and texture evolution during the extrusion process were analyzed using various tech-niques,including optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and electron probe microanalysis(EPMA).The findings revealed that the RE texture in the extruded Mg-2Gd-0.4Zr alloy emerged during the dynamic recrystallization(DRX)process and was further strengthened during the subsequent static recrystallization and grain growth *** nu-cleation and growth of grains in the streamline region of Zr particles were delayed in comparison to other regions due to the pinning effect of Zr particles,ultimately resulting in the formation of pseudofiber bi-modal microstructure in the extruded Mg-2Gd-0.4Zr alloy.

关键词： Magnesium alloys Ductility Rare earth texture Bimodal microstructure

Interaction mechanism of ferrate(Ⅵ) with arsenopyrite surface and its effect on flotation separation of chalcopyrite from arsenopyrite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2022年第11期32卷 3731-3743页

作者： Run-peng LIAO pan-jin hu Shu-ming WEN Yong-xing ZHENG Xian-hui QIU jin-fang LÜ Jian LIU State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming 650093China Faculty of Resource and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collector was investigated by flotation experiments,contact angle measurements,adsorption measurements,localized electrochemical impedance spectroscopy(LEIS)measurements,and X-ray photoelectron spectroscopy(XPS)*** results showed that K_(2)FeO_(4)strongly depressed arsenopyrite in a pH range of 4−11,and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^(−4)mol/L K_(2)FeO_(4)and 5×10^(−5)mol/L PEX at pH 8 or *** the presence of K_(2)FeO_(4) and PEX,the contact angle and the xanthate adsorption capacity of arsenopyrite decreased *** measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite *** analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.

关键词： ferrate(Ⅵ) arsenopyrite chalcopyrite low-alkalinity flotation separation