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Design Guidelines for Composition of Brazing Filler Metals and Evolution Mechanisms of Typical Microstructures 被引量:6
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作者 Long Weimin 《稀有金属材料与工程》 北大核心 2025年第4期837-853,共17页
Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler ... Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects. 展开更多
关键词 design of brazing filler metals design guidelines for composition Ag based brazing filler metals eutectic structures evolution
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Quantitative Analysis of the Fatty Acid Compositions of Different Oils and Associations with Antioxidant Capacity and Oxidative Stability 被引量:1
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作者 LIU Junchen SUN Xiaoman +3 位作者 ZHANG Huirong SHAO Haofan LING Xiao LI Li 《现代食品科技》 北大核心 2025年第4期305-315,共11页
Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w... Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils. 展开更多
关键词 gas chromatography-mass spectrometry vegetable oil fatty acid composition oxidative stability antioxidant capacity
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Research progress of structural regulation and composition optimization to strengthen absorbing mechanism in emerging composites for efficient electromagnetic protection 被引量:4
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作者 Pengfei Yin Di Lan +7 位作者 Changfang Lu Zirui Jia Ailing Feng Panbo Liu Xuetao Shi Hua Guo Guanglei Wu Jian Wang 《Journal of Materials Science & Technology》 2025年第1期204-223,共20页
With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electro... With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well. 展开更多
关键词 Microwave absorption Structural regulation Performance optimization Emerging composites Synthetic strategy
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Dynamic Analysis and Optimal Parameter Design of FlexibleComposite Structures via Absolute Nodal Coordinate Formulation 被引量:1
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作者 杨丹 余海东 林张鹏 《Journal of Shanghai Jiaotong university(Science)》 EI 2023年第5期621-629,共9页
The composite structure with the dielectric elastomer and soft materials is the main form of theactuators in soft robots. However, the theoretical model is hard to obtain due to the nonlinear large deformationof mater... The composite structure with the dielectric elastomer and soft materials is the main form of theactuators in soft robots. However, the theoretical model is hard to obtain due to the nonlinear large deformationof materials. In this paper, a new composite element model is established based on the absolute nodal coordinateformulation. The consistent deformation conditions at the contact interface between two thin plates are deduced.The hyperelastic constitutive model and the dielectric elastomer constitutive model are introduced for the twothin plates. Then the dynamic model is established to study the dynamic behaviors of the composite flexiblestructure with various parameters. The results show that the nonlinear deformation appears obviously whenthe flexible composite plate structure is driven by various voltages, and the warping deformation becomes moreobvious with the increase of the voltage. The width and thickness of the driven thin plate influence the stabilityof the whole structure. With the decrease of the width or thickness, the deformation of the structure is moreconsistent with obvious periodicity, and the control performance is improved. Finally, the structural parametersof the composite structures are optimized to improve the control performance based on the dynamic performance.Additionally, smaller width and thickness parameters are preferred to obtain better performance in the design offlexible actuator of soft robot. 展开更多
关键词 flexible composite structure absolute nodal coordinate formulation dynamic behavior deformation compatibility optimal design
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Exploring the Scientific Connotation of Gypsum in Baihu Decoction Compatibility with Heat-clearing Effect Based on Phase Composition 被引量:2
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作者 Yunyun Wang Zhengxian Zhang +2 位作者 Haotian Peng Huahui Zeng Xiangxiang Wu 《Chinese Medicine and Natural Products》 2025年第1期35-46,共12页
Objective This study aimed to study the effects of different crystalline states of Sheng Shigao(raw gypsum,RG)and its inorganic elements on the antipyretic efficacy of Baihu Decoction(BHT).Methods RG samples calcined ... Objective This study aimed to study the effects of different crystalline states of Sheng Shigao(raw gypsum,RG)and its inorganic elements on the antipyretic efficacy of Baihu Decoction(BHT).Methods RG samples calcined at different temperatures were prepared.The phase composition of RG and Duan Shigao(calcination of gypsum,CG)as well as the changes in phase composition before and after adding water to RG calcined at specific temperatures,were determined using X-ray diffraction(XRD).A fever model was established by subcutaneously injecting 20%yeast suspension(10 mL·kg~(-1))into the backs of rats.The effects of BHT containing RG in different crystalline states on rat body temperature were measured.Serum levels of IL-1β,IL-6,and hypothalamic prostaglandin E2(PGE_2)were detected using ELISA.Serum Ca~(2+)levels were measured using a microplate method.The content of trace elements in RG and CG and the corresponding freeze-dried BHT powder was determined using inductively coupled plasma mass spectrometry(ICP-MS).The complexation of representative inorganic elements with mangiferin,a major active component in BHT,was investigated using UV-Vis spectroscopy and fluorescence spectroscopy.A validation model was established using RAW264.7 mouse macrophages.Drug-containing serum of BHT with different inorganic elements was prepared,and the nitric oxide(NO)levels in the cell supernatant of different treatment groups were measured using the Griess method.The mRNA levels of IL-6,TNF-α,and PGE2in each group were detected using qPCR(real-time fluorescent quantitative PCR).Results After calcination,the phase composition of RG changed,and the content of inorganic elements in RG,CG170(RG calcined at 170°C),and CG350(RG calcined at 350°C)showed similar trends.Compared with RG,the content of Ca,Sr,Al,and Na in CG changed significantly.Compared with BHT,the content of Ca,Sr,Si,and Na in CG changed significantly when incorporated into the formula.Intermolecular interactions confirmed strong binding between mangiferin and Cu~(2+)and Al~(3+).Cu~(2+)and Fe~(3+)exhibited fluorescence quenching effects on mangiferin solution,while Al~(3+)and Zn~(2+)showed strong fluorescence enhancement,with fluorescence intensity increasing by 120-fold and 30-fold,respectively.In vitro evaluation of synergistic anti-inflammatory effects confirmed that Ca,Fe,Cr,Al,and Si exhibited synergistic anti-inflammatory effects.Conclusion The crystalline state of RG has little effect on its antipyretic properties,while Ca,Sr,Na,Fe,and Al are likely the key material bases influencing its efficacy. 展开更多
关键词 GYPSUM Baihu Decoction heat-clearing compatibility of medicines phase composition
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Prediction of alloy composition and microhardness by random forest in maraging stainless steels based on a cluster formula 被引量:1
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作者 Zhen Li Dong-hui Wen +5 位作者 Yue Ma QingWang Guo-qing Chen Rui-qian Zhang Rui Tang Huan He 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2018年第7期717-723,共7页
Fe-Ni-Cr-based super-high-strength maraging stainless steels were generally realized by multiple-element alloying under a given heat treatment processing. A series of alloy compositions were designed with a uniform cl... Fe-Ni-Cr-based super-high-strength maraging stainless steels were generally realized by multiple-element alloying under a given heat treatment processing. A series of alloy compositions were designed with a uniform cluster formula of [Ni16Fe192](Cr32(Ni16-x-y-z-m-n MoxTiyNbzAlmVn)) (at.%) that was developed out of a unique alloy design tool, a cluster- plus-glue-atom model. Alloy rods with a diameter of 6 mm were prepared by copper-mold suction-cast processing under the argon atmosphere. These alloy samples were solid-solutioned at 1273 K for 1 h, followed by water-quenching, and then aged at 783 K for 3 h. The effect of the valence electron concentration, characterized with the number of valence electrons per unit cluster (VE/uc) formula of 16 atoms, on microhardness of these designed maraging stainless steels at both solid- solutioned and aged states was investigated. The relationship between alloy compositions and microhardness in maraging stainless steels was firstly established by the random forest (RF, a kind of machine learning methods) based on the experimental results. It was found that not only the microhardness of any given composition alloy within the frame of cluster formula, but also the alloy composition with a maximum microhardness for any given VE/uc, could be predicted in good agreement with the guidance of the relationship by RF. The contributions of minor-alloying elements to the microhardness of the aged alloys were also discussed. 展开更多
关键词 Maraging stainless steel composition design MICROHARDNESS Valence electron concentration Random forest
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Central composite design for optimization and formulation of desulphurization of iron ore concentrate using atmospheric leaching process 被引量:1
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作者 Ali Mostafavi Hassan Rezvanipour +2 位作者 Dariush Afzali Tayebeh Shamspur Amir Hajizadehomran 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2018年第1期57-64,共8页
Owing to the negative effects of sulphur in iron ore on steelmaking process and environment, a tank leaching process was performed in atmospheric conditions to remove the sulphur from the iron ore concentrate and simu... Owing to the negative effects of sulphur in iron ore on steelmaking process and environment, a tank leaching process was performed in atmospheric conditions to remove the sulphur from the iron ore concentrate and simultaneously to transform sulphide minerals into useful by-products. To achieve desirable sulphur removal rate and efficiency, central composite design was adopted as a response surface methodology for the optimization and evaluation of the process. A full-quadratic polynomial equation between the sulphur removal and the studied parameters was established to assess the behaviour of sulphur removal as a function of the factors and to predict the results in various conditions. The optimum conditions were obtained based on the variance tests and response surface plots, from which the optimized ranges for each factor resulting in the best response (corresponding to the highest percentage of desulphurization) could be then achieved. The results show that most desirable conditions are atmospheric leaching in 1.39 mol/dm3 nitric acid and 0.88 mol/dm3 sulphuric acid for 47 h. The designed process under the optimized desulphurization conditions was applied to a real iron ore concentrate. More than 75% of the total sulphur was removed via the leaching process. In addition to the desulphurization, the conversion of sulphide-bearing minerals into useful by-products, extraction of valuable metals, and executing the process under atmospheric conditions are the other advantages of the proposed method. 展开更多
关键词 DESULPHURIZATION Iron ore concentrate Sulphide mineral leaching Central composite design Atmosphericleaching process
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PREDICTION OF MECHANICAL PROPERTY OF WHISKER REINFORCED METAL MATRIX COMPOSITE: PART-I. MODEL AND FORMULATION 被引量:1
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作者 刘秋云 梁乃刚 刘晓宇 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2000年第3期-,共6页
Based on study of strain distribution in whisker reinforced metal matrix composites, an explicit precise stiffness tensor is derived. In the present theory, the effect of whisker orientation on the macro property of c... Based on study of strain distribution in whisker reinforced metal matrix composites, an explicit precise stiffness tensor is derived. In the present theory, the effect of whisker orientation on the macro property of composites is considered, but the effect of random whisker position and the complicated strain field at whisker ends are averaged. The derived formula is able to predict the stiffness modulus of composites with arbitrary whisker orientation under any loading condition. Compared with the models of micro mechanics, the present theory is competent for modulus prediction of actual engineering composites. The verification and application of the present theory are given in a subsequent paper published in the same issue 展开更多
关键词 whisker short fiber reinforced composite whisker orientation ANISOTROPY mechanical property prediction
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Synthesis and microencapsulation of oleic acid sterol ester liquid crystals for its application in sunscreen formulations
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作者 Xuze Liu Chang Xu +1 位作者 Liangliang Lin Hujun Xu 《日用化学工业(中英文)》 北大核心 2025年第11期1408-1418,共11页
This study reports the synthesis of oleic acid sterol ester with liquid crystalline properties and its enhanced stability and UV-blocking performance through microencapsulation.Oleic acid sterol ester was synthesized ... This study reports the synthesis of oleic acid sterol ester with liquid crystalline properties and its enhanced stability and UV-blocking performance through microencapsulation.Oleic acid sterol ester was synthesized via the esterification of phytosterol and oleic acid,whose structure was characterized using Fourier-transform infrared spectroscopy(FTIR)and mass spectrometry(MS).Its liquid crystalline behavior was confirmed via the polarized optical microscopy(POM),thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),wide-angle X-ray scattering(WAXS),and small-angle X-ray scattering(SAXS).UV absorption tests were conducted to assess the UV-blocking performance of the oleic acid sterol ester liquid crystals.To improve the stability of its liquid crystalline structure,the oleic acid sterol ester was encapsulated into microcapsules through the emulsion polymerization.SPF measurements were performed on the sunscreen formulations containing liquid crystal microcapsules.The oleic acid sterol ester displayed cholesteric liquid crystalline behavior and strong UVA absorption,which indicates its suitability as a natural UV absorber.Microencapsulation further enhanced its stability and UV-blocking properties.SPF testing showed that the formulations with microcapsules achieved an SPF value of 7.01,which surpasses the nano titanium dioxide(SPF=6.23)and significantly outperform the unencapsulated liquid crystal formulations(SPF=2.65).This study highlights the potential of microencapsulated oleic acid sterol ester as a novel UV absorber in the sunscreen formulations,offers the enhanced stability and effective UV protection,and showcases its application potential in the innovative cosmetic products. 展开更多
关键词 PHYTOSTEROL liquid crystals MICROENCAPSULATION UV absorption sunscreen formulations SPF testing
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Micro-mechanical model for predicting the elasto-plastic behavior of composites based on secant formulation method 被引量:1
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作者 Junhao LIANG Xinhai HE Wenlong TIAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2021年第1期281-295,共15页
To predict the Elasto-Plastic Behaviors(EPBs)of aligned inclusions reinforced composites,this paper develops an interpolative Mori-Tanaka/Double-Inclusion(MT-DI)homogenization model with the secant formulation,and giv... To predict the Elasto-Plastic Behaviors(EPBs)of aligned inclusions reinforced composites,this paper develops an interpolative Mori-Tanaka/Double-Inclusion(MT-DI)homogenization model with the secant formulation,and gives the numerical implementation algorithms of the developed MT-DI model with the secant formulation.The Finite Element(FE)homogenization method is implemented to provide the "exact" EPBs of the composites and thus validate the MT-DI model with the secant formulation.The MT-DI model with the 2 nd-order secant formulation is validated to provide the more accurate predictions,while the MT-DI model with the 1 st-order secant formulation always gives the stiffer predictions.The results show that using the macro-stress and macrostrain as the inputs,the MT-DI model with the secant formulation gives the identical predictions.The predictions of the MT-DI model with the secant formulation vary between those of the MT and DI models with the secant formulation.Meanwhile,the MT-DI model with the secant formulation does not predict the accurate EPBs for the phases of the composites. 展开更多
关键词 Elasto-plastic behavior FE homogenization Mean-field homogenization MT-DI model Secant formulation
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High-resolution Simulation Dataset of Hourly PM_(2.5)Chemical Composition in China(CAQRA-aerosol)from 2013 to 2020 被引量:1
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作者 Lei KONG Xiao TANG +14 位作者 Jiang ZHU Zifa WANG Bing LIU Yuanyuan ZHU Lili ZHU Duohong CHEN Ke HU Huangjian WU Qian WU Jin SHEN Yele SUN Zirui LIU Jinyuan XIN Dongsheng JI Mei ZHENG 《Advances in Atmospheric Sciences》 2025年第4期697-712,共16页
Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategi... Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategies.A high-resolution PM_(2.5) chemical composition dataset(CAQRA-aerosol)is developed in this study,which provides hourly maps of organic carbon,black carbon,ammonium,nitrate,and sulfate in China from 2013 to 2020 with a horizontal resolution of 15 km.This paper describes the method,access,and validation results of this dataset.It shows that CAQRA-aerosol has good consistency with observations and achieves higher or comparable accuracy with previous PM_(2.5) composition datasets.Based on CAQRA-aerosol,spatiotemporal changes of different PM_(2.5) compositions were investigated from a national viewpoint,which emphasizes different changes of nitrate from other compositions.The estimated annual rate of population-weighted concentrations of nitrate is 0.23μg m^(−3)yr^(−1) from 2015 to 2020,compared with−0.19 to−1.1μg m^(−3)yr^(−1) for other compositions.The whole dataset is freely available from the China Air Pollution Data Center(https://doi.org/10.12423/capdb_PKU.2023.DA). 展开更多
关键词 PM_(2.5)composition dataset black carbon organic carbon AMMONIUM NITRATE SULFATE
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Composition optimization of inconel 718 via cluster formula and experimental verification 被引量:2
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作者 Yancheng Li Mo Li +6 位作者 Qing Wang Yajun Zhao Shuang Zhang Cunlei Zou Ying Li Lianchao Wang Chuang Dong 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第9期249-259,共11页
Superalloys feature multi-elements and complex elemental ranges,which makes the proper composition selection difficult.In fact,more strict composition standards generally apply in practical productions.The objective o... Superalloys feature multi-elements and complex elemental ranges,which makes the proper composition selection difficult.In fact,more strict composition standards generally apply in practical productions.The objective of this paper is to understand and eventually to renew the composition standard via example of the most common grade Inconel 718.We have recently shown that t he alloy chemistry originates from a nearest-neighbor cluster[center-shell]plus a few next-neighbor glue atoms,or expressed in cluster for-mula[center-shell](glue atoms).By grouping the elements into Ni=(Ni,Co,Cu,Fe),Cr=(Cr,Mn,Si,Mo),and Nb=(Nb,Al,Ti),it is found that the reported alloys fall within a narrow composition zone Ni_(11.0-13.0)-Cr_(3.5-4.5)-Nb_(1) confined by cluster formulas of 16 and 18 atoms.This composition zone is also expressed in terms of 288-atom supercluster formulas,Ni_(198-208)-Cr_(63-72)-Nb_(16-18),which leads to coordi-nated elemental variations in wt.%:69.0≤Ni+Co+Cu+Fe≤72.7;19.8≤Cr+Mn+1.7 Si+0.6 Mo≤22.8;8.7≤Nb+3.2 Al+1.9 Ti≤9.8.Within this composition zone,Ni_(206)-Cr_(65.5)-Nb_(16.5) is further pinpointed and validated by our own experiments to possess the optimal match of strength and plasticity both at room and at 923 K. 展开更多
关键词 Inconel 718 superalloy Cluster-plus-glue-atom model Cluster formula composition standard
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Sensory Characterizations and Optimization of Cashew Apple Jam Formulations Using Baobab Powder as a Source of Pectin
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作者 Marie Bianoun Louise Dégni Doudjo Soro +3 位作者 Essan Bla Zita N’Goran-Aw Djedjro Clément Akmel Nogbou Emmanuel Assidjo Kouassi Benjamin Yao 《Food and Nutrition Sciences》 2025年第1期120-136,共17页
Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value o... Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value of cashew apples by transforming them into jam. Specifically, the aim was first to characterize the sensory properties of cashew apple jam formulations using baobab powder as a source of pectin and then to optimise the formulations. A Box-Behken design with pH, Sugar, and Baobab as factors was used to model and characterize the jam sensory descriptors, and a multivariate analysis with SensomineR was used to characterize the jam formulations. The desirability function was used to optimise the formulations. The results show globally significant regressions at the 0.05 threshold for the sensory descriptors Gelling, Brilliance, Smell, Sweetness, and (-)Astringency, with the exception of (-)Salinity. The R2 coefficients are greater than 80%. The factors studied could have effects on the sensory descriptors of cashew jam formulations. The Baobab had the main effect on the gelling, smell, and astringency of the jams. Brilliance depended on the added sugar. A product effect (p < 0.001) was observed for the descriptors Smell, Gelling, Brilliance, and Sweetness, as these allowed the panelists to find differences between the formulations. Optimum jam formulation can be achieved with 51.56% sugar and 2.12% Baobab at a pH of 3.15. Cashew apple jam using Baobab offers opportunities to add value to apples that have long been abandoned in the field. It would be important to find conditions for prolonged storage of this jam. 展开更多
关键词 Cashew Apple Sensory Characterization Jam formulation Area Design Product Effect Overall Desirability
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Effect of preprocessing on performances of machine learning-based mineral composition analysis on gas hydrate sediments,Ulleung Basin,East Sea 被引量:1
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作者 Hongkeun Jin Ju Young Park +3 位作者 Sun Young Park Byeong-Kook Son Baehyun Min Kyungbook Lee 《Petroleum Science》 2025年第1期151-162,共12页
Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-... Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide. 展开更多
关键词 Sample-based preprocessing X-ray diffraction(XRD) Machine learning Mineral composition Gas hydrate(GH) Ulleung basin
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Products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball
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作者 ZHANG Chao QIN Yuehai 《中山大学学报(自然科学版)(中英文)》 北大核心 2025年第2期160-169,共10页
The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic fu... The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic functions in the unit ball by radial derivative.Then we extend the Sharma's results. 展开更多
关键词 composition operator multiplication operator differentiation operator weighted Bergman space
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A new 3-D element formulation on displacement of steel-concrete composite box beam 被引量:2
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作者 周凌宇 余志武 贺桂超 《Journal of Central South University》 SCIE EI CAS 2013年第5期1354-1360,共7页
Slip of a composite box beam may reduce its stiffness, enlarge its deformation and affect its performance. In this work, the governing differential equations and boundary conditions of composite box beams were establi... Slip of a composite box beam may reduce its stiffness, enlarge its deformation and affect its performance. In this work, the governing differential equations and boundary conditions of composite box beams were established. Analytic solutions of combined differential equations were also established. Partial degree of freedom was adopted to establish a new FEA element of three-dimensional beam, taking into account the slip effect. Slip and its first-order derivative were introduced into the nodes of composite box beams as generalized degree of freedom. Stiffness matrix and load array of beam elements were established. A three-dimensional nonlinear calculation program was worked out. The results show that the element is reliable and easy to divide and is suitable for special nonlinear analysis of large-span composite box beams. 展开更多
关键词 steel-concrete composite box beam shear deformation slip effect variational method finite beam element method
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Effect of Nitrocellulose-modified HTPB Binder on the Thermal Decomposition Behavior of Ammonium Nitrate/Magnesium Solid Propellant
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作者 Mohammed Jouini Amir Abdelaziz +4 位作者 Ahmed Fouzi Tarchoun Fateh Chalghoum Yash Pal Weiqiang Pang Djalal Trache 《火炸药学报》 北大核心 2025年第4期372-381,I0004,共11页
An energetic binder based on hydroxyl-terminated polybutadiene(HTPB),doped with different ratios of nitrocellulose(NC)(10%,20%,30%,and 50%),was developed to study the effect of NC doping on the thermal decomposition b... An energetic binder based on hydroxyl-terminated polybutadiene(HTPB),doped with different ratios of nitrocellulose(NC)(10%,20%,30%,and 50%),was developed to study the effect of NC doping on the thermal decomposition behavior of a composite propellant(CP)comprising ammonium nitrate(AN)as an oxidizer and magnesium(Mg)as a fuel.Optimization of the propellant formulation was conducted using Chemical Equilibrium with Applications-National Aeronautics and Space Administration(CEA-NASA)software,which demonstrated an increase in specific impulse by 12.09 s when the binder contained 50%NC.Fourier-transform infrared spectroscopy(FTIR)analysis confirmed the excellent compatibility between the components,and density measurements revealed an increase of 6.4%with a higher NC content.Morphological analysis using optical microscopy showed that NC doping improved the uniformity and compactness of the surface,reduced cavities,and achieved a more homogeneous particle distribution.Differential scanning calorimetry(DSC)analysis indicated a decrease in the decomposition temperature of the propellant as the NC content increased,while kinetic studies revealed a 48.68%reduction in the activation energy when 50%NC was incorporated into the binder.These findings suggest that the addition of NC enhances combustion efficiency and improves overall propellant performance.This study highlights the potential of the new HTPB-NC energetic binder as a promising approach for advancing solid propellant technology. 展开更多
关键词 physical chemistry composite propellant HTPB NITROCELLULOSE energetic binder thermal behavior
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Eigen value analysis of composite hollow shafts using modified EMBT formulation considering the shear deformation along the thickness direction
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作者 Pavani Udatha A.S.Sekhar Velmurugan R 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第10期1-12,共12页
Composite hollow shafts are used in power transmission applications due to their high specific stiffness and high specific strength.The dynamic characteristics of these shafts are important for transmission applicatio... Composite hollow shafts are used in power transmission applications due to their high specific stiffness and high specific strength.The dynamic characteristics of these shafts are important for transmission applications.Dynamic modelling of these shafts is generally carried out using Equivalent Modulus Beam Theory(EMBT)and Layerwise Beam Theory(LBT)formulations.The EMBT formulation is modified by considering stacking sequence,shear normal coupling,bending twisting coupling and bending stretching coupling.It is observed that modified EMBT formulation is underestimating the shafts stiffness at lower length/mean diameter(l/dm)ratios.In the present work,a new formulation is developed by adding shear deformation along the thickness direction to the existing modified EMBT formulation.The variation of shear deformation along the thickness direction is found using different shear deformation theories,i.e.,first-order shear deformation theory(FSDBT),parabolic shear deformation theory(PSDBT),trigonometric shear deformation theory(TSDBT),and hyperbolic shear deformation theory(HSDBT).The analysis is performed at l/d_(m) ratios of 5,10,15,20,25,30,35,and 40 for carbon/epoxy composites,E-glass/epoxy composites,and boron/epoxy composite shafts.The results show that new formulation has improved the bending natural frequency of the composite shafts for l/d_(m)<15 in comparison with modified EMBT.The effect of new formulation is more significant for the second and third bending modes of natural frequencies. 展开更多
关键词 composite hollow shafts Bending natural frequency Modified EMBT formulation Thickness effect
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Study and Formulation of a Dietary Cold Sauce Based on Pumpkin Seed Oil and Quail Eggs
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作者 Koumba Hawa Toundoufedouno Kéloua Kourouma Adama Moussa Sakho 《Journal of Environmental Science and Engineering(B)》 2025年第1期36-45,共10页
This work focuses on the formulation of a dietary cold sauce,mayonnaise,which combines the therapeutic properties of two basic ingredients:PSO(Pumpkin Seed Oil)and quail egg,both of which are renowned for their high f... This work focuses on the formulation of a dietary cold sauce,mayonnaise,which combines the therapeutic properties of two basic ingredients:PSO(Pumpkin Seed Oil)and quail egg,both of which are renowned for their high functional properties.PSO is essentially made up of unsaturated fatty acids(50%to 65%)including linoleic acid,from the omega 6 family,oleic acid(20%to 50%),a monounsaturated fatty acid(omega 9),cucurbitin,phytosterols,tri-terpenes and vitamin E(3.5 mg%).The nutritional,fatty acid,vitamin and mineral compositions of the mayonnaise compared with the ingredients,the physico-chemical characteristics of the quail egg,the PSO and the tasting of the mayonnaise were determined and gave results in terms of variable contents which are recorded in Tables 2-8.The results obtained were satisfactory.Mayonnaise,a semi-solid emulsion of oil in water with viscoelastic properties due to the network formed by lipoproteins adsorbed around neighbouring drops of oil,was prepared using the ratio of quail egg and PSO 1/4.This study may offer an alternative way of making dietary sauces. 展开更多
关键词 Nutritional study food formulation dietary sauce PSO quail eggs
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Identification of bioactive compounds and molecular targets of Fuke Huahuang formulation to treat vaginitis
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作者 Huiyu Liu Jie Mo +3 位作者 Cheng Liang Qingting Chen Bin Yang Jiaqi Liu 《Animal Models and Experimental Medicine》 2025年第6期1095-1104,共10页
Background:Fuke Huahuang formulation(FHF)is widely used in the treatment of vaginitis,with clinical evidence indicating its promising anti-inflammatory properties.Methods:We explored the bioactive components and poten... Background:Fuke Huahuang formulation(FHF)is widely used in the treatment of vaginitis,with clinical evidence indicating its promising anti-inflammatory properties.Methods:We explored the bioactive components and potential mechanisms of FHF for treating vaginitis,and reveal its pharmacological activities against vaginitis.Results:A total of 12 anti-inflammatory components in FHF and 584 pharmacological targets were identified.Furthermore,1427 vaginitis-associated targets were identified,and 184 intersection targets between FHF and vaginitis were constructed for network analysis.Gene Ontology and pathway analysis revealed that the therapeutical targets of FHF against vaginitis are involved in modulating inflammatory stress,enhancing immunoregulation,reconstructing the microenvironment,and suppressing cell damage.Molecular docking analysis further suggested the possible direct binding of the bioactive compounds of FHF(fumarine)to the core targets,including AKT Serine/Threonine Kinase 1(AKT1),Signal Transducer and Activator of Transcription 3(STAT3),and nuclear factor-kappaB(NF-κB).Experimental validation found that FHF-treated vaginitis rats exhibited reduced intracellular AKT1,STAT3,and NF-κB protein expressions.Conclusion:Overall,we identified the bioactive compounds and pharmacological mechanisms of FHF against vaginitis,thus offering a theoretical fundament for exploring FHF for treating vaginitis in the future. 展开更多
关键词 biological validation biotargets Fuke Huahuang formulation MECHANISM VAGINITIS
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