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Additivity of pore structural parameters of granular activated carbons derived from different coals and their blends 被引量:7
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作者 Yao Xin Xie Qiang +3 位作者 Yang Chuan Zhang Bo Wan Chaoran Cui Shanshan 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第4期661-667,共7页
A series of granular activated carbons (GACs) were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET speci... A series of granular activated carbons (GACs) were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET specific surface area (SBEr), total pore volume (Vr) and average pore diameter (da) were measured and cal- culated as well as process parameters such as yield of char (CY) and burn-off (B). The relationship between the pore structural parameters of the GAC from coal blend (BC-GAC) and the ones of the GACs from corresponding single coals (SC-GACs) was analyzed, in which an index, the relative error (δ), was presented to define the bias between fitted values and experimental values of these parameters of the BC-GACs. The results show that the BC-GAC keeps qualitatively the pore structural features of the SC-GACs; as concerned as the quantitative relationship, the pore structural parameters of the BC-GAC from coal blend consisting of non-caking coals can be obtained by adding proportionally the pore structural parameters of the SC-GACs with a less than 10%. Meanwhile, for the BC-GAC from coal blend containing weak caking bituminous coal, the δ increases up to 25% and the experimental pore size distribution differs greatly from the fitted one. 展开更多
关键词 Granular activated carbon Coal blend Pore structural parameters additivity
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Additivity rule for electron-molecule total cross section calculations at 50-5000 eV: a new geometrical approach
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作者 施德恒 孙金锋 +1 位作者 朱遵略 刘玉芳 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期2103-2109,共7页
Taking into consideration the changes of the geometric shielding effect in a molecule as the energy of incident electrons varies, this paper presents an empirical fraction, which depends on the energy of incident elec... Taking into consideration the changes of the geometric shielding effect in a molecule as the energy of incident electrons varies, this paper presents an empirical fraction, which depends on the energy of incident electrons, the target's molecular dimension and the atomic and electronic numbers in the molecule. Using this empirical fraction, it proposes a new formulation of the additivity rule. Employing the new additivity rule, it calculates the total cross sections of electron scattering by C2H4, C6H6, C6H14 and C8H18 over the energy range from 50 to 5000eV. In order to exclude the calculation deviations caused by solving the radial Schrodinger equation of electron scattering by atoms, here the atomic cross sections are derived from the experimental total cross section results of simple molecules (H2, O2, CO) via the inversion algorithm. The quantitative total cross sections are compared with those obtained by experiments and other theories, and good agreement is obtained over a wide energy range, even at energy of several tens of eV. 展开更多
关键词 electron scattering total cross section additivity rule geometric shielding effect
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Scale-Invariant Occupancy of Phase Space and Additivity of Nonextensive Entropy S_q
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作者 赵伟 伞冶 《Journal of Shanghai Jiaotong university(Science)》 EI 2010年第4期441-446,共6页
Phase space can be constructed for N equal and distinguishable binary subsystems which are correlated in a scale-invariant manner. In the paper, correlation coefficient and reduced probability are introduced to charac... Phase space can be constructed for N equal and distinguishable binary subsystems which are correlated in a scale-invariant manner. In the paper, correlation coefficient and reduced probability are introduced to characterize the scale-invariant correlated binary subsystems. Probabilistic sets for the correlated binary subsystems satisfy Leibnitz triangle rule in the sense that the marginal probabilities of N-system are equal to the joint probabilities of the (N - 1)-system. For entropic index q ≠ 1, nonextensive entropy Sq is shown to be additive in the scale-invariant occupation of phase space. 展开更多
关键词 nonextensive entropy additivity correlation SCALE-INVARIANCE
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Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs
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作者 Lu Wang Yifan Chen +2 位作者 Yuansen Yang Nuo Xiao Changhua Lai 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第4期1657-1668,共12页
Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of o... Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil supplemented.An experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing pigs.Methods Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal ileum.The experimental diets included a fat-free basal diet and 5 oil-added diets.The 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal diet.The 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,respectively.Results The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:2.The AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:2.Fitted one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),respectively.The determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and UFA.However,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).Conclusions The optimal U:S for improving the utilization efficiency of mixed oil was 4.14.The SID of fat and UFA for palm oil and canola oil were additive in growing pigs,whereas the SID of SFA in the mixture of two oils was greater than the sum of the values of pure oils.Differences in fat digestibility caused by oils differing in degree of saturation has a significant impact on bacterial community in the foregut. 展开更多
关键词 additivity Bacterial community Fat and fatty acids Growing pigs Ratio of unsaturated to saturated fatty acids Standardized ileal digestibility
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Total cross sections for electron scattering from fluoromethanes:A revised additivity rule method
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作者 谭晓明 赵刚 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期167-171,共5页
The additivity rule for electron-molecule scattering is revised by considering the difference between the free atom and the bound atom in the molecule. The total cross sections for electron scattering from fluorometha... The additivity rule for electron-molecule scattering is revised by considering the difference between the free atom and the bound atom in the molecule. The total cross sections for electron scattering from fluoromethanes (CF4, CF3H, CF2H2, and CFH3) are calculated in an energy range from 100 eV to 1500 eV by the revised additivity rule. The present calculations are compared with the original additivity rule results and the available experimental data. Better agreement with each other is obtained. 展开更多
关键词 total cross section electron scattering revised additivity rule
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On the Stability of Orthogonal Additivity in β-Homogeneous F-Spaces
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作者 Qi LIU Linlin FU Yongjin LI 《Journal of Mathematical Research with Applications》 CSCD 2022年第3期289-296,共8页
In this paper,we study the stability of the orthogonal equation,which is closely related to the results by W.Fechner and J.Sikorska in 2010.There are some differences that we consider the target space with theβ-homog... In this paper,we study the stability of the orthogonal equation,which is closely related to the results by W.Fechner and J.Sikorska in 2010.There are some differences that we consider the target space with theβ-homogeneous norm and quasi-norm.Overcoming theβ-homogeneous norm and quasi-norm bottlenecks,we get some new results. 展开更多
关键词 Hyers-Ulam stability β-homogeneous F-spaces quasi-Banach spaces orthogonal additivity
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基于空洞因果卷积的学生成绩预测及分析方法
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作者 赖英旭 张亚薇 +1 位作者 庄俊玺 刘静 《北京工业大学学报》 北大核心 2026年第3期252-267,共16页
针对使用循环神经网络对学生长序列行为数据进行特征提取存在梯度消失或爆炸、长期依赖关系提取能力不足、深度学习模型缺乏可解释性等问题,提出一种面向长序列数据的空洞因果卷积(dilated causal convolution,DCC)成绩预测及分析方法... 针对使用循环神经网络对学生长序列行为数据进行特征提取存在梯度消失或爆炸、长期依赖关系提取能力不足、深度学习模型缺乏可解释性等问题,提出一种面向长序列数据的空洞因果卷积(dilated causal convolution,DCC)成绩预测及分析方法。首先,采用生成对抗网络(generative adversarial network,GAN)生成符合少数类学生原始行为数据分布规律的新样本,并将新样本加入学生数据集中以达到均衡数据集的目的;然后,提出一种基于DCC的成绩预测模型,DCC和门控循环单元(gated recurrent unit,GRU)相结合的结构提高了模型对长序列数据依赖关系的提取能力;最后,使用沙普利加性解释(Shapley additive explanations,SHAP)方法并结合三因素理论对影响学生成绩的因素进行重要性分析和解释。在公开数据集上的实验结果表明,在成绩预测任务中提出的方法与基线方法相比,加权F1分数提高了约6个百分点,并进一步验证了所提方法中关键模块的有效性和模型的泛化能力。此外,通过对比优秀学生和风险学生的学习特点发现,良好的学习习惯、课堂学习的主动性以及不同行为环境等因素会对学生成绩产生重要影响。 展开更多
关键词 学生成绩预测 空洞因果卷积(dilated causal convolution DCC) 不均衡数据 生成对抗网络(generative adversarial network GAN) 沙普利加性解释(Shapley additive explanations SHAP)方法 成绩影响因素分析
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Comparison of methods for estimating basal endogenous losses of amino acids and additivity of digestibility of amino acids in corn and soybean meal for broilers 被引量:2
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作者 June Hyeok Yoon Changsu Kong 《Animal Nutrition》 SCIE CAS CSCD 2023年第4期233-241,共9页
This study was to compare the estimates of basal endogenous losses(BEL)of amino acids(AA)determined by 3 methods including feeding a nitrogen-free diet(NFD)or a low-casein diet(LCD,containing casein at 30 g/kg diet)or... This study was to compare the estimates of basal endogenous losses(BEL)of amino acids(AA)determined by 3 methods including feeding a nitrogen-free diet(NFD)or a low-casein diet(LCD,containing casein at 30 g/kg diet)or using the regression method.Another objective was to investigate whether the ileal AA digestibility of corn calculated from a casein-supplemented corn diet is additive for a cornsoybean meal(SBM)mixed diet in broilers.On d 31 of age,168 Ross 308 male broilers were assigned to 8 dietary treatments with 6 replicates in a randomized complete block design.An NFD and 3 diets containing 30,60,or 90 g/kg of casein were formulated to determine the BEL of AA and ileal AA digestibility of casein.The other 4 diets consisted of a corn diet,SBM diet,casein-supplemented corn diet,and corn-SBM mixed diet.On d 35 of age,digesta from the distal section of the ileum were collected.The BEL of AA in birds fed the LCD were greater(P<0.05)than those of the NFD and the regression method.There were no differences in the BEL of AA determined between the NFD and the regression method.Apparent ileal digestibility(AID)and standardized ileal digestibility(SID)of AA for corn calculated from the casein-supplemented corn diet were greater(P<0.05)than those of the corn diet.The predicted AID of Thr in the corn-SBM mixed diet based on the AID of AA for corn in the corn diet was lower(P<0.05)than the measured AID.However,the predicted AID of AA in the mixed diet based on the AID of AA for corn in the casein-supplemented corn diet did not differ from the measured AID.The predicted SID of AA in the mixed diet did not differ from the measured SID irrespective of casein supplementation.In conclusion,feeding an NFD or using the regression method yields similar BEL of AA,but not feeding an LCD.Casein supplementation in the corn diet increases the ileal AA digestibility for corn,which is additive for the corn-SBM mixed diet. 展开更多
关键词 Amino acid CASEIN BROILER additivity Basal endogenous loss
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Testing for additivity with B-splines 被引量:1
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作者 Heng-jian CUI Xu-ming HE Li LIU 《Science China Mathematics》 SCIE 2007年第6期841-858,共18页
Regression splines are often used for fitting nonparametric functions,and they work especially well for additivity models.In this paper,we consider two simple tests of additivity:an adaptation of Tukey’s one degree o... Regression splines are often used for fitting nonparametric functions,and they work especially well for additivity models.In this paper,we consider two simple tests of additivity:an adaptation of Tukey’s one degree of freedom test and a nonparametric version of Rao’s score test.While the Tukey-type test can detect most forms of the local non-additivity at the parametric rate of O(n-1/2),the score test is consistent for all alternative at a nonparametric rate.The asymptotic distribution of these test statistics is derived under both the null and local alternative hypotheses.A simulation study is conducted to compare their finite-sample performances with some existing kernel-based tests.The score test is found to have a good overall performance. 展开更多
关键词 additivity B-SPLINES dimension reduction score test SMOOTHING Tukey test
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Structure-activity correlation mechanism of additive-modified Cu-based catalysts for methanol synthesis via CO_(2)hydrogenation
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作者 HUANG Wenbin SI Meng +4 位作者 XU Zhen YANG Han BAI Tianyu ZHOU Yasong WEI Qiang 《燃料化学学报(中英文)》 北大核心 2026年第2期76-87,共12页
Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prep... Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol. 展开更多
关键词 carbon dioxide CATALYST additive modification HYDROGENATION METHANOL
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Mechanism of microstructural evolution in coke during the co-pyrolysis of coking coal with organic additives
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作者 ZHAO Xinni TIAN Lu +3 位作者 YU Peng XU Xiuli DOU Jinxiao YU Jianglong 《燃料化学学报(中英文)》 北大核心 2026年第2期153-165,共13页
To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and ... To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and waste plastic(HDPE),into a blended coal sample and carried out pyrolysis experiments.The pyrolysis process and the microstructure of char were systematically characterized using various analytical techniques,including thermogravimetric analysis(TGA),X-ray diffraction(XRD)and Raman spectroscopy.Data correlation analysis was performed to reveal the mechanism of carbon structural ordering evolution within the critical temperature range(350−600℃)from colloidal layer formation to semi-coke conversion in coking coal,and to elucidate the regulatory effects of different additives on coal pyrolysis pathways.The results indicate that HDPE releases free radicals during high-temperature pyrolysis,accelerating the pyrolysis reaction and increase the yield of volatile components.Conversely,CTP facilitates pyrolysis at low temperatures through its light components,thereby delaying high-temperature reactions due to the colloidal layer’s effect.XRD results indicate that during the process of pyrolysis,there is a progressive decrease in the interlayer spacing of aromatic layers(d002),while the aromatic ring stacking height(L_(c))and lateral size(L_(a))undergo significant of carbon skeleton ordering.Further comparative reveals that CTP partially suppresses structural ordering at low temperatures,whereas HDPE promotes the condensation and alignment of aromatic clusters via a free radical mechanism.Raman spectroscopy reveals a two-stage reorganization mechanism in the microstructure of the coal char:the decrease in the I_(D)/I_(G)ratio between 350 and 550℃is primarily attributed to the cleavage of aliphatic side chains and cross-linking bonds,leading to a reduction in defective structures;whereas the increase in ID/IG between 550 and 600℃is closely associated with enhanced condensation reactions of aromatic structures.Correlation analysis further demonstrates progressive graphitization during pyrolysis,with a significant positive correlation(R^(2)>0.85)observed between d002 and the full width at half maximum of the G-band(FWHM-G). 展开更多
关键词 coking coal organic additives CO-PYROLYSIS colloidal layer carbon structure
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Research Progress on Process Optimization and Performance Control of Additive Manufacturing for Refractory Metals
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作者 Lu Durui Song Suocheng Lu Bingheng 《稀有金属材料与工程》 北大核心 2026年第2期345-364,共20页
Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durabili... Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application. 展开更多
关键词 refractory metals additive manufacturing mechanical properties microstructure evolution optimization of printing process
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SLM-3D Printed Soft Magnetic Alloys:Process,Performance,and Prospects
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作者 Liu Bingxu You Caiyin +4 位作者 Wang Fenghui Tian Na Liu Heguang Zhang Jing Zhu Xiaopei 《稀有金属材料与工程》 北大核心 2026年第2期365-388,共24页
Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applicati... Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applications,complex-shaped components are increasingly required for performance enhancement.Additive manufacturing technique,particularly selective laser melting(SLM),has emerged as an effective method for fabricating such complex-shaped soft magnetic components.SLM,a laserbased additive manufacturing technique,employs high-power-density lasers to melt and fuse metal powders within a powder bed selectively.This approach enables rapid prototyping,precise geometrical control,and the integration of multi-material designs.This review highlights recent advancements in the application of SLM technique for the production of soft magnetic alloys,focusing on Fe-Si,Fe-Ni,Fe-Co,and amorphous alloy systems.Moreover,it explores the implementation of SLM in manufacturing processes and evaluates both the opportunities and challenges associated with SLM-based production of soft magnetic alloys. 展开更多
关键词 additive manufacturing selective laser melting soft magnetic alloys magnetic properties
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Numerical Simulation on Thermomechanical Coupling Process in Friction Stir-Assisted Wire Arc Additive Manufacturing
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作者 Li Long Xiao Yichen +2 位作者 Shi Lei Chen Ji Wu Chuansong 《稀有金属材料与工程》 北大核心 2026年第1期1-8,共8页
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit... Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties. 展开更多
关键词 friction stir processing wire arc additive manufacturing numerical simulation thermomechanical coupling temperature field DEFORMATION
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Effect of Nb Addition on Tensile and Wear Properties of 18Ni300 Mold Steel Fabricated by LPBF
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作者 Jian Changhuang Yang Yang +5 位作者 Wang Chengyong Yu Bowen Niu Liuhui Hu Gaofeng Liu Jianye Huang Zhenghua 《稀有金属材料与工程》 北大核心 2026年第1期18-26,共9页
Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely us... Laser powder bed fusion(LPBF)is highly suitable for forming 18Ni300 mold steel,thanks to its excellent capability in manufacturing complex shapes and outstanding capacity for regulating microstructures.It is widely used in fields such as injection molding,die casting,and stamping dies.Adding reinforcing particles into steel is an effective means to improve its performance.Nb/18Ni300 composites were fabricated by LPBF using two kinds of Nb powders with different particle sizes,and their microstructures and properties were studied.The results show that the unmelted Nb particles are uniformly distributed in the 18Ni300 matrix and the grains are refined,which is particularly pronounced with fine Nb particles.In addition,element diffusion occurs between the particles and the matrix.The main phases of the base alloy are α-Fe and a small amount of γ-Fe.With the addition of Nb,part of the α-Fe is transformed into γ-Fe,and unmelted Nb phases appear.The addition of Nb also enhances the hardness and wear resistance of the composites but slightly reduces their tensile properties.After aging treatment,the molten pools and grain boundaries become blurred,grains are further refined,and the interfaces around the particles are thinned.The aging treatment also promotes the formation of reverted austenite.The hardness,ultimate tensile strength,and volumetric wear rate of the base alloy reach 51.9 HRC,1704 MPa,and 17.8×10^(-6) mm^(3)/(N·m),respectively.In contrast,the sample added with fine Nb particles has the highest hardness(56.1 HRC),ultimate tensile strength(1892 MPa)and yield strength(1842 MPa),and the volume wear rate of the sample added with coarse Nb particles is reduced by 90%to 1.7×10^(-6) mm^(3)/(N·m). 展开更多
关键词 laser powder bed fusion 18Ni300 mold steel Nb addition microstructure mechanical property
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;oxicity models of metal mixtures established on the basis o "additivity" and "interactions"
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作者 Yang Liu Martina G. Vijver +1 位作者 Bo Pan Willie J. G. M. Peijnenburg 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2017年第2期11-23,共13页
Observed effects of metal mixtures on animals and plants often differ from the estimates, which are commonly calculated by adding up the biological responses of individual metals. This difference from additivity is co... Observed effects of metal mixtures on animals and plants often differ from the estimates, which are commonly calculated by adding up the biological responses of individual metals. This difference from additivity is commonly referred to as being a consequence of specific interactions between metals. The science of how to quantify metal interactions and whether to include them in risk assessment models is in its infancy. This review summarizes the existing predictive tools for evaluating the combined toxicity of metals present in mixtures and indicates the advantages and disadvantages of each method. We intend to provide eco-toxicologists with background information on how to make good use of the tools and how to advance the methods for assessing toxicity of metal mixtures, It is concluded that statistically significant deviations from additivity are not necessarily biologically relevant. Incorporation of interactions between metals in a model does not on forehand mean that the model is more accurate than a model developed based on additivity only. It is recommended to first use a relatively simple method for effect prediction of uninvestigated metal mixtures. To improve the reliability of toxicity modeling for metal mixtures, further efforts should focus on balancing the relationship between the significance of statistics and the biological meaning, and unraveling the toxicity mechanisms of metals and their mixtures. 展开更多
关键词 METAL MIXTURES TOXICITY additivity Modeling INTERACTIONS
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Additive manufacturing techniques for WC−Co cemented carbides: Principle, progress, and perspective
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作者 Zhan-he LIU Ke-chao ZHOU +5 位作者 Kai-hua SHI Xiao-zan WU He XIAO Chao-qun PENG Ri-chu WANG Xiao-feng WANG 《Transactions of Nonferrous Metals Society of China》 2026年第1期1-24,共24页
Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipmen... Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipment manufacturing,and electronic information.This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides.The fundamental principles and classification of AM techniques are introduced,followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides.These techniques are classified as either direct AM technology(DAM)or indirect AM technology(IDAM),depending on their inclusion of post-processes like de-binding and sintering.Through an analysis of microstructure features,the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology,such as binder jet printing(BJP),which integrates AM with conventional powder metallurgy. 展开更多
关键词 cemented carbides additive manufacturing WC−Co direct additive manufacturing indirect additive manufacturing microstructure complex shapes
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Synergistic additive engineering with sulfur-terminated Ti_(3)C_(2)T_(x)MXene towards efficient and stable perovskite solar cells
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作者 Zhe Wu Hui Li +1 位作者 Yuhang Bao Jizheng Wang 《Science China Materials》 2026年第3期1691-1697,共7页
Two-dimensional MXene Ti_(3)C_(2)T_(x)demonstrates great promise in perovskite solar cells(PSCs).Herein,sulfur-terminated Ti_(3)C_(2)T_(x)(S-Ti_(3)C_(2)T_(x))is developed by modifying Ti_(3)C_(2)T_(x)via a facile hydr... Two-dimensional MXene Ti_(3)C_(2)T_(x)demonstrates great promise in perovskite solar cells(PSCs).Herein,sulfur-terminated Ti_(3)C_(2)T_(x)(S-Ti_(3)C_(2)T_(x))is developed by modifying Ti_(3)C_(2)T_(x)via a facile hydrothermal method using thioacetamide.As a perovskite additive,S-Ti_(3)C_(2)T_(x)outperforms pristine Ti_(3)C_(2)T_(x)by(1)significantly promoting grain growth,enhancing carrier mobility,and reducing defect density;(2)optimizing energy level alignment to lower interfacial energy barriers and minimize interface non-radiative recombination;(3)stabilizing uncoordinated Pb2+and[PbI6]4-octahedra via Pb-S bonds while alleviating bulk lattice strain,as this Pb-S interaction exerts a“tape-like”effect.Based on this synergistic mechanism,PSCs with S-Ti_(3)C_(2)T_(x)achieve a champion efficiency of 25.51%—outperforming control(23.46%)and pristine Ti_(3)C_(2)T_(x)-based devices(24.54%)—with enhanced stability.This work highlights terminal group engineering as a critical strategy for advancing high-performance PSCs and their potential for emerging photovoltaic technologies. 展开更多
关键词 perovskite solar cells MXene sulfur-terminated ADDITIVE strain release
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Additive Manufacturing for Nanogenerators:Fundamental Mechanisms,Recent Advancements,and Future Prospects
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作者 Zhiyu Tian Gary Chi-Pong Tsui +3 位作者 Yuk-Ming Tang Chi-Ho Wong Chak-Yin Tang Chi-Chiu Ko 《Nano-Micro Letters》 2026年第1期782-826,共45页
Additive manufacturing(AM),with its high flexibility,cost-effectiveness,and customization,significantly accelerates the advancement of nanogenerators,contributing to sustainable energy solutions and the Internet of Th... Additive manufacturing(AM),with its high flexibility,cost-effectiveness,and customization,significantly accelerates the advancement of nanogenerators,contributing to sustainable energy solutions and the Internet of Things.In this review,an in-depth analysis of AM for piezoelectric and triboelectric nanogenerators is presented from the perspectives of fundamental mechanisms,recent advancements,and future prospects.It highlights AM-enabled advantages of versatility across materials,structural topology optimization,microstructure design,and integrated printing,which enhance critical performance indicators of nanogenerators,such as surface charge density and piezoelectric constant,thereby improving device performance compared to conventional fabrication.Common AM techniques for nanogenerators,including fused deposition modeling,direct ink writing,stereolithography,and digital light processing,are systematically examined in terms of their working principles,improved metrics(output voltage/current,power density),theoretical explanation,and application scopes.Hierarchical relationships connecting AM technologies with performance optimization and applications of nanogenerators are elucidated,providing a solid foundation for advancements in energy harvesting,self-powered sensors,wearable devices,and human-machine interaction.Furthermore,the challenges related to fabrication quality,cross-scale manufacturing,processing efficiency,and industrial deployment are critically discussed.Finally,the future prospects of AM for nanogenerators are explored,aiming to foster continuous progress and innovation in this field. 展开更多
关键词 Additive manufacturing NANOGENERATORS Output performance Energy harvesting Self-powered sensors
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Temporally stepwise crystallization via dual-additive orchestration:Resolving the crystallinity-domain size paradox for high-efficiency organic photovoltaics
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作者 Huan Wang Zemin He +9 位作者 Xingpeng Liu Jingming Xin Ziqi Geng Kuan Yang Yutong Zhang Yan Zhang Mingzhi Duan Bei Qin Qiuju Liang Jiangang Liu 《Journal of Energy Chemistry》 2026年第1期370-383,I0009,共15页
Achieving simultaneous enhancement of crystallinity and optimal domain size remains a fundamental challenge in organic photovoltaics(OPVs),where conventional crystallization strategies often trigger excessive aggregat... Achieving simultaneous enhancement of crystallinity and optimal domain size remains a fundamental challenge in organic photovoltaics(OPVs),where conventional crystallization strategies often trigger excessive aggregation of small-molecule acceptors.This work pioneers a kinetic paradigm for resolving the crystallinity-domain size trade-off in organic photovoltaics through dual-additive-guided stepwise crystallization.By strategically pairing 1,2-dichlorobenzene(o-DCB,low binding energy to Y6)and 1-fluoronaphthalene(FN,high binding energy),we achieve temporally decoupled crystallization control:o-DCB first mediates donor-acceptor co-crystallization during film formation,constructing a metastable network,whereupon FN induces confined Y6 crystallization within this framework during thermal annealing,refining nanostructure without over-aggregation.Morphology studies reveal that this synergy enhances crystallinity of(100)diffraction peaks by 21%–10%versus single-additive controls(o-DCB/FN alone),while maintaining optimal domain size.These morphological advantages yield balanced carrier transport(μh/μe=1.23),near-unity exciton dissociation(98.53%),and a champion power conversion efficiency(PCE)of 18.08%for PM6:Y6,significantly surpassing single-additive devices(o-DCB:17.20%;FN:17.53%).Crucially,the dual-additive strategy demonstrates universal applicability across diverse active layer systems,achieving an outstanding PCE of 19.27%in PM6:L8-BO-based devices,thereby establishing a general framework for morphology control in high-efficiency OPVs. 展开更多
关键词 Organic photovoltaics Stepwise crystallization Dual additives Carrier transport Morphology
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