检索结果-南通市图书馆

Machine learning enabling prediction in mechanical performance of Ti6Al4V fabricated by large-scale laser powder bed fusion via a stacking model

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第4期19卷 29-43页

作者： Changjun HAN Fubao YAN Daolin YUAN kai li Yongqiang yang jiong ZHANG Di WANG School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510641China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China

Determining appropriate process parameters in large-scale laser powder bed fusion(LPBF)additive manufacturing pose formidable challenges that necessitate advanced approaches to minimize trial-and-error during *** work proposed a data-driven approach based on stacking ensemble learning to predict the mechanical properties of Ti6Al4V alloy fabricated by large-scale LPBF for the first *** method can adapt to the complexity of large-scale LPBF data distribution and exhibits a more generalized predictive capability compared to base ***,the stacking model utilized artificial neural network(ANN),gradient boosting regressor,kernel ridge regression,and elastic net as base models,with the Lasso model serving as the *** optimization and cross-validation were utilized for model optimization and training based on a limited data set,resulting in higher predictive accuracy compared to traditional artificial neural network *** statistical analysis of the ANN and stacking models indicates that the stacking model exhibits superior performance on the test set,with a coefficient of determination value of 0.944,mean absolute percentage error of 2.51%,and root mean squared error of 27.64,surpassing that of the ANN *** statistical metrics demonstrate superiority over those obtained from the ANN *** results confirm that by integrating the base models,the stacking model exhibits superior predictive stability compared to individual base models alone,thereby providing a reliable assessment approach for predicting the mechanical properties of metal parts fabricated by the LPBF process.

关键词： machine learning laser powder bed fusion ensemble learning stacking algorithm additive manufacturing

Nickel-modified In_(2)O_(3) with inherent oxygen vacancies for CO_(2) hydrogenation to methanol

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science china Chemistry 2024年第5期67卷 1715-1728页

作者： Zixuan Zhou Yuchen Wang Yuanjie Bao Haiyan yang jiong li Chunran Chang shenggang li Peng Gao CAS Key Laboratory of Low-Carbon Conversion science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China university of Chinese Academy of sciences Beijing 100049China School of Physical science and technology ShanghaiTech UniversityShanghai 201210China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization School of Chemistry and Chemical EngineeringYulin UniversityYulin 719000China

Methanol synthesis is one of the most important industrially-viable approaches for carbon dioxide(CO_(2)) utilization, as the produced methanol can be used as a platform chemical for manufacturing green fuels and chemicals. The In_(2)O_(3) catalysts are ideal for sustainable methanol synthesis and have received considerable attention. Herein, Co-, Ni-and Cu-modified In_(2)O_(3) catalysts were fabricated with high dispersion and high stability to improve the hydrogenation performance. The Ni-promoted In_(2)O_(3) catalyst in the form of high dispersion possessed the largest amount of oxygen vacancies and the strongest ability for H_(2) activation, leading to the highest CO_(2) conversion and space time yield of methanol of 0.390 g_(Me OH)g_(cat)^(-1)h^(-1) with CH_(3)OH selectivity of 68.7%. In addition, the catalyst exhibits very stable performance over 120 h on stream, which suggests the promising prospect for industrial applications. Further experimental and theoretical studies demonstrate that surface Ni doping promotes the formation of oxygen defects on the In_(2)O_(3) catalyst, although it also results in lower methanol selectivity. Surprisingly, subsurface Ni dopants are found to be more beneficial for methanol formation than surface Ni dopants, so the Nipromoted In_(2)O_(3)catalyst with a lower surface Ni content at the similar Ni loading can reach higher methanol selectivity and productivity. This work thus provides theoretical guidance for significantly improving the CO_(2) reactivity of In_(2)O_(3)-based catalysts while maintaining high methanol selectivity.

关键词： carbon dioxide hydrogenation methanol synthesis indium oxides Ni doping sites transition metal promoters

A Fault Detection Method for Electric Vehicle Battery System Based on Bayesian Optimization SVDD Considering a Few Faulty Samples

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2024年第9期121卷 2543-2568页

作者： Miao li Fanyong Cheng jiong yang Maxwell Mensah Duodu Hao Tu School of Electronics and Electrical Engineering Anhui Polytechnic UniversityWuhu241000China

Accurate and reliable fault detection is essential for the safe operation of electric *** vector data description(SVDD)has been widely used in the field of fault ***,constructing the hypersphere boundary only describes the distribution of unlabeled samples,while the distribution of faulty samples cannot be effectively described and easilymisses detecting faulty data due to the imbalance of sample ***,selecting parameters is critical to the detection performance,and empirical parameterization is generally timeconsuming and laborious and may not result in finding the optimal ***,this paper proposes a semi-supervised data-driven method based on which the SVDD algorithm is improved and achieves excellent fault detection *** incorporating faulty samples into the underlying SVDD model,training deals better with the problem of missing detection of faulty samples caused by the imbalance in the distribution of abnormal samples,and the hypersphere boundary ismodified to classify the samplesmore *** Bayesian Optimization NSVDD(BO-NSVDD)model was constructed to quickly and accurately optimize hyperparameter *** the experiments,electric vehicle operation data with four common fault types are used to evaluate the performance with other five models,and the results show that the BO-NSVDD model presents superior detection performance for each type of fault data,especially in the imperceptible early and minor faults,which has seen very obvious ***,the strong robustness of the proposed method is verified by adding different intensities of noise in the dataset.

关键词： Fault detection vehicle battery system lithium batteries fault samples

Quick-scanning X-ray absorption fine structure beamline at SSRF

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2024年第6期35卷 1-13页

作者： Yu Chen Qian Gao Zheng Jiang jiong li Shuo Zhang Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

The layout and characteristics of the hard X-ray spectroscopy beamline(BL11B)at the Shanghai synchrotron radiation facility are described ***11B is a bending-magnet beamline dedicated to conventional and millisecond-scale quick-scanning X-ray absorption fine *** is equipped with a cylindrical collimating mirror,a double-crystal monochromator comprising Si(111)and Si(311),a channel-cut quick-scanning Si(111)monochromator,a toroidal focusing mirror,and a high harmonics rejection *** can provide 5-30 keV of X-rays with a photon flux of~5×10^(11)photons/s and an energy resolution of~1.31×10^(-4)at 10 *** performance of the beamline can satisfy the demands of users in the fields of catalysis,materials,and environmental *** paper presents an overview of the beamline design and a detailed description of its performance and capabilities.

关键词： Bending magnet beamline X-ray absorption fine structure Quick-scanning XAFS In situ Synchrotron radiation

Effect of dietary supplement of inactivated Lactobacillus plantarum Ep-M 17 on growth performance,immune response,disease resistance,and intestinal microbiota in Penaeus vannamei

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and limnology 2024年第2期42卷 676-694页

作者： Ting WU Xiaoman HU Wenlong XU yang DU jiong CHEN State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products Ningbo UniversityNingbo 315211China Laboratory of Biochemistry and Molecular Biology School of Marine SciencesNingbo UniversityNingbo 315211China Key Laboratory of Applied Marine Biotechnology of Ministry of Education Ningbo UniversityNingbo 315211China

Our previous study found that feeding with Lactobacillus plantarum Ep-M17 could effectively affect the growth performance,immune response,and gut microbiota of Penaeus ***,high temperature and pressure during feed pelletizing is the main problem that can lead to a decrease in the activity of probiotics or cause their *** investigation needs to investigate whether inactivated Ep-M17 can exert similar effects as live ***,we evaluated the effects of inactivated *** Ep-M17 on growth performance,immune response,disease resistance,and gut microbiota in *** show that adding inactivated Ep-M17 to the feed also promoted body weight gain and increased relative immune protection in ***,histological examination revealed that the administration of inactivated Ep-M17 led to improvements in the density and distribution of microvilli in the intestines and enhancements in the abundance of B and R cells in the ***,the inactivated Ep-M17 supplementation resulted in increased activity levels of nutrient immune-related enzymes in both the shrimp hepatopancreas and ***,it stimulated the expression of Lvlec,PEN-3a,Crustin,LGBP,Lysozyme,and proPo genes in both the hepatopancreas and ***,the inactivated Ep-M17 also increased bacterial diversity in the gut of shrimp and promoted the abundance of specific flora,facilitating the host organism’s metabolism and immunity to improve the disease resistance of ***,supplementation of inactivated *** Ep-M17 in shrimp diets can exert similar effects as live *** Ep-M17 effectively improving growth performance,gut microbiota,immune response,and disease resistance in ***.

关键词： Penaeus vannamei Lactobacillus plantarum Ep-M17 inactivated probiotics immune response gut flora

An electron-transfer[Fe_(2)Co_(2)]square complex exhibiting unprecedented wide room-temperature hysteresis

在线全文

学校读者我要写书评

暂无评论

science china Chemistry 2024年第4期67卷 1198-1207页

作者： Xin-Hua Zhao Yi-Fei Deng Jia-Tao Chen jiong yang Yuan-Zhu Zhang Department of Chemistry Southern University of Science and Technology(SUSTech)Shenzhen 518055China

Switchable molecules with magnetic bistability that can function at standard conditions are highly desirable from the perspective of practical *** the last decade,significant progress has been made in modulating thermally induced electrontransfer-coupled spin transition(ETCST)events between diamagnetic{Fe_(LS)^(Ⅱ)(μ-CN)Co_(LS)^(Ⅲ)}and paramagnetic{Fe_(LS)^(Ⅲ)(μ-CN)-Co_(HS)^(Ⅱ)}electron configurations(named LS and HS,respectively,for short)within the Fe/Co mixed-valence cyanometallate ***,we prepared a novel[Fe_(2)Co_(2)]square complex[(pzTp)Fe(CN)_(3)Co(bnbpen)]_(2)[NO_(3)]_(2)·4CH_(3)OH·2.5H_(2)O(1·Solv)and its desolvated phase[(pzTp)Fe(CN)_(3)Co(bnbpen)]_(2)[NO_(3)]_(2)(1),obtained via single-crystal-to-single-crystal(SCSC)*** 1·Solv remaining in the diamagnetic state below room temperature exhibits an irreversible ETCST behavior accompanied by desolvation upon ***,complex 1 displays an unprecedented rate-dependent ETCST behaviour involving with two diamagnetic LS states(a dynamically favoured LS1 state and a thermodynamically favoured LS2state),between which a net one-way transition from LS1 to LS2 is accessible likely via a structural phase transition(SPT)above255 ***,two well separated transition channels(HS?LS1 at around 255 K and HS←→LS2 in the temperature range of 317-350 K)are achieved according to either fast(>20 K/min)or slow rate(lity within this fascinating cyanometallate family.

关键词： switchable molecules cyanometallate complexes electron transfer hysteresis structural phase transition

Spectral Radius of Non-negative Matrices and Digraphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2002年第2期18卷 293-300页

作者： ZHANG Xiao Dong Department of mathematics.East china Normal university,Shanghai 200062.P.R.china E-mail:xdzhang2@hotmail.comli jiong sheng Department of mathematics.university of science and technology of china,hefei 230026,P.R china Department of mathematics East China Normal University Shanghai P. R. China Department of mathematics University of Science and Technology of China Hefei P. R. China

We present,an upper and a lower bound for the spectral radius of non-negative matrices. Then we give the bounds for the spectral radius of digraphs.

关键词： Non-negative matrix Digraph Spectral radius

Cholangiocarcinoma combined with biliary obstruction:an exosomal circRNA signature for diagnosis and early recurrence monitoring

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第6期9卷 2642-2654页

作者： Ningyuan Wen Dingzhong Peng Xianze Xiong Geng liu Guilin Nie Yaoqun Wang Jianrong Xu Shaofeng Wang Sishu yang Yuan Tian Bei li jiong Lu Nansheng Cheng Division of Biliary Surgery Department of General SurgeryWest China HospitalSichuan UniversityChengduSichuanChina Research Center for Biliary Diseases West China HospitalSichuan UniversityChengduSichuanChina

Cholangiocarcinoma(CCA)is a highly malignant biliary tract cancer with currently suboptimal diagnostic and prognostic *** present a novel system to monitor CCA using exosomal circular RNA(circRNA)via serum and biliary liquid biopsies.A pilot cohort consisting of patients with CCA-induced biliary obstruction(CCA-BO,n=5)and benign biliary obstruction(BBO,n=5)was used to identify CCA-derived exosomal circRNAs through microarray *** was followed by a discovery cohort(n=20)to further reveal a CCA-specific circRNA complex(hsa-circ-0000367,hsa-circ-0021647,and hsa-circ-0000288)in both bile and serum *** vitro and in vivo studies revealed the three circRNAs as promoters of CCA *** and prognostic models were established and verified by two independent cohorts(training cohort,n=184;validation cohort,n=105).An interpreter-free diagnostic model disclosed the diagnostic power of biliary exosomal circRNA signature(Bile-DS,AUROC=0.947,RR=6.05)and serum exosomal circRNA signature(Serum-DS,AUROC=0.861,RR=4.04)compared with conventional CA19-9(AUROC=0.759,RR=2.08).A prognostic model of CCA undergoing curative-intent surgery was established by calculating early recurrence score,verified with bile samples(Bile-ERS,C-index=0.783)and serum samples(Serum-ERS,C-index=0.782).These models,combined with other prognostic factors revealed by COX-PH model,enabled the establishment of nomograms for recurrence monitoring of *** study demonstrates that the exosomal triple-circRNA panel identified in both bile and serum samples serves as a novel diagnostic and prognostic tool for the clinical management of CCA.

关键词： biliary diagnosis Serum

Efficient epoxidation of propylene over non-noble nickel-based catalyst promoted by alkali metals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science china Chemistry 2024年第11期67卷 3697-3705页

作者： Wenqian li Wanting li Xinxin Cao Longfei Chen Yibo Qin Yanfeng Zhu Yanfei Zhang Gai Miao lingzhao Kong jiong li Xinqing Chen State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization CAS Key Laboratory of Low-carbon Conversion Science and Engineering Shanghai Advanced Research Institute Chinese Academy of Sciences university of Chinese Academy of sciences School of Environmental science and Engineering Suzhou University of Science and Technology Shanghai Synchrotron Radiation Facility Zhangjiang National Lab Shanghai Advanced Research Institute Chinese Academy of Sciences

The application of non-noble metal catalysts in the catalytic direct gas-phase epoxidation of propylene with H2and O2to produce propylene oxide is valuable and challenging. The introduction of alkali metal promoters is one of the effective methods to improve the catalytic activity of catalysts. Herein, a series of alkali metal（li, Na, K, Rb, and Cs）-promoted Ni/TS-1 catalysts were prepared to deeply understand the effect of alkali metals on the structure-activity relationship for gas-phase epoxidation of propylene. Among them, the Na-Ni/TS-1 catalyst exhibits the highest catalytic activity(propylene conversion of 7.35% and PO formation rate of 157.9 g h-1kgcat-1) and the best stability（long-term stability exceeding 140 h at 200 °C）. X-ray absorption and photoelectron spectroscopy revealed that the electronic structure of Ni can be tuned by the addition of alkali metal ***3-TPD-MS, CO2-TPD-MS, and C3H6-TPD-MS results indicate that the acidity of the catalyst can also be adjusted by the introduction of alkali metal, whereas the Na-Ni/TS-1 catalyst exhibits the strongest C3H6adsorption capacity. Thus, the suitable acid-base properties, unique electronic properties of Ni species, and the strongest propylene adsorption capacity resulted in improved propylene gas-phase epoxidation activity of Na-Ni/TS-1 catalyst. This study not only provides a new strategy for the practical application of nickel-based catalysts in the gas-phase epoxidation of propylene but also provides insights into the promoting effect of alkali metals.

关键词： propylene epoxidation Ni/TS-1 catalyst alkali metal precipitating agents