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Development and validation of an online calculator to predict the pathological nature of colorectal tumors
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作者 Ya-Dan Wang Jing Wu +9 位作者 Bo-Yang Huang Chun-Mei Guo Cang-Hai Wang Hui Su Hong Liu Miao-Miao Wang Jing Wang Li Li Peng-Peng Ding Ming-Ming Meng 《World Journal of Gastrointestinal Oncology》 SCIE 2023年第7期1271-1282,共12页
BACKGROUND No single endoscopic feature can reliably predict the pathological nature of colorectal tumors(CRTs).AIM To establish and validate a simple online calculator to predict the pathological nature of CRTs based... BACKGROUND No single endoscopic feature can reliably predict the pathological nature of colorectal tumors(CRTs).AIM To establish and validate a simple online calculator to predict the pathological nature of CRTs based on white-light endoscopy.METHODS This was a single-center study.During the identification stage,530 consecutive patients with CRTs were enrolled from January 2015 to December 2021 as the derivation group.Logistic regression analysis was performed.A novel online calculator to predict the pathological nature of CRTs based on white-light images was established and verified internally.During the validation stage,two series of 110 images obtained using white-light endoscopy were distributed to 10 endoscopists[five highly experienced endoscopists and five less experienced endoscopists(LEEs)]for external validation before and after systematic training.RESULTS A total of 750 patients were included,with an average age of 63.6±10.4 years.Early colorectal cancer(ECRC)was detected in 351(46.8%)patients.Tumor size,left semicolon site,rectal site,acanthosis,depression and an uneven surface were independent risk factors for ECRC.The C-index of the ECRC calculator prediction model was 0.906(P=0.225,Hosmer-Lemeshow test).For the LEEs,significant improvement was made in the sensitivity,specificity and accuracy(57.6%vs 75.5%;72.3%vs 82.4%;64.2%vs 80.2%;P<0.05),respectively,after training with the ECRC online calculator prediction model.CONCLUSION A novel online calculator including tumor size,location,acanthosis,depression,and uneven surface can accurately predict the pathological nature of ECRC. 展开更多
关键词 Pathological nature Colorectal tumors White-light endoscopy Online calculator Early colorectal cancer
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应用Tier Ⅰ Eco-Risk Calculator模型评估二嗪磷对鸟类的风险
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作者 韩志华 程燕 +1 位作者 周军英 单正军 《农药学学报》 CAS CSCD 北大核心 2011年第2期209-212,共4页
在室内急性毒性试验的基础上,应用Tier I Eco-Risk Calculator模型对50%二嗪磷乳油对日本鹌鹑的生态风险进行了评价。50%二嗪磷乳油的经口毒性LD50值为每1 kg体重4.61 mg;经食毒性LC50值为每1 kg饲料120.0 mg。模型预测结果表明:直接经... 在室内急性毒性试验的基础上,应用Tier I Eco-Risk Calculator模型对50%二嗪磷乳油对日本鹌鹑的生态风险进行了评价。50%二嗪磷乳油的经口毒性LD50值为每1 kg体重4.61 mg;经食毒性LC50值为每1 kg饲料120.0 mg。模型预测结果表明:直接经口暴露时,50%二嗪磷乳油对鹌鹑具有急性高风险;经食暴露时,其对鹌鹑产生急性风险的可能性也较高。因此,应禁止在鸟类保护区或其临近地区使用二嗪磷,在不影响药效的基础上尽可能减少使用量,改变剂型或使用方法等,以降低二嗪磷对鸟类的风险。 展开更多
关键词 二嗪磷 鸟类 风险评价 Tier I Eco-Risk calculator 模型
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Risk calculators for hepatocellular carcinoma in patients affected with chronic hepatitis B in Asia 被引量:5
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作者 Hwai-I Yang Mei-Hsuan Lee +1 位作者 Jessica Liu Chien-Jen Chen 《World Journal of Gastroenterology》 SCIE CAS 2014年第20期6244-6251,共8页
Risk calculators are widely used in many clinical fields, and integrate several important risk factors through the conversion of a risk function into a single measure of risk. Several studies have been carried out to ... Risk calculators are widely used in many clinical fields, and integrate several important risk factors through the conversion of a risk function into a single measure of risk. Several studies have been carried out to create risk calculators for the prediction of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). Most of them were hospital-based, with limited sample sizes and insufficient external validation. These study groups collaborated to establish the REACH-B risk score, which incorporated five clinical variables to predict HCC risk. This risk score was then validated in international clinical cohorts. Evidence suggests that quantitative serum HBsAg level provides additional predictability of HCC, especially in patients with low levels of hepatitis B virus DNA. This novel marker was incorporated into a risk calculator and was internally validated. This tool will hopefully be externally validated in the near future. Risk calculators can be used to support clinical practice, and to establish preventive measures; several &#x0201c;off-label&#x0201d; extension usages have also been implemented. Albeit beneficial, several precautions and discussions should be noted in using the risk calculators. The future development of risk calculators for CHB patients can be extended by applying them to additional CHB-related outcomes, and by incorporating emerging risk parameters. 展开更多
关键词 Chronic hepatitis B Hepatocellular carcinoma Risk calculator Hepatitis B virus
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Online calculator for predicting the risk of malignancy in patients with pancreatic cystic neoplasms: A multicenter, retrospective study 被引量:1
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作者 Dong Jiang Zi-Xiang Chen +10 位作者 Fu-Xiao Ma Yu-Yong Gong Tian Pu Jiang-Ming Chen Xue-Qian Liu Yi-Jun Zhao Kun Xie Hui Hou Cheng Wang Xiao-Ping Geng Fu-Bao Liu 《World Journal of Gastroenterology》 SCIE CAS 2022年第37期5469-5482,共14页
BACKGROUND Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms(PCNs)are lacking.AIM To establish a nomogram-based online calculator for predicting the ris... BACKGROUND Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms(PCNs)are lacking.AIM To establish a nomogram-based online calculator for predicting the risk of malignancy in patients with PCNs.METHODS In this study,the clinicopathological data of target patients in three medical centers were analyzed.The independent sample t-test,Mann–Whitney U test or chi-squared test were used as appropriate for statistical analysis.After univariable and multivariable logistic regression analysis,five independent factors were screened and incorporated to develop a calculator for predicting the risk of malignancy.Finally,the concordance index(C-index),calibration,area under the curve,decision curve analysis and clinical impact curves were used to evaluate the performance of the calculator.RESULTS Enhanced mural nodules[odds ratio(OR):4.314;95%confidence interval(CI):1.618–11.503,P=0.003],tumor diameter≥40 mm(OR:3.514;95%CI:1.138–10.849,P=0.029),main pancreatic duct dilatation(OR:3.267;95%CI:1.230–8.678,P=0.018),preoperative neutrophil-to-lymphocyte ratio≥2.288(OR:2.702;95%CI:1.008–7.244,P=0.048],and preoperative serum CA19-9 concentration≥34 U/mL(OR:3.267;95%CI:1.274–13.007,P=0.018)were independent risk factors for a high risk of malignancy in patients with PCNs.In the training cohort,the nomogram achieved a C-index of 0.824 for predicting the risk of malignancy.The predictive ability of the model was then validated in an external cohort(C-index:0.893).Compared with the risk factors identified in the relevant guidelines,the current model showed better predictive performance and clinical utility.CONCLUSION The calculator demonstrates optimal predictive performance for identifying the risk of malignancy,potentially yielding a personalized method for patient selection and decision-making in clinical practice. 展开更多
关键词 Pancreatic cystic neoplasms Risk of malignancy NOMOGRAM Model PREDICTION calculator
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Dose Comparison between Eclipse Dose Calculation and Fast Dose Calculator in Single- and Multi-Field Optimization Intensity-Modulated Proton Therapy Plans with Various Multi-Beams for Brain Cancer
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作者 Ryosuke Kohno Wenhua Cao +5 位作者 Pablo Yepes Xuemin Bai Falk Poenisch David R. Grosshans Tetsuo Akimoto Radhe Mohan 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2017年第4期421-432,共12页
The purpose of this study was to grasp current potential problems of dose error in intensity-modulated proton therapy (IMPT) plans. We were interested in dose differences of the Varian Eclipse treatment planning syste... The purpose of this study was to grasp current potential problems of dose error in intensity-modulated proton therapy (IMPT) plans. We were interested in dose differences of the Varian Eclipse treatment planning system (TPS) and the fast dose calculation method (FDC) for single-field optimization (SFO) and multi-field optimization (MFO) IMPT plans. In addition, because some authors have reported dosimetric benefit of a proton arc therapy with ultimate multi-fields in recent years, we wanted to evaluate how the number of fields and beam angles affect the differences for IMPT plans. Therefore, for one brain cancer patient with a large heterogeneity, SFO and MFO IMPT plans with various multi-angle beams were planned by the TPS. Dose distributions for each IMPT plan were calculated by both the TPS’s conventional pencil beam algorithm and the FDC. The dosimetric parameters were compared between the two algorithms. The TPS overestimated 400 - 500 cGy (RBE) for minimum dose to the CTV relative to the dose calculated by the FDC. These differences indicate clinically relevant effect on clinical results. In addition, we observed that the maximum difference in dose calculated between the TPS and the FDC was about 900 cGy (RBE) for the right optic nerve, and this quantity also has a possibility to have a clinical effect. The major difference was not seen in calculations for SFO IMPT planning and those for MFO IMPT planning. Differences between the TPS and the FDC in SFO and MFO IMPT plans depend strongly on beam arrangement and the presence of a heterogeneous body. We advocate use of a Monte Carlo method in proton treatment planning to deliver the most precise proton dose in IMPT. 展开更多
关键词 FAST DOSE calculator Monte Carlo INTENSITY-MODULATED Proton Therapy Single-Field OPTIMIZATION (SFO) Multi-Field OPTIMIZATION (MFO)
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Augmenting prostate magnetic resonance imaging reporting to incorporate diagnostic recommendations based upon clinical risk calculators
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作者 Karisma Gupta Jordan D Perchik +2 位作者 Andrew M Fang Kristin K Porter Soroush Rais-Bahrami 《World Journal of Radiology》 2022年第8期249-255,共7页
Risk calculators have offered a viable tool for clinicians to stratify patients at risk of prostate cancer(PCa)and to mitigate the low sensitivity and specificity of screening prostate specific antigen(PSA).While init... Risk calculators have offered a viable tool for clinicians to stratify patients at risk of prostate cancer(PCa)and to mitigate the low sensitivity and specificity of screening prostate specific antigen(PSA).While initially based on clinical and demographic data,incorporation of multiparametric magnetic resonance imaging(MRI)and the validated prostate imaging reporting and data system suspicion scoring system has standardized and improved risk stratification beyond the use of PSA and patient parameters alone.Biopsy-naïve patients with lower risk profiles for harboring clinically significant PCa are often subjected to uncomfortable,invasive,and potentially unnecessary prostate biopsy procedures.Incorporating risk calculator data into prostate MRI reports can broaden the role of radiologists,improve communication with clinicians primarily managing these patients,and help guide clinical care in directing the screening,detection,and risk stratification of PCa. 展开更多
关键词 Prostatic adenocarcinoma Multiparametric magnetic resonance imaging NOMOGRAMS Risk calculators BIOPSY
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Carbon Footprint of Tourism Sector in Portugal-Calculator Development
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作者 Marco Fernandes Pedro Neves +2 位作者 Patrícia Araújo Isabel Brás Elisabete Silva 《Journal of Tourism and Hospitality Management》 2021年第6期365-380,共16页
A carbon footprint(CF)calculator was developed to apply to a Portuguese touristic accommodation to contribute to a sustainable touristic activity.Although some calculators are available online,they are related to the ... A carbon footprint(CF)calculator was developed to apply to a Portuguese touristic accommodation to contribute to a sustainable touristic activity.Although some calculators are available online,they are related to the country reality or use outdated emission factors.A calculator based on national emission factors is important.The calculator was developed in Microsoft Excel(version 365)and is based on the CO2e emissions resulting from electricity,water,fuels and food use,laundry and waste production.The calculator development involved:study the accommodation emission sources,selection the environmental indicators,determination of the emission factors and development of the CF formulas.Total CF calculation was made considering the partial CF per component,a monthly and annual comparison of each indicator’s emissions contribution using graphs.The emissions amount per overnight stay,per room,per area,were also assessed and these values were transformed into global hectare(gha).Avoided emissions calculation gives the information about the efforts in CF reduction,and two indicators were considered:electricity production from renewable energy sources and the amount of separated waste for recycling.It was considered reforestation measures to achieve carbon neutrality.This calculator incorporates four components not often used:water,laundry,waste,food,and avoided emissions. 展开更多
关键词 calculator carbon footprint greenhouse gases environmental indicators sustainable tourism
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10Key Calculator
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《数字家庭》 2008年第7期33-33,共1页
我们都知道笔记本电脑是很少带有数字键盘区的,这样或多或少给需要使用数字键盘的人带来不便。而10Key Calculator就能够解决这一问题,通过USB接口和笔记本电脑连接后,它就成了一个独立的数字键盘。除了数字键盘的功能外,10Key Calc... 我们都知道笔记本电脑是很少带有数字键盘区的,这样或多或少给需要使用数字键盘的人带来不便。而10Key Calculator就能够解决这一问题,通过USB接口和笔记本电脑连接后,它就成了一个独立的数字键盘。除了数字键盘的功能外,10Key Calculator还可以作为一个单独的计算器来使用,非常实用。 展开更多
关键词 笔记本电脑 数字键盘区 10Key calculator USB接口
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Critical appraisal of novel prediction models and risk calculators for post-hepatectomy liver failure and complications: practicability and generalisability in the real-world setting
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作者 Darren Weiquan Chua Yun Zhao Ye Xin Koh 《Hepatobiliary Surgery and Nutrition》 SCIE 2024年第4期696-698,共3页
Over the last few decades,the evolution of liver resection has progressed through numerous milestones in peri-operative management,operative techniques and novel technologies that have dramatically improved patient sa... Over the last few decades,the evolution of liver resection has progressed through numerous milestones in peri-operative management,operative techniques and novel technologies that have dramatically improved patient safety and outcomes(1).Consequently,such developments have enabled surgeons to embark on liver resections of lesions in technically challenging locations,whereby extended resection or bilovascular reconstruction may be required to ensure oncologic clearance.In the context of extended resections or resection of lesions from heavily diseased livers,concerns remain regarding the adequacy of the remnant future liver remnant(FLR)and liver function,placing patients at risk of the clinical phenomenon known as post-hepatectomy liver failure(PHLF).Although relatively uncommon,PHLF has a reported incidence of up to 32%in the literature and remains an important cause of post-hepatectomy morbidity and mortality(2).Presently,several definitions have been proposed to describe PHLF,the most recent of which was proposed by the International Study Group of Liver Surgery(ISGLS).In this definition,PHLF was defined as an increased international normalized ratio(INR)or hyperbilirubinemia on or after post-operative day 5,with further stratification of severity grades(A,B or C)based on the extent of clinical management(3).While definitions in PHLF assist in providing a common diagnostic framework among physicians,establishing predictors in PHLF is conceivably more helpful as it allows surgeons to have important decision-making details prior to planned liver resection. 展开更多
关键词 HEPATECTOMY post-hepatectomy liver failure(PHLF) predictive model risk calculation
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Machine learning algorithms able to predict the prognosis of gastric cancer patients treated with immune checkpoint inhibitors
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作者 Hong-Wei Li Zi-Yu Zhu +4 位作者 Yu-Fei Sun Chao-Yu Yuan Mo-Han Wang Nan Wang Ying-Wei Xue 《World Journal of Gastroenterology》 SCIE CAS 2024年第40期4354-4366,共13页
BACKGROUND Although immune checkpoint inhibitors(ICIs)have demonstrated significant survival benefits in some patients diagnosed with gastric cancer(GC),existing prognostic markers are not universally applicable to al... BACKGROUND Although immune checkpoint inhibitors(ICIs)have demonstrated significant survival benefits in some patients diagnosed with gastric cancer(GC),existing prognostic markers are not universally applicable to all patients with advanced GC.AIM To investigate biomarkers that predict prognosis in GC patients treated with ICIs and develop accurate predictive models.METHODS Data from 273 patients diagnosed with GC and distant metastasis,who un-derwent≥1 cycle(s)of ICIs therapy were included in this study.Patients were randomly divided into training and test sets at a ratio of 7:3.Training set data were used to develop the machine learning models,and the test set was used to validate their predictive ability.Shapley additive explanations were used to provide insights into the best model.RESULTS Among the 273 patients with GC treated with ICIs in this study,112 died within 1 year,and 129 progressed within the same timeframe.Five features related to overall survival and 4 related to progression-free survival were identified and used to construct eXtreme Gradient Boosting(XGBoost),logistic regression,and decision tree.After comprehensive evaluation,XGBoost demonstrated good accuracy in predicting overall survival and progression-free survival.CONCLUSION The XGBoost model aided in identifying patients with GC who were more likely to benefit from ICIs therapy.Patient nutritional status may,to some extent,reflect prognosis. 展开更多
关键词 Gastric cancer Machine learning Immune checkpoint inhibitors Web-based calculator Progression-free survival Overall survival
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A defective iron-based perovskite cathode for high-performance IT-SOFCs:Tailoring the oxygen vacancies using Nb/Ta co-doping 被引量:2
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作者 Bayu Admasu Beshiwork Xinyu Wan +6 位作者 Min Xu Haoran Guo Birkneh Sirak Teketel Yu Chen Jun Song Chen Tingshuai Li Enrico Traversa 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期306-316,I0008,共12页
The sluggish kinetics of the electrochemical oxygen reduction reaction(ORR)in intermediatetemperature solid oxide fuel cells(IT-SOFCs)greatly limits the overall cell performance.In this study,an efficient and durable ... The sluggish kinetics of the electrochemical oxygen reduction reaction(ORR)in intermediatetemperature solid oxide fuel cells(IT-SOFCs)greatly limits the overall cell performance.In this study,an efficient and durable cathode material for IT-SOFCs is designed based on density functional theory(DFT)calculations by co-doping with Nb and Ta the B-site of the SrFeO_(3-δ)perovskite oxide.The DFT calculations suggest that Nb/Ta co-doping can regulate the energy band of the parent SrFeO_(3-δ)and help electron transfer.In symmetrical cells,such cathode with a SrFe_(0.8)Nb_(0.1)Ta_(0.1)O_(3-δ)(SFNT)detailed formula achieves a low cathode polarization resistance of 0.147Ωcm^(2) at 650℃.Electron spin resonance(ESR)and X-ray photoelectron spectroscopy(XPS)analysis confirm that the co-doping of Nb/Ta in SrFeO_(3-δ)B-site increases the balanced concentration of oxygen vacancies,enhancing the electrochemical performance when compared to 20 mol%Nb single-doped perovskite oxide.The cathode button cell with NiSDC|SDC|SFNT configuration achieves an outstanding peak power density of 1.3 W cm^(-2)at 650℃.Moreover,the button cell shows durability for 110 h under 0.65 V at 600℃ using wet H_(2) as fuel. 展开更多
关键词 Solid oxide fuel cell CATHODE Oxygen reduction reaction Power density DFT calculation
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Active MoS_(2)-based electrode for green ammonia synthesis 被引量:1
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作者 Xin Liu Lei Yang +2 位作者 Tao Wei Shanping Liu Beibei Xiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期268-275,共8页
Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology i... Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology is to discover the catalysts with high selectivity and efficiency.In this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal elements.Our results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR inefficiency.Specifically,MoS_(2)functionalized via edge W-substitution exhibits an exceptional activity.The energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 V.Overall,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments. 展开更多
关键词 Nitrogen reduction reaction Density functional theory calculations Molybdenum disulfide ELECTROCHEMISTRY CATALYST THERMODYNAMICS
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Tuning interface mechanism of FeCo alloy embedded N,S-codoped carbon substrate for rechargeable Zn-air battery 被引量:1
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作者 Hui Chang Lulu Zhao +4 位作者 Shan Zhao Zong-Lin Liu Peng-Fei Wang Ying Xie Ting-Feng Yi 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期400-410,I0010,共12页
The interface mechanism between catalyst and carbon substrate has been the focus of research.In this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple ... The interface mechanism between catalyst and carbon substrate has been the focus of research.In this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple one-step pyrolysis strategy.The experimental results and density functional theory(DFT)calculation show that the formation of FeCo alloy is conducive to promoting electron transfer,and the introduction of S atom can enhance the interaction between FeCo alloy and carbon substrate,thus inhibiting the migration and agglomeration of particles on the surface of carbon material.The FeCo/SNC catalysts show outstanding performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).FeCo/S-NC shows a high half-wave potential(E_(1/2)=0.8823 V)for ORR and a low overpotential at 10 mA cm^(-2)(E_(j=10)=299 mV)for OER.In addition,compared with Pt/C+RuO_(2) assembled Zn-air battery(ZAB),the FeCo/S-NC assembled ZAB exhibits a larger power density(198.8 mW cm^(-2)),a higher specific capacity(786.1 mA h g_(zn)~(-1)),and ultra-stable cycle performance.These results confirm that the optimized composition and the interfacial interaction between catalyst and carbon substrate synergistically enhance the electrochemical performance. 展开更多
关键词 FeCo alloy N S co-doped carbon DFT calculation Zn-air batteries Interfacial interaction
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Transformation of long-period stacking ordered structures in Mg-Gd-Y-Zn alloys upon synergistic characterization of first-principles calculation and experiment and its effects on mechanical properties 被引量:1
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作者 Mingyu Li Guangzong Zhang +4 位作者 Siqi Yin Changfeng Wang Ying Fu Chenyang Gu Renguo Guan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期1867-1879,共13页
Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process... Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are discussed.Results reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,respectively.After solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO phase.The Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on first-principles.Results show that the alloying ability of 18R is stronger than that of 14H.The reaction energies show that the 14H LPSO phase is more stable than the 18R LPSO.The elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental results.The precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the alloy.After solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,respectively.The elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr alloy.The improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed. 展开更多
关键词 Mg-Gd-Y-Zn alloys Long-period stacking ordered First-principles calculations ENTHALPIES Mechanical properties
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Prediction of the thermal conductivity of Mg–Al–La alloys by CALPHAD method 被引量:1
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作者 Hongxia Li Wenjun Xu +5 位作者 Yufei Zhang Shenglan Yang Lijun Zhang Bin Liu Qun Luo Qian Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期129-137,共9页
Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al addition.The accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high ther... Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al addition.The accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal conductivity.Thus,databases for predicting temperature-and composition-dependent thermal conductivities must be established.In this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were designed.The influence of the second phase(s) and Al solid solubility on thermal conductivity was investigated.Experimental results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La amount.The degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal conductivity.On the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)method.With a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental data.The established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects. 展开更多
关键词 magnesium alloy thermal conductivity thermodynamic calculations materials computation
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Dual-single-atoms of Pt-Co boost sulfur redox kinetics for ultrafast Li-S batteries 被引量:1
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作者 Hanyan Wu Xuejie Gao +7 位作者 Xinyang Chen Weihan Li Junjie Li Lei Zhang Yang Zhao Ming Jiang Runcang Sun Xueliang Sun 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期53-63,共11页
Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetic... Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetics,the sulfur redox kinetics for Li-S batteries is still not ultrafast.Herein,in this work,a catalyst with dual-single-atom Pt-Co embedded in N-doped carbon nanotubes(Pt&Co@NCNT)was proposed by the atomic layer deposition method to suppress the shuttle effect and synergistically improve the interconversion kinetics from polysulfides to Li_(2)S.The X-ray absorption near edge curves indicated the reversible conversion of Li_(2)Sx on the S/Pt&Co@NCNT electrode.Meanwhile,density functional theory demonstrated that the Pt&Co@NCNT promoted the free energy of the phase transition of sulfur species and reduced the oxidative decomposition energy of Li_(2)S.As a result,the batteries assembled with S/Pt&Co@NCNT electrodes exhibited a high capacity retention of 80%at 100 cycles at a current density of 1.3 mA cm^(−2)(S loading:2.5 mg cm^(−2)).More importantly,an excellent rate performance was achieved with a high capacity of 822.1 mAh g^(−1) at a high current density of 12.7 mA cm^(−2).This work opens a new direction to boost the sulfur redox kinetics for ultrafast Li-S batteries. 展开更多
关键词 DFT calculation dual-single-atoms of Pt-Co fast Li-sulfur batteries sulfur redox kinetics XANES analysis
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p-d Orbital Hybridization Engineered Single-Atom Catalyst for Electrocatalytic Ammonia Synthesis 被引量:1
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作者 Jingkun Yu Xue Yong Siyu Lu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期119-125,共7页
The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,... The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,the roles of individual metals,coordination atoms,and their synergy effect on the electroanalytic performance remain unclear.Therefore,in this work,a series of 2DMOFs with different metals and coordinating atoms are systematically investigated as electrocatalysts for ammonia synthesis using density functional theory calculations.For a specific metal,a proper metal-intermediate atoms p-d orbital hybridization interaction strength is found to be a key indicator for their NRR catalytic activities.The hybridization interaction strength can be quantitatively described with the p-/d-band center energy difference(Δd-p),which is found to be a sufficient descriptor for both the p-d hybridization strength and the NRR performance.The maximum free energy change(ΔG_(max))andΔd-p have a volcanic relationship with OsC_(4)(Se)_(4)located at the apex of the volcanic curve,showing the best NRR performance.The asymmetrical coordination environment could regulate the band structure subtly in terms of band overlap and positions.This work may shed new light on the application of orbital engineering in electrocatalytic NRR activity and especially promotes the rational design for SACs. 展开更多
关键词 first-principle calculations Nitrogen reduction p-d orbital hybridization single-atom catalysts
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Boosting oxygen reduction activity and CO_(2) resistance on bismuth ferrite-based perovskite cathode for low-temperature solid oxide fuel cells below 600℃ 被引量:1
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作者 Juntao Gao Zhiyun Wei +5 位作者 Mengke Yuan Zhe Wang Zhe Lü Qiang Li Lingling Xu Bo Wei 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期600-609,I0013,共11页
Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)... Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs. 展开更多
关键词 Low-temperature solid oxide fuel cell Perovskite cathode DFT calculations CO_(2) tolerance
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Li-promoted C_(3)N_(4) catalyst for efficient isomerization of glucose into fructose at 50℃ in water 被引量:1
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作者 Wang Liu Yanfei Zhang +5 位作者 Mengya Sun Xinpeng Zhao Shenggang Li Xinqing Chen Liangshu Zhong Lingzhao Kong 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第9期1419-1426,共8页
Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous catalyst.However,hi... Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous catalyst.However,high yield and selectivity of fructose cannot be simultaneously obtained under mild conditions which hamper the scale of application compared with enzymatic catalysis.Herein,a Li-promoted C_(3)N_(4) catalyst was exploited which afforded an excellent fructose yield(40.3 wt%)and selectivity(99.5%)from glucose in water at 50℃,attributed to the formation of stable Li–N bond to strengthen the basic sites of catalysts.Furthermore,the so-formed N_(6)–Li–H_(2)O active site on Li–C_(3)N_(4) catalyst in aqueous phase changes the local electronic structure and strengthens the deprotonation process during glucose isomerization into fructose.The superior catalytic performance which is comparable to biological pathway suggests promising applications of lithium containing heterogeneous catalyst in biomass refinery. 展开更多
关键词 GLUCOSE FRUCTOSE ISOMERIZATION Li–C_(3)N_(4) Density functional theory calculations
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Composition Engineering Opens an Avenue Toward Efficient and Sustainable Nitrogen Fixation 被引量:1
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作者 Xiaolin Wang Liming Yang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第1期313-325,共13页
In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active ... In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction. 展开更多
关键词 composition engineering strategy diatomic catalysts electrocatalytic nitrogen reduction reaction first-principles calculations graphdiyne hierarchical high-throughput screening synergistic effects
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