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Multifunctional catalytic sites regulation of atomic-scale iridium on orthorhombic-CoSe_(2)for high efficiency dual-functional alkaline hydrogen evolution and organic degradation
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作者 Jingjing Huang Chenglin Zhong +14 位作者 Yanjie Xia Jia Liu Guizhen Li Chao Yang Jiahong Wang Qian Wang Zhenbao Zhang Feng Yan Jianghua Wu yu Deng Zhenjiang Zhou Xingchen He Paul K.Chu Woon-Ming Lau xue-feng yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期271-281,共11页
The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporat... The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation. 展开更多
关键词 Orthorhombic-CoSe_(2) Multifunctional sites design Hydrogen evolution reaction Synergistically catalyze Methylene blue oxidation
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Therapeutic Effectiveness of Leukocyte-and Platelet-rich Fibrin for Diabetic Foot Ulcers:A Retrospective Study
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作者 Fen WANG Xiao-ling ZHANG +9 位作者 Jing ZHANG Song GONG Jing TAO Hui XIANG Xiao-qing FU Xu-na BIAN xue-feng yu An-hui XU Cheng-la YI Shi-ying SHAO 《Current Medical Science》 SCIE CAS 2024年第3期568-577,共10页
Objective Diabetic foot ulcer(DFU)is one of the most serious complications of diabetes.Leukocyte-and platelet-rich fibrin(L-PRF)is a second-generation autologous platelet-rich plasma.This study aims to investigate the... Objective Diabetic foot ulcer(DFU)is one of the most serious complications of diabetes.Leukocyte-and platelet-rich fibrin(L-PRF)is a second-generation autologous platelet-rich plasma.This study aims to investigate the clinical effects of L-PRF in patients with diabetes in real clinical practice.Methods Patients with DFU who received L-PRF treatment and standard of care(SOC)from 2018 to 2019 in Tongji Hospital were enrolled.The clinical information including patient characteristics,wound evaluation(area,severity,infection,blood supply),SOC of DFU,and images of ulcers was retrospectively extracted and analyzed.L-PRF treatment was performed every 7±2 days until the ulcer exhibited complete epithelialization or an overall percent volume reduction(PVR)greater than 80%.Therapeutic effectiveness,including overall PVR and the overall and weekly healing rates,was evaluated.Results Totally,26 patients with DFU were enrolled,and they had an ulcer duration of 47.0(35.0,72.3)days.The severity and infection of ulcers varied,as indicated by the Site,Ischemia,Neuropathy,Bacterial Infection,and Depth(SINBAD)scores of 2–6,Wagner grades of 1–4,and the Perfusion,Extent,Depth,Infection and Sensation(PEDIS)scores of 2–4.The initial ulcer volume before L-PRF treatment was 4.94(1.50,13.83)cm3,and the final ulcer volume was 0.35(0.03,1.76)cm3.The median number of L-PRF doses was 3(2,5).A total of 11 patients achieved complete epithelialization after the fifth week of treatment,and 19 patients achieved at least an 80%volume reduction after the seventh week.The overall wound-healing rate was 1.47(0.63,3.29)cm3/week,and the healing rate was faster in the first 2 weeks than in the remaining weeks.Concurrent treatment did not change the percentage of complete epithelialization or healing rate.Conclusion Adding L-PRF to SOC significantly improved wound healing in patients with DFU independent of the ankle brachial index,SINBAD score,or Wagner grade,indicating that this method is appropriate for DFU treatment under different clinical conditions. 展开更多
关键词 diabetic foot ulcer autologous platelet-rich plasma leukocyte-and platelet-rich fibrin standard of care percentage volume reduction
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Interaction between circulating cancer cells and platelets:clinical implication 被引量:3
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作者 Xiao-Liang Lou Jian Sun +3 位作者 Shu-Qi Gong xue-feng yu Rui Gong Huan Deng 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2015年第5期450-460,共11页
Metastasis is the main cause of cancer-associated mortality. During this complicated process, some cancer cells, also called circulating tumor cells (CTCs), detach from primary sites, enter bloodstream and extravasa... Metastasis is the main cause of cancer-associated mortality. During this complicated process, some cancer cells, also called circulating tumor cells (CTCs), detach from primary sites, enter bloodstream and extravasate at metastatic site. Thrombocytosis is frequently observed in patients with metastatic cancers suggesting the important role of platelets in metastasis. Therefore this review focuses on how platelets facilitate the generation of CTCs, protect them from various host attacks, such as immune assaults, apoptosis and shear stress, and regulate CTCs intravasation/extravasation. Platelet-derived cytokines and receptors are involved in this cascade. Identification the mechanisms underlie platelet-CTCs interactions could lead to the development of new platelet-targeted therapeutic strategy to reduce metastasis. 展开更多
关键词 Circulating tumor cells (CTCs) PLATELET epithelial-mesenchymal transition (EMT) immunesurveillance METASTASIS
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Expert Consensus on Cognitive Dysfunction in Diabetes 被引量:5
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作者 Yan YANG Jia-jun ZHAO xue-feng yu 《Current Medical Science》 SCIE CAS 2022年第2期286-303,共18页
The incidence of diabetes is gradually increasing in China,and diabetes and associated complications,such as cognitive dysfunction have gained much attention in recent time.However,the concepts,clinical treatment,and ... The incidence of diabetes is gradually increasing in China,and diabetes and associated complications,such as cognitive dysfunction have gained much attention in recent time.However,the concepts,clinical treatment,and prevention of cognitive dysfunction in patients with diabetes remain unclear.The Chinese Society of Endocrinology investigated the current national and overseas situation of cognitive dysfunction associated with diabetes.Based on research both in China and other countries worldwide,the Expert Consensus on Cognitive Dysfunction in Diabetes was established to guide physicians in the comprehensive standardized management of cognitive dysfunction in diabetes and to improve clinical outcomes in Chinese patients.This consensus presents an overview,definition and classification,epidemiology and pathogenesis,risk factors,screening,diagnosis,differential diagnosis,treatment,and prevention of cognitive dysfunction in patients with diabetes. 展开更多
关键词 DIABETES cognitive dysfunction antidiabetic agents
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Changing trends of clinicopathologic features and survival duration after surgery for gastric cancer in Northeast China 被引量:2
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作者 Zhao Zhai Zi-yu Zhu +11 位作者 Xi-Liang Cong Bang-Ling Han Jia-Liang Gao Xin Yin yu Zhang Sheng-Han Lou Tian-Yi Fang Yi-Min Wang Chun-Feng Li xue-feng yu Yan Ma Ying-Wei Xue 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2020年第10期1119-1132,共14页
BACKGROUND Through analyzing the data from a single institution in Northeast China,this study revealed the possible clinicopathologic characteristics that influence the prognosis of patients with gastric cancer(GC).AI... BACKGROUND Through analyzing the data from a single institution in Northeast China,this study revealed the possible clinicopathologic characteristics that influence the prognosis of patients with gastric cancer(GC).AIM To evaluate the changing trends of clinicopathologic features and survival duration after surgery in patients with GC in Northeast China,which is a highprevalence area of GC.METHODS The study analyzed the difference in clinicopathologic features and survival duration after surgery of 5887 patients who were histologically diagnosed with GC at the Harbin Medical University Cancer Hospital.The study mainly analyzed the data in three periods,2000 to 2004(Phase 1),2005 to 2009(Phase 2),and 2010 to 2014(Phase 3).RESULTS Over time,the postoperative survival rate significantly increased from 2000 to 2014.In the past 15 years,compared with Phases 1 and 2,the tumor size was smaller in Phase 3(P<0.001),but the proportion of high-medium differentiated tumors increased(P<0.001).The proportion of early GC gradually increased from 3.9%to 14.4%(P<0.001).A surprising improvement was observed in the mean number of retrieved lymph nodes,ranging from 11.4 to 27.5(P<0.001).The overall 5-year survival rate increased from 24%in Phase 1 to 43.8%in Phase 3.Through multivariate analysis,it was found that age,tumor size,histologic type,tumor-node-metastasis stage,depth of invasion,lymph node metastasis,surgical approach,local infiltration,radical extent,number of retrieved lymph nodes,and age group were independent risk factors that influenced the prognosis of patients with GC.CONCLUSION The clinical features of GC in Northeast China changed during the observation period.The increasing detection of early GC and more standardized surgical treatment effectively prolonged lifetimes. 展开更多
关键词 Gastric cancer Clinicopathologic features SURVIVAL Time trends EPIDEMIOLOGY GASTRECTOMY
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Deep gold mineralization features of Jiaojia metallogenic belt,Jiaodong gold Province:Based on the breakthrough of 3000 m exploration drilling 被引量:2
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作者 xue-feng yu Da-peng Li +7 位作者 Jing-xiang Tian De-ping Yang Wei Shan Ke Geng yu-xin Xiong Nai-jie Chi Peng-fei Wei Peng-rui Liu 《China Geology》 2020年第3期385-401,共17页
Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus ... Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus become an internationally noteworthy gold ore cluster.The gold exploration depth has been increased to about 2000 m from the previous<1000 m.To further explore the mineralization potential of the Jiaodong area at a depth of about 3000 m,the Shandong Institute of Geological Sciences has drilled an exploratory drillhole named“Deep drillhole ZK01”to a depth of 3266 m.Hence,as reported herein,the mineralization characteristics of the Jiaojia metallogenic belt have been successfully documented.ZK01 is,to date,the deepest borehole with an gold intersect in China,and constitutes a significant advance in deep gold prospecting in China.The findings of this study further indicate that the depth interval of 2000 m to 4000 m below the ground surface in the Wuyi Village area incorporates 912 t of inferred gold resources,while the depth interval of 2000 m to 4000 m below the surface across the Jiaodong area possesses about 4000 t of inferred gold resources.The Jiaojia Fault Belt tends to gently dip downward,having dip angles of about 25°and about 20°at vertical depths of 2000 m and 2850 m,respectively.The deep part of the Jiaojia metallogenic belt differs from the shallow and moderately deep parts about fracturing,alteration,mineralization,and tectonic type.The deep zones can generally be categorized from inside outward as cataclastic granite,granitic cataclasite,weakly beresitized granitic cataclasite,beresitized cataclasite,and gouge.These zones exhibit a gradual transitional relation or occur alternately and repeatedly.The mineralization degree of the pyritized cataclastic granite-type ore in the deep part of the Jiaojia metallogenic belt is closely related to the degree of pyrite vein development;that is,the higher the pyrite content,the wider the veins and the higher the gold grade.Compared to the shallow gold ores,the deep-seated gold ores have higher fineness and contain joseite,tetradymite,and native bismuth,suggesting that the deep gold mineralization temperature is higher and that mantle-sourced material may have contributed to this mineralization.ZK01 has also revealed that the deep-seated ore bodies in the Jiaojia metallogenic belt are principally situated above the main fracture plane(gouge)and hosted within the Linglong Granite,contradicting previous findings indicating that the moderately shallow gold ore bodies are usually hosted in the contact zone between the Linglong Granite and Jiaodong Group or meta-gabbro.These new discoveries are particularly significant because they can help correct mineralization prospecting models,determine favorable positions for deep prospecting,and improve metallogenic prediction and resource potential evaluation. 展开更多
关键词 Au deposit Alteration rock type Fracture zone 3000 m scientific drilling Deep mineral exploration engineering Jiaojia metallogenic belt Shandong Province China
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Prognostic significance of Borrmann type combined with vessel invasion status in advanced gastric cancer 被引量:1
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作者 Zhao Zhai Zi-yu Zhu +10 位作者 yu Zhang Xin Yin Bang-Ling Han Jia-Liang Gao Sheng-Han Lou Tian-Yi Fang Yi-Min Wang Chun-Feng Li xue-feng yu Yan Ma Ying-Wei Xue 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2020年第9期992-1004,共13页
BACKGROUND Borrmann classification(types I-IV)for the detection of advanced gastric cancer has been accepted worldwide,and lymphatic and/or blood vessel invasion(LBVI)status is related to the poor prognosis after gast... BACKGROUND Borrmann classification(types I-IV)for the detection of advanced gastric cancer has been accepted worldwide,and lymphatic and/or blood vessel invasion(LBVI)status is related to the poor prognosis after gastric cancer.AIM To evaluate the significance of Borrmann type combined with LBVI status in predicting the prognosis of advanced gastric cancer.METHODS We retrospectively studied the clinicopathological characteristics and long-term survival data of 2604 patients who were diagnosed with advanced gastric adenocarcinoma at Harbin Medical University Cancer Hospital from January 2009 to December 2013.Categorical variables were evaluated by the Pearson’sχ^2 test,the Kaplan-Meier method was used to identify differences in cumulative survival rates,and the Cox proportional hazards model was used for multivariate prognostic analysis.RESULTS A total of 2604 patients were included in this study.The presence of LVBI[LBVI(+)]and Borrmann type(P=0.001),tumor location(P<0.001),tumor size(P<0.001),histological type(P<0.001),tumor invasion depth(P<0.001),number of metastatic lymph nodes(P<0.001),and surgical method(P<0.001)were significantly correlated with survival.When analyzing the combination of the Borrmann classification and LBVI status,we found that patients with Borrmann type Ⅲ disease and LBVI(+)had a similar 5-year survival rate to those with Borrmann IV+LBVI(-)(16.4%vs 13.1%,P=0.065)and those with Borrmann IV+LBVI(+)(16.4%vs 11.2%,P=0.112).Subgroup analysis showed that the above results were true for any pT stage and any tumor location.Multivariate Cox regression analysis showed that Borrmann classification(P=0.023),vascular infiltration(P<0.001),tumor size(P=0.012),pT stage(P<0.001),pN stage(P<0.001),and extent of radical surgery(P<0.001)were independent prognostic factors for survival.CONCLUSION Since patients with Borrmann Ⅲ disease and LBVI(+)have the same poor prognosis as those with Borrmann IV disease,more attention should be paid to patients with Borrmann Ⅲ disease and LBVI(+)during diagnosis and treatment,regardless of the pT stage and tumor location,to obtain better survival results. 展开更多
关键词 Advanced gastric cancer Borrmann type Vascular invasion Long-term survival
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Subsurface intercalation activating basal plane of black phosphorus for nitrogen reduction
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作者 Xue Zhang Haitao Zhao +2 位作者 Paul K.Chu Jiahong Wang xue-feng yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第9期293-299,共7页
Ammonia(NH3)is not only an important chemical in many fields,but also provides a promising intermediate for energy stor-age[1,2].To produce NH3 from naturally abundant N2,the strong N≡N bond in the inert N2 molecules... Ammonia(NH3)is not only an important chemical in many fields,but also provides a promising intermediate for energy stor-age[1,2].To produce NH3 from naturally abundant N2,the strong N≡N bond in the inert N2 molecules must be broken firstly. 展开更多
关键词 Subsuface intercalation Nitrogen reduction reaction Basal surface sites Intrinsic activity SELECTIVITY
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Bias Dependence of Radiation-Induced Narrow-Width Channel Effects in 65 nm NMOSFETs
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作者 郑齐文 崔江维 +4 位作者 魏莹 余学峰 陆妩 任迪远 郭旗 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第4期74-77,共4页
The bias dependence of radiation-induced narrow-width channel effects(RINCEs) in 65-nm n-type metal-oxidesemiconductor field-effect transistors(NMOSFETs) is investigated. The threshold voltage of the narrow-width6... The bias dependence of radiation-induced narrow-width channel effects(RINCEs) in 65-nm n-type metal-oxidesemiconductor field-effect transistors(NMOSFETs) is investigated. The threshold voltage of the narrow-width65 nm NMOSFET is negatively shifted by total ionizing dose irradiation, due to the RINCE. The experimental results show that the 65 nm narrow-channel NMOSFET has a larger threshold shift when the gate terminal is kept in the ground, which is contrary to the conclusion obtained in the old generation devices. Depending on the three-dimensional simulation, we conclude that electric field distribution alteration caused by shallow trench isolation scaling is responsible for the anomalous RINCE bias dependence in 65 nm technology. 展开更多
关键词 Bias Dependence of Radiation-Induced Narrow-Width Channel Effects in 65 nm NMOSFETs
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Engineering the axial coordination of cobalt single atom catalysts for efficient photocatalytic hydrogen evolution
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作者 Ning Kang Lingwen Liao +9 位作者 Xue Zhang Zhen He Binlu yu Jiahong Wang Yongquan Qu Paul KChu Seeram Ramakrishna xue-feng yu Xin Wang Licheng Bai 《Nano Research》 SCIE EI CSCD 2024年第6期5114-5121,共8页
Improving the catalytic activity of non-noble metal single atom catalysts(SACs)has attracted considerable attention in materials science.Although optimizing the local electronic structure of single atom can greatly im... Improving the catalytic activity of non-noble metal single atom catalysts(SACs)has attracted considerable attention in materials science.Although optimizing the local electronic structure of single atom can greatly improve their catalytic activity,it often involves in-plane modulation and requires high temperatures.Herein,we report a novel strategy to manipulate the local electronic structure of SACs via the modulation of axial Co-S bond anchored onto graphitic carbon nitride(C_(3)N_(4))at room temperature(RT).Each Co atom is bonded to four N atoms and one S atom(Co-(N,S)/C_(3)N_(4)).Owing to the greater electronegativity of S in the Co-S bond,the local electronic structure of the Co atoms is available to be controlled at a relatively moderate level.Consequently,when employed for the photocatalytic hydrogen evolution reaction,the adsorption energy of intermediate hydrogen(H*)on the Co atoms is remarkably low.In the presence of the Co-(N,S)/C_(3)N_(4)SACs,the hydrogen evolution rates reach up to 10 mmol/(g·h),which is nearly 10 and 2.5 times greater than the rates in the presence of previously reported transition metal/C_(3)N_(4)and noble platinum nanoparticles(PtNPs)/C_(3)N_(4)catalysts,respectively.Attributed to the tailorable axial Co-S bond in the SAC,the local electronic structure of the Co atoms can be further optimized for other photocatalytic reactions.This axial coordination engineering strategy is universal in catalyst designing and can be used for a variety of photocatalytic applications. 展开更多
关键词 transition metal single-atom local electronic structure photocatalytic hydrogen evolution graphitic carbon nitride axial coordination environment
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CsPbBr_(3)-DMSO merged perovskite micro-bricks for efficient X-ray detection
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作者 Tongyu Shi Wenjun Liu +11 位作者 Jiongtao Zhu Xiongsheng Fan Zhengyu Zhang Xingchen He Rui He Jiahong Wang Kezhen Chen Yongshuai Ge Xiangming Sun Yanliang Liu Paul K.Chu xue-feng yu 《Nano Research》 SCIE EI CSCD 2023年第7期9983-9989,共7页
Inorganic perovskite wafers with good stability and adjustable sizes are promising in X-ray detection but the high synthetic temperature is a hindrance.Herein,dimethyl sulfoxide(DMSO)is used to prepare the CsPbBr_(3)m... Inorganic perovskite wafers with good stability and adjustable sizes are promising in X-ray detection but the high synthetic temperature is a hindrance.Herein,dimethyl sulfoxide(DMSO)is used to prepare the CsPbBr_(3)micro-bricks powder at room temperature.The CsPbBr_(3)powder has a cubic shape with few crystal defects,small charge trap density,and high crystallinity.A trace amount of DMSO attaches to the surface of the CsPbBr_(3)micro-bricks via Pb-O bonding,forming the CsPbBr_(3)-DMSO adduct.During hot isostatic processing,the released DMSO vapor merges the CsPbBr_(3)micro-bricks,producing a compact and dense CsPbBr_(3)wafer with minimized grain boundaries and excellent charge transport properties.The CsPbBr_(3)wafer shows a large mobility-lifetime(μτ)product of 5.16×10^(-4)cm^(2)·V^(-1),high sensitivity of 14,430μC·Gyair^(-1)·cm^(-2),low detection limit of 564 nGyair·s^(-1),as well as robust stability in X-ray detection.The results reveal a novel strategy with immense practical potential pertaining to high-contrast X-ray detection. 展开更多
关键词 CsPbBr_(3)-DMSO inorganic perovskites wafer grain growth crystal defect X-ray detector
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Data-driven structural descriptor for predicting platinum-based alloys as oxygen reduction electrocatalysts
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作者 Xue Zhang Zhuo Wang +7 位作者 Adam Mukhtar Lawan Jiahong Wang Chang-yu Hsieh Chenru Duan Cheng Heng Pang Paul.K.Chu xue-feng yu Haitao Zhao 《InfoMat》 SCIE CSCD 2023年第6期102-113,共12页
Owing to increasing global demand for carbon neutral and fossil-free energy systems,extensive research is being conducted on efficient and inexpensive electrocatalysts for catalyzing the kinetically sluggish oxygen re... Owing to increasing global demand for carbon neutral and fossil-free energy systems,extensive research is being conducted on efficient and inexpensive electrocatalysts for catalyzing the kinetically sluggish oxygen reduction reaction(ORR)at the cathode of fuel cells.Platinum(Pt)-based alloys are considered promising candidates for replacing expensive Pt catalysts.However,the current screening process of Pt-based alloys is time-consuming and labor-intensive,and the descriptor for predicting the activity of Pt-based catalysts is generally inaccurate.This study proposed a strategy by combining high-throughput first-principles calculations and machine learning to explore the descriptor used for screening Pt-based alloy catalysts with high Pt utilization and low Pt consump-tion.Among the 77 prescreened candidates,we identified 5 potential candidates for catalyzing ORR with low overpotential.Furthermore,during the second and third rounds of active learning,more Pt-based alloys ORR candidates are identi-fied based on the relationship between structural features of Pt-based alloys and their activity.In addition,we highlighted the role of structural features in Pt-based alloys and found that the difference between the electronegativity of Pt and heteroatom,the valence electrons number of the heteroatom,and the ratio of heteroatoms around Pt are the main factors that affect the activity of ORR.More importantly,the combination of those structural features can be used as structural descriptor for predicting the activity of Pt-based alloys.We believe the findings of this study will provide new insight for predicting ORR activ-ity and contribute to exploring Pt-based electrocatalysts with high Pt utiliza-tion and low Pt consumption experimentally. 展开更多
关键词 high-throughput DFT calculation machine learning oxygen reduction electrocatalysts platinum-based alloys structural descriptor
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激光正入射和斜入射下黑磷角分辨偏振拉曼光谱的理解 被引量:3
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作者 林妙玲 冷宇辰 +7 位作者 从鑫 孟达 王佳宏 李晓莉 喻彬璐 刘雪璐 喻学峰 谭平恒 《Science Bulletin》 SCIE EI CAS CSCD 2020年第22期1894-1900,M0004,共8页
由于双折射和二向色性效应,从群论方法得到的各向同性材料声子角分辨偏振拉曼(ARPR)强度的选择定则无法应用于各向异性层状材料(ALMs).这两种效应会导致入射激光和散射信号的偏振和强度在ALMs内部依赖于传输深度,使得预测任意激光入射... 由于双折射和二向色性效应,从群论方法得到的各向同性材料声子角分辨偏振拉曼(ARPR)强度的选择定则无法应用于各向异性层状材料(ALMs).这两种效应会导致入射激光和散射信号的偏振和强度在ALMs内部依赖于传输深度,使得预测任意激光入射方向下的ARPR强度面临巨大的挑战.本文以面内各向异性的黑磷作为范例,发展了所谓的双折射-二向色性(BLD)模型,定量理解了黑磷在正入射和斜入射时的ARPR强度.特定激发光下两者采用的是同一套实拉曼张量且不需要任何拟合参数,其中双折射和二向色性效应通过复折射率加以考虑.本文还提出了实拉曼张量和复折射率可分别通过主轴的相对拉曼强度及菲涅尔公式拟合入射角依赖的反射率得到.这些结果表明,在BLD模型基础上通过考虑由双折射和二向色性效应所导致的入射激光和散射信号深度依赖的偏振和强度以及多层结构的干涉效应,可定量理解前面报道的置于多层衬底上的ALMs超薄片在激光正入射时依赖于激发光波长、ALM厚度和衬底介质层厚度的反常ARPR强度.该研究可以广泛应用到任意不透明的各向异性晶体中,为预测和操控相关声子的偏振行为提供了一种有效的方法. 展开更多
关键词 二向色性 菲涅尔公式 选择定则 斜入射 各向异性晶体 复折射率 散射信号 入射激光
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Mapping the elastic properties of two-dimensional MoS_(2) via bimodal atomic force microscopy and finite element simulation 被引量:5
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作者 yuhao Li Chuanbin yu +12 位作者 Yingye Gan Peng Jiang Junxi yu yun Ou Dai-Feng Zou Cheng Huang Jiahong Wang Tingting Jia Qian Luo xue-feng yu Huijuan Zhao Cun-Fa Gao Jiangyu Li 《npj Computational Materials》 SCIE EI 2018年第1期246-253,共8页
Elasticity is a fundamental mechanical property of two-dimensional(2D)materials,and is critical for their application as well as for strain engineering.However,accurate measurement of the elastic modulus of 2D materia... Elasticity is a fundamental mechanical property of two-dimensional(2D)materials,and is critical for their application as well as for strain engineering.However,accurate measurement of the elastic modulus of 2D materials remains a challenge,and the conventional suspension method suffers from a number of drawbacks.In this work,we demonstrate a method to map the in-plane Young’s modulus of mono-and bi-layer MoS_(2) on a substrate with high spatial resolution.Bimodal atomic force microscopy is used to accurately map the effective spring constant between the microscope tip and sample,and a finite element method is developed to quantitatively account for the effect of substrate stiffness on deformation.Using these methods,the in-plane Young’s modulus of monolayer MoS_(2) can be decoupled from the substrate and determined as 265±13 GPa,broadly consistent with previous reports though with substantially smaller uncertainty.It is also found that the elasticity of mono-and bi-layer MoS_(2) cannot be differentiated,which is confirmed by the first principles calculations.This method provides a convenient,robust and accurate means to map the in-plane Young’s modulus of 2D materials on a substrate. 展开更多
关键词 MODULUS MODAL element
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Black Phosphorus: An Effective Feedstock for the Synthesis of Phosphorus-Based Chemicals 被引量:1
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作者 Lie Wu Shi Bian +4 位作者 Hao Huang Jiahong Wang Danni Liu Paul K.Chu xue-feng yu 《CCS Chemistry》 CAS 2019年第2期166-172,共7页
We propose and demonstrate the novel concept of synthesizing organophosphorus compounds directly from black phosphorus(BP)nanoparticles as the feedstock.Compounds such as alkyl phosphines,alkyl phosphine oxides,phosph... We propose and demonstrate the novel concept of synthesizing organophosphorus compounds directly from black phosphorus(BP)nanoparticles as the feedstock.Compounds such as alkyl phosphines,alkyl phosphine oxides,phosphine sulfide,and hexafluorophosphate anion are prepared with good isolation yields under mild conditions.Selective synthesis of primary,secondary,and tertiary organophosphorus compounds is also demonstrated utilizing this one-pot approach.Reaction mechanisms are proposed and discussed.Compared with traditional white phosphorus(P 4)-based methods,the new synthetic concept and process utilizing elemental phosphorus are more efficient and environmentally friendly. 展开更多
关键词 black phosphorus NANOMATERIALS organophosphorus compounds phosphorus chemistry P-C coupling
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