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WO_(3)-TiO_(2)负载的Pt单原子催化剂光热协同催化丙烷和丙烯氧化
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作者 朱锐杰 康磊磊 +8 位作者 李林 潘晓丽 王华 苏杨 李广亿 程鸿魁 李仁贵 刘晓艳 王爱琴 《物理化学学报》 SCIE CAS CSCD 北大核心 2024年第1期26-27,共2页
单原子催化剂(single-atom catalyst,SAC)可以最大化金属原子利用率,并具有独特的电子特性,已经在各种催化反应中进行了广泛的探索。然而,与纳米催化剂相比,贵金属SAC在烃类氧化反应中通常被认为是不活泼的。在本文中,证明了WO_(3)-TiO_... 单原子催化剂(single-atom catalyst,SAC)可以最大化金属原子利用率,并具有独特的电子特性,已经在各种催化反应中进行了广泛的探索。然而,与纳米催化剂相比,贵金属SAC在烃类氧化反应中通常被认为是不活泼的。在本文中,证明了WO_(3)-TiO_(2)负载的Pt SAC(Pt1/WO_(3)-TiO_(2))在光热协同催化氧化C3H8和C3H6这两种典型的挥发性有机化合物(VOCs)中表现出比相应的纳米催化剂(PtNP/WO_(3)-TiO_(2))高得多的活性。研究发现,Pt1/WO_(3)-TiO_(2)和PtNP/WO_(3)-TiO_(2)都可以通过克服氧中毒来提高光热协同催化C3H8氧化的活性。值得注意的是,Pt1/WO_(3)-TiO_(2)的反应速率达到了3792μmol∙gPt−1∙s^(−1),这对C3H8氧化是一个新的突破。更有趣的是,由于C3H6在PtNP/WO_(3)-TiO_(2)上的强吸附导致催化剂C3H6中毒,因此PtNP/WO_(3)-TiO_(2)上的光热协同催化C3H6氧化无法进行。但是,得益于C3H6和Pt单原子之间适中的相互作用,Pt1/WO_(3)-TiO_(2)上的C3H6中毒在光照下可以被克服。因此,Pt1/WO_(3)-TiO_(2)在光热协同催化C3H6氧化中显示出更高的活性。这项工作表明,SAC的优势不仅在于节约贵金属,还在于可以根据其独特的电子特性发现新的催化反应。 展开更多
关键词 单原子催化剂 光热协同催化 氧化反应 氧中毒 丙烯中毒
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Petrogenesis, oxidation state and volatile content of Dongga tonalite in the Gangdese belt, Xizang: Implication for porphyry Cu mineralization
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作者 Liqiang Zhang Xilian Chen +3 位作者 Shaohao Zou Deru Xu Xuena wang hua wang 《Acta Geochimica》 EI CAS CSCD 2024年第2期280-295,共16页
The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassi... The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassic intrusions have been identified in the belt. Apart from the quartz diorite porphyry in the large Xietongmen deposit, the Cu mineralization potential of other Jurassic intrusions in this belt remains unclear. This study presents zircon U–Pb dating and trace elements, apatite major and trace elements as well as published whole-rock geochemical and isotopic data of the Dongga tonalite in the central part of the Gangdese belt, aiming to reveal the petrogenesis, oxidation state, volatile content, and Cu mineralization potential of this intrusion. The Dongga tonalite has a zircon U–Pb age of 179.4 ± 0.9 Ma. It exhibits high whole-rock V/Sc values(8.76–14.6), relatively low apatite CeN/CeN*ratios(1.04–1.28), elevated zircon(Eu/Eu*)Nvalues(an average of 0.44), high Ce4+/Ce3+values(205–1896), and high ?FMQ values(1.3–3.7), collectively suggesting a high magmatic oxygen fugacity. The Dongga tonalite features amphibole phenocrysts, relatively high whole-rock Sr/Y ratios(20.3–58.9), and lower zircon Ti temperatures (502–740 ℃), reflecting a high magmatic water content. Estimation of magmatic sulfur content(0.002–0.024 wt%) based on apatite SO3contents indicates an enriched magma sulfur content. Combined with previous studies and the collected Sr–Nd–Hf isotopes, the Dongga tonalite is derived from juvenile lower crust related with subduction of the Neo-Tethys oceanic slab. When compared with Xietongmen orebearing porphyries, the Dongga tonalite exhibits remarkable similarities with the Xietongmen ore-bearing porphyries in terms of magma source, tectonic background, magmatic redox state, and volatile components, which indicates that the Dongga tonalite has a high porphyry Cu mineralization potential, and therefore, provides important guidance for the future mineralization exploration. 展开更多
关键词 TONALITE Zircon APATITE Mineralization potential Dongga area Gangdese belt
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A review on electrocatalytic CO_(2) conversion via C-C and C-N coupling
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作者 Zhuangzhi Zhang Sijun Li +6 位作者 Zheng Zhang Zhou Chen hua wang Xianguang Meng Wenquan Cui Xiwei Qi Jiacheng wang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第2期167-194,共28页
Electrochemical C-C and C-N coupling reactions with the conversion of abundant and inexpensive small molecules,such as CO_(2) and nitrogencontaining species,are considered a promising route for increasing the value of... Electrochemical C-C and C-N coupling reactions with the conversion of abundant and inexpensive small molecules,such as CO_(2) and nitrogencontaining species,are considered a promising route for increasing the value of CO_(2) reduction products.The development of high-performance catalysts is the key to the both electrocatalytic reactions.In this review,we present a systematic summary of the reaction systems for electrocatalytic CO_(2) reduction,along with the coupling mechanisms of C-C and C-N bonds over outstanding electrocatalytic materials recently developed.The key intermediate species and reaction pathways related to the coupling as well as the catalyst-structure relationship will be also discussed,aiming to provide insights and guidance for designing efficient CO_(2) reduction systems. 展开更多
关键词 C-C coupling C-N coupling CO_(2) conversion ELECTROCATALYSIS urea synthesis
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Numerical investigation of sinusoidal pulsating gas intake to intensify the gas-slag momentum transfer in the top-blown smelting furnace
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作者 Zhanghao Wan Shiliang Yang +3 位作者 Desong Kong Dongbo Li Jianhang Hu hua wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第2期301-314,共14页
The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace were explored by means of the computational fluid dynamics method.The essenti... The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace were explored by means of the computational fluid dynamics method.The essential aspects of the fluid phase(e.g.,splashing volume,dead zone of copper slag,and gas penetration depth)were explored together with the effect of sinusoidal pulsating gas intake on the momentum-transfer performance between phases.The results illustrated that two relatively larger vortices and two smaller vortices appear in the bubble waist and below the lance,respectively.The expansion of larger ones as well as the shrinking of smaller ones combine to cause the contraction of the bubble waist.Compared to the results of the case with a fixed gas injection velocity(V_(g)=58 m/s),the splashing volume and dead zone volume of the slag under the V_(g)=58+10sin(2πt)condition are reduced by 24.9%and 23.5%,respectively,where t represents the instant time.Gas penetration depth and slag motion velocity of the latter are 1.03 and 1.31 times high-er than those of the former,respectively. 展开更多
关键词 top-blown smelting furnace pulsed flow volume of fluid penetration depth splashing volume
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Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice
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作者 Han Duan Ning Tao +8 位作者 Lin Lv Kai-Xin Yan Yong-Gang You Zhuang Mao Chang-Yao wang Xue Li Jia-Yan Jin Chu-Tse Wu hua wang 《World Journal of Stem Cells》 SCIE 2024年第5期575-590,共16页
BACKGROUND Atherosclerosis(AS),a chronic inflammatory disease of blood vessels,is a major contributor to cardiovascular disease.Dental pulp stem cells(DPSCs)are capable of exerting immunomodulatory and anti-inflammato... BACKGROUND Atherosclerosis(AS),a chronic inflammatory disease of blood vessels,is a major contributor to cardiovascular disease.Dental pulp stem cells(DPSCs)are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflam-mation-related diseases.Hepatocyte growth factor(HGF)is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases.AIM To modify DPSCs with HGF(DPSC-HGF)and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout(ApoE-/-)mouse model and an in vitro cellular model.METHODS ApoE-/-mice were fed with a high-fat diet(HFD)for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs(DPSC-Null)through tail vein at weeks 4,7,and 11,respectively,and the therapeutic efficacy and mechanisms were analyzed by histopathology,flow cytometry,lipid and glucose measurements,real-time reverse transcription polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay at the different time points of the experiment.An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells(HAOECs),and indirect co-cultured with supernatant of DPSC-Null(DPSC-Null-CM)or DPSC-HGF-CM,and the effect and mechanisms were analyzed by flow cytometry,RT-PCR and western blot.Nuclear factor-κB(NF-κB)activators and inhibitors were also used to validate the related signaling pathways.RESULTS DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors,and the percentage of macrophages in the aorta,and DPSC-HGF treatment had more pronounced effects.DPSCs treatment had no effect on serum lipoprotein levels.The FACS results showed that DPSCs treatment reduced the percentages of monocytes,neutrophils,and M1 macrophages in the peripheral blood and spleen.DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-αstimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway.CONCLUSION This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/-mice on a HFD,and could be of greater value in stem cell-based treatments for AS. 展开更多
关键词 ATHEROSCLEROSIS Apolipoprotein E-knockout mice Cell therapy Dental pulp stem cells Hepatocyte growth factor
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Experimental Study on Relieving Physical Fatigue of Mice by Qixue Shuangbu Tinctura 被引量:3
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作者 Lin-Wei Chen Bao-Chang Cai +5 位作者 Nan Chen Qin wang De-Xi Peng hua wang Cheng-Ye Yuan Chun-hua Cao 《Food Therapy and Health Care》 2019年第1期8-15,共8页
Objective:To explore the effect of Qixue Shuangbu Tinctura on alleviating the physical fatigue of mice.Method:Male ICR mice were randomly divided into 6 groups,high dose,middle dose and low dose group,liquor control g... Objective:To explore the effect of Qixue Shuangbu Tinctura on alleviating the physical fatigue of mice.Method:Male ICR mice were randomly divided into 6 groups,high dose,middle dose and low dose group,liquor control group,positive control group and negative control(saline)group.According to"Health Food Test and Evaluation Technical Specifications"(2003 edition)on the effect of alleviating physical fatigue experimental study,the weight-bearing swimming test of mice was carried out after gavage for 30 days.Result:Qixue Shuangbu Tinctura can effectively prolong the time of weight-bearing swimming in mice,reduce the production of blood lactic acid in vivo,and timely eliminate serum urea nitrogen,and promote the reserve of hepatic glycogen in mice after weight-bearing swimming exercise.Conclusion:Qixue Shuangbu Tinctura has the function of relieving physical fatigue. 展开更多
关键词 Qixue Shuangbu Tinctura PHYSICAL FATIGUE Weightbearing SWIMMING
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硫酸化氧化锆负载的Ru单原子催化甲烷直接转化制甲醇 被引量:1
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作者 刘华 康磊磊 +3 位作者 王华 蒋齐可 刘晓艳 王爱琴 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第3期64-71,共8页
天然气作为一种低碳清洁能源,其储量大、价格低、热值高,被认为是最有前途的石油替代资源之一.甲烷是天然气的主要成分,直接转化为甲醇是有效利用甲烷的一种途径,也是一个极具挑战性的课题.一方面,甲烷的C-H键(439.3 kJ^·mol^(-1)... 天然气作为一种低碳清洁能源,其储量大、价格低、热值高,被认为是最有前途的石油替代资源之一.甲烷是天然气的主要成分,直接转化为甲醇是有效利用甲烷的一种途径,也是一个极具挑战性的课题.一方面,甲烷的C-H键(439.3 kJ^·mol^(-1))强度非常高,活化十分困难;另一方面,在反应条件下,甲醇等产物比甲烷更容易被氧化,从而导致目标产物的选择性不高.因此,设计高效催化剂是解决该难题的有效途径之一.研究(J. Catal., 1993, 144.238-253和Catal. Today, 2021, 365,71-79)发现,硫酸化的氧化锆(SZ)负载的贵金属(例如Pt等)等超强酸催化剂能够促进甲烷在脱氢芳构化反应中的活化.受该工作启发,本文通过模拟均相催化设计了固体超强酸负载的Ru单原子催化剂(SAC),并在温和条件(70 ℃)下将其用于甲烷直接转化制甲醇反应.结果发现,在Ru/SZSAC上的含氧化合物(CH_(3)OH, CH_(3)OOH和HCOOH)收率(18.32 μmol,≥80 h^(-1))显著超过SZ(0.67 μmol)和Ru/ZrO_(2)(0.29 μmol),这表明在Ru/SZSAC上形成了新的活性中心.结合^(13)CH_(4)同位素标记实验、吡啶吸附红外光谱(PY-IR)、电子顺磁共振(EPR)和X射线光电子能谱(XPS)等表征结果,提出了Ru单原子和超强酸位点协同催化甲烷转化制甲醇的反应机理.首先,通过AC-HADDF-STEM证明了Ru/SZSAC的成功制备;PY-IR谱和氨气程序升温脱附结果证明了在该体系中硫酸化处理有效增加了催化剂表面的强酸位点(包括B-酸和L-酸).EPR结果表明,与ZrO_(2)和0.1Ru/ZrO_(2)相比,在SZ和0.1Ru/SZ上产生更多^(·)OH.进一步结合催化剂表面酸性变化情况和文献报道说明,催化剂表面的强酸位点(包括B-酸和L-酸)可以促进H_(2)O_(2)有效分解成^(·)OH和^(·)OOH,而^(·)OH在甲烷活化的过程中起着至关重要的作用,这合理解释了0.1Ru/SZ比0.1Ru/ZrO_(2)催化性能更好的原因.结合XPS结果推测,硫酸根的强吸电子作用使与其相邻的Ru^(δ+)和Zr^(γ+)的价态都高于+4 (δ> 4, γ> 4).综上提出了Ru^(δ+)和Zr^(γ+)协同催化甲烷C-H键断裂的反应机理:CH_(4)和H_(2)O_(2)分别在Ru^(δ+)和Zr^(γ+)上形成Ru^(δ+)-CH_(4)和Zr^(γ+)-^(·)OH;然后, Zr^(γ+)-^(·)OH提取相邻Ru^(δ+)-CH_(4)的氢原子并生成CH_(3)OH.Ru单原子与SZ的协同作用有效地促进了CH_(4)向C1含氧化合物的转化,这为设计高效的多功能协同催化甲烷直接转化制甲醇反应的SACs开辟了新途径. 展开更多
关键词 单原子钌 硫酸化氧化锆 强酸位点 直接CH4转化 协同催化
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退役军人社会融合的属间差异及属内差异逻辑 被引量:1
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作者 胡国恒 王增文 汪华 《公共行政评论》 北大核心 2023年第4期105-123,197,198,共21页
党的二十大报告着重强调要“做好退役军人服务保障工作”,社会融合作为其中一项议题,具有重要的现实意义。当退役军人离开军队时空后,已内化的价值观和符号规则仍连续性存在;惯习转换的惰性会因军转民的瞬时性引发退役军人的适应性困境... 党的二十大报告着重强调要“做好退役军人服务保障工作”,社会融合作为其中一项议题,具有重要的现实意义。当退役军人离开军队时空后,已内化的价值观和符号规则仍连续性存在;惯习转换的惰性会因军转民的瞬时性引发退役军人的适应性困境,直接影响其社会融合进程。论文以时空社会学为视角,结合军队时空与平民时空在物质、实践和象征维度的异质性,基于CFPS数据库,采用PSM估计和混合OLS回归方法实证检验了时空转换对退役军人社会融合的影响效应。研究发现:(1)从属间差异看,退役军人在经济整合、社会适应和心理调适方面整体高于反事实模拟的同龄平民,存在显著的身份优势。(2)从属内差异看,相比同龄退役军人,参军年限愈久的退役军人因其更充足的退役准备、优渥的经济补偿和制度保障水平,社会融合反而表现良好;退役年龄愈早的退役军人经济整合和社会适应水平越高,该影响效应呈正U形;退役期经历社会急剧转型的退役军人心理调适水平更弱。(3)社会融合维度的互动中,经济整合属内差异会扩大退役军人社会适应和心理调适的属内差异。研究为理解退役军人社会融合问题拓展了新的理论视角,为优化退役军人服务供给机制提供了政策启示。 展开更多
关键词 时空转换 退役军人 社会融合 差异逻辑
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Effects of gradient high-field static magnetic fields on diabetic mice 被引量:3
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作者 Biao Yu Chao Song +11 位作者 Chuan-Lin Feng Jing Zhang Ying wang Yi-Ming Zhu Lei Zhang Xin-Miao Ji Xiao-Fei Tian Guo-Feng Cheng Wei-Li Chen Vitalii Zablotskii hua wang Xin Zhang 《Zoological Research》 SCIE CAS CSCD 2023年第2期249-258,共10页
Although 9.4 T magnetic resonance imaging(MRI) has been tested in healthy volunteers,its safety in diabetic patients is unclear.Furthermore,the effects of high static magnetic fields(SMFs),especially gradient vs.unifo... Although 9.4 T magnetic resonance imaging(MRI) has been tested in healthy volunteers,its safety in diabetic patients is unclear.Furthermore,the effects of high static magnetic fields(SMFs),especially gradient vs.uniform fields,have not been investigated in diabetics.Here,we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients(>10 T/m vs.0-10 T/m)on type 1 diabetic(T1D) and type 2 diabetic(T2D) mice.We found that 14 h of prolonged treatment of gradient(as high as 55.5 T/m) high SMFs(1.0-8.6 T) had negative effects on T1D and T2D mice,including spleen,hepatic,and renal tissue impairment and elevated glycosylated serum protein,blood glucose,inflammation,and anxiety,while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects.In regular T1D mice(blood glucose>16.7 mmol/L),the>10 T/m gradient high SMFs increased malondialdehyde(P<0.01) and decreased superoxide dismutase(P<0.05).However,in the severe T1D mice(blood glucose≥30.0 mmol/L),the>10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate.In vitro cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation.Therefore,this study showed that prolonged exposure to high-field(1.0-8.6 T)>10 T/m gradient SMFs(35-1 380 times higher than that of current clinical MRI)can have negative effects on diabetic mice,especially mice with severe T1D,whereas 9.4 T high SMFs at 0-10T/m did not produce the same effects,providing important information for the future development and clinical application of SMFs,especially high-field MRI. 展开更多
关键词 Type 2 diabetes Type 1 diabetes Magnetic resonance imaging(MRI) Gradient static magnetic field Quasi-uniform static magnetic field
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Environmental and spatial contributions to tree community assembly across life stages and scales in evergreen-deciduous broadleaf karst forests,southwest China
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作者 Liang Su Hu Du +5 位作者 Fuping Zeng Wanxia Peng hua wang Kelin wang Menzhen Lu Tongqing Song 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1323-1331,共9页
Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly,depending on sampling scale and life history.However,the processes that determine... Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly,depending on sampling scale and life history.However,the processes that determine community assembly have not been studied in the karst region of southwest China.In this study,a 25-ha(500 m×500 m)monitoring plot within the subtropical climax forest in the karst region was established and canonical correspondence analysis was used to reveal the effects of topography and soil on the spatial patterns of tree community assembly.Our study suggests that spatial processes dominate species composition and the combined effects of spatial and environmental processes play an important role.Overall interpretation rate increases with enlarging the sampling scale.However,the pattern of variation partitioning was similar in different life stages.Environmental variables significantly affected species composition at different sampling sizes and life histories and had a higher interpretation rate of species composition on larger s ampling sizes.Topographic wetness index was the most important variable to explain species composition of the environmental variables.These results suggest that it is necessary to consider the relative importance of environmental and spatial factors on community assembly to better understand,conserve,and manage subtropical karst forests. 展开更多
关键词 Species composition Spatial distribution Variation partitioning Community assembly Karst ecosystems
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Nanosensitizers for sonodynamic therapy for glioblastoma multiforme: current progress and future perspectives
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作者 Qing-Long Guo Xing-Liang Dai +5 位作者 Meng-Yuan Yin Hong-Wei Cheng Hai-Sheng Qian hua wang Dao-Ming Zhu Xian-Wen wang 《Military Medical Research》 SCIE CAS CSCD 2023年第1期94-112,共19页
Glioblastoma multiforme(GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as w... Glioblastoma multiforme(GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as well as the presence of the blood–brain barrier(BBB), have reduced the efficacy of GBM treatment. The emergence of a novel therapeutic method, namely, sonodynamic therapy(SDT), provides a promising strategy for eradicating tumors via activated sonosensitizers coupled with low-intensity ultrasound. SDT can provide tumor killing effects for deep-seated tumors, such as brain tumors. However, conventional sonosensitizers cannot effectively reach the tumor region and kill additional tumor cells, especially brain tumor cells. Efforts should be made to develop a method to help therapeutic agents pass through the BBB and accumulate in brain tumors. With the development of novel multifunctional nanosensitizers and newly emerging combination strategies, the killing ability and selectivity of SDT have greatly improved and are accompanied with fewer side effects. In this review, we systematically summarize the findings of previous studies on SDT for GBM, with a focus on recent developments and promising directions for future research. 展开更多
关键词 Glioblastoma multiforme(GBM) Blood–brain barrier(BBB) Sonodynamic therapy(SDT) Sonosensitizers Combination therapy
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Influence of band microstructure on carbide precipitation behavior and toughness of 1 GPa-grade ultra-heavy gauge low-alloy steel
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作者 Peng Han Zhipeng Liu +4 位作者 Zhenjia Xie hua wang Yaohui Jin Xuelin wang Chengjia Shang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第7期1329-1337,共9页
This study investigated the influence of band microstructure induced by centerline segregation on carbide precipitation behavior and toughness in an 80 mm-thick 1 GPa low-carbon low-alloy steel plate.The quarter-thick... This study investigated the influence of band microstructure induced by centerline segregation on carbide precipitation behavior and toughness in an 80 mm-thick 1 GPa low-carbon low-alloy steel plate.The quarter-thickness(1/4t)and half-thickness(1/2t)regions of the plate exhibited similar ductility and toughness after quenching.After tempering,the 1/4t region exhibited~50%and~25%enhancements in both the total elongation and low-temperature toughness at-40°C,respectively,without a decrease in yield strength,whereas the toughness of the 1/2t region decreased by~46%.After quenching,both the 1/4t and 1/2t regions exhibited lower bainite and lath martensite concentrations,but only the 1/2t region exhibited microstructure bands.Moreover,the tempered 1/4t region featured uniformly dispersed short rod-like M_(23)C_(6)carbides,and spherical MC precipitates with diameters of~20–100 nm and<20 nm,respectively.The uniformly dispersed nanosized M_(23)C_(6)carbides and MC precipitates contributed to the balance of high strength and high toughness.The band microstructure of the tempered 1/2t region featured a high density of large needle-like M3C carbides.The length and width of the large M3C carbides were~200–500 nm and~20–50 nm,respectively.Fractography analysis revealed that the high density of large carbides led to delamination cleavage fracture,which significantly deteriorated toughness. 展开更多
关键词 band microstructure carbides TOUGHNESS heavy gauge steel centerline segregation
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Advances on Axial Coordination Design of Single‑Atom Catalysts for Energy Electrocatalysis:A Review
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作者 Linjie Zhang Na Jin +4 位作者 Yibing Yang Xiao‑Yong Miao hua wang Jun Luo Lili Han 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第12期188-230,共43页
Single-atom catalysts(SACs)have garnered increasingly growing attention in renewable energy scenarios,especially in electrocatalysis due to their unique high efficiency of atom utilization and flexible electronic stru... Single-atom catalysts(SACs)have garnered increasingly growing attention in renewable energy scenarios,especially in electrocatalysis due to their unique high efficiency of atom utilization and flexible electronic structure adjustability.The intensive efforts towards the rational design and synthesis of SACs with versatile local configurations have significantly accelerated the development of efficient and sustainable electrocatalysts for a wide range of electrochemical applications.As an emergent coordination avenue,intentionally breaking the planar symmetry of SACs by adding ligands in the axial direction of metal single atoms offers a novel approach for the tuning of both geometric and electronic structures,thereby enhancing electrocatalytic performance at active sites.In this review,we briefly outline the burgeoning research topic of axially coordinated SACs and provide a comprehensive summary of the recent advances in their synthetic strategies and electrocatalytic applications.Besides,the challenges and outlooks in this research field have also been emphasized.The present review provides an in-depth and comprehensive understanding of the axial coordination design of SACs,which could bring new perspectives and solutions for fine regulation of the electronic structures of SACs catering to high-performing energy electrocatalysis. 展开更多
关键词 Single-atom catalyst Axial coordination Synthetic strategy Electrocatalytic application
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A Scheme Library-Based Ant Colony Optimization with 2-Opt Local Search for Dynamic Traveling Salesman Problem
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作者 Chuan wang Ruoyu Zhu +4 位作者 Yi Jiang Weili Liu Sang-Woon Jeon Lin Sun hua wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第5期1209-1228,共20页
The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant... The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant colony optimization(ACO)with a two-optimization(2-opt)strategy to solve the DTSP efficiently.The work is novel and contributes to three aspects:problemmodel,optimization framework,and algorithmdesign.Firstly,in the problem model,traditional DTSP models often consider the change of travel distance between two nodes over time,while this paper focuses on a special DTSP model in that the node locations change dynamically over time.Secondly,in the optimization framework,the ACO algorithm is carried out in an offline optimization and online application framework to efficiently reuse the historical information to help fast respond to the dynamic environment.The framework of offline optimization and online application is proposed due to the fact that the environmental change inDTSPis caused by the change of node location,and therefore the newenvironment is somehowsimilar to certain previous environments.This way,in the offline optimization,the solutions for possible environmental changes are optimized in advance,and are stored in a mode scheme library.In the online application,when an environmental change is detected,the candidate solutions stored in the mode scheme library are reused via ACO to improve search efficiency and reduce computational complexity.Thirdly,in the algorithm design,the ACO cooperates with the 2-opt strategy to enhance search efficiency.To evaluate the performance of ACO with 2-opt,we design two challenging DTSP cases with up to 200 and 1379 nodes and compare them with other ACO and genetic algorithms.The experimental results show that ACO with 2-opt can solve the DTSPs effectively. 展开更多
关键词 Dynamic traveling salesman problem(DTSP) offline optimization and online application ant colony optimization(ACO) two-optimization(2-opt)strategy
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Effects of Heat Stress during Seed Filling Stage on Brassica napus Seed Oil Accumulation and Chlorophyll Fluorescence Characteristics
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作者 Ruizhi huang huasheng Yu +7 位作者 Yong Yang Heqin Liu Xuelong Wu Zhihong Liu Haiyan He Gengwei Wu Wengjia wang hua wang 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第2期333-348,共16页
As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to h... As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified. 展开更多
关键词 Brassica napus L. heat stress seed filling stage oil accumulation chlorophyll fluorescence characteristics
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Captiva EMR-Lipid技术结合UPLC-Q-TOF/MS测定压片糖果中非法添加的美托拉宗
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作者 王华 陈婵 +2 位作者 刘虹虹 何姗珊 罗达龙 《中国药师》 CAS 2023年第11期355-360,共6页
目的 建立一种超高效液相色谱-四极杆飞行时间质谱(UPLC-QTOF/MS)分析方法对压片糖果中的非法添加药物美托拉宗进行快速筛查与定量检测。方法 使用乙腈提取待测组分,Captiva EMR-Lipid净化柱进行净化,经Agilent RRHD Eclipse Plus C_(18... 目的 建立一种超高效液相色谱-四极杆飞行时间质谱(UPLC-QTOF/MS)分析方法对压片糖果中的非法添加药物美托拉宗进行快速筛查与定量检测。方法 使用乙腈提取待测组分,Captiva EMR-Lipid净化柱进行净化,经Agilent RRHD Eclipse Plus C_(18)(100 mm×2.1 mm,1.8μm)色谱柱进行分离,运用UPLC-Q-TOF/MS的Targeted MS/MS模式进行检测分析。结果 美托拉宗在浓度范围50~1 000 ng·mL^(-1)内线性良好(r=0.999 0);检测限为1.0μg·g^(-1);定量限为2.5μg·g^(-1),平均回收率为98.15%,RSD为2.2%(n=18)。结论 该方法具有操作简易快速、定性定量准确等特点,能应用于日常样品的检验检测。 展开更多
关键词 美托拉宗 Captiva EMR-Lipid固相萃取 四极杆飞行时间质谱 压片糖果 非法添加药物
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MmWave extra-large-scale MIMO based active user detection and channel estimation for high-speed railway communications
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作者 Anwen Liao Ruiqi wang +5 位作者 Yikun Mei Ziwei Wan Shicong Liu Zhen Gao hua wang Hao Yin 《High-Speed Railway》 2023年第1期31-36,共6页
The current High-Speed Railway(HSR)communications increasingly fail to satisfy the massive access services of numerous user equipment brought by the increasing number of people traveling by HSRs.To this end,this paper... The current High-Speed Railway(HSR)communications increasingly fail to satisfy the massive access services of numerous user equipment brought by the increasing number of people traveling by HSRs.To this end,this paper investigates millimeter-Wave(mmWave)extra-large scale(XL)-MIMO-based massive Internet-of-Things(loT)access in near-field HSR communications,and proposes a block simultaneous orthogonal matching pursuit(B-SOMP)-based Active User Detection(AUD)and Channel Estimation(CE)scheme by exploiting the spatial block sparsity of the XLMIMO-based massive access channels.Specifically,we first model the uplink mmWave XL-MIMO channels,which exhibit the near-field propagation characteristics of electromagnetic signals and the spatial non-stationarity of mmWave XL-MIMO arrays.By exploiting the spatial block sparsity and common frequency-domain sparsity pattern of massive access channels,the joint AUD and CE problem can be then formulated as a Multiple Measurement Vectors Compressive Sensing(MIMV-CS)problem.Based on the designed sensing matrix,a B-SOMP algorithm is proposed to achieve joint AUD and CE.Finally,simulation results show that the proposed solution can obtain a better AUD and CE performance than the conventional CS-based scheme for massive IoT access in near-field HSR communications. 展开更多
关键词 High-speed railway communications Massive access Activeuser detection Channel estimation Millimeter-wave extra-large scale MIMO Near-field spatial non-stationarity
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Endoscopic Ruler for varix size measurement:A multicenter pilot study
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作者 Yi-Fei huang Sheng-Juan Hu +29 位作者 Yang Bu Yi-Ling Li Yan-Hong Deng Jian-Ping Hu Shao-Qi Yang Qian Shen Mark McAlindon Rui-Chun Shi Xiao-Qin Li Tie-Ying Song Hai-Long Qi Tai-Wei Jiao Meng-Yuan Liu Fang He Jun Zhu Bin Ma Xiao-Bin Yu Jian-Yang Guo Yue-hua Yu Hai-Jiang Yong Wen-Tun Yao Ting Ye hua wang Wen-Fu Dong Jian-Guo Liu Qiang Wei Jing Tian Xiao-Guo Li Xavier Dray Xiao-Long Qi 《World Journal of Gastrointestinal Endoscopy》 2023年第9期564-573,共10页
BACKGROUND We invented Endoscopic Ruler,a new endoscopic device to measure the size of varices in patients with cirrhosis and portal hypertension.AIM To assess the feasibility and safety of Endoscopic Ruler,and evalua... BACKGROUND We invented Endoscopic Ruler,a new endoscopic device to measure the size of varices in patients with cirrhosis and portal hypertension.AIM To assess the feasibility and safety of Endoscopic Ruler,and evaluate the agreement on identifying large oesophageal varices(OV)between Endoscopic Ruler and the endoscopists,as well as the interobserver agreement on diagnosing large OV using Endoscopic Ruler.METHODS We prospectively and consecutively enrolled patients with cirrhosis from 11 hospitals,all of whom got esophagogastroduodenoscopy(EGD)with Endoscopic Ruler.The primary study outcome was a successful measurement of the size of varices using Endoscopic Ruler.The secondary outcomes included adverse events,operation time,the agreement of identifying large OV between the objective measurement of Endoscopic Ruler and the empirical reading of endoscopists,together with the interobserver agreement on diagnosing large OV by Endoscopic Ruler.RESULTS From November 2020 to April 2022,a total of 120 eligible patients with cirrhosis were recruited and all of them underwent EGD examinations with Endoscopic Ruler successfully without any adverse event.The median operation time of Endoscopic Ruler was 3.00 min[interquartile range(IQR):3.00 min].The kappa value between Endoscopic Ruler and the endoscopists while detecting large OV was 0.52,demonstrating a moderate agreement.The kappa value for diagnosing large OV using Endoscopic Ruler among the six independent observers was 0.77,demonstrating a substantial agreement.CONCLUSION The data demonstrates that Endoscopic Ruler is feasible and safe for measuring the size of varices in patients with cirrhosis and portal hypertension.Endoscopic Ruler is potential to promote the clinical practice of the two-grade classification system of OV. 展开更多
关键词 Oesophageal varices CIRRHOSIS Portal hypertension ESOPHAGOGASTRODUODENOSCOPY Endoscopic ruler
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微创玻璃体切除联合无菌空气填充治疗玻璃体视网膜手术后孔源性视网膜脱离 被引量:13
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作者 程育宏 吉梦 +3 位作者 齐赟 谢安明 王华 刘思伟 《国际眼科杂志》 CAS 北大核心 2021年第2期360-363,共4页
目的:观察微创玻璃体切除联合空气填充治疗玻璃体视网膜手术后上方裂孔源性视网膜脱离的有效性及安全性。方法:回顾分析2017-11/2019-10在我院收治的,经历过一次或多次玻璃体视网膜手术后发生的由上方裂孔(3∶00~9∶00水平线以上)引起... 目的:观察微创玻璃体切除联合空气填充治疗玻璃体视网膜手术后上方裂孔源性视网膜脱离的有效性及安全性。方法:回顾分析2017-11/2019-10在我院收治的,经历过一次或多次玻璃体视网膜手术后发生的由上方裂孔(3∶00~9∶00水平线以上)引起且未合并严重增殖性玻璃体视网膜病变(PVR)的(PVR-C级以下)孔源性视网膜脱离患者,施行经平坦部入路玻璃体切除术,充分切除残留玻璃体后,行气液交换复位视网膜,确保裂孔周围视网膜下液充分排出后激光封闭视网膜裂孔,使用无菌空气行玻璃体腔填充。术后患者严格俯卧位24h。主要观察指标为视网膜初始及最终复位成功率,最佳矫正视力(BCVA),次要观察指标为并发白内障及高眼压比率。结果:共纳入符合标准且术后随访时间≥6mo患者31例31眼,脱位范围6.7±3.8个钟点位,裂孔数1.2±0.7个,脱离累及黄斑23眼(74%),人工晶状体18眼(58%),联合白内障超声乳化人工晶状体植入者6眼(19%)。入组患者Ⅰ期视网膜复位成功率87%(27/31),最终视网膜复位成功率100%(31/31),发生一过性眼压升高者5眼(16%)。术后6mo时BCVA(LogMAR)由术前2.17±1.27改善至0.53±0.25(P<0.001)。结论:对于具有玻璃体视网膜手术史的不合并严重PVR的上方裂孔源性视网膜脱离患者,采用玻璃体切除术联合空气填充,可取得较高的视网膜复位成功率,且具有术后俯卧时间短,并发症少等优点。 展开更多
关键词 孔源性视网膜脱离 上方视网膜裂孔 玻璃体视网膜手术后 平坦部玻璃体切除术 空气填充
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Depositional setting analysis using seismic sedimentology: Example from the Paleogene Lishagang sequence in the Fushan depression,South China Sea 被引量:4
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作者 Yuan Li Song Lin +1 位作者 hua wang Denggui Luo 《Geodesy and Geodynamics》 2017年第5期347-355,共9页
The Fushan depression is a classic lacustrine rifted sub-basin in the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the depression. Using thre... The Fushan depression is a classic lacustrine rifted sub-basin in the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the depression. Using three-dimensional (3-D) seismic data and logging data, we analyzed depositional setting of the Liushagang sequence. We use wave impedance inversion to describe progradational directions of provenance and the general distribution of sand body. The seismic facies was analyzed by using the seismic sedimentology approach based on 3-D seismic data, and summed into eight types of seismic facies which could be well related to sedimentary facies. Seismic attributes with six objective sequence boundaries were extracted. Consequently, four provenance system of Liushagang sequence in the study area were confirmed by the corresponding relationship between the geologic information and the warm color and higher value area of seismic attributes: (i) the Hainan uplift provenance area in the south, (ii) the Linggao uplift provenance area in the west, (iii) the Yunlong uplift provenance area in the east and (iv) the northern provenance area. The seismic sedimentology used in this study may provide new in- sizhts into a better understanding of depositional setting in continental lacustrine rifted basins. 展开更多
关键词 Fushan depressionSeismic sedimentologySeismic faciesSeismic attribute
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