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Molecular insights into the simultaneous removal mechanisms of As(Ⅴ) and Cd(Ⅱ) in iron tailings slag-biochar composites
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作者 Menglu Wang Yujian Lai +7 位作者 Xuemei Wang Meng Zhang wei han Yuhuan Li Xinlian Zhong Jiaxiang Chen Hongbing Ji Zifu Li 《Journal of Environmental Sciences》 2025年第8期470-482,共13页
Arsenic and cadmium contamination frequently coexist in the real environment.However it remains a challenge for their simultaneous removal due to their distinct physicochemica properties at low cost.To this end,a cost... Arsenic and cadmium contamination frequently coexist in the real environment.However it remains a challenge for their simultaneous removal due to their distinct physicochemica properties at low cost.To this end,a cost-effective magnetic biochar adsorbent (ITBNa800was prepared using biomass waste and iron tailings slag.This composite adsorbent exhibits excellent performance in the simultaneous removal of aqueous As(Ⅴ) and Cd(Ⅱ) even at high concentrations with removal efficiencies of up to 99.98%and 96.04%,respectively.Electro static action,precipitation,and complexation were adsorption mechanisms.As(Ⅴ) and Cd(Ⅱ were synergistic and competitive adsorption.As(Ⅴ) removal was mainly due to physical and chemical adsorption,and 42.40%-58.59%of As(Ⅴ) had been converted to As(Ⅲ ).Cd(Ⅱ) re moval was mainly due to chemical adsorption.Iron oxide and aluminum oxide in ITBNa800were the keys to As(Ⅴ),As(Ⅲ ),and Cd(Ⅱ) adsorption.DFT calculations revealed iron oxide complex As(Ⅴ),As(Ⅲ ),and Cd(Ⅱ) molecular clusters through bidentate binuclear,bidentate binuclear,and monodentate binuclear pathways,respectively.Aluminum oxide complex Cd(Ⅱ) molecular cluster through a bidentate mononuclear pathway.We hope the ITBNa800adsorbent and its involved mechanism could offer inspiration in the simultaneous treat ment of As and Cd pollution. 展开更多
关键词 ARSENIC CADMIUM Simultaneous adsorption DFT Molecular mechanism
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Recent advances in energy storage mechanism of aqueous zinc-ion batteries 被引量:17
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作者 Duo Chen Mengjie Lu +2 位作者 Dong Cai hang Yang wei han 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第3期712-726,共15页
Aqueous rechargeable zinc-ion batteries(ZIBs)have recently attracted increasing research interest due to their unparalleled safety,fantastic cost competitiveness and promising capacity advantages compared with the com... Aqueous rechargeable zinc-ion batteries(ZIBs)have recently attracted increasing research interest due to their unparalleled safety,fantastic cost competitiveness and promising capacity advantages compared with the commercial lithium ion batteries.However,the disputed energy storage mechanism has been a confusing issue restraining the development of ZIBs.Although a lot of efforts have been dedicated to the exploration in battery chemistry,a comprehensive review that focuses on summarizing the energy storage mechanisms of ZIBs is needed.Herein,the energy storage mechanisms of aqueous rechargeable ZIBs are systematically reviewed in detail and summarized as four types,which are traditional Zn^(2+)insertion chemistry,dual ions co-insertion,chemical conversion reaction and coordination reaction of Zn^(2+)with organic cathodes.Furthermore,the promising exploration directions and rational prospects are also proposed in this review. 展开更多
关键词 Zinc-ion batteries Energy storage mechanism Rechargeable aqueous battery Zn-MnO_(2)battery Electrolytic battery
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Changes in the Proportion of Precipitation Occurring as Rain in Northern Canada during Spring–Summer from 1979–2015 被引量:6
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作者 wei han Cunde XIAO +1 位作者 Tingfeng DOU Minghu DING 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第9期1129-1136,共8页
Changes in the form of precipitation have a considerable impact on the Arctic cryosphere and ecological system by influencing the energy balance and surface runoff. In this study, station observations and ERA-Interim ... Changes in the form of precipitation have a considerable impact on the Arctic cryosphere and ecological system by influencing the energy balance and surface runoff. In this study, station observations and ERA-Interim data were used to analyze changes in the rainfall to precipitation ratio(RPR) in northern Canada during the spring–summer season(March–July)from 1979–2015. Our results indicate that ERA-Interim describes the spring–summer variations and trends in temperature and the RPR well. Both the spring–summer mean temperature [0.4℃–1℃(10 yr)^(-1)] and the RPR [2%–6%(10 yr)^(-1)] increased significantly in the Canadian Arctic Archipelago from 1979–2015. Moreover, we suggest that, aside from the contribution of climate warming, the North Atlantic Oscillation is probably another key factor influencing temporal and spatial differences in the RPR over northern Canada. 展开更多
关键词 climate change rainfall to precipitation ratio northern Canada North Atlantic Oscillation
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Grain Size-Dependent Mechanical Properties of a High-Manganese Austenitic Steel 被引量:3
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作者 Xiao-Jiang Wang Xin-Jun Sun +4 位作者 Cheng Song Huan Chen Shuai Tong wei han Feng Pan 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2019年第6期746-754,共9页
The effect of grain size on the mechanical properties of a high-manganese(Mn)austenitic steel was investigated via electron-backscattered diffraction,transmission electron microscope,X-ray diffraction,and tensile and ... The effect of grain size on the mechanical properties of a high-manganese(Mn)austenitic steel was investigated via electron-backscattered diffraction,transmission electron microscope,X-ray diffraction,and tensile and impact tests at 25°C and-196°C.The Hall–Petch strengthening coefficients for the yield strength of the high-Mn austenitic steels were 7.08 MPa mm 0.5 at 25°C,which increased to 14 MPa mm 0.5 at-196°C.The effect that the grain boundary strengthening had on improving the yield strength at-196°C was better than that at 25°C.The impact absorbed energies and the tensile elongations were enhanced with the increased grain size at 25°C,while they remained nearly unchanged at-196°C.The unchanged impact absorbed energies and the tensile elongations were primarily attributed to the emergence of the micro-twin at-196°C,which promoted the cleavage fracture in the steels with large-sized grains.Refining the grain size could improve the strength of the high-Mn austenitic steels without impairing their ductility and toughness at low temperature. 展开更多
关键词 High-Mn steel Grain size LOW-TEMPERATURE TOUGHNESS Hall–Petch Micro-twin
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Gold-leaching performance and mechanism of sodium dicyanamide 被引量:3
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作者 Gen-zhuang Li Jue Kou +4 位作者 Yi Xing Yang Hu wei han Zi-yuan Liu Chun-bao Sun 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第11期1759-1768,共10页
In this work,sodium dicyanamide(SD)was used as a leaching reagent for gold recovery,and the effects of the SD dosage and solution pH on the gold-leaching performance were investigated.A gold recovery of 34.8%was obtai... In this work,sodium dicyanamide(SD)was used as a leaching reagent for gold recovery,and the effects of the SD dosage and solution pH on the gold-leaching performance were investigated.A gold recovery of 34.8%was obtained when SD was used as the sole leaching reagent at a dosage of 15 kg/t.In the presence of a certain amount of potassium ferrocyanide(PF)in the SD solution,the gold recovery was found to increase from 34.8%to 57.08%.Using the quartz crystal microbalance with dissipation(QCM-D)technique,the leaching kinetics of SD with and without PF were studied.The QCM-D results indicate that the gold-leaching rate increased from 4.03 to 39.99 ng·cm^(–2)·min^(–1) when the SD concentration was increased from 0 to 0.17 mol/L,and increased from 39.99 to 272.62 ng·cm^(–2)·min^(–1) when 0.1 mol/L of PF was used in combination with SD.The pregnant solution in the leaching tests was characterized by X-ray photoelectron spectroscopy and electrospray mass spectrometry,which indicated that Au and(N(CN)2)–in the SD solution formed a series of metal complex ions,[AuNax(N(CN)2)x+2]–(x=1,2,3,or 4). 展开更多
关键词 gold leaching sodium dicyanamide QCM-D leaching kinetics potassium ferrocyanide
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The mechanism study of low-pressure air plasma cleaning on large-aperture optical surface unraveled by experiment and reactive molecular dynamics simulation 被引量:2
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作者 Yuhai LI Qingshun BAI +9 位作者 Yuheng GUAN Hao LIU Peng ZhanG Buerlike BATELIBIEKE Rongqi SHEN Lihua LU Xiaodong YUAN Xinxiang MIAO wei han Caizhen YAO 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第6期77-87,共11页
Low-pressure air plasma cleaning is an effective method for removing organic contaminants on large-aperture optical components in situ in the inertial confinement fusion facility.Chemical reactions play a significant ... Low-pressure air plasma cleaning is an effective method for removing organic contaminants on large-aperture optical components in situ in the inertial confinement fusion facility.Chemical reactions play a significant role in plasma cleaning,which is a complex process involving abundant bond cleavage and species generation.In this work,experiments and reactive molecular dynamics simulations were carried out to unravel the reaction mechanism between the benchmark organic contaminants of dibutyl phthalate and air plasma.The optical emission spectroscopy was used to study the overall evolution behaviors of excited molecular species and radical signals from air plasma as a reference to simulations.Detailed reaction pathways were revealed and characterized,and specific intermediate radicals and products were analyzed during experiments and simulation.The reactive species in the air plasma,such as O,HO_(2)and O_(3)radicals,played a crucial role in cleaving organic molecular structures.Together,our findings provide an atomic-level understanding of complex reaction processes of low-pressure air plasma cleaning mechanisms and are essential for its application in industrial plasma cleaning. 展开更多
关键词 organic contaminants large-aperture optical components low-pressure air plasma plasma cleaning reactive species reactive molecular dynamics
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Fermented soy whey induced changes on intestinal microbiota and metabolic influence in mice 被引量:2
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作者 wei han Xuhui Zhuang +3 位作者 Qian Liu Bo Sun Haijiang Miao Xiaolin Zhang 《Food Science and Human Wellness》 SCIE 2022年第1期41-48,共8页
Soy whey(SW)is generated as process waste while preparing soy protein isolates(SPI),and causing severe environmental pollution.Therefore,its value-added utilization is of prime importance for transforming and upgradin... Soy whey(SW)is generated as process waste while preparing soy protein isolates(SPI),and causing severe environmental pollution.Therefore,its value-added utilization is of prime importance for transforming and upgrading traditional industry.This study aims to utilize SW as a substrate for the growth of probiotics and produce a SW based synbiotics.By a series of trials,the effect of the dietary supplementation with this fermented SW(FSW)was analyzed on ICR mice's body weight,metabolites,and intestinal microbiota in 4 weeks.The results showed that,when SW was concentrated 15 times,the count of viable Lactobacillus casei reached 3.4×10^(9) CFU/mL by liquid fermentation method,which was the highest viable cell count among all test strains.In this FSW,the protein,amino acid,total dietary fibre,soluble dietary fibre,and oligosaccharide were 2.10%,1.63%,0.52%,0.51% and 0.79%,respectively.Compared to two control group,the total yields of the short chain fatty acids(SCFAs)were significantly improved(75%-125% at average),while the SCFAs structure was also significantly changed(especially acetic acid and butyrate)in the faeces of mice fed FSW.Meanwhile,FSW dietary addition was associated with the diversity and richness of the intestinal microbiota.Obviously,with mice's body weight loss,Firmicutes/Bacteroides ratio reduced accordingly(<1.21),and the abundance of Akkermansia muciniphila was significantly increased(the maximum amount was about 0.013%).In summary,our results indicated that the dietary supplementation of FSW affected mice's intestinal microbiota and metabolism and improved their health profile. 展开更多
关键词 Soy whey MICROBIOTA Short chain fatty acids Lactobacillus casei Akkermansia muciniphila
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Cretaceous-Neogene Exhumation of the Daqing Shan,North China Constrained by Apatite Fission Track Thermochronology 被引量:1
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作者 Junlin Zhou Yuhong Li +5 位作者 wei han Yunpeng Zhang Gaochao Chen Qiao Zhang Jianshe wei Yazhuo Niu 《Journal of Earth Science》 SCIE CAS CSCD 2024年第1期99-111,共13页
The Daqing Shan(DQS)located in the Yinshan-Yanshan Orogenic Belt plays an important role in the Mesozoic to Cenozoic evolution of the North China Craton.However,the cooling and exhumation history since the Cretaceous ... The Daqing Shan(DQS)located in the Yinshan-Yanshan Orogenic Belt plays an important role in the Mesozoic to Cenozoic evolution of the North China Craton.However,the cooling and exhumation history since the Cretaceous is still controversial.Integrating the apatite fission track(AFT)data in both this study and previous works,a three-stage exhumation history from Cretaceous to Neogene of the DQS is proposed.(1)The first stage is composed of the early exhumation during Early Cretaceous driven by the collision between the North China and Siberia cratons(ca.148-132 Ma)and the far-field effect of the subduction of the Pacific Plate(ca.132-114 Ma).(2)Due to the subsidence of the Hetao Basin and the subsequent compensation between the DQS and the Hetao Basin,the DQS experienced the second rapid exhumation from Early Eocene to Early Oligocene(ca.54-29 Ma).(3)Since the Late Miocene(ca.13.5 Ma),the third rapid cooling and exhumation of the DQS occurred due to the far-field effect of the uplift of the Tibetan Plateau and the subduction of the Pacific Plate. 展开更多
关键词 Daqing Shan Hetao Basin Cretaceous-Neogene apatite geochronology apatite fission track cooling and exhumation
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Mechanisms of rotenone-induced neurotoxicity in PC 12 cells 被引量:1
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作者 wei han Lizhong Sun +3 位作者 Jiafeng Chen Ming Chang Hongyan Huo Linsen Hu 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第12期1281-1285,共5页
BACKGROUND: Rotenone-induced neurotoxicity in PC 12 cells has been widely used to study the pathogenesis of Parkinson's disease. However, the precise mechanisms underlying rotenone-induced dopaminergic neuronal dege... BACKGROUND: Rotenone-induced neurotoxicity in PC 12 cells has been widely used to study the pathogenesis of Parkinson's disease. However, the precise mechanisms underlying rotenone-induced dopaminergic neuronal degeneration in Parkinson's disease remains unclear. OBJECTIVE: To establish rotenone-induced neurotoxicity in PC 12 cells, and to investigate the possible action pathways to rotenone-induced neural cell injury at the protein level. DESIGN, TIME AND SETTING: A controlled proteomics study was performed at the Department of Neurology, First Hospital, Jilin University between March 2006 and March 2007. MATERIALS: PC 12 cells were obtained from Shanghai Cell Bank of Chinese Academy of Sciences, China. Rotenone was provided by Sigma, USA. METHODS: PC 12 cells in logarithmic growth phase were treated under experimental and control conditions, respectively. A total of 0.5 μmol/L rotenone, or the same amount of Dulbecco's modified eagle's medium (DMEM), was added in the experimental and control conditions, respectively. MAIN OUTCOME MEASURES: Following 72 hours of rotenone treatment, cellular survival rate was determined by methyl thiazolyl tetrazolium assay, and apoptotic changes were detected by Hoechst 33342 staining. Total cellular protein was extracted to acquire differential protein expression data utilizing two-dimensional differential in-gel electrophoresis. To identify differential protein spots, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) was used. RESULTS: In the MTT assay, the experimental condition induced significantly less cell survival compared to the control condition (P 〈 0.01). Hoechst 33342 staining revealed a larger number of apoptotic cells under the experimental condition compared to the control condition (P 〈 0.01), as determined by the presence of nuclear condensation, pyknosis, and nuclear fragmentation. Two-dimensional electrophoresis results showed that the differential expression of protein spots 1069 and 1538 was increased by 144% and 124%, respectively, while that of protein spot 1094 was decreased by 123% in the experimental condition compared to the control condition (P 〈 0.01). By MALDI-TOF-MS analysis and database retrieval, γ-enolase, triosephosphate isomerase 1, and eukaryotic translation initiation factor 4A were confirmed to be involved in rotenone-induced neural cell injury. CONCLUSION: γ-enolase, triosephosphate isomerase 1, and eukaryotic translation initiation factor 4A might participate in rotenone-induced neurotoxicity in PC 12 cells. 展开更多
关键词 PC 12 cells ROTENONE PROTEOMICS cytotoxic effect
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Simple synthesis of novel phosphate electrode materials with unique microstructure and enhanced supercapacitive properties 被引量:1
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作者 Maocheng Liu Jiajia Li +1 位作者 wei han Long Kang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第4期601-608,共8页
Flower-like Ni3P2O8 and flower-like Fe3P2O8 center dot 8H(2)O have been successfully synthesized by a simple chemical precipitation method. X-ray diffraction (XRD) patterns reveal an amorphous phase formation of nicke... Flower-like Ni3P2O8 and flower-like Fe3P2O8 center dot 8H(2)O have been successfully synthesized by a simple chemical precipitation method. X-ray diffraction (XRD) patterns reveal an amorphous phase formation of nickel phosphate (Ni3P2O8) and pure monoclinic phase of Fe3P2O8 center dot 8H(2)O. The novel flower-like Ni3P2O8 and flower-like Fe3P2O8 center dot 8H(2)O when used for supercapacitor electrode materials exhibit a high specific capacitance (C-m) of 1464 F/g and 200 F/g at a current density of 0.5 A/g, respectively. Eventually, an asymmetric supercapacitor is fabricated using Ni3P2O8 as positive electrode and Fe3P2O8 center dot 8H(2)O as negative electrode. A high specific capacitance of 94 F/g is achieved in the high-voltage region of 0 similar to 1.6V, and a large energy density of 32.6 Wh/kg is delivered at power density of 420 W/kg. The findings demonstrate the important and great potential of developing metal phosphate based materials for supercapacitors. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved. 展开更多
关键词 Nickel phosphate Ferrous phosphate Asymmetric supercapacitor PSEUDOCAPACITANCE
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工艺参数对Al_(2)O_(3)-C耐火材料抗氧化性和抗水化性的影响
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作者 张瑞 孙旭东 +5 位作者 魏瀚 袁彪 王俊涛 袁林 刘士范 陈松林 《耐火材料》 北大核心 2025年第1期65-69,共5页
为了研究各因素对Al_(2)O_(3)-C耐火材料抗氧化和抗水化性能的影响,以优化其制备工艺,以板状刚玉、Al粉、电熔锆刚玉、活性氧化铝粉、鳞片石墨为主要原料,使用热固性酚醛树脂为结合剂,采用液压成型制成?50 mm×50 mm的圆柱体试样,... 为了研究各因素对Al_(2)O_(3)-C耐火材料抗氧化和抗水化性能的影响,以优化其制备工艺,以板状刚玉、Al粉、电熔锆刚玉、活性氧化铝粉、鳞片石墨为主要原料,使用热固性酚醛树脂为结合剂,采用液压成型制成?50 mm×50 mm的圆柱体试样,在埋碳气氛下对试样进行了热处理。选取Al粉加入量(加入质量分数分别为6%、9%和12%)、石墨加入量(加入质量分数分别为5%、15%和25%)、热处理温度(680、950、1 500℃)和保温时间(3、6、9 h)为研究因素,每个因素选取3个水平进行正交设计,分析了其对Al_(2)O_(3)-C耐火材料抗氧化和抗水化性能的影响。结果表明:1)Al粉加入量和石墨加入量为影响抗氧化性能的主要因素,而热处理温度和保温时间为次要因素;2)Al粉加入量和热处理温度是影响抗水化性能的主要因素,而石墨加入量和保温时间为次要因素;3)综合考虑,最优工艺为:Al粉加入量9%(w),石墨加入量5%(w),热处理温度1 500℃,保温时间6 h,制备的试样中存在柱状的Al_(4)O_(4)C,能够显著提高材料的抗氧化和抗水化性能。 展开更多
关键词 Al_(2)O_(3)-C耐火材料 Al_(4)O_(4)C 抗水化性能 抗氧化性能
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COL4A2 enhances thyroid cancer cell proliferation through the AKT pathway
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作者 LIANG HE wei han +1 位作者 KAI YUE XUDONG WANG 《Oncology Research》 SCIE 2024年第9期1467-1478,共12页
Objectives:Thyroid cancer(THCA)is the most common malignant tumor in endocrine system and the incidence has been increasing worldwide.And the number of patients dying from THCA has also gradually risen because the inc... Objectives:Thyroid cancer(THCA)is the most common malignant tumor in endocrine system and the incidence has been increasing worldwide.And the number of patients dying from THCA has also gradually risen because the incidence continues to increase,so the mechanisms related to effective targets is necessary to improve the survival.This study was to preliminarily investigate the effects of the COL4A2 gene on the regulation of thyroid cancer(THCA)cell proliferation and the associated pathways.Methods:Bioinformatics analysis revealed that COL4A2 was closely associated with cancer development.COL4A2 expression in THCA tissues was analyzed using immunohistochemistry,and survival information was determined via Kaplan-Meier curves.The expression of COL4A2 and AKT pathway-related genes were analyzed using qPCR and western blot analyses.Colony formation as well as CCK-8 assays exhibited the cell proliferation level and cell activity,respectively.Downstream of COL4A2 was identified by Gene set enrichment analysis(GSEA).The effects of the COL4A2 and AKT pathways on THCA tumor growth in vivo were determined using a mouse model.Results:Bioinformatics analysis exhibited that COL4A2 plays a significant role in cancer and that the AKT pathway is downstream of COL4A2.THCA patients with high COL4A2 expression had shorter recurrence-free survival.Upregulation of COL4A2 gene expression in 2 THCA cell lines promoted tumor cell growth and activity.The use of AKT pathway blockers also restrained the growth and activity of the 2 THCA cell lines.The use of AKT pathway blockers reduced tumor volume and mass and prolonged mouse survival.Conclusions:COL4A2 can promote the growth as well as development of THCA through the AKT pathway and COL4A2 could be used as a target for THCA. 展开更多
关键词 Thyroid cancer(THCA) PROLIFERATION COL4A2 AKT pathway Biomarker cancer progression
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超双疏表面耐久性研究进展及其应用 被引量:1
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作者 覃冰黎 梅益 +3 位作者 周学湫 罗鸿 韦函 汪希奎 《表面技术》 北大核心 2025年第3期17-38,共22页
超双疏表面通常指对水和油均表现出高接触角和低滚动角的特殊润湿性表面。超双疏表面在日常生活、工业生产、液体运输、航空航天及航海等多个领域具有潜在应用前景,受到了科研人员的广泛关注。由于超双疏表面微纳粗糙结构较为脆弱,一旦... 超双疏表面通常指对水和油均表现出高接触角和低滚动角的特殊润湿性表面。超双疏表面在日常生活、工业生产、液体运输、航空航天及航海等多个领域具有潜在应用前景,受到了科研人员的广泛关注。由于超双疏表面微纳粗糙结构较为脆弱,一旦表面微结构或化学物质受到破坏,其超双疏性可能会受到影响,甚至失效,因此材料表面的低耐久性是限制超双疏表面规模化推广应用的技术瓶颈,如何提高超双疏表面的机械耐久性,是当前业内亟待解决的重点课题之一。首先概述了超双疏表面的润湿理论和设计基础,并系统总结了包括层层自组装法、模板法、电化学沉积法和气相沉积法在内的多种制备方法,并深入分析了上述制备方法所获得超双疏表面的耐久特性。随后,重点探讨了提升超双疏表面耐久性的技术和方法,如自修复技术、底面复合技术和微结构保护技术等,并阐述了各方法的耐久性提升原理。最后,总结了超双疏表面在自清洁、防冰除冰、防雾、抗黏附和抗菌等领域的应用,分析了当前制约其规模化应用的原因及其解决策略,并对超双疏表面未来的工程应用前景及发展方向进行了展望。 展开更多
关键词 超双疏 润湿性 耐久性 微结构
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间伐对柏木人工林细根变化及根区土壤水文性质的影响
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作者 普思媛 张景峰 +10 位作者 侯贵荣 任定桥 陈睿萱 廖望东 魏涵 李贤伟 范川 谭波 徐振锋 何淑勤 张云奇 《四川农业大学学报》 北大核心 2025年第3期658-668,共11页
【目的】通过探究不同间伐强度下柏木(Cupressus funebris Endl.)人工林细根生长特征,阐明细根生长变化对根区土壤水文性质的影响机制,为长江上游柏木人工林制定管理策略提供理论依据。【方法】以川中丘陵区4种林分保留密度柏木人工林(... 【目的】通过探究不同间伐强度下柏木(Cupressus funebris Endl.)人工林细根生长特征,阐明细根生长变化对根区土壤水文性质的影响机制,为长江上游柏木人工林制定管理策略提供理论依据。【方法】以川中丘陵区4种林分保留密度柏木人工林(重度-1 000株/hm^(2)、中度-1 500株/hm^(2)、轻度-2 000株/hm^(2)、CK-3 000株/hm^(2))为研究对象,结合微根管监测和土壤调查等方法测定柏木人工林细根性状和土壤水文特性等数据,分析间伐对细根生长和土壤水文特性的影响。【结果】(1)根系性状指标随时间的变化差异极显著(P<0.001);不同间伐强度下柏木细根性状随水平距离和垂直深度增加呈现先增大后减小的趋势;随着间伐强度增大,根系表现出其特有的可塑性。(2)间伐抚育改善了土壤孔隙结构与持水情况;中度间伐下土壤水分稳渗速率极显著大于其他间伐强度(P<0.001),为对照组的4倍;间伐后土壤有机质、全磷、全氮和速效钾等养分含量增加,在中度或重度间伐时最丰富。(3)RDA分析表明根长密度、比根表面积和比根长是影响土壤水文性质的主要因子,总贡献率达96.6%,其中又以对非毛管孔隙度、有效持水量的影响最为明显。【结论】间伐后细根形态变化通过多种机制形成多层次的水文功能调控网络,基于土壤水文性质考虑,建议长江上游柏木人工林采用中度间伐进行林分密度管理,林分保留密度约为1 500株/hm^(2),为森林生态系统的可持续管理提供科学依据。 展开更多
关键词 柏木人工林 间伐 细根性状 土壤水文特性
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SAP混凝土抗压强度的影响规律及其孔隙特征 被引量:2
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作者 魏瀚 吕镇锋 +2 位作者 李昊 王行行 杨镇华 《市政技术》 2025年第2期214-222,共9页
高吸水树脂(SAP)作为一种内养护材料,有效解决了外部养护对高性能混凝土养护效果不佳的问题。为探究不同水胶比下SAP对高性能混凝土力学性能的影响规律,通过抗压强度试验探究了3种水胶比下SAP掺量和SAP预吸水倍数对高性能混凝土力学性... 高吸水树脂(SAP)作为一种内养护材料,有效解决了外部养护对高性能混凝土养护效果不佳的问题。为探究不同水胶比下SAP对高性能混凝土力学性能的影响规律,通过抗压强度试验探究了3种水胶比下SAP掺量和SAP预吸水倍数对高性能混凝土力学性能的影响。同时,通过灰色关联理论和回归分析探究了各因素与高性能混凝土抗压强度的关联度,以及各因素之间是否存在协同作用,并构建了SAP混凝土抗压强度预测模型。此外,通过压汞试验探究了SAP掺量对高性能混凝土孔隙结构的影响。试验结果表明:当SAP的预吸水倍数为10且掺量为0.1%时,对高性能混凝土力学性能的改善效果最好;水胶比与SAP掺量和SAP预吸水倍数之间存在协同作用,不同的水胶比改变了SAP掺量和SAP预吸水倍数对高性能混凝土抗压强度的影响程度;高性能混凝土的微观孔径分布会随着SAP的掺入发生改变,其中孔隙率和大孔径数量会随着SAP掺量的增加而增大。 展开更多
关键词 高性能混凝土 SAP 抗压强度 压汞法 灰色关联 孔隙结构
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经阴道彩色多普勒超声与超声造影在盆腔结核的诊断效能比较
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作者 侯鹏 魏晗 左卫娜 《分子影像学杂志》 2025年第8期991-995,共5页
目的比较经阴道彩色多普勒超声与超声造影(CEUS)对盆腔结核诊断的应用效能。方法选取河北省胸科医院2022年6月~2023年12月收治的90例盆腔结核患者为研究对象,所有患者均行经阴道彩色多普勒超声检查以及CEUS检查,评价两者诊断盆腔结核的... 目的比较经阴道彩色多普勒超声与超声造影(CEUS)对盆腔结核诊断的应用效能。方法选取河北省胸科医院2022年6月~2023年12月收治的90例盆腔结核患者为研究对象,所有患者均行经阴道彩色多普勒超声检查以及CEUS检查,评价两者诊断盆腔结核的准确率,观察两者影像学表现特征差异。结果经阴道彩色多普勒超声诊断准确率60.00%,(54/90),低于CEUS检查诊断准确率82.22%(74/90),差异有统计学意义(P<0.05),二者检测输卵管、输卵管卵巢、子宫内膜以及盆腔腹膜等不同部位结核的准确率差异无统计学意义(P>0.05);彩色多普勒超声中,盆腔结核形态以囊性包块、囊实性包块为主,包囊壁厚,粗糙,且包块形态不规则,边界不清晰。输卵管增大多呈腊肠样病变(34.44%)。检测回声以混合型回声为主(65.56%),可检测到病灶周围I~Ⅲ级血流信号,病灶最大直径为45.38±15.37 mm;CEUS检查中盆腔结核形态以囊性包块为主,包块形态不规则,造影剂存在充盈不均匀,边界不清晰,宫腔内血流丰富。检测回声以混合型回声为主(80.00%)。病灶最大直径为46.47±14.56 mm,与彩色多普勒超声检查病灶直径的差异无统计学意义(P>0.05)。结论经阴道CEUS较彩色多普勒超声诊断盆腔结核的准确率更高,且其能客观反映病灶血流灌注情况以及周围组织回声情况,为提高早期盆腔结核诊断准确率起到重要作用。 展开更多
关键词 盆腔结核 经阴道彩色多普勒超声 超声造影 早期诊断 效能 比较研究
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新型氧化物-非氧化物烧结助剂制备Si_(3)N_(4)复相陶瓷及其显微结构与力学性能研究
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作者 黄俊伟 王俊涛 +5 位作者 胡建辉 陈松林 魏瀚 孙旭东 李欢 葛昌纯 《中国建材科技》 2025年第S1期230-236,共7页
本文针对难烧结Si_(3)N_(4)陶瓷材料相变与晶粒结构调控困难的特性,设计了氧化物-非氧化物(Y_(2)O_(3)-Al_(2)O_(3)-ZrN-AlN)复合烧结助剂体系,并通过热压烧结技术实现Si_(3)N_(4)陶瓷的相变调控与微观结构优化,提高其力学性能,同时减... 本文针对难烧结Si_(3)N_(4)陶瓷材料相变与晶粒结构调控困难的特性,设计了氧化物-非氧化物(Y_(2)O_(3)-Al_(2)O_(3)-ZrN-AlN)复合烧结助剂体系,并通过热压烧结技术实现Si_(3)N_(4)陶瓷的相变调控与微观结构优化,提高其力学性能,同时减少晶界玻璃相生成。通过多尺度表征手段(XRD/SEM/TEM)与力学性能测试,揭示了氧化物-非氧化物烧结助剂对Si_(3)N_(4)相变、晶粒形貌、晶界特性及力学性能的影响机制。结果表明,相比于传统氧化物(Y_(2)O_(3)-Al_(2)O_(3))烧结助剂体系,氧化物与非氧化物的协同效应显著优化了烧结动力学过程,高温下形成的氧化物固溶相促进了α→β相变,同时形成的非氧化物固溶相有效调控了β-Si_(3)N_(4)柱状晶的生长,优化了相组成和显微结构。同时,制备的Si_(3)N_(4)陶瓷展现出优于传统Y_(2)O_(3)-Al_(2)O_(3)烧结助剂体系的力学性能,其抗弯强度、断裂韧性和维氏硬度分别为787.61±58.03 MPa、7.78±0.30 MPa·m1/2和17.80±0.26 GPa。本工作可为氧化物-非氧化物复合烧结助剂体系的设计及开发高可靠性氮化硅结构陶瓷提供理论指导与技术支撑。 展开更多
关键词 Si_(3)N_(4)陶瓷 氧化物-非氧化物 烧结助剂 显微结构 力学性能
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Computed tomography enterography-based radiomics for assessing mucosal healing in patients with small bowel Crohn's disease
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作者 Hao Ding Yuan-Yuan Fang +5 位作者 Wen-Jie Fan Chen-Yu Zhang Shao-Fei Wang Jing Hu wei han Qiao Mei 《World Journal of Gastroenterology》 SCIE CAS 2025年第3期62-72,共11页
BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significan... BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients. 展开更多
关键词 Crohn’s disease Computed tomography enterography Mucosal healing NOMOGRAM Radiomics
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锂电池直驱式磁阻发射器系统设计与实现
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作者 王淇锐 向红军 +4 位作者 曹根荣 孙也尊 魏晗 乔志明 苑希超 《火炮发射与控制学报》 北大核心 2025年第4期102-107,共6页
针对磁阻发射器在非致命防暴应用场景中的高射速性能需求,研制了一种新型锂电池直驱式磁阻发射器系统。通过分析锂电池直驱式磁阻发射器的基本原理,给出了功率电路拓扑结构,建立了磁阻发射器的电路动力学模型与运动学解析模型。通过有... 针对磁阻发射器在非致命防暴应用场景中的高射速性能需求,研制了一种新型锂电池直驱式磁阻发射器系统。通过分析锂电池直驱式磁阻发射器的基本原理,给出了功率电路拓扑结构,建立了磁阻发射器的电路动力学模型与运动学解析模型。通过有限元数值计算,基于位置-时序映射方法确定了磁阻发射器最优触发-关断时序,并研究了磁阻发射器锂电池焦耳热积累及温度变化,评估了多级磁阻发射器系统设计的可行性。搭建原理样机试验系统并开展了射击测试,试验结果表明,该锂电池直驱式磁阻发射器能够将给定电枢加速至86.26 m/s,射速达到277发/min,相对传统磁阻发射器射速提升了2倍以上。 展开更多
关键词 磁阻发射器 高射速 锂电池直驱 时序优化
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内镜下乳头括约肌小切开术联合球囊扩张术治疗胆总管结石的临床价值 被引量:24
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作者 王庆华 韩玮 +2 位作者 包洁 王炳芳 陆永高 《中国内镜杂志》 2020年第2期32-36,共5页
目的探讨采用内镜下乳头括约肌小切开术联合球囊扩张术(sEST+EPBD)治疗胆总管结石的临床疗效及可能存在的机制。方法选取2013年1月-2017年12月因胆总管结石入住该院的200例患者,分为单纯内镜下乳头括约肌切开术(EST)组和sEST+EPBD组,每... 目的探讨采用内镜下乳头括约肌小切开术联合球囊扩张术(sEST+EPBD)治疗胆总管结石的临床疗效及可能存在的机制。方法选取2013年1月-2017年12月因胆总管结石入住该院的200例患者,分为单纯内镜下乳头括约肌切开术(EST)组和sEST+EPBD组,每组100例。对两组患者的手术时间、住院时间、总费用、并发症以及炎症指标进行比较分析。结果两组患者术后均未发生胰腺炎,所有患者均治愈。其中,sEST+EPBD组患者平均手术时间、住院时间、出血量及术后胆道感染均明显少于EST组(P<0.05)。两组患者总费用和胆道穿孔比较,差异无统计学意义(P>0.05)。术后1及24 h,sEST+EPBD组白细胞(WBC)、环氧化酶-2(Cox-2)、降钙素原(PCT)、C反应蛋白(CRP)以及肿瘤坏死因子(TNF-α)水平均明显低于EST组(P<0.01),而sEST+EPBD组的血淀粉酶水平明显升高(P<0.01);术后72 h,sEST+EPBD组WBC及Cox-2水平均明显低于EST组(P<0.05),PCT、CRP、淀粉酶以及TNF-α水平则差异无统计学意义(P>0.05)。结论sEST+EPBD是治疗胆总管结石的一种有效、安全的方法,能减少手术时间、住院时间,有效控制术后胆道感染的发生,并且能明显降低炎症反应。 展开更多
关键词 胆总管结石 内镜括约肌切开术 内镜乳头气囊扩张术 随机对照试验 炎症反应
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