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Pore pressure evolution and entrainment mechanism of convex unsaturated colluvial beds with divergent compositions under debris flow overriding
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作者 Pu Li Kaiheng Hu Jiading Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期278-298,共21页
A debris flow descending through an erodible convex colluvial bed,originating from a landslide dam and its upstream deposits,can entrain massive amounts of sediment,dramatically increasing the debris flow volume.Most ... A debris flow descending through an erodible convex colluvial bed,originating from a landslide dam and its upstream deposits,can entrain massive amounts of sediment,dramatically increasing the debris flow volume.Most existing erosion models assume that bed sediments are fully saturated,although this condition is rarely observed in nature.Therefore,a thorough understanding of debris flow overtopping erosion on a convex unsaturated bed is crucial for quantifying disaster risk.In this study,we experimentally investigated the effects of sediment composition,specifically coarse-grain size distribution and fine particle content,on the pore pressure evolution and entrainment of debris flows overriding a convex unsaturated colluvial bed.The average entrainment rate at convex sites for continuously graded bed sediment was higher than its discontinuous counterpart.The measured pore pressures within the unsaturated bed sediments were primarily generated by the passing debris flows.Furthermore,it was found that these pressures decreased as the fine particle content increased and the coarse-grain size of the erodible substrates decreased.When the coarse-grain size of the debris flow was smaller than that of the bed sediment,only a portion of the eroded material was entrained by the moving debris flow.In contrast,when the coarse-grain size of the debris flow was equal to or greater than that of the bed sediment,nearly all of the eroded material was entrained.The findings of this study could contribute to the assessment of hazard amplification and inform the design of mitigation and prevention strategies. 展开更多
关键词 Debris flow Convex colluvial bed Sediment composition Unsaturated bed Pore pressure ENTRAINMENT
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Multi-scale simplified residual convolutional neural network model for predicting compositions of binary magnesium alloys
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作者 Xu Qin Qinghang Wang +6 位作者 Xinqian Zhao Shouxin Xia Li Wang Jiabao Long Yuhui Zhang Yanfu Chai Daolun Chen 《Journal of Magnesium and Alloys》 2026年第1期117-123,共7页
This study proposes a multi-scale simplified residual convolutional neural network(MS-SRCNN)for the precise prediction of Mg-Nd binary alloy compositions from scanning electron microscope(SEM)images.A multi-scale data... This study proposes a multi-scale simplified residual convolutional neural network(MS-SRCNN)for the precise prediction of Mg-Nd binary alloy compositions from scanning electron microscope(SEM)images.A multi-scale data structure is established by spatially aligning and stacking SEM images at different magnifications.The MS-SRCNN significantly reduces computational runtime by over 90%compared to traditional architectures like ResNet50,VGG16,and VGG19,without compromising prediction accuracy.The model demonstrates more excellent predictive performance,achieving a>5%increase in R^(2) compared to single-scale models.Furthermore,the MS-SRCNN exhibits robust composition prediction capability across other Mg-based binary alloys,including Mg-La,Mg-Sn,Mg-Ce,Mg-Sm,Mg-Ag,and Mg-Y,thereby emphasizing its generalization and extrapolation potential.This research establishes a non-destructive,microstructure-informed composition analysis framework,reduces characterization time compared to traditional experiment methods and provides insights into the composition-microstructure relationship in diverse material systems. 展开更多
关键词 Magnesium alloys Composition prediction Scanning electron microscope images Multi-scale simplified residual convolutional neural network
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Quantitative Analysis of the Fatty Acid Compositions of Different Oils and Associations with Antioxidant Capacity and Oxidative Stability 被引量:3
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作者 LIU Junchen SUN Xiaoman +3 位作者 ZHANG Huirong SHAO Haofan LING Xiao LI Li 《现代食品科技》 北大核心 2025年第4期305-315,共11页
Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w... Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils. 展开更多
关键词 gas chromatography-mass spectrometry vegetable oil fatty acid composition oxidative stability antioxidant capacity
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All Polyethylene Compositions Based on Ultrahigh Molecular Weight Polyethylene Synthesized over Binary Catalyst including Zirconocenes of Various Designs
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作者 Tatiana M.Ushakova Elena E.Starchak +5 位作者 Sergey S.Gostev Sergey S.Gusarov Igor I.Arutyunov Vadim G.Krasheninnikov Aleksandr Z.Voskoboynikov Ludmila A.Novokshonova 《Chinese Journal of Polymer Science》 2025年第11期2094-2101,I0012,共9页
Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)... Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained. 展开更多
关键词 Ultrahigh molecular weight polyethylene Reactor polymer compositions POLYMERIZATION Organometallic catalysts Tensile properties Melt indexes
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Geochemical Compositions and Transport Patterns of Surface Sediments from the Malacca Strait
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作者 AI Lina LIU Shengfa +6 位作者 ZHANG Hui CAO Peng LI Xue QI Wenjing WU Kaikai MOHAMED Che Abd Rahim SHI Xuefa 《Journal of Ocean University of China》 2025年第6期1613-1623,共11页
The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical ... The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical characteristics of surface sediments in the MS to elucidate the relationship between terrestrial material inputs and modern oceanic dynamic transport processes in the strait.The results reveal that the MS can be divided into three distinct geochemical provinces.ProvinceⅠ,located in the central region of the strait,is characterized by residual deposits.The preservation of these residual deposits can be attributed to the restricted sediment supply and the relatively weaker modern sedimentary hydrodynamic conditions.ProvinceⅡ,situated to the north of ProvinceⅠ,exhibits provenance differences between its southern and northern regions.The northern region is primarily supplied by sediments originating from the eastern shelf of the Andaman Sea,whereas sediments derived from Sumatra and the Sunda Shelf are predominantly deposited in the southern part of ProvinceⅡ.ProvinceⅢextends along the western coast of the Malaysian Peninsula,with sediments primarily sourced from the Malaysian Peninsula and the Sunda Shelf,while contributions from Sumatra and the eastern shelf of the Andaman Sea are negligible.River sediments from the Malaysian Peninsula and Sumatra are transported northwestward along their respective coasts by prevailing currents,which also facilitate the transportation of Sunda Shelf sediments within the strait,while sediments from the eastern shelf of the Andaman Sea are delivered to the MS via southward coastal currents during the southwest monsoon period.The southward currents and well-developed eddies potentially impede the northward transport of sediments from the Sunda Shelf and restrict the distribution of Andaman Sea sediments within the strait.This study substantially enhances the understanding of source-to-sink processes in the Indo-Pacific region. 展开更多
关键词 surface sediment geochemical composition PROVENANCE SEDIMENTATION Malacca Strait
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Optical properties and compositions of dissolved organic matter(DOM)along trophic gradients:Implications for a COD proxy in urban lakes
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作者 Xi Huang Jincheng Xu +5 位作者 Yan Wang Meththika Vithanage Chamindra L.Vithana Yang Wang Danni Yuan Siyue Li 《River》 2025年第3期330-340,共11页
Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for es... Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for estimating organic matter(OM)composition,and can thus serve as a proxy for conventional chemical oxygen demand(COD_(Mn))measurements,which are considered as imprecise and environmentally unfriendly.Hence,we conducted a field campaign across 30 lakes in Wuhan's metropolitan area,collecting 255 samples from varying trophic states to evaluate the predictive capability of COD_(Mn)using DOM optical measurements combined with parallel factor(PARAFAC)analysis.The DOM optical properties and chemical composition exhibited considerable variability across varying trophic state levels(TSLs).Fluorescence components C1-C3 and C5,fluorescence index(FI),and absorption at 254 nm(α_(254)),increased as TSL increased,while the DOM spectral slope(SR)decreased.COD_(Mn)was positively and significantly correlated with fluorescence components C1-C3 and C5,freshness index(β/α),autochthonous index(BIX),humification index(HIX),α_(254),the ratio ofα_(250)toα_(365)(E2/E3)while being negatively correlated with SR.Parametersα_(254),C1,C3,C4,FI,β/α,and HIX were identified as key predictors of COD_(Mn).The multiple linear regression model successfully predicted COD_(Mn)(r^(2)=0.63,p<0.01,n=1113)and demonstrated superior performance in mesotrophic lakes.These findings highlight the potential for establishing high-frequency,continuous,and multi-regional COD monitoring programs. 展开更多
关键词 chemical oxygen demand DOM chemical composition DOM quality EUTROPHICATION water quality
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REMARKS ON ASYMPTOTIC EXPANSIONS OF COMPOSITIONS WITH THE ELEMENTARY FUNCTIONS
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作者 LUO Xiao-Yu SHI Yong-Guo JIANG Zhi-Jie 《数学杂志》 2025年第2期131-139,共9页
In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the com... In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem. 展开更多
关键词 asymptotic expansion asymptotic power series trigonometric function composite function
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Chemical Compositions of Volatile Oil from Fruiting Body of Armillaria luteo-virens 被引量:30
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作者 周劲松 熊辉岩 +2 位作者 杨春江 焦迎春 盛海彦 《Agricultural Science & Technology》 CAS 2008年第2期90-92,共3页
The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic p... The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil. 展开更多
关键词 Armillaria luteo-rirens Volatile oil Chemical compositions GC-MS
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Functional evaluation for effective compositions in seed oil of Korean pine 被引量:14
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作者 王振宇 陈小强 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期215-217,共3页
The effect of seed oil of Korean pine (Pinus koraiensis) on the rats' blood-fat and its anti-ageing function was stud-ied for appraising the efficacy of the seed oil of Korean pine. Sixty experimental rats were ra... The effect of seed oil of Korean pine (Pinus koraiensis) on the rats' blood-fat and its anti-ageing function was stud-ied for appraising the efficacy of the seed oil of Korean pine. Sixty experimental rats were randomly divided into 5 groups (half males and half females in each group) as normal control group, high fat diet control group, and three groups (Group 1 Group 2, Group 3) that were fed with feedstuff with the contents of the seed oil of 2.0g/(kgd-1), 4.0g/(kgd-1) and 8.0g/(kgd-1), respec-tively. The indexes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and anti-oxidation capacity (AOC) were measured by Reagent Kit method. It was found that the seed oil of the Korean pine could reduce the content of triglyc-eride and improve SOD as well as GSH-PX activity in serum. These indexes of the rats in Group 2 fed with Korean pine seed oil of 4.0 g/(kgd-1) reached the significant level and those of rats in Group 3 fed with the seed oil of 8.0 g/(kgd-1) reached the extremely significant level. The results indicated the seed oil of Korean pine had function of regulating the level of blood-fat and anti-ageing. 展开更多
关键词 Korean pine seed oil Effective compositions Functional evaluation Blood-fat ANTI-AGEING
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Inheritance of Fat and Fatty Acid Compositions in Peanut (Arachis hypogaea L.) 被引量:6
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作者 张新友 祝水金 +6 位作者 韩锁义 徐静 刘华 汤丰收 董文召 臧秀旺 张忠信 《Agricultural Science & Technology》 CAS 2011年第7期943-946,974,共5页
[Objective] The aim was to explore the inheritance of fat and fatty acid compositions in peanut.[Method] Genetic and correlation analyses were performed using a mixed genetic model of major gene plus polygene with 215... [Objective] The aim was to explore the inheritance of fat and fatty acid compositions in peanut.[Method] Genetic and correlation analyses were performed using a mixed genetic model of major gene plus polygene with 215 F9 RILs and their parents ZHENG 8903 and YUHUA No.4.[Result] The optimal genetic model of the fat content was two linked complementary major gene plus polygene inheritance model.The heritability of major genes was 22.88%.Oleic,linoleic,and palmitic acid content were controlled by two major genes and the heritability was 75.11%,75.00% and 60.95%,respectively.Stearic and arachidic acid content were controlled by two major genes plus polygenes,the heritability of major genes was 26.43% and 33.17%,respectively.O/L ratio and behenic acid content were controlled by three major genes,the heritability was 70.65% and 30.70%,respectively.[Conclusion] The result in this study was that accumulating polygenes should be emphasized in the improvement of fat content,while utilization of major genes is enhanced in improvement of oleic and linoleic acids. 展开更多
关键词 PEANUT FAT Fatty acid composition INHERITANCE
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轻钢轻混凝土组合墙板平面外受力性能试验研究
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作者 董宏英 王瑞 +2 位作者 曹万林 杨兆源 刘思源 《建筑结构》 北大核心 2026年第5期51-58,共8页
为适应装配式建筑的发展,提出了一种轻钢轻混凝土组合墙板,由轻钢龙骨与轻质泡沫颗粒混凝土组合而成。为研究风荷载作用下轻钢轻混凝土组合墙板的受弯性能,对3个足尺轻钢轻混凝土组合墙板进行了平面外加载试验。组合墙板通过自攻钉与轻... 为适应装配式建筑的发展,提出了一种轻钢轻混凝土组合墙板,由轻钢龙骨与轻质泡沫颗粒混凝土组合而成。为研究风荷载作用下轻钢轻混凝土组合墙板的受弯性能,对3个足尺轻钢轻混凝土组合墙板进行了平面外加载试验。组合墙板通过自攻钉与轻钢框架上的角钢件连接。集中力通过简支分配梁形成四点加载模式以模拟均布荷载,加载点设置球铰支座。分析了墙板内部轻钢龙骨壁厚、墙板两侧是否复合轻质泡沫颗粒混凝土钢丝网层及高性能抗裂砂浆层等因素对组合墙板的荷载-挠度曲线和破坏模式的影响。基于试验结果,结合静力平衡条件和虚功原理,推导出组合墙板平面外极限抗弯承载力计算公式,计算结果与试验符合较好。研究表明:该墙板具有良好的抗弯刚度和弹塑性变形能力;减小内部轻钢龙骨厚度对墙板平面外极限承载力和刚度有一定削弱;墙体内外叶砂浆面层构造对组合墙板承载力有显著增强作用。 展开更多
关键词 装配式建筑 轻钢组合结构 轻钢轻混凝土组合墙板 受力性能 试验研究
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基于AIGC的造型基础课程教学改革探索与实践 被引量:1
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作者 杨西惠 张爱梅 刘小院 《高教学刊》 2026年第2期9-12,共4页
随着人工智能生成内容(AIGC)技术的快速发展,设计教育正面临前所未有的变革与挑战。该文以造型基础课程为切入点,探讨AIGC技术在教学中的深度融合路径,提出基础为本、AI为用、人机协同的教学理念,构建基于AIGC的新型教学框架。通过重构... 随着人工智能生成内容(AIGC)技术的快速发展,设计教育正面临前所未有的变革与挑战。该文以造型基础课程为切入点,探讨AIGC技术在教学中的深度融合路径,提出基础为本、AI为用、人机协同的教学理念,构建基于AIGC的新型教学框架。通过重构课程内容、优化教学方法、引入智能工具及多元化评价体系,探索激发学生创意潜能、提升综合设计能力的教学实践方案。实践表明,AIGC融入造型基础课程提升学生的创意广度、表现力与思维深度,增强学习积极性与批判性思维能力,深化在智能时代背景下设计教育教学的改革。 展开更多
关键词 AIGC 造型基础 教学改革 人机协作 创新思维
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性腺发育不同时期雌性红九棘鲈肌肉营养成分的分析与评价
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作者 李雪 陈张帆 +3 位作者 卢昇 王崇伟 李超伟 陈松林 《渔业科学进展》 北大核心 2026年第1期70-80,共11页
为探究雌性红九棘鲈(Cephalopholis sonnerati)不同生长阶段肌肉的营养价值和肌肉营养组成变化规律,本研究对红九棘鲈性腺发育不同时期(Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ期)肌肉的营养成分进行了分析,并通过计算氨基酸评分(AAS)、化学评分(CS)和必需... 为探究雌性红九棘鲈(Cephalopholis sonnerati)不同生长阶段肌肉的营养价值和肌肉营养组成变化规律,本研究对红九棘鲈性腺发育不同时期(Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ期)肌肉的营养成分进行了分析,并通过计算氨基酸评分(AAS)、化学评分(CS)和必需氨基酸指数(EAAI)等指标评价了其肌肉品质。结果显示,在雌性红九棘鲈性腺Ⅰ~Ⅴ期发育过程中,水分和蛋白含量呈持续上升趋势,脂肪含量Ⅳ期达到最高,随后在Ⅴ期下降。红九棘鲈肌肉中检测出的16种氨基酸总量为(18.20±0.26)%~(19.63±0.06)%,在卵巢发育Ⅰ~Ⅴ期过程中呈上升趋势,其中,包含人体所需的7种必需氨基酸,4种主要呈味氨基酸总量为(7.00±0.04)%~(7.55±0.07)%。此外,在肌肉中共检测出25种脂肪酸,含量最高的C16:0和C18:1随红九棘鲈性腺发育呈下降的趋势;而DHA+EPA含量呈先下降后上升的趋势。另外,红九棘鲈肌肉中矿物质含量分析结果显示,红九棘鲈肌肉具有丰富的矿物质,检测到5种常量元素及3种微量元素,且Ⅴ期亲鱼的含硒量高于其他石斑鱼类。本研究揭示了红九棘鲈不同生长阶段肌肉的营养价值和肌肉营养组成变化规律,为红九棘鲈不同发育时期配合饲料的研制和营养价值评价提供了科学依据,并为进一步开展红九棘鲈人工规模化养殖实践奠定了理论基础。 展开更多
关键词 红九棘鲈 肌肉 营养成分 性腺发育
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新质生产力背景下竹资源多途径综合利用全产业链的构建
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作者 孙云娟 罗彦卿 +3 位作者 丁玉 杜官本 王戈 蒋剑春 《林产化学与工业》 北大核心 2026年第1期1-14,共14页
围绕新质生产力背景下竹资源多途径综合利用全产业链的构建,介绍了“以竹代塑”的国内外发展形势,包括提出以“以竹代塑”的时代背景、“以竹代塑”的发展机遇,以及竹资源的优势。阐述了“以竹代塑”的全产业链的发展现状,涵盖竹类资源... 围绕新质生产力背景下竹资源多途径综合利用全产业链的构建,介绍了“以竹代塑”的国内外发展形势,包括提出以“以竹代塑”的时代背景、“以竹代塑”的发展机遇,以及竹资源的优势。阐述了“以竹代塑”的全产业链的发展现状,涵盖竹类资源现状、创新技术产品研发、机械装备发展和高质量发展政策等方面。总结了“以竹代塑”全产业链在竹林培育、竹材加工产业链效能、竹产业创新人才和政策支持力度等方面的发展困境。最后提出了夯实竹资源培育建设、加强竹材采运和加工创新升级、强化科技与人才支撑、加强政策支持力度、深化国际合作与交流等建设性意见。 展开更多
关键词 种质资源 复合材料 以竹代塑
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湖北观音寺长江大桥主桥纵向约束体系研究
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作者 李秋 刘新华 +2 位作者 冯鹏程 易蓓 欧阳泽卉 《桥梁建设》 北大核心 2026年第1期9-16,共8页
湖北观音寺长江大桥主桥为主跨跨径1160 m的双塔双索面混合梁斜拉桥,边跨377 m长主梁采用预应力混凝土整体式箱梁,中跨1106 m长主梁采用钢-UHPC组合梁,为寻求该桥优异的静、动力性能,对其纵向约束体系进行研究。通过MIDAS Civil软件建... 湖北观音寺长江大桥主桥为主跨跨径1160 m的双塔双索面混合梁斜拉桥,边跨377 m长主梁采用预应力混凝土整体式箱梁,中跨1106 m长主梁采用钢-UHPC组合梁,为寻求该桥优异的静、动力性能,对其纵向约束体系进行研究。通过MIDAS Civil软件建立主桥有限元模型,对采用常规半飘浮体系、固结体系、弹性约束体系、阻尼约束体系的主桥静、动力性能进行对比分析,在此基础上,结合弹性约束体系和阻尼约束体系的特点,提出可同时兼顾结构静、动力性能的弹簧+阻尼复合约束体系,并进行静、动力参数取值分析。结果表明:采用常规纵向约束体系均无法兼顾该桥的静、动力性能;弹簧+阻尼复合约束体系中弹簧刚度K取4000 kN/m、阻尼系数C取4100 kN·(m/s)-α、速度指数α取0.3时,主桥静、动力性能得到综合改善,同时弹簧力及阻尼力吨位满足复合约束装置的制造要求;采用弹簧+阻尼复合约束体系后,该桥静力下梁端纵向位移幅值减小24.7%、塔顶纵向位移幅值减小22.4%、塔底纵向弯矩幅值减小10.9%,E2地震作用下梁端纵向位移幅值减小78.6%、塔顶纵向位移幅值减小77.2%、塔底纵向弯矩幅值减小56.2%。 展开更多
关键词 斜拉桥 钢-UHPC组合梁 纵向约束体系 弹簧+阻尼复合约束体系 静动力性能 参数分析
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考虑楼板组合效应的装配式钢混组合边节点滞回性能分析
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作者 吴成龙 丁晓娟 +2 位作者 尚育卿 任杰 王修军 《江苏大学学报(自然科学版)》 北大核心 2026年第1期93-103,共11页
为探讨楼板组合效应对装配式型钢混凝土柱(SRC)-钢梁节点抗震性能的影响,在拟静力试验的基础上,利用ABAQUS软件对栓焊混合连接的装配式边节点开展有限元建模和有效性验证.在此基础上,通过增设楼板来进一步分析楼板组合效应对装配式钢混... 为探讨楼板组合效应对装配式型钢混凝土柱(SRC)-钢梁节点抗震性能的影响,在拟静力试验的基础上,利用ABAQUS软件对栓焊混合连接的装配式边节点开展有限元建模和有效性验证.在此基础上,通过增设楼板来进一步分析楼板组合效应对装配式钢混组合边节点滞回性能的影响,重点分析楼板宽度、厚度、配筋率及轴压比的影响.结果表明:楼板构造参数、轴压比对核心区模块及楼板应力大小和分布影响显著,但节点的抗震性能受楼板构造参数的影响较小;节点的承载能力和耗能性能随轴压比增加而显著提高,但轴压比增大使节点发生脆性破坏的可能性增大;当轴压比为0.3时,其承载力、延性和耗能性能等抗震性能指标达到最优状态. 展开更多
关键词 预制装配式 组合节点 楼板组合效应 滞回性能 数值模拟
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华北平原北部徐水南断裂和牛东断裂晚第四纪活动性——来自钻孔联合地质剖面的证据
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作者 黄雄南 杨晓平 +12 位作者 刘保金 石峰 庄其天 郝海健 石金虎 孙浩越 鲁人齐 胡宗凯 李康 曹筠 疏鹏 任光雪 王振南 《地震地质》 北大核心 2026年第1期19-42,共24页
华北平原新生代正断裂大多在晚更新世以来停止活动,但大量历史强震震中却位于这些隐伏断裂的附近。那么,强震是先存正断裂的继续活动还是新生断裂造成的?文中通过钻孔探测结合年代学测定,研究雄安新区徐水南断裂和牛东断裂晚第四纪活动... 华北平原新生代正断裂大多在晚更新世以来停止活动,但大量历史强震震中却位于这些隐伏断裂的附近。那么,强震是先存正断裂的继续活动还是新生断裂造成的?文中通过钻孔探测结合年代学测定,研究雄安新区徐水南断裂和牛东断裂晚第四纪活动性,探讨华北平原区新生代先存正断裂的继承性活动及其机制。钻孔联合剖面探测确定徐水南断裂中段和牛东断裂中段东支的上断点分别深约24m和42m。测年结果表明,断裂分别在距今约20ka和36ka仍然活动,皆为晚更新世断层。结合浅层地震勘探,可知徐水南断裂和牛东断裂晚更新世之后活动性减弱,仅在中段活动。徐水南断裂和牛东断裂作为容城凸起和牛驼镇凸起的边界断层,其深部具有特殊的岩石圈结构,断裂易于积累应变,且又为深部流体通道,虽然晚第四纪以来活动性减弱,但仍有可能被触发,从而发生强震。 展开更多
关键词 钻孔联合剖面 断裂活动性 雄安新区 华北平原
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基于牛粪纤维的复合燃料制备及燃烧性能探讨
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作者 牛明芬 张一明 +4 位作者 林妍 郭英达 赵泽 李刚 郭书海 《农业资源与环境学报》 北大核心 2026年第2期416-423,共8页
本研究以肉牛牛粪为主要材料,经过脱水处理后,与花生壳及干化煤泥混合制备复合燃料,获得了最优的掺比参数,并对该复合燃料的燃烧性能进行了分析。结果表明:经过脱水处理,牛粪固相中的灰分降低63.3%,挥发分和固定碳分别增加3.5%和173.8%... 本研究以肉牛牛粪为主要材料,经过脱水处理后,与花生壳及干化煤泥混合制备复合燃料,获得了最优的掺比参数,并对该复合燃料的燃烧性能进行了分析。结果表明:经过脱水处理,牛粪固相中的灰分降低63.3%,挥发分和固定碳分别增加3.5%和173.8%,发热量提高53%,氮元素和硫元素含量分别降低48.3%和43.7%,碳元素含量增加6.6%。采取优化后的花生壳和煤泥的混配比例,显著提高了复合燃料的热值,改善了燃烧性能,同时降低了灰分含量。特别是少量煤泥的加入,其高固定碳含量可有效延长复合燃料的燃烧持续时间。此外,成型压力对燃料热值有重要影响,研究表明该复合燃料的最佳成型压力范围为15~20 MPa,此时燃料的松弛密度为1.76~1.77 g·cm^(-3),热值达到最高。本研究为肉牛牛粪的资源化利用提供一个新的可行途径。 展开更多
关键词 牛粪 复合燃料 热值 燃烧特性
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光响应螺吡喃复合凝胶对溶液中铀的吸附性能研究
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作者 刘淑娟 郑雪帆 +4 位作者 戴辰璟 赵宏凌 胡茂松 罗建强 马建国 《东华理工大学学报(自然科学版)》 北大核心 2026年第1期104-114,共11页
核废水中铀的高效绿色回收对核能可持续发展至关重要,传统吸附剂依赖化学洗脱剂和高能耗解吸过程,易产生二次污染。将羧基功能化螺吡喃(SPCOOH)嵌入聚乙二醇基质(PEG),构建光响应螺吡喃复合凝胶材料(SPCOOH@PEG),可实现铀吸附与光控解... 核废水中铀的高效绿色回收对核能可持续发展至关重要,传统吸附剂依赖化学洗脱剂和高能耗解吸过程,易产生二次污染。将羧基功能化螺吡喃(SPCOOH)嵌入聚乙二醇基质(PEG),构建光响应螺吡喃复合凝胶材料(SPCOOH@PEG),可实现铀吸附与光控解吸协同调控,减少化学试剂使用量。通过核磁共振氢谱验证SPCOOH结构,利用傅里叶红外光谱和扫描电镜-能谱证实SPCOOH在PEG网络中的成功负载。在pH=6的避光条件下,材料对铀的最大理论吸附容量达149.10 mg/g。等温吸附性能符合Langmuir模型,揭示单层化学吸附机制,吸附动力学符合准二级动力学模型。随着入射可见光波长的减小和辐照度的增加,光解吸率不断提升。在波长450 nm,辐照度40 mW/cm^(2)的可见光条件下,经6次吸附-解吸循环,光解吸效率由87.3%降至52.2%,但后续经0.01 mol/L HCl处理后,解吸率可提高至96.0%。X射线光电子能谱分析显示羧基氧和酚氧基团是主要配位点。可见光诱导螺吡喃由开环结构向闭环结构转化,削弱其配位作用,从而实现铀的光响应解吸。与传统吸附材料相比,此吸脱附过程显著降低外加能源消耗以及洗脱剂的使用量。尽管其吸附容量与部分新型材料相比存在差距,但其独特的光控解吸机制大幅提升了环境兼容性和操作经济性,为核废水处理开辟了绿色技术新路径。 展开更多
关键词 光响应材料 螺吡喃 复合凝胶 吸附
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