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Seasonal emission patterns of airborne phytoncides in temperate forests from autumn to early spring:a case study of Xishui National Forest Park(Yichun,Northeast China)
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作者 Hongda Cai Yitong Wang +6 位作者 Xianwen Huang Sen Zhang Yankun Liu Jian Zhang Dongmei Zhao Peng Zhao Xiuhua Zhao 《Journal of Forestry Research》 2026年第1期256-271,共16页
Xishui National Forest Park in Heilongjiang Province hosts China's most pristine temperate forests and serves as a key site for ecotourism and forest therapy.However,the emission patterns of phytoncides(key bio ac... Xishui National Forest Park in Heilongjiang Province hosts China's most pristine temperate forests and serves as a key site for ecotourism and forest therapy.However,the emission patterns of phytoncides(key bio active compounds) remain poorly understood,limiting their therapeutic application.This study provides the first comprehensive characterization of spatiotemporal dynamics in airborne phytoncides and their synergistic interactions with environmental factors throughout the autumn-early spring seasonal transition in a temperate forest ecosystem.We analyzed the compositional dynamics of phytoncides and terpenoid content variations using thermal desorption-gas chromatography-mass spectrometry(TD-GC-MS) from September 2024 to March 2025.This period encompassed seasonal transitions from autumn to early spring,including diurnal variations in September and snowfall events in November.The method demonstrated detection limits(LODs) ranging from 1.35 to 5.33 ng m-3 and quantification limits(LOQs) from 4.09 to 16.15 ng m-3.Our results revealed pronounced seasonal fluctuations in phytoncide composition.In September,terpenoids,esters,alcohols,and alkanes displayed a diurnal "decrease-increase" trend,whereas aldehydes and ketones peaked at midday.Notably,esters and alcohols were undetectable in November and January.By January,terpenoids reached their lowest proportion(0.17±0.02%) at noon.Five terpenoids(α-pinene,myrcene,D-limonene,camphene,p-cymene) were detected in September,four(α-pinene,D-limonene,camphene,p-cymene) in November,two(D-limonene,p-cymene) in January,and only p-cymene in March.The total concentration and emission rate of the five terpenoids peaked in September afternoons at 1961.58±106.67 ng m^(-3) and653.86±35.56 ng m^(-3) h^(-1),respectively.Nocturnal emissions(32131.95±2522.21 ng m^(-3)) significantly surpassed daytime levels(14473.04±958.49 ng m^(-3)),with emission rates escalating from 1447.30±95.85 ng m^(-3) h^(-1)(day) to 5355.33±420.37 ng m^(-3) h^(-1)(night),marking a3.7-fold increase.Snowfall dramatically elevated terpenoid concentrations(pre-snowfall:158.58±14.12 ng m^(-3);post-snowfall:1080.57±57.76 ng m^(-3)) and emission rates(pre-snowfall:52.86±4.71 ng m^(-3) h^(-1);post-snowfall:360.19±19.25 ng m^(-3) h^(-1)),reflecting a 6.8-fold surge.This study underscores the profound influence of light intensity,seasonal shifts,and climatic conditions on airborne phytoncide levels,offering a scientific foundation for optimizing forest therapy and ecotourism strategies. 展开更多
关键词 Phytoncides Seasonal variation Diurnal-nocturnal patterns Snowfall impact Emission patterns
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青绿苔草CbSH4基因克隆及基因编辑靶点筛选
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作者 黄扬洁 滕珂 +5 位作者 范希峰 岳跃森 张辉 温海峰 尹淑霞 刘凌云 《草地学报》 北大核心 2026年第2期437-446,共10页
青绿苔草(Carex breviculmis)是一种节水抗旱的重要乡土物种,具有绿期长、耐阴、结实率高等优点。但在实际采收过程中,种子极易落粒的问题限制了种子机械化收获和大规模生产应用。为探究SH4基因在青绿苔草落粒过程中的功能,进一步利用... 青绿苔草(Carex breviculmis)是一种节水抗旱的重要乡土物种,具有绿期长、耐阴、结实率高等优点。但在实际采收过程中,种子极易落粒的问题限制了种子机械化收获和大规模生产应用。为探究SH4基因在青绿苔草落粒过程中的功能,进一步利用基因编辑技术创制低落粒新种质,本研究克隆青绿苔草CbSH4基因并进行基因编辑靶点筛选。结果表明,CbSH4编码319个氨基酸残基,其编码产物是亲水性蛋白,与康藏嵩草(Carex littledalei)亲缘关系最近。CbSH4含有1个高度保守的Myb4 DNA结合域,属于典型的MYB转录因子。烟草瞬时表达结果显示,CbSH4定位于细胞核和细胞质。实时荧光定量结果表明,CbSH4在穗中的相对表达量显著高于根和叶,在不同发育时期的离区中均有表达。同时,为了在青绿苔草中实现高效的基因编辑,本研究设计了3个特异性靶点,利用sgRNA体外转录和筛选,获得切割效率58.3%的sgRNA1,可用于后续青绿苔草基因编辑。本研究成功克隆了CbSH4并完成初步功能分析,筛选出了高效基因编辑靶点,为创制低落粒的青绿苔草新种质提供了基础。 展开更多
关键词 青绿苔草 sh4基因 亚细胞定位 表达分析 靶点筛选 落粒性
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SH3BGRL调控自噬影响宫颈癌细胞增殖和迁移的分子机制研究
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作者 朱鑫丽 李伟欣 +4 位作者 夏宗一 赵博 程豪政 者湘漪 潘泽民 《石河子大学学报(自然科学版)》 北大核心 2026年第1期76-83,共8页
目的本研究旨在探讨SH3BGRL通过EGFR-mTOR-ULK1通路调控细胞自噬影响宫颈癌细胞增殖和迁移的分子机制。方法选取感染HPV16的宫颈癌SiHa细胞系和HPV18感染的HeLa细胞系,构建SH3BGRL过表达与敲低的宫颈癌细胞模型,运用蛋白质免疫印迹实验(... 目的本研究旨在探讨SH3BGRL通过EGFR-mTOR-ULK1通路调控细胞自噬影响宫颈癌细胞增殖和迁移的分子机制。方法选取感染HPV16的宫颈癌SiHa细胞系和HPV18感染的HeLa细胞系,构建SH3BGRL过表达与敲低的宫颈癌细胞模型,运用蛋白质免疫印迹实验(Western blot)、实时荧光定量PCR(qRT-PCR)、MTT实验、细胞集落形成实验、细胞划痕愈合实验、生物信息学和荧光染料单丹磺酰尸胺(Monodansylcadaverine,MDC)分析方法进行研究。结果使用qRT-PCR和Western blot实验发现SH3BGRL过表达与敲低的宫颈癌细胞模型构建成功;过表达SH3BGRL基因后,宫颈癌SiHa和HeLa细胞增殖和迁移显著降低,差异具有统计学意义(P<0.01,P<0.001,P<0.0001),敲低SH3BGRL基因后,宫颈癌细胞增殖和迁移能力显著增强,差异具有统计学意义(P<0.05,P<0.01,P<0.001,P<0.0001);研究发现SH3BGRL与EGFR直接结合并且能够影响EGFR的表达水平,Western blot实验发现过表达SH3BGRL基因后,EGFR、mTOR和P62蛋白质表达水平明显降低,ULK1和LC3表达水平明显增高;敲低SH3BGRL基因后,EGFR、mTOR和P62蛋白质表达水平明显增高,ULK1和LC3表达水平明显降低,差异具有统计学意义(P<0.05,P<0.01,P<0.001,P<0.0001)。MDC实验发现过表达SH3BGRL基因后,SiHa和HeLa细胞的荧光与对照组比较明显增强,敲低SH3BGRL基因后,SiHa和HeLa细胞的荧光与对照组比较明显减弱,差异具有统计学意义(P<0.01,P<0.001,P<0.0001),表明SH3BGRL基因可以影响细胞自噬。结论SH3BGRL基因能够通过EGFR-mTOR-ULK1途径增加宫颈癌细胞自噬水平,从而抑制宫颈癌细胞的增殖和迁移。 展开更多
关键词 宫颈癌 sh3BGRL基因 EGFR-mTOR-ULK1通路 细胞自噬
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Regional differences and formation mechanisms of watershed territorial space patterns evolution:A case study of the critical areas in the Pearl River Basin 被引量:2
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作者 LIN Shugao WANG Pengcheng +2 位作者 ZHU Peixin HUANG Ke LU Rucheng 《Journal of Geographical Sciences》 2025年第5期941-963,共23页
Clarifying the mechanisms that control the evolution of territorial space patterns is essential for regulating and optimizing the geographical structure and processes related to sustainable development.Using the Guang... Clarifying the mechanisms that control the evolution of territorial space patterns is essential for regulating and optimizing the geographical structure and processes related to sustainable development.Using the Guangdong and Guangxi sections of the Pearl River Basin as examples,the transfer-matrix method and standard deviation ellipse model were applied to characterize the evolution of territorial space patterns from 1990 to 2020.A trend surface analysis and the Theil index were used to analyze regional differences in the evolution process,and geodetectors were used to identify the underlying mechanisms of the changes.There were three key results.(1)In these critical areas of the Pearl River Basin,agricultural and ecological spaces have rapidly declined due to urban expansion,with transfers between these spaces dominating the evolution of territorial space patterns.Spatial pattern changes in the Guangdong section were more intense than in the Guangxi section.(2)Regional differences in urban space have decreased,whereas differences in agricultural and ecological spaces have intensified.Driven by socio-economic growth,the cross-regional transfers of territorial space have created a“high in the east,while low in the west”inter-regional difference,and a“high in the south,while low in the north”intra-regional difference shaped by natural conditions.The regional differences in space patterns were greater in Guangdong than in Guangxi.(3)The evolution of watershed territorial space patterns resulted from scale changes,locational shifts,structural reorganizations,and directional changes driven by multiple factors.Natural environment,social life,economic development,and policy factors played foundational,leading,key driving,and guiding roles,respectively.Additionally,the regional differences in the evolution of watershed territorial space patterns originated from the differential transmission of the influence of various factors affecting spatial evolution.Enhancing urban space efficiency,restructuring agricultural space,and optimizing ecological space are key strategies for building a complementary and synergistic territorial space pattern in the basin. 展开更多
关键词 territorial space patterns urban-agricultural-ecological space(UAES) formation mechanisms regionaldifferences Pearl River Basin
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Transport Patterns of Seasonal Suspended Particulate Matter Around the Western Sunda Shelf 被引量:1
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作者 ZHANG Hui LIU Shengfa +9 位作者 WU Kaikai AI Lina CAO Peng BAI Yazhi WANG Xiaojing WANG Hongmin MOHAMED Che Abd Rahim KHOKIATTIWONG Somkiat KORNKANITNAN Narumol SHI Xuefa 《Journal of Ocean University of China》 2025年第6期1561-1574,共14页
The transport of suspended particulate matter is a crucial aspect of studies on sediment source-to-sink processes.However,research on its transport patterns in high-erosion areas of low-latitude seas remains limited.T... The transport of suspended particulate matter is a crucial aspect of studies on sediment source-to-sink processes.However,research on its transport patterns in high-erosion areas of low-latitude seas remains limited.To elucidate modern land-sea interaction processes controlled by the monsoon climate,this study investigates the seasonal transport patterns and control mechanisms of suspended particulate matter in the western Sunda Shelf.Results reveal significant seasonal variations in the spatial distribution of suspended particulate matter concentrations,with elevated levels observed during autumn compared with spring.These differences are directly attributed to the East Asian monsoon,including seasonal monsoon precipitation and the associated transport dynamics.During the northeast monsoon,the Malay Peninsula serves as a primary source for the western sea area,with terrestrial materials from its rivers transported to the northern Gulf of Thailand.This transport pattern shifts to an S-shaped,clockwise circulation during upwelling events.Conversely,in the southwest monsoon,rivers in the northern Gulf of Thailand become the predominant sources for the Sunda Shelf,with terrestrial materials carried by clockwise currents toward the eastern Malay Peninsula.When upwelling occurs off the southern Indochina Peninsula,one branch heads toward the South China Sea and the other toward the southern tip of the Malay Peninsula.The seasonal variation in material sources is further supported by the distribution of clay minerals and the discrimination results of rare earth element proxies,including(La/Sm)UCC-(Gd/Yb)UCCand(La/Yb)UCC-(Gd/Yb)UCC,in surface sediments from the Sunda Shelf and surrounding marine areas. 展开更多
关键词 suspended particulate matter sediment source transport pattern monsoon precipitation sedimentary response Sunda shelf
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Application of Fractal Technology in the Generative Design of Chaoshan Drawnwork Patterns
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作者 CHEN Jia-jun ZHANG Ya CHEN Zhao-yang 《印刷与数字媒体技术研究》 北大核心 2025年第5期179-194,共16页
Chaoshan drawnwork handkerchief design exhibits self-similarity and fractal characteristics due to their grid-based structure,overall symmetry,and the way local motifs reflect the whole pattern.To explore the potentia... Chaoshan drawnwork handkerchief design exhibits self-similarity and fractal characteristics due to their grid-based structure,overall symmetry,and the way local motifs reflect the whole pattern.To explore the potential of fractals in traditional textile design,a fractal-based generative framework was proposed for efficiently creating drawnwork patterns suitable for practical handicraft production.The research was initiated with an analysis of the structural composition of center,skeleton,and filler motifs extracted from a pattern sample library.Based on this hierarchical classification,the box-counting method was employed to calculate their respective fractal dimensions.Building on fractal art theory,generative algorithms,and studies on the application of Ultra Fractal,a Chaoshan drawnwork fractal design model was established.Using this model,51 drawnwork fractal patterns and 153 handkerchief patterns were generated.These patterns were subsequently applied in real-world production to validate the feasibility and value of fractal techniques in textile design. 展开更多
关键词 Chaoshan drawnwork Fractal pattern Generative design Cultural heritage
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基于SH0导波与频域SAFT成像的储罐底板缺陷检测方法
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作者 李关 刘保余 吕福在 《油气储运》 北大核心 2026年第1期78-84,共7页
【目的】储罐底板在长期服役过程中因腐蚀易发生结构安全风险,传统的储罐底板检测方法存在效率低、需停罐清洗、成本高等问题,难以满足现代储罐高效、在线、大面积检测的生产需求,亟需探索一种适用于复杂工况下储罐底板的高灵敏度、高... 【目的】储罐底板在长期服役过程中因腐蚀易发生结构安全风险,传统的储罐底板检测方法存在效率低、需停罐清洗、成本高等问题,难以满足现代储罐高效、在线、大面积检测的生产需求,亟需探索一种适用于复杂工况下储罐底板的高灵敏度、高分辨率、远距离检测方法。【方法】将SH0剪切模态导波与频域合成孔径聚焦技术(Synthetic Aperture Focusing Technique,SAFT)相结合,建立了一种无损检测成像新方法:利用自主研发的磁致伸缩剪切导波换能器激励非频散、低衰减的SH0导波,并创新性地引入频域SAFT进行信号处理与成像重构。通过建立厚度为12 mm钢板的Lamb波与SH0导波频散特性对比模型,明确SH0导波在64 kHz、128 kHz等频段激励下具有优异的传播稳定性与抗干扰能力。在此基础上,构建包含激励设计、信号采集、频域补偿及SAFT成像的检测流程。【结果】选取长度为8000 mm的真实储罐底板样板开展试验验证,分别采用64 kHz、128 kHz换能器进行扫查,结果表明所建检测方法展现出优异性能:64 kHz的低频SH0导波可有效识别2550 mm处等效横截面损失0.82%的缺陷,128 kHz的高频SH0导波成功检测出近场区等效横截面损失0.32%~0.59%的小尺寸缺陷。将SH0导波与频域SAFT深度融合,显著提升了储罐底板缺陷成像分辨率与可靠性。【结论】新建方法在液体环境下表现更优,且计算效率更高,为储罐底板提供了不停罐检测的新途径,并对桥梁、船舶、压力容器等大型板状结构的安全监测具有重要借鉴意义。 展开更多
关键词 储罐底板 缺陷 超声导波 sh0导波 频域SAFT 成像 磁致伸缩 无损检测
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Quality of Life and Long-Term Complications of Diabetic Patients in Bangladesh: Does Treatment Pattern Differ the Quality of Life of Diabetic Patients?
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作者 A. B. M. Nahid Hasan Abu Saleh +7 位作者 Mst. Roni Khatun Md. Sharif Uddin Miah Taufikul Islam Mst. Tasnima Akter Shikha G. M. Yousuf Mahadi Prosenjit Basak Golam Rabby Mst. Rokshana Rabeya 《Journal of Diabetes Mellitus》 2025年第1期71-91,共21页
Background: Diabetes Mellitus (DM) is a growing health issue in Bangladesh, with significant complications affecting the quality of life (QoL). This study aims to assess long-term complications, treatment patterns, an... Background: Diabetes Mellitus (DM) is a growing health issue in Bangladesh, with significant complications affecting the quality of life (QoL). This study aims to assess long-term complications, treatment patterns, and QoL of diabetic patients during COVID-19. Methods: A cross-sectional study was conducted on 385 diabetic patients (aged 18-80) from tertiary hospitals in Dhaka and Mymensingh between May and October 2022. Data were collected via a semi-structured questionnaire on sociodemographics, complications, treatment patterns, and QoL (SF-12 scale). Chi-square tests, ANOVA, and linear regression were used for inferential analysis. Results: The sample predominantly included middle-aged males (41 - 55 years) with type 2 diabetes. Diabetic retinopathy (34.5%), polyneuropathy (32.2%), and hypertension (52.3%) were the most common complications. Oral medications were used by 59.7% of patients, with 29.1% on insulin. Chi-square analysis showed a significant association between treatment adherence and complications (p β = 0.45, p Conclusion: Complications in diabetic patients significantly affect QoL in Bangladesh. Treatment adherence, especially with oral medications, positively impacts QoL. There is a need for improved access to diabetes care to manage complications and enhance the overall well-being of diabetic patients. 展开更多
关键词 Diabetes Mellitus Quality of Life Long-Term Complications Treatment patterns BANGLADEsh
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Application of Chinese Traditional Decorative Patterns on Bronze Ware of Shang Dynasty in the Film & TV Costume Design
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作者 DU Bing-bing WANG Qi-fan 《Journal of Literature and Art Studies》 2025年第2期79-85,共7页
In contemporary China,some domestic films are deeply rooted in traditional Chinese culture,contributing to more and more excellent film&TV programs,among which,the styling inspired by animal patterns on Late Shang... In contemporary China,some domestic films are deeply rooted in traditional Chinese culture,contributing to more and more excellent film&TV programs,among which,the styling inspired by animal patterns on Late Shang Dynasty bronze ware has given strong vitality to the film&TV programs.This paper is intended to compile and understand the cultural value and artistic features of the patterns on Late Shang Dynasty bronze ware as well as its value in the traditional pattern application.It provides certain references regarding the role of film&TV styling in the inheritance and application of traditional patterns,if we analyze the cognition and status quo of the Late Shang Dynasty bronze ware patterns in the contemporary film&TV styling,and if we go deep into its artistic value and its application within such makeup design and identify the problems and laws in current design cases.Such analysis also provides a way of thinking for the application of traditional patterns in current film&TV costume design. 展开更多
关键词 animal patterns on bronze ware of Late shang Dynasty film&TV styling film&TV costume design traditional patterns
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Patterns of plant species richness and diversity across treelines in Himachal Pradesh,Western Himalaya
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作者 Rohit SHARMA Sanjay Kr.UNIYAL Shalinder KAUR 《Journal of Mountain Science》 2025年第5期1586-1599,共14页
Treelines are ecologically unique,fragile,and rich in natural resources.They harbour high species diversity and at the same time are under threat due to anthropogenic activities.Recognizing this,the present study has ... Treelines are ecologically unique,fragile,and rich in natural resources.They harbour high species diversity and at the same time are under threat due to anthropogenic activities.Recognizing this,the present study has been framed to document the patterns of species richness and diversity in the state of Himachal Pradesh,western Himalaya.A total of six treeline sites(three disturbed and three undisturbed)were identified for vegetation sampling.Trees,shrubs,and herbs were sampled at each site using nested plots of 10 m^(2),5 m^(2),and 1 m^(2),respectively.The study exhibits the rich diversity of treeline communities,the patterns of which varied between treeline sites.Altogether,221 species of vascular plants belonging to 47 families and 140 genera were recorded from the area.Amongst families,Asteraceae was the dominant family followed by Apiaceae and Ranunculaceae.The study also revealed the presence of threatened species like Aconitum heterophyllum,Angelica glauca,Bergenia stracheyi,Dactylorhiza hatagirea,Picrorhiza kurroa,and Trillium govanianum etc.at treeline.Moreover,species composition revealed high densities of Betula utilis followed by the under canopy of Rhododendron campanulatum and R.anthopogon at treeline sites.Overall,species richness of herbs,shrubs,and trees were higher at undisturbed site as compared to disturbed one.The diversity indices of herbs and shrubs varied significantly between treeline sites while that of trees was non-significant.At the same time,soil properties showed distinct patterns wherein pH and available nitrogen significantly varied between treeline sites.Present study provides detailed insights into the floristic and ecological aspects of treeline communities from the unexplored ecoregion of western Himalaya.The treelines in the area are anthropogenically depressed and continued land-use activities might result in habitat fragmentation and displacement of plant communities in the near future. 展开更多
关键词 Alpine treeline DISTURBANCE Floristic diversity HIMALAYA Soil Vegetation patterns
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Spatiotemporal distribution patterns of macrobenthic communities and their relationship with environmental factors in the Shengsi Archipelago(Zhejiang,China)
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作者 Lingxiang Jin Yibo Liao +6 位作者 Peisong Yu Yanbin Tang Qinghe Liu Rongliang Zhang Lu Shou Jiangning Zeng Quanzhen Chen 《Acta Oceanologica Sinica》 2025年第1期113-126,I0001-I0011,共25页
Macrobenthic organisms are commonly employed as biomonitors for environmental risk assessment.In this study,we aimed to investigate the spatial and temporal patterns of the macrobenthic community,which is influenced b... Macrobenthic organisms are commonly employed as biomonitors for environmental risk assessment.In this study,we aimed to investigate the spatial and temporal patterns of the macrobenthic community,which is influenced by environmental factors of sediments and bottom water layer.We sampled a total of 12,11,10,and 11 stations in the Shengsi Archipelago during June 2010,August 2010,November 2020,and April 2021 respectively.A total of 124 species of macrobenthos were identified,with polychaetes being the dominant group.The abundance,biomass,and diversity indices exhibited no significant temporal differences.Similarly,biodiversity did not exhibit a clear spatial gradient,likely due to the small study area and the absence of significant differences in key factors such as depth.However,the stations with the lowest biodiversity values consistently appeared in the southwest region,possibly due to the impact of human activities.Significant differences in the macrobenthic community were observed between all months except between June and August,and mollusk Endopleura lubrica and polychaete Sigambra hanaokai were important contributors to these differences according to the results of the Similarity Percentages analysis.Suspended particulate matter(SPM)was identified as the primary driving factors of macrobenthic variability.In summary,the community structure underwent temporal changes influenced by complex current patterns,while biodiversity remained relatively stable.This study contributes to our understanding of the key environmental factors affecting macrobenthic communities and biodiversity.It also provides valuable data support for the long-term monitoring of macrobenthos and the environment in the Shengsi Archipelago. 展开更多
关键词 macrobenthic community shengsi Archipelago distribution pattern BIODIVERSITY environmental factors
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Fluctuations in the relationship between the Silk Road Pattern and the summer North Atlantic Oscillation
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作者 Yong Liu Zhencai Du 《Atmospheric and Oceanic Science Letters》 2025年第4期35-40,共6页
This study investigated the fluctuations in the relationship between the Silk Road Pattern(SRP)and the boreal summer North Atlantic Oscillation(SNAO).The results indicated that the SRP–SNAO relationship was relativel... This study investigated the fluctuations in the relationship between the Silk Road Pattern(SRP)and the boreal summer North Atlantic Oscillation(SNAO).The results indicated that the SRP–SNAO relationship was relatively weak during 1958–2022,which was primarily due to fluctuations,particularly the reversal in their relationship since the late 1990s.Using wavelet coherence analysis,the authors identified a strong SRP–SNAO linkage on a 4–8-yr timescale,in particular during the mid-1970s to the early/mid-1990s.This strong linkage is mainly attributable to the intensification and eastward movement of the southern part of the SNAO around the mid/late 1970s,which favored the strong connection between the SNAO and the SRP.Additionally,the interdecadal changes of the atmospheric circulations over the North Atlantic and Eurasia around the mid/late 1970s that resembled the circulation anomalies related to the strong SRP–SNAO linkage,may also have provided a favorable background for the strong connection between the two teleconnections.These findings on the fluctuations in the SRP–SNAO linkage may offer important implications for understanding the impact of the SNAO on the SRP and the variability of the SRP. 展开更多
关键词 Silk Road pattern North Atlantic Oscillation Relationship fluctuation
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An Investigation into Dust Migration Patterns in Small-Section Tunnels and Large Steep-Sloped Inclined Shafts
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作者 Baoli Zang Liyang Shao +2 位作者 Yang Li Hao Ran Liangwen Wei 《Fluid Dynamics & Materials Processing》 2025年第3期555-571,共17页
This study focuses on addressing ventilation and dust removal challenges during the construction of small-section tunnels using drilling and blasting techniques.Specifically,the research examines the shale gas gatheri... This study focuses on addressing ventilation and dust removal challenges during the construction of small-section tunnels using drilling and blasting techniques.Specifically,the research examines the shale gas gathering and transmission trunk line project in the Weiyuan and Luzhou blocks.To gain deeper insights into dust migration patterns,numerical simulations were conducted.The study further analyzed dust migration behavior in small-section tunnels and large steep-sloped shafts,taking into account various factors such as ventilation distance,tunnel slope,and section size.The results indicate that optimal ventilation occurs at distances of 15 and 13 m.Additionally,dust concentration was notably lower when the tunnel slope was 0°,suggesting that a flat slope is more advantageous for construction projects where the outlet wind speed remains constant.Moreover,as the tunnel’s cross-sectional size increases,dust concentration decreases significantly,further underscoring the benefits of larger tunnel sections in mitigating dust accumulation. 展开更多
关键词 Small cross-section tunnels tunnel ventilation dust movement patterns
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The deformation evolution and the formation pattern of hot regions of particle cloud with cavity under shock impact
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作者 Shuai Li Yingming Si +2 位作者 Baoqing Meng Baolin Tian Wenjun Sun 《Acta Mechanica Sinica》 2025年第6期36-49,共14页
The formation of hotspots and ignition phenomena in cavitated explosive particle clouds under shock wave impacts have garnered widespread attention.However,at the mesoscale,under shock wave impact,there is a notable s... The formation of hotspots and ignition phenomena in cavitated explosive particle clouds under shock wave impacts have garnered widespread attention.However,at the mesoscale,under shock wave impact,there is a notable scarcity of research on the deformation,temperature rise patterns,and heat transfer mechanisms of particle clouds.Most studies focus on loading methods such as drop hammer and falling tests.In our study,we introduce a particle motion elastoplastic contact model based on the discrete element method,enabling precise analysis of particle motion and collision behavior.Furthermore,we consider bidirectional coupling between the particle and gas phases,optimizing momentum and energy equations for the particle phase.This approach allows for a detailed analysis of the dynamics and thermodynamics between particles,systematically considering the elastoplastic collision and shear history between particles.Friction,rolling resistance,plastic dissipation,inter-particle heat transfer,and heat transfer between particles and the fluid are regarded as source terms in the energy equation.In this investigation,the deformation behavior and temperature rise process of particle clouds under shock wave impacts are thoroughly discussed.The temporal evolution of particle cloud temperature under shock wave impacts represents a spatiotemporal correlation phenomenon,delineated into two stages:accelerated temperature rise and steady temperature rise,resulting in the formation of symmetric critical hightemperature regions near the cavity perpendicular to the incoming shock wave direction.Notably,during the accelerated temperature rise stage,plastic dissipation,and two-phase heat transfer jointly contribute,whereas during the steady temperature increase stage,heat is primarily provided by two-phase heat transfer.Sustained heat transfer from the high-temperature shock-impacted gas phase to the particle phase acts as the primary mechanism triggering the formation of wide-range high-temperature regions.The role of plastic dissipation is mainly evident in the plastic collisions of particles near the cavity in the early stages.Additionally,we analyze the influence of incoming shock wave Mach numbers on temperature evolution and hot region formation patterns:stronger shock waves lead to quicker completion of the impact process and higher stable average temperatures.Under shock wave impact,the spatiotemporal characteristics of particle clouds differ from the results of the falling process.Prolonged two-phase heat transfer and intense plastic contact among particles near the cavity in the initial stages are factors triggering critical high-temperature regions. 展开更多
关键词 Particle cloud Heat transfer Cavity collapse Temperature rise pattern Dissipation mechanism
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Adaptive beam-shaping enabled high-precision patterned laser micro-grooving
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作者 Pei Qiu Jun Li +3 位作者 Dandan Yuan Zixuan Xin Jiaxu Huang Shaolin Xu 《International Journal of Extreme Manufacturing》 2025年第6期390-402,共13页
Microgrooves with diverse cross-sections are required in various fields but remain a significant challenge in precision machining,especially for hard-to-machine materials.Patterned laser ablation offers an avenue for ... Microgrooves with diverse cross-sections are required in various fields but remain a significant challenge in precision machining,especially for hard-to-machine materials.Patterned laser ablation offers an avenue for fabricating microgrooves on any material with notably enhanced shape diversity.However,it is hard to precisely control the grooves'cross-sectional profiles due to the complex ablation process,including the diffraction-induced energy distribution variations away from the focal plane and the inconsistent polarization-related energy absorption.These factors complicate the relationship between beam spot shape and ablated groove shape,making it challenging to design appropriate spot shapes for specific groove requirements.Here,we propose an adaptive beam-shaping method for laser spot design to improve microgrooves'shape accuracy.Combining laser diffraction and polarization effects,a profile evolution model of the laser ablation is established to accurately predict groove shapes,guiding the iterative beam-shaping procedure.The beam spot shape is iteratively fine-tuned until the deviation between the simulated and the target grooves'profile meets the accuracy requirements.The grooves'profile deviations are significantly reduced,with the final profile's root mean square error decreased to less than 0.5μm when processing microgrooves with a width of 10μm.Various microgrooves with precise cross-sections,including triangles,trapezoids,and functionally contoured micro structures,are achieved by patterned laser direct writing assisted with the adaptive beam-shaping method.This method paves the way for laser ablation of microgrooves with high shape accuracy for traditional hard-to-machine materials. 展开更多
关键词 laser ablation patterned laser adaptive beam-shaping ablation profile evolution MICROGROOVES
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Effects of infill patterns on properties of slurry extrusion-based additive manufactured shell moulds
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作者 Jiao Liu Hong-jun Liu +1 位作者 Guo-liang Su Ya-min Li 《China Foundry》 2025年第5期574-582,共9页
Investment casting shell moulds are widely applied to cast alloys, but how to efficiently form a hierarchical porous structure inside the wall is an innovation and challenge. In this research, porous shell moulds with... Investment casting shell moulds are widely applied to cast alloys, but how to efficiently form a hierarchical porous structure inside the wall is an innovation and challenge. In this research, porous shell moulds with three infill patterns(rectilinear, grid, and honeycomb) were prepared using bauxite slurry and slurry extrusionbased additive manufacturing technology, and the effects of infill patterns on the properties were evaluated. The hierarchical pores inside the wall are composed of the macropores formed by infills and the micropores among bauxite particles. Different infill patterns result in changes in distribution and shape of pores, thereby affecting the properties of the shell moulds. The honeycomb pattern has more comprehensive advantages compared to the other two infill patterns. The samples prepared with the honeycomb pattern exhibit the highest bending strength(11.62 MPa) and porosity(41.6%), as well as good heat-transfer ability, with an average shrinkage rate within 2.0%. This work provides an attractive feasibility for fabricating shell moulds with hierarchical porous walls. 展开更多
关键词 additive manufacturing slurry extrusion infill pattern casting shell mould BAUXITE investment casting
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HCHO and NO_(2) profile characteristics under different synoptic patterns in Shanghai,China
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作者 Yuhan Shi Shanshan Wang +7 位作者 Sanbao Zhang Jiaqi Liu Dan Jin Juntao Huo Ruibin Xue Jian Zhu Chuanqi Gu Bin Zhou 《Journal of Environmental Sciences》 2025年第10期821-834,共14页
Large-scale synoptic patterns significantly affect meteorological conditions and air pollution,yet their impacts on the vertical distribution of formaldehyde(HCHO)and nitrogen dioxide(NO_(2))have been little studied.F... Large-scale synoptic patterns significantly affect meteorological conditions and air pollution,yet their impacts on the vertical distribution of formaldehyde(HCHO)and nitrogen dioxide(NO_(2))have been little studied.From 1 June 2020 to 31 December 2021,Multi-AXis-Differential Optical Absorption Spectroscopy(MAX-DOAS)was used to observe NO_(2) and HCHO vertical profiles in three typical environments of Shanghai,China,representing urban,suburban and coastal rural environments,respectively.HCHO level is the highest at suburban site,NO_(2) is the highest at urban site.HCHO is mainly distributed between 0 and 1 kmin altitude,and NO_(2) is concentrated near the ground.The ratio of HCHO to NO_(2) is used to identify ozone formation regimes,ozone sensitivities vary with environmental area,season and altitude.The principal component analysis in the T-mode approach and typhoon“In-Fa”case is applied to analyze the effects of synoptic patterns on HCHO and NO_(2) vertically.HCHO concentrations show a pattern of low-pressure type>uniform-pressure type>high-pressure type at each altitude layer,while NO_(2) concentrations follow the opposite pattern.Meteorological factors(especially radiation,temperature,relative humidity,cloud cover and wind),external transport and initial emissions contribute to the differences in HCHO and NO_(2) levels across synoptic types.The“In-Fa”case shows how this special synoptic pattern elevates HCHO and NO_(2) levels by improving meteorological conditions,boosting biogenic precursors and shifting air mass directions.This study assesses the impacts of synoptic patterns on HCHO and NO_(2) vertical distribution in Shanghai,offering insights into understanding causes of pollution. 展开更多
关键词 MAX-DOAS HCHO/NO_(2) Ozone sensitivity Synoptic patterns TYPHOON Urban-suburban-coastal rural areas
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The Ecological Code of Landscape Cities:Traditional Feng Shui Patterns for Modern Sustainable Spatial Designs
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作者 Bowen Dong 《Journal of Architectural Research and Development》 2025年第2期14-21,共8页
The traditional Feng Shui pattern embodies rich ecological wisdom and philosophical thoughts,which are of great significance to the modern sustainable space design.The core concepts of Feng Shui patterns from traditio... The traditional Feng Shui pattern embodies rich ecological wisdom and philosophical thoughts,which are of great significance to the modern sustainable space design.The core concepts of Feng Shui patterns from traditional civilization can provide a theoretical foundation and research framework for this study.By integrating these principles,such as“hiding the wind and gathering the Qi”and“backing the mountain and facing the water”,a functional relationship between urban structures can be established.This approach can help optimize the spatial layout of urban elements,minimize energy consumption,and enhance environmental comfort.It also examines the influence of the ShanShui City pattern in traditional Feng Shui on guiding the development of modern urban ecological networks,as well as its role in protecting and restoring biodiversity through ecological corridors and ecological nodes.The modern urban design of traditional Feng Shui culture focuses on the inheritance and innovation of riotous things and the combination of traditional Feng Shui concepts and modern design concepts to form ecological spaces with cultural connotation.This paper hopes to give some inspiration or methods for contemporary urban design and to reconcile the relationship between human and nature through these thoughts. 展开更多
关键词 shanshui City Ecological code Traditional Feng shui pattern Modern sustainable space design Ecological balance
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Evaluation of water quality and water resources carrying capacity using a varying fuzzy pattern recognition model: A case study of small watersheds in Hilly Region
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作者 Su-duan Hu Wen-da Liu +6 位作者 Jun-jian Liu Jiang-Yulong Wang Jun-jie Yang Zhao-yi Li Zhi-yang Tang Guo-qiang Wang Tian-cun Yu 《Journal of Groundwater Science and Engineering》 2025年第4期386-405,共20页
Water scarcity and environment deterioration have become main constraints to sustainable economic and social development.Scientifically assessing Water Resources Carrying Capacity(WRCC)is essential for the optimal all... Water scarcity and environment deterioration have become main constraints to sustainable economic and social development.Scientifically assessing Water Resources Carrying Capacity(WRCC)is essential for the optimal allocation of regional water resources.The hilly area at the northern foot of Yanshan Mountains is a key water conservation zone and an important water source for Beijing,Tianjin and Hebei.Grasping the current status and temporal trends of water quality and WRCC in representative small watersheds within this region is crucial for supporting rational water resources allocation and environment protection efforts.This study focuses on Pingquan City,a typical watershed in northern Hebei Province.Firstly,evaluation index systems for surface water quality,groundwater quality and WRCC were estab-lished based on the Pressure-State-Response(PSR)framework.Then,comprehensive evaluations of water quality and WRCC at the sub-watershed scale were conducted using the Varying Fuzzy Pattern Recogni-tion(VFPR)model.Finally,the rationality of the evaluation results was verified,and future scenarios were projected.Results showed that:(1)The average comprehensive evaluation scores for surface water and groundwater quality in the sub-watersheds were 1.44 and 1.46,respectively,indicating that both met the national Class II water quality standard and reflected a high-quality water environment.(2)From 2010 to 2020,the region's WRCC steadily improved,with scores rising from 2.99 to 2.83 and an average of 2.90,suggesting effective water resources management in Pingquan City.(3)According to scenario-based predic-tion,WRCC may slightly decline between 2025 and 2030,reaching 2.92 and 2.94,respectively,relative to 2020 levels.Therefore,future efforts should focus on strengthening scientific management and promoting the efficient use of water resources.Proactive measures are necessary to mitigate emerging contradiction and ensure the long-term stability and sustainability of the water resources system in the region.The evalua-tion system and spatiotemporal evolution patterns proposed in this study can provide a scientific basis for refined water resource management and ecological conservation in similar hilly areas. 展开更多
关键词 Varying fuzzy pattern recognition model Dynamic assessment Small watershed Water qual-ity evaluation Water resources carrying capacity
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Seismicity patterns and geodynamics of the Hindukush seismic zone:A comprehensive study through relocation of moderate to large earthquakes
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作者 Bilal SAIF Mohammad TAHIR +2 位作者 Muhammad Zafar IQBAL Talat IQBAL Muhammad Ali SHAH 《Journal of Mountain Science》 2025年第5期1768-1785,共18页
The widespread variation of focal depths and fault plane solutions observed in the Hindukush region depicts continuous deformation along the Indian-Eurasian collision zone.For period of twelve years i.e.from 2010 to 2... The widespread variation of focal depths and fault plane solutions observed in the Hindukush region depicts continuous deformation along the Indian-Eurasian collision zone.For period of twelve years i.e.from 2010 to 2022,a total of 89 intermediate-depth earthquakes of magnitude(Mw)≥5.5 of the Hindukush Region were considered,relocated using both regional and tele seismic data with 90 per cent confidence limits of less than 20 km.Two distinct seismic activity clusters:First one at a deeper depth and second at a shallower depth having different P-axes were observed that verifies the internal structure and geometry of Hindukush zone as suggested in previous studies.Beneath the Hindukush collision zone,there exists a complex pattern of deformation,arising from a combination of compression,tension,shearing and necking states due to an unusual and a rare case of subduction that is not from oceanic plate.The Hindukush seismic zone extends from 70 to 300 km depth and mostly strikes east-west and then turns northeast.The relocated seismicity by merging data of seismic network close to Hindukush along with international data shows that the Hindukush zone may be divided vertically into upper and lower slabs separated by a gap at about 150 km depth at which strike and dip directions change sharply with significant structural changes.Seismicity rate is higher in the lower part of Hindukush,having large magnitude events in a small volume below 180 km forming complex pattern of source mechanisms.Contrary in upper part seismicity rate is lower and scattered.The Global CMT(Global Centroid-Moment-Tensor Project)source mechanisms of intermediate depth earthquakes have a systematic pattern of reverse faulting with the vertical T-axes,while shallow events do not have such pattern.The vertical T-axes of the intermediate-depth events may be attributed to negative buoyancy caused by subduction of the cold and denser slab. 展开更多
关键词 Hindukush seismic zone Seismicity gap Earthquake relocations Focal mechanism solutions shear stress Tectonic collision Deformation patterns Subduction zone
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