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Intramolecular carbon isotopic fractionation of propane via thermochemical sulfate reduction(TSR)in natural gas reservoirs
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作者 Peng Liu xiaofeng wang +7 位作者 Hanlin Liu Juske Horita Guoxiao Zhou Hongping Bao Ying Lin Ruiliang Guo Dongdong Zhang Wenhui Liu 《Natural Gas Industry B》 2026年第1期1-8,共8页
Thermochemical sulfate reduction(TSR)is an important organic-inorganic reaction that occurs within sedimentary basins and alters the original chemical compositions and isotopic structures of hydrocarbons in natural ga... Thermochemical sulfate reduction(TSR)is an important organic-inorganic reaction that occurs within sedimentary basins and alters the original chemical compositions and isotopic structures of hydrocarbons in natural gases.We used the GC-Py-GC-IRMS method to study TSR and obtained a novel finding related to intramolecular carbon isotope fractionation in natural propane.The results show that theΔC-T(δ^(13)C_(central)-13 C_(terminal))andδ^(13)C_(central)values significantly increased to 44.7‰and 11.9‰,respectively,with increasing TSR alteration.In contrast,the 13 C_(terminal)values of propane remained largely unaltered by the TSR reaction.This difference in position-specific isotope fractionation can be attributed to the central carbon’s reactivity being higher than that of terminal carbon during TSR.In sum,the results indicate that theδ^(13)C_(terminal)values of propane can serve as robust indicators for source rock identification of natural gas altered by post-generation reactions such as TSR and anaerobic microbial oxidation. 展开更多
关键词 Thermochemical sulfate reduction(TSR) Hydrocarbons PROPANE Position-specific isotope
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基于FDM-3D打印的聚(L-丙交酯-co-ε-己内酯)/聚乳酸共混物管状支架结构制备及其形状记忆特性
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作者 张森 刘雪迪 +5 位作者 王小峰 靳洪燕 张舒雅 蒋晶 宇山浩 李倩 《高分子材料科学与工程》 北大核心 2025年第11期125-135,共11页
聚(L-丙交酯-co-ɛ-己内酯)(PLCL)是一种可生物降解弹性体,其力学强度低,加工性能差,限制了其应用。文中通过加入聚乳酸(PLA)对其进行增强,并对其形状记忆性能进行研究。发现PLA的加入有效改善了PLCL的加工性能和结晶性能,解决了PLCL作... 聚(L-丙交酯-co-ɛ-己内酯)(PLCL)是一种可生物降解弹性体,其力学强度低,加工性能差,限制了其应用。文中通过加入聚乳酸(PLA)对其进行增强,并对其形状记忆性能进行研究。发现PLA的加入有效改善了PLCL的加工性能和结晶性能,解决了PLCL作为柔性材料打印困难的问题。基于3D打印的加工方式得出,PLCL/PLA 8/2具有较高的断裂伸长率和拉伸强度,此时共混物的形状记忆固定率和恢复率均在85%以上。另外,文中对PLCL/PLA 8/2的3D打印管状支架的结构图案对形状记忆功能的影响做了分析,发现正六边形结构支架具有高度对称性和几何稳定性,其形状记忆恢复率最高,这一发现为生物支架的设计奠定了基础。 展开更多
关键词 聚(L-丙交酯-co-ɛ-己内酯) 聚乳酸增强 熔融沉积成型技术3D打印 形状记忆性能
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放疗在初诊晚期食管鳞癌一线治疗中的应用研究进展
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作者 曾海 王小凤 +3 位作者 柏慧 张为家 蔡君(综述) 袁智勇(审校) 《中国肿瘤临床》 北大核心 2025年第11期582-587,共6页
由于食管鳞癌起病隐匿且缺乏早期筛查意识,大量患者初诊时已处于晚期。免疫联合化疗是当前晚期食管鳞癌的一线标准治疗,但患者生存仍面临瓶颈。放疗凭借其精准局部控制能力及潜在的免疫调节作用,有望与免疫联合化疗协同增效,为突破生存... 由于食管鳞癌起病隐匿且缺乏早期筛查意识,大量患者初诊时已处于晚期。免疫联合化疗是当前晚期食管鳞癌的一线标准治疗,但患者生存仍面临瓶颈。放疗凭借其精准局部控制能力及潜在的免疫调节作用,有望与免疫联合化疗协同增效,为突破生存局限提供新方向。本文系统总结放疗在晚期食管鳞癌一线治疗中的发展历程,重点探讨放疗联合免疫化疗的协同机制、临床应用价值及挑战。 展开更多
关键词 食管鳞状细胞癌 放射治疗 免疫化疗 综合治疗
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滇中高原亚热带半湿润常绿阔叶林植物群落多样性特征 被引量:8
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作者 杨涛 沈泽昊 +16 位作者 王晓凤 饶杰生 刘文聪 田希 陈稀 张秋雨 刘倩 钱恒君 解宇阳 刘其明 徐衍潇 涂梦灵 单子铭 张玉坤 侯波 李建斌 欧晓昆 《生物多样性》 CAS CSCD 北大核心 2023年第11期15-28,共14页
森林动态监测样地是研究群落构建和物种多样性维持机制的重要平台。半湿润常绿阔叶林是滇中高原的地带性植被类型。但由于人类活动的长期影响,半湿润常绿阔叶林天然群落当前仅呈片断化状态,零星分布于偏远山地。参照美国史密森热带研究... 森林动态监测样地是研究群落构建和物种多样性维持机制的重要平台。半湿润常绿阔叶林是滇中高原的地带性植被类型。但由于人类活动的长期影响,半湿润常绿阔叶林天然群落当前仅呈片断化状态,零星分布于偏远山地。参照美国史密森热带研究院热带森林研究中心的样地建设标准,我们分别在云南省曲靖珠江源(ZJY)、楚雄雕翎山(DLS)和大理鸡足山(JZS)建立了面积为10 ha (500 m×200 m)、8.24 ha (1个260 m×240 m的小样地和2个100 m×100 m的小样地)和20.16 ha (720 m×280 m)的3个森林动态监测样地。本文以这3个样地的植物群落为研究对象,运用背包式激光雷达、激光测距仪等获取相关基础数据,并对各样地的植物群落进行物种鉴定、区系分析、群落分类及群落结构分析。结果表明:(1) 3个样地共发现维管植物619种,隶属于120科355属,其中珠江源样地70科120属157种,雕翎山样地92科224属319种,鸡足山样地100科255属353种;(2)DBH≥1 cm的木本植物存活个体共有103,951株,其中珠江源样地24,932株、雕翎山样地25,222株、鸡足山样地53,797株,活个体密度分别为2,493.2株/ha、3,060.9株/ha、2,689.9株/ha;(3)样地群内所有维管植物在属和种水平上的温带区系成分合计占比分别为51.3%和24.7%,中国特有种的比例为33.0%;(4)样地群内的植物群落可分为8个群系,分别为元江栲(Castanopsis orthacantha)群系、高山栲(C.delavayi)群系、白穗石栎(Lithocarpus craibianus)群系、滇石栎(L.dealbatus)群系、云南松(Pinus yunnanensis)群系、黄毛青冈(Cyclobalanopsis delavayi)群系、光叶石栎(L.mairei)群系和灰背栎(Quercus senescens)群系;雕翎山样地群系类型最多、珠江源样地最少;(5)鸡足山样地和雕翎山样地乔木树种的径级结构呈倒“J”型,珠江源样地呈单峰型;鸡足山样地在80–100年以前经历过一次局部性的严重干扰,雕翎山样地在50–80年前后经历过一次普遍性的轻中度干扰迹象,珠江源样地在37年前曾经历过一次覆盖性的火干扰,样地间森林群系类型和径级结构的差异主要取决于群落演替程度和地形差异。 展开更多
关键词 滇中高原 半湿润常绿阔叶林 森林动态监测样地 物种组成 群落分类
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苯并噻唑酮类热活化延迟荧光材料的合成及其光电性能研究 被引量:11
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作者 张越华 聂飞 +5 位作者 周路 王晓烽 刘源 霍延平 陈文铖 赵祖金 《有机化学》 SCIE CAS CSCD 北大核心 2023年第11期3876-3887,共12页
以苯并噻唑-2-基(苯基)甲酮作为受体,具有强给电子能力的吩噁嗪和吩噻嗪作为给体构筑给体-受体(D-A)型分子,设计合成了两种具有聚集诱导发光(AIE)特性的热活化延迟荧光(TADF)红光材料3和4,并对它们的热稳定性、电化学性质、单晶结构、... 以苯并噻唑-2-基(苯基)甲酮作为受体,具有强给电子能力的吩噁嗪和吩噻嗪作为给体构筑给体-受体(D-A)型分子,设计合成了两种具有聚集诱导发光(AIE)特性的热活化延迟荧光(TADF)红光材料3和4,并对它们的热稳定性、电化学性质、单晶结构、光物理性质和电致发光性能进行了系统研究.两种化合物具有较小的单三线态能级差(ΔEST,0.04和0.16 eV)以及微秒级延迟寿命(0.63和1.30μs),表现出明显的TADF特性.通过对比化合物在粉末状态下研磨前后的发射光谱,发现化合物4具有明显的力致变色发光现象.在纯薄膜下,两种化合物的发射峰分别为683和654 nm,光致发光量子产率(PLQY)分别为0.8%和3.6%.基于化合物3和4的非掺杂有机发光二极管(OLED)器件,均获得了纯红光发射(662和652 nm),器件的最大外量子效率(EQE)分别为0.15%和0.34%.虽然基于这两种化合物的器件发光效率有待提升,但它们的合成过程简便,能为开发苯并噻唑酮类TADF红光材料提供一定的启发. 展开更多
关键词 聚集诱导发光(AIE)特性 热活化延迟荧光(TADF)红光材料 力致变色发光 苯并噻唑酮类
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Morphotectonic Analyses of LiDAR-Derived DEMs:Insights into Tectonic Activity of the Xinhua Fault within the Three Gorges Area(Central China)
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作者 xiaofeng wang Xiaohan Yin +4 位作者 Tonghui Liu Xuan Li Hongming wang Yaqi Zhong Gang Rao 《Journal of Earth Science》 2025年第2期823-829,共7页
0 INTRODUCTION.The global availability of digital elevation model(DEM)data,such as 90-m Shuttle Radar Topography Mission(SRTM)DEM and 30-m Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital ... 0 INTRODUCTION.The global availability of digital elevation model(DEM)data,such as 90-m Shuttle Radar Topography Mission(SRTM)DEM and 30-m Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model(ASTER GDEM),has been extensively utilized in morphotectonic analyses(e.g.,Wang et al.,2024;Cheng et al.,2018;Pérez-Pe?a et al.,2010;El Hamdouni et al.,2008). 展开更多
关键词 xinhua fault morphotectonic analyses egwang three gorges area digital elevation model aster lidar derived dems tectonic activity morphotectonic analyses digital elevation model dem datasuch
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Near-complete de novo genome assemblies of tomato(Solanum lycopersicum)determinate cultivars Micro-Tom and M82
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作者 Shuangshuang wang Lei Lu +9 位作者 Min Xu Jian Jiang xiaofeng wang Yao Zheng Yitao Liang Tianqi Zhang Minghui Qin Pinkuan Zhu Ling Xu Yina Jiang 《Journal of Genetics and Genomics》 2025年第6期856-859,共4页
Tomato is one of the most essential vegetable crops worldwide,with the highest annual production rate of all agricultural staples(Kimura and Sinha,2008).Long-term domestication of tomatoes has led to the selection of ... Tomato is one of the most essential vegetable crops worldwide,with the highest annual production rate of all agricultural staples(Kimura and Sinha,2008).Long-term domestication of tomatoes has led to the selection of favorable agronomic traits that often come at the expense of stress resistance.To identify potential genetic targets for improved stress tolerance,whole-genome sequencing(WGS)has been applied to wild and cultivated accessions. 展开更多
关键词 TOMATO Solanum lycopersicum determinate cultivars agricultural staples kimura M micro tom selection favorable agronomic traits de novo
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Experimental Study of Hydrogen Distribution in Natural Gas under Static Conditions
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作者 Mengjie wang Jingfa Li +3 位作者 Bo Yu Nianrong wang xiaofeng wang Tao Hu 《Fluid Dynamics & Materials Processing》 2025年第12期3055-3072,共18页
The adaptation of existing natural gas pipelines for hydrogen transportation has attracted increasing attention in recent years.Yet,whether hydrogen and natural gas stratify under static conditions remains a subject o... The adaptation of existing natural gas pipelines for hydrogen transportation has attracted increasing attention in recent years.Yet,whether hydrogen and natural gas stratify under static conditions remains a subject of debate,and experimental evidence is still limited.This study presents an experimental investigation of the concentration distribution of hydrogen–natural gas mixtures under static conditions.Hydrogen concentration was measured using a KTL-2000M-H hydrogen analyzer,with a measurement range of 0–30%(by volume),an accuracy of 1%full scale(FS),and a resolution of 0.01%.Experiments were conducted in a 300 cm riser,filled with uniformly mixed hydrogen–methane standard gas,under various static conditions,including different hydrogen blending ratios(5.03%,10.03%,and 19.79%),pressures(0.5 MPa,2 MPa,and 4 MPa),and inclination angles(0◦,45◦,and 90◦).Results show that,at identical pressures and an inclination angle of 90◦,the presence of hydrogen at both ends of the riser remain nearly the same,indicating that the blending ratio exerts no significant influence on stratification.Moreover,across different pressures,the composition of the mixture remains highly uniform,with the maximum difference between the top and bottom of the riser limited to approximately 0.02%,well within the instrument’s margin of error—demonstrating that pressure has a negligible effect on hydrogen stratification.Similarly,variations in inclination angle exert minimal influence on hydrogen distribution.At 4 MPa,the concentration difference between the top and bottom ranges from 0.01%to 0.02%,confirming the absence of measurable stratification within experimental accuracy. 展开更多
关键词 Hydrogen-blended natural gas hydrogen blending ratio concentration distribution hydrogen stratification RISER inclination angle
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Integrating species diversity, ecosystem services, climate and ecological stability helps to improve spatial representation of protected areas for quadruple win
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作者 Hui Dang Yihe Lü +2 位作者 xiaofeng wang Yunqi Hao Bojie Fu 《Geography and Sustainability》 2025年第1期47-57,共11页
Establishing and maintaining protected areas is a pivotal strategy for attaining the post-2020 biodiversity target. The conservation objectives of protected areas have shifted from a narrow emphasis on biodiversity to... Establishing and maintaining protected areas is a pivotal strategy for attaining the post-2020 biodiversity target. The conservation objectives of protected areas have shifted from a narrow emphasis on biodiversity to encompass broader considerations such as ecosystem stability, community resilience to climate change, and enhancement of human well-being. Given these multifaceted objectives, it is imperative to judiciously allocate resources to effectively conserve biodiversity by identifying strategically significant areas for conservation, particularly for mountainous areas. In this study, we evaluated the representativeness of the protected area network in the Qin ling Mountains concerning species diversity, ecosystem services, climate stability and ecological stability. The results indicate that some of the ecological indicators are spatially correlated with topographic gradient effects. The conservation priority areas predominantly lie in the northern foothills, the southeastern, and southwestern parts of the Qinling Mountain with areas concentrated at altitudes between 1,500-2,000 m and slopes between 40°-50° as hotspots. The conservation priority areas identified through the framework of inclusive conservation optimization account for 22.9 % of the Qinling Mountain. Existing protected areas comprise only 6.1 % of the Qinling Mountain and 13.18 % of the conservation priority areas. This will play an important role in achiev ing sustainable development in the region and in meeting the post-2020 biodiversity target. The framework can advance the different objectives of achieving a quadruple win and can also be extended to other regions. 展开更多
关键词 Protected areas Nature conservation Ecological representation Qinling Mountains Spatial planning
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stu-miR159a negatively regulates anthocyanin-specific MYB transcription factor to mediate drought stress tolerance in potato
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作者 Yurong Deng Jiangwei Yang +5 位作者 Jingjing Wei Shengyan Liu Liang Yang xiaofeng wang Ning Zhang Huaijun Si 《Horticultural Plant Journal》 2025年第5期1917-1929,共13页
MicroRNAs(miRNAs) are a class of small endogenous non-coding RNAs that direct post-transcriptional gene silencing.In plants,numerous miRNAs have been demonstrated to be regulated under drought-induced stress.However,t... MicroRNAs(miRNAs) are a class of small endogenous non-coding RNAs that direct post-transcriptional gene silencing.In plants,numerous miRNAs have been demonstrated to be regulated under drought-induced stress.However,the role of miRNAs in drought regulation remains unclear in potato.In this work,the function of stu-miR159a was investigated in responding to drought stress in potato.Upon examination,StGAMyb-like1 was identified as the target gene for stu-miR159a.Overexpression of stu-miR159a(stu-miR159a OE plants) increased sensitivity to drought,interference with stu-miR159a activity by target mimics(stu-miR159a ST plants) resulted in drought resistance.During drought treatment,the target gene StGAMyb-like1 showed increased activation in stu-miR159a ST plants compared to non-transgenic plants.In contrast,drought stress induced weaker activation of the target gene in stu-miR159a OE plants.In stu-miR159a ST plants,the expression of critical genes in the anthocyanin biosynthesis pathway(StF3'5'H,StF3'H and StCHS2)was increased by decreasing stu-miR159a activity and simultaneously increasing that of StGAMyb-like1.Meanwhile,with drought treatment,stu-miR159a ST plants exhibited higher anthocyanin accumulation than non-transgenic ones,indicating enhanced antioxidant capacity and improved drought tolerance.The above data support that stu-miR159a is a negative regulator of drought stress and provide new insights into the stu-miR159a-mediated regulation of the anthocyanin biosynthesis pathway in controlling drought tolerance in potato. 展开更多
关键词 POTATO miR159-GAMYB pathway Drought ANTHOCYANIN Antioxidant activity
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Beyond gold:the chemoenhancing mechanism and therapeutic potential of auranofin in melanoma
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作者 xiaofeng wang Yingnan Liu +8 位作者 Wuqiong Zhang Zhongda Li Su Li Jiaxin Chen Qi Li Xiaoman Suo Yanqiao Zeng Guofang Zhang Yang Li 《Cancer Biology & Medicine》 2025年第6期672-689,共18页
Objective:The objective of the current study was to evaluate the chemosensitizing capacity of auranofin(AF),a gold(I)complex traditionally used in rheumatoid arthritis treatment,in potentiating the cytotoxic effects o... Objective:The objective of the current study was to evaluate the chemosensitizing capacity of auranofin(AF),a gold(I)complex traditionally used in rheumatoid arthritis treatment,in potentiating the cytotoxic effects of doxorubicin(DOX)in melanoma cell models,specifically drug-sensitive(B16F10)and multidrug-resistant(B16F10/ADR)variants.Methods:Experimental measurements,including in vitro cytotoxicity and apoptosis assays,surface plasmon resonance(SPR),immunoblotting assays,as well as theoretical calculations,such as molecular docking and molecular dynamics(MD)simulations,were used to systematically delineate the interaction dynamics between AF and thioredoxin reductase 1(TrxR1).The anti-tumor efficacy of co-treatment with AF and DOX was assessed by examining cell viability and apoptotic rates.Results:Co-treatment with AF and DOX significantly increased anti-tumor efficacy,as evidenced by reduced cell viability and increased apoptotic rates.This synergistic effect was attributed to inhibition of TrxR1 by AF,which compromised tumor cell antioxidant defenses and elevated intracellular reactive oxygen species(ROS),thereby enhancing apoptotic pathways.Notably,AF treatment mitigated the heightened TrxR activity in DOX-resistant cells,intensifying the pro-oxidant effects of DOX,leading to increased ROS production and cell death.The data also showed that AF binds with high affinity to the selenocysteine residue within the catalytic site of TrxR1,which partially overlapped with the binding site of the endogenous substrate,thioredoxin(Trx),but with greater avidity.This unique binding configuration impedes the reduction of Trx by TrxR1,triggering an apoptotic response in cancer cells.Conclusions:This study underscores the chemosensitizing potential of AF in overcoming multidrug resistance in cancer therapy through redox modulation.The molecular mechanism of action underlying AF on TrxR1 demonstrated the unique binding configuration that impedes the reduction of Trx by TrxR1 and instigates an apoptotic response in cancer cells.These findings pave the way for the clinical application of AF as a chemosensitizer,offering a novel approach to augment the efficacy of existing chemotherapy regimens. 展开更多
关键词 AURANOFIN TrxR1 ANTI-CANCER drug resistance molecular dynamics simulation
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Pressure sensor with wide detection range and high sensitivity for wearable human health monitoring
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作者 Lingchen Liu Ying Yuan +4 位作者 Hao Xu Xiaokun Qin xiaofeng wang Zheng Lou Lili wang 《Journal of Semiconductors》 2025年第4期72-79,共8页
High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneous... High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces.However,the development of flexible pressure sensors that simultaneously achieve high sensitivity,a wide detection range,and good mechanical stability remains a challenge.In this paper,we propose a flexible piezoresistive pressure sensor based on a Ti_(3)C_(2)Tx(MXene)/polyethylene oxide(PEO)composite nanofiber membrane(CNM).The sensor,utilizing MXene(0.4 wt%)/PEO(5 wt%),exhibits high sensitivity(44.34 kPa^(−1)at 0−50 kPa,12.99 kPa^(−1)at 50−500 kPa)and can reliably monitor physiological signals and other subtle cues.Moreover,the sensor features a wide detection range(0−500 kPa),fast response and recovery time(~150/45 ms),and excellent mechanical stability(over 10000 pressure cycles at maximum load).Through an MXene/PEO sensor array,we demonstrate its applications in human physiological signal monitoring,providing a reliable way to expand the application of MXene-based flexible pressure sensors. 展开更多
关键词 flexible pressure sensor wide detection range high sensitivity pulse wave detection
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SMNDNet for Multiple Types of Deepfake Image Detection
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作者 Qin wang xiaofeng wang +3 位作者 Jianghua Li Ruidong Han Zinian Liu Mingtao Guo 《Computers, Materials & Continua》 2025年第6期4607-4621,共15页
The majority of current deepfake detection methods are constrained to identifying one or two specific types of counterfeit images,which limits their ability to keep pace with the rapid advancements in deepfake technol... The majority of current deepfake detection methods are constrained to identifying one or two specific types of counterfeit images,which limits their ability to keep pace with the rapid advancements in deepfake technology.Therefore,in this study,we propose a novel algorithm,StereoMixture Density Network(SMNDNet),which can detect multiple types of deepfake face manipulations using a single network framework.SMNDNet is an end-to-end CNNbased network specially designed for detecting various manipulation types of deepfake face images.First,we design a Subtle Distinguishable Feature Enhancement Module to emphasize the differentiation between authentic and forged features.Second,we introduce aMulti-Scale Forged Region AdaptiveModule that dynamically adapts to extract forged features from images of varying synthesis scales.Third,we integrate a Nonlinear Expression Capability Enhancement Module to augment the model’s capacity for capturing intricate nonlinear patterns across various types of deepfakes.Collectively,these modules empower our model to efficiently extract forgery features fromdiverse manipulation types,ensuring a more satisfactory performance in multiple-types deepfake detection.Experiments show that the proposed method outperforms alternative approaches in detection accuracy and AUC across all four types of deepfake images.It also demonstrates strong generalization on cross-dataset and cross-type detection,along with robust performance against post-processing manipulations. 展开更多
关键词 Convolutional neural network deepfake detection generative adversarial network feature enhancement
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Correction:Efficacy of Intravenous Treprostinil in High-Risk Single Ventricle Patients Undergoing Glenn Procedure
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作者 xiaofeng wang Xingwei Chen +4 位作者 Shilin wang Xia Li Zhongyuan Lu Wenlong wang Xu wang 《Congenital Heart Disease》 2025年第3期401-402,共2页
In the article“Efficacy of Intravenous Treprostinil in High-Risk Single Ventricle Patients Undergoing Glenn Procedure”by Xiaofeng Wang,Xingwei Chen,Shilin Wang,Xia Li,Zhongyuan Lu,Wenlong Wang,Xu Wang(Congenital Hea... In the article“Efficacy of Intravenous Treprostinil in High-Risk Single Ventricle Patients Undergoing Glenn Procedure”by Xiaofeng Wang,Xingwei Chen,Shilin Wang,Xia Li,Zhongyuan Lu,Wenlong Wang,Xu Wang(Congenital Heart Disease,2024,vol.19,no.5,pp.489-498.DOI:10.32604/chd.2024.054441,URL:https://www.techscience.com/chd/v19n5/59166). 展开更多
关键词 intravenous treprostinil glenn procedure high risk single ventricle patients Glenn procedure
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Experimental study on the dynamic response of HSTM under combined shock waves and sub-millimeter particle swarms loading
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作者 RuiJun Fan xiaofeng wang +3 位作者 ShaoHong wang JinYing wang He Huang AiGuo Pi 《Defence Technology(防务技术)》 2025年第10期230-248,共19页
Low collateral damage weapons achieve controlled personnel injury through the coupling of shock waves and particle swarms,where the particle swarms arise from the high-explosive dispersion of compacted metal particle ... Low collateral damage weapons achieve controlled personnel injury through the coupling of shock waves and particle swarms,where the particle swarms arise from the high-explosive dispersion of compacted metal particle ring.To investigate the dynamic response of the human target under combined shock waves and particle swarms loading,a physical human surrogate torso model(HSTM)was developed,and the dynamic response test experiment was conducted under the combined loading.The effects of particle size on the loading parameters,the damage patterns of the ballistic plate and HSTM,and the dynamic response parameters of the HSTM with and without protection are mainly analyzed.Our findings revealed that particle swarms can effectively delay the shock wave attenuation,especially the best effect when the particle size was 0.28–0.45 mm.The ballistic plate mainly exhibited dense perforation of the outer fabric and impacted crater damage of ceramic plates,whereas the unprotected HSTM was mainly dominated by high-density and small-size ballistic cavity group damage.The peak values of the dynamic response parameters for the HSTM under combined loading were significantly larger than those under bare charge loading,with multiple peaks observed.Under unprotected conditions,the peak acceleration of skeletons and peak pressure of organs increased with the particle size.Under protected conditions,the particle size,the number of particles hit,and the fit of the ballistic plate to the HSTM together affected the dynamic response parameters of the HSTM. 展开更多
关键词 Low collateral damage Particle swarms Dynamic response Human surrogate torso model
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中国中亚热带常绿阔叶林群落木本植物多样性比较 被引量:7
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作者 王晓凤 米湘成 +4 位作者 王希华 江明喜 杨涛 张健 沈泽昊 《生物多样性》 CAS CSCD 北大核心 2023年第11期3-14,共12页
常绿阔叶林是我国亚热带的地带性植被类型,也是我国最重要的植被类型之一。常绿阔叶林植被型下各种群落类型的物种组成、结构、动态等特征已有大量研究,本研究基于浙江的天童和古田山、湖南的八大公山以及云南的珠江源、雕翎山和鸡足山... 常绿阔叶林是我国亚热带的地带性植被类型,也是我国最重要的植被类型之一。常绿阔叶林植被型下各种群落类型的物种组成、结构、动态等特征已有大量研究,本研究基于浙江的天童和古田山、湖南的八大公山以及云南的珠江源、雕翎山和鸡足山6个大型常绿阔叶林动态监测样地的调查数据,对其木本植物的物种组成、区系成分、生长型类型百分比、种–面积关系进行了综合比较,以期进一步了解中国中亚热带常绿阔叶林在东、中、西部地区的物种多样性差异。结果显示:(1)中国中亚热带中部的八大公山样地物种的科、属、种丰富度最高,其次为东部的天童和古田山样地,而西部的珠江源、雕翎山和鸡足山样地的丰富度最低,相同植被类型样地的物种组成相似性最高,东、中、西部的常绿阔叶林植被的物种组成存在显著的差异;(2)东部样地木本植物的科、属均以热带区系为主,尤其泛热带分布的科、属最多,而中、西部样地虽然以热带科为主,但以温带属居多,北温带分布属最多;(3)东、中部3个样地木本植物以乔木成分为主,天童、古田山和八大公山样地乔木种比例分别是57.4%、51.6%和55.9%,西部样地灌木(珠江源、雕翎山和鸡足山样地分别是56.9%、54.2%、48.5%)成分均高于乔木(43.1%、41.7%、42.7%),中部样地木本植物落叶种(59.2%)占比远高于常绿种(40.8%),东、西部样地则是常绿种比例高于落叶种,天童、古田山、珠江源、雕翎山、鸡足山样地常绿种比例分别是51.3%、59.1%、62.7%、69.8%、58.3%;(4)八大公山和雕翎山样地的常绿种(分别有97种和67种)和落叶种(141种,29种)在数量上差距最大,雕翎山和珠江源样地的常绿种(69.8%,62.7%)和落叶种(30.2%,37.3%)在比例上差距最大。上述研究结果反映了中国中亚热带典型常绿阔叶林、山地常绿落叶阔叶混交林、半湿润常绿阔叶林的群落物种组成、物种多样性和群落结构的差异,为指示中亚热带常绿阔叶林植被从东到西的物种周转特征和植被变化规律提供了科学依据。 展开更多
关键词 动态监测样地 物种组成 区系成分 生长型 种–面积曲线
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云南鸡足山半湿润常绿阔叶林群落木本植物多样性格局与环境解释 被引量:6
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作者 王晓凤 饶杰生 +10 位作者 杨涛 刘文聪 田希 陈稀 刘其明 徐衍潇 张秋雨 张洪强 张旭 欧晓昆 沈泽昊 《生物多样性》 CAS CSCD 北大核心 2023年第11期29-44,共16页
生物多样性格局是生物群落构建过程的反映,有助于理解生态系统的物种共存机制。半湿润常绿阔叶林是亚热带西部半湿润气候下的地带性植被类型,对其群落内物种多样性的空间异质格局及影响因子的认识还比较缺乏,基于大样地的研究还未见报... 生物多样性格局是生物群落构建过程的反映,有助于理解生态系统的物种共存机制。半湿润常绿阔叶林是亚热带西部半湿润气候下的地带性植被类型,对其群落内物种多样性的空间异质格局及影响因子的认识还比较缺乏,基于大样地的研究还未见报道。本文基于鸡足山20.16 ha森林动态监测样地504个样方的木本植物调查数据和TWINSPAN群落分类结果,分析了样方尺度上α多样性和β多样性的空间分布格局及其环境影响因子。结果表明:(1)样地内云南松(Pinus yunnanensis)群落及其乔木和灌木的物种丰富度均高于高山栲(Castanopsisdelavayi)群落和元江栲(C.orthacantha)群落;高山栲群落及其灌木物种丰富度低于元江栲群落,乔木物种丰富度则高于元江栲群落。相反,元江栲群落的Shannon-Wiener多样性指数最高,其次为高山栲群落,云南松群落的最低。基于净种间亲缘关系指数,元江栲群落、高山栲群落、云南松群落的谱系结构分别为聚集、随机、发散。(2)对物种丰富度存在普遍性影响的因子有土壤总氮、pH值、相对海拔高度、木本植物的胸高断面积之和;导致乔木种丰富度变化的主要因子有土壤总氮、pH值、胸高断面积之和;导致灌木种丰富度变化的主要因子是相对海拔高度、土壤总氮、坡度和地形湿度指数。(3)物种β多样性格局显示,随着空间距离和环境距离的增大,物种差异性和物种周转率增大,即环境越相似,群落越相似。上述结果表明,鸡足山样地中先锋性的云南松群落与稳定的元江栲群落和高山栲群落在物种多样性和构成上存在显著差异,指示了半湿润常绿阔叶林异质斑块所对应的物种共存和物种多样性维持特征,为进一步的机理性研究提供了有效证据。 展开更多
关键词 鸡足山 Α多样性 Β多样性 环境因子 地理加权回归模型 Mantel检验
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杂原子掺杂石墨烯的制备及其作为超级电容器电极材料 被引量:5
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作者 吴云鹏 王晓峰 +2 位作者 李本仙 赵旭东 刘晓旸 《化学进展》 SCIE CAS CSCD 北大核心 2023年第7期1005-1017,共13页
石墨烯具有比表面积大、导电性高等特点,在电化学储能领域得到了广泛的关注。然而其作为电极材料时体积能量密度较低,因此在应用中存在着一定的困难。杂原子掺杂是一种提高石墨烯电化学性质的有效手段,可以增强石墨烯作为电极材料时的... 石墨烯具有比表面积大、导电性高等特点,在电化学储能领域得到了广泛的关注。然而其作为电极材料时体积能量密度较低,因此在应用中存在着一定的困难。杂原子掺杂是一种提高石墨烯电化学性质的有效手段,可以增强石墨烯作为电极材料时的储能性能。本文概述了杂原子掺杂石墨烯的制备方法,介绍了不同种类的杂原子掺杂对石墨烯电化学性质的影响,及其应用于超级电容器的代表性工作,最后展望了该研究领域未来的发展方向。 展开更多
关键词 石墨烯 杂原子掺杂 超级电容器 能量储存
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基于背包LiDAR的半湿润常绿阔叶林及其常见树种的垂直结构特征 被引量:9
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作者 饶杰生 杨涛 +4 位作者 田希 刘文聪 王晓凤 钱恒君 沈泽昊 《生物多样性》 CAS CSCD 北大核心 2023年第11期45-55,共11页
森林的垂直结构是地上植被要素在垂直方向上的排列,它影响动植物多样性和生态系统功能,是许多植物生态学家关注的重点。背包激光雷达技术的发展为大面积、高精度扫描三维森林结构提供了基础。直观反映生物量的冠层高度(canopy height,CH... 森林的垂直结构是地上植被要素在垂直方向上的排列,它影响动植物多样性和生态系统功能,是许多植物生态学家关注的重点。背包激光雷达技术的发展为大面积、高精度扫描三维森林结构提供了基础。直观反映生物量的冠层高度(canopy height,CH)、代表植物光合能力的叶面积指数(leaf area index,LAI)和单木尺度上的特征是森林垂直结构最重要的参数。本研究旨在探索鸡足山半湿润常绿阔叶林样地尺度和单木尺度上的垂直结构特征。本研究基于背包激光雷达,对滇中高原20.16 ha半湿润常绿阔叶林样地群落的CH和LAI进行了精细扫描和点云定量分析,在进行地形校正和群落分类的基础上,精细提取和分析了森林群落的叶面积指数的垂直变化和水平格局,并定量提取了群落常见乔木种的单木形态和垂直结构参数。结果显示:(1)以20 m×20 m标准样方为统计单位的CH和LAI的分布接近正态分布;(2)根据LAI的垂直分布,森林动态监测样地群落冠层由上至下可划分为林冠上层、林冠中层、林冠下层与灌木层4个层次;(3)元江栲(Castanopsisorthacantha)和高山栲(C.delavayi)群落的LAI垂直变化呈单峰格局,峰值高度分别为15m和13m,云南松(Pinusyunnanensis)群落为双峰格局,峰值高度为5 m和10 m;(4)不同树种的各单木参数表现出较大的差异性,但冠幅面积/胸径比表现出相对的稳定性。本研究在国内首次基于激光雷达技术定量分析具有复杂结构的半湿润常绿阔叶林的叶面积指数的三维格局,或可对以后该类型森林生物多样性的研究和不同森林类型之间的比较研究提供数据基础。 展开更多
关键词 半湿润常绿阔叶林 垂直结构 叶面积指数 冠层高度 背包激光雷达 单木
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云南鸡足山半湿润常绿阔叶林优势树种的种群结构与更新特征 被引量:3
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作者 刘文聪 田希 +7 位作者 杨涛 饶杰生 王晓凤 钱恒君 涂梦灵 单子铭 欧晓昆 沈泽昊 《生物多样性》 CAS CSCD 北大核心 2023年第11期71-81,共11页
亚热带半湿润常绿阔叶林是中国西南地区独特的森林类型,研究群落优势种更新的时空格局和策略对理解其动态特征和驱动机制具有重要意义。基于云南鸡足山半湿润常绿阔叶林动态监测样地第一次群落调查数据,我们对5个优势树种的幼苗、幼树... 亚热带半湿润常绿阔叶林是中国西南地区独特的森林类型,研究群落优势种更新的时空格局和策略对理解其动态特征和驱动机制具有重要意义。基于云南鸡足山半湿润常绿阔叶林动态监测样地第一次群落调查数据,我们对5个优势树种的幼苗、幼树数量特征进行统计,比较其种群结构,用概率密度函数g(r)分析了更新种群与成树种群的多尺度空间格局,运用普通最小二乘回归模型和多尺度地理加权回归模型评估了优势树种更新密度的影响因素。结果表明:(1)阔叶树种元江栲(Castanopsis orthacantha)、高山栲(C.delavayi)、银木荷(Schima argentea)以及白穗石栎(Lithocarpus craibianus)具有增长型种群的径级结构;而针叶树种云南松(Pinus yunnanensis)种群具有衰退型种群结构。(2)5个优势树种的更新种群与成树种群格局在小尺度(0–50 m)上均呈聚集分布,随着尺度增大聚集强度下降,转为随机分布或均匀分布。其中4个阔叶树种更新种群和成树种群的分布在小尺度上显著正关联,而云南松的更新种群与成树种群分布呈显著负关联。(3)对于种群更新密度变化,多尺度地理加权回归模型对幼苗和幼树的解释量(R~2)比普通最小二乘回归模型分别提升了58.7%和26.9%,显示了空间自相关的影响。模型结果表明,幼苗密度格局受生境因子的限制较弱,而受种子扩散等随机过程的影响更大;相对地,幼树密度格局受生境因子的限制更强。研究结果为理解这一植物群落类型的动态和构建机制提供了科学证据。 展开更多
关键词 半湿润常绿阔叶林 径级结构 空间结构 天然更新 影响因子
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