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A study of the soil water potential threshold values to trigger irrigation of ‘Shimizu Hakuto’ peach at pivotal fruit developmental stages
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作者 Yusui Lou Yuepeng Han +4 位作者 Yubin Miao Hongquan Shang Zhongwei Lv Lei wang shiping wang 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期376-386,共11页
Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established man... Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established manly based on the effects of water deficits on final fruit quality.Few studies have focused on the real-time effects of water status on fruit and shoot growth.To establish soil water potential (ψ_(soil)) thresholds to trigger irrigation of peach at pivotal fruit developmental stages,photogrammetry,^(13)C labelling,and other techniques were used in this study to investigate real-time changes in stem diameter,fruit projected area,net leaf photosynthetic rate (P_(n)),and allocation of photoassimilates to fruit under soil water potential conditions ranging from saturation to stress in 6-year-old Shimizu hakuto’peach.Stem growth,fruit growth,and P_n exhibited gradually decreasing sensitivity to water deficits during fruit developmental stages I,II,and III.Stem diameter growth was significantly inhibited whenψ_(soil)dropped to-8.5,-7.6,and-5.4 k Pa,respectively.Fruit growth rate was low,reaching zero when theψ_(soil)was-9.0 to-23.1,-14.9 to-21.4,and-16.5 to-23.3 k Pa,respectively,and P_ndecreased significantly when theψ_(soil)reached-24.2,-22.7,and-20.4 kPa,respectively.In addition,more photoassimilates were allocated to fruit under moderateψ_(soil)conditions (-10.1 to-17.0 k Pa) than under otherψ_(soil)values.Our results revealed threeψ_(soil)thresholds,-10.0,-15.0,and-15.0 kPa,suitable for triggering irrigation during stages I,II,and III,respectively.These thresholds can be helpful for controlling excessive tree vigor,maintaining rapid fruit growth and leaf photosynthesis,and promoting the allocation of more photoassimilates to fruit. 展开更多
关键词 PEACH Soil water potential Irrigation threshold Fruit expansion PHOTOSYNTHESIS
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Numerical Investigation of the Angle of Attack Effect on Cloud Cavitation Flow around a Clark-Y Hydrofoil
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作者 Di Peng Guoqing Chen +1 位作者 Jiale Yan shiping wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2947-2964,共18页
Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering,predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater vehic... Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering,predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater vehicles.The re-entrant jet and compression wave resulting from the collapse of cavity vapour are pivotal factors contributing to cavity instability.Concurrently,these phenomena significantly modulate the evolution of cavitation flow.In this paper,numerical investigations into cloud cavitation over a Clark-Y hydrofoil were conducted,utilizing the Large Eddy Simulation(LES)turbulence model and the Volume of Fluid(VOF)method within the OpenFOAM framework.Comparative analysis of results obtained at different angles of attack is undertaken.A discernible augmentation in cavity thickness is observed concomitant with the escalation in attack angle,alongside a progressive intensification in pressure at the leading edge of the hydrofoil,contributing to the suction force.These results can serve as a fundamental point of reference for gaining a deeper comprehension of cloud cavitation dynamics. 展开更多
关键词 Cloud cavitation re-entrant jet compression wave clark-Y hydrofoil
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Conditional selection with CNN augmented transformer for multimodal affective analysis
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作者 Jianwen wang shiping wang +3 位作者 Shunxin Xiao Renjie Lin Mianxiong Dong Wenzhong Guo 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第4期917-931,共15页
Attention mechanism has been a successful method for multimodal affective analysis in recent years. Despite the advances, several significant challenges remain in fusing language and its nonverbal context information.... Attention mechanism has been a successful method for multimodal affective analysis in recent years. Despite the advances, several significant challenges remain in fusing language and its nonverbal context information. One is to generate sparse attention coefficients associated with acoustic and visual modalities, which helps locate critical emotional se-mantics. The other is fusing complementary cross‐modal representation to construct optimal salient feature combinations of multiple modalities. A Conditional Transformer Fusion Network is proposed to handle these problems. Firstly, the authors equip the transformer module with CNN layers to enhance the detection of subtle signal patterns in nonverbal sequences. Secondly, sentiment words are utilised as context conditions to guide the computation of cross‐modal attention. As a result, the located nonverbal fea-tures are not only salient but also complementary to sentiment words directly. Experi-mental results show that the authors’ method achieves state‐of‐the‐art performance on several multimodal affective analysis datasets. 展开更多
关键词 affective computing data fusion information fusion multimodal approaches
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钾改性氧化铝基羰基硫水解催化剂及其失活机理 被引量:2
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作者 雷淦昌 郑勇 +5 位作者 曹彦宁 沈丽娟 王世萍 梁诗景 詹瑛瑛 江莉龙 《物理化学学报》 SCIE CAS CSCD 北大核心 2023年第9期109-118,共10页
天然气、油田伴生气、高炉煤气等化工生产过程中伴生COS气体,不仅会腐蚀管道和毒害催化剂,还会严重污染环境并危害人类健康。COS催化水解反应可在温和条件下高效的将COS脱除,是最具应用前景的COS脱除技术之一。碱金属元素因其具有独特... 天然气、油田伴生气、高炉煤气等化工生产过程中伴生COS气体,不仅会腐蚀管道和毒害催化剂,还会严重污染环境并危害人类健康。COS催化水解反应可在温和条件下高效的将COS脱除,是最具应用前景的COS脱除技术之一。碱金属元素因其具有独特的电子供体性质、表面碱性和静电吸附等特性,常被用作助催化剂以提高Al_(2)O_(3)的COS催化水解性能。近年来,以钾为助剂改性的Al_(2)O_(3)催化剂(K_(2)CO_(3)/Al_(2)O_(3))在COS催化水解反应中得到广泛的应用,但由于负载在Al_(2)O_(3)上的K物种的组成复杂,目前研究者对K_(2)CO_(3)/Al_(2)O_(3)催化剂上COS水解机理的理解仍存在一定的困惑和争议。本论文通过湿法浸渍法合成出一系列钾盐和钠盐改性的Al_(2)O_(3)催化剂,并利用各类先进的表征技术对这些催化剂进行分析。活性测试表明,以K_(2)CO_(3)、K_(2)C_(2)O_(4)、NaHCO_(3)、Na_(2)CO_(3)和NaC2O4改性Al_(2)O_(3)催化剂均有助于COS的水解。其中K_(2)CO_(3)/Al_(2)O_(3)拥有最佳的COS水解性能,连续运行20 h后其COS转化率仍高于~93%,远远优于未改性的Al_(2)O_(3)(~58%)。我们利用原位红外光谱和X射线光电子能谱探明了反应过程中催化剂的化学结构特征,阐明了H_(2)O分子在K_(2)CO_(3)/Al_(2)O_(3)上的水解作用机制。原位红外表明COS在K_(2)CO_(3)/Al_(2)O_(3)上的水解过程中形成了硫代碳酸氢盐中间产物。X射线光电子能谱表征证明催化剂的失活主要是因为催化剂表面积累了硫酸盐和单质硫。此外,我们还研究了水蒸气含量对COS水解性能的影响,研究发现,由于H_(2)O和COS分子在催化剂表面存在竞争吸附,过量的H_(2)O会引起催化活性的下降。上述研究表明,K_(2)CO_(3)/Al_(2)O_(3)催化剂上COS水解性能的提高主要是形成了HO-Al-O-K界面活性位。更为重要的是,所制备的催化剂都是在模拟工业工况条件下进行的,这为后续的工业应用提供了宝贵理论指导。本工作为理解助剂钾在Al_(2)O_(3)催化剂上COS水解活性的增强提供了新的见解,这为未来设计稳定高效的COS水解催化剂打开了新的发展方向。 展开更多
关键词 羰基硫 催化水解 HO-Al-O-K界面活性位点 失活机理 工业工况条件
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快速HE染色在周围型肺癌穿刺活检快速现场细胞学评价中的应用 被引量:2
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作者 何剑 夏桂兰 +1 位作者 王世平 陈锟 《中国肺癌杂志》 CAS CSCD 北大核心 2023年第8期572-578,共7页
背景与目的快速现场评价(rapid on-site evaluation,ROSE)是在活检术中同步实施的标本快速细胞学染色和评价技术。迪夫(Diff-Quik,DQ)染色是快速现场细胞学评价(cytological ROSE,C-ROSE)最常用的染色方法,但国内大部分病理医生不使用D... 背景与目的快速现场评价(rapid on-site evaluation,ROSE)是在活检术中同步实施的标本快速细胞学染色和评价技术。迪夫(Diff-Quik,DQ)染色是快速现场细胞学评价(cytological ROSE,C-ROSE)最常用的染色方法,但国内大部分病理医生不使用DQ染色进行现场细胞学判读,因此难以开展C-ROSE。本研究拟在周围型肺癌穿刺活检过程中分别使用快速苏木素-伊红(hematoxylin-eosin,HE)染色和DQ染色进行C-ROSE,评估快速HE染色在C-ROSE中的应用价值。方法对300例术前拟诊周围型肺癌患者实施胸部计算机断层扫描(computed tomography,CT)引导肺活检,随机分成两组且分别使用快速HE染色和DQ染色,进行C-ROSE判读,并对两种染色方法进行比较和评价。结果C-ROSE与组织病理诊断符合率为96.7%。快速HE染色的中位时间为160 s,而DQ染色为120 s,两组存在统计学差异(P<0.001)。但两组的肺活检时间、组织病理符合率、细胞学标本脱片率和严重不良反应发生率均无统计学差异(P>0.05)。结论在周围型肺癌活检过程中,两种染色方法均能满足C-ROSE要求,快速HE染色可应用于C-ROSE,且更符合国内临床需求,具有潜在的推广价值。 展开更多
关键词 肺肿瘤 周围型肺癌 CT引导肺活检 快速现场细胞学评价 快速HE染色
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Chromosome-scale genome assembly of Prunus pusilliflora provides novel insights into genome evolution, disease resistance, and dormancy release in Cerasus L. 被引量:1
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作者 Songtao Jiu Baozheng Chen +23 位作者 Xiao Dong Zhengxin Lv Yuxuan wang Chunjin Yin Yan Xu Sen Zhang Jijun Zhu Jiyuan wang Xunju Liu Wanxia Sun Guoqian Yang Meng Li Shufeng Li Zhuo Zhang Ruie Liu Lei wang Muhammad Aamir Manzoor Quero-García José shiping wang Yahui Lei Ling Yang Elisabeth Dirlewanger Yang Dong Caixi Zhang 《Horticulture Research》 SCIE CSCD 2023年第5期220-235,共16页
Prunus pusilliflora is a wild cherry germplasm resource distributed mainly in Southwest China.Despite its ornamental and economic value,a high-quality assembled P.pusilliflora genome is unavailable,hindering our under... Prunus pusilliflora is a wild cherry germplasm resource distributed mainly in Southwest China.Despite its ornamental and economic value,a high-quality assembled P.pusilliflora genome is unavailable,hindering our understanding of its genetic background,population diversity,and evolutionary processes.Here,we de novo assembled a chromosome-scale P.pusilliflora genome using Oxford Nanopore,Illumina,and chromosome conformation capture sequencing.The assembled genome size was 309.62 Mb,with 76 scaffolds anchored to eight pseudochromosomes.We predicted 33035 protein-coding genes,functionally annotated 98.27%of them,and identified repetitive sequences covering 49.08%of the genome.We found that P.pusilliflora is closely related to Prunus serrulata and Prunus yedoensis,having diverged from them∼41.8 million years ago.A comparative genomic analysis revealed that P.pusilliflora has 643 expanded and 1128 contracted gene families.Furthermore,we found that P.pusilliflora is more resistant to Colletotrichum viniferum,Phytophthora capsici,and Pseudomonas syringae pv.tomato(Pst)DC3000 infections than cultivated Prunus avium.P.pusilliflora also has considerably more nucleotide-binding site-type resistance gene analogs than P.avium,which explains its stronger disease resistance.The cytochrome P450 and WRKY families of 263 and 61 proteins were divided into 42 and 8 subfamilies respectively in P.pusilliflora.Furthermore,81 MADS-box genes were identified in P.pusilliflora,accompanying expansions of the SVP and AGL15 subfamilies and loss of the TM3 subfamily.Our assembly of a high-quality P.pusilliflora genome will be valuable for further research on cherries and molecular breeding. 展开更多
关键词 PRUNUS resistance RELEASE
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Emerging Negative Warming Impacts on Tibetan Crop Yield 被引量:3
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作者 Tsechoe Dorji Shilong Piao +5 位作者 Xuhui wang Chuang Zhao Baohua Liu Anping Chen shiping wang Tao wang 《Engineering》 SCIE EI CAS 2022年第7期163-168,共6页
Preserving Tibet’s unique history and cultural heritage relies on the sustainability of the Tibetan croplands,which are characterized by highland barley,the only cereal crop cultivated over 4000 m above sea level.Yet... Preserving Tibet’s unique history and cultural heritage relies on the sustainability of the Tibetan croplands,which are characterized by highland barley,the only cereal crop cultivated over 4000 m above sea level.Yet it is unknown how these croplands will respond to climate change.Here,using yield statistics from 1985 to 2015,we found that the impact of temperature anomalies on the Tibetan crop yield shifted from nonsignificant(P>0.10)in the 1980s and 1990s to significantly negative(P<0.05)in recent years.Meanwhile,the apparent sensitivity of the crop yield to temperature anomalies almost doubled,from(–0.13±0.20)to(–0.22±0.14)t·ha^(-1)℃^(–1).The emerging negative impacts of higher temperatures suggest an increasing vulnerability of Tibetan croplands to warmer climate.With global warming scenarios of+1.5 or+2.0℃above the pre-industry level,the temperature sensitivities of crop yield may further increase to(–0.33±0.10)and(–0.51±0.18)t·ha^(-1)℃^(–1),respectively,making the crops 2–3 times more vulnerable to warmer temperatures than they are today. 展开更多
关键词 Tibet WARMING Crop yield BARLEY Negative warming impacts
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Contrastive Consensus Graph Learning for Multi-View Clustering 被引量:2
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作者 shiping wang Xincan Lin +2 位作者 Zihan Fang Shide Du Guobao Xiao 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第11期2027-2030,共4页
Dear Editor,This letter proposes a contrastive consensus graph learning model for multi-view clustering.Graphs are usually built to outline the correlation between multi-model objects in clustering task,and multiview ... Dear Editor,This letter proposes a contrastive consensus graph learning model for multi-view clustering.Graphs are usually built to outline the correlation between multi-model objects in clustering task,and multiview graph clustering aims to learn a consensus graph that integrates the spatial property of each view. 展开更多
关键词 LETTER INTEGRATE PROPERTY
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Dynamic Response of Floating Body Subjected to Underwater Explosion Bubble and Generated Waves with 2D Numerical Model 被引量:1
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作者 Zhaoli Tian Yunlong Liu +2 位作者 shiping wang A Man Zhang Youwei Kang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2019年第2期397-423,共27页
The low frequency load of an underwater explosion bubble and the generated waves can cause significant rigid motion of a ship that threaten its stability.In order to study the fluid-structure interaction qualitatively... The low frequency load of an underwater explosion bubble and the generated waves can cause significant rigid motion of a ship that threaten its stability.In order to study the fluid-structure interaction qualitatively,a two-dimensional underwater explosion bubble dynamics model,based on the potential flow theory,is established with a double-vortex model for the doubly connected bubble dynamics simulation,and the bubble shows similar dynamics to that in 3-dimensional domain.A fully nonlinear fluid-structure interaction model is established considering the rigid motion of the floating body using the mode-decomposition method.Convergence test of the model is implemented by simulating the free rolling motion of a floating body in still water.Through the simulation of the interaction of the underwater explosion bubble,the generated waves and the floating body based on the presented model,the influences of the buoyancy parameter and the distance parameter are discussed.It is found that the impact loads on floating body caused by underwater explosion bubble near the free surface can be divided into 3 components:bubble pulsation,jet impact,and slamming load of the generated waves,and the intensity of each component changes nonlinearly with the buoyance parameter.The bubble pulsation load decays with the increase in the horizontal distance.However,the impact load from the generated waves is not monotonous to distance.It increases with the distance within a particular distance threshold,but decays thereafter. 展开更多
关键词 UNDERWATER explosion BUBBLE DYNAMICS fluid-structure INTERACTION double-vortex model WAVES GENERATED by UNDERWATER explosion.
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The weak effects of fencing on ecosystem respiration,CH4,and N2O fluxes in a Tibetan alpine meadow during the growing season 被引量:1
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作者 YiGang Hu ZhenHua Zhang +3 位作者 shiping wang ZhiShan Zhang Yang Zhao ZengRu wang 《Research in Cold and Arid Regions》 CSCD 2017年第6期642-655,共14页
Fencing is the most common land-management practice to protect grassland degradation from livestock overgrazing on the Tibetan Plateau. However, it is unclear whether fencing reduces CO_2, CH_4, and N_2O emission. Her... Fencing is the most common land-management practice to protect grassland degradation from livestock overgrazing on the Tibetan Plateau. However, it is unclear whether fencing reduces CO_2, CH_4, and N_2O emission. Here, we selected four vegetation types of alpine meadow(graminoid, shrub, forb, and sparse vegetation) to determine fencing effects on ecosystem respiration(Re), CH_4, and N_2O fluxes during the growing season. Despite increased average monthly ecosystem respiration(Re) for fenced graminoid vegetation at the end of the growing season, there was no significant difference between grazing and fencing across all vegetation types. Fencing significantly reduced average CH_4 uptake by about 50% in 2008 only for forb vegetation and increased average N_2O release for graminoid vegetation by 38% and 48% in 2008 and 2009,respectively. Temperature, moisture, total organic carbon, C/N, nitrate, ammonia, and/or bulk density of soil, as well as above-and belowground biomass, explained 19%~71% and 6%~33% of variation in daily and average Re and CH_4 fluxes across all vegetation types, while soil-bulk density explained 27% of variation in average N_2O fluxes. Stepwise regression showed that soil temperature and soil moisture controlled average Re, while soil moisture and bulk density controlled average CH_4 fluxes. These results indicate that abiotic factors control Re, CH_4, and N_2O fluxes; and grazing exclusion has little effect on reducing their emission—implying that climatic change rather than grazing may have a more important influence on the budgets of Re and CH_4 for the Tibetan alpine meadow during the growing season. 展开更多
关键词 FENCING ecosystem RESPIRATION methane nitrous oxide TIBETAN ALPINE MEADOW
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Effects of 12% Chlorothalonil and 12% Procymidone Smoke Agents on Physiology and Yield of Quinoa in Greenhouse
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作者 Wei LU Yiming LIU +5 位作者 Jianhan HE Meiyan PEI shiping wang Zhimin WEI Chuan LU 《Medicinal Plant》 CAS 2020年第1期80-81,共2页
[Objectives]To study the effects of 12%chlorothalonil and 12%procymidone smoke agent on physiology and yield of quinoa in greenhouse.[Methods]The chlorophyll content and photosynthesis rate of quinoa were determined b... [Objectives]To study the effects of 12%chlorothalonil and 12%procymidone smoke agent on physiology and yield of quinoa in greenhouse.[Methods]The chlorophyll content and photosynthesis rate of quinoa were determined by using the conventional application method of smoke agent at the dosage of 3 kg/ha.Finally,the total yield and increased yield of quinoa were calculated.[Results]The chlorophyll content and photosynthesis rate of leaves were all increased by two kinds of smoke agents,and the photosynthesis rate was also increased significantly.[Conclusions]These two smoke agents can promote the growth of quinoa,including the increase of chlorophyll and the enhancement of photosynthesis,and its further mechanism needs to be further discussed. 展开更多
关键词 QUINOA Smoke agents PESTICIDES
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Application of integrated geophysical interpretation on accumulation body
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作者 Caikun GAO Huakun DU +3 位作者 Jingtian TANG Kangxiu WU Chang'an XIAO shiping wang 《Global Geology》 2008年第3期191-196,共6页
Integrated geophysical interpretation is a method of combinating different geophysics prospecting methods based on different physical properties of accumulation. As different geophysical methods own different interpre... Integrated geophysical interpretation is a method of combinating different geophysics prospecting methods based on different physical properties of accumulation. As different geophysical methods own different interpretations and varying detection accuracies, the key issue becomes how to integrate the results of several geophysical methods to corrently carry out a comprehensive explanation. Based on different geophysical results, the authors proposed an integrated geophysical explanation method and successfully applied it in practical engineering problems. 展开更多
关键词 hydropower project ACCUMULATION integrated geophysical methods WEIGHT RELIABILITY
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Application of BIM with IPD in Design for a Construction Project
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作者 shiping wang Wenming Liu +1 位作者 Guoping Peng Nuowei Zhang 《Journal of Architectural Research and Development》 2021年第6期1-8,共8页
Integrated Project Delivery(IPD)is a new delivery system that fosters integration of combining design and construction in a collaborative team environment.Building Information Modeling(BIM)is a smart technological too... Integrated Project Delivery(IPD)is a new delivery system that fosters integration of combining design and construction in a collaborative team environment.Building Information Modeling(BIM)is a smart technological tool that make significant advancements in coordinating the planning and construction processes.IPD process with BIM technology allows all building data to maintain in a communicating platform that make all participants share data.In reality,some technical and process obstacles exist,that are hampering full implementation of IPD with BIM in the project.The paper introduced the application of IPD with BIM on the design in a project.The results showed the impact of BIM implementation on IPD mode which can result in improved productivity,better coordination,reduced energy consumption,clash and rework of construction. 展开更多
关键词 Collaboration platform IPD projects BIM Design coordination
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Drought decreases the positive impact of warming on an alpine grassland community
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作者 wang A wangwang LV +6 位作者 Yang ZHOU Bowen LI Jianping SUN Jingya LV Lanying CHEN Dorji TSECHEO shiping wang 《Science China Earth Sciences》 SCIE EI CAS CSCD 2024年第10期3226-3238,共13页
Temperature and precipitation are the main factors determining plant community succession and aboveground net primary productivity(ANPP)in natural grasslands.However,most climate manipulative experiments have mainly f... Temperature and precipitation are the main factors determining plant community succession and aboveground net primary productivity(ANPP)in natural grasslands.However,most climate manipulative experiments have mainly focused on their impacts in isolation,especially in alpine regions.Here we explored the relative effects and interaction of warming and precipitation alteration on succession and ANPP using a 7-year experiment involving warming with precipitation alteration(increase(IP)or decrease(DP))in precipitation relative to ambient precipitation(AP)on the Tibetan Plateau.Our results showed that warming and warm-wet conditions increased species richness,diversity index,height and cover of overall species.Conversely,decreasing precipitation reduced them,but increased S.purpurea and the rate of change in community composition.Importantly,warming mitigated the impacts of decreased precipitation on plant community composition,and the interactive effects of warming and altered precipitation on cover,height and plant ANPP varied with year and plant species.Generally,warming increased community ANPP through increases in forb ANPP or non-dominant species ANPP and biodiversity regardless of change in precipitation.However,decreased precipitation reduced community ANPP via decreases in the ANPP of sedges and forbs and biodiversity.Precipitation alteration affected the relationship between biodiversity and community ANPP regardless of warming(IP<AP<DP).Therefore,generally warming and decreased precipitation have opposite effects on ANPP in the alpine grassland,suggesting that warming mitigated the negative impacts of drought on the ANPP of the alpine grassland. 展开更多
关键词 Alpine grassland Climate warming Precipitation alteration Community composition BIODIVERSITY Above-ground net primary productivity
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青藏高原高寒植物对生长季偶发性霜冻事件表现出深度过冷却现象
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作者 Ji Suonan wangwang +9 位作者 Aimée TClassen Wenying wang Ben La Xuwei Lu Cuo Songzha Chenghao Chen Qi Miao Fanghui Sun Lhamo Tsering shiping wang 《Journal of Plant Ecology》 SCIE CSCD 2024年第3期84-94,共11页
气候变暖促进了植物的春季物候,打破了气候与植物生长之间原有的平衡。随着极端气候事件出现更加频繁,气候与植物生长之间的不匹配性会影响植物的生存、生长和繁殖。为了防止生长季节在细胞内结冰,植物会采用过冷却策略。然而,气候事件... 气候变暖促进了植物的春季物候,打破了气候与植物生长之间原有的平衡。随着极端气候事件出现更加频繁,气候与植物生长之间的不匹配性会影响植物的生存、生长和繁殖。为了防止生长季节在细胞内结冰,植物会采用过冷却策略。然而,气候事件的严重程度和物候期可能会影响植物在霜冻事件后的恢复。本研究通过实验探究了4种不同严重程度的极端霜冻事件如何影响青藏高原上两种优势物种钉柱委陵菜(Potentilla saundersiana,仲夏开花)和小龙胆(Gentiana parvula,夏末开花)的过冷却点和枯黄期。探讨了物候期如何影响钉柱委陵菜对霜冻事件的反应。结果发现,两个物种在遭受霜冻损害时都表现出过冷现象。钉柱委陵菜的平均过冷却点为−6.9℃,并受最低温度、持续时间和物候期的影响,而小龙胆的平均过冷却点为−4.8℃,最低温度和持续时间对其过冷却点影响不显著。此外,两个物种在最低温度(−10℃)处理持续4小时后均快速枯黄。本研究首次探索并定量了青藏高原高寒植物的过冷却点。鉴于高寒植物遭遇霜冻事件的概率不断增加,上述结果对了解高寒植物的生长和生存如何应对极端气候的不利影响具有重要意义。 展开更多
关键词 气候变化 极端霜冻事件 过冷却现象 物候期 枯黄
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青藏高原植被结构变化反映环境变迁 被引量:1
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作者 王艳芬 薛凯 +41 位作者 胡容海 丁柏阳 曾弘 李瑞津 徐斌 庞哲 宋小宁 李聪佳 杜剑卿 杨秀春 张泽林 郝彦宾 崔骁勇 郭柯 高清竹 张扬建 朱军涛 孙建 李耀明 姜丽丽 周华坤 罗彩云 张振华 高庆波 陈世龙 纪宝明 徐兴良 陈槐 李奇 赵亮 徐世晓 刘雅莉 胡林勇 武建双 杨其恩 董世魁 贺金生 赵新全 汪诗平 朴世龙 于贵瑞 傅伯杰 《Science Bulletin》 SCIE EI CAS CSCD 2023年第17期1928-1937,共10页
草地植被结构对于其生产和生态功能至关重要,但大尺度信息严重匮乏.本研究结合多源遥感数据和深度学习,在区域尺度上厘清了青藏高原高寒草地基于群系的植物群落结构空间格局,并比较了其历史变化.过去40年,高寒草甸在高寒草地中的比例从... 草地植被结构对于其生产和生态功能至关重要,但大尺度信息严重匮乏.本研究结合多源遥感数据和深度学习,在区域尺度上厘清了青藏高原高寒草地基于群系的植物群落结构空间格局,并比较了其历史变化.过去40年,高寒草甸在高寒草地中的比例从50%上升到69%,反映了变暖变湿的环境变化.此外,高寒草甸和高寒草原中高山嵩草草甸和紫花针茅草原的优势度分别增强到76%和92%.其中,气候因子驱动了紫花针茅草原近些年的分布;高山嵩草草甸近些年的分布则并非完全由气候驱动,人类活动可能起重要作用.本研究首次探索了区域尺度植被结构特征与历史变化,为认识青藏高原草地变化的驱动力及其空间异质性提供了新视角. 展开更多
关键词 高寒草地 植被结构 草地植被 多源遥感数据 深度学习 植物群落结构 区域尺度 高寒草原
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高山嵩草植物群落花期物候对增水的响应比对恒定增温和逐步增温的响应更敏感 被引量:1
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作者 Bowen Li Jianping Sun +14 位作者 shiping wang wangwang Lv Yang Zhou Peipei Liu Qi wang wang A Suren Zhang Lu Xia Huan Hong Lili Jiang Caiyun Luo Zhenhua Zhang Shilong Piao Yanfen wang Tsechoe Dorji 《Journal of Plant Ecology》 SCIE CSCD 2023年第2期88-101,共14页
有研究表明长期观测的植物花期物候变化温度敏感性与野外控制恒定增温试验所得出的花期物候温度敏感性结果不一致,这可能是由于两种观测方法具有不同的增温模式引起的。因为长期观测的气候变暖实际上是气温逐渐升高的情景,而野外控制增... 有研究表明长期观测的植物花期物候变化温度敏感性与野外控制恒定增温试验所得出的花期物候温度敏感性结果不一致,这可能是由于两种观测方法具有不同的增温模式引起的。因为长期观测的气候变暖实际上是气温逐渐升高的情景,而野外控制增温试验所增加的温度是突然增加且每年保持不变。不同的增温模式是否会导致不同的结果目前还缺乏野外试验证据。此外,不同增温模式的效应还受到降水变化的调控。因此,我们于2015–2018年在高寒高山嵩草草甸开展了一项恒定增温(和对照相比,每年保持恒定增温1°C)和逐步增温(和对照相比,2015年增温0.25°C,以后逐年在前一年基础上再增温0.25°C,到2018年相比对照增温1°C)以及与增水(100%/50%)耦合的野外控制试验。研究结果发现,增温模式并没有显著改变群落花期物候。然而,增水显著提前了早花植物和中花植物的初花期,提前了早花植物的末花期,推迟了中花植物的末花期。增水处理并没有显著改变早花植物的开花持续期,但却显著延长了中花植物的开花持续期,进而延长了该群落的开花持续期。增温速率和增水处理并没有显著的交互作用。前一年的干旱会显著抑制第二年该植物群落的现存最大开花数。因此,无论增温模式如何,降水的改变对该高山嵩草植物群落花期物候的影响要大于增温对其的影响。 展开更多
关键词 恒定增温和逐步增温 增水 群落花期物候 初花期和末花期 开花功能群 高寒草原 青藏高原
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Synergistic Pd/Cu catalysis enabled cross-coupling of glycosyl stannanes with sulfonium salts to access C-aryl/alkenyl glycals
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作者 Weitao Yan Mingwen Zheng +4 位作者 Peihsuan Chuang Hao Sun shiping wang Chunfa Xu Fen-Er Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第7期102-106,共5页
A highly efficient coupling of glycosyl stannanes and sulfonium salts enabled by synergistic Pd/Cu catalysis is disclosed, facilitating the construction of C-aryl/alkenyl glycals under mild conditions in high yields.T... A highly efficient coupling of glycosyl stannanes and sulfonium salts enabled by synergistic Pd/Cu catalysis is disclosed, facilitating the construction of C-aryl/alkenyl glycals under mild conditions in high yields.The protocol tolerates a wide scope of functional groups including ketone, cyano, ester, amide, nitro,halide. The one-pot formal C–H glycosylation starting from arene is demonstrated with a reaction sequence of dibenzothiophenylation/Stille coupling. Besides, a gram-scale reaction is performed successfully,showing the high applicability of this protocol. 展开更多
关键词 C-glycals Sulfonium salts Synergistic catalysis CARBOHYDRATE Glycosyl stannanes Stille coupling
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青藏高原生态系统对气候变化的响应及其反馈 被引量:106
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作者 朴世龙 张宪洲 +4 位作者 汪涛 梁尔源 汪诗平 朱军涛 牛犇 《科学通报》 EI CAS CSCD 北大核心 2019年第27期2842-2855,共14页
近几十年来,青藏高原正经历快速的气候变化,高原生态系统因此发生了深刻变化,并对周边地区产生了深远影响.本文围绕青藏高原生态系统结构和功能对气候变化的响应与反馈这一主线,系统总结了气候变化对物候、高山树线、生物多样性、植被... 近几十年来,青藏高原正经历快速的气候变化,高原生态系统因此发生了深刻变化,并对周边地区产生了深远影响.本文围绕青藏高原生态系统结构和功能对气候变化的响应与反馈这一主线,系统总结了气候变化对物候、高山树线、生物多样性、植被生产力和生态系统碳汇功能的影响,阐述了青藏高原植被变化对区域气候的反馈及对亚洲季风的远程影响的研究进展.主要结论如下:气候变暖导致植被返青期总体提前,高原树线位置上升,高寒草原植物物种丰富度和多样性下降;气候变暖总体促进了高原植被生产力、增强了生态系统碳汇功能,但受限于土壤极大的空间异质性和对深层土壤碳动态理解的匮乏,目前对高原土壤碳库及土壤碳汇功能大小的估算仍具有较大不确定性.同时,青藏高原植被变化对近地表气温产生'负反馈'作用;植被活动增强还对东亚季风产生远程影响,导致我国东部夏季降水变化呈现'华南增加-长江黄河中间区域减少'的空间分异格局.未来的研究需要在完善观测体系基础上,加强对高寒生态系统对气候变暖的适应机理及生物地球物理反馈等过程的认知,为优化生态系统管理和保障青藏高原的生态安全提供理论基础. 展开更多
关键词 青藏高原 气候变化 植被变化 碳汇 反馈
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Rice MtN3/saliva/SWEET gene family: Evolution,expression profiling, and sugar transport 被引量:15
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作者 Meng Yuan Junwei Zhao +3 位作者 Renyan Huang Xianghua Li Jinghua Xiao shiping wang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2014年第6期559-570,共12页
The rice MtN3/saliva/SWEET gene family consists of 21 paralogs. However, their functions in physiological processes are largely unknown, although at least three of the 21 paralogs are used by pathogenic bacteria to in... The rice MtN3/saliva/SWEET gene family consists of 21 paralogs. However, their functions in physiological processes are largely unknown, although at least three of the 21 paralogs are used by pathogenic bacteria to infect rice. Here, we report the evolutionary features, transcriptional characteristics, and putative functions in sugar transport of this gene family. The wild rice accessions in this study included those with AA, BB, CC, BBCC, CCDD, EE, and GG genomes, which appeared approximately 0.58-14.6 million years ago. The structures, chromosomal locations, phylogenetic relationships, and homologous distribution among the accessions suggest that the number of rice MtN3/saliva/SWEET paralogs gradual y increased as the Oryza genus evolved, and one third of the paralogs may have originated recently. These paralogs are differentially expressed in vegetative and reproductive tissues, in the leaf senescence process, and in signaling dependent on gibberel ic acid, cytokinin, or 1-naphthalene acetic acid (an analog of auxin), suggesting that they may be associated with multiple physiological processes. Four paralogs could transport galactose in yeast, which suggests that they may have a similar function in rice. These results will help to elucidate their roles and biochemical functions in rice development, adaptation to environment, host-pathogen interaction, and so forth. 展开更多
关键词 EVOLUTION MtN3/saliva domain Oryza sotivo TRANSPORTER
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