检索结果-南通市图书馆

Insights into the provenance implication of leaf wax n-alkanes along the lower Yellow River

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 2001-2018页

作者： Liang ZHANG jinzhao LIU Chong JIANG Fei ZHANG Zhisheng AN School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710054China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China National Observation and Research Station of Earth Critical Zone on the Loess Plateau of Shaanxi Xi’an 710061China

Serving as one of the largest rivers in terms of both sediment and organic carbon transport fluxes in the world,the Yellow River plays a crucial role in regional biogeochemical process as well as in the global carbon ***,although a large number of studies have been carried out on the flux,composition,source and seasonal variation of total particulate organic carbon in the Yellow River so far,studies on molecular biomarkers at different spatial and temporal scales are still *** this study,we focus on the molecular and hydrogen isotopic properties of leaf wax n-alkanes among different types of samples which obtained from different seasons(flood ***-flood)along the lower Yellow *** molecular distribution of n-alkanes show that the riparian topsoils are subject to inputs from the overlying vegetation,while the suspended sediments from the flood season are characterized by the mixing of soil materials which originate from various stratigraphy with different ages on the Chinese Loess *** to the contrasting hydrodynamic conditions,the n-alkanes in suspended sediments also show distinct molecular composition between flood and non-flood ***,considering the effect of climatic factors,the proportion of monocots in flood-season suspended sediments is calculated from a semi-quantitative perspective using δ^(2.H_(wax).Our findings may bring to light new considerations for the interpretation of leaf wax proxies in studies of organic matter sources of Yellow River.

关键词： Molecular distribution Hydrogen isotopic composition Leaf wax n-alkanes Suspended sediments Lower Yellow River

In Situ Reconfiguration of Assembling Pattern for Modular Continuum Robots

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第4期21卷 1695-1706页

作者： Jie Zhang Jiannan Cai Ke Ma jinzhao Yang Zhigang Wu Haijun Peng Jianing Wu School of Mechanical Engineering Dalian University of TechnologyDalian116024People’s Republic of China School of Advanced Manufacturing Sun Yat-Sen UniversityShenzhen518107People’s Republic of China School of Aeronautics and Astronautics Sun Yat-Sen UniversityShenzhen518107People’s Republic of China

Modular continuum robots possess significant versatility across various scenarios;however,conventional assembling methods typically rely on linear connection between *** limitation can impede the robotic interaction capabilities,especially in specific engineering ***,inspired by the assembling pattern between the femur and tibia in a human knee,we proposed a multidirectional assembling *** strategy encompasses linear,oblique,and orthogonal connections,allowing a two-module continuum robot to undergo in-situ reconfiguration into three distinct initial *** anticipate the final configuration resulting from diverse assembling patterns,we employed the positional formulation finite element framework to establish a mechanical model,and the theoretical results reveal that our customizable strategy can offer an effective route for robotic *** showcased diverse assembling patterns for coping with interaction *** experimental results indicate that our modular continuum robot not only reconfigures its initial profile in situ but also enables on-demand regulation of the final *** capabilities provide a foundation for the future development of modular continuum robots,enabling them to be adaptable to diverse environments,particularly in unstructured surroundings.

关键词： Assembling patterns Continuum robot In-situ reconfiguration Tensegrity structure Varying stiffness

Plant type effect overweighs seasonal variation in n-alkanoic acid biomarker on regional Loess Plateau of China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第8期67卷 2547-2562页

作者： jinzhao LIU S.Nemiah LADD Jiaju ZHAO Dongna YAN Ding HE Yunning CAO Zhisheng AN State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China CAS Center for Excellence in Quaternary Science and Global Change Xi’an 710061China Department of Environmental Sciences University of BaselBasel 4056Switzerland Department of Ocean Science and Center for Ocean Research in Hong Kong and Macao The Hong Kong University of Science and TechnologyHong Kong 999077China

The effect of plant type on n-alkane biomarker has been widely studied,but the influence of plant type on n-alkanoic acids(n-FAs)has received less *** the effect of the distribution of n-FAs and their hydrogen isotope composition(δ^(2.H_(FA))is critical for interpreting sedimentaryδ^(2.H_(FA)values as proxies of hydroclimate and/or vegetation *** this study,we systematically investigated the distribution ofn-FAs andδ^(2.H_(FA)values across seasons on the Chinese Loess Plateau(CLP).Our results showed that there were no significant seasonal differences in n-FAs distribution andδ^(2.H_(FA)values,but there were significant differences inδ^(2.H_(FA)values across plant ***δ^(2.H_(FA)values ranged from-185‰to-12.‰in dicots(-161‰±2.‰),and from-2.5‰to-170‰in monocots(-196‰±2.‰)on the *** fractionation betweenδ^(2.H_(FA)values and precipitationδ^(2.H(ε_(FA-P))was also^(2.H-enriched in dicots relative to *** the regional scale of the CLP,δ^(2.H_(FA)values were not correlated withδ^(2.H values of ***,δ^(2.H_(FA)values from the CLP were similar to expectations from a global comparison,both in terms of their mean values and high variability among plants growing in sites with similarδ^(2.H values of *** some of this variability inεFA-Pis due to the effect of plant type,a careful assessment of the likely sources of waxes in terrestrial sediments is critical when usingδ^(2.H_(FA)values for paleohydroclimate reconstruction.

关键词： n-Alkanoic acid Hydrogen isotope Plant type Paleohydroclimate Chinese Loess Plateau

Aerodynamic breakup of emulsion droplets in airflow

在线全文

学校读者我要写书评

暂无评论

Droplet 2024年第4期3卷 48-54页

作者： Zhikun Xu jinzhao Liu Houpeng Zhang Tianyou Wang Zhizhao Che State Key Laboratory of Engines Tianjin UniversityTianjinChina National Industry-Education Platform of Energy Storage Tianjin UniversityTianjinChina

Aerodynamic breakup refers to the process where large droplets are fragmented into small droplets by the aerodynamic force in airflow,which plays a vital role in fluid atomization and spray *** research has primarily concentrated on the aerodynamic breakup of single-component droplets,but investigations into the breakup of emulsion droplets are *** study experimentally investigated the aerodynamic breakup of water-in-oil emulsions in airflow,utilizing high-speed photography to observe the breakup process and digital in-line holography to measure fragment *** analyses between emulsion droplets and single-component droplets are conducted to examine the breakup morphology,breakup regime,deformation characteristics,and fragment size *** emulsion droplets exhibit higher apparent viscosity and shorter stretching lengths of the bag film and peripheral rim due to the presence of a dispersed *** breakup regime transitions of emulsions are modeled by integrating the viscosity model of emulsions and the transition model of the pure *** fragment sizes of emulsion droplets are larger due to the shorter lengths of the bag film and peripheral rim.

关键词： emulsion viscosity sizes

Mo-doped one-dimensional needle-like Ni_(3)S_(2. as bifunctional electrocatalyst for efficient alkaline hydrogen evolution and overall-water-splitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ChemPhysMater 2024年第1期3卷 74-82页

作者： Junjie Huang Yupeng Xing jinzhao Huang Fei Li Gang Zhao Xingmin Yu Binxun Li Xinran Zhang School of Physics and Technology University of JinanJinan 250022China

Hydrogen energy plays an important role in clean energy system and is considered the core energy source for future technological development owing to its lightweight nature,high calorific value,and clean combustion *** electrocatalytic conversion of water into hydrogen is considered a highly promising *** electrocatalyst is indispensable in the electrocatalytic process,and finding an efficient electrocatalyst is ***,the current commercial electrocatalysts(such as Pt/C and Ru)are expensive;therefore,there is a need to find an inexpensive and efficient electrocatalyst with high stability,corrosion resistance,and high electrocatalytic *** this study,we developed a cost-effective bifunctional electrocatalyst by incorporating molybdenum into nickel sulfide(Ni_(3)S_(2.)and subsequently tailoring its structure to achieve a one-dimensional(1D)needle-like *** hydrogen production efficiency of nickel sulfide was improved by changing the ratio of Mo *** analyzing the electrochemical performance of different Mo-doped catalysts,we found that the Ni_(3)S_(2.-Mo-0.1 electrocatalyst exhibited the best electrocatalytic effect in 1 M KOH;at a current density of 10 mA cm^(-2.,it exhibited overpotentials of 12. and 2.9 mV for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),respectively;at a higher current density of 100 mA cm^(-2.,the HER and OER overpotentials were 396 and 495 mV,***,this electrocatalyst can be used in a two-electrode water-splitting ***,we thoroughly investigated the mechanism of the overall water splitting of this electrocatalyst,providing valuable insights for future hydrogen production via overall-water-splitting.

关键词： Hydrogen evolution reaction Molybdenum doped Nickel sulfide Overall water splitting Needle-like multistage structure

Research on Biometric Identification Method of Nuclear Cold Source Disaster Based on Deep Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer and Communications 2024年第1期12卷 162-176页

作者： Kai Liu Yadong Wu Dan Luo jinzhao Zhang Weihan Zhang College of Computer Science and Engineering Sichuan University of Science and Engineering Yibin China

In this paper, an improved Fast-R-CNN nuclear power cold source disaster biological image recognition algorithm is proposed to improve the safety operation of nuclear power plants. Firstly, the image data sets of the disaster-causing creatures hairy shrimp and jellyfish were established. Then, in order to solve the problems of low recognition accuracy and unrecognizable small entities in disaster biometrics, Gamma correction algorithm was used to optimize the image of the data set, improve the image quality and reduce the noise interference. Transposed convolution is introduced into the convolution layer to increase the recognition accuracy of small targets. The experimental results show that the recognition rate of this algorithm is 6.75%, 7.5%, 9.8% and 9.03% higher than that of ResNet-50, MobileNetv1, GoogleNet and VGG16, respectively. The actual test results show that the accuracy of this algorithm is obviously better than other algorithms, and the recognition efficiency is higher, which basically meets the preset requirements of this paper.

关键词： Image Recognition Image Recognition Gamma Adjust Transposed Convolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

流场波系引导的三维消波翼优化设计方法

航空学报 2024年第6期45卷 183-197页

作者：戴今钊陈海昕清华大学航天航空学院北京100084

为提升高超声速飞行器的升阻比,一种重要设计思想是让飞行器各组件的激波、膨胀波产生有利的相互作用,获得增升、减阻的效果。基于上述设计思想的高升阻比构型通常根据无黏二维/轴对称流场的激波-膨胀波关系设计。由于三维效应与空气黏... 详细信息

为提升高超声速飞行器的升阻比,一种重要设计思想是让飞行器各组件的激波、膨胀波产生有利的相互作用,获得增升、减阻的效果。基于上述设计思想的高升阻比构型通常根据无黏二维/轴对称流场的激波-膨胀波关系设计。由于三维效应与空气黏性的影响,其实际性能相比理想设计性能往往存在较明显的退化。针对上述问题,提出流场波系引导的优化设计方法。不同于以气动性能指标为目标的传统优化方法,该方法以设计流场的波系形态为目标引导几何参数的优化方向。设计方法在一种主翼、上翼产生有利干扰的三维消波翼的设计中得到应用验证。通过将优化构型的流场、气动性能与根据二维无黏方法设计的初始构型对比,证明了优化设计方法的有效性。通过与菱形翼对比,验证了消波翼在设计工况下相比于常规构型的升阻比优势。

关键词：优化设计消波高超声速高升阻比气动布局

在线全文

学校读者我要写书评

暂无评论

需要嵌入逻辑的中国法理学

中国法律评论 2024年第4期 155-166页

作者：陈金钊华东政法大学法律方法研究院

中国法理学是对西方法理学知识论、价值论及认识论等的借鉴,可其内容并不全是对西方法理学的全面移植,而是运用辩思方式的整合,其典型特点是没有经过刻意论证,就在无意识层面消解了逻辑的重要性。中国法理学至今没有对法律的逻辑性(如... 详细信息

中国法理学是对西方法理学知识论、价值论及认识论等的借鉴,可其内容并不全是对西方法理学的全面移植,而是运用辩思方式的整合,其典型特点是没有经过刻意论证,就在无意识层面消解了逻辑的重要性。中国法理学至今没有对法律的逻辑性(如法律的一般性、体系性、独立性、自主性等)展开有效的研究。法律体系的塑造及法治的实现都离不开逻辑。为塑造与法治中国建设相匹配的思维方式,需要在中国法理学的研究中嵌入逻辑,从而在辩思与逻辑的契合中形成中国式法理。嵌入逻辑的路径包括:在法的概念定义之中,承认法律不仅是行为规范,还是思维规则;在此前提下找到融贯中西法理的契合点,即在辩证思维中嵌入形式逻辑。

关键词：法理思维法律拟制据法思考辩证思维法治逻辑法律思维

在线全文

学校读者我要写书评

暂无评论

现代法治精神及其探寻方法

上海师范大学学报（哲学社会科学版） 2024年第5期53卷 55-67页

作者：陈金钊华东政法大学法律方法研究院上海201620

现代法治精神是指捍卫法治的心理姿态、促进法治的思维方式以及对公正等价值目标的追求。法治是拟制的概念,因而法治的实现需要精神力量的支持。没有捍卫法治的心理姿态以及对据法思考之思维方式的坚守,很难在行为上接近法治。法治精神... 详细信息

现代法治精神是指捍卫法治的心理姿态、促进法治的思维方式以及对公正等价值目标的追求。法治是拟制的概念,因而法治的实现需要精神力量的支持。没有捍卫法治的心理姿态以及对据法思考之思维方式的坚守,很难在行为上接近法治。法治精神对思维和行为具有指引功能,而这种指引是以尊重法律的权威以及恪守法律的一般性、规范性、体系性、稳定性、安定性等为前提的。法治的筹划或法律所预设的概念、规范、原则以及价值等能够最大化地实现,离不开法治精神的支持。现代法治精神的展开,需要捍卫法治的心理姿态、恪守思维方式上的据法思考;在言说方式上使用法治话语,遵从修辞立其诚的原则,尽其所思促成法治的实现。

关键词：法治精神现代法治法治思维法治文化法律精神

维普期刊数据库博看期刊