检索结果-南通市图书馆

The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation

引用

Advances in Atmospheric Sciences 2024年第1期41卷 173-187页

作者： Lei ZHU Chunsong LU Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan WANG Fan WANG collaborative innovation center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science and TechnologyNanjing 210044China Nanjing Joint Institute for Atmospheric Sciences Nanjing 210019China College of Aviation Meteorology Civil Aviation Flight University of ChinaGuanghan 618307China collaborative innovation center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Department of Geography Hong Kong Baptist UniversityHong Kong SAR 999077China

The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization.

关键词： large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magneto-optic Kerr Effect Measurement of TbMn_(6)Sn_(6) at mK Temperature

引用

Chinese Physics Letters 2024年第4期41卷 159-163页

作者：黄代强汪洋王贺王健刘阳 International center for Quantum Materials Peking UniversityBeijing 100871China Department of Physics Capital Normal UniversityBeijing 100048China collaborative innovation center of Quantum Matter Beijing 100871China Hefei National Laboratory Hefei 230088China

Novel electron states stabilized by Coulomb interactions attract tremendous interests in condensed matter physics.These states are studied by corresponding phase transitions occurring at extreme conditions such as mK temperatures and high magnetic field.In this work,we introduce a magneto-optical Kerr effect measurement system to comprehensively explore these phases in addition to conventional transport measurement.This system,composed of an all-fiber zero-loop Sagnac interferometer and in situ piezo-scanner inside a dilution refrigerator,operates below 100 m K,with a maximum field of 12 Tesla and has a resolution as small as 0.2μrad.As a demonstration,we investigate TbMn_(6)Sn_(6),where the manganese atoms form Kagome lattice that hosts topological non-trivial Dirac cones.We observed two types of Kerr signals,stemming from its fully polarized ferromagnetic ground state and positive charged carriers within the Dirac-like dispersion.

关键词： interferometer scanner system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Persistent greening against drying in northeast Asian semiarid grasslands:Asymmetrical responses of direct and legacy effects to intensified drought

引用

Advances in Climate Change Research 2024年第1期15卷 9-20页

作者： Yu-Tong MA Hai-Shan CHEN Yao-Ming SONG Bo-Tao ZHOU Shan-Lei SUN Xin-Guan DU Yue SUN Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/collaborative innovation center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

Despite experiencing a decadal shift towards drought conditions at the end of the 2Oth century,semiarid grasslands in northeast Asia(NEA)exhibited an evident greening trend from 1982 to 2020.However,the mechanism behind this phenomenon remains unclear.Hence,we analysed the interdecadal changes in vegetation response to drought on the basis of the standardised precipitation evapotranspiration index(SPEI)and Global Inventory Modelling and Mapping Studies LAI4g datasets,with an emphasis on the differences between direct and legacy effects(as measured by resilience),to explore the mechanism of persistent grassland greening.Results revealed that during the post-drought shift period(2000-2020),the sudden decrease in the water content of the intermediate soil layer triggered an intensified vegetation response to drought.Specifically,although direct effects and resilience were amplified,they exhibited asymmetric changes.Resilience was stronger than direct effects,and this difference increased with increasing drought(drought recovery)levels.These combined effects may account for persistent greening against intensified drying in the semiarid grasslands in NEA.Given the projected exacerbation of future droughts,this study holds notable importance for comprehending the long-term change dynamics of dryland ecosystems.

关键词： Semiarid grassland Drought decadal shift Direct effect Legacy effect(resilience) Northeast Asia

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Constructing high-capacity and flexible aqueous zinc-ion batteries with air-recharging capability using organic cathodes

引用

Chinese Chemical Letters 2024年第3期35卷 468-472页

作者： Xiaojuan Chen Haoqi Su Baozhu Yang Xiaocen Liu Xiuting Song Lixin Su Gui Yin Qi Liu Jiangsu Key Laboratory of Advanced Catalytic Materials and technology Advanced Catalysis Green Manufacturing Collaborative Innovation Center and School of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China State Key Laboratory of Coordination Chemistry Nanjing UniversityNanjing 210093China

Flexible aqueous zinc-ion batteries(AZIBs)with air-recharging capability are a promising self-powered system applied in future wearable electronics.It is desired to develop high-capacity air-rechargeable AZIBs.Herein,we developed a flexible AZIB with air-recharging capability based on trinitrohexaazatrinaphthylene(TNHATN)cathode and a ZnSO_(4)electrolyte.The flexible Zn//TNHATN battery exhibits high volumetric energy density(21.36 mWh/cm^3)and excellent mechanical flexibility.Impressing,the discharged flexible Zn//TNHATN battery can be chemical self-charged via the redox reaction between TNHATN cathode and O_(2)from the air.After oxidation in air for 15 h,such flexible Zn//TNHATN battery can deliver a high specific capacity of 320 mAh/g at 0.5 A/g,displaying excellent air-recharging capability.Notably,this flexible Zn//TNHATN battery also works well in chemical or/and galvanostatic charging mixed modes,showing reusability.This work provides a new insight for designing flexible aqueous self-powered systems.

关键词： Aqueous zinc-ion battery Trinitrohexaazatrinaphthylene Organic cathode materials Flexible air-rechargeable battery Self-powered system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Continuous-flow synthesis of polysubstituted γ-butyrolactones via enzymatic cascade catalysis

引用

Chinese Chemical Letters 2024年第4期35卷 404-408页

作者： Liliang Chu Xiaoyan Zhang Jianing Li Xuelei Deng Miao Wu Ya Cheng Weiping Zhu Xuhong Qian Yunpeng Bai State Key Laboratory of Bioreactor Engineering Shanghai Collaborative Innovation Center for BiomanufacturingEast China University of Science and TechnologyShanghai 200237China The Extreme Optoelectromechanics Laboratory School of Physics and Materials ScienceEast China Normal UniversityShanghai 200241China

Polysubstituted chiral γ-butyrolactones are the core structural units of many natural products and high value-added flavors and fragrances used in the food and cosmetic industry. Current enzymatic cascade synthesis of these molecules faces the problems of low enzyme activity and phase separation in batch reaction, resulting in low productivity. Herein, we report a new continuous-flow process to synthesize the optically pure Nicotiana tabacum lactone(3S,4S)-4a and whisky lactone(3R,4S)-4b from α,β-unsaturatedγ-ketoesters. A new ene reductase(ER) from Swingsia samuiensi(Ss ER) and a carbonyl reductase(Ss CR)were engineered by directed evolution to improve their activity and thermostability. The continuous-flow preparative reactions were performed in two 3D microfluidic reactors, generating(3S,4S)-4a(99% ee and87% de) and(3R,4S)-4b(99% ee and 98% de) with space-time yields 3 and 7.4 times higher than those of the batch reactions. The significant enhancement in the productivity of enzyme cascade catalysis brought by cutting-edge continuous microfluidic technology will benefit the general multi-enzyme catalytic systems in the future.

关键词： Enzyme catalysis Cascade catalysis Directed evolution Continuous-flow γ-Butyrolactones

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Towards catalytic reactions of Cu single-atom catalysts:Recent progress and future perspective

引用

Chinese Chemical Letters 2024年第2期35卷 197-207页

作者： Yitao Zhao Lei Tao Jiangsu Province Engineering Research center of Special Functional Textile Materials Changzhou Vocational Institute of Textile and GarmentChangzhou 213164China Jiangsu Key Laboratory of Advanced Catalytic Materials and technology Advanced Catalysis and Green Manufacturing Collaborative Innovation CenterSchool of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China

One of the urgent and challenging topics in diversified sustainable energy conversion is the development of high-performance,low-cost,and well durable catalysts.Cu single-atom catalysts(SACs)have become promising catalysts for diversified sustainable energy conversion due to their capability to maximize the utilization efficiency,acquire modulated electronic structure and optimized binding strength with intermediates.In this review,we have provided an interview of the recent progress achieved in the field of electrocatalysis,photocatalysis,and heterogeneous reaction based on Cu SACs.Started by this review,we have summarized some advanced synthetic strategies for the construction of Cu SACs.Subsequently,the performance-improving strategies are discussed in terms of the coordination environments of the reaction center,reaction mechanism and selectivity,based on free energy diagram and electron structure analysis.Finally,the remaining issues,challenges,and opportunities of Cu SACs are also provided,affording a perspective for future studies.This review not only offers us a deep understanding on the catalytic mechanism of Cu SACs for energy conversion,but also encourages more endeavors in prompting their practical application.

关键词： Cu SACs Energy conversion Catalysis Coordination environment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of resistant starch supplementation on the diversity and composition of human gut microbiota: A systematic review and meta-analysis

引用

Food Science and Human Wellness 2024年

作者： Jiaxin Xu Haocun Kong Caiming Li Xiaofeng Ban Zhaofeng Li collaborative innovation center of Food Safety and Quality Control Jiangnan University School of Food Science and technology Jiangnan University State Key Laboratory of Food Science and technology Jiangnan University

Resistant starch (RS) has attracted much researchers’ attention because of its health-beneficial effects. Gut microbiota obviously shapes human health， but the effects of RS supplementation on the changes of human gut microbiota remain unclear. This observational meta-analysis aimed to reveal the effects of RS intake on alpha diversity and composition of gut microbiota through meta-analysis. Two independent authors systematically searched articles from inception until February 2023 on four electronic databases. Twenty-four highly relevant trials were included conforming to Preferred Reporting Items for Systematic reviews and Meta-Analysis protocol， and a total of 816 individuals were included. Significant heterogeneity analyses revealed that RS intake notably decreased Shannon index (WMD: –0.11; 95% CI: –0.21， –0.01)， and stimulated the composition of health promoting bacteria genera， including Bifidobacterium (WMD: 1.75; 95% CI: 0.39， 3.11; WMD: 0.36; 95% CI: 0.04， 0.69)， Faecalibacterium (WMD: 0.70; 95% CI: 0.20， 1.20; ES: 0.91; 95% CI: 0.60， 1.23)， and Prevotella (WMD: 0.35; 95% CI: 0.01， 0.69). Taken together， the present study revealed that changes in the gut microbiota diversity and genera were correlated with RS supplementation， which may contribute to benefits in human health.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Summer extreme precipitation patterns and synoptic-scale circulation precursors over the Tibetan Plateau

引用

Science China Earth Sciences 2024年第5期67卷 1625-1638页

作者： Zhiyuan DING Yao HA Zhong ZHONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing 210023China Jiangsu collaborative innovation center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing 210023China

In the context of global warming,the extreme summer precipitation over the Tibetan Plateau(TP)has changed significantly.In this study,the summer(June–August)extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution(1/30°)precipitation dataset(TPHi Pr,1979–2020).The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were investigated.The results showed that the summer extreme precipitation of the TP can be categorized into northwestern(NW),southeastern(SE),and southern Himalayan(HS)types based on extreme precipitation thresholds.The NW and SE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them,whereas the HS type is controlled by the localized subtropical anomalous circulation.On the 8th day before the onset of the NW type,an anomalous cyclone was observed in the western Atlantic Ocean(60°W,50°N),which triggered the west-to-east quasi-latitudinal propagation of Rossby waves.On the onset day of the NW type,the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian Sea,the western part of Xinjiang,to the northeastern TP.Moisture entered from the Arabian Sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern TP.Compared to the NW type,the precursors of the SE type appeared at higher latitudes and were more intense.On the 8th day before the onset of the SE type,an anomalous cyclone occurred near Greenland(60°W,70°N)and excited Rossby waves propagating southeastward.On the onset day of the SE type,the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast direction and entered the southeastern TP from the Bay

关键词： Tibetan Plateau Summer extreme precipitation Atmospheric circulation anomaly Precursor Teleconnection wave train

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3（001） via metallic δ-doping

引用

National Science Review 2024年第3期11卷 119-127页

作者： Xiaotong Jiao Wenfeng Dong Mingxia Shi Heng Wang Cui Ding Zhongxu Wei Guanming Gong Yanan Li Yuanzhao Li Binjie Zuo Jian Wang Ding Zhang Minghu Pan Lili Wang Qi-Kun Xue State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University School of Physics&Information technology Shaanxi Normal University Beijing Academy of Quantum Information Sciences Department of Physics Southern University of Science and Technology International center for Quantum Materials School of Physics Peking University Department of Physics The Pennsylvania State University collaborative innovation center of Quantum Matter Hefei National Laboratory

Superconductivity transition temperature（Tc） marks the inception of a macroscopic quantum phase-coherent paired state in fermionic systems. For 2D superconductivity, the paired electrons condense into a coherent superfluid state at Tc, which is usually lower than the pairing temperature, between which intrinsic physics including Berezinskii–Kosterlitz–Thouless transition and pseudogap state are hotly debated. In the case of monolayer FeSe superconducting films on SrTiO3（001）, although the pairing temperature（Tp） is revealed to be 65–83 K by using spectroscopy characterization, the measured zero-resistance temperature（Tc0） is limited to 20 K. Here, we report significantly enhanced superconductivity in monolayer FeSe films by δ-doping of Eu or Al on SrTiO3（001） surface, in which Tc0is enhanced by 12 K with a narrowed transition width ΔTc～8 K, compared with non-doped samples. Using scanning tunneling microscopy/spectroscopy measurements, we demonstrate lowered work function of the δ-doped SrTiO3（001） surface and enlarged superconducting gaps in the monolayer FeSe with improved morphology/electronic homogeneity. Our work provides a practical route to enhance 2D superconductivity by using interface engineering.

关键词： monolayer FeSe interface superconductivity δ-doping zero-resistance temperature superconductivity transition temperature

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Comprehensive understanding of the thriving electrocatalytic nitrate/nitrite reduction to ammonia under ambient conditions

引用

Journal of Energy Chemistry 2024年第5期92卷 459-483页

作者： Xinying Zhao Yuzhuo Jiang Mengfan Wang Yunfei Huan Qiyang Cheng Yanzheng He Tao Qian Chenglin Yan collaborative innovation center of Suzhou Nano Science and technology College of EnergySoochow UniversitySuzhou 215006JiangsuChina School of Chemistry and Chemical Engineering Nantong UniversityNantong 226019JiangsuChina School of Petrochemical Engineering Changzhou UniversityChangzhou 213164JiangsuChina

Ammonia(NH_(3))is a multifunctional compound that is an important feedstock for the agricultural and pharmaceutical industries and attractive energy storage medium.At present,NH_(3)synthesis is highly dependent on the conventional Haber–Bosch process that operates under harsh conditions,which consumes large quantities of fossil fuels and releases a large amount of carbon dioxide.As an alternative,electrosynthesis is a prospective method for producing NH_(3)under normal temperature and pressure conditions.Although electrocatalytic nitrogen reduction to ammonia has attracted considerable attentions,the low solubility of N_(2)and high N≡N cracking energy render the achievements of high NH_(3) yield rate and Faradaic efficiency difficult.Nitrate and nitrite(NO_(x)^(-))are common N-containing pollutants.Due to their high solubilities and low dissociation energy of N=O,NO_(x)^(-)−are ideal raw materials for NH_(3) production.Therefore,electrocatalytic NO_(x)^(-)−reduction to NH_(3)(eNO_(x)RR)is a prospective strategy to simultaneously realise environmental protection and NH_(3) synthesis.This review offers a comprehensive understanding of the thriving eNO_(x)RR under ambient conditions.At first,the popular theory and mechanism of eNO_(x)RR and a summary of the measurement system and evaluation criteria are introduced.Thereafter,various strategies for developing NO_(x)−reduction catalysts are systematically presented and discussed.Finally,the challenges and possible prospects of electrocatalytic NO_(x)^(-1) reduction are outlined to facilitate energy-saving and environmentally friendly large-scale synthesis of NH_(3) in the future.

关键词： Electrocatalytic nitrate reduction Electrocatalytic nitrite reduction Ammonia synthesis Pollutant removal Electrosynthesis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：