检索结果-南通市图书馆

Patterns and drivers of avian taxonomic and phylogenetic beta diversity in China vary across geographical backgrounds and dispersal abilities

引用

Zoological Research 2024年第1期45卷 125-135页

作者： Jian-Chao Liang Zhi-feng Ding Chun-Lin Li Yi-Ming Hu Zhi-Xin Zhou Gan-Wen Lie Xiao-Nan Niu Wen-Bin Huang Hui-Jian Hu xing-feng si Guangdong Key Laboratory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouGuangdong 510260China School of Resources and Environmental Engineering Anhui UniversityHefeiAnhui 230601China Guangdong Eco-Engineering Polytechnic GuangzhouGuangdong 510520China Huizhou Institute of Forestry(Huizhou Botanical Garden Management Service Center) HuizhouGuangdong 516001China Administration of National Nature Reserve for Marine Ecology of Guangdong Nanpeng Islands ShantouGuangdong 515900China Zhejiang Zhoushan Archipelago Observation and Research Station Institute of Eco-ChongmingZhejiang Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China

Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity ***,we examined whether the patterns and drivers of taxonomic beta diversity(TBD)and phylogenetic beta diversity(PBD)of breeding birds in China vary across(1)regions on both sides of the Hu Line,which demarcates China’s topographical,climatic,economic,and social patterns,and(2)species with different dispersal *** and PBD were calculated and partitioned into turnover and nestedness components using a moving window *** representing climate,habitat heterogeneity,and habitat quality were employed to evaluate the effects of environmental *** distance was considered to assess the impact of dispersal *** partitioning analysis was applied to assess the relative roles of these *** general,the values of TBD and PBD were high in mountainous areas and were largely determined by environmental ***,different dominant environmental filters on either side of the Hu Line led to divergent beta diversity ***,climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line,***,bird species with stronger dispersal ability were more susceptible to environmental filtering,resulting in more homogeneous *** results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns,and dispersal ability determines the response of assemblages to these ecological *** a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete ***,a comprehensive understanding of large-scale beta diversity patterns and effective pla

关键词： Beta diversity Environmental filtering Dispersal limitation Hu Line Species dispersal ability Breeding birds

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

Multidimensional amphibian diversity and community structure along a 2600 m elevational gradient on the eastern margin of the Qinghai-Tibetan Plateau

引用

Zoological Research 2022年第1期43卷 40-51页

作者： Xiao-Yi Wang Mao-Jun Zhong Jian Zhang xing-feng si Sheng-Nan Yang Jian-Ping Jiang Jun-Hua Hu Chengdu Institute of Biology Chinese Academy of SciencesChengduSichuan 610041China Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education College of Life SciencesSichuan UniversityChengduSichuan 610065China Zhejiang Tiantong Forest Ecosystem National Observation and Research Station School of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China University of Chinese Academy of Sciences Beijing 100049China

Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for ***,the associated elevational gradients and underlying mechanisms of amphibian diversity in most mountain systems remain poorly ***,we explored amphibian phylogenetic and functional diversity along a 2600 m elevational gradient on Mount Emei on the eastern margin of the Qinghai-Tibetan Plateau in southwestern *** also assessed the relative importance of spatial(area)and environmental factors(temperature,precipitation,solar radiation,normalized difference vegetation index,and potential evapotranspiration)in shaping amphibian distribution and community *** showed that the phylogenetic and functional diversities were unimodal with elevation,while the standardized effect size of phylogenetic and functional diversity increased linearly with *** net relatedness,nearest taxon index,and functional net relatedness index all showed a positive to negative trend with elevation,indicating a shift from clustering to overdispersion and suggesting a potential change in key processes from environmental filtering to competitive ***,our results illustrate the importance of deterministic processes in structuring amphibian communities in subtropical mountains,with the dominant role potentially switching with *** study provides insights into the underlying assembly mechanisms of mountain amphibians,integrating multidimensional diversity.

关键词： Community structure Elevational gradient Environmental filtering Functional and phylogenetic diversity Mountain systems

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

Rogue wave solutions and rogue-breather solutions to the focusing nonlinear Schr?dinger equation

引用

Communications in Theoretical Physics 2024年第3期76卷 33-41页

作者： si-Jia Chen xing Lü College of Science Tianjin University of TechnologyTianjin 300384People's Republic of China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044People's Republic of China Beijing Laboratory of National Economic Security Early-warning Engineering Beijing Jiaotong UniversityBeijing 100044People's Republic of China

Based on the long wave limit method,the general form of the second-order and third-order rogue wave solutions to the focusing nonlinear Schr?dinger equation are given by introducing some arbitrary *** interaction solutions between the first-order rogue wave and one-breather wave are constructed by taking a long wave limit on the two-breather *** applying the same method to the three-breather solutions,two types of interaction solutions are obtained,namely the first-order rogue wave and two breather waves,the second-order rogue wave and one-breather wave,*** influence of the parameters related to the phase on the interaction phenomena is graphically *** occur among the rogue waves and breather *** the collisions,the shape of them remains *** abundant interaction phenomena in this paper will contribute to a better understanding of the propagation and control of nonlinear waves.

关键词： nonlinear Schrodinger equation rogue wave solutions interaction solutions

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

Properties of collective flow and pion production in intermediate-energy heavy-ion collisions with a relativistic quantum molecular dynamics model

引用

Nuclear Science and Techniques 2024年第1期35卷 155-169页

作者： si-Na Wei Zhao-Qing feng School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(***). Using the ***, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the *** are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich ***, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.

关键词： Heavy-ion collision Collective flow Pion production Symmetry energy Relativistic mean field

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

The noise spectral characteristics and noise reduction schemes of screw air-source heat pump:A case study

引用

Building simulation 2024年第1期17卷 53-70页

作者： Dongsheng Liu Yaohan feng Jikang Jia Pengfei si Ya feng China Southwest Architecture Design and Research Institute Co.Ltd. Chengdu 610041China CSCEC Green Construction Engineering Research Center Chengdu 610041China

The screw air-source heat pump can cause incessant high noise levels during operation,which might hinder adoption of this energy-efficient heat ***,acoustic measurements and comparison testing were performed in this *** measurements revealed that the compressor is the main noise source of the heat pump,and it shows a multipeak frequency distribution and a wide frequency spectrum under different work conditions,with multiple peaks at 63,250,and 1000 ***,a compressor sound insulation cover with broadband absorption was proposed,and it was experimentally proven that the insulation cover can reduce the maximum sound pressure level of one unit from 89.8 dBA to 79.1 ***,we proposed several noise reduction strategies and compared their noise reduction effects using computer *** results showed that the noise problem can be effectively improved through the rational design of the sound barrier and the layout and opening options of heat *** distance between the sound barrier and heat pump and the sound attenuation due to diffraction ALa exhibit a U-shaped *** buildings of different heights,the optimal heights of noise barrier are *** 5.5-meter is the optimal height of the sound barrier for single-story *** conclusions can be applied to other building projects for heat pump noise reduction.

关键词： acoustic simulation broadband noise noise reduction air-source heat pump sound barrier

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

Mineralogical properties and co-sintering characteristics of fluxed iron ore with magnetite concentrates

引用

Journal of Iron and Steel Research(International) 2024年第2期31卷 318-328页

作者： Le-le Niu Zheng-jian Liu Jian-liang Zhang Yao-zu Wang Zhen-xing Yang si-da Li Chang-dong Shan Ben feng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing100083China Xinxing Casting Pipe Xinjiang Co. Bayingol841300XinjiangChina

To investigate the feasibility of co-sintering of fluxed iron ore with magnetite concentrates, the mineralogical properties of a novel fluxed iron ore were studied using particle size analysis, microscopic morphology characterization, and X-ray diffraction Rietveld analysis. Following that, the experiments for granulation performance and basic sintering characteristics were designed under seven different fluxed iron ore ratios, and the integrated ranking of different fluxed iron ore ratios was determined using gray relation analysis. Finally, the results of the industrial trails were combined with the feasibility analysis. Test and experimental results show that the fraction of the fluxed iron ore particles larger than 0.5 mm can account for more than 48%, and the particles have two morphologies: spherical-rough and flaky-smooth. Ca elements are found in the form of calcite (CaCO3) and dolomite (CaMg(CO3)2). The average particle size of granules and powder removal rate can be improved from 2.50 to 3.16 mm and 39.60% to 24.20%, respectively, with the increase in the fluxed iron ore ratio. Furthermore, the fluxed iron ore can improve assimilability and liquid fluidity of magnetite concentrates. In terms of overall granulation performance and sintering characteristics, the fluxed iron ore ratios are graded from best to worst as follows: 12%, 15%, 9%, 18%, 21%, 6% and 3%. The industrial trails show that when the fluxed iron ore ratio is increased, the beneficial effect of the superior sintering characteristics of the fluxed iron ore itself is ideally balanced with the negative effect of the lower amount of additional CaO at 12% ratio, and thus, it is feasible to bring the fluxed iron ore into production at a level of roughly 12%.

关键词： Fluxed iron ore Magnetite concentrate Granulation performance sintering characteristics Gray relation analysis

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

Syntheses and properties of associative acrylamide copolymers containing short hydrophobic chains used in a friction reducer for slick-water fracturing

引用

Petroleum Science 2024年第3期21卷 1889-1901页

作者： Ya-xing Dai Xian-Li Zhang si-Yuan Liu feng-Run-Ze Zhang Yi-Xi Zhang Yu-Tong Sang Jing-Xi Zheng Zhao-Sheng Liu Peng Zhang College of Chemistry and Chemical Engineering Chongqing University of Science and TechnologyChongqing401331China College of Ecology and Environment Chongqing Resources and Environmental Protection of UniversityChongqing401331China China China Property Project Department of Dezhou Mining Property Service CenterShengli Oilfield Company of SinopecDezhou253000ShandongChina

Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2),were synthesized and used to prepare modified polyacrylamide *** new drag reducers were synthesized from acrylamide(AM),sodium acrylate(Na AA)and a cationic modified monomer(AQAS1 or AQAS2)via aqueous solution polymerization,and the copolymers were named P(AM/Na AA/AQAS1)and P(AM/Na AA/AQAS2),*** structures of the drag reduction agents were confirmed by IR and1H NMR *** molecular weight(Mw)of P(AM/Na AA/AQAS1)was 1.79×10^(6)g/*** the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min,in fresh water the highest drag reduction rate was 75.8%,in 10,000 mg/L Na Cl solution the drag reduction rate decreased to 72.9%.The molecular weight of P(AM/Na AA/AQAS2)was 3.17×10^(6)g/*** the copolymer concentration was500 mg/L and the flow rate was 45 L/min,the drag reduction rate reached 75.2%,and in 10,000 mg/L Na Cl solution the drag reduction rate was 73.3%,decreased by approximately 1.9%.The drag reduction rate for partially hydrolyzed polyacrylamide(HPAM)was also investigated,and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2%and 49.0%in brine,*** with HPAM,both of the above copolymers presented better drag reduction capacities.

关键词： Shale gas Slick water Drag reducer Modified monomer Copolymerization

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

Added value of ratio of cross diameters of the appendix in ultrasound diagnosis of acute appendicitis

引用

World Journal of Gastrointestinal Surgery 2024年第1期16卷 21-28页

作者： feng-Wa Gu si-Ze Wu Department of Ultrasound The First Affiliated Hospital of Hainan Medical UniversityHaikou 570102Hainan ProvinceChina

BACKGROUND The maximum outer diameter(MOD)of the appendix is an essential parameter for diagnosing acute appendicitis,but there is space for improvement in ultrasound(US)diagnostic *** To investigate whether combining the ratio of the cross diameters(RATIO)of the appendix with MOD of the appendix can enhance the diagnostic performance of acute *** A retrospective study was conducted,and medical records of 233 patients with acute appendicitis and 112 patients with a normal appendix were *** MOD and RATIO of the appendix were calculated and tested for their diagnostic performance of acute appendicitis,both individually and in *** The RATIO for a normal appendix was 1.32±0.16,while for acute appendicitis it was 1.09±*** cut-off value for RATIO was determined to be≤*** area under the receiver operating characteristic curve(AUC)for diagnosing acute appendicitis using RATIO≤1.18 and MOD>6 mm was 0.870 and 0.652,*** was a significant difference in AUC between RATIO≤1.18 and MOD>6 mm(P6 mm with MOD>6 mm alone,the combination showed increased specificity,positive predictive value(PPV),and ***,the sensitivity and negative predictive value *** Combining RATIO of the appendix≤1.18 and MOD>6 mm can significantly improve the specificity,PPV,and AUC in the US diagnosis of acute appendicitis.

关键词： Acute appendicitis Diameter Ratio Diagnosis Ultrasound

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

Adhesive Contact of Elastic Solids with Self-Affine Fractal Rough Surfaces

引用

Acta Mechanica Solida sinica 2024年第2期37卷 265-270页

作者： Xuan-Ming Liang Shi-Wen Chen si-He Wang Zhen-Yuan Gong Jun feng Gang-feng Wang Department of Engineering Mechanics SVL and MMMLXi’an Jiaotong UniversityXi’an710049China OPPO Mobile Telecommunications Corporation Ltd. Dongguan523860China

The elastic adhesive contact of self-affine fractal rough surfaces against a rigid flat is simulated using the finite element method. An array of nonlinear springs, of which the force-separation law obeys the Lennard–Jones potential, is introduced to account for the interfacial adhesion. For fractal rough surfaces, the interfacial interaction is generally attractive for large mean gaps, but turns repulsive as the gap continuously shrinks. The interfacial interactions at the turning point corresponding to the spontaneous contact are shown for various surfaces. For relatively smooth surfaces, the probability density distributions of repulsion and attraction are nearly symmetric. However, for rougher surfaces, the simulation results suggest a uniform distribution for attraction but a monotonously decreasing distribution with a long tail for repulsion. The pull-off force rises with increasing ratio of the work of adhesion to the equilibrium distance, whereas decreases for solids with a higher elastic modulus and a larger surface roughness. The current study will be helpful for understanding the adhesion of various types of rough solids.

关键词： Fractal rough surfaces Adhesion Contact mechanics Lennard-Jones potential

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

Experimental quantum state compression from two identical qubits to a qutrit

引用

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 1-5页

作者： Qiao Xu Lin-Xiang Zhou Tian-feng feng Shang-feng Qiu si-Wu Li Wu-Ji Zhang Hui Luo Xiao-Qi Zhou State Key Laboratory of Optoelectronic Materials and Technologies and School of Physics Sun Yat-sen UniversityGuangzhou 510000China Hefei National Laboratory Hefei 230088China

In the realm of modern information technology,data compression technology occupies a pivotal *** advancements in quantum information technology,the need to compress large-scale qubits ensembles has become urgent,aiming to reduce the demand on quantum storage ***,existing quantum state compression schemes generally face a limitation:the particles before and after compression must reside in the same dimensional *** specific scenarios,compressing qubits into particles of higher dimensions not only enhances the efficiency of quantum state compression but also further reduces the usage of quantum storage *** we experimentally demonstrated a quantum state compression between particles of different dimensions,successfully compressing two qubits into a single *** average fidelity of the resulting qutrit with the ideal quantum state is *** study may have potential applications in future quantum information,such as increasing quantum communication bandwidth and reducing storage resource consumption in quantum computing.

关键词： quantum state compression quantum information technology optics

来源：

维普期刊数据库

同方期刊数据库

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：