检索结果-南通市图书馆

A phylogenetic approach identifies patterns of beta diversity and floristic subregions of the Qinghai-Tibet Plateau

Plant Diversity 2024年第1期46卷 59-69页

作者： Haibin yu Man Yang Zixin Lu Weitao Wang Fangyuan yu Yonghua Zhang Xue Yin Hongjun yu Junjie hu David C.Deane Key Laboratory of Conservation and Application in Biodiversity of South China School of Life SciencesGuangzhou UniversityGuangzhou 510006China School of Ecology Sun Yat-Sen UniversityShenzhen 510275China School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006China College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China Centre for Future Landscapes and Department of Environment and Genetics La Trobe UniversityBundooraVIC 3083Australia

Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional *** Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic *** this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet *** also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the *** also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic *** environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic *** dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the *** results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.

关键词： Biogeographical regionalization Phylogenetic beta diversity Seed plants Sørensen dissimilarity Qinghai-Tibet Plateau

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

Controllable nucleation and deformation of skyrmions on surface of magnetic nanotubular monolayer

引用

Rare Metals 2024年第7期43卷 3250-3259页

作者： Xin-Xin Zhang Chen-yu Zhang Yi-Xin Xing Chao Man Jiao Liu Yong hu Department of Physics College of SciencesNortheastern University School of Materials and Mineral Resources Engineering Universiti Sains MalaysiaEngineering Campus State Key Laboratory of Rolling and Automation Northeastern University

Magnetic skyrmions emerge when the energy of ferromagnetic exchange interaction promoting parallel alignment of spins enters in competition with energies favoring non-collinear alignment of spins such as Dzy aloshinskii-Moriya interaction(DMI),long-rang dipole-dipole interaction(DDI),or higher-order exchange *** perform an unbiased Monte Carlo simulation to study the DMI-based skyrmion nucleation and stabilization on the surface of magnetic nanotubular monolayer controlled by tuning constants of DDI(g) and next-nearest-neighbor antiferromagnetic exchange interaction(j') with appropriate *** g and j',the loosely distributed skyrmions initially nucleate on the surface of nanotube approaching to the magnetic field(h) direction with increasing h in the intermediate ***,the skyrmion size,shape,density,distribution and crystal structure,as well as its driven field range,are tailored by g and j'.This work demonstrates the skyrmion nucleation mechanisms in three-dimensional magnetic nanostructures with curvature effect and multiple interactions,serving as a benchmark for a guide to experimentalists for preparation of samples in magnetic skyrmion states.

关键词： Magnetic nanotube Magnetic skyrmion Dzyaloshinskii–Moriya interaction Dipole–dipole interaction Monte Carlo simulation

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

Effects of deformation temperatures on microstructures,aging behaviors and mechanical properties of Mg-Gd-Er-Zr alloys fabricated by hard-plate rolling

引用

Journal of Magnesium and Alloys 2024年第6期12卷 2345-2359页

作者： Ke Liu Dalong hu Feng Lou Zijian yu Shubo Li Xian Du Wenbo Du Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

In this investigation,a high-strength Mg-12Gd-1.0Er-0.5Zr(wt.%)alloy sheet was produced by hot extrusion(HE)and subsequent hard-plate rolling(HPR)at different *** results indicate that the microstructures of these final-rolled sheets are inhomogeneous,mainly including coarse deformed grains and dynamic recrystallized(DRXed)grains,and the volume fraction of these coarse deformed grains increases as the rolling temperature ***,more DRXed grains can be found in R-385℃sheet,resulting in a smaller average grain size and weaker basal texture,while the biggest grains and the highest strong basal texture are present in R-450℃*** of dynamic precipitation ofβphases which are mainly determined by the rolling temperature are present in these sheets,and its precipitation can consume the content of Gd solutes in the *** a result,the lowest number density ofβphase in R-450℃sheet is beneficial to modify the age hardening ***,the R-450℃sheet displays the best age hardening response because of a severe traditional precipitation ofβ’(more)andβH/βM(less)precipitates,resulting in a sharp improvement in strength,*** tensile strength(UTS)of∼518±17 MPa and yield strength(YS)of∼438±18 ***,the elongation(EL)of this sheet reduces greatly,and its value is∼2.7±0.3%.By contrasting,the EL of the peak-aging R-385℃sheet keeps better,changing from∼4.9±1.2%to∼4.8±1.4%due to a novel dislocation-induced chain-like precipitate which is helpful to keep good balance between strength and ductility.

关键词： Mg-Gd-Er-Zr sheets Age hardening response Precipitates Mechanical properties

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 Formation of SO_(2) and Emission Reduction Solutions in the Preparation of a Hydrogenation Catalyst Support

引用

China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 98-106页

作者： hu Anpeng Wang Zhen Yang Qinghe hu Dawei Gong yu Jia Yanzi Dai Qiaoling Pu Ning SINOPEC Research Institute of Petroleum Processing Beijing 100083China Zibo Qimao Catalyst Co. Ltd.Zibo 255400China

The key reason for SO_(2) formation during the production of a residue hydrogenation catalyst support was identified and subsequent emission reduction solutions were then investigated and verified *** results demonstrated that carbon-containing organic materials,including sesbania powder and cellulose,did not completely decompose over the temperature range of 350−600℃during the heating stage of the calcination process,but rather underwent a condensation reaction within the same temperature range to form carbon-containing species with a lower ratio of hydrogen to carbon and a higher condensation degree,which promoted the decomposition of sulfate to form SO_(2).Systematic experimental work revealed that three different measures,i.e.,applying the staged calcination method,reducing the heating rate,and increasing the air flow rate,during the calcination process could all achieve the effect of reducing SO_(2) emissions.

关键词： alumina sesbania powder cellulose sulfur dioxide

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

Floating plants reduced methane fluxes from wetlands by creating a habitat conducive to methane oxidation

引用

Journal of Environmental Sciences 2024年第1期135卷 149-160页

作者： Fuwei Wang Songhe Zhang Xiuren hu Xin Lv Min Liu yu Ma Benjamin Manirakiza Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationHohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 210098China China Machinery International Engineering Desigh and Research Institute co. Ltd.East China Regional CenterNanjing 210008China

Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane ***,the effects of floating plants on methane release are *** this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa *** found that ***,***,and *** plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to Control,*** fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and *** the same biomass,root of *** (36.44%) had the highest methane oxidation potential,followed by *** (12.99%) and *** (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known *** I methanotrophs accounted for 95.07%of total *** pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root *** of pmoA gene was significantly positively correlated with environmental *** (5.40%) and methanotrophy (3.75%) function were closely related to methane *** study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.

关键词： Floating plants Methane fluxes Aerenchyma Methanotrophs

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

Ultrafast laser-chemical modification hybrid fabrication of hydrostatic bearings with a superhydrophobicity solid-liquid interface

引用

Science China(Technological Sciences) 2024年第3期67卷 696-708页

作者： GUO Minghui RONG YouMin huANG yu FENG XiaoLin hu HaiDong WU CongYi ZHANG GuoJun State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Faculty of Engineering and Life Sciences Universiti Selangor Bestari JayaSelangor 45600Malaysia

Oil film vortex severely reduces the stability of hydrostatic bearings. A solid-liquid interface with drag and slip properties can weaken the oil film vortex of the bearing. Here, a combined picosecond laser ablation and chemical modification method is proposed to prepare surfaces with microbulge array structure on 6061 aluminum alloy substrates. Because of the low surface energy of the perfluorododecyltriethoxysilane modification and the bulge geometry of the microbulge array structure, the surface shows excellent superhydrophobicity. The optimum contact angle in air for water is 164°, and that for oil is 139°. Two surfaces with “lotus-leaf effect” and “rose-petal effect” were obtained by controlling the processing parameters. The drag reduction properties of superhydrophobic surfaces were systematically investigated with slip lengths of 22.26 and 36.25 μm for deionized water and VG5 lubricant, respectively. In addition, the superhydrophobic surface exhibits excellent mechanical durability and thermal stability. The proposed method provides a new idea for vortex suppression in hydrostatic bearings and improves the stability of bearings in high-speed operation.

关键词： superhydrophobicity surface ultrafast laser drag reduction solid-liquid interface microbulge array structure

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

Predicting stability of integrated circuit test equipment using upper side boundary values of normal distribution

引用

The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 85-93页

作者： Zhan Wenfa hu Xinyi Zheng Jiangyun yu Chuxian Cai Xueyuan Zhang Lihua School of Electronic Engineering and Intelligent Manufacturing Anqing Normal UniversityAnqing 246133China School of Computer and Information Technology Anqing Normal UniversityAnqing 246133China

In response to the growing complexity and performance of integrated circuit(IC),there is an urgent need to enhance the testing and stability of IC test equipment.A method was proposed to predict equipment stability using the upper side boundary value of normal ***,the K-means clustering algorithm classifies and analyzes sample *** accuracy of this boundary value is compared under two common confidence levels to select the optimal threshold.A range is then defined to categorize unqualified test *** experimental verification,the method achieves the purpose of measuring the stability of qualitative IC equipment through a deterministic threshold value and judging the stability of the equipment by comparing the number of unqualified data with the threshold value,which realizes the goal of long-term operation monitoring and stability analysis of IC test equipment.

关键词： K-means clustering algorithm the upper side boundary of normal distribution threshold integrated circuit(IC)test equipment stability analysis

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

Asymptotic behavior of an SIQR epidemic model driven by Lévy jumps on scale-free networks

引用

International Journal of Biomathematics 2024年第2期17卷 51-86页

作者： yuncheng Xu Sanyang Liu Xiaojun Sun hua hu yu Wang School of Mathematics and Statistics Xidian University Xi'an 710071P.R.China School of Mathematics and Statistics Ning Xia University Ningria 750021P.R.China School of Mathematics and Information Science Bao Ji University of Arts and Sciences Baoji 721013 P.R.China College of Mathematics Science and Center for Applied Mathematical Science Inner Mongolia Normal University Hohhot 010022 P.R.China

To investigate the effect of information transmission,Levy jumps and contact heterogeneity of individuals on the asymptotic behavior of epidemic,a stochastic SIQR epidemic model with non-monotone incidence rate and Levy jumps on scale-free networks is *** first,the global dynamics of the deterministic model is studied by constructing appropriate Lyapunov *** the stochastic model is made in accordance with the ecological significance,the existence and uniqueness of the global positive solution of the stochastic SIQR model is ***,by constructing suitable stochastic Lyapunov functions and applying Ito formula with jump,the asymptotic behavior of solutions of stochastic model around equilibrium of the corresponding deterministic model is *** last,the correctness of the analytical results is verified by numerical simulations.

关键词： Lévy jumps asymptotic behavior non-monotone incidence rate scale-free networks SIQR.

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

Causal associations between gastroesophageal reflux disease and essential hypertension: A bidirectional Mendelian randomization study

引用

World Journal of Clinical Cases 2024年第5期12卷 880-890页

作者： Ning Wei Ming-hui Liu yu-hu Song Department of Gastroenterology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina

BACKGROUND Clinical studies have reported that patients with gastroesophageal reflux disease(GERD)have a higher prevalence of *** To performed a bidirectional Mendelian randomization(MR)analysis to investi-gate the causal link between GERD and essential *** Eligible single nucleotide polymorphisms(SNPs)were selected,and weighted median,inverse variance weighted(IVW)as well as MR egger(MR-Egger)re-gression were used to examine the potential causal association between GERD and *** MR-Pleiotropy RESidual Sum and Outlier analysis was used to detect and attempt to reduce horizontal pleiotropy by removing outliers *** MR-Egger intercept test,Cochran’s Q test and“leave-one-out”sen-sitivity analysis were performed to evaluate the horizontal pleiotropy,heterogen-eities,and stability of single instrumental *** IVW analysis exhibited an increased risk of hypertension(OR=1.46,95%CI:1.33-1.59,P=2.14E-16)in GERD *** the same result was obtained in replication practice(OR=1.002,95%CI:1.0008-1.003,P=0.000498).Meanwhile,the IVW analysis showed an increased risk of systolic blood pressure(β=0.78,95%CI:0.11-1.44,P=0.021)and hypertensive heart disease(OR=1.68,95%CI:1.36-2.08,P=0.0000016)in GERD ***,we found an decreased risk of Barrett's esophagus(OR=0.91,95%CI:0.83-0.99,P=0.043)in essential hypertension *** We found that GERD would increase the risk of essential hypertension,which provided a novel prevent and therapeutic perspectives of essential hypertension.

关键词： Gastroesophageal reflux disease Essential hypertension Hypertensive heart disease Mendelian randomization study

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

Rate transient analysis methods for water-producing gas wells in tight reservoirs with mobile water

引用

Energy Geoscience 2024年第1期5卷 311-320页

作者： Qingyan yu Ying Jia Pengcheng Liu Xiangyang hu Shengye Hao Research Institute of Petroleum Exploration and Development of SINOPEC Beijing100083China School of Energy Resources China University of GeosciencesBeijing100083China

Tight gas reservoirs with mobile water exhibit multi-phase flow and high stress *** analyzing the reservoir and well parameters using conventional single-phase rate transient analysis methods proves *** study introduces novel rate transient analysis methods incorporating evaluation processes based on the conventional flowing material balance method and the Blasingame type-curve method to examine fractured gas wells producing *** positing a gas-water two-phase equivalent homogenous phase that considers characteristics of mobile water,gas,and high stress sensitivity,the conventional single-phase rate transient analysis methods can be applied by integrating the phase's characteristics and defining the phase's normalized parameters and material balance *** rate transient analysis methods based on the equivalent homogenous phase can be used to quantitatively assess the parameters of wells and gas reservoirs,such as original gas-in-place,fracture half-length,reservoir permeability,and well drainage *** facilitates the analysis of production dynamics of fractured wells and well-controlled areas,subsequently aiding in locating residual gas and guiding the configuration of well *** specific evaluation processes are ***,a numerical simulation mechanism model was constructed to verify the reliability of the developed *** methods introduced have been successfully implemented in field water-producing gas wells within tight gas reservoirs containing mobile water.

关键词： Gas reservoirs with mobile water Gas-water two phase flow High stress sensitivity Equivalent homogenous phase Rate transient 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

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：