检索结果-南通市图书馆

Body size induced changes in metabolic carbon of soil nematodes under N deposition and precipitation regime change in a temperate grassland

引用

Ecological Processes 2024年第1期13卷 120-131页

作者： Shuyan cui Xiaomei Mo Guo Zheng College of Life Science Shenyang Normal University

Background Global climate change has resulted in precipitation regimes exhibiting an increasing trend in rainfall intensity but a reduction in its frequency. Nitrogen(N) deposition is a crucial component of the global N cycling. Nematode body size is a trait that responds to climate change and is used as a standard trait-based indicator in soil community analysis. Variations in body size influence metabolic carbon(C). We examined the ways by which body size and metabolic C of nematodes respond to changing precipitation regimes and how N deposition regulates these responses by an 8-year manipulative *** Nematode body size was indicated by the community-weighted mean(CWM) mass. We quantified C metabolism components of soil nematodes including production C, respiration C, and corresponding C use efficiency(CUE) under different precipitation intensities and N addition in a semi-arid steppe on the Mongolian Plateau. The Mantel test was used to determine the correlations between CWM, CUE and environmental factors. The partial least squares path modeling(PLS-PM) was conducted to quantify direct or indirect contributions among latent *** We found that heavy precipitation intensity increased the CWM mass of total nematodes and omnivorespredators without N addition. N addition decreased CWM mass of bacterivores across all the precipitation intensity treatments. Stronger precipitation intensities might be favorable for nematode production and respiration C. Variations in the nematode CWM mass drove the CUE to change with N *** Our findings provide new insights into the mechanisms underlying nematode body size and C metabolism, and highlight that explorative studies, such as manipulative experiments, are needed to identify traits underlying size-related effects and to investigate how they affect CUE of nematodes. These efforts may increase our understanding of how changes in precipitation regimes and N deposition may alter soil nema

关键词： Community-weighted mean Metabolic footprint Nitrogen addition Precipitation intensity

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

Topological and superconducting properties of monolayered CoN and CoP:A first-principles comparative study

引用

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 98-108页

作者： Jiaqing Gao Zhenyu Zhang Ping cui International Center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at Microscale(HFNL)University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum ***,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to *** two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each *** a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band ***,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced *** different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon *** central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.

关键词： topological yielding otherwise

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

Alignment of inertialess spheroidal particles in flow-structure-dominated regions of turbulent channel flow:shape effect

引用

Acta Mechanica Sinica 2024年第8期40卷 45-66页

作者： Zhiwen cui Lihao Zhao Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua UniversityBeijing100084China Laboratory of Flexible Electronics Technology Tsinghua UniversityBeijing100084China

The alignment of elongated fibers and thin disks is known to be significantly influenced by the presence of fluid coherent structures in near-wall turbulence(cui et al.2021).However,this earlier study is confined to the spheroids with infinitely large or small aspect ratio,and the shape effect of finite aspect ratio on the alignment is not *** current study investigates the shape-dependent alignment of inertialess spheroids in structure-dominated regions of channel *** utilizing an ensemble-averaged approach for identifying the structure-dominated regions,we analyze the eigensystem of the linear term matrix in the Jeffery equation,which is governed by both particle shape and local fluid velocity *** contrast to earlier conventional analysis based on local vorticity and strain rate,our findings demonstrate that the eigensystem of the Jeffery equation offers a convenient,effective,and universal framework for predicting the alignment behavior of inertialess spheroids in turbulent *** leveraging the eigensystem of the Jeffery equation,we uncover a diverse effect of fluid coherent structures on spheroid alignment with different particle ***,we provide explanations for both shape-independent alignments observed in vortical-core regions and shape-dependent alignments around near-wall streamwise vortices.

关键词： Non-spherical particle Direct numerical simulation Wall turbulence Particle-laden flow

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

Thermal-hydraulic performance analysis and multi-objective optimization of a microchannel with staggered semi-elliptical ribs

引用

Science China Technological Sciences 2024年第10期67卷 3152-3167页

作者： cui Pan LIU Wei LIU ZhiChun School of Energy and Power Engineering Huazhong University of Science and Technology

To enhance the cooling capacity of traditional microchannels for high heat flux electronic devices,a microchannel design with staggered semi-elliptical ribs is proposed in this *** numerical simulations,the flow characteristics of the designed microchannel are compared with those of a smooth one,and the effects of rib width（Wr）,rib height（Hr）,and rib length（Lr）,on the thermal-hydraulic performance are investigated under laminar flow *** results show that the periodically arranged ribs induce periodic vortices within the microchannel,effectively promoting fluid mixing and enhancing heat *** Hrhave similar effects on microchannel performance,with an increase in them leading to an enhanced thermal performance at the expense of deteriorated hydraulic ***,Lrhas a comparatively weaker influence,with both the heat transfer and flow resistance initially growing with increasing Lrand then *** strike a balance between the two performances,a multi-objective optimization on the three geometrical parameters is conducted at a Reynolds number（Re） *** with simulation data,artificial neural networks are trained as surrogate models,and a multi-objective genetic algorithm is employed to derive the Pareto *** the TOPSIS decision-making method,an optimal compromise solution is determined as Wr=0.2415 mm,Hr=0.0976 mm,and Lr=0.6486 *** testing on the optimized microchannel reveals that it exhibits high heat transfer,middle flow resistance,and excellent overall performance,with the performance evaluation criterion（PEC） falling between 1.572 and 1.723 within the Re range of 220–660.

关键词： heat transfer enhancement microchannel semi-elliptical rib numerical simulation multi-objective optimization

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

Multiscale method for identifying and marking the multiform fractures from visible-light rock-mass images

引用

Underground Space 2024年第3期16卷 279-300页

作者： Yongbo Pan Junzhi cui Zhenhao Xu School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China The State Key Laboratory of Scientific and Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Geotechnical and Structural Engineering Research Center Shandong UniversityJinan 250100China

Multiform fractures have a direct impact on the mechanical performance of rock *** accurately identify multiform fractures,the distribution patterns of grayscale and the differential features of fractures in their neighborhoods are *** on this,a multiscale processing algorithm is *** multiscale process is as *** the neighborhood of pixels,a grayscale continuous function is constructed using bilinear interpolation,the smoothing of the grayscale function is realized by Gaussian local filtering,and the grayscale gradient and Hessian matrix are calculated with high *** small-scale blocks,the pixels are classified by adaptively setting the grayscale threshold to identify potential line segments and *** the global image,potential line segments and mini-fillings are spliced together by progressing the block frontier layer-by-layer to identify and mark multiform *** accuracy of identifying multiform fractures is improved by constructing a grayscale continuous function and adaptively setting the grayscale thresholds on small-scale *** the layer-by-layer splicing algorithm is performed only on the domain of the 2-layer small-scale blocks,reducing the *** using rock mass images with different fracture types as examples,the identification results show that the proposed algorithm can accurately identify the multiform fractures,which lays the foundation for calculating the mechanical parameters of rock masses.

关键词： Visible light rock-mass images Continuous grayscale function Small-scale blocks Multiform fractures

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

Edge Device Fault Probability Based Intelligent Calculations for Fault Probability of Smart Systems

引用

Tsinghua Science and Technology 2024年第4期29卷 1023-1036页

作者： Shasha Li Tiejun cui Wattana Viriyasitavat School of Environmental and Chemical Engineering Shenyang Ligong UniversityShenyang 110159China Chulalongkorn Business School Faculty of Commerce and AccountancyChulalongkorn UniversityBangkok 10900Thailand

In a smart system, the faults of edge devices directly impact the system’s overall fault. Further, complexity arises when different edge devices provide varying fault data. To study the Smart System Fault Evolution Process (SSFEP) under different fault data conditions, an intelligent method for determining the Smart System Fault Probability (SSFP) is proposed. The data types provided by edge devices include the following: (1) only known edge device fault probability;(2) known Edge Device Fault Probability Distribution (EDFPD);(3) known edge device fault number and EDFPD;(4) known factor state of the edge device fault and EDFPD. Moreover, decision methods are proposed for each data case. Transfer Probability (TP) is divided into Continuity Transfer Probability (CTP) and Filterability Transfer Probability (FTP). CTP asserts that a Cause Event (CE) must lead to a Result Event (RE), while FTP requires CF probability to exceed a threshold before RF occurs. These probabilities are used to calculate SSFP. This paper introduces a decision method using the information diffusion principle for low-data SSFP determination, along with an improved method. The method is based on space fault network theory, abstracting SSFEP into a System Fault Evolution Process (SFEP) for research purposes.

关键词： smart systems intelligent science edge device fault probability decision method

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

热处理对哈氏合金X焊接接头组织与性能的影响

引用

稀有金属材料与工程 2019年第9期48卷 3029-3034页

作者：孙宇博靳朋礼马锦晖和晶崔景豪周可人崔梦茜丁坤英中国民航大学天津300300 天津市民用航空器适航与维修重点实验室天津300300

本实验研究不同热处理工艺对哈氏合金X焊接接头组织和力学性能的影响,分析焊后热处理对哈氏合金X焊接接头性能的影响规律。结果表明:焊缝中心区域组织主要以等轴晶为主,熔合区以枝晶为主。经1050℃热处理的焊缝未析出二次相,经1100℃处... 详细信息

本实验研究不同热处理工艺对哈氏合金X焊接接头组织和力学性能的影响,分析焊后热处理对哈氏合金X焊接接头性能的影响规律。结果表明:焊缝中心区域组织主要以等轴晶为主,熔合区以枝晶为主。经1050℃热处理的焊缝未析出二次相,经1100℃处理的焊缝在晶界处与晶粒内析出大量二次相,经1150℃处理的焊缝析出物发生重溶。经1150℃热处理工艺后接头抗拉强度最高达773.49 MPa;经1100℃处理的焊接接头断裂形式为沿晶脆性断裂,其他焊缝接头的断裂形式为韧性断裂。

关键词：哈氏合金X TIG焊接热处理微观组织力学性能

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

自主验配与常规验配助听器的短期效果对比研究

引用

听力学及言语疾病杂志 2023年第3期31卷 226-231页

作者：郗昕崔梦茜周颖田丽阳苏俊中国人民解放军总医院第一医学中心耳鼻咽喉头颈外科国家耳鼻咽喉疾病临床医学研究中心聋病教育部重点实验室聋病防治北京市重点实验室北京100853 浙江中医药大学医学技术与信息工程学院首都医科大学第四临床医学院

目的比较成年听力减退患者常规验配与自主验配助听器后的短期效果差别,探讨非处方自主验配助听器在我国中老年弱听人群中的应用前景。方法招募20例中度至中重度感音神经性听力减退的55~75岁中老年人,随机分为甲乙两组,每组10例,参与两... 详细信息

目的比较成年听力减退患者常规验配与自主验配助听器后的短期效果差别,探讨非处方自主验配助听器在我国中老年弱听人群中的应用前景。方法招募20例中度至中重度感音神经性听力减退的55~75岁中老年人,随机分为甲乙两组,每组10例,参与两款助听器验配效果的前瞻性二阶段随机对照研究;一款为由听力师优化调配的常规助听器,另一款为由使用者操控的自主验配助听器。在实验不同阶段交替佩戴常规助听器与自主验配助听器各4周。入组时及第一、二阶段结束时均采用纯音听阈、安静条件下的语句识别率等指标及助听器收益缩略简表(abbreviated profile of hearing aid benefit,APHAB)、筛查版老年听力障碍量表(hearing handicap inventory for the elderly-screening version,HHIE-S)等主观指标,比较在未助听、常规验配、自主验配助听三种状态下的结果,评价两类助听器的配戴效果。结果最终14例患者完成试验。在常规验配与自主验配两类助听器后,受试者的纯音听阈(37.9±12.8、42.6±6.3 dB HL)相较未助听时(49.4±6.8 dB HL)均明显下降(P0.05);佩戴两类助听器后的语句识别率(65.0%±19.1%、76.1%±13.7%)较未助听(50.4%±13.4%)均显著提升(P<0.01),且两类助听方式间存在显著差异(P<0.01);APHAH量表中交流便利(EC)、混响环境(RV)、嘈杂背景(BN)、烦扰声厌恶(AV)四个亚项及总体收益(GBL),常规验配和自主验配后的得分均明显高于未助听时(P<0.05);HHIE-S量表也到了相同的结果,受试者在配戴两类助听器后听力障碍指数(9.6±8.3、11.4±8.6)明显低于未助听时(17.7±7.7)(P<0.01)。结论常规助听器与自主验配助听器均可对中老年人提供有效听力补偿和言语识别助益,两类助听器之间无显著差别。但该结论尚需更广地域、更大样本数据的论证。

关键词：助听器老年人非处方验配

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

Analytical model for predicting time-dependent lateral deformation of geosynthetics-reinforced soil walls with modular block facing

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 711-725页

作者： Luqiang Ding Chengzhi Xiao Feilong cui School of Civil and Transportation Engineering Hebei University of TechnologyTianjin300401China

To date,few models are available in the literature to consider the creep behavior of geosynthetics when predicting the lateral deformation(d)of geosynthetics-reinforced soil(GRS)retaining *** this study,a general hyperbolic creep model was first introduced to describe the long-term deformation of geosynthetics,which is a function of elapsed time and two empirical parameters a and *** conventional creep tests with three different tensile loads(Pr)were conducted on two uniaxial geogrids to determine their creep behavior,as well as the a-Pr and b-Pr *** test results show that increasing Pr accelerates the development of creep deformation for both ***,a and b respectively show exponential and negatively linear relationships with Pr,which were confirmed by abundant experimental data available in other *** on the above creep model and relationships,an accurate and reliable analytical model was then proposed for predicting the time-dependent d of GRS walls with modular block facing,which was further validated using a relevant numerical investigation from the previous *** evaluation and comparison of the proposed model with six available prediction models were *** a parametric study was carried out to evaluate the effects of wall height,vertical spacing of geogrids,unit weight and internal friction angle of backfills,and factor of safety against pullout on d at the end of construction and 5 years *** findings show that the creep effect not only promotes d but also raises the elevation of the maximum d along the wall ***,the limitations and application prospects of the proposed model were discussed and analyzed.

关键词： Geosynthetics Creep behavior Geosynthetics-reinforced soil(GRS)walls Lateral deformation Analytical model

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

Fault diagnosis of a marine power-generation diesel engine based on the Gramian angular field and a convolutional neural network

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 470-482页

作者： Congyue LI Yihuai HU Jiawei JIANG Dexin cui Merchant Marine College Shanghai Maritime UniversityShanghai 201306China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics&InformationShanghai 201411China

Marine power-generation diesel engines operate in harsh *** vibration signals are highly complex and the feature information exhibits a non-linear *** is difficult to extract effective feature information from the network model,resulting in low fault-diagnosis *** address this problem,we propose a fault-diagnosis method that combines the Gramian angular field(GAF)with a convolutional neural network(CNN).Firstly,the vibration signals are transformed into 2D images by taking advantage of the GAF,which preserves the temporal *** raw signals can be mapped to 2D image features such as texture and *** integrate the feature information,the images of the Gramian angular summation field(GASF)and Gramian angular difference field(GADF)are fused by the weighted average fusion ***,the channel attention mechanism and temporal attention mechanism are introduced in the CNN model to optimize the CNN learning *** the concept of residuals in the attention mechanism improves the feasibility of ***,the weighted average fused images are fed into the CNN for feature extraction and fault *** validity of the proposed method is verified by experiments with abnormal valve *** average diagnostic accuracy is 98.40%.When−20 dB≤signal-to-noise ratio(SNR)≤20 dB,the diagnostic accuracy of the proposed method is higher than 94.00%.The proposed method has superior diagnostic ***,it has a certain anti-noise capability and variable-load adaptive capability.

关键词： Multi-attention mechanisms(MAM) Convolutional neural network(CNN) Gramian angular field(GAF) Image fusion Marine power-generation diesel engine Fault diagnosis

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：