检索结果-南通市图书馆

How interfacial electron-donating defects influence the structure and charge of gold nanoparticles on TiO_(2)support

引用

Nano Research 2024年第7期17卷 5965-5974页

作者： guang-Jie xia Yu Fu Wei Cao jun Li Yang-Gang Wang Department of Chemistry and guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China School of Physical Sciences Great Bay UniversityDongguan 523000China Department of Chemistry Tsinghua UniversityBeijing 100084China

The reduction degree of TiO_(2)support is critical to the performances of metal *** many previous theoretical calculations,only the bridge oxygen vacancy(Ov)was considered as the electron-donating defect on reduced rutile TiO_(2)(r-TiO_(2−x))***,titanium adatoms(Tiad.),oxidized titanium islands(***),and acid hydroxyls(ObrH)also exist at the metal/support *** conducting density functional theory(DFT)calculations and ab initio molecular dynamics(AIMD)simulations,we compared r-TiO_(2−x)surfaces with Ov,Tiad.,***,and ObrH sites loaded with Au nanoparticles(NPs).The results showed the Au NPs were oxygen-phobic but titanium-philic,resulting in wetting of Ov and *** short contact with *** and *** Bader charges of Au NPs(QM)showed a good linear relationship with the ideal number of donating electrons(Ne)from the defective sites(QM=−KeNe+QM,S),demonstrating the intrinsic electron allocation at the *** Ov,Tiad.,and *** exhibited similar slopes(Ke),relatively steeper than that of *** means in the scope of Au NP charge state,the *** *** have a close electron-donating ability with Ov,but the ObrH donates relatively fewer *** linear relationship can be extended approximately to other *** higher the metal work function,the steeper the Ke for easier electron donation from defective *** stronger the metal oxygen affinity,the more positive the intercept(QM,S).That explains the easy generation of metallic or negative Pt and Au NPs on r-TiO_(2−x),but hard for Cu and Zn in *** provides theoretical guidance for regulating the charge of metal NPs over TiO_(2−x)supports.

关键词： metal-support interaction titanium oxide oxygen vacancy surface hydroxyl titanium adatom

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

Pretreating and normalizing metabolomics data for statistical analysis

引用

Genes & Diseases 2024年第3期11卷 188-205页

作者： jun Sun Yinglin xia Division of Gastroenterology and Hepatology Department of MedicineDepartment of Microbiology/ImmunologyUIC Cancer CenterUniversity of Illinois ChicagoJesse Brown VA Medical Center Chicago(537)ChicagoIL 60612USA Division of Gastroenterology and Hepatology Department of MedicineUniversity of Illinois ChicagoChicagoIL 60612USA

Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological *** is emerging as a powerful tool generally for pre-cision ***,integration of microbiome and metabolome has revealed the mechanism and functionality of microbiome in human health and ***,metabo-lomics data are very ***/pretreating and normalizing procedures on metabolomics data are usually required before statistical *** this review article,we comprehensively review various methods that are used to preprocess and pretreat metabolo-mics data,including MS-based data and NMR-based data preprocessing,dealing with zero and/or missing values and detecting outliers,data normalization,data centering and scaling,data *** discuss the advantages and limitations of each *** choice for a suitable preprocessing method is determined by the biological hypothesis,the characteristics of the data set,and the selected statistical data analysis *** then provide the perspective of their applications in the microbiome and metabolome research.

关键词： Data centering and scaling Data normalization Data transformation Missing values MS-Baseddata preprocessing NMRData preprocessing Outliers Preprocessing/pretreatment

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

Derivatives of Intersection Local Time for Two Independent Symmetricα-stable Processes

引用

Acta Mathematica Sinica,English Series 2024年第5期40卷 1273-1292页

作者： Huan ZHOU guang jun SHEN Qian YU Department of Mathematics Anhui Normal UniversityWuhu 241002P.R.China Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106P.R.China

In this paper,we consider the derivatives of intersection local time for two independent d-dimensional symmetricα-stable processes X^(α) and X^(α)with respective indices α and α.We first study the sufficient condition for the existence of the derivatives,which makes us obtain the exponential integrability and H?lder *** we show that this condition is also necessary for the existence of derivatives of intersection local time at the ***,we also study the power variation of the derivatives.

关键词： Symmetric stable processes intersection local time exponential integrability power variation

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

Effects of the Rainfall-Triggered Lisse Effect on the Stability of Loess Slopes

引用

Journal of Earth Science 2024年第4期35卷 1254-1262页

作者： Zhizhou Yang Donghui Cheng jun xia School of Water and Environment Chang’an UniversityXi’an710054China Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education Chang’an UniversityXi’an710054China Key Laboratory of Eco-Hydrology and Water Security in Arid and Semi-Arid Regions of the Ministry of Water Resources Chang’an UniversityXi’an710054China Key Laboratory of Water Cycle&Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China State Key Laboratory of Water Resources&Hydropower Engineering Sciences Wuhan UniversityWuhan430000China

This paper coupled a water-air two-phase hydrodynamic(WATPH)model with the Iverson’s method to analyze the influence of the Lisse effect on the fast groundwater pressure(P_(w))response and the slope ***,the sensitivities of the driving force and loess soil parameters were *** showed that the WATPH model simulated the height and rise of the depth to the water table reasonably *** depth to water table before rainfall(H0)had a significant impact on the Lisse effect and the slope *** the H_(0) was less than approximately 1 m,the rainfall triggered a significant Lisse effect and decreased the slope factor of safety(F_(s)).When the rainfall intensity(R_(i))was higher than the saturated hydraulic conductivity(K_(s)),the Lisse effect and the F_(s) slightly changed with the increase of the R_(i),and the slope tended to be unstable with continuous *** increasing K_(s),the Lisse effect noticeably increased,and the minimum F_(s) quickly *** analysis of the normalized sensitivity coefficient revealed that H_(0) had a dramatic impact on the Lisse effect and loess slope *** different R_(i) and K_(s) values had prominent influences on the Lisse effect and slight impacts on F_(s).

关键词： Lisse effect landslides safety factor rainfall

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

DEM investigation of strength and critical state behaviours of granular materials under true triaxial loadings

引用

Particuology 2024年第2期85卷 198-212页

作者： Minyi Zhu Guobin Gong jun xia Stephen Wilkinson Department of Civil Engineering Xi'an Jiaotong-Liverpool UniversityChina Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolUK Faculty of Engineering and Information Sciences University of Wollongong in DubaiUnited Arab Emirates

This paper investigates the strength and critical state(CS)behaviours of granular materials via DEM simulations of true triaxial drained tests under three different loading modes including constant b(in-termediate stress ratio)tests with constantσ'1(major principal stress),constant p(mean pressure)and constantσ'3(minor principal stress)*** this end,a series of samples are generated with the same particle size distribution,and with the confining stresses ranging from 100 kPa to 900 *** CS is achieved for all *** the macroscopic behaviours and the microscopic behaviours are examined and compared considering different loading modes,confining stresses and intermediate stress ratios(b).The critical state lines(CSLs)are found to be unique and independent of the loading modes,but dependent on the b *** CSLs with b=0 and b=1 form the two boundaries of CSLs respectively beyond which CSLs under all other b tests cannot go *** different strength criteria are examined and compared in terms of both peak and CS *** Mohr-Coulomb strength criterion is found to be only suitable for axisymmetric loading *** Lade-Duncan criterion is only suitable for describing peak strengths,which is dependent on the loading modes and confining *** Satake criterion and Matsuoka-Nakai criterion are the more appropriate strength criteria for describing CS failures,indicating that the CS values of both the Satake parameter and the Matsuoka-Nakai parameter describe an inherent property that characterizes the CS failure for a given type of *** CS mechanical coordination number is fitted by a curved line for a given b value,which is unique regardless of the loading *** peak and CS values of both major and minor principal fabric tensors decrease with increasing b values,while they increase with increasing b values for the intermediate principal fabric tensor.

关键词： Discrete element method Intermediate stress ratio Dilation Critical state Failure criterion

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

Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

引用

Nuclear Science and Techniques 2024年第1期35卷 81-95页

作者： Ming xia Yong-jun Ye Shu-Yuan Liu School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001China

Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the *** these measurement methods,the closed-loop method is frequently ***,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation *** CFD-based technique was applied to predict the radon concentration distribution in a limited space,allowing radon accumulation and exhalation inside the chamber intuitively and *** this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the *** consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was *** effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were *** on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion *** CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate.

关键词： Radon exhalation Numerical simulation Accumulation chamber

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

Effects of Plant Oil Mixture on Production Performance,Carcass and Beef Quality in Beef Cattle

引用

Animal Husbandry and Feed Science 2011年第6期3卷 12-16页

作者： xia guang-jun YAN Chang-guo LIU Cheng-ming Agricultural College Yanbian University Yanji 133000 China Hunchun Tianyi Livestock Husbandry Co. Ltd. Hunchun 133300 China

[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy Yanbian yellow bulls having close body weight were selected and randomly divided into four groups, four cattle per group. Been oil, safflower oil and sunflower oil were mixed respectively at a volume ratio of 11：5：4. The oil blend was added to the daily diets of beef cattle respectively at a proportion of 4%, 5% and 6%. The effects of the plant oil mixture on production performance, carcass and beef quality were investigated. [ Result.] Compared with the control cattle, the experimental cattle had significantly lower feed intake （P 〈 0.05）, non-significantly higher efficiency of feed utilization, and significantly lower digestibility of crude fiber and calcium （P 〈 0.05）. With the increasing level of plant oil, the digestibility of dry matter showed a decreasing trend. The digestibility of dry matter was significantly lower in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. The plant oil mixture had no effect on the digestibility of crude protein, ether extract, crude ash, nitrogen-free extract and phosphorus. With the increasing level of plant oil, the serum content of high-density lipoprotein showed an increasing trend. The serum content of high-density lipoprotein was significantly higher in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. With the increasing level of plant oil, the content of total cholesterol showed an increasing trend, whereas the content of low-density lipoprotein showed a decreasing trend. Moreover, other indicators did not change significantly. The experimental cattle had larger eye muscle area and better beef quality than the control group. The content of crude protein and ether extract in beef increased with the increasing level of plant oil. [ Conclusion] The plan

关键词： Plant oil Beef cattle Production performance Carcass Beef quality

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

Focal mechanics and disaster characteristics of the 2024 M 7.6 Noto Peninsula Earthquake,Japan

引用

Frontiers of Structural and Civil Engineering 2024年第9期18卷 1378-1387页

作者： guang-qi CHEN Yan-qiang WU Ming-yao xia Zhi-yuan LI School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300131China Graduate School of Engineering Kyushu UniversityFukuoka 819-0395Japan The First Monitoring and Application Center China Earthquake AdministrationTianjin 300180China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

On January 1,2024,a devastating M 7.6 earthquake struck the Noto Peninsula,Ishikawa Prefecture,Japan,resulting in significant casualties and property *** information from the first six days after the earthquake,this article analyzes the seismic source characteristics,disaster situation,and emergency response of this *** results show:1)The earthquake rupture was of the thrust type,with aftershock distribution showing a north-east-oriented belt-like feature of 150 km.2)Global Navigation Satellite System(GNSS)and Interferometric synthetic aperture radar(InSAR),observations detected significant westward to north-westward co-seismic displacement near the epicenter,with the maximum horizontal displacement reaching 1.2 m and the vertical uplift displacement reaching 4 m.A two-segment fault inversion model fits the observational data well.3)Near the epicenter,large Peak Ground Velocity(PGV)and Peak Ground Acceleration(PGA)were observed,with the maxima reaching 145 cm/s and 2681 gal,respectively,and the intensity reached the highest level 7 on the Japanese(Japan Meteorological Agency,JMA)intensity standard,which is higher than level 10 of the United States Geological Survey(USGS)Modified Mercalli Intensity(MMI)standard.4)The observation of the very rare multiple strong pulse-like ground motion(PLGM)waveform poses a topic worthy of research in the field of earthquake engineering.5)As of January 7,the earthquake had left 128 deaths and 560 injuries in Ishikawa Prefecture,with 1305 buildings completely or partially destroyed,and had triggered a chain of disasters including tsunamis,fires,slope failures,and road ***,this paper summarizes the emergency rescue,information dissemination,and other disaster response and management measures taken in response to this *** work provides a reference case for carrying out effective responses,and offers lessons for handling similar events in the future.

关键词： Noto Peninsula Earthquake earthquake rupture mechanism earthquake disaster emergency response pulse-like ground motion

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

A Novel Disturbance Observer Based Fixed-Time Sliding Mode Control for Robotic Manipulators With Global Fast Convergence

引用

IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 661-672页

作者： Dan Zhang Jiabin Hu jun Cheng Zheng-guang Wu Huaicheng Yan IEEE Zhejiang University of Technology guangxi Normal University Zhejiang University the East China University of Science and Technology

This paper proposes a new global fixed-time sliding mode control strategy for the trajectory tracking control of uncertain robotic ***,a fixed-time disturbance observer(FTDO) is designed to deal with the adverse effects of model uncertainties and external disturbances in the manipulator *** an adaptive scheme is used and the adaptive FTDO(AFTDO) is developed,so that the priori knowledge of the lumped disturbance is not ***,a new non-singular fast terminal sliding mode(NFTSM) surface is designed by using an arctan function,which helps to overcome the singularity problem and enhance the robustness of the *** on the estimation of the lumped disturbance by the AFTDO,a fixed-time non-singular fast terminal sliding mode controller(FTNFTSMC)is developed to guarantee the trajectory tracking errors converge to zero within a fixed *** settling time is independent of the initial state of the *** addition,the stability of the AFTDO and FTNFTSMC is strictly proved by using Lyapunov ***,the fixed-time NFESM(FTNFTSM) algorithm is validated on a 2-link manipulator and comparisons with other existing sliding mode controllers(SMCs) are *** comparative results confirm that the FTNFTSMC has superior control performance.

关键词： Disturbance observer(DO) fixed-time non-singular sliding mode control robotic manipulator trajectory tracking

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

Enhancing reversible hydrogen storage performance of 2LiBH4–MgH2 via in-situ building heterogeneous nucleation sites

引用

Rare Metals 2024年第9期43卷 4367-4376页

作者： Wei Chen Ya-Hui Sun Tian Xu Xue-Bin Yu guang-Lin xia Department of Materials Science Fudan University

2LiBH4-MgH2composite is one of the most attractive reactive hydride composites with a theoretic hydrogen capacity of 10.8 wt%.However,the large nucleation restriction of MgB2during the second step of dehydrogenation results in sluggish hydrogen storage kinetics and high operating temperature,which hinders its practical application as on-board hydrogen storage ***,Al3Ti doped Al nanoparticles （AT NPs） are prepared by a facile chemical reduction reaction to improve the hydrogen storage performance of *** the initial H2desorption process,MgAlB4and TiB2that have identical crystal structure and low d-value mismatch with MgB2resulting from the reaction between AT NPs and 2LiBH4-MgH2composite serve as effective nucleation sites for the formation of *** a result,the apparent activation energy of the two-step H2desorption of AT NPs doped 2LiBH4-MgH2composite are notably decreased to （110.0±5.9） and（119.6±1.4） kJ·mol-1,which is 55.5 and 33.5 kJ·mol-1lower than that of the undoped *** importantly,a reversible hydrogen storage capacity of 9.2 wt%after 10cycles of H2desorption and adsorption could be achieved,corresponding to a capacity retention rate of 99%.The building of reactive bimetallic catalyst towards in situ formation of heterogeneous nucleation sites provides a new strategy for improving the hydrogen storage performance of reactive hydride composites.

关键词： Catalytic effects Heterogeneous nucleation Reactive hydride composites Reversible hydrogen storage

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

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：