检索结果-南通市图书馆

A fast and simple algorithm for calculating flow accumulation matrices from raster digital elevation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2019年第2期13卷 317-326页

作者： guiyun ZHOU Hongqiang WEI suhua FU Center for Information geoscience University of Electronic Science and Technology of ChinaChengdu 611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of SciencesYangling 712100China Faculty of geographical Science Beijing Normal UniversityBeijing 100875China

Calculating the flow accumulation matrix is an essential step for many hydrological and topographical *** study gives an overview of the existing algorithms for flow accumulation calculations for singleflow direction matrices.A fast and simple algorithm for calculating flow accumulation matrices is proposed in this *** algorithm identifies three types of cells in a flow direction matrix: source cells,intersection cells,and interior *** traverses all source cells and traces the downstream interior cells of each source cell until an intersection cell is *** intersection cell is treated as an interior cell when its last drainage path is traced and the tracing continues with its downstream *** are conducted on thirty datasets with a resolution of 3 *** with the existing algorithms for flow accumulation calculation,the proposed algorithm is easy to implement,runs much faster than existing algorithms,and generally requires less memory space.

关键词： flow accumulation flow direction DEM gIS

Numerical simulation and visualization of fiber suspension in a turbulent round jet

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

Applied Mathematics and Mechanics(English Edition) 2017年第12期38卷 1651-1662页

作者： Wenqian LIN Shouqian SUN Fangyang YUAN suhua SHEN College of Computer Science Zhejiang UniversityHangzhou 310027China State Key Laboratory of Fluid Power Transmission and Control Zhejiang UniversityHangzhou 310027China

The turbulent properties of the fiber suspension in a turbulent round jet are numerically simulated and visualized, and some of the results are compared with the experimental data. The effects of the Reynolds number, fiber volume fraction, and aspect ratio are analyzed. The results show that the fiber injection in the flow has a delay effect on the streamwise velocity decay along the jet axis, and such an effect becomes more obvious with the increases in the fiber volume fraction and aspect ratio and the decrease in the Reynolds number. The flow with fibers shows an increase in the streamwise velocity along the radial direction, and the increase magnitude is directly proportional to the fiber volume fraction and aspect ratio and inversely proportional to the Reynolds number. The presence of fibers makes the turbulent kinetic energy and Reynolds stress increase, and the extent increases with the fiber volume fraction, Reynolds number, and fiber aspect ratio.

关键词： fiber suspension turbulence round jet numerical simulation visualization

Efficient nonlocal two-step entanglement concentration protocol for three-level atoms in an arbitrary less-entangled W state using cavity input-output process

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2014年第8期57卷 1511-1518页

作者： ZHANg Ru ZHOU suhua CAO Cong Department of Communications & Information Engineering Century College Beijing University of Posts and Telecommunications School of Science Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

We present an efficient two-step entanglement concentration protocol(ECP)for three-level atoms trapped in one-sided optical micro-cavities in an arbitrary three-particle less-entangled W state,using the coherent state input-output process in low-Q cavity quantum electrodynamics *** each step of the new proposed protocol,one of the three remote users prepares the auxiliary coherent optical pulses to perform cavity input-output process and then utilizes the standard homodyne measurement to discriminate the final outgoing coherent *** both of the two steps are successful,remote parties can deterministically concentrate the less-entangled W state atoms to a standard maximally entangled W *** with previous ECPs for W state,this protocol has some advantages and can be widely used in current quantum repeater and some quantum information processing tasks.

关键词： entanglement concentration protocol W state cavity input-output process

In situ IR study of dimethyl oxalate hydrogenation to ethylene glycol over Cu/SiO_2 catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Natural gas Chemistry 2012年第6期21卷 753-758页

作者： Shengguo Hui Bo Zhang suhua Zhang Wei Li State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

The mechanism of dimethyl oxalate hydrogenation to ethylene glycol over Cu/SiO2 catalyst was investigated by in situ Fourier transform infrared （FTIR） spectroscopy. It was found that dimethyl oxalate and methyl glycolate proceeded via dissociative adsorption on Cu/SiO2 catalyst, and four main intermediates, CH3OC（O）（O）C-M （1655 cm-1）, M-C（O）（O）C-M （1618 cm-1）, HOCH2（O）C--M （1682 cm-1） and CH3O-M （2924-2926 cm-1）, were identified during the reaction. It was concluded that dimethyl oxalate hydrogenation to ethylene glycol mainly proceeded along the route： dimethyl oxalate ／rightarrow CH3OC（O）（O）C-M → methyl glycolate →HOCH2（O）C-M → ethylene glycol. Finally a schematic reaction network was proposed.

关键词： dimethyl oxalate ethylene glycol FTIR hydrogenation Cu/SiO2

Comparison and quantitative assessment of two regional soil erosion survey approaches

在线全文

学校读者我要写书评

暂无评论

International Soil and water Conservation Research 2023年第4期11卷 660-668页

作者： Lixia Dong suhua Fu Baoyuan Liu Bing Yin Faculty of geographical Science Beijing Normal UniversityBeijing100875PR ChinaFaculty of Geographical ScienceBeijing Normal UniversityBeijing100875PR China Advanced Institute of Natural Sciences Beijing Normal University at Zhuhai519087PR China State Key Lab Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityPR China

Regional soil erosion surveys are the first step of soil conservation *** and sampling ap-proaches are commonly used for soil erosion surveys at the regional *** the grid approach,the region is divided into grids(e.g.,1 km × 1 km),and the soil erosion rate of each grid was *** the sampling approach,a small portion of the area(typically 4%or less)was taken and then the soil erosion rate was *** on the above calculation,both approaches evaluated the soil erosion area(which is the area where the soil erosion rate is greater than the soil loss tolerance(t))and its distribution in the whole *** purpose of this paper is to compare the assessment results of the two approaches and analyse their practicality using Yunyang County,Chongqing,China(area is 3636 km^(2)).The soil erosion rate,percentage of soil erosion area(PSEA,which is the ratio of the area where the soil erosion rate is greater than the soil loss tolerance(t)to the area of the total study region)and its spatial distribution were compared between the two *** results showed that the grid approach overestimated the average soil erosion rate and PSEA overall for all 33 sample units and the whole region in comparison to the sampling *** sampling approach can yield a reasonable spatial distribution of the soil erosion rate in the whole *** addition,the soil erosion regions were more clustered than those using the grid approach,which can be more suitable for soil conservation ***,the sampling approach is an efficient and practical approach in regional soil erosion *** results can provide insights into regional soil erosion surveys.

关键词： Regional soil erosion Soil erosion survey grid approach Sampling approach CSLE

Cross-Linked Hollow graphitic Carbon as Low-Cost and High-Performance Anode for Potassium Ion Batteries

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

Energy & Environmental Materials 2021年第3期4卷 451-457页

作者： Yanhong Feng suhua Chen Dongyang Shen Jiang Zhou Bingan Lu School of Physics and Electronics Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and DevicesState Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyHunan UniversityChangsha 410082China School of Materials Science and Engineering Central South UniversityChangsha 410083China

Large-scale and low-cost preparation of carbon-based potassium anode with long life and high capacity is one of the footstones for the development of potassium ion batteries(PIBs).Herein,a low-cost carbon-based material,cross-linked hollow graphitic carbon(HgC),is large scale synthesized to apply for PIBs *** hollow structure can afford sufficient space to overcome the damage caused by the volume expansion of graphitic carbon(gC).While the cross-linked structure forms a compact interconnection network that allows electrons to rapid transfer between different gC *** measurements demonstrated that the HgC anode exhibited low charge/discharge plateau(about 0.25 V and 0.1 V)and excellent specific capacity as high as 298 m A h g^(-1)at the current density of 50 m A g^(-1).And more important,after 200 cycles the capacity of HgC anode still shows 269 m A h g^(-1)(the decay rate of per cycle is only 0.048%).Meanwhile,the use of commercial traditional electrolyte(KPF_(6))and cheap raw materials that provide new hope for trying and realizing the large-scale production of PIBs based on carbon anode materials.

关键词： cross-linked hollow structure graphitic material high reversibility potassium ion battery

Stepping up after spinal cord injury:negotiating an obstacle during walking

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第7期20卷 1919-1929页

作者： Alain Frigon Charly g.Lecomte Department of Pharmacology-Physiology Faculty of Medicine and Health SciencesUniversitéde SherbrookeCentre de recherche du Centre Hospitalier Universitaire de SherbrookeSherbrookeQCCanada

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate *** spinal cord injury,stepping over an obstacle becomes *** over an obstacle requires sensorimotor transformations in several structures of the brain,including the parietal cortex,premotor cortex,and motor *** information and planning are transformed into motor commands,which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory,coordinate the limbs,and maintain *** spinal cord injury,bidirectional communication between the brain and spinal cord is disrupted and animals,including humans,fail to voluntarily modify limb trajectory to step over an ***,in this review,we discuss the neuromechanical control of stepping over an obstacle,why it fails after spinal cord injury,and how it recovers to a certain extent.

关键词： biomechanics locomotion neurophysiology obstacle negotiation spinal cord injury

Effect of ionization of drug on drug solubilization in SMEDDS prepared using Capmul MCM and caprylic acid

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Pharmaceutical Sciences 2017年第1期12卷 73-82页

作者： suhua Li Parshotam Madan Senshang Lin School of Pharmacy Fairleigh Dickinson UniversityFlorham ParkNJ 07932USA College of Pharmacy and Health Sciences St.John’s UniversityQueensNYUSA

The purpose of this study was to investigate the effect of ionization of drug on drug solubilization in SMEDDS(self-microemulsifying drug delivery system) prepared using Capmul MCM and caprylic acid. Solubilization capacity of blank SMEDDS dispersions for danazol,indomethacin and haloperidol as model drugs was determined. Based on the outcomes of solubilization capacity study, drug-loaded SMEDDS formulations were prepared and subjected to dispersion/precipitation study and droplet size analysis. Blank SMEDDS dispersions exhibited the highest solubilization capacity for haloperidol followed by indomethacin and danazol. Furthermore, the solubilization of the three drugs in blank SMEDDS dispersions was explained by a modified mathematical model. Dispersion/precipitation studies indicate that drug-loaded SMEDDS formulations exhibited superiority in solubilizing the drugs in comparison to their respective drug powder. In addition, indomethacin and haloperidol were found to reduce the droplet size of the microemulsions while danazol did not affect droplet size formation for drug-loaded SMEDDS formulations. These findings suggest that ionization of drug affects drug solubilization, droplet size formation, drug loading and drug dispersion/precipitation profiles for the SMEDDS formulations.

关键词： SMEDDS Capmul MCM Caprylic acid Ionization Indomethacin Haloperidol

Selective catalytic reduction of NO by C_2H_2 over Ce-Al_2O_3 catalyst with rate-determining step of NO oxidation

在线全文

学校读者我要写书评

暂无评论

Journal of Natural gas Chemistry 2012年第3期21卷 332-338页

作者： suhua Yan Xinping wang Wenchen wang Zequn Liu Jiahao Niu State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024LiaoningChina

Ce-A12O3 catalysts prepared by co-precipitation are investigated both in NO oxidation by 02 and in selective catalytic reduction of NO by C2H2 （C2H2-SCR）. It is found that C2H2-SCR is initiated and controlled by NO oxidation to NO2 over A12O3. Ce loading on A12O3 is almost inactive for NO oxidation below 350℃, since NO2 strongly adsorbs on cerium oxide, leading to the active sites being blocked, which was characterized by temperature-programmed desorption of NO and NO2 and Fourier transform infrared spectroscopy after NO＋O2 coadsorption over the samples. However, in the case of C2H2-SCR, Ce loading on A1203 significantly improves the reaction by accelerating the NO oxidation step in the temperature range of 250-450℃, since the nitrate species produced by NO2 adsorption is an active intermediate required by C2H2-SCR.

关键词： NOx removal NO oxidation nitrate species Ce-A1203 acetylene