检索结果-南通市图书馆

OBSERVING THE HEAT EQUATION ON A TORUS ALONG A DENSE GEODESIC

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 1991年第2期4卷 186-192页

作者： Lance D.Drager robert L.foote Clyde f.martin Department of Mathematics Texas Tech.University.LubbockTX 79409USA Department of Mathematics Wabash CollegeCrawfordsvilleIN 47933USA Department of Mathematics Texas Tech.UniversityLubbockTX 79409USA

Several authors have considered observability problems for the heat equation and relatedpartial differential equations.A basic problem is to determine what kinds of sampling providesufficient information to uniquely determine the initial heat *** address the case wherethe temperature is measured while travelling along a *** consider the special case where the space is a flat torus(of arbitrary dimension)and thecurve is a *** is shown that,in this case,the observed temperature is sufficient informationto uniquely determine the initial heat distribution if and only if the geodesic is dense in the *** the case of a torus,fourier analysis techniques can be used to write down the solution of theheat *** allows us to derive an explicit representation of the observed temperature interms of the initial *** use this representation and some ideas from the theory ofalmost periodic functions to show that the fourier coefficients of the initial distribution can berecovered from the observation.

关键词： Observability heat equation inverse problems

Optimization of product characteristics of porous carbon agglomerates using a design of experiments in fluidized bed agglomeration

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 258-269页

作者： martin Oelofse robert Rack Marcelle Hilden Peter Langguth Department of Pharmaceutical Technology and Biopharmaceutics Johannes Gutenberg UniversityMainzGermany Carbon Advanced Solutions GmbH HeuchelheimGermany

Spraying parameters during particle agglomeration processes can affect the agglomeration kinetics and particle *** study was conducted to better understand the influence of the spraying parameters in a fluidized bed wet agglomeration process,and the influence on the stability characteristics of carbon tablets.A formulation based on fine carbon and peroxide powder,as well as carboxymethyl cellulose as a binder,was used to produce agglomerates in a first production *** in a second production step carbon tablets with a high porosity were molded for the customer goods *** optimization of the compressive strength of these carbon tablets was the goal of the *** agglomerates were produced with a laboratory scale granulator called“ProCell”and were compressed with a five-cavity mechanical *** screening of the agglomeration process parameters and their influence on the agglomerates quality,as well as the performance characteristics of the carbon tablets,were investigated using a multilevel factorial *** experimental runs were done by varying atomized air pressure and feed rate of the *** was determined by the design *** findings of the statistical trials showed that low atomized air pressure and a low feed rate lead to a higher tablet compressive strength.

关键词： Wet agglomeration fluidized bed Design of experiments Carbon agglomerates and tablets

Mitigation of atrazine,S-metolachlor,and diazinon using common emergent aquatic vegetation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2017年第6期29卷 114-121页

作者： Matthew T.Moore martin A.Locke robert Krǒger Water Quality and Ecology Research Unit USDA Agricultural Research ServiceNational Sedimentation LaboratoryOxfordMS 38655USA

By the year 2050, the population of the United States is expected to reach over 418 million, while the global population will reach 9.6 billion. To provide safe food and fiber, agriculture must balance pesticide usage against impacts on natural resources. Challenges arise when storms cause runoff to be transported to aquatic receiving systems. Vegetated systems such as drainage ditches and constructed wetlands have been proposed as management practices to alleviate pesticide runoff. Twelve experimental mesocosms （1.3 ±0.71 ± 0.61 m） were filled with sediment and planted with a monoculture of one of three wetland plant species （Typha latifolia, Leersia oryzoides, and Sparganium arnericanurn）. Three mesocosms remained unvegetated to serve as controls. All mesocosms were amended with 9.2 ± 0.8 μg/L, 12 ± 0.4 μg/L, and 3.1 ± 0.2 μg/L of atrazine, metolachlor, and diazinon, respectively, over a 4 hr hydraulic retention time to simulate storm runoff. following the 4 hr amendment, non-amended water was flushed through mesocosms for an additional 4 hr. Outflow water samples were taken hourly from pre-amendment through 8 hr, and again at 12, 24, 48, 72, and 168 hr post-amendment. L. oryzoides and T. latifolia had mean atrazine, metolachlor, and diazinon retentions from B1%-55% for the first 4 hr of the experiment. Aside from S. arnericanum and atrazine （25% retention）, unvegetated controls had the lowest pesticide retention （17%-28%） of all compared mesocosms. While native aquatic vegetation shows promise for mitigation of pesticide runoff, further studies increasing the hydraulic retention time for improved efficiency should be examined.

关键词： Phytoremediation Pesticide Mesocosm Wetland

NEAR-INfRARED IMAGING SENSOR WITH IMPROVED HANDLING AND DIRECT LOCALIZATION IN SIMULTANEOUS MAGNETIC RESONANCE IMAGING MEASUREMENTS

在线全文

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2011年第2期4卷 191-198页

作者： SONJA SPICHTIG MARCO PICCIRELLI robert S.VORBURGER martin WOLf Biomedical Optics Research Laboratory Division of Neonatology University Hospital of Zurich8091 ZurichSwitzerland Institute for Biomedical Engineering University and ETH Zurich ZurichSwitzerland Laboratory for Social and Neural Systems Research Department of Economics University of Zurich ZurichSwitzerland

We present a novel optical sensor to acquire simultaneously functional near-infrared imaging(fNIRI)and functional magnetic resonance imaging(fMRI)data with an improved handling and direct localization in the MRI compared to available *** phantom and interference measurements showed that both methods can be combined without reciprocal adverse *** direct localization of the optical sensor on MR images acquired with a T1-weighted echo sequence simplifies the co-registration of NIRI and MRI *** addition,the optical sensor is simple to attach,which is crucial for measurements on vulnerable *** fNIRI and T2^(*)-weighted fMRI data of a cerebral activation were simultaneously acquired proving the practicability of the setup.

关键词： Medical optics instrumentation imaging systems functional monitoring and imaging

Selection for production-related traits in Pelargonium zonale: improved design and analysis make all the difference

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Horticulture Research 2017年第1期4卷 365-373页

作者： Heike Molenaar martin Glawe robert Boehm Hans-Peter Piepho Institute of Crop Science University of HohenheimBiostatistics UnitStuttgart70599Germany Klemm+Sohn GmbH&Co.KG Stuttgart70378Germany

Ornamental plant variety improvement is limited by current phenotyping approaches and neglected use of experimental *** present study was conducted to show the benefits of using an experimental design and corresponding analysis in ornamental breeding regarding simulated response to selection in Pelargonium zonale for production-related *** required establishment of phenotyping protocols for root formation and stem cutting counts,with which 974 genotypes were assessed in a two-phase experimental *** present paper evaluates this *** possibility of varietal improvement through indirect selection on secondary traits such as branch count and flower count was assessed by genetic *** response to selection varied greatly,depending on the genotypic variances of the breeding population and traits.A varietal improvement of over 20%is possible for stem cutting count,root formation,branch count and flower *** contrast,indirect selection of stem cutting count by branch count or flower count was found to be *** established phenotypic protocols and two-phase experimental designs are valuable tools for breeding of ***.

关键词： breeding traits branch

NeuroPNM:Model reduction of pore network models using neural networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第3期86卷 239-251页

作者： robert Jendersie Ali Mjalled Xiang Lu Lucas Reineking Abdolreza Kharaghani martin Monnigmann Christian Lessig Otto-von-Guericke-Universitat Magdeburg Universitatsplatz 2Magdeburg39106Germany Ruhr-Universitat-Bochum Universitatstraβe 150Bochum44801Germany

Reacting particle systems play an important role in many industrial applications,for example biomass drying or the manufacturing of *** numerical modeling and simulation of such systems is therefore of great importance for an efficient,reliable,and environmentally sustainable operation of the *** complex thermodynamical,chemical,and flow processes that take place in the particles are a particular challenge in a ***,typically a large number of particles is involved,rendering an explicit treatment of individual ones impossible in a reactor-level *** approach for overcoming this challenge is to compute effective,physical parameters from single-particle,high-resolution *** can be combined with model reduction methods if the dynamical behaviour of particles must be *** network models with their unrivaled resolution have thereby been used successfully as high-resolution models,for instance to obtain the macroscopic diffusion coeffcient of *** parameter identification and model reduction have recently gained new impetus by the dramatic progress made in machine learning in the last *** report results on the use of neural networks for parameter identification and model reduction based on three-dimensional pore network models(PNM).We believe that our results provide a powerful complement to existing methodologies for reactor-level simulations with many thermally-thick particles.

关键词： Porenetwork models Neural networks Parameter estimation Reduced order model

3D modeling and motion parallax for improved videoconferencing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational Visual Media 2016年第2期2卷 131-142页

作者： Zhe Zhu Ralph R.martin robert Pepperell Alistair Burleigh TNList Tsinghua University School of Computer Science & Informatics Cardiff University Cardiff School of Art & Design Cardiff Metropolitan University

We consider a face-to-face videoconferencing system that uses a Kinect camera at each end of the link for 3D modeling and an ordinary2 D display for output. The Kinect camera allows a 3D model of each participant to be transmitted;the(assumed static) background is sent ***, the Kinect tracks the receiver's head,allowing our system to render a view of the sender depending on the receiver's viewpoint. The resulting motion parallax gives the receivers a strong impression of 3D viewing as they move, yet the system only needs an ordinary 2D display. This is cheaper than a full3 D system, and avoids disadvantages such as the need to wear shutter glasses, VR headsets, or to sit in a particular position required by an autostereo *** studies show that users experience a greater sensation of depth with our system compared to a typical 2D videoconferencing system.

关键词： naked-eye 3D motion parallax videoconferencing real-time 3D modeling

The transjugular intrahepatic portosystemic shunt: Smaller stent diameters are required to optimize pressure response

在线全文

学校读者我要写书评

暂无评论

iLIVER 2023年第2期2卷 89-96页

作者： martin Rossle Dominik Bettinger robert Thimme Michael Schultheiss Department of Medicine II Medical Center University of FreiburgFaculty of MedicineUniversity of FreiburgFreiburgGermany Berta-Ottenstein-Programme Faculty of MedicineUniversity of FreiburgGerman

Background and aims:The present treatment goal of the transjugular intrahepatic portosystemic shunt(TIPS)is a portosystemic pressure gradient of12 mmHg or its reduction by>50%.This study relates the stent diameter to the reduction of the pressure gradient and attempts to predict the appropriate stent diameter necessary to reach the treatment ***:Pressure response,super response,and poor response were investigated in 208 de-novo TIPS patients and defined as post-TIPS gradients between>6 and 12 mmHg,6 mmHg,or not reaching the goal(>12 mmHg,reductionf the radiographic ***:Responders(65%),super responders(26%),or poor responders(9%)had comparable stent diameters of 7.21.0 mm,but different post-TIPS gradients(9.71.9 mmHg,4.51.5 mmHg,and 14.21.4 mmHg,pf pre-TIPS gradients(51.711.4%,73.611.1%,and 34.09.1%,pfic reduction per mm of stent diameter(7.52.0%/mm,10.12.0%/mm,and 4.81.4%/mm,pf the stent diameter required to reach response was not *** two super responders had a stent diameter offfered by the increase in the right atrial pressure(+5.0 mmHg vs.+3.1 mmHg,p=0.026)and reduction in the portal vein pressure(-8.6 mmHg vs.-4.6 mmHg,pffunction may play an important role by its effect on the right atrial(preload)and portal pressure(afterload).

关键词： Portal hypertension Transjugular intrahepatic portosystemic stentshunt TIPS Portosystemic pressure gradient Stent diameter Hepatic encephalopathy Cardiac function

Review of operative considerations in spinal cord stem cell therapy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2021年第2期13卷 168-176页

作者： Pavan S Upadhyayula Joel R martin robert C Rennert Joseph D Ciacci Department of Neurological Surgery University of CaliforniaSan DiegoLa JollaCA 92037United States

Spinal cord injury(SCI)can permanently impair motor and sensory function and has a devastating cost to patients and the United States healthcare *** cell transplantation for treatment of SCI is a new technique aimed at creating biological functional *** techniques in stem cell transplantation for SCI are *** review various clinical treatment paradigms,surgical techniques and technical considerations important in SCI *** NCBI PubMed database was queried for“SCI”and“stem cell”with a filter placed for“clinical trials”.Thirty-nine articles resulted from the search and 29 were included and evaluated by study authors.A total of 10 articles were excluded(9 not SCI focused or transplantation focused,1 canine model).Key considerations for stem cell transplantation include method of delivery(intravenous,intrathecal,intramedullary,or excision and engraftment),time course of treatment,number of treatments and time from injury until *** are no phase III clinical trials yet,but decreased time from injury to treatment and a greater number of stem cell injections both seem to increase the chance of functional recovery.

关键词： Stem cell Spinal cord injury Operative techniques Stem cell transplantation Intramedullary