检索结果-南通市图书馆

Exploring the light-quark interaction

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2009年第12期33卷 1189-1196页

作者：常雷 Ian C. CLOЁT Bruno El-BENNICH thomas KLHN Craig d. ROBERTS Institute of Applied Physics and Computational Mathematics department of Physics University of Washington Seattle WA 98195 USA Physics division Argonne National Laboratory Argonne Illinois 60439 USA department of Physics Peking University

Two basic motivations for an upgraded JLab facility are the needs： to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking （dCSB）; and to understand nucleon structure and spectroscopy in terms of QCd＇s elementary degrees of freedom. during the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a dyson- Schwinger equation perspective on this effort with numerous illustrations, amongst them： an interpretation of string^breaking; a symmetry-preserving truncation for mesons; the nucleon＇s strangeness σ-term; and the neutron＇s charge distribution.

关键词： Bethe-Salpeter equations bound-states confinement dynamical chiral symmetry breaking,dyson-Schwinger equations Faddeev equation nucleon electromagnetic form factors

Prospective evaluation of the short access cholangioscopy for stone clearance and evaluation of indeterminate strictures

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic diseases International 2017年第1期16卷 96-103页

作者： Athanasios d Sioulas Muhammad A El-Masry Stefan Groth Guido Schachschal Mario Anders thomas Rosch Ulrike denzer department of Interdisciplinary Endoscopy University Hospital Hamburg-Eppendorf MartinistraBe 52 20246 Hamburg Germany division of Gastroenterology Department of Internal Medicine Assiut University Hospital Al Walideyah Al Qebleyah Qesm Than Asyut Assiut Governorate Egypt

BACKGROUNd： Peroral cholangioscopy facilitates diagnosis and therapy of biliary disorders. This study prospectively evaluated a new short access cholangioscopy. METHOdS： Consecutive patients were included as follows： difficult stones （group 1） underwent cholangioscopy with electrohydraulic lithotripsy and indeterminate biliary strictures （group 2） were evaluated with macroscopic assessment and cholangioscopy guided biopsy sampling. We evaluated the complete stone clearance rate （group 1） and diagnostic accu- racy （group 2）. Follow-up was performed over a median of 13 and I6 months, respectively. RESULTS： Group 1 （n=21）： complete stone clearance defined as lack of stones in cholangiography and stone removal dur- ing cholangioscopy was achieved in 15 （71.4%） patients. Clini- cal stone clearance defined as lack of symptoms, laboratory abnormalities and hospital visits during follow-up, irrespec- tive of stone clearance was evident in 17 （81.0%） patients. One serious adverse event occurred （bile duct perforation）. Group 2 （n=28）： malignancy was confirmed in 15 patients. Sensitiv- ity, specificity and diagnostic accuracy of cholangioscopy were 85.7%, 75.0% and 80.7%, respectively. Sensitivity, specificity and diagnostic accuracy of biopsies were 54.5%, 100.0% and 72.2%, respectively. No serious adverse events occurred, and one patient was lost to ***： The novel system enabled complex stone treatment and biliary stricture diagnosis. Cholangioscopy outperformed direct biopsy regarding characterization of in- determinate strictures.

关键词： biliary tract diseases novel cholangioscopy feasibility

Effect of particle size distribution on particle based composite anode models

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2013年第3期29卷 357-369页

作者： Vaughan L.thomas Baltimore USA

Particle based models of composite anodes are useful tools for exploring the behavior of SOFC systems. As part of our efforts to develop models for understanding fuel cells, we have been building models of Ni-YSZ composite anodes using experimentally measured particle size distributions. The objectives of this study were to characterize the percolation threshold and conductivity of these models in comparison to simpler mono dispersed and biphasic particle size distributions from the literature. We found that the average values for the onset of percolation and the measured conductivity of the models with experimentally measured particle size distributions are similar to those for the simple distributions and the experimentally measured distributions. For all of the configurations evaluated, the onset of percolation in the Nickel phase occurred at a solid fraction of Nickel between 20% and 25%. This corresponded almost exactly to the point at which the coordination number between Nickel phase particles reached 2.2. The significant finding was that the variation in the value for the conductivity, as measured by the standard deviation of the results, was several orders of magnitude higher than for the simpler systems. We explored the validity of our assumptions, specifically the assumption of random particle placement, by building a particle model directly from FIB-SEM data. In this reconstruction, it was clear that the location of particles was not random. Particles of the same type and size had much likelihood of contact higher than would indicated by random location.

关键词： Resistor network Composite electrodes 3d particle packing Solid oxide fuel cells

Nanoscale 3d ordered polymer networks

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第1期61卷 25-32页

作者： Edwin L. thomas department of Materials Science and NanoEngineering Rice University Houston TX 77030 USA

Structures having nanoscale 3d geometries are valuable as multifunctional materials, where multi-continuous microphases can synergistically influence mechanical, optical, transport and other properties. Such very high interface surface to volume ratio structures occur in a variety of materials including natural materials such as butter fly wings and sea urchin exoskeletons and in synthetic self-assembled structures such as surfactant/water systems and block polymers. Quantitative morphological characterization of such complex geometric structures is quite challenging. Unit cell sizes range from 10-300 nm with corresponding feature sizes on the 2-50 nm scale. Since these nanoscale network structures are bicontinuous, when one constituent is removed, the structure is still self supporting. Removal of one component produces a nanoporous material that may be in-filled with another component, or the surfaces of the nanopores can be coated with ultra-thin layers by atomic layer deposition to offer multiftmctional capabilities. due to the ability to individually tailor the properties of the network（s） and matrix, for example, to create strong dielectric or impedance contrast, such spatially periodic structures are excellent for the interference of waves （electromagnetic for photonic applications and acoustic for phononic applications） that can lead to bandgaps and hence the control of wave propagation in the material. This mini-review will focus on networks formed by bottom up self assembly of block polymers. In addition to structural issues, we emphasize the special physical properties related to bi- or tri-continuous networks.

关键词： self assembly block polymer network morphologies bicontinuous

Real-Time Watercolor for Animation

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2006年第2期21卷 159-165页

作者： thomas Luft Oliver deussen depurtment of Computer and Information Science University of KonstanzKonstanzGermang

We present algorithms that allow for reat-time rendering of 3d-scenes with a watercolor painting appearance,Our approach provides an appropriate simplification of the visual complexity,initates characteristic natural effects of watercolor,and provides two essential painting techniques,the wet-on-wet and the wet-on-dry *** concentrate on efficient algorithms based on image space processing rather than on an exact *** allows for the real-time rendering of *** an animation a high frame-to-frame coherence can be achieved due to a stable segmentation ***,we seamlessly integrate a smooth illumination into the watercolor renderings nsing information from the 3d-scenc.

关键词： non-photorealistic rendering watercolor painting,real-time rendering

Mesenchymal stem cells as living anti-inflammatory therapy for COVId-19 related acute respiratory distress syndrome

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

World Journal of Stem Cells 2020年第10期12卷 1067-1079页

作者： Feng Lin thomas E Ichim Sandeep Pingle Lawrence d Jones Santosh Kesari Shashaanka Ashili Research and development CureScienceSan DiegoCA 92121United States Cancer Center John Wayne Cancer Institute and Pacific Neuroscience Institute at Providence Saint John's Health CenterSanta MonicaCA 90404United States

Coronavirus disease 2019(COVId-19),a pandemic disease caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV2),is growing at an exponential rate *** of this disease are heterogeneous;however,advanced cases often exhibit various acute respiratory distress syndrome-like symptoms,systemic inflammatory reactions,coagulopathy,and organ involvements.A common theme in advanced COVId-19 is unrestrained immune activation,classically referred to as a“cytokine storm”,as well as deficiencies in immune regulatory mechanisms such as T regulatory *** mesenchymal stem cells(MSCs)themselves are objects of cytokine regulation,they can secrete cytokines to modulate immune cells by inducing antiinflammatory regulatory Treg cells,macrophages and neutrophils;and by reducing the activation of T and B cells,dendritic and nature killer ***,they have therapeutic potential for treating severe cases of *** we discuss the unique ability of MSCs,to act as a“living antiinflammatory”,which can“rebalance”the cytokine/immune responses to restore *** also discuss current MSC trials and present different concepts for optimization of MSC therapy in patients with COVId-19 acute respiratory distress syndrome.

关键词： Mesenchymal stem cells SARS-CoV-2 COVId-19 Cytokine storm Acute respiratory distress syndrome Immunomodulation

X-波段电子顺磁共振的微观有序宏观无序谱分析

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

光谱学与光谱分析 2007年第2期27卷 209-212页

作者：吴雪 Edmund Howard Yuri Nesmelov david d thomas 南开大学物理学院南开大学生物活性材料教育部重点实验室天津300071 department of Biochemistry Molecular Biology and BiophysicsUniversity of Minnesota

相关时间和序参量是表征自旋探针标记大分子运动与分布的两个重要参数。用合适的物理模型,通过线型分析同时确定这些参数在电子顺磁共振谱的解析中非常有意义。文章应用微观有序宏观无序(MO-Md)模型,在X-波段对具有轴对称磁参量自旋探针... 详细信息

相关时间和序参量是表征自旋探针标记大分子运动与分布的两个重要参数。用合适的物理模型,通过线型分析同时确定这些参数在电子顺磁共振谱的解析中非常有意义。文章应用微观有序宏观无序(MO-Md)模型,在X-波段对具有轴对称磁参量自旋探针的EPR谱进行了模拟计算,测量了波形的实验参数,比较了与经验公式分析的误差。对于MOMd谱,作者提出了分辨标准来筛选实验参数进行线型分析,以此确定了同时解析相关时间及内部序参量的有效区间。

关键词： EPR模拟 MOMd模型相关时间序参量

Strategically designing layered two-dimensional SnS_(2)-based hybrid electrodes: A futuristic option for low-cost supercapacitors

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第10期85卷 394-417,I0011页

作者： Susmi Anna thomas Jayesh Cherusseri Centre for Advanced Functional Materials(CAFM) Department of PhysicsBishop Moore CollegeMavelikaraKerala 690110India Sunway Centre for Electrochemical Energy and Sustainable Technology(SCEEST) School of Engineering and TechnologySunway UniversityNo.5 Jalan UniversityBandar SunwayPetaling Jaya 47500Malaysia

Supercapacitors are promising energy storage devices in current century due to their high specific capacitance, cyclic stability, high power density, and high voltage rating. due to their excellent electrochemical properties, supercapacitors are invariably used in a multitude of applications ranging from portable electronics to electric vehicles. The electrochemical performance of a supercapacitor mainly depends on the type of electrode-active material used in it. Thereby a careful selection is mandatory to achieve the excellency. Nanostructured electrode-active materials such as carbon nanomaterials, transition metal oxides,transition metal dichalcogenides(TMds), electronically conducting polymers, etc. are invariably used for supercapacitor application. Among these, TMds have received great interest, particularly transition metal disulfides such as molybdenum disulfide, tin disulfide(SnS_(2)), etc. Tin is abundant on the earth with excellent charge storage capabilities, attracted great scientific interest for application as electrode materials in supercapacitors. Good electronic conductivity, long cycling life and low-cost are its added ***, we discuss the recent trends in layered two-dimensional(2d) SnS_(2)-based electrodes to develop low-cost supercapacitors. Initially, their crystal structure, basic properties, synthesis methods are discussed. Further, strategically designing electrode nanostructures to achieve excellent electrochemical performance is reviewed then after. This includes material design in terms of morphology, pore-size,and shape as well as preparation of 2d SnS_(2)-based nanocomposite electrodes. Furthermore, the challenges and future perspectives of 2d SnS_(2)-based supercapacitors are included.

关键词： SnS_(2) Supercapacitor Transition metal dichalcogenides Electrochemical energy storage

22-gauge core vs 22-gauge aspiration needle for endoscopic ultrasound-guided sampling of abdominal masses

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2016年第39期22卷 8820-8830页

作者： William Sterlacci Athanasios d Sioulas Lothar Veits Pervin G?nüllü Guido Schachschal Stefan Groth Mario Anders Christos K Kontos Theodoros Topalidis Andrea Hinsch michael Vieth thomas R?sch Ulrike W denzer Institute of Pathology Clinic of Bayreuth department of Interdisciplinary Endoscopy University Hospital Hamburg-Eppendorf department of Biochemistry and Molecular Biology University of Athens Institute of Pathology Institute of Pathology University Hospital Hamburg-Eppendorf

AIM To compare the aspiration needle(AN) and core biopsy needle(PC) in endoscopic ultrasound-guided fine needle aspiration(EUS-FNA) of abdominal *** Consecutive patients referred for EUS-FNA were included in this prospective single-center trial. Each patient underwent a puncture of the lesion with both standard 22-gauge(G) AN(Echo Tip Ultra; Cook Medical, Bloomington, Indiana, United States) and the novel 22 G PC(Echo Tip Pro Core; Cook Medical, Bloomington, Indiana, United States) in a randomized fashion; histology was attempted in the PC group only. The main study endpoint was the overall diagnostic accuracy, including the contribution of histology to the final diagnosis. Secondary outcome measures included material adequacy, number of needle passes, and *** Fifty six consecutive patients(29 men; mean age 68 years) with pancreatic lesions(n = 38), lymphadenopathy(n = 13), submucosal tumors(n = 4), or others lesions(n = 1) underwent EUS-FNA using both of the needles in a randomized order. AN and PC reached similar overall results for diagnostic accuracy(AN: 88.9 vs PC: 96.1, P = 0.25), specimen adequacy(AN: 96.4% vs PC: 91.1%, P = 0.38), mean number of passes(AN: 1.5 vs PC: 1.7, P = 0.14), mean cellularity score(AN: 1.7 vs PC: 1.1, P = 0.058), and complications(none). A diagnosis on the basis of histology was achieved in the PC group in 36(64.3%) patients, and in 2 of those as the sole modality. In patients with available histology the mean cellularity score was higher for AN(AN: 1.7 vs PC: 1.0, P = 0.034); no other differences were of statistical *** Both needles achieved high overall diagnostic yields and similar performance characteristics for cytological diagnosis; histological analysis was only possible in 2/3 of cases with the new needle.

关键词： Endoscopic ultrasound Cytology Fine needle aspiration Abdominal tumors Core biopsy needle