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Exact Efficient Handling of Interrupted Illumination in Helical Cone-Beam Computed Tomography with Arbitrary Pitch

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Tsinghua Science and Technology 2010年第1期15卷 36-43页

作者： harald Schndube Karl Stierstorfer Frédéric Noo Department of radiology University of UtahSalt Lake CityUT 84132-2140USA Siemens Healthcare 91301 ForchheimGermany

We present a theoretically-exact and stable computed tomography （CT） reconstruction algorithm that is capable of handling interrupted illumination and therefore of using all measured data at arbitrary pitch This algorithm is based on a differentiated backprojection （DBP） on M-lines. First, we discuss the problem of interrupted illumination and how it affects the DBP. Then we show that it is possible to take advantage of some properties of the DBP to compensate for the effects of interrupted illumination in a mathematically exact way. From there, we have developed an efficient algorithm which we have successfully implemented. We show encouraging preliminary results using both computer-simulated data and real data. Our results show that our method is capable of achieving a substantial reduction of image noise when decreasing the helix pitch compared with the maximum pitch case. We conclude that the proposed algorithm defines for the first time a theoretically-exact and stable reconstruction method that is capable of beneficially using all measured data at arbitrary pitch.

关键词： computed tomography (CT) theoretically-exact and stable image reconstruction differentiated backprojection M-lines redundant data

Energy Consumption and greenhouse gas Emission of Korean Offshore Fisheries

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Journal of Ocean University of China 2018年第3期17卷 675-682页

作者： LEE Jihoon KIM Taeho ELLINgSEN harald HOgNES Erik Skontorp HWANg Bokyu Division of Marine Technology Chonnam National University 50 Daehak-ro Yeosu Jeollanam-Do 59626 Korea The University Center in Svalbard NO-9171 Longyearbyen Norway Asplan Viak AS Abels Gate 9 NO-7030 Trondheim Norway Department of Marine Science and Production Kunsan National University 558 Daehak-ro Kunsan 54150 Korea

This paper presents the energy and greenhouse gas(gHg) emission assessments of Korean offshore fisheries. The consumption of energy by fisheries is a significant concern because of its attendant environmental effect, as well as the cost of the fuel consumed in fishing industry. With the global attention of reducing gHg emission and increasing energy efficiency of fuel, the seafood industry needs to further understand its energy use and reduce its gHg emission. In the present study, the amount of energy consumed and the gHg emission of Korean offshore fisheries in a period from 2009 to 2013 were examined. Offshore fisheries accounted for 24% of Korean production in 2013 and 60% of fuel consumption related gHg emission. Whereas the total gHg emission intensity of this sector improved slightly between 2009 and 2012; as such emission decreased by approximately 1.9%, which increased again in 2013. The average amount of total gHg emission in this five years period was 1.78 × 10~6 tons of carbon dioxide equivalent/year(tCO_2eq. y^(-1)). Active fishing gear was found to consume 20% more fuel than passive gear. However, the production from passive gear was 28%, lower than 72% from active gear. The reason for this is that less abundant stationary resources are harvested using passive gear. Furthermore, the consumption of fuel was significantly influenced by the fishing method. Implementation and development of new fishing technologies and methods are important for improving energy efficiency and reducing the climate impact on fisheries. To realize these purposes, the fishery management system needs to be established by centralizing on energy efficiency and climate effect.

关键词： fuel consumption greenhouse gas emission Korean offshore fishery fuel use intensity

水泥基材料水化过程中通过缓凝作用达到促凝效果(英文)

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硅酸盐学报 2010年第9期38卷 1618-1622页

作者： JUSTNES harald SINTEF Building and Infrastructure 7465 Trondheim Norway

"通过缓凝作用达到促凝效果"的含义是通过抑制石膏的溶解并用除石膏以外的外加剂抑制铝酸三钙(C3A)的水化这2个过程,配制一种加速水泥凝结的外加剂组分。小掺量(水泥含量的0.02%～0.03%)的邻苯二酚导致水泥的闪凝,这很可能是由于抑制了... 详细信息

"通过缓凝作用达到促凝效果"的含义是通过抑制石膏的溶解并用除石膏以外的外加剂抑制铝酸三钙(C3A)的水化这2个过程,配制一种加速水泥凝结的外加剂组分。小掺量(水泥含量的0.02%～0.03%)的邻苯二酚导致水泥的闪凝,这很可能是由于抑制了硫酸钙的分解以及C3A的快速水化。而这些小剂量的邻苯二酚好像对硅酸三钙(C3S)的水化没有影响。通过水化热和物理性能测试表明:由邻苯二酚导致的"闪凝",而其他比石膏掺量小的缓凝剂(例如:葡萄糖酸钠)可以减缓"闪凝",使样品较快凝结(即加速凝结)。但这些缓凝剂会延迟C3S的水化,从而也延迟水泥浆体强度的发展。如果假定上述机理是正确的,那么被抑制溶解的石膏会在水化后期发生反应,导致延迟钙矾石生成并使水泥浆体产生膨胀开裂。制备了掺加或不掺加这种外加剂的混凝土,测定了这些混凝土的线性膨胀和体积膨胀,以检验其发生膨胀的可能性,但是两个月后没有发现混凝土表现出非正常膨胀。

关键词：促凝膨胀闪凝石膏水化热缓凝

Optical microcavities: new understandings and developments

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Photonics research 2017年第6期5卷 8-10页

作者： LI gE LIANg FENg harald g.L.SCHWEFEL Department of Engineering Science and Physics College of Staten IslandCUNY The graduate Center CUNY Department of Materials Science and Engineering University of Pennsylvania The Dodd-Walls Centre for Photonic and Quantum Technologies Department of Physics University of Otago

Optical microcavities have attracted tremendous interest in both fundamental and applied research in the past few decades, thanks to their small footprint, easy integrability, and high quality factors. Using total internal reflection from a dielectric interface or a photonic band gap in a periodic system, these photonic structures do not rely on conventional metal-coated mirrors to confine light in small volumes, which have brought forth new developments in both classical and quantum optics. This focus issue showcases several such developments and related findings, which may pave the way for the next generation of on-chip photonic devices based on microcavities.

关键词： Optical microcavities new understandings and developments

Using water isotopes and hydrogeochemical evidences to characterize groundwater age and recharge rate in the Zhangjiakou area,North China

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Journal of geographical Sciences 2020年第6期30卷 935-948页

作者： ZHANg Qinghua LUO Zhuanxi LU Wen harald Zepp ZHAO Yufeng TANg Jialiang Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentCASXiamen 361021FujianChina College of geographical Science Shanxi Normal UniversityLinfen 041000ShanxiChina Institute of Mountain Hazards and Environment CASChengdu 610041China geographical Institute Ruhr-University BochumBochum D-44780Germany

Despite the increasing depletion of the groundwater at the Zhangjiakou aquifer system in the northwest of Beijing-Tianjin-Hebei region,little information is available on the hydrological process of groundwater in this *** this study,we utilized water isotopes composition(51sO,5D and 3H)of groundwater,river and precipitation to identify the characteristics of hydrochemistry,groundwater age and recharge rates in different watersheds of the Zhangjiakou *** showed that the river water and groundwater could be characterized as HCO3-Mg Na,HCO3 CI-Na and HCO3-Mg Na,HCO3 CI-Na,HCO3 CI-Na Mg types,*** 5D and 5180 values in precipitation were linearly correlated,which is similar to the global Meteorological Water Line(gMWL).Furthermore,the decreasing values of the 6D and 5180 from precipitation to surface water and groundwater indicate that groundwater is mainly recharged by atmospheric *** addition,the variation of 3H concentration with depth suggests that groundwater shallower than around 100 m is generally modern *** contrast,groundwater deeper around 100 m is a mixture of modern and old waters,which has longer residence *** showed a relatively low tritium concentration in the confined aquifers,indicating the groundwater recharged might be relatively old groundwater of over 60 *** flow velocity of the groundwater in the study area varied from 1.10 to 2.26 m/a,and the recharge rates ranged from 0.034 to 0.203 m/*** obtained findings provide important insights into understanding the groundwater recharge sources and hydrochemistry in the Zhangjiakou area,in turn developing a sustainable groundwater management plan.

关键词： hydrogen and oxygen isotopes tritium isotope water cycle groundwater Zhangjiakou

A square root information filter for multi-gNSS real-time precise clock estimation

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Satellite Navigation 2021年第1期2卷 400-413页

作者： Xiang Zuo Xinyuan Jiang Pan Li Jungang Wang Maorong ge harald Schuh Department of geodesy GeoForschungsZentrum(GFZ)Telegrafenberg14473 PotsdamGermany Institut Für geodäsie und geoinformationstechnik Technische Universität BerlinKaiserin-Augusta-Allee 104-10610553 BerlinGermany.

real-time satellite orbit and clock estimations are the prerequisite for global Navigation Satellite System(gNSS)real-time precise positioning *** meet the high-rate update requirement of satellite clock corrections,the computational efficiency is a key factor and a challenge due to the rapid development of multi-gNSS *** Square root Information Filter(SrIF)is widely used in real-time gNSS data processing thanks to its high numerical stability and computational *** real-time clock estimation,the outlier detection and elimination are critical to guarantee the precision and stability of the product but could be *** this study,we developed a new quality control procedure including the three standard steps:i.e.,detection,identification,and adaption,for real-time data processing of huge gNSS *** is made to improve the computational efficiency by optimizing the algorithm to provide only the essential information required in the processing,so that it can be applied in real-time and high-rate estimation of satellite *** processing procedure is implemented in the PANDA(Positioning and Navigation Data Analyst)software package and evaluated in the operational generation of real-time gNSS orbit and clock *** demonstrated that the new algorithm can efficiently eliminate outliers,and a clock precision of 0.06 ns,0.24 ns,0.06 ns,and 0.11 ns can be achieved for the gPS,gLONASS,galileo,and BDS-2 IgSO/MEO satellites,*** computation time per epoch is about 2 to 3 s depending on the number of existing ***,the algorithm can satisfy the IgS real-time clock estimation in terms of both the computational efficiency and product quality.

关键词： SrIF Precise clock estimation Quality control real-time gNSS

Can picnic influence floral diversity and vitality of trees in Bhawal National Park of Bangladesh?

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Forestry Studies in China 2009年第3期11卷 148-157页

作者： Md. Mizanur rAHMAN harald VACIK Institute of Silviculture Department of Forest and Soil Sciences University of Natural Resources and Applied Life Sciences Vienna A-1190 Austria

We examined the impact of picnic activities on forest diversity, structure, regeneration and vitality of tree species in the Bhawal National Park of Bangladesh. The study area was classified as a non-used, occasionally used and frequently used area on the basis of the intensity of the picnic activities. A total of 43 plant species were enumerated in the whole study area. The highest plant species richness （41 species） was observed in the non-used area whereas the lowest species richness （11 species） in the frequently used area. The diversity index decreased with the increase of picnic intensity whereas the concentration of dominance increased. Density of all plant groups except mature trees, and the basal area of the mature trees showed a declining trend from the non-used to frequently used area. The frequently used area exhibited very poor regeneration. Tree vitality decreased with the increase of picnic intensity. The relevance of our study as a basis for further research to determine the impact of tourism on biodiversity in Bangladesh is discussed.

关键词： species richness diversity index concentration of dominance regeneration intensity

Main Wear Mechanisms of SEN Slag Band Materials

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China's refractories 2017年第1期26卷 1-7页

作者： harald HArMUTH Volkmar KIrCHEr Nathalie KOLBL Chair of Ceramics Montanuniversitaet Leoben 8700 Austria

This paper summarizes experimental approaches and simulation results in order to establish a general proposition regarding SEN wear *** convection is considered to be a major contribution to continuous SEN wear,usually causing characteristic corrosion *** is governed by the interface tension gradient in the vicinity of the three phase boundary slag/refractory/*** interface tension gradient is caused by a lower activity of the oxygen dissolved in the steel close to the refractory/steel *** is due to the reducing action of the solid carbon,which is a component of the *** a simulation model using the Effective Equilibrium reaction Zone technique a calculation of the interface tension differenceΔσwas *** for an LC steel and the related slag a valueΔσ=150mN/m was received,this quantity is negligible in the case of a TrIP ***,also the wear is much less for the TrIP *** convection is decisive for the mass transfer at the refractory/slag *** dissolution of zirconia,but also oxidation of carbon takes *** the latter one,the above mentioned simulation showed that reduction of silica in the mold slag takes place at the three phase boundary slag/refractory/steel by solid carbon,as the activity of silicon is reduced by dissolution in the liquid *** is the main source of oxygen for carbon oxidation at the three phase *** the three phase boundary is the focus of SEN wear：It unites intense bath movement due to Marangoni convection,oxidation of carbon by SiO_2reduction and zirconia erosion and dissolution into the *** the refractory itself,a thin layer of several millimetres shows reactions with slag *** causes especially destabilisation of stabilised zirconia and prepares later erosive *** does not penetrate into the SEN microstructure,carbon dissolution is only possible at the steel/refractory *** results quoted here e

关键词： SEN wear zirconia dissolution Marango-ni convection

Evolving management of colorectal cancer

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World Journal of gastroenterology 2008年第25期14卷 3956-3967页

作者： Jochem van der Voort van Zijp harald J Hoekstra Marc D Basson Department of radiation Oncology Leiden University Medical Center Department of Surgery University of Groningen Medical Center John D. Dingell VA Medical Center and Wayne State University

This article reviews recent advances in surgical techniques and adjuvant therapies for colorectal cancer, including total mesorectal excision, the resection of liver and lung metastasis and advances in chemoradiation and foreshadows some interventions that may lie just beyond the frontier. In particular, little is known about the intracellular and extracellular cascades that may influence colorectal cancer cell adhesion and metastasis. Although the phosphorylation of focal adhesion kinases and focal adhesion associated proteins in response to integrin-mediated cell matrix binding ("outside in integrin signaling") is well described, the stimulation of cell adhesion by intracellular signals activated by pressure prior to adhesion represents a different signal paradigm. However, several studies have suggested that increased pressure and shear stress activate cancer cell adhesion. Further studies of the pathways that regulate integrin-driven cancer cell adhesion may identify ways to disrupt these signals or block integrin-mediated adhesion so that adhesion and eventual metastasis can be prevented in the future.

关键词： Adhesion Colorectal Signaling Cancer Surgery