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Gravitational Deflection of Particles of Light by the Earth and by the Sun: A Reconstruction of the Calculations Done by Soldner in 1801

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International Journal of Astronomy and Astrophysics 2022年第1期12卷 147-165页

作者： frans F. van Kampen The Hague The Netherlands

In 1801, the year of the discovery of Ceres, Johann Georg von Soldner calculated with classical means the gravitational deflection of a lightray grazing the surface of the Sun as 0.84”. According to General Relativity (GR) and using present-day data the deflection amounts to 1.75”. The formula for the deflection is derived with a classical method, with GR and as done by Soldner. The GR formula gives twice as large a deflection as the classical formula. It is shown that the formula of Soldner is equivalent to the classical one. Soldner’s numerical calculation of the classical deflection by the Earth comes out a factor 6.9 larger than using present-day data. This discrepancy is for a factor 6.25 due to a mistaken value for the velocity of the grazing lightray. This factor 6.25 can numerically be accounted for by assuming Soldner made a conceptual mistake related to the Axial Tilt of the Earth. The remaining discrepancy is due to the use of data less accurate than the present-day data. Soldner’s numerical calculation of the deflection by the Sun comes out correctly to the data of those days. In case of the Sun he did not give any further information regarding the data he used. A reconstruction reveals that for the surface gravity of the Sun he used a value close to the present-day value.

关键词： Johann von Soldner Gravitational Deflection of Light History of Science

Qualifying the suitability of living donor livers for pediatric liver transplantation:are we doing the right thing?

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Hepatobiliary Surgery and Nutrition 2023年第3期12卷 462-464页

作者： Henkjan J.Verkade frans C.J.Cuperus Aad P.van den Berg Division of Pediatric Gastroenterology and Hepatology Department of PediatricsUniversity of GroningenBeatrix Children’s HospitalUniversity Medical Center GroningenGroningenThe Netherlands Department of Gastroenterology and Hepatology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands

Over the last decades,liver transplantation has become the standard care for many forms of end-stage liver disease,both in adults and in *** prognosis after pediatric liver transplantation(pLT)has steadily increased up to a patient survival at 5 years of 85%and an estimated graft half life of 31 years(1,2).In the early days of pLT,the transplanted organ originated from deceased *** 1990,adult-to-child living donor liver transplantation(LDLT)programs have developed,which rapidly gained popularity,particularly in Europe and Asia(2,3).A major stimulus for LDLT has been the limited availability of deceased *** indications for liver transplantation have expanded,particularly for adult patients,at a higher rate than the availability of donor ***,the quality of donor organs has steadily declined,resulting in a decreased utilization of livers from deceased donors for transplantation(4).The limited availability of qualified deceased donor livers has further stimulated LDLT:in Europe,for example,the percentage of living donor organs used for pLT increased from 7%before 2000 to 40%since 2010(1).

关键词： Steatosis graft survival pediatric liver transplantation(pLT) patient survival

Nitridation of Ni-based alloys:thermodynamics,kinetics,and deformation phenomena accompanying internal precipitation

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Rare Metals 2006年第5期25卷 501-511页

作者： Alexander A.Kodentsov Jorma K.Kivilahti frans J.J.van Loo Laboratory of Materials and Interface Chemistry Eindhoven University of TechnologyP.O.Box 5135600 MBEindhovenThe Netherlands Laboratory of Electronics Production Technology Helsinki University of TechnologyFIN-02150 EspooFinland

When a moderately stable phase is precipitated out during an intemal reaction, the behaviour of the penetrating atoms within the diffusion zone can be interpreted based on thermodynamic considerations. Evidence for “up-hill” diffusion of the penetrating species through the matrix towards the precipitation front during the intemal nitridation of Ni-Cr alloys at 1125℃ and 6000 bar of N2-pressure was predicted. Such behaviour of nitrogen is opposite to the boundary conditions in Wagner＇s description of internal reactions. A volume change associated with the precipitation reaction resulted in a stress gradient between the alloys surface and the intemal nitridation front. Stress relief occurred mainly by transport of nickel to the gas/metal interface. Pipe diffusion-controlled creep is the dominant stress accommodation mechanism during nitriding of dilute Ni-Cr alloys at 700℃ under a flowing NH3 ＋ H2 gas mixture.

关键词： nitridation nickel alloys thermodynamics diffusion internal precipitation

Learning curves in minimally invasive esophagectomy

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World Journal of Gastroenterology 2018年第44期24卷 4974-4978页

作者： frans van Workum Laura fransen Misha DP Luyer Camiel Rosman Department of Surgery Radboud University Medical Center Department of Surgery Catharina Hospital

Surgical innovation and pioneering are important for improving patient outcome, but can be associated with learning curves. Although learning curves in surgery are a recognized problem, the impact of surgical learning curves is increasing, due to increasing complexity of innovative surgical procedures, the rapid rate at which new interventions are implemented and a decrease in relative effectiveness of new interventions compared to old interventions. For minimally invasive esophagectomy(MIE), there is now robust evidence that implementation can lead to significant learning associated morbidity(morbidity during a learning curve, that could have been avoided if patients were operated by surgeons that have completed the learning curve). This article provides an overview of the evidence of the impact of learning curves after implementation of MIE. In addition, caveats for implementation and available evidence regarding factors that are important for safe implementation and safe pioneering of MIE are discussed.

关键词：学习曲线相对有效性 MIE 外科复杂性证据保险箱病态

Economic overview of a two-agent process for underground coal gasification with Fischer-Tropsch- based poly-generation

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Clean Energy 2019年第1期3卷 34-46页

作者： Johan F.Brand Johan C.van Dyk frans B.Waanders African Carbon Energy PO Box 450Standerton 2430South Africa Centre of Excellence in Carbon-based Fuels North-West UniversityPotchefstroom 2520South Africa African Carbon Energy PO Box 254SasolburgSouth Africa

Underground Coal Gasification(UCG)is a mining-gasification process that produces synthesis gas from in situ coal by injecting air(or oxygen and steam)and extracting the produced gas via *** resulting synthesis gas(‘syngas’)produced by UCG can be used directly as a fuel-gas or deep-cleaned to produce many other products like chemicals,liquid fuels,hydrogen and synthetic natural *** has significant environmental,safety and practical advantages over conventional coal mining and utilization,foremost being cost and emissions *** South Africa,facilities of an industrial-scale Fischer-Tropsch(FT)have been operating for decades on coal-to-liquid and gas-to-liquid ***-blown UCG produces syngas,which contains a mixture of carbon monoxide(CO)and hydrogen,and these molecules can be conditioned to serve as feed for synthetic-crude-oil(‘syncrude’)conversion technologies based on the FT *** Carbon Energy(Pty)Ltd.(Africary)completed a study integrating its UCG technology with mini gas-to-liquids *** from Africary’s Theunissen Underground Coal Gasification(TUCG)project will be used for power production and synthesis of liquid fuels in a unique poly-generation *** TUCG process will consist of two parallel gasifiers,operated on different agents,making the component parts of UCG and coal-to-(any product)(CtX)tightly linked and interdependent,but reducing both cost and ***-CtX offers a lower capital investment to conventional underground mining and surface gasification due to the removal of the surface gasifier and coal-mine *** gas clean-up systems will remove undesirable components from each gasifier and blend the cleaned syngas for H2:CO ratio control and provide implementation of carbon capture and *** study has minimized the complexity and optimized the process flow to provide own-use electricity and about 4000 barrels/day equivalent fuels at a capital cost estimate(2017)of

关键词： underground coal gasification Fischer-Tropsch coal to liquids gas to liquids CCS UCG FT LNG CtX economic study South Africa

Cavity enhanced absorption spectroscopy for N_2O detection at 2.86 μm using a continuous tunable color center laser

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Chinese Optics Letters 2003年第6期1卷 361-363页

作者：李少成于清旭 Maarten van Herpen Sacco te Lintel Hekkert frans J.M.Harren Department of Physics Dalian University of Technology Dalian 116024 Life Science Trace Gas Exchange Facility Department of Molecular and Laser Physics University of Nijmegen 6525 ED Nijmegen The Netherlands

The cavity enhanced absorption technique is applied to N2O detection around 2.86 μm using a continuous-wave color center laser. A high-finesse triangular ring cavity is used in this technology. Transmission through the cavity is obtained by jittering the cavity-length with a piezo on one of the cavity mirrors. A minimum detectable absorption coefficient of 2 × 10-6 cm-1 is achieved with a mirror reflectivity of 99.24%, corresponding to a N2O detection limit of 600 parts per billion.

关键词： Continuous wave lasers Gas detectors Nitrogen oxides

Outcomes of curative esophageal cancer surgery in elderly:A metaanalysis

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World Journal of Gastrointestinal Oncology 2021年第2期13卷 131-146页

作者： Nikolaj S Baranov Cettela Slootmans frans van Workum Bastiaan R Klarenbeek Yvonne Schoon Camiel Rosman Department of Surgery Radboud University Medical CenterNijmegen 6525GAthe Netherlands Department of Geriatrics Radboud University Medical CenterNijmegen 6525GAthe Netherlands

BACKGROUND An increasing number of older patients is undergoing curative,surgical treatment of esophageal *** meta-analyses have shown that older patients suffered from more postoperative morbidity and mortality compared to younger patients,which may lead to patient selection based on ***,only studies including patients that underwent open esophagectomy were ***,it remains unknown whether there is an association between age and outcome in patients undergoing minimally invasive *** To perform a systematic review on age and postoperative outcome in esophageal cancer patients undergoing *** Studies comparing older with younger patients with primary esophageal cancer undergoing curative esophagectomy were ***-analysis of studies using a 75-year age threshold are presented in the manuscript,studies using other age thresholds in the Supplementary ***,Embase and the Cochrane Library were searched for articles published between 1995 and *** of bias was assessed with the Newcastle-Ottawa *** outcomes were anastomotic leak,pulmonary and cardiac complications,delirium,30-and 90-d,and in-hospital *** outcomes included pneumonia and 5-year overall *** Seven studies(4847 patients)using an age threshold of 75 years were included for meta-analysis with 755 older and 4092 younger *** patients(9.05%)had higher rates of 90-d mortality compared with younger patients(3.92%),(confidence interval=1.10-5.56).In addition,older patients(9.45%)had higher rates of in-hospital mortality compared with younger patients(3.68%),(confidence interval=1.01-5.91).In the subgroup of 2 studies with minimally invasive esophagectomy,older and younger patients had comparable 30-d,90-d and in-hospital mortality *** Older patients undergoing curative esophagectomy for esophageal cancer have a higher postoperative mortality *** invasive esopha

关键词： Elderly Minimally invasive esophagectomy Open esophagectomy Esophageal cancer Clinical outcome Perioperative mortality

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蛋鸡遗传育种计划:成功的关键因素

国外畜牧学（猪与禽） 2015年第8期35卷 54-56页

作者：肖昌何闪 frans van sambeek Jeroen Visscher Hendrix育种公司动物选育研究所

ISA(BV公司动物选育研究所)是世界领先的蛋鸡育种公司,本文将探讨ISA是如何一步步提高蛋鸡生产性能,保障其能够在2020年培育出适应各种恶劣环境,并能产出500枚高品质鸡蛋的蛋鸡品种。

关键词：育种计划蛋鸡品种育种公司蛋鸡生产性能选育研究育种价值 Gallus 蛋鸡饲养蛋白高度蛋

Mental Wellbeing Monitoring in a Sample of Emergency Medical Service Personnel

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Occupational Diseases and Environmental Medicine 2020年第1期8卷 26-33页

作者： Charles van Wijk frans Cronje Jack Meintjes Private Simon’s Town South Africa Hyperbaric Medicine Unit Emergency Medical Services Cape Town South Africa Division of Health Systems and Public Health Department of Global Health Stellenbosch University Cape Town South Africa Tygerberg Academic Hospital Occupational Health Department Cape Town South Africa

Background: There have been concerns regarding the mental wellbeing of emergency medical service staff, particularly when faced with multiple trauma exposures. This study aimed to describe a cross-sectional view of the mental wellbeing status of emergency medical service workers, as well as to comment on the usefulness of an electronic survey tool to reach staff that is distributed across large geographical areas. Methods: The data presented here are drawn from an anonymous, voluntary, electronic survey, made available via the internet, to emergency medical service workers in the Western Cape province of South Africa. This paper reports on four domain expressions of mental wellbeing, namely disordered mood, problematic substance use, post-traumatic stress disorder, and domestic discord. Results: Elevated rates were reported by this sample, across all four distress domains, i.e. mood disorder = 12.3%;problematic substance use = 14.9%;post-traumatic stress disorder = 11.9%;and domestic discord = 11.9%. These rates were generally similar to data from comparable emergency worker groups, and much higher than local population estimates. Conclusions: The data support earlier findings that emergency medical work is associated with increased risk for symptoms of psychological distress, which present a strong case for regular organizational monitoring of employees’ mental wellbeing. In this regard, a brief, internet delivered, survey-type tool showed promise for screening employees, in order to guide further streaming of distressed individuals towards appropriate support services. Further work is required to develop clear mechanisms for referral and intervention in order to optimize a confidential and supportive monitoring program.

关键词： Emergency Medical Service Employees Internet Screening Mental Wellbeing Psychological Distress