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Science Bulletin 2018年第1期63卷 24-30页

作者： Lijie Zhong Jens Oluf Jensen Lars Nilausen Cleemann Chao Pan Qingfeng Li Department of Energy Conversion and Storage Technical University of Denmark

The graphitic-layer encapsulated iron-containing nanoparticles(G@Fe) have been proposed as a potential type of active and stable non-precious metal electrocatalysts(NPMCs) for the oxygen reduction reaction(ORR). However, the contribution of the encapsulated components to the ORR activity is still unclear compared with the well-recognized surface coordinated FeN_x/C structure. Using the strong complexing effect of the iron component with anions, cyanide(CN^-) in alkaline and thiocyanate(SCN^-) in acidic media, the metal containing active sites are electrochemically probed. Three representative catalysts are chosen for a comparison including the as-prepared encapsulated G@Fe, commercial Fe/N/C catalyst with iron–nitrogen coordinated surface functionalities and molecular iron phthalocyanine(Fe Pc) containing well-defined structures and compositions. It was found that all samples showed significant shifts of half-wave potentials indicating that surface Fe coordinated sites in all cases. The G@Fe catalyst showed the weakest poisoning effect(the lowest shifts of half-wave potential) compared to the Fe/N/C and Fe Pc catalysts in both electrolytes. These results could be explained that the encapsulated iron components influence the FeN_x/C and/or N_xC surface functionality.

关键词：电气化学含铁地点反应探查催化剂包氧表面功能

Low- and Non-Pt Catalysts for Proton Exchange Membrane Fuel Cells

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Low- and Non-Pt Catalysts for Proton Exchange Membrane Fuel ...

Proton Exchange Membranes for Fuel Cells Challenges and Recent Developments

中国化学会2019能源材料和缺陷化学研讨会

作者： Qingfeng Li Yang Hu Benedikt Axel Brandes Lars Nilausen Cleemann Jens Oluf Jensen Section of Electrochemistry Department of Energy Storage and Conversion Technical University of Denmark

＜正＞Electrocatalysts for low temperature fuel cells are based on noble metals, the resource issue of which will be briefly reviewed. Approaches and efforts towards low platinum load catalysts by means of alloying and nano architecturing. Significant progress has been achieved by development of Pt alloys with late transition metals such as Ni and Co, which exhibit much-enhanced performance.[1,2] It has been predicted that Pt alloys with rare earth metals exhibit remarkable activity and high stability towards the oxygen reduction reaction.

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复旦学报（自然科学版） 2005年第5期44卷 666-667页

作者： Jens Oluf Jensen Pernille P. Noyé Niels J. Bjerrum Materials Science Group Department of Chemistry Technical University of DenmarkMaterials Science Group Department of Chemistry Technical University of DenmarkMaterials Science Group Department of Chemistry Technical University of Denmark

The current technology of proton exchange membrane fuel cells (PEMFC) is based on perfluorosulfonic acid (PFSA) membranes (e. g. Nafion(R)) as electrolyte. It operates on pure hydrogen and oxygen/air at typically 80℃ with high power density and long-term durability. For the membranes to be conductive, a minimum threshold of absorbed water molecules is about 6 to 7 mole per sulfonic site. The highest conductivity is only obtained under fully hydrated conductions, i.e. 21 - 22 mole water per sulfonic acid site. In other words, the proton conductivity is achieved by the locally liquid-like hydrophilic domain of the nanostructure.This strong dependence of conductivity on the water content in membranes limits the operational temperatureof PEMFC below 100℃.

关键词：质子交换燃料电池隔膜电化学电解液

Fuel Cells: A Promise of Electrochemistry and Challenges for Electrochemists

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Fuel Cells: A Promise of Electrochemistry and Challenges for...

Incidental findings at MRI-enterography in patients with suspected or known Crohn's disease

第十三次全国电化学会议

作者： Jens Oluf Jensen Pernille P.Noyé Niels J．Bjerrum Department of Chemistry Technical University of DenmarkDK-2800LyngbyDenmark Department of Chemistry Technical University of DenmarkDK-2800LyngbyDenmark Department of Chemistry Technical University of DenmarkDK-2800LyngbyDenmark

＜正＞The availability of fossil fuels is expected to decrease significantly in the coming decades. At the same time, as a result of fossil fuel use, carbon dioxide is accumulating in the atmosphere and global wanning is accelerating at an increasing rate. These ever growing concerns are stimulating worldwide research on renewable 21st century energy technologies. Fuel cells have been recognized as amongst the most promising solutions for both automobile and stationary uses.

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World Journal of Gastroenterology 2010年第1期16卷 76-82页

作者： Michael Dam jensen Torben Nathan jens Kjeldsen Sφren Rafael Rafaelsen Department of Internal Medicine Section of GastroenterologyVejle Hospital part of Lillebaelt Hospital Department of Medical Gastroenterology Odense University Hospital Department of Radiology Vejle Hospital part of Lillebaelt Hospital

AIM:To determine the frequency and clinical impact of incidental findings detected with magnetic resonance imaging(MRI)-enterography in patients with suspected or known Crohn's disease(CD). METHODS:Incidental findings were defined as unexpected lesions outside the small intestine,not previously known or suspected at the time of referral, and not related to inflammatory bowel disease.Through a systematic review of medical charts we analyzed the clinical impact of incidental findings,and compared the MRI findings with subsequent diagnostic procedures. RESULTS:A total of 283 patients were included in the analysis,and MRI detected active CD in 31%,fistula in 1.4%and abscess in 0.7%.Extra-intestinal findings notrelated to CD were recorded in 72 patients(25%),of which 58 patients(20%)had 74 previously unknown lesions.Important or incompletely characterized findings were detected in 17 patients(6.0%).Incidental findings led to 12 further interventions in 9 patients(3.2%) revealing previously unknown pathological conditions in 5(1.8%).One patient(0.4%)underwent surgery and one patient was diagnosed with a malignant disease. MRI detected incidental colonic lesions in 16 patients of which additional work-up in 4 revealed normal anatomy. Two patients(0.7%)benefitted from the additional examinations,whereas incidental findings led to unnecessary examinations in 9(3.2%). CONCLUSION:In a minority of patients with suspected or known CD,important incidental findings are diagnosed at MRI-enterography.However,a substantial number of patients experience unnecessary morbidity because of additional examinations of benign or normal conditions.

关键词： Magnetic resonance imaging Incidental findings Crohn’s disease Small intestine

Urban-induced changes in tree leaf litter accelerate decomposition

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Ecological Processes 2015年第1期4卷 1-16页

作者： jens Dorendorf Anja Wilken Annette Eschenbach Kai jensen Applied Plant Ecology Biocenter Klein FlottbekUniversität HamburgOhnhorstraße 1822609 HamburgGermany Institute for Soil Science CENUniversität HamburgAllende-Platz 220146 HamburgGermany.

Introduction:The role of urban areas in the global carbon cycle has so far not been studied conclusively.Locally,urbanization might affect decomposition within urban boundaries.So far,only few studies have examined the effects of the level of urbanization on decomposition.This study addresses the influence of the level of urbanization on decomposition processes.It explores whether potential influences are exerted through leaf litter quality alterations or through direct effects of decomposition site’s level of urbanization.Leaf litter of five different tree species was sampled at urban and periurban sites.Decomposition of this litter was analyzed in three different experiments:a climate chamber incubation,a reciprocal litterbag transplant at urban and periurban sites,and a common garden litterbag transplant.Results:Decomposition site’s level of urbanization did not show a significant effect.However,in all species,when significant differences were observed,leaf litter of urban origin decomposed significantly faster than leaf litter of periurban origin.This effect was observed in all three experiments.In the reciprocal litter transplant experiment,62%±3%mass loss in litter of urban origin compared to 53%±3%in litter of periurban origin was observed.The difference was not as pronounced in the other two experiments,with 94%±1%mass loss of litter originating in urban habitats compared to 92%±1%mass loss of litter originating in periurban habitats in the common garden experiment and 225±13 mg CO2 released from litter originating in urban habitats compared to 200±13 mg CO2 released from litter originating in periurban habitats in the climate chamber incubation.Conclusions:We conclude that the level of urbanization affects decomposition indirectly through alterations in leaf litter quality even over short urban to periurban distances.

关键词： Litterbags Urban gradients Carbon cycling Mass loss Respiration Urban ecology Urban forests Paired studies Suburban Urban–rural contrast

WSA-DC——下一代高浓度高转化率WSA工艺

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硫酸工业 2009年第5期 10-14页

作者： Frands E.jensen jens K.Laursen 王爱群托普索公司

介绍了托普索公司新开发的WSA-DC工艺,详述其流程、优点、性能、消耗和生产数据。WSA-DC工艺是一个两次冷凝工艺,它结合了WSA工艺与两转两吸工艺的优点,通过对中间冷凝器的设计改进和仔细控制气体中的H_2O/SO_2比率,可以用(?)(SO_2)等... 详细信息

介绍了托普索公司新开发的WSA-DC工艺,详述其流程、优点、性能、消耗和生产数据。WSA-DC工艺是一个两次冷凝工艺,它结合了WSA工艺与两转两吸工艺的优点,通过对中间冷凝器的设计改进和仔细控制气体中的H_2O/SO_2比率,可以用(?)(SO_2)等于或高于13%的原料气生产w(H_2SO_4)为99%的硫酸。以1套540 t/d硫磺制酸装置为例,对WSA-DC工艺和传统干法两转两吸工艺进行了技术经济比较。

关键词：硫酸生产湿式硫酸两次冷凝工艺

Long-term survival following radiofrequency ablation of colorectal liver metastases: A retrospective study

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World Journal of Gastrointestinal Surgery 2015年第3期7卷 33-38页

作者： Simeon Niyi Babawale Thomas MandФe jensen jens BrФndum FrФkjr Department of Radiology Aalborg University Hospital Department of Clinical Medicine Aalborg University

AIM: To retrospectively evaluate the long-term survivalof patients that received radiofrequency ablation(RFA) therapies of colorectal liver metastases. METHODS: In 2005 to 2008, RFA of 105 colorectal liver metastases(CRLM) were performed on 49 patients in our institution. The liver metastases were evaluated, both before and after ablation therapies, with contrast enhanced computerised tomography and contrast enhanced ultrasonography. Histological evidence of malignant liver metastases was obtained in the few instances where contrast enhanced ultrasonography gave equivocal results. Accesses to the CRLM were guided ultrasonically in all patients. The data obtained from records of these ablations were retrospectively analysed and survival data were compared with existing studies in the literature.RESULTS: 1-, 2-, 3-, 4- and 5-year survival rates, when no stringent selection criteria were applied, were 92%, 65%, 51%, 41% and 29% respectively. To explore the impact of the number and size of CRLM on patients' survival, an exclusion of 13 patients(26.5%) with number of CRLM ≥ 5 and tumour size ≥ 40 mm resulted in 1-, 2-, 3-, 4- and 5-year survival rates improving to 94%, 69%, 53%, 42% and 31% respectively. It is of note that 9 of 49 patients developed extra-hepatic metastases, not visible or seen on pretreatment scans, just after RFA treatment. These patients had poorer survival. The development of extra-hepatic metastases in nearly 20% of the patients included in our study can partly account for modestly lower survival rates as compared with earlier studies in the literature.CONCLUSION: Our study underscores the fact that optimum patients' selection before embarking on RFA treatment is vitally important to achieving a superior outcome.

关键词： Colorectal cancer Liver metastasis

Impaired contractility and remodeling of the upper gastrointestinal tract in diabetes mellitus type-1

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World Journal of Gastroenterology 2007年第36期13卷 4881-4890页

作者： jens BrΦndum FrΦkjΦr SΦren Due Andersen Niels EjskjΦr Peter Funch-jensen AsbjΦrn Mohr Drewes Hans Gregersen Center for Visceral Biomechanics and Pain Aalborg Hospital Aalborg Denmark Department of Radiology Aalborg Hospital Aalborg Denmark Department of Endocrinology M Aarhus University Hospital Aarhus Denmark Department of Surgical Gastroenterology L Aarhus University Hospital Aarhus Denmark Center for Sensory-Motor Interaction Department of Health Science and Technology Aalborg University Denmark Center for Sensory-Motor Interaction Department of Health Science and Technology Aalborg University Denmark National Center for Ultrasound in Gastro-enterology Haukeland University Hospital Bergen Norway

AIM: To investigate that both the neuronal function of the contractile system and structural apparatus of the gastrointestinal tract are affected in patients with longstanding diabetes and auto mic neuropathy. METHODS: The evoked esophageal and duodenal contractile activity to standardized bag distension was assessed using a specialized ultrasound-based probe. Twelve type-1 diabetic patients with autonomic neuropathy and severe gastrointestinal symptoms and 12 healthy controls were studied. The geometry and biomechanical parameters (strain, tension/stress, and stiffness) were assessed. RESULTS: The diabetic patients had increased frequency of distension-induced contractions (6.0 ± 0.6 vs 3.3 ± 0.5, P 0.14). CONCLUSION: The impaired contractile activity with an imbalance in the distension-induced contractions likely reflects neuronal abnormalities due to autonomic neuropathy. However, structural changes and remodeling of the gastrointestinal tract are also evident and may add to the neuronal changes. This may contribute to the pathophysiology of diabetic gut dysfunction and impact on future management of diabetic patients with gastrointestinal symptoms.

关键词：糖尿病神经病生物力学收缩性

Chronic intestinal ischemia and splanchnic blood-flow:Reference values and correlation with body-composition

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World Journal of Gastroenterology 2013年第6期19卷 882-888页

作者： Helle Damgaard Zacho jens Henrik Henriksen Jan Abrahamsen Department of Clinical Physiology Viborg Regional Hospital Department of Clinical Physiology Hvidovre HospitalUniversity of Copenhagen

AIM:To determine the splanchnic blood flow and oxygen uptake in healthy-subjects and patients and to relate the findings to body-composition.METHODS:The total splanchnic blood flow (SBF) and oxygen uptake (SO2U) were measured in 20 healthy volunteers (10 women) and 29 patients with suspected chronic intestinal ischemia (15 women),age 40-85 years,prior to and after a standard meal.The method is based on the Fick principle using the continuous infusion of an indicator (99mTechnetium-labelled mebrofenin) and catheterization of an artery and the hepatic vein.An angiography of the intestinal arteries was performed during the same investigation.A whole-body dual-energy x-ray absorptiometry scan was performedin healthy volunteers to determine body composition.RESULTS:Angiography revealed no atherosclerotic lesions in the intestinal arteries.The mean baseline SBF was 1087mL/min (731-1390),and this value increased significantly to 1787 mL/min after the meal in healthy volunteers (P<0.001).The baseline SBF in patients was 1080 mL/min,which increased to 1718 mL/min postprandially (P<0.001).The baseline SBF was independent of age,sex,lean body mass and percentage of body fat.The mean meal-induced increase in SBF was equal to 282mL/min + 5.4mL/min × bodyweight,(P=0.025).The SO2U in healthy volunteers and patients was 50.7mL/min and 48.0mL/min,respectively,and these values increased to 77.5 mL/min and 75mL/min postprandially,respectively.Both baseline and postprandial SO2U were directly related to lean body mass.Age and sex exerted no impact on SO2U.CONCLUSION:A direct correlation between body weight and the postprandial increase in SBF was observed.The effect of body weight should be considered in the diagnosis of chronic intestinal ischemia.

关键词： Splanchnic circulation Postprandial period Body composition Mesenteric vascular occlusion Middle aged