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利用Picarro测试石笋包裹体水氢、氧同位素的方法

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科学通报 2020年第32期65卷 3626-3634页

作者：田野张海伟宗保云段鹏珍 Hubert B.Vonhof Yuri V.Dublyansky 宁有丰 christoph spotl 蔡演军程海西安交通大学全球环境变化研究院西安710054 Department of Climate Geochemistry Max Planck Institute for ChemistryMainz 55128Germany Institute of Geology University of InnsbruckInnsbruck 6020Austria

基于当前石笋包裹体水提取测试过程中面临的制约条件,本研究设计了用于提取石笋包裹体水的真空装置,将其与水同位素分析仪Picarro L2140-i相连接组成石笋包裹体水氢、氧同位素(δD、δ18O)测试系统.该系统能够快速地提取石笋包裹体中的... 详细信息

基于当前石笋包裹体水提取测试过程中面临的制约条件,本研究设计了用于提取石笋包裹体水的真空装置,将其与水同位素分析仪Picarro L2140-i相连接组成石笋包裹体水氢、氧同位素(δD、δ18O)测试系统.该系统能够快速地提取石笋包裹体中的水,并对其δD和δ18O的值进行测量.包裹体水真空提取装置使用了以高压气缸为驱动的破碎研磨器,具有良好的破碎效果;在120°C真空条件下破碎获得的包裹体水随后被高纯氮气带入到Picarro L2140-i中进行测量分析.为了验证包裹体水测试系统的可靠性和准确性,本研究分别将石笋包裹体水真空提取装置以及Picarro液态水自动进样器与Picarro L2140-i主机连接,对相同的水样品进行了对比测试.两种方法测得的δ18O和δD值在误差范围内接近.使用该系统对东亚季风区石笋样品进行的测试结果显示:石笋包裹体水的δ18O和δD值分布在全球大气降水线附近,表明测试过程中分馏作用较小;包裹体含水量对测试精度有一定影响,对于水汽浓度为2500~50000 ppm(1 ppm=1μL/L)的样品,δ18O、δD的标准差分别为0.5‰、2‰,与同类型系统相当.研究结果表明该系统能如实测量石笋包裹体水的δ18O和δD值,将为利用水-碳酸钙平衡分馏方程重建古温度提供重要的技术支撑.

关键词：石笋包裹体稳定同位素水同位素分析仪(Picarro) 波长扫描光腔衰荡光谱古温度

Energy enhancement of laser-driven ions by radiation reaction and Breit-Wheeler pair production in the ultra-relativistic transparency regime

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High Power Laser Science and Engineering 2024年第1期12卷 60-73页

作者： Shikha Bhadoria Mattias Marklund christoph H.Keitel Max-Planck-Institut für Kernphysik HeidelbergGermany Department of Physics University of GothenburgGöteborgSweden

The impact of radiation reaction and Breit±Wheeler pair production on the acceleration of fully ionized carbon ions driven by an intense linearly polarized laser pulse has been investigated in the ultra-relativistic transparency *** initial expectations, the radiation reaction and pair production at ultra-high laser intensities are found to enhance the energy gained by the ions. The electrons lose most of their transverse momentum, and the additionally produced pair plasma of Breit±Wheeler electrons and positrons co-streams in the forward direction as opposed to the existing electrons streaming at an angle above zero degree. We discuss how these observations could be explained by the changes in the phase velocity of the Buneman instability, which is known to aid ion acceleration in the breakout afterburner regime, by tapping the free energy in the relative electron and ion streams. We present evidence that these non-classical effects can further improve the highest carbon ion energies in this transparency regime.

关键词： ion acceleration quantum electrodynamic effects

Implementation and validation of a bonded particle model to predict rheological properties of viscoelastic materials

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Particuology 2024年第6期89卷 198-210页

作者： Michael Mascara Arno Mayrhofer Stefan Radl christoph Kloss Institute of Process and Particle Engineering Graz University of TechnologyInffeldgasse 13Graz8010Austria DCS Computing GmbH Industriezeile 35Linz4020Austria

This work focuses on implementing a particle-based method able to characterize viscoelastic materials whose rheological properties,such as storage modulus G′and loss modulus G″,are *** is based on the bonded particle model,with the elastic constitutive relation here substituted with a viscoelastic one to capture time-scale *** Burgers model,vastly used in literature to model viscoelastic systems,is discretized and *** test case used for calibration comprises of a cubic lattice,sheared with a periodic motion,to mimic the effect of a shear *** appropriate filtering of the stress response,the rheological properties are obtained,highlighting the effect of the lattice geometry,as well as the particle size,on the accuracy of the ***,the Burgers parameters are calibrated by analytically fitting the experimental dataset,showing the limitation of the Burgers *** micro-contact parameters are obtained from the macro parameters through appropriate *** completing a frequency sweep,the simulated G′and G″show a relatively large error,around 25%for G’for *** this reason,a more robust model,namely the generalized Maxwell model,has been *** calibration procedure is performed in the same fashion as for the Burgers ***,the tangential micro-contact parameters are scaled *** normal *** scaling parameter,calledα,is calibrated by minimizing the root mean square error between simulation and experimental data,giving errors below 10%in both G′and G″for a large ***,a full ring plate-plate rheometer setup is simulated,and the simulation is compared with the given experimental dataset,again finding a good agreement.

关键词： DEM Rheology Numerical modeling Viscoelasticity

Recycled graphite for more sustainable lithium-ion batteries

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Carbon Energy 2024年第5期6卷 15-24页

作者： Mayokun Olutogun Anna Vanderbruggen christoph Frey Martin Rudolph Dominic Bresser Stefano Passerini Helmholtz Institute Ulm(HIU) Ulm Germany Karlsruhe Institute of Technology(KIT) KarlsruheGermany Helmholtz Zentrum Dresden-Rossendorf(HZDR) Helmholtz Institute Freiberg for Resource Technology(HIF)FreibergGermany ProGraphite GmbH UntergriesbachGermany Chemistry Department Sapienza University of RomeRomeItaly

The demand for lithium-ion batteries(LIBs)is driven largely by their use in electric vehicles,which is projected to increase dramatically in the *** great success,however,urgently calls for the efficient recycling of LIBs at the end of their ***,we describe a froth flotation-based process to recycle graphite—the predominant active material for the negative electrode—from spent LIBs and investigate its reuse in newly assembled *** has been found that the structure and morphology of the recycled graphite are essentially unchanged compared to pristine commercial anode-grade graphite,and despite some minor impurities from the recycling process,the recycled graphite provides a remarkable reversible specific capacity of more than 350 mAh g^(−1).Even more importantly,newly assembled graphite‖NMC532 cells show excellent cycling stability with a capacity retention of 80%after 1000 cycles,that is,comparable to the performance of reference full cells comprising pristine commercial graphite.

关键词： anode graphite lithium-ion battery recycling sustainability

Machine learning prediction of methane, ethane, and propane solubility in pure water and electrolyte solutions: Implications for stray gas migration modeling

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Acta Geochimica 2024年第05期43卷 971-984页

作者： Ghazal Kooti Reza Taherdangkoo Chaofan Chen Nikita Sergeev Faramarz Doulati Ardejani Tao Meng christoph Butscher Institute of Geotechnics TU Bergakademie Freiberg Department of Petroleum Engineering Amirkabir University of Technology Freiberg Center for Water Research ZeWaF TU Bergakademie Freiberg School of Mining College of Engineering University of Tehran Taiyuan University of Science and Technology

Hydraulic fracturing is an effective technology for hydrocarbon extraction from unconventional shale and tight gas reservoirs. A potential risk of hydraulic fracturing is the upward migration of stray gas from the deep subsurface to shallow aquifers. The stray gas can dissolve in groundwater leading to chemical and biological reactions,which could negatively affect groundwater quality and contribute to atmospheric emissions. The knowledge oflight hydrocarbon solubility in the aqueous environment is essential for the numerical modelling offlow and transport in the subsurface. Herein, we compiled a database containing 2129experimental data of methane, ethane, and propane solubility in pure water and various electrolyte solutions over wide ranges of operating temperature and pressure. Two machine learning algorithms, namely regression tree（RT）and boosted regression tree（BRT） tuned with a Bayesian optimization algorithm（BO） were employed to determine the solubility of gases. The predictions were compared with the experimental data as well as four well-established thermodynamic models. Our analysis shows that the BRT-BO is sufficiently accurate, and the predicted values agree well with those obtained from the thermodynamic models. The coefficient of determination（R2） between experimental and predicted values is 0.99 and the mean squared error（MSE）is 9.97 × 10-8. The leverage statistical approach further confirmed the validity of the model developed.

关键词： Boosted regression tree Gas solubility Groundwater contamination Hydraulic fracturing Regression tree Thermodynamic models

Sol-gel derived B_(2)O_(3)-CaO borate bioactive glasses with hemostatic,antibacterial and pro-angiogenic activities

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Regenerative Biomaterials 2024年第1期3卷 108-118页

作者： Kai Zheng Faina Bider Mahshid Monavari Zhiyan Xu Christina Janko christoph Alexiou Ana M.Beltran Aldo R.Boccaccini Jiangsu Province Engineering Research Center of Stomatological Translational Medicine College of StomatologyNanjing Medical UniversityNanjing 210029China Jiangsu Key Laboratory of Oral Diseases Nanjing Medical UniversityNanjing 210029China Institute of Biomaterials University of Erlangen-Nuremberg91058 ErlangenGermany Department of Oto-Rhino-Laryngology Head and Neck SurgerySection of Experimental Oncology and Nanomedicine(SEON)Else Kroener-Fresenius-Stiftung ProfessorshipUniversitaetsklinikum Erlangen91058 ErlangenGermany Departamento de Ingenier�ıa y Ciencia de los Materiales y del Transporte Escuela Politecnica

Sol-gel borate bioactive glasses(BGs)are promising ion-releasing biomaterials for wound healing ***,we report the synthesis of a series of binary B_(2)O_(3)-CaO borate BGs(CaO ranging from 50 to 90mol%)using a sol-gel-based *** influence of CaO content in B_(2)O_(3)-CaO borate BG on morphology,structure and ion release behavior was investigated in *** dissolution(ion release)and crystallization could be observed in borate BGs when CaO content increased,while the morphology was not significantly altered by increasing CaO *** results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B_(2)O_(3)/CaO molar *** also evaluated the in vitro cytotoxicity,hemostatic,antibacterial and angiogenic activities of borate *** was validated for all borate ***,borate BGs exhibited composition-dependent hemostatic,antibacterial and angiogenic ***,higher contents of Ca in borate BGs facilitated hemostatic activity,while higher contents of B_(2)O_(3) were beneficial for pro-angiogenic *** synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings,given their fast ion release behavior and favorable hemostatic,antibacterial and angiogenic activities.

关键词： borate glasses sol-gel processing glass composition wound healing

Effects of P301L-TAU on post-translational modifications of microtubules in human iPSC-derived cortical neurons and TAU transgenic mice

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Neural Regeneration Research 2025年第8期20卷 2348-2360页

作者： Mohamed Aghyad Al Kabbani christoph Köhler Hans Zempel Institute of Human Genetics Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany Center for Molecular Medicine Cologne(CMMC) University of CologneCologneGermany Center Anatomy Department ⅡMedical FacultyUniversity of CologneCologneGermany

TAU is a microtubule-associated protein that promotes microtubule assembly and stability in the *** is missorted and aggregated in an array of diseases known as *** are essential for neuronal function and regulated via a complex set of post-translational modifications,changes of which affect microtubule stability and dynamics,microtubule interaction with other proteins and cellular structures,and mediate recruitment of microtubule-severing *** impairment of microtubule dynamics causes neuronal dysfunction,we hypothesize cognitive impairment in human disease to be impacted by impairment of microtubule *** therefore aimed to study the effects of a disease-causing mutation of TAU(P301L)on the levels and localization of microtubule post-translational modifications indicative of microtubule stability and dynamics,to assess whether P301L-TAU causes stability-changing modifications to *** investigate TAU localization,phosphorylation,and effects on tubulin post-translational modifications,we expressed wild-type or P301L-TAU in human MAPT-KO induced pluripotent stem cell-derived neurons(i Neurons)and studied TAU in neurons in the hippocampus of mice transgenic for human P301L-TAU(p R5 mice).Human neurons expressing the longest TAU isoform(2N4R)with the P301L mutation showed increased TAU phosphorylation at the AT8,but not the p-Ser-262 epitope,and increased polyglutamylation and acetylation of microtubules compared with endogenous TAU-expressing neurons.P301L-TAU showed pronounced somatodendritic presence,but also successful axonal enrichment and a similar axodendritic distribution comparable to exogenously expressed 2N4R-wildtype-TAU.P301L-TAU-expressing hippocampal neurons in transgenic mice showed prominent missorting and tauopathy-typical AT8-phosphorylation of TAU and increased polyglutamylation,but reduced acetylation,of microtubules compared with non-transgenic *** sum,P301L-TAU results in changes in micr

关键词： human induced pluripotent stem cell microtubules P301L pR5 mice TAU tauopathy tubulin code

Towards engineering a portable platform for laparoscopic pre-training in virtual reality with haptic feedback

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虚拟现实与智能硬件（中英文） 2024年第2期6卷 83-99页

作者： Hans-Georg ENKLER Wolfgang KUNERT Stefan PFEFFER Kai-Jonas BOCK Steffen AXT Jonas JOHANNINK christoph REICH Furtwangen University 78120 FurtwangenGermany University Hospital and Faculty of Medicine Tuebingen 72076 TuebingenGermany

Background Laparoscopic surgery is a surgical technique in which special instruments are inserted through small incision holes inside the *** some time,efforts have been made to improve surgical pre training through practical exercises on abstracted and reduced *** The authors strive for a portable,easy to use and cost-effective Virtual Reality-based(VR)laparoscopic pre-training platform and therefore address the question of how such a system has to be designed to achieve the quality of today's gold standard using real tissue *** VR controllers are limited regarding haptic *** haptic feedback is necessary or at least beneficial for laparoscopic surgery training,the platform to be developed consists of a newly designed prototype laparoscopic VR controller with haptic feedback,a commercially available head-mounted display,a VR environment for simulating a laparoscopic surgery,and a training *** To take full advantage of benefits such as repeatability and cost-effectiveness of VR-based training,the system shall not require a tissue sample for haptic *** is currently calculated and visually displayed to the user in the VR *** the prototype controller,a first axis was provided with perceptible feedback for test *** of the prototype VR controllers can be combined to simulate a typical both-handed use case,e.g.,laparoscopic suturing.A Unity based VR prototype allows the execution of simple standard *** The first prototype enables full operation of a virtual laparoscopic instrument in *** addition,the simulation can compute simple interaction *** challenges lie in a realistic real-time tissue simulation and calculation of forces for the haptic *** weaknesses were identified in the first hardware prototype,which will be improved in subsequent *** degrees of freedom of the controller are to be provided with haptic *** make forces t

关键词： Laparoscopic surgery Training Virtual reality Controller Haptic feedback Kinesthetic skills

Prospective cohort study on facial profile changes in infants with Robin sequence and healthy controls

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World Journal of Pediatrics 2024年第6期20卷 581-589页

作者： Cornelia Wiechers Julian Sowula Karen Kreutzer christoph E.Schwarz Christina Weismann Michael Krimmel Christian F.Poets Bernd Koos Department of Neonatology Tuebingen University HospitalCalwerstrasse 772076 TuebingenGermany Center for Cleft Lip Palate and Craniofacial MalformationsTuebingen University HospitalTuebingenGermany Department of Orthodontics Tuebingen University HospitalTuebingenGermany Department of Oral and Maxillofacial Surgery Tuebingen University HospitalTuebingenGermany

Background Various conservative and surgical approaches exist to treat Robin sequence(RS),but their effects on facial profile and mandibular catch-up growth are unclear.A functional treatment concept,used in our centre for 25 years,includes an individualized palatal plate with a velo-pharyngeal extension and intensive feeding *** We performed a prospective study to objectively describe facial profiles in infants with RS treated with the above *** with isolated RS were admitted to our tertiary perinatal and national referral centre for craniofacial malformations between May 2018 and Nov *** with RS received 3D-photographs during clinically indicated *** controls were recruited from Dec 2018 to Sep 2019 and received 3D-photographs every 3 *** digitally measured jaw index(JI),defined as alveolar overjet(O)x maxillary arch(U)/mandibular arch(L),and the soft tissue reference points A’-point,Nasion’,B’-point angle(ANB’),describing the relative position of maxilla to mandible,were *** mixed models were used to examine time trajectories in JI and ANB’.Results A total of 2073D images,obtained in 19 infants with RS and 32 controls,were *** and ANB’decreased over time in both groups[for JI−0.18(95%CI−0.25 to−0.10);for ANB’:−0.40°per month[(95%CI−0.48 to−0.32)]]but remained lower in controls[for JI−2.5(95%CI−3.2 to−1.8);for ANB’-1.7°(95%CI−2.4 to−1.0)].Also,the ANB’model showed a significant effect of the interaction term diagnosis x *** Based on longitudinal 3D images,we describe changes in objective parameters of facial profile in infants with and without RS during the first year of *** findings indicate catch-up growth in infants treated for RS.

关键词： Infant Mandibular catch-up growth Pre-epiglottic Baton Plate Robin sequence Three-dimensional photography