| 21. |
- Qiu, Zhengfu, et al.
(författare)
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Surface activated polyethylene separator promoting Li+ ion transport in gel polymer electrolytes and cycling stability of Li-metal anode
- 2019
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 368, s. 321-330
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a strategy to fabricate surface activated polyethylene (PE)-supported gel polymer electrolyte (GPE) with high ion transport ability, excellent electrolyte retention and mechanical properties to stabilize lithium (Li)-metal anodes. The inert outer and inner pore surface activation of polyethylene is demonstrated by coating an ultrathin zirconium oxide nanocrystal (ZrO2)/polyhedral oligomeric silsesquioxane (POSS) composite layer through a simple layer by layer (LBL) assembly method prior to the in situ polymerization. It is found that the activation layer may improve the Li+ ion transference number and induce the formation of GPE with a gradient structure by the interaction with the initiator system, giving rise to higher ion transport ability of final GPE. On the other hand, the GPE using the activated PE separator as support improves the Li/electrolyte interfacial stability during storage and repeated lithium plating/stripping cycling. A stable voltage profile with cycling for more than 800 h in a Li/Li symmetric cell was obtained by using surface activated PE-supported GPE. When it is assembled into the cells with metallic lithium anodes and lithium cobalt oxide (LiCoO2) cathodes, the cells show excellent rate capability and cycling performance, as well as effective dendrite inhibition.
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| 22. |
- Ruilope, LM, et al.
(författare)
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Design and Baseline Characteristics of the Finerenone in Reducing Cardiovascular Mortality and Morbidity in Diabetic Kidney Disease Trial
- 2019
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Ingår i: American journal of nephrology. - : S. Karger AG. - 1421-9670 .- 0250-8095. ; 50:5, s. 345-356
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background:</i></b> Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. <b><i>Patients and</i></b> <b><i>Methods:</i></b> The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate ≥25 mL/min/1.73 m<sup>2</sup> and albuminuria (urinary albumin-to-creatinine ratio ≥30 to ≤5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level α = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. <b><i>Conclusions:</i></b> FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049.
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| 23. |
- Schewe, Jacob, et al.
(författare)
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State-of-the-art global models underestimate impacts from climate extremes
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Global impact models represent process-level understanding of how natural and human systems may be affected by climate change. Their projections are used in integrated assessments of climate change. Here we test, for the first time, systematically across many important systems, how well such impact models capture the impacts of extreme climate conditions. Using the 2003 European heat wave and drought as a historical analogue for comparable events in the future, we find that a majority of models underestimate the extremeness of impacts in important sectors such as agriculture, terrestrial ecosystems, and heat-related human mortality, while impacts on water resources and hydropower are overestimated in some river basins; and the spread across models is often large. This has important implications for economic assessments of climate change impacts that rely on these models. It also means that societal risks from future extreme events may be greater than previously thought.
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| 24. |
- Wang, Yanan, et al.
(författare)
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Gel Polymer Electrolyte with High Li+ Transference Number Enhancing the Cycling Stability of Lithium Anodes
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 11:5, s. 5168-5175
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Tidskriftsartikel (refereegranskat)abstract
- Lithium anodes suffer from severe safety problems in liquid electrolyte systems that result from an unstable Li plating/stripping process and Li dendrite growth, leading to rapid degradation of Li metal batteries. A polyethylene (PE)-supported gel polymer electrolyte (GPE) with excellent electrolyte uptake/retention capability was simply prepared in this paper by the construction of cross-linked polymer networks (PNs) on the surface of a poly(ethylenimine)-primed PE separator to stabilize the lithium anode. The highly delocalized negative charge of p-styrene sulfonate groups on PNs plays a role in regulating the Li+ and anion transport, giving rise to a high Li+ transference number. This GPE extended the electrochemical stability to 4.8 V and improved the stability of interface between the electrolyte and lithium metal anode (reduced overpotential and suppressed lithium dendrites) during storage and repeated lithium plating/stripping cycling. The Li metal anode-based battery employing this GPE exhibits excellent cycling stability and C-rate capability.
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| 25. |
- Zhang, Hao, et al.
(författare)
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A simple method to enhance the lifetime of Ni-rich cathode by using low-temperature dehydratable molecular sieve as water scavenger
- 2019
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Ingår i: Journal of Power Sources. - : ELSEVIER. - 0378-7753 .- 1873-2755. ; 435
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Tidskriftsartikel (refereegranskat)abstract
- Ni-rich cathode materials have received much attention because of their high specific capacity, low cost and environmentally friendly characteristic. However, the nickel-rich cathode is extremely sensitive to moisture, which results in poor structure stability and electrochemical performance. Herein, we demonstrate an efficient and simple route to prolong the lifetime of nickel-rich cathode by introducing a low-temperature dehydratable molecular sieve as water scavenger. The residual water content in electrolyte measurement and nuclear magnetic resonance test manifest that molecular sieve can effectively fix the trace H2O and reduce the decomposition rate of electrolyte from 16.6% to 4.0%, respectively. Transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy confirm that the molecular sieve inhibits the fragmentation of the electrode and the side reactions on the surface of the cathode. This approach improves structural integrity and stabilizes surface structure of the cathode, which increases the capacity retention without sacrificing rate performance. This effective strategy can be extended to other cathode materials which are sensitive to moisture to realize good cycling stability.
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| 26. |
- Zhang, Tianmeng, et al.
(författare)
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Observations of a Fast-expanding and UV-bright Type Ia Supernova SN 2013gs
- 2019
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 872:1
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present extensive optical and ultraviolet (UV) observations of the type Ia supernova (SN Ia) 2013gs discovered during the Tsinghua-NAOC Transient Survey. The photometric observations in the optical show that the light curves of SN 2013gs are similar to those of normal SNe Ia, with an absolute peak magnitude of M-B = -19.25 +/- 0.15 mag and a post-maximum decline rate Delta m(15)(B) = 1.00 +/- 0.05 mag. Gehrels Swift Ultr-Violet/Optical Telescope observations indicate that SN 2013gs shows unusually strong UV emission (especially in the uvw1 band) at around the maximum light (M-uvw1 similar to -18.9 mag). The SN is characterized by relatively weak Fe II III absorptions at similar to 5000 angstrom in the early spectra and a larger expansion velocity (v(Si) similar to 13,000 km s(-1) around the maximum light) than the normal-velocity SNe Ia. We discuss the relation between the uvw1 - v color and some observables, including Si II velocity, line strength of Si II lambda 6355 and Fe II/III lines, and Delta m(15)(B). Compared to other fast-expanding SNe Ia, SN 2013gs exhibits Si and Fe absorption lines with similar strength and bluer uvw1 - v color. We briefly discussed the origin of the observed UV dispersion of SNe Ia.
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| 27. |
- Zhao, Dandan, et al.
(författare)
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Proton irradiation induced defects in T92 steels: An investigation by TEM and positron annihilation spectroscopy
- 2019
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 442, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate proton irradiation damage on ferritic/martensitic T92 steels, both the unaged and aged (650 °C for 15,000 h) T92 steels were irradiated with 250 keV protons to 0.01, 0.05 and 0.20 dpa at room temperature due to the lower dose rate of protons compared with heavy-ions. The microstructural evolution induced by thermal aging and proton irradiation was studied by transmission electron microscopy and positron annihilation spectroscopy, and the corresponding micromechanical property changes were investigated by nano-indentation. After 0.20 dpa proton irradiation, the dominant irradiation-induced dislocation loops were a0100 type loops for both the unaged and aged samples. The dislocation-type defects in the aged T92 sample were larger in size and higher in number density, compared with those in the unaged samples. Less vacancy-type defects induced by protons were detected in the aged than the unaged T92 samples under the same irradiation conditions. The higher number density of dislocation-type defects led to more severe irradiation hardening in the aged T92 samples.
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| 28. |
- Zhao, Shengzhong, et al.
(författare)
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Re-direction of smoke flow in inclined tunnel fires
- 2019
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Ingår i: Tunnelling and Underground Space Technology. - : Elsevier BV. - 0886-7798 .- 1878-4364. ; 86, s. 113-127
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Tidskriftsartikel (refereegranskat)abstract
- The re-direction of smoke flow in inclined tunnel fires refers to the phenomenon that the smoke flow direction suddenly changes due to the changes of thermal buoyancy or outside pressure or the activation of fans. This poses special risk for fire rescue services fighting fires in tunnels. Both small-scale tunnel fire tests (28 scenarios) and numerical simulations of full-scale tunnel fires (31 scenarios) were conducted to study this special phenomenon. A one-dimensional model was used to predict the flow velocity in the inclined tunnels, based on two different methods for calculating the mean smoke temperature (Method I and Method II, respectively). Results show that the smoke flow direction could be well predicted by the model with Method II. When the ventilation velocity is relatively large and the flow tends to be one dimensional, both methods produce similar results. Further, the influences of important factors on the re-direction of smoke flows were systematically analyzed. These factors include heat release rate, tunnel slope, tunnel length, friction factor, tunnel cross sectional area and fire source location.
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| 29. |
- Zhao, Z., et al.
(författare)
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Responses of the radial growth of the endangered species Keteleeria fortunei to climate change in southeastern China
- 2019
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Ingår i: Trees-Structure and Function. - : Springer Science and Business Media LLC. - 0931-1890. ; 33:4, s. 977-985
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge on the responses of endangered species to current global changes can highlight the necessity and importance of protecting these species. Tree-ring-based studies provide a longer term perspective than monitoring studies on the responses and adaptations of the growth of endangered species to climate change and forest disturbances. Therefore, this study conducted a tree-ring case study on Keteleeria fortunei, an endangered and endemic species in southern China, and presents the first tree-ring chronology of K. fortunei from 1850 to 2013 in the Fuzhou area, which is located west of the Taiwan Strait. K. fortunei trees tend to grow in moister locations in closed forests and are more sensitive to forest disturbances and sunshine than Pinus massoniana. Our study shows that missing rings are more frequent for K. fortunei than for P. massoniana in the same area, which agrees with previous findings that wedging and missing rings tend to occur in trees experiencing growth suppression in closed forests.
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