Lithium (Li) metal anodes have the highest theoretical capacity and lowest electrochemical potential making them ideal for Li metal batteries (LMBs). However, Li dendrite formation on the anode ...impedes the proper discharge capacity and practical cycle life of LMBs, particularly in carbonate electrolytes. Herein, we developed a reactive alternative polymer named P(St‐MaI) containing carboxylic acid and cyclic ether moieties which would in situ form artificial polymeric solid electrolyte interface (SEI) with Li. This SEI can accommodate volume changes and maintain good interfacial contact. The presence of carboxylic acid and cyclic ether pendant groups greatly contribute to the induction of uniform Li ion deposition. In addition, the presence of benzyl rings makes the polymer have a certain mechanical strength and plays a key role in inhibiting the growth of Li dendrites. As a result, the symmetric Li||Li cell with P(St‐MaI)@Li layer can stably cycle for over 900 h under 1 mA cm−2 without polarization voltage increasing, while their Li||LiFePO4 full batteries maintain high capacity retention of 96 % after 930 cycles at 1C in carbonate electrolytes. The innovative strategy of artificial SEI is broadly applicable in designing new materials to inhibit Li dendrite growth on Li metal anodes.
A reactive surrogate polymer containing carboxylic acid and cyclic ether moieties is developed, that can form an artificial polymeric SEI (APSEI) in situ with lithium metal anodes. This APSEI greatly facilitates the induction of uniform deposition of lithium ions while suppressing the growth of lithium dendrites. The APSEI significantly improved the performance of lithium metal batteries.
The uneven zinc‐ion flux and interfacial contact between the anode and electrolyte trigger malignant dendrites and byproducts, significantly hindering the practical application of zinc‐metal ...batteries. Herein, a H‐bonded supramolecular organic framework (HSOF) is proposed to help regulate Zn2+ flux and stabilize interfacial chemistry. The self‐assembled supermolecule structures by in‐plane H‐bond networks firmly trap water molecules to assist Zn2+ de‐solvation and block interfacial corrosion. The abundant polar groups provide strong guidance for Zn2+ distribution, ensuring homogeneous, and rapid ion transport‐deposition kinetics. Meanwhile, the π–π stacked space‐layout structure affords preferred Zn(002) plane stacking for smooth and flat growth. Benefiting from these advantages, the HSOFs are employed on Zn surface for interfacial adjustment and on separator decoration for spatial manipulation, successfully realizing an overall “interface‐space” dual‐regulation effect. It delivers over 3000 h for the HSOF@Zn anode in symmetric cell and up to 5000 h for HSOF‐decorated separator in Zn||Zn symmetric cell, respectively. The HSOF@Zn||V2O5 full cell with the HSOF‐decorated separator demonstrates enhanced capacity retention of 92.7% after 2500 cycles at 5 A g−1. The full cell can be easily scaled up into a pouch cell, which still has a capacity retention rate of 94% after 1000 cycles.
The HSOFs utilize hydrogen bonding networks to efficiently capture water molecules, thereby preventing interfacial corrosion. Additionally, the abundant polar groups and π–π stacking spaces in the structure are conducive to the flat growth of Zn. Consequently, HSOF is employed for interfacial modulation on the Zn surface, and for spatial manipulation through separator decoration, successfully achieving an overall “interface‐space” dual‐regulation effect.
The practical implementation of the lithium metal anode (LMA) has long been pursued due to its extremely high specific capacity and low electrochemical equilibrium potential. However, the unstable ...interfaces resulting from lithium ultrahigh reactivity have significantly hindered the use of LMA. This instability directly leads to dendrite growth behavior, dead lithium, low Coulombic efficiency, and even safety concerns. Therefore, artificial solid electrolyte interfaces (ASEI) with enhanced physicochemical and electrochemistry properties have been explored to stabilize LMA. Polymer materials, with their flexible structures and multiple functional groups, offer a promising way for structurally designing ASEIs to address the challenges faced by LMA. This Concept demonstrates an overview of polymer ASEIs with different functionalities, such as providing uniform lithium ion and single‐ion transportation, inhibiting side reactions, possessing self‐healing ability, and improving air stability. Furthermore, challenges and prospects for the future application of polymeric ASEIs in commercial lithium metal batteries (LMBs) are also discussed.
The practical implementation of lithium metal anode (LMA) is hindered by unstable interfaces, dendrite growth, low efficiency, and safety concerns. Artificial solid electrolyte interfaces (ASEI) are explored to stabilize LMA. Polymer ASEIs offer a promising solution, providing uniform ion transport, inhibiting side reactions, self‐healing, and improving stability. This Concept reviews polymer ASEIs with different functionalities and discusses challenges and prospects for their application in commercial lithium metal batteries.
Recent studies have shown that the hydrogen absorption–desorption kinetics in magnesium can be improved by milling magnesium hydride (MgH2) with transition metal oxides. Accordingly, the present ...study investigates the particle size, crystalline structure and hydrogen absorption properties of MgH2 composite samples containing zirconium dioxide (ZrO2) nano-powder in molar fractions ranging from 1 to 5%. Hydrogen absorption kinetics isotherms are presented for temperatures in the range of 25–150 °C. The hydriding processes and kinetics of MgH2–ZrO2 alloy powers at different temperatures have also been studied. By theoretical analysis of the experimental data of the pyrolytic hydriding reaction, and fitting this with the Johnson–Mehl–Avrami (JMA) equation, the kinetic equation and the corresponding kinetic parameters, including the reaction order, the reaction rate constant, and the reaction activation energy, have been obtained. In general, the results show that ZrO2 acts as a refining agent, and is thus beneficial in decreasing the MgH2 activation energy and reducing the crystalline size during the milling process.
•Nanocrystalline structure of MgH2 + ZrO2 composite was created, and the hydrogenation at room temperature were achieved.•ZrO2 nanoparticles working as a medium for ball milling have an extensive effect on grain size reduction of Mg.•The sample absorbed hydrogen up to 2.96 wt% at 298 K and 5.8 wt% at 423 K.
A
bstract
We study the mass spectra of
Q
¯
Q
Q
¯
Q
(
Q
=
c, b
) systems in QCD sum rules with the complete next-to-leading order (NLO) contribution to the perturbative QCD part of the correlation ...functions. Instead of meson-meson or diquark-antidiquark currents, we use diagonalized currents under operator renormalization. We find that differing from conventional mesons
q
¯
q
and baryons
qqq
, a unique feature of the multiquark systems like
Q
¯
Q
Q
¯
Q
is the operator mixing or color configuration mixing induced by NLO corrections, which is crucial to understand the color structure of the states. Our numerical results show that the NLO corrections are very important for the
Q
¯
Q
Q
¯
Q
system, because they not only give significant contributions but also reduce the scheme and scale dependence and make Borel platform more distinct, especially for the
b
¯
b
b
¯
b
in the
MS
¯
scheme. We use currents that have good perturbation convergence in our phenomenological analysis. With the
MS
¯
scheme, we get three
J
PC
= 0
++
states, with masses
6.35
−
0.17
+
0.20
GeV,
6.56
−
0.20
+
0.18
GeV and
6.95
−
0.35
+
0.21
GeV, respectively. The first two seem to agree with the broad structure around 6
.
2 ~ 6
.
8 GeV measured by the LHCb collaboration in the
J/ψJ/ψ
spectrum, and the third seems to agree with the narrow resonance
X
(6900). For the 2
++
states we find one with mass
7.03
−
0.26
+
0.22
GeV, which is also close to that of
X
(6900), and another one around
7.25
−
0.35
+
0.21
GeV, which has good scale dependence but slightly large scheme dependence.
Objective
This article outlines the advantages and applicability of the rounded insertion technique of cochlear implants in patients with cystic inner ear malformation. This technique enables the ...insertion of the maximum number of electrodes and prevents the unwanted entry of electrodes into the internal auditory canal.
Methods
We conducted a retrospective chart review of consecutive patients with cochlear hypoplasia (CH) and/or common cavity (CC) who underwent CI (cochlear implantation) via rounded insertion technique. The position of the electrode array in each patient was confirmed postoperatively via X‐ray, and the number of functional electrodes was confirmed during the mapping process.
Results
This study included five male and two female patients (median age: 3 years; age range: 2–7 years). Among the seven patients, four received a cochlear implant on the right side, one on the left side, and two bilaterally. Of the nine ears, six were cases of CH, and three were CC. All cochlear implant surgeries via rounded insertion technique were completed without complications. The maximum number of electrode contacts with fair function in the cystic cochlea was confirmed via postoperative X‐ray and the subsequent mapping process.
Conclusion
This consecutive series of patients demonstrated the safety and reliability of rounded insertion technique for CI in patients with CH and/or CC.
Level of Evidence
4 Laryngoscope, 130:2229–2233, 2020
The numerical simulations by turbulent water forced convection in a three-dimensional twisted elliptical tube with constant wall temperature are investigated in this study. Flow resistance and heat ...transfer characteristics of water in the twisted elliptical tube are studied with the parameters, including Reynolds number and the twist pitch. Effects of the above-mentioned parameters on the performance of the twisted elliptical tubes are analyzed and the overall thermal-hydraulic performance is evaluated. The thermal resistance of the heat exchanger is defined based on the entransy dissipation theory. The results show that in the twisted elliptical tubes, rotational motions are produced in the flowing fluid that improves the synergy between velocity vectors and the gradient of temperature and enhances the heat transfer performance compared with an oval tube. The twist elliptical tubes bring on the pressure drop because of the twisted wall. The results are then compared with the results of the oval tube, the pressure drop of the twisted elliptical tube with d = 96 mm increases 58%–60%. The averaged Nusselt number with d = 96 mm increases 16%–19% compared with the oval tube. In addition, the average Nusselt number and the pressure drop both increase with increasing Reynolds number, while both decrease with the increasing of the twist pitch. The twisted elliptical tube can reduce the entransy dissipation based thermal resistance that provides the great benefit in heat transfer. The twist pitch has an influence on the overall thermal-hydraulic performances. The results show that the twisted elliptical tube with d = 128 mm has the best overall thermal-hydraulic performance.
•Turbulent water forced convection in a 3D twisted elliptical tube is investigated.•Due to the twisted wall, the twist elliptical tubes bring on the pressure drop.•The twist elliptical tubes can enhance heat transfer.•Twisted elliptical tube reduces the entransy dissipation based thermal resistance.•The twist pitch has an influence on the overall thermal-hydraulic performances.
Abstract
Background
The previous model-based cost-effectiveness analyses regarding elective oocyte cryopreservation remained debatable, while the usage rate may influence the cost per live birth. The ...aim of this study is to disclose the usage and cost-effectiveness of the planned cryopreserved oocytes after oocyte thawing in real-world situations.
Methods
This was a retrospective single-center observational study. Women who electively cryopreserved oocytes and returned to thaw the oocytes were categorized as thawed group. The oocytes were fertilized at our center and the sperm samples for each individual was retrieved from their respective husbands. Clinical outcomes were traced and the cumulative live birth rate per thawed case was calculated. The costs from oocyte freezing cycles to oocyte thawing, and embryo transfer cycles were accordingly estimated. The cumulative cost per live birth was defined by the cumulative cost divided by the live births per thawed case.
Results
We recruited 645 women with 840 oocyte retrieval cycles for elective oocyte freezing from November 2002 to December 2020. The overall usage rate was 8.4% (54/645). After the storage duration exceeded ten years, the probabilities of thawing oocytes were 10.6%, 26.6%, and 12.7% from women who cryopreserved their oocytes at the age ≤ 35 years, 36–39 years, and ≥ 40 years, respectively (
P
= 0.304). Among women who thawed their oocytes, 31.5% (17/54) of women achieved at least one live birth. For the age groups of ≤ 35 years, 36–39 years, and ≥ 40 years, the cumulative live birth rates per thawed case were 63.6%, 42.3%, and 17.6%, respectively (
P
= 0.045), and the cumulative costs for one live birth were $11,704, $17,189, and $35,642, respectively (
P
< 0.001).
Conclusions
The overall usage rate was 8.4% in our cohort. The cumulative live birth rate was greatest in the youngest group and the cumulative cost per live birth was highest in the oldest group, which was threefold greater than that in the group aged ≤ 35 years. The findings added to the limited evidence of the usage rate in real-world situations, which could hopefully aid future analysis and decision-making in public health policy and for women willing to preserve fertility.
Trial registration
None.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this study, we reported the synthesis of the two-dimensional (2D) nanocomposite of molybdenum disulfide and nitrogen-doped graphene oxide (MoS
2
/nGO) as a platinum-free counter electrode (CE) for ...dye-sensitized solar cells (DSSCs). X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy were used to examine the characteristics of the 2D nanocomposite of MoS
2
/nGO. The cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and the Tafel polarization measurements were carried out to examine the electrocatalytic abilities. XPS and Raman results showed the 2D behaviors of the prepared nanomaterials. HRTEM micrographs showed the direct evidence of the 2D nanocomposite of MoS
2
/nGO. The results of electrocatalytic examinations indicated the MoS
2
/nGO owning the low charge transfer resistance, high electrocatalytic activity, and fast reaction kinetics for the reduction of triiodide to iodide on the electrolyte–electrode interface. The 2D nanocomposite of MoS
2
/nGO combined the advantages of the high specific surface of nGO and the plenty edge sites of MoS
2
and showed the promoted properties different from those of their individual constituents to create a new outstanding property. The DSSC with MoS
2
/nGO nanocomposite CE showed a photovoltaic conversion efficiency (PCE) of 5.95 % under an illumination of AM 1.5 (100 mW/cm
2
), which was up to 92.2 % of the DSSC with the conventional platinum (Pt) CE (PCE = 6.43 %). These results reveal the potential of the MoS
2
/nGO nanocomposite in the use of low-cost, scalable, and efficient Pt-free CEs for DSSCs.
Advanced Chemical-mechanical polishing (CMP) process not only needs to maintain stable run-to-run thickness control but also achieve better within wafer/within chip planarization performance. ...Furthermore, slurries or other consumable parts, like PAD and Disks selection are also the keys for CMP process optimization. The most difficult thing in CMP process is to have capability to predict and cover the various topologies and layout densities patterned wafers and preventing the hot spots occurrences. In this study, different Neural-Network algorithm with data pre-processing models are implemented to the in-line CMP CLC tuning and dishing/erosion prediction at various topology/pattern density test vehicle pattern wafers. Transfer learning technique is implemented on the original Neural -Network algorithm model, the behavior of real product can be simulated and predicted based on the knowledge of test vehicle database successfully. With the aid of multiple layer erosion/ dishing Neural-Network algorithm model prediction, the potential high risky hot spots can be highlighted at the initial layout design stage, then further shorten the turn-around time of design layout validation.
PDF
