Gilesbagge6089
The sluggish charge transport kinetics that exist in the energy storage process of all-solid-state supercapacitors (ASSSCs) can be improved by designing open hierarchical porous structures for binder-free electrodes. Herein, a template-directed strategy is developed to fabricate open hierarchical porous Ni-Co-Zn-P nanoplate arrays (NCZP6T) through phosphating the electrodeposited NiCo-LDH nanosheets loaded on a template. At first, porous conductive NiZn alloy nanoplate arrays are rationally devised as the template by a strong magnetic field (SMF)-assisted electrodeposition. The Lorentz force caused by coupling the SMF with the electrical current induces a magnetohydrodynamic (MHD) flow (including the micro-MHD flow), which homogenizes the deposition coating, tunes the nucleation and growth of the NiZn alloy, and produces pores in the nanoplates. The open hierarchical porous structure offers a larger specific surface area and pore volume for accelerating charge transport and gives a synergistic effect between the inner porous conductive NiZn array template and the outer electrochemical active phosphides for high-performance hybrid ASSSCs. Accordingly, the battery-type electrode of NCZP6T shows a much higher specific capacitance of 3.81 F cm-2 at 1 mA cm-2, enhanced rate capability, and remarkable cycling stability at progressively varying current densities. Finally, the NCZP6T//FeS ASSSC delivers a high energy density of 77 μW h cm-2 at a large power density of 12 mW cm-2, outperforming most state-of-the-art supercapacitors.It is the intention of this study to elucidate the nested formation of calcium carbonate polymorphs or polyamorphs in the different nanosized compartments. With these observations, it can be concluded how the bacteria can survive in a harsh environment with high calcium carbonate supersaturation. The mechanisms of calcium carbonate precipitation at the surface membrane and at the underlying cell wall membrane of the thermophilic soil bacterium Geobacillus stearothermophilus DSM 13240 have been revealed by high-resolution transmission electron microscopy and atomic force microscopy. In this Gram-positive bacterium, nanopores in the surface layer (S-layer) and in the supporting cell wall polymers are nucleation sites for metastable calcium carbonate polymorphs and polyamorphs. In order to observe the different metastable forms, various reaction times and a low reaction temperature (4 °C) have been chosen. Calcium carbonate polymorphs nucleate in the confinement of nanosized pores (⌀ 3-5 nm) of the S-layer. The hydrous crystalline calcium carbonate (ikaite) is formed initially with [110] as the favored growth direction. It transforms into the anhydrous metastable vaterite by a solid-state transition. In a following reaction step, calcite is precipitated, caused by dissolution of vaterite in the aqueous solution. In the larger pores of the cell wall (⌀ 20-50 nm), hydrated amorphous calcium carbonate is grown, which transforms into metastable monohydrocalcite, aragonite, or calcite. Due to the sequence of reaction steps via various metastable phases, the bacteria gain time for chipping the partially mineralized S-layer, and forming a fresh S-layer (characteristic growth time about 20 min). Thus, the bacteria can survive in solutions with high calcium carbonate supersaturation under the conditions of forced biomineralization.Solute descriptors have been widely used to model chemical transfer processes through poly-parameter linear free energy relationships (pp-LFERs); however, there are still substantial difficulties in obtaining these descriptors accurately and quickly for new organic chemicals. In this research, models (PaDEL-DNN) that require only SMILES of chemicals were built to satisfactorily estimate pp-LFER descriptors using deep neural networks (DNN) and the PaDEL chemical representation. The PaDEL-DNN-estimated pp-LFER descriptors demonstrated good performance in modeling storage-lipid/water partitioning coefficient (log Kstorage-lipid/water), bioconcentration factor (BCF), aqueous solubility (ESOL), and hydration free energy (freesolve). Then, assuming that the accuracy in the estimated values of widely available properties, e.g., logP (octanol-water partition coefficient), can calibrate estimates for less available but related properties, we proposed logP as a surrogate metric for evaluating the overall accuracy of the estimated pp-LFER descriptors. When using the pp-LFER descriptors to model log Kstorage-lipid/water, BCF, ESOL, and freesolve, we achieved around 0.1 log unit lower errors for chemicals whose estimated pp-LFER descriptors were deemed "accurate" by the surrogate metric. The interpretation of the PaDEL-DNN models revealed that, for a given test chemical, having several (around 5) "similar" chemicals in the training data set was crucial for accurate estimation while the remaining less similar training chemicals provided reasonable baseline estimates. Lastly, pp-LFER descriptors for over 2800 persistent, bioaccumulative, and toxic chemicals were reasonably estimated by combining PaDEL-DNN with the surrogate metric. Overall, the PaDEL-DNN/surrogate metric and newly estimated descriptors will greatly benefit chemical transfer modeling.The controlled growth of metallic single-wall carbon nanotubes (m-SWCNTs) is very important for the fabrication of high-performance interconnecting wires, transparent conductive electrodes, light and conductive fibers, etc. However, it has been extremely difficult to synthesize m-SWCNTs due to their lower abundance and higher chemical reactivity than semiconducting SWCNTs (s-SWCNTs). Here, we report the kinetically controlled growth of m-SWCNTs by manipulating their binding energy with the catalyst and promoting their growth rate. We prepared CoRe4 nanoparticles with a hexagonal close-packed structure and an average size of ∼2.3 nm, which have a lower binding energy with m-SWCNTs than with s-SWCNTs. The selective growth of m-SWCNTs from the CoRe4 catalyst was achieved by using a low concentration of carbon source feed at a relative low temperature of 760 °C. The m-SWCNTs had a narrow diameter distribution of 1.1 ± 0.3 nm, and their content was over 80%.Optical anticounterfeiting tags utilize the photoluminescent properties of materials to encode unique patterns, enabling identification and validation of important items and assets. These tags must combine optical complexity with ease of production and authentication to both prevent counterfeiting and to remain practical for widespread use. Metal-organic frameworks (MOFs) based on polynuclear, rare earth clusters are ideal materials platforms for this purpose, combining fine control over structure and composition, with tunable, complex energy transfer mechanisms via both linker and metal components. Here we report the design and synthesis of a set of heterometallic MOFs based on combinations of Eu, Nd, and Yb with the tetratopic linker 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene. The energetics of this linker facilitate the intentional concealment of the visible emissions from Eu while retaining the infrared emissions of Nd and Yb, creating an optical tag with multiple covert elements. Unique to the materials system reported herein, we document the occurrence of a previously not observed 11-metal cluster correlated with the presence of Yb in the MOFs, coexisting with a commonly encountered 9-metal cluster. We demonstrate the utility of these materials as intricate optical tags with both rapid and in-depth screening techniques, utilizing orthogonal identifiers across composition, emission spectra, and emission decay dynamics. This work highlights the important effect of linker selection in controlling the resulting photoluminescent properties in MOFs and opens an avenue for the targeted design of highly complex, multifunctional optical tags.A two-dimensional (2D) nonvolatile memory device architecture to improve the long-term charge retention with the minimum charge loss without compromising storage capacity and the extinction ratio for practical applications has been an imminent demand. To address the current issue, we adopted a novel type-II band-aligned heterobilayer channel comprising vertically stacked monolayer WSe2 nanodots on monolayer WS2. The band offset modulation leads to electron doping from WSe2 nanodots into the WS2 channel without any external driving electric field. As a result, the tested device outperformed with a memory window as high as 34 V and a negligible charge loss of 7% in a retention period of 10 years while maintaining a high extinction ratio of 106. The doping technique presented in this work provides a feasible route to modulate the electrical properties of 2D channel materials without hampering charge transport, paving the way for high-performance 2D memory devices.Near-field electrospinning (NFES) is a micro- or nanofiber production technology based on jetting molten polymer or polymer solution. Thanks to the programmable collector and nozzle movement, it can generate designed patterns in the presence of an electric field. learn more Despite a few shortcomings of NFES, its high resolution, simplicity, precision, high throughput, reproducibility, and low costs have convinced researchers to employ it for various purposes. Furthermore, as the paradigm of fiber-based structures shifts from random textures toward delicate designs, NFES can bridge the gap between existing inefficient processes and aspired technologies for precise patterning. NFES facilitates the production of ultrafine nanofibers because it can be used to fabricate them in every laboratory. These robust fibers are convenient tools for small and additive manufacturing. As such, NFES is considered a potent additive fabrication technology that facilitates the production of complicated patterns as well. It is suggested that near-field electrospun fibers exhibit outstanding results in various applications, owing to their precise and controllable positioning. Meanwhile, the ongoing development of NFES has yet to reach its climax, making it attractive for further research. In this review, the basic principles of NFES, derivatives, limitations, and applications in nanomanufacturing, tissue engineering, microscale electronics, biosensors, and optics are presented.
Cardiac output (CO) measurements employing the direct Fick principle represent the gold standard in right-sided heart catheterization (RHC). The current widespread approach in hemodynamic workup however uses the indirect Fick principle with assumed values for oxygen uptake (VO
) leading to incorrect CO values in up to 25% of patients. We have tested a contemporary breath-by-breath gas analyzer that allows precise real-time measurements of VO
with appropriate time and effort to serve the direct Fick principle.
By means of a small and mobile metabolic cart assembled with widely used components of a standard spiroergometer, we performed bedside measurements of individual VO
In 33 unselected, consecutive patients with various indications for RHC we compared CO values derived from indirect vs. direct Fick calculations.
In 28 of the 33 patients, VO
measurements were completed with a plausible dataset within a median of 3.2 (interquartile range 2.8-6.2) min. In nine of the 28 patients, CO values based on measured VO
values differed by more than 20% from CO calculations based on assumed VO
values with value deviations scattering over a broad range in both directions (maximally +52% to minimally-46%).