● Dolomite-doped biochar/bentonite was synthesized for phosphate removal. ● DO/BB exhibited a high phosphate adsorption capacity in complex water environments. ● PVC membrane incorporated with DO/BB ...can capture low concentration phosphate. ● Electrostatic interaction, complexation and precipitation are main mechanisms.
The removal of phosphate from wastewater using traditional biological or precipitation methods is a huge challenge. The use of high-performance adsorbents has been shown to address this problem. In this study, a novel composite adsorbent, composed of dolomite-doped biochar and bentonite (DO/BB), was first synthesized via co-pyrolysis. The combination of initial phosphate concentration of 100 mg/L and 1.6 g/L of DO/BB exhibited a high phosphate-adsorption capacity of 62 mg/g with a removal efficiency of 99.8%. It was also stable in complex water environments with various levels of solution pH, coexisting anions, high salinity, and humic acid. With this new composite, the phosphate concentration of the actual domestic sewage decreased from 9 mg/L to less than 1 mg/L, and the total nitrogen and chemical oxygen demand also decreased effectively. Further, the cross-flow treatment using a PVC membrane loaded with DO/BB (PVC-DO/BB), decreased the phosphate concentration from 1 to 0.08 mg/L, suggesting outstanding separation of phosphate pollutants via a combination of adsorption and separation. In addition, the removal of phosphate by the PVC-DO/BB membrane using NaOH solution as an eluent was almost 90% after 5 cycles. The kinetic, isotherm and XPS analysis before and after adsorption suggested that adsorption via a combination of electrostatic interaction, complexation and precipitation contributed to the excellent separation by the as-obtained membranes.
A nanohybrid of titanium dioxide (TiO2) and single-walled carbon nanotubes (SWCNTs) with dual functions of collecting electrons and transparent electrode layer is synthesized by nano-cluster ...deposition technology. The super-hollow structure of the SWCNTs was directly fabricated via arc discharge and fully covered with a thin layer (∼15 nm) of TiO2, which formed the SWCNT/TiO2 core/shell sponge. The developed SWCNT/TiO2 core/shell sponge is used directly as scaffolding for a light absorber and electron collector in transparent conducting oxide (TCO) electrode-free perovskite solar cells (PSCs) for the first time, which exhibited a power conversion efficiency of 7.2%. The large surface area of the core/shell bundle is sufficiently effective in transferring the photogenerated electron from the Perovskite absorber to the SWCNTs. More importantly, the findings of this work could support the concept of replacing the conventional TCO in PSCs and pave the way to further work for developing inexpensive and flexible PSCs.
•Replacing conventional transparent conducting oxide electrode with carbon nanotube in perovskite solar cell.•Dual functions of SWCNT/TiO2 core/shell sponge as electron collector and scaffold for light absorber.•The photovoltaic performance of SWCNT and FTO-based devices was shown in comparative investigation.•The use of high quality SWCNT/TiO2 sponge was believed in further development of low-cost PSC.
Micro/nano lab‐on‐chip power systems with poor energy storage/conversion ability are one of the major obstacles that circumvent the further practical applications of the micro/nano smart devices. In ...this work, the multilayer Si/TiN/Sb nanorod (NR) arrays composites anodes are successfully fabricated and impressively display improved electrochemical properties in 3D Si‐based lithium/sodium ion microbatteries (L/SIMBs). Both the 3D Si configuration and the efficient TiN interlayer are together responsible for the obtained enhanced cyclability of the Sb nanoelectrode. Moreover, the Li/Na ion storage behaviors are also experimentally investigated from the postmorphology characterizations and further evidences the structure stability of the whole Si/TiN/Sb NRs anodes during the repeated Li/Na ions inserting/de‐inserting process. These multilayer Si/Ti/Sb NR arrays composites should be a promising anode for the 3D Si‐based L/SIMBs.
Multilayer Si/TiN/Sb nanorod arrays composites anodes are successfully fabricated using the semiconductor micromachining technology. The introduction of the efficient TiN interlayer combined with the patterned Si substrate and the Sb active material impressively display superior electrochemical performance when applied in 3D Si‐based lithium/sodium ion microbatteries.
In recent years, the remarkable energy density of high-nickel ternary materials has captured considerable attention. Nevertheless, the high-nickel ternary cathode material encounters several ...challenges, including cationic mixing, microcrack formation, poor cycling capability, and limited thermal stability. Coating, as a viable approach, proves to be effective in enhancing the material properties. In this study, the LiNi0.8Co0.1Mn0.1O2 (NCM811) sample underwent a dry grinding process, followed by Y2O3 coating and subsequent sintering at varying temperatures. The microstructure, morphology, and electrochemical properties of the materials were meticulously examined, and the underlying mechanism of coating modification was meticulously explored. The outcomes demonstrate the attainment of dual coating and doping effects through Y2O3 modification. Y2O3 coating mitigates the direct interaction between the NCM811 surface and the electrolyte, thereby inhibiting undesired side reactions at the interface. Moreover, the Y element infiltrates the crystal structure, imparting stability at elevated sintering temperatures. Remarkably, the Y2O3-coated cathode materials exhibit significantly enhanced cycling stability, discharge capacity, and rate performance. These findings can provide novel insights that can be harnessed to improve the energy density cathode material of NCM811.
On progressive functions Deliu, Anca; Deng, Baiqiao
Journal of mathematical analysis and applications,
03/2015, Letnik:
423, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Progressive functions at time t involve only the progressive functions at time before t and some nice compactly supported function at time t. We give sufficient conditions and explicit formulas to ...construct progressive functions with exponential decay and characterize the conditions on which the positive integer translates of a progressive function are orthonormal or a Riesz sequence. We provide explicit ways for construction of orthonormal progressive functions and for construction of the biorthogonal functions of nonorthogonal progressive functions. Such progressive functions can be used to construct wavelets with arbitrary smoothness on the half line if they are generated by a smooth refinable compactly supported function.
PP1084 protein was exposed to gamma irradiation ranging from 5 to 500kGy. Native PAGE showed minor structural changes in PP1084 at 5kGy, and major structural changes at >15kGy. Size-exclusion ...chromatography (SEC) showed the formation of a new shoulder peak when the protein was irradiated with 15 and 30kGy, and a double peak appeared at 100kGy. The results of PAGE and SEC imply that PP1084 protein is degraded by gamma irradiation, with simultaneous oligomerization. PP1084 chaperone activity reached the highest level at 30kGy of gamma irradiation, and then, decreased in a dose-dependent manner with increasing gamma irradiation. However, the peroxidase activity significantly decreased following exposure to all intensities of gamma irradiation. The improvement of chaperone activity using gamma irradiation might be promoted by the oligomeric structures containing covalently cross-linked amino acids. Consequently, PP1084 modification using gamma irradiation could elevate chaperone activity by about 3–4 folds compared to the non-irradiated protein.
► The structure of PP1084 protein was drastically changed above 15kGy gamma irradiation. ► PP1084 chaperone activity reached the highest level at 30kGy of gamma irradiation. ► PP1084 modification using gamma irradiation could elevate chaperone activity by about 3–4 folds.
We present an adaptive multilevel Monte Carlo (MLMC) method for
weak approximations of solutions to Itô stochastic
differential equations (SDE). The work Oper. Res. 56 (2008), 607–617
proposed and ...analyzed an MLMC method based on a hierarchy of uniform time
discretizations and control variates to reduce the computational
effort required by a single level Euler–Maruyama Monte
Carlo method from
to
for a mean
square error of
.
Later, the work Lect. Notes Comput. Sci. Eng. 82, Springer-Verlag, Berlin (2012), 217–234 presented an MLMC method using a hierarchy of adaptively
refined, non-uniform time discretizations, and, as such, it may be
considered a generalization of the uniform time discretization MLMC method.
This work improves the adaptive MLMC algorithms presented
in Lect. Notes Comput. Sci. Eng. 82, Springer-Verlag, Berlin (2012), 217–234
and it also provides mathematical analysis of the improved algorithms.
In particular, we show that under some assumptions our
adaptive MLMC algorithms are asymptotically accurate and
essentially have the correct complexity
but with improved control of the complexity constant factor in the asymptotic
analysis.
Numerical tests include one case with singular drift and
one with stopped diffusion, where the complexity of a uniform single
level method is
. For both these cases the results
confirm the theory, exhibiting savings in the computational cost
for achieving the accuracy
from
for the
adaptive single level algorithm to essentially
for the adaptive
MLMC algorithm.
Let
G
be a finite nonabelian group. Bent functions on
G
are defined by the Fourier transforms at irreducible representations of
G
. We introduce a dual basis
G
^
, consisting of functions on
G
...determined by its unitary irreducible representations, that will play a role similar to the dual group of a finite abelian group. Then we define the Fourier transforms as functions on
G
^
, and obtain characterizations of a bent function by its Fourier transforms (as functions on
G
^
). For a function
f
from
G
to another finite group, we define a dual function
f
~
on
G
^
, and characterize the nonlinearity of
f
by its dual function
f
~
. Some known results are direct consequences. Constructions of bent functions and perfect nonlinear functions are also presented.
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