There is a demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen ...energy. Lithium and sodium borohydride, ammonia borane, hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. Significant advances, such as hydrogen generation temperatures and reaction kinetics, have been made in the catalytic hydrolysis of aqueous lithium and sodium borohydride and ammonia borane as well as in the catalytic decomposition of hydrous hydrazine and formic acid. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid‐phase chemical hydrogen storage materials.
The search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. Lithium and sodium borohydride (aq.), ammonia borane (aq.), hydrous hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid‐phase chemical hydrogen storage materials.
This article deals with the issue of asymptotic stabilization for a linear parabolic partial differential equation (PDE) with an unknown space‐varying reaction coefficient and multiple local ...piecewise uniform control. Clearly, the unknown reaction coefficient belongs to a function space. Hence, the fundamental difficulty for such issue lies in the lack of a conceptually simple but effective parameter identification technique in a function space. By the Lyapunov technique combined with a variant of Poincaré‐Wirtinger inequality, an update law is derived for estimate of the unknown reaction coefficient in a function space. Then a spatiotemporal adaptive state feedback control law is constructed such that the estimate of the unknown coefficient is bounded and the closed‐loop PDE is asymptotically stable in the sense of spatial ℋ1$$ {\mathscr{H}}^1 $$ norm if a sufficient condition given in terms of space‐time varying linear matrix inequalities (LMIs) is fulfilled for the estimated coefficient and the control gains. Both analytical and numerical approaches are proposed to construct a feasible solution to the space‐time varying LMI problem. With the aid of the semigroup theory, the well‐posedness and regularity of the closed‐loop PDE is also analyzed. Moreover, two extensions of the proposed adaptive control scheme are discussed: the PDE in N$$ N $$‐D space and the PDE with unknown diffusion and reaction coefficients. Finally, numerical simulation results are presented to support the proposed spatiotemporal adaptive control design.
Abstract
Hematite (α‐Fe
2
O
3
) as a photoanode material for photoelectrochemical (PEC) water splitting suffers from the two problems of poor charge separation and slow water oxidation kinetics. The ...construction of p–n junction nanostructures by coupling of highly stable Co
3
O
4
in aqueous alkaline environment to Fe
2
O
3
nanorod arrays with delicate energy band positions may be a challenging strategy for efficient PEC water oxidation. It is demonstrated that the designed p‐Co
3
O
4
/n‐Fe
2
O
3
junction exhibits superior photocurrent density, fast water oxidation kinetics, and remarkable charge injection and bulk separation efficiency (η
inj
and η
sep
), attributing to the high catalytic behavior of Co
3
O
4
for the oxygen evolution reaction as well as the induced interfacial electric field that facilitates separation and transportation of charge carriers. In addition, a cocatalyst of cobalt phosphate (Co‐Pi) is introduced, which brings the PEC performance to a high level. The resultant Co‐Pi/Co
3
O
4
/Ti:Fe
2
O
3
photoanode shows a photocurrent density of 2.7 mA cm
−2
at 1.23 V
RHE
(V vs reversible hydrogen electrode), 125% higher than that of the Ti:Fe
2
O
3
photoanode. The optimized η
inj
and η
sep
of 91.6 and 23.0% at 1.23 V
RHE
are achieved on Co‐Pi/Co
3
O
4
/Ti:Fe
2
O
3
, respectively, corresponding to the 70 and 43% improvements compared with those of Ti:Fe
2
O
3
. Furthermore, Co‐Pi/Co
3
O
4
/Ti:Fe
2
O
3
shows a low onset potential of 0.64 V
RHE
and long‐time PEC stability.
Less noble: The Co0.30Au0.35Pd0.35 nanoalloy supported on carbon is reported as a stable, low‐cost, and highly efficient catalyst for the CO‐free hydrogen generation from formic acid dehydrogenation ...at room temperature (see picture). The method may strongly encourage the practical application of formic acid as a hydrogen storage material for fuel cells.
Efficient and selective dehydrogenation of formic acid is a key challenge for a fuel‐cell‐based hydrogen economy. Though the development of heterogeneous catalysts has received much progress, their ...catalytic activity remains insufficient. Moreover, the design principle of such catalysts are still unclear. Here, experimental and theoretical studies on a series of mono‐/bi‐metallic nanoparticles supported on a NH2‐N‐rGO substrate are combined for formic acid dehydrogenation where the surface energy of a metal is taken as a relevant indicator for the adsorption ability of the catalyst for guiding catalyst design. The AuPd/NH2‐N‐rGO catalyst shows record catalytic activity by reducing the energy barrier of rate controlling steps of formate adsorption and hydrogen desorption. The obtained excellent results both in experiments and simulations could be extended to other important systems, providing a general guideline to design more efficient catalysts.
A AuPd/NH2‐N‐rGO catalyst shows supreme catalytic performance for the decomposition of formic acid at room temperature, with a turnover frequency (TOF) of 4445.6 h−1. Developments in the experiments and simulations of high‐performance catalysts may promote the practical application of formic acid as a promising hydrogen storage material.
Sentiment analysis (SA) is widespread across all fields and has become one of the most active topics in education research, and there is a growing body of papers published. So far, however, there has ...been little discussion about comprehensive literature reviews in SA in education. Therefore, this study aims to review the high-qualified scientific literature of SA in education and reveals the future research prospects of SA based on the reviewed papers. After systematically searching five online bibliographic databases, 41 relevant articles were located and included in the study. Results show that most studies focus on higher education, and more studies adopt smaller datasets. SA is actively employed in the learning domain of engineering and technology, and teachers/educators are the primary stakeholders considered of studies. Further, utilizing hybrid approaches for SA research is predominant, more studies have refined the granularity of sentiment categories in education. Finally, four major SA research topics, including designing SA methods/systems, investigating learners' satisfaction/attitude/concerned topics, evaluating teachers' teaching performance as well as examining the relationship among sentiment, behavior, performance, and achievement, were identified and discussed deeply. Accordingly, several implications and research issues for SA in education research are provided.
Human infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) and there is no cure currently. The 3CL protease (3CLpro) is a highly ...conserved protease which is indispensable for CoVs replication, and is a promising target for development of broad-spectrum antiviral drugs. In this study we investigated the anti-SARS-CoV-2 potential of Shuanghuanglian preparation, a Chinese traditional patent medicine with a long history for treating respiratory tract infection in China. We showed that either the oral liquid of Shuanghuanglian, the lyophilized powder of Shuanghuanglian for injection or their bioactive components dose-dependently inhibited SARS-CoV-2 3CLpro as well as the replication of SARS-CoV-2 in Vero E6 cells. Baicalin and baicalein, two ingredients of Shuanghuanglian, were characterized as the first noncovalent, nonpeptidomimetic inhibitors of SARS-CoV-2 3CLpro and exhibited potent antiviral activities in a cell-based system. Remarkably, the binding mode of baicalein with SARS-CoV-2 3CLpro determined by X-ray protein crystallography was distinctly different from those of known 3CLpro inhibitors. Baicalein was productively ensconced in the core of the substrate-binding pocket by interacting with two catalytic residues, the crucial S1/S2 subsites and the oxyanion loop, acting as a "shield" in front of the catalytic dyad to effectively prevent substrate access to the catalytic dyad within the active site. Overall, this study provides an example for exploring the in vitro potency of Chinese traditional patent medicines and effectively identifying bioactive ingredients toward a specific target, and gains evidence supporting the in vivo studies of Shuanghuanglian oral liquid as well as two natural products for COVID-19 treatment.
TDP-43 is a nuclear factor that functions in promoting pre-mRNA splicing. Deletion of the N-terminal domain (NTD) and nuclear localization signal (NLS) (i.e., TDP-35) results in mislocalization to ...cytoplasm and formation of inclusions. However, how the NTD functions in TDP-43 activity and proteinopathy remains largely unknown. Here, we studied the structure and function of the NTD in inclusion formation and pre-mRNA splicing of TDP-43 by using biochemical and biophysical approaches. We found that TDP-43 NTD forms a homodimer in solution in a concentration-dependent manner, and formation of intermolecular disulfide results in further tetramerization. Based on the NMR structure of TDP-43 NTD, the dimerization interface centered on Leu71 and Val72 around the β7-strand was defined by mutagenesis and size-exclusion chromatography. Cell experiments revealed that the N-terminal dimerization plays roles in protecting TDP-43 against formation of cytoplasmic inclusions and enhancing pre-mRNA splicing activity of TDP-43 in nucleus. This study may provide mechanistic insights into the physiological function of TDP-43 and its related proteinopathies.
To achieve a high reversibility and long cycle life for Li–O2 battery system, the stable tissue‐directed/reinforced bifunctional separator/protection film (TBF) is in situ fabricated on the surface ...of metallic lithium anode. It is shown that a Li–O2 cell composed of the TBF‐modified lithium anodes exhibits an excellent anodic reversibility (300 cycles) and effectively improved cathodic long lifetime (106 cycles). The improvement is attributed to the ability of the TBF, which has chemical, electrochemical, and mechanical stability, to effectively prevent direct contact between the surface of the lithium anode and the highly reactive reduced oxygen species (Li2O2 or its intermediate LiO2) in cell. It is believed that the protection strategy describes here can be easily extended to other next‐generation high energy density batteries using metal as anode including Li–S and Na–O2 batteries.
A stable tissue‐directed/reinforced bifunctional separator/protection film (TBF) is in situ fabricated on the surface of a metallic lithium anode. The Li–O2 battery cell with the TBF‐modified lithium anodes exhibits an excellent anodic reversibility and effectively improved cathodic long lifetime.
To turn waste into treasure, a facile and cost‐effective strategy is developed to revive electroless nickel plating wastewater and cotton‐textile waste toward a novel electrode substrate. Based on ...the substrate, a binder‐free PB@GO@NTC electrode is obtained, which exhibits superior electrochemical performance. Moreover, for the first time, a novel tube‐type flexible and wearable sodium‐ion battery is successfully fabricated.
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