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A CoCe/ZSM-5 catalyst was prepared by ultrasonic-assisted impregnation for the catalytic combustion of toluene. To study the effect of Na+ on catalytic performance of CoCe/ZSM-5 catalysts, a series of different Si/Al ZSM-5 zeolites and catalysts doped with Na were synthesized. The experimental results show that 0.71 wt% Na+ can inhibit active growth, generate more active small crystal grains, and promote improvement of the catalytic activity by the grain boundary segregation block mechanism, and the catalyst with 0.71 wt% of Na shows toluene conversion of 90 vol% at 250 °C. Over 0.71 wt% of Na+ content will neutralize the acid centre of the catalyst, lowering the specific surface area of the catalyst and resulting in a gradual decrease in the catalytic activity.

Above-threshold ionization (ATI) is one of the most fundamental processess when atoms or molecules are subjected to intense laser fields. Analysis of ATI process in intense laser fields by a Wigner-distribution-like (WDL) function is reviewed in this paper. The WDL function is used to obtain various time-related distributions, such as time-energy distribution, ionization time distribution, and time-emission angle distribution and so on, of atoms in laser field pulses with different laser parameters. For the linearly polarized laser pulses, the time-energy distribution intuitively shows from a quantum point of view the relationship between the ionization moment and the final energy and clearly reveals the origin of interference structures in the photoelectron spectrum. In particular, for linearly polarized few-cycle laser pulses, all calculated distributions show the dependence of electron behavior on the ionization time, emission direction, and carrier-envelope phase (CEP). For elliptically polarized few-cycle pulses, we calculate the angular distribution, ionization time distribution, and time-emission distribution, which are compared with the semiclassical calculations. Analysis shows that the offset angle (difference between positions of the peaks in the angular distributions obtained by two methods) in the angular distributions does not correspond to the offset time (difference between positions of the peaks in the ionization time distributions obtained by two methods) in the ionization time distributions, which implies that the attosecond angular streaking technique based on this correspondence between the offset angle and time is in principle inaccurate. Furthermore, the offset time cannot be interpreted as tunneling time.

Based on the strong-field approximation (SFA), we investigate the interference between different returning orbits of the rescattering electron in nonsequential double ionization. We find that the effect of interference is negligible in the recollision-impact ionization process but is prominent in the recollision excitation with subsequent ionization process and induces fast oscillation with constant period in the laser intensity dependence of the asymmetry parameter. The dominant contribution to the fast oscillation comes from the mixed interference between different pairs of returning orbits in different excitation channels. However, the oscillation disappears after laser focus averaging is performed due to its rather small period.

The serious problems of environmental pollution and energy shortage have pushed the green economy photocatalysis technology to the forefront of research. Therefore, the development of an efficient and environmentally friendly photocatalyst has become a hotpot. In this work, magnetic Fe3O4/C/MnO2/C3N4 composite as photocatalyst was synthesized by combining in situ coating with low-temperature reassembling of CN precursors. Morphology and structure characterization showed that the composite photocatalyst has a hollow core–shell flower-like structure. In the composite, the magnetic Fe3O4 core was convenient for magnetic separation and recovery. The introduction of conductive C layer could avoid recombining photo-generated electrons and holes effectively. Ultra-thin g-C3N4 layer could fully contact with coupled semiconductor. A Z-type heterojunction between g-C3N4 and flower-like MnO2 was constructed to improve photocatalytic performance. Under the simulated visible light, 15 wt% photocatalyst exhibited 94.11% degradation efficiency in 140 min for degrading methyl orange and good recyclability in the cycle experiment.

As a substitute for bisphenol A (BPA), bisphenol S (BPS) has a longer half-life, higher chemical inertness and better skin permeability than BPA, and it also has a strong endocrine disruption effect. Relatively few studies have focused on the main processing technology for BPS biodegradation, and the findings indicate that the biodegradation efficiency of BPS was relatively low. Therefore, this paper used an NZVI-HA composite-modified bio-anode to enhance the anaerobic degradation of BPS in a Bioelectrochemical Systems (BES). The results showed that the degradation efficiency of BPS was improved from 31.1% to 92.2% with the NZVI-HA modification compared with the control group (CC-BES). FTIR and XPS analyzes demonstrated that HA can accelerate the reduction rate of Fe3+ and increase the ratio of Fe2+/Fe3+. In addition, HA can form Fe-O-HA complexes with NZVI to promote electron transfer. An analysis of the NZVI-HA-BES intermediate metabolites revealed that complex modification properties altered the BPS degradation pathway. An analysis of microbial diversity indicated that the bacteria related to the degradation of BPS may be Terrimonas, Lysobacter, and Acidovorax.

We have performed a comparison study of the Rydberg-state excitation of model molecules (1π g and 1π u states) in different laser fields by the approaches of time-dependent Schrödinger equation and a fully quantum-mechanical model, and both simulations show good accordance. It is found that the peak structure of the Rydberg-state population vs laser intensity becomes pronounced for longer laser pulses due to the stronger interference effect between the subwave packets released in different optical cycles, and the locations of the intensity-dependent peaks closely satisfy the multi-photon resonant transition condition. In addition, it is demonstrated that the populations of the Rydberg states possessing the identical parity oscillate in an inverse manner with increasing laser intensity for different initial states (1π g and 1π u ), and the aforementioned distinct phenomenon is attributed to the additional phase introduced by the symmetry of 1π g state with respect to that of 1π u state.

A Wigner distributionlike function based on the improved strong-field approximation theory is proposed to calculate the rescattering time-energy distribution (RTED) of high-energy photoelectrons of atomic above-threshold ionization process in few-cycle laser fields with different frequencies. The RTED shows bell-like stripes and the outermost stripe is compared with semiclassical results given by the simple-man model with consideration of different positions of tunnel exit and different initial longitudinal momenta. Analysis indicates the existence of the tunnel exit. However, though it shifts farther away from the core with decreasing frequency, the position of the tunnel exit is significantly less than the prediction by adiabatic theory even for the low-frequency case which is well in the tunneling regime. Our results also imply that the effect of the tunnel exit is more important than that of the initial longitudinal momentum at the tunnel exit for the backward-scattering electrons. Moreover, the inner stripe structures in the RTED are attributed to interference between electrons with the same final energy emitted at different ionization times.

Wireless energy transfer (WET) has recently emerged as an appealing solution for power supplying mobile/Internet of Things (IoT) devices. As an enabling WET technology, resonant beam charging (RBC) is well documented for its long-range, high-power, and safe “WiFi-like” mobile power supply. To provide high-quality wireless charging services for multiple users in a given region, we formulate a deployment problem of multiple RBC transmitters for balancing the charging fairness and quality of charging service. Based on the RBC transmitter’s coverage model and receiver’s charging/discharging model, a genetic algorithm (GA)-based scheme and a particle swarm optimization (PSO)-based scheme are put forth to resolve the above issue. Moreover, we present a scheduling method to evaluate the performance of the proposed algorithms. The numerical results corroborate that the optimized deployment schemes outperform uniform and random deployment in 10%–20% charging efficiency improvement.

As a reader of di-methylated arginine on various proteins, such as histone, RNA polymerase II, PIWI and Fragile X mental retardation protein, the Tudor domain of Tudor domain-containing protein 3 (TDRD3) mediates transcriptional activation in nucleus and formation of stress granules in the cytoplasm. Despite the TDRD3 implication in cancer cell proliferation and invasion, warheads to block the di-methylated arginine recognition pocket of the TDRD3 Tudor domain have not yet been uncovered. Here we identified 14 small molecule hits against the TDRD3 Tudor domain through NMR fragment-based screening. These hits were further cross-validated by using competitive fluorescence polarization and isothermal titration calorimetry experiments. The crystal structure of the TDRD3 Tudor domain in complex with hit 1 reveals a distinct binding mode from the nature substrate. Hit 1 protrudes into the aromatic cage of the TDRD3 Tudor domain, where the aromatic residues are tilted to accommodate a sandwich-like π-π interaction. The side chain of the conserved residue N596 swings away 3.1 A to form a direct hydrogen bond with hit 1. Moreover, this compound shows a decreased affinity against the single Tudor domain of survival motor neuron protein, but no detectable binding to neither the tandem Tudor domain of TP53-binding protein 1 nor the extended Tudor domain of staphylococcal nuclease domain-containing protein 1. Our work depicts the structural plasticity of the TDRD3 Tudor domain and paves the way for the subsequent structure-guided discovery of selective inhibitors targeting Tudor domains. Database Structural data are available in the PDB under the accession number 5YJ8.

We investigate the ionization dynamics of one-electron model diatomic molecules with different orbital symmetries ($1{\ensuremath{\sigma}}_{g}$ and $1{\ensuremath{\sigma}}_{u}$) in a strong laser field via the full three-dimensional time-dependent Schr\"odinger equation. It is shown that the ionization probabilities of the molecules with different initial states ($1{\ensuremath{\sigma}}_{g}$ and $1{\ensuremath{\sigma}}_{u}$) oscillate out of phase vs internuclear distance, and the photoelectron spectra of the aforementioned two molecules also show out-of-phase oscillation structures. The above intriguing features are well reproduced by the simulations of the length-gauge strong-field approximation, which can be ascribed to the distinct interferences of electronic wave packets released from different atomic centers.

By performing a joint theoretical and experimental investigation on the high-order above-threshold ionization (HATI) spectrum, the dominant role of the 3rd-return-recollision trajectories in the region near the cutoff due to the ionic Coulomb field is identified. This invalidates the key assumption adopted in the conventional laser-induced electron diffraction (LIED) approach that the 1st-returnrecollision trajectories dominate the spectrum according to strong field approximation (SFA). Our results show that the incident (return) electron beams produced by the 1st and 3rd returns possess distinct characteristics of beam energy, beam diameter and temporal evolution law due to the influence of Coulomb field, and therefore the extracted results in the LIED will be altered if the significance of the 3rd-return-recollision trajectories is properly considered in the analysis. Such Coulomb field effect should be taken into account in all kinds of laser-induced imaging schemes based on recollision., 7 pages, 4 figures

Roadway floor rock burst is an important manifestation of rock bursts in deeply buried mines. With the increase of mining depth and mining intensity, rock burst disasters in the roadway floor such as floor heaves are becoming more serious. The article investigated the roadway floor severe heave caused by floor rock burst during excavation of the No. 3401 working face, which was controlled by an anticlinal structure and deep mining in Shandong Mine, China. Firstly, by analyzing geological conditions of the working face, roadway support parameters, and characteristics of coal and rock, it was revealed that high tectonic stress and high crustal stress were main causes of the floor rock burst. Secondly, based on the Theory of Mechanics and Theory of Energy, the energy conversion process in the roadway floor was discussed, and the rock burst condition caused by elastic energy in the roadway floor was analyzed. The failure characteristics of roadway-surrounding rock were also inspected, using a borehole recorder. The roof and sidewalls of roadway mainly contained fissures and cracks, whereas cracks and broken areas are distributed in the roadway floor. Finally, based on the deformation and failure characteristics of roadway-surrounding rock, a method termed “overbreaking-bolting and grouting-backfill” was proposed to control roadway floor rock burst. The method was tested in the field, and the results showed that it could effectively control the deformation of roadway floor and rock burst, guaranteeing the stability of roadway floor. This impact control method for the roadway floor can provide a reference for the prevention and control of roadway rock burst in mines with similar geological conditions.

In blasting operation, some undesirable impacts, such as fly-rock, fragmentation, and back break, are induced. If the blasting design is not optimized, these mentioned impacts would reduce the blasting efficiency. To improve and optimize the blast design, blasting effect evaluation is essential. Due to the complexity of interactions among blasting parameters, empirical methods may not be appropriate for blast design optimization. A two-level mathematical model based on fuzzy mathematics, is proposed in this work. In total, 11 typical parameters were chosen and classified into three groups. The blasting effect is evaluated from three aspects, and then the comprehensive evaluation is given. A blasting effect evaluation system was developed based on the mentioned method on the platform of VC++. Some other techniques, such as image processing, were integrated into the system, which allowed for obtaining all of the parameters rapidly and conveniently. The system was applied in practical bench blast engineering. The results obtained from the system can provide effective information for the optimization of the next blast design.

Quantum interference plays an important role in various intense-laser-driven atomic phenomena, e.g., above-threshold ionization and high-order-harmonic generation, and provides a useful tool in ultrafast imaging of atomic and molecular structure and dynamics. However, it has eluded observation in nonsequential double ionization (NSDI), which serves as an ideal prototype to study electron-electron correlation. Thus far, NSDI usually could be well understood from a semiclassical perspective, where all quantum aspects have been ignored after the first electron has tunneled. Here we perform coincidence measurements for NSDI of xenon subject to laser pulses at 2400 nm. It is found that the intensity dependence of the asymmetry parameter between the yields in the second and fourth quadrants and those in the first and third quadrants of the electron-momentum-correlation distributions exhibits a peculiar fast oscillatory structure, which is beyond the scope of the semiclassical picture. Our theoretical analysis indicates that this oscillation can be attributed to interference between the contributions of different excited states in the recollision-excitation-with-subsequent-ionization channel. Our work demonstrates the significant role of quantum interference in NSDI and may create an additional pathway towards manipulation and imaging of the ultrafast atomic and molecular dynamics in intense laser fields.

We experimentally investigate the recoil-ion momentum distribution along the laser polarization direction for nonsequential double ionization of Xe by 50 fs, 2400 nm laser pulses at intensities of $(22\ensuremath{-}68) \mathrm{TW}/{\mathrm{cm}}^{2}$. The observed doubly charged ion momentum distribution exhibits a distinct transition from a flat-top structure near zero longitudinal momentum at $22\phantom{\rule{0.16em}{0ex}}\mathrm{TW}/{\mathrm{cm}}^{2}$ to the one with two maxima at nonzero longitudinal momentum at $37\phantom{\rule{0.16em}{0ex}}\mathrm{TW}/{\mathrm{cm}}^{2},\phantom{\rule{4pt}{0ex}}52\phantom{\rule{0.16em}{0ex}}\mathrm{TW}/{\mathrm{cm}}^{2}$, and $68\phantom{\rule{0.16em}{0ex}}\mathrm{TW}/{\mathrm{cm}}^{2}$, which is remarkably different from the case of 800 nm. Simulation based on a semiclassical model is used to obtain the ratios of contributions from the recollision-impact ionization (RII) and the recollision-induced excitation with subsequent field ionization (RESI) in nonsequential double ionization. Our calculation reveals that the increasing contribution of the RII channel is responsible for the more prominent double-hump structure at longer wavelength or higher laser intensity. Moreover, a simple fitting based on the calculated ratios allows one to reproduce the experimental ion momentum distributions well and obtain contributions from these two channels.

Sporolactobacillus inulinus is a superior d-lactic acid-producing bacterium and proposed species for industrial production. The major pathway for d-lactic acid biosynthesis, glycolysis, is mainly regulated via the two irreversible steps catalyzed by the allosteric enzymes, phosphofructokinase (PFK) and pyruvate kinase. The activity level of PFK was significantly consistent with the cell growth and d-lactic acid production, indicating its vital role in control and regulation of glycolysis. In this study, the ATP-dependent PFK from S. inulinus was expressed in Escherichia coli and purified to homogeneity. The PFK was allosterically activated by both GDP and ADP and inhibited by phosphoenolpyruvate; the addition of activators could partly relieve the inhibition by phosphoenolpyruvate. Furthermore, monovalent cations could enhance the activity, and Na+ was the most efficient one. Considering this kind activation, NaOH was investigated as the neutralizer instead of the traditional neutralizer CaCO3. In the early growth stage, the significant accelerated glucose consumption was achieved in the NaOH case probably for the enhanced activity of Na+-activated PFK. Using NaOH as the neutralizer at pH 6.5, the fermentation time was greatly shortened about 22 h; simultaneously, the glucose consumption rate and the d-lactic acid productivity were increased by 34 and 17%, respectively. This probably contributed to the increased pH and Na+-promoted activity of PFK. Thus, fermentations by S. inulinus using the NaOH neutralizer provide a green and highly efficient d-lactic acid production with easy subsequent purification.

Cadmium is a major toxic heavy-metal pollutant considering their bioaccumulation potential and persistence in the environment. The hyperaccumulating ecotype of Sedum alfredii Hance is a Zn/Cd co-hyperaccumulator inhabiting in a region of China with soils rich in Pb/Zn. Investigations into the underlying regulatory mechanisms of molecular Cd tolerance are of substantial interest. Library screening for genes related to cadmium tolerance resulted in the discovery of a gene resembling the rubber elongation factor gene and here it is designated as SaREFl based on the preliminary bioinformatics analysis. The heterologous expression of SaREFl rescued the growth of a transformed Cd-sensitive strain (ycf1). Furthermore, Cd tolerance was enhanced in Arabidopsis plants expressing SaREFl with improvement in the fresh weight and root length of seedlings, as well as physiological indexes of adult plants. The investigation of gene expression profiles exposed to four different heavy metal treatments found that SaREFl exhibited different modes of transcriptional regulation upon heavy metal excess responding most strongly to Cd and the root was the plant organ most sensitive to this heavy metal. Screening a S. alfredii Hance cDNA library using the yeast two-hybrid technology with SaREFl as a bait led to the identification of five target genes possibly interacting with SaREFl and a gene named prenylated Rab acceptor 1 (PRA1) domain protein which was detected with a high frequency. Subcellular localization revealed that SaREFl mainly distributed in the cytosol. Our findings would further enrich the connotation of REF-like genes and provide theoretical assistance for the application in breeding heavy metal-tolerant plants.

We introduce an ab initio approach and the modified strong-field approximation to investigate the alignment-dependent ionization of H2+(1πu) exposed to different few-cycle laser fields. The ab initio calculations are performed by the B-splines one-center method and the Crank-Nicolson method in spherical coordinates. It is shown that the peak ionization probabilities appear around alignment angles 50° and 40° at the laser intensities 3×1013 W/cm2 and 5×1013 W/cm2, respectively, and the above distinct features come from the resonant excitation of the molecular ion, which is confirmed by calculation including and excluding the state 2σg in the basis expansion. Furthermore, the results obtained by including the state 2σg in the ab initio simulations can be qualitatively reproduced by the modified molecular length gauge strong-field approximation (SFA) taking account of the 1πu and 2σg states simultaneously. Analysis indicates that a part of electron is directly emitted from the 1πu orbital and another portion of electron is released from 2σg orbital and other excited state after the single-photon resonant transition between 1πu and 2σg orbitals.