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Because of the coupling between nanoshell and core, the geometrical parameters of nanoshell have significant influence on the localized electric field factor (LEF) and sensitivity. In this paper, the effects of the inner core radius and the thickness of outer shell on LEF of gold-dielectric-silver (GDS) nanoshell and silver-dielectric-gold (SDG) nanoshell are investigated using quasi-static approximation. The result shows that the longer wavelength has a red-shift, while the shorter wavelength has a blue-shift as the inner core radius increases. The longer wavelength and the shorter wavelength mix together for LEF of GDS nanoshell with increasing the middle dielectric radius, while split for SDG nanoshell. Thus, the effects of geometric parameters on LEF of GDS nanoshell are different from that of SDG nanoshell. In addition, the effects of geometrical parameters on the sensitivity of GDS nanoshell and SDG nanoshell are also studied, a higher sensitivity of nanoshell can be obtained by varying the geometrical parameters. Our study provides a approach to study optical properties of GDS and SDG nanoshell and also broaden their applications in sensor.

Boulders are spheroidal and weathered rock fragments that exist in softly weathered granite strata. Boulders can cause severe damage to the cutter heads of shield machines and can even lead to the failure of shield tunneling during the excavation of metro tunnels in granite strata. However, there is no effective method to safely and rapidly cope with this problem on a large scale. This study proposes a method to detect and to pretreat boulders during shield tunneling within granite strata. The detection method is a combination of microtremor surveying and supplementary drilling exploration to ensure both rapid, large-scale detection and high detection accuracy. Based on the microtremor survey results, principles of interpretation are developed to predict the presence of boulders and evaluate the safety status of shield tunneling. Furthermore, the predicted boulders are precisely confirmed by supplementary drilling exploration. After the boulder locations are detected, a combined surface drilling and preblasting technique are adopted to pretreat the boulders. This method was successfully applied in the shield tunneling of Fuzhou Metro Line 5 in China. The application shows that this method is effective for the prediction and pretreatment of boulders during shield tunneling. The prediction of boulders has high accuracy. The preblasting of boulders improves the tunneling efficiency, which significantly reduces the total thrust and torque on the cutter head, and markedly increases the tunneling speed.

SnTe is an emerging IV-VI metal chalcogenide, but its low Seebeck coefficient and high thermal conductivity mainly originating from the high hole concentration limit its thermoelectric performance. In this work, an amorphous carbon core-shell-coated PbTe nanostructure prepared by a "bottom-up" method is first incorporated into the Sn1-ySbyTe matrix to enhance the thermoelectric performance of SnTe. The square-like PbTe nanoparticles maintain their original cubic morphology and do not grow up obviously after the SPS process due to the coating of the C layer, bringing about the formation of nanopores locally, while Sb alloying induces Sb point defects and Sb-rich precipitates. All these unique hierarchical microstructures finally lead to an ultralow lattice thermal conductivity (∼0.48 W-1 m-1 K-1) approaching amorphous limits (∼0.40 W-1 m-1 K-1). In addition, the incorporation of PbTe@C core-shell nanostructures decreases the carrier mobility obviously with a slight loss in carrier concentration, resulting in the deterioration of electrical properties to a certain extent. As a result, a peak thermoelectric figure of merit (ZT) of 1.07 is achieved for Sn0.89Sb0.11Te-5%PbTe@C at 873 K, which is approximately 154.76% higher than that of pristine SnTe. This work provides a new strategy to enhance the thermoelectric performance of SnTe and also offers a new insight into other related thermoelectric systems.

Herein, we show that we can synergistically optimize the electrical and thermal transport properties of CaMnO3 via doping Sr. All the samples exhibit a single phase with an orthorhombic symmetry within the experimental doping range (0-10%). Sr doping significantly reduces resistivity while maintaining a relatively high absolute value of Seebeck coefficient, resulting in an effective enhancement in the electrical properties of the material. The maximum power factor (∼ 3.01 μ W cm−1 K−2) is achieved at 873 K for Ca0.96Sr0.04MnO3, which is three times larger than that of the un-doped CaMnO3. The thermal conductivity governed by lattice thermal conductivity is notably decreased compared with the un-doped sample, which is mainly attributed to the decreased grain size and large mass and strain fluctuations caused by Sr doping, and the thermal conductivity decreases with increasing Sr doping level. The enhanced power factor and significantly reduced thermal conductivity lead to a maximum ZT value of 0.15 at 873 K in the Ca0.90Sr0.10MnO3 sample, indicating that CaMnO3 is a potential candidate for high-temperature application.

4H-SiC substrates and homo-epitaxial layers were obtained using the traditional methods of physical vapor transport and chemical vapor deposition. Defect morphology has been studied using both Synchrotron White Beam X-ray Topography and Monochromatic Beam X-ray Topography. Molten KOH etching method was adopted to further investigate the dislocation behavior mechanisms. Deflected dislocations were observed at the periphery regions in both substrate and epitaxial wafers. 3C polytypes and half loop arrays were observed in the 4H-SiC epitaxial wafer. It is also found that the majority of basal plane dislocations are converted to threading edge dislocations in the epitaxial wafer samples. The proportion of BPD to TED conversion depends on the surface step morphology and growth mode in epitaxial growth which in turn depends on the C/Si ratio. By the optimization of etching time prior to epitaxy and C/Si ratio, high-quality epitaxial wafers with extremely low basal plane dislocations densities (＜0.1 cm-2) was obtained.

Herein, a series of (Sn1.06Te)1-x-(InSb)x (x = 0, 0.025, 0.05, 0.075) samples are fabricated, and their thermoelectric performances are studied. The all-scale structure defects containing the atomic-scale In doping defects, the nanoscale Sb precipitates, and the mesoscale grain boundary scatter phonons collectively in a wide range of frequencies to give the ultralow lattice thermal conductivity. Concurrently, the incorporation of InSb decreases carrier concentration with marginal loss in carrier mobility, resulting in a little variation of electrical properties over a wide temperature range. The significantly decreased thermal conductivity and the preserved high power factor lead to a maximum ZT value of ∼0.84 at 823 K in the (Sn1.06Te)0.95(InSb)0.05 sample. This strategy of rapidly constructing all-scale structure defects could be applied to other thermoelectric systems to enhance thermoelectric performance.

In this paper, we investigate the influences of inner core radius, shell thickness, dielectric function of inner core and surrounding medium on the refractive index sensitivity of dielectric–metal nanotube based on the quasi-static theory. Theoretical calculation results show that the refractive index sensitivity of dielectric–metal nanotube can be well optimized by tuning the geometrical parameters. The refractive index sensitivity of two-layered dielectric–metal nanotube increases exponentially with decreasing the wall thickness, but increases linearly with decreasing the refractive index of surrounding medium. In addition, the refractive index sensitivity of metal–dielectric–metal nanotube is also investigated, the calculation shows that the refractive index sensitivity of silver–dielectric–silver nanotube is higher than that of gold–dielectric–gold nanotube under the same parameter. The physical mechanism is investigated based on the plasmon hybridization theory. Our study provides a way to analyze and broaden the applications in sensor ability.

De-domestication is a unique evolutionary process during which crops re-acquire wild-like traits to survive and persist in agricultural fields without the need for human cultivation. The re-acquisition of seed dispersal mechanisms is crucial for crop de-domestication. Common wheat is an important cereal crop worldwide. Tibetan semi-wild wheat is a potential de-domesticated common wheat subspecies. However, the crucial genes responsible for its brittle rachis trait have not been identified. Genetic mapping, functional analyses and phylogenetic analyses were completed to identify the gene associated with Qbr.sau-5A, which is a major locus for the brittle rachis trait of Tibetan semi-wild wheat. The cloned Qbr.sau-5A gene is a new Q allele (Qt ) with a 161-bp transposon insertion in exon 5. Although Qt is expressed normally, its encoded peptide lacks some key features of the APETALA2 family. The abnormal functions of Qt in developing wheat spikes result in brittle rachises. Phylogenetic and genotyping analyses confirmed that Qt originated from Q in common wheat and is naturally distributed only in Tibetan semi-wild wheat populations. The identification of Qt provides new evidence regarding the origin of Tibetan semi-wild wheat, and new insights into the re-acquisition of wild traits during crop de-domestication.

Optical properties and refractive index sensitivity abilities of three-layered silver/gold-dielectric-silver bimetallic nanoshells are investigated based on quasi-static theory. The results show that absorption spectra of silver/gold-dielectric-silver bimetallic nanoshells can be well tuned by changing the inner core radius, middle dielectric radius and outer shell layer thickness. Local surface plasmon resonance (LSPR) shifts of | ω − − 〉 mode show a red-shift with increasing the inner core radius and the thickness of middle dielectric layer, while a blue-shift with increasing the thickness of outer shell. It is interesting to find that the shifts of | ω − + 〉 mode are related to the ratio e 2 ∕ e 4 , the component of core and nanoshell. In addition, the refractive index sensitivity abilities of three-layered silver/gold-dielectric-silver bimetallic nanoshells are also reported. A higher refractive index sensitivity ability can be obtained by adjusting its geometric size and component. | ω − − 〉 mode gets more intensity with increasing the surrounding medium dielectric function, while | ω − + 〉 mode fades down. The intensity difference between | ω − − 〉 mode and | ω − + 〉 mode is mainly effected by the surrounding medium dielectric function, its geometric parameter, middle layer dielectric function, the component of core and nanoshell. Our study provides a way to analyze sensitivity application of nanoshells and broadens the application of nanoshells in sensor ability.

Based on the elastic theory and the seepage flow theory, a new analytical solution with consideration of the seepage force is proposed to determine the external stress on the lining of a circular TBM tunnel. According to this solution, the relationships between the permeability coefficient of rock masses and the maximum allowable drainage flow are studied. The influence of the controlled drainage flow and the elastic modulus of surrounding rocks on the external stress is discussed. Moreover, in order to validate the results obtained from the elastic analytical solution developed in this paper, a comparison between the results obtained from the solution considering the seepage force and that without consideration of the seepage force is performed.

Parity-time ($\mathcal{PT}$)-symmetric systems, featuring real eigenvalues despite their non-Hermitian nature, undergo spontaneous $\mathcal{PT}$ symmetry breaking at the exceptional point (EP). The phase transition from $\mathcal{PT}$ symmetry to $\mathcal{PT}$ symmetry breaking has shown exotic functionalities in the classical realm, such as loss-induced transparency or lasing revival. This transition is also expected to produce a more unconventional effect in pure quantum $\mathcal{PT}$ devices. Here, we report experimental evidences of spontaneous $\mathcal{PT}$ symmetry breaking in a single cold $^{40}\mathrm{Ca}^{+}$ ion and, more importantly, a counterintuitive effect of perfect quantum coherence occurring at the EP. Excellent agreement between experimental results and theoretical predictions is identified. In view of the versatile role of cold ions in building a quantum memory or processor, our experiment provides an alternative platform to explore $\mathcal{PT}$-symmetric physics and utilize pure quantum EP effects.

This paper presents the results regarding the prevention and control of gas hazards in a high-gas tunnel under construction. First, some effective methods were introduced, and the results of the gas pressure and gas content measured with and without the prevention methods were compared. Next, the gas emission amounts were predicted according to the measurements, and the required air volume for preventing a potential gas explosion hazard was determined. Finally, a computational study was carried out to investigate the effects of the transverse and longitudinal outlet locations of the ventilation duct on the gas movement in the tunnel. The results showed that with an increase in the longitudinal distance between the outlet and the heading face, the percentage of dead zones at the heading face of the upper bench increased, while the percentage of dead zones at the heading face of the lower bench observably decreased at first and then increased gradually. Additionally, the maximum methane concentration decreases initially and then increases. The percentages of dead zones were at relatively low levels when the outlet was located at the tunnel vault, whereas some relatively higher percentages of dead zones existed when the outlet was located at the tunnel spandrel or hance. The maximum methane concentration increased gradually when the location of the ventilation outlet moved away from the tunnel axis. In this case, the optimal outlet location for the ventilation duct was suggested to be 20 m away from the heading face of the upper bench and located near the tunnel vault.

Excess micromotion of trapped ions leads to several adverse effects, such as modulating the absorption spectrum, shifting the transition frequency, and causing extra motional heating of ions. Moreover, it is hard to deal with, if there is no rf null point in a Paul trap. In this paper, two methods are proposed to control these adverse effects introduced by excess micromotion. The first method can eliminate the spectral modulation effect while keeping the micromotion unaffected by phase modulating the related laser. The second one can control the amplitude of micromotion or compensate it completely to remove the frequency shift effects by applying ac voltage to the dc electrodes. With these two methods, we are not only able to control the micromotion amplitude in a Paul trap without rf null point, but also to realize effective sideband cooling and quantum state manipulating when ions still undergo large excess micromotion.

Decoherence induced by the laser frequency noise is one of the most important obstacles in the quantum information processing. In order to suppress this decoherence, the noise power spectral density needs to be accurately characterized. In particular, the noise spectrum measurement based on the coherence characteristics of qubits would be a meaningful and still challenging method. Here, we theoretically analyze and experimentally obtain the spectrum of laser frequency noise based on the continuous dynamical decoupling technique. We first estimate the mixture-noise (including laser and magnetic noises) spectrum up to $(2\pi)$530 kHz by monitoring the transverse relaxation from an initial state $+X$, followed by a gradient descent data process protocol. Then the contribution from the laser noise is extracted by enconding the qubits on different Zeeman sublevels. We also investigate two sufficiently strong noise components by making an analogy between these noises and driving lasers whose linewidth assumed to be negligible. This method is verified experimentally and finally helps to characterize the noise., Comment: 7 pages, 5 figures

In this paper, we explore the possibilities of realizing weak value amplification (WVA) using purely atomic degrees of freedom. Our scheme identifies the internal electronic states and external motional states of a single trapped $^{40}$Ca$^+$ ion as the system degree and pointer degree respectively, and their controllable weak coupling is provided by a bichromatic light field. In our experimental demonstration, by performing appropriate postselection on the internal states, a position displacement of 4 angstroms (in phase space) of the trapped ion is amplified to 10 nanometers. The sensitivity of the amplification effect to the relative phase of the quantum state is also demonstrated. The high operational flexibility of this procedure allows fully exploration of the peculiarities of WVA., 8 pages, 8 figures

The course of electromagnetic fields and waves has properties of abstract concept, strong theory and complex calculation, thus this course is difficult to study and understand, and then is also difficult to teach. In order to make the understanding of the course easier, MATLAB software is used as a platform in classroom teaching of electromagnetic fields and waves. This paper mainly discusses the electrical field intensity distribution of media sphere materials and the properties of electromagnetic wave propagation with MATLAB software. The optical properties of dielectric-metal core-shell multi-layered nano-shell are also studied with Laplace's equation. To enrich the teaching content and improve a better teaching effect, the optical property of nano-materials and electromagnetic wave propagation are visualized with MATLAB software, which makes the properties of nano-materials and electromagnetic wave propagation understand easily.

Quantum measurement remains a puzzle through its stormy history from the birth of quantum mechanics to state-of-the-art quantum technologies. Two complementary measurement schemes have been widely investigated in a variety of quantum systems: von Neumann's projective 'strong' measurement and Aharonov's weak measurement. Here, we report the observation of a weak-to-strong measurement transition in a single trapped $40Ca^+$ ion system. The transition is realized by tuning the interaction strength between the ion's internal electronic state and its vibrational motion, which play the roles of the measured system and the measuring pointer, respectively. By pre- and post-selecting the internal state, a pointer state composed of two of the ion's motional wavepackets is obtained, and its central-position shift, which corresponds to the measurement outcome, demonstrates the transition from the weak-value asymptotes to the expected-value asymptotes. Quantitatively, the weak-to-strong measurement transition is characterized by a universal transition factor $e^{-\Gamma^2}$, where $\Gamma$ is a dimensionless parameter related to the system-apparatus coupling. This transition, which continuously connects weak measurements and strong measurements, may open new experimental possibilities to test quantum foundations and prompt us to re-examine and improve the measurement schemes of related quantum technologies., Comment: 6 pages, 3 figures, accepted by Nature Physics

By using the perturbation expansion method and self-consistent iterative method, we evaluate the effect of the conduction band nonprabolicity on the wave vector ( k t ) dependent Rashba coefficient ( α ) and nonlinear Rashba spin splitting (Δ E ) in the Al 0.5 Ga 0.5 N/GaN quantum well (QW). The effective mass (energy) under the first order approximation m t1 ( E k1 ) is in proximity to the iterative result m tp ( E kp ) and m t1 > m tp , E k1 E kp , showing the higher order contributions to m t ( E k ) are small. The sign of the nonparabolic correction to E k is just opposite to that of the correction to m t . The increase of α and Δ E due to the conduction band nonparabolicity reaches about 3% at k t =1 nm −1 . Around the left heterointerface, the probability density is high and E k0 > E kp > E k1 , so α 0 α p α 1 , Δ E 0 E p E 1 . With increasing k t , α decreases, and Δ E increases slowly. For small k t , α 0 (Δ E 0 ), α 1 (Δ E 1 ) and α p (Δ E p ) are nearly the same. While for large k t , the difference between α 0 and α 1 ( α p ) increases rapidly, but the difference between Δ E 0 and Δ E 1 (Δ E p ) increases slowly.

Zircon U–Pb dating of two samples of metagabbro from the Riwanchaka ophiolite yielded early Carboniferous ages of 354.4 ± 2.3 Ma and 356.7 ± 1.9 Ma. Their positive zircon eHf(t) values (+7.9 to +9.9) indicate that these rocks were derived from a relatively depleted mantle. The metagabbros can be considered as two types: R1 and R2. Both types are tholeiitic, with depletion of high-field-strength elements (HFSE) and enrichment of large-ion lithophile elements (LILE) similar to those of typical back-arc basin basalts (BABB), such as Mariana BABB and East Scotia Ridge BABB. Geochemical and isotopic characteristics indicate that the R1 metagabbro originated from a back-arc basin spreading ridge with addition of slab-derived fluids, whereas the R2 metagabbro was derived from a back-arc basin mantle source, with involvement of melts and fluids from subducted ocean crust. The Riwanchaka ophiolite exhibits both mid-ocean ridge basalts- and arc-like geochemical affinities, consistent with coeval ophiolites ...

Localized surface plasmon resonances (LSPRs) of Ag-dielectric-Ag multi-layered nanoshell are studied by quasi-static approximation and plasmon hybridization theory. Absorption properties of multi-layered nanoshell with the silver core and nanoshell separated by a dielectric layer exhibit strong coupling between the core and nanoshell. The result shows absorption spectrum of LSPRS is influenced by the refractive index of surrounding medium, the dielectric constant of middle dielectric layer, the thickness of inner core radius and outer shell layer. LSPR shift of the longest wavelength $\left |\omega _{-}^{-}\right >$ is red-shifted with increasing the inner core radius. It is interesting to find that longer wavelength $\left |\omega _{-}^{+}\right >$ mode is mainly effected by the ratio constant of the surrounding medium refractive index e 4 to the middle layer dielectric constant e 2. $\left |\omega _{-}^{+}\right >$ mode takes place a blue-shift with increasing inner core radius when e 2 > e 4, a red-shift when e 2 < e 4, and no-shifting when e 2 = e 4. However, the influence of dielectric layer radius to $\left |\omega _{-}^{+}\right >$ mode shows the different property as that of increasing the inner core radius. The underlying mechanisms are analyzed with the plasmon hybridization theory and the distribution of induced charge interaction between the inner core and outer shell. In addition, the influence of core radius, middle dielectric layer radius and outer shell radius to sensitivity of Ag-dielectric-Ag multi-layered nanoshell are also reported, a higher sensitivity could be gotten by adjusting geometrical parameters. Our theoretical study could give an easy way to analyze properties of the core-shell nanosphere based on plasmon hybridization theory and the induced charge interaction, and usefully broaden the applications in nano-optics.

A complete quantum cooling cycle may be a useful platform for studying quantum thermodynamics just as the quantum heat engine does. Entropy change is an important feature which can help us to investigate the thermodynamic properties of the single ion cooling process. Here, we analyze the entropy change of the ion and laser field in the single ion cooling cycle by generalizing the idea in Reference (Phys. Rev. Lett. 2015, 114, 043002) to a single ion system. Thermodynamic properties of the single ion cooling process are discussed and it is shown that the Second and Third Laws of Thermodynamics are still strictly held in the quantum cooling process. Our results suggest that quantum cooling cycles are also candidates for the investigation on quantum thermodynamics besides quantum heat engines.

Salicylic acid (SA) is a key defense hormone associated with wheat resistance against Fusarium head blight, which is a severe disease mainly caused by Fusarium graminearum. Although F. graminearum can metabolize SA, it remains unclear how this metabolic activity affects the wheat&ndash, F. graminearum interaction. In this study, we identified a salicylate hydroxylase gene (FG05_08116, FgNahG) in F. graminearum. This gene encodes a protein that catalyzes the conversion of SA to catechol. Additionally, FgNahG was widely distributed within hyphae. Disrupting the FgNahG gene (&Delta, FgNahG) led to enhanced sensitivity to SA, increased accumulation of SA in wheat spikes during the early infection stage and inhibited development of head blight symptoms. However, FgNahG did not affect mycotoxin production. Re-introducing a functional FgNahG gene into the &Delta, FgNahG mutant recovered the wild-type phenotype. Moreover, the expression of FgNahG in transgenic Arabidopsis thaliana decreased the SA concentration and the resistance of leaves to F. graminearum. These results indicate that the endogenous SA in wheat influences the resistance against F. graminearum. Furthermore, the capacity to metabolize SA is an important factor affecting the ability of F. graminearum to infect wheat plants.

Adiabatic quantum computing (AQC) is an approach for solving optimization problems and has advantages against environmental decoherence and certain kinds of random unitary perturbations; however, long coherence time of quantum systems is required to meet the adiabatic criteria for the implementation of AQC. To break the dilemma of evolution time in AQC, the method of shortcuts to adiabaticity (STA) is employed to speed up the evolution process and suppress the nonadiabatic transitions. In this work we demonstrate the application of STA in AQC by implementing a fast two-bit Grover's algorithm with STA in an ion trap system, and the method here is also applicable for realizing Grover's algorithm with more entries.

A quantum algorithm of SU(N) Yang-Mills theory is formulated in terms of quantum circuits. It can nonperturbatively calculate the Dyson series and scattering amplitudes with polynomial complexity. The gauge fields in the interaction picture are discretized on the same footing with the lattice fermions in momentum space to avoid the fermion doubling and the gauge symmetry breaking problems. Applying the algorithm to the quantum simulation of quantum chromodynamics, the quark and gluon's wave functions evolved from the initial states by the interactions can be observed and the information from wave functions can be extracted at any discrete time. This may help us understand the natures of the hadronization which has been an outstanding question of significant implication on high energy phenomenological studies., 9 pages, 1 figure

The fundamental mechanism of the precipitation kinetics and stability of nano-sized Cu-precipitates are crucial to the development of ultra-high strength low carbon ferritic steels. The effects of Al on the formation and stabilization of B2 Cu-rich precipitates in Fe–Cu based steels were studied using experimental method combining the first-principles calculations and molecular dynamics simulations. With increasing aging time, the Cu-rich particles with B2 structure precipitated in the ferritic matrix with cube-on-cube and coherent relationship, and Al addition leads to a relatively higher precipitation hardening effect. The first-principle calculations indicate that the metastable B2 FeCu phase has relatively higher mixing energy and small lattice mismatch with the ferritic matrix, and the addition of Al leads to the lower mixing energy of B2 precipitates and the B2 structure Fe(CuAl) compound possesses more smaller lattice mismatch with ferritic matrix. To better understanding the effect of Al on the evolution process of Cu-rich particles, it is essential to investigate the migration and clustering process of Cu atoms during the isothermal tempering at the atomic scale. To this end, we first developed a new interatomic potential of Fe–Cu–Al using the force-matching method based on ab initio calculations, then the formation and evolution of Cu clusters in the Fe–Cu–Al ternary were studied using molecular dynamics method with the new EAM potential. The simulation results indicate that Al addition promotes the clustering of Cu atoms due to the attractive interaction between Cu and Al atoms which enhances nucleation rate of the Cu-rich precipitates.

Inspired by concerns about food safety, the metabolic landscape of biogenic amines (BAs) was elucidated during industrial semidry Chinese rice wine fermentation. The main fermentation process represented the largest contribution to BA formation, which corresponded to 69.1% (54.3 mg/L). Principal component analysis revealed that total acid and ethanol were strongly correlated with BAs, indicating that BA formation favored acidic and stressful conditions. Other than putrescine (PUT), spermidine (SPD), and spermine (SPM), 5 BAs exhibited strong relationships with the precursor amino acids (R2 > 0.85). PUT was mainly decarboxylated from arginine (89.6%) whereas SPD (100%) and SPM (83.1%) were obtained from ornithine. Interestingly, some SPD could convert back to PUT (24.3%). All 8 BAs showed good relationships with lactic acid bacteria (LAB) (R2 around 0.75). Moreover, among the five main LAB genera, Lactobacillus had a positive correlation with BA formation.

Tunable properties of localized surface plasmon resonances (LSPR) of gold-dielectric multilayered nanoshells are studied by quasi-static theory and plasmon hybridization theory. Multilayered nanoshells with the gold core and nanoshell separated by a spacer layer exhibit strong coupling between the core and nanoshell plasmon resonance modes. It is found that the absorption spectra characteristics of LSPR are sensitive to multiple parameters including the surrounding medium refractive index, the dielectric constant of spacer layer, the radius of inner core gold sphere, outer shell layer thickness, and their coupling strength. The results show that LSPR is mainly influenced by the ratio of spacer layer dielectric constant e 2 to surrounding medium dielectric constant e 4. Absorption spectrum of $\left |\omega _{-}^{+}\right \rangle $ mode is red-shifted with increasing core radius when e 2 > e 4. It is surprising to find that LSPR is blue-shifted with increasing core radius when e 2 < e 4, and no shift when e 2 = e 4. These interesting contrary shifts of $\left |\omega _{-}^{+}\right \rangle $ mode with different ratios e 2/e 4 are well analysed with plasmon hybridization theory and the distributions of induced charges interaction between the inner core and outer shell. In addition, for the sake of clarity, the distributions of electric filed intensity at their plasmon resonance wavelengths are also calculated. This work may provide an alternative approach to analyse property of the core-shell nanoshell particles based on plasmon hybridization theory and the induced charge interaction.

MXene, a new two-dimensional (2D) material, has been extensively studied in the field of energy storage. However, the restacking and inferior stability of MXene severely affect their development. Herein, we fabricated a Ti3C2Tx-rGO aerogel through ascorbic acid-assisted hydrothermal treatment. It could effectively reduce the restacking of MXene and enhance the electrochemical properties of electrode material. The redox kinetics of electrode materials were analyzed. The diffusion-controlled process contributions from Ti3C2Tx/rGO-4 were significantly higher than Ti3C2Tx owing to the more exposed active sites after reduced graphene oxide (rGO) intercalation and increased layer spacing. Ti3C2Tx/rGO-4 aerogel binder-free electrode achieved a special capacitance of 313 F g−1 (about 174 % of Ti3C2Tx) at 1 A g−1. Moreover, Ti3C2Tx/rGO-4 symmetric supercapacitor demonstrated an outstanding energy density of 7.5 Wh kg−1 at a power density of 500 W kg−1 when the operated potential was at 1 V, showing a good application prospect.

The Weyl equation describes chiral massless relativistic particles, called Weyl fermions, which have important relations to neutrinos. A direct observation of the dynamics of Weyl fermions in an experiment is difficult to achieve. This study investigates a method of simulating the Weyl equation in 1+2-dimension by a single trapped ion. The predictions about a two-dimensional Zitterbewegung and an especially interesting phenomenon of Weyl fermions can be tested by the future trapped ion experiment, which might enhance our understanding of neutrinos., 6 pages, 3 figures

A newly discovered Devonian ophiolite located in the Taoxinghu area of central Qiangtang on the Qinhai–Tibet Plateau is described. The ophiolite consists of gabbro and diabasic dikes, and invasive cumulate gabbros-leucogabbros. The ophiolite has undergone greenschist facies metamorphism and minor deformation. Dating of the metagabbro by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U–Pb techniques yielded a weighted mean age of 367.2 ± 3.3 Ma (Late Devonian). Whole-rock geochemical analyses show that the rocks belong to the tholeiite series, with weak depletion in light rare-earth elements (LREEs), almost no Eu anomalies, weak enrichment in large-ion lithophile elements (LILEs), depletion in Nb and Ta, and weak negative Hf and Ti anomalies. These characteristics are similar to those of back-arc basin basalts. Together, these characteristics suggest that the rocks of the Devonian ophiolite formed by ~30% partial melting of spinel lherzolite, which was enriched by interaction with aqueous fluids during the late-generation phases; there is no evidence of subduction-related melting. The Devonian ophiolite rocks in the Taoxinghu area were first discovered in the LongmuCo–Shuanghu–Lancang suture zone. Detailed geochemical analyses show that the rocks formed in a back-arc ocean basin environment, indicating that the LongmuCo–Shuanghu–Lancang suture zone in central Qiangtang represents a Late Devonian intra-oceanic subduction zone in the Palaeo–Tethys Ocean. The discovery of the central Qiangtang Devonian ophiolite provides essential data for understanding the evolutionary history of the Palaeo–Tethys Ocean, and for identifying and understanding the roles of the different tectonic units on the Qinghai–Tibet Plateau.

Silicon quantum dots (Si QDs) were synthesized by a facile one-step synthesis that involved etching silicon powder through a hydrothermal method. The Si QDs, without any surface modification, maintained good water dispersibility, strong photoluminescence and high pH stability, and can be used as a sensor to detect Cu2+.

A feedback control method for producing an equidistant ion string in a surface-electrode ion trap has been experimentally demonstrated. This method features three advantages: (i) The optimal voltage can be constrained within the specified reachable range. (ii) The height of trapped ions from the trap surface can be maintained at the same value when strings with different number of ions or with different ion spacings are to be trapped. (iii) This method is resistant to a stray electric field near the trap. By this method, the asymmetry of the ion string caused by a stray field is minimized. The robustness of trapping a variable number of ions at the same potential and the dependency of the axial frequency on the number of ions are also investigated experimentally. This work would be a practical method to create a linear ion string with a large number of ions and may find applications in large-scale quantum computing, quantum simulation, and phase transition studies utilizing homogeneous ion strings.

In this paper we report the optimal design and fabrication of a gold-on-silica linear segmented surface-electrode ion trap. By optimizing the thickness and width of the electrodes, we improved the trapping ability and trap scalability. By using some practical experimental operation methods, we successfully minimized the trap heating rate. Consequently, we could trap a string of up to 38 ions, and a zigzag structure with 24 ions, and transport two trapped ions to different zones. We also studied the influences of the ion chip surface on the ion lifetime. The excellent trapping ability and flexibility of operation of the planar ion trap shows that it has high feasibility for application in the development a practical quantum information processor or quantum simulator.

Entangled light beams are important resources for quantum information processing. For some applications like teleportation, only the entanglement between two wave packets (two harmonic oscillators) is needed. So the calculation of output-photon entanglement involves projecting continuous output modes onto wave-packet modes by filter functions, thus resulting in a strong dependence of entanglement on the filter functions. In this paper, we aim at optimizing the filter functions to obtain a large entanglement in a relatively short time, which is important for utilizing the entangled light beams more efficiently in real experiments. We outline the general optimization procedures based on our previous schemes of generating entangled beams in a multimode optomechanical system. Moreover, we give analytic insights into as well as physical explanations of the wave-packet optimization, which are helpful for experimental estimations.

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis.

In this work, we show that the introduction of acidic oxygen functionalities to the surface of carbon nanofibers serves to depress the hydrogenation and the decomposition of hydrogen peroxide during the direct synthesis of H2O2. Moreover, the presence of acidic groups enhances the H2O2 productivity in the case of supported AuPd nanoparticles.