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Existing pion+nucleus Drell-Yan and electron+pion scattering data are used to develop ensembles of model-independent representations of the pion generalised parton distribution (GPD). Therewith, one arrives at a data-driven prediction for the pion mass distribution form factor, $\theta_2$. Compared with the pion elastic electromagnetic form factor, $\theta_2$ is harder: the ratio of the radii derived from these two form factors is $r_\pi^{\theta_2}/r_\pi = 0.79(3)$. Our data-driven predictions for the pion GPD, related form factors and distributions should serve as valuable constraints on theories of pion structure., Comment: 9 pages, 6 figures, 1 table. Version accepted for publication as an Express Letter in Chin. Phys. Lett

Near-infrared (NIR) persistent luminescence nanoparticles (PLNPs) with high brightness, small sizes, good hydro-dispersivity, and intrinsic surface-functional groups are desirable in biological applications. In this work, Cr3+-doped zinc gallogermanates Zn1+x Ga2−2x Ge x O4:Cr (ZGGC) PLNPs were hydrothermally synthesized via 3-aminopropyltriethoxysilane (APTES) as an additive, or APTES and cetyltrimethylammonium bromide (CTAB) as two co-additives. Addition of APTES not only dramatically enhances the 696 nm NIR luminescence intensity, but also obviously decreases the particle size and introduces amino groups. In particular, the x = 0.1 series ZGGC (ZGGC0.1) with the addition of n moles equivalent APTES (ZGGC0.1-nA) had smaller particle sizes than the x = 0.2 counterpart (ZGGC0.2-nA). The NIR afterglow intensities increased with the APTES introduction. The ZGGC0.2-2.5A sample (also named as ZGGC, Si, -NH2) exhibited maximum luminescence intensities both in solid and aqueous states. With APTES, Si atom is doped and –NH2 groups are modified, the trap depth and density become larger, and the afterglow intensities and decay time are significantly enhanced. More notably, co-addition of CTAB (ZGGC0.2-2.5A-C) (also named as ZGGC, Si, −NH2’) further enhances hydro-dispersivity and luminescence intensity, decreases particle sizes, and results in more prominent amino groups. The trap density is drastically higher than that without CTAB (i.e. ZGGC0.2-2.5A). Change of Cr3+ microenvironment in the crystal and more defects introduction contribute to the enhanced brightness. As expected, the ZGGC,Si,-NH2’ PLNPs possess excellent biocompatibility, deep tissue penetration and distinguished bioimaging properties, and rechargeability with orange LED light. The ZGGC,Si,-NH2’ PLNPs should provide to be an excellent nanomaterial for various functionalization and bioimaging applications.

In order to study the influence of cloud cover on solar energy resources, it provides scientific basis for the development and utilization of solar radiation resources. Based on the Cloud and the Earth’s Radiant Energy System (CERES) and European Centre for Medium-Range Weather Forecasts (ECWMF) data from 2014-2018, the correlation between the temporal and spatial distribution of solar energy resources and the cloud cover in Xinjiang was studied and analyzed. The results show that solar energy resources have generally shown an upward trend in the past five years, with an average annual radiation of 7206.5 MJ/m2 and very stable. The overall distribution of solar radiation is mainly dominated by latitude, decreasing from south to north, and the change is relatively uniform. The maximum value of annual total radiation in the southern area of Xinjiang is about 9000 MJ/m2, which is 1.5 times of that in the northern area. The maximum daily total radiation is 28.88 MJ/m2 in July, which is 3.3 times of that in December. The total radiation in summer can reach up to 2200 MJ/m2, which is 2.2 times of that in winter. Summer radiation is high but fluctuating, and winter radiation is small but relatively stable. The autumn is the period with the least amount of total cloud during the year, the cloud cover in the northern area is about 40%, and the winter in the northern area is the highest along the foothills of the Tianshan Mountain, up to 70%. The fitting effect of radiation attenuation and cloud cover in the northern area is higher than that in the southern area, and the maximum correlation coefficient is 0.98 in summer and the minimum is 0.571 in winter. The fitting effect of radiation attenuation and cloud cover in the northern area is higher than that in the southern area, and the maximum correlation coefficient is 0.98 in summer and the minimum is 0.571 in winter. The solar radiation is mainly affected by clouds in summer, while in winter, there are other factors such as aerosols.

The attosecond ionization dynamics of atoms has attracted extensive attention in these days. However, the role of the initial state is not clearly understood. To address this question, we perform simulations on the neon atom and its model atom with different initial states by numerically solving the corresponding two-dimensional time-dependent Schrödinger equations. We theoretically investigate atomic photoelectron momentum distributions (PMDs) by a pair of elliptically polarized attosecond laser pulses. We find that the PMD is sensitive not only to the ellipticities of the pulses, the relative helicity, and time delay of the pulses, but also to the symmetry of the initial electronic states. Results are analyzed by the first-order time-dependent perturbation theory (TDPT) and offer a new tool for detecting the rotation direction of the ring currents.

Surface roughness is an important factor to consider in the field of precision manufacturing. In this study, a model of the surface roughness in inner thread grinding that takes into account the thread helix angle and effect of elastic deflection between the wheel and the workpiece is presented. The surface roughness is analyzed under different spindle speeds, workpiece speeds, grinding depths, and thread helix angles. The proposed model provides a theoretical basis for the optimization of high-precision inner thread grinding.

We propose a new algorithm to solve the quasi-Wigner solution of the gap equation beyond chiral limit. Employing a Gaussian gluon model and rainbow truncation, we find that the quasi-Wigner solution exists in a limited region of current quark mass, $m

In this paper, a four-degree-of-freedom articulated palletizing robot is used as the object of research. Based on the analysis of the overall configuration of the robot, the kinematic mathematical model is established by D-H method to figure out the workspace of the robot. In order to meet the needs of design and analysis, using AutoCAD secondary development technology and AutoLisp language to develop AutoCAD-based 2D and 3D workspace simulation interface program of palletizing robot. At last, using AutoCAD plugin, the influence of structural parameters on the shape and position of the working space is analyzed when the structure parameters of the robot are changed separately. This study laid the foundation for the design, control and planning of palletizing robots.

A Pt–Pb alloy nanoparticle/multi-walled carbon nanotube (Pt–Pb/MWCNT) nanocomposite was prepared by electrodepositing Pt–Pb alloy onto MWCNTs that were vertically aligned on Ta plates. The 10–40 nm diameter Pt–Pb alloy nanoparticles were mainly deposited at the tips, and sparsely dispersed on the sidewalls of the bamboo-like MWCNTs, as demonstrated by scanning electron microscopy, transmission electron microscopy (TEM), and x-ray diffraction. The high resolution TEM (HRTEM) image showed a snowflake-like morphology for the Pt–Pb nanoparticles. This Pt–Pb/MWCNT nanocomposite exhibited much stronger electrocatalytic activity toward glucose oxidation than pristine MWCNTs, Pt–Pb on glassy carbon, and Pt/MWCNT and Au/MWCNT nanocomposites, in both neutral and alkaline solutions. This Pt–Pb/MWCNT nanocomposite electrode is hence promising for development as a nonenzymatic glucose sensor.

Drug screening at cellular level has becomes an attractive field of research. Different researchers have tried to record cellular response to drugs by electrical or optical approach using both invasive and non-invasive methods. Silicon-based microelectrode integrated microchips are useful tools for in situ temporal recording of neurotransmitter releasing from neural cells. A microfabricated electrochemical biochip is presented in this paper. Using dopaminergic cells grown on the chip, the dopamine excytosis can be electrochemical amperomatric detected non-invasively from drug incubated dopaminegic cells by the microelectrode integrated on chip. This silicon-based electrochemical chip has been designed with an electrode array located on the cell culture chamber bottom. Each electrode is individually electrical controlled. MN9D and PC12 dopaminergic cell lines have been demonstrated on this chip for drug effects study. This silicon-based electrochemical microchip provides a non-invasive, in situ , temporal detection of dopamine exocytosis from dopaminegic cells, and holds the potential for applications in studying the mechanisms of dopamine exocytosis and drug screening. It is also extendable for other cell culture and drug effects study.

Generally speaking, the quark propagator is dependent on the quark chemical potential in the dense quantum chromodynamics (QCD). By means of the generating functional method, we prove that the quark propagator actually depends on p4 + iμ from the first principle of QCD. The relation between quark number density and quark condensate is discussed by analyzing their singularities. It is concluded that the quark number density has some singularities at certain μ when T = 0, and the variations of the quark number density as well as the quark condensate are located at the same point. In other words, at a certain μ the quark number density turns to nonzero, while the quark condensate begins to decrease from its vacuum value.

It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics (QCD). Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson–Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudocritical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region.

We discuss the chiral phase transition of quantum chromodynamics (QCD) with a chiral chemical potential μ5 as an additional scale. Within the framework of Dyson–Schwinger equations, we focus particularly on the behavior of the widely accepted as well as interesting critical end point (CEP), using a separable gluon propagator and a Gaussian gluon propagator. We find that there may be no CEP5 in the T–μ5 plane, and the phase transition in the T–μ5 plane might be totally crossover. Our results have apparent consistency with the Lattice QCD calculation. On the other hand, our study may also provide some useful hints to some other studies related to μ5.

Through analysis the actual coal supply and demand in the US and China, the properties of the coal supply-demand market in both countries are investigated based on the energy supply-demand network. The validity of our model is verified by comparing numerical results with empirical results. The comparison of empirical results and the comparison of coal network model parameters between in the US and in China reveal the essence of the internal differences and similarities of coal supply and demand in these two countries. The third stage of China’s coal network was close to that of the US in 1995, indicating that the evolutional situation of China’s coal market begins to transit to an oligopolistic type. Finally, suggestions for China’s coal supply-demand strategy are put forward.

A novel structure of a double-H tuning fork for an angular rate sensor, which can detect two-axial angular rates on a single quartz chip, is proposed in this article. Multiple sensing forks, which are separated from driving forks, guarantee the sensitivities of the two-axial effect and suppress couplings among each mode. Simulation with the finite element method (FEM) is used to analyze the resonance frequencies, electrode distributions, and outputs of this structure. The results show that this double-H tuning fork resonator can be used as an angular rate sensor to detect two-axial angular rates effectively.

In this study, carbon nanotubes (CNTs) were modified to further improve their performance in electrochemical sensing of dopamine (DA) levels. After a redox polymer, poly(vinylimidazole) complexed with Os(4, 4'-dimethyl- 2, 2-bipyridine)(2)Cl (termed PVI-dmeOs) was electrodeposited on multi-wall CNTs (MWCNTs), Nafion and PVI-dmeOs films were successfully layer-by-layer (LBL) assembled on the hydrophilic surface of the as-prepared PVI-dmeOs/CNTs nanocomposites through electrostatic interactions. The LBL assembly was proved by scanning electron microscopy (SEM), electrochemistry and UV-vis spectroscopy measurements. LBL assembly of Nafion/PVI-dmeOs films on CNTs significantly enhanced their linear sweep voltammetry (LSV) response sensitivity to DA, with a maximum enhancement for three Nafion/PVI-dmeOs film-modified MWCNTs. The LSV peak current density of (Nafion/PV I-dmeOs)(3)/CNT electrodes in response to 10 and 50 microM DA solutions was about 7.3 and 3.9 times those for bare CNTs. At the (Nafion/PV I-dmeOs)(3)/CNT electrodes, the limit of detection (LOD) (signal-to-noise ratio: 3) was 0.05 microM DA, the linear range was 0.1-10 microM DA (with a linear regression coefficient of 0.97) and the DA-sensing sensitivity was 8.15 microA cm( - 2) microM( - 1). The newly fabricated (Nafion/PV I-dmeOs)(3)/CNT electrodes may be developed as an ideal biosensor for direct and in situ measurement of DA levels.