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SUMMARYGravity controls directional growth of plants, and the classical starch-statolith hypothesis proposed more than a century ago postulates that amyloplast sedimentation in specialized cells initiates gravity sensing, but the molecular mechanism remains mysterious. Here, we report that gravistimulation by reorientation triggers the Mitogen-Activated Protein Kinase (MAPK) signaling-mediated phosphorylation of LAZY proteins, the key regulators of gravitropism accumulated more on the lower side of the plasma membrane in columella cells in regular growthArabidopsis. Phosphorylation of LAZY increases its interaction with several TOC proteins on the surface of amyloplasts, facilitating the translocation of LAZY proteins from the plasma membrane to the amyloplasts. Amyloplast sedimentation subsequently guides LAZY to relocate to the new lower side of the plasma membrane in columella cells, where LAZY induces asymmetrical auxin distribution and differential growth. Together, this study provides a molecular interpretation for the starch-statolith hypothesis: the organelle movement-triggered molecular polarity formation.

Colletotrichum gloeosporioides is a hemibiotrophic ascomycete fungus that causes anthracnose on numerous plants worldwide and forms a specialized infection structure known as an appressorium in response to various plant surface signals. However, the associated mechanism of host surface signal recognition remains unclear. In the present study, three putative sensors, namely the mucin Msb2, the membrane sensor protein Sho1, and the G‐protein‐coupled receptor Pth11, were identified and characterized. The results showed that CgMsb2 plays a major role in the recognition of various host surface signals; deletion of CgMsb2 resulted in significant defects in appressorium formation, appressorium penetration, cellophane membrane penetration, and pathogenicity. CgSho1 plays a minor role and together with CgMsb2 cooperatively regulates host signal recognition, cellophane membrane penetration, and pathogenicity; deletion of CgSho1 resulted in an expansion defect of infection hyphae. Deletion of CgPth11 in wildtype, ΔCgMsb2, and ΔCgSho1 strains only resulted in a slight defect in appressorium formation at the early stage, and CgPth11 was dispensable for penetration and pathogenicity. However, exogenous cAMP failed to restore the defect of appressorium formation in ΔCgPth11 at the early stage. CgMsb2 contributed to the phosphorylation of the mitogen‐activated protein kinase CgMk1, which is essential for infection‐associated functions, while CgSho1 was unable to activate CgMk1 alone but rather cooperated with CgMsb2 to activate CgMk1. These data suggest that CgMsb2 contributes to the activation of CgMk1 and has overlapping functions with CgSho1 in plant surface sensing, appressorium formation, and pathogenicity., The sensor protein CgMsb2 contributes to the activation of CgMk1 and has overlapping functions with CgSho1 in plant surface sensing, appressorium formation, and pathogenicity.

The development of new cathode materials with high capacity, good stability, and high safety is important for the future improvement of Li batteries. LiFeBO3 is considered to be a type of promising electrode materials for Li-ion batteries due to its low cost, high theoretical capacity of 220 mAh/g (about 30% larger than that of LiFePO4), low toxicity, and small volume change of 2% during the Li+ reversible extraction/insertion process. However, its electronic conductivity and rate performance still need further improvement. To optimize the performance of the LiFeBO3, Mn, Cr, and Ni doping at Fe site have been studied experimentally, while the effect of minor addition of 3d transition metals on the electronic structure of LiFeBO3 is rarely investigated. Thus, density functional theory calculations corrected by on-site Coulomb interactions have been conducted to study the crystal structure and electronic property of the LiFe1−xMxBO3 (M = Mn, Co, and Ni) electrode systems. The results indicate that the coordination geometry about Fe in LiFeBO3 is a distorted trigonal bipyramid with a distortion which can be attributed to a Jahn-Teller effect. The band gap energy of LiFeBO3 is calculated to be 3.40 eV, which is in reasonable agreement with the previously computed values. The doping at Fe site with Mn cannot reduce the distortion of Jahn-Teller effect, whereas Co doping intensifies Jahn-Teller distortion of the FeO5 trigonal bipyramid in LiFeBO3. Ni substitution is predicted to be able to introduce impurity levels, and the Jahn-Teller distortion degree of the trigonal bipyramid decreased from 11.9 of the FeO5 to 8.7% of the NiO5. Thus, Ni doping is expected to increase stability and the electronic conductivity of the LiFeBO3 structure.

This paper addresses the traditional issue of restoring a high-resolution (HR) facial image from a low-resolution (LR) counterpart. Current state-of-the-art super-resolution (SR) methods commonly adopt the convolutional neural networks to learn a non-linear complex mapping between paired LR and HR images. They discriminate local patterns expressed by the neighboring pixels along the planar directions but ignore the intrinsic 3D proximity including the depth map. As a special case of general images, the face has limited geometric variations, which we believe that the relevant depth map can be learned and used to guide the face SR task. Motivated by it, we design a network including two branches: one for auxiliary depth map estimation and the other for the main SR task. Adaptive geometric features are further learned from the depth map and used to modulate the mid-level features of the SR branch. The whole network is implemented in an end-to-end trainable manner under the extra supervision of depth map. The supervisory depth map is either a paired one from RGB-D scans or a reconstructed one by a 3D prior model of faces. The experiments demonstrate the effectiveness of the proposed method and achieve improved performance over the state of the arts.

The DArk Matter Particle Explorer (DAMPE) is a satellite-borne, calorimetric-type, high-energy-resolution detector for the precise measurement of high-energy electrons, gamma rays, and nuclei from deep space. The DAMPE electromagnetic calorimeter consists of bismuth germanate (BGO) crystals that can measure incident hadron energies from 50 GeV to 100 TeV. For an inorganic scintillator, such as BGO, the nonlinear fluorescence response when measuring ions contributes to the difference between the experimental data and Monte Carlo simulations. This article reports the BGO quenching nonlinearity occurring in the DAMPE experiment. The ionization energy response of BGO to several kinds of ions lighter than iron is investigated by conducting beam tests and analyzing flight data. We compare the scintillator output with the energy loss according to GEANT4 simulations and determine the quenching parameters. The combined result of beam test and flight experiment shows that the quenching effect strongly depends on the density of the ionization energy loss.

Density functional theory calculations corrected by on-site Coulomb interactions have been conducted to study the crystal structure and electronic property of the LiV1–xMxPO4F (M = Mn, Fe, Co, and Ni) electrode systems. The calculation results show that the substitution of V atoms in LiVPO4F by Fe-dopants resulted in the lowest formation energy, and the crystal structure is, therefore, most thermodynamically stable, while Co and Ni doping seems to be difficult due to their relatively higher formation energy than that of doping with Fe and Mn. Furthermore, Fe substitution can effectively suppress the volume change of the LiVPO4F materials during electrochemical delithiation, leading to improvement of the cycle performance of LiVPO4F electrode. The results of charge analysis predict that Fe substitution is able to donate extra electrons for charge compensation during the Li+ reversible extraction/insertion process. The calculation of energy band structure and density of states indicate that the Mn, Fe, Co, and Ni doping reduce the band gaps through variations of V-3d spin orbitals. However, only Fe doping introduced impurity level located at 0.75 eV above valence band in the forbidden band of LiVPO4F, providing a platform for electronic transition, which is helpful to enhance electronic conductivity of the LiVPO4F electrode.

The application of hydrogen energy urgently requires a high-capacity hydrogen storage technology that can release hydrogen at low temperature. The composite of LiAlH4 and NH4F has a hydrogen storage capacity of up to 8.06 wt%, but the release of hydrogen requires a reaction temperature of about 170 °C, and the reaction is difficult to control. In this work, the reaction between LiAlH4 and NH4F is proposed to be carried out in diethyl ether to improve its hydrogen release performance. It exhibits good hydrogen release performance over a wide temperature range of −40–25 °C, and the hydrogen release capacity at −40 °C, −20 °C, 0 °C and 25 °C can reach 4.41 wt%, 6.79 wt%, 6.85 wt% and 7.78 wt%, respectively. The activation energy of the reaction is 38.41 kJ mol−1, which is much lower than many previously reported catalytic hydrolysis systems that can release hydrogen at room temperature. Our study demonstrates a high-performance hydrogen storage system with very low operating temperature, which may lay the foundation for the development of practical mobile/portable hydrogen source in the north and the Arctic.

Heterojunction structure has been extensively employed for the design of novel catalysts. In the present study, density functional theory was utilized to investigate the electronic structure and hydrogen evolution performance of Ti3C2O2 MXene quantum dots/graphene (QDs/G) heterostructure. Results show that a slight distortion can be observed in graphene after hybriding with QDs, due to which the electronic structure of QDs have been changed. Associated with such QDs-graphene interaction, the catalytic activity of Ti3C2O2 QDs has been optimized, leading to excellent HER catalytic performance.

Electronic fitness function (EFF, achieved by the electrical transport properties) as a new quantity to estimate thermoelectric (TE) performance of semiconductor crystals is usually used for screening novel TE materials. In recent years, because of the high EFF values, an increasing number of two-dimensional materials have been predicted to have the potential for TE applications via high-throughput calculations. Among them, the GeS2 monolayer has many interesting physical properties and is being used for industrial applications. Hence, in this work, we systematically investigated the TE performance, including both electronic and thermal transport properties, of the GeS2 monolayer with first-principles calculations. The results show that the structure of the GeS2 monolayer at 700 K is thermally unstable, so we study its TE performance only at 300 and 500 K. As compared with other typical TE monolayers, the GeS2 monolayer exhibits excellent electronic transport properties but a relatively high lattice thermal conductivity of 5.71 W m−1 K−1 at 500 K, and thus an unsatisfactory ZT value of 0.23. Such a low ZT value indicates that it is necessary to consider not only the electron transport properties but also the thermal transport properties to screen the thermoelectric materials with excellent performance through high-throughput calculations.

The DArk Matter Particle Explorer (DAMPE), which is a Chinese space telescope for the precise measurement of high-energy electrons, gamma rays, and nuclei from deep space, was successfully launched on December 17, 2015. The DAMPE electromagnetic calorimeter made of bismuth germanium oxide (BGO) crystals can measure incident hadron energies from 50 GeV to 100 TeV. The calorimeter was tested with ion beams at CERN in 2015. The energy responses to ions from helium to argon are investigated. The result is reproduced by a Monte Carlo simulation based on Geant4 with two physics process models. It shows that the simulation results of a beam test are independent of the physics models adopted. Additionally, quenching effects of the BGO crystal on the ions are observed with this beam test. The quenching attenuations increase with the atomic number and were approximately 7% for boron and 40% for argon.

Melanin is recognized as a dark pigment that can protect fungi from the harm of environmental stresses. To investigate what roles of melanin played in the pathogenicity and development of Colletotrichum gloeosporioides, a causal agent of poplar anthracnose, genes encoding a transcription factor CgCmr1 and a polyketide synthase CgPks1 were isolated as the ortholog of Magnaporthe oryzae Pig1 and Pks1 respectively. Deletion of CgCmr1 or CgPks1 resulted in melanin-deficient fungal colony. The ΔCgPks1 mutant showed no melanin accumulation in appressoria, and lack of CgCmr1 also resulted in the delayed and decreased melanization of appressoria. In addition, the turgor pressure of the appressorium was lower in ΔCgPks1 and ΔCgCmr1 than in the wild-type (WT). However, DHN melanin was not a vital factor for virulence in C. gloeosporioides. Moreover, deletion of CgCmr1 and CgPks1 resulted in the hypersensitivity to hydrogen peroxide (H2O2) oxidative stress but not to other abiotic stresses. Collectively, these results suggest that CgCmr1 and CgPks1 play an important role in DHN melanin biosynthesis, and melanin was not an essential factor in penetration and pathogenicity in C. gloeosporioides. The data presented in this study will facilitate future evaluations of the melanin biosynthetic pathway and development in filamentous fungi.

Vehicle detection in traffic surveillance videos is a special subtask in object detection, where desired objects are vehicles moving on the road while the background is still within a sequence. The disparity of speed within each frame, i.e. moving and static, is consistent with the vehicle and background semantic to some extent, thus motions can be extracted to enhance the appearance of foreground. In this paper, we propose a motion prior embedded parallel architecture for vehicle detection, aiming at illuminating vehicles and suppressing false positives in the background. We further implement extensive experiments on the UA-DETRAC dataset to validate the effectiveness of our approach, and achieve promising performance in both accuracy and speed.

The hemibiotrophic pathogen Colletotrichum gloeosporioides is the causal agent of poplar anthracnose and causes considerable economic losses. This fungus infects its host through a specialized structure called an appressorium. In a previous study, we demonstrated that the mitogen-activated protein kinase (MAPK) CgMk1 plays a critical role in appressorium formation and pathogenicity. In this study, we identified three upstream components of CgMk1, the putative adaptor protein CgSte50, MAPKKK CgSte11, and MAPKK CgSte7, and showed that CgSte50, CgSte11, and CgSte7 positively regulate the phosphorylation of CgMk1. Deletion of CgSte50, CgSte11, and CgSte7 resulted in the loss of appressorium formation, penetration of the cellophane membrane, invasive growth and pathogenicity, similar to the defects observed in the CgMk1 mutant. CgSte50, CgSte11, CgSte7 and CgMk1 were also required for polarity during conidial germination. At the initial stage of appressorium formation, the accumulation of reactive oxygen species (ROS) was altered in the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants compared with that in wild type (WT). Furthermore, the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants manifested pleiotropic defects during vegetative growth; all mutants exhibited albino colonies, and the aerial hyphae had reduced hydrophobicity. In the mutants, autolysis was detected at the colony edge, and septum formation in the hyphae was elevated compared with that in the WT hyphae. Moreover, deletion of CgSte50, CgSte11, CgSte7 and CgMk1 affected vegetative growth under nitrogen-limiting and osmotic stress conditions. CgSte50, CgSte11, and CgSte7 but not CgMk1 were required for the oxidative stress response. Taken together, these results indicate that the CgMk1 MAPK cascade plays vital roles in various important functions in C. gloeosporioides.

The design of high efficiency, low cost and abundant sources electrocatalysts for oxygen evolution reaction (OER) has attracted more and more attention, because of the depletion of precious and rare metals. Herein, we reported a highly active Co0.7Cu0.3 alloy, which screening from a series of CoxCu1-x alloys (x = 0.1–0.9) via surface composition controlling and electron state modification. Compared with the Co, other CoxCu1-x alloys, as well as commercial RuO2/IrO2, the Co0.7Cu0.3 catalyst exhibited very high activity in electrocatalytic O2 production from alkaline solution (∼207 mV overpotential). Meanwhile the Co0.7Cu0.3 catalyst exhibited excellent durability for OER, after 72,000 s operation, the attenuation rate of Co0.7Cu0.3 catalyst is lower than ∼ 20%. The high catalytic activity of Co0.7Cu0.3 is attributed to positive shift of d-band center and surface species of Co0.7Cu0.3 alloy which facilitates oxygen-containing species (OCS) formation (*H2O2, *OOH, *OH) and electron transfer. This method of improving the catalytic performance by adjusting the alloy composition to achieve the microscopic electronic perturbation effect is expected to attract attention in the later research.

In the present work, on the foundation of Fe–13Cr-4.5Al–2Mo–1Nb-0.2Si alloy, FeCrAl alloys with low Cr content (7, 8, 9 and 10 wt%) and other minor alloying elements (Ta, Zr and Ni) were prepared. The crystal structure, microstructure, tensile properties and oxidation resistance to high-temperature steam of lean-Cr FeCrAl alloys were investigated. As with the decrease of Cr content, the matrix phase of FeCrAl alloys still exhibited the α-ferrite phase, but the lattice parameter of the matrix phase gradually increased. After annealing, the 13Cr alloy occurred complete recrystallization with an average grain size of 33.5 μm. Meanwhile, the amount of Fe2Nb-type Laves phase in FeCrAl alloys gradually decreased with the decrease of Cr content below 9 wt%. Owing to the weakest pinning effect from the small amount of Laves phase particles, many coarse equiaxed grains were observed in 7Cr alloy. 10Cr alloy did not occur full recrystallization due to relatively slow diffusion of elements resulting from the high content of alloying elements and recovered microstructure. Reducing the Cr content did not damage tensile properties of FeCrAl alloys at both room temperature and 800 °C. Due to the incomplete recrystallization, the 10Cr alloy retained higher strength and relatively poor ductility than other low Cr content alloys at room temperature. Decreasing the content of Cr made the oxidation resistance of lean-Cr alloys worse, which was still better than the traditional Zr alloy. The present work showed that small changes in Cr will not have a remarkable impact on tensile properties and oxidation resistance to high-temperature steam, and low-Cr FeCrAl alloys can be used as an accident-tolerant fuel cladding in light water reactors.

In the present study, bulk nanoporous Cu materials with hierarchical porous structure and fine ligaments have been facilely fabricated through chemical dealloying of CuAl alloy that prepared by suction casting. Effect of dealloying temperature on the formation of nanoporous Cu was investigated. Results reveal that robust bulk nanoporous Cu with no noticeable volume shrinkage can be prepared. The Fe adatoms may act as activation barrier for the surface diffusion of Cu adatoms, which is beneficial for the refinement of nanoporous Cu. Moreover, thermal coarsening behavior of nanoporous Cu was also investigated.

The Dark Matter Particle Explorer developed in China was designed to search for evidence of dark matter particles by observing primary cosmic rays and gamma rays in the energy range from 5 GeV to 10 TeV. Since its launch in December 2015, a large quantity of data has been recorded. With the data set acquired during more than a year of operation in space, a precise time-dependent calibration for the energy measured by the bismuth germanate oxide (BGO) electromagnetic calorimeter (ECAL) has been developed. In this paper, the instrumentation and development of the BGO ECAL are briefly described. The calibration on orbit, including that of the pedestal, attenuation length, minimum ionizing particle peak, and dynode ratio, is discussed, and additional details about the calibration methods and performance in space are presented.

In object detection, training samples are divided into negatives and positives simply according to their initial positions on images. Samples which have low overlap with ground-truths are assigned to negatives, and positives otherwise. Once allocated, the negative and positive set are fixed in training. A usually overlooked issue is that certain negatives do not stick to their original states as training proceeds. They gradually regress towards foreground objects rather than away from them, which contradicts the nature of negatives. Training with such inconsistent negatives may confuse detectors in distinguishing between foreground and background, and thus makes training less effective. In this paper, we propose a consistent negative sample mining method to filter out biased negatives in training. Specifically, the neural network takes the regression performance into account, and dynamically activates consistent negatives which have both low input IoUs and low output IoUs for training. In the experiments, we evaluate our method on PASCAL VOC and KITTI datasets, and the improvements on both datasets demonstrate the effectiveness of our method.

The hemibiotrophic ascomycete fungus Colletotrichum gloeosporioides is the causal agent of anthracnose on numerous plants, and it causes considerable economic losses worldwide. Endocytosis is an essential cellular process in eukaryotic cells, but its roles in C. gloeosporioides remain unknown. In our study, we identified an endocytosis-related protein, CgEnd3, and knocked it out via polyethylene glycol (PEG)-mediated protoplast transformation. The lack of CgEnd3 resulted in severe defects in endocytosis. C. gloeosporioides infects its host through a specialized structure called appressorium, and ΔCgEnd3 showed deficient appressorium formation, melanization, turgor pressure accumulation, penetration ability of appressorium, cellophane membrane penetration, and pathogenicity. CgEnd3 also affected oxidant adaptation and the expression of core effectors during the early stage of infection. CgEnd3 contains one EF hand domain and four calcium ion-binding sites, and it is involved in calcium signaling. A lack of CgEnd3 changed the responses to cell-wall integrity agents and fungicide fludioxonil. However, CgEnd3 regulated appressorium formation and endocytosis in a calcium signaling-independent manner. Taken together, these results demonstrate that CgEnd3 plays pleiotropic roles in endocytosis, calcium signaling, cell-wall integrity, appressorium formation, penetration, and pathogenicity in C. gloeosporioides, and it suggests that CgEnd3 or endocytosis-related genes function as promising antifungal targets.

For the past fifty years, the northern Songliao Basin in China was thought to contain Lower Cretaceous coal-measure and gas-generating shale. Oil-type shales did not receive much attention until oil exploration activities made a breakthrough in the Southern Shuangcheng (SSC) depression. In this study, the geochemical characteristics of the newly discovered K1yc4 (fourth member of the Lower Cretaceous YingCheng Formation) oil-type shale in the SSC depression were analyzed, including the organic matter abundance, organic matter type, thermal maturity, hydrocarbon potential, and sedimentary environment. A total of 393 core samples were collected, and Rock-Eval pyrolysis, gas chromatography-mass spectrometry (GC-MS), organic petrography, carbon isotope analysis, and constant and trace element analyses were conducted. The K1yc4 shale was determined to have a good to excellent hydrocarbon potential with high TOC values (mostly 2.0–4.0%). The organic matter was mainly from lower hydrobiont, algae, bacteria, and lesser amounts of terrestrial plants. The organic matter is mainly type I to type II based on the hydrogen index (HI) (average HI = 193.36 mg HC/g TOC), the carbon isotopes of the kerogen (mostly −26 to −30‰), and the organic petrography (average sapropelinite + liptinite of 55.0 vol%). The maturity parameters, i.e., Tmax (mean 452 °C) and vitrinite reflectance (0.8–1.1%), suggest that the shale is in the mature thermal evolution stage. The shale's maximum hydrocarbon-generating intensity is up to 713.29 × 104/km2, and its hydrocarbon-expelling intensity is stable at 116.63 × 104/km2. The constant and trace element analyses (Sr, Ba, V, Ni, Cr, Ti) revealed that the organic matter deposition and preservation occurred in a fresh-brackish and dysoxic-anoxic water environment. Volcanic eruptions probably played a vital role in the enrichment of the organic matter in the oil-type shale. In addition, the results of this study provide evidence that the Lower Cretaceous strata in the northern Songliao Basin meet the geological conditions of oil-prone shale, which expands the petroleum exploration horizon in this region.

It is highly desirable to develop a technology with a high-density hydrogen generation at room temperature in the field of hydrogen energy. Ether solvents are proposed to improve the hydrogen generation properties of the reaction between LiAlH4 and NH4Cl (LiAlH4–NH4Cl) in this paper. The reactions in diethyl ether (LiAlH4–NH4Cl–Et2O), tetrahydrofuran (LiAlH4–NH4Cl-THF) and dimethoxyethane (LiAlH4–NH4Cl-DME) all exhibit good hydrogen generation performances with the H2 yields of about 5.50, 5.52 and 5.31 wt% respectively at 25 °C, which are obviously superior to the pyrolysis behaviors at high temperature of 170 °C required in hydrogen generation reaction of LiAlH4 and NH4Cl. It is found that the higher the LiAlH4 solubility in solvents, the faster the initial hydrogen generation kinetics; and the higher the by-product LiCl solubility in solvents, the shorter the reaction time. In addition, new compounds with a similar molecular formula HAlNH·0.25Ether (the Ether is Et2O, THF or DME) are found in the solid by-products.

A satellite-borne, high energy cosmic ray detector, named the DArk Matter Particle Explorer (DAMPE), was developed in China. The major scientific objectives of the DAMPE mission are observing primary cosmic rays and gamma rays in an energy range from 5 GeV to 10 TeV, to find evidence of the existence of dark matter particle. An electromagnetic calorimeter(ECAL), which contains 308 Bismuth Germanate(BGO) crystal bars, has been built for the DAMPE mission. The performance of 60-cm long BGO crystal bars has been studied with cosmic rays. Electron and ion beam test results of the BGO ECAL are also presented in this paper.

The major scientific goals of the DArk Matter Particle Explorer (DAMPE) are to study cosmic-ray electrons (including positrons) and gamma rays from 5 GeV to 10 TeV and nuclei from Z = 1 to 26 up to 100 TeV. The deposited energy measured by the Bismuth Germanate Oxide (BGO) calorimeter of DAMPE is affected by fluorescence attenuation in BGO crystals that are 600 mm long. In this work, an in-orbit attenuation calibration method is reported, and energy correction of the sensitive detector unit of the BGO calorimeter is also presented.

In this paper, the design, construction, simulation, and performance of a position-sensitive plastic scintillator detector are presented. The readout of the detector uses wavelength-shifting fibers coupled with multi-anode photomultipliers (PMTs) for the x- and y-dimensions. After calibrating the multi-anode PMTs, a two-dimensional projection image of the square scintillator telescope hit by cosmic muons is demonstrated. By performing a cosmic test with the Micromegas telescope, the position resolution of the detector was determined to reach approximately 8.6 mm, which is close to the value obtained in physical simulation.