Search

In this paper, we report in situ preparation of nickel hydroxide nanoflake array on carbon cloth (Ni(OH)2 NA/CC) by a rapid and simple microplasma method. Using this technique, Ni(OH)2 nanoflake can be prepared on carbon cloth in only 1.5 h at atmospheric pressure and ambient temperature. As an electrode with highly efficient catalytic and non-enzymatic sensor for detecting glucose, such a Ni(OH)2 NA/CC electrode showed excellent electrocatalytic activity with a short response time within 5 s, low detection limit (LOD) of 62 nM (S/N=3), and response sensitivity of 2216.2 mA mM−1 cm−2, meanwhile a satisfactory reproducibility and selectivity.

Antifreeze (glyco)proteins (AF(G)Ps) are naturally evolved ice inhibitors incomparable to any man-made materials, thus, they are gaining intensive interest for cryopreservation and beyond. AF(G)Ps depress the freezing temperature (Tf) noncolligatively below the melting temperature (Tm), generating a thermal hysteresis (TH) gap, within which the ice growth is arrested. However, the ice crystals have been reported to undergo a retaliatory and explosive growth beyond the TH gap, which is lethal to living organisms. Although intensive research has been carried to inhibit such an explosive ice growth, no satisfactory strategy has been discovered until now. Here, we report that crowded solutions mimicking an extracellular matrix (ECM), in which AF(G)Ps are located, can completely inhibit the explosive ice growth. The crowded solutions are the condensates of liquid-liquid phase separation consisting of polyethylene glycol (PEG) and sodium citrate (SC), which possess a nanoscale network and strong hydrogen bond (HB) forming ability, completely different to crowded solutions made of single components, that is, PEG or SC. Due to these unique features, the dynamics of the water is significantly slowed down, and the energy needed for breaking the HB between water molecules is distinctly increased; consequently, ice growth is inhibited as the rate of water molecules joining the ice is substantially reduced. The present work not only opens a new avenue for cryopreservation, but also suggests that the ECM of cold-hardy organisms, which also exhibit great water confining properties, may have a positive effect in protecting the living organisms from freezing damage.

In electric motorcycles and light electric cars, permanent magnetic synchronous motor (PMSM) of outer-rotor type are preferred, due to its concise structure and flexible control. Since the body mass and road impact causes vertical eccentricity on shaft bearings, vibration and noise take place during vehicle cruising along with a torque and speed ripple. The torque ripples contain significant features closely related to eccentricity, and those special components can be compensated by an injection current with proper frequency, phase and amplitude. In this paper, a novel control method is used to regulate the injection current to restrain torque ripples. By coarse turning with quadratic spline curve fitting and fine turning with successive approximation, the method can response sudden disturbance and drive the specific torque ripple to minimum in a very short time, so that the performance on ride comfort and handling stability of the vehicle could be improved. Experimental tests show that the method performs favorably with rapid convergence and validity.

Pollen fertility is an agronomic trait that strongly influences rice yield. Recent studies have revealed that the development of the pollen wall is required for pollen fertility and is regulated by several genes. However, the mechanisms underlying pollen and pollen wall development in rice remain largely unknown. In the present study, a point mutation in a gene on chromosome 1 was identified that resulted in the production of less and shrunken pollen (LSP) and led to defects in pollen wall formation. This gene was named LSP1 and was found to encode a member of the adenosine triphosphate-binding cassette (ABC) transporter G subfamily, OsABCG3. Two other loss-of-function mutants of LSP1/OsABCG3, generated using CRISPR/Cas9 technology, showed the same male sterile phenotype. The LSP1/OsABCG3 gene showed a spatio-temporal expression pattern in the developing anthers, and is an ortholog of the Arabidopsis genes AtABCG1 and AtABCG16, which play an important role in pollen wall development. Mutation of LSP1/OsABCG3 affected the expression of several genes involved in pollen and pollen wall formation. These results suggest that LSP1/OsABCG3 is critical for normal pollen fertility and shed light on the molecular mechanisms underlying rice pollen wall development.

In this study, the graphene oxide (GO)-TiO2 nanocomposite film prepared by the sol–gel method was used to optimize the photoelectric performance of the perovskite solar cells (PSCs), which structure is based on the carbon electrode and no hole transport layer. Through a series of scientific experiments, it has been proved that the GO–TiO2 nanocomposite film has excellent electrical properties. The electron transport layer which containing 1 wt% of GO makes the PSCs have the most excellent performance. Compared with the controlling PSCs, the photoelectric conversion efficiency of PSCs, which containing 1 wt% GO, increased by 9.3%, from 12.44 to 13.60%. Short-circuit current density (Jsc) increased by 5.99%, from 21.55 to 22.84 mA/cm2, and open circuit voltage remained basically unchanged. It can be seen from the measurement results that the trend of incident photon-to-electron conversion efficiency spectrum is consistent with J–V characteristics, indicating that the PSCs device containing 1 wt% GO has the best electron extraction and transfer performance. However, when too much GO is used, the increased surface charge trap state will lead to the acceleration of carrier recombination and the decrease of electron transport path, and the photovoltaic parameters show a downward trend.

Memtransistor, a hybrid structure that integrates the function of memristor and transistor, is a promising device prototype for the realization of complex neuromorphic learning owing to its diverse functionality and additional flexibility in emulating synaptic behaviors. Memtransistor of two-dimensional (2D) chalcogenide materials have received many interests as it has distinctive memristive mechanism quite different from conventional oxide memristors. Here, we report a memtransistor based on the two-dimensional thin films (2DTFs) of non-layered β-In2S3. The In2S3 2DTFs grown by physical vapor deposition method have microscopically visible grain boundaries (GBs) formed by the stacking and interconnecting of 2D In2S3 flakes. The memtransistors of In2S3 2DTFs show tunable bipolar resistive states with resistance ratio up to 105, endurance over 200 cycles, and a retention time of 104 s. Illumination of laser light from visible and near-infrared are able to induce intermediate resistance states in memtransistors, enabling optical-modulated multilevel memory storage. Also, the memtransistors are able to emulate the synaptic function of long-term potentiation (LTP) and long-term depression (LTD) with tunable synaptic weight in response to presynaptic stimuli of drain/gate pulses. Interestingly, the plasticity of LTP and LTD behavior can be switched in a highly tunable manner by simply varying the gate voltages. The diverse optoelectronic properties and controllable functionality of memtransistors based on the emerging 2D In2S3 offer a useful guide to potential application in electronic memory and artificial synapses.

The precise information of initial rotor position is very important to high performance Interior Permanent Magnet Synchronous Machine (IPMSM) adopting incremental encoder, which can normally be obtained by the high-frequency (HF) rotating or pulsating voltage injection methods. However, the demodulation procedure may confront with the challenge of constrained stability and limited accuracy. For improving estimation accuracy, an improved impulse injection method with merits of simple and fast is proposed. It is carried out by generating a series of phase-axial injections to calculate the probable rotor position, then injecting two reciprocal voltage pulses to obtain the rotor polarity, and finally injecting iterative voltage vectors to obtain the real position rapidly. During the estimation process, the filters to extract the high frequency current signals are not needed. The method effectiveness is validated by the measured results of IPMSM test platform. In the same time, its application limitation is deduced by comparison with the measured results between IPMSM and surface-mounted PMSM (SPMSM). It is shown that the estimation algorithm is compatible with motor parameter differences and can reduce the influence of inductance saturation and nonlinear voltage error. Therefore, the proposed method not only improves the accuracy and robustness of the PMSM sensorless startup control, but also ensures the fast response.

The main formation of the Yinggehai Basin has been related to the rotation of the Indochina block, resulting in large-scale strike-slip motion along the Red River Fault Zone (RRFZ). Transrotational tectonics played a key role in the evolution of the Yinggehai Basin. In this study, we present analog experiments with a preexisting basal velocity discontinuity boundary, rotation of crustal blocks concerning vertical axes, and syntectonic sedimentations to evaluate how the transrotational tectonics controls the evolutionary process of the Yinggehai Basin. Particle image velocimetry (PIV) was used to monitor the deformation of the model surface. Four successive poles of rotation have been applied to the model. The basin evolution underwent two phases. An early phase of deformation is characterized by the nucleation of the main internal faults above the velocity discontinuity boundary and segmented en echelon border fault systems. In the early phase, the internal and boundary faults mainly accommodated large-scale strike-slip displacement. During progressive extension, the main internal faults deactivated, and tectonic activity is localized along the boundary and secondary internal faults in the late phase. The boundary faults in the rotating block play a dominant role in the widening and deepening of the rift zone at an accelerating rate. The model surface morphology shows similarities to the Yinggehai Basin, which is wide in the middle and converges toward the northwest and southeast. In addition, experimental profiles have been compared with seismic profiles in the Yinggehai Basin. The model results also indicate that the rotation of the Indochina block combines with strong strike-slip motion. The similarities between modeling and nature provide support for ∼250 km sinistral displacement along the RRFZ between ∼32 and ∼21 Ma.

Although materials for ice recrystallization inhibition (IRI) are essential for the cryopreservation of cells and tissues, there exists no guiding mechanism for the design of such materials. Therefore, the construction of materials for IRI relies on the try-and-error strategy. Herein, through changing the tacticity of hydroxyl groups on poly(vinyl alcohol) (PVA) backbones with the affinities of PVAs to ice unchanged, we experimentally find IRI activity decreases significantly for isotactic PVA in comparison to that of atactic PVA. Molecular dynamics simulation shows atactic PVA spreads fully at the ice-water interface due to its much stronger interaction with water. This indicates atactic PVA can cover more ice surface and possess a higher IRI activity when the same amount of PVAs are used, which is consistent with the results that PVA can cover the same amount of ice surface more efficiently through experimentally measuring the adsorption of PVAs on the ice surface. A guiding mechanism of high active IRI materials can be obtained: only having affinity to ice is not enough to obtain high IRI activity ( i.e ., only small amount of materials is required to reduce the size of ice crystals to ca. (35± 10) μm), IRI agents must also have high affinity to water, i.e. , low interfacial energies, to both ice and water. The former is to guarantee the adsorption of the IRI agent on the ice surface, and the latter is required for the IRI agent to spread sufficiently at the ice-water interface. Therefore, each IRI molecule can effectively block the diffusion of water onto the ice surface, and consequently inhibits the growth of ice. A spreading coefficient of IRI agents is therefore introduced to quantitatively assess the capability of IRI agents to spread at the ice-water interface.

Grain size is an important factor determining yield in rice. Here, we identified a recessive mutant gene, grain length and awn 1 (gla1), which caused a significant increase in grain length and weight, and was associated with long awns. The gla1 mutation was mapped to a single-nucleotide polymorphism in a gene encoding a cytoplasmically-localized mitogen-activated protein kinase (MAPK) phosphatase. Overexpression of GLA1 caused a decrease in grain length, and the GLA1 protein interacted with OsMAPK6. These results suggest that GLA1 may serve as a negative regulator of the OsMAPKK4-OsMAPK6 cascade, controlling grain size via the dephosphorylation of OsMAPK6.

Increasing deployment of distributed energy resources (DERs) is re-sculpturing the modern power systems in recent years. Future smart power distribution systems should be competent at accommodating extensive integration of DERs and managing the associated uncertainties at the distribution level. The electricity market has been proved to be an efficient way to employ market signals to direct behaviors of users and DERs with large capacity and homogeneous pattern. However, existing market frameworks cannot effectively handle a large number of small-scale DERs due to their diverse characteristics and arbitrary behavior patterns. In this context, an aggregated model which can represent and manage a diverse collection of DER, load, and storage is proposed. An additional trading platform, namely the energy sharing market, is established to reinforce the coordination and collaboration among various aggregators as well as operators. Energy sharing scheme is applied and a corresponding dynamic dispatch platform is designed to solve the crowdsource problem. The efficiency of the proposed model is validated by the numerical studies, and the market performance and impacts of energy sharing on the power systems are illustrated.

The benzene series is one type of volatile organic compounds (VOCs) which causes significant health and environmental issues. Adsorption is an energy-efficient technique for VOC treatment. With a combination of strong π–π interaction with the benzene series, large specific surface area (SSA), tunable nanostructure hierarchy and favourable hydrophobicity, three-dimensional porous graphene materials are potentially favorable for high adsorption capacity, low-energy regeneration and good resistance to high humidity. In this work, few-layered mesoporous graphene (FLMG) with a large SSA (1990 m2 g−1) is constructed by chemical vapor deposition on porous magnesium oxide templates. The as-prepared mesoporous graphene presents a high adsorption capacity (260.0 mg g−1) for toluene at low toluene concentration (∼120 ppm) and a high desorption ratio of 92% for regeneration even at mild heating conditions of 95 °C. Additionally, FLMG preserves 80.1% of the initial adsorption capacity even under high humidity (78%). The good adsorption performance of FLMG is due to its high SSA and high mesoporosity, which render a stronger adsorption ability, a larger adsorption accommodation and a more facile desorption behaviour. This work illustrates the further development of advanced graphene materials for enhanced VOC treatment and other environmental applications.

In this work, inorganic tin-doped perovskite quantum dots (PQDs) are incorporated into carbon-based perovskite solar cells (PSCs) to improve their photovoltaic performance. On the one hand, by controlling the content of Sn2+ doping, the energy level of the tin-doped PQDs can be adjusted, to realize optimized band alignment and enhanced separation of photogenerated electron–hole pairs. On the other hand, the incorporation of tin-doped PQDs provided with a relatively high acceptor concentration due to the self-p-type doping effect is able to reduce the width of the depletion region near the back surface of the perovskite, thereby enhancing the hole extraction. Particularly, after the addition of CsSn0.2Pb0.8I3 quantum dots (QDs), improvement of the power conversion efficiency (PCE) from 12.80 to 14.22% can be obtained, in comparison with the pristine device. Moreover, the experimental results are analyzed through the simulation of the one-dimensional perovskite/tin-doped PQDs heterojunction.

Because of the special low-dimensional physical properties of quantum dots (QDs) and the excellent optoelectronic properties of perovskite, the combination of perovskite solar cells (PSCs) and QDs may largely be one of the breakthroughs in device performance. However, little attention has been paid to the effect of the size of QDs on device performance except for bandgap tuning. In this work, non-toxic SnS QDs of different sizes were prepared by varying the reaction temperature of the thermal injection method. Their optical bandgaps with sizes were investigated, and they were implanted into the active layers of the carbon-based PSCs without hole transport layer. The effects of implanting SnS QDs with different sizes on the perovskite film quality and PSCs performance were studied. The cells implanted with SnS QDs of the best size (average 6.9 nm) achieved a photoelectric conversion efficiency of 14.26%, reaching a 12.42% improvement. The improved performance was mainly attributed to the presence of SnS QDs, which provided more nucleation sites for the growth of perovskite grains, and contributed to better quality perovskite films (including higher crystallinity, increased grain numbers and fewer surface defects), thus improving the light utilization, accelerating carrier transfer and reducing carrier recombination in the active layers. The successful implantation of QDs with different sizes in this paper has facilitated the development of the combination of perovskite and QDs in mesoporous PSC.

The WSFTB is located outboard of the eastern Tibetan Plateau, western China. It has received great attention due to high earthquake risks and rich resources of oil and gas. For both issues, the detailed structural configuration and deformation mechanism behind it are of great importance, but remain unclear due to the complexity created by the presence of multiple décollements. The effect of regionally distributed shallow Triassic salt décollement (SD) and the basal one (BD) has been well understood. In this paper, we focus on the third décollement situated between them. We conducted three sandbox experiments by varying this mid-level décollement (MD) from absence to presence, and from frictional to viscous, to test the effect on diversity of regional structural configuration. Our experimental results illustrated that 1) Absence of MD facilitated decoupling on SD, forming the greatest contrast between subsurface deformation front and the blind one beneath SD; 2) Frictional MD itself showed little decoupling, while its weakness reduced the bulk strength of deep structural level, lowering decoupling effect on SD and leading to approximating deformation fronts in the shallow and deep; 3) The viscous MD, along with SD relieved the resistance on their interbed layer. Consequently, the fastest deformation propagation rate and farthest deformation front (in all the experiments) occurred in the middle structural level. The modeled fold and thrust structures are comparable with the southern, central and northern WSFTB respectively, suggesting that varied MD may control the along-strike structural variations presented. The results also indicate that MD can alter the deformation partition in depth of any other multiple décollement system.

International audience; In order to better understand the late Paleozoic tectonic evolution of the southwestern Central Asian Orogenic Belt (CAOB), we carried out structural and geochronological studies on the poorly investigated Xiaergou and Wulasitai shear zones around and in the Chinese Central Tianshan. The Xiaergou shear zone is the connecting segment between the North Tianshan Fault and Main Tianshan Shear Zone along the northern margin of the Yili - Central Tianshan blocks, it strikes NW-SE with a width of ∼3-5 km and shows predominant dextral kinematics. Zircon U-Pb ages of pre- and syn-kinematic granitic dykes within the Xiaergou shear zone indicate that the dextral shearing was active at ∼312-295 Ma. The Wulasitai shear zone is a high-strain belt occurring in the interior of the Central Tianshan block, it extends NW-SE for more than 40 km with variable widths of ∼1-5 km, steep mylonitic foliations and sub-horizontal stretching lineation are well developed and various kinematic indicators suggest prevailing sinistral shearing. New biotite 40Ar/39Ar ages of two meta-sedimentary rocks, together with the published metamorphic zircon ages constrain the timing of the sinistral shearing at ∼312-301 Ma. Our new results combined with the previous studies reveal that the dextral strike-slip shear zones framing the Central Tianshan formed almost simultaneously in the latest Carboniferous (∼310 Ma) and lasted until the middle to late Permian. They resulted from the eastward tectonic wedging and relative rotations between continental blocks in the SW CAOB. The sinistral shearing of the Wulasitai shear zone within the Central Tianshan was likely generated due to differential eastward motions of the northern and southern parts of the Central Tianshan.

In this work, the groove depth of the vertical GaN trench MOSFETs have been investigated by TCAD simulation. The groove depth is found to have a crucial influence on the specific on-resistance and breakdown voltage. A deep enough groove is required to annihilate the build-in barrier between the p-body and the n-drift region close to the sidewall of the groove, in order to reduce the specific on-resistance. On the other hand, an increased groove depth will also cause electrical field peak and hence degrade the breakdown voltage. Therefore, there is a trade-off between the specific on-resistance and breakdown voltage, and optimization is required. This study has provided a quantitative analysis on the optimization scheme.

Partial fingerprint verification is a challenging task because of the few features contained in small area as well as the large rotation angle and translation between query images and template images. In this paper, we propose a new framework of partial fingerprint verification based on spatial transformer networks (STN) model, where a transform model, i.e., AlignNet network, is proposed to estimate the alignment parameters, and the verification is modeled as a binary classification task. The experimental results on the simulated datasets created from FVC2004 and the real-world dataset FVC2006 DB1 show that our method is invariant to rotation, and also robust to different kinds of scanners, and dramatically outperforms the rank-1 entry of FVC2006 participants. The EER on FVC2006 DB1 of the proposed algorithm is 3.587% compared to that of 5.564%, the best of FVC2006 DB1 entries.

It is a challenging task to resist adversarial attacks due to the imperceptibility of adversarial examples. The passive defense method is developed based on a series of input transformations and has achieved a promising result, which however suffers from a high computation cost. In this paper, we design a new heatmap-aware method to defend adversarial attacks, leading to a significant decrease in the time cost. To be specific, we compute the classification importance from each part of the input to obtain the heatmap of the data, and the key areas of classification are extracted according to the heatmap. A series of transformations are applied to the key areas of the classification, which reduces the amount of data to be processed and thus reduces the time cost. A set of preliminary experiments are conducted to testify the effectiveness of the proposed approach.

Male reproductive development is vital for crop seed production. However, the mechanism underlying remains largely unknown. Here, we isolated a male sterile mutant osgelp34-1 in rice. Cytological analysis indicated that the mutant exhibited delayed degradation of anther wall layers and abnormal pollen development, which resulted in the production of shrunk and non-viable pollen grains. MutMap and CRISPR/Cas9 analysis confirmed that a point mutation in OsGELP34 is responsible for the male sterile phenotype. OsGELP34 is highly expressed in reproductive tissues and encodes a putative GDSL lipase. OsGELP34 protein is located to the endoplasmic reticulum (ER) and conserved in land plants. Collectively, our findings elaborated that OsGELP34 plays a vital role in rice male reproduction and has potential applications in rice hybrid breeding.

Starch accumulation is key for the maturity of rice pollen grains; however, the regulatory mechanism underlying this process remains unknown. Here, we have isolated a male-sterile rice mutant, abnormal pollen 1 (ap1), which produces nonviable pollen grains with defective starch accumulation. Functional analysis revealed that AP1 encodes an active L-type lectin receptor-like kinase (L-LecRLK). AP1 is localized to the plasma membrane and its transcript is highly accumulated in pollen during the starch synthesis phase. RNA-seq and phosphoproteomic analysis revealed that the expression/phosphorylation levels of numerous genes/proteins involved in starch and sucrose metabolism pathway were significantly altered in the mutant pollen, including a known rice UDP-glucose pyrophosphorylase (OsUGP2). We further found that AP1 physically interacts with OsUGP2 to elevate its enzymatic activity, likely through targeted phosphorylation. These findings revealed a novel role of L-LecRLK in controlling pollen maturity via modulating sucrose and starch metabolism.

A new photoelectrochemical imaging method termed scanning electrochemical photometric sensor (SEPS) is proposed in this work. It was derived from light-addressable potentiometric sensor (LAPS) and scanning photoinduced impedance microscopy (SPIM) using a front-side laser illumination at a field-effect structure. When the laser beam scans across the sensor substrate, local photocurrent changes at inversion due to the light absorption of analytes can be recorded. It will be shown that SEPS could be used for label-free living cell imaging with micro-resolution as well as real-time quantitative absorption analysis, which would broaden the applications of traditional LAPS/SPIM from potentiometric/impedance measurements to local optical analysis.

The accretion of frost on heat exchanging surfaces through the freezing of condensed water in cold and humid environments significantly reduces the operating efficiency of air-source heat pumps, refrigerators and other cryogenic equipment. The construction of hierarchical micro-nanostructured SHSs, with the ability to timely remove condensed water before freezing via self-propelled droplet jumping, serves as a promising anti-frosting strategy. However, the actual relationship between microstructural features and water removal capability through droplet jumping is still not clear, hindering the further optimization of anti-frosting SHSs. Herein, a series of aluminum SHSs with different micro-cone arrays is designed and fabricated via ultrafast laser processing and chemical etching. The effect of microstructural features on water removal capability is elucidated by statistically analyzing the condensation process. As compared to nanostructured SHSs with the micro-cone size ranging from 10 to 40 μm, the water removal through droplet jumping is remarkably enhanced from 3.42 g m-2 to as much as 13.91 g m-2 over 10 minutes of condensation experiments due to the effective transition of condensed microdroplets from the initial high-adhesion partial wetting (PW) state to low-adhesion Cassie state, leading to significantly reduced water accumulation and improved anti-frosting performance. However, a further increase in the micro-cone size decreased the water removal amount due to greater droplet adhesion to the surface, which results in higher chances for immobile coalescence and the formation of large droplets. Herein, by rationally tuning the size scale of the structured micro-cones, the optimal SHSs display the least water accumulation and render excellent frosting delay of over 90 minutes under simulated harsh operating conditions.

Condensation freezing inhibition is of great practical importance for anti-icing applications; however, no coatings with this performance have been reported. Here, we report the inhibition of condensation freezing on patterned polyelectrolyte coatings, including polyelectrolyte brush (PB), polyelectrolyte multilayer (PEM), and polyelectrolyte hydrogel (PH) surfaces, benefiting from their feature in regulating ice nucleation and propagation via changing counterions. On the reported surfaces, ice nucleation can be initiated exclusively at the domains with the polyelectrolytes; moreover, spontaneous ice propagation can be achieved atop the patterned polyelectrolyte surface. Consequently, condensed water surrounding the frozen drops on the patterned polyelectrolyte surface evaporates due to the instantaneously released latent heat in the course of ice propagation. Afterward, ice grows specifically on polyelectrolyte surfaces via desublimation as the saturated vapor pressure of ice is smaller than that of condensed water drops. As such, an ice-free region up to 96% of the entire surface area can be accomplished. We demonstrate that various polyelectrolyte coatings can be easily introduced on almost all surfaces, revealing great promise for anti-icing applications.

Pollen development plays crucial roles in the life cycle of higher plants. Here we characterized a rice mutant with complete male-sterile phenotype, pollen-less 1 (pl1). pl1 exhibited smaller anthers with arrested pollen development, absent Ubisch bodies, necrosis-like tapetal hypertrophy, and smooth anther cuticular surface. Molecular mapping revealed a synonymous mutation in the fourth exon of PL1 co-segregated with the mutant phenotype. This mutation disrupts the exon-intron splice junction in PL1, generating aberrant mRNA species and truncated proteins. PL1 is highly expressed in the tapetal cells of developing anther, and its protein is co-localized with plasma membrane (PM) and endoplasmic reticulum (ER) signal. PL1 encodes an integrin-&alpha, FG-GAP repeat-containing protein, which has seven &beta, sheets and putative Ca2+-binding motifs and is broadly conserved in terrestrial plants. Our findings therefore provide insights into both the role of integrin-&alpha, FG-GAP repeat-containing protein in rice male fertility and the influence of exonic mutation on intronic splice donor site selection.

Preventing condensation frosting is crucial for air conditioning units, refrigeration systems, and other cryogenic equipment. Coalescence-induced self-propelled jumping of condensed microdroplets on superhydrophobic surfaces serves as a favorable strategy against condensation frosting. In previous reports, efforts were dedicated to enhance the efficiency of self-propelled jumping by constructing appropriate surface structures on superhydrophobic surfaces. However, the incorporation of surface structures results in larger area available for condensation to occur, leading to an increase in total amount of condensed water on the surface and partially counteracts the effect of promoted jumping on removing condensed water from the surface. In this paper, we focus on the competing effects between condensing and self-propelled jumping on promoting and preventing water accumulation, respectively. A series of micro- and nanostructured superhydrophobic surfaces are designed and prepared. The condensation process and self-propelled jumping behavior of microdroplets on the surfaces are investigated. Thousands of jumping events are statistically analyzed to acquire a comprehensive understanding of antifrosting potential of superhydrophobic surfaces with self-propelled jumping of condensed microdroplets. Further frosting experiments shows that the surface with the lowest amount of accumulated water exhibits the best antifrosting performance, which validates our design strategy. This work offers new insights into the rational design and fabrication of antifrosting materials.

Ice formation on solid surfaces includes heterogeneous ice nucleation and ice propagation processes. However, no study has been focused on tuning of both ice nucleation and ice propagation via a simple anti-icing coating method. In this work, we have prepared multilayer hydrogels based on simple layer-by-layer (LBL) deposition approach and discover the ion-specific effect on both ice nucleation and ice propagation. A large ice nucleation temperature window of 11 °C is controlled via changing different counterions; meanwhile, the differences in ice propagation time can be tuned up to 4 orders of magnitude. Through synergistically controlling of ice nucleation and propagation delay times, we can tune the freezing delay time of water droplets on multilayer hydrogel surfaces up to 3 orders of magnitude via changing various counterions. Considering the application requirements, these multilayer hydrogels are stable under different conditions and can be coated on various materials without destroying the existing surface. This new insight can inspire the design of anti-icing surfaces based on regulating both ice nucleation and ice propagation.

The Central Tianshan Block is one of the major continental constituents of the Central Asian Orogenic Belt (CAOB) and contains vital information for understanding the amalgamation of the Eurasia continent. Its tectonic affinity remains controversial hindering a better reconstruction of the paleogeographic evolution of the Paleo-Asian Ocean and geodynamic processes of the CAOB. In order to put more constraints on the Precambrian basement composition and crustal evolution of the Central Tianshan Block, we conducted field structural investigations and zircon U-Pb dating on the meta-sedimentary and meta-igneous rocks along the Wulasitai – Wulanmoren ductile shear zone (WWSZ), northern Baluntai area (NW China). The WWSZ is geometrically a SE-NW-striking high-strain deformation zone of ∼1–5 km wide. It is lithologically composed of greenschists, paragneiss, amphibolitic metabasalts, migmatitic granites and mylonitic granites. The greenschist to amphibolite facies meta-sandstones and meta-volcanic rocks belong to the Ahebulake Group, in which NE- or SW-dipping steep mylonitic foliations and sub-horizontal lineations are well developed. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) U-Pb dating of detrital zircons from four representative meta-sedimentary rocks from the Ahebulake Group yielded several major age groups of 3130–2530 Ma, 2450–2150 Ma, 2000–1700 Ma, 1620–1433 Ma, 1170–655 Ma, ∼450 Ma, ∼425 Ma, ∼400 Ma, ∼360 Ma and ∼312 Ma. Three ductilely deformed and metamorphosed granitic samples show four major zircon U-Pb age peaks at ∼430 Ma, ∼400–390 Ma, ∼360 Ma and ∼330 Ma. On the basis of a careful analysis of the texture of the dated zircons and the structural features of their host rocks, and combined with the available isotopic ages and regional geological data, we propose that: (1) meta-sedimentary rocks from the Ahebulake Group were likely deposited later than about 400 Ma instead of in the Silurian, as previously assumed; (2) the distinct Neoproterozoic detrital zircon age population in these meta-sediments probably reflects the widespread occurrence of coeval in-situ basement rocks as source; (3) the Central Tianshan Block may have close tectonic affinities with both the Yili Block and the Tarim Craton during the Proterozoic; and (4) the ductile shearing along the WWSZ is likely later than ∼330 Ma, probably initiated at ∼312–299 Ma. Our new results provide further arguments for the paleogeographic linkage of the microcontinents within the Paleo-Asian Ocean and tectonic reconstruction of the southwestern CAOB.

Background Male fertility is crucial for rice yield, and the improvement of rice yield requires hybrid production that depends on male sterile lines. Although recent studies have revealed several important genes in male reproductive development, our understanding of the mechanisms of rice pollen development remains unclear. Results We identified a rice mutant oslap6 with complete male sterile phenotype caused by defects in pollen exine formation. By using the MutMap method, we found that a single nucleotide polymorphism (SNP) variation located in the second exon of OsLAP6/OsPKS1 was responsible for the mutant phenotype. OsLAP6/OsPKS1 is an orthologous gene of Arabidopsis PKSA/LAP6, which functions in sporopollenin metabolism. Several other loss-of-function mutants of OsLAP6/OsPKS1 generated by the CRISPR/Cas9 genomic editing tool also exhibited the same phenotype of male sterility. Our cellular analysis suggested that OsLAP6/OsPKS1 might regulate pollen exine formation by affecting bacula elongation. Expression examination indicated that OsLAP6/OsPKS1 is specifically expressed in tapetum, and its product is localized to the endoplasmic reticulum (ER). Protein sequence analysis indicated that OsLAP6/OsPKS1 is conserved in land plants. Conclusions OsLAP6/OsPKS1 is a critical molecular switch for rice male fertility by participating in a conserved sporopollenin precursor biosynthetic pathway in land plants. Manipulation of OsLAP6/OsPKS1 has potential for application in hybrid rice breeding. Electronic supplementary material The online version of this article (doi: 10.1186/s12284-017-0191-0) contains supplementary material, which is available to authorized users.

Control of heterogeneous ice nucleation (HIN) on foreign surfaces is of great importance for anti-ice-nucleation material design. In this work, we studied the HIN behaviors on various ion-modified poly(butylene succinate) (PBS) surfaces via chain-extension reaction. Inspired by antifreeze proteins (AFPs), the PBS-based polyampholytes, containing both negative and positive charge groups on a single chain, show excellent performance of ice nucleation inhibition and freezing delay. Unlike the extremely high price and low availability of AFPs, these PBS-based polyampholytes can be commercially synthesized under mild reaction conditions. Through water freezing tests on a wide range of substrates at different temperatures, these PBS-based polyampholytes have shown application value of tuning ice nucleation via a simple spin-coating method.

Ice propagation is of great importance to the accumulation of ice/frost on solid surfaces. However, no investigation has been reported on the tuning of ice propagation through a simple coating process. Herein, we study the ice propagation behavior on polyelectrolyte multilayer (PEM) surfaces coated with the layer-by-layer (LBL) deposition approach. We discover that ice propagation is strongly dependent on the amount of water in the outermost layer of PEMs, that is, the ice propagation rate increases with the amount of water in the outermost layer. The ice propagation rate can be tuned by up to three orders of magnitude by changing the polyelectrolyte pairs, counterions of the outermost polymer layer, or the salt concentration during the preparation of PEMs. Because the simple, versatile, and inexpensive LBL deposition approach is generally applicable to almost all available surfaces, the PEM coatings can tune ice propagation on a wide range of substrates.

A series of Ce 3+ , Tb 3+ co-doped Na 6 Ca 3 Si 6 O 18 phosphors have been synthesized by traditional solid state reaction. The emission spectra of the Na 6 Ca 3 Si 6 O 18 :Ce 3+ ,Tb 3+ phosphors show a blue broad band at 450 nm of the Ce 3+ and a green line peaking at 550 nm. Energy transfer from Ce 3+ to Tb 3+ ions has been investigated. Results indicate that the color of these phosphors changes from blue to green by adjusting the ratio of Ce 3+ to Tb 3+ . In addition, the mechanism of the energy transfer from the Ce 3+ to Tb 3+ ions is demonstrated to be a dipole-quadrupole mechanism. The energy transfer efficiency as well as the critical distance is also estimated. By optimizing the Tb 3+ concentration, the absolute PL quantum yield as high as 43% can be achieved. The results show that this phosphor has potential applications as a single-phased phosphor for UV white-light LEDs.

Samples of the Ba9 (Lu2-x Yx )Si6 O24 :Ce3+ (x = 0-2) blue-green phosphors were synthesized by solid-state reactions. All the samples exhibited a rhombohedral crystal structure. As the Y3+ concentration increased, the diffraction peaks shifted to the small angle region and the lattice parameters increased due to the larger ionic radius of Y3+ (r = 0.900 A) compared with that of Lu3+ (r = 0.861 A). Under 400 nm excitation, samples exhibited strong blue-green emissions around 490 nm. The emission bands had a slight blue shift that resulted from weak crystal-field splitting with increasing Y3+ concentration. Luminescence intensity and quantum efficiency (QE) decreased with increasing Y3+ concentration. The internal QE decreased from 74 to 50% and the external QE decreased from 50 to 34% as x increased from 0 to 2. The thermal stability of the Lu series was better than that of the Y-series. The excitation band peak around 400 nm matched well with the emission light from the efficient near-ultraviolet (NUV) chip. These results indicate promising applications for these NUV-based white light-emitting diodes.

Ice propagation is an essential step when freezing happens on hydrated surfaces. In this work, we choose polyelectrolyte brushes (PB), whose hydration ability can be controlled by simply exchanging the counterions, to demonstrate the distinct ice propagation mechanism on differently hydrated surfaces.

The Central Asian Orogenic Belt (CAOB) was built by amalgamation of diverse geologic units including several microcontinents. The nature and geodynamic evolution of the Precambrian basement of these units are essential to constrain their origin, and thus the geodynamic and paleogeographic reconstruction of the accretionary system. The Yili Block, located in the west of the Chinese Tianshan Orogen, is one of these Precambrian-based continental constituents. Field investigations, zircon U-Pb dating and Lu-Hf isotopic analysis, whole-rock geochemical and Sr-Nd isotopic studies were conducted on the gneissic granitoids from the Giergelang area, southern Yili Block. These rocks yielded early Neoproterozoic zircon U-Pb ages (962–934 Ma), containing substantial number of Paleo- to Mesoproterozoic inherited zircons (2403–1268 Ma); their protoliths belong to peraluminous high-K granite series displaying right-declining REE patterns and Eu negative anomalies together with LILE (K, Rb, U, Th) enrichment and depletions in Ba, Nb, Sr, P, Ti; they have negative eNd(t) values ranging from −2.5 to −4.7, and old Nd model ages varying from 1650 Ma to 1910 Ma; they also exhibit highly variable zircon eHf(t) values (−12.1 to 4.4), and Hf-in-zircon model ages (1558–2574 Ma). Integrating all these results, it is suggested that the primary magma of gneissic granitoids was generated by partial melting of supracrustal rocks with involvement of old crustal materials. A comparison of data from the Yili Block and its neighboring continental units reveals that the Neoproterozoic magmatic event is an important episode of crustal reworking for the major continental blocks within the CAOB. Similar Neoproterozoic magmatic events and comparable upper Neoproterozoic to lower Paleozoic stratigraphic sequences of the Yili, Chinese Central Tianshan and Tarim blocks, suggest that they had a similar crustal evolution and close tectonic and paleogeographic relation during Neoproterozoic, and were likely derived from one single continental plate.

The North Tianshan Belt (NTB) formed by the subduction and accretion of the Junggar Ocean is a key area for reconstructing the Paleozoic tectonic evolution of the southern Central Asian Orogenic Belt (CAOB). Despite numerous studies, the interpretation of the late Paleozoic tectonic evolution of the NTB meets no consensus yet. We conducted field investigations and LA-ICP-MS zircon U-Pb dating on metamorphic rocks from the Julideneng Metamorphic Complex (JMC) in the Harlik Range, which is located between the Turpan-Hami Basin to the south and the East Junggar Belt to the north. The metamorphic rocks are exposed in a NW-SE striking, ~10 km-wide belt and mainly composed of migmatites, garnet-sillimanite mica schists, andalusite schists, and low-grade meta-sandstones. Detrital zircons from the low-grade meta-sandstone yielded ages of 1400–1250, 1000–850, ~780, ~580, ~490, ~445 and ~425 Ma. Three micaschists contain zircon populations of 2500–2175, 1800–1600, 1500–1100, 1000–850, 800–500, ~475, ~425, 420–380, ~346 Ma, and a youngest age peak at ~322 Ma. Two samples of leucocratic dykes in migmatites yielded comparable age populations with two major peaks at 322 Ma and 297 Ma, which are interpreted as two stages of successive partial melting and anatectic melts crystallization. On the basis of structural features, zircon textures and U-Pb ages, combined with already published data, we propose that: (1) the meta-sedimentary rocks of the JMC were deposited after 425 Ma and before 322 Ma (latest Silurian to late Carboniferous); (2) the Precambrian detrital zircons in the meta-sedimentary rocks were probably derived from the Central Tianshan Block, which was once connected with the NTB; and (3) the migmatization and coeval granitic plutonism occurred at ~322–297 Ma (late Carboniferous), most likely associated with crustal thinning resulted from continent-based intra-arc or back-arc or post-orogenic extension.

The selective area growth (SAG) technique has been proved to be an effective method to achieve trench gate normally-off AlGaN/GaN MOSFET. In this paper, the two-dimensional electron gas (2DEG) transport properties of SAG AlGaN/GaN heterostructure are investigated for samples with different insertion layers. As the thickness of the GaN insertion layer increases, the mobility of 2DEG drops at first and then increases dramatically. This is explained by a shift of the location of the 2DEG from the GaN template into the GaN insertion layer. Interface contamination at the template/insertion layer interface is found to be the reason of the degradation of the transport properties. Through optimizing the thickness of the SAG GaN insertion layer, 2DEG mobility is similar to the value of as-grown AlGaN/GaN heterostructure. The proper thickness of SAG GaN insertion layer for device fabrication is 24 nm referring to the variation in 2DEG transport properties.

The influence of different AlGaN Impurity Blocking Layer (IBL) thickness in the GaN/Si (111) structure with GaN/AlN SLs buffer on the material and electrical properties of GaN/Si (111) system was studied in detail. It is found that the insertion of AlGaN IBL can increase the (102) FWHM and decrease the (002) FWHM. Meanwhile, AlGaN IBL with an optimized thickness can further improve the surface roughness and strain-state of GaN-Si (111) system. By using Secondary Ion Mass Spectroscopy, it is found that AlGaN IBL have a strong effect in blocking the Si donor impurities originating from the Si substrate during the high temperature growth, which can decrease the leakage current while the breakdown voltage can be dramatically increased.

A series of bimetallic PdAg catalysts on an activated carbon support were prepared and assessed for the direct synthesis of hydrogen peroxide from hydrogen and oxygen. The ensemble effect and electronic effect between Pd and Ag were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), and temperature-programmed desorption of H2/O2 (H2-/O2-TPD), etc. Our results showed that the Ag additive increased the monomeric Pd sites which were the primary active sites for H2O2 formation. In addition, the content of Pd2+ was increased via the electronic interaction between Pd and Ag, which prevented the decomposition and hydrogenation of H2O2 to some extent. Therefore, the selectivity of this reaction was increased using bimetallic PdAg catalysts, as compared with the monometallic Pd catalyst. The optimal PdAg-40 catalyst achieved a H2O2 productivity of 7022 mol kgPd−1 h−1 and a high selectivity of 70.9%, which were superior to those of the Pd/C catalyst.

High temperature operation(HTO) experiments were performed on industrial GaN HEMTs devices. Several degradation failure modes of DC parameters such as transconductance reduction, threshold voltage shift, and gate leakage current increase were identified. The vertical failure localization and analysis of the devices were carried out by electrical method. The results show that the increase of the degradation of the die attach layer is the main reason for the increase of the junction temperature and thermal resistance of the devices. Furthermore, the results are analyzed by three-dimensional X-ray imaging confirming the degradation of the die attach layer. The voids in the die attach layer expanded during the high temperature operation stress experiments, led to a worse heat dissipation performance, which resulting in increased junction temperature, and further accelerate the performance degradation of the devices.

Deep neural networks can model images with rich latent representations, but they cannot naturally conceptualize structures of object categories in a human-perceptible way. This paper addresses the problem of learning object structures in an image modeling process without supervision. We propose an autoencoding formulation to discover landmarks as explicit structural representations. The encoding module outputs landmark coordinates, whose validity is ensured by constraints that reflect the necessary properties for landmarks. The decoding module takes the landmarks as a part of the learnable input representations in an end-to-end differentiable framework. Our discovered landmarks are semantically meaningful and more predictive of manually annotated landmarks than those discovered by previous methods. The coordinates of our landmarks are also complementary features to pretrained deep-neural-network representations in recognizing visual attributes. In addition, the proposed method naturally creates an unsupervised, perceptible interface to manipulate object shapes and decode images with controllable structures. The project webpage is at http://ytzhang.net/projects/lmdis-rep, Comment: 48 pages

Bulk-like interfacial water, a sub-ensemble of interfacial water, can be a predictor for heterogeneous ice nucleation., Establishing a direct correlation between interfacial water and heterogeneous ice nucleation (HIN) is essential for understanding the mechanism of ice nucleation. Here, we study the HIN efficiency on polyvinyl alcohol (PVA) surfaces with different densities of hydroxyl groups. We find that the HIN efficiency increases with the decreasing hydroxyl group density. By explicitly considering that interfacial water molecules of PVA films consist of “tightly bound water,” “bound water,” and “bulk-like water,” we reveal that bulk-like water can be correlated directly to the HIN efficiency of surfaces. As the density of hydroxyl groups decreases, bulk-like water molecules can rearrange themselves with a reduced energy barrier into ice due to the diminishing constraint by the hydroxyl groups on the PVA surface. Our study not only provides a new strategy for experimentally controlling the HIN efficiency but also gives another perspective in understanding the mechanism of ice nucleation.

Transparent tubes with functions of heating and temperature measurement are badly required in the visualization investigation of two-phase flows and flow-boiling heat transfer. In order to prepare such a tube, we introduced a cost-effective and energy-efficient procedure of hypergravity-assisted chemical liquid deposition (HACLD) to produce transparent and conductive silver (Ag) films on the inner surfaces of quartz tubes, typically 50 mm in length and 8 mm in inner diameter with a set-up that was designed and built for this purpose. Precursors of organometallic Ag precursor solutions were prepared by dissolving silver citrate and 1,2-diaminopropane in 2-methoxyethanol with required concentration for the chemical liquid deposition process. Semitransparent and conductive Ag films formed inside the required quartz tubes under specific heating process in hypergravity. One of the films was about 47 nm in thickness, 23 Ω per square sheet resistance, and 30% optical transmittance. This attempt may pave a way for the understanding of the film forming mechanism in hypergravity, and the development of a film preparation technology of HACLD.

Pollen development in flowering plants is critical for male reproductive success. The pollen wall that protects the pollen from various environment stresses and bacterial infections plays an essential role in pollen development. The formation of pollen wall is associated with the biosynthesis and transport of sporopollenin components. ACOS5 in Arabidopsis encodes an acyl-CoA synthetase 5 required for sporopollenin biosynthesis. We identified the rice homolog of ACOS5 as OsACOS12. The CRISPR/Cas9-mediated OsACOS12 knockout mutant has complete male sterility due to a defect in pollen wall formation. β-Glucuronidase reporter gene analysis and RNA in situ hybridization indicated that OsACOS12 was specifically expressed in tapetum and microspores. The subcellular localization of OsACOS12-YFP demonstrated that OsACOS12 protein was primarily localized in the endoplasmic reticulum and nucleus. Our results suggest that OsACOS12 plays a critical and conserved role in pollen wall formation and pollen development and has implications in rice breeding.

Associating image regions with text queries has been recently explored as a new way to bridge visual and linguistic representations. A few pioneering approaches have been proposed based on recurrent neural language models trained generatively (e.g., generating captions), but achieving somewhat limited localization accuracy. To better address natural-language-based visual entity localization, we propose a discriminative approach. We formulate a discriminative bimodal neural network (DBNet), which can be trained by a classifier with extensive use of negative samples. Our training objective encourages better localization on single images, incorporates text phrases in a broad range, and properly pairs image regions with text phrases into positive and negative examples. Experiments on the Visual Genome dataset demonstrate the proposed DBNet significantly outperforms previous state-of-the-art methods both for localization on single images and for detection on multiple images. We we also establish an evaluation protocol for natural-language visual detection., Comment: IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2017

The concept of critical nitrogen (Nc) concentration can be implemented to diagnose in-season plant nitrogen (N) status for optimizing N fertilizer management. The Nc dilution curves have been established for rice (Oryza sativa L.) grown in different climatic regions, yet no attempt has been made to develop the Nc dilution curve for double cropping rice regions. This study was undertaken to develop the Nc dilution curves for double cropping rice in south China for assessment of in-season N status and to establish the relationships N nutrition index (NNI) and relative yield (RY) for in-season prediction of rice grain yield. Three different N application rate field experiments using six Indica rice varieties, including two early rice hybrids and four late rice hybrids were carried out in east China. The Nc dilution curves based on whole plant N concentration were determined and described as, Nc = 3.37 W−0.44 for early rice and Nc = 3.69 W−0.34 for late rice. The constant N concentration at early growth stage was 3.31 and 3.15% DM for early and late rice, respectively. Late rice showed a higher capacity of N accumulation and a lower rate of N decline per unit shoot biomass as compared to early rice. The curves for present study were different from the existing reference curves for Indica and Japonica rice grown in different rice growing regions. Integrated N nutrition index (NNIint) based on Nc was used to estimate RY at different growth periods using linear regression functions. The results showed that the critical curves and relationship between NNIint and RY could be used as a reliable indicator of N status diagnosis, grain yield prediction as well as to provide technical support in N management for double cropping rice in south China.

In this work, the electrical properties of AlGaN/GaN heterostructure grown on Si substrate with low-temperature AlN (LT-AlN) interlayers were investigated. Hall effect measurement was used to test the electrical properties of AlGaN/GaN heterostructure in all samples with different LT-AlN thickness. It is showed that the thickness of low-temperature AlN interlayers in the bufferlayer obviously effect the electrical properties of two-dimensional electron gas (2DEG) in the heterostructure channel. The sample with 15 nm LT-AlN interlayers reached the maximum electron mobility of 4090 cm2/Vs. Combined with XRD and AFM measurements, it is found that the dislocation density, surface roughness and stress conditions determined the electrical properties of 2DEG.

This work is the first to show that the ion specificity in tuning HIN on ionic surfaces follows the Hofmeister series., Heterogeneous ice nucleation (HIN) on ionic surfaces is ubiquitous in a wide range of atmospheric aerosols and at biological interfaces. Despite its great importance in cirrus cloud formation and cryopreservation of cells, organs, and tissues, it remains unclear whether the ion-specific effect on ice nucleation exists. Benefiting from the fact that ions at the polyelectrolyte brush (PB)/water interface can be reversibly exchanged, we report the effect of ions on HIN on the PB surface, and we discover that the distinct efficiency of ions in tuning HIN follows the Hofmeister series. Moreover, a large HIN temperature window of up to 7.8°C is demonstrated. By establishing a correlation between the fraction of ice-like water molecules and the kinetics of structural transformation from liquid- to ice-like water molecules at the PB/water interface with different counterions, we show that our molecular dynamics simulation analysis is consistent with the experimental observation of the ion-specific effect on HIN.