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Interneuronal subtype diversity lies at the heart of the distinct molecular properties and synaptic connections that shape the formation of the neuronal circuits that are necessary for the complex spatial and temporal processing of sensory information. Here, we investigate the role of Irx6, a member of the Iroquois homeodomain transcription factor family, in regulating the development of retinal bipolar interneurons. Using a knock-in reporter approach, we show that, in the mouse retina, Irx6 is expressed in type 2 and 3a OFF bipolar interneurons and is required for the expression of cell type-specific markers in these cells, likely through direct transcriptional regulation. In Irx6 mutant mice, presumptive type 3a bipolar cells exhibit an expansion of their axonal projection domain to the entire OFF region of the inner plexiform layer, and adopt molecular features of both type 2 and 3a bipolar cells, highlighted by the ectopic upregulation of neurokinin 3 receptor (Nk3r) and Vsx1. These findings reveal Irx6 as a key regulator of type 3a bipolar cell identity that prevents these cells from adopting characteristic features of type 2 bipolar cells. Analysis of the Irx6;Vsx1 double null retina suggests that the terminal differentiation of type 2 bipolar cells is dependent on the combined expression of the transcription factors Irx6 and Vsx1, but also points to the existence of Irx6;Vsx1-independent mechanisms in regulating OFF bipolar subtype-specific gene expression. This work provides insight into the generation of neuronal subtypes by revealing a mechanism in which opposing, yet interdependent, transcription factors regulate subtype identity.

We have investigated the selective photoactivated room temperature chemical vapor deposition (CVD) of aluminum (Al) on functionalized self-assembled monolayers adsorbed on Au. The CVD precursor employed is trimethyl aluminum (TMA). Using a deuterium arc lamp we demonstrate that the rate of the Al film growth is approximately twice that observed for nonphotoactivated Al chemical vapor deposition (CVD) using TMA. At the wavelengths employed, the photolysis of TMA leads to the dissociation of the TMA dimer to its monomer followed by successive release of methyl groups to form (CH(3))(3-x)Al. The photogenerated (CH(3))(3-x)Al species react with -OH- and -COOH-terminated SAMs but not -CH(3)-terminated SAMs. Using these reactions we demonstrate that aluminum can be selectively deposited on -CH(3)/-COOH-patterned SAMs. The possible reaction mechanisms involved in the Al film growth are discussed. These results indicate that photoactivated CVD (laser CVD) processes are suitable for the deposition of stable films of metals and other materials on organic films.

Great progress has been made in the controlled fabrication of nanomaterials with given sizes, shapes, and geometries. However, how such changes in structure potentially affect the bioavailability and toxicity of metal nanoparticles to aquatic organisms remains mostly unknown. The present study reports the different behaviors of two types of Cu2O micro/nanocrystals (micro/nano-Cu2O) with different shapes (cubic and octahedral) and crystallographies (with exposed surfaces as {100} or {111}). The bioaccumulation, median lethal concentration, and biomarker responses of Daphnia magna exposed to the two micro/nanocrystals are also investigated. The Cu accumulation, production of metallothionein (MT), and inhibition ratio of D. magna increased gradually with increasing micro/nano-Cu2O concentration. The two crystals showed slight Cu accumulation differences toward D. magna, and their biomarker responses and toxicities to D. magna differed significantly as well. The octahedral Cu2O micro/nanocrystals were more toxic to D. magna compared with the cubic micro/nanocrystals probably because of the higher surface activities of the {111} facets compared with those of the {100} facets for cuprites. Food ingestion was the main entry pathway of the micro/nanocrystals into organisms, and toxicity was consequently determined based on the dissolution behavior of the micro/nanocrystals in vivo.

The synthesis of polycrystalline aluminum oxynitride (AlON) powders was investigated by the carbothermal reduction and nitridation (CRN) of amorphous precursor obtained by wet chemical processing. Co-precipitation processing was employed to achieve amorphous precursor from Al(NO3)3 solution dispersed by nanosized carbon particles, which was composed of Al(OH)3 and C particles homogeneously. The effects of the content of carbon black, pH value, and calcination temperature on formation of AlON phase were investigated by means of XRD, SEM and TEM, respectively. It was found that single phase AlON powder could be synthesized when the resultant precursors were calcined at 1750°C for 2 hours under flowing N2. Under optimal additional content of C (5.6wt%), the resultant AlON powders exhibited the primary particle size of about 1–3 μm with a specific surface area of 3.2 m2/g, which were superior to that of carbothermal reduction of immediate mixture of γ-Al2O3/C powders.

In a photoelectrochemical (PEC) cell for water splitting, the critical issue is charge separation and transport, which is usually completed by designing semiconductor heterojunctions. TiO2 anatase-rutile mixed junctions could largely improve photocatalytic properties, but impairs PEC water splitting performance. We designed and prepared two types of TiO2 heterostructures with the anatase thin film and rutile nanowire phases organized in different sequences. The two types of heterostructures were used as PEC photoanodes for water splitting and demonstrated completely opposite results. Rutile nanowires on anatase film demonstrated enhanced photocurrent density and onset potential, whereas strong negative performance was obtained from anatase film on rutile nanowire structures. The mechanism was investigated by photoresponse, light absorption and reflectance, and electrochemical impedance spectra. This work revealed the significant role of phase sequence in performance gain of anatase-rutile TiO2 heterostructured PEC photoanodes.

Dye-sensitized solar cell (DSSC) is a promising solution to global energy crisis and environmental problems owing to its easy fabrication, good durability and environmental friendliness. A DSSC consists of several components, the most prominent being an oxide semiconductor-based photoanode, a dye, an electrolyte and a counter electrode. Pt-loaded conducting glass has been widely exploited as the standard counter electrode for DSSCs. However, the high cost and the rarity of Pt limits the commercial applications of DSSCs. Therefore, developing high-efficient counter electrode materials to replace Pt has become research hotspot. Recently, carbon nanostructures have been demonstrated to be promising counter electrode materials for DSSCs due to its high electrochemical activity, low cost and high corrosion resistance. Transition metal sulfides have also found their application in DSSCs as counter electrodes. Particularly, ternary transition metal sulfide (CoNi2S4) has high electronic conductivity and redox ability due to the existence of cobalt and nickel ions. Therefore, it is expected that high conversion efficiency would be achieved by employing the carbon and CoNi2S4 nanostructured composites as counter electrodes.

The WNx precursor WN(NMe2)3 was prepared from WN(OtBu)3 and Zr(NMe2)4 by using an amide/alkoxide exchange reaction. Structural analysis of WN(NMe2)3 revealed an overall pseudo-tetrahedral geometry with a distortion towards trigonal pyramidal. Aerosol-assisted chemical vapor deposition (AACVD) from WN(NMe2)3 resulted in deposition of WNx nanospheres onto Si(100) and Si(111) substrates at low temperatures (75–125 °C). The nanospheres were imaged by SEM and characterized by using energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). These preliminary results demonstrate the viability of WN(NMe2)3 as a single-source precursor for the deposition of WNx at low temperature.

We address multipole surface solitons occurring at the interface between a linear medium and a nonlocal nonlinear medium. We show the impact of nonlocality, the propagation constant, and the linear index difference of two media on the properties of the surface solitons. We find that there exist a threshold value of the degree of the nonlocality at the same linear index difference of two media, only when the degree of the nonlocality goes beyond the value, the multipole surface solitons can be stable.

We address two-dimensional surface solitons occurring at the interface between a semi-infinite linear medium and a semi-infinite nonlocal nonlinear medium. We find that there exist stable single and dipole surface solitons. The properties of the surface solitons can be affected by the degree of nonlocality. Interestingly, only when the degree of nonlocality is greater than a critical value, the surface solitons can exist.

We have investigated the selective electroless deposition (ELD) of Cu on functionalized self-assembled monolayers (SAMs). Previous studies have demonstrated that Cu deposits on -COOH and -CH(3) terminated SAMs using ELD. However, the deposited films were rough and contained irregular crystallites. Further, the copper penetrated through the film. In this Article, we demonstrate that copper can be selectively deposited on -COOH terminated SAMs with improved morphology and without penetration of copper through the organic layer. The method employs a Cu(II) seed layer and an additive, adenine or guanine. We demonstrate the efficacy of the technique on photopatterned -CH(3)/-COOH SAMs. Copper is observed to deposit only atop the -COOH terminated SAM area and not on the -CH(3) terminated SAM. The use of a Cu(II) seed layer increased the Cu ELD rate on both -COOH and -CH(3) terminated SAMs. The deposited copper layer strongly adheres to the -COOH terminated SAMs because the copper layer nucleates at Cu(2+)-carboxylate complexes. In contrast, the deposited copper layer can easily be removed from the -CH(3) terminated SAM surface because there is no specific copper-surface interaction. The additives adenine and guanine mediate the interaction of Cu(2+) and the deprotonated -COOH terminated SAMs via the formation of additive-carboxylate complexes. These complexes lead to significantly reduced copper penetration through the SAM. In the case of adenine, the diffusion of copper through the organic film was eliminated. This new technique for copper deposition will facilitate the development of inexpensive molecular electronics, sensors, and other nanotechological devices.

We investigate numerically surface-wave solitons occurring at the interface between semi-infinite linear and thermal nonlinear optical media, with the refractive index of the linear medium being greater than that of the nonlinear medium (in the absence of light). We find that the threshold energy flows of the existence of the surface solitons depend on the linear refractive index difference of the two media. Their fitting empirical formula has been obtained. Furthermore, we elucidate that the optical beams propagating in thermal nonlinear optical media, either as a single surface soliton or as a dipole surface soliton, can be attracted to the surface, even when launched from far away.

Target irradiation uniformity is very important in laser-produced plasmas experiments. The wavelength dependence of the irradiation uniformity is investigated in the joint scheme using a lens array (LA) and the technique of smoothing by spectral dispersion (SSD). It is proved that, for the long wavelength laser, lateral thermal conduction smoothing within the target is quite effective, while for the ultraviolet laser, SSD is the main smoothing mechanism. So SSD and other temporal smoothing methods are very necessary in producing uniform irradiation with laser beam of short wavelength.

Using CdSe chemical bath deposition (CBD) we demonstrate the selective growth and deposition of monodisperse nanoparticles on functionalized self-assembled monolayers (SAMs) using time-of-flight secondary ion mass spectrometry and scanning electron microscopy. We show that the deposition mechanism involves both ion-by-ion growth and cluster-by-cluster deposition. On –COOH terminated SAMs strongly adherent CdSe nanoparticles form via a mixed ion-by-ion and cluster-by-cluster mechanism. Initially, Cd 2+ ions form complexes with the terminal carboxylate groups. The Cd 2+ -carboxylate complexes then act as the nucleation sites for the ion-by-ion growth of CdSe. After a sufficient concentration of Se 2− has formed in solution via the hydrolysis of selenosulfate ions, the deposition mechanism switches to cluster-by-cluster deposition. On –OH and –CH 3 terminated SAMs monodisperse CdSe nanoparticles are deposited via cluster-by-cluster deposition and they do not bind strongly to the surface. Finally, under the appropriate experimental conditions we demonstrate the selective deposition of CdSe nanoparticles on patterned –CH 3 /–COOH SAMs.

Plasma-based flow control is one of the most promising techniques for aerodynamic problems, such as delaying the boundary layer transition. The boundary layer’s characteristics induced by AC-DBD plasma actuators and applied by the actuators to delay the boundary layer transition on airfoil at Ma = 0.3 were experimentally investigated. The PIV measurement was used to study the boundary layer’s characteristics induced by the plasma actuators. The measurement plane, which was parallel to the surface of the actuators and 1 mm above the surface, was involved in the test, including the perpendicular plane. The instantaneous results showed that the induced flow field consisted of many small size unsteady vortices which were eliminated by the time average. The subsequent oil-film interferometry skin friction measurement was conducted on a NASA SC(2)-0712 airfoil at Ma = 0.3. The coefficient of skin friction demonstrates that the plasma actuators successfully delay the boundary layer transition and the efficiency is better at higher driven voltage.

Classical electromagnetic theory is applied to determine the eigenvalue equation and the fields of the allowed guided modes in a symmetric metal-clad planar uniaxial crystal waveguide for an arbitrary orientation of the optical axes. There are different hybrid guided modes in the different uniaxial crystals. For each mode, the conditions for their existence, the dispersion equation, and the accuracy of the solutions of the modal fields are analytically discussed. We report the propagation conditions and the asymmetry of various electric field distributions of the single modes.

Reservoir method is applied to the feed-forward learning machines for nonlinear regression estimation. Inspired by the existing experience from extreme learning machine (ELM), the new method inherits the basic idea from support vector echo-state machines, but eliminates the internal feedback matrix to adapt for the feed-forward usage. Based on the analysis of nonlinearity in reservoir and regularization in readout weights, the parameters of input scaling and penalty regularization are taken as the hyper-parameters to characterize a static reservoir (ELM), and then a proper reservoir is identified on the @c-C plane based on a generalization error criterion. For outlier suppression, the regularized robust regression is applied in the reservoir feature space, and it leads to an efficient algorithm for large-scale problems, which can be solved by Cholesky decomposition. The proposed method is compared with the classical kernel method and ELM method on several benchmark nonlinear regression datasets, and the results indicate the method is comparable with the existing methods.

As combat aircraft becomes more and more maneuverable, the need to understand the unsteady behavior of aircraft in dynamic flow fields becomes more important. Usually researchers pay more attention to the effects on the changes of AOA, but ignore the effects of velocity variations. It is known that the velocity of aircraft changes greatly when the aircraft undergoes a high angle of attack maneuver, like "cobra" maneuver. To completely simulate and study the effect of rapid changes in both free stream velocity and angle of attack, a pitching motion setup is developed in the unsteady wind tunnel of NUAA. By measuring unsteady loads, unsteady pressure distribution and flow visualization, the unsteady aerodynamic behavior of a pitching isolated delta wing and the pitching delta wing coupled with unsteady free stream are investigated. It is found that the oscillating free stream velocity affects the hysteresis characteristics of the pitching delta wing further. The pressure distribution and flow visualization measurements show that the changes in the structure of the leading-edge vortices are the main reason. These studies conclude that a good understanding of the unsteady aerodynamics is vitally important in the design of super-maneuverable aircraft.

The experimental results show that there are two growth modes of crystalline metal oxide in the colloidal crystal template, which depend on the quality of the colloidal crystal. In well-ordered col...

A novel chaotic time-series prediction method based on support vector machines (SVMs) and echo-state mechanisms is proposed. The basic idea is replacing "kernel trick" with "reservoir trick" in dealing with nonlinearity, that is, performing linear support vector regression (SVR) in the high-dimension "reservoir" state space, and the solution benefits from the advantages from structural risk minimization principle, and we call it support vector echo-state machines (SVESMs). SVESMs belong to a special kind of recurrent neural networks (RNNs) with convex objective function, and their solution is global, optimal, and unique. SVESMs are especially efficient in dealing with real life nonlinear time series, and its generalization ability and robustness are obtained by regularization operator and robust loss function. The method is tested on the benchmark prediction problem of Mackey-Glass time series and applied to some real life time series such as monthly sunspots time series and runoff time series of the Yellow River, and the prediction results are promising.

In this paper, the influences of strake wing on unsteady characteristics of aircraft at high angle of attack during rolling oscillation, yawing oscillation, and coupled motion at different frequencies is investigated by using a forced oscillation test rig. The experiments include dynamic force and flow field measurements. As the results show, the rolling moments are affected by the vortices generated by the strake wing. The rolling moment is large and shows strong hysteresis both in the rolling and yawing oscillations. The value of the rolling moment coefficient is small in the coupled motion. The change of the rolling moment is related to the unsteady development of the strake vortices. The characteristics are almost the same for the yawing moment, which may mainly be affected by the sideslip angle. This paper is for the aerodynamic configuration design and the flight control design using flow control method.

The counter electrode has a great influence on the performance of the dye-sensitized solar cells (DSSCs). The research and development of Pt-free counter electrode is becoming one of the hot areas in the field of DSSCs. Herein, we successfully synthesized a ternary metal sulfide (CoNi2S4) nanostructure on FTO substrate by hydrothermal method and investigated its application as counter electrode. The as-synthesized sample could exhibit better electrocatalystic property than that of Pt, and corresponding DSSCs have comparable conversion efficiency with typical Pt catalyzed cells. The easy synthesis, low cost and excellent electrocatalytic property may help the CoNi2S4 nanostructure stand out as an alternative counter electrode in DSSCs.

We have developed a method by which to selectively and reproducibly deposit ZnO films on functionalized self-assembled monolayers (SAMs) using chemical bath deposition (CBD). The deposition bath is composed of zinc acetate and ethylenediamine. The deposition reaction pathways are shown to be similar to those observed for sulfides and selenides, even though ethylenediamine acts as both an oxygen source and a complexing agent. On -COOH terminated SAMs, Zn-carboxylate surface complexes act as nucleation sites for ion-by-ion growth, leading to the formation of adherent ZnO nanocrystallites. Cluster-by-cluster growth is also observed, which produces weakly adherent micrometer-sized ZnO crystallites. On -CH3 and -OH terminated SAMs, only micrometer-sized ZnO crystallites are observed because Zn(2+) does not complex with the SAM terminal group, preventing nucleation of the nanocrystalline phase. The application of either ultrasound ("sonication-assisted CBD") or stirring promotes ion-by-ion ZnO growth on -COOH terminated SAMs. Stirring produces smoother but less reproducible ZnO films than sonication-assisted CBD.

We report on the nonlocal fundamental defect soliton in parity-time (PT)-symmetric superlattices with defocusing nonlinearity. For positive defect, soliton exist in the second gap, the first gap and the semi-infinite gap. They can be stable in the low power region in the first gap and semi-infinite gap. For negative defect, defect solitons only exist in the second gap, and can also be stable in the low power region. The degree of nonlocality can significantly affect the stability of these defect solitons. We also study the transverse power-flow of these defect solitons in the PT-symmetric superlattices.

We investigate the properties of gap solitons in spin–orbit-coupled Bose–Einstein condensates in mixed linear–nonlinear optical lattices. The mixed linear–nonlinear optical lattices can support parity-time (PT)-symmetric soliton solutions, and these PT-symmetric solitons can stably exist in the semi-infinite gap of linear optical lattices. The PT-symmetric gap-stripe solitons are found by increasing the strength of the spin–orbit coupling. It is found that the amplitude of the nonlinear optical lattices can significantly affect the stability of these gap and gap-stripe solitons. With an increase of the amplitude of the nonlinear optical lattices, the stable domains of the gap and gap-stripe solitons are shrunk. The unstable solitons can show unique evolution characteristics and the stability analyses are also confirmed by the evolution simulations.

The effects of the arrangement position and control parameters of nanosecond dielectric barrier discharge (NS-DBD) plasma actuators on lift enhancement for flying wing aircraft were investigated through wind tunnel experiments at a flow speed of 25 m s−1. The aerodynamic forces and moments were obtained by a six-component balance at angles of attack ranging from −4° to 28°. The lift, drag and pitching moment coefficients were compared for the cases with and without plasma control. The results revealed that the maximum control effect was achieved by placing the actuator at the leading edge of the inner and middle wing, for which the maximum lift coefficient increased by 37.8% and the stall angle of attack was postponed by 8° compared with the plasma-off case. The effects of modulation frequency and discharge voltage were also investigated. The results revealed that the lift enhancement effect of the NS-DBD plasma actuators was strongly influenced by the modulation frequency. Significant control effects were obtained at f = 70 Hz, corresponding to F + ≈ 1. The result for the pitching moment coefficient demonstrated that the plasma actuator can induce the reattachment of the separation flows when it is actuated. However, the results indicated that the discharge voltage had a negligible influence on the lift enhancement effect.

Chemical vapor deposition (CVD) is an attractive technique for the metallization of organic thin films because it is selective and the thickness of the deposited film can easily be controlled. However, thermal CVD processes often require high temperatures which are generally incompatible with organic films. In this paper, we perform proof-of-concept studies of photochemical CVD to metallize organic thin films. In this method, a precursor undergoes photolytic decomposition to generate thermally labile intermediates prior to adsorption on the sample. Three readily available Ru precursors, CpRu(CO)2Me, (η3-allyl)Ru(CO)3Br, and (COT)Ru(CO)3, were employed to investigate the role of precursor quantum yield, ligand chemistry, and the Ru oxidation state on the deposition. To investigate the role of the substrate chemistry on deposition, carboxylic acid-, hydroxyl-, and methyl-terminated self-assembled monolayers were used. The data indicate that moderate quantum yields for ligand loss (φ ≥ 0.4) are required for ruthenium deposition, and the deposition is wavelength dependent. Second, anionic polyhapto ligands such as cyclopentadienyl and allyl are more difficult to remove than carbonyls, halides, and alkyls. Third, in contrast to the atomic layer deposition, acid-base reactions between the precursor and the substrate are more effective for deposition than nucleophilic reactions. Finally, the data suggest that selective deposition can be achieved on organic thin films by judicious choice of precursor and functional groups present on the substrate. These studies thus provide guidelines for the rational design of new precursors specifically for selective photochemical CVD on organic substrates.

We investigate light-beam propagation along the interface between linear and nonlinear media with parity–time symmetry. A novel class of two-dimensional localized surface modes (LSMs) is found analytically and numerically. If the potential is parity–time invariant along the direction parallel to the interface between the two media, stable LSMs can exist. Otherwise, if the potential is parity–time invariant along the direction perpendicular to the interface between the two media, there are no stable LSMs.

We report the successful growth of NiCo2S4 nanosheet films converted from NiCo2O4 nanosheet films on fluorine-doped tin oxide substrates by a low-temperature solution process. Low-cost NiCo2S4 and NiCo2O4 nanosheet films were directly used for replacing conventional Pt and NiO as counter electrodes and photocathodes, respectively, to construct all-nano p-type dye-sensitized solar cells (p-DSSCs) with high performance. Compared to Pt, NiCo2S4 showed higher catalytic activity towards the I-/I3 - redox in electrolyte, resulting in an improved photocurrent density up to 2.989 mA/cm2, which is the highest value in reported p-DSSCs. Present p-DSSCs demonstrated a cell efficiency of 0.248 % that is also comparable with typical NiO-based p-DSSCs.

ZnO nanostructures were manipulated, via a low-temperature solution process, from pure nanorod arrays to complex nanostructures of microflowers on nanorod arrays with adjusted quantities of flowers. We proposed the mechanism of local dissolution-driven growth to rationally discuss the novel growth process. These nanostructures were used as photoanodes in dye-sensitized solar cells. Compared to pure nanorod arrays, the nanorod array-microflower hierarchical structures improved the power conversion efficiency from 0.41% to 0.92%, corresponding to a 124% efficiency increase. The enhancement of the efficiency was mainly ascribed to the synergistic effect of the enhanced surface area for higher dye loading and the improved light harvesting from efficient light scattering. Present results provide a promising route to improve the capability of light-harvesting for ZnO nanorod array-based DSSCs.

We demonstrate that in-bulk vortex localized modes, and their surface half-vortex ("horseshoe") counterparts self-trap in two-dimensional (2D) nonlinear optical systems with $\mathcal{PT}$-symmetric photonic lattices (PLs). The respective stability regions are identified in the underlying parameter space. The in-bulk states are related to truncated nonlinear Bloch waves in gaps of the PL-induced spectrum. The basic vortex and horseshoe modes are built, severally, of four and three beams with appropriate phase shifts between them. Their stable complex counterparts, built of up to 12 beams, are reported too., Comment: 5 pages, 4 figures

It requests the advanced high agile combat aircrafts to have the abilities to do post-stall maneuvers today. And it is meaningful for the design of aircraft and the control law to investigate the unsteady aerodynamic characteristics of the aircraft during the maneuvers. The present work shows some wind tunnel experiment results of the unsteady aerodynamic characteristic of a delta-wing model in the lateral motions, which were roll oscillation, yaw oscillation and coupled motion( rollyaw motion), at Nanjing University of Aeronautics and Astronautics (NUAA for short). The lateral maneuvers were simulated by a two-degree-offreedom forced oscillation test rig and the unsteady force and pressure of the model were measured in the tests also including the dynamic PIV measurement. The moment results show the hysteresis in the roll and yaw oscillation apparently but not in the coupled motion. The further results of the dynamic pressure and PIV measurements show the structure of the flow field and explain the reasons of the hysteresis of the moment in the roll and yaw oscillation, which is the development of the leading edge vortexes during the oscillations. While either the results of the pressure or the PIV seem to be quasi-steady in the coupled motion. It is much clearer about the unsteady aerodynamic characteristics of the delta wing and it is meaningful to explain the reasons of the hysteresis during the maneuvers for the delta wing.

As one of the most important methods of vulnerability mining, the technology of fuzzing is developing rapidly and widely used during vulnerability analysis of various kinds of software. Nowadays, with the widespread craze of Android phones, the security of Android operating system has drawn more and more attention. However, fuzzing technology of Android is still in the beginning and professional fuzzing products of Android are unavailable. In this article, a fuzzing method of Android browser based on bitmap structure is presented. The result of experiment proves that this method is efficient in triggering Android browser crashes and can help with further work of analysis and exploitation.

Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

We numerically study the nonlocal solitons in dual-periodic parity-time ($\mathcal{PT}$) symmetric optical lattices built into a nonlocal self-focusing medium. We state the existence, stability, and propagation dynamics of such $\mathcal{PT}$-gap solitons in detail. Simulated results show that there exist stable gap solitons. The energy flow density and the stable region of the $\mathcal{PT}$-gap solitons in both the propagation constant and the degree of nonlocality are also examined.

Symbolic execution simulates program execution by replacing concrete values with symbolic variables for inputs. It could be used in software behavior analysis, vulnerability detection and software security assessment. In this paper, we analyze the path explosion problem encountered in vulnerability detection with the state-of-the-art symbolic execution technology for large scale file parsing programs. We also propose 4 alleviations to ease the problem, i.e. loop controlling, irrelevant path elimination, path selecting and parallel symbolic execution. Based on these alleviations, we implemented a prototype tool to detect file parsing vulnerability in large scale programs automatically, and evaluate it with a suit of benchmarks chosen from open source programs. Our tool detected not only all reported vulnerabilities of memory overflow in the benchmarks, but also some unreported vulnerabilities. The evaluation results show these alleviations could effectively ease the path explosion problem while analyzing large scale file parsing programs.

This study examines the potential hazard of an individual nanomaterial on the Cu biotoxicity to aquatic organisms.Daphnia magnain the absence or presence of nano-TiO2was exposed to Cu. Maintaining nano-TiO2at a safe concentration cannot eliminate its potential hazard. The biomarkers superoxide dismutase, catalase, and Na+/K+-ATPase inD. magnawere measured. Cu in the presence of nano-TiO2induced higher levels of oxidative stress and physiological damage because of the sorption of Cu. Nano-TiO2also caused Na+/K+-ATPase inhibition possibly by impeding the Na+/K+transfer channel. The correlations among the biomarkers, mortality, and accumulation further showed that the overloading reactive oxygen species generation caused by nano-TiO2contributed to deeper oxidative stress and physiological regulation, thereby causing greater toxic injury.

The room temperature atomic layerlike deposition (ALLD) of ZnS on functionalized self-assembled monolayers (SAMs) was investigated, using diethyl zinc (DEZ) and in situ generated H2S as reactants. Depositions on SAMs with three different terminal groups, –CH3, –OH, and –COOH, were studied. It was found that the reaction of DEZ with the SAM terminal group is critical in determining the film growth rate. Little or no deposition is observed on –CH3 terminated SAMs because DEZ does not react with the methyl terminal group. ZnS does deposit on both –OH and –COOH terminated SAMs, but the grow rate on –COOH terminated SAMs is ∼10% lower per cycle than on –OH terminated SAMs. DEZ reacts with the hydroxyl group on –OH terminated SAMs, while on –COOH terminated SAMs it reacts with both the hydroxyl and carbonyl bonds of the terminal groups. The carbonyl reaction is found to lead to the formation of ketones rather than deposition of ZnS, lowering the growth rate on –COOH terminated SAMs. SIMS spectra show that both –OH and –COOH terminated SAMs are covered by the deposited ZnS layer after five ALLD cycles. In contrast to ZnO ALLD where the composition of the film differs for the first few layers on –COOH and –OH terminated SAMs, the deposited film composition is the same for both –COOH and –OH terminated SAMs. The deposited film is found to be Zn-rich, suggesting that the reaction of H2S with the Zn-surface adduct may be incomplete.

User generated social annotations provide extra information for describing document contents. In this paper, we propose an effective method to model the categorization property of social annotations and explore the potential of combining it with classical language models for improving retrieval performance. Specifically, a novel TR-LDA model is presented to take annotations as an additional source for generating document contents apart from the document itself. We provide strategies for representing and weighting the categorization property and develop an efficient inference algorithm, where space saving is taken into account. Experiments are carried out on synthetic datasets, where documents and queries come from the standard evaluation conference TREC and annotations come from the website Delicious.com. Our results demonstrate the effectiveness of the proposed method on the ad-hoc retrieval task, which significantly outperforms state-of-art baselines.

Although retinal bipolar cells represent a morphologically well defined population of retinal interneurons, very little is known about the developmental mechanisms that regulate their processing. Furthermore, the identity of specific bipolar cell types that function in distinct visual circuits remains poorly understood. Here, we show that the homeobox geneVsx1is expressed in Type 7 ON bipolar cells. In the absence ofVsx1, Type 7 bipolar cells exhibit proper morphological specification but show defects in terminal gene expression.Vsx1is required for the repression of bipolar cell-specific markers, including Calcium-binding protein 5 and Chx10. This contrasts its genetic requirement as an activator of gene expression in OFF bipolar cells. To assess possible ON signaling defects inVsx1-null mice, we recorded specifically from ON-OFF directionally selective ganglion cells (DSGCs), which cofasciculate with Type 7 bipolar cell terminals.Vsx1-null ON-OFF DSGCs received more sustained excitatory synaptic input, possibly due to Type 7 bipolar cell defects. Interestingly, inVsx1-null mice, the directionally selective circuit is functional but compromised. Together, these findings indicate thatVsx1regulates terminal gene expression in Type 7 bipolar cells and is necessary for proper ON visual signaling within a directionally selective circuit.

Electroless nanowire deposition on micropatterned substrates (ENDOM) is a promising new technique by which to direct the synthesis and precise placement of metallic nanowires. ENDOM is generally applicable to the preparation of metallic, semiconducting, and even insulating nanowires on technologically relevant substrates, is inexpensive, and can achieve high growth rates. The deposited nanowires are ultralong (centimeters) and can be patterned in arbitrary shapes. We demonstrate ENDOM using the growth of nickel nanowires. By controlling the deposition time, the width of the nanowires can be varied from 200 to 1000 nm and the height can be varied from 7 to 20 nm.

We numerically study the gray solitons in parity-time (PT) symmetric potentials. Simulated results show that there are two kinds of gray solitons, the dip-shaped gray solitons and the hump-shaped solitons, and both of them can be stable. Hump-shaped solitons can always exist, but the grayness of a stable dip-shaped gray soliton should exceed a threshold value. More interesting, it is discovered that when propagating in PT symmetric potentials, the gray solitons have no transverse deviation, and this is a phenomenon different from the usual gray solitons.

Retinal bipolar cells make up a class of at least 11 distinct interneurons that have been classified through morphological and molecular approaches. Previous work has shown that the paired-like homeodomain transcription factor Vsx1 is essential for the proper development of a subset of these interneurons. In Vsx1-null mice, bipolar cells are properly specified but exhibit terminal differentiation defects characterized by reduced expression of OFF bipolar cell markers and defects in OFF visual signaling. Here, we further examined the role of Vsx1 in OFF bipolar cells using recently identified cell-type-specific markers. In contrast to its previously characterized expression in type 2 OFF bipolar cells, Vsx1 expression was not detected in type 3 OFF bipolar cells, by either immunohistological or transgenic reporter labeling approaches. This observation was unexpected given previous findings that Cabp5 immunolabeling of type 3 bipolar cell axon terminals is reduced in Vsx1-null mice. However, we observed reduced levels of the type 3a bipolar cell marker hyperpolarization-activated and cyclic nucleotide-gated channel 4 (HCN4) in Vsx1-null mice, which is consistent with a requirement for Vsx1 in type 3 bipolar cell differentiation. In contrast, expression of the type 3b bipolar cell marker regulatory subunit RII-beta of protein kinase A was unchanged. Despite the absence of Vsx1 in mature type 3 bipolar cells, colabeling of Vsx1 and HCN4 was observed at postnatal stages. These findings reveal a role for Vsx1 in type 3a bipolar cells and suggest that Vsx1 function is required transiently in this cell type during the postnatal period.