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International audience; As the field of nanocrystal-based optoelectronics matures, more advanced techniques must be developed in order to reveal the electronic structure of nanocrystals, particularly with devicerelevant conditions. So far, most of the efforts have been focused on optical spectroscopy, and electrochemistry where an absolute energy reference is required. Device optimization requires probing not only the pristine material but also the material in its actual environment (i.e., surrounded by a transport layer and an electrode, in the presence of an applied electric field). Here, we explored the use of photoemission microscopy as a strategy for operando investigation of NC-based devices. We demonstrate that the method can be applied to a variety of materials and device geometries. Finally, we show that it provides a direct access to the metal-semiconductor interface band bending as well as the distance over which the gate effect propagates in field-effect transistors.

International audience; After the use of nanocrystals as light down-converters, infrared sensing appears to be one of the first market applications where they can be used while being both electrically and optically active. Over recent years, tremendous progress has been achieved, leading to an apparent rise in the technological readiness level (TRL). So far, the efforts have been focused on PbS nanocrystals for operation in the near-infrared. Here, we focus on HgTe since its narrower band gap offers more flexibility to explore the extended shortwave and mid-wave infrared. We report a photoconductive strategy fort the design of short wave infrared focal plane array with enhanced image quality. An important aspect often swept under the rug at an early stage is the material stability. It appears that HgTe remains mostly unaffected by oxidation under air operation. The evaporation of Hg, a potentially dramatic aging process, only occurs at temperatures far beyond the focal plane array's standard working temperature. The main bottleneck appears to be the particle sintering resulting from joule heating of focal plane array. This suggests that a cooling system is required, with a first role of preventing the material from sintering even before targeting dark current reduction.

International audience; Integration of photonic structures in nanocrystal-based photodetectors has been demonstrated to improve device performances. Furthermore, bias-dependent photoresponse can be observed in such devices as a result of the interplay between hopping transport and inhomogeneous electromagnetic field. Here, we investigate the main physical concepts leading to a voltage-dependent photoresponse. We first bring evidence of bias-dependent carrier mobilities in a nanocrystal array over a wide range of temperatures. Then, we realize an infrared sensing device using HgTe nanocrystals, where the electrodes also play the role of a grating, inducing a spatially inhomogeneous absorption. The obtained device exhibits a significant bias-dependent photoresponse while possessing a competitive detection performance in the extended shortwave and mid-wave infrared, with detectivity reaching 7x10 10 Jones at 80 K and a fast response time of around 70 ns. This work provides the foundation for further advancements in nanocrystal-basedactive photonics devices.

Visible-infrared person re-identification (Re-ID) has received increasing research attention for its great practical value in night-time surveillance scenarios. Due to the large variations in person pose, viewpoint, and occlusion in the same modality, as well as the domain gap brought by heterogeneous modality, this hybrid modality person matching task is quite challenging. Different from the metric learning methods for visible person re-ID, which only pose similarity constraints on class level, an efficient metric learning approach for visible-infrared person Re-ID should take both the class-level and modality-level similarity constraints into full consideration to learn sufficiently discriminative and robust features. In this article, the hybrid modality is divided into two types, within modality and cross modality. We first fully explore the variations that hinder the ranking results of visible-infrared person re-ID and roughly summarize them into three types: within-modality variation, cross-modality modality-related variation, and cross-modality modality-unrelated variation. Then, we propose a comprehensive metric learning framework based on four kinds of paired-based similarity constraints to address all the variations within and cross modality. This framework focuses on both class-level and modality-level similarity relationships between person images. Furthermore, we demonstrate the compatibility of our framework with any paired-based loss functions by giving detailed implementation of combing it with triplet loss and contrastive loss separately. Finally, extensive experiments of our approach on SYSU-MM01 and RegDB demonstrate the effectiveness and superiority of our proposed metric learning framework for visible-infrared person Re-ID.

International audience; Nanocrystals are now established light sources, and as synthesis and device integration have gained maturity, new functionalities can now be considered. So far, the emitted light from a nanocrystal population remains mostly driven by the structural properties (composition, size, shape) of the particle, and only limited post-synthesis tunability has been demonstrated. Here, we explore the design of light amplitude modulators using a nanocrystal-based light-emitting diode operated under reverse bias. We demonstrate strong photoluminescence modulations for devices operating in the visible and near telecom wavelengths using low bias operations (

International audience; As nanocrystal-based devices gain maturity, a comprehensive understanding of their electronic structure is necessary for further optimization. Most spectroscopic techniques typically examine pristine materials and disregard the coupling of the active material to its actual environment, the influence of an applied electric field, and possible illumination effects. Therefore, it is critical to develop tools that can probe device in situ and operando. Here, we explore photoemission microscopy as a tool to unveil the energy landscape of a HgTe NC-based photodiode. We propose a planar diode stack to facilitate surface-sensitive photoemission measurements. We demonstrate that the method gives direct quantification of the diode's built-in voltage. Furthermore, we discuss how it is affected by particle size and illumination. We show that combining SnO2 and Ag2Te as electron and hole transport layers is better suited for extended-short-wave infrared materials than materials with larger bandgaps. We also identify the effect of photodoping over the SnO2 layer and propose a strategy to overcome it. Given its simplicity, the method appears to be of utmost interest for screening diode design strategies.

The hydroxyethyl cellulose (HEC) is a biocompatible and nonperishable natural compound, which makes it an ideal additive for achieving super-low friction in hydration lubrication. In this work, ultra-polished quartz glasses were used as friction pairs with a contact area as large as 50.24 mm2. The lubrication behavior of HEC solutions was studied and the topology of the friction pairs was investigated. A super-low COF of 0.0012 was achieved under lubrication of 1.00 wt.% HEC. Increasing or decreasing the dosage of HEC will lead to defective lubrication. Dehydration tests have shown that saturated salts compete for the water of the hydrated HEC and destroy the lubricating film, demonstrating the importance of hydration in achieving super-low lubrication. The XPS spectra of quartz and quartz covered with lubricant indicate that there is no chemical interaction between the quartz and HEC during the friction. However, a negative shift in the peak of O 1s lines were detected, suggesting that physical adsorption of the oxygen atoms occurs at the interface between the quartz and the lubricant. The lubrication regime was analyzed by Hamrock-Dowson theory and the ratio λ is around 1.7–24.5, which suggested that the lubrication regime was mixed lubrication or hydrodynamic lubrication. According to the experiments and discussions, possible lubrication models are proposed for HEC lubricants with different concentrations, which can contribute to the development of new hydration lubricants with superlubricity properties and are of great importance for scientific exploration and engineering applications.

An experiment of gas-non-Newtonian fluid flow was performed in a horizontal square microchannel to investigate the two-phase pressure drop and flow pattern. The pressure drops were measured and the images of the flow pattern were captured. In the non-Newtonian fluid, the flow pattern and flow regime map were different from those in water. The non-Newtonian behavior of the liquid phase also significantly affected the two-phase pressure drop. The relationship between the two-phase pressure drop and the gas and fluid flow rates relied on the flow pattern. A new two-phase friction multiplier correlation considering the gas-liquid flow rate ratio and the rheological properties of the liquid phase was developed to calculate the two-phase pressure drop. The new correlation can predict the experimental pressure drop data within the root mean square percentage errors of 12% for the gas-non-Newtonian fluid two-phase flow and 17% for the gas-water two-phase flow.

International audience; While the integration of nanocrystals as an active medium for optoelectronic devices progresses, light management strategies become required. Over recent years, several photonic structures (plasmons, cavities, mirrors, etc.) have been coupled to nanocrystal films to shape the absorption spectrum, tune the directionality, and so on. Here, we explore a photonic equivalent of the acoustic Helmholtz resonator and propose a design that can easily be fabricated. This geometry combines a strong electromagnetic field magnification and a narrow channel width compatible with efficient charge conduction in spite of hopping conduction. At 80 K, the device reaches a responsivity above 1 A•W-1 and detectivity above 10 11 Jones (3 µm cutoff) while offering a significantly faster time-response than vertical geometry diodes.

While HgTe nanocrystals (NCs) in the mid-infrared region have reached a high level of maturity, their far-infrared counterparts remain far less studied, raising the need for an in-depth investigation of the material before efficient device integration can be considered. Here, we explore the effect of temperature and pressure on the structural, spectroscopic, and transport properties of HgTe NCs displaying an intraband absorption at 10 THz. The temperature leads to a very weak modulation of the spectrum as opposed to what was observed for strongly confined HgTe NCs. HgTe NC films present ambipolar conduction with a clear prevalence of electron conduction as confirmed by transistor and thermoelectric measurements. Under the application of pressure, the material undergoes phase transitions from the zinc blende to cinnabar phase and later to the rock salt phase which we reveal using joint X-ray diffraction and infrared spectroscopy measurements. We discuss how the pressure existence domain of each phase is affected by the particle size.

International audience; Thanks to their narrow band gap nature and fairly high carrier mobility, HgTe nanocrystals are of utmost interest for optoelectronics beyond the telecom window (λ>1.55 µm). In particular, they offer an interesting cost-effective alternative to the well-developed InGaAs technology. However, in contrast to PbS, far less work has been dedicated to the integrating this material in photodiodes. In the shortwave infrared, HgTe NCs have a more p-type character than in the mid wave infrared, thus promoting the development of new electron transport layers with an optimized band alignment. As for perovskites, HgTe NCs present a fairly deep band gap with respect to vacuum. Thus, we were motivated by the strategy developed for perovskite solar cells, for which SnO2 has led to the best performing devices. Here, we explore the following stack made of SnO2/HgTe/Ag2Te in which the SnO2 and Ag2Te layers behave as electron and hole extractors respectively. Using X-ray photoemission, we show that SnO2 presents a nearly optimal band alignment with HgTe to efficiently filter the hole dark current while letting the photoelectrons flow. The obtained I-V curve exhibits an increased rectifying behavior, and the diode stack presents a high internal efficiency for the diode (above 60%) and an external quantum efficiency that is mostly limited by the absorption magnitude. Furthermore, we tackle a crucial challenge for the transfer of such diode onto readout circuits which prevents backside illumination. We also demonstrate that the diode stack is reversible with a partly transparent conducting electrode on top while preserving the device's responsivity. Finally, we show that such SnO2 layer is also beneficial for electron injection and leads to enhanced electroluminescent signal as the diode is operated under forward bias. This work is an essential step toward the design of a focal plane array with an HgTe NCs-based photodiode.

Based on arrays of Au seeds fabricated with atomic force microscopy (AFM) nanoxerography, the seeded growth of gold nanoparticles (Au NPs) on surface is achieved. The size evolution of Au NPs in each spot is tracked by in situ AFM and SEM images because each spot can be easily localized in the array system. The extinction microspectra extracted in real time with enhanced signals and red-shift can further monitor the increasing size of Au NPs. As a powerful platform, AFM nanoxerography makes it easy to tune the spot size and the intervals among spots in the Au NP arrays without preparing a template. It also allows for fabricating arbitrary patterns including various symbols and graphs. More interestingly, the in situ growth of Au NPs offers an approach to decreasing the interparticle distance, and thus forming closely interconnected Au nanowire assembly, exhibiting immense potential in the nanoelectronic system.

Purpose The purpose of this paper is to evaluate the effect of micro-nano mixed super-hydrophobic structure on corrosion resistance and mechanism of magnesium alloys. Design/methodology/approach A super-hydrophobic surface was fabricated on AZ91 and WE43 magnesium alloys by laser etching and micro-arc oxidation (MAO) with SiO2 nanoparticles coating and low surface energy material modification. The corrosion resistance properties of the prepared super-hydrophobic surfaces were studied based on polarization curves and immersion tests. Findings Compared with bare substrates, the corrosion resistance of super-hydrophobic surfaces was improved significantly. The corrosion resistance of super-hydrophobic surface is related to micro-nano composite structure, static contact angle and pretreatment method. The more uniform the microstructure and the larger the static contact angle, the better the corrosion resistance of the super-hydrophobic surface. The corrosion resistance of super-hydrophobic by MAO is better than that of laser machining. Corrosion of super-hydrophobic surface can be divided into air valley action, physical shielding, pretreatment layer action and substrate corrosion. Originality/value The super-hydrophobic coatings can reduce the contact of matrix with water so that a super-hydrophobic coating would be an effective way for magnesium alloy anti-corrosion. Therefore, the corrosion resistance properties and mechanism of the prepared super-hydrophobic magnesium alloys were investigated in detail.

A valid and reliable method was established to separate six compounds from pigeon pea leaves via elution-extrusion counter-current chromatography. A solvent system composed of n-hexane/methanol/formic acid aqueous solution with pH = 3 (10:6:4, v/v) was screened to achieve satisfactory isolation from the ethanol extract of pigeon pea leaves. Four compounds, 9.2 mg of compound 1 (96.8%), 3.2 mg of 2 (88.0%), 6.2 mg of 4 (94.2%) and 25.2 mg of 5 (94.2%), were obtained by conventional elution from 100 mg of the precipitation fraction, respectively. Two compounds, 14.4 mg of 3 (96.3%) and 28.1 mg of 6 (96.6%), with high K values were obtained by the subsequent extrusion procedure. The compounds 1-6 were identified as 3-methoxy-5-(2-phenylethenyl)-phenol, pinostrobin chalcone, pinostrobin, 2-hydroxy-4-methoxy-6-(2-phenylvinyl)-benzoic acid, longistylin C and cajaninstilbene acid by quadrupole time-of-flight mass spectrometry, and 1 H and 13 C NMR spectroscopy. The in vitro antiproliferation activities of compounds 1, 5 and 6 against human hepatoma cell were evaluated and the half-maximum inhibitory concentrations were acquired.

BACKGROUND Maternal and child health (MCH)–related mobile apps are becoming increasingly popular among pregnant women; however, few apps have demonstrated that they lead to improvements in pregnancy outcomes. OBJECTIVE This study aims to investigate the use of MCH apps among pregnant women in China and explore associations with pregnancy outcomes. METHODS A retrospective study was conducted at 6 MCH hospitals in northern China. Women who delivered a singleton baby at >28 weeks’ gestation at the study hospitals were sequentially recruited from postnatal wards from October 2017 to January 2018. Information was collected on the women’s self-reported MCH app use during their pregnancy, along with clinical outcomes. Women were categorized as nonusers of MCH apps and users (further divided into intermittent users and continuous users). The primary outcome was a composite adverse pregnancy outcome (CAPO) comprising preterm birth, birth weight RESULTS The 1850 participants reported using 127 different MCH apps during pregnancy. App use frequency was reported as never, 24.7% (457/1850); intermittent, 47.4% (876/1850); and continuous, 27.9% (517/1850). Among app users, the most common reasons for app use were health education (1393/1393, 100%), self-monitoring (755/1393, 54.2%), and antenatal appointment reminders (602/1393, 43.2%). Nonusers were older, with fewer years of education, lower incomes, and higher parity (Pany app use and CAPO (6.8% in nonusers compared with 6.3% in any app users; odds ratio 0.77, 95% CI 0.48-1.25). CONCLUSIONS Women in China access a large number of different MCH apps, with social disparities in access and frequency of use. Any app use was not found to be associated with improved pregnancy outcomes, highlighting the need for rigorous development and testing of apps before recommendation for use in clinical settings.

Background Maternal and child health (MCH)–related mobile apps are becoming increasingly popular among pregnant women; however, few apps have demonstrated that they lead to improvements in pregnancy outcomes. Objective This study aims to investigate the use of MCH apps among pregnant women in China and explore associations with pregnancy outcomes. Methods A retrospective study was conducted at 6 MCH hospitals in northern China. Women who delivered a singleton baby at >28 weeks’ gestation at the study hospitals were sequentially recruited from postnatal wards from October 2017 to January 2018. Information was collected on the women’s self-reported MCH app use during their pregnancy, along with clinical outcomes. Women were categorized as nonusers of MCH apps and users (further divided into intermittent users and continuous users). The primary outcome was a composite adverse pregnancy outcome (CAPO) comprising preterm birth, birth weight Results The 1850 participants reported using 127 different MCH apps during pregnancy. App use frequency was reported as never, 24.7% (457/1850); intermittent, 47.4% (876/1850); and continuous, 27.9% (517/1850). Among app users, the most common reasons for app use were health education (1393/1393, 100%), self-monitoring (755/1393, 54.2%), and antenatal appointment reminders (602/1393, 43.2%). Nonusers were older, with fewer years of education, lower incomes, and higher parity (P Conclusions Women in China access a large number of different MCH apps, with social disparities in access and frequency of use. Any app use was not found to be associated with improved pregnancy outcomes, highlighting the need for rigorous development and testing of apps before recommendation for use in clinical settings.

Ocean surges cause seawater inundation of coastal inland areas. Subsequently, seawater infiltrates into coastal aquifers and threatens the fresh groundwater resource. The severity of resulting salinization can be affected by hydrogeological factors including aquifer properties and hydrologic conditions, however, little research has been done to assess these effects. To understand the impacts of hydrogeological factors on groundwater salinization, we numerically simulated an ocean-surge inundation event on a two-dimensional conceptual coastal aquifer using a coupled surface-subsurface approach. We varied model permeability (including anisotropy), inland hydraulic gradient, and recharge rate. Three salinization-assessment indicators were developed, based on flushing time, depth of salt penetration, and a combination of the two, weighted flushing time, with which the impact of hydrogeological factors on groundwater vulnerability to salinization were quantitatively assessed. The vulnerability of coastal aquifers increases with increasing isotropic permeability. Low horizontal permeability (kx) and high vertical permeability (kz) lead to high aquifer vulnerability, and high kx and low kz lead to low aquifer vulnerability. Vulnerability decreases with increasing groundwater hydraulic gradient and increasing recharge rate. Additionally, coastal aquifers with a low recharge rate (R ≤ 300 mm yr − 1 ) may be highly vulnerable to ocean-surge inundation. This study shows how the newly introduced indicators can be used to quantitatively assess coastal aquifer vulnerability. The results are important for global vulnerability assessment of coastal aquifers to ocean-surge inundation.

We investigated the effects of dual-doping in both Bi and Cu sites on the thermoelectric performance of BiCuSeO. The electrical conductivity of Ba and Co dual-doped samples was largely enhanced compared to pristine BiCuSeO due to enhanced carrier concentration. Interestingly, Ba and Co dual-doped samples keep high Seebeck coefficient values as compared to Ba single doped sample, resulting in high power factor. While their thermal conductivities were significantly depressed by enhanced point defect scattering. These favorable factors lead to enhanced ZT of Ba and Co dual-doped samples as compared with Ba single doped sample, Co single doped sample and pristine BiCuSeO. ZT value of 0.082 at 350 K for Ba 0.125 Bi 0.875 Cu 0.85 Co 0.15 SeO was determined by nearly 32 times higher than that of pristine BiCuSeO. Moreover, this value is about five times higher than that of promising Ba 0.125 Bi 0.875 CuSeO. It reveals that dual-doping into both Cu and Bi sites is an effective way for optimizing thermoelectric properties of BiCuSeO. This study opens a new pathway for broadening and designing prospective thermoelectric materials.

Micro pillar arrays were fabricated on silicon surfaces based on the reactive ion etching technology. Low surface energy coatings were deposited on textured surfaces in order to prepare hydrophobic/superhydrophobic surfaces. After measuring the static contact angles and roll angles, the dynamic characteristics of droplets impacting on these hydrophobic/superhydrophobic surfaces were investigated in detail. Both the static contact angle and the roll angle increased with the increase of micro pillars' height. With the increase of micro pillars' spacing, the roll angle decreased, but the change of static contact angle was irregular. On superhydrophobic surfaces, the spreading coefficient of droplet was affected by both the static contact angle and the roll angle, and the rebounding coefficient of droplet was highly relevant with the roll angle. In addition, the bigger the incline angle of surface, the smaller the spreading coefficient and the smaller the rebounding coefficient of droplet.

Person re-identification is a challenging task due to the viewpoint, illumination and pose variations. Recent works focus on extracting part-level features to offer beneficial fine-grained information. However, the part misalignment as well as the multi-stage training process limits their performance. Inspired by the human visual attention mechanism, this paper builds a cascade attention network(CAN) to learn the discriminative person features in a coarse-to-fine manner. Firstly, we employ the human semantic parsing module to generate coarse-grained part-level attention, which corresponds to the division of human body parts and can effectively filter the background noise. Then, to extract the local detailed features within each part, we introduce spatial-channel attention module to generate fine-grained pixel-level attention, which can further highlight the distinctive characteristics and repress the irrelevant ones. Finally, we can obtain an efficient person feature descriptor by combining both the global and local features. The whole learning process is conducted end-to-end. Experimental results show that the proposed method not only considerably outperforms its counter part but also achieves competitive performance on Market-1501 and DukeMTMC.

An effective vehicle-license plate detection and recognition method based on the deep learning was presented that aim to address the limitations of traditional techniques failed in dealing with images from vehicle monitoring system under complex scene. Firstly, the coordinate information of license plate is located by the YOLOv2 algorithm with color clues. Then, the Radon transformation is used to rectify the license plate region which maybe tilted. Finally, the license plate recognition results are obtained by virtue of CRNN based on license plate coding rule. Experiments show the effectiveness and efficiency of our proposed license plate detection and recognition method.

The vortex in the branching microchannel enhances the mixing and heat transfer performance. To investigate the vortex intensity quantitatively, a lattice Boltzmann model for incompressible power-law fluid is developed by setting the range of lattice viscosity (0.001 [Formula: see text] 1). The validation of the current model is carried out by modeling the vortex in a T-shaped branching channel and the Poiseuille flow of power-law fluids. Then the vortex intensity in the [Formula: see text]-shaped microchannel is numerically studied in terms of Reynolds number, branching angle and power-law index. The result indicates that both the recirculation length and height increase with the increase of the Reynolds number. The branching angle has a negative impact on the recirculation length, and it has little effect on the recirculation height. The influence of the power-law index on recirculation length and height depends on the Reynolds number.

Under different inlet pressures and ventilated velocities, the moving process of ventilated bubble in micro scale venturi was recorded by high speed camera system. The effects of inlet pressure and ventilated velocity on bubble dynamics were analyzed in detail. The results show that the bubble breakup depends on the flow pattern. Bubble breaks up in turbulent flow but not in laminar flow. The intensity of bubble breakup becomes more severe with the increase of turbulent intensity. The main mechanism of bubble breakup in venturi is turbulence fluctuation and shearing-off process, the former happens in the condition of high inlet pressure and the latter exits when the inlet pressure is relatively low.

Characteristics of bubble nucleation and growth are critical for its application. It is affected by several factors including viscosity, surface tension and temperature. However, the effect of pressure on bubble nucleation and growth has been underreported, although it processes significant effect on above characteristics. In this work, a micro copper electrode is etched on a slab covered with copper to produce bubble on the surface by current input. The nucleation time of bubble is measured under different heat flux and system pressures. The nucleation and growth processes are recorded with a high speed camera in order to discuss the effects of heat flux and system pressure on bubble characteristics. The experiment results indicate that the micro electrode with higher heat flux produces more thermal energy, which makes the time of bubble nucleation shorter and the speed of bubble growth faster. Higher system pressure causes the increase of the critical nucleation temperature and also baffles the bubble nucleation and growth. Bubble growth includes the stages of rapid growth and dynamic equilibrium, with the speed being from fast to slow. In the former part of rapid growth, heat flux plays a dominant role in bubble growth. While the effect of system pressure on bubble growth becomes significant in the latter part of rapid growth. Both the nucleation time and bubble growth agree well with the theoretical analysis. The obtained results help to accurately control bubble nucleation and growth required in different application.

The transfer of natural waves and sea states into small- and large-scale model teste contributes to the proper design of offshore and coastal structure. Such shallow-water ocean surface waves are highly nonlinear and subject to wave transformation and nonlinear wave-wave interactions. However, the standard methods of wave generation according to conventional wave theories and wave analysis methods are limited to simple regular waves, simple sea states and low-order wave generation without considering the nonlinear wave-wave interactions. The research project Generation of Extreme Transient Waves in Experimental Models (ExTraWaG) aims to accurately generate target transient wave profile at a pre-defined position in the wave flume (transfer point) under shallow water conditions. For this purpose, the KdV-based nonlinear Fourier transform is introduced as a continuative wave analysis method and is applied to investigate the nonlinear spectral character of experimental wave data. Furthermore, the method is applied to generate transient nonlinear waves as specific locations in the wave flume, considering the nonlinear transformation and interactions of the propagating waves.

In this paper, meshing impact on numerical simulation of marine systems is investigated. Different mesh topologies, meshing spacing, meshing refining area are discussed. Different shaped bodies such as ball, AUV and complicated motion such as propeller rotating are simulated with compared meshes in the paper. And its converging time, solution accuracy, and local domain flow characters are compared in detail. The research results of mesh refining area showed that a mesh refining area near the stern is more important than that near the bow, although there are large pressure gradients at both areas. In regards to the necessary of boundary layer mesh, we find out that for a translational motion of a marine system such as surge, sway and heave, the near wall prismatic layer mesh is necessary. And the sensitivity of numerical accuracy to the spacing of the first grid point away from the wall and numbers of layers of the near wall are discussed. While for a rotational motion, such as propeller motion, numerical calculation showed that there is not necessary to construct a boundary layer mesh in the near wall.

In this paper the performance test results of a liquid desiccant air-conditioning (LDAC) system which uses waste hot water from combined cooling, heat and power system (CCHP) as driven heat resource have been presented. The supply air volume of the air-conditioning system is around 7000m 3 /h ~ 7500m 3 /h and its cooling capacity is about 60.43 ~ 95.74KW. It can maintain the supply air temperature under 22°C, while the ambient temperature is 40°C. By the application of LDAC, cooling capacity made from waste heat rises up to 537kW and the energy utilization efficiency of the whole system has reached 94.81% and rose by 8%. Because the application of this technology, the temperature of equipment room falls 4°C and the working condition is greatly improved.

The characteristics of the 1045 steel pairs using serpentine particles as oil additive were investigated by an AMSLER friction and wear tester. The surface topographies and composition of the worn surface of 1045 steel rings were identified by SEM and XPS. The results show that the additives can form a self-repairing film with a large number of micro-hole on the worn metal surface, which reduces the wear extent of the friction pairs significantly. The main elemental compositions of the film are Fe, O, Si, C and Mg, which indicates that the additives directly take part in the formation of the self-repairing film. The mechanism is that the rubbing action of the asperities between the two contact surfaces makes the surface of the particles generate a large numbers of dangling bonds during the process of friction. At the same time, the activated surface formed on the contact metal friction pairs make the particles adhered to it. Under the action of shearing stress on the contact surfaces, the particles spread on the worn metal surface to form self-repairing film.

A kind of composite powder mixed serpentine with silica is used as lubricant additive in this paper. The tribological property of 1045 steel pairs lubricated with composite additive oil was studied using an AMSLER friction and wear tester. The surface topographies and composition of the worn surface of 1045 steel rings were analyzed by SEM and XPS. The experimental results show that the composite additive can achieve an ultra low friction coefficient of 0.007 for the 1045 steel friction pairs. The worn surface is smooth with only a small amount of scratches on the local area. The XPS result after 100h test shows the carbon was concentrated on the worn surface besides Fe, O, Si and Mg. The existence of the carbon-rich surface layer is the main reason for the superlubricity characteristics.

In the past decade, observations in the German estuaries such as the rivers Elbe and Weser show increasingly serious damage to bank protection structures (groins and revetments). This damage is caused mainly by waves induced by the passing of big container ships in the shallow and narrow maritime waterways. These ship-induced 3D wave fields consist of long-periodic primary and short-periodic secondary wave components. Due to missing design approaches for the load of long-period waves on rubble-mound revetments, the current risk assessment for protective structures in maritime waterways is based on short-period, wind-induced waves. Therefore, the structures do not ensure sufficient stability against the long-period ship-induced wave loads within the estuaries. Within the research project “Parameterization of nonlinear ship-induced 3D wave fields for the hydraulic design of protective structures in maritime waterways (PaNSiWa)”, we apply nonlinear Fourier transforms (NFTs) on experimentally generated ship waves in maritime waterways. The objective of the project is to provide better understanding of the underlying nonlinear structure of the long-period primary waves and to separate the nonlinear spectral basic components within the ship-wave data from their nonlinear wave-wave interactions. In this paper, we present first analyses of the decomposition of ship-wave measurements from experimental tests and the identification of hidden solitons within the long-period primary ship wave.

International audience; For short wave infrared (SWIR) sensing, InGaAs is the leading technology combining high carrier mobility, high homogeneity and complete control over n-top doping. In the meanwhile, numerous alternative materials have tried to compete with InGaAs. Among them, colloidal nanocrystals with narrow band gap can address the current issue in designing cost-effective sensors for the SWIR range. Rather than pitting these two materials against each other, here we design a synergistic duo in which HgTe nanocrystals are used to broaden the spectral range of InGaAs while lifting the lattice matching constraints. We propose a diode geometry where a p-type HgTe NC array is coupled with n-type InGaAs wires which are used as high mobility (µ>1000 cm 2 .V-1 s-1) minority carrier extractors. This approach also demonstrates that Van der Waals heterostructures are not limited to graphene-like materials and that bulk-like III-V semiconductors can also be light sensitized by colloidal nanoparticles. This work paves the way toward further synergies between epitaxially grown and colloidally grown semiconductors for infrared detection.