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The great development potential of polymer dielectric capacitors in harsh environments urgently requires enhancing capacitive performance at high temperatures. However, the exponentially increased conduction loss at high temperature and high field results in a drastic drop in energy density and charge-discharge efficiency. Here, a bilayer-structured polyimide (PI) composite film containing a wide-band gap inorganic layer as a charge blocking layer is designed. The inorganic layer improves the charge trapping ability and regulates the charge mobility at the electrode/dielectric interface. The charge injection mechanism in the interface-optimized PI/boron nitride nanosheet (BNNS) composite films is investigated by finite element simulation, and the effect of the BNNS layer on high temperature conduction is further understood. An appropriate thickness of the charge blocking layer establishes an effective energy barrier. Therefore, the composite films exhibit significantly suppressed conduction loss and excellent capacitive performance at a high temperature. A high energy density of 4.37 J cm

Glial cell-line derived neurotrophic factor (GDNF) is a powerful astroglioma (AG) proliferation and migration factor that is highly expressed in AG cells derived from astrocytes. However, it is still unclear whether high levels of GDNF promote AG occurrence or if they are secondary to AG formation. We previously reported that high concentrations of GDNF (200 and 500 ng/mL) can inhibit DNA damage-induced rat primary astrocytes (RA) apoptosis, suggesting that high concentrations of GDNF may be involved in the malignant transformation of astrocytes to AG cells. Here we show that 200 ng/mL GDNF significantly increased the proliferation and migration ability of RA cells and human primary astrocytes (HA). This treatment also induced RA cells to highly express Pgf, Itgb2, Ibsp, Loxl2, Lif, Cxcl10, Serpine1, and other genes that enhance AG proliferation and migration. LOXL2 is an important AG occurrence and development promotion factor and was highly expressed in AG tissues and cells. High concentrations of GDNF promote LOXL2 expression and secretion in RA cells through GDNF family receptor alpha-1(GFRα1)/rearranged during transfection proto-oncogene (RET)/mitogen-activated protein kinase (MAPK)/phosphorylated cyclic AMP response element binding protein (pCREB) signaling. GDNF-induced LOXL2 significantly promotes RA and HA cell proliferation and migration, and increases the expression of Ccl2, Gbp5, MMP11, TNN, and other genes that regulate the extracellular microenvironment in RA cells. Our results demonstrate that high concentrations of GDNF activate LOXL2 expression and secretion via the GFRα1/RET/MAPK/pCREB signal axis, which leads to remodeling of the astrocyte extracellular microenvironment through molecules such as Ccl2, Gbp5, MMP11, TNN. This ultimately results in abnormal astrocyte proliferation and migration. Collectively, these findings suggest that high GDNF concentrations may promote the malignant transformation of astrocytes to AG cells.

The impoundment of the Three Gorges Reservoir (TGR) and upstream cascade reservoirs (UCRs) has altered the hydrologic regime, with inevitable effects on phosphorus transport processes in the TGR. In order to investigate the effects of impoundment, long-term monitoring data of flow rate, suspended sediment (SS), and phosphorus fractions of six stations in the TGR basin were collected and divided into three periods, period 1 (P1) (1985-2002), period 2 (P2) (2003-2012), and period 3 (P3) (2013-2017), based on the periodic impoundment time. The results indicated that the impoundment of the TGR and UCRs considerably decreased the SS concentration. Efficient sediment interception by the UCRs led to a dramatic decline in the concentrations of total phosphorus (TP) and particulate phosphorus (PP) in the mainstream, while the total dissolved phosphorus (TDP) showed a general increasing trend from 2004 to 2017. Different phosphorus fractions in the mainstream exhibited seasonal variations; among them, the concentrations of TP and PP were highest in the wet season, while the highest TDP concentration occurred in the dry season. Further analysis indicated that the seasonal distribution of TP was significantly homogenized in P3. Additionally, the SS concentration was positively correlated with the concentrations of TP and PP in the mainstream, while the correlations in P3 were significantly lower than that in P2. The findings can provide a scientific reference for future investigations dedicated to the long-term effects of the UCRs on the eco-environment in the TGR as well as the downstream.

Self-healing of damage is a common phenomenon in organisms but is hardly ever encountered in rigid polymer materials. For next-generation electricals and electronics, it is crucial to accurately mimic organisms to detect and heal mechanical/electrical damage. Herein, disulfide bond exchange is designed to introduce the self-healing ability in a copolymerized polyimide (copolyimide). A copolyimide insulation film with two diamine monomers is successfully prepared, which also possesses good self-healing ability after being mechanical/electrical damaged. Furthermore, the self-healing copolyimide film still maintains its good Young's modulus (E) >4 GPa, high thermal stability with glass transition temperature (Tg) >190 °C, and excellent insulation property with breakdown strength (Eb) >300 kV mm−1. The combination of the simple copolymerization and unique self-healing ability is suitable for high Tg polyimide to make this an ideal method for insulation field.

The high operating temperature of dielectric capacitors applied in electric vehicles, aerospace and underground exploration require dielectric materials with high temperature resistance and high energy density. Polyimide (PI) turns out to be a potential dielectric material for capacitors applications at high temperature. In this review, the key parameters related to high temperature resistance and energy storage characteristics were introduced and recent developments in all-organic PI dielectrics and PI-matrix dielectric nanocomposites were discussed. Synthetic strategies of new functional PI via modification at the molecular level together with the design engineering of nanofillers and multilayer structures of PIs were also analysed. Finally, a systematic summary of the current challenges and future developments for capacitor materials used at high temperatures were presented.

There is a great demand for low dielectric materials as insulating interlayers in large-scale integrated circuit development. However, it is still a huge challenge to reduce the dielectric permittivity of polymers while maintaining excellent thermal stability and mechanical properties. In this work, the fluorinated polyimides (PIs) in combination with a micro-branched crosslinking structure were prepared successfully by introducing different amounts of 1,3,5-tris(4-aminophenyl) benzene (TAPB) to obtain ultra-low dielectric permittivity. The results revealed that PI film containing 2 mmol TAPB had the lowest dielectric permittivity (2.47) and dielectric loss (0.008) at 1 MHz due to the fluorine atoms and the micro-branched crosslink structure, which not only decreased the molecular polarizability but also increased the free fractional volume. In addition, PI film containing 2 mmol TAPB had the highest tensile strength of 106.02 MPa with an elongation at a break of 15.1% because the presence of TAPB effectively promoted the connection between PI molecular chains, resulting in the inhibition of the molecular mobility. The incorporation of TAPB also enhanced the thermal stability and ultraviolet light-shielding performance of PI films. This method paves the way for the development of PIs with ultra-low dielectric permittivity for the electronic industry.

The interchain space of polyimide is optimized to hinder charge carrier transport, thus improving the energy storage performance at high temperatures.

The introduction of CA effective combines the self-healing and fluorescence characteristics, and provides a reliable method for the development of multifunctional PDMS.

Profenofos residues in the environment pose a high risk to mammals and non-target organisms. In this study, the biodegradation and detoxification of profenofos in an efficient degrading strain, Cupriavidus nantongensis X1

Dielectric polyimides (PIs) are ubiquitous as insulation in electrical power systems and electronic devices. Generally, dynamic polyimide is required to solve irreversible failure processes of electrical or mechanical damage, for example, under high temperature, pressure, and field strength. The challenge lies in the design of the molecular structure of rigid polyimide to achieve dynamic reversibility. Herein, a low-molecular-weight polyimide gene unit is designed to crosslink with polyimide ligase to prepare the smart film. Interestingly, due to the variability of gene unit and ligase combinations, the polyimide films combining hardness with softness are designed into three forms via a "Mimosa-like" bionic strategy to adapt to different application scenarios. Meanwhile, the films have good degradation efficiency, excellent recyclability, and can be self-healable, which makes them reuse. Clearly, the films can be used in the preparation of ultrafast sensors with a response time ≈0.15 s and the application of corona-resistant films with 100% recovery. Furthermore, the construction of polyimide and carbon-fiber-reinforced composites (CFRCs) has been verified to apply to the worse environment. Nicely, the composites have the property of multiple cycles and the non-destructive recycle rate of carbon fiber (CF) is as high as 100%. The design idea of preparing high-strength dynamic polyimide by crosslinking simple polyimide gene unit with ligase could provide a good foundation and a clear case for the sustainable development of electrical and electronic polyimides, from the perspective of Mimosa bionics.

Polymer nanocomposites have attracted increased attention for use in the field of high‐voltage direct current (HVDC) cable insulation. To study the use of polymer nanocomposites for this purpose, 3D flower‐like MgO (flower‐MgO) particles with hierarchical surface morphology are first synthesised. Polypropylene (PP) was simultaneously mixed with styrene‐(ethylene‐co‐butylene)‐styrene triblock copolymer (SEBS) and flower‐MgO to obtain PP/SEBS/flower‐MgO composites. The microstructural, thermal, electrical, and mechanical properties of the obtained nanocomposites were then studied in detail. The results showed that flower‐MgO particles loaded at low concentration were well dispersed in the PP/SEBS matrix. The incorporation of flower‐MgO particles has been found to significantly suppress the injection of homocharges and strengthen the ability to release the charge, thus containing accumulation of the space charge. The DC breakdown strength of PP/SEBS/flower‐MgO composites was increased to 323 MV/m. Meanwhile, the tensile strength and elongation at break of the obtained composites was improved by loading 0.5 phr flower‐MgO because of the synergistic toughening effects of SEBS and MgO. The investigation demonstrates the immense potential to replace nonrecyclable cross‐linked polyethylene as an HVDC cable insulating material.

Multi-hop remote quantum teleportation has significant value in wireless quantum network and long distance quantum information transmission. Due to the long distance transmission of quantum information will be affected by the interference of noise, this makes quantum states nonlocal decoherence, so multi-hop teleportation through intermediate nodes has significant theory and application value to study on this subject. In this paper, we propose a multi-hop teleportation scheme based on wireless mesh network, and the scheme of transmitting arbitrary four-qubit states is optimized. With the aid of auxiliary particles, information can be transmitted with fewer quantum channels. Compared with hop-by-hop transmission, this optimized scheme can remarkably reduce the transmission delay and improve the transmission efficiency. The introduction of wireless mesh network also makes the theory of multi-hop teleportation more practical.

Polymer dielectrics have been widely used in electrical energy storage devices. However, the relatively low operating temperature hinders their applications in harsh environments. Herein, the molecular structure of polyimide (PI) is optimized by adjusting the reaction kinetics of polyamic acid, which improves the energy storage performance of PI at elevated temperature. The PI film with an optimal imidization degree achieves a simultaneous increase in dielectric permittivity (ϵ r) and breakdown strength (E b), resulting in a maximum discharged energy density (U e) of 6.9 J cm −3 with a charge-discharge efficiency of 90.0% at room temperature and a high U e of 3.9 J cm −3 at 150 °C. The introduced -COOH/-CN-OH- polar groups increase the ϵ r through the enhancement of dipole polarization. Moreover, an appropriate number of -COOH/-CN-OH- groups as deep traps reduce the mobility of carriers, thereby increasing the E b. Finite element simulation reveals that PI with an appropriate imidization degree exhibits suppressed space charge accumulation and improved electric field distortion. This method reduces the PI processing temperature, which effectively reduces the production energy consumption. For verifying the universality of the design strategy, two other PIs prepared from different monomers are also demonstrated to have simultaneous improvement in ϵ r and E b.Finally, this production process of only reducing the preparation temperature without adjusting the original commercial PI production equipment is crucial for the practical application of capacitor films in the future.

High-performance epoxy (EP) composites with excellent thermal conductivity and dielectric properties have attracted increasing attention for effective thermal management. In this work, three-dimensional (3D) structural functional fillers were prepared by an electrostatic self-assembly approach. The negatively charged carbon nanotubes (nCNTs) prepared by carboxylation on the surface of CNTs were attached to the positively charged boron nitride (pBN) to form the 3D pBN@nCNTs functional fillers. The morphological characterizations of the formed 3D pBN@nCNTs fillers and epoxy composites were established, illustrating that nCNTs were linearly overlapped between the BN sheets, thus forming a 3D heat conduction network in the epoxy matrix. The synergistic effect of pBN with nCNTs on the enhancement of thermal conductivity and dielectric properties of composites was systematically studied. The experimental results demonstrated that the thermal conductivity of pBN@nCNTs/EP composites could reach 1.986 W m−1K−1 with the loading of 50 wt% fillers at 10:1 mass ratio of pBN:nCNTs, which is 464% and 124% higher than that of pure EP and BN/EP, respectively. Simultaneously, the dielectric permittivity was successfully increased to 15.14. Moreover, the thermal stability of the composites was synchronously enhanced. This study provides a facile path to fabricate thermosetting polymer composites with high thermal conductivity and dielectric properties.

Electroactive polymer (EAP) is a kind of smart material, which can change its shape under the stimulation of electric field. Dielectric elastomer (DE) is an important member of the EAP. DE has the characteristics of excellent performance, such as light weight, low noise, low cost, and so on, which guarantee its wide applications in the fields of actuators, generators, sensors. In this review, the principles of energy conversion, the research status and latest development of new technologies for DEs, and the performance characteristics of DEs are summarised. Simultaneously, it points out the development problems and feasible countermeasures. At last, the application prospects of DE are discussed, combined with the research direction of the international frontier.

High-voltage direct current (HVDC) power cables have been paid more attention due to the big issue concerning the main insulation materials. The residues in the industrial production process will cause space charge generation and accumulation in the materials, which has become one bottleneck to limit the development of power cables up to higher voltage levels. In this paper, the LDPE matrix was modified by three types of ethylene-butyl acrylate (EBA) copolymers (1.0 wt%) with different polarities (BA content) via melt blending to optimize the space charge behavior of the LDPE insulation. The micromorphology and structure of the blends are examined by polarized light microscope and differential scanning calorimetry. The space charge distribution is tested by the pulsed electroacoustic method. The trap level is studied by the thermally stimulated current. The results show that EBA introduces more deep traps and decreases the shallow traps. The medium-polar EBA (16% BA content) can effectively suppress charge accumulation, and have the same suppressed effect on XLPE/EBA blends. This study will provide important insights into the design and development of advanced HVDC power cable applications.

A new surface texturing technique, based on liquid plasma discharging in an aqueous electrolyte, is proposed to modify the surface morphology of grey cast iron. During the process, a grey cast iron sample serves as a cathode where the reduction of hydrogen from the aqueous electrolyte occurs and consequently plasma discharging is generated on the sample surface under applied high voltages (up to 480V). The formed hydrogen bubbles are exploded during the electrical discharging, leaving an irregular array of craters on the sample surface due to the high temperature and shockwaves of the plasma micro-arc discharging. After polishing the crater-like textured surface, surface roughness and oil retention are measured by a profilometer. Reciprocating tribotests are utilized to determine the coefficients of friction. The surface morphology of the polished and tested surface is studied by SEM. The same tests are also conducted for the cast iron with a cross-hatched surface. These two set of results are compared to determine the effects of the texturing and polishing on friction. The results show that the polishing of textured surface can decrease the roughness and coefficients of friction significantly at starved lubricating conditions. This method has potential to be applied on the cylinder bore surface of a cast iron liner for the internal combustion engine (ICE). By honing the textured bore surface, the friction between piston and cylinder bore is expected to decrease and the ICE efficiency to increase for environmental benefits.

Two deterministic schemes are put forward to preparing an arbitrary four-qubit cluster-type state remotely by using two Bell states as quantum channel. The coefficients of the prepared states can be not only real, but also complex. To accomplish the schemes, we introduce some novel sets of ingenious measurement basis vectors. Especially, for complex coefficients case, we give two different forms schemes. The receiver will reconstruct the initial state by means of some appropriate unitary operations. The outstanding advantage of the present schemes is that the success probability in all the considered remote state preparation (RSP) can reach 1.

Flows in river habitats are characterized by unsteady turbulence due to the existence of woody debris, boulders and vegetation. As a representative aquatic species, fish is important for the riverine ecosystems, with its complex behavioural responses to turbulent flows. Previous studies investigated the fish-vortices interaction with vortex streets by placing objects with simplified geometries centred at the flow. Nonetheless, complex river morphology in natural rivers results in much more spatially heterogeneous flows due to randomly distributed obstructions. Thus, a semi-circular cylinder patch located on one side of the flume is used to mimic a vegetation patch at the riverbank. The patch varies in diameter (D

Nuclear factor of activated T-cells, cytoplasmic 4 (NFATc4), a transcription factor of NFAT family, which is activated by Ca2+/calcineurin signaling. Recently, it is reported that aberrantly activated NFATc4 participated and modulated in the initiation, proliferation, invasion, and metastasis of various cancers (including cancers of the lung, breast, ovary, cervix, skin, liver, pancreas, as well as glioma, primary myelofibrosis and acute myelocytic leukemia). In this review, we cover the latest knowledge on NFATc4 expression pattern, post-translational modification, epigenetic regulation, transcriptional activity regulation and its downstream targets. Furthermore, we perform database analysis to reveal the prognostic value of NFATc4 in various cancers and discuss the current unexplored areas of NFATc4 research. All in all, the result from these studies strongly suggest that NFATc4 has the potential as a molecular therapeutic target in multiple human cancer types.

Quantitative predictions of total dissolved gas (TDG) super-saturation are essential for developing operation schemes for high dams. Most TDG generation prediction models have various shortcomings that affect the accuracy of TDG super-saturation estimation, such as oversimplification of influencing factors and uncertainty in parameter values. In this study, the TDG generation process was divided into three parts, gas-liquid mass transfer process in the stilling phase, dilution resulting from the water jet plunging into the stilling phase, and outflow of TDG–super-saturated water from the stilling phase, while considering the water body and bubbles in the stilling phase as a whole. The residence time of the water in the stilling phase (Tr) was introduced to estimate mass transfer time, along with dimensional analysis methods. The properties of TDG generation were evaluated experimentally under varying Tr values. Based on the theoretical analysis and experimental results, a basic water renewal model was proposed and was validated using experimental data. Furthermore, prediction results of this model were compared with those of a classical empirical model and mechanical model based on observed data from a field survey at Xiluodu Dam. The results show that the relative errors between the predicted and experimental measurements were all less than 5%, indicating that the developed prediction model has a good performance. Compared with the mechanism model, the developed model could reduce the standard error (SE), normalized mean error (NME), and error of maximum (REMAX) by 60, 96, and 15%, respectively. Meanwhile, the developed model could reduce the SE, NME, REMAX by 17.4, 36, and 23%, respectively, compared with the empirical model. Considering all the error indexes, it can be concluded that the prediction performance of the water renewal model is the best among the three models. The proposed model was also more generically versatile than the existing models. Prediction results of water regeneration model for TDG could aid the drafting of governing strategies to minimize the risk of super-saturated TDG.

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PURPOSE: To evaluate the differences in efficacy, predictability, safety, and visual quality between topography-guided customized ablation treatment (TCAT) and wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) for the treatment of myopia with and without astigmatism. METHODS: A comprehensive literature search of PubMed, Embase, the Cochrane library, Web of Science, and ClinicalTrials was used to identify randomized controlled trials (RCTs) comparing TCAT-LASIK with WFO-LASIK for myopia with and without astigmatism up to September 2020. The references of all searched literature were checked as supplements. Literature was screened according to the inclusion and exclusion criteria and relative data were extracted. RevMan software version 5.3.0 (Cochrane Collaboration) was used for meta-analysis. RESULTS: A total of seven RCTs (1,168 eyes) were included. There were no statistically significant differences in the ratio of uncorrected distance visual acuity of 20/20 or better (relative risk [RR] = 1.01, 95% CI [0.97 to 1.06], P = .64) and 20/16 or better (RR = 0.96, 95% CI [0.80 to 1.16], P = .69). Compared with WFO-LASIK, TCAT-LASIK achieved a higher proportion of postoperative manifest refractive spherical equivalent within ±0.50 diopters of the target (RR = 1.06, 95% CI [1.02 to 1.11], P = .003) and less surgically induced higher order aberrations (weighted mean difference [WMD] = −0.11, 95% CI [−0.15 to −0.0], P < .00001), spherical aberrations (WMD = −0.04, 95% CI [−0.05 to −0.03], P < .00001), and coma (WMD = −0.15, 95% CI [−0.28 to −0.01], P = .03). No patient lost two or more lines of distance-corrected visual acuity postoperatively in the two groups. CONCLUSIONS: This meta-analysis suggests that both TCATLASIK and WFO-LASIK show excellent efficacy, predictability, and safety for myopia. TCAT-LASIK exhibited more accurate postoperative refraction predictability and less surgically induced higher order aberrations, spherical aberrations, and coma. More randomized, prospective, and large sample-sized studies are needed to confirm these conclusions in the long term. [ J Refract Surg . 2021;37(10):707–714.]

With the increasing demand for safe operation in harsh environments, polymer dielectric capacitors with high energy density ( Ue) and charge-discharge efficiency (η) operating at high temperatures are urgently needed. In this work, the sulfone group-containing polyimide (SO2PI) film with optimal imidization degree is prepared by regulating the kinetics of imidization reaction. The functional groups obtained by partial imidization enable polyimide to achieve excellent energy storage performance, and it is found that the presence of sulfone groups is beneficial for the further improvement of η. The optimal SO2PI film achieves a Ue of 2.40 J cm−3 at 400 MV m−1 and 150 °C, while it maintains a high η of 92%. Moreover, its preparation process without any additional modification steps matches commercial production equipment, indicating a simple and effective strategy for fabrication of a high-performance dielectric film. Thus, this work exhibits great potential in the field of high temperature energy storage.

Operation scenario is very important to smart metro, but it is difficult to validated with real environment. Digital twin achieves the digitization of metro facilities, interface with related control systems, operation as a real metro system, and digital twin based validation platform can be used to validate most of smart metro scenarios. This paper focus on smart metro and its scenarios validation platform with digital twin technology, included conception, architecture, modeling, and data processing etc.

Nowadays, there is no suitable treatment for vibriosis in groupers. So an eco-efficient and environmentally friendly treatment is necessary for the grouper industry. Probiotic-feeding has been a promising strategy to control the bacterial pathogens in aquaculture. A new Bacillus velezensis strain named K2 was isolated from the intestinal tract of healthy grouper, and exhibited wide antimicrobial spectrum of against fish pathogens, including Vibrio harveyi, Vibrio alginolyticus, Aeromonas hydrophila, Aeromonas veronii, Aeromonas caviae, Enterococcus casseliflavus and Lactococcus garvieae. Moreover, results of the safety of B. velezensis K2 showed that intraperitoneal injection of K2 in healthy grouper did not cause any pathological abnormality or death, indicating this bacteria could be considered as a candidate probiotic in aquaculture. Groupers were fed with the diets containing 1 × 107 cfu/g of B. velezensis K2 for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that diets supplemented with K2 significantly increased serum acid phosphatase (ACP) activity (P

This study evaluated the demulsifying capability of magnetic nanoparticles for industrial wastewater treatment and the solid effect during demulsification. In order to evaluate the demulsification capability of magnetic nanoparticles, an oleic acid-coated magnetite (Fe3O4@OA) was used as a demulsifier for demulsification of diluted waste cutting fluid (DWCF) rom machining and manufacturing. The effects of the magnetic nanoparticles dosage (CS), the pH, cetyltrimethyl ammonium bromide (CTAB) and electrolytes (NL and CL) in DWCF on the demulsification efficiency (ED) were investigated. It was observed that the ED enhanced when electrolytes NL and CL were added into DWCF and decreased with pH increasing. Meanwhile, in the magnetic demulsification systems, a significant solid concentration effect (or CS-effect) was observed, that is the equilibrium adsorption amount (Γe) declined as CS increased. These CS-effect data can be explained using the surface component activity (SCA) model. The CS-effect strength (or γ value) declined in turn with the NL, CL and CTAB added and declined with pH increasing. The paper further discusses the rationale for the observed results. This paper provides a new perspective on magnetic demulsification and demonstrates that SCA model can be applied to describe the CS-effect phenomenon exactly in magnetic demulsification systems.

Rationale Hyperpolarized 129 Xe MRI enables quantitative evaluation of regional ventilation. To this end, multiple classifiers have been proposed to determine ventilation defect percentage (VDP) as well as other cluster populations. However, consensus has not yet been reached regarding which of these methods to deploy for multicenter clinical trials. Here, we compare two published classification techniques–linear-binning and adaptive K- means–to establish their limits of agreement and their robustness against reduced signal-to-noise ratio (SNR). Methods A total of 29 subjects (age: 38.4 ± 19.0 years) were retrospectively identified for inter-method comparison. For each 129 Xe ventilation image, 7 images with reduced SNR were generated with equal decrements relative to the native SNR. All 8 sets of images were then analyzed using both methods independently to classify all lung voxels into four clusters: VDP, low-, medium-, and high-ventilation-percentage (LVP, MVP and HVP). For each cluster, the percentage of the lung it comprised was compared between the two methods, as well as how these values persisted as SNR was degraded. Results The limits of agreement for calculating VDP were [+0.2%, +4.0%] with a +1.5% bias for binning relative to K- means. However, the inter-method agreement for the other clusters was moderate, with biases of −5.7%, 8.1%, and −4.0% for LVP, MVP, and HVP, respectively. As SNR decreased below ∼4, both methods began reporting values that deviated substantially from the native image. By requiring VDP to remain within ≤1.8% of that calculated from the native image, the minimum tolerable SNR values were 2.4 ± 1.0 for the linear-binning, and 3.5 ± 1.5 for the K- means. Conclusions Both methods agree well in quantifying VDP, but agreement for LVP and MVP remains variable. We suggest a required SNR threshold be two standard deviations above the minimum value of 3.5 ± 1.5 for robust determination of VDP, suggesting a minimum SNR of 6.6. However, robust quantification of the ventilated clusters required an SNR of 13.4.

The mechanical mating components (e.g., gear teeth and stamping dies) usually have an inclined contact which introduces additional tangential forces and accelerates the formation of the surface fatigue cracking. To study such effects on the surface fatigue behaviours of engineering materials and coatings, an inclined sliding test was adopted to have varying ratios of tangential to normal loads at different positions inside the wear scar during each cyclic loading. In this study, a plasma nitrided ductile cast iron (D6510) was tested under various contact angles, which led to different ratios of tangential to normal loads. The results demonstrated that subsurface cracks occurred at the low ratio while the surface cracks dominated at the high ratio when the inclined sliding contact stresses were very high. Severe surface fatigue failure like chipping could occur as soon as the surface cracking density is higher than 0.13.

Polymer-based composites with ceramic fillers could combine the advantages of both, which can be potentially used in electrical and electronic technology. In this work, the barium titanate (BaTiO 3 ) nanofibres and the core-shell structured BaTiO 3 @Al 2 O 3 nanofibres with Al 2 O 3 insulation layer coated on the BaTiO 3 surface were both prepared via the electrospinning method. The appropriate incorporation of the ceramic nanofibres effectively improves the dielectric properties and energy density of the polymer. Moreover, the poly(vinylidene fluoride- co -hexafluoropropylene)-based composite films with the three-layer sandwich structure were fabricated to further promote the dielectric properties. The results show that the outer two layers with a higher content of BaTiO 3 nanofibres can make more contribution to the improved permittivity of the composites. In addition, the introduction of the interlayer with low loading of BaTiO 3 @Al 2 O 3 nanofibres promotes the breakdown strength. This work gives rise to the potential in high energy storage applications.