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With the development of micro-spacecraft technology, micro-nano satellites have the advantages of small size, low power consumption, short development cycle, formation networking, etc., and can complete many complex space tasks at a lower cost. Micro-nano satellites require a micropropulsion system with the capability of performing precise total impulse and thrust to execute maneuvers, such as attitude control, orbital transfer, and gravitation compensation. In contrast to other micropropulsion systems, solid propellant microthrusters (SPM) arrays based on micro-electromechanical system (MEMS) technology possess a simple structure and quick response, which is a potential micropropulsion system. In recent years, many research groups have done a lot of research on SPM arrays. In this paper, the latest progress of SPM arrays is summarized from the aspects of structure design, propellant selection, bonding technology, ignition unit type and micro-thrust test, and some suggestions for the future development direction are given.

Energetic Semiconductor bridge (ESCB) based on reactive multilayered films (RMFs) has a promising application in the miniature and intelligence of initiator and pyrotechnics device. Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge (SCB) during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices. In this study, a one-dimensional (1D) gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO3 RMFs. In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process, the heat release of chemical reaction in RMFs was used as an internal heat source in this model. It is found that the exothermal reaction in RMFs improved the ignition performance of SCB. In the process of plasma rapid condensation with heat release, the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle, which accelerated the expansion of hot plasma, and heated the solid charge particle as well as gas phase region with low temperature. In addition, it made up for pressure loss in the gas phase. During the plasma dissipation process, the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle, making the surface temperature of the charge particle, gas pressure, and gas temperature rise continuously. This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.

ObjectiveUltrasound-guided techniques have become popular in severe humeral lateral condylar fractures (HLCFs). This study compared the results of ultrasound-guided closed reduction and percutaneous pinning (UG-CRPP) for Song types 4 and 5 and dislocation type of HLCFs.MethodsThis retrospective study was conducted in patients with HLCFs treated between January 2021 and October 2022 at three hospitals. The patients were divided into three groups according to Song's classification and elbow dislocation. The surgical time, reduction failure rate, and outcomes of the three groups were compared.ResultsThe mean surgical time of the 94 patients across the three groups (Song 4 group, 42 cases; Song 5 group, 38 cases; and dislocation group, 14 cases) was the longest for Song 4 (66.14 ± 23.05 min), followed by the dislocation group (59.71 ± 21.07 min) and Song 5 (52.16 ± 14.94 min) (for all, P = 0.009). The failure rate decreased in the following order: dislocation group (5/14), Song 4 group (7/42), and Song 5 group (2/38). The failure rate of closed reduction in Song 4 was 3.2-fold higher than that in Song 5, and for the dislocation group, it was 7.6-fold higher than that in Song 5. Significant differences were observed between the Song 4, Song 5, and dislocation groups in terms of shaft-condylar angle and supination (P = 0.015, P = 0.043). No significant differences (P > 0.05) were observed in the carry angle, flexion, extension, or pronation of the three groups. Two cases of delayed healing, four cases of superficial infection, one case of trochlear necrosis, and 39 cases of lateral spur in the Song 4 group were observed. In the Song 5 group, five had a superficial infection, one had re-displacement, and 26 had a lateral spur. In the dislocation group, there were two cases of superficial infection and 10 of lateral spurs.ConclusionsSong 4 HLCFs require longer surgical time and present more postoperative complications than Song 5 and dislocation-type HLCFs and can easily lead to lateral spurs. The failure rates of closed reduction in Song 4 and the dislocation type were higher than those in Song 5. Thus, UG-CRPP can be used to treat patients with unstable HLCFs.

BackgroundInterventions using ultrasound-guided closed reduction and percutaneous pinning (UG-CRPP) of humeral lateral condylar fractures (HLCFs) have been increasingly applied; however, their effectiveness for unstable HLCFs and the criteria for ultrasound outcomes remain unclear. This study assessed the outcomes of UG-CRPP for HLCFs and evaluated the success criteria in children.MethodsData were retrospectively collected from 106 patients with unstable HLCFs admitted to three hospitals between January 2021 and August 2022. Fifty-five cases were left-sided and 51 cases were right-sided: 74 male patients and 32 female patients were included. Perioperative data, elbow function, complications, and criteria for UG-CRPP were analyzed.ResultsThe mean rate of UG-CRPP was 88%. The mean surgical time was 54.56 ± 21.07 min, and the mean fluoroscopy frequency was 9.25 ± 2.93 times. At the last follow-up, there were significant differences in elbow flexion between the affected side (135.82° ± 6.92°) and the unaffected side (140.58° ± 5.85°) (p = 0.01). The Mayo score of the affected side was 90.28° ± 4.97°, the Baumann angle was 71.4° ± 5.4°, condylar shaft angle was 39.9° ± 6.4°, and the carrying angle was 8.4° ± 3.6°. Seventy patients presented mild lateral spurs and 16 patients exhibited moderate spurs. Fourteen patients presented with pin infection, and one patient exhibited postoperative re-displacement. There was no premature physeal closure, varus, or valgus elbow deformity, delayed union, or non-union. Successful ultrasound-based outcome criteria for UG-CRPP were defined as follows: (i) absent or less than a cartilage thickness step on the cartilage hinge on coronal plane parallel articular surface scanning, (ii) no lateral displacement and intact distal end of the condylar and capitellum on coronal plane vertical articular surface scanning, (iii) no anteroposterior displacement and absent or less than a cartilage thickness step on sagittal plane vertical articular surface scanning, and (iv) intact posterior fracture line or less than a cortex step on posterolateral sagittal plane vertical articular surface scanning.ConclusionUG-CRPP is a procedure with minimal blood loss, less invasive, cosmetic, and no radiation exposure. It yielded good outcomes in unstable HLCFs. The successful criteria make it suitable for clinical application.

Objective: To investigate the optimal process for preparing peppermint essential oil/β-cyclodextrin (β-CD) inclusion complex using high-speed shearing combined with freeze-drying. Methods: The effects of freeze-drying and vacuum drying, high-speed shearing, and stirring on the encapsulation process were compared. Based on single-factor experiments, the ratio of β-CD to essential oil, encapsulation temperature, and mass fraction of β-CD were considered as influencing factors. The comprehensive score of oil content and encapsulation efficiency was used as an evaluation index to investigate the Box-Behnken response surface method for optimizing the encapsulation process. The content of pulegone in the inclusion complex was measured by high-performance liquid chromatography (HPLC). Fourier transform infrared spectroscopy (FTIR) was used to characterize the inclusion complex. Results: The yield of inclusion complex prepared by freeze-drying was higher, with an average yield of 97.6%. The oil content and encapsulation efficiency by the high-speed shearing method were relatively high, being about 3% and 19% higher than those by the stirring method, respectively. The optimized conditions were as follows: The weight ratio of β-CD to volatile oil was 9:1 (g/mL), the encapsulation temperature was 55 ℃, and the mass fraction of β-CD was 17%. Under these conditions, the essential oil content was 10.9%, the encapsulation efficiency was 97.6%, the comprehensive score was 99.7, the RSD value was 1.59%, and the optimized process was stable and feasible. The content of pulegone in the inclusion complex was found to be 2.465 mg/g by HPLC. The formation of the peppermint oil/β-CD inclusion complex was confirmed by analysis using FTIR. Conclusion: The combination of high-speed shearing and freeze-drying for the preparation of peppermint essential oil inclusion complex had the advantages of high efficiency, simple process, and it improved theyield, would provide guidance for the production process.

Abstract The unique band structure of monolayer transition metal dichalcogenides (TMDC) provides an important platform for spintronic and valleytronic devices. Various approaches, such as in‐plane electric field and out‐of‐plane magnetic field, have been proposed to actively control the valley polarization. In this work, we propose a synergistic effect involving chiral near‐field interactions and hot carrier injection to actively control the valley polarization emission of WSe2 at room temperature (RT). The degree of valley polarization is enhanced from near zero (for pure WSe2) to 20% under non‐resonant optical excitation (532 nm) when monolayer WSe2 is coupled with the chiral near field of plasmonic metasurface. More importantly, the application of near‐infrared light (wavelength of 970 to 1600 nm) illumination further enhances the valley polarization from 20% to 30%, which is attributed to plasmonic‐induced hot carrier injection from the metasurface to WSe2. The synergistic effect of the chiral near field and infrared light pumping offers another strategy to manipulate the valley polarization emission in monolayer TMDs at room temperature, paving the way for future applications of opto‐valleytronic/spintronic devices based on these 2D materials.

Abstract Background Lifelong premature ejaculation (LPE) is one of the most common ejaculatory dysfunctions in men. The serotonin (5-HT) synthesis rate-limiting enzyme (TPH2) and receptor (HTR1A) in the 5-HT regulatory system may play a key role in the pathogenesis of LPE. However, there are few studies on the effects of TPH2 and HTR1A polymorphisms on LPE risk. We speculated that TPH2 and HTR1A polymorphisms may affect the occurrence and development of LPE in the Chinese Han population. Methods In this study, 91 patients with LPE and 362 normal controls aged 18 to 64 years were enrolled in the male urology department of Hainan General Hospital in China from January 2016 to December 2018. The SNPs in HTR1A and TPH2, which are related to 5-HT regulation, were selected as indexes to genotype the collected blood samples of participants. Logistic regression was used to analyze the correlation between SNPs of HTR1A and TPH2 with LPE susceptibility, as well as the relationship with leptin, 5-HT and folic acid levels. Results The results revealed that HTR1A-rs6295 increased LPE risk in recessive model. Rs11178996 in TPH2 significantly reduced susceptibility to LPE in allelic (odds ratio (OR) = 0.68, 95% confidence interval (95% CI) = 0.49–0.96, p = 0.027), codominant (OR = 0.58, 95% CI = 0.35–0.98, p = 0.040), dominant (OR = 0.58, 95% CI = 0.36–0.92, p = 0.020), and additive (OR = 0.71, 95% CI = 0.52–0.98, p = 0.039) models. Grs11179041Trs10879352 could reduce the risk of LPE (OR = 0.44, 95% CI = 0.22–0.90, p = 0.024) by haplotype analysis. Conclusion HTR1A-rs6295 and TPH2-rs11178996 are associated with LPE risk in the Chinese Han population based on the finding of this study.

Purpose: Genetic factors play an indispensable role in the pathogenesis of lifelong premature ejaculation (LPE). The susceptibility genes/SNPs that have been discovered are very limited and can only explain part of the genetic effects of LPE. Therefore, discovering more genetic polymorphisms associated with the occurrence and development of LPE will help reveal the pathogenesis of LPE. Materials and Methods: We conducted a genome-wide association study of LPE in 486 Chinese male Han people (cases and controls). We used Gene Titan multi-channel instrument and Axiom Analysis Suite 6.0 software for genotyping. Imputation was performed by IMPUTE2 software and the 1000 Genomes Project (Phase3) was used as reference for haplotype. Finally, logistic regression analysis was performed on all loci that passed the quality control. The odds ratio and 95% confidence interval were calculated to determine the association between each SNPs and Chinese male Han population LPE risk. Results: The results showed that a total of 33 genetic variants in 13 genes (LACTBL1, SSBP3, ACOT11, LINC02486, TMEM154, LINC01098, NONE, HCG27, HLA-C, TNFSF8, TNC, FAM53B, SULF2) have a suggestively significant genomewide association with LPE risk (p

The rise of an integrated energy system requires the integration of multiple sources of energy to be embraced and transited over the power grid; that means the information and communication systems of traditional power systems will be extended, and their complexity will be increased. As the information and communication systems play a more important role in the infrastructure of the power system, a cyber-attack on them may have an impact on the power system and cause a serious threat to the integrated energy system. To analyze the threat to the complex and integrated system, some researchers provide some modeling methods to study the impact of cyber-attacks on the information and communication systems, such as the Attack Tree Model, Attack Graph Model, Petri Net Model for cyber-attack, Attack Description Language Model, State Transition Graph Model, etc. However, these modeling methods have some shortcomings. For example, they cannot describe the systematical cyber-attack and show the secure status during the cyber-attack; it is hard for them to analyze the larger and more complicated information and communication systems. To overcome the shortages, in this paper, a correlated matrix-based object-oriented model is proposed for cyber-attack modeling. With this model, the relationship between the attacker and victim can be directly built; the cyber-attack path and packets from the attacker can be tracked; and the status of the nodes and links can be shown during a cyber-attack. There are two steps to build the cyber-attack model. Firstly, the procedure and approach of the cyber-attack will be modeled by an object-oriented method; then, a correlated matrix model will be built for network topology, attack path, and attack procedure. By combining these two models, the whole cyber-attack model is created. Finally, to demonstrate the modeling method and its benefits, we use the MITM (Man-in-the-middle Attack) attack on measurement data of an AVC (Automation Voltage Control) system as examples, and build a hardware-in-the-loop (HIL) co-simulation platform to verify the model.

A semiconductor bridge (SCB) is an ignition device that provides a safe and efficient method widely used in civilian and military fields. The heating process of an SCB under electrical stimulation has a wide range of applications owing to its unique energy release process. However, the temperature variation of an SCB is challenging to obtain, both experimentally because of the rapid reaction on a microscale and with simulation due to its high demand in nonlinear calculations. In this study, we propose deep learning (DL) approach to study the electrothermal-coupled multi-physical heating process of the SCB initiator. We generated training data with multi-physics simulation (MPS), producing surface temperature distributions of SCBs under different voltages. The model was then trained with partial data in this database and evaluated on a separate test set. A generative adversarial network (GAN) with a customized loss function was used for modeling point-wise temperature dynamics. In the test set, our proposed method can predict the temperature distribution of an SCB under different voltages with high accuracy of over 0.9 during the heating process. We reduced the computation time by several orders of magnitude by replacing MPS with a deep neural network.

Abstract Background Human bladder cancer is one of the common malignant tumors, and it mainly occurs in men. miR-182-5p, a member of miR-183 family, acts as tumor suppressor or oncogene in various kinds of tumors. In this study, we first investigate that the absence of miR-182-5p in human bladder cancer promotes tumor growth by regulating the expression of Cofilin 1, an actin modulating-protein. Methods Human bladder tumor tissue specimens were collected to detect the expression of miR-182-5p and Cofilin 1 by qRT-PCR. Luciferase activity assay was performed to demonstrate the regulation of Cofilin 1 mRNA 3′UTR by miR-182-5p. Then, cell experiments were performed to analysis the effect of miR-182-5p/Cofilin 1 pathway on tumor cell proliferation, migration, invasion and colony forming efficiency. Finally, xenograft tumor models were established to evaluate the role of miR-182-5p in tumorigenesis abilities in vivo. Results qRT-PCR and Western blotting analysis showed that Cofilin 1 expression was up-regulated in both bladder cancer tissues and cell lines compared with normal. Luciferase activity assay showed that miR-182-5p specifically targets Cofilin 1 mRNA 3′UTR and represses the expression of Cofilin 1. Also, miR-182-5p inhibited bladder tumor cell proliferation, migration, invasion and colony forming efficiency. Furthermore, xenograft tumor model assay showed that miR-182-5p plays a negative role in bladder cancer tumorigenesis abilities in vivo. Conclusion Present results suggest that miR-182-5p could inhibit human bladder tumor growth by repressing Cofilin 1 expression. Our findings may provide a new horizon for exploring therapeutic target of bladder cancer.

Recent exploration work in the Tazhong district has gradually transferred to the exploitation of high and over mature oils in deep and ultra-deep layers. This has proved problematic, however, as the distribution of crude oils in the Tazhong is complex. This means that the geochemical characterization of high and over mature oils, especially for light crude oils, have become increasingly important. The stability of concerted ring structure of aromatics makes them having stronger thermal stability and resistance to biodegradation. This means that there are abundant aromatic compounds in high and over mature oils. This study presents a series of geochemical analyses of the maturity parameters of 89 crude oils from the Tazhong area, including stable carbon and hydrogen isotope analyses of compounds from 43 light crude oils. These analyses are then compared with other data from the Tazhong Number I fault zone, as well as the Tazhong Number 10 and Tazhong Uplift structural zones. Results show that the geochemical parameters of oils from Tazhong Number I fault zone generally encompass a wider range than those from the Tazhong Number 10 structural zone, which indicates that the Tazhong Number I slope belt is more active than its counterpart structural belt and generates oils with more complex geochemical characteristics. The positive correlation between the toluene/methyl cyclohexane ratio and the dibenzothiophene/phenanthrene ratio, as well as with the naphthalene/phenanthrene ratio indicates that aromatization parameters can be used to evaluate the maturity of light crude oils, and there may be inherited relationships between toluene and methyl cyclohexane in crude oils.

The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity. Nanothermites have promising applications due to their excellent reactivity. Therefore it becomes extremely important to understand their aging and failure process in the environment before using them. Here, the aging and failure process of Al/CuO in 71 °C/60% RH were investigated, and showed that CuO nanoparticles negatively catalyze Al nanopowders, resulting in rapid hydration. The anti-aging effect of FAS-17-coated Al nanopowder was also examined. The aging process of Al, Al/CuO, and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods. Compared with the aging of pure Al, the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier. This may be caused by CuO catalyzed hydration of Al nanopowder. The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging. In contrast, the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17. It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion, which is an effective means to make nanothermites application in high humidity and heat environment. [ABSTRACT FROM AUTHOR]

Self-destructing chips have promising applications for securing data. This paper proposes a new concept of energetic diodes for the first time, which can be used for self-destructive chips. A simple two-step electrochemical deposition method is used to prepare ZnO/CuO/Al energetic diode, in which N-type ZnO and P-type CuO are constricted to a PN junction. This paper comprehensively discusses the material properties, morphology, semiconductor characteristics, and exploding performances of the energetic diode. Experimental results show that the energetic diode has typical rectification with a turn-on voltage of about 1.78 V and a reverse leakage current of about 3 x 10-4 A. When a constant voltage of 70 V loads to the energetic diode in the forward direction for about 0.14 s or 55 V loads in the reverse direction for about 0.17 s, the loaded power can excite the energetic diode exploding and the current rises to about 100 A. Due to the unique performance of the energetic diode, it has a double function of rectification and explosion. The energetic diode can be used as a logic element in the normal chip to complete the regular operation, and it can release energy to destroy the chip accurately. [ABSTRACT FROM AUTHOR]

Energetic Semiconductor bridge (ESCB) based on reactive multilayered films (RMFs) has a promising application in the miniature and intelligence of initiator and pyrotechnics device. Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge (SCB) during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices. In this study, a one-dimensional (1D) gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO3 RMFs. In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process, the heat release of chemical reaction in RMFs was used as an internal heat source in this model. It is found that the exothermal reaction in RMFs improved the ignition performance of SCB. In the process of plasma rapid condensation with heat release, the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle, which accelerated the expansion of hot plasma, and heated the solid charge particle as well as gas phase region with low temperature. In addition, it made up for pressure loss in the gas phase. During the plasma dissipation process, the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle, making the surface temperature of the charge particle, gas pressure, and gas temperature rise continuously. This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices. [ABSTRACT FROM AUTHOR]

Three types of energetic semiconductor bridges (ESCBs) through integrating different Al/MoOx energetic multilayer nanofilms on a semiconductor bridge have been investigated in this study. The relationships among the critical firing energy, critical firing time, total firing time, and ignition energy as well as the input energy utilization efficiency of these initiators were analyzed. The principal component analysis (PCA) was utilized in the experiments to evaluate the output energy magnitude based on the ignition duration, the maximum flame area, reaction ratio, and other parameters. The results obtained were as follows: (1) The critical firing energy is positively proportional to the modulation periods of nanofilms for the initiators discharged with identical voltage, while the total firing energy and the input energy utilization efficiency do not change significantly; (2) by using PCA, the composite score of the ESCB/50 nm, ESCB/150 nm, ESCB/1500 nm, and SCB is measured at 3.025, 0.250, -1.433, and -1.842, respectively, discharge with 30 V/47 µF, which indicated that the output energy of ESCBs can be increased significantly by decreasing the modulation periods of nanofilms. [ABSTRACT FROM AUTHOR]

The hepatoprotection of histone deacetylase sirtuin 1 (SIRT1) has been identified to attenuate ischemia-reperfusion (IR)-triggered inflammation and liver damage. This study was performed to characterize the function of SIRT1 in hepatic IR injury. In in vivo assays on liver-specific knockout mice of SIRT1, we first validated the effect of SIRT1 knockout on liver damage and XBP1/NLRP3 inflammasome activation. Next, we examined whether knockdown of XBP1/NLRP3 or miR-182 agomir could reverse the effect of SIRT1 knockout. In in vitro assays, NCTC1469 cells subjected to hypoxia/reoxygenation (H/R) were transduced with small interfering RNA (siRNA)/activator of SIRT1 or miR-182 agomir to confirm the effect of SIRT1 on NCTC1469 cell behaviors as well as the regulation of miR-182 and the XBP1/NLRP3 signaling pathway. Hepatic IR injury was appreciably aggravated in SIRT1 knockout mice, and SIRT1 knockdown abolished the inhibition of XBP1/NLRP3 inflammasome activation, which was reversed by NLRP3 knockdown, XBP1 knockdown, or miR-182 agomir. Mechanistically, miR-182 expression was positively regulated by SIRT1 in hepatic IR injury in mice, and miR-182 inhibited the expression of XBP1 by binding to the 3′ untranslated region (UTR) of XBP1. The histone deacetylase SIRT1 inhibits the downstream XBP1/NLRP3 inflammatory pathway by activating miR-182, thus alleviating hepatic IR injury in mice.

Igniter is the basic component of MEMS-based solid propellant microthrusters (SPM) array, which should response fast with low dissipated energy. To satisfy the requirements, micro-semiconductor bridge (MSCB) with dual V-angles contributing to the reduction of dissipated energy is introduced into the array. The electrical explosion characteristics of MSCB investigated under constant voltage, in the considerations of the limit of power supply in the micro/nanosatellite, are similar to those under capacitive discharge. The bridge was completely vaporized and burst into the hot plasma under high-level voltage. While under low-level voltage, the bridge was partly vaporized without detected plasma. The 3#SCB (90 ° V-angle) with the smallest power density resulting in the lowest applied voltage (12.0 V) and the 2#SCB with the smallest narrow width (Wmin) leading to the lowest average power (11.3 W) were chosen to the further optimization. The ignition tests were implemented to examine the ignition reliability of the contractible igniters, which were optimized to satisfy the voltage limitation with sufficient ignition capacity. The results show that the effective SCB with lowest dissipated power is the 3#-3SCB, which function within 100 μs under 7.0 V, and the average power below 5.0 W. [ABSTRACT FROM AUTHOR]

Visibility of optical coherence tomography (OCT) images can be severely degraded by speckle noise. A computationally efficient despeckling approach that strongly reduces the speckle noise is reported. It is based on discrete wavelet transform (DWT), but eliminates the conventional process of threshold estimation. By decomposing an image into different levels, a set of sub-band images are generated, where speckle noise is additive. These sub-band images can be compounded to suppress the additive speckle noise, as DWT coefficients resulting from speckle noise tend to be approximately decorrelated. The final despeckled image is reconstructed by taking the inverse wavelet transform of the new compounded sub-band images. The performance of speckle reduction and edge preservation is controlled by a single parameter: the level of wavelet decomposition. The proposed technique is applied to intravascular OCT imaging of porcine carotid arterial wall and ophthalmic OCT images. Results demonstrate the effectiveness of this technique for speckle noise reduction and simultaneous edge preservation. The presented method is fast and easy to implement and to improve the quality of OCT images. [ABSTRACT FROM AUTHOR]

Real-time optical spectrum analysis is an essential tool in observing ultrafast phenomena, such as the dynamic monitoring of spectrum evolution. However, conventional method such as optical spectrum analyzers disperse the spectrum in space and allocate it in time sequence by mechanical rotation of a grating, so are incapable of operating at high speed. A more recent method all-optically stretches the spectrum in time domain, but is limited by the allowable input condition. In view of these constraints, here we present a real-time spectrum analyzer called parametric spectro-temporal analyzer (PASTA), which is based on the time-lens focusing mechanism. It achieves a frame rate as high as 100 MHz and accommodates various input conditions. As a proof of concept and also for the first time, we verify its applications in observing the dynamic spectrum of a Fourier domain mode-locked laser, and the spectrum evolution of a laser cavity during its stabilizing process. [ABSTRACT FROM AUTHOR]

The oxide shell of Al nanoparticles (Al NPs) prevents further reaction of Al/CuO nanothermites which reduces Al utilization efficiency and the performance of the nanothermites. However, the performance of Al/CuO nanothermites can be improved by adding ammonium perchlorate (AP). In this work, in order to confirm and explain the enhancement mechanism of AP on Al/CuO nanothermites, Al/CuO/NC and Al/CuO/NC/AP composites were prepared using the electrospray method. The composites were characterized by differential scanning calorimetry/thermogravimetric, x-ray diffraction, scanning electron microscope and transmission electron microscopy. Meanwhile, the ignition temperature and the time-resolved analysis of the rapid pyrolysis chemistry of the composites were tested using T-jump and time-of-flight mass spectrometry, respectively. The results show that Al NPs of Al/CuO/NC/AP composite are hollow compared to Al/CuO/NC composite after reaction. Al NPs and CuO NPs reduce the decomposition temperature and facilitate the rapid decomposition of the AP, and the decomposition products of the AP can destroy the oxidation layer of Al NPs. This result facilitates the further conduct of the thermite reaction. A mutually reinforcing relationship exists between the Al/CuO/NC composites and AP. [ABSTRACT FROM AUTHOR]

Nanothermites composed of nano-fuels and oxidants are attractive energetic materials, which have potential applications in microscale energy-demanding systems. Herein, nano-Al/CuO with nitrocellulose (NC) binder have been bottom-up assembled on semiconductor bridge (SCB) chip by electrospray, from nanoparticles to three-dimensional (3D) deposited structure. The morphological and compositional characterization confirms the constituents in Al/CuO@NC are homogeneously mixed at nano scale and the 3D structure at micro scale is tunable. The as-deposited Al/CuO@NC exhibits excellent energy output and superior chemical reactivity. Specifically, the heat release of Al/CuO@NC (1179.5 J g−1) is higher than that of random mixed Al/CuO (730.9 J g−1). Benefiting from outstanding exothermic properties, the material integrated with SCB initiator chip (Al/CuO@NC-SCB) for potential ignition application was investigated. The Al/CuO@NC-SCB micro energetic initiator can be functioned rapidly (with delay time of 2.8 μs) and exhibits superb ignition performances with violent explosion process, high combustion temperature (4636 °C) and successful ignition of B/KNO3 propellant, in comparison to SCB initiator. The strategy provides promising route to introduce nano reactive particles into various functional energy-demanding systems for potential energetic applications. [ABSTRACT FROM AUTHOR]