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Fumonisin B1 (FB1) is a common mycotoxin contamination in agricultural commodities being considered as a significant risk to human and livestock health, while the mechanism of FB1 immunotoxicity are less understood, especially in chicken. Given that extracellular traps as a novel defense mechanism of leukocytes play an important role against foreign matters, in this study we aimed to investigate the effects of FB1 on chicken heterophil extracellular traps (HETs) formation. Our result showed that FB1 induced HETs release in chicken heterophils observed via immunostaining, and it was concentration-dependent during 10 to 40 μM. Moreover, in 40 μM FB1-exposed chicken heterophils, reactive oxygen species (ROS) level was increased, while catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity and glutathione (GSH) content were decreased. Simultaneously, FB1 (40 μM) activated ERK and p38 MAPK signaling pathways via increasing the phosphorylation level of ERK and p38 proteins. However, pretreatment of SB202190, U0126, and diphenyleneiodonium chloride (DPI) did not change FB1-triggered ROS production and HETs formation, suggesting FB1-induced HETs was a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, p38, and extracellular regulated protein kinases (ERK) signaling pathways-independent process. Inhibition of peptidyl arginine deiminase 4 (PAD4) enzyme and P2 × 1 receptor showed their vital role in 40 μM FB1-triggered HETs. This study reported for the first time that 40 μM FB1 induced the release of HETs in heterophils, and it was related to ROS production, PAD4, and P2 × 1, but was independent of NADPH oxidase, p38 and ERK signaling pathways, which might provide a whole novel perspective of perceiving and understanding the role of FB1 in immunotoxicity.

With the advent of the era of big data, key-value storage systems based on LSM-Tree have been widely used. Because of its excellent writing performance, it is favored by data centers. LSM-Tree is divided into two parts, one that SkipList structure located in the memory and the other that level structure resident in the disk. The SkipList structure involves two modules, MemTable and Immutable MemTable, which speed up its read and write performance. However, Immutable MemTable is only single and unchangeable, which will cause the thread to block and affect access efficiency in terms of write-intensive workloads. To solve the issue, we propose multiple Immutable MemTables for rotating storage to improve write performance. Furthermore, due to the increase of memory-resident data in the MemTables, the read rate is also enhanced. Through running the benchmarks of the LevelDB system, In the case of less than 1000,000 key-value items, the read performance can be improved by 15%~65%, and when it comes to less than 10000,000 key-value items, the write performance can be improved by 15%~71%.

Effect of solutes of transition metals (TM = Cr, Fe, Hf, Mn, Mo, Nb, Ni, Pt, Rh, Ru, Re, Ta, Ti, V, W, Y and Zr) on the local phase transition between the L12 and D019 structures in superlattice intrinsic stacking fault (SISF) of Co3TM has been investigated. All the models employed herein, i.e. (1) the SISF-containing supercell, (2) the axial nearest-neighbor Ising (ANNI) model, and (3) both the L12- and D019-containing (L12 + D019) supercell, yield the same result regarding the stability of SISF in L12-type Co3TM. In the view of bonding charge density, the atomic and electronic basis of local D019 phase transition in the SISF fault layers of Co3TM are revealed. Especially, the negative SISF energy predicted by the L12 + D019 model suggests that both the SISF fault layers (i.e. the local D019 structure) and the L12 phase of Co3TM can be stabilized through a coupling interaction between the fault layers and the solutes, paving a pathway to stabilize Co-base superalloys via Co3TM precipitate. Moreover, the consist results of ESISF via the ANNI model with the classical SISF-supercell method utilized in first-principles calculations supports the approach to efficiently distinguish various planar faults and predict their corresponding energies, such as SISF, superlattice intrinsic stacking fault, anti-phase boundaries, and so on.

Transition metal oxides (TMOs) have drawn great attention in applications towards negative electrodes for lithium-ion batteries (LIBs). TMOs undergo conversion reactions upon discharge/charge process, which involves volume changes that cause pulverization and further result in poor cycling performances. Thus, it is important to engineer the microstructure of TMOs to accommodate the volume expansion/contraction during discharge/charge process and to improve the charge-transfer process. Herein, we report nanostructured CuO nanoflake arrays with a highly open microstructure on a nanoporous Cu substrate as binder-free negative electordes for LIBs. Nanoporous Cu substrate was obtained by dealloying process. By oxidizing one single side of a nanoporous Cu substrate under mild conditions, the 2D self-supported CuO nanoflake arrays were fabricated and can provide fast ion diffusion paths and accommodate large volume changes in the process of discharge/charge. Due to the synergistic effects of the highly conductive substrate and the intrinsically stable microstructure, the as-prepared CuO electrodes deliver a high capacity with stable performance of ∼100% capacity retention (∼800 mAh·g−1) after 120 cycles, and good rate performances up to 10 C. Considering the enhanced charge-transfer process, notable structural stability, and low-cost fabrication, the as-prepared CuO negative electrodes hold great promise for advanced LIBs.

Responding to the growing bandwidth demand by emerging applications, such as fixed-mobile convergence for fifth generation (5G) and beyond 5G, 100 Gb/s/ λ access network becomes the next research focus of passive optical network (PON) roadmap. Intensity modulation and direct detection (IMDD) technology is still considered as a promising candidate for 100 Gb/s/ λ PON attributed to its low cost, low power consumption, and small footprint. In this paper, we achieve 100 Gb/s/ λ IMDD PON by using 20G-class optical and electrical devices due to its commercial availability. To mitigate the system linear and nonlinear distortions, neural network (NN) based equalizer is used and the performance is compared with feedforward equalizer (FFE) and Volterra nonlinear equalizer (VNE). We introduce the rules to train and test the data while using NN-based equalizer to guarantee a fair comparison with FFE and VNE. Random data have to be used for training, but for test, both random data and pseudorandom bit sequence are applicable. We found that the NN-based equalizer has the same performance with FFE and VNE in the case of linear distortion, but outperforms them in a strong nonlinearity case. In the experiment, to improve the loss budget, we increase the launch power to 18 dBm, achieving a 30-dB loss budget for 33 GBd/s PAM8 signal at the system frequency response of 16.2 GHz, attributed to the strong nonlinear equalization capability of NN.

The nonlinear degradations and chromatic dispersion induced bandwidth penalty are critical obstacles for implementing the analog radio-over-fiber (A-RoF) technique in future mobile fronthaul (MFH). In this paper, we propose an analog multiple intermediate-frequency-over-fiber (multi-IFoF) MFH system with blind linearity improvement and flexible dispersion-induced bandwidth penalty mitigation. The bias adjustment of a single-electrode driven dual-drive Mach–Zehnder modulator is used to compensate the bandwidth penalty arising from the dispersion-induced power fading of fiber links in different lengths. This operation can increase the available bandwidth for the MFH system free of even-order intermodulation distortions (IMDs). At the receiver, a self-adaptive digital post-processing algorithm is introduced to blindly improve the linearity of the IFoF MFH system by suppressing the residual odd-order IMDs, with no need of training signals or prior knowledge of the transmission channel. In the proof-of-concept experiments, the transmission of 64-QAM-OFDM signals in 1 to 12 IF channels with a 500-MHz bandwidth has been demonstrated over standard single-mode fibers (SSMFs) of 20, 50, and 100 km. For the 50-km (or 100-km) SSMF, the bandwidth penalty for a broadband signal with a bandwidth of 4.5 GHz (or 2.5 GHz) is fully compensated. In addition, the proposed post-processing algorithm can significantly suppress the odd-order IMDs and thus improve the linearity by greater than 5.4 dB in terms of the input RF power range which retains an acceptable error-vector-magnitude (EVM) performance for the 64-QAM-OFDM signal.

The joint radar and communication (JRC) system providing both large-capacity transmission and high-resolution ranging will play a pivotal role in the next-generation wireless networks (e.g., 6G and beyond) and defense applications. Here, we propose and experimentally demonstrate a novel photonics-assisted millimeter-wave (mm-wave) JRC system with a multi-Gbit/s data rate for communication function and centimeter-level range resolution for radar function. The key is the design of the intermediate-frequency (IF) JRC signal through the angle modulation of the linear frequency modulation (LFM) radar carrier using orthogonal frequency division multiplexing (OFDM) communication signal, inspired by the idea of constant-envelope OFDM (CE-OFDM). This IF angle-modulated waveform facilitates the broadband photonic frequency (phase)-multiplying scheme to generate mm-wave JRC signal with multiplied instantaneous bandwidth and phase modulation index for high-resolution LFM radar and noise-robust CE-OFDM communication. It is with fixed low power-to-average power ratio to render robustness against the nonlinear distortions. In proof-of-concept experiments, a 60-GHz JRC signal with an instantaneous bandwidth over 10-GHz is synthesized through a CE-LFM-OFDM signal encoded with a 2-GBaud 16-QAM OFDM signal. Consequently, a 1.5-cm range resolution of two-dimension imaging and an 8-Gbit/s data rate are achieved for both radar and communication functions, respectively. Furthermore, the proposed JRC system is able to achieve higher radar range resolution and better anti-noise communication, when using higher-order photonic frequency multiplying.

Langmuir probes have long been used in experimental plasma physics research as the primary diagnostic for particle fluxes (i.e., electron and ion fluxes) and their local spatial concentrations, for electron temperatures, and for electrostatic plasma potential measurements, since its invention by Langmuir in the early 1920s. Emissive probes are used for measuring plasma potentials. The protocols exhibited in this work serve to demonstrate how these probes may be built for use in a vacuum chamber in which a plasma discharge may be confined and sustained. This involves vacuum techniques for building what is essentially an electrical feedthrough, one that is rotatable and translatable. Certainly, complete Langmuir probe systems may be purchased, but they can also be built by the user at considerable cost savings, and at the same time be more directly adapted to their use in a particular experiment. We describe the use of Langmuir probes and emissive probes in mapping the electrostatic plasma potential from the body of the plasma up to the sheath region of a plasma boundary, which in these experiments is created by a negatively biased electrode immersed within the plasma, in order to compare the two diagnostic techniques and assess their relative advantages and weaknesses. Although Langmuir probes have the advantage of measuring the plasma density and electron temperature most accurately, emissive probes can measure electrostatic plasma potentials more accurately throughout the plasma, up to and including the sheath region.

In the present work, the localized features of adiabatic shear bands (ASBs) of our recently designed damage tolerance α+β dual-phase Ti alloy are investigated by the integration of electron backscattering diffraction and experimental and theoretical Schmid factor analysis. At the strain rate of 1.8 × 104 s−1 induced by a split Hopkinson pressure bar, the shear stress reaches a maximum of 1951 MPa with the shear strain of 1.27. It is found that the α+β dual-phase colony structures mediate the extensive plastic deformations along α/β phase boundaries, contributing to the formations of ASBs, microvoids, and cracks, and resulting in stable and unstable softening behaviors. Moreover, the dynamic recrystallization yields the dispersion of a great amount of fine α grains along the shearing paths and in the ASBs, promoting the softening and shear localization. On the contrary, low-angle grain boundaries present good resistance to the formation of cracks and the thermal softening, while the non-basal slipping dramatically contributes to the strain hardening, supporting the promising approaches to fabricate the advanced damage tolerance dual-phase Ti alloy.

Paper-based books in university libraries are important learning materials for university students, but there are some drawbacks in traditional reading methods, and it is necessary to utilize scientific and technological means to solve the pain points of users, i.e. the students. With the development of information technology, augmented reality (AR) technology has gradually penetrated into all areas of the students’ lives. The fusion of AR technology and traditional paper books brings a potential new approach of reading and a sense of experience. At present, the application of AR technology in library is mainly for book navigation and book protection. AR technology has also appeared in some children’s books, but most of the books are still in the traditional way of reading. Therefore, this research aims to implement AR technology with traditional reading methods, optimize the reading experience of paper books, and enhance the interactivity and interest of paper book reading. This article selects university students in the library of South China University of Technology for the case study. Firstly, it finds the application method of AR technology in the library through the literature, and then observes and interviews the students to summarize the pain points and design opportunities from traditional reading. Based on AR technology, this paper designed a social reading application with a human-oriented design concept, thereby optimizing the reading experience of paper books for library.

A silicon vestigial sideband transmitter consisting of a Mach-Zender modulator and a micro-ring resonator is designed for compensating dispersion-induced power fading in IF-over- fiber mobile fronthaul. It enables a transmission of a 10-Gbaud 16-QAM OFDM signal over 80-km fiber.

The publisher's note contains a correction to [Opt. Express 29 32333 (2021)10.1364/OE.438439]. The article was corrected on 17 June 2022.

Histamine plays a central role in various allergic diseases, such as allergic asthma and allergic rhinitis. Neutrophil extracellular traps (NETs) formation is a novel effector mechanism of neutrophils to defend against various stimuli. In this present study, we aimed to investigate the role of histamine on bovine NET formation, and examined its preliminary molecular mechanisms. Cell Counting Kit-8 (CCK8) and Lactate dehydrogenase assays showed that histamine had no significant influence on PMNs (polymorphonuclear leukocytes) viability. Confocal microscopy analyses identified NET structures by co-localizing the main components of NETs, and NET quantification revealed that histamine-triggered NETs were released in a dose-dependent manner. Furthermore, we found reactive oxygen species (ROS) production, phosphorylated extracellular signal-regulated kinase (ERK) and p38 proteins were significantly elevated in histamine-challenged PMNs. By applying functional inhibitors of nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase), ERK and p38, histamine-triggered NETs were markedly reduced, indicating their importance in histamine-triggered NET formation. Our findings described histamine-triggered NET formation, and revealed its potential molecular mechanisms via NADPH oxidase, ERK and p38 pathways. This is the first study to depict histamine-triggered NET formation, which could provide a new insight into histamine-related diseases.

BackgroundHistamine plays an central role in many allergic diseases including allergic asthma and allergic rhinitis, and is also involved in bovine laminitis through regulating immune responses. Neutrophil extracellular traps (NETs) formation is a novel effector mechanism of neutrophils to defend against various stimuli. In the present study, we aimed to investigate the role of histamine on bovine NET formation and examined its fundamental molecular mechanisms. ResultsFirstly, the effects of histamine on neutrophil viability was measured by Cell Counting Kit-8 (CCK-8) and Lactate dehydrogenase (LDH) assays. The results showed that histamine had no significant influence on neutrophil viability. Then we characterized histamine-triggered NET formation by confocal microscopy and PicoGreen-derived NETs quantification. Confocal microscopy analyses illustrated NET structures by co-localizing the main components of NETs, and NET quantification revealed that histamine-triggered NETs were released in a dose-dependent manner. In addition, we found reactive oxygen species (ROS) production, phosphorylated extracellular signal-regulated kinase (ERK) and p38 proteins were significantly elevated in histamine-challenged neutrophils. By applying functional inhibitors of nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase), ERK and p38, histamine-triggered NETs were markedly reduced, indicating their importance in histamine-triggered NET formation. ConclusionsOur findings described histamine-triggered NET formation, and revealed its potential molecular mechanisms via NADPH oxidase, ERK and p38 pathways. This is the first study to depict NET formation induced by histamine, which could provide a new insight into histamine-related diseases.

The polarization splitter-rotator (PSR) plays a significant role in telecom, Datacom, and quantum circuits to meet significant requirements for polarization processing and multiplexing. We design an ultracompact PSR based on a silicon asymmetrical directional coupler (ADC). One waveguide of the ADC is gradually etched in two levels along the coupling region and the S-bend. A trapezoidal taper on the top of the dual-etched waveguide is first formed to satisfy the phase-matching condition for the TM-TE mode conversion, such that the TM mode is cross-coupled from the input waveguide without etching. Then, the etching width gradually increases in the S-bend and the following to achieve a single-mode waveguide for further removal of the residual TM mode. In this way, a high extinction ratio can be achieved for the polarization mode splitting in an ultracompact silicon ADC. For the designed PSR with a total length of about 24 µm, the simulation results reveal that the minimum extinction ratio is greater than 30, 20, or 15 dB within the bandwidth of 33, 100, or 150 nm, respectively, while the maximum polarization conversion loss is less than 0.4, 0.9, or 1 dB.

Increasing caesarean section (CS) rates are of global concern not only for health care providers but also from a more general public health point of view. Growing concern on the association between CS and offspring's neurodevelopmental outcomes have been raised in recent years, but the effect of CS on offspring's emotional development is rarely reported. By using mice models, we have set up two groups, ie. offspring born via CS and in-fostered by dams with vaginal delivery (VD), and offspring born via VD and in-fostered by their non-biological mothers. Depression-like behavioral was evaluated by sucrose preference test and forced swimming test, and anxiety-like behavioral was evaluated by open-field test and elevated plus maze test, respectively during offspring's adolescence and adulthood. Offspring's prefrontal cortex was collected for HE staining and assessment for DA, HVA, 5-HT, 5-HIAA. It was found that offspring born of CS have anxiety-like and depression-like behaviors in adolescence and adulthood. Male offspring was sensitive to be depressive and female offspring tended to be anxious. Although no significant sex difference was observed, there existed edema and nuclear retraction of neurons in the prefrontal cortex in offspring via CS during adolescence and adulthood. Compared with offspring born via VD, offspring through CS had shown higher DA and HVA levels while lower 5-HT and 5-HIAA levels in adolescence and adulthood, and this difference was observed in female offspring. The findings highlight the sex-specific effect of CS on offspring's emotional development. Variations in key neurotransmitters in the prefrontal cortex may partly explain the association between CS and offspring's emotional symptoms.

Dielectric properties of thermochromic RTV (room temperature vulcanized silicon rubber) composite were investigated and a novel dielectric phenomenon was explored. It was found that in the temperature range of thermochromism, tanδ and AC breakdown strength both decreased conspicuously with temperature, whilst those of pristine RTV changed slightly. Phase transition from solid to liquid with temperature during thermochromism was confirmed by DSC (differential scanning calorimeter) and was proposed to be the possible origin of novel dielectric phenomenon. The temperature dependence of tanδ is explained by a combination of decreased resistance to the reorientation of polar molecules due to collapse of intermolecular force and increased cavity volume due to solid-to-liquid phase transition. Meanwhile, the electric strength of thermochromic fillers decreases with the solid-to-liquid phase transition, facilitating the early breakdown of thermochromic fillers and, consequently, leading to the sharp decrease of AC breakdown strength of thermochromic RTV composite. In comparison, no phase transition was found in pristine RTV with increased temperature, which leads to different temperature dependence of tanδ and AC breakdown strength from thermochromic RTV composite.

The proper design of the flywheel undeniably determines in tuning the engine to confirm the better output engine performance. The aim of this study is to mathematically investigate the effect of various values of the compression ratio on some essential parameters to determine the appropriate value for the flywheel dimension. A numerical calculation approach was proposed to eventually determine the dimension of the engine flywheel on a five-cylinder four-stroke Spark Ignition (SI) engine. The various compression ratios of 8.5, 9, 9.5, 10, 10.5, and 11 were selected to perform the calculations. The effects of compression ratio on effective pressure, indicated mean effective pressure (IMEP), dynamic irregularity value of the crankshaft, and the diameter of the flywheel was clearly investigated. The study found that 2.5 increment value of the compression ratio significantly increases the effective pressure of about 41.53% on the starting of the expansion stroke. While at the end of the compression stroke, the rise of effective pressure is about 76.67%, and the changes in dynamic irregularity merely increase by about 1.79%. The same trend applies to the flywheel diameter and width, which increases 2.08% for both.

This paper studies the flow characteristics and disk friction loss of the rear chamber in a centrifugal pump at a design flow condition with six values of the balance holes at diameters from 0 to 12 mm. The results show that the turbulent boundary layer in the rear chamber is greatly affected by the leakage flow. When the balance hole diameter increases, the flow characteristics of the rear chamber is mainly restricted by the mainstream flow field of the volute. However, when the balance hole diameter is larger than the design value, the disk friction loss of the rear chamber remains basically unchanged. On the contrary, when the balance hole diameter is smaller than the design value, the larger the balance hole diameter the smaller the friction loss of the disk in the rear chamber area. The results of this paper provide a reference for reducing axial force and stable operation of a centrifugal pump.

This erratum corrects a clerical error in the original manuscript [Photon. Res. 9, 1124 (2021)PRHEIZ2327-912510.1364/PRJ.419605].

Dependent security labels (security labels that depend on program states) in various forms have been introduced to express rich information flow policies. They are shown to be essential in the verification of real-world software and hardware systems such as conference management systems, Android Apps, a MIPS processor and a TrustZone-like architecture. However, most work assumes that all (complex) labels are provided manually, which can both be error-prone and time-consuming. In this paper, we tackle the problem of automatic label inference for static information flow analyses with dependent security labels. In particular, we propose the first general framework to facilitate the design and validation (in terms of soundness and/or completeness) of inference algorithms. The framework models label inference as constraint solving and offers guidelines for sound and/or complete constraint solving. Under the framework, we propose novel constraint solving algorithms that are both sound and complete. Evaluation result on sets of constraints generated from secure and insecure variants of a MIPS processor suggests that the novel algorithms improve the performance of an existing algorithm by orders of magnitude and offers better scalability.

Nowadays, the microwave photonics (MWP) concept has been evolved from laboratory tests to practical applications, and related techniques have been widely deployed in many fields including such as wireless communications, medicine, sensing, radars, electronic warfare, and space explorations. In this paper, we concentrate on the featured applications of MWP in the high-speed railways (HSRs), an emerging field and massive market, and an overview about our recent work is presented. The radio-over-fiber based wireless communications in high-mobility scenarios, photonic-assisted electromagnetic interference detection along HSR lines, and fiber sensing for safety protection of railways are investigated systematically in our group. Experiments are then performed to verify the basic functionalities of the three MWP-enabled systems mentioned above. In particular, field trials have been successfully implemented along two in-service HSR lines located in Southwest China, i.e., the Chengdu–Chongqing and the Chengdu–Mianyang–Leshan HSR lines. With these results and achievements, we can expect more MWP-enabled striking applications in the HSR field in near future.

A radio-over-fiber (RoF) system employing subcarrier index modulation (SIM) orthogonal frequency-division multiplexing (OFDM) signal is proposed and experimentally demonstrated in this paper. In the system, the SIM will add a new freedom to the conventional modulation techniques [i.e., on – off keying or quadrature phase-shift keying (QPSK)], which in different subcarrier states (activated and silent) are employed to convey information, leading to an enhanced spectral efficiency. In the proof-of-concept experiments, a 10.5-GHz RoF system carrying QPSK-SIM-OFDM signal is established with a hybrid link of 10-km fiber and 1.5-m free space. The spectral efficiency of the SIM-OFDM can be enhanced by up to 14.5% for 128 subcarriers with 21 silent subcarriers or 15.6% for 512 subcarriers with 97 silent subcarriers, compared with that of conventional OFDM systems. The bit error rates are analyzed and estimated to be less than the forward error correction threshold.

A fast tunable single-bandpass photonic radiofrequency filter (PRF) with multiple arbitrary switching flat-top passbands is proposed and experimentally demonstrated. The PRF is comprised of a narrow, flat-top optical filter based on a fiber Bragg grating with multiple phase shifts, and a high-speed wavelength switch module by incorporating an optical carrier-suppressed single-sideband modulation unit and a direct digital synthesizer. The combination of the single flat-top passband and the high-speed digital controlled wavelength switch in the optical domain enables us to achieve a fast and arbitrarily tunable single passband in the microwave domain. In the experiments, the proposed PRF shows a single flat-top passband with a 3-dB bandwidth of 740 MHz, a rectangular shape factor around 2.27, and an out-of-band rejection ratio greater than 41 dB. In the application demonstrations, the multitone or single-tone continuous-wave RF signals with different frequency components are applied to the PRF and then the desired components or waveforms are temporally separated and successfully recovered, verifying the multiple switching passbands with arbitrarily manipulated center frequencies and numbers over the frequency range from 0 to 12 GHz at a switching speed as fast as 1.73 ns.

Measurement on intra-pulse parameters of complex microwave signals within a wide frequency coverage is essential for radar and communication systems. In this paper, a photonic approach based on a dual-port Mach–Zehnder interferometer (MZI) configuration is proposed to measure the intra-pulse parameters of phase/frequency-coded microwave signals. In the proposed approach, a light wave is externally modulated by a complex signal to be measured under the carrier suppression mode, and then sent to the dual-port MZI to perform frequency-to-power mapping. The optical powers at the two outputs of the MZI are detected as two instantaneous amplitudes, such that an amplitude comparison function (ACF) directly associated with the instantaneous frequency is derived via a division between the two instantaneous amplitudes. Multiple intra-pulse parameters are then identified through temporal analysis of the instantaneous amplitude, ACF, and instantaneous frequency. Measurements to pulsed microwave signals with intra-pulse modulation formats, including phase-shift keying, frequency-shift keying, and linear frequency modulation, are described theoretically and demonstrated experimentally. In addition, the performance of the proposed approach in terms of the signal-to-noise ratio and the minimum power level is discussed.

Increasing the serial bitrate to 25-Gb/s per channel as well as coexisting with the same optical distribution network of the 10G-ethernet passive optical network (EPON) is challenging. The bandwidth limitation and the reduced dispersion tolerance at high date rate make it much more difficult to achieve higher loss budget. In this paper, we have first shown a demonstration of a symmetric 4 × 25-Gb/s time-wavelength-division-multiplexed passive optical network system based on nonreturn-to-zero on-off-keying format supporting 0–20 km reach in O-band. 10G-class directly modulated lasers (DMLs) are employed to serve as both upstream and downstream transmitters owing to the low cost and the frequency chirp induced by DML can be used for bandwidth equalization. Instead of using digital signal processing, the chirp management and frequency equalization are simultaneously realized in optical domain through our proposed dispersion supported equalization technique. By employing a spool of dispersion-shifted fiber in optical line terminal (OLT), a single device can be used to simultaneously equalize the frequency response of multiple downstream and upstream channels. Then, we further use a semiconductor optical amplifier as a booster and preamplifier at the OLT for downstream and upstream, respectively. A power budget of 26 and 32 dB with 0–20 km reach of standard single mode fiber for downstream and upstream transmission at 1310 nm is obtained. The experimental results shown in this paper reveal that our proposed cost-effective scheme would be a promising candidate for the next generation 100G-EPON.

Additive manufacturing (AM) is playing a critical role in the areas of in-space intelligent manufacturing and on-orbital serving technologies. One of challenges is to reveal the composition-processing-microstructure-property relationship during post-treatment process, which would promote the AMed-product with excellent quality. In present work, the integration of heat and magnetic fields provides an approach to optimize microstructures and to enhance the mechanical properties of the selective laser melting (SLM) fabricated Ti–6Al–4V alloy. The conditions for post-treatment processes are set up to 400 °C for 30 min with 2 T, 4 T, 6 T, 8 T and 10 T, respectively. This coupling effects not only promote the phase transformation of α'→α+β, but also modify the width of the α'/α phases. The α'/α morphology after post-treatment becomes finer than the as-built ones, attributing to grain refinement strengthening. Moreover, the yield strength and the ductility of the annealed specimen in 8 T high magnetic field are 1092.1 MPa and 15.1% respectively, which could beat the classical reported SLM-fabricated ones and be comparable to the wrought ones. This work provides the connections between magnetic heating treatments and mechanical properties, paving a path to accelerate the development of space technology and exploration.

Improving surface properties can effectively expand the industrial application of aluminum alloys. In this study, a gradient nanostructured surface layer was successfully fabricated in an aged Al–Zn–Mg–Cu alloy by ultrasonic surface rolling processing (USRP). The microstructure and microhardness of the gradient nanostructured surface layer were investigated. The results show that a perfect gradient lamellae structure was fabricated in the surface layer. The average structural size in the topmost surface layer is approximately 41 nm, and the depth of nanostructure lamellae layer is up to 50 μm. After the USRP and two years of natural aging, the gradient distribution of precipitates was formed in gradient lamellae structure. A large number of discontinuous coarse η phase are formed on the lamellae boundary throughout the lamellae structure. However, the precipitates inside the lamellae have gradient distribution. The volume fractions of precipitates increase gradually from nanostructure to ultrafine-grained structure, and the main precipitates are GPII zones. The microhardness in the topmost surface is increased by 40% and gradually decreases from the surface to the matrix. The increase in microhardness is attributed to the fact that the enhancement of the hardness by the grain refinement is greater than the decrease due to the reduction of the precipitates inside the gradient lamellae structure from the surface to the matrix. This study provides technical method and theoretical basis for improving the surface hardness of Al–Zn–Mg–Cu alloy.

Bongkrekic acid (BKA) produced by pseudomonas cocovenenans is a deadly toxin, and is mainly found in spoiled or fermented foods. However, less is known on its immunotoxicity. Neutrophil extracellular traps (NETs) are a novel effector mechanism of neutrophils against invading pathogens, but excessive NETs also contribute to tissue damage. This study aimed to investigate NET formation triggered by BKA in murine neutrophils, and describe its characteristics and potential mechanisms. Our results showed that BKA triggered NET formation via co-localization of DNA and histone or MPO by immunostaining. Moreover, BKA-triggered NET formation was dose- and time-dependent via NET quantification based on Picogreen-derived fluorescence intensities. Furthermore, BKA increased ROS production in neutrophils. Pharmacological inhibition indicated that BKA-triggered NET formation was associated with ROS-p38 and -ERK signaling pathways, but independent on NADPH oxidase. Besides, PAD4 and P2X1 receptor also mediated BKA-triggered NET formation. To our knowledge, all these findings provide for the first time an initial understanding of BKA on innate immunity, which might be helpful for further investigation on BKA immunotoxicity.

As radiofrequency filtering plays a vital role in electromagnetic devices and systems, recently photonic techniques have been intensively studied to implement radiofrequency filters to harness wide frequency coverage, large instantaneous bandwidth, low frequency-dependent loss, flexible tunability and strong immunity to electromagnetic interference. However, one crucial challenge facing the photonic radiofrequency filter (PRF) is the less impressive out-of-band rejection. Here, to the best of our knowledge, we demonstrate a tunable PRF with a record out-of-band rejection of 80 dB, which is 3 dB higher than the maximum value (~77 dB) reported so far, when incorporating highly selective polarization control and large narrow-band amplification enabled by stimulated Brillouin scattering effect. In particular, this record rejection is arduous to be achieved for a narrow passband (e.g., a few megahertz) and a high finesse in a PRF. Moreover, the proposed PRF is an active one capable of providing negligible insertion loss and even signal gain. Tunable central frequency ranging from 2.1 to 6.1 GHz is also demonstrated. The proposed PRF will provide an ultra-high noise or clutter suppression for harsh electromagnetic scenarios, particularly when room-temperature implementation and remote distribution are needed.

For commercial and military applications, it is highly desired to acquire broadband radio frequency (RF) signals from remotely located receiving antennas to the central office (CO) for centralized signal processing such as down-conversion. In this paper, a photonic approach for image-free microwave frequency down-conversion is proposed for antenna remoting scenarios. The RF signal is captured by the phase modulator (PM) at remote antenna unit and transmitted over a long fiber link to the CO for performing frequency down-conversion. In analog, with the Hartley architecture in the electronic domain, two in-phase (I) and quadrature (Q) intermediate frequency (IF) components are generated by using an electro-optic polarization modulator (PolM) and two polarizers. To achieve large image rejection ratio (IRR), the digital post-processing technique is introduced to accurately compensate the amplitude and phase imbalances between the I and Q IF signals. In the experiments, a 2-km single-mode fiber link is inserted between the PM and PolM. As the local oscillator signals are set as 35 and 3 GHz, two target sinusoidal signals at 35.5 and 3.1 GHz are applied with two image signals, a sinusoidal signal at 34.5 GHz and a broadband RF signal centered at 2.9 GHz, respectively. Then, both real-time analog and off-line digital processing methods are used to process the generated I and Q IF signals for image rejection, yielding an IRR over 45 and 60 dB respectively, when the sinusoidal image signal is applied. The distortions from the broadband 2.9-GHz image RF signal are also effectively suppressed by using the two processing methods. The proposed approach is capable of covering a wide frequency range from 5 to 40 GHz.

Response surface methodology was applied to determine optimal conditions for lipid extraction from shrimp. Box-Behnken Design including independent variables such as extraction time, extraction temperature, and ratio of mixed solvents was used. The optimal conditions for lipids extraction were the use of petroleum ether:ethyl acetate (2.3:1, v/v) with 62 min of extraction at 52oC. Under the optimal conditions, the extraction yields of lipids from Euphausia superba, Penaeuschinesis, Macrobranchium nipponense, and M. rosenbergii were 4.39, 2.80, 2.98, and 3.30%, respectively. Gas chromatographic analysis showed that M. rosenbergii presented the highest level of polyunsaturated fatty acid (PUFA) (48.28%) among the shrimps studied. In addition, the 20:5n3 (EPA) + 22:6n3 (DHA) value (26.43%) was second only to E. superba (31.27%). The finding suggests that M. rosenbergii is a potential PUFA source for food supplementation.

We here propose a parity-time (PT) symmetric optoelectronic oscillator (OEO) with a wide tunable frequency range. Inside the parity-time symmetric OEO, a polarization modulator (PolM) and a polarization control are incorporated to form a reconfigurable dispersion-induced power fading in a fiber link, due to the adjustable ratio between intensity modulation (IM) and phase modulation (PM). The PT-symmetry breaking further enables a fine mode selection, when following the power fading. Thus, a widely tunable PT-OEO is achieved in the absence of a widely tunable, fine-resolution filter. The frequency of the generated signal can be tuned over a wide frequency range from 16 to 30 GHz, when using a 190-m dispersion compensating fiber. The phase noise is estimated as - 116 dBc/Hz @ 10-kHz offset for the generated signal.

We propose and experimentally demonstrate a broadband subcarrier multiplexing (SCM) radio-over-fiber (RoF) system using the optical independent-sideband (O-ISB) modulation, to improve bandwidth efficiency and to compensate for fiber dispersion induced power fading. The O-ISB modulation allows the upper and lower sidebands to carry individual data, thus doubling the spectral efficiency. A novel crosstalk mitigation scheme based on the judicious frequency plan of the low-frequency SCM channels is incorporated with advanced digital signal processing (DSP) algorithms, to effectively harvest the advantages of O-ISB modulation. In proof-of-concept experiments, the transmission of 45 500-MHz QPSK-OFDM SCM channels (corresponding to a data rate of 45 Gbit/s) over a 50-km fiber link is successfully demonstrated, while the required bandwidth is less than 16 GHz.

We propose and experimentally demonstrate a novel digital post-linearization algorithm for the mobile fronthaul system employing bandwidth-efficient multiple intermediate frequency-over-fiber technology and a low-cost directly-modulated laser (DML). The proposed linearization algorithm is distinguished for blind adaption, the absence of training signal, or prior knowledge of the transmission channel. Particularly, it provides a closed-form solution for the estimation of optimal linearizer coefficients, leading to a non-iterative mode without convergence restrictions. In our experiments, one and nine 200 MHz 64-QAM OFDM IF signals (or channels) are transmitted over a 10 km single-mode fiber link using a DML. In both cases (one and nine IF channels), the linearization performance of the proposed algorithm is experimentally validated in terms of the reduction (>8 dB) of the adjacent channel leakage ratio, decrease (>10 dB) of error vector magnitude (EVM), and an increase (>9 dB) of EVM-compliant input RF power range.

Subgame perfect equilibrium in stationary strategies (SSPE) is the most important solution concept used in applications of stochastic games, which makes it imperative to develop efficient numerical methods to compute an SSPE. For this purpose, this paper develops an interior-point path-following method (IPM), which remedies a number of issues with the existing method called stochastic linear tracing procedure (SLTP). The homotopy system of IPM is derived from the optimality conditions of an artificial barrier game, whose objective function is a combination of the original payoff function and a logarithmic term. Unlike SLTP, the starting stationary strategy profile can be arbitrarily chosen and IPM does not need switching between different systems of equations. The use of a perturbation term makes IPM applicable to all stochastic games, whereas SLTP only works for a generic stochastic game. A transformation of variables reduces the number of equations and variables of by roughly one half. Numerical results show that our method is more than three times as efficient as SLTP.

The release of acetone solvent from the adhesive layer is an important part of the curing of DW-1 adhesive, and this process is mainly affected by its diffusion behavior. In order to predict the volatile residual amount of acetone in the adhesive layer, the diffusion phenomenon of acetone solvent was studied. Based on Fick’s law, a numerical model of solvent diffusion is established, and a calculation method of mutual diffusion coefficient suitable for the system of acetone and DW-1 glue is proposed; a simulation model is constructed to reveal the competition mechanism of volatilization phenomenon and diffusion phenomenon, and analyzes the acetone in the diffusion process Distribution status. The theoretical guidance for reducing the residual amount of acetone is provided by this research in the adhesive layer.