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We propose a single low-profile skin metasurface carpet cloak to hide objects with arbitrary shape and size under three different waves, i.e., electromagnetic (EM) waves, acoustic waves and water waves. We first present a metasurface which can control the local reflection phase of these three waves. By taking advantage of this metasurface, we then design a metasurface carpet cloak which provides an additional phase to compensate the phase distortion introduced by a bump, thus restoring the reflection waves as if the incident waves impinge onto a flat mirror. The finite element simulation results demonstrate that an object can be hidden under these three kinds of waves with a single metasurface cloak.

Compact, broadband, multi-channel RF chips with low loss and high integration are required for high-performance phased-array systems. Presented in this paper is a four-channel, multifunction RF chip operating in the 5–18 GHz frequency range that integrates broadband phase shifting, amplitude control, power amplification, and switching functions. The chip is designed to have flip-chip bonding and stacked gold bumps to enable the compact 3D integration of the GaAs pHEMT and Si-CMOS. To ensure high-density interconnects with minimal parasitic effects, a fan-in redistribution process is implemented. The RF front-end part of this chip, fabricated through a 0.15 µm GaAs pHEMT process, integrates 6-bit digital phase shifters, 6-bit digital attenuators, low-noise amplifiers (LNAs), power amplifiers (PAs), and single-pole double-throw (SPDT) switches. To enhance multi-channel isolation and reduce crosstalk between RF chips and digital circuits, high isolation techniques, including a ground-coupled shield layer in the fan-in process and on-chip shield cavities, are utilized, which achieve isolation levels greater than 41 dB between adjacent RF channels. The measurement results demonstrate a reception gain of 0 dB with ±0.6 dB flatness, an NF below 11 dB, and transmit gain of more than 10 dB, with a VSWR of below 1.6 over the entire 5–18 GHz frequency band. The 6-bit phase shifter achieves a root mean square (RMS) phase error below 2.5° with an amplitude variation of less than 0.8 dB, while the 6-bit attenuator exhibits an RMS attenuation error of below 0.5 dB and a phase variation of less than 7°. The RF and digital chips are heterogeneously integrated using flip-chip and fan-in technology, resulting in a compact chip size of 6.2 × 6.2 × 0.33 mm3. These results validate that this is a compact, high-performance solution for advanced phased-array radar applications.

In this letter, molybdenum nitride (MoN) gate AlGaN/GaN HEMT has been investigated with MoN developed in various physical vapour deposition (PVD) conditions. The Schottky gate is studied through forward and reverse characteristics with different processed MoN, which is compared with the standard Ni gate. Similar DC and radio frequency (RF) performances are obtained with MoN and Ni gate, while MoN demonstrated higher reliability than Ni gate through RF aging test. The authors have conducted research on a thermal stable metal compound, molybdenum nitride (MoN), and the application as the gate metal of GaN HEMT. The authors studied the Schottky characteristics of MoN/GaN diode and compared with Ni/GaN diode. The HEMT performance shows that MoN‐gate HEMT has better reliability than Ni‐gate and other performances are on the same level.

Background Lettuce ( Lactuca sativa L.) cultivated in facilities display low vitamin C (L-ascorbic acid (AsA)) contents which require augmentation. Although UV-B irradiation increases the accumulation of AsA in crops, processes underlying the biosynthesis as well as metabolism of AsA induced by UV-B in lettuce remain unclear. Results UV-B treatment increased the AsA content in lettuce, compared with that in the untreated control. UV-B treatment significantly increased AsA accumulation in a dose-dependent manner up until a certain dose.. Based on optimization experiments, three UV-B dose treatments, no UV-B (C), medium dose 7.2 KJ·m − 2 ·d − 1 (U1), and high dose 12.96 KJ·m − 2 ·d − 1 (U2), were selected for transcriptome sequencing (RNA-Seq) in this study. The results showed that C and U1 clustered in one category while U2 clustered in another, suggesting that the effect exerted on AsA by UV-B was dose dependent. MIOX gene in the myo-inositol pathway and APX gene in the recycling pathway in U2 were significantly different from the other two treatments, which was consistent with AsA changes seen in the three treatments, indicating that AsA accumulation caused by UV-B may be associated with these two genes in lettuce. UVR8 and HY5 were not significantly different expressed under UV-B irradiation, however, the genes involved in plant growth hormones and defence hormones significantly decreased and increased in U2, respectively, suggesting that high UV-B dose may regulate photomorphogenesis and response to stress via hormone regulatory pathways, although such regulation was independent of the UVR8 pathway. Conclusions Our results demonstrated that studying the application of UV-B irradiation may enhance our understanding of the response of plant growth and AsA metabolism-related genes to UV-B stress, with particular reference to lettuce.

In this article, the problem of Bayesian detecting rank-one distributed targets under subspace interference and compound Gaussian clutter with inverse Gaussian texture is investigated. Due to the clutter heterogeneity, the training data may be insufficient. To tackle this problem, the clutter speckle covariance matrix (CM) is assumed to obey the complex inverse Wishart distribution, and the Bayesian theory is utilized to obtain an effective estimation. Moreover, the target echo is assumed to be with a known steering vector and unknown amplitudes across range cells. The interference is regarded as a steering matrix that is linearly independent of the target steering vector. By utilizing the generalized likelihood ratio test (GLRT), a Bayesian interference-canceling detector that can work in the absence of training data is derived. Moreover, five interference-cancelling detectors based on the maximum a posteriori (MAP) estimate of the speckle CM are proposed with the two-step GLRT, the Rao, Wald, Gradient, and Durbin tests. Experiments with simulated and measured sea clutter data indicate that the Bayesian interference-canceling detectors show better performance than the competitor in scenarios with limited training data.

Variegation in flower color is commonly observed in many plant species and also occurs on ornamental peaches (Prunus persica f. versicolor [Sieb.] Voss). Variegated plants are highly valuable in the floricultural market. To gain a global perspective on genes differentially expressed in variegated peach flowers, we performed large-scale transcriptome sequencing of white and red petals separately collected from a variegated peach tree. A total of 1,556,597 high-quality reads were obtained, with an average read length of 445 bp. The ESTs were assembled into 16,530 contigs and 42,050 singletons. The resulting unigenes covered about 60% of total predicted genes in the peach genome. These unigenes were further subjected to functional annotation and biochemical pathway analysis. Digital expression analysis identified a total of 514 genes differentially expressed between red and white flower petals. Since peach flower coloration is determined by the expression and regulation of structural genes relevant to flavonoid biosynthesis, a detailed examination detected four key structural genes, including C4H, CHS, CHI and F3H, expressed at a significantly higher level in red than in white petal. Except for the structural genes, we also detected 11 differentially expressed regulatory genes relating to flavonoid biosynthesis. Using the differentially expressed structural genes as the test objects, we validated the digital expression results by using quantitative real-time PCR, and the differential expression of C4H, CHS and F3H were confirmed. In this study, we generated a large EST collection from flower petals of a variegated peach. By digital expression analysis, we identified an informative list of candidate genes associated with variegation in peach flowers, which offered a unique opportunity to uncover the genetic mechanisms underlying flower color variegation.

Waterlogging is a major abiotic stress that restricts plant growth, productivity, and survival by disrupting root aeration and altering hormonal homeostasis. To elucidate the physiological and molecular responses associated with flooding tolerance in Liriodendron hybrids (Liriodendron chinense × Liriodendron tulipifera), this study investigated its morphological, physiological, and transcriptomic changes under 0, 1, 3, and 6 days of waterlogging. Roots exhibited rapid decay, while leaves showed delayed chlorosis and reduced chlorophyll content. Changes in antioxidant enzyme activities reflected enhanced antioxidant capacity, with superoxide dismutase (SOD) activity decreasing and peroxidase (POD) and catalase (CAT) activities increasing. Hormone measurements indicated organ-specific patterns, including abscisic acid (ABA) accumulation in leaves and decreased indole-3-acetic acid (IAA) and gibberellin (GA) levels in both roots and leaves. Transcriptome profiling revealed extensive transcriptional adjustments in hormone biosynthesis, signaling, and stress-responsive pathways, including divergent regulation of ABA-associated genes in leaves and roots and broad downregulation of auxin- and gibberellin-related genes. Key ABA biosynthetic genes (NCED1, ABA2) and signaling components (PYL4, PP2C, ABF) were upregulated in leaves but downregulated in roots, whereas auxin (YUC6) and gibberellin (GA20ox) genes were generally suppressed. These coordinated physiological and molecular responses suggest organ-differentiated adaptation to waterlogging in Liriodendron hybrids, highlighting candidate pathways and genes for further investigation and providing insights for improving flooding tolerance in woody species.

Significance Guiding surface electromagnetic waves around disorder without disturbing the wave amplitude or phase is in great demand for modern photonic and plasmonic devices. In this work, we introduce a class of cloaks capable of remarkable broadband surface electromagnetic waves guidance around ultrasharp corners and bumps with no perceptible changes in amplitude and phase. This work provides strong support for the application of transformation optics to plasmonic circuits and could pave the way for high-performance, large-scale integrated photonic circuits. Guiding surface electromagnetic waves around disorder without disturbing the wave amplitude or phase is in great demand for modern photonic and plasmonic devices, but is fundamentally difficult to realize because light momentum must be conserved in a scattering event. A partial realization has been achieved by exploiting topological electromagnetic surface states, but this approach is limited to narrow-band light transmission and subject to phase disturbances in the presence of disorder. Recent advances in transformation optics apply principles of general relativity to curve the space for light, allowing one to match the momentum and phase of light around any disorder as if that disorder were not there. This feature has been exploited in the development of invisibility cloaks. An ideal invisibility cloak, however, would require the phase velocity of light being guided around the cloaked object to exceed the vacuum speed of light—a feat potentially achievable only over an extremely narrow band. In this work, we theoretically and experimentally show that the bottlenecks encountered in previous studies can be overcome. We introduce a class of cloaks capable of remarkable broadband surface electromagnetic waves guidance around ultrasharp corners and bumps with no perceptible changes in amplitude and phase. These cloaks consist of specifically designed nonmagnetic metamaterials and achieve nearly ideal transmission efficiency over a broadband frequency range from 0 ⁺ to 6 GHz. This work provides strong support for the application of transformation optics to plasmonic circuits and could pave the way toward high-performance, large-scale integrated photonic circuits.

Subtropical China is a global center of biodiversity and one of the most important refugia worldwide. Mountains play an important role in conserving the genetic resources of species. is a Tertiary relict tree largely endemic to subtropical China. In this study, we aimed to achieve a better understanding of the phylogeographical pattern of and to explore the role of mountains in the conservation of genetic resources. Three chloroplast regions ( J- A, 32- F, and K5'- K) were sequenced in 40 populations of for phylogeographical analyses. Relationships among chloroplast DNA (cpDNA) haplotypes were determined using median-joining networks, and genetic structure was examined by spatial analysis of molecular variance (SAMOVA). The ancestral area of the species was reconstructed using the Bayesian binary Markov Chain Monte Carlo (BBM) method according to its geographic distribution and a maximum parsimony (MP) tree based on Bayesian methods. Obvious phylogeographic structure was found in . SAMOVA revealed seven groups matching the major landscape features of the distribution area. The haplotype network showed three clades distributed in the eastern, southwestern, and northwestern regions. Separate northern and southern refugia were found in the Wu Mountains and Yungui Plateau, with genetic admixture in the Dalou Mountains and Wuling Mountains. BBM revealed a more ancient origin of in the eastern region, with a west-east split most likely having occurred during the Mindel glacial stage. The clear geographical distributions of haplotypes suggested multiple mountainous refugia of . The east-west lineage split was most likely a process of gradual genetic isolation and allopatric lineage divergence when the Nanling corridor was frequently occupied by evergreen or coniferous forest during Late Quaternary oscillations. Hotspots of haplotype diversity in the Dalou Mountains and Wuling Mountains likely benefited from gene flow from the Wu Mountains and Yungui Plateau. Collectively, these results indicate that mountain regions should be the main units for conserving and collecting genetic resources of and other similar species in subtropical China.

In this paper, a three-dimensional heterogenous-integrated (3DHI) wafer-level packaging (WLP) process is proposed, and a radio frequency (RF) front-end module with two independent ultra-high frequency (UHF) receiving channels are designed and implemented, which covers 400 MHz–600 MHz and 2050 MHz–2200 MHz respectively for unmanned aerial vehicle (UAV) applications. The module is formed by wafer-to-wafer (W2W) bonding of two high-resistivity silicon (HR-Si) interposers with embedded bare dies and through silicon via (TSV) interconnections. Double-sided deep reactive ion etching (DRIE) and conformal electroplating process are introduced to realize the high-aspect-ratio TSV connection within 290 µm-thick cap interposer. Co-plane waveguide (CPW) transmission lines are fabricated as the process control monitor (PCM), the measured insertion loss of which is less than 0.18 dB/mm at 35 GHz. The designed RF front-end module is fabricated and measured. The measured return loss and gain of each RF channel is better than 13 dB and 21 dB, and the noise figure is less than 1.5 dB. In order to evaluate the capability of the 3DHI process for multi-layer interposers, the module is re-designed and fabricated with four stacked high-resistivity silicon interposers. After W2W bonding of two pairs of interposers and wafer slicing, chip-to chip (C2C) bonding is applied to form a four-layer module with operable temperature gradient.