PLA Electronic Engineering Institute

Abstract. Cloud vertical structure plays a central role in regulating Earth’s radiation balance and hydrological cycle, yet it remains poorly represented in weather and climate models due to limited high-resolution observations. Using a newly established national network of 80 Ka-band cloud radars, we provide the first high-spatiotemporal-resolution characterization of cloud vertical structure across China for 2024 and quantify its thermodynamic, dynamical, and land-surface controls. An improved retrieval algorithm accounting for height-dependent radar sensitivity and clutter suppression is applied to derive cloud boundaries. The national annual mean cloud occurrence frequency is 56.7 %, dominated by single-layer clouds (34.7 %), followed by two-layer (14.7 %) and multi-layer clouds (7.1 %). Single-layer clouds prevail over arid northwestern China, whereas multi-layer clouds are more frequent in humid southeastern regions. Cloud base height exhibits strong seasonality, with higher values in summer and lower values in winter, and distinctly lower bases over the Tibetan Plateau. Diurnally, summer clouds show a pronounced afternoon peak between 3 and 9 km, while winter clouds are mainly confined below 3 km with a near-sunrise maximum. Thermodynamic conditions exert primary control on cloud vertical development. Higher low-level humidity favors deeper clouds and higher tops, whereas stronger lower-tropospheric stability suppresses vertical growth. Wind shear generally limits cloud depth, though moderate shear may enhance organization under unstable conditions. Land-surface characteristics further modulate cloud base height, with higher bases over barren land and lower bases over forests. These results provide national-scale observational benchmarks for improving cloud parameterizations in numerical models.

Nickel-rich nickel phosphide (Ni2P) has emerged as a promising sodium-ion battery anode owing to its high theoretical capacity and intrinsic electronic conductivity, yet its charge storage chemistry remains controversial and is often oversimplified as a conversion reaction. Herein, we design a freestanding Ni2P composite electrode composed of ultrasmall Ni2P nanocrystals embedded within a phosphorus-doped, graphene-like porous carbon matrix. Comprehensive in-situ and ex-situ analyses unequivocally demonstrate an interstitial solid-solution mechanism, wherein Na+ ions reversibly occupy lattice interstitials via (111)-oriented interplanar channels, inducing reversible lattice breathing without phase transformation. This bulk intercalation process is synergistically coupled with a substantial pseudocapacitive contribution, establishing a cooperative dual-mode storage mechanism. Benefiting from this solid-solution-capacitive chemistry, the electrode delivers a high reversible capacity (≈560 mAh g-1), outstanding rate capability (135 mAh g-1 at 10 A g-1), and exceptional long-term stability (263 mAh g-1 after 2000 cycles). When paired with a Na3V2(PO4)3@C cathode, the full cell achieves a high-energy density of 245 Wh kg-1. This work establishes solid-solution-capacitive coupling as a general paradigm for designing high-rate and durable sodium-ion battery anodes.

In the paper [Modern Phys. Lett. A 39 (2024) 2450084], Xin et al. proposed a multiparty semi-quantum secret sharing protocol based on the single qubit sequence and the permutations of the qubit locations. We study the security of the proposed protocol and point out that there exists a security loophole in it, that is, the first and last agents can collude to obtain Tom’s secret without the help of the other agents.

Under alkaline conditions, weakening the OH adsorption at the Ru site avoids the excessive adsorption of OH on Ru sites, prevents the deactivation of Ru, and improves the performance of the alkaline hydrogen evolution reaction.

This article presents a compact variable-gain phase shifter (VGPS) that incorporates both a merged phase-shifted attenuator (ATT) and a merged attenuated phase shifter (PS) unit. The merged phase-shifted ATT achieves an additional phase-shifting capability using a modified switched <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $</tex-math> </inline-formula>-type ATT structure, while the merged attenuated PS provides an additional attenuation function based on revised high-pass/low-pass or high-pass/direct-pass PS topologies. The proposed VGPS achieves a bidirectional 20.5-dB gain control range and a 360° phase control range with a 0.5-dB gain step and 5.625° phase step in standard 65 nm CMOS technology. Measurement results demonstrate a maximum root mean squares (rms) phase error of 3.3° and a maximum rms amplitude error of 0.37 dB across the 33–37GHz. The fully passive circuit exhibits high linearity, featuring a minimum input 1-dB compression point (IP1dB) of 11.1 dBm. The core size is 0.27 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> excluding pads.

ABSTRACT In this paper, a high selectivity integrated passive device (IPD) on‐chip bandpass filter is presented. The passband can be constructed by using a minimum number of three‐order elliptic bandpass filter. The stacked series‐parallel topology is employed to generate two transmission zeros (TZs) and a transmission pole (TP) to maintain high selectivity and high stopband attenuation near the passband. Moreover, in order to deep the attenuation level at the upper stopband, a zero‐pole generation circuit is introduced at the input and output ports to generate a TZ and a TP, which can also adjust the flatness of the passband and improve the impedance matching. An IPD on‐chip filter sample is fabricated with an electric length of 0.12 × 0.05 λg 2 . The measurement results show that the centre frequency is 4.2 GHz, the fractional bandwidth is 78.6%, the minimum in‐band insertion loss is 1.23 dB, and the frequency selectivity SF 20dB and SF 30dB are 1.31 and 1.39, respectively.

We engineered the photocarrier dynamics of the complementary metal–oxide–semiconductor (CMOS)-compatible material germanium tin (GeSn) through controlled phosphorus ion implantation. The incorporation of Sn atoms into the Ge lattice reduces the bandgap, thereby red-shifting the absorption edge into the short-wave infrared (SWIR) region while concurrently enhancing carrier mobility. To overcome the inherently slow carrier recombination associated with the indirect bandgap nature of GeSn, phosphorus implantation was introduced to enable the ultrafast photoresponse in terahertz (THz) photoconductive antenna (PCA) detectors without substantially compromising electrical resistivity or carrier mobility. The ion-implanted detector achieves a broadened detection bandwidth of up to 2.5 THz, a signal-to-noise ratio (SNR) above 65 dB, and a 4-fold increase in response compared with the intrinsic GeSn device counterpart. These findings highlight GeSn as a promising group-IV material for ultrafast THz detection. They also demonstrate a CMOS-compatible THz photonic integrated circuit (PIC) pathway operating at telecommunication wavelengths.

The appearance of maize tassels marks the onset of the tasseling stage, which serves as an important indicator for crop management, variety selection and yield forecasting. The tassel is located at the top of the plants, making them suitable for large-scale remote sensing by UAV platforms. The tassel morphology varies depending on factors including cultivar, irrigation, fertilization and environments. In the field, tassel detection using UAV imagery remains challenging due to some factors, such as the small size of ears, frequent occlusions and low color contrast. To address these challenges, Tassel-YOLOv12n model was developed in this study based on maize_hfnu dataset, which was established with the UAV imagery of typical adapted maize varieties in the Huaibei plain, China. The proposed model employed a combined structure of feature pyramid network and path aggregation network to enhance tassel detection capability. The rfficient multi-scale attention mechanism module and the small object detection layer were also introduced to extract the features of tassels in field environments. During experimental evaluation, our proposed Tassel-YOLOv12n algorithm achieved the mAP@0.5 value of 87.7 and the mAP@0.95 value of 40.4, which is better than well-known object detection approaches. The result showed that Tassel-YOLOv12n achieves strong performance in both counting accuracy and inference speed.

This paper presents an innovative design method for a low loss linearly polarized reconfigurable transmitarray unit with a 2-bit phase resolution at 5.8GHz. The size of the proposed unit is 25×25×6.6 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> (0.48λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf>×0.48λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf>×0.125λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf>). The structure consists of four dielectric substrates and one air layer. The transmitarray antenna unit operates in a receive-transmit architecture which consists of a transmitting component, a receiving component, and a 90-degree phase shifter. 1-bit phase reconfigurability is implemented using current inversion. Switching the PIN diodes in the 90-degree phase shifter enables the generation of a 90°phase control. Simulation results show that the unit can generate a stable 2-bit phase shift within the operating frequency range of 5.5-6.2 GHz, achieving a 3-dB bandwidth of 12%. The average insertion loss in both states is approximately -1.1 dB. This design method facilitates the realization of reconfigurable transmitarray antennas with low loss characteristics, which exhibits promising applications in communication systems, space exploration, and radar systems.